WO2016205692A1

WO2016205692A1 - Compact jack system

Info

Publication number: WO2016205692A1
Application number: PCT/US2016/038142
Authority: WO
Inventors: Ryan Patrick RICE
Original assignee: Actuant Corporation
Priority date: 2015-06-19
Filing date: 2016-06-17
Publication date: 2016-12-22

Abstract

A jack including a first fluid actuator (228) having a first barrel (260) and a first piston (270) slidably received in the first barrel (260). The first piston extends relative to the first barrel in a first direction. The jack further includes at least one second fluid actuator (232) coupled to the first fluid actuator. Each second fluid actuator has a second barrel and a second piston slidably received in the second barrel. The second piston extends from the second barrel in a second direction opposite the first direction.

Description

COMPACT JACK SYSTEM

REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of co-pending, prior-filed U.S. Provisional Patent Application No. 62/182,047, filed June 19, 2015, the entire contents of which is hereby incorporated by reference.

FIELD

[0002] The present application relates to the field of lifting devices, and, specifically, to a fluid jack.

SUMMARY

[0003] Conventional hydraulic jacks include a piston cylinder assembly having a piston slidably received within a cylinder. Pressurized fluid is pumped to the piston cylinder assembly to actuate the piston. In some embodiments, when the piston is being actuated, a force is applied to a working element (i.e., mechanical lever) that in turn transfers force to a work piece. In other embodiments, the piston exerts a force directly on a work piece.

[0004] In one aspect, a jack includes a first fluid actuator and at least one second fluid actuator coupled to the first fluid actuator. The first fluid actuator includes a first barrel and a first piston slidably received in the first barrel, the first piston extending from the first barrel in a first direction. Each second fluid actuator includes a second barrel and a second piston slidably received in the second barrel, the second piston extending from the second barrel in a second direction opposite the first direction.

[0005] In another aspect, a jack includes a housing having a top surface and a bottom surface, a height being defined between the top surface and the bottom surface. The jack further includes a first fluid actuator supported by the housing. The first fluid actuator includes a first barrel and a first piston slidably received in the first barrel. The first piston is movable away from the bottom surface of the housing through a first stroke length less than the height of the housing. The jack further includes a second fluid actuator supported by the housing. The second fluid actuator includes a second barrel and a second piston slidably received in the second barrel. The second piston is movable away from the top surface of the housing through a second stroke length less than the height of the housing. The sum of the first stroke length and the second stroke length is greater than the height of the housing.

[0006] In another aspect, a method of operating a jack includes: positioning the jack beneath a load to be lifted, the jack including a first fluid actuator and at least one second fluid actuator, the first fluid actuator extendable in a first direction, each second fluid actuator extendable in a second direction parallel to and opposite the first direction; introducing pressurized fluid to the first fluid actuator to extend the first piston relative to the first barrel in a first direction; and introducing pressurized fluid to each second fluid actuator to extend the second piston relative to the second barrel in a second direction opposite the first direction.

[0007] Other aspects will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a side view of a fluid cylinder assembly.

[0009] FIG. 2 is a perspective view of a jack supported on a cart.

[0010] FIG. 3 is an enlarged perspective view of the jack of FIG. 2.

[0011] FIG. 4 is an exploded perspective view of the jack of FIG. 3.

[0012] FIG. 5 is an exploded perspective view of a jack according to another embodiment.

[0013] FIG. 6 is a perspective view of a jack according to another embodiment.

[0014] FIG. 7 is a perspective view of the jack of FIG. 6.

