Patent ID: 6708588
Filing Date: 2004-03-23
Classification: B25B,Y10T

Abstract:
In a locking tool comprising a frame, fixed jaw fixedly attached to the frame, movable jaw movably attached to the frame, and a handle pivotally attached to movable jaw, where moving the handle toward the frame causes the movable jaw to move toward the fixed jaw, a self adjusting closure apparatus comprising:a) an extended support rod, mounted to the frame, said support rod having a longitudinal axis; b) a push link pivotally coupled to the handle at a first end and having an opening defined through the second, opposite end, said opening receiving said support rod, said push link having a ridge approximately aligned with and perpendicular to said support rod axis, whereby moving the handle toward the frame causes said push link to rotate between first and second positions, said positions defined in terms of the angle of said push link relative to said support rod; c) at least one friction pawl, adjacent to said push link, having an opening defined therethrough receiving said support rod; d) a back spring, bearing against said at least one friction pawl, urging it into contact with said push link at said ridge; wherein when said push link is in said first position it contacts said at least one friction pawl solely at said ridge, said at least one friction pawl is maintained substantially orthogonal to said support rod axis by the action of said back spring, and said at least one friction pawl and said push link are free to move linearly along said support rod; wherein when said push link is in said second position it contacts said at least one friction pawl at a first point offset from said support rod axis, causing said at least one friction pawl to tilt relative to said support rod, the edges of said opening in said at least one friction pawl contacting and coupling to said support rod whereby linear movement of said pawl and said push link are blocked in at least one direction; and wherein if the movable jaw contacts a workpiece prior to said push link reaches said second position, said second end of said push link and said at least one friction pawl slide along said support rod, compressing said spring, until said push link reaches said second position.