Electrically operated (275) (361)

A device for monitoring the relative position of synchronously moved valve cases in safety valves controlling pneumatic or hydraulic drives. Fixedly attached to each valve case and symmetrically disposed one to the other is a member of a metallic material, arranged proximate to the free ends of a pivotally...     

A mechanical feedback controlled valve regulates the fluid flow into the vane or piston compartment for controlling the direction, position, velocity, acceleration and/or deceleration of the output shaft.

A control valve for a variable displacement pump or motor. The valve includes a pair of solenoids which are independently actuatable to port relatively high pressure fluid to their respective servo motor. A shuttle valve actuated by the high pressure fluid is used to simultaneously port the fluid from...     

A normally closed solenoid valve operates conjunctively with a two position pilot valve to limit the amount of engine braking through the drive train of a vehicle by reducing the drive relief valve setting in the disengaged side of a hydrostatic transmission. A second normally closed solenoid valve operates...     

A fluid system having a source of fluid pressure such as a fluid pump connected to a fluid user such as a fluid motor is provided with a directional control valve between the fluid source and the fluid user for selectively controlling its direction of movement. The directional control valve is a three-position,...     

A differential pressure sensing valve has an axially shiftable spool including axially-spaced spool areas on which a pair of pressure sources connectable with such valve act in a predetermined direction with spool shifting force. Biasing means normally biases such spool with spool shifting force in a...     

An actuator device includes a chamber partly bounded by a movable wall and connected to atmosphere through a permanently open orifice and an electromagnetic valve which is maintained in a closed position when de-energized and which controls the connection to said chamber of a volume of gas at other than...     

A safety control valve for pneumatically operated cyclic machines, such as power presses and press brakes, including a pair of solenoid valves connected to a pneumatic pressure source and adapted to operate as a series flow when the system is on, and a parallel exhaust when the system is off, and with...     

An electrohydraulic proportional actuator for converting an electrical input signal to proportional mechanical output. Fluid power may be derived from pressurized fuel or lubricating oil of an associated engine. The actuator may be used to drive any engine function requiring modulated control. The mechanical...     

A four-way fluid flow control valve for selectively interconnecting opposite sides of a fluid motor with a source of fluid pressure and a low pressure return line for driving the motor in opposite directions. A clevis-like, bifurcated metering member has opposed, cup-shaped elements at its bifurcated...     

A dual lever control mechanism is disclosed for actuating a pair of control devices individually having first and second modes of operation, including a stationary support, a first lever arrangement pivotally mounted on the support for selectively moving both of the control devices into either their...     

A hydraulic circuit for operator pre-selection in one exemplary embodiment of the extension of a lift truck upright which utilizes a fixed displacement hydraulic motor operating to adjust either a rotary switch or a potentiometer which is connected to a valve for interrupting the flow to the lift cylinder...     

A springless impact device including a piston-cylinder mechanism having at least one preselected coacting port and passageway operatively connected to a valve pressurized fluid control apparatus which selectively feeds and exhausts pressurized fluid to and from the device in a predetermined manner. There...     

A servo-operated fluid flow control valve includes a valve body housing a main valve which defines with the body an inlet chamber, an exhaust chamber, and a control chamber. An auxiliary valve is interposed between the control and exhaust chambers and is movable relative to the main valve by a jack controlled...     

A device for cutting trees has two chain saws. For engaging the tree the chain saws are pivotable towards each other with the aid of feeding means. The power supplied to the saw chains is sensed and when an upper power limit is reached the feeding means is irreversibly set to the next lower of a small...     

An hydraulic power system comprising a dual acting work piston adapted to be operatively connected to an external mass to be moved, the piston being instantly directionally responsive to a pair of control valves adapted to be sequentially opened and closed to actuate the work piston for movement in opposite...     

A valve assembly is provided in which a first poppet member and at least one subsequent poppet member each having a valve face engageable with a valve seat between first and second passages. A first and a subsequent pilot valve is operative for selectively establishing communication between a fluid reservoir...     

