Abstract: A hydraulic circuit capable of both a regeneration mode of operation and a full force mode of operation includes a poppet valve controlled by a control valve operating in conjunction with a shuttle valve. The opening of the poppet valve enables the regeneration mode of operation, and the closing of the poppet valve enables the full force mode of operation.
Abstract: A valve actuator assembly for an engine includes a movable engine valve and a movable spool valve. The valve actuator assembly also includes a driving channel interconnecting the spool valve and the engine valve and a first feedback channel and a second feedback channel interconnecting the spool valve and the engine valve. The 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 valve actuator assembly further includes a first on/off valve and a second on/off valve in fluid communication with the first feedback channel and the second feedback channel to enable and disable the first feedback channel and the second feedback channel, whereby the first on/off valve and the second on/off valve control motion of the spool valve.
Abstract: In the present invention, sensors for cylinder control are connected to a main cylinder which has an internal cylinder chamber which is partitioned by a piston into two chambers, and they detect the operational state of the piston. There are provided accumulators connected to one of said two chambers by connecting conduits and whose interiors are pressurized by hydraulic fluid which is expelled from said one chamber, and also stop signal generation mechanisms which generate signals to stop the driving of said main cylinder by pressure differential between said accumulators and said connecting conduits generated at the instant that increase of pressure from said one chamber stops.
Abstract: A work attachment for a commercial work vehicle such as a skid steer loader has a unique hydraulic circuit that splits hydraulic working flow between two hydraulic functions without the need for electronic solenoids. The commercial work vehicle has hydraulic flow through two hydraulic hoses to the work attachment which can be reversed by the operator of the vehicle to provide two different hydraulic signals. During normal operation, hydraulic working output flow is directed toward a first function, such as the rotary motor of a rotary broom or rotary snow blower. To provide for the second function, the circuit includes a diversion valve that may take the form of a check valve that diverts the flow in response to one of the hydraulic signals (e.g. when flow is reversed). The diversion valve directs flow toward the second hydraulic function such as a hydraulic cylinder for positioning a portion of the attachment (e.g. to effect a selected engaging angle of a rotary broom).
Abstract: A hydraulic actuator has a housing, a piston drive chamber in the housing, a fluid inlet into the chamber, and a piston reciprocable in the drive chamber. The piston has diametrical steps exposed to fluid under pressure to cycle the piston. A sleeve spaced from and surrounds over a length of the piston to define a return chamber therebetween. The housing has first and second seats. The first seat and a first surface of the sleeve define an exhaust valve, which has an exhaust port, for the return chamber. The exhaust port is opened and closed by reciprocating the sleeve. The second seat and a second surface of the sleeve an inlet valve for the return chamber. Reciprocating the sleeve opens and closes the return chamber to the drive chamber. The housing also has a bore through which a portion of the sleeve reciprocates to close the exhaust valve and seal the drive chamber.
Abstract: This invention features a small-enveloped (with an outside diameter of at least approximately 38 mm), single-acting, hydraulically-operated, reciprocating, deep-well, fluid-extraction pump, operable in non-straight and angular wells, and its mode of operation. The hydraulically-operated, deep-well pump, in addition to having an above-ground installation of its motor-fluid generator and of its control valving, comprises a compound, stepped piston that is reciprocably mounted within a cylinder which in turn is divided into individual pressure chambers. Hydrostatic pressure created by a hydraulic pump is selectively directed to two outlet ports to produce an overpressure in one of the outlet ports at any given instant. The overpressure in each outlet port leads to creation of overpressure in one or more pressure chambers. Imbalances in pressure among the pressure chambers result in movement of the compound, stepped piston and extraction of hydraulic-well fluid by the compound, stepped piston.
Abstract: A four-way hydraulic control valve automatically reverses flow of hydraulic fluid to a double acting hydraulic cylinder or to a reversible hydraulic motor when a substantial resistance to fluid flow is encountered, such as when the cylinder or a machine being operated by the cylinder or motor reaches a mechanical limit of its motion. The valve has a reciprocating spool in a valve body with two internal control valves, one at each end, and with appropriate internal pressure shunts for directing high pressure fluid into the control valves and drain fluid restrictions to shuttle the spool back and forth in response to an increase in pressure resulting from a substantial resistance to fluid flow.
March 7, 1991
Date of Patent:
December 29, 1992
Town & Country Research & Development, Inc.
