Jack for positioning and supporting a machine

Claim 1

A jack for positioning and supporting a large, heavy object, such as a machine, on its foundation, said jack being adapted to be surrounded by and embedded in hardenable grout after the object has been properly positioned with one portion of the jack engaging the object and supporting it on the grout after hardening of the grout, said jack comprising a base adapted to be supported on the foundation, a support member having a blind bore therein constituting a cylinder, a piston slidably received in the cylinder, and a ball mounted on the base, the lower end of the piston bearing on the ball to permit limited swivel movement of the piston and support member relative to the base, the portion of the cylinder between the upper end of the piston and the cylinder end wall constituting an expansible chamber adapted to receive a pressurized hydraulic working fluid for effecting upward movement of the support member away from the base, the support member having a pair of opposed end faces, one face being generally flat and constituting an upper end face for engaging said object from below and the other face constituting a lower end face extending out beyond the base and adapted to be supported by the hardened grout, and the support member being tapered from its lower to its upper end face providing a tapered surface convergent from its lower to its upper end face, said surface being sufficiently rough to mechanically interlock with the hardened grout thereby to inhibit upward movement of the support member with respect to the foundation.