GB596817A - Self-locking nut or bolt - Google Patents

Abstract

596,817. Locking nuts. PUMMILL, E. W. July 17, 1945, No. 18235. [Class 89 (i)] Lock-nuts of the type in which a projecting neck at the bearing face is constricted on to the bolt thread bv a collar, are formed initially with the collar integral with the nut, but axially spaced therefrom in such manner as to permit manufacture on a screw machine. A groove 15, Fig. 2, is turned in the stock forming a tapering neck 16 on the nut and defining a collar 17 that may have a reduced bearing surface 13. When the blanks are made otherwise than in screw machines, the collar may, if desired, have a greater diameter than the nut. The face 13 may be serrated and in cases where the diameter of the collar is less than that of the nut, the periphery of the collar may be knurled causing rough lateral edges that bite into the face of the nut and work respectively. On screwing up, the collar shears from the nut at 19 and is forced on to the neck 16 crowding this on to the bolt threads. The sheared metal forms an upstanding ridge on the collar and this is finally forced into the nut face, forcing the thread at this point into locking engagement with that of the bolt. In some cases, the neck may be parallel instead of tapered or the taper may be formed in the collar. The bore in the collar may be countersunk and the shape of the neck in shearing may be such as to leave a fin that is closed by the heck to form a flange, Fig. 9, permanently connecting the nut and collar. Locking bolts without nuts.-Set-screws may be provided with grooves 315, 315a, Fig. 6, defining a collar 317 which may be knurled or serrated as above and which shears and locks the screw on tightening against the surface B<1>.