Abstract: Liquid fluid pressure applied to a piston causes advancement thereof at a rapid rate until an external resisting load applied to the piston rod exceeds a predetermined value producing a corresponding increase in the pressure within the opposing pressure chambers to which the piston is exposed. Bi-directional flow, conducted between the opposing chambers during rapid piston movement, is automatically blocked by a differential circuit pressure operated piston valve to cause a rapid increase in the differential pressures acting on the piston, and an increase in the value of the external piston rod load with a corresponding decrease in its rate of movement in the same direction. A modified embodiment permits the piston rod to act under pressure and with a force in both the extending and retracting phases of the stroke with the same rapid extending rate until the external resisting force is encountered.
Abstract: A solenoid powered flow control valve in which the valve spool has split the pump flow across a primary metering orifice and a pilot metering orifice which regardless of spool position maintains a substantially constant flow ratio between the main and pilot flow. The valve spool is controlled by opposing servo chambers which sense the pressure drop in the pilot flow path across a solenoid powered variable orifice.
Abstract: An impact mechanism operated with gaseous fluid under pressure fed from a source of fluid having a casing with an inner cylindrical space. A piston is accommodated for reciprocation within the cylindrical space of the casing to divide the space into a work stroke chamber and an idle stroke chamber. The chambers are in communication with the source of gaseous fluid through a distribution means for reciprocation of the piston under the action of fluid. A valve is provided over the inlet port of at least one chamber to admit gaseous fluid under pressure thereto. The valve comprises biasing means in the form of a helical compression spring mounted coaxially with the inlet port of the chamber. One end of the spring is tightly sealed and the other end is fixed over the inlet port of the casing. Gaseous fluids under pressure is admitted to the chamber through gaps between the turns of the spring when the spring is expanded, and the admission is interrupted when the spring is compressed.
November 14, 1977
Date of Patent:
February 3, 1981
Vadim D. Petukhov, Viktor A. Gaun, Oleg I. Bobrov
Abstract: An arrangement for a hydraulic brake booster through which a pump-circulated fluid is throttled for supplying fluid to the brake booster includes a throttle element which is actuated by the booster pressure through a control spring. The control spring and a piston associated therewith limits the maximum amount of pressure that can be throttled so that a separate pressure-limiting valve, for instance, is not necessary.
Abstract: A pressurized fluid supply for an auxiliary power steering system includes a regulator valve assembly controlling the output pressure of a fluid supply pump under the opposing influences of the pump discharge pressure and a signal feedback pressure from a fluid operated servomotor. An adjustable bias applied to the regulator valve assembly establishes a low idling discharge pressure for the pump while no steering action is being performed by the servomotor to which the pump is connected by a control valve biased to a flow blocking position.
Abstract: A device for cushioning hydraulic actuators at the end of travel including a unique valve responsive to hydraulic pressure which, one when under system return pressure ports fluid to a chamber of less volume than the actuator cylinder and then through a line restriction for reduced fluid flow and the consequential slowing of the actuator and two when system pressure is off, drains the chamber for use during the next cycle.
Abstract: The fluid-actuated percussion mechanism includes a housing with an internal ylindrical space wherein a reciprocating piston, which divides the space into a working stroke chamber and an idle stroke chamber, is received. The mechanism further includes fluid distributing means and a distribution unit mounted in the housing for placing the chambers and a source of the working fluid in communication. The housing also accommodates a work-performing member adapted to receive impacts from the piston. The distribution unit includes at the inlet of at least one of the chambers a valve made in the form of a resilient annular element. The surface of the distribution unit has valve seats made in it, the number of which corresponds to that of the inlets for supplying the working fluid into the chambers. The resilient valve element is taut about the surface of the distribution unit in opposition to the inlets and encircles the periphery of the unit.
June 30, 1977
Date of Patent:
March 25, 1980
Institut Gornogo Dela Sibirskogo Otdelenia Akademii Nauk SSSR
Viktor A. Gaun, Anatoly V. Belousov, Vadim D. Petukhov, Gennady I. Suxov, Nikolai A. Belyaev, Vitaly K. Alyabiev, Klimenty E. Rassomakhin
Abstract: Automatic temperature control system for vehicles commonly utilize vacuum pressure as a power source to perform various functions such as operating the mode damper which routes hot or cold air through either lower or upper outlets. The vacuum pressure is directed to the vacuum motor or actuator to the mode door by a vacuum switch. Normally, the switch is of the type having a stationary ported member and an overlying member which is movable to interconnect the various ports. Undesirable split modes of operation occur because of either improper placement of the rotatable switch member or excessive leakage thereby. Split mode operation may undesirably cause improper allocation of hot and cold air through upper and lower outlets. The subject application provides a vacuum switching device or "toggle" located between the vacuum switch and the vacuum or actuator motor.
