Patent GB-1250320-A (GB)
IPC: B60K31/12
Filed: 1968-10-15
Abstract: 1,250,320. Automatic controls. DANA CORP. 15 Oct., 1968 [17 Oct., 1967], No. 48927/68. Addition to 1,185,055. Heading B7H. [Also in Division G3] A device for controlling the throttle setting of a vehicle and for restoring the speed of the vehicle to a preset value after acceleration or deceleration includes a servomotor 18, Fig. 8, connected to the throttle 12, a vacuum source 20, such as the engine intake manifold, a solenoid valve 22 for connecting the vacuum source to the servomotor, and a modulating valve 136 responsive to vehicle speed for imposing atmospheric pressure on the servomotor. When the vehicle has reached a predetermined minimum speed, a centrifugal governor 30, Figs. 1 and 8, closes an adjustable low-speed switch 122 which permits the solenoid valve 22 to be energized from a power source 189 when a switch 200 is manually depressed. A second solenoid valve 178 is simultaneously energized to close a part 172 so that atmospheric air is supplied to the modulating valve 136 only through a bleed orifice 179 in the casing 188 of the device and the speed of the vehicle is thereby increased. The movement of the valve 178 opens a switch 296 in the circuit 269 of a coil 134 arranged to couple the centrifugal governor to the modulating valve so that the coil cannot be energized until the vehicle has reached the desired speed. When the switch 200 is released, the solenoid valve 178 is de-energized to close the circuit 269 and cause the coil 134 to complex the governor 30 to the modulating valve 136 which maintains the required vehicle speed. Energization of the valve 22 is maintained by a holding circuit 274 after the switch 200 has been released and reenergization of the valve 178 is prevented by a diode 220. During braking, or periods when the vehicle is being accelerated by manual operation of the throttle, lost motion connections accommodate the movement of the govenor sleeve 96 and enable the set speed eventually to be restored. Movement of the sleeve 96 during manually-controlled acceleration is accommodated by a spring 145 which is interposed between a pin 132 on a bracket 153 coupled by the coil 134 to the valve 136 and a bracket 129 slotted to accommodate the pin and movable with the sleeve. A plate 133, Fig. 3, mounted on a washer of plastics material to reduce friction and having a tang urged by a torsion spring 170 against a stop pin accommodates the governor sleeve movement during braking while a switch 284, Fig. 8, which is opened when the brakes are applied, operates the valve 22 to isolate the bellows from the vacuum source. A holding circuit 300 keeps the coupling coil 134 energized and a second diode 262 prevents opening of the valve 22 to vacuum. When the brakes are no longer applied the set speed is resumed by closure of a switch 312 which again opens the valve 22 to vacuum. The governor is loaded by an adjustable spring 100 and has a pair of geared shafts 44, 83 for insertion in the speedometer drive while the valve 136 is centred by a spring 142 and has a V-shaped lug 136A to regulate the part 27 admitting atmospheric air to the bellows. Modifications of the electric circuit are described in which the diodes 220 and 262 are omitted the switch 200 can be moved to a position in which the valve 22 and the coil 134 are de-energized while the servomotor 18 is expanded by its spring 19 and by atmospheric pressure to decelerate the vehicle, the controls for the device include a series of slip rings and are mounted on the steering wheel of the vehicle and a brake relay switch with a separate power supply cuts off the vacuum supply to the servomotor whenever the brakes are operated.