Abstract: A sectional pumping apparatus for well casing includes a discharge pipe, a submersible pump, a pump housing, a swab tool, and a central axis. The discharge pipe, the submersible pump, the pump housing, and the swab tool are concentrically positioned along the central axis. The discharge pipe includes a first tubular body and a flange connector. The flange connector is radially connected around the first tubular body. The submersible pump is hermetically attached to a pump end of the first tubular body. The submersible pump and the pump end are positioned within the pump housing as the first tubular body is hermetically attached to a top end of the pump housing through the flange connector. The swab tool is hermetically attached to a bottom end of the pump housing and is in fluid communication with the discharge pipe through the submersible pump.

Abstract: An electromechanical brake pressure generator for a hydraulic braking system of a vehicle, including a threaded drive system for converting a drive-side rotary motion into a translatory motion for brake pressure generation. The system includes a spindle rotatable via an electric motor, a spindle nut cooperating with a thread of the spindle so the spindle nut is axially displaceable with a rotation of the spindle and a brake fluid is loadable or relievable, and a housing which, together with the spindle nut, forms an anti-twist protection which secures the spindle nut against twisting during rotation of the spindle. The spindle nut forms at least one spindle nut reference surface, which cooperates with at least one stop surface, which is stationary with respect to the housing, in a relief end position of the spindle nut in such a way that an instantaneous axial position of the spindle nut is determinable therefrom.

Abstract: A spring brake cylinder having a housing in which a spring store piston which is loaded by at least one spring store spring and which has a piston rod is axially movable, and having an emergency release device with an emergency release actuation device, an emergency release mechanism with a toothed wheel for interrupting the force flow between the spring store piston and piston rod, and a holding device designed for holding the emergency release device in various holding positions, wherein the holding device has a pawl, and the emergency release actuation device has at least one actuation element and a driver for driving the pawl.

Abstract: Actuator (V) for opening an aircraft nacelle cowl (7), comprising a dead travel device (19), characterized in that it comprises means (42a, 42b, 43) for blocking the dead travel device (19) when this actuator (V) is extended.

Abstract: A fluid pressure cylinder can apply a fastening force to an axially movable reciprocating rod. A reciprocating rod 13 is mounted in a case main body 10 so as to be reciprocable in a forward direction and a backward direction, and two lock units 16a and 16b are incorporated in the case main body 10, and the lock units 16a and 16b include: lock sleeves 18a and 18b mounted axially movably and having taper surfaces 22a and 22b; and retainers 19a and 19b holding steel balls 21a and 21b that are fitted in the reciprocating rod 13 axially movably and engaged with the taper surfaces. A fastening cylinder 41 that contains a fastening rod so as to be reciprocable in a fastening direction and a fastening release direction is attached to the case main body 10, a fastening surface 44 contacting with the lock sleeves 18a and 18b being formed in the fastening rod, and the reciprocating rod 13 is fastened by the two lock units 16a and 16b.

Abstract: A cable operated gas cylinder comprises: a base tube; a spindle which is inserted at hollow part in said base tube; a cylinder which is mounted within said spindle; a piston dividing the gas-filled space within said cylinder into upper part and lower part; a pipe holder sealing airtight the upper part of said cylinder; a gas opening/closing pin which is mounted penetratingly through central part of said pipe holder and for controlling getting in and out of the gas filled within said cylinder; a release arm for controlling the opening/closing of said gas opening/closing pin; a cable for controlling turning of said release arm when being pulled by external force; and a taper holder which receives said release arm therein and rotationally intervenes within said spindle, wherein said release arm and said taper holder are capable of rotating together as said cable rotates.

Abstract: A fluid pressure cylinder has a piston rod 18 fixed to a piston 26 and projecting outside a cylinder body 23. A lock surface 43 inclining to a radial direction of the piston rod 18 is formed in an engagement member 31 provided in the piston rod 18. A lock rod 35 reciprocating in an about right-angle direction to the piston rod 18 is built into a lock cylinder 33 provided in the cylinder body 23. The lock rod 35 is provided with: a large-diameter section 35a fitted into a guide hole 36 formed in the lock cylinder 33; and a slide contact section 37 provided in the large-diameter section 35a via a constriction section 35b. The slide contact section 37 contacts with a radial-inner portion of the lock surface 43 when the lock rod 35 comes nearest to the piston rod 18.

