Patent ID: 7331743
Filing Date: 2008-02-19
Classification: B25B,F16B,Y10S

Abstract:
1. In a fastener having a drive socket for receiving a key driver having a plurality of flat surfaces and a plurality of corners at intersections between the plurality of flat surfaces, the improvement comprising: the drive socket having a surface defining a plurality of rounded lobes of substantially equal radius located substantially equidistant from a center of the fastener and substantially equidistant circumferentially from each other, the plurality of rounded lobes receiving a set of alternating ones of said plurality of flat surfaces of the key driver; the drive socket having a corresponding plurality of flat surfaces, each flat surface being located substantially opposite one of the rounded lobes and substantially equidistant from the center of the fastener, and the plurality of corners of the key driver remaining out of contact with said plurality of flat surfaces; and the drive socket surface defining curved recesses smoothly transitioning between the rounded lobes and the flat surfaces, and the plurality of corners of the key driver remaining out of contact with said curved recesses.