Ttapdrive As

Edland, Jone

Jone Edland

David Curtis Goss

Steven P Donovan

David C Goss

Olof Markus Ingemar Bergelin

A drive system including a bit with a bit end configured to provide targeted frictional engagement with a fastener. The bit end has an outer leading wall tapered with respect to the bit end longitudinal axis at a leading wall angle selected from leading wall angle values ranging within a leading wall angle tolerance band and the fastener has an inner recess wall tapered with respect to the fastener longitudinal axis at a recess wall angle selected from recess wall angle values ranging within a recess wall angle tolerance band, wherein the leading wall angle values within the leading wall angle tolerance band and the recess wall angles values within the recess wall angle tolerance band do not overlap when the outer leading wall contacts the inner pilot recess wall at a targeted focal area to achieve a desired level of frictional engagement between the pilot end and the fastener.

Drive system configured to provide frictional fit engagement

Disclosed is a screw head having a slot () in the upper surface of the screw head, an upper peripheral wall () of hexalobular planform extending down into the screw head, the upper peripheral wall () being parallel or near parallel to the axis of the screw, a sloping transition surface () extending downwardly and inwardly with respect to the lower edge of the upper peripheral wall (), and a tapered recess () extending downwardly from the lower edge of the sloping transition surface (), in which the dimensions of the screw head are such that when the screw head is engaged by a tool () having upper () and lower engagement () sections, there is a 'stick fit' between the surface of the tapered recess () and the external surface of the lower engagement section (), and there is no engagement with the sloping transition surface ().

Growing community of inventors

Olso, Norway

Jone Edland