Abstract: A control rod assembly is provided for moving a control surface of a flight vehicle. The control rod assembly includes a first connector for connecting to a first structure of vehicle, and a second connector for connecting to a second structure of the vehicle. A connecting rod may be operably coupled between the first and second connectors, and an actuator may be operably coupled to the connecting rod. The actuator may include a screw-and-nut assembly, and a motor that is configured to drive the screw-and-nut assembly. The actuator may be operable such that driving the screw-and-nut assembly via the motor causes the connecting rod to translate linearly along a longitudinal axis to thereby vary a distance between the first and second connectors. The actuators may be electromechanical actuators which may be controlled by a controller without pilot interaction. Two such actuators may be provided on opposite sides of the assembly.

Abstract: The subject matter of this specification can be embodied in, among other things, an assembly that includes a piston having a piston inner surface defining a cylindrical cavity and includes a first axial portion, a piston face at a first end of the first axial portion, a second axial portion at a second end of the first axial portion, and a helical piston thread defined upon the piston inner surface, a bushing configured to contact the piston inner surface, and a lock nut configured to engage the piston and the bushing.

Abstract: A hydraulic lock for an actuator having a movable shaft includes a lock cylinder having a first end and a second end. A slot is defined through a perimeter of the lock cylinder adjacent to the second end, and a bore is defined through a portion of the lock cylinder at the second end to extend towards the first end. The hydraulic lock includes at least one pawl having a first pawl end and a second pawl end. The first pawl end is releasably coupled to a groove defined in the shaft, and the second pawl end is coupled to the slot. The pawl is movable relative to the slot between a first, locked position in which the first pawl end is coupled to the groove to inhibit movement of the shaft, and a second, unlocked position in which the first pawl end is released from the groove.

Abstract: A linear actuator comprising a housing with a proximal end and a distal end, the housing defining a central cavity extending axially through the housing; a piston tube, where a first portion of the piston tube is slidably positioned axially in the housing, and a second portion of the piston tube extends outwardly from the distal end of the housing; an elongated rotatable screw positioned axially within the central cavity of the housing; a nut positioned within the housing and mounted about the screw, the nut configured to move axially within the housing as the screw rotates; and a spring positioned around the screw, the spring positioned within the housing between the nut and the piston tube; wherein the spring is configured to bias the piston tube away from the nut.

Abstract: The invention relates to an actuator device (8) for moving a movable cowl of a thrust reverser, including: an actuator (12) including a screw (14) and a nut (15) capable of engaging with the screw (14) such that a rotation of the screw relative to the nut translates the nut relative to the screw; a locking device (30) including a locking part (31, 57) which is movable relative to the screw (14) between a locked position in which the locking part (31, 57) prevents the rotation of the screw (14) and an unlocked position in which the locking part (31, 57) allows the rotation of the screw (14), in which the screw (14) includes a body (17) and a lock-inhibiting device (38), the lock-inhibiting device (38) including an inhibiting part (47, 48) which is movable relative to the body (17) between a first position in which the part (47, 48) allows the locking part (31, 47) to move between the locked position and the unlocked position, and a second position in which the inhibiting part (47, 48) prevents the locking part

Abstract: The invention relates to an actuating device (1) for moving a mobile cap of a thrust reverser, comprising: —an actuator comprising a first element (3), such as a screw, and a second element (4), such as a nut, collaborating with the first element in such a way that turning the first element causes the second element to move in a translational movement, —a locking piece (18) rotationally mobile between a locked position in which the locking piece prevents the first element (3) from turning, and an unlocked position in which the locking piece (18) allows the first element (3) to turn, and —an unlocking piece (25) rotationally mobile between an active position in which the unlocking piece (25) urges the locking piece (18) towards the unlocked position and a passive position in which the unlocking piece (25) allows the locking piece (18) to return to the locked position.

Abstract: A thrust reverser actuation system for a jet engine having a turbine engine surrounded by a nacelle to define an annular air flow path between the turbine engine and the nacelle, with a thrust reverser having a movable element to reverse the direction of at least a portion of the air flow along the air flow path, where the thrust reverser actuation system includes a hydraulic actuator configured to be operably coupled to the movable element, and a remote actuator that controls the inhibit function of the hydraulic system.

