Title:
Truck
United States Patent 2059150


Abstract:
This invention relates to electric industrial trucks. More especially, my invention relates to an electric industrial truck having a load platform adapted to be lifted to a predetermined height. It is more particularly the object of my invention to devise a load lifting truck in which a platform...



Inventors:
Schroeder, Charles S.
Application Number:
US67953933A
Publication Date:
10/27/1936
Filing Date:
07/08/1933
Assignee:
YALE & TOWNE MFG CO
Primary Class:
Other Classes:
187/238, 280/43, 414/632
International Classes:
B66F9/08
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Description:

This invention relates to electric industrial trucks. More especially, my invention relates to an electric industrial truck having a load platform adapted to be lifted to a predetermined height.

It is more particularly the object of my invention to devise a load lifting truck in which a platform is adapted to be raised relatively to a supporting member which in turn is adapted to be lifted relatively to a primary supporting member, so that finally, there will be a double lift of the load supporting platform.

More in detail, my invention relates to a truck of the type in which there are a pair of primary standards relatively to which a pair of secondary standards are to be raised, the secondary standards having mounted thereon, for sliding lifting movement, a load carrying platform. In a truck of this type, it is generally arranged that a continuous chain be operated to lift the load carrying platform relatively to the secondary uprights or standards, the operation being designed so that whey the platform has been lifted its full degree of movement on the secondary uprights, those uprights and the load platform will move together relatively to the primary standards.

In the combination just indicated, it is sometimes possible for the load lifting platform to jamb or wedge itself into relatively fixed relation with the secondary pair of uprights before the load lifting platform has been lifted its full amount on the uprights. In this way, the load lifting platform is merely lifted relatively to the secondary uprights a small amount, whereupon the secondary uprights then move with the platform relatively to the primary pair of uprights so that improper and dangerous movement of the load lifting platform and uprights results.

My invention obviates this undesirable condition by providing means for maintaining the secondary set of uprights in fixed relation to the primary set of uprights until the load lifting platform has had a predetermined amount of movement relatively to the secondary uprights. .In a truck of the type being described, and to which my invention is applicable, it is generally arranged to mount the main load carrying portion of the truck frame on a tilting axle so that as the truck traverses an irregular way it is possible for the axle to pivot so that the truck will be supported on all four wheels, the front wheels being mounted relatively rigidly on said frame for contributing the necessary stability to said frame. It will be appreciated that if both axles were pivotally mounted relatively to the frame, the rigidity of the frame would be negligible. When it is desired to obtain the full lift of the elevating platform by the double lift of that platform and the secondary uprights, the free tilting relation of the load supporting axle to the truck is very undesirable because the high lifting of the platform will create a tipping force tending to move the main frame relatively to the axle and to spill the load, and will not permit of sufficient stability for the load to be handled safely. Therefore, means are provided in my invention for locking the axle and frame of the truck against relative tilting movement within predetermined limits so that proper stability of the frame relatively to the axle will be possible. As a more detailed feature of the invention I lock the axle relatively to the truck in a plurality of positions of the axle relatively to the truck, and I accomplish this locking either by manual or automatic means, the latter means being preferably although not necessarily operable by lifting movement of the secondary standards or uprights.

In the usual industrial truck employing standards or uprights, the elevating platform which moves on the uprights is supported by rollers operating in channels especially designed for those rollers, although in some types of trucks the rollers are mounted on opposite outside edges of the standards. It becomes desirable in ar- 80 rangements of this sort, regardless of the particular cooperation of the rollers and standards, to allow for an adjustment of the rollers relatively to the standards. My invention has as one of its objects the design of a particular means on which the rollers may be mounted whereby an adjustment will be readily obtained, and where the means for supporting the rollers will have an inherent mechanical tendency to remain in adjusted position. The preferred embodiment of my invention provides rollers mounted on pivots eccentrically placed on rotatable mounting members, whereby rotation of the mounting members will adjust the pivots.

While I will discuss and illustrate a particular modification of my invention, it should be understood that the various features indicated I consider broadly new in the art, and that I feel myself entitled to broad claims which will be sufficient to protect my contribution to the art against substantial utilization in other forms by those skilled in this field.

For a detailed description of my invention, I shall now refer to the drawings, wherein Fig. 1 is a view of my truck illustrating the parts in various operating positions. Fig. 2 illustrates a section through the truck and the position of the tilting axle relatively to the frame with the means for locking the axle to the frame. Figs. 3 and 4 are detailed views showing two methods, and dogs or detents, for locking the axle and frame against relative tilting movement.

