04/886661

07/11/1972

12/19/1969

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Combustion Engineering, Inc. (Windsor, CT)

269/58

414/910, 414/746.800

B23Q1/76; B23Q3/10; B23Q3/18; B23Q1/00; B23Q3/02; B25J5/00

269/58-61,74 214/1R,1P,DIG.3

3521875

ROTATABLE HANDLING DEVICE

July 1970

Kapelsohn

Lawson, William S.

What is claimed is

1. Work supporting and positioning apparatus including saddle-jack means comprising:

2. Apparatus as recited in claim 1 wherein said work support means includes a generally upstanding ram mounted for sliding movement substantially normal with respect to said base member, work engaging means carried by said ram and wherein said fluid motor means comprises operating parts including a piston and a cylinder, one of said operating parts being fixedly secured to said base member and the other being contiguous with said ram.

3. Apparatus as recited in claim 2 wherein said fluid motor means comprises an upstanding piston having its lower end fixedly secured to said base member, said ram including a lower end portion containing a recess opening to the lower end thereof and adapted for sliding telescopic engagement with the upper end of said piston, said piston and said recess cooperating to define a motive fluid receiving chamber, and means for passing motive fluid to and from said chamber.

4. Apparatus as recited in claim 3 wherein said motive fluid passing means comprises a fluid system including an electrically actuated flow directional control valve operative to selectively admit or discharge motive fluid to or from said chamber.

5. Apparatus as recited in claim 4 wherein said fluid motor actuating means includes switch means attached to said ram and actuable in response to the degree and direction of movement of said actuator means.

6. Apparatus as recited in claim 5 wherein said fluid motor actuating means comprises:

7. Apparatus as recited in claim 6 including electric circuit means containing said switch means and operative to actuate said flow directional control valve to admit motive fluid to said chamber upon upward movement of said ring and to actuate said flow directional control valve to discharge motive fluid from said chamber upon downward movement of said ring.

8. Apparatus as recited in claim 7 wherein said switch means includes means for actuating said valve for preventing the admission and discharge of motive fluid to and from said chamber when said ring is stationary.

9. Apparatus as recited in claim 7 wherein said electric circuit means includes means for actuating said valve for the discharge of fluid from said chamber when said ring is stationary to dispose said ram in supported engagement upon said ring and wedge.

10. Work supporting and positioning apparatus as recited in claim 1 including at least a pair of oppositely disposed saddle-jack means, and means for adjustably interconnecting the base members thereof.

BACKGROUND OF THE INVENTION

In the fabrication of large-diameter pressure vessels, notably those that serve as the reaction containers in nuclear operated power plants, it is usually necessary to machine portions of the vessel to extremely close tolerances. For example, on pressure vessels having a diameter of the order of about 20 feet, it is necessary to face that surface of the vessel flange that mates with a complementary flange on the vessel closure. Such facing requires holding dimensions to within only a few thousandths of an inch and is usually accomplished by machining the vessel flange with a horizontal boring mill in a manner whereby the vessel is fixedly mounted with its axis horizontal and in aligned relation with respect to the axis of the tool. Because of the close tolerances required in this and other fabrication steps, it is necessary that a high degree of accuracy be maintained in positioning the vessel with respect to each of the tools employed. In the past, alignment of the vessel with respect to the tool has been both an expensive and time-consuming proposition in that it has been the practice to effect alignment essentially manually by a trail and error method conducted with the assistance of a line-of-sight device and a heavy load-lifting crane. More specifically, it has been the prior practice to position the vessel on a pair of axially-spaced drum saddles or the like. Thereafter, a workman viewing cross hairs mounted at two axially-spaced points within the vessel by means of a sighting device instructs other workmen to place shims in the respective saddles by a trial and error procedure. Obviously, each time shimming of either of the saddles is desired, it is necessary for the crane to be employed to lift the vessel from its mount and thereafter return it to its position on the saddles after the shims have been inserted or removed.

It is obvious that this manner of aligning vessels with respect to a fabrication tool is very expensive. In addition to requiring a crew of several men for shimming the saddles, it further requires the presence of a load-lifting crane to lift the vessel while shimming is accomplished. In actual practice, such procedure is normally conducted over a 30-hour span and employs a crew of five workmen plus a load-lifting crane to be maintained on standby.

It is therefore to the alleviation of this problem that the present invention is directed.

