Abstract: A pump displacement control device includes: a servo piston that changes a tilt angle; a flow rate control spool that is displaced corresponding to an input pressure; a power control spool that is displaced corresponding to a discharge pressure of the pump; a control pressure regulating spool that regulates a control pressure which controls the servo piston; and a feedback lever connected to the servo piston and the control pressure regulating spool. The feedback lever directly abut on either one of the flow rate control spool or the power control spool for regulating the control pressure.

Abstract: An electrohydraulic valve actuator assembly for an engine includes a movable engine valve, a movable spool valve, and a driving channel interconnecting the spool valve and the engine valve. The electrohydraulic valve actuator assembly includes an actuator operatively cooperating with the spool valve to position the spool valve to prevent and allow fluid flow in and out of the driving channel to position the engine valve. The electrohydraulic valve actuator assembly further includes a mechanical feedback interconnecting the engine valve and the spool valve to control the position of the spool valve.

Abstract: A control system for a pneumatic hoist limits the velocity or acceleration of a load attached to the hoist. The control system includes a controller and a valve. The controller provides a variable gain between an actuator, which controls the speed of the hoist, and the valve, which controls fluid flow into the hoist, thereby controlling the velocity or acceleration of the load. As the velocity or the acceleration of the load reaches a predetermined maximum value, the control system proportionally reduces the gain between the actuator and the valve, thereby closing the valve and reducing the velocity or acceleration of the hoist.

Abstract: A removable side shifter attachment attachable to the carriage bar of a lift truck has a frame shiftable with respect to the truck. The frame includes a shifter carriage bar for receiving a lift fork. A hydraulic cylinder attached to the truck carriage bar having rods contacting the frame at its sides is positioned horizontally forwardly of the truck carriage bar and between the truck carriage bar and the shifter carriage bar. The cylinder is positioned generally within a J-shaped portion of the shifter carriage bar so that the cylinder does not extend substantially above or below the carriage bar and does not appreciable add to the overall thickness of the apparatus. The cylinder further includes two axially aligned chambers separated by a central partition, each chamber containing a piston in contact with a respective rod, each piston dividing its respective chamber into interior and exterior portions.

Abstract: A removable side shifter attachment attachable to the carriage bar of a lift truck has a frame shiftable with respect to the truck. The frame includes a shifter carriage bar for receiving a lift fork. A hydraulic cylinder attached to the truck carriage bar having rods contacting the frame at its sides is positioned horizontally forwardly of the truck carriage bar and between the truck carriage bar and the shifter carriage bar. The cylinder is positioned generally within a J-shaped portion of the shifter carriage bar so that the cylinder does not extend substantially above or below the carriage bar and does not appreciable add to the overall thickness of the apparatus. The cylinder further includes two axially aligned chambers separated by a central partition, each chamber containing a piston in contact with a respective rod, each piston dividing its respective chamber into interior and exterior portions.

Abstract: A control system for a variable displacement hydraulic pump with a two-lever type of feedback lever mechanism. The control system comprises a pressure responding ram for causing, upon receiving pump output pressure or outside pilot pressure, a servo spool of a servo valve to be displaced, the servo valve for causing a larger chamber of a servo cylinder to be selectively supplied with the pump output pressure, the servo cylinder for controlling angle of inclination of a swash plate of the pump in order to control the pump output flow rate, a two-lever type of feedback lever mechanism for linking the pressure responding ram, the servo spool of the servo valve and the servo piston of the servo cylinder to each other.

Abstract: Pressure gain compensation for a single-stage servovalve of the jet pipe type. The pressure gain compensation is provided by a separate reciprocally mounted spool having a feedback wire connected between the spool and the ejector jet. The spool has a differential pressure applied across the ends thereof from the receptors disposed opposed the ejector jet. Movement of the spool applies a force feedback to the ejector jet which is proportional to the pressure differential across the receptors and is opposite the force applied to the ejector by the torque motor to thereby compensate for pressure gain.

Abstract: A servo system includes a tubular drive shaft journalled in a housing. A screw is engaged threadably with a nut which is fixed in the drive shaft. A driven body is secured to an end of the screw so that the screw can effect a rectilinear movement with the driven body but cannot rotate. A motor can rotate the drive shaft in an infinite angle through a gearing so that the drive shaft can move in a first direction continuously. Then, an end of a fork is rotated by an abuttment element which is sleeved on the drive shaft. At this time, the other end of the fork activates a hydromechanical servo, and hence a hydraulic driving unit, to move the drive body in a second direction which is equal and a opposite the first direction. After which, the drive shaft is moved back to the original position by the driven body. The driven body is therefore moved a predetermined distance.

Abstract: An electro-hydraulic proportional servoactuator is disclosed which has built-in fail-safe systems which cause the power turbine nozzles to return to a zero degree angular position in the event of either an electrical system failure or a hydraulic system failure, and features a toggling effect.