[0015] Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Use of "including" and "comprising" and variations thereof as used herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Use of "consisting of and variations thereof as used herein is meant to encompass only the items listed thereafter and equivalents thereof. Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

DETAILED DESCRIPTION

[0016] FIG. 1 illustrates a lifting device, such as a fluid jack 200. The jack 200 includes a first actuator or cylinder assembly 228 and a second actuator or cylinder assembly 232. The first cylinder assembly 228 includes a first rod 268 slidably received within a first barrel 260. The first rod 268 is coupled to a first piston 270 positioned within the first barrel 260 and defines a first chamber in the first barrel 260. The first piston 270 is movable relative to the barrel 260 in response to a force differential between each side of the piston 270. The force differential may be caused by pressurized fluid in the first chamber exerting a larger force on one side of the first piston 270. Similarly, a second rod 272 is slidably received in a second barrel 264. The second rod 272 is coupled to a second piston 274 positioned within the second barrel 264 and defines a second chamber within the barrel 264. In one embodiment, the first and second chambers are in fluid communication with one another.

[0017] As shown in FIG. 1, the first rod 268 of the first cylinder assembly 228 extends in a first direction, and the second rod 272 of the second cylinder assembly 232 extends in a second direction opposite the first direction. When the first and second rods 268, 272 are in a fully retracted or home position, the first and second cylinder assemblies 228, 232 have a combined collapsed height H. As pressurized fluid enters the first barrel 260, the first rod 268 is extended in the first direction (e.g., upwardly in FIG. 1) until the first cylinder assembly 228 reaches a maximum stroke length LI . Similarly, pressurized fluid in the second barrel 264 moves the second rod 272 toward an extended position in the second direction (e.g., downwardly in FIG. 1). The first and second cylinder assemblies 228, 232 have a combined maximum stroke length L2 that is greater than LI . [0018] FIG. 2 illustrates a jack 300 according to another embodiment. In the illustrated embodiment, the jack 300 is supported on a movable cart 304. The cart 304 includes a platform 308, a handle 312, and an elongated frame 316 extending between the platform 308 and the handle 312. The cart 304 further includes wheels 320 supporting the cart for movement over a surface and facilitates maneuvering and positioning the jack 300 relative to a load (e.g., a vehicle, a utility machine, etc.). The elongated frame 316 of the cart 304 allows the jack 300 to be positioned adjacent to the load while maintaining a safe distance for the operator's station. Although the illustrated cart 304 is manually maneuvered by an operator, the cart 304 may alternatively be a powered machine (e.g., skid loader, fork lift, etc.) to facilitate moving the jack 300.

[0019] The jack 300 further includes a fluid pump 324 supported on the cart 304 which is pneumatically driven and in fluid communication with the jack 300. The pump 324 and its controls are positioned proximate the handle 312 to facilitate easy access and control of the pump 324. The pump 324 may include a toggle (e.g., a joystick, a foot pedal, a switch, etc.) to selectively supply pressurized fluid between a fluid reservoir (not shown) and the jack 300. Although the pump 324 is pneumatically driven in the illustrated embodiment, in other embodiments the pump 324 may be driven by another power source (e.g., electricity, battery, gasoline engine, etc.).

[0020] With reference to FIGS. 3 and 4, the jack 300 includes a first cylinder assembly 328, second cylinder assemblies 332, and a housing 336 for supporting the first and second cylinder assemblies 328, 332. The housing 336 is composed of a solid metal block and includes a first or upper surface 340, a second or lower surface 344, and an outer periphery 348 extending between the upper surface 340 and the lower surface 344. In the illustrated embodiment, the jack 300 includes three second cylinder assemblies 332, each of which is disposed in an aperture 350 (FIG. 4) extending through the bottom surface 344. The first cylinder assembly 328 is disposed in an aperture 352 extending through the top surface 340. The second cylinder assemblies 332 are laterally offset from the first cylinder assembly 328 and oriented along axes that are parallel to the axis of the first cylinder assembly 328. In one embodiment, the second cylinder assemblies 332 are positioned around the first cylinder assembly 328 at equal angular intervals. In other embodiments, the jack 300 may include fewer or more second cylinder assemblies and/or the second cylinder assemblies may be positioned in a different configuration with respect to the first cylinder assembly 328. A plurality of fasteners 356 extend through the housing 336 to secure the first and second cylinder assemblies 328, 332 to the housing 336.

