Abstract: An excavation system is disclosed for a machine having a work tool. The excavation system may have at least one sensor to generate a signal indicative of a load exerted on the work tool. The excavation system may also have a lift actuator and a tilt actuator. The excavation system may also have a controller configured to detect engagement of the work tool with a material pile based the signal. The controller may operate the work tool to load the work tool with an amount of material. The controller may determine whether loading of the work tool has been completed. The controller may lift the work tool when the loading has been completed. The controller may also operate the tilt actuator to shake the work tool. Additionally, the controller may cause the machine to withdraw from the material pile after shaking the work tool.

Abstract: A working machine includes: a first switch operable to set an operation amount; a second switch operable by being pressed; a control unit capable of detecting an operation of the first switch and an operation of the second switch, the control unit outputting a control signal based on the operation amount of the first switch and continuously outputting the control signal when the operation of the first switch is detected after detecting a release of the operation of the second switch under a state where the operation of the second switch is detected; an actuator configured to be activated by a hydraulic operation fluid; a solenoid valve capable of controlling, based on the control signal, a pilot pressure; and a control valve configured to supply, based on the pilot pressure, the hydraulic operation fluid to the actuator.

Abstract: An actuator, including a cylinder, an actuator piston displacably arranged in the cylinder, a pressure fluid circuit having a channel mouthing in the cylinder, an indirectly electrically controlled first valve body, arranged in the channel for controlling a flow of a pressure fluid in the channel, and a second valve body, arranged in or at the channel to open and close the channel, the second valve body being a member fixedly connected to the actuator piston, and the first valve body and the second valve body being arranged in series with each other in the channel. The actuator further includes an electrically controlled three-way valve that is arranged to alternately open for a pressure fluid flow from a high pressure source and a pressure fluid flow from a low pressure source, chosen pressure fluid flow being arranged to act against and admit displacement of the first valve body.

Abstract: A rodless power cylinder includes a cylinder body, a piston assembly adapted to reciprocate in the cylinder body, a magnet mounted at each of the two ends of the piston assembly, a valve mounted at each of the two ends of the cylinder body for guiding a flow of air or fluid in and out of the cylinder body to cause the piston assembly to reciprocate, a magnetic sensor mounted in a sensor mounting groove at each of the two valves for sensing the position of the respective magnet, a movable member mounted around the cylinder body and coupled to the piston assembly by a magnetic force for synchronous reciprocating motion

Abstract: Methods and apparatus for converting energy from a stream of compressed gas into mechanical work as systems incorporating such methods and apparatus.

Abstract: In various embodiments, compressed-gas energy storage and recovery systems feature one or more valves, which may be disposed within end caps of cylinder assemblies in which gas is expanded and/or compressed, for admitting fluid to and/or exhausting fluid from the cylinder assembly.

Abstract: A control method for controlling a hydraulic actuator to impart oscillatory excitation to a load, the actuator comprising at least one hydraulic chamber and a movable member capable of moving in said chamber between two extreme positions under the action of a liquid under pressure, wherein the method comprises the steps consisting in: determining an operating point for said actuator, which operating point corresponds to a rest position of said movable member; applying a hydraulic command to bring said movable member into correspondence with said rest position; and applying a hydraulic command to cause said movable member to perform reciprocating movement about said rest position, said reciprocating movement being adapted to apply a desired excitation to said load; the rest position of said movable member being selected to be significantly off-center relative to said extreme positions.

Abstract: A method and apparatus are provided for hydraulic fluid supply between a hydraulic pump and a hydraulic drive unit, switching hydraulic fluid flow direction to the hydraulic drive unit or stopping hydraulic fluid flow to the hydraulic drive unit when measured hydraulic fluid pressure crosses a predetermined pressure threshold value. The method further comprises calculating an amount of mechanical work done by the hydraulic drive unit and warning an operator or limiting hydraulic fluid flow rate to the hydraulic drive unit when the calculated mechanical work for the drive cycle is less than an expected amount of mechanical work. The apparatus for practicing the method further includes a pressure sensor associated with a hydraulic fluid supply conduit between the pump and the drive unit, and an electronic controller programmed to operate the drive system according to the method.

