Through Working Member Patents (Class 91/401)
  • Patent number: 11173954
    Abstract: A self-setting valve assembly for a power steering gear assembly includes a plug, a first plunger, a second plunger, and a biasing member. The plug extends between a first end and a second end. The plug defines a cavity that is disposed between the first end and the second end, a first bore that extends from the first end to the cavity, and a second bore that extends from the second end to the cavity. The first plunger has a first head that is disposed within the cavity and a first stem that extends from the first head through the first bore. The second plunger has a second head that is disposed within the cavity and a second stem that extends from the first head through the second bore. The biasing member is disposed within the bore and extending between the first head and the second head.
    Type: Grant
    Filed: April 9, 2020
    Date of Patent: November 16, 2021
    Assignee: Steering Solutions IP Holding Corporation
    Inventors: Albert C. Wong, Thomas C. Rytlewski, Jason A. Dutsky
  • Patent number: 11066932
    Abstract: An actuating cylinder for an adjustment apparatus of a pivot angle of a hydrostatic axial piston machine has a hydraulic stop which connects an actuating pressure chamber of the actuating cylinder to an interior of the housing of the axial piston machine if the actuating piston is maximally extended. To this end, a channel is provided on the actuating piston side, while a control edge is provided on the housing side. The control edge is formed at the interface of a stop bore with the actuating cylinder bore. The stop bore may also be a leakage bore of the axial piston machine.
    Type: Grant
    Filed: June 16, 2020
    Date of Patent: July 20, 2021
    Assignee: Robert Bosch GmbH
    Inventor: Felix Hoffmann
  • Patent number: 11060537
    Abstract: A piston (6) is hermetically inserted via a sealing member (7) in a cylinder hole (2) provided in a housing (1) so that the piston (6) is movable in an up-down direction. A communication passage (21) provided in an inner peripheral wall of the cylinder hole (2) is communicatively connected to a lock-side supply and discharge passage (13) through which pressurized oil is supplied to and discharged from a lock chamber (11) of the housing (1). An opening area (S1) of the communication passage (21) is designed to be smaller than an opening area (S2) of the lock-side supply and discharge passage (13). When the piston (6) is caused to move for releasing from a raised position to a lower limit position, the sealing member (7) is lowered from the raised position beyond the communication passage (21), to open communication between a release chamber (12) in the housing (1) and the lock-side supply and discharge passage (13) via the communication passage (21).
    Type: Grant
    Filed: October 1, 2018
    Date of Patent: July 13, 2021
    Assignee: KOSMEK LTD.
    Inventor: Ryota Kojima
  • Patent number: 10927862
    Abstract: A double-acting overflow valve of a working cylinder includes a housing with an encompassing wall and a first and a second axial delimiting wall disposed opposite one another. A first valve body has a first valve tappet with a conical shape and passes through the first axial bore to define a first annular gap with a gap width that is dependent on a position of the first valve body along an actuation path thereof. A second valve body has a second valve tappet with a conical shape and passes through the second axial bore to a second annular gap with a gap width that is dependent on a position of the second valve body along an actuation path thereof. A first and second counter bearing are provided. A first actuating element defines a maximum actuation path of the first valve body by acting on the first counter bearing. A second actuating element defines a maximum actuation path of the second valve body by acting on the second counter bearing.
    Type: Grant
    Filed: March 2, 2018
    Date of Patent: February 23, 2021
    Assignee: Buemach Engineering International B.V.
    Inventor: Josef Bueter
  • Patent number: 10723439
    Abstract: An actuator is disclosed comprising: a moveable member; a first hydraulic chamber in contact with a first surface of the moveable member; a second hydraulic chamber in contact with a second, opposing surface of the moveable member; a movable locking mechanism coupled to a moveable wall of the second hydraulic chamber; and a resilient biasing member acting on the moveable wall of the second hydraulic chamber so as to bias the moveable wall and locking mechanism. The actuator is configured to selectively vary the pressure in the second hydraulic chamber so that the resilient biasing member is able to bias the moveable wall to move, thereby moving the locking mechanism to engage the moveable member so as to prevent the movement of the moveable member towards at least one of the first and second hydraulic chambers.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: July 28, 2020
    Assignee: RATIER-FIGEAC SAS
    Inventors: Thibaut Marger, François Pouly, Jean-Christophe Labascoule
  • Patent number: 9890802
    Abstract: A phaser valve for a piston and cylinder assembly helps to keep a pair of pistons in phase with each other. The phaser valve includes a poppet which is slidable between opposing seats of a valve housing. The poppet includes a head and a stem, both the head and the stem having concave portions which facilitate the flow of hydraulic fluid across the valve. The poppet head has two generally conical ends, so that the head makes a fluid-tight seal with a seat when the head is urged towards either seat. Due to its construction, the phaser valve may be built to fit within a very small space, while still allowing a substantial flow of fluid when the head is not in abutment with one of the seats.
