GB648730A - Improvements in and relating to keys for locks - Google Patents

Abstract

648,730. Making keys for locks. YALE & TOWNE MANUFACTURING CO. June 1, 1948, No. 14817. [Classes 83 (i) and 83 (ii)] Casting composite articles. - Keys for lever locks or blanks therefor are made by casting a shank over tangs on a machined bit located in the mould. Bits 2 may be blanked from sheetmetal, or double bits 2, 3, Fig. 3, may be cut from extruded bar having a cross-shaped crosssection, the ward slots 7 being either cut straight across the bit by milling or formed arcuate about the centre line of the portion 4, 5, as shown in Fig. 5, by turning. The bits are then sawn in half through this centre line and the parts placed in dies of a die-casting &c. machine in which the shanks 8, Fig. 7, are cast about the tangs 4a, 5a. Holes 6 may be provided to form recesses 6a in the individual bits. In a modification the bits may be shaped so that the tangs 4a, 5a are thinner than the bit or are of diverging cross-section and extend at one side only of the bits. In a further modification a key shank 18, Fig. 12, is cast over a collar 16 on a square section arm 15 integral with a pin 14 and bit 13. The bits may be made of extruded brass &c. and the shanks 8 cast in aluminium or zinc base alloy &c.