Bias External Of Both Expanding And Contracting Chamber Patents (Class 92/130C)
  • Patent number: 6164184
    Abstract: In accordance with the invention, a booster is not provided with a mechanism which transmits a braking reaction, and accordingly, a reaction cannot be transmitted to a brake pedal. On the other hand, a pseudo-reaction imparting means is provided to impart a pseudo-reaction which depends on an amount of depression of the brake pedal. The pseudo-reaction imparting means imparts a pseudo-reaction having a reduced rate of increase to the brake pedal when a travel of the brake pedal is small, and imparts a pseudo-reaction having an increased rate of increase to the brake pedal when a travel of the break pedal is higher. This arrangement avoids the drawback of the prior art that an abnormally high braking reaction is transmitted to a driver as a result of an operational lag of a conventional booster during a quick braking operation.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: December 26, 2000
    Assignee: Jidosha Kiki Co., Ltd.
    Inventors: Kazuo Kobayashi, Masahiro Ikeda, Tohru Satoh
  • Patent number: 6062534
    Abstract: A rotary valve actuator with movable actuator linkage maintained in a constant "pull-pull" tension, includes a sliding canister, rotatable lever, and a return spring substantially aligned in-line with each other. The linear motion of the canister in response to an expanding and contracting pressurized bladder is converted through chain linkage into rotary lever motion. The return spring is connected through respective chain linkage to the lever so the pulling tension of the spring/lever linkage rotates the lever and maintains tension on both chain linkages. Adjustable travel stops are provided. In an alternate embodiment the return spring chain linkage is configured at right angles to the linear movement of the canister. A double acting rotary valve actuator with pressurized bladders on opposite sides of a rotatable lever. One bladder is oval shaped.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: May 16, 2000
    Assignee: Fisher Controls International
    Inventor: Philip Wayne Eggleston
  • Patent number: 6041804
    Abstract: A subsea actuator and method is disclosed that includes a removable monolithic cap/hydraulic chamber that seals the actuator housing top with seals placed around the monolithic cap, defines a straight hydraulic line and port for control line hydraulic fluid, and provides for fasteners to secure the top of the subsea actuator. The monolithic cap/hydraulic chamber is so limited in metal and machine time that it can be a throw-away maintenance item. A preferably cup-shaped spring lifter is provided in telescoping relationship to the hydraulic chamber. Several short hydraulic fluid passageways are provided in the bottom cup portion of the spring lifter to permit assist hydraulic control fluid into the hydraulic chamber below the piston. The driving stem provides a removable connection to the hydraulic piston from the top of the actuator housing and a quick disconnect permits disconnection of the driving stem from the valve stem.
    Type: Grant
    Filed: February 23, 1998
    Date of Patent: March 28, 2000
    Inventor: Vijay R. Chatufale
  • Patent number: 6000675
    Abstract: A rotary valve actuator with movable actuator linkage maintained in a constant "pull-pull" tension, includes a sliding canister, rotatable lever, and a return spring substantially aligned in-line with each other. The linear motion of the canister in response to an expanding and contracting pressurized bladder is converted through chain linkage into rotary lever motion. The return spring is connected through respective chain linkage to the lever so the pulling tension of the spring/lever linkage rotates the lever and maintains tension on both chain linkages. Adjustable travel stops are provided. In an alternate embodiment the return spring chain linkage is configured at right angles to the linear movement of the canister.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: December 14, 1999
    Assignee: Fisher Controls International, Inc.
    Inventor: Philip Wayne Eggleston
  • Patent number: 5992252
    Abstract: The inventive button pushing mechanism allows pneumatic force to be translated actuate a button on a cellular telephone that is being tested by an automatic testing machine. The mechanism includes an actuating shaft that transmits pneumatic force to a spur gear which rotationally translates the force to actuate the button. The spur gear is also connected to a weighted counter balance shaft which opposes movement of the actuating shaft, such that when the pneumatic force is turned off, the counter balance shaft retracts the mechanism back to an initial state. The uses of gravity provides a constant and known force to oppose the pneumatic force.