Fig. 5 is a view along lines 5-5 of Figs. 6 and 7 illustrating the operation of the upright standards locking hook. Fig. 6 is a view-taken along section 6-6 of Fig. 5 while Fig. 7 is a view taken on the outside of the standards showing the method of releasing the holding hook from engagement with the primary standards. Figs. 8, 9, 10, 11, 12 and 13 are views illustrating the parts and assembly of the roller adjustment device.

Referring now more particularly to the drawings, reference numeral 10 illustrates a usual type of industrial truck supported by front wheels II and rear load supporting wheels 12. The truck has the usual type of forward controls 13 and a storage battery container 14, holding a battery whereby power is imparted by proper agencies to a load tilting rack 15 and to a continuous load lifting chain 16.

The load supporting portion of the truck carries a pair of upright standards 17, on which are mounted by rollers 18 and 19, a pair of secondary standards 20 which are adapted to ride up and down on the standards 17 as best illustrated in Fig. 1, and are adapted to tilt with the standards by operation of the rack 15 as is also best illustrated in Fig. 1.

The secondary standards 20 in turn support through means of a pair of upper rollers 21 and lower rollers 22, a load lifting platform 23 carrying the forks 24 which are adapted to extend close to the ground for the purpose of lifting any usual type of industrial load. The load lifting platform 23 is adapted to be secured to the chain 16 so that as the chain is actuated, the platform 23 will be raised on the secondary standards 20 to the top position illustrated at A in dotted lines in Fig. 1. The operation of the mechanism is such, that subsequent to the raising of the platform 23 to its uppermost position A relatively to the standards 20, the standards 20 and the platform 23 will be moved from the 60 first dotted line position A of the platform to the second position B.

As is indicated generally in the introduction of my description of this invention, it is sometimes possible for the platform 23 to bind relatively to the secondary uprights 20 so that the movement of the platform to the full upper position A illustrated in Fig. 1, is resisted. This resistance is sometimes sufficient for the chain to tend to lift the secondary uprights 20 before lifting platform 23 has reached its upper position A relatively to uprights 20. In order to prevent this accidental operation which prevents proper lifting movement of the member 23, I provide a pair of hook members 25 best illustrated in Figs. 1, 5, 6, and 7. I will now describe the operation of one of the hook members 25 which is secured to a shaft 26 mounted on bearings 27 carried by the secondary uprights 20.

One end of the hook has secured thereto a spring 28 secured at its other end to a collar on the sprocket shaft 29 whereby to exert a tendency on the hook forcing it into its full line position of Fig. 6 wherein it holds the secondary uprights 20 against upward movement relatively to the primary uprights 17 by the cooperation of the hook portion 30 with a cooperative hook portion 31 on the primary uprights 17.

In order to release the hook 26 from its full line position of Fig. 6 to its dotted line release position in the same figure, there is provided on the 6 shaft 26 a release cam 32 whose operation is best shown in Fig. 7. The rearward portion 33 of the load lifting platform 23 is extended as at 34 where it supports the roller 21 so as to cooperate with the extension 35 of the cam 32 for moving the cam as is very definitely illustrated in Fig. 7.

This rotates the shaft 26 and moves the locking portion 30 of the hook 25 from engagement with the locking hook section 31 of the standards 17, whereupon the released secondary uprights 20 will be allowed to move upward to the position illustrated at B in Fig. 1.

I shall now describe the locking of the axle of the truck relatively to the frame, with references to Figs. 2, 3 and 4. In those figures, the rear load supporting wheels 12 are shown as carried by the tilting axle 36 pivoted to the truck frame at 37. The primary uprights I7 are also shown, as are also the secondary uprights 20 which appear in a partially lifted position. A pair of dogs 38 are pivoted at 39 to upward extensions 40 of the main frame member 41 and form the basis of the operation to be described below.

Studs 42 carried on the dogs limit their downward movement so that they will not fall into a position from which they may not easily be moved by the downward movement of the secondary uprights 20 as will be indicated later.

While, of course, it is possible to so mount the dogs 38 that they may be operated directly from the control end of the truck by power or manually operated means, I prefer to have the dogs drop by gravity into their operative positions.

As is illustrated in Fig. 2, the left hand dog has dropped so that its surface 43 is in contact with the surface 44 of the axle and will prevent the tilting of the axle in a clockwise direction, or the tilting of the standards 7I in a counter clockwise direction. This full gravity operation of the dogs 38 is possible only when the standards 20, in the preferred embodiment, are moved to their upper position of Fig. 20 above the camming section 45 of the dogs. When the elevating standards 20 descend, their bottom surfaces will strike the camming portions 45 of the dogs and will move the dogs back into their initial ineffective position as shown in dotted lines in Fig. 3. This is probably the most simple manner of applying my invention so that it will operate automatically in connection with the lifting and lowering of the 65 load.