    Type: Grant
    Filed: October 5, 2014
    Date of Patent: February 13, 2018
    Inventors: David Albrecht, David Albrecht, Jr.
  • Patent number: 9339946
    Abstract: A device automatically mixes bone cement and has two separate plunger space sections with a gas feed and a gas outlet, which are separated from each other through a plunger. A blocking organ is provided in the plunger and can be switched at the turnaround points of the plunger path. Suitable connecting facilities connect the plunger to a mixing facility that is arranged in a mixing vessel. Alternating build-up of a pressure difference and pressure equalization in both plunger space sections causes the plunger to move up and down. The plunger motion effects a simultaneous up-and-down motion and rotation of the mixing facility.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: May 17, 2016
    Assignee: Heraeus Medical GmbH
    Inventors: Sebastian Vogt, Tim Schnieber
  • Patent number: 9151303
    Abstract: A hydraulic actuator containing a hollow body defining a cylindrical cavity and a rod which is mounted to slide within the body along a sliding axis between two end positions and which is integral with a piston sliding in a sealed manner within the cylindrical cavity in order to define two chambers. The rod defines an interior passage, connecting the two chambers, which has a valve comprising a shut-off member which is returned towards a seat and closes the passage. The rod receives a push member which can move relative to the rod between a position apart from the shut-off member and a position forcing the shut-off member to open. The push member is constrained, when the rod reaches the end of its stroke, by the push member engaging with a portion of the hollow body.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: October 6, 2015
    Assignee: MESSIER-BUGATTI-DOWTY
    Inventors: Xavier Jubert, Ludovic Dufay, Sébastien Ernis
  • Patent number: 8863641
    Abstract: A fluid pressure operated actuator device, comprising: a body defining a first chamber (2) comprising an inlet in fluid communication with a pressurized fluid source (1); and a moveable element (5) mounted in the first chamber, the moveable element comprising an operative end (4) and partition means (3) configured to separate a first region of the first chamber comprising the inlet from a second region of the first chamber opposed to the first region during use of the device, the moveable element being moveable relative to the body between an extended configuration and a retracted configuration, with movement from the retracted configuration to the extended configuration occurring in response to a pressure differential across the partition means, wherein the actuator device includes a first passageway (7) for allowing passage of fluid from the pressurized fluid source to a second chamber (9) in the operative end of the moveable element, and a second passageway (8) for allowing passage of fluid from the second
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: October 21, 2014
    Assignee: Isentropic Ltd.
    Inventor: Jonathan Sebastian Howes
  • Patent number: 8850952
    Abstract: A phaser valve for a piston and cylinder assembly helps to keep a pair of pistons in phase with each other. The phaser valve includes a poppet which is slidable between opposing seats of a valve housing. The poppet includes a head and a stem, both the head and the stem having concave portions which facilitate the flow of hydraulic fluid across the valve. The poppet head has two generally conical ends, so that the head makes a fluid-tight seal with a seat when the head is urged towards either seat. Due to its construction, the phaser valve may be built to fit within a very small space, while still allowing a substantial flow of fluid when the head is not in abutment with one of the seats.
    Type: Grant
    Filed: February 22, 2010
    Date of Patent: October 7, 2014
    Inventors: David E. Albrecht, David E. Albrecht, Jr.
  • Patent number: 8065930
    Abstract: The present invention provides a three position hydraulic piston assembly for a gear ratio change mechanism for a transmission exhibiting reduced gear shift noise. The three position hydraulic piston assembly includes a master piston and motion retarding assemblies that act near both travel limits of the master piston. The master piston includes symmetrical passageways that provide hydraulic fluid flow to small chambers at each end of the piston that are closed off as the piston approaches its travel limits. Hydraulic fluid trapped in the chambers decelerates the piston and is bled off through an orifice allowing the piston to reach its travel limit and quickly and quietly engage a gear ratio.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: November 29, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Henryk Sowul, Tejinder Singh, Brian W. Whitmarsh, Brian Tooman, James D. Hendrickson, Richard A. Pashnik
  • Patent number: 7258034
    Abstract: Disclosed is an apparatus for protecting impact to a rack bar of a power steering gearbox comprising an oil pressure cylinder, to which oil which has passed through an oil pressure pump and a rotary valve is supplied through a left port or right port, a rack bar disposed in the oil pressure cylinder and horizontally reciprocating, a piston fixed at the middle of the rack bar, a first lack bush and a second lack bush disposed at both ends of the cylinder, in which the piston moves, to close the cylinder, and bypass holes with a downward convex shape disposed at both ends of the cylinder adjacent to the first and second rack bushes, in which a part of oil pressure is released immediately before a piston of the rack bar moving by the power of oil pressure reaches a rack bush, whereby impact to the cylinder or noise is not generated.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: August 21, 2007
    Assignee: Hyundai Mobis Co., Ltd.
