Patent ID: 9302375
Filing Date: 2016-04-05
CPC Classification: B25B,F16B

Claim Text:
1. A combination of a bit having a star-shaped external contour as viewed axially and a mating socket having a star-shaped internal contour as viewed axially, which comprises: individual arms of the star are pointed arcs, the outer points of which lie on a common outer circle, the pointed arcs being delimited by two radii, the centre points of which lie on an inner circle around the axis of rotation of the driving feature and the contour of the bit having a mating contour on the socket adapted in such a manner that the radii of the flanks of the bit and the socket come to bear against one another so as to produce a flat pressing surface, wherein, the bit and the socket are adapted to one another in that the radii of the bit are 4% to 12% smaller than the associated socket, while the inner circle of the bit and inner circle of the socket on which the centre points of the radii are arranged around the axis of rotation of the bit and the socket have diameter, wherein the diameter of the inner circle of the bit is up to 6% larger than the diameter of the inner circle of the socket, characterised in that, for a driven bit screw head of a fastener an inner transition radius (r i ) is between 9.0% and 12.5% of the flank radius and an outer transition radius (r a ) is between 6.6% and 9.5% of the flank radius and the diameter of the inner circle is between 40% and 45% of the diameter of an outer circle.