US 4,364,136 A · Formation of threaded elements having a self-locking action

Abstract

A fatigue resistant self-locking fastener is formed by screwing two threaded elements into engagement with a part having a thread which is slightly off-size with respect to the threads of those elements, locating the two elements just in contact with one another while in engagement with said part but without tightening them against one another sufficiently to develop any substantial stress in the threads, and then securing the elements together in that relative position, preferably by welding. Because of the off-size relationship of the locating part, the threads of the two elements when so located by the part are aligned axially with one another but are turned relative to one another about their common axis to positions in which the thread of one part is not precisely a true helical continuation of the thread of the other part, so that the two threads when subsequently screwed into engagement with a single coacting threaded element will have an interfering fit therewith attaining a self-locking action and improving resistance to fatigue and tensile failures.

Claims9

Dependent claims

The method of forming a fastener that comprises:

positioning two elements having similar internal threads on an external thread which is dimensioned to fit said internal threads loosely, in a relation allowing each of said elements if engaged individually with the external thread to shift axially relative thereto through a substantial distance without relative rotation or deformation of the engaged threads;
locating said two elements on said external thread in predetermined relative positions in which they are turned so that their internal threads are not true helical continuations of one another, and in which said two elements limit axial and rotary movement of one another and their threads bear in opposite axial directions against the external thread to eliminate looseness between the threads;
attaching said two elements together while in said predetermined relative positions on said external thread;
and
removing the two attached elements from said external thread as a composite integrated unit adapted to have an interfering fit with a threaded part of predetermined size.

2 more elements

Dependencies are inferred from the claim text.

Formation of threaded elements having a self-locking action

Life of this patent

Formation of threaded elements having a self-locking action

Life of this patent

Abstract

Claims9