[0021] In the illustrated embodiment, the first cylinder assembly 328 is in fluid

communication with each of the second cylinder assemblies 332 by a conduit 404. The first cylinder assembly 328 includes a first barrel 360 and a first rod 368 slidably received in the first barrel 360. Each of the second cylinder assemblies 332 includes a second barrel 364 and a second rod 372 slidably received in the second barrel 364. Each of the rods 368, 372 are coupled to a piston 370, 374. The piston 370, 374 of each cylinder assembly 328, 332 defines a rod side proximate the rod and a cap side opposite the rod side. The cap side of a piston defines a first or cap-side chamber of the associated barrel, and the rod side defines a second or rod-side chamber of the associated barrel. In the illustrated embodiment, the conduit 404 provides fluid communication between a fluid source (e.g., the fluid pump 324) and at least one chamber of each cylinder assembly 328, 332. The conduit 404 of the illustrated embodiment is positioned outside of the housing 336 and extends through the outer periphery 348 of the housing 336. In other embodiments, the conduit 404 may be formed on the interior of the housing 336.

[0022] When pressurized fluid flows through the conduit 404 to the first and second cylinder assemblies 328, 332, the first rod 368 of the first cylinder assembly 328 extends from the first barrel 360 in the first direction, whereas the second rods 372 of each second cylinder assembly 332 extends from the second barrel 364 in the second direction opposite the first direction. FIG. 3 illustrates the first and second rods 368, 372 actuated in the extended position. FIG. 4 illustrates the first and second rods 368, 372 retracted in the home position, although each cylinder assembly 328, 332 is shown exploded from the housing 336.

[0023] In the illustrated embodiment, the cap-side chambers of the first and second barrels 360, 364 are in fluid communication with each other and with the fluid source. In the illustrated embodiment, the first and second cylinder assemblies 328, 332 are single-acting cylinders. That is, pressurized fluid is introduced to the cap-side chamber to extend the first and second pistons 370, 374 and rods 368, 372. To retract the first and second pistons 370, 374 and rods 368, 372, pressure in the cap-side chamber is reduced until the pressure exerted by the load overcomes the pressure in the cap-side chamber. Alternatively, each cylinder assembly 328, 332 may include a biasing member (e.g., a spring 378) urging the piston 370, 374 and rod 368, 372 toward the retracted position. When pressurized fluid is introduced to the cap-side chamber, the fluid pressure overcomes the biasing force of the spring 378 and extends the rods 368, 372 and pistons 370, 374. When the pressure drops below a predetermined level, the spring 378 urges the piston 370, 374 toward a retracted position.

[0024] As shown in FIGS. 3 and 4, the first cylinder assembly 328 is a different size than the second cylinder assemblies 332. In particular, the first cylinder assembly 328 is larger in diameter than the second cylinder assemblies 332. Accordingly, the first piston 370 of the first cylinder assembly 328 defines a first cross-sectional area, and the second piston 374 of each second cylinder assembly 332 defines a second cross-sectional area. The sum of the second cross-sectional areas defines a combined second cross-sectional area. In the illustrated embodiment, the combined second cross-sectional area is larger than the first cross-sectional area. As a result, when equal fluid pressure is applied to the cap side of the first and second pistons 370, 374, each second piston 374 and rod 372 (i.e., the actuators with a larger effective area) will extend and reach a fully extended position before the first piston 370 and rod 368 begins to extend.

[0025] In other embodiments, the first cross-sectional area may be larger than the combined second cross-sectional area; in this case, when equal pressure is applied against the first piston 370 and each second piston 374, the first piston 370 and rod 368 will fully extend before each second piston 374 and rod 372. The difference between the first cross-sectional area and the combined second cross-sectional area provides more reliable extension behavior of the rods 368, 372 and minimizes unpredictable lifting conditions.