    Type: Grant
    Filed: February 19, 1998
    Date of Patent: November 30, 1999
    Assignee: Hewlett-Packard Company
    Inventor: Russell Steven Krajec
  • Patent number: 5979864
    Abstract: A rotary valve actuator with movable actuator linkage maintained in a constant "pull-pull" tension, includes a sliding canister, rotatable lever, and a return spring substantially aligned in-line with each other. The linear motion of the canister in response to an expanding and contracting pressurized bladder is converted through chain linkage into rotary lever motion. The return spring is connected through respective chain linkage to the lever so the pulling tension of the spring/lever linkage rotates the lever and maintains tension on both chain linkages. Adjustable travel stops are provided. In an alternate embodiment the return spring chain linkage is configured at right angles to the linear movement of the canister. A double acting rotary valve actuator with pressurized bladders on opposite sides of a rotatable lever. One bladder is oval shaped.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: November 9, 1999
    Assignee: Fisher Controls International, Inc.
    Inventor: Philip Wayne Eggleston
  • Patent number: 5938416
    Abstract: A liquid transfer pump includes a housing having an inner space, a cross head disposed in the inner space of the housing and attached to a driving mechanism to reciprocate inside the housing, a plunger attached to and held by a plunger holder of the cross head, and a pump head situated near the cross head. The pump head includes a pump chamber with an inlet path and an outlet path, and the plunger is disposed in the pump chamber to be reciprocated therein together with the cross head. A resilient O-ring is disposed in the plunger holder, and a plunger seal is disposed in the pump head, wherein one side of the plunger is engaged with and held by the resilient O-ring and the other side of the plunger is engaged with and held by the plunger seal. Accordingly, the plunger can be flexibly supported by the O-ring and the plunger seal. The plunger seal can be used for a long time without leakage.
    Type: Grant
    Filed: March 4, 1998
    Date of Patent: August 17, 1999
    Assignee: Shimadzu Corporation
    Inventors: Katsuhiko Saito, Katsuaki Kaito
  • Patent number: 5626054
    Abstract: Device for absorbing lateral forces generated as a result of a linearly reciprocating pin causing rotation of a scotch yoke, the device including a guide block guided along a guide rod, the guide block carrying a yoke engaging pin as well as having opposed connector-receiving cavities; connectors linking each cavity with opposed rod members, each connector having opposed curved surfaces and one or more flats intermediate adjacent such surfaces, the guide block positioning a plurality of annular members each having an arcuate surface slidably receiving one such curved surface, said block also including a locking device for engagement with each connector flat.
    Type: Grant
    Filed: September 11, 1995
    Date of Patent: May 6, 1997
    Assignee: Bettis Corporation
    Inventors: Michael E. Rembert, Robert W. Milner
  • Patent number: 5601110
    Abstract: A device used in an actuator for locking in place a spring module while under load, the device including a spring return cylinder carrying a spring under compression when under load, a spring guide, a pull rod linked to a piston in a power cylinder, and a connection linking the pull rod and the spring guide, the connection being disengageable when said spring is not under compression, but not so when under compression.
    Type: Grant
    Filed: September 11, 1995
    Date of Patent: February 11, 1997
    Assignee: Bettis Corporation
    Inventors: Michael E. Rembert, Robert W. Milner
  • Patent number: 5244004
    Abstract: A hydraulic pipeline valve operating system (10) includes a tank (12) which holds a quantity of unpressurized hydraulic fluid. A pump (14) provides that fluid under pressure to a valve actuator (11). The valve actuator has an actuator cylinder (40) having a piston (42) which is operatively connected to the pipeline valve (28). The fluid under pressure moves the piston (42) of the cylinder (40) to compress a spring (35) to open the valve (28). When the piston (42) of the cylinder (40) ceases movement, continued pumping moves a piston (53), of a smaller diameter than the piston (42), which also acts against the spring (35). An indicator rod (60) gives a visual indication of the position of the piston (53) and when it is at approximately its midstroke location, pumping of the fluid is terminated and the actuator (11) is set. Should ambient temperature conditions change, the piston (53) moves to accommodate such changes thereby leaving the piston (42) unaffected.