    Inventor: Dae-Jung Kim
  • Patent number: 6957603
    Abstract: A pressure releasing valve structure 36? is provided for a fluid operated device 10. The device has an orifice 42 constructed and arranged to be in fluid communication with a pressure chamber C. The valve structure includes a body 49 having first and second ends. A valve member 40 is provided at the first end of the body and is constructed and arranged to seal the orifice 42. A first spring 38 is associated with the first end of the body and is constructed and arranged to cause the valve member 40 to seal the orifice 42 under first pressure conditions in the pressure chamber C. A second spring 50 is associated with the second end of the body and is constructed and arranged to compress thereby reducing a force exerted by the first spring 38, permitting the valve member 40 to move to a non-sealing position to open the orifice under pressure conditions in the pressure chamber C lower than would be required absent the provision of the second spring.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: October 25, 2005
    Assignee: Latch-Tool Development Co. LLC
    Inventor: Myron D. Tupper
  • Publication number: 20030037668
    Abstract: An under body hydraulic cylinder is disclosed having a poppet relief valve disposed through a piston. As the piston is moved by oil pressure towards the stuffing box, the poppet relief valve engages a stroke stop mounted on a stuffing box surrounding the piston rod. As the poppet engages the stroke stop, the poppet is opened to allow oil to bypass the piston. The cylinder stroke is determined by the length of the stroke stop mounted on the stuffing box.
    Type: Application
    Filed: August 21, 2001
    Publication date: February 27, 2003
    Inventor: Alan Nastasi
  • Patent number: 6161465
    Abstract: A hydraulic shutoff device in the end positions of a servo cylinder is provided to prevent direct hard contact between the working piston (31) and the limit stops (47, 48) under working pressure and to enable withdrawal from end positions with hydraulic assistance. Idler pistons (32, 33) with limited displaceability are located on the working piston (31) and act as a seal, fitting tightly against the sealing edges (34, 35) of the working piston. The sealing edges (34, 35) control a bypass channel (36) located in the working piston (31). A spring (41) is inserted between the idler pistons (32, 33) in a chamber (40) which can be pressurized. When the working piston (31) comes into contact, for instance, with the limit stop (48) of the bush (43), the collar (45) knocks one idler piston (33) away from the sealing edge (35). Junction with the chamber (40) occurs through the bypass channel (36), whereupon the working pressure pushes the idler piston (32) back against the spring (41) away from its sealing edge (34).
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: December 19, 2000
    Assignee: ZF Friedrichshafen AG
    Inventor: Jens-Uwe Hafermalz
  • Patent number: 6050171
    Abstract: A hydraulic power steering gear assembly includes an assembly body defining a piston chamber having opposed chamber ends with plunger passages formed in the ends, a reciprocating piston and a chamber having opposed ends and a passage extending between the piston ends, a check valve at each end of the piston passage, and a plunger assembly in each plunger passage with each assembly including a spring frictionally holding assembly in the passage and a poppet extending into the chamber to unseat a ball valve as the piston is moved toward one end of the chamber.
    Type: Grant
    Filed: April 22, 1998
    Date of Patent: April 18, 2000
    Assignee: R.H. Sheppard Company, Inc.
    Inventor: Peter H. Sheppard
  • Patent number: 5803201
    Abstract: A hydraulic power steering gear assembly includes an assembly body defining a piston chamber having opposed chamber ends with plunger passages formed in the ends, a reciprocating piston and a chamber having opposed ends and a passage extending between the piston ends, a check valve at each end of the piston passage, and a plunger assembly in each plunger passage with each assembly including a spring frictionally holding assembly in the passage and a poppet extending into the chamber to unseat a ball valve as the piston is moved toward one end of the chamber.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: September 8, 1998
    Assignee: R. H. Sheppard Co., Inc.
    Inventor: Peter H. Sheppard
  • Patent number: 5778755
    Abstract: A novel adjustment assembly for use with a hydraulic control apparatus. The hydraulic control apparatus is attached to a hydraulically operated tool to provide a desired hydraulically powered function. The present invention allows the hydraulic control apparatus to be used with either a constant volume (open-center) hydraulic system or constant pressure (closed-center) hydraulic power system. The novel adjustment assembly of the present invention provides a structure which can be configured to force open shuttle spool valves in the control apparatus in a neutral condition for use with a constant volume power supply. The adjustment assembly can also be configured to be disengaged from the shuttle spool valves in a neutral condition for use with a constant pressure hydraulic power system. Operation of the adjustment assembly is made using standard tools and without disassembly of the control apparatus.
    Type: Grant
    Filed: March 1, 1996
    Date of Patent: July 14, 1998
    Assignee: Greenlee Textron Inc.
