Patent GB-358040-A (GB)
Title: Improvements in machines for generating or cutting the teeth of wheels
IPC: B23F5/14
Filed: 1930-05-30
Abstract: 358,040. Gear cutting. SUNDER. LAND, S., Lyndhurst, High Utley, Keighley, and MIDGLEY, A. M., Skirethorne, Threshfield, near Skipton, both in Yorkshire. May 30, 1930, No. 16701. [Class 83 (iii).] In a machine for generating toothed gears by rolling a blank 5 past reciprocating rack cutters, a one revolution shaft is provided which after the complete generation of each tooth withdraws the blank from the cutters and, after indexing, returns the blank for the next cutting cycle. The bed A is provided with a cutter head B having inclined guides C in which the rack cutters 2b, 2c are reciprocated by means of cranks 3, 3a driven from a pulley 4. The work-support comprises an adjustable base-plate D carrying a horizontal slide D<2> having guides for a vertical slide D<3> provided with bearings for a shaft 6 carrying the blank 5. The blank is driven by worm gearing 8, change gears 10, 11, and vertical shaft 12 from a pinion 13 engaging teeth 14 on a sliding member 15, a ratchet coupling 12w being incorporated in the shaft 12 so that the blank is rotated through one pitch during the generating roll and remains stationary during the return roll, thereby effecting the indexing movement. The member 15 has an inclined cam portion 16 which engages a roller 17 on the slide D<3> to move the blank vertically in unision with the rotary movement produced by the rack 14. The slide 15 is also provided with rack-teeth 15b engaging a pinion 24 on a shaft 25 driven through disengageable worm gearing 28, 26, shaft 29, bevel gearing 30, shaft 32, and gearing 33, 34, from the main driving shaft 35. A third series of rack teeth 18 on the member 15 engage a quadrant 19 geared to a rack 22 carrying a roller 23a coacting with a cam 24a on a control shaft 25a. Another cam 40a on this control shaft acts through a lever 38 to disengage the worm 28 of the gear train operating the member 15 at the end of the generating movement. The control shaft 25a carries a worm wheel 40 driven from a worm 41 on the shaft 32. Normally the worm wheel 40 is disconnected from the shaft 25a by the engagement of a bar 50 with a key 25w, Fig. 14, coacting with internal notches in the wheel 40. In operation during the generating roll the teeth 18 act through the quandrant 19 to return the roller 23a into contact with its cam. At a predetermined point one of a pair of projections 15x, 15w, on the member 15 engages a projection 51 to slide the bar 50 so that the key 25w drops into a notch 50a and allows the control shaft to rotate. This causes the forward driving mechanism of the member 15 to be disconnected and the said member to be quickly returned through the cam 24a, rack 22, and quadrant 19. At the same time, a crank-pin on the control shaft engaging a block in the adjustably fixed base-plate D, effects withdrawal of the slide D<2> and blank from the cutters and the subsequent return movement for a fresh cutting cycle. The return movement of the member 15 causes the bar 50 to be again shifted to the Fig. 14 position, so that, after one revolution, the key 25w is disengaged and the control shaft comes to rest.