Abstract: A spring actuated plunger work support seeks variable tolerance level of workpiece and is hydraulically locked in place to provide resistance to workpiece deflection imposed by processing loads. A collet with independent steel segments in a molded rubber body are preloaded in assembly and actuated by conical ended hydraulic piston having minimum travel to lock the work supporting plunger.

Abstract: A piston and cylinder assembly for a vehicle hydraulic system has a retaining device comprising an insert acting between a piston and the cylinder bore in which it works, the insert having a releasable frictional engagement in the bore and acting as an abutment to hold the piston in its retracted position to maintain the effective length of the assembly at a predetermined value for installation, until the assembly is operated hydraulically. The assembly may be an actuator for a self-energizing disc brake, or a slave cylinder for a vehicle clutch system.

Abstract: A pneumatic spring having a cylinder piston and piston rod biased toward extended condition by compressed gas in the cylinder, an elongated cover tube severed at one of its ends to the outer end of the rod, extending over the length of the rod to define an annular space therebetween, and always in axial alignment with and extending over portions of the cylinder. A transversely shiftable plunger lock assembly on the cover tube near its open end includes a fixed body and a lock plunger movable transversely of the piston axis into the annular space when the rod and cylinder are extended, to abut the annular end of the cylinder to securely retain the assembly in one position, preferably a substantially extended condition.

Abstract: Herein disclosed is a cylinder locking device for locking and stopping the piston rod of a hydraulic cylinder in a desired position. There are fitted rotatably in a housing, a pair of thick, semicylindrical halves which are formed by dividing a thick cylinder having eccentric outer and inner circumferential portions axially into two halves at the thickest and thinnest portions. The piston rod of the hydraulic cylinder is inserted slidably into the inner circumferential portions of the two semicylindrical halves. The piston rod is locked in the desired position by turning the two semicylindrical halves in the opposite directions through a pair of leaves which are attached to the two halves.

Abstract: A pneumatic cylinder having an elongated cylinder member, a reciprocally movable piston, transfer means for transferring reciprocal movement of the piston to a work piece and a brake mechanism associated and movable with the transfer means for creating a braking force between the transfer means and a portion of the cylinder member. The brake mechanism includes a first brake surface connected with the transfer means, a second brake surface formed by an exterior surface portion of the cylinder member and a brake actuation mechanism for selectively causing movement of the first and second brake surfaces into braking engagement with one another.

Abstract: The present device is intended to lock a member, such as a tool, substantially without play into a form-locked position which can be released only by a fluid pressure intentionally applied to the device. The construction is such that small clamping strokes or displacements can be performed and so that the form-locking or arresting force is maintained as long as desired and with safety. For this purpose a pull rod having, for example, a ring channel, is insertable into a socket type of receiver equipped with radially movable locking elements which cooperate with their own slanted surfaces with slanted surfaces of the pull rod and with slanted surfaces of a ring piston. Certain cooperating surfaces have a slant angle which is smaller than a self-locking angle. The release is possible only if the ring piston is exposed to a fluid under pressure.

Abstract: A locking apparatus for fluid operated valves having a piston connected to the valve actuator which moves in response to applied pressure within a cylinder housing having a cylinder head, a catch block is secured to the piston, and the cylinder head incorporates a catch pin. Pressure applied to the cylinder to open the valve moves the piston adjacent to the cylinder head where the catch pin automatically engages the catch block preventing futher movement of the piston or premature closure of the valve. Application of pressure to the cylinder to close the valve, retracts the catch pin, allowing the valve to close. Included are one or more selector valves, for selecting pressure application to other apparatus depending on the gate valve position, open or closed, protecting such apparatus from damage due to premature closing caused by pressure loss or operational error.