Abstract: An electropneumatic actuator system for operating assemblies of an internal combustion engine includes a housing, in which an actuator is movably accommodated, which in turn is configured to be hollow and includes an aeration channel and a deaeration channel. A control slide valve is assigned to the actuator which is operated by a magnetic coil and which aerates, deaerates or closes a pressure chamber of the housing as a function of the relative position of the actuator.

Abstract: A turbine (2) driven electric power production system (1),—said turbine (2) arranged for being driven by a fluid (3) having a fluid speed (v) varying in time,—said turbine (2) connected to a hydrostatic displacement pump (6) further connected to a hydrostatic displacement motor (8) as part of a closed loop hydrostatic transmission system (7),—said motor (8) arranged for driving an electrical generator (9) supplying AC power (10) at a frequency (fg) near a given desired frequency (fdes), characterized by a closed loop system arranged for controlling a volumetric displacement (13) of the hydrostatic motor (8), comprising—a fluid speed meter (11m) arranged for producing a speed signal (11s) representing a speed (v) of said fluid (3), and—a rotational speed meter (12m) arranged for providing a rotational speed signal (12s) representing a rotational speed measurement (?) of said turbine (2), —a motor displacement control system (15) for continuously receiving said speed signal (11s) and said rotational speed signa

Abstract: A fluid pressure operated piston engine apparatus generally includes a piston unit, a valve configured to selectively direct pressurized fluid into the piston unit, a valve shifting mechanism, and a magnetic detent device. The magnetic detent device includes a valve actuating member coupled to a valve element in the valve. The valve actuating member is movable between first and second magnetically held positions respectively holding the valve element in first and second positions. The valve shifting mechanism includes a biasing device operatively connected to a shaft associated with the piston unit. As the shaft approaches the first and second ends of its stroke, the biasing forces are used at least partially overcome magnetic attraction holding the valve actuating member.

Abstract: A motor including a piston disposed within a cylinder and a valve configured to control a flow of a fluid into the cylinder. In some embodiments, the valve has a housing, a valve member disposed in the housing, and a magnetic detent configured to resist movement of the valve member within the housing.

Abstract: A pneumatic motor that includes a cylinder, a piston disposed in the cylinder, and a pneumatically-reset pilot valve. In certain embodiments, the pneumatically-reset pilot valve is configured to move to a first position in response to a change in pressure in the cylinder.

Abstract: A pneumatic motor having a piston and a magnetically actuated valve. The magnetically actuated valve may be adjacent the piston and, in some embodiments, include a spool valve.

Abstract: A fluid power linear drive device comprises a housing tube on whose outer periphery an output drive slide can slide linearly. For this purpose on the outer periphery of the housing tube there are two guide face pairs each having two guide faces extending along the housing tube on the outer periphery of the housing and, in the axial is direction of a first transverse axis of the housing tube, opposite each other, which in the direction of a second transverse axis, perpendicular to the first transverse axis, are spaced apart.

Abstract: The invention relates to a percussion device comprising two percussion pistons alternately making a percussion motion and a control valve for controlling the percussion pistons. The control valve (7) comprises a slide (8) affected by a force so that the slide is generally in a first position, but moves at the end of the percussion motion of the first percussion piston from the first position to a second position and correspondingly back to the first position at the end of the percussion motion of the second percussion piston (4).

Abstract: A pneumatic motor that includes a cylinder, a piston disposed in the cylinder, and a pneumatically-reset pilot valve. In certain embodiments, the pneumatically-reset pilot valve is configured to move to a first position in response to a change in pressure in the cylinder.