A modular control device which may be used separately or in predetermined multiples to provide desired detection and correction functions along with appropriate control functions normally associated with current day aircraft flight control. The module includes a housing which makes provisions for a plurality...     

A controlling apparatus for bulldozer blade in which the control is carried out automatically or manually. The apparatus comprises an electromagnetic valve for controlling a cylinder of the bulldozer blade, a switch for changing the control of the bulldozer blade automatically or manually, a safety relay...     

A fluid pressure drive device including a primary drive portion operated by receiving an operational command, and a secondary drive portion operated due to the operation of the primary drive portion. In this fluid pressure drive device, at least parts of movable members in the above both drive portions...     

A fast-acting valve actuator utilizes a spring driven pneumatically loaded piston to drive a valve gate. Rapid exhaust of pressurized gas from the pneumatically loaded side of the piston facilitates an extremely rapid piston stroke. A flexible selector diaphragm opens and closes an exhaust port in response...     

A feathering valve system for modulating the fluid inflow to a selected one of first and second chambers of a movable biased assembly. A controller is electrically coupled to a first and second solenoid operated pilot valve assemblies for selectively (1) maintaining the pilot valve assemblies in a valve...     

Two embodiments of closed loop electro-fluidic controlled systems are disclosed for controlling the velocity, acceleration, torque, force of pressure applied to a member. The system includes a source of electrical command signals correlated to the desired magnitude of the parameter being controlled,...     

A valve system for an unbalanced load having a first two stage valve assembly operable for raising the load and a second two stage valve assembly for lowering the load. Each of the second stages has a poppet with a parabolic contour which is dimensioned with orifice parameters to provide substantially...     

A hydraulic control system for use in machine tools, construction machines, hoists and the like, with a driven unit the hydraulic circuit of which is controlled by one or more electromagnetically positioned slide valves, and with an arrangement for automatically regulating the velocity of the hydraulic...     

In a pressure control device for applying modulated pressure to a servo chamber of a vacuum servomotor in response to an output signal from an electric control circuit, the control device includes a modulator valve for modulating pressure in the servo chamber, a solenoid winding to be energized by the...     

A regulation system for steam turbines which includes a servomotor controlled by a servovalve (1) and two safety valves (31, 31') controlled by two electrically-operated valves (19, 19'). When the control inlet (7) of the servomotor is connected to the drain pipe (6) by at least one of the safety valves,...     

An improved pneumatic operating mechanism construction is provided including the usual stationary operating cylinder with a movable reciprocally-operable driving piston member movable therewithin, and having an extremely-fast pneumatic valve-device cooperable with a movable valve-sealing member attached...     

A fail-fixed servovalve is provided for use in a digital control system. The servovalve is comprised of a deflecting means which deflects a jet pipe in response to an electrical input signal. Fluid flowing through the jet pipe causes a spool to translate within a sleeve, thereby allowing pressurized...     

A vacuum servomotor comprises a cup-shaped casing having a bottom wall provided thereon with a vacuum nozzle for connection to a source of vacuum and an air nozzle in communication with the atmosphere, the casing being integrally formed with a cylindrical support structure extending inwardly from the...     

A fluidic driver amplifier for a servovalve has its controllably directed fluid jet differentially divided by a divider element which moves with a main valve piston in a manner to equalize the differential pressure received from the jet when the piston reaches the commanded position. In order to permit...     

A hydraulic valve device for controlling a double action, piston-type servomotor adaptable for steering a self-propelled agricultural vehicle and including a pair of identical interconnected valve groups, with each group connected to an opposite side of the servomotor and further connected to a source...     

A simplified fail-fixed electrohydraulic servovalve for operating with a source of fluid under pressure, and a piston translatably disposed within a bore. The piston has a rod side face area which is less than its head side face area and translates in a first direction for electrical input signals above...     