Abstract: The apparatus comprise a generally tubular outer element, a generally cylindrical inner element disposed therewithin and sized relative thereto to provide a generally annular operating space therebetween. An intermediate element is disposed in said operating space and is dimensioned relative thereto to create interference fits with said outer and inner elements and prevent relative movement therebetween. Means are provided to introduce pressurized fluid to the respective element interfaces to expand the outer element within the elastic limit thereof to an extent sufficient to release the interference fits and enable relative outer-inner element movement. Re-locking of the outer and inner elements occurs automatically upon depressurization of the fluid and attendant return of the outer element to its unexpanded configuration. Actuating means to effect relative outer and inner element movement upon apparatus unlocking are also provided, and include means to pressurize the fluid.

Abstract: The present invention relates to a fluid-operated actuator, constituted by a cylinder and by a double-effect piston, provided with a device suitable to automatically locking the same piston at the end of its working stroke.

Abstract: A hydraulic brake actuator including a hydraulic parking brake that can be applied by mechanically locking up either a normal service brake application or a hand pump operated brake application. The lock-up mechanism includes a friction collar that surrounds the piston push rod and a hand pump actuated locking member that surrounds the friction collar. The friction collar and locking member have complementary conical surfaces that are engageable when hydraulic hand pump pressure is applied to a piston face of the locking member to wedge the friction member into pressure engagement with the piston push rod, as a means of locking up the push rod to obtain a parking brake. The locking member also includes a plurality of spring-like fingers that project axially from the periphery of the locking member and are provided with latching tabs adapted to enter a recess in the body to prevent return-movement of the locking member when the hydraulic hand pump operation is terminated.

Abstract: A hydraulic actuator with reduced interior volume includes a locking mechanism engageable with the main ram of the actuator to hold it in a fully retracted position without backlash. The locking mechanism comprises three locking jaws that move synchronously in a radial direction between lock or unlock position. Each of the jaws engage a groove cut into a rod adjacent the piston head of the main ram; the jaws are cammed into a locking position by a conical sleeve actuated by hydraulic pressure under the control of the main control valve. Jaw deactivation is accomplished by an opposed pressure which disengages the conical sleeve and the jaws are then spring biased into a cammed open position as the main ram begins to extend. Springs located between the individual jaw segments assist the camming action for opening the jaws.

Abstract: A fluid actuator includes an internal lock assembly for locking an actuator piston to a cylinder of the actuator. A circumferential slot is located on the inner surface of the cylindrical wall for receiving locking latches which are radially extendable and retractable on the piston, and ball bearings are located between an inner aspect of each latch and a first abutment member on the piston. A second abutment member has a thickness less than about half the diameter of the ball bearings and is adapted to become wedged between the ball bearings and the first abutment means to force the latches radially outwardly into the slot for locking the piston relative to the cylinder and thereafter to abut only the latches to maintain locking.

Abstract: The servomotor arrangement has a moving system comprising a piston movable in a cylinder. A latching or retaining member movable transversely of the direction of movement of the system is provided to retain or latch the moving system. The latching member is in operative connection with a pressure chamber, and the pressure chamber is in communication by way of a stop member with a pressure medium source and with a pressure medium sink. The latching member is controllable, a feature which has advantages for the operating behavior of the servomotor arrangement.

Abstract: A locking device for a circumferentially grooved reciprocating member is disclosed. In one embodiment the locking device includes a housing, through which the reciprocating member passes, having a pair of spring biased locking elements and a release element disposed therein. Locking is achieved by insertion of the locking elements into the reciprocating member circumferential groove. Unlocking is effected by displacement of the release element towards the locking elements along a line perpendicular to the reciprocating member to withdraw the locking elements. In an alternative embodiment a spring biased retention pin is provided to selectively engage and retain the release element in proximity to the locking elements. An annular ring may be disposed about the reciprocating member adjacent the circumferential groove to displace and disengage the retention pin from the release element.