Abstract: Actuator assembly includes a housing assembly, a ball screw, a ball nut, and a lock. The ball screw is rotationally mounted on and extends from the housing assembly, is coupled to receive an actuator drive torque, and is configured, upon receipt thereof, to rotate. The ball nut is rotationally supported on the ball screw and is configured, in response to rotation of the ball screw, to translate thereon between a stowed position and a deployed position. The lock is disposed at least partially within the housing assembly and is configured to move between a lock position and an unlock position. The lock prevents the ball nut from translating out of the stowed position when the lock is in the lock position and the ball nut is in the stowed position.

Abstract: An integrated thrust reverser and variable area fan nozzle actuator includes a ballscrew shaft having a first ballnut and a second ballnut. The second ballnut is fastened to a first translatable object. A bearing is affixed to the ballscrew shaft between the first ballnut and the second ballnut. A second translatable object is coupled to the bearing. A drive mechanism is operably coupled to the first ballnut for rotation and a locking mechanism selectively couples the ballscrew shaft to the first ballnut.

Abstract: The present invention is directed to a remote control system for controlling a railway vehicle. The remote control system including a remote control device for transmitting signals to a first controller module. The first controller is mounted to the railway vehicle and controls and monitors the functions of the railway vehicle. The first controller module also relays information to the remote control device. The remote control system can also include a portable safety switch allowing any individual in proximity to the railway vehicle to send a stop signal to the first controller module to stop the railway vehicle if any unsafe conditions exist.

Abstract: The present invention is directed to a remote control system for controlling a railway vehicle. The remote control system including a remote control device for transmitting signals to a first controller module. The first controller is mounted to the railway vehicle and controls and monitors the functions of the railway vehicle. The first controller module also relays information to the remote control device. The remote control system can also include a portable safety switch allowing any individual in proximity to the railway vehicle to send a stop signal to the first controller module to stop the railway vehicle if any unsafe conditions exist.

Abstract: A self-locking braking device, for rotary shafts connectable to external loads, comprises braking means which can be operated to lock, respectively to release the rotation of a drive shaft; the braking means consist of a rigid braking disk, rotating with the drive shaft, and slidingly supported in an axial direction between two clutch members, one of which is secured to a support body for the drive shaft, while the other clutch member is supported by a plate which is elastically biased against the braking disk and operatively connected to a pneumatic cylinder for releasing the brake.

Abstract: A hydraulic shock absorber enables its piston rod to be locked near its minimum length position and allows the locked condition to be visually confirmed easily. A cap member is secured to a distal end portion of a piston rod extending from a cylinder part, and a dust cover is secured to the cap member. A lock member is secured to an end of the cylinder part from which the piston rod extends to the outside. The lock member is cut and bent upward to form engaging portions. The cap member is cut and bent downward to form engaging pieces and windows. With the piston rod contracted to near its minimum length position, the cap member is rotated to engage the engaging portions and the engaging pieces with each other, thereby locking the piston rod. The engaged condition of the engaging portions and the engaging pieces can be visually confirmed through the windows.

Abstract: A lock mechanism is provided in a head cover of a cylinder tube. The lock mechanism comprises a holder, which is installed in the head cover, a plurality of balls that are retained displaceably in a radial direction with respect to the holder, and a displacement member that displaces the balls under a resilient action of an elastic member. The balls engage with a ball groove of a lock pin. The balls are retained by a resilient force of the elastic member, in order to restrict displacement of the lock pin.

Abstract: A lockable working cylinder comprising a housing and a piston that can be displaced in a primary pressure chamber of the housing. A piston rod tube leads from the piston out of the pressure chamber and a spindle rotates in the piston or piston rod tube, the spindle being allocated to a unit that halts the rotational displacement. The spindle or a rotational sleeve that is placed over the spindle has a radial pressure chamber, in which a locking bolt engages, said bolt being introduced radially.

Abstract: An apparatus for locking a valve having a valve member movable between an open position and a closed position. The apparatus includes an actuator assembly, a locking base, a locking shaft, and a locking pin. The actuator assembly moves the valve member between the open position and the closed position. The locking base has a through-bore extending from the lower portion to an upper portion, a first thread provided on the upper portion, and a first locking bore extending transversely therethrough. The locking shaft reciprocally extends through the through-bore of the locking base and includes an upper end having a second thread that is selectively engagable with the first thread of the locking base when the valve member is in a predetermined position, and a second locking bore extending transversely through the locking shaft.