Abstract: A metering device of the type in which a shuttle moves axially within a chamber between two terminal positions, with the chamber having fluid inlet and outlet at each end so that fluid may enter through one end to move the shuttle to cause fluid to be ejected through the other end, and vice versa. A control valve is provided to control the fluid flow, the control valve being a spool valve having a spool sealingly slidable within a bore, the spool valve being associated with a device to drive the spool between two alternate positions in response to the shuttle reaching each end of the chamber.

Abstract: The present invention relates to a hydraulic DEVICE having a valve housing (1) with a movable valve body (2) arranged inside the valve housing, a hydraulic cylinder with at least a hydraulic chamber (115), and at least a control mechanism (4) for the control of said movable valve body (2), the valve body (2) is substantially sleeve-shaped and arranged inside an annular space (128) in the valve housing (1), and said valve body (2) is provided with a plurality of apertures (250, 251, 252; 206, 202) to make a flow of hydraulic liquid possible in the radial direction through the valve body (2).

Abstract: A hydraulic drive system is provided to produce a smoothed or near sinusoidal output flow characteristic for reciprocating piston pumps. The device occupies a smaller footprint than conventional mechanical reciprocating pumps and allows a standard reciprocating pump to operate at its maximum rated pressure while retaining its maximum rated flow. Several embodiments are disclosed and the drive system may be coupled to standard duplex and triplex pumps. A solution to hydraulic hammer caused by rapid flow reversal in the hydraulic control valves used within the system is presented.

Abstract: An apparatus and method for creating vibration of an appendage of a work vehicle is disclosed. The apparatus includes a hydraulic cylinder, first and second valve assemblies, and a control element. The hydraulic cylinder is coupled between a first portion of the work vehicle and the appendage and includes a first chamber, a second chamber, and a piston. The first and second valve assemblies respectively govern whether hydraulic fluid is provided from a pump to, or to a tank from, the first and second chambers. The control element automatically causes a status of the second valve assembly to repeatedly alternate with time so that the vibration occurs at the piston and is in turn provided to the appendage.

Abstract: An air pulser is provided which can intermittently form pulse air by continuously supplying compressed air. The interior of the body is partitioned into an air supply chamber and an air exhaust chamber by a diaphragm. An air blast cylinder opened and closed by the diaphragm is provided in the air supply chamber. In the air exhaust chamber, a valve plate having a valve hole and comprising a magnetic member is provided to partition it into a first chamber and a second chamber. A valve body with a permanent magnet is movably mounted in the second chamber. Compressed air can be continuously fed into the air supply chamber to open the valve body due to an increase in pressure in the first chamber, thereby exhausting compressed air in the air exhaust chamber through an air exhaust port, and to deform the diaphragm toward the air exhaust chamber due to a drop in pressure in the air exhaust chamber, thereby discharging compressed air in the air supply chamber through the air blast cylinder.

Abstract: A hydraulic amplifier system for an ultra-high pressure liquid chromatography system. The hydraulic amplifier system includes a hydraulic cylinder comprising a primary piston chamber in which a primary piston is disposed and a secondary piston chamber in which a secondary piston is disposed. The cross-sectional area of the primary piston is larger than the cross-sectional area of the secondary piston. The difference in the cross-sectional areas of the pistons creates an amplification of the pressure in the primary piston chamber and a reduction in flow rate.

Abstract: An apparatus and method for creating vibration of an appendage of a work vehicle is disclosed. The apparatus includes a hydraulic cylinder, first and second valve assemblies, and a control element. The hydraulic cylinder is coupled between a first portion of the work vehicle and the appendage and includes a first chamber, a second chamber, and a piston. The first and second valve assemblies respectively govern whether hydraulic fluid is provided from a pump to, or to a tank from, the first and second chambers. The control element automatically causes a status of the second valve assembly to repeatedly alternate with time so that the vibration occurs at the piston and is in turn provided to the appendage.

