GB351027A - A method or process and machine for cutting gears - Google Patents

Abstract

351,027. Gear-cutting. GENY, A. J., 84, Rue Lemerchier, Amiens, Somme, France. Feb. 14, 1930, No. 5001. Convention date, Oct. 23, 1929. Addition to 338,436, [Class 83 (iii), Metals, Cutting]. [Class 83 (iii).] Milling-cutters.-The method of hobbing bevel gears described in the parent Specification, wherein a rotary cutter having straight-sided teeth arranged along part of a single turn of a helix is employed to generate the tooth profiles on the blank, is adapted to the production of gears having inclined teeth or to hyperbolic gears. Thus in Fig. 1, if, for the cutting of straight gears, the cutter moves along the vertical line YV and represents a crown wheel having inner and outer circles R, S, respectively then, if the cutter is displaced so that it describes the path O<1>M it will trace out a wheel having inclined teeth such as DB. The complete generation of a tooth having the generatrix DB will require angular movements of the cutter slides over the arc AK and in order to reduce this to the normal arc AC the cutter slides are inclined so that the cutter starts cutting at the point Y and remains (in the mid-position of the generating swing) in the vertical line YV while generating a tooth represented by the line Y<1>V tangential to the circle having the radius OO<1>. For this purpose the reversal of the movement of the worm 3 actuating the generating movement of the tool head is controlled, through reversing bevel gearing 20, by a lever 17 actuated by an abutment 14 coacting with adjustable projections 12 on a screw 13. The abutment 14 is carried on an arcuate segment 15 slidable in a guide in the slides 1. The segment is slotted at 21, and a pin carried by an arm 25 on the tool slide engages in the slot. Thus at the commencement of the operation, the slides are in the position shown in Fig. 3 and at the end of the operation the Fig 5. position is reached, the cutter tracing out the tooth generatrix Y<1>V and the segment 15 sliding in its guides so as to maintain the abutment 14 in the vertical line passing through the point O. By adjusting the relative positions of the cutter and blank the invention may be applied to the production of hyperbolic gears.