Abstract: An anti-theft system prevents release of the brakes of a tractor/trailer land vehicle after the manual brake control has been set and after the anti-theft system has been activated. With the anti-theft system activated, any attempt to release the brakes of the vehicle will not be successful and will activate an alarm. The anti-theft system cannot be activated until after the manually operated brake control has been activated. The anti-theft system can be applied to the brakes of either or both the tractor and/or the trailer of the vehicle.

Abstract: An anti-skid control system includes a hydraulic pressure generator for generating hydraulic brake pressure, hydraulic pressure control valves which control the brake hydraulic pressure of the wheel cylinders, wheel speed sensors for detecting the rotational speed of the wheels, and a controller for controlling the hydraulic pressure control valves to decompress or pulse-boost the brake hydraulic pressure in the wheel cylinders based on the output signal of the wheel speed sensors. A brake pedal depression amount detecting device detects the amount of depression of the brake pedal. The controller includes a road surface change judging device for judging that the road surface has shifted from a surface having a low coefficient of friction to a surface having a high coefficient of friction when a continuous run pulse number or a continuous run time of the pulse boost control exceeds a preset value.

Abstract: A conversion block for converting porting from a brake control valve to an electronic control unit so as to allow for electronic control of an air braking system for a train. This conversion block has particular utility for converting 26 porting and is one part of the entire unit that allows access to 26-Type equipment for the purpose of overlaying features with an electronic controlled pneumatic braking system. The conversion block provides access to porting to allow all of the advantages of electronic controlled braking to take effect such as shorter stopping distances, system performance feedback, and continuous recharging features. The present invention also provides access to the necessary porting through hook-ups on the conversion block so as to perform a single car test of the braking equipment within a remote mounting arrangement of a 26-Type braking system.

Abstract: A modular locomotive brake control unit having a manifold with electropneumatic modules each including electropneumatic and pneumatic elements removably mounted thereon each as a unit from the manifold. An electropneumatic equalization reservoir module controls the pressure at the equalization port. A brake pipe module controls brake pipe port pressure in response to the equalization reservoir port. An electropneumatic independent brake module controls pressure at the independent brake port as a locomotive brake signal. An electropneumatic brake signal module provides a pneumatic train brake signal. A controller controls the electropneumatic modules. Each electropneumatic unit includes an electropneumatic supply valve and an electropneumatic exhaust valve and preferably an electropneumatic valve having a first input connected to the supply and exhaust valves.

Abstract: The present invention is a valve system for exhausting air from a brakepipe in a remote portion of a train. It has a pressure containment structure having a cylindrical bore and a piston mounted in the bore. A first valve chamber is on one side of the piston and a second valve chamber on a second side. A diaphragm seals between piston and bore, the diaphragm having an annular fold for permitting movement of the piston within the bore. The system has a first brakepipe pressure passageway for conveying air from the brakepipe to the first valve chamber and a control pressure connection for conveying air from a control chamber to the second valve chamber. A biasing means is provided for urging the piston toward the first valve chamber.

Abstract: In the case of a pressure control device for electropneumatic brake systems of vehicles, particularly utility vehicles, an electromagnetically operable intake valve is provided between a compressed air supply and a consuming device of the brake system. The pressure of the consuming device in the form of a brake cylinder is measured by a pressure sensor and transmitted for the controlled actuating of the intake valve to an electronic control unit. The intake valve is constructed as a valve piston which acts with respect to a valve seat and which, on its approach flow end situated upstream of the valve seat, acts such by means of an intake cross-section which can be changed as a function of the piston stroke, with respect to the housing receiving the valve piston. Thus, according to the values determined by the pressure sensor, a controlled feeding of compressed air is permitted corresponding to the selected contouring.