Abstract: The invention relates to a fluid power actuator with a cylinder, a piston and a piston rod whose motion is controlled by a positioning device which halts it in selected settings. The positioning device has a row of depressions, for example gaps between the teeth of a rack, running parallel to the piston rod. A positioning plunger moves into a selected depression to lock the rod. A shutter with at least one opening therein covers the row of depressions and is adjustably affixed thereto so as to allow adjustment of the position at which the control plunger aligns with the shutter opening and slips into the selected uncovered depression to stop and lock the piston and rod.

Abstract: A method and arrangement for reciprocating a piston in a cylinder of a fluid actuated actuator between one and another alternate positions, and using the piston fluid actuator fluid to move a lock member from a first position to a second position to lock the cylinder when it is moved from one position to its other alternate position. Actuator fluid is communicated to unlock the lock member and to move the piston back to its one position. In another form, the lock member is moved to its first position by the actuator pressure fluid which actuates a valve to communicate actuator fluid pressure from the lock member to the cylinder to move the piston back to its said other position.

Abstract: A fluid-pressure-operated, double-acting working cylinder which dampens the final braking of the work piston, includes a cylinder housing with a movable work piston disposed therein, the work piston dividing the cylinder into two work chambers. A piston rod, on which the work piston is mounted, extends through the housing. At least one auxiliary braking member is disposed on at least one side of the work piston in an offset slidable relation to the work piston. A braking arrangement disposed on the auxiliary braking member is controlled by fluid pressure to brake the auxiliary braking member to a desired position within the cylinder. A dampening chamber, a dampening spring configuration is disposed between the auxiliary braking member work piston such that, following braking of the auxiliary braking member, continued movement of the work piston is effectively dampened.

Abstract: A pneumatic cylinder device with a locking mechanism has a pneumatic cylinder constituted by a cylinder, a piston slidably received in the cylinder and a piston rod extended from the piston outwardly of the cylinder, and a locking mechanism connected to the pneumatic cylinder and adapted to selectively lock the piston rod against movement. The locking mechanism comprises a housing through which the piston rod is slidably extended; a flexible tubular member disposed in the housing so as to surround the piston rod, the flexible tubular member being contractable and expandable radially; and annular pressure chamber formed around the flexible tubular member and having a variable volume; a volume changing means for causing a change in the volume of the pressure chamber; and a pressure transmission medium accommodated in the pressure chamber and adapted to transmit a pressure change, produced in the pressure chamber as a result of a volume change, to the flexible tubular member.

Abstract: There is disclosed an improved device for locking reciprocating piston type fluid actuators in a desired position. The device includes a body, a piston having a lost motion connection to the body, a locking piston being movable with respect to the piston, an actuating cone supported on the piston, split locking cone elements surrounding the actuating cone and having a connection to the body, a split locking ring interconnected to the lock piston and surrounding the split locking cone elements, a housing containing the elements, a movable rod extending into the housing for engagement by said body, and means to supply fluid under pressure to the locking assembly, the application of pressure initially moving the locking assembly and when the rod is in its desired position for locking and further movement provides wedging locking of the structure in its housing bore and locks said rod in position.

Abstract: An air brake includes a service brake chamber which actuates a push rod. A collet brake chamber is partially defined by a collet brake diaphragm. A locking collet is mounted to the collet brake diaphragm and includes a bore through which the push rod passes. A collet brake spring biases the collet into a tapered collet hole to clamp the collet onto the push rod to prevent the movement of the push rod toward the brake off position. Application of pressure to the collet brake chamber overcomes the force of the collet brake spring and moves the collet away from the tapered collet hole to allow the push rod to move freely. An air supply system, including a quick release valve, a two way check valve, an emergency and parking air supply tank and a pilot check valve, in conjunction with a conventional quick release valve or another type of exhaust valve, automatically supplies air to the service brake chamber from the tank whenever the spring brake supply line is vented.

Abstract: A piston-controlled locking mechanism including an external cylinder having annular retaining means, a first elongated piston located adjacent the cylinder and having ball lock positioning apertures in the extension, a second coaxially located piston positioned inside of the skirt of the first piston and having indentations capable of mating with the ball positioning portions of the first piston, and positioning elements for first moving the inner piston to release the balls and thereafter moving the outer piston to either release or lock the cylinder.