Abstract: The invention relates to a spring brake cylinder with an emergency release device, comprising the following: a housing in which a spring-loaded piston can be moved axially with a piston rod, at least one spring-loaded spring, wherein the emergency release device comprises an actuation device, an emergency release mechanism to interrupt the power transmission between the spring-loaded piston and the piston rod and a holding device for holding the emergency release device in a transmission condition.

Abstract: An hydraulic bath seat lift has a hydraulic cylinder assembly comprising an inner cylinder fixed with the floor and an outer cylinder, which can be raised and lowered by supplying hydraulic fluid to the assembly. The outer cylinder supports a seat at the end of a horizontal arm. The inner cylinder has a pin at its upper end projecting outwardly into one of two sets of longitudinal grooves along the inner surface of the outer cylinder to prevent the outer cylinder rotating relative to the inner cylinder. The grooves open into one another at the lower end of the outer cylinder so that when the outer cylinder is raised fully, to lift the seat above the bath, the cylinder can be rotated to swing the seat over the bath and then lowered with the pin engaging the other set of grooves.

Abstract: A removable cartridge seal and dilatable collet retainer for a hydraulic plunger is provided to permit ready removal and replacement of the plunger and seal in a hydraulic intensifier device or the like.

Abstract: In a pressure-intensifying type fluid pressure cylinder, an auxiliary cylinder chamber is provided outside a rod cover, a pressure intensifying piston is axially and slidably disposed on the outer peripheral portion of a piston rod in the auxiliary cylinder chamber, and steel balls are disposed around the piston rod in space having a tapered surface in the pressure intensifying piston. Or, a lock concave portion is formed on the outer peripheral portion of the piston rod and a lock member is provided in the pressure intensifying piston which lock member makes the pressure intensifying piston and the piston rod one body by being fixed in the lock concave portion. When the piston rod reaches a little before the end of extrusion, fluid pressure comes through a way in the auxiliary cylinder chamber between the pressure intensifying piston and the rod cover.

Abstract: A piston for forcing a liquid metal out of a casting cylinder of a die-casting press, having a mounting piece with an end surface and an outer peripheral surface; and a cap having an inner cover surface, an inner peripheral surface, and a free edge surface. The cap is mounted on the mounting piece so that the inner cover surface faces the end surface, and the inner peripheral surface has, proximate to said free edge surface, a plurality of notches formed therein. The outer peripheral surface has a plurality of bayonet-catch projections extending therefrom which are received in the plurality of notches.

Abstract: A fluid cylinder mechanism couplable to a vehicle and having a piston slidable within the cylinder, a rod couplable to an implement and shiftable within an opening in the piston, the rod being adapted to shift vertically within the piston a an implement rides over ground undulations, and an abutment mechanism coupled to the rod for abutment with the piston when the piston shifts upwardly due to selective forcing of fluid into the rod end of the cylinder by the operator to transfer the weight of the implement to the vehicle or to lift the implement for transport.

Abstract: A piston stem insert to be received within a hollow receptacle that is molded at the interior of a carpule based piston, so that a piston stem may be easily attached to and detached from the piston by way of the insert. In a first embodiment of the invention, a set of flexible, anti-displacement wings extend radially from the insert to releasable and frictionally engage the inside walls of a carpule, so as to prevent an inadvertent and premature displacement of the piston through the carpule. In a second embodiment, a set of anti-rotation wings extend radially from the piston stem insert to be received within respective cavities of the receptacle that are shaped so that the wings may be rotated in a single (e.g. clockwise) direction but blocked from rotation in an opposite direction.

Abstract: A power cylinder of the type in which the piston may be locked to maintain the associated tool or clamp in a fixed position. A pair of guide rods extend in parallel spaced fashion through the bore of the cylinder from end to end of the cylinder and the piston includes a pair of spaced apertures passing the guide rods so that the piston may slide within the bore of the cylinder on the guide rods. The piston apertures are internally threaded and the guide rods include an externally threaded portion so that, following movement of the piston within the bore through a rapid advance portion of its stroke under the influence of pressure fluid, the internal threads in the piston apertures are brought into engagement with the externally threaded portions of the guide rods and the guide rods are thereafter rotated so as to threadably advance the piston to its final desired position in which the piston is lockingly held by the coacting threads.

Abstract: The present invention is directed to a self-adjusting servo mechanism (10). The servo pin (30) presented from the servo mechanism (10) will protract sufficiently to effect operative engagement of a friction band assembly (13) with a rotating member (18) in a planetary gear set--even though the required axial displacement of the servo pin (30) during such protraction may exceed the axial displacement through which the servo pin (30) was previously retracted. The servo mechanism (10) is incorporated in a housing (20). The housing (20) presents a socket cavity (24) within which an actuating piston (33) is received for axial displacement.

