Fluid Spring Patents (Class 92/85B)
  • Patent number: 4970943
    Abstract: A steering angle limiter is built into an auxiliary power steering mechanism wherein the limits of steering can be variably preset to any predetermined degree within limits in a continuous manner. The limiter is a device built into the power cylinder. Such device comprises a mechanism having threaded telescopic members. One member is axially fixed and manually rotatable by a tool exteriorally of the cylinder to axially shift the other member to a predetermined distance from a respective end of the power piston. The other member may be non-rotative and threaded to the first member or it may be rotative but threaded to the housing. In either event, it is guided for axial movement. The axial setting of the other member effects a limit stop or abutment for the moving piston for such distance of movement as desired to limit the steering angle of the vehicle wheels in a particular direction of steering. For a double acting cylinder a steering limiter as described is provided for each end of the cylinder.
    Type: Grant
    Filed: January 18, 1989
    Date of Patent: November 20, 1990
    Assignee: Zahnradfabrik Friedrichshafen, AG.
    Inventors: Ditmar Salg, Michael Paul
  • Patent number: 4967702
    Abstract: A bistable electronically controlled pneumatically powered transducer for use, for example, as a valve mechanism actuator in an internal combustion engine is disclosed. The transducer has a piston which is coupled to an engine valve, for example. The pistion is powered by a pneumatic source and is held in each of its extreme positions by pneumatic pressure under the control of control valves which are in turn held in their closed positions by pressurized air and/or permanent magnet latching arrangements and are released therefrom to supply air to the piston to be pneumatically driven to the other extreme position by an electromagnetic neutralization of the permanent magnet field. A pair of auxiliary pistons movable with the piston compress air to a pressure above the pressure of the pneumatic source for aiding reclosure of the control valves as well as aiding maintenance of those control valves in their closed positions thereby reducing the size and cost of the latching permanent magnets.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: November 6, 1990
    Assignee: Magnavox Government and Industrial Electronics Company
    Inventors: William E. Richeson, Frederick L. Erickson
  • Patent number: 4942852
    Abstract: A bistable electronically controlled pneumatically powered transducer for use, for example, as a valve mechanism actuator in an internal combustion engine is disclosed. The transducer has a piston which is coupled to an engine valve, for example. The piston is powered by a pneumatic source and is held in each of its extreme positions, and air control valves are held in their closed positions by pressurized air and/or permanent magnet latching arrangements and the control valves are released therefrom to supply air to the piston, and the piston is released therefrom to be pneumatically driven to the other extreme position by an electromagnetic neutralization of the permanent magnet field. The piston forms a part of the magnetic latching circuit and that magnetic circuit also includes a radially slotted ferromagnetic member to both complete the magnetic circuit and provide a good air communication path from a high pressure air inlet to the control valve.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: July 24, 1990
    Assignee: Magnavox Government and Industrial Electronics Company
    Inventors: William E. Richeson, Frederick L. Erickson
  • Patent number: 4915015
    Abstract: A pneumatically powered valve actuator is disclosed and includes a valve actuator housing, a working cylinder within the housing having a pair of opposed contoured end faces, and a main piston reciprocable within the cylinder along an axis. The main piston has a pair of oppositely facing primary working surfaces contoured substantially the same as the opposed end faces of the working cylinder to mate therewith providing a small minimum volume and, therefor, a high compression ratio. A pair of air control valves are reciprocable along the axis relative to both the housing and the main piston between open and closed positions for selectively supplying high pressure air to the piston primary working surfaces. The contoured end faces each include a central opening, an outer annular flat surface, and an intermediate frustoconical surface connecting the central opening and the flat surface.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: April 10, 1990
    Assignee: Magnavox Government and Industrial Electronics Company
    Inventors: William E. Richeson, Frederick L. Erickson
  • Patent number: 4884642
    Abstract: A percussive action machine for changing the shape of solids objects comprises a housing (1) accommodating a hammer (2) capable of reciprocations. A tail piece (3) of the hammer (2) is disposed inside a power cylinder (6) to impart energy thereto during the work stroke of the hammer, the tail piece being capable of engagement with a drive for executing the return stroke of the hammer (2). The machine is also provided with a unit for decelerating the forward travel of the hammer (2) in the form of an annular projection (20) in the midportion of the hammer (2), and a cavity (17) which accommodates this projection (20), and has a hammer deceleration chamber (21) of a cross-section substantially equal to the cross-section of the projection (20). The side surface of either the hammer decleration chamber (21) or the annular projection (20) is tapered.