    Type: Grant
    Filed: December 2, 1992
    Date of Patent: September 14, 1993
    Assignee: The Shafer Valve Company
    Inventor: Russell E. Robertson
  • Patent number: 5239778
    Abstract: A quick release door closer including a hydraulic assembly and a spring assembly connected at a quick release connection. The quick release connection includes a retaining element and element housing structured to allow the door closer to be easily maintained and, if necessary, the hydraulic assembly to be easily removed and replaced.
    Type: Grant
    Filed: March 24, 1992
    Date of Patent: August 31, 1993
    Assignee: MTH Industries
    Inventor: Harold Towler
  • Patent number: 5178360
    Abstract: The invention is a valve actuator or a booster module for an existing valve actuator that provides an incremental force to the valve stem at a position close to valve closure. The force is stored in a spring which is held in the compressed position by a collet. Upon sufficient movement of the valve actuator stem in the direction towards valve closure, the collet which had previously held the spring in a compressed position is freed to move to allow the spring to expand against the collet. Since movement of the collet has caused it to be engaged to the valve actuator stem, the spring forces are transmitted directly to the valve actuator stem via the collet. The spring is oriented in a direction substantially parallel to the valve stem so that substantially all of its retained energy is transmitted directly to the valve stem through the collet.
    Type: Grant
    Filed: September 19, 1990
    Date of Patent: January 12, 1993
    Assignee: Baker Hughes Incorporated
    Inventor: Terry G. Young
  • Patent number: 5079995
    Abstract: The positively acting mechanism comprises a jack (2) with a rod (10) connected, at one of its ends, to a member whose actuation or retention it ensures, and, at its other end, to a thrust piece (16), on which a spring (18) comes to bear, in order to actuate or retain the member. An axle (25) parallel to the rod (10) of the jack is rotatably mounted in a housing (14) fixed relative to the body (3) of the jack (2) and has a threaded part (26) in engagement with a nut (34) forming an engagement fork for the thrust piece (16) of the rod (10). The axle (25) has an end part (30) engaging with a tool allowing the axle (25) to be set in rotation remotely. It is thus possible, in the event of failure of the jack, to rotate the axle (25) and displace the rod (10) of the jack (2) in the direction of release of the mechanism.
    Type: Grant
    Filed: May 30, 1990
    Date of Patent: January 14, 1992
    Assignees: Framatome, Cogema
    Inventors: Alain Netter, Michel Bline
  • Patent number: 5070766
    Abstract: This hydraulic actuator has a drive volume (11) pressurized by extreme-pressure oil. The oil pressure is converted into a valve movement by a drive piston (10). A spring element acts upon the drive piston (10) in a manner opposing the oil pressure. The actuator is to be constructed such that extreme-pressure oil escaping from the drive volume (11) cannot cause any consequential damage. This is achieved in that the drive volume (11) is completely surrounded by a safety volume (3, 7) filled with low-pressure oil.
    Type: Grant
    Filed: July 26, 1990
    Date of Patent: December 10, 1991
    Assignee: Asea Brown Boveri Ltd.
    Inventors: Heinz Frey, Kamil Prochazka
  • Patent number: 5044160
    Abstract: The disclosed mechanism is designed so as to be impervious and give a motion of translation enabling, for example the driving of a hinged arm. The mechanism has a hydraulic circuit with fluid, a jack associated with a pull-back spring and a pump to bring the jack to the working position. The pump is actuated by a motor. The pump and the motor are entirely placed inside a common enclosure so that the motor, with its shaft, bathes in the fluid of the hydraulic circuit. The mechanism is designed for sonars, to unfold and fold their antennas mounted on hinged arms.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: September 3, 1991
    Assignee: Thomson-CSF
    Inventors: Francois Warnan, Alain Penain
  • Patent number: 5007330
    Abstract: A rotary actuator comprising a housing which defines an arcuate chamber, the housing including a first monolithic portion in which the arcuate chamber is completely contained, a piston disposed in the housing for reciprocable movement in the arcuate chamber, a shaft journaled in the housing and connected to the piston and being rotated in response to movement of the piston, a floating seal assembly carried by one of the piston or the housing for effecting sealing between the piston and the housing, a fluid pressure port to introduce fluid into the housing to effect movement of the piston in the first direction and a means such as fluid pressure or a spring return to effect movement of the piston in an opposite second direction, the actuator in one preferred embodiment employing a spring return which provides a substantially constant torque acting upon the shaft as the spring moves from a compressed first position to an uncompressed second position such that the torque acting upon the shaft in both rotational
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: April 16, 1991
    Assignee: Keystone International Holdings Corp.
