THREADED MALE FASTENING ELEMENT PREVENTING MISALIGNMENT Russian patent published in 2019 - IPC F16B35/04 

FIELD: construction.

SUBSTANCE: invention relates to threaded fastening elements, such as screws and bolts, and more specifically to threaded fasteners eliminating incorrect connection. Female threaded fastener preventing misalignment comprises a rod having a lead-in end and an end interacting with the tool, at least one outer fastening thread formed on the outer surface of the rod as a plurality of thread turns, made with possibility of interfacing with internal fastening thread, at least one external attachment thread formed on outer surface of the rod as a plurality of thread turns, made with possibility of interfacing with the internal fastening thread, at least one external lead-in thread formed on the outer surface of the rod on its lead-in end, which extends, at least, half the turn around the rod and comprises curved profile defined by arc, having radius approximately equal to arc radius, tangent to both lateral surfaces of profile of at least one external attachment thread and extending below dividing line of at least one external attachment thread.

EFFECT: reduced probability of misalignment, screwing and not need for threaded ledge without exit when screwing out of envelope over entire length of fastener.

36 cl, 52 dwg