apparatus for tightening threaded fasteners, geometry of a fastener, apparatus for coupling a threaded fastener and a torque input device, geometry for coupling a threaded fastener and a torque input device

摘要

According to a first aspect of the invention we provide an apparatus for torsionally coupling a threaded fastener and a torque output device including:-a first coupling member: rotatably and threadedly engagable with the threaded fastener; rotatably and taperedly engagable with a second coupling member; non-rotatably engagable with an action portion of the torque output device; the second coupling member non-rotatably engagable with a reaction portion of the torque output device; and wherein the first coupling member, when rotated by the action portion of the torque output device, applies a load to the threaded fastener. Advantageously apparatus with alternative geometries for torsion coupling allow for more efficiently and evenly distributed load stress distribution; higher torsion strength; and lower fastener mass and volume.