FASTENER WITH HELICAL SPLINE WITH SLOPED ENGAGEMENT SURFACE Russian patent published in 2009 - IPC F16B23/00 F16B35/06 B21K1/46 B23G9/00 

FIELD: mechanics.

SUBSTANCE: fastener has a head with a spline wherein drive surfaces are spiral-shaped, and it is made in the hole bored in fastener's upper surface. Lugs of drive surfaces have upper surfaces sunk at the specified distance into the bored hole. There is a sloped surface on each of upper surfaces, which allows the rotating pin to enter the spline with engagement. Sloped surfaces consist of sloped removal section and sloped installation section. A die meant for forming the above spline in the fastener's head, and manufacturing method of that die is also proposed.

EFFECT: simplifying insertion of rotating tools with mechanical drive into fastener's spline.

19 cl, 13 dwg