    Inventor: Thomas Gene Boese
  • Patent number: 5647722
    Abstract: A linkage mechanism which allows a substantially 180.degree. pivoting motion of a frame, and hence a boom arm secured to the frame, around the frame's pivot axis includes a mast to which the frame is fixedly secured, the mast being pivotably mounted on a pivot axis to an associated support frame. First and second hydraulic cylinders, each having a piston rod end and a cylinder end, are connected to respective sides of the mast. A control member is operatively associated with the first and second hydraulic cylinders for effecting a linear movement of the piston rods thereof and hence a pivotal movement of the mast and thus the boom arm secured to the mast about the mast's pivot axis. An overload protection circuit is connected to at least one of the first and second hydraulic cylinders such that the mast, and the frame and boom arm, will pivot around the pivot axis in the event an associated tool secured to the boom arm meets an obstruction. This avoids damage to the associated tool as well as the boom arm.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: July 15, 1997
    Inventor: Jack O. Cartner
  • Patent number: 5611256
    Abstract: The main feature of the differential pressure detecting system of the present invention resides in that, when a mechanical arm is to clamp a workpiece, a differential pressure can be produced for operating a cylinder and in turn triggering a responsive switch to activate a display device; when it clamps the workpiece, the differential pressure still exists for maintaining the said activating, when it clamps nothing, the cylinder will be restored and in turn turn off the responsive switch to turn off the display device.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: March 18, 1997
    Inventor: Chang S. Chung
  • Patent number: 5562017
    Abstract: An apparatus (10) including a housing (14) defining a chamber (16) and a movable piston (18, 100) dividing the chamber (16) into first and second chamber portions (20, 22). An apparatus (38, 40) directs fluid pressure into either the first or second chamber portion and vents the other to effect movement of said piston (18, 100). A relief valve (12) communicates the first and second chamber portions (20, 22) when the piston (18, 100) is near the end of its work stroke. The relief valve (12) includes a valve member (76) and a valve seat (74) which are relatively movable between open and closed positions. A method is performed to make the apparatus and includes forming a press-fit connection between the piston means (18, 100) and the valve seat (74).
    Type: Grant
    Filed: April 17, 1995
    Date of Patent: October 8, 1996
    Assignee: TRW Inc.
    Inventor: Bernd F. Wuenscher
  • Patent number: 5511460
    Abstract: A clip valve for limiting the stroke of an exhaust-valve-operating hydraulic actuator piston in a compression release engine brake has a plunger which follows the actuator piston down until the motion of the plunger is stopped by a retaining ring in a bore in which the plunger reciprocates. When the plunger is thus stopped, an aperture in the slave piston is uncovered, thereby allowing pressurized hydraulic fluid to escape from the actuator piston cylinder and preventing further downward motion of the actuator piston. The clip valve apparatus is constructed to facilitate assembly of the plunger and retaining ring in the bore, as well as to provide secure and fail-safe retention of those components in the bore. The parts of the clip valve are simplified and preferably also reduced in number as compared to the prior art.
    Type: Grant
    Filed: January 25, 1995
    Date of Patent: April 30, 1996
    Assignee: Diesel Engine Retarders, Inc.
    Inventor: Dennis R. Custer
  • Patent number: 5322142
    Abstract: This invention relates to a pressure turnoff device in the terminal positions of the steering deflection in an auxiliary power steering. In steering systems that reveal a working piston (2) that can be shifted in the steering housing, one inserts this turnoff device in a passage borehole (17) of working piston (2). For each steering direction, one provides a turnoff valve (20, 22 or 21, 23) which can be activated by a plunger (24 or 25) that bumps into a wall (30 and 31). To avoid any time consuming adjustment work on the turnoff valves (20, 22; 21, 23), the walls (30 and 31) contain screwed-in bolts (40 and 41) with pressed-on sleeves (32 and 33), with the sleeves working as stops. After installation of the auxiliary power steering in the vehicle, one can automatically press the sleeves (32 and 33) into the terminal position corresponding to the wheel steering angle.
    Type: Grant
    Filed: February 9, 1993
    Date of Patent: June 21, 1994
    Assignee: ZF Friedrichshafen, AG.
    Inventor: Dieter Elser
  • Patent number: 5292220
    Abstract: A linkage mechanism which allows a substantially 180.degree. pivoting motion of a frame, and hence a boom arm secured to the frame, around the frame's pivot axis includes a mast to which the frame is fixedly secured, the mast being pivotably mounted on a pivot axis to an associated support frame. A first hydraulic cylinder having a piston rod end and a cylinder end is pivotably secured at the piston rod end to a first side of the mast. A second hydraulic cylinder having, a piston rod end and a cylinder end is pivotably secured at the piston rod end to a second side of the mast. A control member is operatively associated with the first and second hydraulic cylinders for effecting a linear movement of the piston rods and hence a pivotal movement of the mast and thus the boom arm secured to the mast about the mast's pivot axis.
