Abstract: A fluid pressure operable servo positioner for selectively positioning a mechanical member or lever by a power cylinder selectively positionable in accordance with the degree of operating fluid pressure supplied thereto through a control valve device at a pressure determined by the degree of a selectively variable control pressure supplied to the control valve device, the power cylinder including a counteracting spring for balancing the force of the operating pressure to maintain the power cylinder in the selected position and a cam member engaging the control valve device and positionable according to the position of the power cylinder for maintaining the control valve device in the selected pressure supply position.

Abstract: A pneumatic fastener driving tool in which a piston-driver assembly is moved in opposed working and return strokes within a cylinder. Vent passage means of a predetermined area are provided adjacent the lower end of the cylinder to permit greatly increased velocity on the working stroke. Valve means may be provided for the vent passage to enable the use of air under pressure to drive the piston in a return stroke.The cylinder may be defined by an axially movable sleeve, which cooperates with sealing means to provide one or more valving functions.

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 motor grader including a wheeled main frame and a drawbar structure attached thereto is disclosed wherein a circle-mounted working implement, such as a blade or the like, is supported on the drawbar by improved guide shoes. The improved guide shoes include surfaces in engagement with both upper and lower surfaces of the circle at all times and remotely controlled mechanical apparatus for varying the frictional forces exerted by such guide shoes on the circle, whereby undesirable effects due to wearing of the engaging surfaces in operation are reduced.

Abstract: A servoactuator for stopping a ram in its existing position or retracting the ram at a fixed rate to a locked position.

Abstract: A load supporting hydraulic system having a pilot operated main control valve is provided with pilot controlled load check valve operative to permit free flow of fluid from said control valve toward the load supporting means of the system in response to pilot pressure and to block fluid flow from the load supporting means toward the control valve. The system includes vent valve means operative with the main control valve to permit the load check valve to be opened by fluid pressure in the load supporting means to allow fluid flow therefrom to the reservoir.

Abstract: A blind riveter has a housing with a tubular body and a nosepiece containing a rivet-mandrel-gripping chuck extending transverse to this body. The body is provided with three in-line tubes constituting a liner separated by two partitions so as to form three compartments each provided with a respective longitudinally reciprocal piston. A stem interconnects the three pistons and is provided at the forward end with an end piece engaging a roller on the long arm of a bell-crank lever pivoted on the housing and having a short arm pivoted on a puller body carrying the rivet-gripping chuck.

Abstract: A fluid actuating device for an electric switching apparatus such as a high-voltage power circuit breaker or the like includes an actuator for actuating the electric switching apparatus. The actuator includes a cylinder and an actuator differential piston movable in the cylinder between first and second positions corresponding to the open and closed positions of the switching apparatus. The actuator differential piston has two end-faces for receiving fluid pressure force and one of the end-faces has a larger surface area than the other one of the end-faces. A pressure fluid supply supplies fluid under pressure and is connected to the actuator for continuously supplying fluid under pressure to the other one of the end-faces. A switching-valve alternately interrupts and connects the fluid from the pressure fluid supply to the one end-face of the actuator differential piston whereby the actuator differential piston is caused to move between its first and second positions.

Abstract: A control circuit for an actuator having an operation valve for selectively distributing hydraulic oil from a pump to plural actuators which has a plurality of conduits, a plurality of pilot-operated valves for controlling the flow direction of oil to the actuator side or the tank side, and a pilot spool valve, whereby the operating force of the operation valve can be greatly reduced in simple operation.

Abstract: The invention relates to a hydraulic steering unit for automotive vehicles. A main feature of the unit is that pressure relief means are provided for relieving excessively high pressures developed in the unit which are caused by the steered wheels encountering road obstacles. The unit includes a pump, a drain tank and a working motor which is connectable to the wheels to be steered. The working motor has complementary expansible chamber means and a control valve is connected to the motor with a pair of supply and exhaust conduits which are selectively connectable to the pump and the tank by the control valve. A shunt line is provided between the pump and the tank and a pressure relief valve is in the shunt line. A manually operated valve controlled by a steering wheel is connected to the pump and the drain tank. A pair of control lines are connected to the manually operated valve which are selectively connectable to the pump and the drain tank by the manually operated valve.

Abstract: A hauling device, for example for a mining machine, has two clamping elements which grip on ramps each of which elements is attached to an operating rod of a hauling jack. The jacks are operated alternately, in conjunction with the clamping elements to advance or retract the machine, and the hauling jacks are hydraulically interconnected in a manner to avoid hunting.

