Abstract: An automatic parking brake system is provided in which a parking piston that enables a parking brake state to be obtained by forward movement in response to a parking control fluid pressure acting on a rear face of the parking piston is slidably fitted into a casing, and a lock mechanism is provided within the casing in back of the parking piston to automatically lock in response to forward movement of the parking piston in order to mechanically lock the parking piston at a forward position and unlock in response to a parking release control fluid pressure acting on the lock mechanism, the parking control fluid pressure and the parking release control fluid pressure being obtained by a fluid pressure control mechanism for controlling a fluid pressure generated by a fluid pressure source. This enables an automatic parking brake state to be obtained by a simple structure without consuming power.

Abstract: The present invention is directed to a transmission brake disengagement apparatus which eliminates the disadvantages of transmission brake disengagement apparatus having mechanical switches thereby improving the starting consistency of a drag race car. In particular, the present invention provides an improved transmission brake disengagement apparatus which incorporates a mechanical actuation switch for providing an electrical signal to effect the disengagement of an electrically actuated transmission brake of a drag race car, without the need of applying continuous pressure on the switch.

Abstract: A braking force maintaining apparatus of a vehicle includes a reference braking force setting section, a threshold value setting section, a braking force change rate detecting section, and a change rate determining section. The reference braking force setting section sets, as a reference braking force, a braking force acting on wheels of the vehicle after a reference time has elapsed since stopping of the vehicle. The threshold value setting section sets a threshold value by adding the reference braking force to a predetermined reference value. The braking force change rate detecting section detects a change rate of the braking force acting on the wheels after the threshold value has been set. The change rate determining section determines whether the detected change rate is a negative value.

Abstract: A parking brake system is provided in which a parking brake state of a wheel brake is obtained by forward movement of a parking piston slidably fitted into a casing with the rear side of the parking piston facing a parking control fluid pressure chamber, a lock piston forming part of a lock mechanism for mechanically locking the forwardly moved state of the parking piston is slidably fitted into the casing to the rear of the parking piston and urged forwardly by a spring, an opening provide in a portion of the casing that the rear side of the lock piston faces is closed by a detachable lid member, a tool connection part enables a tool inserted through the opening to be detachably connected to the tool connection part. This enables an automatic parking brake state to be obtained by a simple structure without consuming power, and the parking brake state to be released by a manual operation for maintenance or inspection.

Abstract: A lock piston operates to automatically lock a parking brake piston which achieves a parking brake applied state in response to hydraulic pressure in a parking brake application control hydraulic chamber and operates to release a locked state in response to hydraulic pressure in a parking brake release control hydraulic chamber, and a manual change-over unit holding the hydraulic pressure in the parking brake release control hydraulic chamber to a hydraulic pressure on a lock release side, is provided among the wheel brake side hydraulic path, the parking brake application control hydraulic chamber and the parking brake release control hydraulic chamber by bypassing a hydraulic pressure control unit which changes over the application or release of hydraulic pressure to the parking brake application control hydraulic chamber and the parking brake release control hydraulic chamber.

Abstract: A clamping device for clamping a rotatably supported shaft, is provided with a thin-walled sleeve arranged such that a gap is provided along a circumferential direction of the shaft. The clamping device clamps the shaft by deforming the thin-walled sleeve towards the shaft.

Abstract: Normally opened control valves 5A, 5B are configured into short-time rating valves, and normally opened opening/closing valves 4A, 4B, which are electrically controlled to open and close and are configured into long-time rating valves, are connected in series to the normally opened control valves 5A, 5B between a fluid pressure generating unit M and wheel brakes 8A to 8D.

Abstract: A process for operating the brake arrangement of a vehicle is presented, which comprises an electrically controllable service brake system, which is set to generate brake forces independently of driver actuation, and which comprises an electrically controllable parking brake system, which is set to generate brake forces and maintain these forces. So that the parking brake system or its electromechanical actuating unit only needs to cope with relatively small load situations, it is proposed that, when, for certain operating conditions, the parking brake system has to maintain brake forces which are greater than the brake forces it is able to generate itself, the service brake system generates the additionally required brake forces.

