Locking and unlocking sliding clamp on column - utilises hydraulic jack to release pressure on clamp bolts, esp. for materials testing machine

摘要

Two elements which slide w.r.t. each other, such as elements on a materials testing machine, are locked or unlocked by tightening or releasing jaws on one element. A traction shaft provides this pressure for the jaws. A clamp comprises two identical units (12) located one above the other on a column (2). A shaft (13) with a threaded section (14, 15) at each end passes through the jaws (10, 11) perpendicular to a slot (9). The hole (16) in one jaw (10) allows the shaft to slide while the othre jaw is threaded (18) to receive the shaft which is locked by a locknut (19). The other end of the shaft is screwed to a piston (20) of a hydraulic jack (21) and in the absence of pressure, it clamps the jaws to the column. Fluid pressure releases the clamping action.