    Type: Grant
    Filed: April 9, 1992
    Date of Patent: March 8, 1994
    Inventor: Jack O. Cartner
  • Patent number: 5205372
    Abstract: A device comprising a cylinder and a piston slidably fitted therein and having a metal piston ring attached to its outer periphery. The cylinder has a recess in each of a plurality of portions thereof dividing the inner periphery of the cylinder circumferentially thereof and opposed to the piston ring when the piston is brought close to each of its opposite stroke ends, the recess having a width smaller than the width of fit of the piston to the cylinder. The piston has a recess corresponding to the recess in the cylinder inner periphery and formed in each of a plurality of portions of the piston in the vicinity of the piston ring and diving the outer periphery of the piston circumferentially thereof. The cylinder has two oil chambers formed on the respective opposite sides of the piston and adapted to communicate with each other through the cylinder recess and the piston recess upon the piston being brought close to each stroke end.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: April 27, 1993
    Assignees: Koyo Seiko Co., Ltd., Mitsubishi Jidosha Kogyo Kabushiki Kaisha
    Inventors: Yoshimi Kotake, Tatsuro Motoyama
  • Patent number: 5139106
    Abstract: The invention relates to an auxiliary power steering system, especially for motor vehicles having a double acting servocylinder with two working chambers and a servopiston. A hydraulic steering limitation device has a valve that coacts with the servopiston responsive to a predetermined extent of power stroke to open a flow path from the pressurized working chamber to the tank connected working chamber to promptly stop the power stroke leaving the servopiston in position for prompt reversal of steering direction under pressure power. A stationary flow channel member extends the substantial length of the servocylinder and passes through a bore in the servopiston with which it has a sliding relationship. At a predetermined end of a power stroke, bores and a passage in the channel member communicate with the working chambers of the servocylinder to equalize the pressure at tank pressure for stopping the power stroke.
    Type: Grant
    Filed: January 29, 1991
    Date of Patent: August 18, 1992
    Assignee: Zahnradfabrik Friedrichshafen, AG
    Inventors: Dieter Elser, Heinrich Holub
  • Patent number: 5129311
    Abstract: A piston assembly comprising a primary piston and a co-centric secondary piston. The pistons are received within a housing for reciprocating movement therein and relative to each other. The housing and the pistons are arranged for operating pressure to be applied to the secondary piston so as to drive both pistons within the housing. The secondary piston is provided with means enabling the operating pressure to be equalized across the secondary piston and at least one bypass passage extends through the secondary piston. The arrangement is such that upon completion of the stroke of the pistons pressure equalization occurs across the secondary piston which causes the pistons to separate. The bypass passage becomes fully operable subsequent to pressure equalization, whereby a fast return stroke is achieved.
    Type: Grant
    Filed: July 16, 1990
    Date of Patent: July 14, 1992
    Assignee: National-Oilwell (UK) Ltd.
    Inventor: R. Hart
  • Patent number: 5094081
    Abstract: A hydraulic vehicle brake system of the type having a high system return pressure is provided. In order to minimize the size and strength of brake return springs required, the invention provides a device to be interposed between the brake and the brake control valve. Preferred embodiments of the device include an inlet port communicating with a brake valve and an outlet port communicating fluid pressure to a vehicle brake. A control assembly is provided intermediate the inlet and outlet ports and includes mechanisms for amplifying the hydraulic pressure effect in the direction from the outlet port to the return pressure system so that the brake return pressure exerted by the brake return springs can be substantially less than the hydraulic system return pressure.
    Type: Grant
    Filed: September 8, 1987
    Date of Patent: March 10, 1992
    Inventor: Lyle E. Osborne
  • Patent number: 5086864
    Abstract: The invention is concerned with a device that cuts off pressure in the final positions of the steering movement in an auxiliary-power steering device. In steering devices that have movable working pistons in the steering gear housing, this cut-off device is installed in a through drilled hole in the working piston. A by-pass valve that is activated by a push rod touching the wall of the housing is provided for every direction of steering. To avoid time-consuming adjustment work on the by-pass valves the walls contain bushings located opposite the push rods that are automatically pushed into the final positions corresponding to the wheel steering angle after the auxiliary-power steering device is installed in the vehicle. That happens as a result of rotating, first without auxiliary power, against the wheel limit stops, with the front axle jacked up, after the preliminary installation of the bushings in their drilled holes.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: February 11, 1992
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventor: Dieter Elser
  • Patent number: 4870889
    Abstract: A hydraulic device includes a piston slidable within a cylinder. Fluid under pressure is admitted to one end of the cylinder through an inlet which contains a restrictor. The piston is formed with an orifice and is biased by a first spring towards the one end of the cylinder. A thrust rod is engageable by the piston to transmit the movement of the piston to an external mechanism. When the piston is moved by rising fluid pressure the orifice is closed by the end of the thrust rod so that a higher value of fluid pressure is required to effect the initial movement of the piston than is required to allow the return movement of the piston.