Abstract: A dual redundant servomechanism for moving aircraft control surfaces is disclosed. The servomechanism is of the type whose input commands, from the pilot of the aircraft, are transmitted electrically. Force fight, which is associated with such dual servomechanisms when they are connected to a common aircraft control surface, is minimized. This is accomplished by providing the control system for each servomechanism with input signals which are electrically summed. Each control system includes electrical transducers which provide a signal indicative of actuator position and the pressure associated with the hydraulic motor used in each servomechanism.

Abstract: A hydraulic force booster for actuating master cylinder pistons in brake systems of automotive vehicles, comprises a lever system including two levers (33,34) pivotably interconnected by way of a journal (35). The second lever, by way of a coupling (45) is in communication with a set element (46) provided at the control piston (13) of a brake valve (9). The coupling (45) comprises a coupling element (53) provided at the second lever (34), and at least one guide surface provided at the set element (46) is connected to the control piston (13) by way of joint (47) and, at the other end, by providing another joint (48), is guided in a substantially co-axial housing bore (49). The coupling element (53) can be formed by a loose roller thereby substantially precluding that transverse forces be exerted on the control piston (13) of the brake valve (9) likely to result in lockings.

Abstract: A brake actuating system for use with a brake assembly having a body, a brake actuator and at least one friction member cooperating with the actuator and the body to brake a brakeable member. The invention provides a system with improved operator "feel" of braking force, and has a first fluid valve receiving pressurized fluid and controlling actuation of the actuator, with a signal input adapted to receive a signal from an operator and to be responsive to extension of the actuator. In this way, a change in brake signal from the operator produces a corresponding change of extension of the actuator which produces a corresponding change in fluid output signal to the actuator.

Abstract: A system (10) of parallel hydraulic actuators (15) and (20) includes a pair of laterally spaced, longitudinally extending, discrete feedback levers (180) and (185) which independently provide feedback signals to a pair of actuator control valves (50) and (55) with enhanced accuracy and minimal lateral loading of the system.

Abstract: A hydraulic power booster arrangement includes a brake valve which is arranged substantially in parallel to a booster piston and which is operative for controlling the connection from a pressure chamber to a auxiliary pressure source or to an unpressurized return reservoir. To control the movement of the brake valve, there is provided a multipart lever actuation mechanism including a support lever and at least one control lever which are pivotally connected to one another intermediate their respective ends. One end of the support lever is pivotally mounted on a retaining member which is rigidly connectible to the power booster housing. The housing is provided with a mounting hole through which the lever actuation mechanism is adapted to be inserted into the pressure chamber and which is adapted to be closed by the retaining member.

Abstract: The device comprises a directional valve body which is movable with respect to guide means, and a spool which is slidably mounted in the body and connected to a control lever. The latter is pivotally mounted on a pin which is fixed relative to the body. This pin is carried by a support which is mounted on the body and means are provided for adjusting the position of the support relative to the body.

Abstract: A hydraulic brake booster which has an input valve control member acting through a controlled rate spring and through a lever pivoted on the booster housing in the power chamber to move a spool valve in a bore parallel to the power piston so that the input is strictly through the spring. The lever has no connection to the power piston. The control valve is hydraulically unbalanced to a release position and is also urged to the release position by a valve spring. This maintains a proportion between the input force due to the reaction spring, through which input force is applied, and booster pressure. Upon power runout or failure the input and reaction piston overtravels and contacts the output rod to move that rod without moving the power piston.

Abstract: A hydraulic brake booster includes a housing (10) which movably supports a piston (16) and a control valve (20). The housing also substantially defines a pressure chamber (22) for receiving fluid pressure via the control valve (20) to move the piston (16). The housing (10) is formed from a first cylinder (90) and a second cylinder (92) which is substantially perpendicular to the first cylinder. The first cylinder receives the piston and the second piston receives the control valve. A linkage assembly (40) imparts movement to the control valve during a brake application.

Abstract: A hydraulic brake booster includes a housing substantially defining a pressure chamber and movably supporting a control valve and a piston. An input assembly extends into the pressure chamber and cooperates with the control valve to communicate fluid pressure to the pressure chamber. The input assembly is pivotal relative to the piston to a first position wherein fluid pressure communicated to the pressure chamber acts against the piston to move the same while the input assembly remains substantially stationary in the first position. In particular, the input assembly includes a lever with a slot for receiving a portion of the piston. When the lever is pivoted to the first position, the piston portion moves within the slot from one end of the slot to the other end. A pair of springs extend between the housing and the piston and lever, respectively, to bias the piston and lever to a rest position abutting the housing.

