Abstract: A dismount brake device (1) is tethered by a cable (4) to a snowmobile rider (3). Pulling on the cable (4) displaces a trigger (17) which frees a piston (34). The piston (34) is biased by a main spring (39) to decrease the volume of a chamber (11) containing hydraulic fluid and which is interconnected to the brake line (13). A plunger (36) extends from the head of the piston (34) and seals a port (40) leading to the master cylinder (42). As the volume of the chamber (11) continues to decrease, the pressure in the brake line (13) reaches a value that will activate the brakes and stop rotation of snowmobile track (47). Activation of the brake handle (46) resets the device (1) for further use. An alternate embodiment (48) utilizes a solenoid (50) instead of the tether (4) to physically move a modified trigger (56) when a switch senses that the seat (64) of the snowmobile (2) is unoccupied.

Abstract: The present invention provides for an anti-theft system which is located within a fluid line. This anti-theft system will control the directional flow of the hydraulic fluid in the fluid line. The system of the present invention includes a control panel and a blockage means. The control panel permits for an authorized person to activate or deactivate the anti-theft system. Upon activation or deactivation, a signal is transmitted to a motor via an electrical cable. The motor will activate or deactivate the blocking means.

Abstract: An automatic vehicle brake locking system, including an actuator (16) which segregates an auxiliary hydraulic fluid pump (42) from the normally used vehicle master cylinder (2). The actuator (16) is formed as a cylinder including a piston (36) which is biased to permit passage of hydraulic fluid which is pressurized by the vehicle master cylinder (2) through the actuator (16).

Abstract: A system for disabling a stolen motor vehicle including a control device and a trigger device. The stolen motor vehicle has a master cylinder housing brake fluid and coupled to brakes by brake lines. The control device controls the flow of brake fluid between the master cylinder and the brakes, initially allowing bidirectional flow of brake fluid. The trigger device triggers the control device to restrict the flow of brake fluid to one direction in response to initiation of the system, tilting of the stolen motor vehicle forward at an angle with respect to ground equal to or greater than a preset angle, and application of the brakes. The trigger device includes a first switch, an operator switch, a motion activated switch, and a brake switch. The first switch is coupled in series between the control device and ground and is initially open. The first switch is operable to activate the control device to restrict the flow of brake fluid to one direction when closed.

Abstract: In a brake system with an automatic braking mechanism of the present invention, a master cylinder pressure developed by pedaling a brake pedal 1 is supplied to wheel cylinders through first and second brake paths 6,7, first and second center valves 26', 26 and first and second outlets 24', 24 of an automatic broke actuator 8 so that the normal brake is actuated. An electronic control unit (ECU) 40 actuates a thrust generator 38 and thus an automatic braking signal pressure is developed, whereby first and second small-diameter pistons 18', 18 and first and second large-diameter pistons 16', 16 are moved forward to close the first and second center valves 26', 26 to develop pressures which are supplied to the Wheel cylinders, with the result that the automatic brake is actuated.

Abstract: A vehicle security system for immobilizing a vehicle to prevent theft and other unauthorized movement of the vehicle. The system includes a brake blocking valve for selectively preventing fluid communication between the vehicle wheel brake cylinders and the vehicle brake master cylinder. The brake blocking valve is activated after the vehicle is brought to a stop, the service brakes are applied, and either an activation pushbutton is pressed to engage the system while the engine is running, or, alternatively, the system is automatically activated by turning off the ignition switch while foot pressure is maintained on the service brake. In addition to blocking vehicle movement by locking the service brakes in the brake engaged condition, the system also disables the starter by opening the starter circuit, and it disables the ignition coil by opening the ignition circuit, thereby further deterring and preventing unintended vehicle movement.

Abstract: A pressure-holding valve for a brake system having a body with a blind bore therein. The body has a first passage which connects the blind bore with a variable pressure inlet port and a pressure outlet port. The blind bore is closed by seals carried on a plug having an axial passage therein connecting said inlet port with a second passage connected to the first passage. A non-return valve is located in said blind bore between the plug and the bottom of the blind bore while a valve controlled by an electromagnet is locate in the plug. In response to an operational signal the valve controlled by the electromagnet is moved into engagement with a seat to interrupt communication between the inlet port and the first passage.