Abstract: A double-acting reciprocating motor with a uni-directional fluid flow path comprises a piston disposed within a cylinder. Within the cylinder, the piston defines a first chamber between the piston and a cylinder base and a second chamber between the piston and a cylinder head. Fluid is introduced into the first chamber of the motor through an inlet port associated with the cylinder base. A pass-through valve controls the flow of fluid from the first chamber to the second chamber. An outlet valve regulates the draining of fluid from the second chamber through an outlet port associated with the cylinder head. Fluid pressure within the first chamber urges the piston towards the cylinder head when the pass-through valve is closed and the outlet valve is open. The piston surface facing the second chamber is larger than the piston surface facing the first chamber, so the piston moves towards the cylinder base when the pass-through valve is open and the outlet valve is closed.

Abstract: A mud pump is provided with two cylinders for pumping mud in connection with water well drilling, and two sets of hydraulic oil cylinders with pistons connected to and driving the pistons of the mud pump by piston rod connecting plates. A flow divider located downstream from a hydraulic oil power supply pump applies hydraulic power evenly to two sets of mud pump driving cylinders, but the flow divider accommodates re-routing of hydraulic oil to one driving cylinder during a directional valve shift for the other driving cylinder. Rod position sensing switches coupled to an electro-hydraulic control system coordinates the action of the sets of pump driving cylinders and thereby of the mud pumping cylinders, to control and phase the mud driving pistons produce a steady mud pump output simulating the effect of constant velocity pistons.

Abstract: Actuator (140) for providing intermittent movement to a member (151). The actuator (140) has actuator cushion members (150) which extend with the entry of air and which contract with the egress of air provided through air supply lines (151, 152) connected to the actuator through a valve (172). The member (161) moved by the actuator cushion members (150) is located between the actuator cushion members (150). As one actuator cushion member (150) fills with air, force is applied to the member (161) thereby to provide movement force. Simultaneously, air exits from the opposite actuator cushion member (150) allowing the movement of the member to proceed. A control system (161) provides the cycle and frequency of the air application to the actuator (140).

Abstract: An auto cycle pump in accordance with the invention includes a housing having a reservoir for storing hydraulic fluid. A hydraulic pump in the housing provides hydraulic flow. A directional valve has neutral, advance and retract positions to respectively restrict hydraulic flow, direct hydraulic flow to an advance port and direct hydraulic flow to a retract port, the ports for hydraulic connection to the hydraulic tool, in use. Fluid conduits are provided connecting the pump and reservoir to the directional valve. A flow switch detects return flow from the directional valve to the reservoir. A pressure sensor sense hydraulic pressure from the pump. A dump valve is operatively connected to the pump for directing hydraulic flow back to the reservoir when the directional valve is in the neutral position. A control is operatively connected to the pump, the directional valve, the flow switch and the pressure sensing means for controlling operation of the auto cycle pump in automatic mode of operation.

Abstract: A pneumatic valve, designed to control/pressurize a membrane pump, compresses a valve body (1) having gates (8-12) for compressed-air-flow/operation/pressurization of said pump. The valve body is closed by ends (2), between which a plunger (5) is to move between two end positions. The ends of the plunger and the ends of the valve body co-operate physically magnetically in order to generate just and only a retaining force, which constitutes a threshold for a certain minimum control pressure from a control-air-gate (13 or 14) and guarantees a rapid initial movement as well as a rapid transfer of the plunger to its opposite end position. Permanent magnets (15) are inserted in said plunger ends and/or in said valve body ends and designed to co-operate with projections and/or processes (17,18,20) in the opposite member in order to obtain a so-called air-cushion-damping.

Abstract: A fluid pressure operated piston engine assembly, such as a pump assembly, including a fluid pressure operated piston engine and a fluid valve for coupling fluid under pressure to alternative portions of the piston chamber of the piston engine. The fluid valve includes a valve spool which is translated to effect the alternative modes of coupling pressurized fluid to the piston chamber. The translation is accomplished by a shifter assembly having a shifter rod attached to the valve spool. The shifter rod includes a pair of diametrically opposed magnets attached thereto. A fork is attached to the piston engine drive shaft at one end and is mounted for limited movement along the shifter rod between the pair of magnets of the shifter rod.