Abstract: An electropneumatic brake controller of the present invention including a main reservoir, pneumatic brake pipe relay and first and second restrictions connected in series with the main reservoir, the brake pipe relay and brake pipe and first electropneumatic valve connected in parallel to the second restriction. The second restriction is smaller than the first restriction. The first electropneumatic valve is responsive to an electric release signal to cut out the second restriction. When the two restrictions are in series, this is the running mode whereas when the second restriction is cut out, this is the release mode. A control unit controls the electropneumatic valves to produce an overcharge cycle in response to a release brake signal. This cycle includes overcharging the brake pipe, holding the overcharged condition for a fixed period of time and bleeding to a normal release brake pipe pressure.

Abstract: An electronic load weigh device is used with a railcar truck control unit. A relay valve provides to a brake cylinder a pressure proportional to the pressure impinging upon its control port. A first feedback signal is indicative of the pressure at the control port. A second feedback signal is indicative of the load borne by the truck. A pressure switch opens when pressure within a trainline changes to a level indicative of an emergency. By controlling the opening and closing of application and release magnet valves, a controller controls the pressure impinging on the control port and thereby service braking of the wheels of the truck. The load weigh device includes (i) circuitry for electronically compensating for the load during braking and (ii) a mechanism for granting the circuitry exclusive control over the magnet valves. Should such emergency occur, the mechanism responds to such emergency by disconnecting the controller from the magnet valves.

Abstract: A pedal simulator for a vehicle braking system. The pedal simulator is coupled to a brake pedal, and includes an electrical actuator operatively coupled to the brake pedal to selectively exert a force on the brake pedal. A position sensor is provided for generating a position signal indicative of the position of the brake pedal. A force sensor is provided for generating a force signal indicative of the force exerted upon the brake pedal by a driver. An electronic control unit is provided which has programmed therein a desired relationship between the position signal and the force signal. The electronic control unit determines an actual relationship between the position signal and the force signal and compares the actual relationship thus determined with the desired relationship. The electronic control unit controls the electrical actuator to selectively exert a force on the brake pedal to conform the actual relationship to the desired relationship.

Abstract: A method and apparatus for braking a vehicle ensures the correct braking deceleration for every deceleration demand of the driver, without the need for a load sensor. The load condition of the vehicle is represented by a predetermined linking signal, which is stored in an electronic control system. The control system evaluates the deceleration demand of the driver with respect to the actual braking deceleration, and determines the dimensioning of braking energy as a function of the linking signal and the deceleration demand. An actual-deceleration feedback signal is monitored by the control system, in order to enable it to equalize the deceleration demand and the actual vehicle deceleration.

Abstract: An electronic load weigh device is used with a railcar truck control unit. A relay valve provides to a brake cylinder a pressure proportional to the pressure impinging upon its control port. A first feedback signal is indicative of the pressure at the control port. A second feedback signal is indicative of the load borne by the truck. A pressure switch opens when pressure within a trainline changes to a level indicative of an emergency. By controlling the opening and closing of application and release magnet valves, a controller controls the pressure impinging on the control port and thereby service braking of the wheels of the truck. The load weigh device includes (i) circuitry for electronically compensating for the load during braking and (ii) a mechanism for granting the circuitry exclusive control over the magnet valves. Should such emergency occur, the mechanism responds to such emergency by disconnecting the controller from the magnet valves.

Abstract: A train control system is for a train comprising at least first and second train segments including a brake pipe being separated between adjacent train segments. The train control system preferably comprises a first control subsystem for installation in a locomotive of the first train segment and a second control subsystem for installation in a locomotive of the second train segment. The first and second control subsystems communicate with one another for controlling train braking. The system also preferably includes a third control subsystem for installation in a railcar adjacent an end of the first train segment. This third control subsystem preferably includes at least one pressure transducer for sensing brake pipe pressure adjacent the end of the first train segment, and at least one control valve for controlling brake pipe pressure adjacent the end of the first train segment.

