Patent ID: 8251374

Claim:
A power-operated chuck ( 1 ) having at least two radially adjustable clamping jaws ( 5 ), each of which is attached to an articulation lever ( 10 ) that is axially adjustable against a force of a spring ( 12 ) and which is mounted in a chuck body ( 2 ) and can swivel, the articulation levers ( 10 ) being actuatable by driving jaws ( 8 ) acting on ends of the articulation levers ( 10 ) opposite to the clamping jaws ( 5 ), with the driving jaws ( 8 ) being acted upon by a piston ( 6 ) by means of inclined surfaces ( 7 or 9 ), the chuck body ( 2 ) having a contact surface for the workpiece (W) to be clamped, wherein each of the articulation levers ( 10 ) is mounted in a swiveling arrangement on articulation pins ( 21 ) that pass therethrough, the articulation pins ( 21 ) being supported in the chuck body ( 2 ) non-rotatably and guided to permit limited axial movement, and each of the articulation pins ( 21 ) that passes through the articulation levers ( 10 ) is provided with a centrally arranged cylindrical bearing surface ( 22 ) for engagement with the articulation levers ( 10 ), and contact surfaces ( 23 , 24 or 25 , 26 ) in end areas provide support without rotation in the lever ( 10 ) and limit the axial travel, wherein the contact surfaces ( 23 , 24 or 25 , 26 ) act in conjunction with counter surfaces ( 27 , 28 or 29 , 30 ) provided on the chuck body ( 2 ).