Abstract: A pneumatic windshield wiper includes a compressed air motor provided with a piston which mounts a pair of actuator vanes one of which functions with a fixed electric sensor on the motor housing to establish the "park" position of the wiper blade. The other sensor actuator vane is adjustable along the length of the piston rod and functions with the sensor to establish the extended, adjustable position of the wiper blade. The sensor is included in an electronic circuit which controls operation of an electric solenoid valve and hence delivery of compressed air to the wiper motor.

Abstract: Holding device for a piston position detector, contained in a casing and being displaceably mounted on the outside of a fluid pressure cylinder. The holding device consists essentially of a U-shaped yoke being displaceable along two mutually parallel guides and being lockable in a desired axial position. The yoke is locked by means of a first fastening screw, whereas the casing is insertable between the shanks of the yoke and is lockable in inserted position by means of a second fastening screw. The casing is protected by the yoke and is detachable from the latter, also when the yoke is located to the guides.

Abstract: A double diaphragm pump having diaphragms connected by a coupling rod and separating two diaphragm chambers, a control spool displaceable in dependence on the position of the diaphragms, with closure means for alternate freeing and closing control passages arranged in a control spool housing for alternate pressurizing and relieving of a driving medium chamber with driving medium, and an actuating member coupled with the diaphragm movement and magnetically with the control spool.

Abstract: A two cylinder thick matter pump has two hydraulic drive cylinders, two pistons supported and driven within each respective drive cylinder, and two feed cylinders. Each feed cylinder is adapted to receive a respective piston therein to pump the matter therethrough. A hydro-pump is coupled to the drive cylinders to supply hydraulic fluid thereto. A reversing valve is coupled to the hydro-pump to reverse the direction thereof. Two pressure switching valves are coupled to one of the drive cylinders and to the reversing valve to actuate the reversing valve upon a change in cylinder pressure. Two electronic proximity switches are supported adjacent to the pistons and coupled to the reversing valve. The proximity switches actuate the reversing valve in parallel with the switching valves.

Abstract: A method and an apparatus for control of the movement of a control piston an air control valve for a compressed air-operated double diaphragm pump, wherein the control piston is moved between the end positions in a control cylinder having inlet bores and outlet bores for the compressed air. The control piston is adjusted by a control medium. The method includes initially maintaining the control piston in an end position by a holding device against the pressure of the control medium for a predetermined period of time or until a counterpressure reaches a predetermined pressure level. Subsequently, the control piston is moved with a pushing force which is always greater than the maximum frictional forces. The holding device operates independently of the movement of the pump diaphragm, preferably using elastically, magnetically, or electromagnetically operating structural elements. The control cylinder includes separate connections for a control medium for moving the control piston.

Abstract: An intensifier for delivering ultra high pressure water to a cutting head of a water jet cutting apparatus. The intensifier has a power piston and cylinder assembly connected to piston members extended into pumping chambers in housing located at opposite ends of the piston and cylinder assembly. Inlet poppet valves located in the pumping chambers control the flow of water from inlet passages into the pumping chambers. Outlet poppet valves allow ultra high pressure water to be pumped out of the pumping chamber into an accumulator fluidly connected to the cutting head. Hydraulic fluid under pressure is sequentially directed to opposite ends of the piston and cylinder assembly with a solenoid operated reversing valve. Limit switches operable in response to movement of the piston members control the reversing valve. Linear motion transfer mechanisms are moved with ramps on the piston members to actuate the limit switches to control the reciprocating action of the piston and cylinder assembly.