Abstract: The invention relates to a safety system having electrical consumers (18a, 18b) which are supplied with electrical energy in normal operation from an electrical energy source (2, 4, 6). The safety system includes an electrical energy store (14a, 14b) which supplies the electrical consumers (18a, 18b) with electrical energy when the instantaneous operating voltage at the energy source (2, 4, 6) drops below a limit value. The rated voltage of the energy store (14a, 14b) is less than the rated voltage of the electrical energy source (2, 4, 6) and the electrical energy store (14a, 14b) is connected to the electrical energy source (2, 4, 6) via a switchover element (16a, 16b) which assumes the function of a diode. The switchover element (16a, 16b) ensures that a switchover from normal operation to an emergency operation takes place automatically and that, during normal operation, the electrical energy store (14a, 14b) is not charged unintentionally by the electrical energy source (6).

Abstract: A manifold (24) is interposed between a pipe bracket (26) and a service valve (30) of a passenger rail car (20) braking system (22) also having a brake application relay valve (32), a primary control reservoir (48), a emergency control reservoir (54), and a main reservoir (44). The manifold includes electronically controlled emergency fill (78), normal fill (80), vent (82), and bypass (84) valves and pneumatically controlled secondary emergency fill (136), secondary normal fill (138), secondary vent (140) and manifold relay (142) valves. Electrical signals are received by the electronically controlled valves (78, 80, 84) which then operate the pneumatically controlled valves (136, 138, 142) to transmit pressure from the control reservoirs (48,54) to a brake application relay valve (32). The brake application relay valve then operates to transmit pressure from a main reservoir (44) to a braking device (36) which brakes the passenger rail car (20).

Abstract: A method and an apparatus for controlling the brake system of a vehicle consisting of at least two component vehicles are proposed, where at least one of these component vehicles is equipped with an electrically controlled brake system. As a function of the actuation of the brake pedal, nominal values for the control of the wheel brakes are formed. An actuating variable for controlling the wheel brakes of the second component vehicle is formed in this first component vehicle. During a braking operation of the complete vehicle, the actuating variable for one component vehicle is modified by a value which, in the event that the brakes of the first component vehicle are not engaged, is determined by adjustment of the actuating variable for the second component vehicle or by adjustment of the nominal values for the wheel brake of the first component vehicle.

Abstract: A brake control system includes a master cylinder for developing a brake fluid pressure in response to brake pedal displacement, wheel cylinders mounted to front and rear wheels and adapted to develop a braking force, an actuator for feeding the brake fluid pressure to the respective wheel cylinders, and a controller adapted to enable the actuator to provide a controlled brake fluid pressure to the respective wheel cylinders. Two switch valves are adapted to normally prevent fluid communication between the master cylinder and the wheel cylinders and in the event of a system failure, permit fluid communication between the master cylinder and the wheel cylinders and prevent fluid communication between the actuator and the wheel cylinders. The switch valves are mounted solely to the wheel cylinders of the front wheels.

Abstract: The present invention relates to a method of operating a hydraulic brake system for automotive vehicles, which includes an anti-lock system (ABS), a brake force booster which is electrically actuatable independently of the driver's wish, and a pressure or deceleration controller which is used to actuate the brake force booster.In order to enhance the quality of ABS control in particular, according to the present invention, a signal (ABSM) indicative of the ABS mode is sent to the pressure or deceleration controller (12) and, upon commencement of ABS control, the instantaneous pressure or deceleration actual value (Pi.sub.ist1, P.sub.ist11, P.sub.ist12) is stored and the brake force booster (2) is actuated so that the pressure or deceleration actual value (P.sub.ist) is maintained constant.

Abstract: An improved method is used to control the pressure in the IAR pipe of a train. The train is typically equipped with an independent brake handle, a control reservoir, an IAR control portion and a computer for controlling the IAR control portion generally according to position of the brake handle. The method involves the steps of: moving the brake handle to a point along its range of motion; and storing in the computer as a setpoint the value desired for the pressure within the IAR pipe. At whichever point the brake handle occupies along its range of motion, there is a particular pressure setpoint corresponding thereto. The method next includes the steps of: directing the computer to modify the actual pressure in the control reservoir to the setpoint thereby also causing the actual IAR pipe pressure to approach the setpoint.