Abstract: An automatic vehicle brake locking system, including an actuator (16) which segregates an auxiliary hydraulic fluid pump (42) from the normally used vehicle master cylinder (2). The actuator (16) is formed as a cylinder including a piston (36) which is biased to permit passage of hydraulic fluid which is pressurized by the vehicle master cylinder (2) through the actuator (16).

Abstract: A device for the automatic control of vehicular brake systems on hills, in order to allow the vehicle to remain stopped on a hill even after the brake pedal of the vehicle has been released. The device automatically releases the brakes when the driving torque produced by the engine against the wheel braking elements is equal to, or greater than, the opposite braking torque resulting from the slope of the hill. An electromechanical control valve is mounted to the brake system of the vehicle, in order to allow or block the release of the braking fluid pressure applied to the wheel braking elements upon the activation of the valve by a control unit, which receives information about the applied driving torque from a load sensor mounted to the braking elements of at least one wheel of the vehicle.

Abstract: A vehicle anti-theft system includes components for engaging the brakes of the vehicle through the vehicle's hydraulic brake lines. In its preferred embodiment the system includes an auxiliary vacuum booster, an air plunger and cylinder assembly, a compressor for producing compressed air for moving the plunger, an arm connecting the plunger with the vacuum booster, an auxiliary brake master cylinder, and hydraulic fluid lines between the auxiliary brake master cylinder and the conventional fluid lines of the vehicle. Once parked, the compressor automatically engages and pressurizes the plunger and cylinder. The plunger presses against the vacuum booster utilizing the remaining vacuum available from the existing system. The vacuum booster acts against the auxiliary master cylinder to apply pressure on the fluid lines between the auxiliary master cylinder and the vehicle's existing hydraulic lines, thereby locking the vehicle brakes.

Abstract: An anti-theft device for a motor vehicle equipped with hydraulic brakes. A key switch is electrically connected to the vehicle's battery and to a small motor. When the key switch is turned, power from the battery causes the motor to reciprocate a piston which is connected to a valve. The positiion of the piston either blocks or unblocks the flow of hydraulic fluid between the brakes and the hydraulic fluid reservoir while one-way flow is allowed between master reservoir and brakes whether the device is armed or unarmed. The key switch and connecting wiring are isolated from the ignition system, preferably passing through the structural frame of the vehicle.

Abstract: A lock-out assembly having a latching mechanism by which means a plunger may be manually depressed and latched in a lock-out position in which a lock pin is pre-set by engagement with an actuator rod of an empty/load valve or the like, so that in response to axial extension of the actuator rod sufficient to align a locking groove in the actuator rod with the lock pin, locking engagement therebetween will occur to limit further axial extension of the actuator rod, without any further action on the part of the operator. Automatic disengagement of the lock pin from the locking groove of the actuator rod occurs in response to axial retraction of the actuator rod, by effecting disengagement of the latching mechanism to allow a return spring to reset the plunger.

Abstract: A parking brake valve includes a magnetically attractable sled containing fluid stoppers and fluid passers that moves along a track, a fluid exchange unit, solenoids at either end of the track and a remote actuator. The parking brake valve is added to an existing hydraulic vehicle braking system. When the existing braking system is actuated, braking fluid is forced through the parking brake valve. Activating a locking solenoid attracts the sled into a fluid interrupting or locking position, thereby locking the brake system in a braking state. Activating an unlocking solenoid moves the sled such that brake fluid can again flow through the parking brake valve, thereby allowing the braking system to function normally. Integral fluid pressure valves allow the monitoring of fluid pressure within the parking brake valve allowing operation to be monitored.

Abstract: An hydraulic braking system for a vehicle comprises a pedal-operated combined hydraulic booster and master cylinder assembly (1) for applying a brake (15, 18) on a wheel (16, 19) and having a master cylinder (6) and a servo chamber (7), an auxiliary hydraulic power supply (10) defining a booster pressure in the servo chamber, a flow valve (17, 20) through which fluid is supplied to the brake, and a solenoid-controlled valve (27) for controlling the setting of the flow valve for brake re-application during ABS by the application to it of control fluid from the servo chamber (7) in response to signals from a control module (38).

