05/372051

11/12/1974

06/21/1973

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MacGregor-Comarain S.A. (D'Avray, FR)

14/71.100

414/143.200, 405/218, 414/141.500, 414/139.900, 414/141.300, 14/71.300

B63B27/14; B63B27/00; B65G11/00

14/71,1,7,17,37 214/15R 61/48

3468280	RAMP FOR LST	September 1969	Williams
3580404	LOADING RAMPS FOR TRAILERS	May 1971	Moser
3687308	SHIP'S LOADING RAMP	August 1972	Apelstrand
3747354	RETRACTABLE PIER	July 1973	Macomber

Byers Jr., Nile C.

Kenyon & Kenyon Reilly Carr & Chapin

What is claimed is

1. A movable device forming a foldable access ramp to interconnect a vehicle with an outside platform, said ramp being adapted to swing in parallel relation to a vertical plane so as to be raised into inoperative stowed position on said vehicle and lowered into operative working position to rest at least partially on said platform, said ramp comprising at least two successive ramp sections pivotally interconnected endwise in the longitudinal direction and the first one of which forming an innermost section is pivotally connected to said vehicle and attached with at least one point of said ramp section to at least one constantly tensioned handling cable winding up on at least one winch located on said vehicle whereas the other or second ramp section may be folded back and downwards against and along said innermost ramp section and is attached to at least one handling cable controlling its outward extension for raising said other ramp section into the extended position in at least approximatively aligned registering relationship with said innermost ramp section in the lowered working position, wherein the improvement consists in that each handling cable for controlling the outward extension of said second ramp section is connected to means for automatically tensioning and taking up the slack of said cable through the action of potential energy, said means being provided on said vehicle and comprising self-acting means for stopping said cable and holding it unidirectionally against motion, said latter means being adapted to form a stationary fastening means for generating, through blocking of the effective useful length of said cable, a tractive reaction force tending to raise said second ramp section into its outward extended position during the lowering motion through gravity of said innermost ramp section which is constantly suspended from each one of its own handling cables.

2. A device according to claim 1, comprising selectively adjustable load transfer means for varying at will the bearing reaction force of said ramp onto said platform in the working extended position of the ramp to thereby transfer at least one selectively variable part of the weight and instant load of said second ramp section to either of said innermost ramp sections and of independent auxiliary supporting means provided on said vehicle.

3. A device according to claim 1, wherein said self-acting means for automatically stopping said handling cables and unidirectionally holding same against motion are arranged so as to be operative only from a given angle of slope of said innermost ramp section with respect to the vertical direction during the starting period of lowering motion thereof.

4. A device according to claim 1, wherein each handling cable for controlling the relative outward extension of said second ramp section is reeved over at least one elevated loose guide pulley mounted on said vehicle and terminates in a movable counterweight forming said automatic tensioning and slack taking-up means whereas said automatic means for stopping said handling cables and unidirectionally holding same against motion consist of a stationary stop means limiting the upward motion of said counterweight provided on said vehicle.

5. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is reeved on at least one elevated loose guide pulley mounted on said vehicle and terminates into a movable counterweight forming said tensioning and slack taking-up means whereas said automatic means for stopping said handling cables and unidirectionally holding same against motion consist of a stationary stop means limiting the upward motion of said counterweight and provided on said vehicle, the weight of each counterweight being selectively adjustable so that said counterweight forms said load transfer means.

6. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of an adjusting member having a selectively variable length and forming one aforesaid tensioning and load transfer means.

7. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a linear-displacement type pressure fluid operated actuator generating a selectively adjustable force and forming one aforesaid tensioning and load transfer means.

8. A device according to claim 1, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of at least one resiliently deformable spring-like member constituting said automatic tensioning and slack taking-up means whereas said automatic means for stopping said handling cables and unidirectionally holding same against motion consist of a stationary stop means limiting the strain of said spring-like member under maximum stress.

9. A device according to claim 1, wherein each cable controlling the relative outward extension of said second ramp section is connected to a self-acting winding-up appliance forming said self-acting tensioning and slack taking-up means whereas said automatic means for stopping said handling cable and unidirectionally holding samd against motion consist of a stationary fastening means for the end of said cable on said appliance.

10. A device according to claim 1, wherein each handling cable controlling the device outward extension of said second ramp section is connected to an automatic winding-up appliance forming said self-acting tensioning and slack taking-up means whereas said automatic means for stopping said cable and unidirectionally holding same against motion consist of braking means for braking said appliance at the end of the useful paying out motion.

11. A device according to claim 2, wherein each handling cable controlling the relative outward extension of said second ramp section is connected to a power-operated winch providing for constant cable tensioning and which is located on said vehicle to form one aforesaid load transfer means.

12. A device according to claim 2, wherein said load transfer means consist of at least one counterweight having a selectively adjustable weight and located on a lever arm integral with said second ramp section so as to urge the latter towards its rasied outward extended position.

13. A device according to claim 1, comprising a third or outermost ramp section forming a supporting pad to bear on said outside platform and pivotally connected with an intermediate point thereof to the corresponding outer end of said second ramp section forming now an intermediate ramp section, said device comprising operated means for raising said outermost ramp section.

14. A device according to claim 13, wherein each handling cable controlling the extension of said intermediate ramp section is reeved over at least one associated loose main guide pulley carried by said intermediate ramp section and said cable is secured with its outer end to said outermost ramp section at a point located outwards beyond the pivotal connection of the latter with said intermediate ramp section to form said operated raising means.

15. A device according to claim 13, wherein at least one ram-like pressure fluid operated actuator is provided between said intermedate and outermost ramp sections to form said operated raising means.

16. A device according to claim 1, wherein one of said first and second ramp sections extends beyond its pivotal connection with the other ramp section with at least one longitudinal projecting integral boom carrying towards its free end at least one auxiliary guide pulley for each handling cable controlling the relative outward extension of said second ramp section and each cable for operating said first ramp section is reeved over several elevated auxiliary guide pulleys mounted in a same pulley block provided on said vehicle and on a plurality of main guide pulleys mounted in a same pulley block carried by said innermost or first ramp section, so as to form a reeving whereas each handling cable is reeved over several guide pulleys mounted on two pulley blocks, respectively, carried by each projecting boom, respectively, and by said other ramp section so as to form a reeving.

17. A device according to claim 16, wherein said second ramp section extends beyond its pivotal connection with said innermost or first ramp section with at least one integral projecting longitudinal boom carrying towards its free end each aforesaid main guide pulley whereas said innermost ramp section carries at least one auxiliary guide pulley for each handling cable controlling the relative outward extension of said second ramp section and leading from each main guide pulley.

18. A device according to claim 1, comprising automatic control means for keeping said innermost ramp section spaced from said platform in its lowered working position, each handling winch being phase-locked in follow-up relationship to said control means which consist of at least one sensor member secured to one of said first and second ramp sections adjacent to their pivotal connection and adapted to bear upon said platform for detecting any variation in the difference between the levels of said vehicle and said platform.

19. A device according to claim 1, comprising automatic control means for adjusting the relative angular positions of said first and second ramp sections to keep same in substantially aligned registering relationship or at an optimum slope, each handling winch being phase-locked in follow-up relationship to said control means which consist of at least one sensor member mounted on one of said ramp sections in the vicinity of its pivotal connection with the other ramp section, said sensor member being adapted to engage said other ramp section so as to measure the angle formed therebetween in particular during any upward motion of said vehicle.

20. A device according to claim 7, comprising automatic control means for adjusting the bearing reaction of said ramp onto said platfrom, each aforesaid load transfer means being phase-locked in follow-up relationship to said control means which consist of at least one pressured-detecting sensor member mounted on said ramp towards its outer end for bearing upon said platform in the working position of said ramp and for measuring said bearing reaction.

21. A device according to claim 1, comprising push ram means mounted on said vehicle and adapted to freely engage said innermost ramp section in its raised position to initiate its downward swinging motion through gravity and to brake or slow down its upward swinging motion at the end thereof, abutment and rest means being provided on said vehicle and engageable by said ramp in its raised and stowed position.

22. A device according to claim 1, wherein said innermost ramp section is provided with a pair of side frame members at least one of which carries a buttressing ram the line of action of which is spaced from the geometrical axis of pivotal connection between said adjacent innermost and second ramp sections, said buttressing ram being adapted to bear removably against an abutment means intergral with the corresponding side of said adjacent ramp section in the lowered and extended working position of said ramp for blocking said pivotal connection in the direction of rotation of increasing extension of the ramp, in a relative angular position which is selectively variable through the adjustable operative length of stroke of said ram, whereas selectively variable connecting means are provided between said side frame member and said corresponding side, respectively, of both ramp sections for blocking said pivotal connection in the direction of rotation of folding back said ramp, in the same relative angular position, and wherein on the one hand said ram is of the double-acting kind and pivotally connected with its body onto said side frame member of said innermost ramp section while extending in substantially parallel relation to the longtiudinal relative vertical plane of said side frame member, said ram being located higher than the geometrical axis of said pivotal connection between both ramp sections in their working position and said adjacent second ramp section also comprising a pair of side frame members on its opposite sides, respectively, whereas on the other hand said ram is provided with a movable push head adapted to freely and directly engage at least one substantially concave abutment pad forming said abutment means and secured to the adjacent end of said corresponding side frame member of said second ramp section; operated locking means being provided on said corresponding side frame member of said adjacent second ramp section to rigidly connect said movable push head with said abutment pad thereby to form said selectively variable connecting means.

23. A device according to claim 22, wherein said movable push head of said ram comprises at least one sidewise projecting portion adapted to engage said abutment pad; said abutment pad being substantially square shaped and said locking means comprising at least one movable retaining member actuated by an associated actuator and mounted on said adjacent second ramp section, said retaining member being adapted to bear against said sidewise projecting portion to keep same in engagement with said abutment pad.

