Patent ID: 6375178
Filing Date: 2002-04-23
Classification: B23Q

Abstract:
A pivotal work piece holding device comprising: a frame;a work piece holding fixture pivotally mounted to the frame for rotation about a fixture pivot axis between a first position and a second position; a crank arm connected to the fixture; a first cylinder assembly including a first cylinder and a first piston rod movable within the first cylinder between extended and retracted positions, the first cylinder being pivotally connected to the frame and the first rod being pivotally connected to the crank arm at a drive point offset from the fixture pivot axis; a second cylinder assembly including a second cylinder and a second piston rod movable within the second cylinder between extended and retracted positions, the second cylinder being pivotally connected to the frame and the second rod of the second cylinder assembly being pivotally connected to the crank arm at the drive point so as to form an oblique angle with the first rod in both the first and second positions of the fixture; and control means connected to the first and second cylinder assemblies for forcibly and independently moving the first rod and the second rod between extended and retracted positions in a coordinated cycle such that the fixture rotates with respect to the frame and at least one of the first and second rods is being forcibly moved by the control means at any instant during rotation of the fixture.