Abstract: Improvements in the device and method of providing portable electrical, hydraulic and compressed air power to a variety of job site applications requiring the use of hand held industrial tools.

Abstract: A power source attachment, and a method of manufacture, that runs only off the auxiliary hydraulics of a skid-steer loader or other prime mover. It can run lights and still have extra power to run one or more electrically operated tools on a construction or other jobsite, such as but not limited to welders, jackhammers, air compressors, saws, drills, grinders, and the like. The preferred embodiment comprises a frame, hydraulic hoses, an hydraulic motor, a generator with 110v and 220v plug-ins, and a hydraulic fluid flow control assembly. Optionally, the present invention can be adapted to hydraulically operate devices such as pumps and compressors simultaneously with the electrically powered tools. Since the present invention uses only the hydraulic power and engine horsepower of the prime mover to operate or be moved between locations, it does not require a diesel motor, ignition system, fuel tank, cooling system, or wheels.

Abstract: Workability and operability of hydraulically-operated equipment is enhanced by optimally changing in accordance with the work content a responsiveness of an output signal relative to an input signal of each hydraulic control device, which constitutes a hydraulic system, at times heightening quick reaction capabilities, and at other times heightening steadiness. As a quantity of state of a load pressure signal of a hydraulic actuator, for example, is inputted to a response suppressing portion, and in accordance with a high-pass filter, a higher frequency fluctuation component in a pressure signal is extracted.

Abstract: A bi-directional power conversion system interconnects hydraulic and electrical power systems on-board a vehicle such as an air-craft, whereby the power conversion system can selectively convert available electrical power to needed hydraulic power or vice versa. The power conversion system includes a hydraulic machine (15) connected to the hydraulic system (10) of the vehicle, an electrical machine (20) connected to the electrical system (3) of the vehicle through a power converter and control unit (22), a rotational drive shaft (14) mechanically interconnecting the hydraulic machine (15) and the electrical machine (20), and a priority and safety control unit (26) that controls the operation of the system.

Abstract: A control system for an aircraft's electrically driven hydraulic pump. An electronic motor controller having closed loop feedback is utilized to directly control the prime mover speed in response to pump loading.

Abstract: This invention is for an object moving actuator composed of a stack of independently controllable layers which convert thermal exobaric pulses into mechanical motion. Each layer can be a lifter for moving the stack normal to the object to be moved or a tangenter for moving the stack tangentially to the object. Each layer has a plurality of chambers having a heat source and a thermal expansive material contained therein. The heat source is controlled by a controller to generate a heat pulse which expands the thermal expansive material thereby moving a rolling barrier to make the layer move normally or tangentially. Preferably two pair of actuator stacks work together to alternately engage and move the object. The first pair makes contact with the object by lifter motion and moves the object by tangenter motion while the second pair is lifted off the object and retraces to get into position to contact and translate the object.

Abstract: A control for a variable displacement hydraulic motor (12) is disclosed. The control includes an electrically controlled hydraulic servo valve (14) for controlling displacement of the hydraulic motor for varying position of a wobbler (28) in response to a servo valve control signal (92); a velocity transducer (72) coupled to a shaft (30) driven by the motor for producing a velocity signal (66) indicative of the velocity of the shaft; a controller (16) for producing the servo valve control signal, the controller including a first signal summer (70) which produces an output signal equal to a difference between a velocity command (68) and the velocity signal, the output signal being applied to an integrator (104) and to a proportional amplifier (76) to produce a wobble position command (82) which is a sum of outputs from the integrator and the proportional amplifier which is processed by the controller to produce the control signal.

Abstract: The precise and smooth control of the hydraulic fluid supplied to a hydraulic system, such as the lifting cylinders of a turret stockpicker, under varying operating conditions includes an optical encoder on the operator's control handle connected to an electronic control of a hydraulic pump motor, which s initially operated at a predetermined minimum speed, and a hydraulic valve which provides the initial control of hydraulic fluid under the control of an operator's handle. Because the pump is initially at a low speed, greater efficiency of the system is realized, an important feature in a battery operated vehicle. As the operator moves the handle from the off or neutral towards the fully open position, the hydraulic valve will open and reach its fully open position as the handle passes approximately the one-third on position.