[0026] In still other embodiments, one or more of the cylinder assemblies 328, 332 may be double-acting cylinders such that the rod-side chambers of the first and second barrels 360, 364 are also in fluid communication with a fluid source. That is, in addition to a conduit providing fluid communication between a fluid source and the cap-side chambers, another conduit may provide fluid communication between the fluid source and the rod-side chambers of the barrels 360, 364. The rod-side chambers of the barrels 360, 364 may also be in fluid communication with one another. As such, pressurized fluid is introduced to the cap-side chambers to extend the first and second pistons 370, 374 and rods 368, 372, and pressurized fluid is introduced to the rod-side chambers of the first and second barrels 360, 364 to retract the pistons 370, 374 and rods 368, 372.

[0027] As discussed above, the cross-sectional area of the cap side in the first cylinder assembly 328 may be different from the cross-sectional area of the cap sides for the second cylinder assemblies 332 (e.g., the combined second cross-sectional area is larger than the first cross-sectional area). In some embodiments, the relationship may be the same for the rod side of each piston 370, 374, such that each second piston 374 and rod 372 may fully retract before the first piston 370 and rod 368 begins to retract. Alternatively, the effective cross-sectional area for the rod sides of each piston 370, 374 may have a different relationship. For example, the first piston 370 and rod 368 may be dimensioned to have an effective rod-side area that is greater than the effective rod-side area of the second pistons 374 and rods 372, such that the first piston 370 and rod 368 fully retracts before the second pistons 374 and rods 372 begin to retract. The compact system with double-acting cylinders could provide a longer pulling stroke, allowing the system to exert a pulling force between two points that are spaced apart by a greater distance than a single cylinder assembly could accommodate. In some embodiments, extending or retracting the rods 368, 372 (whether single-acting or double-acting) without a direct load may result in some variation in the speed/sequence of the rods' movements.

[0028] In one embodiment, particularly if the cylinder assemblies 328, 332 are double- acting cylinders, the system further includes an over-center or counterbalance flow valve (not shown). Because the weight of a load urges the rods 368, 372 to retract, the counterbalance valve prevents the load from creating a vacuum in the rod-side chamber and drawing oil from the pump 324. The counterbalance valve imposes a false load on the pump 324 and restricts the pressure of the fluid returning to the reservoir to keep the load from forcing fluid out of the barrels 360, 264 and uncontrollably retracting the rods 368, 372.

[0029] In other embodiments, a second pump is in communication with the jack 300 and selectively supplies pressurized fluid between the fluid source and the jack 300. In particular, the first cylinder assembly 328 is in fluid communication with at least one of the first pump and the second pump, and the second cylinder assembly 332 is in fluid communication with the other one of the first pump and the second pump. For example, the first cylinder assembly 328 may be fluidly connected to the first pump while the second cylinder assembly 332 is fluidly connected to the second pump. As a result, the first cylinder assembly 328 and the second cylinder assembly 332 may be actuated independently of each other upon based on independent activation of each respective pump. In other embodiments, both cylinder assemblies 328, 332 could be fluidly connected to a single pump with a toggle to selectively supply fluid to each cylinder assembly.

[0030] FIG. 5 illustrates a housing 436 according to another embodiment. The housing 436 includes a first or upper portion 376 and a second or lower portion 380. The upper portion 376 includes an upper plate 384 having a central aperture 452 extending through the plate 384. The lower portion 380 includes a lower plate 392 with cylindrical receptacles 396 extending from the plate 392. The receptacles 396 are sized to correspondingly receive respective first and second cylinder assemblies 328, 332. The plate 392 of the lower portion 380 includes three apertures 450 extending through the plate 392. The apertures 450, 452 of the lower and upper plate 392, 384 coaxially align with each receptacle 396 such that the first cylinder assembly 328 can extend beyond the upper plate 384 while the second cylinder assemblies 332 can extend beyond the lower plate 392. The apertures 450, 452 of the upper and lower plates 384, 392 are sized to retain the barrels 360, 364 within the receptacles 396 once the upper and lower portions 376, 380 are coupled together. Furthermore, fasteners 356 extend through the upper and lower plates 384, 392 to releasably secure the first and second cylinder assemblies 328, 332 within the receptacles 396. The housing 436 is formed from less material compared to the housing 336 described above and therefore may weigh less and/or require less material to manufacture.