Abstract: Two fluid passages are connected through flow restrictors to a fluid supply. Downstream of the restrictors the fluid supply has a drooping pressureload characteristic. Venting means for the fluid passages comprises vent openings therein downstream of the restrictors and variable position obstructor means cooperating with vent openings to vary the venting and thereby vary fluid pressures in the fluid passages. This forms a mechanical to fluidic translator. Pressures at the translator's outputs are a function of the obstructor's position. This translator forms the transmitter of a servo or remote control or indicator system.Fluid conduits connect these pressure outputs to a fluid to mechanical translator comprising a double acting piston moving in a cylinder whose opposite ends are connected to the fluid conduits. The piston and cylinder form the responder of the system, which may be adjacent the mechanical to fluidic translator and form part of the transmitter.

Abstract: A hydraulic control system having a load-lifting hydraulic motor, a source of pressurized fluid and a pilot-operated directional control valve for directing fluid for operation of the motor is provided with a combined restrictor and shuttle valve assembly that is operative to direct fluid from a pump for pilot-operation of the main control valve when the pump is in operation, but is operative upon failure of the pump system to provide pressure from the load-lifting side of the lifting motors to a pilot control valve for pilot operation of the directional control valve. This assembly provides an emergency source of hydraulic pilot fluid for pilot operation of the main control valve for lowering the implements or load supported by the hydraulic motors should the engine of the vehicle fail.

Abstract: A fluid system for work elements of a work vehicle has first and second fluid circuits each having a pump connected to a work element through a control valve assembly that is operated by a pilot pump. A control means is provided for controllably passing fluid between the first and second fluid circuits in response to power demands of said circuits.

Abstract: Method and apparatus for the electric hydraulic control of a hydraulic actuator, said control comprising a redundant servovalve circuit with switching and monitoring logic. The apparatus has a plurality of electrohydraulic servovalves each controlled by separate electrical input channels and connected to a central pressure medium source. The control further has a control spool triggered by the servovalve to control the actuator and a hydraulic logic system for monitoring errors in the servo output signal. The positioning land of the control spool is acted upon on the one side by one group of signals consisting of the combined output signals of the same sign from one selected group of servovalves and is acted upon on the other side by the central pressure medium supply while the remaining sevovalve signals are applied separately to a hydraulic logic system including a comparator and alarm means.

Abstract: A hydraulic swivel drive with two adjusting cylinder-piston systems the connecting rods of which are pivotally connected to a pivotally mounted member to be actuated by the hydraulic swivel drive. The cylinder-piston units are mounted on a base member, e.g. a base plate, which base member is provided with a servo-valve controlling the supply of actuating fluid to the cylinder-piston units which are arranged in V-formation and are hooked up with the pivotally mounted member so as to be symmetrically arranged with regard to the pivot axis of the pivotally mounted member. The cylinder-piston units are directly connected to the base member and their connecting rods are pivotable relative to the axis of their pertaining cylinder.

Abstract: A two stage solenoid actuated valve and method of actuation within a predetermined time interval. The valve provides fluid flow having a predetermined flow profile for displacement of a mass through a particular distance with a minimization of shock applied to the mass. The valve has a first and second stage in fluid communication each with the other. The first stage includes a solenoid valve and associated plug member for opening or closing flow through the first stage. The second stage includes a plug member having a predetermined contour head insertable within an orifice whose movement is responsive to the flow state of the first stage.

Abstract: A diaphragm valve has a relatively long seating formed by a plurality of ribs which engage with one air operated diaphragm. An annular valve is provided by slotting the outer surface of an annular seating member which engages an endless diaphragm, alternate slots communicating with the inlet or outlet of the valve. A pneumatic actuator for a vehicle braking system is provided with internal valve means for controlling the flow of air through the movable wall carrying the actuating member. An anti-skid braking system employs such a pneumatic brake actuator, the internal valve means being operated by skid sensing means.

Abstract: The invention is a control system for a hydraulic clamping device adapted to be connected to a source of pressurized hydraulic fluid and to a hydraulically operated clamp, which system comprises a path for supply of pressurized fluid to and from the clamp, a check valve in the said path, a hydraulically operated pilot piston movable between a non-actuating position and an actuating position in which it urges open the check valve, means to hold the pilot piston in the actuating position and thereby maintains the check valve open and a switching means for controlling the supply of pressurized fluid to and from the pilot piston, the switching means being capable of occupying a neutral position, a position in which pressurized fluid is supplied to the pilot piston to urge the pilot piston to the actuating position to open the check valve and a position in which pressurized fluid is supplied to the pilot piston to return the pilot piston to the non-actuating position and thereby permit the check valve to close.

Abstract: A control system for the hydraulically powered auger of a self-loading auger scraper that has an ejector operated by a hydraulic cylinder. One manual control valve starts and stops the auger in conjunction with loading. A second manual control valve powers the ejector cylinder and simultaneously operates a valve to start the auger independently of the first manual control valve.