24. A device according to claim 23, wherein each retaining member is automatically urged constantly towards its operative locking position by a resilient biasing means or through gravity so that its associated actuator is only used for unlocking purposes.

25. A device according to claim 22, wherein said retaining member consists of at least one arm adapted to swing in a plane substantially at right angles to said sidewise projecting portion and to be lowered into engagement with said sidewise projecting portion on that surface portion thereof which is opposite from said abutment pad to hold said sidewise projecting portion against motion, said swinging arm being on the other hand adapted to be swung upwards and away from said sidewise projecting portion to release same, said arm being engageable with said sidewise projecting portion through the tip of its free end portion, said tip having a mating shape which is complementary of that of the lateral surface of said sidewise projecting portion.

26. A device according to claim 25, wherein said movable push head of said ram comprises a pair of transversely opposite and coaxially aligned thrust pins forming said sidewise projecting portions and adapted to co-operate with a pair of corresponding associated transversely spaced abutment pads whereas said retaining member is a fork-shaped part of the legs of which form locking arms spaced from each other according to the spacing between said abutment pads, said fork-shaped part being rotatably mounted on a transverse shaft fitted on said adjacent second ramp section, said fork-shaped part being connected through a radial crank arm to an auxiliary linear-displacement type pressure fluid operated actuator mounted on said adjacent second ramp section for rotating said fork-shaped part.

27. A device according to claim 22, comprising automatic safety means for avoiding any wrong operation and rendering the device fail-safe, said means being mounted on said adjacent second ramp section and adapted to check and to report the relative position of said locking means at the ends of the locking and unlocking strokes, respectively.

28. A device according to claim 22, comprising self-acting means for controlling the relative position of said movable push head of said ram, at the end of its stroke, against each abutment pad, said means consisting of at least one proximity detector which is phase-locked in follow-up relationship to means operating said locking means.

29. A device according to claim 22, comprising means for detecting the maximum motion of outward extension of both aforesaid successive ramp sections into their substantially aligned registering position and accordingly the end of maximum retraction stroke of said ram, said ram comprising inner mechanical stop means and said detecting means being adapted to discontinue the energizing of said ram.

30. A device according to claim 25, comprising by means for forced guiding of the movable push head of said ram, said means consisting of each sidewise projecting portion which is of elongated shape so as to project sidewise beyond said associated abutment pad and engage a guide slot carried by an associated supporting structure integral with the side frame member of said innermost ramp section.

The present invention relates generally and is essentially directed to a movable device forming an access ramp or like gangway, horse or bridge means adapted to provide a communication, passage, conveyance, transhipment or like means between on the one hand any vehicle in particular of land or marine character such as for instance a ship, boat or like floating vessel and on the other hand an outside loading or unloading area or platform such as a quay, pier, wharf, bank, shore or beach or yet another vehicle as well as the various applications and uses resulting from implementing same and the systems, arrangements, assemblies, appliances, equipments and installations provided with such devices.

There are already known in particular in naval or marine applications, transport or cargo ships of the roll on-roll off type for conveying for instance wheeled vehicles and in particular automotive or motor vehicles or various goods and products. In the case of automotive vehicles, the shipping and unshipping thereof are effected by their own self-contained or independent propulsion or drive means by rolling individually or separately and directly on a movable access ramp interconnecting the ship (and more specifically the loading deck or flooring thereof) and the quay or the like. In the case of general cargo, such a ramp is also used directly by automotive handling carriages, trucks or like carts or wheeled cargo-handling gears running on said ramp in a shuttle-like manner enabling them to have direct access to the ship and to come back to the quay for loading or shipping and unloading or unshipping goods and like cargoes. For this purpose, the ship is provided either aft or astern, or afore at the bow, or yet sidewise, with at least one large ramp of the kind pivotally connected with its inboard end to the ship for swinging vertically so as to be liftable or raisable upwards to a substantially inoperative upstanding position in a stowed or lashed condition on the ship during its sea trip and lowerable in operative working position to bear onto the quay with its opposite, i.e. outboard end. As the ship is generally moored or secured along the quay berth in parallel relation thereto, said ramp, when it is located astern i.e. at the rear end of the ship, is generally positioned slantwise in its lowered working condition with respect to the longitudinal central vertical plane of the ship so that the longitudinal direction of the ramp is at an angle of about 45° with respect to the longitudinal direction of the ship. Such a ramp thus enables various kinds of wheeled vehicles to be taken aboard the ship for instance from quays which are not fitted up or suited for such a use.

To enable the ship to use various kinds of quays while retaining an acceptable slope with respect to the horizontal direction for the passage of wheeled vehicles, said ramp is required to be long enough and for this ground it is necessary that the ramp may be folded vertically back against the planking or structure of the ship so as not to offer a too strong hold to the wind when the ship is at sea or an excessive height likely to affect the stability of the ship.

For example, from the U.S. Pat. No. 3,687,308 is already known such a ramp consisting of three successive sections pivotally interconnected to each other, respectively, in the longitudinal direction, the innermost end or inboard section being pivoted to the ship in particular at the level of any opening thereof for example at a cargo port provided at one of its ends or laterally in the side of the ship whereas the outer end or outboard section serves as a bearing or supporting flap member onto the quay and is pivotally connected with an intermediate point thereof to the corresponding outer end portion of the intermediate section. In this known arrangement, the intermediate and outermost sections may be folded back together by being laid downwards against the bottom portion of the innermost or inboard section alongside thereof in a substantially upward raised or vertical position and both opposite side frame members or like girders or spars of the inboard section are extended outwards through a pair of booms or arm-like beams extending beyond the vehicle runway carried therebetween and on either side of and along the intermediate section so as to bear in the lowered and extended working condition onto a pair of sidewise outwards projecting supports provided on the intermediate section on either side thereof, through the medium of a pair of longitudinal lower levers pivotally connected to the side frame members so that said levers may be swung in a vertical plane to an adjustable relative angular position by pressure fluid operated ram-type actuators or like power means. This arrangement enables to adjust the angle between the outboard and intermediate sections in the lowered and extended working state. The innermost or inboard section is secured with an intermediate point of one or each side frame member thereof and adjacent to its pivotal connection with the intermediate section to at least one handling cable or rope or to a pair of handling cables or ropes each one of which is wound up on an associated operating winch located on the ship whereby the ramp may be raised through a powered action or lowered through gravity. The innermost section is partially suspended from each handling rope because the latter is kept taut with a determined constant tension corresponding for instance to the total weight of the loading ramp and each rope may be automatically wound up or paid out according to the variation in the load. At least one winch and possibly both powered winches for extending the intermediate section are mounted on one or both of the side frame members, respectively, of the innermost section and the rope of each winch is successively reeved onto a first guide sheave or pulley carried by the free end of said extension boom and onto a second guide pulley or sheave carried by the intermediate section to be made fast at a stationary point of said boom. The outermost section, forming a supporting pad or flap member to enable the ramp to bear onto the quay, is pivotally connected substantially at its centre of gravity to said intermediate section so as to be always at poise, i.e. in a state of indifferent equilibrium or like balanced condition about its substantially horizontal pivot axis.

This known appliance exhibits various inconveniences since on the one hand it requires a relatively complex special mechanism to achieve a temporary engagement or like bearing connection between each boom end in extension of one side frame member of the innermost section with a corresponding sidewise projecting supporting pad of the intermediate section and on the other hand it requires the provision of at least one operating winch and possibly of a pair of operating winches for extending the intermediate section of the ramp into the lowered working condition. Moreover as the outermost section for bearing on the quay is in a state of indifferent equilibrium, i.e. likely to take any relative angular position about its swivel axis, there may be a possibility that this section, when being lowered onto the quay, is not in the proper relative position, i.e. substantially in parallel relation to the quay surface so that there may be a wrong bearing in particular in view of some buttressing or abutting effect so that a manual action has to be taken to overcome or obviate such a difficulty.

One main object of the invention is therefore to remove the aforementioned drawbacks inherent in the prior known state of the art by providing a device of a simpler hence more economical construction performing a more effective and reliable operation. For this purpose the invention is starting from the known kind of movable device forming a foldable access ramp for interconnecting a vehicle and an outside platform, which is swingable in parallel relation to a vertical plane so that it may be raised upwards to an inoperative position in a stowed or lashed condition on said vehicle and lowered downwards to an operative working position for resting partially on said platform, said ramp comprising at least two successive sections pivotally interconnected endwise in the longitudinal direction thereof, the first one of which forms the innermost or inboard section which is pivotally connected to said vehicle and secured with at least one point to at least one handling cable always kept taut and wound up onto at least one winch located on said vehicle whereas the other or second section may be folded back downwards against and along the first one and is fastened to at least one handling cable for extending said other section to a position which is at least approximatively in aligned registering relation to said innermost section in the lowered working condition of the ramp. To solve the technical problem set, the invention therefore proposes a device of the aforesaid kind which is characterized in that each handling cable for extending said other section is connected to means for tensioning and for automatically taking up any possible slack of said cable through the action of potential energy, which means are located on said vehicle and include self-acting means for automatically and unidirectionally stopping the cable and holding it against motion, said means being adapted to provide a stationary fastening point for causing through locking of the effective useful length of said cable, a tractive reaction force to arise for extending said other section during the downward motion of said innermost section which is always suspended from each aforesaid handling cable.

Such an arrangement offers the advantage to enable the second ramp section to be extended without the use of any powered winch for this purpose but by exclusively making use of the potential energy stored in the innermost ramp section in its raised position whereby said innermost section tends by itself to rock or tilt naturally downwards through gravity under the action of its own weight while causing at the same time the adjacent ramp section to be extended accordingly. At the beginning or during the initial period of downward motion of the innermost section from its substantially vertically or upright raised and stowed position, the component of the total ramp weight which is likely to act upon each handling cable for extending said adjacent portion is inadequate for exerting any significant rotary effect thereon, so that according to another characterizing feature of the invention, said automatic means for stopping and unidirectionally holding against motion each handling cable for extending said adjacent section are arranged so as to be operative only from some determined angle of slope for instance of about 20° of the innermost section with respect to the vertical direction during the starting period of downward motion thereof.