Abstract: A locking mechanism for installing between a master cylinder and a brake line includes a housing having an internal bore, an inlet port, a passage, and an outlet port. A reciprocating piston is movable within the bore. A locking lever is coupled to the reciprocating piston for actuating the reciprocating piston. A fastener having an internal fluid passage for providing fluid communication between the passage and the master cylinder secures the housing to the master cylinder. The locking lever is moveable between a first position, wherein the hydraulic fluid can flow freely between the master cylinder and the brake line for engaging and disengaging the vehicle brake and a second position, wherein the hydraulic fluid is prevented from returning to the master cylinder for maintaining the vehicle brake in an engaged state.

Abstract: The invention is an easy-to-use one-piece air brake securing device designed for use in recreational vehicles, trucks, and other automotive vehicles employing air-operated parking brakes. The device is designed to fit around the shaft of the air brake plunger and to prevent the plunger from being moved unintentionally or inadvertently in a manner that may disengage the air brake.

Abstract: A system is used with a boom pivoted on a frame about a horizontal pivot axis between raised and lowered positions by a first fluid ram joining the frame and the boom. A releasable locking mechanism locks the boom relative to the frame to prevent pivotal movement of the boom about its horizontal pivot axis. A second fluid ram is disposed between the frame and the boom, the second fluid ram compressed between the frame and the boom when the boom is adjacent the raised position, but prior to the boom achieving a latched position substantially coinciding with the raised position. A fluid circuit of the second fluid ram has two selectable pressure levels. The first level substantially prevents the boom from achieving the latched position, the second level permits the boom to achieve the latched position while providing fluid cushioning to dissipate impact forces between the boom and frame.

Abstract: The invention relates to a device for protecting against unauthorized removal of a trailer, with an electronic brake system (EBS) and a brake assembly, characterized by a control device which is set up in order to be actuated to activate and deactivate the protection such that the electronic brake system is activated so as to bring about protection by means of the brake assembly and thus to brake the trailer by means of the brake assembly if unauthorized removal is attempted.

Abstract: A parking brake system is provided in which a parking brake state for a wheel brake (2A) is obtained by forward movement of a parking piston (44) slidably fitted into a casing (23) with the rear side of the parking piston (44) facing a parking control fluid pressure chamber (47), and the forwardly moved state of the parking piston (44) is mechanically locked by spheres (58) pushed up as a result of forward movement of a lock piston (56) of a lock mechanism (31). Moreover, a plurality of guide grooves (126), into which parts of the spheres (58) are rollably fitted, are provided on the inner face of a large diameter hole (38), the inner face of a restricting step (42), and the inner face of a small diameter hole (39), the guide grooves (126) having a concavely curved cross-sectional shape and extending in the axial direction of an insertion shaft (59). This enables an automatic parking brake state to be obtained by a simple structure without consuming power.

Abstract: An actuating mechanism (1) for operating a parking-lock mechanism of the drive chain of a vehicle with an automatic drive. The actuating mechanism has a piston unit (4), a detent element and an electromagnetic operating device (6) for operating a release element (7), which is intended for deactivating the detent element (5). The piston unit communicates with an emergency unlocking mechanism (14) and is positioned to open the locking mechanism by way of the piston unit. The detent element, the piston unit and the release element interact such that the locking mechanism remains in the currently engaged state when the locking mechanism is open and the operating device is not electrified, as well as when the locking mechanism is closed and a fluid pressure is applied to the piston unit.

Abstract: A system and method for controlling the unintended rolling of a rolling stock, the rolling stock having a driver park brake, and an in-vehicle network for signals transmission, the method comprises the steps of selecting among the signals transmitted over the in-vehicle network, a set of predefined signals, then analyzing the status of the selected signals to determine a regulation process to be applied to the rolling stock, and monitoring the regulation process.

Abstract: A motor vehicle with a parking brake (3) which, in addition to functioning as a parking brake (3), may also be used as an auxiliary brake for assisting the main brake (2) and/or a sustained-action brake. The parking brake (3) is preferably incorporated in the transmission (1) of the vehicle and designed as a rotary disk brake in an oil bath.