Abstract: A hydraulic motor control apparatus comprising a plurality of standard multiple function modules adapted to be selectively programmed in various arrays to effect substantially any required hydraulic control function.

Abstract: A hydraulic interlock arrangement for ensuring that an inlet valve is closed before a discharge valve is opened, and vice versa, each inlet or discharge valve having a hydraulic piston-cylinder unit for actuating the same, a hydraulic pilot valve for operating the piston-cylinder unit and a blocking member for preventing actuation of the pilot valve, the first blocking member being connected to the pressure chamber of the second piston-cylinder unit, and vice versa, so that when the pressure chamber in one piston-cylinder unit is under pressure, the pilot valve of the other piston-cylinder unit cannot be actuated.

Abstract: An overrunning load control for a hydraulic jack includes a pair of variable orifice means in series, with the degree of metering of one of such orifices being determined by fluid pressure in the end of the hydraulic jack resisting the load. The degree of metering of the other variable orifice may be selectively chosen, through actuation of a relatively low pressure hydraulic pilot system.

Abstract: A servo-pressure operated piston arrangement includes a pilot valve which is movable by a torque motor against a biasing spring. A closed chamber is defined between one end of the piston and its surrounding cylinder, and this chamber communicates with an orifice which is shut by the pilot valve, under control of the biasing spring, to lock the piston relative to the cylinder if the torque motor fails.

Abstract: A fluid actuating device for an electric switching apparatus such as a high-voltage power circuit breaker or the like includes an actuator for actuating the switching apparatus. The actuator in turn is made up of a cylinder and an actuator differential piston movable in the cylinder between positions corresponding to the open and closed positions of the switching apparatus. A fluid supply provides fluid under high-pressure to the end-faces of the actuator differential piston. A main-valve arrangement includes a main-valve differential piston movable for alternately interrupting and connecting fluid from the fluid supply to one of the end-faces of the actuator differential piston whereby the actuator differential piston is caused to move between its end positions. The main-valve differential piston also has end-faces fluidly connected to the fluid supply.

Abstract: A fluid-operated apparatus receiving an input pressure signal exhibits a hysteresis or deadband effect by responding to an increasing pressure signal at a first level and a decreasing signal at a second and lower level. The apparatus includes a spool valve to which the input pressure signal is applied at one end of the spool. The opposite end of the spool having a given cross sectional area projects into a pressure chamber and contacts the poppet of a poppet valve held closed by a regulated pressure in opposition to forces produced by the spool. The seat of the poppet valve surrounds an opening into the pressure chamber so that the regulated pressure is admitted into the pressure chamber when the spool pushes the poppet open.

Abstract: In a system comprising first and second drive units each including one or more hydraulic motors, a two-position valve is provided in circuit with the motors of one drive unit, the motors of the other drive unit being supplied independently of the valve; the valve has a first operative position for blocking flow of working fluid to the one drive unit and a second operative position for permitting flow of working fluid to the one drive unit, the valve being operable between its first and second positions for selective operation of one or both drive units.

Abstract: A hydraulic control system having a plurality of hydraulic motors is provided with a sequencing control means for sequentially controlling or operating the motors from a single selector valve. The selector valve is operative to direct pilot fluid through a sequential controlling valve for pilot operation of separate pilot-operated control valves for the separate motors. The sequential control valve is operative to direct the fluid for operation of one of the control valves first for full operation of the first motor and then for directing pilot fluid to the second valve for operating the second motor. For operating the motors in the reverse direction, the second control valve is operative to control the second motor to its fully retracted position and then the first control valve becomes operative until the first motor is fully retracted.

Abstract: In a mineral mining installation employing a series of shifting rams for advancing a scraper-chain conveyor provided with a guide for a mining machine a control system with a central control station for transmitting control signals. The control signals serve to actuate local control valves, possibly in time dependence, to cause a selected one or group of metering devices to transfer a pre-determined volume of pressure fluid to one or more of the rams to effect said advancement. This volume of pressure fluid is some fraction of the total capacity of the ram or rams in question so that by repeatedly transmitting control signals the device or devices can perform successive cycles of operation to thereby cause the ram or rams associated therewith to extend in defined increments.

Abstract: A hydraulic valving mechanism for controlling an object in a normally level position such that upon a shifting of the same from level an actuating mechanism is driven to return the object to the desired level, such valving mechanism including a valve housing with control ports therein with a gravity responsive member therein to open and close selected ones of the ports depending upon the direction the same is shifted from level with the ports being interconnected to a main control valve for shifting of the same to direct fluid to the proper side of the actuating mechanism to return the object to its normal, level position.

Abstract: A fast exhaust circuit for hydraulic jacks includes a bypass conduit communicating a hydraulic jack with a tank, and a bypass valve disposed in the bypass conduit normally positioned for blocking fluid flow therethrough so that all fluid exhausted from the hydraulic jack passes through and is modulatably controlled by a control valve with the bypass valve being selectively positionable for returning a greater portion of the exhausted fluid directly to the tank and bypassing the control valve.

