GB601879A - Improvements in the hardening and tempering of scissor and other blades - Google Patents

Abstract

601,879. Hardening and tempering blades. JACKSTEAD ENGINEERING CO., Ltd., and JACKSON, D. B. Oct. 9, 1945, No. 26375. [Class 72] A method of hardening scissors and like long blades, comprises heating the blade to hardening temperature, clamping the blade directly between metal dies, except for strip along the cutting edge left exposed, and applying quenching fluid to the exposed edge to harden only the edge. The application of quenching fluid may be stopped so that the blade edge can be tempered by heat flowing back from the dies, and the blade then allowed to cool, assisted by further fluid, if desired. In the form shown, a die 14 overlaps a die 13 having a recess 18, to receive a heated blade 19 with the cutting edge 23 exposed. The dies may be closed by a fly-press handle 17 whereupon the table 10 carrying eight dies is rotated, the next pair of dies loaded and the rotation repeated. Rotation every 45 degrees may be checked by a spring-controlled plunger 39 in a bore 40 engaging a notch 41 in a disc 42 on the shaft 11, which may be driven through a worm-wheel 45. As each pair of dies depresses the spring-controlled lever 25, an air or liquid jet 32 from a sump 44, by way of the pump 31 and union 34, strikes the surface 21 and evenly quenches the exposed edge of the blade. At the same time the following pair is loaded and the preceding and now tempered blade reaches, and is further quenched by, the jet 38 from the pipe 37. A modified arrangement for treating small scissor blades consists of two fly-presses having rods depending from the upper dies to depress the plungers of supply valves when the dies are clamped whereby the exposed edge is quenched. The presses are alternately fed by hand, the final cooling fluid being unnecessary.