Abstract: A lockable hydraulic power-assisted steering system for steering one or more wheels of a vehicle, the system comprising: a hydraulic pump (1) having an inlet (2) and an outlet (3); a hydraulic reservoir (4) having an inlet (5) and an outlet (6); said pump inlet (2) being connected to the reservoir outlet (6); a hydraulic power steering housing (7a), the steering housing being operable by means of a steering wheel and the steering housing having an inlet port (8) and an outlet port (9); a hydraulic circuit, including: a pressure conduit connecting the pump outlet (3) to the steering housing inlet port (8), a return conduit connecting the steering housing outlet port to the reservoir inlet (5), a user operable lock valve (10) which selectively allows to connect and disconnect the steering housing inlet port (8) from the pump outlet (3) and/or to connect and disconnect the steering housing outlet port (9) from the reservoir inlet (5), characterized in that at the inlet port (8) of the hydraulic power steering ho

Abstract: A valve unit for an electro-pneumatic brake control is connected to an input of an air-quantity-boosting valve for the aeration/venting thereof. A double-armature solenoid valve includes primary and secondary armatures each spring-loaded and actuated by common magnet coil. The primary armature is a switch for a vent valve; the secondary armature is a switch for an intake valve. When the coil is not drawing current, the armatures are in spring-loaded position, the intake valve blocking intake and the vent valve venting. When a first current flows through the coil, the primary armature enters switching position, with the secondary armature in spring-loaded position; the intake valve blocking intake and the vent valve blocking venting. When a second current greater than the first flows through the coil, both primary and secondary armatures are moved into switching positions, so that the intake valve admits air and the vent valve blocks venting.

Abstract: An apparatus for externally controlling one or more brakes on a vehicle having a pressurized fluid braking system. The apparatus can include a pressurizable vessel that is adapted for fluid-tight coupling to the braking system. Impact to the rear of the vehicle by a pursuit vehicle, shooting a target mounted on the vehicle or sending a signal from a remote control can all result in the fluid pressures in the braking system of the vehicle being modified so that the vehicle is stopped and rendered temporarily inoperable. A control device can also be provided in the driver's compartment of the vehicle for similarly rendering the vehicle inoperable. A driver or hijacker of the vehicle preferably cannot overcome the stopping action from the driver's compartment.

Abstract: A method and system for automatic braking is described. A service brake which can be operated electrically with a compressed air pressure and a parking brake which can be operated electrically are provided. When the vehicle stops due to the service brake being applied, the service brake is released and the parking brake is applied as a function of a release criterion. The release criterion includes the parking brake not being applicable manually because of a defect, and the operation of a control element for application of the parking brake.

Abstract: The present disclosure relates to a pump system for parking brakes for a rail vehicle. The pump system includes at least one actuator, at least one pump and a reservoir as a fluid source. Also included is a manifold in fluid communication with the reservoir and the actuator. Further included are a plurality of valves and fluid paths internal to the manifold to allow fluid flow among the at least one pump and the reservoir.

Abstract: A vehicle immobilization system having a controller and a brake system that is capable of maintaining the vehicle brakes in an engaged position to prevent rotation of the wheels.

Abstract: When a solenoid is operated so as to move an engaging pawl to a disengaged position, if a displacement detection device (an angular position sensor and a controller) detects that a motor rotor has not been displaced by an amount equal to or exceeding a predetermined level, that is, if the motor has not returned by an amount equal to or exceeding the predetermined level within a predetermined time period, a defect in an unlocked condition (an unlocking failure of a park braking lock mechanism) is determined. In this case, a driver is notified of the failure, so that prompt action can be taken to rectify the unlocking failure of the park braking lock mechanism.

Abstract: A method for the operation of a hydraulic vehicle brake is provided. The brake includes a brake housing in which a hydraulic working pressure chamber is delimited by a displaceable brake piston, which is movable into operative connection with a brake disc in order to achieve a braking effect. A parking brake device acts on the brake piston and, in a condition where the brake piston is in operative connection with the brake disc, is lockable by a locking device. The locking device is activated by a force-transmitting element, which is operable by an electromagnetic actuator with at least one coil, one yoke and one armature, wherein the position of the force-transmitting element connected to the armature is determined because the change in inductance of the coil is determined depending on the armature movement in such a way that the result of the determination is independent of the ambient temperature.

Abstract: A brake cylinder for brakes of a motor vehicle, in particular for utility vehicles, comprising a spring loaded brake section and a service brake section is configurable in such a way that a total length is substantially shortened. In the inventive cylinder, the spring loaded brake section and the service brake section are constructed in such a way that they form a single unit. The brake cylinder comprises a pressurized piston for service braking and a spring-loaded piston for parking braking. The two pistons are connected to each other through a shift cylinder and are disconnected by the pressure relief in a second pressure chamber through the shift cylinder in such a way that the piston is displaceable by a spring-loaded spring. In order to release the brake, the piston for service braking is pressurized and reconnected to the piston. The unit is displaced to a release position by the action of a return spring through the pressure relief of the piston.