Abstract: A security brake system comprising a plurality of braking modules, each module coupled between a brake master cylinder and a set of wheel cylinders of a vehicle, each module further comprising a body having a first, second, third ports, and a plurality of channels disposed therein between the ports, the first port allowing the transfer of braking pressure to the body from the brake master cylinder, the second port allowing the transfer of braking pressure from the body to a set of wheel cylinders, the channels transferring brake pressure therethrough between the ports; a valve mechanism coupled to the third port of the body and extended within a channel between the first and second ports for controlling brake pressure between the first and second ports, whereby allowing the brakes of the vehicle to be locked or unlocked; and an activation mechanism for activating the valve mechanism in one orientation, whereby unlocking the brakes of the vehicle, and deactivating the valve mechanism in another orientation, th

Abstract: Disclosed is a method and device for preventing theft of an automotive vehicle, in particular, one which engages the brakes to prevent the vehicle from moving. An anti-theft device is coupled to the brake system, and, upon leaving the vehicle, manually actuating a concealed switch to enable the anti-theft device. The device is designed so that it is not operable until the brakes are operated by the thief. Once the brake system has been used by the thief after actuating the switch, engagement of the brake system is maintained, preventing movement of the vehicle.

Abstract: The present invention involves a hydraulic device for immobilizing the wheel of a stationary trailer. The locking brake is spliced into a brake line of a trailer carrying a surge brake system and allows an individual to manually activate the trailer brake when the trailer is stopped. The brake device includes a housing block with a cylindrical bore and a spring biased piston. A shank is connected to the piston and provides a manual handle for shifting the position between an inner and outer position. In the outer position, brake fluid may flow from the brake system actuating device. In its inner position, brake fluid is prevented from flowing from the actuating device and is pressurized to lock each brake. The housing block also includes a pivotally secured lock pin which engages a hole on the shank to secure the shank to the housing block. In this manner, the brakes of the trailer may be secured in a locked position.

Abstract: An anti-theft device is coupled in series with a supply line and a service line of a trailer. When activated, the anti-theft device prevents theft of the trailer by decoupling the supply and service lines of the trailer from the reservoir and brake cylinders of the trailer, and by coupling the supply and service lines to the atmosphere, thereby preventing a prospective thief from releasing the trailer's brakes by restoring air to the supply and service lines. When the anti-theft device is deactivated, the supply and service lines are re-coupled to the reservoir and brake cylinders to allow the driver to release the trailer brakes.

Abstract: A brake release lock interposable between the master cylinder of a hydraulic vehicle braking system and the wheel cylinders, including a first connecting element for connection to the master cylinder, a second connecting element for connection to the wheel cylinders, a first passageway connecting the first and second member, having a valve seat and bore for a check valve spring-biased against the seat and configured in such a way as to permit fluid to flow from the master cylinder to the wheel cylinders, but to prevent fluid from returning from the wheel cylinders to the master cylinder, a second passageway connecting the first and second connecting elements, bypassing the first passageway, and a solenoid valve responsive to signals producible by an authorized user of the vehicle, for cutting off the second passageway after the vehicle has been parked, and for re-establishing the second passageway prior to driving off the vehicle.

Abstract: The present invention relates to a vehicle anti-theft system which, when activated, will block the vehicle's hydraulic brakes into the locked position preventing the vehicle from being driven or towed. Once activated, the system is immune to power failure. The system can use one of several control means to activate the system including keypad, scanners, key system, or wireless remote.

Abstract: An anti-theft device is installed in a vehicle brake line which carries braking fluid. The device defines a valve seat and a valve body adapted to close against said valve seat, the valve body having a passageway therethrough and being rotatable against said seat about an axis substantially perpendicular to the passageway, between a first position in which it permits fluid flow in one direction and inhibits fluid flow in the opposite direction, and a second position in which it permits fluid flow in both directions. The valve can easily be switched between the first and second positions, and can be locked in the first position. By allowing braking fluid to flow only toward the wheels, it will be evident that the wheel brakes, once applied, cannot, be released.