A pneumatically actuated adjusting device, particularly for throttle flap adjustment on mixture-compressing combustion engines, with a diaphragm held between a housing upper portion and a housing lower portion. This diaphragm forms a vacuum-charged working chamber with the housing upper portion. With...     

A mechanism for controlling the position of a movable member and for locking it in any desired position comprising a hydraulic displacement device movable with the member and a slide valve hydraulically connected to the displacement device to control flow of liquid to or from the device. The slide valve...     

A 4-way, 2-position pilot valve having two ball valves seatable at approximately the same time without a precise spacing.

A compressed air engine having a throttle with compressed air being supplied to the throttle. The engine includes at least two cylinders each having a reciprocating piston therein. Air is supplied from the throttle to the cylinders to drive the pistons within the cylinders. A crankshaft is coupled to...     

A system for regulating the flow of a fluid in dependence of an input signal includes a valve housing, a valve between an inlet and an outlet of the valve housing, a cylinder substantially closed off from the cartridge valve housing, and a piston in driving connection with the valve, and movable within...     

An electromagnetic valve assembly including a housing, a diaphragm member provided in the housing and defining first and second chambers therein, a first heat conducting plate member secured to the diaphragm member, a heat conductive output member secured to the first heat conductive plate member and...     

The invention relates to an electrohydraulic control assembly of the type having a slide valve unit for controlling the operating direction of a hydraulic servomotor. The assembly includes a bridge circuit between the pressure source and the drain tank which has a pressure operated valve in each of its...     

A hydraulic servo valve suitable for controlling flow of a pressurized fluid in dirty and explosive environments, comprises a control valve actuated by a contamination-free sealed pilot circuit of electroviscous fluid commanded by electroviscous valves requiring minimal electrical power. Fluid is circulated...     

A hydraulic drive for an electrical switch is disclosed including magnetically operated control signal organs for initiating closing and opening of the electrical switch which is hydraulically driven by a drive with a differential piston moving in a drive cylinder. A switch-over control valve is employed...     

A pneumatically operated speed governor (26) for moving an engine throttle member (10) for controlling the speed of a vehicle includes a pneumatically operated actuator having an output connected to the engine throttle member. A pivotally mounted valve member (44) is positioned intermediate a vacuum...     

A dual solenoid pneumatic pressure control valve having two oppositely acting solenoids, each solenoid containing a valve means responsive to solenoid activation signals for controllably opening one of a plurality of pressure communication conduits disposed within the body of the valve to enable modulated...     

A device for moving filter plates from one end of a filter press to the other end, includes carriages which selectively couple to each of the plates and which are driven to slide along the frame members of the press by a hydraulic motor. A control means is provided to control the operation of the hydraulic...     

Disclosed is a pump comprising a rotatable barrel, a tiltable pump cam, and a proportional servo actuator operatively connected to the pump cam to affect the angle between the pump cam and the axis of the barrel.

A hydraulic control system for use in machine tools, construction machines, hoists and the like, with a driven unit the hydraulic circuit of which is controlled by one or more electromagnetically positioned slide valves, and with an arrangement for automatically regulating the velocity of the hydraulic...     

In a hydraulic elevator, in which fluid is pumped to and from a tank into a piston to raise and lower the car, the flow of fluid is controlled by an apparatus which includes an electric motor that opens and closes a single valve to control the motion profile of the elevator car.

An improvement in facility management systems that allows an electronic control unit to be interfaced with a pneumatic cylinder unit. The digital pneumatic modulator of the improvement includes a solenoid valve controlled pneumatic input port, a solenoid valve controlled pneumatic exhaust port, and a...     

An energy conserving air motor with rotary actuation includes a pair of cooperating different diameter pistons coaxially arranged and connected rigidly to one another by a central connecting member provided with spur gear section adaptable of receiving a meshing pinion assembled inside an elongated housing...     