    Type: Grant
    Filed: August 24, 1988
    Date of Patent: December 5, 1989
    Assignee: Institut Gidrokinamiki Im, Lavrentieva
    Inventors: Petr Y. Fadeev, Vladimir Y. Fadeev, Vladlen V. Korobkov, Rim A. Kulagin, Nikolai P. Ermilov
  • Patent number: 4871035
    Abstract: Damping device for a percussion rock drilling machine. A damper piston (22) and a compressed air cushion in a damping chamber (23) transfer feeding force from the drill machine housing (11) to the drill string (15). A venting valve (51) is arranged for venting the damping chamber (23) after which the damping chamber can be pressurized with a selectable pressure.
    Type: Grant
    Filed: October 7, 1987
    Date of Patent: October 3, 1989
    Assignee: Atlas Copco Aktiebolag
    Inventor: Berndt Ekwall
  • Patent number: 4862786
    Abstract: A cushioning system for a fluid power cylinder includes a first passage for the flow of fluid to and from the space between the piston and end cap closure of the cylinder, and a second passage including a throttling valve for throttling the flow of fluid from the space as the piston approaches the end cap closure to cushion the piston. An O-ring seal is centered in the first passage and relative to a seal actuating sleeve on the piston by a plurality of spaced projections extending outwardly from the O-ring. An improved method of forming the valve seat of the throttling valve is also disclosed, wherein the second passage is deformed to substantially conform to the width and shape of the throttling valve and provide substantially zero clearance between the valve and its valve seat.
    Type: Grant
    Filed: June 16, 1988
    Date of Patent: September 5, 1989
    Assignee: Bimba Manufacturing Company
    Inventors: Peter W. Boyer, Roger W. Haczynski
  • Patent number: 4815694
    Abstract: A gas valve for providing a short duration, high volume gas pulse includes an outer chamber having an exhaust gas outlet at its front and an inner chamber which extends along the outer chamber, and terminates, at its forward end, in an opening aligned with the gas outlet of the outer chamber and spaced rearwardly therefrom. Within the inner chamber, a piston is mounted for front-to-rear reciprocal movement, and the length of the piston is selected to be greater than the distance between the valve outlet and inner chamber opening. The piston is provided with an intermediate forwardly-directed, peripheral seat, and the piston's front is dimensioned to close the exhaust gas outlet when the inner chamber is filled with gas at a moderate pressure, which forces the piston forward. The outer chamber can then be filled with a charge of gas at a high pressure.
    Type: Grant
    Filed: March 31, 1987
    Date of Patent: March 28, 1989
    Assignee: The Bran Ferren Corporation
    Inventors: Bran Ferren, Phillip Cullum, Charles F. Harrison, Kenneth R. Wisner
  • Patent number: 4807514
    Abstract: A differential hydraulic jack with a damping system for the control of electric circuit-breakers is provided with a floating ring which produces a damping action at the end of travel and is also provided with a damping extension stud which forms part of the jack piston and penetrates into the damping ring. No provision is made on the jack piston for any packing ring forming a seal with the jack cylinder. The damping ring carries two projecting lips constituting a double valve which forms a leak-tight seal with the bottom face of the jack piston and the internal face of the cylinder end. At the end of the travel of the piston, the damping ring forms a double sealing valve for shutting-off the supply/drain orifice of the jack.
    Type: Grant
    Filed: April 4, 1988
    Date of Patent: February 28, 1989
    Inventor: Claude A. Gartzmuller
  • Patent number: 4779513
    Abstract: A pneumatic cylinder device having a decleration mechanism. The pneumatic cylinder device has a pneumatic cylinder including a cylinder accomodating a piston movable in the cylinder in response to supply and discharge of compressed air and having a connected piston rod. The pneumatic cylinder further includes a position detector such as a combination of proximity switches and a magnet carried by the piston designed for producing a deceleration signal and a stopping signal when the piston rod has reached a predetermined deceleration starting position and a designated stopping position, respectively. A brake which is connected to the pneumatic cylinder is adapted for stopping the movement of the piston rod in response to the stopping signal produced by the position detector. The pneumatic cylinder device further comprises a deceleration stage connected to the brake and adapted for decelerating the piston rod in response to the deceleration signal produced by the position detector.
    Type: Grant
    Filed: March 14, 1985
    Date of Patent: October 25, 1988
    Assignee: Nippon Joucomatic Co., Ltd.
    Inventor: Takashi Kimura
  • Patent number: 4776408
    Abstract: A pneumatic impact tool having a special cushioning assembly for cushioning the repeated recoil of a hammer piston and thereby providing substantially reduced tool vibration during use. The cushioning assembly includes an energy-dissipating damping sub-assembly and an energy-storing coil spring sub-assembly arranged in series with each other such that they operate simultaneously, yet independently, to cushion the hammer piston's rearward movement over a wide range of operating speeds.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: October 11, 1988
    Assignee: Deutsch Fastener Corporation
    Inventors: Robert D. Elkin, Ahmed El Dessouky
  • Patent number: 4761118
    Abstract: The invention disclosed relates to the art field embracing positive displacement reciprocating compressors of the type featuring hydraulic drive, and sets out to simplify the construction of such units, rendering them more functional at the same time. Four coaxial bulkheads are adopted, set apart one from the next by three cylinder barrels, and three pistons which are mounted to a common rod and reciprocated thus, each in its respective barrel; the central piston and barrel are of either greater or smaller diameter than the remainder. Hydraulic oil from a power pack driving the compressor flows alternately into chambers which are occupied by the rod, and bounded at one end by one of the pistons of smaller or greater diameter.