Abstract: A vehicle anti-theft device which upon activation, maintains the braking function of the braking fluid by preventing reverse flow thereof from the wheel cylinder back to the master cylinder once the brake pedal of the vehicle has been pushed. Improvements over prior art are; no brake fluid is trapped between the wheel cylinder and the one-way valve upon activation of the device until after the brake pedal of the vehicle has been pushed; no indication exists either with the switching device or with the mechanism itself, to indicate to other than to an authorized user, the state in which the valve is currently set.

Abstract: A brake fluid pressure control apparatus is disclosed which is capable of providing a good brake feel at the initial stage of pressure reapplication. The brake fluid pressure control apparatus comprises a pressure receiving device 25 and a valve mechanism 19 for closing a fluid passage 10 from a master cylinder 7 to wheel cylinders 8. The wheel cylinder fluid pressure is held by closing the fluid passage when the vehicle is brought to a halt with the brake applied, so that the vehicle can be held stationary if the driver takes his food off the brake pedal. When the pressure is to be applied again from the master cylinder 7, the pressure applied during the initial period of this reapplication of the master cylinder pressure is received by the pressure receiving device.

Abstract: A brake holding apparatus for vehicles with conventional hydraulic systems for the purpose of locking the least loaded brakes only, after the vehicle has been braked to a stop which permits unloading, during stops, the most loaded brakes, thereby prolonging their life and making driving easier for the operator. A hold mode indicator light is provided to alert the driver that the system is in the holding mode.

Abstract: An apparatus for actuating a hydraulic brake has a housing with a cavity communicating with an input and an output for hydraulic fluid. The housing is adapted to be positioned between a master cylinder and a wheel cylinder in a vehicle hydraulic brake system. The cavity receives a valve apparatus in the form of a sleeve and a piston for opening and closing to control a flow of hydraulic fluid. The cavity also receives a seat, and the seat movably receives a transmission assembly that communicates with the valve apparatus. A driving system drives the transmission assembly to actuate the valve apparatus. A control circuit receives a code from a user to activate the driving system. A measuring device determines a duration of activation of the driving system. The valve is open during normal operation of the vehicle. To lock the brakes for security, the code is entered and if correct, the valve closes, thereby acting as a check valve. Hydraulic medium is forced through the valve to the wheel cylinders.

Abstract: A method of shortening the braking distance in critical driving situations uses the criterion of exceeding of a first threshold value by the actuating speed of the brake pedal (v.sub.BP) by the vehicle driver for initiating an automatic braking operation. A brake pressure (p.sub.B,max) which corresponds to the value of the brake pressure with optimum deceleration of the vehicle is built up automatically immediately after initiation of the automatic braking operation.

Abstract: An anti-theft system for vehicles pressurizes and locks the hydraulic brakes whenever voltage is removed from a special master brake cylinder. The master brake cylinder has all the conventional parts, but the central rod which carries the hydraulic pistons extends past the usual point and attaches to a permanent magnet at the end of the rod. A coil spring forces the rod in the direction of rod movement needed for brake activation, toward a solenoid. The solenoid is powered by the vehicle battery. The spring is prevented from continuously engaging the brakes by the magnetic repulsion of the permanent magnet by the solenoid. The magnetic force acts to disengage the brakes. When the current is cut off, so is the magnetic repulsion, and the unbalanced force of the spring pushes the rod to engage the brakes. The solenoid current can be switched on or off by a remote switch. The switch may be closed and opened remotely through a radio link.

Abstract: An assembly is provided for use with a trailer including a plurality of wheels, normally engaged air brakes coupled to the wheels, and an air supply line coupled to the air brakes for supplying air to release the air brakes. The assembly includes a valve for selectively venting the air supply line to the atmosphere to prevent the release of the air brakes from their normally engaged position. The valve is coupled to the air supply line and is adjustable between a first position and a second position. In the first position, the valve seals the air supply line to permit the air brakes to be released when air is supplied to the air supply line. In the second position, the valve vents the air supply line to the atmosphere. When the valve is in its second position and air is supplied to the air supply line, the air is vented to the atmosphere. Therefore, in the second position, the valve means prevents the air brakes from being released when air is being supplied to the air supply line.