SUMMARY OF THE INVENTION

According to the present invention, workpiece support and positioning apparatus is provided to mount and manipulate workpieces of great size such as large diameter, high pressure reactor vessels. The apparatus is further operative to effect remote controlled manipulation of the workpiece supports to permit adjustment of the workpiece position in order to effect alignment thereof with respect to a reference point on a metal processing tool, for example. The apparatus embodies a plurality of rectangularly disposed support elements upon which a workpiece is capable of being mounted. Each of the support elements, referred to hereinafter as saddle-jacks, contains fluid motor means operative to raise or lower the workpiece-engaging element thus to alter the position of the workpiece. A remotely actuated electro-mechanical control system is employed to operate the respective fluid motors and include means to operate the fluid motors either singly or jointly in any number to facilitate rapid adjustment of the workpiece positions.

All of the above can be accomplished through the efforts of a single workman operating without the need of an overhead crane beyond first placing the workpiece in the apparatus. Once the workpiece is mounted upon the saddle-jacks precision alignment of it with respect to any given reference point can be effected by the workman's simply operating various control switches on a control board and/or portable pendant, thereby reducing the time, effort, and expense attendant with setup of a workpiece with respect to a tool to a minimum.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims.

The invention itself, however, both as to its construction and its mode of operation, together with additional objects and advantages thereof, will be best understood from the following description of a specific embodiment when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial representation of an embodiment of the invention;

FIG. 2 is an elevational view of a pair of saddle-jacks employed in the present invention;

FIG. 3 is a plan view of a typical saddle-jack of FIG. 2;

FIG. 4 is an elevational section taken along lines 4--4 of FIG. 6;

FIG. 5 is a sectional view taken along line 5--5 of FIG. 6;

FIG. 6 is a vertical section taken along lines 6--6 of FIG. 4;

FIGS. 7 and 8 are two views of the fluid motor actuator ring employed in the present invention;

FIGS. 9 through 11 are enlarged detail views illustrating the various limit switches employed in the present invention;

FIG. 12 is a schematic representation of the fluid system employed to operate each of the saddle-jacks;

FIG. 13 is a schematic representation of the electrical circuit employed to operate the apparatus of the present invention;

FIG. 14 represents the face of the control console employed in the present invention;

FIG. 14a represents in greater detail the upper right quadrant of the control console of FIG. 14; and

FIG. 15 illustrates the face of the pendant employed to control the present apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 of the drawing illustrates a typical application of work positioning apparatus according to the present invention. In the illustrated application a workman employs the apparatus for the purpose of aligning a large diameter, heavy pressure vessel 10 with respect to a reference point associated with a work station or tool (not shown). In broad terms, this is accomplished by mounting the vessel 10 upon four rectangularly disposed saddle-jacks 12 each carrying vertical adjustable vessel-mounting rockers 14 whose positions are controlled by the workmen through operation of apparatus controls associated with a console 16 and pendant 18. As shown, the controls are operated by the workmen to adjust the position of the respective rockers 14 to alter the attitude of the vessel 10 as determined by viewing the center line-defining cross hairs located in spiders 20 that are mounted at each end of the vessel. An optical alignment structure 22 is employed for this purpose.

Referring now to FIGS. 2 through 6 of the drawing, each saddle-jack 12 comprises a base frame 24 defined by a metal casting. The base frame 24 contains means described hereinafter for mounting the rocker 14 upon which the workpiece is borne and also the means for adjustably varying the position of the rocker to, in turn, alter the position of the workpiece. Preferably, the saddle-jacks 12 are arranged in units of two with the pair of saddle-jacks defining each unit being oppositely spaced and interconnected by tie beams 26. It will be noted that in the hereindescribed arrangement of FIG. 1 the vessel 10 is supported by two axially-spaced saddle-jack units.

The base frames 24 are formed with generally rectangularly disposed top, bottom, and opposing sides 28, 30, and 32, respectively. The interior of the base frame casting is substantially open to carry various operating parts of the saddle-jack mechanism. Opposed longitudinal sides 32 of the base frame 24 are each provided at 34 and 36, respectively, with oppositely, vertically spaced upper and lower shoulders that cooperate with attached elongated bars 38 and 40 to form guideways adapted to slidingly receive the tie beams 26.