Abstract: A linear unit (10) is provided with a cylinder (50) and a pressure-fluid actuated piston (52). The piston (52) runs in a borehole (51) of the cylinder (50). A slider (55) runs at the cylinder (50). A band (53) connects the piston (52) to the slider (55) and leads via deflection structure (54a, 54b) at the heads (11a, 11b) of the cylinder (50). Valves (15a, 15b) are screwed into the cylinder heads (11a, 11b) for feeding a pressure fluid to and discharging a pressure fluid from the borehole on two sides of the piston (52). The linear unit (10) provides an increased liberty of direction in a position-mounting of the linear cylinder heads (11a, 11b) and of the linear unit with valves (15a, 15b) as well as in the positioning of the connection terminal pieces. The linear unit (10) is flexible and is of modular construction and allows different types of device components to be flanged in the same position.

Abstract: Presented is a fluid drive motor that may be attached to a conventional garden hose, for instance, to effect reciprocating motion of a drive shaft that may be connected to a utilitarian device, such as a scrub brush. The fluid drive motor is provided with a piston assembly that responds to the pressure of the fluid to translate the piston assembly from one position to another and in so doing imposes rotational reciprocation on a drive shaft that extends out of the motor block of the fluid drive motor. The reciprocating characteristics of the piston assembly are controlled by the imposition of fluid pressure, and the imposition of fluid pressure is controlled by a valve assembly cooperating with a reciprocable magnetic bar to channel fluid under pressure alternately to opposite ends of the piston assembly.

Abstract: A pressure-driven engine is provided therein with an intake valve and an exhaust valve the opening and closing operations of which are controlled by a combination of the urging force of the respective springs and the attractive force of the respective magnets. The engine automatically repeats reciprocating motion merely by supplying a pressure source such as steam or various kinds of compression gas. The reciprocating motion or the rotational motion converted from the reciprocating motion is utilized as a power.

Abstract: In accordance with an illustrative embodiment of the present invention, an expansible chamber device includes a piston movable within a cylinder, a head on the cylinder having intake and exhaust ports, a normally-open intake valve for closing the intake port automatically when the flow rate or velocity of a working medium entering the cylinder reaches a predetermined value, variable restraining means for inhibiting closing of the intake valve in response to flow, an exhaust valve for preventing escape of working medium from the cylinder until cylinder pressure is reduced to a set level, spring means for opening the exhaust valve at that level, and means operable near the top-dead-center position of the piston for automatically opening the intake valve and for closing the exhaust valve to enable the cycle to repeat. A unique system for controlling the variable restraining means, as well as methods for regulating the flow or working medium through said valves, also is disclosed.

Abstract: Apparatus for driving a medical appliance has a single compressor for generating both the positive and negative pressures. The switching valves are connected to the outlet and inlet terminals of the compressor. The outlet and inlet terminals of the compressor are also connected to the positive pressure accumulator and the negative pressure accumulator, respectively. The apparatus has the pressure sensors to sense the pressures in the positive and negative pressure accumulators. When the pressure in the accumulator reaches a set pressure, at least one of the switching valves is closed. The apparatus further has the relief valves connected to the outlet and inlet terminals of the compressor. These relief valves open when the pressures of the compressor become excessive.

Abstract: For the production and exact control and regulation of very high pressures, in particular for actuating a press, two pressure intensifiers are provided which each have a differential piston. The second pressure intensifier is connected via a shutoff valve to the first pressure intensifier and to the load or consumer. Both pressure intensifiers have a small volume compared with the volume required by the consumer. By activating the second pressure intensifier fluid can be exchanged between the consumer and the first pressure intensifier to replenish the first pressure intensifer in a pressure buildup phase and to empty the first pressure intensifier in a pressure relief phase.

Abstract: A fluid pressure oscillator is provided with a cylinder containing a piston assembly. Fluid actuated reciprocation of the piston assembly is controlled by a valve mounted externally of the cylinder. The valve is alternately shifted between "advance" and "retract" settings by a reciprocating actuating rod removably received in the cylinder. A magnet on the piston assembly cooperates with magnetic elements on the actuating rod to automatically reciprocate the latter.