A modification of the devices shown in Figs. 2 and 3 is illustrated in Fig. 4 wherein the dogs 38 have a series of stepped ratchet portions 46 which cooperate with a pawl like shoulder 47 of the axle instead of the surface portion 44 of the modification of Figs. 2 and 3. The ratchet like portions 46 in cooperation with the pawl like portion 47 contribute a more positive cooperation of the frame and axle so as to better maintain the pawl in locking engagement.

I shall now refer to Figs. 8, 9, 10, 11, 12 and 13 inclusive, which illustrate that portion of my invention dealing with the adjustment of the bearing rollers relatively to the standards. For the purpose of better indicating my invention, I will describe it relatively to the roller 21 which supports the load lifting platform 23. This roller 21 is carried on a pivot shaft 48 having a usual pressure lubrication device 49. The pivot 48 is 7T integral with the circular bearing portion 50 while offset in eccentric relation thereto as is clearly shown. The circular portion 50 has a bearing 51 in the rearward portion 33 of the carriage 23 and is securely held in the bearing by a /backing member 52 which in turn is held in backing position by a series of screw threads 53. It will be readily understood that when the screw threads 53 are loosened so as to relieve the pressure of the backing member 52 against the circular bearing portion 50 of the stud member 48, it will be possible to rotate the stud on its circular bearing 51. Obviously, also, the eccentric relation of the stud -48 relatively to its bearing 50, will, by this rotation, be able to position the pivot 48 in an infinite number of positions within the range of its eccentricity. The positions and their variations are considerable, considering the accuracy with which the particular structure is designed, so that it is quite simple to get a ready, full, and easy adjustment of the roller 21. Also, because of the particular stresses of the load, a considerable pressure moment is applied between the circular bearing portion 50 of the stud and its bearing 51 in the plate 33, so that great stability of the stud in its mounting will be obtainable.

I claim: 1. In a truck, an axle carrying supporting wheels and itself tiltably mounted for movement relatively to said truck, means for stabilizing said truck and axle against relative tilting movement, said means comprising a pair of detent members mounted for movement into any one of a series of stabilizing positions depending upon the angularity of the axle relatively to the truck, means whereby said detents are held out of stabilizing position, said means being movable to release said detent members for movement into one of several axle stabilizing positions, depending on the then degree of tilting of said axle.

2. In a truck, an axle carrying supporting wheels and itself tiltably mounted for movement relatively to said truck, means for stabilizing said truck and axle against tilting relatively to one another in a particular tilted position of said truck, said means comprising a pair of pivoted pawls on the truck cooperable with a pair of cam surfaces on the axle, said pawl and surfaces being adapted for variable engagement, and with said pawls occupying varying pivoted positions, depending on the angle of tilting of the axle.

3. In a truck, an axle carrying supporting wheels and itself tiltably mounted for movement relatively to said truck, means for stabilizing said truck and axle in a particular tilted position against further tilting movement relatively to one another, said means comprising a detent on . the truck adapted to engage automatically a detent surface on said axle in one of a plurality of stabilizing positions, means holding said detent out of contact with said detent surface on the axle, and means mounting said detent for automatic movement, when released, into engagement with said detent surface in a particular stabilizing position dependent on the then degree of tilting of said axle.

4. In a truck, an axle carrying supporting wheels and itself tiltably mounted for movement relatively to said truck, means for stabilizing said truck and axle in a plurality of tilted positions against further tilting from a particular one of said tilted positions, said means comprising a detent member on said truck adapted to engage automatically a cooperating detent member on 76 said axle, means holding said detent out of contact with said cooperating detent member on the axle, and means mounting said detent for automatic movement, when released, into engagement with said detent member in a particular stabilizing position dependent on the then degree of 6 tilting of said axle.