According to a further characterizing feature of the invention, as said innermost ramp section is suspended from the end of each aforementioned handling cable, there are provided selectively adjustable load transfer means for varying at will the bearing reaction of the ramp onto said platform in the extended working configuration of the ramp thereby transferring at least one selectively variable part of the weight and instant load of said second ramp section either onto said innermost ramp section or onto an independent auxiliary supporting system mounted on said vehicle. Such an arrangement offers the advantage to possibly achieve an automatic control of the bearing pressure force of the ramp onto said platform in accordance with the true load carried by said second ramp section.

According to still another characterizing feature of the invention, the means for tensioning and automatically taking up the slack of each cable controlling the extension of said second ramp section consist of a movable counterweight and for this purpose each handling cable for controlling the extension of said second ramp section is reeved on at least one preferably elevated or overhead loose guide pulley or idle sheave mounted on said vehicle to terminate into said counterweight whereas said automatic means for stopping and unidirectionally holding against motion consist of a stationary stop means provided on said vehicle for limiting the upward motion or stroke of said counterweight.

According to a further characterizing feature of the invention, each aforesaid counterweight has a selectively adjustable weight to provide one aforesaid load transfer means.

According to an alternative embodiment, each aforesaid handling cable for controlling the extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of an adjusting member having a selectively variable length, such as a turn buckle or like tension shackle, rope tightener or stretcher forming an aforesaid tensioning and load transfer means.

According to a modification, each aforesaid handling cable for controlling the extension of said second ramp section is connected to a pressure fluid-operated linear-displacement actuator for example of the ram type having a selectively adjustable force to form an aforesaid tensioning and load transfer means.

According to still another alternative embodiment, said automatic tensioning and slack taking-up means consist of at least one resiliently deformable spring-like member and for this purpose each aforesaid handling cable for controlling the extension of said second ramp section is connected to a stationary fastening point provided on said vehicle through the medium of this spring, whereas said automatic means for stopping and unidirectionally holding against motion consist of a stationary stop means for limiting the strain or deformation of said spring under maximum stress.

According to a further alternative embodiment, said automatic tensioning and slack taking-up means consist of a possibly self-acting winding-up appliance to which each aforesaid handling cable for controlling the extension of said second ramp section is connected whereas said automatic means for stopping and unidirectionally holding against motion consist either of the stationary fastening point of the end of said cable on said appliance or of a locking or braking member of said appliance for braking said cable at the end of its useful paying-out motion.

According to still a further modification of the invention, each aforesaid handling cable for controlling the extension of said second ramp section is connected to a power winch as known per se and the winding-up device consists of said winch which is preferably provided with means for keeping the cable tension constant and is located on said vehicle to form an aforesaid load transfer means.

Finally according to still another alternative embodiment, said load transfer means consist of at least one counterweight or like counterbalancing or weighting body and preferably of a body with an adjustable weight fitted on one lever arm fast with said second ramp section so as to bias or urge same upwards i.e. towards its extended position.

When the ramp comprises, as known per se, a third or outermost section forming a supporting pad for bearing engagement with said outside platform and which is pivotally connected preferably with an intermediate point thereof to the corresponding outer end of said second section forming an intermediate section, there are provided self-acting or operated means for raising said outermost section. For this purpose and according to one embodiment of the invention, each handling cable for controlling the extension of said intermediate section is reeved as known per se on at least one associated main loose guide pulley or sheave carried by said intermediate section and this cable is secured with its aforesaid outer end at a point located outwards beyond the pivotal connection of said outermost section with said intermediate section. Such an arrangement offers the advantage to enable said outermost section to be automatically raised so as to assume a proper flat-laid position when engaging the quay thereby preventing any possibility of buttressing or abutting against some projection of the quay.

According to an alternative embodiment, an operated means for controlling the raising of said outermost element may consist of at least one preferably linear-displacement, pressure fluid operated for instance ramp-like actuator mounted between the intermediate and outermost ramp sections and remote-controlled either automatically or by an operator from a remote-control station or desk.

Moreover, in the device according to the invention, the ramp, in its lowered and extended working condition, remains at least partially suspended from its handling cables or ropes reeved on the associated king-posts, respectively, of the ship and made fast adjacent to the outer end of the inboard ramp section (i.e. that section which is pivoted to the ship) so a to relieve the quay from the load sustained by decreasing the bearing pressure of the free end of the ramp thereon by transferring or carrying over at least one part of the total ramp weight and of its possible instant load to the ship. The bearing pressure exerted onto the quay by the outermost ramp section may also or in addition be decreased by applying a suitable adequate tension to the handling cables or ropes for controlling the extension of said intermediate section, so that their reeved portions between pulley or tackle blocks, interconnecting the innermost ramp section and the adjacent outer or intermediate ramp section pivotally connected thereto thereby exerts a relative lifting force on the combination of said intermediate ramp section and outermost ramp section for thereby transferring at least one part of the weight of such an assembly and of the instant load possibly carried thereby to said innermost ramp section while unidirectionally blocking the pivotal direction between both innermost and intermediate ramp sections in the relative swinging direction for holding same together (and this at least to some extent).

Such a load transfer to said handling cables required at least in part owing to the fact that the ramp forms a beam consisting of several pivotally interconnected sections results in applying corresponding tractive forces to the tops of said king-posts which are extending upwards to a relatively large height above the level of the horizontal centre line passing through the centre of gravity of the ship so that such tractive forces are applied to the ship with a rather significant lever arm generating a corresponding tilting moment tending to cause the ship to list or to be tilted to the side where the ramp is located thereby heeling over.

To remove or obviate such a drawback to a large extent, i.e. to prevent the ship from listing or heeling over during the use of the ramp, it is known in particular from the U.S. Pat. No. 3,687,308 to provide on at least one side frame member of the innermost ramp section pivotally connected to the ship, a pressure-operated extensible and retractable actuator with a substantially linear displacement in translatory motion, in particular of the ram-type formingg a cylinder and piston assembly the line of action of which is spaced from the geometrical pivot axis of the pivotal connection between both inner and outer or intermediate adjacent ramp sections, said actuator being adapted to removably bear against an abutment member rigidly secured to the corresponding side of said adjacent outer section in the extended and lowered working configuration of said ramp for locking said pivotal connection in the direction of rotation of increasing extension in a selectively variable relative angular position through the adjustable active extension length of said actuator whereas selectively variable connecting means between said side frame member and said corresponding side, respectively, of both ramp sections involved enable to lock said pivotal connection in the direction of rotation of ramp folding in the same relative angular position. In this known prior art arrangement, said actuator bears upon the adjacent outer ramp section through the medium of an arm pivotally connected to said inner ramp section and slidably engageable with the adjacent outer ramp section and said selectively variable connecting means consist of handling cables or ropes for controlling the extension of said outer ramp section and one reeved portion of which interconnects both pivotally interconnected ramp sections, these cables being operated by at least one winch mounted on the inner ramp section and adapted to exert a selectively adjustable fixed tension on said cables controlling the extension of said outer ramp section. Such a combined system enables to achieve a buttressing effect locking or holding against motion the pivotal connection between both aforesaid ramp sections in both opposite directions of rotation thereby preventing any variation in the relative angular position of both ramp sections involved (with attendant upward or downward motion of the absolute position of the pivotal connection in space), so that the ramp behaves bodily as a bridge-like stiff or rigid continuous beam which is suported on the quay and by the pivotal connections with the ship at a location very close to the centre line of gravity of the ship thereby reducing by a corresponding amount the length of the lever arm generating the aforementioned tilting or tipping moment hence the possible resulting list of the ship.

The aforesaid known construction exhibits several inconveniences. On the one hand, the pushing buttressing actuator and pivoted arm assembly engaging a sidewise projecting abutment directly intergral with the runway forming the intermediate or outer ramp section which is devoid of side frame members, is of a rather complicated construction. On the other hand the use of a cable or rope system in combination with the buttressing actuator exhibits the disadvantage of separating the buttressing functions in both opposite directions of rotations, respectively, of the pivotal connection, thereby also complicating the construction to a significant extent. Moreover, the locking effect achieved by the cables controlling the relative extension of the intermediate or outer section by means of their associated individual winch does not allow to achieve an absolutely positive locking effect, i.e. resulting in an adequate stiffness of the ramp in the relative lifting direction of the pivotal connection, thereby decreasing the effectivenes of the desired locking action by a corresponding amount. Said known system is accordingly rather expensive, of a rather difficult handling in view of the difficult mutual adaptation of both separate locking functions in opposite directions, respectively, and of a rather unreliable effectiveness and operation.

There are in addition known ramps consisting of three pivotally interconnected sections the innermost section of which is pivoted to the ship while being suspended from a pair of cables or ropes made fast with one end to the ship and with the opposite end to the opposite longitudinal edges, respectively, of said innermost ramp section adjacent to the outer end thereof. On either longitudinal side of the innermost section is pivoted the bottom or back end of the cylinder of a linear-displacement type pressure fluid operated actuator extending substantially in parallel relation to the relative vertical longitudinal plane of said side frame member and the piston rod of which s pivotally connected with its end to the adjacent inner end of the adjacent intermediate ramp section.

