Fastener system comprising an externally threaded bolt and an internally threaded nut for the avoidance of cross-threading of the mating threads during assembly

Abstract

A threaded fastener system, incorporating a bolt and a nut assembly, wherein the bolt has a threaded lead entry point 22 whose pitch 39 and helix angle are of a higher magnitude than that of those on the body / shank 21 of the bolt.

Description

[0001] Cross References to Related Applications [0002] This application claims the benefit of US Provisional Application No. 61 / 987,138, filed May 1, 2015, the contents of which are hereby incorporated by reference. Background technique [0003] in general and with reference to figure 1 , it will be appreciated that an assembly requiring the insertion of a standard scale bolt thread 1 into a standard scale pre-threaded nut 2 may often result in a situation where the crests of the bolt threads 10, 10a initially contact the bottoms of the nut threads . Reverse rotation of the nut and bolt threads will then cause the threads 3, 3a to snap into each other and will further restrict the action of the cooperating threads enabling relative axial movement of the nut anchor and bolt. This action is known as "cross-threading", as is well known to those skilled in the art. [0004] As will be appreciated by those skilled in the art, cross-threading becomes more prevalent where the ...

AI Technical Summary

Problems solved by technology

In the case where there is no extension point feature between the nut and bolt axes and with a small amount of misalignment there is still figure 1 The possibility of initial assembly conditions as outlined and discussed, and due to the effect of constant thread pitch 12, cross-threading can still occur

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