Driving tool for tamper resistant screw

Claim 1

A tool for driving a tamper resistant screw having a conical head provided with three equiangularly spaced slots extending longitudinally along the surface of the conical head, comprising: (a) a body having a bit end and defining a longitudinal axis, (b) said bit end including three equiangularly spaced tangs separated from each other by a central recess, the recess thereof adapted to receive the conical head of the tamper resistant screw; (c) each said tangs having substantially planar, parallel side walls engageable with the side walls of the slots of the screw, pairs of substantially planar, parallel side walls on adjacent said tangs defining portions of an inwardly curved surface; (d) each said tangs having a generally inwardly facing surface defining a portion of a frustum of a cone, said surfaces disposed at a smaller acute angle to said axis and merging into a generally conical surface disposed at a larger acute angle to said axis, and (e) said bit end having a diameter no larger than the base diameter of the conical end of the tamper resistant screw whereby said tangs are visible for engagement with the slots in the head of the tamper resistant screw allowing the head to be installed within a similarly sized counterbore.