    Type: Grant
    Filed: April 4, 1988
    Date of Patent: October 3, 1989
    Assignee: Lucas Industries Public Limited Company
    Inventor: Robin C. Wall
  • Patent number: 4860646
    Abstract: A compactor includes a longitudinally extending ground supported frame having an open end and a closed end. A cylinder and piston assembly is positioned within the frame and extends longitudinally therealong and a ram is secured to the piston for transferring waste through the open end. The cylinder has fluid ports at opposite ends thereof. An hydraulic fluid supply assembly introduces pressurized fluid to said ports for causing selective movement of the piston relative to the cylinder. An hydraulic spool valve is carried by the piston for permitting fluid to flow between the ports and for thereby preventing displacement of the piston when the dwell assembly engages one of the ends.
    Type: Grant
    Filed: February 10, 1987
    Date of Patent: August 29, 1989
    Assignee: Marathon Corporation
    Inventor: Kent Spiers
  • Patent number: 4821624
    Abstract: A stroke limiter for a hydraulic cylinder comprises two sleeve portions each having a channel located therein that are frictionally mounted to the piston rod adjacent to the piston. An elongated contactor is slidably received in each of the channels. The contactor is longer than the sleeve portion and extends past the bottom of the sleeve. The top of the sleeve is provided with a cutout portion which is adjacent to the contactor and provides a hydraulic fluid flow path from the piston mounted poppet valves. When the contactor contacts the end cap of the cylinder, the contactor slides upwardly in the sleeve and contacts the poppet valves in the cylinder unseating the valves and creating a hydraulic fluid flow path across the piston.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: April 18, 1989
    Assignee: Deere & Company
    Inventor: James R. Smith
  • Patent number: 4798125
    Abstract: This invention pertains to a pneumatic mode under which the structure of a hydraulic system is driven, particularly denoting the pneumatic mode under which a mini air compressor is being used as a means to elevate a hydraulic jack.This invention makes use of a working lever and a working body attached to the hydraulic mechanism which is compactly closed inside a body to drive the hydraulic lever of the hydraulic mechanism which is compactly closed at the other end of the body to conduct a continuous backward/forward movement which will press against and elevate the hydraulic jack. Such a movement is similar to a continuous backward/forward movement conducted by a piston in a cylinder body. However, the entire structure and effected of this invention is found much better because of its easy fabrication and its function of elevating the hydraulic jack by means of a pneumatic mode, which saves both time and strength and thus meet the requirement of a simple and automatic operation.
    Type: Grant
    Filed: November 3, 1987
    Date of Patent: January 17, 1989
    Inventors: Fung M. Chang, Chien C. Hsu, Wen C. Chen
  • Patent number: 4779843
    Abstract: A jack with drain valve including a housing having a first cylinder and a first piston; the first piston defining a second cylinder into which a second piston is reciprocally mounted. A drainage tube is defined by the first piston, the drainage tube extending between the second cylinder and the bottom, workpiece engaging surface of the piston. When both first and second piston engage a workpiece, hydraulic fluid may be forced through an inlet port into the first cylinder, placing pressure against both first and second pistons in their engagement with the workpiece; the drainage tube being obstructed by the second piston. Once the workpiece is moved or the jack retracted, pressure on the hydraulic fluid in the first cylinder, which may be applied by upward pressure on the first piston, forces the second piston downwardly beyond the inlet port of the drainage tube. In this manner the cylinders may be readily drained for reuse of the jack.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: October 25, 1988
    Inventor: John M. Lostra
  • Patent number: 4773303
    Abstract: An apparatus for readjusting first and second adjustable pressure relief poppet valves to vent the fluid pressure moving a piston when the piston is at the ends of a second work stroke which is of a length less than a first work stroke for which the poppet valves are adjusted. Each of the poppet valves is carried by the piston and includes a valve seat and a valve member movable relative to the valve seat. The piston is disposed in a fluid chamber defined by a housing. The piston divides the fluid chamber into first and second chamber portions. One of the chamber portions is pressurized and the other is vented to move the piston in a work stroke. The apparatus includes a member supported by the housing for moving the seat of the second poppet valve outwardly relative to the piston in response to the member moving relative to the housing and engaging the seat of the first poppet valve to move the seat of the first poppet valve inwardly relative to the piston.
    Type: Grant
    Filed: December 21, 1987
    Date of Patent: September 27, 1988
    Assignee: TRW Inc.
    Inventor: Donald R. Stroud
  • Patent number: 4736671
    Abstract: A fluid pressure control device is described effective to actuate an external device when the differential-pressure between a high-pressure fluid source and a lower pressure fluid source rises to a predetermined magnitude. The control device comprises a housing having a partition wall therein dividing its interior into two compartments communicating with each other through an opening in the partition wall. A differential-pressure sensing member is disposed in one of the compartments and is movable therein in response to the sensed differential-pressure. A stem is fixed to the differential-pressure sensing member so as to be moved therewith and carries a valve member at one end for moving it with respect to the valve opening to control the flow of the fluid therethrough and thereby to actuate the external device.