Abstract: Disclosed is a brake locking mechanism of the anti-theft type for use with a vehicular brake system having a brake actuating push rod reciprocable by a driver operated lever into the brake applying position. The brake lock comprises a locking mechanism attached to the brake pedal by an elongated linking member and a remote switch for engaging and disengaging the lock. The locking mechanism preferably comprises a pawl and ratchet assembly or a piston and fluid operated cylinder. The lock may be either manually activated by pressing on the brake pedal or automatically activated by positioning a three-way valve and engaging a pump.

Abstract: A vehicle anti-theft system is activated by a magnetically coded card and associated card reader to activate a normally closed solenoid valve which is connected in the brake line to permit normal operation of the vehicle, the valve being closed when unoperated, preventing brake fluid to return to the master cylinder, whereby the brakes of the vehicle are locked, preventing operation of the vehicle. The valve has its fluid inlet connected to the brake line and its fluid outlet connected to the outlet of the master brake cylinder.

Abstract: An automatic brake locking system, for locking the brakes of a vehicle having a hydraulic brake system, is operated every time the ignition switch is turned off to apply pressure through an auxiliary brake actuating device to lock the brakes and hold them locked until the auxiliary brake actuating device is released. A safety switch is provided to operate in conjunction with the ignition switch; so that the safety switch and the ignition switch both must be operated to an "on" position to release the auxiliary brake actuating device to allow normal operation of the vehicle. Turning on the ignition switch without operation of the safety switch does not permit movement of the vehicle since the auxiliary brake actuating device continues to be operated. The system is a passive system, which it does not require any separate actions on the part of the vehicle operator to cause the auxiliary brake actuating device to be operated when the vehicle ignition switch is turned off.

Abstract: An automobile brake system includes a master cylinder, a wheel cylinder and a solenoid actuated valve between the master cylinder and the wheel cylinder. The solenoid actuated valve is actuatable for maintaining high fluid pressure in the wheel cylinder after a brake pedal associated with the master cylinder has been released in order to prevent unwanted rearward rolling movement of a vehicle once it has stopped.

Abstract: A braking system having a disk brake that is mechanically connected to at least one wheel of the vehicle and cooperates with a brake caliper that is actuated by a threaded rod screwed through a threaded connection in a control nut rotatively mounted inside the caliper body, the threaded connection being irreversible by axial forces alone. The brake linings are made of an elastomeric material having a high friction coefficient when the disk is not rotating. This system provides a compact parking brake having a high power and a large remote-indication capacity, and is particularly useful in railroad vehicles.

Abstract: An automatic braking system for a vehicle having a multichambered brake unit includes a control unit movement of the vehicle or obstacles behind the vehicle. This control unit is interconnected with a three-directional electromagnetic valve for controlling pressures within the various chambers of the brake unit. The system can prevent unwanted rearward movement of a vehicle when it is has been stopped on a slope or flat surface and is restarted. Further, obstacles behind the vehicle can be sensed when the vehicle is in reverse and a warning may be provided to the driver. If the vehicle continues to approach the obstacles, the braking system can stop the movement of the vehicle before an accident can occur.

Abstract: An anti-theft device for a motor vehicle having an hydraulically-operated braking system comprises a plunger engagable with a flexible sealing ring, to close the fluid path between the pressure fluid supply and the brake cylinders. The plunger is inserted into the ring to seal with generally axially extending portion of the ring projecting freely in the direction of flow towards the vehicle's brakes. Application of pressure from the supply flexes said portion to away from sealing contact with the plunger to permit flow of fluid from the pressure fluid supply to the brake cylinders. Return flow of fluid from the brake cylinders to the supply is however prevented, whereby the brakes can be applied but cannot thereafter be removed until the plunger is withdrawn. The device further comprises means for locking the plunger in its operative position.

