Bias Other Than Coil Spring Patents (Class 92/130B)
  • Patent number: 6146114
    Abstract: A fluid pump and expandable energy storage device includes a substantially igid circular band, a substantially rigid central hub, a membrane fixed to the band and to the hub, the membrane being enlargeable by a fluid introduced into the device, and a plurality of rods interconnecting the band and the hub. The enlargeable membrane is adjacent the rods, such that enlargement of the membrane causes movement of the hub and portions of the rods away from a plane of the band. The movement causes twisting and bending of the rods, biasing the rods to return to their original positions upon release of the fluid. Upon such release, the membrane and the rods immediately return to their non-enlarged states, forcing the fluid out of the device at a high velocity.
    Type: Grant
    Filed: May 22, 1998
    Date of Patent: November 14, 2000
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Nicholas M. Nardacci, Jeffrey L. Cipolla
  • 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: 5964333
    Abstract: A slave cylinder for the operation of a friction clutch, especially in motor vehicles, with a housing, an inner portion, an annular or cylindrical piston which annular piston is positioned between the housing and the inner portion, a clutch release sleeve or clutch throwout sleeve or coupling socket joint which clutch release sleeve is in contact with the annular piston and can be axially displaced with respect to the housing, as well as a spring or pressure spring or compression spring which is supported by both the clutch release sleeve and the housing, and radial shoulders or steps or reliefs provided at the clutch release sleeve and at the housing to secure against torsion. The pressure spring may be characterized as a sinuous spring or zig-zag or no-sag spring. The ends of the pressure spring are positioned to make contact at the ends of the shoulders which shoulders act in the opposite direction to secure against torsion.
    Type: Grant
    Filed: June 5, 1997
    Date of Patent: October 12, 1999
    Assignee: Fichtel & Sachs AG
    Inventors: Wolfgang Grosspietsch, Herbert Voit, Angelika Ebert
  • Patent number: 5915930
    Abstract: An oscillating pump (10) includes a housing (11) which carries the components thereof. These components include an electromagnetic coil (24) surrounding an armature (23) carried by an impeller (12) which is positioned longitudinally between an inlet area (16) and an outlet area (17) of the pump (10). The armature (23) moves longitudinally upon activation of the coil (24) to the point of the greatest magnetic force generated by the coil (24). The impeller (12) includes a pair of bellows (19, 20) and carries a valve (13). The bellows (19, 20) define an inlet chamber (21) and a discharge chamber (22). Another valve (15) is carried by the housing adjacent to the discharge chamber (16). Upon activation of the coil (24) the valve (13) forces fluid in the discharge chamber (22) through the valve (15) and allows fluid to pass from the inlet chamber (21) to the discharge chamber (22) upon deactivation of the coil (24).
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: June 29, 1999
    Assignee: The Gorman-Rupp Company
    Inventor: Michael H. McNaull
  • Patent number: 5797309
    Abstract: In order to economize the manufacture and assembly as well as reduce the expenditure of components and functionally improve a steering valve for supplying an actuator with hydraulic pressure, comprising an input shaft 2, an output shaft 3, a torsion rod 4 that is connected to one end to the input shaft 2 and with the other end to the output shaft 3, a valve sleeve 5 that surrounds the input shaft and a reaction piston 8 that may be axially moved relative to the input shaft 2, but is arranged such that it is unable to rotate and is connected to the valve sleeve 5 via an elastic rotary driver, a torsion-proof, axially elastic element 13 is arranged in the steering valve 1, with one end of said element being fastened on the input shaft 2 and its other end being fastened on the reaction piston 8.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: August 25, 1998
    Assignee: TRW Fahrwerksysteme GmbH & Co. KG
    Inventor: Eugen Eberhart
  • Patent number: 5784948
    Abstract: A positive displacement pump including a plurality of pistons reciprocally driven in respective cylinders by a swashplate assembly to expel fluid during the pressure stroke of the piston from a chamber in communication with each piston. Oppositely disposed magnets are located respectively in an upper pressure face of each piston and in a check valve housing adjacent each cylinder to produce a magnetic force circuit accelerating movement of each piston toward and in continual contact with a cluster bearing associated with the swashplate assembly during the suction stroke of each piston. Like poles of each magnet face each other to produce a permanent levitating force on each piston.
    Type: Grant
    Filed: August 18, 1997
    Date of Patent: July 28, 1998
    Assignee: FMC Corporation
    Inventors: Brian M. Chrestoff, Robert H. Ash, Jr.