Abstract: A brake actuator assembly includes a housing defining a spring chamber. A spring is disposed in the spring chamber, the spring being biased toward an extended position and movable against the bias toward a caged position. A release assembly is provided for selectively moving and retaining the spring against the bias toward the caged position, the release assembly comprising a hollow release bolt having a fluid passage passing therethrough by which fluid passage the spring chamber is in fluid communication with an environment surrounding the housing. A filter is disposed within the fluid passage in the hollow release bolt for filtering fluid passing through the fluid passage.

Abstract: A handling equipment of the swingable arm type comprises a double acting cylinder within whose chamber a main piston is sealingly mounted, which is slidable owing to the selective delivery of fluid under pressure at opposite zones of the chamber, which is connected to a rod associated to the arm with a toggle joint. The equipment comprises a device for controlling the oscillation of the arm, including: a cavity of the rod having a nut screw, a screw member with a threaded shank in engagement with the nut screw, a rotatable head opposite to the rod and not slidably mounted with respect to the cylinder, and means for controlling the rotation of the screw member, associated with its head in order to brake the rotation of the screw member following to an anomalous condition in the feeding of fluid under pressure to the chamber of the cylinder.

Abstract: A hydraulic cylinder having an integral self-contained locking mechanism is described. A locking cylinder includes a housing that contains a screw shaft and a rod/piston assembly. A rod end of the rod/piston assembly can be connected to one load and the end cap, which is located opposite to the rod end, can be connected to another load. The two loads may be two levels of a car trailer. During an extension stroke the screw shaft is released from a locking mechanism inside the housing, allowing the screw shaft to rotate freely. The rod piston assembly, which is in threaded engagement with the screw shaft, moves freely along a longitudinal axis as a pressure is applied, and it unscrews from the screw shaft. When the assembly reaches a desired or maximum extension, the pressure is removed. The piston retracts slightly until the screw shaft re-engages with the locking mechanism.

Abstract: A dual end stop is provided for setting precise open and closed positions for the valve to which the pneumatic actuator is attached. In a preferred embodiment, a stop assembly housing contains two stop adjustment bolts as well as a cam that defines first and second stop surfaces. The stop assembly housing is preferably mounted to the actuator housing outside of the pressurized zone contained by the actuator housing. The stop bolts and associated threaded apertures are designed for minimum overhang of the stop bolts to provide more support. The stop assembly housing not only preferably houses the stop assembly components but also preferably serves as an adaptor plate for the various valves to which the actuator may be mounted. The stop bolts preferably have a convex head to provide a defined point contact rather than a random point contact as may be produced with flat heads.

Abstract: This fluid pressure cylinder with a lock mechanism is adapted to provide, on the lock mechanism cover, an area where valves for controlling the cylinder and lock mechanism can be installed. In the cylinder, a brake shoe grips a piston rod 6 via balls held by a retainer inside a lock mechanism cover 21 using a tapered ring which is driven by a brake spring and returned to its original position by a release piston. A cylinder port 8 that supplies or discharges compressed air to drive the piston is provided on the side of a cylinder 1 inside the lock mechanism cover 21. On the opposite side an unlocking port 34 which leads to a pressure chamber driving a release piston is disposed and a manual opening actuator 45 is provided. This arrangement is intended to ensure a flat area 48 where valves can be installed to control compressed air fed through the ports.

Abstract: A lockout device is used to prevent linear movement of a piston rod in a pneumatic cylinder actuator used for controlling the position of a valve flow control member or other applications. The lockout device includes a locking plate having a piston rod hole formed therein whereby the locking plate is threaded onto an end of the piston rod. Fastener holes are provided in the locking plate whereby the locking plate is fastened to the actuator housing to prevent movement thereof. A lockout cover assembly may be attached to the locking plate to prevent access by unauthorized personnel to fasteners placed in the fastener holes. A groove may be provided along the circumference of the locking plate whereby the lockout cover assembly is attached to the locking plate.

