Abstract: An aspirator using positive pressure from a suitable source generates a vacuum pressure when the primary source of vacuum pressure, typically the engine intake manifold, prodcuces insufficient vacuum pressure to operate a device such as a road speed control servomotor. The aspirator assembly is connected to the source of positive pressure and the engine intake manifold as well as to atmosphere and to the device to be operated by vacuum power. When there is sufficient intake manifold vacuum pressure for the desired purpose, there is no flow through the aspirator and the engine intake manifold supplies all of the vacuum needs of the servomotor. When aspirator vacuum pressure is required due to insufficient manifold vacuum pressure, the aspirator is opened to generate aspirated vacuum pressure and the connection between the servomotor and manifold vacuum is closed. The aspirated air is delivered to the engine intake manifold.

Abstract: To provide an electrical vehicle speed signal as well as a traditional speedometer cable drive, a sleeve member for mounting in a port of the transmission housing and a driven gear on a shaft journaled in the sleeve member are modified by providing a magnet on the gear for rotation therewith, an annular sensing coil around the sleeve member and a U-shaped polepiece linked through the coil and extending into magnetic coupling relationship with the magnet so that electrical pulses are induced in the coil upon gear rotation.

Abstract: A vehicle road speed control system has a differential pressure actuated servomotor as a part of a power unit including an integral solenoid controlled valve assembly. The servomotor and valve assembly includes a servomotor output position feedback path. The solenoid valve assembly is of the repulsion armature type with the load spring coupled to the servomotor power wall to introduce position feedback. Two modifications of the valve orifice control arrangement are disclosed.

Abstract: A wheel lock control system for a vehicle is described that is responsive to wheel speed to provide a brake release signal when the wheel speed signal characteristics represent an incipient wheel lock condition. The braking forces on the vehicle wheels are relieved by the wheel lock control system for the duration of the brake release signal. A monitoring circuit monitors selected system parameters and provides a fault signal while the parameters represent a fault condition.