Patent GB-441925-A (GB)
Title: Transmission and change-speed mechanism
IPC: F16H61/02
Filed: 1934-06-29
Abstract: 441,925. Variable-speed gearing. RILEY, P., c/o Riley Engine Co., Ltd., Aldbourne Road, Coventry. June 29, 1934, Nos. 19229 and 22084. [Class 80 (ii)] A variable - speed gear has coaxial driving and driven shafts 14, 15, a parallel layshaft 26, three constant-mesh gear pairs 22, 24; 18, 27; 23, 25, of which some of the gears are free ; and two clutching systems 19, 20 to obtain four forward speeds. The clutching systems are arranged on opposite sides of the gear pairs, which are substantially adjacent one another. In the form shown, an intermediate shaft 13 carries the gear 18 and the gears 22, 23 are mounted on loose sleeves 16, 17. The driving shaft 14 may be connected to the shaft 13 or sleeve 16 by the clutch 19, and the driven shaft 15 to the shaft 13 or sleeve 17 by the clutch 20. The gear 24 may be connected to the layshaft 26 by an overrunning clutch, or by a toothed clutch 21a, Fig. 2, which is disengaged for certain speeds. Control is effected by a slidable and rotatable rod 43 moved by a lever operating in the usual gate. During speed changing, the clutch 19 is disengaged by depressing the clutch pedal 28, which through a rod 29 tilts a lever 31 which lifts a pair of levers 33a, 33b, which thus lift valves 34a, 34b to the position shown, in which both sides of the clutch-operating piston 38 are connected to exhaust and the presser plate 64 is held by the springs 63, 65 in its disengaged position. When the rod 43 is in its intermediate neutral position, the toothed plate 41 prevents both of the valves from falling, but when the control lever is moved fore or aft in the gate, the consequent endwise movement of the rod 43 acts by means of the inclined projection 53 and pins 54 to tilt the plate 41 and permit one of the valves to drop when the pedal 28 is released, thus admitting pressure oil to one side or the other of the piston 38, thus clutching the driving shaft 14 to the sleeve 16 through the clutch plates 67 or to the shaft 13 through the plates 79. Endwise movement of the rod 43 also rotates through a rack 43c and pinion 44, a cam 69 engaging a pivoted lever 70 which controls the movements of the clutch 21a. The rocking of the lever 43 between each gear change causes the arm 43a to move the pinion up or down as seen in Fig. 4, thus operating a valve 46 through a bell-crank 45 so as to admit pressure oil to one side or other of a piston 51 which controls the clutch 20. Extreme rocking of the rod 43 brings clutch teeth 89 into engagement with a disc 91, which, on the ensuing endwise movement of the lever 43, is rotated to slide the reversing train 92 into engagement with the gears 23, 24. The clutch 20, and in some cases the clutch 19, is a positive clutch with synchronizing friction means. Specification 435,497 is referred to. Specifications 423,454 and 423,455 also are referred to in the first Provisional Specification. According to the second Provisional Specification, the clutching system 20 may be replaced by a double hydraulic clutch of the kind described in Specification 405,429, a ring with opposed cam faces being secured in a cage fast on the driven shaft and a pair of blocks carrying pistons being splined to the sleeve 17 and intermediate shaft 13. The supply of oil is controlled by a slide valve c connected by a bell-crank to the gear lever so as to be affected only by the lateral movement of the lever. The clutching system 19 is replaced by a piston fixed to the driving shaft and carrying projections by which it drives an axially movable cylinder whose outer faces coact with friction discs carried by the sleeve 16 and shaft 13. Reverse drive is preferably introduced by means of a sliding gear operated hydraulically.