    Type: Grant
    Filed: February 7, 1986
    Date of Patent: August 2, 1988
    Inventor: Franco Zanarini
  • Patent number: 4700611
    Abstract: A cushioning mechanism in a pneumatic cylinder utilizing a supplied air pressure, and a method of cushioning a piston in the pneumatic cylinder. Cushioning chambers are provided at opposite ends of a cylinder body of the pneumatic cylinder. Respective differential pressure valves and relief valves are provided between each of the cushioning chambers and an air supply. A cushioning member is disposed between each cushioning chamber and a cylinder bore. Air supplied under pressure from the air supply is stored in one of the cushioning chambers. When the piston is displaced to push the cushioning member, the air in the cushioning chamber is compressed to cushion the piston. As the cushioning member is moved a prescribed interval, the cushioning chamber is vented to atmosphere.
    Type: Grant
    Filed: September 13, 1984
    Date of Patent: October 20, 1987
    Assignee: Shoketsu Kinzoku Kogyo Kabushiki Kaisha
    Inventor: Junya Kaneko
  • Patent number: 4681172
    Abstract: A cushioning device for use with a pneumatic impact tool which utilizes a part of compressed air for driving the piston of the tool as cushioning means and is self controllable.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: July 21, 1987
    Assignee: Nitto Kohki Co., Ltd.
    Inventors: Toshio Mikiya, Minoru Kaneko, Yasuo Kazama
  • Patent number: 4671169
    Abstract: A fluid actuated ram assembly includes a cylindrical barrel and a rear end cap attached to a rear end of the cylindrical barrel. A piston is located within the cylindrical barrel and both the piston and the cylindrical barrel are adapted for relative movement with respect to each other. There is also provided a piston rod having a piston attached to one end portion thereof. There is also provided a bearing member or guide bush located adjacent to the piston which has a central aperture for the piston rod and also one or more longitudinal passages communicating with the piston. There is also provided a front end cap releasably attached to the cylindrical barrel which has a fluid port communicating with the one or more longitudinal passages of the bearing member or guide bush.
    Type: Grant
    Filed: September 6, 1984
    Date of Patent: June 9, 1987
    Assignee: Delibes Pty. Ltd
    Inventor: Raymond G. Hillier
  • Patent number: 4669298
    Abstract: A press comprises a bed affixed to a frame, a slide vertically movably provided above the bed, a lower cushion mounted to the underside of the bed and having chambers, an upper cushion mounted to the slide and having chambers, a pneumatic hydraulic control circuit for a pressure source of each of the cushions, and a control for controlling individually the pressure within the chambers, wherein a complicated workpiece can be formed in one stroke of the slide.
    Type: Grant
    Filed: September 25, 1986
    Date of Patent: June 2, 1987
    Assignee: Amada Company, Limited
    Inventors: Shigeyoshi Kono, Yoshimitsu Tsutsui, Fumio Koshiji, Tomohiko Sawayanagi
  • Patent number: 4656924
    Abstract: A pulsation limiter for a manually actuated hydraulic valve includes a spring biased, motion retarding plunger in an auxiliary bore within the valve housing and having a helical groove disposed on its periphery abuts against the input sleeve during the initial portion of its travel to actuate the brakes, a check valve in the plunger allowing filling of the expanding cavity in the auxiliary bore behind the motion retarding plunger. When the brake pedal is released partially or completely, the input sleeve moves until it abuts against the plunger. Thereafter, the pressure buildup in the auxiliary bore cavity closes the check valve in the plunger and the input sleeve can only move relatively slowly back to its initial position as the fluid trapped in the auxiliary bore cavity exits through the helical groove.
    Type: Grant
    Filed: December 18, 1985
    Date of Patent: April 14, 1987
    Assignee: Dresser Industries, Inc.
    Inventor: Probir K. Chatterjea
  • Patent number: 4651623
    Abstract: A work cylinder having a piston of single-body construction and a cushioning arrangement integrally formed on the piston includes a cylinder housing having a chamber formed therein divided into first and second work chambers by the piston. First and second piston extensions extend into first and second graduated chamber portions formed at opposite ends of the cylinder housing. A sealing material, bonded to the exterior surface of the piston, exhibits a dual cup-shaped piston seal around the center portion and annular cushion seals on the piston extensions. The cushion seals are at an angle such that, when in contact with a first chamber reduction, a seal results. Additionally, in the opposite direction, the cushion seals act as a check valve whereby fluid pressure introduced to a second chamber reduction depresses the cushion seals and flows into the selected work chamber.