Abstract: A power chuck assembly has a lathe spindle extending along and rotatable about an axis and having axially opposite front and rear ends. An axially displaceable actuator rod extends at the axis through the spindle and has front and rear rod ends at the respective spindle ends. This rod is rotatable about the axis between two angularly offset end positions. A coupling head secured to the front spindle end has a plurality of bolts displaceable radially between inner and outer positions. A chuck provided with an axially rearwardly projecting annular flange engageable over the head is formed with at least one radially but not axially open recess in which the bolts are engageable in the outer positions thereof. Actuators are connected to the bolts for displacing them from the inner to the outer positions so that, when the chuck is fitted over the coupling head, the bolts engage in the recess and axially lock the chuck on the coupling head.

Abstract: A brake apparatus is provided to retard the relative movement between two members. The apparatus comprises a housing positioned around the perimeter of a portion of one of the members. A collar is fixedly secured to the housing generally around the perimeter of a portion of one of the members. Clamping elements are fixedly secured to the collar and have a first surface positioned generally coaxial with at least one of the members. The clamping elements move radially to frictionally engage one of the members to apply a braking force. Each of the clamping elements have a ball in abutting rolling relationship with a second surface generally radially opposite the first surface. The balls urge each of their respective clamping elements into such frictional engagement upon axial movement of an actuating device having a third surface in rolling engagement with the ball. One of the second and the third surfaces has a preselected incline with respect to a longitudinal axis of one of the members.

Abstract: A braking device for a fluid power actuator, which braking device automatically brakes the movement of a piston rod in response to a failure in the supply of pressurized fluid to the fluid power actuator. Ball elements are urged radially inwardly between a pair of converging surfaces to cause a drive ring member having a ramp surface thereon to move into engagement with a brake ring to effect a contracting thereof into engagement with the piston rod.

Abstract: The apparatus comprise a generally tubular outer element, a generally cylindrical inner element disposed therewithin and sized relative thereto to provide a generally annular operating space therebetween. An intermediate element is disposed in said operating space and is dimensioned relative thereto to create interference fits with said outer and inner elements and prevent relative movement therebetween. Means are provided to introduce pressurized fluid to the respective element interfaces to expand the outer element wherein the elastic limit thereof to an extent sufficient to release the interference fits and enable relative outer-inner element movement. Re-locking of the outer and inner elements occur automatically upon depressurization of the fluid and attendant return of the outer element to its unexpanded configuration. Actuating means to effect relative outer and inner element movement upon apparatus unlocking are also provided, and include means to pressurize the fluid.

Abstract: A shift rod air interlock system provides a mechanical apparatus for insuring a neutral position in a two-speed air shifted compound transmission whenever air to an auxiliary air shift cylinder is interrupted. The apparatus prevents the transmission from being shifted into gear whenever an associated vehicle is stationary and when a power take-off unit is operative. In addition, a two-position air interlock plunger assembly provides a locking plunger which interfaces with a pair of detents in the shift rod, thus insuring that the auxiliary transmission is prevented from being shifted into neutral whenever the air system is interrupted while the vehicle is moving. In a preferred form, the invention utilizes a shift rod selectively movable between at least three positions, including an intermediate neutral position.

Abstract: A hydraulic cylinder having a locking device disposed in either, or both head ends which attach to the cylinder, has a piston reciprocally movable within a piston chamber formed in the cylinder. A stud member having a groove portion and a stud portion, secures to the piston for reciprocal movement therewith. The stud member axially moves within a stud bore formed in the head end such that, the stud bore acts as a variable volume stud chamber. A plunger member, disposed in the head end, is in fluid communication with the variable volume stud bore such that, movement of the stud member into the stud bore increases the fluid pressure, thus forcing the plunger out of contact with the stud portion of the stud member. When a predetermined pressure occurs, an outlet valve to the stud bore opens, reducing the fluid pressure and allowing the plunger to be urged into engagement with the groove portion of the stud member thus effecting a locked condition.