A servovalve apparatus comprising a servovalve and a force motor operatively connected to a valve element of the servovalve for driving the valve element. The force motor includes an annular magnet, and first and second members cooperating with each other to define therebetween an annular gap concentric...     

An electrohydraulic set device includes, as an output element, a piston which is operable by a hydraulic pressure against the action of a return force. The hydraulic pressure is led to the working side of the piston via a valve passage. The valve passage is opened and closed by an electromagnet operated...     

An electro-pneumatic door control apparatus for use on public vehicles and including reversing mechanism for changing the direction of door movement, either automatically or operator-initiated, in the event of an obstruction in the door. The control apparatus further includes a flip-flop for recording...     

The invention contemplates a prestressed rolling mill incorporating a system of hydraulically operated load-transfer blocks, wherein the blocks are of unitary construction and bodily interposed between vertically opposed regions of upper and lower back-up roll chocks, at the respective inlet and exit...     

Pressurization of closing and opening chambers of a door operator is controlled by first and second magnet valves coupled to the source of air. These valves are alternately energized by a switching network, e.g., a flip-flop, when sequentially actuated to close and open the door. The second magnet valve...     

An electropneumatic door valve for use with pneumatic door operations as are used on mass transit vehicles. The single valve housing arrangement provides either a through passageway or a throttled passageway for pressurizing the opening or closing chamber of a pneumatic door drive unit. Provisions are...     

In a high pressure hydraulic system a slave unit is supplied with fluid from a source through a control valve assembly. The assembly has a valve mechanism to control flow between ports communicating with the source and slave unit. The valve mechanism has two members, a first member controlling flow through...     

A vacuum actuator having a vacuum chamber and an atmospheric chamber separated from each other by means of a diaphragm, and an actuator rod connected at its one end to the diaphragm and extending across the atmospheric chamber to the outside of the actuator so as to be connected to an object to be actuated....     

A hydraulically-operated breaking device of this invention uses a hydraulically-operated differential piston for driving an electric circuit switching unit, and making and breaking pilot valves for actuating the differential piston. In this device, a control valve operated by the action of the pilot...     

A pneumatic door control equipped with a door control valve for operating a door drive to an open or a closed position. The door control valve has an opening and a closing solenoid-operated pilot valve and an opening and closing spool valve, each operable to a passage or a vent position. A shuttle valve...     

A pressure regulator includes an inlet adapted to be connected to a pressure source and a chamber in which the pressure is to be regulated. An orifice is provided between the inlet and the chamber for metering the flow of hydraulic fluid therebetween. In addition, regulating means is provided adjacent...     

A vacuum responsive switch for detecting a failure in creation of a control vacuum within the control diaphragm chamber. A solenoid valve is provided which functions to equalize pressure within one of a power diaphragm chamber and a leak chamber with the other when vacuum represented by a signal from...     

A control arrangement for a hydraulic motor has an adjustable pressure medium supply device with a container, an unblockable check valve with a control connection, a plurality of chambers including a supply chamber, a motor chamber, first and second return chambers, and a control chamber, a control slider...     

An electro dynamic set device including an output set element, a piston having a piston rod and operable against the action of a force of hydraulic pressure and means defining a valve passage which communicates with an operating side of the piston to which hydraulic pressure is supplied. The passage...     

A first front face of a main control spool of a main control valve is loaded with a constant pressure, whereas the opposite face is loaded with a controlled pressure to control the fluid passages to and from a hydraulic actuator. The control pressure is adjusted by means of a two-edge control of the...     

A continuously variable transmission (2) is constructed utilizing a constant displacement pump (4) of fixed fluid power stroke, rather than a variable displacement pump with a variable pump stroke. A fluid motor (14) is driven by the pump and has an output stroke. Means (22) are provided for varying...     

An actuator for controlling the pressure in an internal space defined by a spring-biased diaphragm and a housing by solenoid valve. The internal space is selectively communicated with a negative pressure port or an atmospheric pressure port through a first solenoid valve. The pressure in the internal...     