Abstract: The invention relates to a control device for a gas spring which can be locked as desired by displacement of a sliding control finger. Two axially elongated, diametrically opposed windows (14), at least one of which is larger at the end nearest to the gas spring, pass through a tubular connector (1) coaxial with the control finger (6). A lever (2) which has thinner parts (25, 26) flanking a wide part (24) engages in these windows. Devices (7) are provided so that, after mounting on the gas spring, the wide part (24) is unable to reach the wide section of the window, thus preventing the lever from being dislodged. The edges of the windows (14) form bearing points for the pivoting movement of the leaver and the actuation of the control finger (6).

Abstract: An actuating cylinder having a fluid pressure operated piston member connected by a friction member to a push rod to which a brake shoe, or the like, may be attached as the output member. A force transfer lever is arranged between the piston and push rod to transmit the piston force to the output member with mechanical advantage only after the friction connection is overcome by resistance at the push rod, such as occurs by engagement of the brake shoe with the wheel of a railway vehicle.

Abstract: The cylinder has a sealed back wall through which the rod passes. A piston assembly mounted on the rod between the back wall and a cylinder front end-piece contains a fluid-pressure-activated clamp. The front end-piece also has a clamp. By sequenced operation alternatively fixing the piston or the cylinder to the rod through the respective clamp, the relative travel of cylinder and rod can be extended to any desired length.

Abstract: An assembly and disassembly system for a spring of a brake actuation unit, in particular for rail vehicles including a fluid pressure cylinder and a piston slidable in the cylinder. A cylindrical nut member is provided having a tubular portion extending outwardly of the piston. An output head is connected to the tubular portion and includes an outer tubular portion extending towards the piston. A compression spring is provided disposed between the tubular portion of the cylindrical nut member and the outer tubular portion of the output head. A sleeve member is disposed between the spring and the outer tubular portion of the output head. This sleeve is provided with a slot which extends in an axial direction along the sleeve. The outer tubular portion includes an opening which may be aligned with the sleeve slot. A member such as a pin is provided which extends through the opening into the slot holding the sleeve and the outer tubular portion in a position engaged around the spring.

Abstract: A dispensing device of the hand-help pump type has an internal piston which is pulled up by a rod passing through the piston, which rod is moved by an actuator. When the contents of the piston are emptied, in order to attach a refill, a dog release mechanism operates to release the dogs which, in normal use when the device is full, function to prevent the piston from being drawn downwardly so that the piston can be removed to allow attachment of the refill which has a new piston.

Abstract: An integrated manual brake device on a brake actuation unit, particularly for rail vehicles, and it includes a hydraulic or pneumatic cylinder. The brake actuation unit contains a linkage setter including two parts displaceable relative to each other in a telescopic fashion. One of the parts is formed as a threaded spindle and the other tubular part is firmly connected with a nut which is screwed on the spindle with a nonselflocking thread. A stop is provided on the tubular part fixed in an axial direction but easily turnable. An actuating spring is clamped between the piston and the output part.

Abstract: A spring brake assembly having a body portion in which a piston is mounted for reciprocal movement. A piston guide means engages a stem portion of the piston and an end of the body portion. A brake spring is caged between an inner surface of a face portion of the piston and an end of the body portion. Engageable at one end thereof with the stem portion of the piston is a pushrod which also extends coaxially out of the end of the body portion. A clutch including control and operating devices is provided.

Abstract: A railroad truck having at least four wheels comprising brakes for braking the wheels; a single enclosed air cylinder mounted on the truck; the air cylinder having first and second chambers; a conduit to supply service air pressure to the first chamber; the first chamber containing a piston pneumatically operated by service air pressure to apply controlled service braking pressure, emergency braking pressure and, when the truck is stopped, parking braking pressure, to the brakes; the second chamber containing a spring which applies automatic parking pressure to the brakes when the truck is stopped, and applies emergency fail-safe pressure to the brakes when there is a pneumatic system failure to supply air to the first chamber; apparatus to supply pressurized air to the second chamber to keep the spring from applying pressure to the brakes so long as adequate air pressure is maintained in the second chamber; a handbrake assembly mounted on the truck in a position readily accessible for manual operation when t

Abstract: A spring brake cylinder assembly in which a pushrod connectable to a brake assembly is extendable from an end of such cylinder housing the piston member. The spring brake cylinder further includes a clutch release mechanism for manually releasing the brake force being applied.