Abstract: A magnetic valve with a connection device is proposed, in which the housing is rotatable relative to the connection device, which encompasses a connector stub formed onto the housing. Embodying the connection device as a male fitting enables the alignment of the housing and the cable plug located on it, which is especially useful when the magnetic valve is installed in a wheel connection of a master brake cylinder. In another version, in which the connector stub is connected to the connection device positively with a snap-in ring, the magnetic valve can be inserted even at inaccessible locations. If the connection device is embodied as part of a brake cylinder, then the magnetic valve can be inserted directly, and the result is a connection that is secure against manipulation.

Abstract: In a vehicle such as a tractor or a trailer having fluid-operated spring brakes to which fluid is supplied under pressure for releasing the brakes from a locked condition, security means are provided to prevent unauthorized release of the brakes. The security means comprises a bistable solenoid valve for controlling the supply of fluid to the brakes, energizing circuit means for operating the valve, and limited access switching means operable to set the solenoid valve selectively in an open or a closed condition.

Abstract: A brake control apparatus for a vehicle includes a brake apparatus of the drum brake type; an electromagnetic valve arranged in a conduit between a wheel cylinder and a master cylinder; and a detector for detecting one directional movement of the brake friction members of the brake apparatus due to a backward rotational force of a wheel and another directional movement of the brake friction members due to a forward rotational force of the wheel when the brake friction members are pressed to the frictional surface of the rotator. The brake friction members being able to move within a predetermine range in accordance with the torque of the wheel. The detector includes a slide anchor slidably fitted to a through hold in a stationary anchor, the brake friction members being engaged with the slide anchor, and an electrical switch for detecting the movement of the slide anchor. The valve being closed and opened by the detecting output of the electrical switch.

Abstract: In a hydraulic brake system for a vehicle of the kind comprising a fluid pressure source having a reservoir and a hydraulic booster having a power piston arranged to receive the pressure fluid of a control fluid chamber which is proportional to a stepping down force on a brake pedal, a normally open type valve is disposed in a fluid passage provided for returning the pressure fluid of the control fluid chamber to the reservoir and is arranged to close in response to a braking pressure retaining signal produced when the vehicle is stopped by brake application.

Abstract: An anti-theft hydraulic brake device is provided and consists of a valve placed in hydraulic fluid conduit going from a master cylinder to wheel brake cylinders that will keep the brakes locked when the valve is activated from the dashboard after the brake pedal is released. In a modification the valve can be selectively operated from the key operated ignition switch as an additional safety factor.

Abstract: A booster unit for moving a vehicle on a slope and having a booster and a master cylinder coupled to the booster, comprising a brake fluid pressure holding valve having an actuator and provided at a brake fluid pressure piping system for either maintaining or releasing the brake fluid pressure in accordance with the conditions of the vehicle on a slope, a plurality of sensors for detecting the vehicle conditions and a control unit including a microprocessor having a CPU, a RAM, and a ROM so as to receive detected signals from the sensors and to calculate and produce control signals to the actuator of the brake fluid pressure holding valve in accordance with the conditions of the vehicle on a slope, and a method of controlling the booster unit. With this construction, a smooth moving of the vehicle can be realized on a slope.

Abstract: A brake control apparatus for a vehicle includes brake apparatus for the respective wheels which are operated by pressurized fluid from a master cylinder; an electro-magnetic valve arranged in a conduit connecting the master cylinder with at least one of the brake apparatus, the electro-magnetic valve being normally in the communicating state and being changed over into the intercepting state by an external instruction; at least one of the brake apparatus being of the disc brake type, the one comprising; (a) a disc rotor; (b) first and second friction pad assemblies for engagement with opposite sides of the disc rotor, the assemblies being guided for movement towards the disc rotor; (c) a caliper body straddling the peripheral edge of the disc rotor and the first and second friction assemblies; (d) an actuating member arranged in the caliper body for urging the first and second friction pad assemblies into engagement with the disc rotor, and (e) elastically deformable retainers for supporting the first and se