In Applicant's co-pending U.S. Pat. Application Ser. No. 380,469 filed on July 18, 1973 and not yet publicly disclosed is proposed a foldable ramp which may be raised and lowered and consists of three pivotally interconnected sections the innermost section of which is pivoted to the ship and suspended from handling cables or ropes kept taut or stretched with an adjustable constant tension (and wound up on respective winches provided on the ship) adjacent to its outer ends of its opposite side frame members forming a kind of guard-railing. The central or intermediate ramp section also comprises side frame members forming a kind of guard-railing on its opposite sides and a linear-displacement buttressing actuator is mounted on either longitudinal side of the ramp on the adjacent ends of the side frame members of the inner and central ramp sections, respectively, above the pivotal connection therebetween and in the relative longitudinal vertical plane of the side frame members in the lowered working position of the ramp, thereby interconnecting these ends so as to exert a buttressing effect onto the ramp. The cylinder of each actuator is mounted on the innermost ramp section so that each actuator exerts through its piston rod a thrust or pushing force onto the adjacent intermediate ramp section, whereby the pivotal connection between both of these ramp sections may be lifted upwards or raised in space so as to form an upward projecting angle therebetween.

One object of the invention is also to remove said drawbacks by providing a double buttressing arrangement of a simpler hence less expensive construction and combining into one single and same assembly the functions of locking the pivotal connection between both ramp sections in either of the opposite directions of relative rotation thereof, respectively. For this purpose the device according to the invention is characterized in that on the one hand said actuator is pivotally connected with its casing or body portion onto the side frame member of said innermost ramp section and extends substantially in parallel relation to the relative longitudinal vertical plane of said side frame member and higher than the geometrical pivot axis between both innermost and central ramp sections in the working position of the ramp whereas said central ramp section also comprises a pair of side frame members on its opposite longitudinal sides, respectively and on the other hand the movable thrust or pushing head of said actuator is freely engageable directly with at least one substantially concave thrust or buffer or like pad means forming said abutment member and secured onto the adjacent end of a corresponding side frame member of said outer ramp section, operated or boosted locking means being provided on said corresponding side frame member of said outer ramp section to rigidly connect said actuator head with said thrust or buffer member, these means forming said selectively variable connecting means.

In addition to the aforesaid advantages aimed at by the objects of the present invention, such an arrangement is also advantageous in view of its rather more reduced size as compared with the known system. Moreover the buttressing actuator serves itself as a bracing or like tie-member invariably connecting together both interconnected ramp sections in the locking position of the actuator thereby positively and effectively preventing any relative folding or rotary motion about the pivotal connection between both ramp sections involved.

According to another characterizing feature of the invention, the movable thrust head of said actuator comprises at least one sidewise projecting portion such as for instance a transverse projecting stud-pin adapted to bearingly engage said buffer member or pad or like abutment means which is preferably a substantially square-shaped bracket and said locking means comprise at least one movable retaining member actuated in particular by an associated power-operated actuator and mounted on said adjacent outer ramp section, said retaining member being adapted to engage said stud-pin or like trunnion member to keep it in abutting engagement with said thrust or buffer pad.

According to still another characterizing feature of the invention, each aforesaid retaining member is constantly biased or urged automatically towards its operative locking position either by a resilient spring-like biasing or return means or by gravity so that its associated power-operated actuator serves for unlocking purposes only.

This retaining member thus provides a temporary rigid working assembly secured against any separation, disengagement or like disconnection and against any slipping or sliding motion through mutual displacement, preferably by a shape-conditioned stop means or fit or the like thereby achieving a closed assembly.

Owing to its technical unobvious effects and advantageous results obtained the device according to the present invention brings about a substantial progress or advance or significant improvement over previously known devices of the same kind.

The invention will be better understood and further objects, characterizing features, details and advantages thereof will appear as the following explanatory description proceeds with reference to the diagrammatic accompanying drawings given by way of non limiting examples only illustrating various presently preferred specific forms of embodiment of the invention and wherein:

FIG. 1 shows a perspective view of the ramp of the invention according to a first embodiment thereof, with a second ramp section provided with cantilever booms or outriggers or like projecting arms, the ramp being mounted astern i.e. at the rear portion of a ship moored longitudinally along a quay berth and shown in its lowered extended working configuration wherein its longitudinal direction makes an acute angle with the general backwards pointing longitudinal direction of the ship;

FIG. 2 is a fragmentary top view of the arrangement shown in FIG. 1;

FIG. 3 is a fragmentary side view on a larger scale showing the ramp in a raised and folded stowing position, in an intermediate handling position in a partially lowered and extended state and in two lowered and extended working positions, respectively, in both cases where the access area of the ship is located higher or lower than the quay surface, respectively;

FIG. 4 is a partial side view of the upper right-hand portion of FIG. 3 showing the use of a counterweight for each handling cable controlling the extension of said second ramp section;

FIG. 5 is a view similar to FIG. 4, showing an alternative embodiment illustrating the use of a hydraulic actuator for each handling cable controlling the relative extension of said second ramp section;

FIG. 6 is a view similar to FIGS. 4 or 5, showing another modification illustrating the use of a spring for each handling cable controlling said relative extension of the second ramp section;

FIG. 7 is a view similar to FIGS. 4 to 6, showing still a further alternative embodiment illustrating the use of a constant-tension winch for each handling cable controlling the relative extension of said second ramp section;

FIG. 8 is a partial side view of the ramp portion adjacent to the quay in its working condition, illustrating by way of another alternative embodiment, the use of a counterweight on each projecting boom or cantilever outrigger of the second ramp section;

FIG. 9 is a perspective view similar to FIG. 1 at a smaller scale, showing a second embodiment of the invention wherein said cantilever booms or projecting outriggers are carried by the innermost ramp section instead of being carried by the intermediate ramp section;

FIG. 10 is a fragmentary side view of the preceding device shown in its raised and folded stowing position;

FIG. 11 is a view similar to the preceding one but corresponding to the configuration shown in FIG. 9 when assuming the level of the access area of the ship to be approximately the same as or slightly higher than that of the quay;

FIG. 12 is a fragmentary side view on a larger scale in the encircled detail XII of FIG. 3;

FIG. 13 is a view similar to FIG. 11 but wherein the access area of the ship is assumed to be located higher than the quay surface;

FIG. 14 is an enlarged fragmentary side view of the encircled detail XIV in FIG. 13;

FIG. 15 is a view similar to FIG. 11 or 13 but wherein the level of the access area of the ship is assumed to be located below the quay surface level;

FIG. 16 is an enlarged fragmentary side view of the encircled detail XVI in FIG. 15;

FIG. 17 is a fragmentary side view on a larger scale, similar to FIGS. 10, 11, 13 and 15 and showing the ramp in different successive end and intermediate positions, respectively, to show the various steps of its operation in both cases where the access area of the ship is located lower and higher, respectively, than the quay surface;

FIG. 18 is a fragmentary outside lateral view, with parts broken away, of the ramp portion located adjacent to the pivotal connection between the innermost and central or intermediate ramp sections in a relative configuration partially folded with an upward projecting angle, said portion being provided with a device according to the invention, placed in its retracted inoperative position, i.e. without producing any buttressing effect;

FIG. 19 is a fragmentary side view on a larger scale of a still more reduced ramp portion about its pivotal connection in a relative lowered and extended working position with the innermost and intermediate ramp sections substantially aligned in mutually registering relationship in extension of each other, said buttressing appliance being in its operative extended position; and

FIG. 20 is a fragmentary top view of the adjacent end portions of both corresponding side frame members of both ramp sections involved, respectively, shown in the preceding Figure.

According to the exemplary form of embodiment shown in FIGS. 1 to 8, a ship, generally denoted by the reference numeral 1 and the stern or rear end portion of which only is shown, is moored adjacent a quay 2 for instance alongside thereof, so that the longitudinal direction 3 of the ship is substantially parallel or co-extensive with the direction of the quay edge. The rear portion of the ship is fitted with a movable access ramp 4 consisting of three successive innermost or foremost, central or intermediate and rearmost or outermost sections 4a, 4b and 4c, respectively, pivotally connected to each other in the longitudinal direction in substantially aligned mutually registering relationship in the lowered extended working position by pivot hinges or the like 5, 5', respectively. The outermost section 4c is desirably in the shape of a bearing pad or like engaging plate serving to support the ramp onto the quay 2, so that this section automatically conforms to the quay surface irrespective of the relative slope of the intermediate section 4b. In order to facilitate the passage of vehicles on the ramp, the outermost section 4c is as known per se wider on at least one side and at least towards its free end than the adjacent intermediate section 4b. The innermost or inboard section 4a is made desirably wider at least towards one side as known per se at its forward or inner end through which it is pivoted at 6 to the ship 1.

At least the innermost section 4a is provided on either side thereof with two side frame members 7. The innermost section 4a is secured preferably at its outer end or adjacent to its pivotal connection 5 with the intermediate section 4b to at least one handling cable or rope wound up on an associated power-operated handling winch located on the ship. There are preferably provided at least two handling cables 8, 8' made fast at 9, 9', respectively, onto the side frame members 7 of the ramp section 4a and winding up on two corresponding handling winches 10, 10', respectively, desirably located at an overhead or elevated level, for instance on the upper deck 11 of the ship. Each handling cable 8, 8', extending from its associated power-operated winch 10, 10' passes at first on at least one preferably elevated auxiliary guide pulley or sheave mounted for instance on a deck erection or like superstructure such as a suitable king-post or mast 13, 13' (at the bottom portions of which the winches 10, 10' are located) and then on at least one main guide-pulley 9, 9' mounted on the side frame members 7 of the ramp section 4a. In order to reduce the tractive force to be exerted on the handling cables 8, 8', it is advantageous that each handling cable 8, 8' forms a suitable reeved portion or the like interconnecting the ramp section 4a with the corresponding king-post 13, 13' while thus passing successively on several auxiliary guide-pulleys 12, 12' mounted in a same pulley or tackle block carried by the corresponding king-post 13, 13' and then on several main guide-pulleys 9, 9' also fitted together in a same tackle block secured to the corresponding side frame member 7, 7'. Each cable 8, 8' thus exhibits multiple runs extending between the ship and the ramp. To balance the tensions in the various runs of the cables 8, 8', one single cable only is used which, extending from the winch 10 and after having passed on the pulley-blocks 12 and 9 is reeved at 8" successively onto the guide-pulleys 9a, 9'a located beneath the ramp section 4a at the outlet of pulley-block 9 and the inlet of pulley-block 9', respectively, for passing then on the latter and afterwards on the tackle-block 12' to be finally taken up by the other winch 10'.