Abstract: An actuator is driven in a first direction by equal working fluid pressures acting on different piston areas acting in opposite directions, and is driven in a second direction by applying equal pressures on both sides of one of the piston areas. Working fluid from an inlet port, acting in a working fluid chamber, pushes up a valve plate, closes ventilation holes and opens working fluid discharge holes, thereby permitting the working fluid to push the piston upward. Working fluid contained in the working fluid chamber is exhausted from working fluid discharge holes to the outside of the system through a working fluid discharge pipe. When the upward movement of piston reaches its limit, a valve plate is pushed by a spring, thereby causing simultaneous closing of the working fluid discharge holes and the opening of the ventilation holes. As a result of the opened ventilation holes, working fluid pressures in a lower working fluid chamber and an upper working fluid chamber become equal.
Abstract: A quick acting diversion valve can be constructed so that a pressure difference between the sides of a bistable diaphragm can be used to cause the diaphragm to change in configuration so as to move a valve body in a housing in order to change the manner in which passages or ports in the housing are connected.
Abstract: A fluid operable engine has a cylinder in which a piston slides up and down. The cylinder has a cylindrical wall and two end walls. The piston divides the cylinder into two chambers. The piston is hollow, has a cylindrical wall and two end walls, with a rigid tube extending from and through one end wall of the piston through an adjacent end wall of the cylinder so that the interior of the piston communicates with the exterior through the tube. The cylinder has an aperture in each end wall or in its cylindrical wall close to the end walls and the piston has an opening in each of its end walls. A closure member is provided for alternately closing the openings or the apertures as the piston reaches each end wall. The engine is operated either in a positive or negative manner, with fluid being charged into or sucked from the piston or the cylinder. The openings may be closed from within or without and the apertures may be closed from inside or outside. The closure member may be mechanically or fluid operable.
Abstract: This invention provides a valving arrangement for a reciprocating engine in which there are two valve assemblies, each with a pressure responsive valve member. As the piston approaches the end of its stroke in either direction, the exhaust port is closed, such as by an extension on the piston, causing fluid pressure to build up in the end of the cylinder. This pressure is conducted to the valve assemblies through fluid lines, causing the pressure-responsive valve members to move in response to the pressure build-up in the end of the cylinder. These valve members control the inlet and exhaust connections to the cylinder so that the piston is caused to reciprocate by the working fluid as the valve members are moved pneumatically to open and close the lines.
Abstract: A piston for a striker is displaceable in a cylinder and forms compartments on opposite sides which can selectively be connected by hydraulically controlled valve elements to a pump and to an accumulator. A hydraulic controller for the valve elements initially connects a compartment on one side of the piston to contribute the pressure from a respective compartment to the accumulator during a lifting operation, cuts off the valve element affording this pressure accumulation to brake the piston, and other such valve elements enable the accumulator to be charged with the piston in its raised position so that, upon triggering by the controller of the valve elements, the pressure which drives the ram is equal to the total pressure delivered by the accumulator and the pump to the piston.
January 10, 1986
Date of Patent:
August 25, 1987
Intreprinderea de Utilaj Greu "Progresul"
Abstract: A pneumatic metering pump apparatus, having a pump member, working in combination with power head means wherein a pneumatically driven piston would cooperate with the pump means. There would be further provided a fluid inlet providing fluid flow to the power head and a valving element in communication with the first fluid inlet and the piston. Further, a timer would be in fluid communication with the valve and piston, would also include a valving element housed in the valving member for providing fluid communication between the valving member and the piston when the valving member is in the first position and blocking fluid communication between the valving member and the piston and establish fluid communication between the piston and an exhaust when the valving member is in a second position.
Abstract: This invention relates to an automatic hydraulic reversing valve for a double-action working cylinder. The purpose of the invention is to employ valves of this type without the requirement of an expensive servo-control mechanism, but nevertheless having a high operating reliability. The present invention, in avoiding the use of servo-control devices, utilizes a separate thrust piston which urges a control piston into a startup position, at which position the hydraulic medium is directed to the thrust piston end of the control piston, a blocking slide valve also being employed in the system and being mounted in the control piston for connecting the thrust piston end of the control piston to a tank or for blocking the connection to the tank.
Abstract: A hydraulic pumping unit is provided that is especially adapted for use for pumping oil from a well, and that provides for independent upstroke and downstroke speed control of the well sucker rod. The pumping unit includes a load sensing, pressure and flow compensated pump that is destroked under no load conditions, a pumping cylinder including a polished rod coupled to the sucker rod, and a unique hydraulic valving assembly that couples the hydraulic fluid pump with the pumping cylinder. The hydraulic valving assembly includes a cylinder control module for independent control of the rates at which the polished rod is raised and lowered, and a signal control module for indicating the upper and lower limits of polished rod travel within the pumping cylinder. The cylinder control module provides for soft turnaround of the polished rod, thereby guarding against stretching of the sucker rod and subsequent degradation of the unit's pumping capacity.