    Type: Grant
    Filed: January 23, 1986
    Date of Patent: April 12, 1988
    Inventor: Mordeki Drori
  • Patent number: 4729283
    Abstract: This invention relates to a valve suitable for location within a passage or bore of a piston or piston rod of a hydraulic ram assembly. The valve includes a valve body mountable in the bore or passage and a chamber provided in the valve body having a pair of fluid access ports preferably having a relatively narrow outer passage and an enlarged inner space which may function as a valve seat. There is also provided a pair of valve members wherein each valve member may co-operate with a respective valve seat to close or open same to fluid flow through the valve chamber.
    Type: Grant
    Filed: November 3, 1986
    Date of Patent: March 8, 1988
    Assignee: Delibes Pty. Ltd.
    Inventor: Raymond G. Hillier
  • Patent number: 4726284
    Abstract: A hydraulic cylinder is disclosed having a hollow cylinder with a closed first end and an open second end. A rod is positioned in the interior of the hollow cylinder and the rod is securely connected to the first end of the cylinder. The rod is positioned in substantially the center of the hollow cylinder and is substantially parallel to the longitudinal axis of the cylinder. The end of the rod that is spaced apart from the first end of the cylinder has an area of enlarged cross-section. A movable piston having a first end and a second end positioned with the first end of the piston being in the interior of the hollow cylinder. The second end of the piston extends from the open end of the hollow cylinder. The first end of the piston defines a slot for receiving the end of the rod having an enlarged cross-section. The slot is disposed to receive the end of the rod having the enlarged cross-section when the slot and the end of the rod are properly aligned.
    Type: Grant
    Filed: February 3, 1986
    Date of Patent: February 23, 1988
    Inventor: Robert H. Green
  • Patent number: 4700955
    Abstract: A fluid-operated ram, for example comprising a cylinder 10 and piston 12, is provided for actuating a device such as a chuck having jaws 15. When the jaws are moved by the ram to grip a workpiece this constitutes a limiting position which impedes the flow of fluid thus causing a build-up of fluid pressure within the ram. This build-up can be detected to give an indication as to when a workpiece has been securely and safely gripped. To ensure that a false indication is not given if the ram reaches an end of its working stroke before the workpiece is securely gripped, means (22) are provided to relieve pressure within the ram when the ram reaches an end of its working stroke.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: October 20, 1987
    Assignee: Pratt Burnerd International Limited
    Inventor: Joseph F. Jackson
  • Patent number: 4687449
    Abstract: A hydraulic trim-tilt system for an outboard motor (10) utilizes a first pilot operated relief valve (48) in one trim piston (21) to limit the stroke of the trim pistons (21, 22) under load. After the trim pistons have reached the top of their stroke, under reduced load, the first pilot operated relief valve (48) is blocked and a second pilot operated relief valve (58) operates to allow a higher pressure to be supplied to the trim-tilt unit (16) to lift the outboard propulsion unit (15) in a higher shallow water drive range.
    Type: Grant
    Filed: December 20, 1985
    Date of Patent: August 18, 1987
    Assignee: Brunswick Corporation
    Inventor: William G. Fenrich
  • Patent number: 4681021
    Abstract: A driving apparatus for producing a to-and-fro movement and having four plunger cylinders and four external non-return valves. Such driving apparatus is distinguished by a particularly simple construction.
    Type: Grant
    Filed: May 7, 1986
    Date of Patent: July 21, 1987
    Assignee: Krupp Polysius AG
    Inventors: Otto Heinemann, Heinz-Herbert Schmits
  • Patent number: 4648307
    Abstract: A power assist steering gear for use in vehicles having a housing that defines a chamber. A piston dividing the chamber into first and second chamber portions. The piston is movable through a work stroke in opposite directions in the chamber. A steering valve directs fluid pressure into the first chamber portion and vents the second chamber portion to effect piston movement in a first direction and directs fluid pressure into the second chamber portion and vents the first chamber portion to effect piston movement in a second direction. An input shaft moves to effect actuation of the steering valve. A relief valve for communicates the first and second chamber portions when the piston is near the end of its work stroke.
    Type: Grant
    Filed: October 10, 1985
    Date of Patent: March 10, 1987
    Assignee: TRW, Inc.
    Inventor: William T. Rabe
  • Patent number: 4572054
    Abstract: An apparatus for the exact position feedback of a double-acting power piston in a hydraulic power cylinder subjected to extreme environmental conditions, especially high temperatures, comprising a double-acting detecting (measuring), or follower cylinder, having a volume corresponding to that of said power cylinder and including a detecting piston the position of which is sensed by an electrical detector, wherein a pair of working spaces of power and detecting cylinders are in fluid communication with each other via a connecting pipe, while the respective other working spaces are adapted to be connected to a (pressursized) fluid pump or a reservoir through a control valve.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: February 25, 1986
    Assignee: Zimmermann & Jansen GmbH
    Inventors: Heinz D. Hannes, Josef Lothmann, Ludwig Walther
  • Patent number: 4554991
    Abstract: An improved hydraulic auxiliary drive system for driving the normally non-driven wheels of a vehicle is disclosed. A variable displacement motor having a tiltable swash plate operable between zero and full displacement positions drives the normally non-driven wheels and a variable displacement pump supplies pressure fluid to the motor. A spring biases the swash plate toward its zero displacement position and a servo mechanism is connected with the swash plate for tilting the same. A first supply delivers pressure fluid to the servo mechanism to tilt the swash plate toward its full displacement position and a second supply delivers pressure fluid to the servo mechanism to tilt the swash plate toward its zero displacement position. The first supply includes a pressure control valve to control the pressure thereof.