Abstract: A multi-condition responsive vehicle restraining apparatus includes a hook member having an edge for contacting an ICC bar on a vehicle and a tip located at one end of the edge and extending upwardly therefrom for restraining the ICC bar from passing the hook member. A beam arrangement mounts the hook member and is movable for moving the hook member on a forward stroke from an inoperative lowered toward an operative raised position and on a return stroke away from the operative raised toward the inoperative lowered position. A double-acting hydraulic cylinder is connected to the beam arrangement for actuating the same to move the hook member on its forward and return strokes. Components are provided for sensing the presence of any one of three conditions concerning the placement of the vehicle ICC bar with respect to the hook member and concurrently therewith providing an indication of which condition prevails.

Abstract: Apparatus for controlling the flow of a foam uses a bellow enclosed in a housing. The bellows is filled with foam under pressure from a foam generator and expands a preselected amount at which point the flow of foam into the bellows is interrupted. Simultaneously with the interrupting of the flow of foam into the bellows, air under pressure is routed into the housing which causes the bellows to collapse forcing the foam out of the bellows. The apparatus is particularly useful in the froth flotation (benefication) of minerals.

Abstract: An abrasive cutting system has an abrasive cutting wheel, a holder for the object to be cut, and means for advancing and retracting the wheel and holder relative to each other. Preferably, the advancing and retracting means is connected to the holder, while the cutting wheel is stationary except for its rotary motion. In accordance with this invention, apparatus for automatically, intermittently advancing the wheel and holder toward each other while the wheel is cutting the object is provided. This automatic, intermittent advancement provides significant improvements over a uniform rate of advancement.

Abstract: A double-acting diaphragm pump system for pumping and spraying materials, particularly corrosive liquids and abrasive fluids. The system includes a hydraulically driven double-acting diaphragm pmup which is electrically controlled for alternately pumping material through the dual pump chambers to an outlet pipe. The diaphragms of the double-acting pump are moved back and forth by a dual-acting hydraulic cylinder powered by a hydrostatic transmission for providing automatic response to pumped fluid needs, coupled with overpressure protection. An expansion tank maintains a constant pressure on the fluid as it is discharged from the pump. The system is capable of spraying abrasive slurries of a wide variety, at an even spray pattern, as the system wears, and hardened wear rings around the inlet and outlet valves permit the pump to be inexpensively rebuilt after extended use pumping abrasive slurries.

Abstract: A double-acting accelerated forging hammer and method of operation are disclosed. The hammer is of the type having a vertically oriented cylinder, a piston slidably mounted within the cylinder having a downwardly depending piston rod extending along the cylinder and attached to a hammer. A gas accumulator communicates with the cylinder above the piston for supplying gas under pressure thereto during a forging stroke, and a fluid accumulator communicating with the cylinder below the piston for supplying fluid thereto at a higher pressure than the gas to dirve the piston upwardly during a return stroke. A fluid tank supplies fluid to recharge the accumulator and receives fluid from the cylinder during the forging stroke. Variable valves control the rate of fluid flow from the cylinder and thereby control the rate at which the piston descends within the cylinder.

Abstract: A hydraulic control valve for a single-acting cylinder includes a valve housing having a cylindrical valve bore. A supply port present in the valve housing is in communication with the valve bore, as is a discharge port and a delivery port. A valve pin is slidable within the valve bore between first and second pin positions, the valve pin including a pin groove positionable to establish communication at the first pin position between the supply port and the delivery port to the exclusion of the discharge port. The pin is slidable from the first position to the second position to establish simultaneous communication with the pin groove between the supply port, the discharge port and the delivery port.

Abstract: A double action diaphragm type pump wherein oppositely positioned diaphragm pumping units are reciprocally operated by a hydraulic cylinder assembly positioned between the pumping units. Separate piston rods extend oppositely from a piston in a hydraulic cylinder, each rod operating a diaphragm in one of the pumping units.