Abstract: A pressure locking master cylinder including a fluid reservoir for storing a hydraulic fluid, a housing, a piston slidably received within the housing and defining a working chamber and a blocking chamber, wherein the blocking chamber is in fluid communication with the reservoir, and a valve positioned between the blocking chamber and the reservoir, the valve being adapted to selectively trap the hydraulic fluid within the blocking chamber to lock the piston in a position with respect to the housing.

Abstract: A system and method of remotely controlling the parking brake of a disabled vehicle to be towed by a towing vehicle includes using the hydraulic fluid of towing vehicle to control the parking brake operation of the disabled vehicle. The towing vehicle is equipped with a control valve and brake release manifold assembly. The brake release manifold assembly provides a source of hydraulic fluid of controlled pressure. The towing vehicle has means to conned the controlled pressure hydraulic fluid of the towing vehicle to the parking brake system. The towing vehicle also has means to control and monitor the flow of hydraulic fluid to the disabled vehicle in order to either release or apply the brakes when desired.

Abstract: In a method for stabilising a motor vehicle which is decelerated into a rest position and in a corresponding motor vehicle brake system which is provided with a service brake and a parking brake which can be actuated independently of the driver, when activation of the parking brake is initiated, the service brake changes from a first braking-force distribution of a service brake mode to a mode simulating a second braking-force distribution of the parking brake, and a switch-back to the first braking-force distribution of the service brake mode is enabled at least during the transition.

Abstract: An electric parking brake includes an actuating device, which provides a force to lock and unlock the parking brake using power supplied by manipulation of a control button, and an equalizer, which is coupled at a first end thereof to the actuating device and is coupled at a second end thereof to a parking cable to pull or release the parking cable, which operates a braking device of a wheel, depending on operation of the actuating device. The electric parking brake further includes an operating load measuring unit, which measures operating load that pulls the equalizer in the parking cable and sends the measured signal to an ECU that controls the actuating device.

Abstract: A system and method of remotely controlling the parking brake of a disabled vehicle to be towed by a towing vehicle includes using the hydraulic fluid of towing vehicle to control the parking brake operation of the disabled vehicle. The towing vehicle is equipped with a control valve and brake release manifold assembly. The brake release manifold assembly provides a source of hydraulic fluid of controlled pressure. The towing vehicle has means to connect the controlled pressure hydraulic fluid of the towing vehicle to the parking brake system. The towing vehicle also has means to control and monitor the flow of hydraulic fluid to the disabled vehicle in order to either release or apply the brakes when desired.

Abstract: A locking unit for the locking of the movement of a piston. An electromagnet is provided the armature, respectively the armature bar, of which acts on an operating element. The operating element co-operates with a catching element in such a way that the catching element blocks in a locking position the movement of the piston, respectively the catching element unlocks in an unlocking position the movement of the piston. Catching element and operating element co-operate surface-to-surface.

Abstract: A parking brake system pneumatically actuates an air cylinder to mechanically lock a wheel brake in an applied position in response to a parking demand request. The parking brake system includes a dual hand control that has an electronic control element and a pneumatic control element. The electronic control element communicates with an electronic braking system control unit and the pneumatic control element communicates with a parking brake air reservoir. When the dual hand control is moved to a park position, the electronic control element generates an electronic control signal that applies a parking brake force to the wheel brake. The pneumatic control element generates an air signal that is sent to the air cylinder. The air cylinder includes an extendable shaft that supports a lock member. The air signal moves the lock member into engagement with a brake operating member to lock the wheel brake in the applied condition.

Abstract: A locking mechanism for installing between a master cylinder and a brake line includes a housing having an internal bore, an inlet port, a passage, and an outlet port. A reciprocating piston is movable within the bore. A locking lever is coupled to the reciprocating piston for actuating the reciprocating piston. A fastener having an internal fluid passage for providing fluid communication between the passage and the master cylinder secures the housing to the master cylinder. The locking lever is moveable between a first position, wherein the hydraulic fluid can flow freely between the master cylinder and the brake line for engaging and disengaging the vehicle brake and a second position, wherein the hydraulic fluid is prevented from returning to the master cylinder for maintaining the vehicle brake in an engaged state.