In order that vessels of various diameters or workpieces other than vessels can be accommodated, means are provided to adjust the lateral expanse between the saddle-jacks 12 of each unit. This means includes a plurality of regularly longitudinally spaced, circular openings 42 provided along the length of each tie beam 26 and connecting pins 44 adapted to pass through selected openings in the tie beams with their leading ends being received in oppositely disposed accommodating recesses 46 that are provided in the base frame casting. The pins 44 are retained in connected relation between the tie beams 26 and the base frames 24 by means of lock plates 48 each having one that is threadedly attached to the outer ends of the respective pins by connectors 50 and whose other ends extend into grooves 52 provided along the upper edge of the lower bars 40. With the plates 48 connected to the pins 44 and having their ends lodged in the respective grooves 52, axial movement of the pins from the recesses 46 is prevented.

The mechanism employed for raising and lowering the rockers 14 in the respective saddle-jacks 12 is mounted on the base frame 24. In general terms, this mechanism comprises a fluid motor organization and an electrically-actuated mechanical drive therefor. The fluid motor organization includes a stationary cylindrical piston 54 fixedly mounted in upstanding relation to the bottom 28 of the base frame 24 adjacent the forward end thereof. The lower end of the piston 54 is received in cylindrical recess 56 formed in the bottom 28 of the base frame. A boss 58 having a finished upper surface 60 surrounds the recess. The piston 54 carries a vertically movable ram 62 that is slideable within the bore of an upstanding cylindrical guide 64 formed integrally with the base frame casting. At its lower end the guide 64 possesses a depending extension 66 that is disposed on the forward side of the guide and which is coextensive with only a portion (about 100°) of its periphery. The depending extension 66 provides added supporting surface in order to assist in restraining the ram 62 against canting within the bore, such tendency being created by the lateral component of the load imposed on the rocker 14 by the supported workpiece.

At its upper end the ram 62 is provided with oppositely spaced chordal flats 68 defining a staff 70 containing through-bores 72 for pivotally mounting the rocker 14 by means of connecting pins 74. As shown in FIGS. 2 and 4, the rocker 14 comprises a member that is generally U-shaped in section and has a work-engaging surface 76 formed of slightly diverging segments. Oppositely spaced legs 78 depend from the sides of the segments and contain openings 80 for reception of the connecting pin 74.

Operation of the ram 62 is effected by the regulated admission or release of motive fluid to or from a cylindrical chamber 84 provided in the interior of the ram at the lower end thereof. As shown in FIG. 6, the bottom end of chamber 84 is open and receives the piston 54 in telescoping relation therewith. An hydraulic system including fluid line 86 connects the chamber 84 with a fluid reservoir formed by a tank 88 mounted on the rear end of the casting. The line 86 is attached by a releasable coupling 90 to the lower end portion of the piston 54 and communication with the chamber 84 is effected by means of interconnected radial and axial bores 92 and 94, respectively, that extend through the piston. Fluid pump 96 and its operating motor 98 are employed to pass fluid under pressure through the line 86 from the tank 88 to the chamber 84. To discharge entrapped air from the hydraulic system, the ram 62 is provided with interconnected axial and radial bores 100 and 102 that extend between the chamber 84 and the exterior of the ram. A release valve 104 provided at the outer end of the radial bore 102 is capable of being manually opened to release any air contained in the system prior to the apparatus being placed in operation.

The fluid motor system that operates the ram 62 is operated in response to the movement of a wedge 110 that is driven by a reversible electric motor 108 as hereinafter described. The wedge 110 bears an inclined upper surface 111 that is of the order of a 5 to 1 incline such that a correspondingly greater degree of movement of the wedge is required to effect a slight amount of movement of the ram. In this way the sensitivity and accuracy of the fluid motor apparatus is increased. The wedge 110 is also employed after final adjustment as a weight-supporting member of the apparatus. In the disclosed arrangement, the electric motor 108 is operative to drive the wedge 110 forwardly or rearwardly to raise or lower a fluid motor actuator ring 112 for regulating the admission or release of motive fluid to or from the chamber 84 in response to the actuation of limit switch means as hereinafter described. The wedge 110 is a yoke-shaped member having tapered legs 114 connected by a nexus plate 116. The nexus plate 116 is formed with oppositely spaced, downwardly facing shoulder recesses 118 that slidingly engage the upper surface of a pair of support bars 120, the latter being attached as by means of threaded connectors to opposite sides 30 of the interior of the base frame casting 24. A captive nut 122 is attached to an opening through the nexus plate 116 and operatively engages a lead screw 124 that is directly connected to, and driven by, the motor 108. The lead screw 124 has its one end secured in appropriate bearings 126 in a bushing 128 and is connected to the motor through reduction gearing (not shown). Depending on the direction of rotation of the lead screw 124, therefore, the wedge 110 will be caused to traverse the support bars 120 either forwardly or rearwardly, and in so doing, will cause the fluid motor actuator ring 112 to be raised or lowered into or out of engagement with an appropriately positioned limit switch 130 that is responsible for the admission or release of fluid to or from the chamber 84.