  • Patent number: 5518377
    Abstract: A miniature metering pump of the type possessing a body provided with an inlet opening out into a metering chamber, associated with an inlet valve having a valve member, and with a piston having a plunger provided with an axial nozzle and flared at its bottom end to form a hood receiving a sealing gasket, its internal channel being associated with an outlet valve having a valve member, wherein said outlet valve member forms a portion of a single elastically deformable part that constitutes said gasket, shaped to have a bottom U-shaped ring assembled round the hood of the plunger, and connected at the top on the outside to a substantially cylindrical skirt for sealing and for returning the piston to its rest position, which skirt runs on from an annular flange for providing sealed connection with the body; and on the inside by a folded valve member that is generally conical or mitral-valve shaped, with a narrow top end carrying a cutout surrounded by a lip that opens to provide an outlet orifice.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: May 21, 1996
    Assignee: Sofab
    Inventors: Jean-Louis Bougamont, Pierre Dumont, Herve Lompech
  • Patent number: 5335763
    Abstract: A spring retainer for a clutch piston has a cylindrical through portion engaged with the shank of a clutch drum and abutting a snap ring at one end. A dish bearing portion is connected to a second end of the through portion and extends in a frusto-conical manner in an axial direction of the shank. In use, the dish bearing portion abuts a dish spring, and a clearance is maintained between the dish bearing portion and the snap ring.
    Type: Grant
    Filed: March 18, 1993
    Date of Patent: August 9, 1994
    Assignee: Jatco Corporation
    Inventor: Tatsuya Katoh
  • Patent number: 5307730
    Abstract: A return spring (40,60) operable with piston means (30) for use in fluid operated friction torque transmission devices (11) including relatively rotatable members (12,13) carrying a plurality of torque plates (18,22), one of the members providing a fluid chamber (34) in which the piston means is reciprocable. Such a spring comprises flexible base means (41,61) carried within a recess (50,51) provided in the rotatable member and spring tab means (43,66) extending from the flexible base means and engageable with a wall (52) of the piston means; the tab means being movable with the piston means upon movement thereof in and out of the chamber in response to activation of the piston means.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: May 3, 1994
    Assignee: General Motors Corporation
    Inventor: Robert D. Erwin
  • Patent number: 5125234
    Abstract: In a hydraulic cylinder apparatus of a type actuated by a booster, a plunger chamber (39) of a booster (32) is connected in communication with an extension cylinder chamber (35) of a hydraulic cylinder (30). An annular oil make-up chamber (48) is disposed outside an outer peripheral surface of the cylinder chamber (35). The oil make-up chamber (48) is connected in communication with the plunger chamber (39) and an electromagnetically opened and closed type shutoff valve (49) is interposed between both said chambers (39) (48).
    Type: Grant
    Filed: April 25, 1991
    Date of Patent: June 30, 1992
    Assignees: Kabushiki Kaisha Kosmek, Mori Seiki Co., Ltd.
    Inventors: Keitaro Yonezawa, Kouichi Kojyo
  • Patent number: 5046404
    Abstract: A magnetic disk brake retractor is described as having a magnet mounted in the housing of a hydraulic disk brake and adjustable in position relative to a brake piston. In one modification described, the magnet is in the form of permanent magnets. The brake housing is constructed of a non-ferrous substance to prevent degradation of the magnetic field. The magnet is used to exert a force upon the piston to urge the piston to retract when the brake pedal is released. The position of the magnet is adjustable within the brake housing chamber to vary the strength of the magnetic field acting upon the piston and to also mechanically limit the amount of retraction permitted for the piston.
    Type: Grant
    Filed: November 19, 1990
    Date of Patent: September 10, 1991
    Inventor: Walter H. Schnorenberg, Jr.
  • 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: 4925154
    Abstract: An improved gate valve having a body with a chamber and an inlet and an outlet extending therethrough into said chamber, a gate mounted for reciprocation in said chamber between open and closed positions, a pressure responsive actuator having a housing, a piston, a connection to the gate and an actuating stem extending from the housing, a supplemental actuator having a connection to the actuator housing, an operating stem connected to the actuating stem, the operating stem having a shoulder facing in the direction opposite to the direction of closing movement of the gate, roller levers pivotally mounted to be in engagement with the exterior of the operating stem and a spring urging the roller levers into tight engagement with the operating stem, the roller levers pivoting on engagement with the stem shoulder to exert a closing force on the stem.
    Type: Grant
    Filed: August 18, 1989
    Date of Patent: May 15, 1990
    Assignee: Cameron Iron Works USA, Inc.
