Patent GB-367876-A (GB)
Title: Improvements in or relating to power transmission systems
Filed: 1930-11-13
Abstract: 367,876. Controlling engine, changespeed gearing, and clutches of motor vehicles. GILLETT, E. H. J. C., 51, Priory Road, West Hampstead, London. Nov. 13, 1930, No. 34215. [Classes 79 (ii) and 79 (v).] A motor vehicle transmission and control system comprises in combination variable speed gearing of constant mesh, epicyclic, synchronized or other silent engaging type and a servooperated clutch controlled by the engine accelerator. Reference is made to Specifications 321,637, 324,950, and 334,894, [all in Class 79 (v), Motor vehicles, Steering &c.], which describe servo-operated clutches controlled by the accelerator. The clutch may be between the engine and gear-box or between the gearbox and the road wheels. In the construction shown in Fig. 1, the engine shaft 15 drives the propeller shaft 44 through a clutch 14 and constant-mesh change-speed gear 41, 45. The clutch is engaged by the usual internal spring or springs (not shown) but is normally disengaged by a strong tension spring 23 acting through a lever 22, 20 on a concentrically pivoted lever 19, 18 the lower arm or foot of which acts on the clutch-disengaging collar 17. To cause the clutch to engage the disengaging spring 23 is overcome by means of a servomotor 27 controlled by the accelerator pedal 32. The accelerator is connected by a lost-motion pin-and-slot connection 33 to the throttleoperating rod 34 and is further connected by linkwork 30 to the servomotor, so that on the accelerator being depressed the servomotor is first operated to overcome the spring 23 and allow the clutch to engage, after which the throttle is opened in the usual manner, the lostmotion at 33 having been taken up. The servomotor 27 may be hydraulic or pneumatic or may embody a pilot clutch and screw gearing, and is preferably so arranged that the engagement of the clutch is completed after a predetermined number of engine revolutions. In the construction of servomotor shown in Figs. 1 and 3 an engine-driven pump 36 delivers liquid.through a pipe 28 this liquid passing through a byepass 76 to the outlet pipe 77 when a byepass valve 78 is open. When the accelerator 32 is depressed the valve 78 is closed, a plunger 75 is raised and acts through a cam arm 73 on a roller 72 carried by an arm 71 on a shaft 70 which is connected by an arm 26 and link 25 to the lever 22 coacting with the spring 23. The outer face of the cam arm 73 is an arc concentric with the shaft 74 on which the arm is mounted so that when the plunger 75 is raised to its. full extent the roller 72 bears on this are and has no reaction on the plunger. In its raised position the plunger uncovers a bore 79 through which the liquid passes to the outlet pipe 77. A construction of changespeed gear having synchronizing means is shown in Fig. 2. The driving shaft 16 carries a pinion 41 driving a pinion 45, loose on the driven shaft 44, through a lay shaft 49, the drive from the shaft 16 being either direct or through the lay shaft according to whether a sliding clutch member 50 engages clutch teeth on the pinion 41 or 45. Friction cones 57, 58 on the pinions 41, 45 are adapted to be engaged by corresponding surfaces on a slidable sleeve 59. The clutch member 50 is splined on the shaft 44 and has a groove engaged by a ring 62, this ring being connected by a lug 61, passing through a slot 60 in the sleeve 49, to a ring 65 which slides on the sleeve 59 and is controlled by the gear-selector finger 54. The ring 62 is provided with a spring detent 63 adapted to engage a notch 64 in the sleeve 59 so as to tend to hold the parts in the position shown. When a gear is to be engaged the finger 54 moves the ring 65, the ring 62, and the clutch member 50 axially, the sleeve 59 sliding with these parts until one of the coned surfaces on the sleeve engages with the cone on the corresponding pinion 41 or 45. The sleeve 59, and therefore the clutch member 50, and shaft 44, is thus caused to rotate and its speed made to synchronize with the pinion. Further movement of the selector finger causes the clutch member 50 to move along the sleeve 59, the detent 63 moving out of the notch 64, until clutch teeth 42 or 46 on the pinion 41 or 45 are silently engaged by the clutch member 50.