Abstract: A brake release tool incorporates a two-part structure wherein a portion accessible from outside the brake actuator does not move axially away from the brake actuator during caging. In this way, less room is necessary outwardly of the brake actuator housing than has been required in the prior art. An operator turns an outer bolt, which turns a threaded inner nut. The threaded inner nut moves axially to contact a piston, and moves the piston to cage the power spring. The bolt need not move axially outwardly, although in one embodiment it may move slightly axially inwardly as the spring is caged to provide a visual indication that the spring is not uncaged.

Abstract: This invention relates to an assembly of a hydraulic motor and of a brake which is coupled thereto, comprising in particular a brake shaft which traverses said motor and brake entirely. According to the invention, the brake shaft comprises an axial through recess allowing passage of a link, such as a movement transmission shaft. One application of the invention is the production of a reliable compactor.

Abstract: A power cylinder of the type in which the piston may be locked to maintain am associated tool or clamp in a fixed position. A nut is provided in an end wall of the cylinder and the piston rod of the piston passes through the nut. The initial portion of the forward stroke of the piston is accomplished by the introduction of fluid pressure into the cylinder and, as the piston approaches the final portion of its stroke, the threaded portion of the piston rod engages the nut whereupon the nut is rotated to threadably advance the piston through the final portion of its stroke. The rotation of the nut is accomplished by pressurized fluid acting against a piston rack which rotates a gear which in turn rotates the nut. The center line of the piston rod is offset from the center line of the piston to preclude rotation of the piston and of the piston rod.

Abstract: This invention relates to an assembly of a hydraulic motor and a combined device for immobilization, comprising: a reaction cam; a cylinder-block mounted to rotate with respect to the reaction cam; a first immobilization member fast with the cylinder-block; a second immobilization member fast with the reaction cam and capable of being disposed in a first position, in which the first and second immobilization means are fast with one another, and a second position, in which these first and second immobilization members do not cooperate for their mutual immobilization. The device for adjusting the relative position of the first and second immobilization members comprising a jack comprising a chamber.

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: A spring force actuator comprising a housing, an output member axially moveable in the housing, a spring captive between the member and the end wall of the housing. The actuator further comprises an axially located screw-threaded wind-off element operable to apply an opposing force to the spring between the output member and the end wall. The wind-off element is threadedly cooperable with a nut which is non-rotationally captive in an externally accessible recess of the end wall.

Abstract: An assembly for stopping and retaining a floating piston within a closed cylinder includes a plurality of retaining ring segments which are seated within a groove provided in the internal wall of the cylinder. The retaining ring segments are held securely in place by a plurality of retaining plates which are clamped together by a plurality of threaded fasteners. The assembly is positioned deep within the cylinder at a specific location by a special tool. This tool also activates portions of the stop assembly to initially seat the retaining ring segments in the groove. A floating piston and associated seals are used in a combination oil and gas cylinder to separate the pressurized oil chamber from the compressed gas chamber. In order to maintain the piston in the cylinder while one chamber is evacuated and the other chamber remains pressurized, a piston stop and retainer assembly is required.

Abstract: The invention is directed to a penumatic or hydraulic drive for opening and closing of doors, in which the linear motion of a double-acting piston 5 driven by a pressure medium is converted into a rotary motion of a spindle 2 through a piston rod 6 and a helical gear box 3. Herein a blocking lever 10 supported in a stationary manner is provided, which in the closed position of the door engages under the action of a spring 18 at a part 11 connected with a piston 5, wherein said blocking lever secures the piston in its end position and is held in its open position counter to the force of an additional spring 15 by a power cylinder 14 acted upon by the pressure means.

Abstract: A fluidic power-assisted setting device has a setting motor having an output torque; a threaded spindle supported for rotation; a spindle nut threadedly mounted on the spindle for linear displacement; a setting member attached to the spindle nut for linear travel therewith; a gearing for transmitting the output torque of the setting motor to the spindle; a signalling device coupled to the gearing for generating an output signal when the linear force derived from the output torque of the setting motor is insufficient to overcome an external force opposing linear displacement of the setting member; and a fluidic power device including a hydraulic motor connected to the setting member for applying thereto a linear force to overcome the external force; and a hydraulic control valve hydraulically connecting the hydraulic motor with pressurized hydraulic fluid as a function of the output signal of the signalling device for causing the hydraulic motor to generate a force applied to the setting member for overcoming