The fluid motor actuator ring 112, shown in detail in FIGS. 7 and 8, comprises a generally cylindrical member having a through-bore 132 permitting the ring to be slidingly received upon the piston 54. Oppositely spaced chordal undercuts 134 are formed on the outer surface of the ring to provide undersurfaces 136 with a taper corresponding to that on the upper surfaces 111 of the wedge legs 114. The undersurfaces 136 are a adapted for engagement with the surfaces 111 of the wedge legs 114 such that translation of the wedge 110 with respect to the ring 112 will cause the latter to be slidingly raised or lowered with respect to the piston 54. A radial recess 138 extends through the wall of the ring, opening from the bottom thereof, and provides a clearance space through which the fluid line 86 can unobstructedly connect with the bore 92 in the piston 94. A radially protruding arm or shelf 140 is disposed on the outer peripheral surface of the ring 112 with the upper surface of the former being arranged as a coplanar extension of the latter. The shelf 140 is located at a point on the ring whereby it can operatively engage the follower of the limit switch 130 as shown in FIG. 9.

In addition to the switch 130, a plurality of limit switches positioned at various points about each of the saddle-jacks 12 are effective, in conjunction with manually operated actuating buttons or switches on the console 16 and pendant 18, to control the various electrically operated components of the work-positioning apparatus. The arrangement of these switches is described with particular reference to FIGS. 9, 10, and 11 of the drawing while their function within the electrical control system of the apparatus will be described with reference to the circuit diagram of FIG. 13.

Limit switches 130 and 144 are mounted by means of brackets 146 to the external surface of the ram 62 adjacent the lower end thereof. Limit switch 130 is a double acting switch as represented schematically in the drawing by upper and lower contacts 148 and 150 that are respectively actuated by the action of the limit switch follower 152 with respect to the ring 112 whose shelf 140 it is adapted to engage. This limit switch 130 is operated in the fluid system of FIG. 12 to control the admission or discharge of motive fluid to or from the chamber 84. Limit switch 144 is a normally closed switch that has its follower 154 adapted to contact the undersurface of the top 28 of the base frame casting 24. Contacts 145 of this switch are connected to the fluid system of FIG. 12 in a manner to prevent further upward movement of the ram when the switch is actuated to its open position.

A platform pad 156 formed on one side of the boss 58 mounts two independently operated limit switches 158 and 160 by means of mounting brackets 146. Each of the limit switches 158 and 160 is positioned such that the respective followers 162 and 164 are located within a milled groove 166 in the adjacent wedge leg 114. The limit switch 158 is a normally closed switch and is operatively associated with the wedge motor 108 to terminate its operation when the follower 162 is extended by running off the forward edge of the groove 166 when the wedge 110 reaches its retracted limit of movement.

The limit switch 160 is a double acting switch having a normally open contact 166 and normally closed contact 170. This switch is operatively connected to various indicating lights 172, 176, and 178 on the console 16. When the follower 164 of switch 160 is in the milled groove 166, it is extended whereby contact 168 is open and contact 170 is closed. With contact 170 closed, indicating light 172 is actuated thereby indicating that the ram 62, as measured by the distance between the top of the boss 58 and the center of the rocker pin 74 is below its median position. In the described installation the median position of the ram 62 is taken to be that in which the center of the pin 74 is approximately 68 inches above the boss.

The right-hand end of the groove 166 possesses a gradual run-out 174 and is located at a point on the wedge leg 114 with respect to the follower 164 of switch 160 such that when the latter contacts the former, the ram 62 is approximately at its median position. The switch 160 is structured to permit approximately a 0.015 inch movement of the follower 164 by the action of the run-out surface 174 during which both contacts 168 and 170 are open. With both contacts in the open position, light 176 on the console 16 is illuminated to indicate that the ram 62 is in its median position. With continued movement of the wedge 110 to the left, the follower 164 is caused to contact the external side surface of the wedge leg 114 and thereby achieve its fully depressed position whereupon contact 168 is caused to close and contact 170 open. This action actuates light 178 on the console 16 to indicate that the ram is positioned above its median position. By means of this arrangement, therefore, a workman operating the apparatus is able to continuously monitor the relative positions of the respective rams 62 with respect to their median positions.

