US 8,616,816 B2 · Screw for composite/plastic materials

Abstract

A fastener for composite or plastic material having a dense composition employs a head which has a socket and a recessed underside and a lower rim. In one embodiment, the shank has an upper portion with an enlarged diameter and a left hand thread while the lower portion has a tri-lobed configuration and is traversed by a right hand thread. The right hand thread may have a plurality of notches which, in one embodiment, are arranged in a spiral array. One embodiment of a fastener has longitudinally spaced rings which project from an enlarged diameter portion of the shank. The lower portion of the shank has a thread with a plurality of notches. The rings have a major diameter and spacing greater than the major diameter and spacing of the thread.

Claims13

Dependent claims

A fastener for composite or plastic material comprising:

a head rotatably couplable for application of a torque and having a recessed underside and a lower cutting rim;
an elongated shank extending from said head and terminating at a distal tip and comprising a neck portion having a uniform neck diameter adjacent said head and extending a neck distance, a first portion having a first diameter less than said neck diameter and a lower second portion having a reduced second diameter less than said first diameter;
said first portion being traversed by a plurality of longitudinally spaced rings spaced a ring distance less than said neck distance;
and
said lower portion being traversed by a right-hand thread with a spiral array of notches, said right-hand thread having a pitch spacing less than that of said ring distance, said rings having an effective major diameter greater than that of said right hand thread.

2 more elements

Dependencies are inferred from the claim text.

Screw for composite/plastic materials

Life of this patent

Screw for composite/plastic materials

Life of this patent

Abstract

Claims13