As known per se, the intermediate section 4b is foldable downwards against the innermost section 4a along the latter and secured at at least one point and preferably at two points 19, 19' located for example sidewise of each side on the opposite longitudinal edges, respectively, to at least one and preferably two handling cables 15, 15' controlling the relative extension of said intermediate section and passing each one on at least one loose guide sheave and for instance two loose guide-sheaves 16, 16' which are preferably at an elevated position and carried for instance by a king-post or the like 13, 13', respectively, to be made fast through the medium of a turn-buckle, rope stretcher or stiffener or like cable tensioning or tightening device 17, 17' to a stationary point 18, 18' fast for instance with the associated king-post 13, 13'.

As known per se the intermediate section 4b extends beyond its pivotal connection 5 with the innermost section 4a with at least one longitudinal projecting arm-like boom or integral outrigger carrying towards its free end at least one auxiliary guide-sheave for each handling cable 15, 15' controlling the extension of said intermediate section. For this purpose there are desirably provided two such cantilever arm-like booms or projecting outriggers 23, 23' consisting of outwards offset extensions of the corresponding longitudinal edges of the intermediate section 4b beyond the pivotal connection 5 forming the outer end of the vehicle runway supported by the side frame members 7 of the innermost section 4a, these booms being preferably arranged so as to be located higher than the innermost section 4a in the extended position of the ramp and to embrace the latter. Each projecting boom 23, 23' carries at least one auxiliary guide-pulley 19, 19' for the handling cable 15,15' controlling the extension of said intermediate section, which thus is reeved successively over this pulley 19, 19' and then on a main loose associated guide-pulley 14, 14' carried by the innermost secton 4a respectively at the corresponding auxiliary sheave 19, 19' to be made fast at a stationary point 14a, 14b on the associated side frame member of the innermost section 4a. There are desirably provided, on each boom 23, 23', several auxiliary loose guide-pulleys 19, 19' mounted in a same tackle-block and, on the innermost section 4a on either side thereof, several loose main guide-pulleys 14, 14' also mounted in a same tackle-block so as to form a force-reducing reeving between each boom 23, 23' and the innermost section.

At least one (hydraulic or pneumatic) pressure fluid operated actuator, preferably of the linear-displacement type consisting of a cylinder and piston assembly mounted between the intermediate ramp section 4b and the innermost ramp section 4c and pivotally connected with its cylinder bottom or back end to the end of the section 4b and with its piston rod to the end portion forming the heel part of the section 4c located under the section 4b (see FIG. 3). This actuator is desirably provided and remote-controlled for raising the innermost section 4c so that the latter rests entirely throughout its seating surface in a flat-laid condition onto the quay 2, so as to properly connect the runway surface of the intermediate section 4b to the quay surface and to distribute the load uniformly on the latter to avoid any buttressing, punching or like effect. FIG. 2 shows that it is advantageous to provide two such actuators 26 preferably arranged in symmetrical relation to the longitudinal vertical center plane of the ramp towards the side edges, respectively, of the innermost ramp section 4c. Independent segmented flap elements 27 pivoted to the transverse end edge of the section 4c in juxtaposed relationship across the latter serve to engage the quay 2 to facilitate through their tapering wedge-shaped cross-sectional contour the access to the section 4c. Also, a set of similar flap elements 28 are likewise pivoted to the inner transverse end edge of the ramp section 4a to facilitate the access to the tween-deck 29 of the ship while spanning the cargo port 30 in the side thereof.

The tractive reaction force at the fastening point of each handling cable 15, 15' controlling the extension of the intermediate section, on its associated derrick or king-post 13, 13' may be produced in various ways. Thus in FIGS. 1 and 3, this reaction force is merely produced by the stationary fastening point 18, 18' of each cable at the top of the associated king or derrick post. In the alternative embodiment according to FIG. 4, each cable 15, 15', after having been reeved over a first guide-pulley 16 located at the free end of the jib portion of the associated king-post or derrick mast 13, 13' passes on a second guide-pulley 16a located at the opposite end of this jib portion to extend downwards again along the king-post and to terminate into a movable counterweight or the like 31 mounted for instance on rollers 32 for riding on or within a corresponding forced-guide track 33 sloping downwards from top to bottom and away from the ramp in the downward direction. This guide-track 33 is provided at its upper end with a stationary stop means 34 for limiting the upward stroke of the associated counterweight 31. The position of the counterweight obviously varies with the relative position of the ramp during operation thereof, the engagement of the counterweight 31 with the stop means 34 automatically causing the relative raising and extension of the intermediate ramp section 4b.

In the alternative embodiment according to FIG. 5, each cable 15, 15', after passing over the associated guide-pulley 16a is reeved on a guide-pulley 35 carried by the piston rod of a linear-displacement pressure fluid operated, for example, hydraulic actuator 36 mounted on the associated king-post 13, 13', the thus returning run of each cable 15, 15' being made fast at a stationary point 37 of the corresponding derrick mast or king-post. Each actuator 36 thus allows to vary at will and preferably at the same time or synchronously the tension in the associated cable 15, 15' in particular through selective adjustment of the control fluid pressure fed into the cylinder of actuator 36.

In the alternative embodiment shown in FIG. 6, the pressure fluid operated actuator 36 has been replaced by a spring-operated actuator or the like 38 secured to the corresponding king-post 13, 13' and comprising for instance a cylinder containing at least one for instance helical compression spring with one end of which co-operates a sliding piston coaxially integral with a rod carrying at its free outer end the pulley 35. The helical spring could possibly be replaced by a compressible preferably gaseous fluid such s nitrogen.

In the embodiment of FIG. 7, each cable 15, 15', after passing on the guide-pulley 16, 16', is wound up on a power-operated winch 39 preferably applying a constant tension to the cable and mounted on the associated king-post 13, 13', said winch being driven for example hydraulically or electrically.

The actuators 36 in the embodiment of FIG. 5 or the winches 39 in the embodiment of FIG. 7 allow to selectively vary the tension in the cables 15, 15' in the extended and lowered working configuration of the ramp 4, thereby tending to lift the intermediate ramp section 4b upwards to thus release selectively the bearing pressure exerted on the quay 2 by the outermost ramp section 4c. Another means enabling to produce the same relief effect consists according to the embodiment of FIG. 8 to provide on each projecting boom 23, 23' of the intermediate ramp section 4b a counterweight or the like 40 having for instance a selectively variable weight and desirably located endwise of the associated projecting boom 23, 23'. Each counterweight 40 thus applies a tilting moment to the section 4b about its pivot axis 5 in the upward direction or direction of raising of said section. Instead of a counterweight it is also possible to correspondingly weight the structure of the booms 23, 23' by increasing their mass.

Automatic control means are desirably provided to keep the innermost section 4a away or spaced from the quay in the lowered working configuration of the ramp in order that it never directly engages the quay and each operating winch 10, 10' is phase-locked in follow-up relationship to these control means which consist for instance of at least one sensor or like detector 21 (see FIGS. 2, 3 and 8) secured for example to the intermediate section 4b in particular below same and towards its inner end and adapted to bear upon the surface of the quay 2, preferably adjacent to the edge of the quay to detect any variation in relative position in height or in the level difference between the ship 1 and the quay as caused in particular by an upward motion of the ship. Such a sensor 21 may consist for example of an electric limit switch with normally open contacts adapted to control the simultaneous or synchronized operation of the respective motors or prime movers of the handling winches 10, 10' by acting for instance either upon an electromagnetic valve in the case of pressure-fluid operated motors such as hydraulic or pneumatic motors or upon an electric switch relay in the case of electric motors.

The system is desirably fitted with automatic control means for adjusting the relative angular position of the innermost and intermediate ramp sections 4a and 4b, respectively, to keep same substantially aligned or inclined with an optimum slope in the lowered extended working configuration of the ramp, each aforesaid handling winch 10, 10' being then phase-locked in follow-up relationship to such control means. These control means consist for example of at least one sensor or like detector 22 mounted on one of the two adjacent ramp sections 4a, 4b, preferably in the vicinity of its pivotal connection 5 with the other section and adapted to engage said other section so as to measure the angle formed therebetween in particular during the raising motion of the ship. In the example shown, this detector 22 is mounted on the protruding boom 23 of the intermediate ramp section 4b between the latter and the side frame member 7 of the innermost ramp section 4a. This detector 22 may as well as the sensor 21 consist advantageously of an electric limit switch or of a position pick-up or detecting means with an equivalent action.

In the embodiment of FIGS. 1 through 8, each aforesaid protruding boom 23, 23' is in extension of the corresponding side edge of the intermediate section 4b. It is apparent however that generally each projecting boom may be in extension of any one of the two innermost and intermediate ramp sections 4a, 4b, respectively, while extending beyond the common pivotal connection between the adjacent ends thereof towards the other section which then carries at least one main guide-pulley or tackle-block for the handling cable 15, 15' controlling the extension of the intermediale section whereas the free end of the corresponding boom then carries at least one auxiliary guide-pulley or tackle-block for this cable.