Abstract: A parallel actuator pair force transmission system including a mechanical feedback apparatus capable of detecting differential movement between the actuator pair and providing a feedback signal to control valves phased in such a manner as to correct for and counteract the differential motion between the actuator pair.

Abstract: A fail-safe fluid control valve comprises a first sleeve accommodated in and fixed to a valve housing, a second sleeve slidably received in the first sleeve, and a valve spool slidably received in the second sleeve. The first and second sleeves are properly formed with grooves and ports while the valve spool is properly formed with spaced large diameter portions. When there occurs such an abnormal condition that the valve spool is jammed or stuck to the second sleeve, the second sleeve is axially moved in unison with the valve spool by an input lever for actuating the fail-safe control valve under the same condition as a normal condition in which the valve spool is axially moved by the input lever.

Abstract: A position control valve provided for controlling a first hydraulic unit is also operable to control a second hydraulic unit. The apparatus comprises the first hydraulic unit for raising and lowering a primary working implement, the second hydraulic unit for raising and lowering a secondary working implement, the control valve for controlling the first hydraulic unit, and a feedback mechanism for returning the control valve to its neutral position for every position of a control lever in operative relation to the upward or downward movement of the primary working implement. A guide plate for the control lever for operating the control valve provides a second operation range for the secondary working implement having a neutral position corresponding to a maximum lift position for the primary working implement. Elastic regulating means is mounted on the guide plate for the second operation range to set the control lever in position.

Abstract: A control system is specifically designed to improve the performance of an aircraft or other vehicle having undesirable dynamic characteristics. For this purpose there is employed a compensator, either hydromechanical or electrical (hydro-electrical) depending upon the basic control system, which is incorporated into that system and modifies command inputs to the directional controls of the vehicle. This compensator is designed and preset to impose predetermined dynamic characteristics on the command inputs so as to create a resulting input which eliminates or substantially diminishes the undesirable dynamic characteristics.

Abstract: The disclosure relates to a valve operator which may be used for controlling an inlet valve to a steam turbine. The valve operator has a trip position for rapidly closing the steam inlet valve and a reset position whereby the position of the steam inlet valve may be hydraulically controlled. The valve operator includes a manual operator and a remote powered operator. A trip relay and a reset pilot are fluidly interconnected so that the valve operator must be reset after each trip. The valve operator also includes a valve position feedback mechanism.

Abstract: A remote control system controlled by fluid pressure in which a master and a slave each having a mechanical position feedback mechanism therein are installed in spaced position from each other and connected via only a pilot fluid pipe to form an open loop control system as a whole. A control rod in the master can be moved by a small force independently of the magnitude of a load applied to the slave and an actuating piston in the slave is positioned in accordance with the amount of movement of the control rod in the master.

Abstract: A power assisted pedal assembly comprises a brake pedal pivotally connected at one end to a lever which is pivotal about a fixed point, the brake pedal having a connection intermediate its ends with an actuating member of a master cylinder to apply an operating force to the actuating member, and a power assistor operable in response to movement of the brake pedal to apply an assisting force to the brake pedal. The power assistor has a force-transmitting member which is separate from the actuating member and which is in force-transmitting engagement with the lever on or close to the line of action of the force applied to the actuating member by the brake pedal. The brake pedal and the lever pivot about the fixed point when the power assistor is operative and the pedal pivots about a point intermediate the fixed point and the connection between the lever and the actuating member upon failure of the power assistor.

Abstract: A train of fluid pulses representative of a process variable is processed by digital fluidic circuits and is then converted into an analog fluid pressure signal which is compared to an analog command signal, the difference between the two compared signals being caused to appear in the form of a displacement. This displacement is amplified by means of a fluid servo system, the amplified output of which is utilized for directly driving a control element for a process.

Abstract: A generally conically shaped cam formed internally of the actuator piston and a follower connected to a rotary shaft serves to provide a position feedback signal within a minimum of space.

Abstract: A hydromechanical servo system having mechanical feedback is stabilized by damping the control valve and providing limited motion yieldable means for allowing limited yielding movement of feedback means relative to biasing means which biases such feedback means to a passive position.

Abstract: A vehicular power steering system including a primary hydraulic circuit for operating the steered wheels and a secondary hydraulic circuit for operating auxiliary equipment such as an implement or the like which may be attached to the vehicle. The system includes a fluid controller for controlling the flow of pressurized fluid from a power pump to the primary or steering circuit and the implement or secondary circuit. The fluid controller includes a valve mechanism which is constructed and arranged to provide the primary hydraulic circuit with pressurized fluid in the amount necessary to produce the desired steering maneuver while furnishing the secondary hydraulic circuit with the excess pressurized fluid supplied by the power pump. Thus the requirements of the primary hydraulic circuit may be always satisfied and have priority over the requirements of the secondary circuit in all modes of operation. .Iadd.