GB167172A - Method for the production of double helical teeth - Google Patents

Abstract

167,172. Krupp Akt.-Ges., F. July 28, 1920, [Convention date]. Void [Published under Sect. 91 of the Act]. Gear-cutting.-Double helical spur gears may be generated on the rolling principle by means of a milling-cutter B, the cutting-edges b<1> of which may be regarded as moving, during the rolling of the blank, along the flanks of a rack as shown in Figs. 1 and 2. The cutter is advanced along each half of the tooth flanks a<2>, a<3> in the direction of the arrows, and at the end of the advance movement the bounding circle b<2> of the cutter crosses the lines 3, 4, 6, 7, where the tooth flanks intersect at the intermediate points 5, 8 respecively. Thus at points near the centre line of the rack, part of the tooth flanks, as indicated by the non-hatched portions in Fig. 1, are not engaged by the cutter so that in cutting a spur-wheel C, Fig, 3, ribs c<1> will be left in the gaps between the teeth. In order to allow two gears cut by this method to engage fully with each other, a peripheral groove c<2> of V-shaped contour, corresponding to the cross-section of the rib c<1> is cut in the blank before the teeth are cut so that the cutter may be advanced freely up to the inner end positions shown in Fig. 1. The invention is stated to be applicable also to the milling of double helical bevel gears.