Abstract: A brake actuation unit comprises a fluid pressure cylinder with a piston movable in the cylinder which has a central projection portion with a recess having axially spaced opposed coupling surfaces. The spindle is centrally arranged in respect to the piston and a nut is threadable on the spindle and has a tubular portion terminating in a flange which has a flange projecting portion extending into the recess of the piston projection portion and it has opposed coupling surfaces engageable with respective opposed coupling surfaces of the piston projecting portion so as to form respective axially opposite direction of movement coupling pairs. The guide sleeve is positioned over in spaced relationship to the nut tubular portion and has a radially extending collar on an end thereof adjacent the piston. An output head is movable in an axial direction to apply a braking force and has a tubular portion telescopically engaged over the guide sleeve.

Abstract: A spring brake cylinder assembly having a spring-biased piston positioned therein. A pushrod is engaged with the piston through a clutch, which clutch includes both a clutch control device and a clutch operating mechanism that can manually release a brake application being applied by the assembly.

Abstract: A device for discontinuing and automatically restoring the operational function of a spring brake actuator. The device includes a piston with a piston rod and a spring for actuating the piston and piston rod in a working direction for brake application at falling brake fluid pressure on the piston. A slitted, resilient locking ring is arranged in grooves facing each other in the piston rod and a piston rod sleeve coaxial therewith. The locking ring can either be constrained to rest in both of the grooves, so that the piston rod and piston rod sleeve are locked together, or be free to be forced completely into one of the grooves, which is at least as deep as the thickness of the ring, so that the piston rod and piston rod sleeve are free to move independently of each other.

Abstract: A system of hydraulic tools utilizing removably, replaceable and substantially interchangeable valve assemblies, fluid reservoirs and hydraulic driving mechanisms. The fluid reservoir maintains the hydraulic fluid under moderate pressure. The valve assembly can contain a hydraulic pump for powering the driving mechanism. The hydraulic pump preferably has displacement varying means for changing the power transfer ratio of the pump. The hydraulic assemblies are removably received in a variety of tool bodies.

Abstract: A drive ram, particularly for a yarn winder, has the piston rod freely movable relative to both the piston and the ram cylinder in a first condition in which a locking washer is perpendicular to the longitudinal axis of the piston rod. Upon application of fluid pressure to effect relative movement of the piston and the cylinder, the locking washer is spring-urged against a wedge-like tipping washer which skews the lockingwasher and causes it to clamp the piston rod whereby the piston rod is then driven by the ram through a predetermined travel, from a starting position which is governed only by the diameter of the package at the time of operation of the package lift mechanism.This allows a virtually constant lift travel of the ram, regardless of the diameter of the package at the time of operation of the ram.

Abstract: An hydraulic booster has a housing provided with a bore, an inlet connected to a source of pressure fluid, and an outlet connected to a reservoir for fluid, a boost piston being advanced in the bore in response to pressurization of a boost chamber, the boost chamber being pressurized under the control of a valve mechanism operative in response to a load applied to an input member. Two connections are provided between the source and the boost chamber, both connections being closed when the booster is inoperative, and when the booster is operated the first connection is opened following initial movement of the input member, and the second connection is opened following initial movement of the boost piston in response to pressurization of the boost chamber. Thus the booster is in a closed center mode when inoperative, but operates in an open center mode. The connections are preferably controlled by valves. The input load may be applied in tension or compression.

Abstract: A delayed restraint releaseable device utilized to restrain and controllably release the lower end of an inflating escape slide at a predetermined pressure, orientation and time. The device combines two distinct restraint mechanisms into one combination unit. The primary release is accomplished by means of shear pin or pins located at the first end of the device. Under normal conditions, the release is accomplished by shearing of the pin or pins under the load provided by the tied back inflating slide. The back-up release, in series with the primary release, occurs when the pressure of the reduced load causes a piston within the restraint to move against both a spring and captive fluid. As the piston moves, the fluid transfers through a precise sized orifice in the piston, from one side of the piston to the other. The piston moves eventually to a point at which the interlocking leg of the piston support shaft is released, thus allowing the ends of the mechanism to separate.