    Type: Grant
    Filed: December 7, 1984
    Date of Patent: March 24, 1987
    Assignee: American Standard Inc.
    Inventor: Larry K. Rogers
  • Patent number: 4640503
    Abstract: In a sheet-separating suction device a suction piston carrying a suction nozzle is reciprocally movable in a sleeve secured to a housing of the device. An additional piston having at least one throttle is reciprocally movable in another sleeve also secured to the housing. The additional piston cooperates with the suction piston so as to brake the latter in its movement to an initial position and prevent impacts of the suction piston against the wall of the housing.
    Type: Grant
    Filed: January 30, 1985
    Date of Patent: February 3, 1987
    Assignee: VEB Kombinat Polygraph "Werner Lamberz" Leipzig
    Inventor: Reinhard Naumann
  • Patent number: 4638717
    Abstract: A rotary actuator having a piston travel adjustment mechanism and a cushioning mechanism associated in a single attached unit, with side porting for fluid pressure, thus having a more compact structure that is lighter in weight and yet completely adjustable.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: January 27, 1987
    Assignee: Flo-Tork, Inc.
    Inventor: Paul Carr
  • Patent number: 4633758
    Abstract: A fluid-pressure-operated, double-acting working cylinder which dampens the final braking of the work piston, includes a cylinder housing with a movable work piston disposed therein, the work piston dividing the cylinder into two work chambers. A piston rod, on which the work piston is mounted, extends through the housing. At least one auxiliary braking member is disposed on at least one side of the work piston in an offset slidable relation to the work piston. A braking arrangement disposed on the auxiliary braking member is controlled by fluid pressure to brake the auxiliary braking member to a desired position within the cylinder. A dampening chamber, a dampening spring configuration is disposed between the auxiliary braking member work piston such that, following braking of the auxiliary braking member, continued movement of the work piston is effectively dampened.
    Type: Grant
    Filed: October 26, 1984
    Date of Patent: January 6, 1987
    Assignee: WABCO Westinghouse Steuerungstechnik GmbH & Co.
    Inventor: Heinrich Kedzierski
  • Patent number: 4611634
    Abstract: A high pressure accumulator for supplying working fluid of a hydraulic control system includes a cylinder, walls disposed on ends of the cylinder, a piston movable within the cylinder defining a space for the working fluid on one side of the piston and a space for gas forming a gas spring on the other side of the piston, a support tube disposed at one of the walls in the gas space, a spring disposed on the support tube, and a stop disposed on the spring for limiting movement of the piston upon the occurrence of a gas loss in the gas space.
    Type: Grant
    Filed: September 26, 1984
    Date of Patent: September 16, 1986
    Assignee: Brown, Boveri & Cie AG
    Inventors: Wilfried Kruckewitt, Horst Plettner
  • Patent number: 4606709
    Abstract: An intensifier pump has a primary fluid cylinder including a primary piston and which has shaft portions received within a separate coaxial fluid chamber. A secondary fluid cylinder having a secondary piston has shaft portions reciprocally received within a separate coaxial fluid chamber. The secondary piston is of a smaller relative diameter than the primary piston. The sizing of the hydraulic pistons in the operating fluid cylinders is used to sequence the pistons in the cylinders with the largest diameter piston being stroked first followed by the second largest diameter cylinder being stroked next, followed in turn by any additional fluid cylinders in the order of the piston diameter size. When the smallest diameter cylinder has been stroked, a pressure switch signals a reverse flow pump to change the direction of circulation of the operating fluid to cycle the pistons.
    Type: Grant
    Filed: August 26, 1985
    Date of Patent: August 19, 1986
    Assignee: Special Projects Mfg. Co.
    Inventor: James P. Chisolm
  • Patent number: 4601457
    Abstract: A gas pressure actuator for effecting the reciprocation of the stem of a valve subject to high-pressure loading comprises a tubular housing secured to the valve bonnet and defining a main cylinder chamber connected in axially series relationship with an auxiliary piston chamber which, in turn, communicates with a secondary fluid pressure chamber containing a compressible spring. A rod-like actuator is slidably and sealably mounted within the actuator housing and carries a main piston which cooperates with the main cylinder chamber in sliding and sealable relationship. The auxiliary piston chamber slidably and sealably mounts an auxiliary piston which is movable independently of the main piston. The actuating movement of the main piston produced by the introduction of gas pressure into the main cylinder produces an axial movement of the actuating rod and a compression of the spring. The spring-containing secondary chamber defined by the actuator housing is filled with a virtually non-compressible fluid.