Abstract: There is disclosed a blowout preventer having rams each of which is moved between opened and closed positions by a fluid-operated actuator having a rod adapted to be axially reciprocated by piston means within a cylinder and extending from the cylinder for connection to the ram, means for locking the rams in closed position including locking elements carried by the rod for movement into locking position within the cylinder automatically in response to movement of the ram with the rod into closed position.

Abstract: High speed pipe handling apparatus is disclosed. A pipe gripping system includes fluid pressure piston-and-cylinder propulsion systems to manipulate pipe gripping slip members, and includes a mechanical latching system that locks the pistons to the cylinders in the pipe-gripping configuration by latch members. The latching system is released by application of fluid pressure.

Abstract: This invention relates to direct acting rotary actuator cylinders wherein the linear motion of the piston is directly converted to angular motion by a means completely enclosed within the cylinder, which means comprises a slidable partitioning body engaging the circular cylindrical cavity in the cylinder in an air-tight sliding relationship and a circular cylindrical rod coaxially and rotatably disposed in said circular cylindrical cavity having a mid-section with a noncircular cross section of a diametrical dimension greater than the diameter of said circular cylindrical rod.

Abstract: The hoisting device comprises two ramps rigidly connected, intended to support at least one of the wheel pairs of the vehicle to be hoisted and including a single acting hydraulic cylinder operative to rotate the ramps upwardly from the position with the free end thereof resting on the floor. The ramps are pivoted at one end thereof at a selected level to two floor engaging side plates and a hydraulic system is provided for pivoting the ramps which cooperates with a safety mechanism against the unintentional lowering of the ramps.

Abstract: A continuous mining machine cutting head structure is set forth. The mining machine is of a type having a support member and an elongated mining head member mounted on the forward end of the support member. The head member is powered for rotation about its longitudinal axis. The head member is of the type having axially extensible and retractable end portions. Included within the head member is a hydraulic piston cylinder arrangement for selectively extending and retracting these end portions. At least one latch element is included within each side of the head member and can be moved into locking engagement with the end portions when it is in an extended position thereby preventing retraction thereof. Also included is a mechanism operatively connected to the piston cylinder arrangement which is capable of moving the latch element out of engagement with the end portion thereby permitting retraction thereof.

Abstract: A fluid motor comprising a piston and cylinder combination includes mechanism for locking an output shaft which is helically displaceable along its longitudinal axis upon actuation of the piston. The locking mechanism includes a locking element driven by a fluid operated motor for displacement in a direction transverse to and spaced from the longitudinal axis of the shaft, and a notch in the shaft for receiving the locking element, the notch and locking element have mating surfaces which are inclined with respect to the longitudinal axis of the shaft and transverse to the shaft's helical path of travel. The locking element motor comprises the piston and cylinder chamber defined within a body upon which there is also mounted a cam guide for guiding a cam member which is secured to the shaft on the opposite side of the notch. The locking element is secured to and extends transversely of the locking piston into an opening within the body adjacent the shaft.

Abstract: A double acting piston and cylinder arrangement comprising an elongated cylinder and a piston assembly slidably mounted within the cylinder. The piston assembly comprises a first part and a second part which are axially adjacent each other and movable with respect to each other between a locking and nonlocking position. In the locking position, the piston assembly forces a split ring radially outwardly and against the walls of the cylinder to lock the piston assembly to the cylinder at any adjusted position. Conversely, in its nonlocking positon the ring contracts radially inwardly and permits the piston assembly to freely axially slide along the cylinder.

Abstract: A fluid actuator including a lock mechanism for locking the actuator against movement in one position and a fluid operated sequence-power valve which when actuated by fluid pressure releases the lock mechanism and then ports such fluid pressure directly to the actuator to cause movement thereof in the desired direction following release of the lock mechanism.