[0031] With reference to FIG. 6, the jack 300 may include a plate 408 interconnecting each of the second rods 372 of the second cylinder assemblies 332. The plate 408 rigidly connects the second rods 372 together such that the second pistons 374 extend and retract at approximately the same rate. The plate 408 inhibits the second pistons 374 from actuating independently of each other, thereby minimizing unpredictable or unstable jacking conditions when actuating the second pistons 374 toward the extended or home position. [0032] With reference to FIG. 7, the jack 300 further includes a plurality of lock rings or cribbing rings 412. When the first rod 368 is in the extended position, one or more cribbing rings 412 may be positioned between the top surface 340 of the housing 336 and the load.

Similarly, when the second rods 372 are extended, the rings 412 are positioned between the bottom surface 344 of the housing 336 and one of the plate 408 and the ground surface. The cribbing rings 412 may be C-shaped which enables the rings 412 to be slid around the extended first and second rods 368, 372. The cribbing rings 412 mechanically lock the load in an elevated position even if hydraulic pressure in the first and second cylinder assemblies 328, 332 drops. In fact, the first and second rods 368, 372 can be retracted to the home position such that the interior of the C-shaped cribbing ring 412 is vacant and the housing 336 and the cribbing rings 412 support the load. To raise the load to a higher position, one or more pucks (not shown) are positioned within the vacant space of the C-shaped cribbing ring prior to actuating the first and second rods 368, 372. As the first and second rods 368, 372 move toward the extended position, the ends of the rods 368, 372 engage the pucks and raise the load. In one embodiment, the cribbing rings 412 and pucks are supported on the elongated frame 316 of the cart 304 when not in use (FIG. 2).

[0033] The embodiment described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles. As such, it will be appreciated that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of one or more independent aspects as described.

Claims

CLAIMS What is claimed is:

1. A j ack compri sing :

a first fluid actuator including a first barrel and a first piston slidably received in the first barrel, the first piston extending relative to the first barrel in a first direction; and

at least one second fluid actuator assembly coupled to the first fluid actuator, each second fluid actuator including a second barrel and a second piston slidably received in the second barrel, the second piston extending from the second barrel in a second direction opposite the first direction.

2. The jack of claim 1, wherein the first piston and the first barrel define a first chamber, and the second piston and the second barrel define a second chamber, wherein the first chamber and the second chamber are in fluid communication with each other and with a fluid source.

3. The jack of claim 1, wherein the first piston defines a first cross-sectional area, and each second piston of the at least one second fluid actuator defines a second cross-sectional area, wherein the sum of the second cross-sectional areas defines a combined second cross-sectional area different from the first cross-sectional area.

4. The jack of claim 3, wherein the combined second cross-sectional area is larger than the first cross-sectional area, wherein when equal pressure is applied against a cap side of the first piston and against a cap side of each second piston, the second piston moves to an extended position before the first piston moves to an extended position.

5. The jack of claim 1, wherein the jack further includes a first fluid pump and a second fluid pump, wherein the first fluid actuator is in fluid communication with the first fluid pump, wherein the second fluid actuator is in fluid communication with the second fluid pump.

6. The jack of claim 5, wherein the first fluid actuator and the second fluid actuator are actuated independently of each other.

7. The jack of claim 1, further comprising a housing and a channel, the housing supporting the first fluid actuator and the second fluid actuator, the channel providing fluid communication between the first barrel and a fluid source, the channel providing fluid communication between the second barrel and the fluid source.

8. The jack of claim 7, further comprising a first housing portion and a second housing portion removably coupled to the first housing portion, the first fluid actuator supported on the first housing portion, the second fluid actuator supported on the second housing portion.