    Type: Grant
    Filed: October 1, 1985
    Date of Patent: July 22, 1986
    Assignee: Baker CAC, Inc.
    Inventors: Peter W. Austin, Dennis R. Cutcher
  • Patent number: 4590818
    Abstract: A speed change gear shift rod with cushioning function which is performed when the speed change gear is being operated is shown. The shift rod is supported in a freely slideable manner in the direction of the shaft, within a blind supporting hole provided inside a main case. An oil containment section is provided at the back of the supporting hole, formed between the end surface of the shaft end section and the back surface of the supporting hole during a speed change operation, when the shaft end section slides to the back of the supporting hole. An oil channel is also provided in the shaft end section or in the supporting hole, making it possible to divert oil from the inside to the outside of the previously mentioned shaft end section.
    Type: Grant
    Filed: April 6, 1984
    Date of Patent: May 27, 1986
    Assignee: Tochigifujisangyo Kabushikigaisha
    Inventor: Masao Teraoka
  • Patent number: 4589627
    Abstract: The pressure-medium-actuated valve has a pressure medium inlet, a pressure medium outlet and a cylinder. A piston which is connected to a lid is movable in the cylinder and subdivides the cylinder into a first piston chamber and a second piston chamber. Two relief lines, each comprising a control valve are connected to the piston chambers and extend to a pressure medium sink. A first connecting line comprising a control valve extends from the inlet to the first piston chamber and a second connecting line comprising a control valve extends from the inlet to the second piston chamber. A third connecting line is disposed in the wall of the valve body and extends at one end into the first connecting line. The other end of the third connecting line is connected to the cylinder at a place which, with the piston in the operative position, extends into the second piston chamber and, with the piston in the safety position, extends into the first piston chamber.
    Type: Grant
    Filed: January 28, 1985
    Date of Patent: May 20, 1986
    Assignee: Sulzer Brothers Limited
    Inventor: Karlheinz Grotloh
  • Patent number: 4582304
    Abstract: A gas spring, having a collapse safety feature operable in the event of psure loss, is provided, for use, for example, as a counterbalance for flaps or vertically adjustable structures. A movable partition is arranged between the piston and the head of the cylinder of the gas spring, and is exposed on one side to a closed gas chamber under pressure, while on the other side the gas volume effecting the extension force of the piston rod is present between the piston and the partition. In event of pressure loss in the gas volume on either side of the piston, the movable partition will meet the piston and act as a safety to prevent abrupt release or lowering of the object for which the gas spring is to serve as a counterbalance.
    Type: Grant
    Filed: December 12, 1984
    Date of Patent: April 15, 1986
    Assignee: Gas Spring Company, Div. of Fichtel & Sachs Industries, Inc.
    Inventor: Gerhard Reichert
  • Patent number: 4582144
    Abstract: Disclosed herein is a percussive tool having a piston and a ram slidably mounted within a cylinder which is axially displaceable. An air chamber is defined in front of the ram, and the cylinder has exhaust openings formed therein. With the cylinder in its retracted position, the exhaust openings communicate with the front air chamber so that the air cushion therein is vented during forward movement of the ram, and with the cylinder in its advanced position, the exhaust openings are closed to seal the air chamber so that the ram is limited in its rearward movements.
    Type: Grant
    Filed: April 23, 1985
    Date of Patent: April 15, 1986
    Assignee: Makita Electric Works, Ltd.
    Inventor: Makoto Mizutani
  • Patent number: 4555979
    Abstract: A fluid-powered lift unit having a plurality of pistonrods attached to a piston which translates axially but within a tube. The tube is provided with an end cap and a base which in conjunction with the piston defined two fluid-tight regions. The pistonrods extend from the piston and sealingly extend through the end cap thereby preventing piston rotation and causing the lift unit to be rigid with the piston in the extended or contracted position.
    Type: Grant
    Filed: August 6, 1984
    Date of Patent: December 3, 1985
    Inventor: Robert Cetnarowski
  • Patent number: 4543977
    Abstract: A balance valve for maintaining two fluid pressure systems at a predetermined pressure relative to one another. The valve comprises a piston slidably received within a bore and subjected on opposite ends to the pressure in the two systems. Each of the two systems is provided with a relief line whose communication with the associated system is controlled by movement of the piston such that any imbalance of forces acting on the piston causes the appropriate relief line to be opened to balance out the forces. The ports controlled by the piston and communicating with the relief lines are triangular in shape. In one embodiment a respective spring acts on each end of the piston to determine the relative pressure levels in the two systems. In another embodiment means is provided to resist movement of the piston in response to rapid pressure fluctuations.