April 17, 1978
Date of Patent:
March 4, 1980
General Motors Corporation
Ronald D. Freiberger, Richard D. Reprogle
Abstract: The invention, in an embodiment shown, employs a piston-controlled metering valve to attenuate oil-pressure biasing of a thrust piston as discharge pressure in the gas compressor diminishes, and to increase the biasing as the discharge pressure increases. Discharge pressure of the compressor is impressed on one surface of the valve piston, and compressor oil pressure is addressed to the opposite surface of the piston from the oil pressure line. A shunt line communicates with a valve-metered orifice to bypass oil flow therethrough, from the oil pressure line, upon the compressor discharge diminishing, and the orifice becomes constricted--to impede an oil bypass--upon the compressor discharge increasing. The degree of oil bypassing or shunting from the oil pressure line results in a modulation of the oil line pressure which, in turn, is addressed to the thrust piston.
Abstract: A hydraulic mine prop comprises a cylindrical top ram portion and a bottom ram portion which is telescopically engageable in said top ram portion and has an upper piston portion in sliding sealing engagement with the interior of said top ram portion. A ram head closes the top of said ram portion and a valve seat body is disposed between the ram head at a spaced location therefrom adjacent the top of the top ram portion and defines a vent space therebetween. The valve seat body also encloses a pressure space between itself and the piston and a passage is defined through the valve body within a valve seat portion thereof which communicates the pressure space to the vent space. The passage is closed by a spring-biased valve which may open against the biasing force of the spring.
Abstract: A power steering pump flow and pressure control valve comprising a valve spool located on the high pressure side of the pump and on the upstream side of the vehicle steering gear. The valve includes a spool slidably situated in a valve chamber and a metering pin that is moved relative to the spool to either a first operating position or a second operating position. The metering pin registers with a flow control orifice located at one end of the valve chamber to provide a high flow or a low flow depending upon its operating position.
Abstract: A fluid circuit connects a first pump to a first motor and has a control valve for controlling fluid flow to the first motor. The control valve is movable between a first position at which the first pump is blocked from communication with the first motor, a second position at which fluid flow to the motor is controllably modulated and a third position at which substantially the full output of the first pump is directed to the first motor. A valve device connects a second pump to the fluid circuit and is movable between a first position at which the second pump is in communication with a tank and a second position at which the output of the second pump is combined with the output of the first pump. The valve device is moved to the second position in response to the control valve being moved from said second position toward said third position.
Abstract: A valve device having a pressure operable valve piston, particularly for booster steering system, to selectively control pressure flow to a consumer device such as a hydraulic servomotor in order to permit use of a reserve pump in event of failure of a main pump. The valve in a neutral position combines the output of both pumps but is responsive to a first increase in the flow rate beyond a predetermined limit to shunt flow from the reserve pump to a sump. Upon further increase in the flow rate the valve piston moves to a position to also shunt part of the output from the main pump to a sump. Signal means is actuated by movement of the valve piston to apprise a vehicle driver that the steering system is operative.
Abstract: 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 is an area differential between the top and bottom ends of the piston head. The device includes an inverted "U"-shaped seal ring on the piston head which functions as a one-way check valve to effect piston reciprocation in coaction with the area differential on the piston head.
Abstract: A device for opening and closing a rotary valve by remote control comprising a cylinder having a main bore in which a movable unit is slidably mounted in fluid tight manner and which can be displaced in opposite directions by a pressurized fluid supplied by either of two pressurized fluid sources which can be remotely actuated in independent fashion. A sequencing mechanism is mounted in the cylinder for simultaneously applying the pressurized fluid from an activated source to a corresponding end face of the movable unit while connecting the other end face with the atmosphere. The movement of the slidable unit is transmitted to the rotary valve through a rack and pinion arrangement and a linkage composed of cranks and a connecting rod so arranged that when the valve is in either of its end positions it cannot produce movement of the linkage due to alignment of the axis of rotation of the pinion and the connection points of the rod to the cranks.
Abstract: A hydraulic swing motor which is provided so as to assure an improved cushioning effect near the end of its stroke and ultimately to make possible a reduction in the cushion stroke sector or an increase in the effective stroke, with fluid inlet and outlet passages at the casing being connected to chambers partitioned with a first vane fixed to the shaft side and a second vane fixed to the casing side and which are closed by means of the said first vane when the relative motion of the first and the second vanes nears its end, and with throttle valves to control the fluid discharge rate and relief valves to release the discharge fluid when its pressure rises beyond a certain limit in a section which remains open throughout the whole stroke.