Abstract: An auxiliary coupler pressure relief hydraulic system for off-road vehicles including a battery, an engine, an engine ignition system, a reservoir of hydraulic fluid, and a pump for providing hydraulic fluid under pressure. Quick couplers couple hydraulic fluid to an attachment mounted to the vehicle. An electro-hydraulic spool valve is connected to a source of pilot pressure and controls the flow of hydraulic fluid to the quick couplers in response to valve actuating signals. Forward and reverse auxiliary control switches are coupled to the spool valve and provide valve actuating signals resulting in fluid flow to the quick couplers in forward and reverse directions. Also included is an ignition switch having RUN, OFF and RELIEF positions.

Abstract: A servo system having a circuit for developing an error signal representing the deviation of a load condition from a desired condition represented by a command signal and forward and feedback paths at least one of which includes an impedance therein represented by a transfer function comprises a limiter receiving the command signal and connected to the error signal developing circuit for controllably limiting the command signal wherein the limiter has a variable saturation point and a circuit coupled to the limiter and to the impedance for controlling the saturation point of the limiter in accordance with the transfer function of the impedance to enable fast response without damage to an output device controlled by the servo system.

Abstract: A fail-safe electric actuator, for use with a control mechanism such as a valve, is disclosed. The actuator device eliminates the possibility of the control mechanism being locked in operative position by the interruption of electric power, by automatically and mechanically returning the control mechanism to its inopertive position as soon as current is cut off. This is accomplished by the release of a torsion spring, wound previously by the rotation of a fluid-driven vaned torque actuator in turning both the control-mechanism and the electric fail-safe actuator into operative position.

Abstract: An emergency supply system for maintaining the emergency flight control of a high-performance aircraft of aerodynamically unstable design having three energy systems, namely, two identical hydraulic systems, connected in parallel for redundancy, for actuation of the control surfaces of the aircraft required for its ability to fly, and an electric on-board system having at least one generator, a rechargeable battery and a non-rechargeable emergency battery, the three energy systems being interconnectible in terms of energy by a power transmission unit, and wherein the two hydraulic systems are divided into subsystems associated with single or several rudder functions which, if necessary, can be disconnected singly.

Abstract: An hydraulic control system is disclosed for energizing a load, such as the lift cylinder of an electric lift truck, with a minimum of power loss during the transition from zero to full energization, i.e. during the feathering range. An electric motor drives a positive displacement pump which supplies the flow requirements of different load circuits, one having a greater flow requirement than the other and requiring higher pump speed. A proportioning valve of the open center type provides full flow to the tank when the valve is closed and full flow to the load circuit having the greater flow requirement when the valve is open. A manually actuable lever actuates the valve through the feathering range with the pump motor in a low speed range and actuates a speed control switch to operate the motor in the high speed range when the valve is fully open.

Abstract: A power generating system comprising a hydraulic transmission driven by an electric motor. The hydraulic transmission drives electric generators for recharging the electric motor battery, and a speed reducing mechanism and reverse speed reducing mechanism before and after the hydraulic transmission, respectively, allow the system to operate in optimum efficiency.

Abstract: An electronic control system for a variable displacement pump comprises apparatus for sensing the actual position of the displacement determinative element and the actual rotational speed of the pump cylinder block, and for producing representative signals which are combined to produce a signal indicative of actual output flow rate. The displacement determinative elements position and the cylinder rotational speed are sensed directly by sensors mounted within the housing of the pump. The speed sensor is disposed in close proximity to, and aligned with marks inscribed on, the outer surface of the rotatable cylinder block. The volumetric efficiency of the pump is also sensed by and used to determine the actual flow rate.

Abstract: A power drive unit and control system therefor avoiding performance degradation which can occur in control of the variable displacement hydraulic motor of the power drive unit by measurement of the angle of a displacement-setting wobbler of the motor and the speed of the motor. This is avoided by sensing flow through the motor which provides an indirect measure of wobbler position and speed of motor operation. The power drive unit and control system therefor has a variable displacement hydraulic motor with a displacement-setting wobbler positioned by pressure applied to a servo piston by an electro-hydraulic servo valve. The control system responds to a speed command having a value dependent upon a position loop which determines the relation between the actual position of a load and a commanded position, with the control providing for a maximum possible speed of motor operation under a particular load condition with a substantially constant rate of fluid flow through the motor.