Abstract: A fluid actuator includes a lock mechanism for releasably locking the actuator against movement, and a lock release lever engageable by a lock piston upon application of system pressure thereto to release the lock mechanism. The lock mechanism includes an axially movable lock member for respectively engaging and disengaging the lock mechanism depending on its position. Attached to the movable lock member is a proximity sensor target which moves with the axially movable lock member toward and away from a proximity switch to provide an electrical signal indicating the locked or unlocked condition of the lock mechanism in accordance with the proximity of the target to the switch. A cover may also be provided for respectively concealing or exposing the target depending on the position of the axially movable member to provide a visual indication of the unlocked or locked condition of the lock mechanism.

Abstract: An actuator assembly has two actuators mounted back-to-back such that their actuator rods are displaced in opposite directions. Each actuator has a spring embracing the rod between two slidable collars. The spring urges the collars apart towards stops on the rod and stops on the actuator housing, so that, on failure of the actuator, the rod is displaced to a central position. The rod is driven by a motor which also rotates two discs of different diameters. Each disc has a notch in its edge which align only at the central position of the rod and allow a roller to drop into the notch. When the actuator fails, a solenoid releases a locking arm which engages the rollers, keeping them in the notches thereby preventing rotation of the discs and displacement of the rod.

Abstract: An actuator for use in or with a glassware forming machine for driving a member through an arcuate path, such member being a pusher cylinder for moving glassware articles. The pusher member comprises a linearly movable piston for linearly moving a convoluted shaft attached thereto. The convoluted shaft has three surfaces thereon which act as tracks for three roller bearings mounted on a hub which is disposed about the shaft. Linear motion of the shaft is converted into rotary motion in the hub by the action of the bearings running on the convoluted sides of the linearly moving shaft.

Abstract: A fluid controlled rotary shaft speed limiting arrangement has a brake disk secured to the shaft for rotational movement therewith. A braking arrangement exerts a braking force on the brake disk according to the amount of fluid pressure present in a brake piston chamber. The flow of pressurized fluid into and the flow of pressurized fluid out of the brake piston chamber is controlled by a valve arrangement, a portion of which is formed on the brake disk. The portion of the valve arrangement formed on the brake disk effects a change in the flow of pressurized fluid through the brake piston chamber if the rotational velocity of the shaft and brake disk varies from a preselected value. Such variation in the rotational velocity corresponds to such change in pressurized fluid flow such that, a proportional braking force is exerted on the brake disk.

Abstract: An actuator for use in or with a glassware forming machine for pneumatically driving a member through a predetermined path, such member being, in one embodiment, a pusher cylinder for moving one or more glassware articles through a predetermined arcuate path. The velocity of the actuator is controlled according to a predetermined velocity profile and is effected by an electromechanical control means which controls the linear velocity of the piston of a pneumatic cylinder in one direction of motion.

Abstract: A piston member is mounted in a cylinder body to be axially movable and unrotatable relative thereto. A ball nut retaining balls is fixed to the piston member, and a screw shaft having a helical groove in engagement with the balls is mounted to be rotatable and axially immovable relative to the cylinder body. The screw shaft makes many rotations when the piston under fluid pressure slightly advances axially inside the cylinder.

Abstract: Fluid actuator includes a lock mechanism for releasably locking the actuator against movement, and a lock release assembly including a lock piston engageable with a toggle linkage upon application of fluid pressure to the lock piston to release the lock mechanism. The toggle linkage is fixedly mounted on a rotatable cross shaft which may also be manually rotated by manual rotation of an external lock release lever attached to one end of the cross shaft for effecting manual release of the lock mechanism. The engaged or disengaged condition of the lock mechanism may be sensed electrically as by providing a target on the external lock release lever for movement therewith toward and away from a proximity switch.

Abstract: A double-acting hydraulic jack, comprising a hollow piston reciprocable in a surrounding cylinder, includes a tubular shaft extending axially inside and carrying a nut of the circulating-ball type which coacts with a screw coaxially disposed in that shaft. The screw is rigid with the piston whereby an axial displacement of the latter is translated into a rotation of the shaft; a toothed wheel on the shaft, engaged by a spring-loaded detent, acts as a one-way brake enabling such rotation only in one direction and blocking it in the opposite direction unless the detent is withdrawn by a hydraulic servomotor which is pressurized concurrently with the admission of fluid to the cylinder tending to displace the piston in the normally blocked direction.