Abstract: Actuator includes a lock mechanism for locking the actuator against movement in one end position, and a separate lock release assembly exteriorly mounted on the side of the actuator housing. The lock release assembly includes a toggle linkage directly engageable with the movable lock part to disengage the lock when a suitable force is applied to the toggle linkage exteriorly of the actuator. A lock spring is located immediately between the movable lock part and actuator piston for resetting the lock as the actuator nears such one end position.

Abstract: A safety brake for hydraulic rams, particularly for hydraulic elevators, includes a plurality of braking members disposed around the piston in a circular array. The outer surfaces of the spaced apart braking members together form the shape of a truncated cone, and the inner surface of a stationary housing surrounding the brake members is complementarily shaped. The angle of inclination of the two conical surfaces is small, and the braking members move downwardly and inwardly only a short distance to engage the piston, so that the conical geometry of the brakes and housing surfaces does not produce significantly mismatched sliding surfaces as the brake members move downwardly.

Abstract: A brake assembly is provided for a fluid operated piston and cylinder device having a force applying cross head operating through a slot in the cylinder wall. The brake assembly is integrated with the cross head and consists of brake lining concentrically arranged about the cylinder for engagement with the outer surface of the cylinder. The brake assembly is actuated by a drive mechanism to engage the cylinder outer surface so as to stop, lock and/or position the piston as required.

Abstract: A bracing jack comprising a cylinder and a jack bar slidable in the cylinder from a bar extended position to a bar retracted position, the jack having an internal locking mechanism including a hydraulic and a mechanical actuator for unlocking under load.

Abstract: A new and improved ram lock and blowout preventer are provided for locking a blowout preventer ram in any of a number of variable, adjustable sealing positions in a bore in the preventer. A ram carrier is mounted in a housing to move the ram to and from the sealing positions. The housing is provided with a tapered inner surface which selectively engages locking wedge members mounted with the ram carrier. A locking cone mounted with the ram carrier responds to fluid pressure during movement of the ram carrier to move the locking wedges into engagement with the tapered inner surface for locking purposes.

Abstract: A hydraulic actuator comprises: a cylinder; a piston axially slidably received in the cylinder and having a hollow bore axially extending therein; at least a locking member radially movably retained in the piston; a ram axially slidably received in the hollow bore of the piston and having an inclined portion connecting a lower engaging portion and an upper engaging portion with a circumferential length longer than that of said lower engaging portion, said inclined portion being slidably engageable with the radially inner face of the locking member for radial movement thereof; a switch piston radially slidably mounted on the cylinder to have a radially inner face engageable with the radially outer face of the locking member; and detecting means for detecting the piston under conditions locked and unlocked with the cylinder by detecting radial movement of the locking member through the switch piston.

Abstract: An assembly comprising an inner and an outer cylindrical members, the inner member being displaceable within the outer member and provided with an annular recess, a locking ring being housed in the recess to allow displacement of the inner member in a first direction but locking the members relative one another upon attempt to displace the inner member in a second direction.

Abstract: A fail safe mechanism is provided for locking an actuating piston rod of a fluid operated actuator in a selected axial position in the event of a failure, or significant decrease in, the fluid pressure applied to the actuator. Preferably, a secondary cylinder is provided within the actuator cylinder and is in fluid communication therewith. A piston in the secondary cylinder is biased toward a locking position by a spring and is shiftable toward a released position by the existence of a predetermined amount of fluid pressure in the main cylinder. An annularly extending locking mechanism is provided in surrounding relationship to the actuating piston rod and is radially movable into engagement with a locking shoulder on such piston rod when the rod is shifted to one of its selected axial positions by the application of fluid pressure to the cylinder.

Abstract: An assembly comprising an inner and an outer cylindrical members, the inner member being displaceable within the outer member and provided with an annular recess, a locking ring being housed in the recess to allow displacement of the inner member in a first direction but locking the members relative one another upon attempt to displace the inner member in a second direction.