FIGS. 9 through 17 show another embodiment of the invention wherein the relative arrangement of said booms and sheaves or pulley-blocks has been reversed with respect to that of the first embodiment shown in FIGS. 1 to 8. In this alternative embodiment, it is the innermost ramp section 4a which extends beyond its pivotal connection 5 with the intermediate section 4b with at least one integral projecting longitudinal arm-like boom or outrigger and preferably with two such booms 7a, 7b substantially co-extensive in parallel relationship with the general longitudinal direction of the ramp in extension of the side frame members 7, on either side of the intermediate section 4b while being desirably transversely offset outwards so as to be spaced sidewise from the intermediate section 4b and preferably somewhat elevated or higher with respect thereto. Each projecting boom 7a, 7b then carries the or each main guide-pulley or tackle-block 19, 19' for the handling cable 15, 15' controlling the relative extension of the intermediate section, whereas the intermediate section 4b carries at an intermediate point thereof at least one auxiliary guide-pulley or tackle-block 14, 14' for each handling cable 15, 15' controlling the extension of said intermediate section and leading from each main guide-pulley or tackle-block 19, 19'. Each handling cable 8, 8' for the ramp is then made fast for instance with a tackle-block at a point 9, 9' of the innermost section 4a towards the pivotal connection 5 or outer end of same. On each king-post or derrick mast 13, 13', the free downward extending run of each cable 15, 15' terminates in a counterweight or the like 31, 31'. Each king-post 13, 13' comprises a stationary stop means 34, 34' limiting the upward vertical stroke of the associated counterweight 31, 31'.

Each handling cable 15, 15' controlling the relative extension of the intermediate ramp section is desirably made fast with the end of its run leading from the corresponding reeving portion 14, 14' thereof and after having passed over an additional guide-pulley 25, 25' (FIGS. 10, 11, 13, 15) to the outermost section 4c at a point 20, 20' located outwards beyond the pivotal connection 5' of this outermost section with the intermediate section 4b. The cables 15, 15' also serve to automatically raise or lift the outermost section 4c so that the latter rests entirely throughout its seating surface on the quay 2 thereby properly connecting the runway surface of the intermediate section 4b to the quay surface and distributing the load uniformly on the latter to avoid any punching or like buttressing effect. This arrangement is also applicable to the embodiment of FIGS. 1 through 8 instead of the actuators 26 and it is advantageous that each guide-pulley 25, 25' for each handling cable 15, 15' controlling the relative extension of the intermediate section be located preferably substantially at the pivotal connection 5 between the innermost section 4a and the intermediate section 4bfor instance in coaxial relationship therewith to return or guide backwards the associated cable 15, 15' leading from the guide-pulley or tackle-block 14, 14' to the fastening point 20, 20' provided on the outermost section 4c.

Pushing or thrust means such as one or several linear-displacement type pressure-fluid operated for instance hydraulic or pneumatic actuators with a cylinder and piston assembly 24 mounted on the ship 1 are adapted to bear freely in abutting relationship against the innermost ramp section 4a in the fully raised position thereof (FIG. 3) to initiate its downward tilting or swinging motion through gravity and possibly to brake or slow down same at the end of its raising motion at which it is engageable with stationary stop or rest means 41 forming wooden or rubber buffers or like pads provided on the ship. Alternatively these thrust actuators 24 could themselves form such stop or abutment means. Each actuator 24 instead of being mounted on the ship 1 could as well be mounted on the innermost ramp section 4a so as to be freely engageable with a stationary portion of the ship's structure at the start of the downward tilting or swinging motion of the ramp or at the end of the raising motion thereof.

The innermost section 4a is desirably enlarged or widened at 4' towards its inner end and preferably at least towards the obtuse angle defined between its own longitudinal direction and the longitudinal direction of the ship in the case of a ramp arranged towards one end for example aft of the ship with a view to facilitate access therto.

A lashing or locking appliance 42 is desirably provided on the ship for locking or holding the ramp 4 against motion in the stowed noperative position, i.e. when it is folded back and swung up (see FIGS. 3 to 7). Each locking or lashing device 42 is adapted to preferably engage the intermediate ramp section 4b folded downwards against the innermost section 4a which has come in abutment with the buffers 41 after having been run or extended through the latter. Each locking device 42 may be operated either manually or automatically for instance may hydraulic actuators and consist in particular of a latch, lockbolt or like hook member adapted to engage a bolt-clasp or equivalent catch or keeper means integral with the intermediate section 4b while preferably exerting a tractive force urging said ramp to bear against its abutment pads or buffers 41. Instead of being placed on the ship 1, each locking device 42 could also be provided on the ramp 4 to be engageable with a complementary or mating stationary catch element integral with the ship's structure.

Automatic control means, not shown, are advantageously provided to selectively vary the bearing reaction of the ramp 4 on the platform or quay 2, each aforesaid load transfer means, such as in particular the hydraulic actuators 36 or the winches 39 applying a constant tension to the associated cables, being then phase-locked in follow-up relationship to said control means. These control means consist for instance for a sensor or like detector forming a pressure pick-up device mounted on the ramp towards its outer end for bearing upon the quay 2 in the working position so as to measure the bearing reaction of said quay.

As shown in particular in FIGS. 10 to 16, each sensor element 21 is here secured to the innermost section 4a in particular underneath the latter and towards its outer end whereas the detector 22 is mounted on the intermediate ramp section 4b between the latter and the projecting boom 7a of the innermost ramp section 4a.

The operation of the ramp 4 is then the following with reference at first to FIG. 3 showing the first embodiment when assuming the ramp initially in the position C ₁ wherein it is folded back and entirely raised to an upstanding position. In this position, the ramp is held against motion in abutment against the buffers 41 by the locking arrangement 42, the ramp sections 4b and 4c being folded back against the section 4a. To lower the ramp into the extended working position, the locking device 42 is at first unlocked in order to disengage or release the ramp 4 and the winches 10, 10' which are desirably provided with means for automatically braking their unwinding or paying out motion, are operated in the unwinding direction so as to relieve the tension in the handling cables 8, 8' with a view to give them some slack during the downward swinging motion of the ramp. If the tilting moment through gravity about the pivot axis 6 is then inadequate initially to start the downward swinging motion of the ramp, the pushing rams 24 are actuated to force the ramp section 4a away in the downward direction thereby initiating the swinging motion. The operation for extending or relatively raising the ramp section 4b together with the ramp section 4c is effected differently according to the manner of connecting each cable 15, 15' to the ship. This operation is initiated upon tensioning the cables 15, 15' caused by the reaction of the stationary fastening points 18, 18' in the case of FIGS. 1 and 3 or of the stop means 34 limiting the upward stroke of the counterweights 31 in the case of FIG. 4 or of the fastening points 37 in the case of FIG. 5 (the ram 36 being then blocked) or also of the fastening points 37 in the case of FIG. 6 when the spring-operated actuators 38 are blocked or have reached an adequate resilient stress or force to cause the relative tilting or swinging of the ramp section 4b. From that time and as the ramp section 4a is swinging downwards, this reaction of the stationary fastening point results in each cable 15, 15' in an adequate tension to provide for the gradual automatic raising or extension of the ramp sections 4b, 4c thereby fully using the potential energy of the gravity induced downward motion of the ramp as shown for instance at the intermediate position C ₂ of the ramp in FIG. 3. The outermost ramp section 4c is moreover raised either by the actuation of the actuators 26 in the case of FIG. 3, or automatically by means of the cables 15, 15' when same are made fast, as in the embodiment of FIGS. 9 to 11, 13 and 15, at points 20, 20', respectively, of the ramp section 4c for causing same to swing about its pivot axis 5'. In the position C ₃ of FIG. 3, the ramp 4 has come to rest with its outermost section 4c on the quay 2 when the pivotal connection 6 connecting the ramp with the ship 1 is located lower than the quay. The position C ₄ of FIG. 3 illustrates the case where the ramp rests on the quay 2 when the pivotal connection 6 is located higher than the quay. In both of these cases, the outermost ramp section 4c presents itself in a substantially flat-laid position above the quay owing to its individual control. At the end of the operation for swinging or moving the ramp downwards, the handling cables 15, 15' for extending the intermediate section may possibly become fully slackened or loosened.

When the pivotal connection 6 between the ramp and the ship is lower than the quay 2 (position C ₃ in FIG. 3), the sensor 21 will then engage the quay and actuate the handling winches 10, 10' in the winding up direction to raise the ramp section 4a high enough so that it will not bear directly onto the quay. If however the pivotal connection 6 between the ramp and the ship is located higher than the quay 2 (position C ₄ in FIG. 3), it is then the angle detector 22 located on the ramp section 4b which becomes operative through engagement with the ramp section 4a for actuating the handling winches 10, 10' in order to adjust the angle between these two ramp sections to achieve an aligned relationship or the best slope of the ramp. The detectors 21 and 22 thus act automatically and separately. The detector 21 always operates befre the detector 22 and takes precedence of the latter, i.e. when the detector 21 is allowed to act, the detector 22 is inoperative but when the detector 22 is allowed to act, the detector 21 may operate also.

In the case of the embodiment of FIG. 5 or 7, when the bearing pressure of the ramp section 4b onto the ramp section 4c hence the bearing pressure of the ramp section 4c onto the quay 2 reaches a permissible upper limit value, the pressure detector mentioned hereinabove starts to operate for actuating the hydraulic actuators 36 or the winches 39 so as to give the cables 15, 15' an adequate tension to decrease the bearing pressure of the ram onto the quay by transferring a part of the weight and of the load of the ramp sections 4b and 4c to the ramp section 4a through the medium of the reeving 14, 19 and therefore to the handling cables 8, 8' from which the ramp section 4a is suspended with its outer end at 9, 9'. In the case of the embodiment of FIG. 8, this load transfer is effected automatically through the medium of the counterweight 40.