    Type: Grant
    Filed: February 23, 1984
    Date of Patent: November 26, 1985
    Assignee: Mud Hog Corporation
    Inventor: Brent E. Eden
  • Patent number: 4525999
    Abstract: A pneumatic actuator for deploying flexible bodies and the like is disclosed. The actuator is a plurality of telescoping tubes made of high temperature resistant graphite material which are extended by the pressure of gases produced internally by a gas generator contained within the innermost tube. The extended tubes are locked in position automatically and venting of the gases from the tube interior is provided for simultaneously with full and locked extension of the tubes.
    Type: Grant
    Filed: December 23, 1982
    Date of Patent: July 2, 1985
    Assignee: Thiokol Corporation
    Inventor: Frank S. Inman
  • Patent number: 4490120
    Abstract: A hydraulic system for trimming and tilting an outboard propulsion unit (10) includes both trim piston-cylinder units (22, 23) and a trim-tilt piston-cylinder unit (17). The flow of hydraulic fluid from the reversible pump (49) is controlled by a spool valve (26). A pressure relief valve (71) is mounted in the spool (50) to maintain pressure on one side of the spool (50) when the pump (49) is turned off to rapidly close the return valve (56) and prevent further movement of the piston-cylinder units.
    Type: Grant
    Filed: December 20, 1982
    Date of Patent: December 25, 1984
    Assignee: Brunswick Corporation
    Inventor: James M. Hundertmark
  • Patent number: 4487019
    Abstract: The present invention relates to a hoisting gear for patient-lifting device whereby a plunger device (6) is displaceably mounted in a hydraulic cylinder (4), is supporting patient-carrier means (3) such as a seat or a patient-carrying plate and is raisable my means of a pump device (8) provided to move hydraulic oil between two hydraulic-cylinder chambers (9a, 9b) separated by the plunger device, and whereby a lowering device (39) is provided to permit lowering of the plunger device by producing a counter flow of hydraulic oil between the hydraulic-cylinder chambers.
    Type: Grant
    Filed: February 22, 1984
    Date of Patent: December 11, 1984
    Inventor: Hans A. V. Johansson
  • Patent number: 4471685
    Abstract: Fluid introduced into an actuator moves the piston, against the force of a return spring, to extend the actuator. After the actuator has extended a sufficient amount to perform its intended function, the piston contacts and moves a sleeve type closure for an outlet port. The additional extension of the actuator moves the sleeve to open the outlet port. This allows fluid from the source to flow through the actuator and out through the outlet port to an expansible chamber in a second actuator. In a preferred system, the second actuator is also a single acting linear motor and it includes a return spring. At the conclusion of the function of both actuators, a bypass valve in a return line is opened to allow fluid to flow out from the expansible chambers of both actuators back to a reservoir. The fluid from the second actuator flows back to the outlet port of the first actuator and from such port through a passageway which connects such port with the inlet-outlet port of the first actuator.
    Type: Grant
    Filed: September 16, 1982
    Date of Patent: September 18, 1984
    Assignee: The Boeing Company
    Inventor: Robert L. Beck
  • Patent number: 4448262
    Abstract: A starting arrangement for a reciprocating piston pneumatic hammer provides a passageway in the piston which couples a pneumatic piston subchamber to an exit port to exhaust pressurized pneumatic fluid from the subchamber to prevent the piston from centering.
    Type: Grant
    Filed: May 19, 1982
    Date of Patent: May 15, 1984
    Assignee: Cooper Industries, Inc.
    Inventor: Robert R. Vincent
  • Patent number: 4442929
    Abstract: The present invention discloses a hydraulic clutch comprising friction plates; a hydraulic piston for pressing the friction plates; a pair of annular protrusions respectively formed at radially outer portion and relatively inner portion of the piston with an annular space therebetween, said protrusions being designed to press the adjacent friction plate; an oil passage formed in the piston through which the annular space is connected to a pressure chamber at the back of the piston; a check valve arranged in the oil passage, said valve including a ball forced to close toward the friction plates and partially projecting beyond the protrusions toward the friction plates; an accumulation chamber formed in the piston and connected to the annular space; and a drain means connected to a space in which the friction plates are arranged.
    Type: Grant
    Filed: April 26, 1982
    Date of Patent: April 17, 1984
    Assignee: Kabushiki Kaisha Daikin Seisakusho
    Inventor: Shinobu Uchida