Abstract: A braking device for arresting an axial relative movement between a bearing, and a shaft slidably engaging the bearing and extending through a cylinder which is axially immovable to the bearing. The device comprises: an annular piston slidably received in the cylinder and slidably engaging the shaft; a brake shoe engaging the shaft axially immovably relative to the cylinder and radially contractible to apply a brake to the shaft; a resilient radial clamp member engaging the outer surface of the brake shoe, axially compressible by axial movement of the annular piston and thereby reduced in inside diameter to force the brake shoe against the surface of the shaft; and a piston driving device for moving the shaft along its axis through a controlled selective supply of a pressurized fluid to the cylinder. The piston driving device may comprise a coil spring to bias the piston to cause an axial compression of the radial clamp member, and a device for effecting the controlled supply of the fluid.

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.

Abstract: A spring-applied, air-released parking/emergency brake is combined with an air-actuated service brake through a friction clutch between the parking/emergency brake piston and a first nut member that is threaded onto a screw rod of the service piston. The screw rod and service piston are connected through another friction clutch. The screw rod is provided with a second nut member that is integral with a thrust rod to which the brake rigging is connected. A friction lock slack adjuster arrangement limits retraction of the thrust rod during brake release in accordance with the desired brake shoe clearance to be maintained. When the thrust rod movement is inhibited by the slack adjuster, the service piston clutch becomes disengaged to permit rotation of the screw rod during the release stroke of the service piston corresponding to overtravel due to shoe wear. Brake shoe clearance is thus maintained constant.

Abstract: A manually operable quick-release mechanism for use with a spring-loaded brake cylinder including an energy-storing piston operable by fluid pressure to a brake release position with a ball type clutch for locking said piston and a piston rod in said brake release position, and a manually rotatable member effective, when angularly displaced, for releasing the ball clutch and the piston and allowing the piston and piston rod to move to a brake-applying position.

Abstract: A spring-loaded brake cylinder has a slideable braking piston one side of which is acted upon by a first spring in the braking direction and a second side acted upon by air under pressure in the release direction against the force of the spring. There is a releaseable mechanical coupling between the braking piston and a piston rod upon which is mounted a quick-acting piston. The quick-acting piston is actuated by air. The position of the braking piston controls a supply of air to and a discharge of air from the quick-acting piston so as to achieve pressurization and depressurization of the quick-acting piston.

Abstract: A telescoping jack having a cylinder and a plurality of coaxial tubular elements mounted within the cylinder, the elements being movable between a retracted position where they are nested within the cylinder and an advanced position. Each pair of adjacent tubular elements has two pairs of cooperating annular recesses on their inner and outer surfaces which pairs of recesses cooperate, in combination with an elastic ring, to limit the outward movement of an inner tubular element relative to its adjacent outer element.

Abstract: An automatic mechanism is provided for locking the piston rod of a multi-position fluid operated linear actuator in its existing extreme axial position and to maintain such piston rod's position against unbiased forces acting on the piston rod, in the event of a failure of, or significant decrease in, the fluid pressure applied on the piston. A lost motion connection is provided between a piston head and the piston rod opposite the locking mechanism, permitting a limited amount of axial movement of the piston head relative to the piston rod. A locking mechanism is provided to automatically engage the piston rod whenever it reaches one of its two extreme axial positions and to lock the piston rod at that position. The locking mechanism is releasable by a cam structure provided on the piston head. The initial movement of the piston head relative to the piston rod in a direction toward the other axial position of the piston rod effects the camming of the locking mechanism to an unlocked position.

Abstract: A hydraulic ram for use in thrust-jacking of tunnel linings comprises a cylindrical outer member, a cylindrical inner member reciprocable within the outer member, and an extension member reciprocable within the inner member. A two-part clamping ring is provided for releasably locking the extension member to the inner member. An auxiliary drive is provided for retracting the extension member rapidly within the inner member. The auxiliary drive may be a mechanical spindle drive, or a hydraulic drive having an auxiliary piston reciprocable within an axial bore formed in the extension member. The clamping ring comprises spring means for urging the parts of the clamping ring in to the closed position, and piston-and-cylinder means for urging the parts of the clamping ring apart, against the biasing force of the spring means, to open the clamping ring.

Abstract: A servomotor which actuates the throw-out device of a clutch, particularly in an automotive vehicle, has a piston which is reciprocable in a housing and is adapted to be coupled to a reciprocable motion transmitting rod for the throw-out device by a compensating device having cylindrical rollers which establish a motion transmitting connection between the piston and the rod as soon as the piston leaves its starting position in response to evacuation of air from the housing at one side of the piston. The rollers are automatically disengaged from the rod when the piston returns to its starting position so that the rod can be moved by the clutch in a first direction to compensate for wear upon the parts of the clutch or in a second direction to compensate for expansion of one or more friction discs in the clutch.