Abstract: Automobile theft is running rampant throughout the country, and many automobile stealing organizations are well organized, and have the necessary techniques to enable them to select and steal virtually any automobile. In a matter of a few hours they can change numbers, and other identifying data and give the automobile a new identity and appearance so that the automobile can be quickly sold at somewhat reduced prices. The overall profits are indeed very substantial. We have devised a theft proof locking system, including a key operated unit, which can be positioned at any desired location in the vehicle, and is operable to fully apply the brakes to all four wheels of the vehicle. This renders the vehicle immobile, even though the engine can be started and run. The only way that this locking system can be rendered inoperable is by the act of unlocking it with the key. It is therefore impossible to move the vehicle without lifting it bodily to load it onto a trailer or transport.

Abstract: An automatic stop valve device adapted to be mounted in the fluid pressure brake system of a vehicle and having a valve mechanism capable of being shifted between an open and a closed state and operative by closing to maintain fluid pressure in the system to hold the brakes in an applied condition. An electromagnetic mechanism having a coil and an armature actuated by the coil is capable of shifting the valve mechanism to its closed state. The electromagnetic mechanism is arranged to be energized to hold the brakes in the applied condition when a moving vehicle is brought to a stop, to maintain the valve mechanism closed while the vehicle remains stopped to hold the brakes in the applied condition and to open the valve mechanism when the operation of the vehicle resumes to release the brakes.

Abstract: Brake holding apparatus for use in a vehicle having a fluid pressure operated braking system including a master cylinder and at least one brake cylinder. The apparatus includes a trapping valve movable to an open position allowing fluid communication between the master and brake cylinders, and to a closed position blocking this fluid communication so as to trap fluid pressure in the brake cylinder. The trapping valve is biased for movement to its open position. Means are provided for moving the trapping valve to its closed position. A bypass valve allows fluid communication from the master cylinder to the brake cylinder, but blocks fluid communication in the opposite direction. The trapping valve is fluid pressure balanced such that fluid pressure trapped in the brake cylinder has no effect on the position of the valve.

Abstract: Highway trailer for hauling cargo has air actuated brakes. Valve mounted on the trailer connected in the air line maintains brake-on air pressure in the line while trailer is parked. Valve has locking handle to inhibit trailer theft.

Abstract: A brake control device (16) includes a control member (70) cooperating with a housing (36) to partially define separate brake circuits. The control member is operable by an actuator (68) to close one way communication in the separate brake circuits via valves (86, 100) cooperating therewith.

Abstract: A siloxane-modified polyimide precursor which can be converted into a polyimide having excellent adhesion and moisture resistance is produced by simultaneously polymerizing a diaminosiloxane and a diamine containing no silicon atoms in its molecule with 3,3',4,4'-biphenyltetracarboxylic dianhydride, wherein the diaminosiloxane is used in an amount of 1 to 4 mole % per mole of the total diamino compounds and such that the silicon content in the final reaction product is 0.5 wt % or less. The thus obtained precursor solution is further heat aged to reduce the molecular weight of the precursor so that solution viscosity is decreased to a proper level suitable for coating operation.

Abstract: An anti-theft device, having application for preventing unauthorized operation of a vehicle, includes a moveable lock member biased toward the actuating member for the vehicle's parking brakes. An electric solenoid is energized along with the ignition system to retract the lock member and allow the parking brakes to be released. The preferred device also includes a timer apparatus that requires the parking brakes to be released according to a predetermined timing sequence in order to substantially prevent theft of the vehicle.

Abstract: A brake control device for preventing backward movement of a vehicle on an uphill road during operation of the clutch pedal after release of the brake pedal, the device including a cylinder body having oil passages for connection between the master cylinder and the wheel cylinders of the vehicle. A spring biased hollow plunger is reciprocably received within the cylinder body to provide flow communication between the oil passages in a first position thereof when the brake pedal is actuated, and to prevent the oil from returning from the wheel cylinders in a second position thereof when the clutch pedal is actuated upon release of the brake pedal. An electromagnetic switch-activated system moves the hollow plunger from the first position to the second position when the clutch pedal is actuated.