Abstract: The invention relates to drain devices in hydraulic control circuits, particularly for hydraulic ultrarapid release control of a circuit breaker. In order to enable rapid decompression and draining of high pressure fluid in an hydraulic jack which controls the circuit breaker, a plurality of drain valves are mounted directly on the jack in a cascade arrangement. The valves are hydraulically controlled by oil pressure on pilot jacks and are of progressively increasing cross-sectional areas. All the valves in cascade are physically coupled to one another and the setting to drain of the valve with the smallest cross-section is controlled by an electrovalve.

Abstract: The valve arrangement includes four main control valves connected in a bridge circuit connected, at one end of a first diagonal, to a source of fluid under pressure and, at the other end of the first diagonal, to a fluid reservoir. Opposite ends of a second diagonal of the bridge are connected to inlet and outlet ports of the operated device. The arrangement includes two pressure adjusting valves, each connected to a respective pair of main control valves. In one bridge circuit, the main control valves are pressure limiting valves and each pair of main control valves includes one main control valve in one branch of the bridge circuit and another main control valve in the other branch of the bridge circuit.

Abstract: There is disclosed a control device for an air cylinder unit which functions to automatically orient the unit to retract if all air is shut off to the unit during the extension operation thereof. The device includes a control piston having a first passage connecting supply pressure to only one side thereof and a second restricted passage intercommunicating opposite sides thereof.

Abstract: A distributing unit for a dual-action hydraulic electro-distributor of the type comprising, firstly, a distribution stage provided with a bore in which a slide is mounted so as to slide between two end positions with a spring return to a central or neutral position and, secondly, a piloting stage with valves controlled selectively by solenoids, each of the valves being adapted, when actuated, to communicate the feed pressure to the corresponding end of the slide and, when not actuated, to set the corresponding end chamber of the bore to return to the tank, wherein untimely displacement of the slide, e.g.

Abstract: 1.

Abstract: A load supporting hydraulic system having a pilot operated main control valve is provided with pilot controlled load check valve operative to permit free flow of fluid from said control valve toward the load supporting means of the system in response to pilot pressure and to block fluid flow from the load supporting means toward the control valve. The system includes valve means operative independent of the main control valve to permit the load check valve to be opened by fluid pressure in the load supporting means to allow fluid flow therefrom to the reservoir. The system further includes safety valve means for blocking fluid flow to pilot control means.

Abstract: A servo mechanism for a prime mover interconnected to a hydrostatic transmission includes a source of pressurized fluid, a fluid reservoir, an actuator having a piston operatively connected to the hydrostatic transmission and being provided with large and small hydraulic receiving areas which are exposed to first and second hydraulic chambers, respectively within the actuator housing, a first passage for connecting the pressurized fluid source to the second chamber, a second passage for connecting the pressurized fluid source to the first chamber, a third passage for connecting the first chamber to the reservoir, and a pair of spool valve means disposed, respectively, within the second and third passages and responsive to a signal indicative of the power required of the prime mover and an actual speed or feedback signal of the prime mover.

Abstract: A valving arrangement for a winch motor powered by air or other pneumatic uid. The valving arrangement includes normally closed valves in the working fluid lines which are held open by air in the pilot fluid lines. In the event of a rupture or break in the pilot line, a normally closed valve is allowed to close, thereby stopping the winch and preventing it from overrunning its travel limits.

Abstract: An injection molding control provides for the programmable control of ram velocity as a function of the position of the ram through closed-loop feed-back of the measured actual velocity. Closed-loop feed-back of the actual mold cavity pressure overrides the velocity program in an analog fashion to stop the ram when a preset cavity pressure has been attained associated with a desired charge size. Programmable control of the ram screw speed and/or back pressure during injection as a function of ram position or time is used to impart a predetermined temperature profile to the charge along the length thereof while it is in the barrel prior to injection. This enables controlled variation in density of the molded article throughout its volume to achieve desired levels in preselected characteristics such as surface wear, gloss, resolution and the like.

Abstract: In an earthmoving scraper a low volume, low pressure, pilot pump supplies fluid pressure to a pilot control valve which routes this fluid through bleed lines to a remote scraper control valve that operates the bowl jacks on the scraper from a separate source of pressurized hydraulic fluid. By manually varying the bleed rates of the output of the pilot pump with the spool of the pilot valve, proportion actuation of the control valve can be obtained through differential pressures in the bleed lines connecting it to the pilot valve. A safety valve connected in the bowl carry circuit supplies an alternate source of fluid pressure to the pilot valve if the pilot pump fails, ensuring positive fail-safe operation of the system.