    Inventors: William B. Scobie, Robert A. Frenzel
  • Patent number: 4967785
    Abstract: A valve actuator is disclosed which is encased in a housing with a bonnet mounted at one end and an end cap on the other end. Inside, an actuator shaft is slidably mounted through a bore on a guide connected to the bonnet. A piston is slidably mounted with respect to the guide and creates a variable-volume cavity between itself and the guide. The shaft is connected to the piston by virtue of a disk which, when bolted down to the top of the shaft, puts a preload in the spring. A connecting member is placed into contact with the disk and the piston once the spring has been preloaded. The connecting member is segmented and fits between spacers which hold the spring at a distance from the disk and allow insertion of the connecting member after preloading of the spring. The spring bears on the connecting member. Pressurization of the cavity results in an overcoming of the spring force and movement of the shaft between a first and second position.
    Type: Grant
    Filed: April 27, 1990
    Date of Patent: November 6, 1990
    Assignee: Baker Hughes Incorporated
    Inventor: Terry G. Young
  • Patent number: 4884495
    Abstract: A fluid motor actuator of the type in which an actuator member is moved in either one of two opposite directions from a rest position to an actuated position includes a fail-safe mechanism having compression springs coupled with the actuator member for compression of the compression springs in response to actuation of the actuator member in either of the two opposite directions for establishing a restoring force which, upon loss of motive power, will return the actuator member to the rest position and maintain the actuator member in the rest position pending restoration of motive power.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: December 5, 1989
    Assignee: EL-O-MATIC-USA, Inc.
    Inventor: Floris J. Groeneveld
  • Patent number: 4765229
    Abstract: A portable vacuum pump for desoldering applications has a hollow cylindrical barrel forming a vacuum cylinder containing a plunger. The pump has a trigger housing containing a single compression spring. The spring is mounted outside the barrel. No separate return spring is required to hold the trigger in the latched position. The single trigger keeps the spring end out of the barrel and thus out of contact with the soldering debris. This allows more space for the plunger, producing a longer stroke and a higher vacuum.
    Type: Grant
    Filed: July 2, 1984
    Date of Patent: August 23, 1988
    Inventors: William S. Fortune, Robert E. Dallons
  • Patent number: 4744386
    Abstract: A surface safety valve hydraulic actuator of modular construction. The actuator includes separately installable, removable, and interchangeable wirecutting and non-wirecutting spring modules, used with the same hydraulic cylinder and bonnet. The bonnet is attached to the body of the valve. A lower stem extends through a lower seal and into the valve body cavity, and is connected to the gate segments of the valve. A hydraulic cylinder is removably attached to the bonnet. An upper stem with a central bore is disposed in the cylinder chamber and carries a piston thereon, and extends through an upper seal in the top of the hydraulic cylinder. A spring module is removably attached to the hydraulic cylinder, and includes a spring can telescoped over the top of the cylinder. The spring can is rotatably connected to an annular spring retainer, which in turn is mounted on the cylinder. A coupling rod is inserted through the upper stem and screwed into the top of the lower stem.
    Type: Grant
    Filed: August 11, 1987
    Date of Patent: May 17, 1988
    Assignee: Cameron Iron Works USA, Inc.