Abstract: A tire pressure control system includes means for restoring and maintaining specified tire pressure by applying intermittent regulated air pressure to the tire through a rotating seal near the wheel when the air pressure is too low. If the air pressure in the tire is at a predetermined safe operating level, the air pressure through the rotating seal is blocked.
Abstract: A valve mechanism for a water actuated waste disposal unit includes a reciprocating control valve for actuating an operating piston with cutters attached thereto. The control valve is cycled by a pilot valve. Passages in the valve mechanism are constructed and arranged for optimum operation and cycle time with minimum leakage.
Abstract: A pneumatic fastener applying tool featuring a self-cycling control valve with one moving port. A trigger actuated valve sets the cycling valve in motion. The cycling valve alternatively pressurizes and vents the working piston of the fastener tool. A valve stem is positioned by an integral reciprocating piston. The position of the reciprocating piston is determined by the balance of forces between a biasing spring tending to vent the working piston and a pressure-force tending to pressurize the working piston. Two flow paths, internal to the valve stem, determine the pressure applied to the reciprocating piston. One path pressurizes the reciprocating piston. Another path vents the reciprocating piston. Positive feedback of air pressure from the working cylinder positions the reciprocating piston and valve stem so as to vent the reciprocating piston when the working piston is vented and to pressurize the reciprocating piston when the working piston is pressurized.
Abstract: Hydraulic door closer apparatus has associated with it means for counter-balancing the bias of a return spring, to assist in opening the door by reducing the force needed to open it, or to open the door by over-balancing the bias of the return spring. Remotely manually operable means may initiate opening of the door.
Abstract: Disclosed is a liquid inertia tool in which the kinetic energy of flowing liquid is converted to useful work by decelerating the liquid flow and directing the inertia force in the water against a movable element in the liquid flow-containing structure which in turn moves against a work piece. Flow deceleration is achieved by an orifice-effect valve. The valve is reset for flow resumption or acceleration by automatically or selectively applying hydraulic pressure to a reset mechanism. Use of the inertia tool in pile driving and punch press applications is disclosed.
Abstract: An automatic, hydraulically actuated, sequencing valve for use with a pair of hydraulic actuators (e.g. double acting hydraulic cylinders). The valve includes a valve body, a bore therein, and a valve spool axially shiftable in the bore. The valve spool shifts automatically due to creation of a differential in hydraulic pressures on opposite ends of the valve spool during each admission of hydraulic fluid under actuating pressure to the valve.
Abstract: A rock drill feed system moves a drill toward and away from a wall with a reciprocating hydraulic motor powered by pressurized fluid. The pressurized fluid is controlled by a movable control valve that has a first position obtained manually to move the drill inwardly to drill, a second position obtained automatically when the drill has completed drilling, and a third position obtained automatically when the drill has been completely withdrawn. The sensing of the location of the drill to position the control valve is accomplished by measuring the pressure and flow rate of the hydraulic fluid delivered to the motor with pressure responsive switches. When the pressure exceeds a preselected level and the flow rate drops below a preselected level, the two pressure switches close to produce a signal that moves the valve to another position.
February 14, 1977
Date of Patent:
June 30, 1981
George P. Schivley, Jr., Peter L. Madonna
Abstract: A cylinder control device of a hydraulic cylinder apparatus including a main directional control valve having a pilot chamber for controlling the reciprocatory movement of the piston, and a first valve including a plurality valve members for selectively communicating the pilot chamber, via an auxiliary directional control valve, to the fluid discharging tank side of the working fluid circuit when the piston reaches a predetermined position in its rearward stroke. The pilot chamber is brought into communication, via a passage, to the pump side of the working fluid circuit by a second valve when the piston reaches the end of its forward stroke. A control valve using the pump side pressure as a pilot pressure is mounted in the passage connecting the second valve to the pilot chamber or in the passage connecting the pilot chamber to the auxiliary directional control valve.
Abstract: A hydraulic turning device for a turn plow comprises a substantially upright double acting cylinder having a piston dividing the cylinder into an upper and a lower compartment and being operatively connected to the turn plow for turning the latter in two steps between a first and a second through 180.degree. reversed position. The upper and lower cylinder compartments are connected by fluid passage with a control device having a fluid inlet passage and a fluid return passage, and which is provided for reversing the movement of the piston in the cylinder wth a valve having an axially movable valve spool, a reversing piston and a reversing valve, in which the valve spool controls filling of the lower cylinder compartment. The control device includes further a pressure valve located between the upper cylinder compartment and the fluid return passage.
