Base mounting for instruments and machines to be tilted

Claim 1

A mounting for an instrument or machine which has to be tilted in the operation of aligning the instrument or machine with an object, said mounting comprising a housing, a cylindrical bore in the housing, a cylindrical piston in the housing bore, the piston periphery having working clearance from the bore periphery, a cylindrical extension of the piston concentric with the piston body and projecting beyond the housing, retaining means having a hole therethrough fIxed to the housing with the cylindrical piston body extension passing through the retaining means hole, said retaining means restraining the piston against axial movement but permitting rotary movement thereof, sealing means held in position by the retaining means and sealing the housing to render it liquid tight, means on the housing whereby the housing is mountable on a mounting system; machine support, a first leg on said machine support fixed to the piston extension, a second leg on the support, a stub axle on the housing axially aligned with the piston, a hole in the second leg of the support engaging the stub axle and clamp means to lock the second leg of the support to the stub axle so as to prevent rotary movement of the piston in the housing.