    Inventor: Gerald S. Baker
  • Patent number: 4871143
    Abstract: An improved gate valve having a body with a chamber and an inlet and an outlet extending therethrough into said chamber, a gate mounted for reciprocation in said chamber between open and closed positions, a pressure responsive actuator having a housing, a piston, a connection to the gate and an actuating stem extending from the housing, a supplemental actuator having a connection to the actuator housing, an operating stem connected to the actuating stem, the operating stem having a shoulder facing in the direction opposite to the direction of closing movement of the gate, roller levers pivotally mounted to be in engagement with the exterior of the operating stem and a spring urging the roller levers into tight engagement with the operating stem, the roller levers pivoting on engagement with the stem shoulder to exert a closing force on the stem.
    Type: Grant
    Filed: February 15, 1989
    Date of Patent: October 3, 1989
    Assignee: Cameron Iron Works USA, Inc.
    Inventor: Gerald S. Baker
  • Patent number: 4830737
    Abstract: Apparatus for controlling the flow of a foam uses a bellow enclosed in a housing. The bellows is filled with foam under pressure from a foam generator and expands a preselected amount at which point the flow of foam into the bellows is interrupted. Simultaneously with the interrupting of the flow of foam into the bellows, air under pressure is routed into the housing which causes the bellows to collapse forcing the foam out of the bellows. The apparatus is particularly useful in the froth flotation (benefication) of minerals.
    Type: Grant
    Filed: November 16, 1987
    Date of Patent: May 16, 1989
    Inventor: Howard W. Cole, Jr.
  • Patent number: 4762475
    Abstract: A thrust piston pump for the delivery of media has a spring constructed in one piece with the piston rod of a piston unit and located in the pump chamber, which is guided on a sloping surface formed by an internal cone. The piston rod is constructed in such a way that an axially resiliently compressible, sleeve-like piston collar can be fitted from the outer end of the piston rod. The fastening cap can be constructed in one piece with a flange edge, a ring packing and/or a component of the cylinder casing, particularly its cylinder cover. This leads to high pump reliability, in the case of simple construction and easy assembly.
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: August 9, 1988
    Assignee: Ing. Erich Pfeiffer GmbH & Co., KG
    Inventor: Karl-Heinz Fuchs
  • Patent number: 4593607
    Abstract: A manually operated actuator for a pump employs a vertical hollow chamber. A piston is vertically slidable in the chamber between a bottom position at which no pumping action can take place and a top position at which pumping action can occur. The piston and the chamber are contained in a housing. A trigger is pivotally secured in the housing and is connected to the piston. The trigger has a first position at which the piston is held in the bottom position and has a second position at which the piston is held in the top position. The trigger is normally in the first position and is manually movable into the second position. A spring device is disposed in the housing, being secured to the trigger and spaced from the chamber and piston. The device biases the trigger into the first position whenever there is no manual pressure on the trigger.
    Type: Grant
    Filed: February 28, 1985
    Date of Patent: June 10, 1986
    Assignee: Specialty Packaging Products, Inc.
    Inventor: Robert A. Bennett
  • Patent number: 4552056
    Abstract: An automatic reset arrangement for a manual release mechanism in a spring-applied, air-released brake comprising a sleeve member having axially projecting fingers that slide axially within the bore of the spring piston push rod. The ends of the projecting fingers are formed with outturned lugs having a conically-shaped surface adapted to engage a correspondingly-shaped shoulder in the bore of the piston push rod to provide a drive connection through which the spring brake force is transmitted to the sleeve member. A cylindrical plug member is normally arranged within the sleeve member at the flange end thereof to prevent inward deflection of the fingers and to thus maintain the integrity of the drive connection. A spring-returned, manually operable release lever is arranged to withdraw the plug member when it is desired to release the spring brake in the absence of air.
    Type: Grant
    Filed: December 24, 1984
    Date of Patent: November 12, 1985
    Assignee: WABCO Ltd.
    Inventor: Albert A. McKay
  • Patent number: 4523516
    Abstract: A pressure actuator is provided for a valve having a housing and an actuating stem, wherein an annular housing is attachable at one end of the valve housing and a cylindrical piston element is concentrically fixedly mounted to the other end of the annular housing. A cup-shaped cylinder is provided to cooperate in sliding and sealing relationship with the exterior of the piston. The cylinder defines an annular space between its exterior surface and the interior bore of the annular housing and spring elements are mounted in the annular space. If desired, an indicating stem passes through a bore in the fixed piston element and is interiorly engaged with the movable cylinder element, thus providing an indicating actuator wherein the total length of the actuator is not substantially in excess of twice the stroke of the actuator.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: June 18, 1985
    Assignee: Baker CAC, Inc.