In the case of the embodiment of FIGS. 9 to 16, the operation of the ramp is illustrated in FIG. 17 wherein it is assumed that the cables 15, 15' are tensioned by the counterweights 31, 31', respectively, it being of course understood that the alternative embodiments of FIGS. 5 and 6 are also applicable to this form of embodiment. Referring to FIG. 17, it is seen that in the position B ₁ wherein the ramp is folded back and fully raised to an upstanding position, each counterweight 31, 31' is in an intermediate position at A ₁ between the lower limit level provided by the deck surface 11 and an upper limit level provided by the associated stop means 34, 34' for limiting the upward stroke of each counterweight. The operation of this embodiment is substantially the same as that described with reference to the first embodiment according to FIG. 3. Thus, at the beginning of the downward swinging motion of the ramp, each counterweight 34, 34', the weight of which is not high enough to raise or extend the intermediate and outermost ramp sections 4b and 4c, respectively, is then pulled or drawn by its associated cable 15, 15' and raises until it engages the associated stationary stop means 34, 34' limiting its upward stroke when the ramp section 4a has reached the intermediate position B ₂ inclined through an angle for example of about 20° with respect to the vertical direction. From that time and as the ramp section 4a is swinging downwards, the reaction produced by the stationary stop means 34, 34' provides in each cable 15, 15' an adequate tension to cause the gradual automatic raising or extension of the ramp sections 4b, 4c. At the end of the downward motion and extension of the ramp 4, the counterweights 31, 31' begin to move downwards to reach the lower end position A ₃ when the ramp 4 has been caused to rest in the position B ₃ onto a quay located higher than the pivotal connection 6 between the ramp and the ship 1 or to attain an intermediate level position A ₄ higher than the initial position A ₁ when the ramp has been caused to rest in the position B ₄ onto a quay 2 located lower than said pivotal connection 6. During the extension or raising motion of the intermediate ramp section 4b, the outermost ramp section 4c is simultaneously swinging about its pivot axis 5' in the direction of its relative raising owing to the action of the cables 15, 15' acting directly upon the section 4c through the medium of their fastening points 20, 20' provided on the latter. At the end of the operation for moving the ramp downwards, the cables 15, 15' may possibly slacken or become loosened completely if in the instant lowered position each counterweight 31, 31' is allowed to rest on a stationary support provided at the final level reached by the corresponding counterweight.

FIGS. 15 and 16 show the relative position of the detectors 21 and 22 in the case where the pivotal connection 6 between the ramp and the ship is located lower than the quay 2 whereas FIGS. 11 and 12 show the corresponding situation in the case where the pivotal connection 6 is located adjacent to or about the surface level of quay 2. FIGS. 13 and 14 show the relative position of the detectors 21 and 22 when the pivotal connection 6 on the ship 1 is located higher than the surface of the quay 2, the detector 22 mounted on the ramp section 4b then engaging the projecting boom 7a of the ramp section 4a. The operation sequence and the order of priority action or of precedence of these detectors are the same as in the first embodiment.

In both aforesaid embodiments the operation for raising and folding back the ramp 4 is effected in the reverse order of the operations previously described. When using tensioning or stretching devices like turn-buckles 17, 17' on the cables 15, 15' as in the embodiment shown in FIG. 1, the tensioning of these cables to decrease the bearing pressure of the ramp onto the quay 2 may be effected by means of these turn-buckles or tighteners through manual operation of the movable lantern or like socket members thereof.

It should be pointed out that, during said angular displacement by 20° of the ramp in relation to its fully raised upstanding position, no relative motion is imparted to the ramp sections 4b and 4c with respect to the ramp section 4a.

According to the examplary embodiment of FIGS. 18 through 20 of the drawings, each side frame member 7 extending along one longitudinal side of the innermost ramp section 4a down to its outer or pivot end 5 preferably without projecting beyond the latter, carries a desirably hydraulic actuator 101 preferably of the kind adapted to perform a linear displacement in straight translatory motion, consisting of a cylinder and piston assembly the body or cylinder 102 of which is pivotally connected with its bottom or back end by means of a substantially horizontal pivot pin 103 positioned transversely of the longitudinal direction of the ramp to a support forming a fork-like bracket, clevis or like yoke 104 for pivotal connection integral with the top of the side frame member 7 in the vicinity of the outer end of the latter. The movable piston rod 105 of the actuator 101 is thus located towards the pivotal connection 5' between the adjacent ramp sections 4a and 4b and carries at its free end a pushing or thrust head 106 carrying at least one sidewise projecting pin and preferably a pair of sidewise projecting pins 107a, 107b arranged in transversely opposed and coaxially aligned relationship and located on either side, respectively, of the movable head 106 while extending substantially horizontally in transverse relation to the longitudinal direction of the ramp hence in parallel relation to the geometrical pivot axis 5. The relative position of the ram-like actuator 101 could of course be reversed so that it is its piston rod 105 which is either pivoted through a connecting pin 103 to the bracket or clevis 104 and that the cylinder 102 carries the pushing head 106 at its free bottom or back end.

Forced-guide means are desirably provided on either side for the movable pushing head 106 of the ram-like actuator 101 and advantageously consist preferably of each pin 107a or 107b which are long enough to engage an associated stationary slideway consisting desirably of a stationary upright plate 108a, 108b secured to the top of the associated side frame member 7 while extending in the longitudinal direction thereof for projecting beyond the outer end of the innermost ramp section 4a that is towards the pivotal connection 5. This guiding slideway is desirably formed with a slot, groove or like elongated recess 109 (FIG. 18) wherein is relatively freely inserted and guided the associated thrust pin 7a or 7b. The guide slot 109 is of a substantially curved configuration the longitudinal centre line of which has the shape of an arc of circumference concentric with the geometrical axis of the pivotal connection 5 between both innermost and intermediate ramp sections 4a, 4b, respectively. The curvilinear or circumferential length of each guide slot 109 is long enough for accommodating a useful stroke of the movable head 106 adapted to any relative buttressing angular configurations of both ramp sections in the extended and lowered working position thereof. Both parallel guide slideways 108a, 108b are thus constantly supporting the free end of the actuator 101 in particular in all of its positions wherein it does not exert any buttressing effect.

The adjacent intermediate ramp section 4b is also provided on either longitudinal side and on at least one portion of the length thereof with a side frame member or like girder 110 which is possibly formed with an associated longitudinal boom 23 projecting as a cantilever beam beyond the pivotal connection 5 generally in parallel relation to the longitudinal direction of the intermediate ramp section 4b when such booms are not provided on the innermost ramp section 4a to extend beyond the pivotal connection 5 but in the reverse direction that is towards the intermediate ramp section 4b. Each side frame member 110 carries substantially at its inner end, i.e. the end located towards the pivotal connection 5, a kind of thrust bearing or recessed abutment bracket forming a stop pad adapted to be engaged by and to receive the thrust of each thrust pin 107a, 107b of the movable head 106 of the actuator 101. There are thus advantageously provided one pair of such abutment pads 111a, 111b located in symmetrical relation to a substantially longitudinal vertical center plane of the associated side frame member 110 while being spaced from each other by a distance large enough to accommodate with clearance or loosely the free end of the movable head 106 between both aforesaid abutment pads (see FIG. 20). The relative position in the longitudinal direction of the pad assembly 111a, 111b with respect to the intermediate ramp section 4b, the relative position and the curvilinear or circumferential length of the guide slots 109 as well as the relative position and the least total length of each actuator 101 in its fully retracted configuration are preferably determined so that in the buttressing position shown in FIG. 19 wherein both ramp sections 4a, 4b are substantially aligned with and in straight extension of each other, each actuator 101 be in its fully or utmost retracted state so that the piston is in mechanical abutment against the bottom of back end wall of the corresponding cylinder 102. The thrust pins 107a and 107b of each movable pushing head 106 therefore project sidewise by a distance long enough beyond the associated respective pads 111a, 111b for engaging the parallel guide slideways 108a, 108b, respectively, extending outside on either side.

In FIGS. 18 and 19, the top level of the respective runway surfaces of the ramp sections 4a, 4b have been shown in straight dotted lines at 112a, 112b and these runway surfaces project in overhanging relationship at their adjacent ends above the pivotal connection 5 to provide a continuous passageway in the extended working position of the ramp.

As mentioned hereinbefore, each abutment pad or like thrust plate 111a, 111b is desirably square shaped with its concavity facing the innermost ramp section in the extended working position thereof and with each pad is associated a locking means adapted to block one thrust pin 107a, 107b of the movable head 106 when it is accommodated in the recess or depression of the corresponding abutment pad. Each locking means advantageously comprises one retaining member having the shape of at least one arm actuated in particular by an ssociated power-operated control or positioning means and swinging in a plane substantially at right angles to said thrust pin while being adapted on the one hand to be lowered until abutting engagement preferably substantially with the tip of its free end having for example a mating and complementary bearing shape with the thrust pin involved on that face of the latter which is opposite to the corresponding pad to hold said thrust pin against motion and on the other hand to be moved upwards away from said thrust pin to release or be disengaged from the latter. As in this instance the movable pushing head 106 comprises a pair of transversely opposite coaxial thrust pins 107a, 107b adapted to co-operate with both corresponding pads 111a, 111b, respectively, the respective locking means for these thrust pins are desirably combined into one single retaining member which consists for instance of a fork-like or yoke-shaped part 113 which is substantially symmetrical with respect of said plane of symmetry of both pads 107a, 107b and the substantially parallel legs 113a, 113b form locking arms spaced from each other according to the spacing of said pads so as to be located substantially above the thrust pins 107a, 107b, respectively. The fork 113 is rotatably mounted on a substantially horizontal transverse shaft 114 supported in stationary bearings 115 of the associated side frame member 110, said shaft being desirably located higher than the pads and being longitudinally offset with respect to the latter towards the innermost ramp section 4a in the extended working position of the ramp. The fork or clevis 113 is rotatably mounted on this shaft by means of its transverse portion 116 having the shape of a tubular sleeve slipped over the shaft 114. This sleeve carries desirably a radial bracket or like clevis 117 forming a kind of crank arm through which the fork 110 is connected to an associated rotary control member consisting desirably of an auxiliary linear-displacement type preferably hydraulic actuator 118 mounted on the side frame member 110 of the intermediate ramp section 4b. This auxiliary actuator 118 is pivotally connected for instance with the back end or bottom of its cylinder to a supporting bracket 119 fast with the side frame member 110 and with the outer end of its piston rod to the clevis 117 fast with the fork 113 in a vertical plane substantially at right angles to the transverse shaft 114.

