Abstract: A vehicle speed control device in a vehicle having a variable speed engine and drive train arrangement connecting the engine to a drive wheel therefore includes a foot pedal movable in first and second directions, a vehicle speed transducer arrangement for generating a signal in response to vehicle speeds in excess of a predetermined speed and a control arrangement for varying the value of the predetermined speed. A throttle arrangement is responsive to movement of the foot pedal in the first direction for increasing the vehicle speed and is responsive to movement of the foot pedal in the second direction for decreasing the vehicle speed. A coupling arrangement transfers movement of a movable actuator to the foot pedal, to move the foot pedal in the first and second directions. A regulating arrangement is responsive to the signal of the speed transducer arrangement for regulating the vehicle speed at or just below the predetermined speed.

Abstract: A stored energy-type propulsion system for a vehicle employing a free piston engine-pump hydraulically connected to a drive motor, which in turn connects to the vehicle wheels. The hydraulic connection between the engine-pump and the drive motor includes a large-capacity pressure accumulator which is normally isolated from the system, and which is opened for communication with the system to supply pressure fluid to the drive motor only under conditions demanding peak operating pressure for limited time durations. An auxiliary accumulator of significantly smaller capacity is also connected to the hydraulic connection.

Abstract: Actuator control system includes two parallel connected orifices between a pair of fluid passages providing communication between an actuator and a flow control valve. Relief valves in series with the respective orifices block fluid flow through the orifices at low differential pressures between the fluid passages, thereby preserving the original high pressure gain of the control valve in a region about valve null. At higher differential pressures outside the valve null region, the relief valves open to permit restricted flow through the respective orifices to reduce the pressure gain of the control valve in a region outside the valve null region, which effectively reduces the stiffness of the control valve.

Abstract: A position control device for use in association with a foot pedal member controlling the fuel flow to an engine of a vehicle. The device includes an elongated and hollow chamber means and an actuator piston slidably disposed in the chamber means and movable between first and second positions therein. The first position represents a position of maximum fuel supply to the engine. Structure separately supporting the foot pedal member is provided for movement between first and second positions but permitting an operative connection of the foot pedal member to the actuator piston for movement along a path.

Abstract: A free piston engine pump system operates in response to internal combustion for pressurizing a working fluid to provide hydraulic power output. The free piston engine pump has double acting power pistons and pumping pistons fixedly attached as a main reciprocating member and movable relative to a housing, which itself may be relatively movable for mass balancing purposes. Air is supplied and exhaust products are exhausted from a pair of opposite combustion chambers by respective common intake and common exhaust valves that preferably are operated by a common actuator in direct or indirect (via a phasing valve) response to position of the main reciprocating member. Moreover, operation of fuel injectors and exhaust valves associated with respective combustion chambers is directly or indirectly (via the phasing valve) controlled in response to the position of the main reciprocating member in the housing and/or fluid pressure in respective pumping chambers.

Abstract: Plural servo actuators are coupled to provide a redundant system for operating a common output device. Each servo actuator has plural servo valves each having one active output that causes controlled opposite operation of the output device and one passive output. A fault detector coupled to each servo actuator compares the sum of the passive output pressures with the pressures of two other fluid signals, in one case the supply and return fluid signals and in another case the two active output signals of the servo valves, to detect the condition thereof. A convenient checkout system and a fluid by-pass mechanism also are provided in the fault detector.

Abstract: A combined feedback control system for a servo actuator including a ram that produces a mechanical displacement output of the system as directed by a position command signal. In the combined feedback control system a lever arrangement mechanically combines displacement and velocity information of the ram, and such combined information is conveniently transduced and electrically combined with the position command signal to develop an error signal that controls an electro-hydraulic valve. The latter preferably through a fluid amplification stage controls the delivery of fluid to the ram and, thus, the position thereof. Through the lever arrangement a mechanical failure control is operative to move the ram to a predetermined position upon failure of the electro-hydraulic valve and a manual control is operable to control the ram position via the fluid amplification stage.

Abstract: A hybrid propulsion system, particularly for a vehicle, having a free piston type engine-pump unit connected to a working fluid circuit for controlling pressurization of a working fluid, which fluid in turn drives a hydraulic motor interconnected to the vehicle wheels. The motor-pump unit includes a free piston assembly having a pair of fixedly connected power pistons, each of which has a pump piston fixed thereto. The fluid system includes high and low pressure accumulators in communication with pumping chambers associated with the pump pistons. The power pistons are used for driving the pump pistons to pressurize the working fluid when self-sustained operation of the engine-pump unit is desired. However, the flow of working fluid to the pumping chambers can be reversed during startup of the engine so that the high pressure fluid is used for driving the free piston assembly until same is reciprocated at a rate rapidly enough to permit self-sustained reciprocation thereof.