Abstract: In a vehicle having a duty brake and a sustained-action brake (retarder), the actual braking moment produced by the sustained-action brake, as well as the braking command of the driver, are taken into consideration in the electrically controlled adjustment of the duty brake.

Abstract: A brake valve system for a pair of railroad freight cars mechanically connected together in a substantially semi-permanent manner. Each of such pair of freight cars has a brake pipe pneumatically connected together. The brake valve system comprises a brake control valve disposed on a first one of such pair of cars and is pneumatically connected to the brake pipe and to a reservoir disposed on the first one of the pair for applying and releasing brakes disposed on both of the pair of freight cars. A vent valve is disposed on a second one of the freight cars and is pneumatically connected to the brake pipe disposed on the second one of the pair of cars for emergency venting of air from the brake pipes of the pair of cars for emergency application of the brakes of the pair of cars.

Abstract: A fully protective multi-unit railroad freight car for carrying motor vehicles on two or three levels with the lowest level being in a cargo well between a pair of deep side sills. A pair of vehicle-carrying decks are adjustable in height and are counterbalanced against each other during adjustment of their locations. A roof structure is light in weight and constructed of corrugated sheet metal with a self-supporting central portion. The ends of the car are equipped with three-panel folding doors, and a flexible diaphragm closes the space between articulated adjacent car units supported by a shared truck. A modular brake operating system is mounted on the car body. An easily removable brake system module incorporates a compressed air reservoir, a dummy reservoir, a brake control valve, train line and brake cylinder connector lines, and a support structure. The module is easily removable and replaceable, allowing for repair and system testing at a shop.

Abstract: The brake system of a motor vehicle has a wheel-brake actuator for each wheel brake. The wheel-brake actuator, which is controlled by the brake pedal via electric lines, presses the brake linings against the brake disk. A force sensor senses the circumferential force produced by the brake torque. The output signal of the sensor is taken into account as the current value by the control of the wheel-brake actuator when setting the contact force between the brake linings and the brake disk.

Abstract: An brake application solenoid valve arrangement for use in an electronic freight train brake control system on a railway car. Such braking system having a brake pipe normally charged with fluid at a certain pressure, separate compartment auxiliary and emergency reservoirs charged at certain pressures with fluid from the brake pipe and a fluid pressure activated brake cylinder device. Flow of pressurized fluid from the separate auxiliary and emergency reservoirs can be selectively supplied concurrently to the brake cylinder device via the single brake application valve. Backflow check valves between each reservoir and the brake application valve prevent the transfer of pressurized fluid between the reservoirs. The electronic controller can operate the application valve to control the braking and release functions responsive to electrical command signals. A pneumatic control valve can also be operatively incorporated into the brake control system.

Abstract: A modular locomotive brake control unit having a manifold with electropneumatic modules each including electropneumatic and pneumatic elements removably mounted thereon each as a unit from the manifold. An electropneumatic equalization reservoir module controls the pressure at the equalization port. A brake pipe module controls brake pipe port pressure in response to the equalization reservoir port. An electropneumatic independent brake module controls pressure at the independent brake port as a locomotive brake signal. An electropneumatic brake signal module provides a pneumatic train brake signal. A controller controls the electropneumatic modules. Each electropneumatic unit includes an electropneumatic supply valve and an electropneumatic exhaust valve and preferably an electropneumatic valve having a first input connected to the supply and exhaust valves.

Abstract: A locomotive brake control unit includes a manifold having a brake cylinder module for controlling pressure at the brake cylinder port in response to at least train braking signals and first and second ports on the control unit for receiving electropneumatic resetting and non-resetting dynamic brake interlocks respectively to control the train braking signals during dynamic braking, if an interlock module is present in one of the interlock ports.

Abstract: A method and device for regulating the pressure in at least one wheel brake, such that a controller is provided for pressure regulation which forms at least one activation signal magnitude for a pressure-influencing valve arrangement on the basis of, among other things, a stored correlation between the activation signal magnitude and the pressure conditions at the valve arrangement. The method and device allow for the correlation to be adapted to changes to the braking system during operation.