Abstract: A wheeled vehicle includes a cylinder having a receiving chamber, a retractable piston rod movably mounted on the cylinder to support a bearing seat, and an anti-reverse safety device mounted on the cylinder to provide an anti-reverse effect to the cylinder. Thus, when the piston rod is pressed downward, the anti-reverse safety device provides an anti-reverse effect to the cylinder to prevent the fluid in the receiving chamber of the cylinder from flowing backward, so that the bearing seat is fixed at a normal position without being lowered down accidentally.

Abstract: A system is provided for permitting movement of a vehicle having brakes while an auxiliary component of the vehicle is operated by the vehicle. The system includes a pressurized fluid source. A control device is coupled to the pressurized fluid source and the brakes of the vehicle to release the brakes in response to a first signal and to at least partially apply the brakes in response to a second signal. A controller applies the first signal to the control device when at least one of a first set of conditions exist and applies the second signal to the control device when a second set of conditions exist.

Abstract: A parking brake for a vehicle, including a parking brake unit, an actuating device situated inside the vehicle and operable to transmit an actuation signal to a control unit, a hydraulic circuit of a service brake of the vehicle connected to the parking brake unit, and an actuator and locking device for locking the parking brake in a braking position; the parking brake is actuatable by means of the hydraulic circuit and the actuator is a brake booster of the service brake.

Abstract: A system and procedures for adjusting brake mechanisms for an aircraft having an electric brake system are disclosed. The brake actuator mechanisms are controlled to achieve different parking brake actuation states as a function of the current engine run status (e.g., engine off, engine idle, or engine above idle). Procedures for adjusting an aircraft parking brake as disclosed herein include setting the brake actuator mechanisms to achieve a relatively low clamping force when the aircraft engines are off or idling, and setting the brake mechanisms to achieve a relatively high clamping force when the aircraft engines are running above idle, and to maintain commanded brake force without active or battery power by engaging a mechanical clutch or latch to the brake actuator.

Abstract: The present disclosure relates to a pump system for parking brakes for a rail vehicle. The pump system includes at least one actuator, at least one pump and a reservoir as a fluid source. Also included is a manifold in fluid communication with the reservoir and the actuator. Further included are a plurality of valves and fluid paths internal to the manifold to allow fluid flow among the at least one pump and the reservoir.

Abstract: A hydraulic parking brake device is selectively switched between a braking state and a non-braking state. A braking force decreases as a pressure in the control oil chamber increases and increases as the pressure in the control oil chamber decreases. The device includes a discharged oil restrictor located in a discharge passage and an accumulator connected to the control oil chamber. The accumulator is capable of releasing hydraulic oil to the control oil chamber when the braking force is greater than that at the time when the parking brake device is switched from the non-braking state to the braking state and the braking force can further be increased during the braking state of the parking brake device. Thus, the parking brake device can gradually brake the vehicle from the running state.

Abstract: An actuation device for a brake has an accumulator (14). The accumulator (14), when in a parking brake position, acts on a ball ramp actuator (10) via a connecting element to actuate the brake as a parking brake. If the accumulator (14) is in a released position, an actuator (16) is activated to displace a catch (17) and to hold the accumulator (14) in this released position.

Abstract: An actuator responsive to fluid signals to retract and extend a piston. The actuator includes a cylinder and a pressure piston carried inside the cylinder. Also included is a shaft, and a rod connected to the pressure piston. The actuator further includes a first port for receiving a fluid pressure to move the pressure piston to a first position. The actuator also has a locking mechanism. The locking mechanism has a first and second surface, and both surfaces are movable in response to the fluid pressure at the first port. The surfaces lock the pressure piston in a first position upon removal of the fluid pressure at the first port.

Abstract: A parking braking system for a vehicle uses an electronic braking system (EBS) as a primary source for generating a parking brake force via pneumatic brake actuators. Each pneumatic actuator actuates a piston that is adapted to rotate a pivoted lever, which moves to apply brake pads against a brake disc. The parking braking system includes a hand control that controls actuation of the pneumatic brake actuators. Vehicle brakes for non-parking braking purposes are controlled by electronic signals generated in response to a driver's foot-generated braking demand. An electronic controller is adapted to control a supply of pressurized air to the pneumatic brake actuators in accordance with the driver's braking demand.

Abstract: A parking brake system for motor vehicle air brakes provides automatic engagement of the parking brakes when a gearshift lever is moved to park, but requires manual disengagement of the parking brakes. The effect is achieved in part by controlling the discharge conditions of two piloted latch valves connected to feed air to a cab mounted push pull double check valve.