Abstract: A control having a primary work system, a secondary work system, a first fluid flow generating system, and a second fluid flow generating system is provided. A control signal delivering device is provided to deliver a control signal having a magnitude responsive to a relative location of a control valve between a first and second position of a control valve. A control signal receiving device receives the control signal and separately controls the flow rate deliverable from the first and second flow generating system in response to the magnitude of the control signal received. The control signal receiving device has a set point value which is representative of a preselected magnitude of the received control signal. The second fluid flow generating system is controlled to deliver fluid only in response to the magnitude of the received control signal having a value greater than preselected deliverable flow rate.

Abstract: A switch and valve assembly for inflating or deflating a pair of bladders mounted in the back and seat regions of a vehicle seat. The assembly houses two normally-closed valve assemblies and two normally-open electrical switch assemblies, with two pushbutton-actuated stems adapted to selectively either partially open the valve assemblies by partial depression of the pushbuttons to thereby bleed-off fluid under pressure from respective bladders, or to fully open the valve assemblies while closing the switch assemblies by full depression of the pushbuttons to thereby actuate the pump to provide fluid under pressure to fill the respective bladders as desired for operator riding comfort or support. Pressures in the two bladders may be changed individually or concurrently.

Abstract: This invention relates to an energy efficient variable displacement motor-driven power drive unit using a multi-variable feedback control system to control system output position and speed. More particularly, a variable displacement hydraulic motor connected to drive a load has a variable-position wobbler, with the position controlled by electro-hydraulic servo means including an electrically-operable servo valve which receives a control signal from signal summing means which has summed feedback signals representing speed and position of a load with a torque signal representative of wobbler position. The latter signal is mechanically inputted to the servo valve by means of a mechanical connection including a link connected to the wobbler and a spring interconnecting the link to the servo valve and with the link carrying a servo piston movable in a servo cylinder associated with the servo valve.

Abstract: This disclosure pertains to a completely digital, electrically powered servo wherein the servo actuator is minutely incremented at a frequency proportional to the magnitude of an error binary number. The binary error is derived from the difference of a binary reference representing the commanded position of the actuator and a binary feedback representing the position of the actuator. The direction of each increment has the polarity which reduces the difference between the reference and feedback binary numbers. The power unit of the servo is electrohydraulic; however, the servo is entirely electrically controlled and powered. Hydraulic fluid is confined to the power unit where it serves as a link between two solenoid driven piston pumps, a common mode volume adjuster and a hydraulic actuator. The direction the actuator is incremented is dependent on which of the two solenoids the error polarity directs pulsed electrical power.

Abstract: A control system for a hydraulic circuit having a variable displacement hydraulic pump, and an actuator driven by the pump, in which a pump control controls a displacement volume varying member of the pump based on an operating signal giving a command with respect to the position thereof and a detector signal indicative of the actual position thereof while restricting the operating speed of the member to a level below a predetermined maximum speed.

Abstract: A microprocessor (158) based control for a hydraulic pump motor (26) used to control the operation of a mast assembly (12) on a work vehicle (10). The speed of each function performed by the mast assembly (12) is programmable to one of a plurality of possible speeds. An additional function for performing lifting of the mast (12) produces incremental speed variations relative to incremental movement of a corresponding control lever (14). Each of the functions have a predetermined priority such that attempted operation of multiple functions results in a pump motor speed requested by the function of highest priority.

Abstract: An apparatus for use in controlling a variable displacement pump in a hydrostatic transmission comprises servo-positioning means for varying the displacement of the variable displacement pump, signal producing means for producing a first signal dependent on the rotational speed of the input shaft of the variable displacement pump and means communicating the first signal dependent on the rotational speed of the input shaft to the servo-positioning means to increase or decrease the displacement of the variable displacement pump as the rotational speed of the input shaft increases or decreases. A second signal dependent on the output pressure of the variable displacement pump is communicated to the servo-positioning means to act in opposition to the first signal to tend to reduce or increase the displacement of the variable displacement pump.

Abstract: The rotational speed of a hydraulic pump motor for a fork lift hydraulic control system is varied basically in accordance with the displacement of spools of manual control valves to allow the pressure supplied to servo cylinders to be smoothly increased. The rotational speed may also be varied in response to additional parameters such as the load to be moved by the servo cylinders, the amount of displacement of the load and the rate at which the spools of the manual control valves are moved to provide improved start free safe load handling characteristics.

