GB653595A - An improved method of manufacturing tens transfer pinions for use in counting mechanism - Google Patents

Abstract

653,595. Making wheels for counters. LANDIS & GYR SOC. ANON. Nov. 12, 1948, No. 29485. Convention date, Dec. 3, 1947. [Classes 83 (ii) and 83 (iv)] Drawing-dies ; forging-dies ; die-rolling axial rolling.-In making a tens-transfer actuating- pinion for use in counting-mechanism, the pinion blank 1, Fig. 1, is produced from a lightmetal rod by turning, drilling and pressing to form small bearing holes 5, 6 at each end, driving and detent teeth 11, 12 are then formed by a further pressing operation, and finally the shape of the teeth is corrected by a rolling and trimming operation. The rod is machined in an automatic lathe to form a hub part 5, drilled to provide an enlarged recess 3 and smaller bearing-hole 8, constricted at one end on a pin to form the bearing-hole 6, and then separated from the rod on the line 4. Teeth are produced on the blank by-engaging the flange thereof on a die, Fig. 2, formed with teeth-cutting edges, and locating the bearings 5, 6 on a mandrel 10a projecting from a punch 8 which has teeth-forms 9, 10, the teeth. 9 projecting in front of the punch to produce a smaller bearing area than those on the die. The teeth 9, consequently, penetrate the blank at a faster rate than the blank is advanced through the die until they have reached their maximum penetration, when the base of the punch 8 contacts the blank which is then advanced through the die at the same speed as the punch to produce the pinion shown in Fig. 4 in which alternate teeth 11 are of halflength. The teeth may be formed in two stages by the use of a second die. Axial rolls 13, Fig. 5, having edge-cutting discs 18, 19, pockets 16, 17, to receive the teeth of the blank 1, and cutting edges 17a, are provided to cut the edges of the gear to square-form and roll the flanks of the teeth. The rolls, which are interconnected by gearing (not shown), to rotate in the same direction through one complete revolution for each pinion operated upon, may have a crankhandle in the gearing to engage a releasable abutment at the end of each revolution, or may be driven automatically by power means. A mandrel 22 for delivering pinions to the roll pass is actuated against spring-pressure by a hand lever 24 pivoted at 23 and caused to separate the rolls 13 by cam action between a pin 28 on the mandrel and tracks 29 carried by the rolls. A pinion is placed on an extension 25 and located by projections 26 on the end of the mandrel, with the latter raised through the roll pass, and delivered to the roll pass through cut-away portions in the discs 18, 19, the rolls being actuated by spring-pressure to grip and retain the pinion. After the rolling operation, the mandrel 22 is raised to remove the finished pinion from the roll pass. In a modification, the axial rolls 13 may be replaced by racks sliding in parallel guides.