    Inventor: Neil F. Frazer
  • Patent number: 4702150
    Abstract: A spring-return type actuator for valves including a piston cylinder mechanism, a movement conversion-transmission means disposed in the piston cylinder mechanism for converting reciprocation of a piston into a rotary motion of a valve drive shaft, a spring mechanism disposed in series relative to the piston cylinder mechanism, and a plurality of tie rods each including a male member having one end thereof attached to a flange portion of one side wall of the spring mechanism and having an external thread portion, and a female member having one end thereof screwed into a flange portion of the other side wall of the spring mechanism and having an internal thread portion helically meshed with the external thread portion of the male member and having a winglike member attached to the outer periphery thereof for engaging the female member with the outer periphery of the spring box to prevent the female member from rotating, and each tie rod having a length set larger than the free length of a spring when assumed i
    Type: Grant
    Filed: November 26, 1985
    Date of Patent: October 27, 1987
    Assignee: Kitz Corporation
    Inventor: Shoichi Kaji
  • Patent number: 4688661
    Abstract: A casing (10) has a bore (14) and a clutch face (48) concentric with the bore. In the bore (14) a tappet (30) of variable length is slidably guided and includes two threaded members (34,36) interconnected by a self-locking screw thread pair (38). A clutch member (50) connected to one of the two threaded members (34) by a non-self-locking screw thread pair (52) is associated with the clutch face (48). A support member (60 ) having an aperture (68) through which the other one of the two threaded members (36) extends is fixed to the casing (10). A clutch spring (70) is inserted between the support member (60) and the clutch member (50) and urges the clutch member (50) into abutment against the clutch face (48). A sealing boot (72) which is disposed outside of the support member (60) with respect to the casing (10) provides an external seal for the screw thread pairs (38,52) and the clutch member (50). The support member (60) and the sealing boot (72) are separately fixed to the casing (10).
    Type: Grant
    Filed: November 8, 1985
    Date of Patent: August 25, 1987
    Assignee: Lucas Industries Public Limited Company
    Inventors: Harald Gockel, Reiner Thewalt, Wilfried Giering
  • Patent number: 4568011
    Abstract: A vacuum pump for a desoldering iron gun which comprises a cylinder closed at one end with a piston movable in the cylinder, and device including a valve connecting the closed end of the cylinder to the gun. A spring normally urges the piston away from the closed end of the cylinder, and drive linkage connects the piston to a motor for moving the piston toward the closed end of the cylinder against the urging of the spring. Latch device holds the piston in position adjacent the closed end of the cylinder. Trip device for releasing the latch is operated by the same motor. Operation is initiated by a switch on the gun that starts the motor, causing the trip mechanism to release the latch, and the spring to force the piston away from the closed end to produce a partial vacuum. The motor continues to run through its cycle, again compressing the spring and moving the piston back to its latched position.
    Type: Grant
    Filed: December 14, 1984
    Date of Patent: February 4, 1986
    Inventors: Clyde B. DeArmitt, Samuel F. Sims, Bjorn Westly
  • Patent number: 4519575
    Abstract: There is disclosed a gate valve which is moved to open position by an extendible and retractable, fluid-operated actuator, and which is moved to closed position, upon exhaust of operating fluid, by coil springs which urge follower parts reciprocable with a stem on the gate, and which extend from the valve body into a housing connected on the valve body, into engagement with cam surfaces on the housing. The cam surfaces are so arranged that the coil springs initially move the gate from open toward closed position with a relatively small force, and then move it into fully closed position with a force which is sufficiently larger to shear a wire line or other obstruction in the flowway of the valve body which would otherwise prevent closing of the gate.
    Type: Grant
    Filed: April 20, 1984
    Date of Patent: May 28, 1985
    Assignee: Ava International Corporation
    Inventors: Neil H. Akkerman, Daniel O. Dewey
  • Patent number: 4487111
    Abstract: Apparatus for generating linear motion comprises a body on one end of which is mounted a cylinder. A piston in the cylinder is joined to an actuating beam extending into the body. The actuating beam has moving surfaces that cooperate with fixed surfaces in the body to define a linear bearing. Fluid under pressure is introduced through a duct in the body to a port in the fixed surface of the linear bearing. It enters the space in the cylinder above the piston via a port in a moving surface of the actuating beam which leads to a duct in the actuating beam that opens through the crown of the piston. A resilient sealing member between the fixed and moving surface of the linear bearing maintains fluid-tight communication between the fixed and movable part over their range of relative movement. The actuating beam may carry a rack that drives a pinion through ninety degrees as the piston travels, and two opposed cylinders may be provided to give a reciprocatory movement, or a spring return may be provided.