    Type: Grant
    Filed: October 27, 1983
    Date of Patent: October 1, 1985
    Assignee: Beloit Corporation
    Inventor: Ronnie A. Arav
  • Patent number: 4527674
    Abstract: A shock absorber (10) has a rebound stop assembly (22). The rebound stop assembly (22) rests upon a shoulder (30) fixed to a piston rod (16). The rebound stop assembly (22) includes an elastomeric ring (24) interposed between two collars (26 and 28) forming an annular chamber (74) therebetween. At the end of the rebound stroke of the piston rod (16), the rebound stop assembly (22) is axially compressed between the shoulder (30) of the piston rod (16) and the rod guide (18) until the elastomeric ring (24) deforms to abut the inner wall (64) of the working cylinder. As the elastomeric ring deforms, the annular chamber decreases in volume. A restrictive passage (71) allows a restrictive flow of fluid therefrom. An additional chamber (70) is formed which is in restrictive fluid communication through the passage (71) with a section (68) of a rebound chamber (20).
    Type: Grant
    Filed: September 20, 1982
    Date of Patent: July 9, 1985
    Assignee: Ford Motor Company
    Inventor: Jack W. Mourray
  • Patent number: 4517878
    Abstract: A shock absorbing device for a hydraulic cylinder including a shock absorbing hole formed in an end wall of cylinder, a passageway having a port opening in the shock absorbing hole at its inner peripheral surface and a shock absorbing member attached to the piston and aligned with the shock absorbing hole so that it enters the hole during shock absorbing stroke. During movement of the shock absorbing member, it throttles the flow of fluid in the hole to perform a first stage shock absorption, then throttles the flow of fluid through the port to perform a second stage shock absorption, and at last compresses the fluid in the bottom of the hole to perform a third stage shock absorption.
    Type: Grant
    Filed: August 24, 1982
    Date of Patent: May 21, 1985
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Hisayoshi Hashimoto, Morio Tamura
  • Patent number: 4514148
    Abstract: An hydraulic cylinder for driving a reciprocating pump at 5000 to 10,000 psi pressures having a separate spool casing which serves as a detachable extension of the cylinder. The detachable spool casing houses in a single grouping seals for the fluid being pumped, seals for the hydraulic fluid driving the piston, a bearing for the piston rod, and lubricating means for the seals and bearings. This construction provides ready access to these parts for repair and assures concentricity between the piston rod and the bearings and seals in which it reciprocates.In one embodiment a wiper ring is provided between seals to scrape from the piston rod abrasive material in the fluid being pumped and discharge it from the cylinder. In another embodiment an external shock absorber decelerates the piston at one end of its extended stroke, the shock absorber also serving to actuate a valve controlling flow of hydraulic fluid to the cylinder.
    Type: Grant
    Filed: November 1, 1982
    Date of Patent: April 30, 1985
    Assignee: Carter Controls, Inc.
    Inventor: George F. Topinka
  • Patent number: 4508017
    Abstract: A power cylinder of a hydraulic percussion implement, in whose bore a ram with an enlarged piston head is vertically reciprocable to strike a tool at the lower end of the bore, has a control chamber above the piston head alternately communicating with the high-pressure side and the low-pressure side of a source of hydraulic fluid, an annular recess in the bore being permanently or intermittently connected to high pressure acting upon the underside of the piston head. An annular drainage chamber formed by the bore at a lower level, disposed above an oil seal, collects liquid leaking down from that recess and returns it to the source. A pneumatic buffer lies in or communicates with that drainage chamber for absorbing hydraulic shocks generated when the ram strikes the tool.
    Type: Grant
    Filed: July 14, 1982
    Date of Patent: April 2, 1985
    Assignee: Etablissements Montabert
    Inventor: Roger Montabert
  • Patent number: 4506591
    Abstract: There is provided a hoist as for an ocean floor dredging operation, which is capable of providing hydraulic heavy lifting capacity, for raising or lowering the dredging means between a surface ship and the ocean floor, and further can routinely provide the ship heave compensation when lifting capacity is not required, for example during dredging operation, or if the raising or lowering of pipe during pipe deployment and retrieval operations is discontinued for any other reasons, such as extremely high seas. The pneumohydraulic system comprises a piston slidably sealably movable within a cylinder and dividing the cylinder into upper and lower portions; a pneumohydraulic accumulator for providing hydraulic fluid to each of the cylinder portions and the necessary valve means to open and close the necessary connections for filling and evacuating one of the cylinder portions with hydraulic fluid without rendering hydraulically inoperative the second portion of the cylinder.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: March 26, 1985
    Assignee: Deepsea Ventures, Inc.
