Apparatus for making locking nuts

Abstract

Improved apparatus and process for applying locking patches of resilient resin to internally threaded articles such as nuts having openings at both ends of the threaded portions in which apparatus and process, a support and treating member, preferably a rotatable, circular table with edge notches complementary to a portion of the exterior of a threaded article to be treated, receives a succession of threaded articles heated to a temperature above the melting point of the resin to be applied and moves the articles along a path for treatment with the axes of the threaded articles in an up and down position and with the openings at the upper and lower ends of the threaded portions substantially uncovered, conduits on the support and treating member are associated with each threaded article to direct particles of heat fusible resin upwardly through the opening at the lower end of the article against a portion of the threaded surface of the article to form a first deposit of resin on an area of the threaded surface during movement along a first portion of the treatment path and a turning device at an intermediate location on the treatment path turns each threaded article, as it reaches that location, a predetermined angle so that the conduit associated with the article directs resin against a further area of the threaded surface to form a second deposit of resin during movement along a further portion of the treatment path. The temperature of the article, the rate of movement along the treatment path, the supply of the resin particles, the location of the turning device, and the turning angle may be correlated so that thin edge portions of the first resin deposit may be spaced from or may be overlapped by thin edge portions of the second resin deposit up to an extent that the total thickness of resin in the overlapped portions may approximate the thickness of the central portions of the first and second deposits of resin.