    Type: Grant
    Filed: August 19, 1981
    Date of Patent: December 11, 1984
    Assignee: Worcester Controls Corporation
    Inventor: Brian E. Prince
  • Patent number: 4475335
    Abstract: A Stirling cycle heat engine, specially suitable for use in environments subject to acceleration or large temperature variations, including a free and reciprocating displacer piston fitted with a non-contact device which acts with increasing force to oppose further movement whenever the piston overshoots desired limits of its movement. The device may include a magnet which is carried by the piston shaft and which experiences repulsion from like poles of magnets carried by the shaft housing.
    Type: Grant
    Filed: February 3, 1983
    Date of Patent: October 9, 1984
    Assignee: National Research Development Corporation
    Inventor: Gordon Davey
  • Patent number: 4469016
    Abstract: A self-contained spring biasing device, particularly useful for providing a movement-resisting force on the power shaft of a valve actuator, comprises spring cartridge means and safety means. The spring cartridge means has therein a compression spring and a bearing plate that is pushed by the power shaft to compress the spring and resist movement of the shaft. The safety means is accessible from the exterior of the spring cartridge means and removably secures the power shaft to the bearing plate, thus preventing the spring from launching the spring cartridge means from the actuator.
    Type: Grant
    Filed: January 28, 1982
    Date of Patent: September 4, 1984
    Assignee: International Telephone and Telegraph Corporation
    Inventors: Ronald G. Butler, John R. Lehman
  • Patent number: 4423748
    Abstract: An emergency shut down device for a gate valve utilizes a pre-assembled spring cartridge assembly which includes a container and a compression spring pre-loaded therein. Suitable openings are provided in the end plates of the cartridge to permit the remaining components, including a ram cup, a piston and cylinder arrangement, a base mounting member and a stem for connection to the valve gate, to be assembled within the cartridge without fear of a spring-initiated explosion of parts as the spring is safely contained within the container before final assembly begins. The device is operable to rapidly close a gate valve when there is a loss of fluid pressure within the device.
    Type: Grant
    Filed: November 7, 1975
    Date of Patent: January 3, 1984
    Assignee: Barlorne Resources Limited
    Inventor: James R. Ellett
  • Patent number: 4379543
    Abstract: In the preferred and illustrated embodiment of a valve actuator, a vane type fail safe actuator is disclosed. The actuator comprises a housing enclosing a vane which is integral with a shaft extending through the housing to a rotary operable valve. Fail safe operation is provided by a spring return mechanism connected to the housing. Compressed air is utilized to operate the actuator and the spring return mechanism which assures complete valve closure when the air supply fails or is reduced below a predetermined minimum setting.
    Type: Grant
    Filed: August 5, 1980
    Date of Patent: April 12, 1983
    Assignee: Valinco, Inc.
    Inventor: V. Randon Reaves
  • Patent number: 4355566
    Abstract: A valve driving apparatus comprising a case proper provided in the interior thereof with a movement conversion-transmission mechanism, a cylinder mechanism freely detachably fixed to one end of the case proper and a piston rod supporting mechanism freely detachably fixed to the other end of the case proper so as to be applicable to any kind of valve merely by the replacement of the mechanisms between which the case proper intervenes.
    Type: Grant
    Filed: January 3, 1980
    Date of Patent: October 26, 1982
    Assignee: Kitazawa Valve Co., Ltd.
    Inventor: Shoichi Kaji
  • Patent number: 4350081
    Abstract: A piston-cylinder type actuator is provided with a fail-safe unit for returning the piston 10 to a fail-safe position in the event of failure of the power supply to the cylinder 12. The fail-safe device comprises a housing unit 27 which is detachably connected to the casing 18 of the actuator. The housing contains a pre-loaded spring 30 acting between the closed end 29 of the housing and a movable cap member 31 which is engaged by the piston rod 17. The cap member is retained in the housing by a fixed ring 32 which is connected to a flange 38 of the actuator. Removal of the fail-safe unit is prevented unless the piston is in its fail-safe position by means of a bayonet-type fitting comprising lugs 35 on the housing which are axially and rotatably engaged with locking recesses on the remote surface of the adaptor flange 38.
