Patent GB-347450-A (GB)
Title: Automobile variable speed gear control
IPC: F16D23/10
Filed: 1930-04-04
Abstract: 347,450. Controlling change s p e e d gearing. FORD, J. M., 89, Clarence Road, Teddington, Middlesex. April 4, 1930, No. 10693. [Classes 80 (i) and 80 (ii).] Gear change control mechanism upon a vehicle comprises a stop W2, Fig. 1, connected to the engine clutch pedal W<1> which stop prevents the gear change lever Y being moved to bring in a new speed until one of a set of differentials A, B, C, Fig. 2, has, when synchronism of gear or clutch teeth has been attained, operated to remove the stop. The stop W<2> is a pivoted lever with a notch adapted to engage with play a pin V on an arm U carried by the lever Y. The stop lever is biassed by a spring W3 so that gear can be changed at any time in the usual way by depressing a lever W<1> with the foot and operating the gear lever Y. The pedal W<1> is connected to a piston M<1> adapted to be connected to engine suction at M5 when a valve M<2> is opened by an electromagnet M<6>. Change can be effected freely from " in gear" " position such as P or Q to neutral, in course of which a pin V riding on a ramp L<1> or L<2> raises a stop lever W2 to close a switch W<5>, which energizes a magnet M<6> and causes the servomotor M<1> to open the engine clutch. In the neutral position shown, the current from the vehicle lighting terminals N is broken, and the clutch is closed. To move to " ingear" position, two switches T and K must be closed. The switch T on the arm U coacts with separate quadrantal terminals S, R, and a separate switch K is operated by its own differential for each speed. Shafts E, D, Fig. 2, are driven proportionally to engine speed and to road-wheels speed respectively. When the change-gears to be enmeshed are synchronized, the middle element F of the corresponding differential stops, or reverses. A switch member G, Fig. 3, riding frictionally on the element F then moves down or up so as to close the switch K momentarily. To change to in-gear position Q, Fig. 1, from neutral, the lever Y is moved until the pin V strikes the stop W<2>. The switch T contacts with the terminal R, and the circuit is not closed until, on synchronism, the proper switch K is also closed. The magnet M<6> and servomotor M<1> then act to depress the pedal W<1>, open the engine clutch, and raise the stop W<2> clear of the pin V. The movement of the lever Y can then be continued to the position Q to enmesh the synchronized gears. On the completed stroke of the lever Y, the switch T passes clear of the terminal R so that the servomotor is thrown out and the engine clutch is reclosed by its spring. The change from one speed to another involves double declutching, the clutch being open during gearshifting but closed in neutral. The switches K, by moving over additional contacts, might indicate by lamps &c. whether the engine speed was too high, or too low, or correct for making speed change. For the electric gear, fluid pressure gear may be substituted, valves taking the place of switches. The stop acting on the gear lever might be replaced or supplemented by stops acting on the gear-shift rods. Friction-gearing.-For the bevel toothed type of differential A &c. shown, a thrust ball bearing may be substituted acting as a frictional epicyclic train, a spring being used to keep the races, which need not be hardened, in action. The ball cage then functions as the middle element F above.