GB428779A - Improvements in variable-speed gearing - Google Patents

Abstract

428,779. Variable-speed and reversing gearing. EVANS, 0., 27, Chancery Lane, London.-(Demag Akt.-Ges. ; 64, Werthauserstrasse, Duisburg, Germany) Nov. 13, 1933, No. 31637. [Class 80 (ii)] Variable - speed gearing, for a vehicle or a winch, comprises a series arrangement of twospeed epicyclic or countershaft gears, controlled in stages by groups of friction clutch discs, so arranged that a clutch disc to be put into engagement presses upon and disengages a disc to be disengaged, without the occurrence of any " free " position of the gear during the change. Similarly-controlled reversing-gearing is also provided. The epicyclic gears 18, 18<a>, 18<b>, 18<c>, Fig. 1, are changed from reduced to solid drive when clutch-cones 19 secured to their annuli 17, are pushed out of clutching engagement with an inner rotating casing 21, by advancement of solid - driving clutch cones 22, such advancement being produced in succession by continued movement, in either direction of a hand - lever 9. The clutchcones 22 are secured to slidable shafts, each carrying the sun - wheel of one stage and the planet-carrier of the preceding stage, the shaft in the case of the first stage being the driving shaft 5. The inner casing 21 is permanently driven from the final driven shaft 23 by a constant-mesh countershaft train 26. The driving shaft 5 is driven by a double clutch-cone 4 adapted to be pushed off a fixed brake-ring 7, against a spring 12, by advance. ment of either of two oppositely-rotating clutch - cones 3, 33, the latter being driven through bevel reversing wheels 30, 31, 32 by a motor A, which directly drives the cone 3. Forward movement of the controllever 9 acts through a lever 11 on the forward clutch cone 3, continued movement successively locking the epicyclic trains 18. Rearward movement acts through a lever 34 on the reverse cone 33, continued movement operating the gear stages, as before. In Fig. 2, each gearstage is changed from a reduced drive through a countershaft 80, to a directdrive, when a clutch cone 79, secured to the driven shaft of a preceding stage, engages a cone 82, secured to the driving shaft of the following stage, such engagement pushing the cone 82 away from a clutch-ring 81, 81, secured to the driven wheel of the preceding stage. The gear is driven through a reversing- gear as in Fig. 1, with the exception that the hand-lever 70 acts on the clutch-levers 74, 76 through cams 71, 72, and a spring 70<a> assists the movement of the lever in either direction. In order to prevent top-speed being engaged under heavy load, the latter is caused to react back on the control lever by taking off the drive through a helically-toothed wheel 86. Each clutch-unit E, F, or G, together with a gear wheel on either side of it, may be withdrawn from the gear casing, for inspection, by a lateral movement, loose couplings 84 being provided for this purpose.