    Inventors: Stephen R. Foster, Peter W. Austin
  • Patent number: 4502847
    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 staged 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 spring means during each pressure decreasing phase of each pressure pulsation whereby the pump assembly is operable to pump air from the vacuum source throughout a wide range of engine speeds and loads including high speeds and loads.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: March 5, 1985
    Assignee: General Motors Corporation
    Inventors: Donald J. Pozniak, Gerald F. Robertson, Michael J. McClain
  • Patent number: 4498318
    Abstract: Apparatus for supplying foam from the outlet of a continuously operated foam generator to a consumer which applies the liquid fraction of the foam to a substrate has a conduit which receives foam from the outlet and contains a storing device serving to take up the surplus of foam when the requirements of the consumer are less than the output of the foam generator and to satisfy the requirements of the consumer when such requirements exceed the output of the foam generator. The storing device contains a compensating device which ensures that the pressure of foam in the interior of the storing device is substantially constant, and such compensating device (which may consist of a reciprocable piston and a hollow piston rod receiving foam from the foam generator) can actuate a monitoring device which regulates the operation of the foam generator, of a pump which is installed between the foam generator and the storing device and/or a valve which can divert foam into a collecting receptacle.
    Type: Grant
    Filed: December 15, 1982
    Date of Patent: February 12, 1985
    Inventor: Mathias Mitter
  • Patent number: 4487110
    Abstract: A clamping element comprises a single-acting cylinder and a piston with strong spring return which can be cancelled out by introduction of a pressure medium into the pressure chamber of the cylinder. The spring return is brought about, at least mainly, by means of a sleeve (6a, 6b) of rubber or rubber-like material which occupies a gap (5, 5b) between the piston (3, 3a, 3b) and the cylinder wall (7, 7a, 7b) or a lining (40) arranged in the cylinder. The rubber sleeve is firmly vulcanized, firmly glued or surface-fixed in some other manner against the cylindrical exterior of the piston and against the wall of the cylinder or the said lining along an axial length which considerably exceeds the thickness of the gap.
    Type: Grant
    Filed: December 6, 1982
    Date of Patent: December 11, 1984
    Assignee: E.M.E. System Aktiebolag
    Inventors: Olof Olofsson, Gunnar Larsson
  • 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: 4445424
    Abstract: A pressure actuator is provided for a valve having a housing and an actuating stem, wherein an annular housing is attachable at one end of the valve housing and a cylindrical piston element is concentrically fixedly mounted to the other end of the annular housing. A cup-shaped cylinder is provided to cooperate in sliding and sealing relationship with the exterior of the piston. The cylinder defines an annular space between its exterior surface and the interior bore of the annular housing and spring elements are mounted in the annular space. If desired, an indicating stem passes through a bore in the fixed piston element and is interiorly engaged with the movable cylinder element, thus providing an indicating actuator wherein the total length of the actuator is not substantially in excess of twice the stroke of the actuator.
    Type: Grant
    Filed: October 2, 1981
    Date of Patent: May 1, 1984
    Assignee: Baker Cac, Inc.
    Inventors: Stephen R. Foster, Peter W. Austin
  • Patent number: 4442757
    Abstract: An improved valve actuator is provided for employment in environments such as subterranean wells where highly corrosive gases and fluids are contained in the well fluid which is normally pressurized and employed to operate the actuator. The bias element opposing the pressure induced movements of the piston unit of the actuator is disposed in an isolation chamber defined between two axially spaced, radial shoulders provided on the piston and having sealing engagement with the bore of the cylindrical wall, thus defining constant volume annular chamber that is isolated from the highly corrosive fluids and gases. The isolated chamber moves with the piston and thus does not provide fluid pressure opposition to the fluid pressure induced movement of the piston.
    Type: Grant
    Filed: August 24, 1981
    Date of Patent: April 17, 1984
    Assignee: Baker CAC, Inc.
    Inventor: Kip B. Goans
  • Patent number: 4336746
    Abstract: Actuating piston of disk brake is provided with self-retracting 3-element control unit carried, typically, in surrounding annular piston recess with one element in frictional or tensioned registration with wall of piston chamber. Elements are (a) radially tensioned anchorage ring which frictionally abuts chamber wall at piston-extension position, (b) axially compressible/resilient co-axial ring such as elastomeric O-ring, compression spring, or corrugated metallic washer which is compressed by piston extension, (c) positioning and limit bracket which locates a and b and provides axial channel for reciprocation of piston in response to fluid pressure from brake pedal. Upon relief of fluid pressure, expansion of compressed co-axial ring b "lifts" piston to retracted position. Unit may be installed as original equipment on vehicles, etc. or existing piston assemblies may be modified to incorporate such.