    Type: Grant
    Filed: July 16, 1980
    Date of Patent: September 21, 1982
    Assignee: Rotork Controls Limited
    Inventors: Jeremy J. Fry, Christopher Warnett
  • Patent number: 4085659
    Abstract: A powered tool control device having a pair of coaxial pistons, with the first piston effective to move the second piston after completing a predetermined amount of pretravel initiated by a prescribed operational condition of the powered tool and with resulting movement of the second piston controlled by fluid directional regulators responsive to different operational conditions of the powered tool.
    Type: Grant
    Filed: May 28, 1976
    Date of Patent: April 25, 1978
    Inventor: Barry A. Stunkel
  • Patent number: 4077303
    Abstract: A mechanism for generating a high impact force for hammering, pounding, stamping, forging or similar operations. A piston is slidably mounted in a fluid pressure chamber, and has a larger cross sectional area at one end of the chamber than at the other end thereof. A fluid is introduced into the chamber under pressure, and exerts a net axial force on the large cross section end of the piston. One end of the piston outside the chamber forms a cam, which is engaged by a spring loaded cam follower to prevent axial movement of the piston until the force thereon exceeds a predetermined value. When the force on the piston exceeds said value, the cam is suddenly disengaged from its follower, permitting rapid movement of the piston under the fluid pressure. When the piston reaches the end of its travel, fluid is permitted to leave the chamber so that the pressure on the piston rapidly decreases, and the spring loaded cam follower acts on the cam to return the piston to its initial position.
    Type: Grant
    Filed: April 14, 1976
    Date of Patent: March 7, 1978
    Inventor: Peder Ulrik Poulsen
  • Patent number: 4046167
    Abstract: A mechanical accumulator for holding and supplying a volume of hydraulic fluid under pressure comprising a variable volume fluid pressure chamber including a piston and a cylinder member, a plurality of coil springs acting on one of said members for biasing the same towards the other of said members to minimize the volume of said chamber and pressurize the fluid therein, a fluid conduit for directing pressurized fluid into and out of said chamber and switch means externally of said chamber and actuated by one of said members in response to the volume changes of said chamber for controlling the operation of a fluid device using fluid from the chamber.
    Type: Grant
    Filed: February 6, 1976
    Date of Patent: September 6, 1977
    Assignee: Kawneer Company, Inc.
    Inventors: Joseph Papp, Richard A. Meisterheim, S. Eugene Hubbard
  • Patent number: 4013174
    Abstract: A load handling device is disclosed having an improved swing drive assembly including a hydraulically driven pivotally mounted swing drive pinion biased against a segmented ring gear by a hydraulic actuator with a guide roller adjacent the pinion engaging a guide flange concentric with the ring gear to limit the maximum tooth engagement between the pinion and ring gear and thereby provide essentially constant backlash on the pinion gear regardless of eccentricities or other irregularities in the ring gear during swing drive operation. When the swing drive pump is shut down a bypass valve is automatically actuated shunting the flow of hydraulic fluid around the pump and a spring operates to counteract the separating force between the pinion and ring gear due to wind induced rotating force which produces torque on the pinion as a result of the back pressure in the motor and the shunted supply-return lines.
    Type: Grant
    Filed: October 22, 1975
    Date of Patent: March 22, 1977
    Assignee: The Manitowoc Company, Inc.
    Inventors: James G. Morrow, Sr., David J. Pech
  • Patent number: 3939872
    Abstract: A pressure transfer unit having a movable partition including a flexible bellows for separating an internal, controlled-pressure chamber from a reference-pressure chamber. A valve is provided for limiting the volume of liquid that can be injected into and received in the controlled-pressure chamber during filling or refilling thereof. A spring biases the partition to apply a predetermined force to the partition and to shut off fluid transfer in the event of bellows failure. The unit is arranged for simple and rapid assembly and disassembly.
    Type: Grant
    Filed: October 17, 1973
    Date of Patent: February 24, 1976
    Assignee: Borg-Warner Corporation
    Inventor: Robert S. Wentworth, Jr.