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 fluid pressure actuator includes a lock mechanism for locking the actuator against movement in one end position, and an external lock release lever engageable with an external extension of the lock mechanism for releasing same. The lock release lever is engageable by a lock piston upon application of system pressure thereto to release the lock mechanism. During movement of the lock piston in the unlocking direction, and after disengagement of the lock mechanism, system pressure is ported through the lock piston both to the extend side of the actuator and the opposite end of the lock piston. By using substantially the same size seals on the opposite pressurized side of the lock piston and external extension of the lock mechanism, any effect of fluid pressure acting on such external extension of the lock mechanism is substantially negated.

Abstract: A hydraulic cylinder comprising a hydraulically operated power lifting ram for lifting heavy loads further includes a guide cylinder concentric about and enclosing the ram, the guide cylinder being secured to the lift platform for further support of the load and reciprocating in unison with the ram under application of hydraulic pressure. The guide cylinder is equipped with a safety locking means which prevents the hydraulic cylinder and its load from lowering in the event of a sudden loss in hydraulic pressure. The safety locking means is in contact with the guide cylinder substantially during the full stroke of the hydraulic operated ram, providing a unique method of locking the cylinder in any position within tolerances normally associated with gear driven devices.

Abstract: A testing mechanism for a ram lock for blowout preventer rams which permits testing of lock mechanism by overriding the automatic unlocking capability of the mechanism.

Abstract: A ram lock for blowout preventer rams which permits locking of the ram at multiple and adjustable positions. Automatic locking of the ram at a desired position, such as in adjustable sealing positions to compensate for ram elastomer wear, is obtained. The ram also automatically unlocks in response to opening fluid pressure acting on a cylinder liner which contains a ram carrier moving the ram.

Abstract: Disclosed herein is a hydraulic jack comprising a cylinder and a piston rod assembly which is movable between a retracted position and an extended position relative to the cylinder. The jack also has mechanical locking means including a rotatable shaft and movable into engagement with the piston rod assembly in response to rotation of the shaft, thereby to lock the piston rod assembly in its extended position. The locking means reinforces the piston rod assembly in its extended position along substantially the entire length of the piston rod assembly.

Abstract: The present invention relates to hydraulic prestressing nuts for setting a tensile stress in a bolt whereon the nut of the present invention is turned. The invention involves a nut body wherein an annular piston is arranged to be hydraulically extended from a bottom face thereof against a plate, head, platen, or the like, elevating the nut and extending the bolt therewith. A concentric loading ring is arranged with the nut body for turning into engagement with the place, such that when the loading ring is so extended, it provides a rigid columnar support to the annular piston. Tensile stress on the bolt is maintained by the loading ring. The nut of the present invention further involves a failsafe arrangement for providing a backup repressurization capability consisting of a second piston arrangement that can be independently pressurized at a primary seal failure, extending the primary piston therewith.

Abstract: A parking brake for use primarily on railway vehicles of the mass transit type in conjunction with the service brake apparatus but operable independently thereof. A parking brake hydraulic cylinder is mechanically connected to the brake shoe hanger of the brake unit. After the vehicle has been brought to a stop, a parking brake application may be made by supplying pressure, by a handpump, to the hydraulic cylinder which also includes a lock-nut actuable by the pressure, in excess of a certain pressure for locking the parking brake hydraulic cylinder in its applied position. A relief valve is provided for relieving the hydraulic cylinder of hydraulic pressure when the application is to be released.

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: A control rod drive for a nuclear reactor which has an index tube coupling a control rod at one end and connecting a drive piston at the other end is adapted to vertically move the index tube by hydraulic pressure applied thereto. The index tube is formed with at least one helical groove on the outer surface and a plurality of recesses on the bottom surface of the helical groove. Collet fingers each having one end always urged against the index tube and the other end secured to a drive cylinder are provided for controlling the movement of the index tube. The collet fingers are able to engage with and disengage from the helical groove during rapid insertion of the control rod into a reactor core while able to slide in the helical groove during extraction of the control rod out of the core and to engage with the recess to prevent the movement of the control rod.