A device of this nature incorporates at least one control piston displaceable within a casing, the casing having at least one venting nozzle authorizing the insertion of the piston into one of its possible operating positions, which nozzle may be shut off by means of an electromagnetically operated closing...     

The invention relates to a pneumatic setting device having oppositely operable magnetic valves for alternately pressurizing and exhausting expansible chambers formed by one or more diaphragms to which a reciprocatable setting element is attached. In this construction a return spring may be omitted.

An electrohydraulic servovalve which includes as an integral part thereof a monitor valve which senses the absence or lack of system pressure in the first or second stages of the valve and translates in the absence thereof to deactivate load control. The torque motor of the electrohydraulic servovalve...     

A servo valve comprising a source pressure valve whose inlet port receives a source pressure and whose outlet port communicates with the output of the servo valve, a pressure relief valve, which may operate independently from the source pressure valve, whose inlet port communicates with the outlet port...     

A hydraulic system in which a pilot operated hydraulic four-way main valve (11) controls the direction and rate of fluid flow to a hydraulic load (13), includes a flow sensor (15) which is capable of operating bidirectionally and may therefore be located in one of the service lines (25, 26) from the...     

A valve assembly for controlling fluid flow between a fluid source and a load has an intake valve having a valve body displaceable between a closed position preventing flow through the intake valve and an open position permitting such flow and an output valve having a valve body displaceable between...     

A cylinder driving apparatus, wherein a head chamber and a rod chamber of a cylinder for driving a load upwardly and downwardly are communicated with a pressure accumulation tank by way of a balance pipeway equipped with an electromagnetic proportional flow control valve and a recycling pipeway equipped...     

A pilot operated relief valve has a main relief valve (10) and a pilot relief valve (31) connected between a control chamber (23) and drain. A restriction (16) connects the control chamber (23) to the inlet chamber (22) which is separated from the control chamber by a piston (24) integral with the main...     

A system and method for pulse-width modulation of multiple solenoid-operated valves in an electrohydraulic servo system employing a microprocessor-based digital controller. Solenoid-energization pulse widths are identified by comparison of operator command input signals to feedback signals responsive...     

The hydraulic system of this invention is for operating a tree processing implement on a work vehicle so that during a first part of an operating cycle the implement is supplied by two hydraulic pumps jointly, while during another part of the operating cycle the implement is supplied by only one of the...     

A brake booster can switch operating mode from a positive-pressure mode using a signal-controlled fluid pressure supplier to a vacuum-pressure mode and vice versa. The booster includes a booster converter holding both an air valve and a vacuum valve of the booster closed in the positive-pressure mode...     

(a) Hydraulic servo motor comprising a jack (1, 14) intended to be connected by its rod (3.sub.1, 3.sub.2, 15.sub.1) to a moving member to be displaced and accurately positioned, said jack being completely filled with liquid; (b) Servo motor characterized in that the displacement of the piston (2) is...     

A hydraulic servo actuator has an outer case, a rotatable shaft extending through the case, an input sleeve rotatably mounted on the shaft and having hydraulic fluid supply and discharge passages therein and having surface grooves communicating with the passages, an output member on the shaft and movably...     

A hydraulic control arrangement for height regulation of an agricultural vehicle has a control valve with a control slider provided with a first piston portion with a control edge and a second piston portion with a throttle point. In the positions of neutral and lifting of the control slider the control...     

A hydraulic lifting and lowering system for battery-powered lift trucks includes an electronic control system which reduces or limits operator selected lifting commands in accordance with the current being drawn by an electric motor connected to drive a variable-displacement pump, and in accordance with...     

A vacuum actuator having a vacuum chamber and an atmospheric chamber separated from each other by a diaphragm, and an actuator rod connected at one end to the diaphragm and extending across the atmospheric chamber to the outside of the actuator so as to be connected to an object to be actuated. At least...     