Abstract: An electronic closed loop piston pump servo control system including a swash plate within the pump housing which controls pump output as a function of its position about a rotational axis, means for altering the position of said swash plate, means for producing electric signals representative of the desired and actual swash plate angular positions, and means for comparing these signals and producing a control or error signal to the means for altering the swash plate position as a function of these signal differences. The means for producing electric signals representative of the actual swash plate position includes a rotary potentiometer mounted in the pump housing and directly connected to the swash plate along a common axis of rotation. This potentiometer produces a d.c. signal indicating the angular position of the swash plate on this common axis.

Abstract: The invention relates to an electro-hydraulic control system for a power drive unit having a wobbler controlled variable displacement hydraulic motor wherein the electro-hydraulic control system causes the displacement of the hydraulic motor to match a load to be driven by a power drive unit output shaft coupled to the motor. The system results in the hydraulic motor displacement matching the load as a combined function of the input command signal, the actual wobbler position, as well as the velocity and position of the power drive unit output shaft.

Abstract: A fuel-saving energy storage vehicle drive system which saves fuel, primarily under stop-and-go driving conditions, by collecting, storing and using energy normally lost in the braking or deceleration of the vehicle, by automatically controlled operation of the engine under certain conditions, and by automatically controlled use of the stored energy and engine respectively as alternative or supplemental prime movers for each other for driving the vehicle. Subsystems for preventing waste of deceleration energy and stored energy are provided, and compact transmission layout and packaging are provided which facilitate installation of the new system in existing vehicles.

Abstract: The disclosure relates to improvements in a hydraulically-actuated control device used in an operation unit of treatment chair and the like in an interlocking relation with reciprocating movement of a hydraulic piston. The device is of the construction in which two control valves slow in closing and opening operation are disposed in the oil supply and discharge passages leading to a hydraulic cylinder having a hydraulic piston therein so as to prevent shock in starting and stopping of the operation unit by controlling opening and closing of the two control valves and operation of the hydraulic pump disposed in the oil supply passage.

Abstract: A fuel-saving energy storage vehicle drive system which saves fuel, primarily under stop-and-go driving conditions, by collecting, storing and using energy normally lost in the braking or deceleration of the vehicle, by automatically controlled operation of the engine under certain conditions, and by automatically controlled use of the stored energy and engine respectively as alternative or supplemental prime movers for each other for driving the vehicle. Subsystems for preventing waste of deceleration energy and stored energy are provided, and compact transmission layout and packaging are provided which facilitate installation of the new system in existing vehicles.

Abstract: A fuel-saving energy storage vehicle drive system which saves fuel, primarily under stop-and-go driving conditions, by collecting, storing and using energy normally lost in the braking or deceleration of the vehicle, by automatically controlled operation of the engine under certain conditions, and by automatically controlled use of the stored energy and engine respectively as alternative or supplemental prime movers for each other for driving the vehicle. Subsystems for preventing waste of deceleration energy and stored energy are provided, and compact transmission layout and packaging are provided which facilitate installation of the new system in existing vehicles.

Abstract: The hydraulic power system includes a single electrical motor for driving a fluid pump which supplies fluid under pressure to a plurality of series connected fluid motors, with the first motor in the series directly to the pump outlet and the last motor in the series to a fluid reservoir that constitutes the fluid source for the pump. The electrical motor is operable in response to a call for the actuation of any one of said fluid motors, and requires a maximum power output relative to the pump fluid capacity so that the fluid pressure and flow characteristics delivered by the pump satisfy the full load operating requirements of the last fluid motor in the series of motors when all of the other fluid motors are under full load operation.

Abstract: A control system is disclosed for use with pressure-driven loads, such as reversible motors. The system allows the loads to be driven at varying speeds and also allows the loads to be reversed. However, the system is so designed that an operator cannot subject the loads to pressure shock caused by abrupt changes in pressure by adjusting the system too rapidly. The system disclosed is suitable for use with either hydraulic or pneumatic loads.

Abstract: An electro-rheological fluid damped actuator having an actuator housing w a moveable element such as a piston and rod assembly disposed within the housing. The actuator further comprises a hydraulic circuit with an electro-rheological fluid disposed in the hydraulic circuit. The hydraulic circuit and rheological fluid provides an active and variable damping force on the moveable element. The damping force is controlled by the output of an electrical circuit which creates an electric field within the hydraulic circuit. The electric field will cause the viscosity of the electro-rheological fluid which is exposed to the electric field to increase or decrease in accordance with the magnitude of the electric field. The increase in viscosity of the electro-rheological fluid as it flows through the actuator provides an active damping force on the actuator which allows a more precise control of the output motions of the actuator.