GB112779A - Improvements in Methods of Generating the Teeth of Helical Gear Wheels. - Google Patents

Abstract

112,779. Bradner, H. T., (Assignees of Schurr, C. H.). Jan. 15,1917, [Convention date]. Gear-cutting.-Relates to cutting helical gears by means of a rotary hob and comprises a method in which definite ratios are established between the rotation of the blank, the rotation of the hob, and a relative feed movement with reference to a third rotating member, so that two of such ratios can be varied independently of the other. A machine for carrying out this method is shown to some extent diagrammatically. It is driven by a pulley 1 which, through gear shown, drives a helical wheel 5 in gear with two wheels 6, 7. The wheel 6 is on a shaft 8 and through the index change-gear 9, a shaft 10 bevel gear and spur gear including changewheels 15, 16 drives a shaft 22 carrying a worm 23 by which a worm wheel on a table carrying the blank 25 is driven. The shaft 10 through worm gear 59, 40, a clutch 41, spur gear 44, 45, 46 and other worm gear 48, 49 also drives a shaft 50 which is geared to a spindle 64 carrying a worm. This spindle can be swung to place the worm in gear with a worm wheel 66 on the screw 61 which moves the table to and from the hob 36 for instance when a worm-wheel is to cut. The screw can also be rotated by the hand-wheel 60. The shaft 50 is also bevel-geared to a vertical spindle 53 which, as shown in Fig. 2, is bevel geared to' a feed-screw 59 for the cutter slide. The cutter spindle 35 is carried in a head 37 which can be swiveted on the slide and is secured in position by bolts. The wheel 7 is mounted on a vertical shaft 26, which, through two sets of bevel-gear and a short shaft 29, drives a spindle carrying a long pinion 33 in gear with a pinion on the cutterspindle. The various change gears are ascertained partly by calculation from formula given in the Specification and partly from charts or diagrams, examples of which are given also in the Specification.