Another limit switch indicated as 180 in FIG. 11 is attached to the nexus plate 116 of the wedge 110 with its follower 182 being disposed downwardly. This limit switch is normally closed and is operatively connected to the wedge drive motor 108 to deactivate the motor when the wedge reaches its inner limit of travel. The switch 180 is tripped to its open position by the coaction of its follower 182 with a trip plate 184 that is attached to the bottom 30 of the base frame casting 24 closely rearwardly adjacent the boss 58. The limit switch 180 also actuates a light 186 on the console 16 so as to activate the light when the switch is tripped thereby indicating that the wedge 110 has reached its inner limit of travel.

A typical motor fluid control system, one of the four employed in the described embodiment, is shown schematically in FIG. 12. The control system comprises the fluid reservoir 88 connected to the chamber 84 of the rocker ram 62 by line 86, the latter containing fluid pump 96 and pump drive motor 98. Between the reservoir and the pump, line 86 contains a fluid filter 188 and manually actuable shutoff valve 190. Downstream of the pump 96 line 192 extends from line 86 and contains automatically actuable pressure relief valve 194. This valve 194 is set to open upon experiencing a pressure of approximately 4,750 psi in the line 86 and its discharge is connected to the reservoir 88. Connected next in series in the line 86 is a three-position directional control valve 196 having inlet and outlet ports 198 and 200 to which line 86 connects. Other ports 202 and 204 attach a fluid return actuator line 206 and valve discharge, the latter being connected with the reservoir 88. Flow control solenoids for operating with control valve 196 are indicated at 208 and 210, the former being operable to effect passage of motive fluid to the chamber 84, thereby to raise the ram 62, and the latter being effective to cause fluid to flow from the chamber in order to lower the ram. Outlet port 200 of the valve 196 is connected to a pilot operated check valve 212 by bypass line 214 containing ball check valve 216 and through which flow is permitted in the upward direction. Between the bypass line connections, line 86 contains a variable orifice 218 for regulating the return speed of operation of the ram 62 and fluid filters 220. Shown schematically as the dotted line 206 is the fluid return actuator line connecting the pilot operated check valve 212 and port 202 of the directional control valve 196. This line 206 is effective when the solenoid 210 is actuated to pass fluid to the ball of the pilot operated check valve to raise it against the action of a spring 213, thereby to permit return flow of motive fluid through the filter 220 and orifice 218 to lower the ram. Another variable orifice 222 may be positioned in the line 206 in order to regulate the speed at which the valve 212 is caused to open. Also connected to this line is a pressure relief line 224 containing valve 226 that is set to open at approximately 1,200 psi.

FIG. 13 is a schematic representation of the electrical circuitry utilized in the apparatus of the present invention. In describing this circuit additional reference will be made to FIGS. 14 and 15, the former being a representation of the layout of the face of the console 16 containing various switches and indicating lights employed in the operation of the apparatus, and the latter representing the face of the pendant 18 which is hand-held by the operator and contains further switches to permit operation and control of the apparatus remote from the console. As shown, the console 16 is divided into four identical quadrants with each containing duplicate switches and lights associated with each of the four saddle-jacks that comprise the apparatus. With regard to FIG. 13, that portion thereof that is enclosed by the dotted line represents the circuitry associated with the pendant 18. The remainder of the figure represents the circuitry associated with one of the four saddle-jacks 12. It should be understood that the remaining saddles utilize circuitry that is identical with that shown.