The point at which pump out pressure exceeds load is sensed to provide a point for scheduling flow to an actuator in a hydraulic system. Flow is controlled by a stepper motor (28) that moves a flow control valve (27). The steps needed to achieve fixed flow changes are greater for high flow positions....     

A full hydraulic power steering system for a forklift truck is disclosed wherein in order to correct the position of a steering wheel in relation to an actuator for a steered wheel, hydraulic fluid is discharged from a portion of hydraulic fluid line means interconnecting a steering unit operable by...     

A control system for a hydraulic circuit having an on-off valve interposed between the control valve and the actuator for allowing and blocking a flow of hydraulic fluid therebetween in which the control valve and on-off valves are actuated and switched in accordance with an operation signal from an...     

The apparatus disclosed herein provides controlled operation of a pneumatic actuator by effecting charging and discharging of the actuator through an intermediate step volume, the pressure in the step volume being regulated as a respective function of the existing pressure in the actuator during charging...     

The invention relates to a 5/3-valve, which contains two separately controllable control members which are arranged coaxially with one another in the valve housing, are movable independently of one another and each bear two sealing surfaces which in the two end positions of the relevant control member...     

A hydraulic valve assembly which can be used for controlling a motor or the like includes a first directional control member which selectively allows hydraulic fluid to flow from an associated hydraulic pump through a hydraulic fluid circuit to an associated reservoir and to an associated hydraulic motor....     

A direct drive servo valve includes a housing and a series of conduits connecting the housing to a fluid pressure source and to an associated actuator, a sleeve in the housing having a plurality of passageways interconnecting the conduits and a spool valve member rotatable within the sleeve to connect...     

In hydraulic control devices comprising a two-way flow regulator in a resoir return passage, in which the flow regulator comprises a metering restriction and a pressure equalizer including a control piston with the piston ends disposed in control chambers and subjected to the action of control pressures,...     

A hydraulic actuator for automobiles includes a hydraulic actuator body composed of a hydraulic cylinder and a plurality of solenoid valves, and an electric control circuit disposed adjacent to the hydraulic actuator body for controlling the operation of the solenoid valves. The electric control circuit...     

An electronic tractor hitch control system in which the position of an implement hitch relative to a tractor can be set using a main control operable by a tractor operator from his normal location on the tractor and can also be set using a secondary control located at a location remote from the normal...     

Electrically controlled combined valve/cylinder apparatus. The apparatus includes a housing having a cylindrical body and spaced first and second end walls closing the body. A cylinder is positioned inside the body and a piston is positioned inside the cylinder for reciprocal movement. A control ram...     

A pneumatic constant-velocity running apparatus employing a diaphragm type actuator in which a portion or the whole of a control circuit for the actuator is made of a hybrid IC and the hybrid IC portion with a protector is fixedly mounted onto the outer surface of an housing of the actuator. The apparatus...     

In a motor vehicle such as a truck or the like having a battery-operated low voltage electrical system, an hydraulically powered system for operating one or more high power hydraulic rams or the like and a pneumatic system for regulating the operation of the hydraulic system, the improvement wherein...     

A bistable electronically controlled fluid powered valve actuator for use in an internal combustion engine of the type having engine intake and exhaust valves has a piston reciprocative in a cylinder housing for driving the engine valves to open and close. Control valves are mounted separately from the...     

A bistable electronically controlled fluid powered valve actuator for use in an internal combustion engine of the type having engine intake and exhaust valves has a piston reciprocative in a cylinder housing for driving the engine valves to open and close. Control valves are mounted separately from the...     

An electronic pneumatic limb control system for a pneumatically actuated flexible limb is disclosed. The system includes a computer for providing signal data corresponding to a plurality of successive events of air introduction and non-air introduction, respectively, into the flexible limb during a predetermined...     

A hydraulic operating apparatus for a circuit interrupter comprises a conversion unit for converting input information from the exterior concerning a speed control pattern into an electrical signal for driving a linear or servo motor according to the closing and interrupting commands, the motor drive...