9. The jack of claim 7, wherein the channel is provided on the exterior of the housing.

10. The jack of claim 1, wherein the at least one second fluid actuator includes a plurality of second fluid actuators, and further comprising a plate interconnecting the rods of the plurality of second fluid actuators.

11. The jack of claim 1, wherein the at least one second fluid actuator includes three fluid actuators laterally offset from the first fluid actuator, the second fluid actuators positioned around the first fluid actuator at equal angular intervals.

12. The jack of claim 1, wherein the first fluid actuator includes a first biasing member biasing the first piston in the second direction, wherein each second fluid actuator includes a second biasing member biasing the second piston in the first direction.

13. A j ack compri sing :

a housing including a top surface and a bottom surface, a height being defined between the top surface and the bottom surface;

a first fluid actuator supported by the housing, the first fluid actuator including a first barrel and a first piston slidably received in the first barrel, the first piston movable away from the bottom surface of the housing until the first piston reaches a first stroke length less than the height of the housing; and

a second fluid actuator supported by the housing, the second fluid actuator including a second barrel and a second piston slidably received in the second barrel, the second piston movable away from the top surface of the housing through a second stroke length less than the height of the housing, wherein the sum of the first stroke length and the second stroke length is greater than the height of the housing.

14. The jack of claim 13, wherein the first stroke length is substantially equal to the second stroke length.

15. The jack of claim 13, wherein the first piston and the first barrel define a first chamber, and the second piston and the second barrel define a second chamber, wherein the first chamber and the second chamber are in fluid communication with each other and with a fluid source.

16. The jack of claim 13, wherein the first piston defines a first cross-sectional area, and each second piston of the at least one second fluid actuator defines a second cross-sectional area, wherein the sum of the second cross-sectional areas defines a combined second cross-sectional area, the combined second cross-sectional area being different from the first cross-sectional area.

17. The jack of claim 16, wherein the combined second cross-sectional area is larger than the first cross-sectional area, wherein when equal pressure is applied against a cap side of the first piston and against a cap side of each second piston, the second piston moves to an extended position before the first piston moves to an extended position.

18. The jack of claim 13, wherein the first fluid actuator and the second fluid actuator are actuated independently of each other in opposite directions.

19. The jack of claim 13, further comprising a housing and a channel, the housing supporting the first fluid actuator and the second fluid actuator, the channel providing fluid communication between the first barrel and a fluid source, the channel providing fluid communication between the second barrel and the fluid source.

20. The jack of claim 13, wherein the at least one second fluid actuator includes a plurality of second fluid actuators, and further comprising a plate interconnecting the rods of the plurality of second fluid actuators.

21. The jack of claim 13, wherein the at least one second fluid actuator includes three fluid actuators laterally offset from the first fluid actuator, the second fluid actuators positioned around the first fluid actuator at equal angular intervals.

22. The jack of claim 13, wherein the first fluid actuator includes a first biasing member biasing the first piston in the second direction, wherein each second fluid actuator includes a second biasing member biasing the second piston in the first direction.

23. A method of operating a jack comprising:

positioning the jack beneath a load to be lifted, the jack including a first fluid actuator and at least one second fluid actuator, the first fluid actuator extendable in a first direction, each second fluid actuator extendable in a second direction parallel to and opposite the first direction; introducing pressurized fluid to the first fluid actuator to extend the first piston relative to the first barrel in a first direction; and

introducing pressurized fluid to each second fluid actuator to extend the second piston relative to the second barrel in a second direction opposite the first direction.

24. The method of operating the jack of claim 23, wherein introducing pressurized fluid to each second fluid actuator occurs simultaneously with introducing pressurized fluid to the first fluid actuator, wherein the second piston is actuated before the first piston when an equal pressure is introduced simultaneously to both the first and second fluid actuator due to a combined second cross-sectional area of each second piston being greater than a first cross- sectional area of the first piston.