US 10,519,995 B2 · Dual-threaded screw structure

Abstract

The dual-threaded screw structure 1 has a first thread (S1) and a second thread (S2) with various leads formed on the dual-thread portion and has a function of preventing loosening without insufficiency in strength of the dual-thread portion. This dual-thread portion is composed of a first thread (S1) consisting of a coarse thread with a standard pitch P and a specific second thread (S2). The second thread (S2) is formed continuously on the thread ridge of the first thread (S1). The second thread (S2) has a sectional shape of this thread groove same as or substantially same as the first thread (S1), has a same twisting direction as the first thread (S1) and is a multi-threaded thread having threads with a triangular sectional shape and having a lead (L=n*P) a determined number (n)-times of a standard pitch P.

Claims17

Dependent claims

A dual-threaded screw structure having two kinds of threads formed on the shank, said dual-threaded screw structure comprising:

a first thread formed on the shank with a pitch to have a triangular sectional shape of the thread ridge, and
a second thread formed on said thread ridge of the first thread successively in the same twisting direction as said thread ridge of the first thread to have a triangular sectional shape of the thread ridge, the second thread consisting of a thread or threads in which the number of threads is less by at least one thread than that of a primary multi-threaded thread having a lead equal to a determined number (n)-times of the pitch of the thread and the second thread yet having a lead same as that of said primary multi-threaded thread.

Dependencies are inferred from the claim text.

Dual-threaded screw structure

Life of this patent

Dual-threaded screw structure

Life of this patent

Abstract

Claims17