    Inventor: James Blanchet
  • Patent number: 4502848
    Abstract: A vacuum pump assembly which is driven by pulsating exhaust gases emanating from an internal combustion engine is disclosed. The pump assembly includes a double-acting pump means for pumping air from a vacuum source and having a reciprocable pumping member, an actuating means including a reciprocable actuating member drivingly connected to the pumping member and which is driven through first and second strokes to move the pumping member through first and second strokes, respectively, one side of the actuating member being in communication with the exhaust gases and with the actuating and pumping members being movable through their first strokes during the pressure increasing phase of each pressure pulsation and being moved through their second strokes by a nonlinear variable rate air spring means during each pressure decreasing phase of each pressure pulsation.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: March 5, 1985
    Assignee: General Motors Corporation
    Inventors: Gerald F. Robertson, Donald J. Pozniak
  • Patent number: 4492147
    Abstract: A reciprocatory air motor has a main plunger valve the position of which controls the flow of air to opposite sides of a main motor piston. Positioning of the plunger valve is itself controlled by a pair of cushion pistons carried on the piston rod of the motor. A space between the cushion pistons is used for the compression of air to effect absorption of the kinetic energy of the moving parts of the motor at opposite ends of the stroke.
    Type: Grant
    Filed: December 30, 1983
    Date of Patent: January 8, 1985
    Assignee: Knapp Pneumatics, Inc.
    Inventor: Wallace C. Knapp
  • Patent number: 4486917
    Abstract: A door closer includes a spring-loaded piston forming part of a conventional pneumatic dashpot, which retards the speed of a door during closing, and an elastomeric sleeve which is longitudinally compressed during opening of the door to retard the speed of the door during opening and to apply substantial resistance to further opening movement as the door approaches its fully open position. Closing speed of the door is also initially retarded by the compressed sleeve.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: December 11, 1984
    Assignee: National Manufacturing Co.
    Inventors: James R. Johnston, Cordell E. Meiste
  • Patent number: 4483044
    Abstract: Door speed is controlled by a pneumatic dashpot including a spring-loaded piston having a piston rod which extends through an elastomeric silicone rubber braking sleeve which is longitudinally compressed as the door opens to increase the friction between the piston rod and the sleeve. One or more enlargements on the piston rod provide increased friction as the rod moves through the braking sleeve to control closing speed and to provide greater wind resistance.
    Type: Grant
    Filed: August 8, 1983
    Date of Patent: November 20, 1984
    Assignee: National Manufacturing Co.
    Inventors: James R. Johnston, Cordell E. Meiste
  • Patent number: 4479765
    Abstract: A vacuum pump assembly which is driven by pulsating exhaust gases emanating from an internal combustion engine is disclosed.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: October 30, 1984
    Assignee: General Motors Corporation
    Inventors: Gerald F. Robertson, Donald J. Pozniak, Michael J. McClain
  • Patent number: 4471687
    Abstract: The disclosure describes a new type of pressure cylinder to provide clamping force while fabricating deep drawn metal parts. The piston is a hollow cylinder connected to the clamping pad. The drawing tools are connected to the draw ram by a rod passing through the hollow piston. This arrangement provides a smaller overall press height and an axisymmetric clamping force. In addition, the symmetry of the parts described means that the wear parts can be reversed to double their useful lives.
    Type: Grant
    Filed: November 17, 1981
    Date of Patent: September 18, 1984
    Assignee: American Can Company
    Inventors: Richard P. Nightingale, Robert P. Vandlik
  • Patent number: 4440068
    Abstract: A single ended hydraulic actuator requiring hydraulic pressure to extend the piston for raising the cowl door of a jet engine and the like. A preload spring device carried in the piston-rod assembly produces an extend force when the actuator is retracted and the door is closed which preloads the actuator to help eliminate fretting of the bearings and piston rod which otherwise can occur due to flight vibrations when unloaded.
    Type: Grant
    Filed: March 19, 1981
    Date of Patent: April 3, 1984
    Assignee: Pneumo Corporation
    Inventor: James N. Tootle
  • Patent number: 4406215
    Abstract: The drive cylinder comprises: an elongated rigid element having an internal chamber in which is located a rod guide dividing the chamber into two compartments; the rod, adapted to move longitudinally within the chamber, carries at one end a piston accommodated in one compartment and, at the other end, a head accommodated in the other compartment; a longitudinal aperture is arranged in the body of the cylinder, allowing a drive finger, secured to the head of the rod, to extend to the outside of the rigid element and to impart, to a slide carried by the cylinder, a longitudinal movement parallel with the axis of the cylinder.
    Type: Grant
    Filed: March 26, 1981
    Date of Patent: September 27, 1983
    Inventor: Ernest Lacasse
  • Patent number: 4397220
    Abstract: The invention disclosed comprises an air cushion system that utilizes a two-diameter piston and a floating bushing to create an effective air cushion seal which prevents the piston from hitting the barrel bridge.