With reference now to FIGS. 13, 14, and 15, and it being assumed that the portion of the circuit shown in FIG. 13 is associated with the saddle-jack 12 located on the right side of the front end of the vessel 10, the manually operated PUMP START switch 232 located on the console 16 is depressed to actuate the pump start relay 234 which energizes the motor 98 of fluid pump 96 and closes contacts 236 to maintain the relay 234 energized after switch 232 is released. Closure of contacts 236 will also effect the passage of current to illuminate light 238 on the console 16 to indicate that the pump motor 98 has been energized. Contacts 236 are arranged to remain closed until the PUMP STOP switch 240 has been actuated to de-energize the relay. Contacts 242 are associated with the relay 244 that is energized by actuation of the HYDRAULIC RESET switch 266 on the pendant 18. Actuation of these contacts also illuminates light 246 to indicate that the reset switch is actuated. Contacts 248 and 250 that are connected in series with contacts 242 are associated with the FORWARD and REVERSE buttons 252 and 254, respectively, on the pendant 18 and are closed when either of the respective buttons are depressed to energize relays 256 or 258. Contacts 248 are operated by the former and contacts 250 by the latter. The contacts 260, 262, 264, and 266 are associated with the PENDANT CONTROL switch 268 on the console 16. Contacts 260 and 264 are arranged to be closed when the switch 268 is set in the "UP" position and contacts 262 and 266 are to be closed when it is in the "DOWN" position. With switch 268 in the "OFF" position, none of the contacts 260 through 266 are closed. Contacts 260 are connected in series with relay 270 whose actuation energizes the wedge drive motor 108 to move the wedge 110 in the direction of the ring 112. Also connected in the line are normally open contacts 272 that are associated with the relay 274 which is in turn operated by the normally closed contacts 276 of the limit switch 180 (FIG. 11). These contacts 276 are actuated to their open position when the wedge 110 reaches its preset inner limit of travel defined by the trip plate 184 whereby the follower 182 of the switch is tripped by contacting the trip plate. When contacts 276 are opened, the wedge motor 108 is deenergized to prevent further movement of wedge 110 in its forward direction. Also associated with relay 274 are the contacts 278 whose closure illuminates indicating light 280 on the console 16 to indicate that the wedge has reached its forward limit. Contacts 282 are also connected in series with the relay 270. These contacts are normally closed and are operated to their open position when the wedge reverse relay 284 is actuated. Actuation of these contacts prevents energization of the wedge motor 108 in the forward direction when reverse motion is desired. Indicating light 286 on the console 16 is connected in parallel with the relay 270 and is illuminated when the relay is actuated to indicate that the wedge 110 is undergoing forward movement.

The wedge reverse relay 284 is connected in series with contacts 288 and 290. Contacts 288 are normally open and operated to their closed position by energization of relay 292 which is tripped by the opening of contacts 294 associated with the limit switch 158 (FIG. 10) when the wedge 110 reaches its outer limit of travel. Relay 292 also actuates contacts 296 that illuminate indicating light 298 on console 16 to indicate that the wedge has reached its rearward limit. Contacts 290 are normally closed contacts that are operated by the wedge forward relay 270 to deactuate the reverse relay 284 when forward movement of the wedge is desired. Indicating light 300 is connected in parallel with the relay 284 and is illuminated when the relay is actuated to indicate that the wedge 110 is undergoing reverse movement.

The circuit of FIG. 13 further includes the operating solenoids 208 and 210 that are associated with the motive fluid directional flow control valve 196 and whose energization is effective to cause the rocker ram 62 to be urged upwardly or downwardly. The solenoids can be energized either directly from the console 16 or remotely from the pendant 18. Direct energization of the solenoids 208 or 210 is achieved by means of depressible switches 302 or 304, respectively, on the console. The lines containing the respective switches have normally closed contacts 306 and 308 connected in series between the switches and the solenoids. These contacts are operated by the relays 310 and 312, each of the contacts being actuated by the relay in the line containing the other. Operation of any of the respective rams 62 directly from the console 16 may be desired for maintenance or other similar purposes when the workmen would wish to operate the rams either upwardly or downwardly without having to actuate the wedge 110.

Direct operation of the "DOWN" solenoid 210 can also be achieved from the pendant 18 by means of RAM DOWN switch 314 whose actuation effects energization of relay 316 to close the contacts 318. The latter are connected in parallel across switch 302 and thus, when actuated, are effective to energize the solenoid 210.

Remote operation of the ram 62 is essentially achieved by means of the coaction between the wedge 110, ring 112, and limit switch 130. The limit switch 130 which is located on the ram 62 and whose follower 152 is operated by engagement with the shelf 140 on the ring 112 contains two contacts 148 and 150. Closure of the former, as when there is no contact between the follower 152 and the ring shelf 140, causes the "DOWN" solenoid 210 of the control valve 196 to be energized, thus relieving the chamber 84 of fluid. When contacts 150 of the limit switch are closed by the required amount of depression of the follower 152 by the ring 112, the circuit is completed to energize the "UP" solenoid of the valve 196 thereby to admit motive fluid to the ram chamber 84. The contacts 148 and 150 of the limit switch 130 are further arranged with respect to one another such that at a point intermediate the points of closure of the contacts 148 and 150 a slight amount (approximately one sixty-fourth inch) of relative movement can occur between the ring 112 and the ram 62 and neither of the contacts 148 or 150 will be closed. This is considered to be the neutral position of the limit switch 130 in which neither of the solenoids 208 or 210 will be energized and the ram will therefore be stationary.