Abstract: A percussive device for creating impact impulses, which device comprises a housing accommodating a striker. The striker has a tail portion located in a power cylinder which is joined to the housing and is filled with a fluid medium under pressure, said fluid medium operating the striker. Provision is made of an arresting mechanism which is kinematically connected to a drive designed to engage the striker for effecting its backward stroke in the process of which the fluid medium under pressure is compressed, storing potential energy. According to the invention, the striker backward stroke drive is constructed in the form of several hydraulic cylinders equidistantly spaced round the periphery of the housing. The rod of each of the hydraulic cylinders is connected to the striker arresting mechanism.

Abstract: A brake cylinder device combining a pneumatically-applied service brake and a spring-applied parking brake in a compact unit made possible by limiting the stroke of the parking brake piston to minimize the expansion of the spring and thus the amount of force relaxation, so that a relatively small spring may be used. The service brake piston carries a threaded shaft on which a nut is rotatably carried for locking engagement with the parking brake piston.

Abstract: A process for controlling pneumatic servomotor of the type comprising a control by a motor jack supplied with pressurized fluid by a pressure modulator of said fluid and a first slaving loop causing said jack to slave in a given reference position, wherein each reference position is stored in analogue manner by movable mechanical friction means carrying said modulator and displaced by means of a second disengageable slaving loop which is substituted for the first during reference position changes and which takes its displacement energy for the movable mechanical means directly from the motor jack.

Abstract: A hydraulically actuable piston and cylinder unit comprising a hollow piston rod, slidably housing, at least partially, an elongate extension piece having a circular outer periphery, means to connect mechanically, the extension piece to the piston rod at the outer end of the latter remote from the piston head, at least one fluid passageway communicating between the annulus side of the piston head and the hollow interior of the piston rod, and a fluid seal carried by the extension piece and sealing against the internal periphery of the hollow piston rod, the arrangement being such that the seal always lies between the passageway and the outer end of the hollow piston rod.

Abstract: A spring-loaded braking cylinder has a rapid release mechanism which disengageably connects the spring-loaded piston with the piston rod. A damping mechanism damps the relative movement between the piston and the piston rod which occurs upon release of the coupling between the spring-loaded piston and the piston rod. The piston rod is coupled to the piston by a transverse pin a portion of which projects into a transverse slot on the piston rod and another portion of which is movable within an L-shaped slot on the piston rod. An adaptor connected to the pin has a flange which acts as a piston within a closed chamber formed with the piston rod and filled with fluid. The spaces on both sides of the piston-like flange are interconnected by throttle passages.

Abstract: A spring-applied, air-released parking brake, having a manual release mechanism with an automatic reset feature. To release a spring-applied parking brake, in the absence of air, a torsion bolt having a cam member formed on it is manually rotated to a position aligning the cam with an elongated slot in the piston push rod of the parking brake cylinder. This allows the piston to be extended in a direction to extend the spring, thus relieving the spring force. Reapplication of air pressure moves the piston push rod out of the elongated slot to permit angular rotation of the bolt by its torsion spring, so as to prevent its entry in the elongated slot until the bolt is again rotated manually.

Abstract: A spring brake actuator has a quick release clutch for deactivating the brake in absence of fluid pressure and a governing device operating the clutch in response to the relative pressures prevailing at the service brake and spring brake cylinders. The governing device comprises a biased pilot valve and a signal valve which permit alternate operation of the brake release clutch manually or automatically.

Abstract: A vacuum booster including a casing, a power piston having a resilient diaphragm and dividing the interior of the casing into two chambers, an input rod for actuating a valve mechanism to generate differential pressure between the two chambers, and an output rod receiving a force in accordance with the differential pressure from the power piston, wherein the inner end of the output rod is received slidably on a member of power piston side with male and female engagement therebetween, and a groove is formed in the male member for engaging with a clip which allows a predetermined amount of relative sliding movement between the male and female members.

Abstract: A locking mechanism for hydraulically actuated devices is disclosed herein. The mechanism includes a slotted lock shaft coaxially mounted with respect to a piston assembly, the piston assembly being disposed in a hydraulic cylinder. The lock shaft has end faces or shoulders which engage a portion of a shaft associated with the piston assembly to lock the piston assembly and the ram shaft in a predetermined position. The lock shaft has a configured surface which cooperates with a configured surface of the piston assembly for unlocking the mechanism. The locking mechanism is described for use with a ram type blowout preventer but can be used with various types of hydraulically actuated devices.