GB682454A - Improvements in or relating to methods of manufacturing nuts - Google Patents

Abstract

682,454. Forging nuts. SECURIT'S E.D.L.C. Dec. 8, 1949 [Dec. 10, 1948], No. 31589/49. Classes 83 (ii) and 83 (iv). In a method of manufacturing locking nuts of the type comprising an inner element 1, Fig. 1, and an outer element 2 which fit one within the other without being capable of relative rotation, a bevelled annular member 14, Fig. 8, is first formed from a flat blank and is adapted to serve as the starting element for the manufacture of either the inner or outer element, and the inner or outer element is then struck from the member 14 in a separate stamping operation including only a single pressing stroke, the inner element being subsequently threaded and slit longitudinally. To form the annulus 14 the flat blank is placed in a die 6, Fig. 6, on an anvil 7 having a slightly elevated surface portion 10 with an inclined edge, and pressed by a punch 8 to produce a hollowed block 9. This is placed in a die 12, Fig. 7, and punched through by a punch 13 to complete the annulus 14, which has a substantial upper bevel and a narrow lower bevel 11<SP>1</SP>. For stamping the outer element 2 the member 14 is placed in a die 16, Fig. 9, having internally the desired outside shape of the element 2, and pressed by a punch 17, the outside shape of which has frusto-conical, polygonal, and cylindrical portions. Extruding.-The diameter of the cylindrical portion is slightly less than that of the guideway through the die 16 to form a clearance space 18 into which metal is forced during the striking operation to produce a flange 4. For obtaining an inner element 1, there are employed a die 19, Fig. 10, having a polygonal and a frusto-conical portion and a smooth cylindrical punch 20. The bore of the element thus obtained is tapped and then slit longitudinally. Specification 502,477 is referred to.