GB396109A - A new or improved method of transmitting the drive and varying the gear ratios chiefly for use on motor vehicles - Google Patents

Abstract

396,109. Change - speed gearing ; friction clutches. ROSE, R. H., Red Roof, Penn Road, Penn, Wolverhampton. Nov. 3, 1931, No. 30402. [Class 80 (ii).] Change-speed gearing suitable for vehicles comprises aligned driving and driven shafts 1, 6, Fig. 1, a countershaft 4 constantly driven through a gear pair 2, 3, and change-gear friction clutches A, B, C operated hydraulically, as by oil. The clutch A effects a direct drive, the clutch B middle speed through train 2, 3, 7, 5, and the clutch C low speed through train 2, 3, 8, 9. The clutch C may be larger than the others. Each clutch comprises slidable cone members 42 adapted to be thrust apart into engagement with a loose double female cone 43 by pairs of oppositely arranged pistons 37 sliding in cylinders 40 formed in a block 50 secured to the shaft 4 or 6. Alternatively, the pistons may be annular. The annular cone members 42 are supported on projections 41 on the ends of the pistons 37. Springs 44 disengage the clutch when the cylinders 37 exhaust. Reversed drive is effected by connecting the separated gears 8, 9 by an idler 10, Fig. 2, which may be slid into position hydraulically. Oil drawn from a sump 12 by a pump 11 passes by a pipe 14 to a main control cylinder 13. Raising a lever 16 by hand or foot allows the oil to escape past a taper valve 17 through a pipe 18 to the sump, and so disconnects the drive at any time. Oil from the cylinder 13 passes by a pipe 19 past a main relief valve 20 and through a pipe 22 to a valve box 21. A pipe 36 leads from the box 21 to each of the clutches A, B, C. There are three valves 25 admitting oil to the three pipes 36 selectively, and three corresponding exhaust valves 30 connecting the pipes 36 to an exhaust pipe 48. Each pair of valves 25, 30 is operated by a rocking lever 32, and the three levers 32 are operated by a selective manual control cam shaft 26. Each lever 32 is biased by a spring 31 to hold its exhaust valve 30 open. In order to produce a residual oil pressure to effect lubrication, a low pressure relief valve 46 is arranged through which oil from the main relief valve 20 and from the clutch exhaustpipe 48 must pass before passing back to the sump by a pipe 47. A rotary distributing valve is described which may be used instead of the rocking lever selector.