Movable clamping apparatus

摘要

A bolster of a press machine has a T-shaped groove, into which a T-shaped leg of a hydraulic clamp is fitted. The clamp advances and retreats along the T-shaped groove by a pneumatic cylinder. A housing of the clamp has a side surface to which a block is fixed. The block is provided with a hydraulic locking device. When placing the clamp in a waiting condition at a retreated position, a push piston of the locking device is projected downwards from a retracted position. Then the push piston pushes an upper surface of the bolster and the thus resulting reaction force fixes the T-shaped leg to a peripheral wall of the T-shaped groove.