    Type: Grant
    Filed: November 21, 1980
    Date of Patent: June 29, 1982
    Inventor: Franklin J. Morith
  • Patent number: 4333391
    Abstract: A pressure-fluid operated actuator with a vane pivoting in a casing has a biasing spring in a two-part housing attached at one end to one part of the housing and at the other end to the vane. To adjust the spring bias said one housing part is rotatable by a worm and wormwheel mechanism. The worm is carried by said one housing part. The other housing part is fixed to the casing and has the wormwheel integrally formed on it. The wormwheel teeth are quadrant-form with an end face in a plane normal to the vane pivot axis and containing the worm axis so that the housing parts can be die cast or moulded and can be brought together axially to intermesh the worm and wormwheel. The transverse force on the worm is transmitted through its toothing to its housing part.
    Type: Grant
    Filed: February 29, 1980
    Date of Patent: June 8, 1982
    Inventor: Alan R. B. Nash
  • Patent number: 4308788
    Abstract: A differential pressure unit having overrange valves loosely mounted on a valve stem connected between the ends of a respective pair of movable bellows ends. A pair of spiral range springs bias both valves toward open positions. The valves include annular elastomers bonded to the edges of the apertured discs. The apertures in the discs act to allow the elastomers to seat and to unseat without causing lock-up. The discs are retained between plates and snap rings.
    Type: Grant
    Filed: April 15, 1980
    Date of Patent: January 5, 1982
    Assignee: International Telephone and Telegraph Corporation
    Inventor: William J. Cooper
  • Patent number: 4301948
    Abstract: This invention relates to a dispenser for paste-like products of the type having a container containing a product and closed at one end by a slidable piston in sealing engagement with the inner wall surface thereof, the other end being provided with a head member carrying on applicator and forming a pump chamber the volume of which is variable by the exertion of exterior pressure, the pump chamber being closed towards said container by a first check valve adapted to open only towards the pump chamber, and towards the outlet of the applicator by a second check valve adapted to open only towards said outlet.
    Type: Grant
    Filed: December 12, 1979
    Date of Patent: November 24, 1981
    Assignee: Joachim Czech
    Inventors: Joachim Czech, Hans D. Sieghart
  • Patent number: 4103864
    Abstract: A positioner having a differential piston which is hydraulically locked by the oil pressure of a tripout valve and which in turn cocks a closing and an opening spring against each other, in which, after the tripout oil pressure falls, the closing spring is first released, pulling the piston up, thereby permitting the opening spring to open the valve suddenly.
    Type: Grant
    Filed: December 27, 1976
    Date of Patent: August 1, 1978
    Assignee: Siemens Aktiengesellschaft
    Inventor: Heinrich Hagendorn
  • Patent number: 4070002
    Abstract: An actuator for a valve in which valve opening and closing is effected via a rectilinearly movable member having, at one end, a driving device and, at its other end, a return-movement arrangement. To-and fro movement of the member under the control of the driving device and return-movement arrangement opens or closes the valve, or vice versa.The return-movement arrangement includes a ramp connected to the member and a resilient energy storing cushion for acting oppositely to the driving device on the member with a bridging roller transmission rolling contacting the ramp so that, depending on direction of movement of the member, energy is either stored in or dissipated from the cushion.
    Type: Grant
    Filed: March 17, 1976
    Date of Patent: January 24, 1978
    Assignee: Applications Mecaniques et Robinetterie Industrielle A.M.R.I.
    Inventor: Maurice Bonafous
  • Patent number: 4018140
    Abstract: A hydraulic disc brake actuator is disclosed. The actuator uses a first hydraulic motor for actuating a service brake, and a spring-applied, hydraulically released motor for emergency or handbrake applications. If the braking system malfunctions or is disengaged from its source of hydraulic pressure, the spring motor may be used to apply the brake by merely venting its associated hydraulic motor. The spring brake may be released by energizing a second hydraulic motor, or by using a mechanical restraction device to compress the spring motor. The spring-applied brake may be used as a parking brake or as an emergency brake.
    Type: Grant
    Filed: June 17, 1974
    Date of Patent: April 19, 1977
    Assignee: General Signal Corporation
    Inventor: Thomas H. Engle