    Type: Grant
    Filed: May 4, 1981
    Date of Patent: August 9, 1983
    Assignee: Ingersoll-Rand Company
    Inventors: Mario A. Russo, Edward I. Auerbach
  • Patent number: 4388972
    Abstract: A vibrationless pneumatic impact tool comprises: a housing; a cylinder axially displaceable in the housing; a hammer piston reciprocably driven by pressure air in the cylinder; a recoil cushioning air volume disposed between the housing and the cylinder; a first valve arrangement located in a fixed disposition relative to the housing; and a second valve arrangement located in a fixed disposition relative to the cylinder and arranged to cooperate with the first valve. The first valve comprises at least one air inlet opening communicating with a pressure air source and at least one air venting port communicating with the atmosphere.
    Type: Grant
    Filed: April 21, 1981
    Date of Patent: June 21, 1983
    Assignee: Atlas Copco Aktiebolag
    Inventor: Per A. L. Gidlund
  • Patent number: 4382361
    Abstract: There is provided a hoist, as for an ocean floor dredging operation, which is capable of providing hydraulic heavy lifting capacity, for raising or lowering the dredging means between a surface ship and the ocean floor, and further can routinely provide for ship heave compensation when lifting capacity is not required, for example during dredging operation, or if the raising or lowering of pipe during pipe deployment and retrieval operations is discontinued for any other reasons, such as extremely high seas. The pneumohydraulic system comprises a piston slidably sealably movable within a cylinder and dividing the cylinder into upper and lower portions; a pneumohydraulic accumulator for providing hydraulic fluid to each of the cylinder portions and the necessary valve means to open and close the necessary connection for filling and evacuating one of the cylinder portions with hydraulic fluid without rendering hydraulically inoperative the second portion of the cylinder.
    Type: Grant
    Filed: May 6, 1980
    Date of Patent: May 10, 1983
    Assignee: Deepsea Ventures, Inc.
    Inventor: James Blanchet
  • Patent number: 4373426
    Abstract: A helical rotary actuator has a torque transmitting section that can be a sealing section or a clearance section but which is welded to a ring gear so that torque forces imposed on the ring gear can be carried through the torque transmitting section to the base of the actuator. In the method of fabrication, the splines on the ring gear are cut after a weldment is made between the ring gear and the torque transmitting section of the cylinder. The pistons within the cylinder are hydraulically cushioned.
    Type: Grant
    Filed: November 3, 1980
    Date of Patent: February 15, 1983
    Inventor: Paul P. Weyer
  • Patent number: 4344609
    Abstract: Resilient positioning apparatus for sustaining repeated shock loads from heavy work pieces, with ability to reposition work pieces accurately and quickly with negligible loss of accuracy after long service. Apparatus has telescoping assembly having two portions which can be accurately positioned relative to each other and a gas cylinder which has a partition cooperating with one of the portions. The partition defines a chamber with the portions of the telescoping assembly, and the chamber is exposed to pressurized gas which forces the partition, and with it the telescoping assembly against a datum. When the telescoping apparatus is subjected to shock load from a work piece, it is momentarily shifted off the datum, thus cushioning the telescoping assembly, and is then quickly returned due to force from the gas cylinder. The invention is simple and eliminates complex valving associated with shock absorbing hydraulic circuits and is not subjected to buckling under compression loads.
    Type: Grant
    Filed: April 21, 1980
    Date of Patent: August 17, 1982
    Assignee: Kockums Industries Limited
    Inventor: Harold U. Bond
  • Patent number: 4311086
    Abstract: A system for damping abrupt movement of a punch press ram at the moment of cut-breakthrough with the use of at least two damping pistons disposed within cylinders and arranged to engage the press ram before and during cut-breakthrough. The cylinders within which the damping pistons are carried are connected to a hydraulic control system which permits the pistons to yield with the ram until the instant of cut-breakthrough, whereupon the damping pistons act as rigid bodies and prevent abrupt breakthrough movement of the ram.
    Type: Grant
    Filed: March 19, 1980
    Date of Patent: January 19, 1982
    Inventor: Hans Schoen
  • Patent number: 4292886
    Abstract: A hydraulic cushioning device, hereinafter called cushion device, improvement in which a spring loaded piston, with an axial orifice, is slidably installed in the expansion chamber, and when return pressure from a hydraulic actuator, hereinafter called actuator is routed to the expansion chamber, by the cushion device, the piston, responding to this pressure moves slowly compressing a spring until it hits a stop at which time the remaining fluid from the actuator must pass through the cushion device restriction thus slowing the actuator rod speed and as the actuator bottoms the cushion device will cease routing actuator fluid under pressure to the expansion chamber and will open the expansion chamber to drain at which time the spring, in the expansion chamber, will force the piston toward the starting end of the expansion chamber, hastening the emptying thereof.
    Type: Grant
    Filed: December 31, 1979
    Date of Patent: October 6, 1981
    Inventor: William R. Weber