Switch 160 that is mounted on the platform pad 156 and whose follower 164 is operated in response to movements of the wedge 110 is a double-acting switch that is operable to actuate the respective rocker position lights 172, 176, or 178 on the console 16. The respective lights are illuminated when the follower 164 is placed in one of three possible positions. The first occurs when the relative position between the limit switch 160 and the surface of the wedge 110 is such as to place the follower within the milled groove 156. In this position the follower is fully extended, thereby contacts 168 are open and contacts 170 are closed to actuate the light 172. Actuation of this light indicates that the associated rocker ram 62 is below its median position. The follower 164 is in a second, fully depressed position when the relative position of the wedge 110 with respect to the switch 160 is such as to place the follower outside the grooves 166 and in contact with the side surface of the wedge. With the follower in this position, contacts 168 are closed and 170 are open thereby actuating light 178 to indicate that the associated rocker ram 62 is above its median position. The third light 176 is positioned in series with two normally closed contacts 320 and 322 and is actuated to indicate that the rocker ram 62 is in its median position. Actuation of this light is effected when the follower 164 contacts the run-out 174 of the milled groove 166 to partly depress it and thereby place each of the contacts 168 and 170 in their open position. With contacts 168 and 170 open and contacts 320 and 322 closed, current passes to the light 176 to illuminate it. Contacts 320 and 322 are each associated with relays 324 and 326, respectively, the former being actuated to open contact 320 when light 172 is actuated and the latter being actuated to open contact 122 when light 178 is activated. Thus with either of the lights 172 or 178 activated, current is incapable of passing to the light 176.

The operation of the herein described work-supporting and positioning apparatus is as follows. The vessel 10 to be worked upon is deposited by means of a load lifting crane or the like (not shown) in horizontal attitude upon the rockers 14 of four rectangularly arranged saddle-jacks 12, the lateral spacing between the opposed jacks in each unit having been set by the connection of the respective base frames 24 to the tie beams 26. Spiders 20 containing cross hairs defining the axial center of the vessel are positioned at two axially spaced points within the vessel. A platform is positioned adjacent one end of the vessel 10 and mounts the console 16, the workman who is to operate the apparatus, and an optical alignment instrument 22. The height and position of the platform is such that the instrument 22 is in alignment with the reference point with which it is desired to align the vessel axis. The pendant 18 is hand-held by the workman.

For the sake of this description, it is assumed that the rams 62 of all four saddle-jacks 12 are located in their median position as indicated by the illumination of the lights 176 in each of the four quadrants of the face of console 16. It is further assumed that the workman, in viewing the cross hairs in spiders 20 through the optical alignment instrument 22, determines that the vessel axis should first be adjusted in the horizontal plane. The necessary manipulation of the apparatus to effect this adjustment requires that, of the front saddle-jacks 12, i.e. those located closest the platform, that on the left must be raised and that on the right lowered. Of those in the rear, the one on the left must be lowered and that on the right raised.

Initially, the workman sets each of the PENDANT CONTROL switches 268 in the position to deliver the desired direction of movement of the respective rams 62. With the switches 268 associated with the left front and right rear jacks 12 in the UP position, contacts 260 and 264 in the circuit of FIG. 13 will be closed and contacts 262 and 266 opened. Conversely, with the switches 268 associated with right front and left rear saddle-jacks 12 in the DOWN position, contacts 262 and 266 will be closed and contacts 260 and 264 opened. Next, the workman depresses the HYDRAULIC RESET button 246 on the pendant 18. Depression of this button actuates relays 244 associated with each jack which, in turn, close contacts 242 and 245. The closing of the contacts 242 arms the control system for its operation in the automatic mode while closure of contacts 245 enables the relays 244 to be held in until relays 316 have been actuated to open the contacts 243 and thereby de-energize the relays 244 and the rest of the system.

