Patent ID: 8561506
Filing Date: 2013-10-22
Classification: B25B

Abstract:
1. A hand operated gripping tool comprising: a fixed jaw unit having a first workpiece engaging portion; a support member extending transversely with respect to said fixed jaw unit, said support member defining a first reaction surface and a second reaction surface disposed opposite and facing away from said first reaction surface and having a first end disposed closest to said fixed jaw unit and a second end disposed furthest from said fixed jaw unit; a movable jaw unit having a second workpiece engaging portion and a cam surface engagable with said first reaction surface and being slidable relative to said fixed jaw unit on said support member such that a variable size workpiece receiving space is defined between said first and second workpiece engaging portions; a fixed handle connected with said second end of said support member; a movable handle provided with a cam to apply a force to said second jaw unit via said second reaction surface, said cam surface being engagable with said first reaction surface such that, in use, in response to the force applied by said movable handle said movable jaw unit turns on said first reaction surface so that said second workpiece engaging portion is forced against a workpiece received in said workpiece receiving space; a pivotal link pivotally connected to said fixed handle and said movable handle and provided with a slide pin that is slidable in a slot defined by said fixed handle; an automatic locking device for locking said movable jaw unit to fix the size of said workpiece receiving space, said automatic locking device comprising a locking member movable between a withdrawn non-operative position and an operative position to be engagable by said pivotal link to lock said movable jaw unit; and an elongate extension portion extending from said second workpiece engaging portion and provided with a pivot member aperture, wherein said movable handle is connected with said elongate extension portion by a pivot member received in said pivot member aperture, said pivot member aperture is positioned such that said support member extends between said cam surface and said pivot member and said second reaction surface faces and is spaced from said pivot member, said cam and cam surface are arranged such that when said movable handle applies said force to said second reaction surface said cam surface engages said first reaction surface at a position further from said first end and closer to said second end than a position at which said force is applied to said second reaction surface, and wherein said extension portion has a bend promoting portion disposed between said second workpiece engaging portion and said pivot member aperture, wherein said bend promoting portion is configured to promote limited bending of said extension portion in a direction away from said fixed jaw unit in response to a reaction force generated by engagement with the workpiece between said fixed and movable jaw units to permit movement of said pivotal link to engage said locking member.