Suction operated lifting device

Claim 1

A lifting device comprising a fluid cylinder, a piston slidable in said cylinder and having a rod portion extending outwardly through the top thereof for engagement by a lifting device, a ball joint member connected to the bottom of said cylinder and having a lower ball-shaped end, a suction disc member having an interior ball-shaped receiving cavity engaged around the ball-shaped end of said ball member, a packing within said suction disc bearing against the underside of said ballshaped end, a gasket seal having its inner periphery engaged with said ball-shaped member and its outer periphery engaged with said disc and defining on the underside of said gasket seal a suction cavity, said suction cavity being communicated by a passage through said ball member to the interior of said cylinder for communicating a suction pressure therethrough to said cavity upon movement of said piston within said cylinder, means for clamping said gasket seal to said ball member, and means adjacent said sealing disc for limiting the rotative movement of said sealing disc about a vertical axis, including a pin carried on said ballshaped portion of said member and extending radially outwardly, said suction disc having a receiving cavity for said pin of a certain circumferential extent defining the limit of the path of movement of said disc.