Following this, the workman depresses button 252 marked FORWARD on the pendant 18. This will energize the relays 256 associated with each saddle-jack 12 which close their associated contacts 248. In those units set for upward ram movement, closure of contacts 248 will cause relays 270 to be actuated thus to energize the respective wedge drive motors 108 to move the wedges 110 forwardly to raise the rings 112. In the units that are set for downward ram movement closure of contacts 248 will cause the relays 284 to be actuated thereby energizing motors 108 to move the wedges 110 rearwardly thus lowering the rings 112. As long as the button 252 on the pendant 18 is depressed, the respective wedges 110 will continue to move in the direction indicated. When wedges 110 raise the rings 112, the latter will be caused to depress the followers 152 (FIG. 9) an amount sufficient to close contacts 150 thereby energizing the solenoids 208 on the fluid directional flow container valve 196 (FIG. 12). With solenoids 208 energized, ports 198 and 200 on the valves are interconnected and motive fluid proceeds to flow from the respective reservoir tanks 88 through lines 86 past check valves 216 and 212 to the chambers 84 of the respective rams 62 thus causing them together with their rockers 14 to be raised. Conversely, when relays 284 are actuated in the units set for downward movement, the motors 108 associated with these units will be energized to cause the wedges 110 to move rearwardly. With this direction of movement occurring, the followers 152 on the limit switches 130 will be positioned such that contacts 148 will be closed thus energizing solenoids 210 on the valves 196. Energizing these solenoids will connect the ports 198 and 202 of the valves as well as ports 200 and 204. Connection of ports 198 and 202 will cause actuating fluid to flow through the line 206 to open the pilot operated check valve 212 thereby causing fluid to flow from the chamber 84 in the affected rams 62 back through lines 86 to the ports 200 and thence from ports 204 to the reservoir tanks 88, thus causing the rams to descend.

The workman will maintain the FORWARD button 252 depressed until, sighting through the optical alignment instrument 22, he observes the vertical cross hairs in the spiders being brought into mutual alignment. When this occurs, the RAM DOWN button 314 on the pendant 18 is depressed which actuates relay 316 to open their associated contacts 243 which will deactivate the associated relay 244, thereby removing the apparatus from the automatic mode of operation by opening contact 245. At the same time, actuation of relay 316 closes contacts 318 which energize all four of the solenoids 210 to cause the rams 62 to descend to bring the undersurfaces 136 on the rings 112 into abutment with the upper surface 111 of the wedge legs 114. Thereafter, support of the vessel is undertaken by the wedges in order that the fluid motors can be deactivated. The amount of descent of the ram 62 will be slight. Relative movements between the respective rams 62 will be less than 0.015 inch and will therefore have no significant effect upon vessel alignment.

In the alternative, if the workman maintains the FORWARD button 252 depressed for too long a period of time, thereby resulting in the respective rams 62 being moved too great an extent, a corrective operation can be performed by the workman depressing REVERSE button 254 on the pendant 18. With button 252 released and button 254 depressed, relay 256 is deactivated and relay 258 actuated. Deactuation of relay 256 opens the contacts 248 while actuation of relay 258 closes contacts 250 whereupon the relays 270 and 284 that are responsible for energization of the respective wedge motors 108 will be actuated, but in a manner to have a reverse effect upon the wedges. Thus, with REVERSE button 254 on the pendant 18 depressed and contacts 250 closed, the wedges associated with the units having their PENDANT CONTROL switches 268 set for movement in the upward direction will move downwardly and vice versa for those set for downward movement. In this way, an overshooting of the ram by the workman can be corrected and thereafter the RAM DOWN button 314 on the pendant 18 can be depressed to set the vessel-supporting mechanism down in supported relation upon the upper surfaces of the wedge legs 114 as described hereinabove.

It will be appreciated that the operation described herein represents only one of several that can be performed by the present apparatus. In addition to aligning the vertical cross hairs in the spiders 20, the apparatus will thereafter be employed by the workman to align the horizontal cross hairs by viewing the relative positions of the respective cross hairs with the optical alignment instrument 22, determining which of the saddle-jacks 12 must be adjusted and in which direction, and thereafter operating the apparatus in a manner similar to that just described to accomplish alignment of the vessel axis in the other plane.

By means of the invention, therefore, there is provided work supporting and positioning apparatus together with the controls therefor that is capable of significantly reducing the amount of time, effort, and expense required to set up a large, heavy workpiece with respect to a tool or the like. Where the inventive apparatus is employed, a single workman in just a few hours can accurately perform alignment functions upon a workpiece that previously required five or more workmen over a day's time to perform by means of a much less accurate trial and error procedure. Use of the invention also obviates the need of maintaining a valuable load-lifting crane on standby for long periods of time, such device only being required to initially load the workpiece upon the saddle-jack units.

It will be understood that various changes in the details, materials, and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.