Abstract: A fluid pressure actuator which locks in the extended position. The lock is a roller operated, dual segment pawl mechanism that unlocks in response to a pressure difference between extend and retract pressures. The two lock segments, chamfered for engagement with the cylinder end, are in diametrically opposed slots in the actuator piston head. A cylindrical section projects from the segment portion. An end view of the lock is mushroom shaped. Two rollers, held in alignment normal to the actuator centerline by a cage integral with the unlock rod, operate in conjunction with the lock cam surfaces in such a manner as to carry the radial loading imposed when in the lock mode.In operation, when the actuator is driven to its extreme extend position, the pawls are driven out by the rollers and lock against the cylinder end. The linear force on the rollers is due to the preload spring plus the hydraulic pressure differential (extend pressure greater than retract pressure).

Abstract: A radially expandable and contractable split lock ring selectively to unlock and lock a piston and cylinder actuator includes at least one lapped axially extending surface substantially conforming to the surface of the cylinder or piston with which it is in sliding contact when in the unlocked position. The split lock ring has each of its ends slightly inwardly tapered to reduce the thickness thereof to distribute the bending load uniformly throughout the ring and has a flat on the outer diametrical surface diametrically opposed from such tapered ends to provide load carrying symmetry for the ring.

Abstract: Disclosed is a mechanical locking device for locking a rod in a conventional hydraulic actuator, such as a hydraulic cylinder or a rotary actuator. The device comprises a radially contractible locking ring having a cylindrical inner surface for gripping the rod when the locking ring is contracted and an outer surface which is axially inclined, means for positively securing the locking ring around the rod in a position axially fixed in at least one direction with respect to the actuator housing, a ring-contracting member around the locking ring and having an inner surface which is axially inclined at the same angle as the outer surface of the locking ring for engaging that surface, and means for applying an axial force to the ring-contracting member in the direction of the inner surface axial inclination to cause the ring-contracting member to slide axially on the locking ring thereby causing the locking ring to contract and grip the rod.

Abstract: Herein disclosed is a hydraulic actuator which comprises an outer cylinder; an inner cylinder attached at its one end to the axial inner one end of the outer cylinder in coaxial relation with the outer cylinder to define an annular gap between the outer and inner cylinders; a piston having a hollow bore axially extending from its one end to the other end and closed at the other end and slidably received in the annular gap; and a locking mechanism temporarily locking the piston with the outer cylinder upon the farthest movement of the piston to the other end thereof; the locking mechanism including a locking member coupled with one end portion of the piston and which is radially movable, a ram resiliently received in the other end of the inner cylinder and having an inclined stepped portion and a hollow bore axially extending from its one end to the other end and opened at the other end, and an annular locking groove formed at the inner periphery of the other end of the outer cylinder, whereby the locking memb

Abstract: A lock actuator attachment for a pneumatic service brake has a spindle follower for the service brake piston. A freely rotating nut is threaded on the spindle and a brake for preventing nut rotation is operated by a piston that may be pneumatically or hydraulically operated to hold the service brake in actuated position.

Abstract: An air brake includes a service brake chamber which actuates a push rod. A collet brake chamber is partially defined by a collet brake diaphragm. A locking collet is mounted to the collet brake diaphragm and includes a bore through which the push rod passes. A collet brake spring biases the collet into a tapered collet hole to clamp the collet onto the push rod to prevent the movement of the push rod toward the brake off position. Application of pressure to the collet brake chamber overcomes the force of the collet brake spring and moves the collet away from the tapered collet hole to allow the push rod to move freely. An air supply system, including a quick release valve, a two way check valve, an emergency and parking air supply tank and a pilot check valve, in conjunction with a conventional quick release valve or another type of exhaust valve, automatically supplies air to the service brake chamber from the tank whenever the spring brake supply line is vented.