GB242378A - Improvements in speed changing gear - Google Patents

Abstract

242,378. Fitter, W. C. Aug. 28, 1924. Variable-speed and reversing gearing. - Comprises an epicyclic ratchet gear capable of yielding a solid drive. The driving crank or eccentric is variable in throw. Planet gears 37, Figs. 1 and 2, are constructed to roll round on an anchored sun pinion 71, the carrier 33 of the planet gears being the driven element of the gearing and secured to a shaft 34, which passes through the sun gear 71. Reversed driving of a tail shaft 32 is effected through a lever 122 by an arrangement of clutches and stops by which the planet carrier 33 is anchored and the sun pinion 71 is made the driven element. The driving crank 6 is connected by links 39 and arms 38 to the planet spindles 36, which are oscillated thereby. With each spindle 36 there oscillates an internally-toothed drum 41, Figs. 7 and 8, which is turn oscillates pinions 45 supported upon each planet gear 37. Friction pawls 6 in the form of wedges supported by the planets 37 are spring-pressed between a friction surface 65 within the drum 41 and friction surfaces 43 on the pinions 45 so as to bind and drive in one direction only. The links 39, Fig. 2, act in tension to pull the planets 37 round on the sun 71. The crank is shown in Figs. 3 and 5. The crank pin 6 is integral with a disc 4, which turns about an eccentric pivot 5 upon a disc 3 fast on the driving-shaft 2. The throw of the crank is varied by means of a pin 9 fast in the disc 4 and projecting rearwardly into a radial slot 11 in a disc 12 mounted upon a sleeve 13 adapted to be turned relatively to the shaft 2. The variable crank is balanced by a fourth disc 14 pivoted at 15 on the disc 3 and moved oppositely to the crank disc 4 by a slot 19 in the control disc 12. The variable-speed gear shown in Fig. 1 is controlled by the axial sliding of a sleeve 26, which through helices effects the required relative turning of the sleeve 13. As a control lever 20 is moved to the right, the sleeve 13 turns so as to increase the throw of the crank 6 and raise the speed of the shaft 32. Eventually a catch 95 on this lever engages a notch 94 in a rod 93 and pulls a lever 84 which sets the sun gear 71 free to rotate. On further increase of the length of the crank 6, the crank linkage locks to produce a solid high-speed drive.