5. In a truck, an axle carrying supporting wheels and itself tiltably mounted for movement relatively to said truck, means for stabilizing said axle and truck against relative tilting movement in a plurality of tilted positions of said axle relatively to said truck, comprising gravity detents and detent surfaces cooperable therewith, means for holding said gravity detents in an inoperative position relatively to said detent surfaces, and means mounting said gravity detents for automatic movement into engagement with said detent surfaces in a particular stabilizing position dependent on the then degree of tilting of said axle. 6. In a truck, an axle carrying supporting wheels and itself tiltably mounted for movement relatively to said truck, means for automatically and instantly stabilizing said axle and truck against relative tilting movement in a plurality of tilted positions of said axle relatively to said truck, comprising detents movable into stabilizing position, means for holding said detents out of stabilizing position, and means mounting said detents for instant movement, when released, into one of a plurality of stabilizing positions dependent on the then tilted position of said axle.

7. In a truck, an axle carrying supporting wheels, a main frame, means mounting said axle for tilting movement relatively to said main frame as said truck traverses an uneven way, said frame being mounted so as to tend to remain in a vertical plane while said axle tilts on an uneven way, means for stabilizing said frame in a vertical plane and relatively to said axle while said axle occupies a more or less tilted position relatively to said frame, said means comprising a pair of detents, means mounting said detents for automatic movement from an inoperative position to a particular frame stabilizing position dependent on the tilted position of said axle, and means for initiating the said automatic movement.

8. In a truck, a wheel carrying axle supporting said truck and adapted to move relatively to the truck while traversing an uneven way, a load lifting platform mounted on said truck, and means responsive to the lifting of the platform for stabilizing said truck relatively to said axle as the load platform is lifted. 9. In a truck, a wheel carrying axle supporting said truck and adapted to move relatively to the truck while traversing an uneven wa.: a load lifting platform mounted on said truck, means for lifting the platform, and means responsive to the lifting of the platform for stabilizing said truck in one of a plurality of positions relatively to said axle as the load platform is lifted.

10. In a truck, a wheel carrying axle supporting said truck and adapted to move relatively to the truck while traversing an uneven way, a load lifting platform mounted on said truck, means for lifting said platform, and means responsive to the lifting of the platform for automatically stabilizing said truck in a plurality of positions relatively to said axle as the load platform is lifted.

11. In a truck, a wheel carrying axle supporting said truck and adapted to move relatively to the truck while traversing an uneven way, a load lifting platform mounted on said truck, means for stabilizing said truck in a plurality of positions relatively to said axle, and means for actuating said stabilizing means responsive to the lifting of said platform.

12. In a truck, a wheel carrying axle pivotally mounted on said truck and adapted to move on its pivot relatively to the truck depending upon the irregularity of the way traversed by said truck, a load lifting platform mounted on said truck, and means responsive to the actuation of said platform to stabilize said axle against a particular tilting movement relatively to said truck.

13. In a truck, an axle pivotally mounted on said truck and adapted to move on its pivot depending upon the irregularity of the way traversed by said truck, a load lifting platform mounted on said truck, detent means for stabilizing said axle in a plurality of tilted positions against further particular tilting movement, and means for operating said detent means responsive to the actuation of said lifting platform.

14. In a truck, a standard, a platform slidable on said standard by means of a roller cooperable Swith the standard, a pivot for said roller eccentrically mounted relatively to said platform whereby rotation of said pivot will move it and the roller in an adjusting relation to said platform and standard, means for holding said pivot against rotation, said means being so arranged that the stresses on said pivot incidental to the support of said platform will tend to maintain it fixed against rotation.

15. In a truck, a standard, a load platform having a roller cooperable with said standard whereby said platform may move up and down on said standard, a pivot for said roller, a rotatable mounting member supporting said pivot and itself mounted on the load platform, means for securing said mounting member against rotation, said means being so arranged that the stresses on said pivot incidental to the support of said platform will tend to maintain it fixed against rotation.

16. In a truck, a pair of standards, a load platform having rollers cooperable with said standards for guiding and supporting the platform for vertical movement on said standards, adjustable pivots for said rollers for adjusting the position of said rollers, rotary supporting members for said pivots, said pivots being mounted eccentrically relatively to said rotary supporting members whereby rotation of said supporting members will adjust the positions of said pivots, means for securing said rotary supporting members against rotation, said means being so arranged that the stresses on said pivots will tend to maintain them fixed against rotation.

17. In a truck, a pair of standards, a load platform having rollers coopexable with said standards, pivots for said rollers, means for adjusting the position of each of said pivots and rollers comprising a rotary member on which a pivot is eccentrically secured, means mounting said rotary member for rotation on said platform, and means for securing said member in a particular rotated position in which the eccentrically rotated pivot will occupy a particular desired position, said securing means being so arranged that the stresses on said pivot incidental to the support of said platform will tend to maintain it fixed against rotation.