As shown in particular in FIG. 19, when the auxiliary actuator 118 moves its piston rod outwards its extended position, it causes the fork 113 to rotate in the clockwise direction in FIG. 19 thereby moving the legs 113a, 113b away from the thrust pins 107a, 107b, respectively whereas upon the retracting motion of the piston rod of actuator 118, the legs 113a, 113b are lowered into buttressing engagement in abutting relationship with said respective thrust pins to thereby hold same against motion onto their respective pads 111a, 111b. For this purpose the relative position of the fork 113 and the lengths of the legs 113a, 113b are designed so as to achieve such a buttressing effect onto the thrust pins and the free end of each leg 113a, 113b is advantageously formed with an arcuate concave recess 120 conforming to the curved side surface of the associated thrust pin when the corresponding locking leg is caused to rest upon that portion of this side surface which is away or opposite from the corresponding pad 111a, 111 b. The fork 113 thus locks or jams in the position shown in FIG. 19 the thrust pins of the movable head 116 substantially in the re-entrant angles of the pads to exert a slantwise directed action from top to bottom and towards the pads at least approximatively in the vicinity of the bisecting plane thereof thereby to prevent the movable head 106 from being lifted off or leaving said pads.

Preferably self-acting safety means for rendering the system fail-safe are desirably provided on the intermediate ramp section 4b and adapted to check, detect and report the relative position of said locking means at the ends of the locking and unlocking strokes, respectively, thereof. These safety means consist desirably of electric limit switches 121, 122 for limiting the locking and unlocking strokes, respectively, which are adapted to be actuated separately by a suitable striker, dog or lug 123 integral with the locking fork 113.

Preferably automatic means are provided to check or control the relative position at the end of the stroke of the movable push head 106 of the buttressing ram 101 against said abutment pads 111. These check or control means consist forinstance of a proximity detector or sensor 124 in particular of electromagnetic character controlling in phase-locked or follow-up relationship the operation of said locking means, i.e. of the auxiliary actuator 118. According to FIG. 19, this proximity detector 124, mounted on the side frame member 110 of the ramp section 4b, is located somewhat behind or rearwards of the pads 111a, 111b substantially in the vertical plane of symmetry thereof to face the space between the pads hence the movable head 106 of the ram 101 when said head is engagingly co-operating with the pads. This detector 124 thus enables to detect the presence and to accurately locate the position of the movable push head 106.

One of the two ramp sections 4a or 4b is moreover desirably provided with means for detecting the end of the relative movement of maximum extension of both successive ramp sections when they are registering in substantially aligned relationship as shown in FIG. 19, such a position corresponding advantageously to the end of the maximum retracting stroke of the buttressing ram 102 until its piston is mechanically stopped by abutting against the inner end wall inside of the ram cylinder thereby forming an actual mechanical stop means for the end of the stroke of relative angular rotation of both ramp sections with respect to each other in the direction of extension of said ramp sections. These detecting means consist desirably of at least one electric limit switch 125 mounted on the terminal end face of the side frame member 110 of the ramp section 4b substantially in front of the terminal end face of the side frame member 7 of the ramp section 4a thereby being adapted to be operated by a corresponding striker 126 integral with the side frame member 7 of the ramp section 4a. This electric switch 125, when it is actuated by the striker 126 in the relative position shown in FIG. 19, is adapted to switch or cut off the power supply energizing the ram 101, i.e. to discontinue the feeding thereof with pressure fluid or to prevent such a power supply.

In the foregoing description has been disclosed the buttressing device and its locking arrangement as mounted on the side frame members on one side of the ramp and this description is of course fully applicable to the buttressing and locking devices mounted on the side frame members on the opposite longitudinal side of the ramp in substantially symmetrical relationship with respect to the longitudinal vertical center plane of the ramp.

The operation of said device is then the following with the assumption that initially the ramp assumes an intermediate relative position shown in FIG. 18 while being moved to its operating working position. When the ramp has been lowered and extended into working position to bear upon the quay with its outermost section, the buttressing rams 101 are together fed with pressure fluid simultaneously so as to cause their piston rods 105 to move outwards into their extended position until the movable push heads 106 move to abutting engagement through their thrust pins 107a, 107b with the associated pads 111a, 111b. When each movable push head 106 assumes the proper buttressing position relative to the associated pads, the proximity detector 124 connected in series to the electric limit switch 122 checks and reports that the movable push head 106 has been caused to assume its proper position in the recesses of the associated abutment pads. The function of this proximity detector is thus to avoid or prevent that the locking fork 113 is actuated untimely or in advance before the movable push head 106 has reached its proper buttressing position. At this time each locking fork 113 is initially raised in inoperative or unlocking position due to the action of the associated auxiliary actuator 118 which is kept energized or fed with pressure fluid so as to retain its piston rod in its outward extended position, this actuator being for instance adapted to carry out the unlocking step only so that for this purpose it may be a single-acting actuator only. The initial unlocking position of the fork 113 is indicated or reported by the electric limit switch 14 actuated by the striker 123.

To cause the movable push head 106 to be locked it is then only necessary to allow the auxiliary unlocking actuator 118 to be exhausted by discharging its pressure fluid therefrom so that the locking fork 113 then drops through the action of gravity i.e. of its own weight by swinging downwards about the shaft 114 until its legs 113a, 113b are caused to rest onto the associated thrust pins 107a, 107b, respectively, to embrace same with the mating complementary recessed tips or end portions of the fork legs. During this swinging locking motion, the striker 123 rigidly connected to the fork 113 has been moved into engagement with the electric limit switch 122 for operating same, the latter indicating or reporting then that the buttressing operation has been properly carried out. The handling winches are then actuated and adjusted to keep the handling cables 8 taut with a substantially constant tension during the loading or unloading of goods or cargo according to a roll on-roll off process to restrict the pressure exerted upon the quay. The handling cables 15 for extending the intermediate section may however desirably remain substantially slack or untensioned or may be loosened or slackened during the loading or unloading steps.

When raising and folding back the ramp, the aforesaid operations are carried out in their reverse order of succession or sequence. Thus the auxiliary unlocking actuators 118 are first supplied with pressure fluid to raise the locking forks 113 thereby releasing the movable push heads 106. The electric limit switches 121 are then checking or monitoring through the action of the strikers 123 the proper inoperative or unlocking position of these forks and then allow the following steps to be carried out consisting successively in energizing the double-acting buttressing ramps 101 to retract their piston rods 105 the push heads 106 of which then move away or disengage the pads 111 and afterwards actuating the handling winches to swing upwards and fold back the ramp.

It should be pointed out that in the relative position shown in FIG. 19, the electric limit switch 125 is operated by the striker 126 thereby causing each associated buttressing ram 101 to have its pressure fluid exhausted or discharged since this ram then forms a mechanical stop means for the intermediate ramp section 4b. In the locked buttressing position the combination of each buttressing ram 101 and of its mechanical locking arrangement 113 then achieves an invariable connection between both ramp sections 4a, 4b both of which are then together equivalent to a rigid beam.

The device according to the invention thus offers the main following advantages:

simplicity of handling operation which may use one of the two handling winches 10, 10' only so that the use of the two handling winches 10, 10' is more advantageous than the use of one single winch provided with a double drum since it is then possible to operate with one of the two winches only at half speed in particular upon failure of the other winch;

automatic compensation for variations in the difference between the levels of the ship and quay, respectively, due to the tide and to a variation in the draught of the ship;

no outside power supply is required for operating the ramp sections 4b and 4c whereas in most of the prior art systems there are provided one or several electric winches for operating these sections 4b, 4c or hydraulic winches setting requirements or limitations regarding the installations of wiring and piping as well as the requirement of providing accommodations for receiving their power generating means;

simplicity of construction since in particular the pivotal connections between the various ramp sections remain free thereby allowing for a simple arrangement to achieve an automatic compensation for the differences in height or level of the quay with respect to the ship;

automatic raising of the outermost ramp section 4c when approaching the quay to avoid any damage through buttressing effect;

mobility of the end of each handling cable 15, 15' controlling the outward extension of the intermediate ramp section, on the ship, due to the mobility of the associated counterweight 31, 31' thereby enabling to take up the slack in these cables at the start and at the end of operation;

utilization of the potential energy of the ram and especially of the innermost ramp section 4a for operating the two other ramp sections 4b and 4c during their downward motion. During the ramp raising operation towards the upstanding stowing position of the ramp, it is the potential energy of both ramp sections 4b and 4c which assists in swinging the innermost ramp section 4a upwards thus relieving the handling winches 10, 10' and the handling cables 8, 8' by a corresponding amount;

in the lowered working position of the ramp, the innermost ramp section 4a is always suspended from its handling cables 8, 8' so that it does not bear upon the two other ramp sections 4b, 4c, the ramp section 4b merely resting through its pivotal connection 5 on the ramp section 4a, possibility for selective adjustment of the bearing pressure of the ramp onto the quay through transfer of at least one part of the weight and load sustained by the intermediate ramp section 4b to the ramp section 4a hence to the cables 8, 8' when the cables 15, 15' are connected on the ship, respectively, either to variable pressure hydraulic actuators or rams, or to hydraulic or electric winches keeping the cable tension constant, or to hand operated turn-buckles or like cable tighteners or still when using suitable counterweights on the intermediate ramp section 4b.

It should be understood that the invention should not be construed as being limited to the embodiments described and shown herein which have been given by way of examples only. In particular the invention comprises all the means constituting technical equivalents of the means described as well as their combinations if same are carried out according to the gist and used within the scope of the appended claims.