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US 4,323,141 AGranted
Rail-mounted vehicle jack
AssigneeFMC Corporation
InventorsMarshall P. Ragan, Peter H. Sytsma
Life of this patent
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AssigneeFMC Corporation
InventorsMarshall P. Ragan, Peter H. Sytsma
Estimating the term…
A vehicle jack adapted to mount on a drive-on vehicle hoist comprises a lower platform suspended between the two rails of the hoist, an upper platform having a plurality of shoes adapted to contact the vehicle frame, an air bag between the upper and lower platforms to provide the force necessary to raise the vehicle from the rails, and a pair of scissor-type assemblies each having opposite corners attached to the upper and lower platforms respectively and adapted to maintain the upper and lower platforms in a parallel orientation. A plurality of latch plates connected to the upper platform are canted against latch posts mounted on the lower platform in such a way that downward movement of the upper platform is prevented unless the latch plates are moved out of contact with the posts. A pneumatic interlock system allows the latch plates to be moved only when there is sufficient air pressure in the air bag to support the vehicle. In this way, sudden collapse of the jack is avoided.
A mobile vehicle jack for use with a vehicle lift including spaced runways for supporting the wheels of an automotive vehicle, said jack comprising a frame structure extending between said runways, means mounting the jack for travel along said runways, a platform mounted to said frame structure for movement toward and away from said frame structure while maintaining a parallel relationship thereto, vehicle supporting shoes mounted upon said platform, fluid-actuated lifting means secured between said frame structure and said platform for moving said platform upwardly to cause said shoes to engage the undersides of a vehicle, an upright post mounted upon said frame structure and a pivotable latch plate secured to said platform, said latch plate having an aperture therethrough received about said post and causing the latch plate to bind on the post when it is urged to move downwardly relative to the post for preventing an elevated platform from being lowered, a fluid-actuated mechanism for pivoting the latch plate to place the aperture in alignment with the post for permitting relative movement therebetween to permit the platform to be lowered, and fluid-actuated control means for blocking the flow of fluid pressure to said means for releasing, said control means communicating with said pressure in said lifting means so that when such pressure drops below a predetermined level as would properly control the descent of the platform said control means is caused to block the flow of fluid pressure to said means for releasing.
A mobile vehicle jack for use with a vehicle lift including spaced runways for supporting the wheels of an automotive vehicle, said jack comprising a frame structure extending between said runways, means mounting the jack for travel along said runways, a platform mounted to said frame structure for movement toward and away from said frame structure while maintaining a parallel relationship thereto, vehicle supporting shoes mounted upon said platform, fluid-actuated lifting means secured between said frame structure and said platform for moving said platform upwardly to cause said shoes to engage the undersides of a vehicle, latching means secured between said frame structure and platform for preventing an elevated platform from being lowered, said latching means comprising an upright post secured to said frame structure, a latch plate secured to said platform and having an aperture therethrough for receiving said post, the size of said aperture being such in relationship that the exterior dimensions of said post that diametrically opposed upper and lower side edges of the aperture are caused to bite into the post when the platform is urged to move downwardly on said post, and means for releasing said latching means to permit the platform to be lowered, said means for releasing comprising an actuatable member which is movable to change the orientation of the latch plate relative to said post to release the biting edges of the plate and allow the plate to move downwardly about the post.
A mobile vehicle jack for use with a vehicle lift including spaced runways for supporting the wheels of an automotive vehicle, said jack comprising a frame structure extending between said runways, means mounting the jack for travel along said runways, a platform mounted to said frame structure for movement toward and away from said frame structure while maintaining a parallel relationship thereto, vehicle supporting shoes mounted upon said platform, fluid-actuated lifting means secured between said frame structure and said platform for moving said platform upwardly to cause said shoes to engage the undersides of a vehicle, latching means comprising a post secured to said frame structure and a pivotable latch plate secured to said platform, said latch plate having an aperture therethrough received about said post and causing the latch plate to bind on the post when the platform moves downward relative to the frame structure for preventing an elevated platform from being lowered, fluid-actuated means for pivoting the latch plate to place the aperture in alignment with the post for permitting relative movement between said latch plate and said post to permit the platform to be lowered, and fluid-actuated control means for blocking the flow of fluid pressure to said means for releasing, said control means communicating with said pressure in said lifting means so that when such pressure drops below a predetermined level as would properly control the descent of the platform said control means is caused to block the flow of fluid pressure to said means for releasing.
Dependencies are inferred from the claim text.