Abstract: A fluid pressure supply apparatus includes a fluid pressure source, a fluid supply circuit to receive fluid under pressure from the fluid pressure source, and a fluid return circuit. These circuits are to be coupled to an hydraulic motor through first and second fluid paths. The supply apparatus further includes first means to couple the fluid supply circuit to the first fluid path to cause the hydraulic motor to be operated by the fluid pressure in a predetermined sense, and second means simultaneously to couple the second fluid path either to the fluid supply circuit, to provide a regenerative coupling for the motor, or to a fluid return path. This latter coupling is initially to the second fluid path, the second means being arranged to transfer that coupling from the fluid supply circuit to the fluid return path during operation of the motor in the predetermined sense.
Abstract: Automatically Self-Reciprocating sequencing valve for use with pneumatic power cylinders/actuators in systems operated at frequencies of a few cycles to a few thousand cycles per minute comprises a valve housing with a central bore adaptable to receive a shuttle member that makes or breaks fluid communication between a fluid supply source and a receiver such as a power cylinder or an actuator of a positive displacement pump in response to fluid pressures acting over surfaces such shuttle member entails as controlled by appropriate slave valve housed alongside therein including fluid supply and exhaust ports entering and leaving said valve housing, and together with said slave valve allowing an automatic reciprocating-valve-operation for as long as the pressurized fluid is supplied thereto to result in self-reciprocating operator responsive to not only system pressures for cycle regulation but also to an externally provided biasing flow regulator for an easy control of cycle frequencies within the desired prac
Abstract: A source of fluid, regulated as to pressure intensity before entry into a control valve assembly, drives a fluid biased piston motor. A mechanically actuated and fluid held valve in the control valve assembly controls pressurization of a pressure chamber in the piston motor displacing the motor piston through its return stroke. Pressure differential on opposite sides of a fluid operated valve actuator insures rapid opening of the valve and holding thereof in its open position during the motor piston return stroke. At the end of the return stroke, the pressure differential is eliminated to allow spring-biased closing of the valve and venting of the pressure chamber.
Abstract: A waste disposal unit having cutters which are driven with a rotary reciprocating motion by a water powered piston moving in a toroidal chamber. An automatic servo controlled valve, responsive to differential pressure on opposite sides of the piston, reverses the piston direction at the end of a stroke, or when an obstruction is encountered. The driving water is exhausted into the cutting chamber to flush waste material through the stacked cutters, which are arranged to reduce the waste material progressively to small particles.
Abstract: A hammer and more particularly a fluid operable hammer wherein alternating impetus provided by pressurized liquid and gas means actuates a reciprocable hammer piston to generate repetitive impact loads.
Abstract: A pressure responsive semi-automatic directional control valve for controlling a hydraulic cylinder. Manual movement of the valve from neutral to starting position applies pressure to one side of the cylinder. The pressure buildup at the end of this stroke causes the valve to move to return position. The pressure build up at the end of the return stroke then causes the valve to return to neutral position.A modification causes movement of the valve back to starting position thus providing continuous repeat cycle operation of the control valve.
Abstract: The piston of a pneumatic cylinder is reciprocated with a controllable dwell time at each end of its stroke, under the control of a digital fluidic circuit which responds to the termination of exhaust flow at the end of each piston stroke to initiate the reverse piston stroke. The air for driving the piston is supplied alternately to opposite ends of the piston through respective cylinder ports, by way of a corresponding pair of pilot valves which are controlled by the fluidic circuit so that one or the other of the pilot valves may supply driving air to the piston at any time.
Abstract: A fluid operable engine has a cylinder in which a piston slides up and down. The cylinder has a cylinder wall and two end walls. The piston divides the cylinder into two chambers. The piston is hollow, has a cylindrical wall and two end walls, with a rigid tube extending from and through one end wall of the piston through an adjacent end wall of the cylinder so that the interior of the piston communicates with the exterior through the tube. The cylinder has an aperture in each end wall or in its cylindrical wall close to the end walls and the piston has an opening in each of its end walls. A closure member is provided for alternately closing the openings or the apertures as the piston reaches each end wall. The engine is operated either in a positive or negative manner, with fluid being charged into or sucked from the piston or the cylinder. The openings may be closed from within or without and the apertures may be closed from inside or outside. The closure member may be mechanically or fluid operable.