Abstract: A valve is used in a system employed on a vehicle for effecting the selected automatic disengagement of the transmission or main clutch upon the application of the vehicle service brakes, as well as the reengagement of the transmission when the brakes are released. Such valve allows rapid pressure buildup to the brakes, so that they may be rapidly applied, but delays the release of the brakes to allow ample time for reengagement of the transmission.
Abstract: A hydraulic system for use in engines having reciprocating pistons and rotary piston rods wherein hydraulic fluid is supplied to each cylinder to not only lubricate the piston and cylinder but also to facilitate the movement of the piston to the top dead center position.
Abstract: A motor vehicle fluid power circuit is provided with a constant displacement pump, a control valve, an open center steering valve, a hydraulic ratio type brake booster, and a ratio override valve. The control valve includes a shuttle piston which controls fluid flow between the pump and the brake booster, between the pump and the steering valve, and between the brake booster working chamber and the downstream side of the steering valve. The brake booster includes a trapped volume chamber in which a larger area input rod moves to provide greater movement of an output rod and power piston assembly.
Abstract: The valve has an input end through which hydraulic fluid is introduced and a main output end through which the hydraulic fluid is transmitted to the mechanism which is controlled. Intermediate the input and output ends is a bypass through which the hydraulic fluid can flow back to the sump which flow occurs until a movable piston within the device closes off the bypass.
Abstract: A stroke control mechanism for a hydraulic actuator having a piston and cylinder device including a blocking valve for selectively blocking fluid flow from one side of the actuator, the blocking valve consisting of a spring biased check valve mounted on one end of a valve stem and actuable by a control bar on the piston rod at the end of the stroke of the piston, the spring biased check valve being constructed to be opened by fluid pressure flowing to the extending side of the piston without movement of the valve stem so that creepage of the piston during its retracting movement resulting in contact between the valve stem and the actuating member will not prevent reversal of the piston.
Abstract: An adjustable stroke length fluid cylinder used to move agricultural or industrial machinery is disclosed. The cylinder is an enclosed unit having a movable piston therein which is attached to an axial piston rod secured to the load. A fluid valve directs the application of pressure fluid to either side of the piston to extend or retract the piston rod. One end of the cylinder houses a head unit containing an internal valve which is operated by a stop member positioned on the piston rod. The internal valve is effective to stop retraction of the piston rod when actuated by the stop member by blocking fluid flow through the cylinder. Subsequent extension of the piston rod automatically returns the internal valve to its open position.
Abstract: Hydraulic mechanism in a transmission for engaging a clutch for forward or reverse before a clutch for first, second, or third speed. Flow of pressure fluid to the latter clutch is by way of a quick fill spool having a large orifice, a rate of rise spool, and a poppet therein having a small orifice. A restricted orifice of appreciable, helically turned length is used in connection with the spools and the poppet in such a way that, after the power unit for the clutch for first, second, or third speed is filled with fluid, pressure of the fluid in the power unit is raised at controlled rate to its maximum.
Abstract: A control apparatus for use with cylinder assemblies for cushioning the piston as it reaches the end of its stroke so as to control the speed at which the piston approaches the cylinder ends and to prevent damage to the cylinder assembly. The control apparatus includes a body which has an inlet port that is adapted for connection to the cylinder assembly and an outlet port that is aligned with the inlet port and is adapted to vent to atmosphere or for line connection. An expansion chamber is provided within the body and includes a valve for controllably venting the chamber. A first passageway connects the inlet port, outlet port and expansion chamber, and a second passageway connects the inlet port and the first passageway for controlling flow between the inlet port and expansion chamber.
Abstract: A source of hydraulic fluid is connected with a user by a hydraulic circuit in which a pump is interposed so as to supply the hydraulic fluid under pressure to the user. A housing is interposed in the circuit, having a bore communicating with the circuit. An air venting passage communicates with the bore and a valve body is located in the bore upstream of the passage and defines a throttling gap through which air in the circuit can pass into and out of the passage, but at which subsequent flow of hydraulic fluid will create sufficient pressure to displace the valve body to a position in which it seals the air venting passage.
Abstract: Disclosed herein is a hydraulic modulator valve for a control system of a hydraulically operated mechanism having a casing with a bore therein, a stepped spool axially and slidably engaged within the bore to form an annular fluid throttle passage against the circumference of the bore between a first and a second ports drilled through the casing, and spool actuator for controlling axial displacement of the spool. The stepped spool comprises a large diameter portion to be hermetically engaged within the bore, a small diameter portion and a medium diameter portion in sequence, the throttle passage being formed by the bore and the medium and small portions of the spool.