Patent GB-344063-A (GB)
Title: Improvements in or relating to variable speed power transmission
IPC: F16H61/662
Filed: 1929-09-02
Abstract: 344,063. Variable speed gearing. HAYES, F. A., Middletown, New Jersey, U.S.A. Sept. 2, 1929, No. 38705/30. Convention date, May 7, 1929. Divided on 343,988. [Class 80 (ii).] Variable-speed gearing, suitable for vehicles, of the torus disc type operating by the precession of planetary rollers is engaged and disengaged to start and stop the vehicle by the operation of a brake upon an abutment member. Reversed driving and braking of the vehicle are effected manually. The gearing shown comprises a twin epicyclic arrangement described in Specifications 343,988 and 344, 065. The rollers 19, 50, Fig. 1, of the twin-gear sets are supported between pivoted rockers 28, 54, as described in Specification 344,062, and the gearing as a whole is rendered torqueresponsive, as described in Specification 344,061. Control is imparted to one set through a member such as a slider 46, which has a definite position for each gear position of the two sets of rollers 19, 50, which precess in unison. The two sets of rollers are carried upon a sleeve 13a loose on engine shaft 12, and the load is divided between the sets as described in Specification 344,064. These rollers coact with two end discs 10, 11 splined on shaft 12 and with a loose medial abutment disc 15. For forward driving, the load on driven shaft 63 is applied at 56 to the planet-carriers of the second set, and the abutment disc 15 is held by a brake 72, to the drum 71 of which the disc 15 is coupled by clutch drum 67. Starting and stopping of the vehicle are effected by applying and releasing brake 72. This is preferably effected by hydraulic means described also in Specification 344,066. With the car standing and engine idling, pump 85, Fig. 15, driven by the engine shaft, is driving oil ineffectively past " speed " valve 89, which is set for the purpose. To start the car, the driver speeds up the engine by the accelerator, whereby oil overflowing valve 89 passes by pipe 91 to valve 115, which it opens, then by pipe 109 into cylinder 108, pressing piston 106 to the right and applying brake 72 in effect to disc 15. The car starts off in lowest gear, and the " get-away " may be rapid as well as silent in the following manner. Oil banking up in pipe 91 forces valve 135 to the left and passes to speed-control cylinder 96, in which piston 95 is then held at left by a spring and by torque reaction. Sufficient engine speed thrusts piston 95 and slider 46, Fig. 1, to the right, precessing the gear rollers and so accelerating rapidly to the capacity of the engine. Further speeding up of the engine at this point causes piston 95 to uncover pipe 98 by which oil passing to differential valve 116, 115 releases the oil pressure between the brake pistons 106, 107 and applies pressure to a piston 106a so as to release the brake 72 and apply clutch 78, for solid driving, all as described in Specification 343,988. Increased torque or reduced throttle opening restores the parts to the position of Fig. 15 with the brake 72 applied and automatic geared drives in operation. A detent action prevents disc 15 from turning backwards. To stop the car, it is only necessary to close the throttle and apply the service brakes. Closing the throttle returns the gear-rollers to the low-speed position and releases brake 72, so that abutment disc 15 is permitted to revolve freely, and the drive ceases. Depression of service brake pedal 140, Fig. 19, opens valve 92, Fig. 15, which releases the oil pressure in the control system. If the car is on an upgrade when pedal 140 is depressed, valve 92 held open may prevent the car starting. A handbrake is used to hold the car while pedal 140 is released to allow of starting oil pressure. To drive reversely from rest, reverse shift rod 68 is moved manually to the left of Figs. 1 and 15. The planet carriers are connected through clutch drum 67 to brake drum 71, and middle disc 15 is connected through clutch drum 75 to load shaft 63. At the same time, valves 128, 132 are operated. These have the effect of rendering inoperative both the detent action on drum 71, and the speed control cylinder 96 ; the car is started in reverse as in forward driving, but the gear-rollers remain in the low-speed position.