76 18. In a lift truck, a pair of elevating uprights, guide means on which said uprights are elevated, an elevating platform supported and guided by said uprights for lifting movement relatively thereto, a continuous chain or cable member secured to said platform and then to said uprights in such manner that when reeled in, it will act to lift said elevating platform relatively to said uprights and said uprights relatively to said truck, a locking dog carried by said uprights, a spring pressing said dog into locking engagement with its guide means to hold it against lifting movement until said platform is first elevated relatively thereto, hubs on said platform and rollers carried by said hubs for mounting said platform on said uprights, said dogs being movable by said hubs when said platform is elevated whereby to release the said dogs.

19. In a truck, a standard, a platform slidable on said standard by means of a roller cooperable with the standard, and a pivot for said roller eccentrically mounted relatively to said platform whereby rotation of said pivot will move it and the roller in an adjusting relation to said platform and standard.

20. In a truck, a standard, a load platform having a roller cooperable with said standard whereby said platform may move up and down on said standard, a pivot for said roller, and means for moving said pivot to adjust said roller comprising a mounting member to which said pivot is eccentrically secured whereby rotation of said member about its axis will variably position said pivot.

21. In a truck, a pair of standards, a load platform having rollers cooperable with said standards for guiding and supporting the platform for vertical movement on said standards, pivots for said rollers for adjusting the position of said rollers, said pivots being mounted eccentrically relatively to rotary supporting members whereby rotation of said supporting members will adjust the positions of said pivots.

22. In a truck, a pair of standards, a load platform having rollers cooperable with said standards, pivots for said roller means for adjusting the position of each of said pivots and rollers, said means comprising a rotary member on which a pivot is eccentrically secured, means mounting said member for rotation on said platform, and means for securing said member in a particular rotated position in which the eccentrically rotated pivot will occupy a particular desired position.

23. In a truck, an axle, a main frame supported by said axle, a load elevating frame mounted on said main frame, means for elevating said elevating frame, means whereby said axle is tiltably mounted for tilting movement relatively to said main frame, means for stabilizing said main frame and axle against tilting movement in a particular direction relatively to one another, said stabilizing means being movable into stabilizing position in response to the operation of said load elevating frame.

24. In a truck, an axle, a main frame supported by said axle, a load elevating frame mounted on said main frame, means for elevating said elevating frame, means whereby said axle is tiltably mouned for tilting movement relatively to said main frame, means for stabilizing said frame and axle against tilting movement relatively to one another in a particular direction, means maintaining said stabilizing means in an inoperative position, said means being arranged to release said stabilizing means in response to the operation of said load elevating frame. 25. In a truck, an axle, a main frame supported by said axle, a load elevating frame mounted on said main frame, means for elevating said elevating frame, means whereby said axle is tiltably 8 mounted for tilting movement relatively to said main frame, means for stabilizing said frame and axle against tilting movement relatively to one another, a portion of said load elevating frame being arranged to maintain said stabilizing means in an inoperative portion, said elevating platform portion being movable when said frame is lifted so as to release said stabilizing means for movement into locking position.

26. In a truck, an axle, a main frame supported by said axle, a load elevating frame mounted on said main frame, means for elevating said elevating frame, said axle being tiltably mounted for tilting movement relatively to said main frame, means for stabilizing said frame and axle against tilting movement relatively to one another, and means for moving said stabilizing means into and out of stabilizing position in response to the operation of said load elevating frame.

27. In a truck, an axle, a main frame supported by said axle, a load elevating frame mounted on said main frame, means for elevating said elevating frame, said axle being tiltably mounted for tilting movement relatively to said main frame, means for stabilizing said main frame and axle against tilting movement relatively to one another, a portion of said load elevating frame being arranged to maintain said stabilizing means in an inoperative position, said elevating frame portion being movable when said frame is lifted so as to release said stabilizing means for movement into stabilizing position, and to move said stabilizing means to release the axle for free tilting movement as the elevating frame is lowered. 28. In truck, an axle carrying supporting wheels, a main frame, means mounting said axle for tilting movement relatively to said main frame as said truck traverses an uneven way, means mounting said frame so as to tend to maintain a position in a vertical plane while said axle tilts on an uneven way, detent means for stabilizing said frame in a vertical plane and relatively to said axle while said axle occupies a more or less tilted angular position relatively to said frame, means mounting said detents for movement automatically from an inoperative position to an operative position to stabilize said frame and axle against relatively. tilting, and means normally holding said detents against movement into an operative stabilizing position and operable at the will of the operator to release said detents for said automatic movement.

CHARLES S. SCHROEDER.