Patent GB-528676-A (GB)
Title: Control means for change-speed gear for motor propelled vehicles
IPC: F16H61/28
Filed: 1939-02-01
Abstract: 528,676. Controlling variable-speed gearing. WILSON, A. G., and MILLER, A. A. Feb. 1, 1939, No. 3435. [Class 80 (ii)] In a control means for the change-speed gear of motor vehicles, the movement of a single lever b from one gear position to another or to or from neutral position brings about the closing of one or other of two electric circuits B, C according to whether the movement is in a " change-up " or " change-down " direction ; the circuit is closed by a relay or magnetic switch F or K, which is momentarily energized through a switch c moving with the lever b and is held by a retention winding until the circuit is opened at the appropriate movement by a switch moved by the control mechanism. The circuits when closed energize solenoids q, r controlling the engine throttle and the servo mechanism for changing the gear, the sequence of operations being dependent on the particular circuit closed. As shown, the selector lever b is rotatable on the steering column c and carries a quadrant a having teeth d ... d<4> adapted to engage a projection g on the two-way switch element c. During the change from one gear position to another, one of the teeth d ... d<4> tilts the element c into temporary contact with one or other of contacts h, i in the circuits B.C. The " change-up " circuit B includes the shunt winding j of the switch relay F, and a secondary circuit D in parallel with B includes a time switch E, the retention winding p of the relay F, and solenoids q, r ; the solenoid q operates a valve pneumatically connected with a vacuum servomotor operating the bus-bar of a Wilson gearbox, while the solenoid r operates the throttle or other engine control. The time switch E comprises a yoke u which carries contacts v slidable over fixed contacts t and is connected to a piston x in a cylinder y communicating through an adjustable valve 7 and a pipe 6 with the vacuum servomotor. The " change down" circuit C includes the shunt winding m of the relay switch K, and a secondary circuit L in parallel with C includes a switch H, the retention winding 11 of the relay K and the solenoids q, r. When changing-up, operation of the selector lever b engages the contacts e, h momentarily, and the relay F closes contacts o in the circuit D, so that the engine throttle is closed by the solenoid r and the bus-bar servomotor is actuated from the solenoid q to effect gear disengagement. Downward movement of the piston x under suction moves the contact v after a time interval on to a contact 8, breaking the circuit D and supplying current through a resistance 9 direct to the throttle coil r, so that the bus-bar returns and engages the new speed gear, while the throttle is held closed until the piston x is raised by the spring 5. When changing down, the circuit C is closed at i and the relay K closes the circuit L at 10, so that the throttle is closed and the bus-bar servomotor actuated as before. On completion of its stroke, the bus-bar opens the switch H, so that the busbar is allowed to return and effect gear engagement and the throttle is allowed to open.