Abstract: A self propelled power machine is provided with a drive system and a traction lock mechanism. The drive system includes a speed range selector and associated mechanism that can operate the power machine in high and low speed ranges. The traction lock mechanism, when applied stops the drive system from moving the wheels of the power machine. A controller insures the drive system is in the low speed range prior to engaging the traction lock mechanism. The controller determines whether the drive system is operating in a low speed range or a high speed range. If the drive system is in the high speed range, the controller places the drive system in the low speed range and the controller then applies the traction lock after a short time delay to provide some dynamic slowing of the drive. If the system is already in the low speed range, the drive system remains there and the controller applies the traction lock.

Abstract: A parking brake system uses a pneumatically controlled brake actuator to provide both service and parking brake functions. The parking brake system for a vehicle includes a hand control that is manually movable between a plurality of operational positions. A valve is responsive to movement of the hand control and controls air flow from a parking brake air supply to the pneumatically controlled brake actuator. The valve includes a gate that defines the plurality of operational positions, which include a park position, a release position, and an off position. When the hand control is moved out of the off position and into the park position, the pneumatically controlled brake actuator remains pressurized and a latching mechanism is activated to mechanically lock the vehicle brake. When the hand control is moved to the release position, the vehicle brakes are re-applied to unload the latching mechanism.

Abstract: A parking brake for a motor vehicle includes: a manual operating lever; a braking device designed to act on brake disks applied on a bevel pinion for transmission of the motion to the wheels of the motor vehicle; and a cable for transmission of the command imposed via the lever on the braking device. The brake is activated either automatically by a hydraulic actuator when the engine of the motor vehicle is turned off, or alternatively, by a manual command imposed by the operator through the lever whether or not the engine of the motor vehicle is running.

Abstract: A slider locking pin control receives feedback of the actual position of the locking pins. If the locking pins are not engaged in the trailer frame rails, then the interlock valve will vent air to release a parking brake. Once the locking pins are engaged, the interlock valve will allow the flow of air to release the parking brakes. If the vehicle operator attempts to move the vehicle, but the locking pins are not engaged, the operator will be unable to release the parking brakes. This will prevent movement of the trailer until the locking pins are engaged. The interlock valve is placed downstream of a spring brake control valve and pressurized air reservoir, such that the pressurized air reservoir can still receive pressurized air to charge, and provide air for use by various components on the trailer.

Abstract: An electronic unit for automatically activating a parking brake in dependence of at least one specified operating parameter or operating mode of a motor vehicle, which can be started without a mechanical key, is equipped with a device for arbitrarily preventing the automatic activation of the parking brake. In a first alternative, the unit is connected with a key button, which can be directly manually actuated, in the form of an OFF switch for the arbitrary prevention of the automatic activation of the parking brake. In a second alternative, the electronic unit in a motor vehicle, which can be started through an electronic authorization verification device with wireless code transmission, is equipped with a mechanism with which the arbitrary prevention of the automatic activation of the parking brake can be triggered by inserting the authorization verification device in a holding shaft that is provided for this purpose.

Abstract: A brake caliper with an integral parking brake. The brake caliper includes a housing having a bore with tapered walls, a piston having a rod mounted within the bore, a wedge element positioned between the rod and the tapered walls and displaceable to a locking position and a release position, a resilient element positioned to displace the wedge element to the release position, and a locking element for selectively displacing the wedge element to the locking position. When the locking element is momentarily actuated while a hydraulic pressure is present, the wedge element is urged to the locking position, thereby holding the brake caliper in a braking position when the hydraulic pressure is removed and then the locking element is de-actuated. A hydraulic pressure sufficient to cause the resilient element to urge the wedge element to the release position is effective to release the caliper.

Abstract: An anti-theft device is disclosed for use on a vehicle employing air-operated parking brakes. The device is shaped for disposal about the parking brake control knobs when engaged. The device includes a pair of mating halves formed for surrounding and enclosing the control knobs while in an engaged position. A first of the halves includes a tongue having an opening therein and a second of the halves includes a channel for receiving the tongue. A lock is provided with a locking pin being disposed in the second half wherein the locking pin engages the opening in the tongue in order to secure the first and second halves together. Also, an adjustment mechanism is provided for tailoring the device to minor differences between the brake control knobs from one vehicle to another.