Abstract: In a brake system, when a braking force tends to be insufficient, a first switching valve is set at an interrupting position to render a control chamber in a sealed state, and a pump is actuated to render a supplemental pressure-regulating valve in operation. Thus, MCY pressure supplied to a port of the supplemental pressure-regulating valve is increased to move a supplemental pressure piston downwardly to close the supplemental pressure-regulating valve. The fluid pressure from the pump is supplied to a brake cylinder to increase the braking force. In this manner, a supplemental braking control is provided to ensure the braking even when the braking force tends to be insufficient. The system can be made simple.

Abstract: A controllable mechanical brake release system for controllably releasing a mechanical brake included in a hydrostatic machine is disclosed. In the preferred embodiment the hydrostatic machine is located on an incline. The mechanical brake is included in a mechanical braking system. The hydrostatic machine has the braking system, a hydrostatic propulsion system and a controller. A determined hydraulic pressure associated with the hydrostatic propulsion system is compared with an established trip indicator. A release mechanical brake signal is produced in response to the comparison.

Abstract: A pneumatic railcar braking system for freight or passenger cars, wherein the system is operable as an electronically controlled pneumatic brake system in conjunction with a head end unit in the locomotive or as a conventional pneumatic brake system in conjunction with a pneumatic brake control in the locomotive.

Abstract: A method and apparatus for controlling the braking system of a vehicle having at least two subvehicles. For at least one subvehicle, an electrically controlled braking system is provided, where the driver's braking inputs and control variables resulting in application and/or release of the wheel brakes are taken into account. The corresponding application or release control variables for the second subvehicle are ascertained from the equilibrium of forces of the overall vehicle.

Abstract: An adaptor for connecting brake pipe, brake cylinder, emergency and auxiliary reservoir ports on a standard pipe bracket to an electropneumatic control valve. The adaptor also includes threaded post to mount the electropneumatic valve to the adaptor and fastener apertures to receive fasteners to mount the adaptor to the pipe bracket.

Abstract: Two methods of calibrating Fax machines are disclosed. The first method utilizes a pre-printed calibration chart and a computer connected to the Fax machine to be calibrated. The calibration chart is fed into the Fax machine which sends the resultant data to the computer. This data is analyzed by the computer to determine when the Fax machine started to scan the calibration chart. If the scan process did not occur at an optimum point, the computer sends a correction value back to the Fax machine to cause the Fax machine to begin scanning subsequent documents at an optimum point. In the second method, a calibration chart is printed by the Fax machine and then fed back into the machine. A copy of the scanned calibration chart is made to determine at what point the Fax machine began scanning the chart. If the Fax machine did not begin scanning at an optimum point, a user reads the copy and manually enters a corrective offset in to the Fax machine such that subsequent documents are scanned properly.

Abstract: The railway freight car brake control utilizes sequential pressurization of the brake cylinder from a first auxiliary reservoir and a second auxiliary reservoir during emergency. Embodiments utilize a first supply reservoir larger in volume than a second supply reservoir. The first supply reservoir is used during a service braking mode. The larger first supply reservoir provides improved braking in a service mode, while the sequential utilization of both reservoirs provides an improved level of emergency braking available during a loaded freight car condition.

Abstract: A motor vehicle is prevented from being parked with an unactivated parking brake. This vehicle has a roll-away preventer normally to apply a brake pressure which prevents the motor vehicle from rolling. To prevent unintentional rolling of the vehicle upon failure of the roll-away preventer, deactivation of the drive engine by using the ignition key is prevented when a brake pressure is not present to prevent the motor vehicle from rolling.

Abstract: Electropneumatic brake control valve for control of brakes on a railway vehicle. It has a supply valve and release valve moved by a common displaceable actuator. The supply valve connects an air supply passage to a delivery passage and the release valve connects the delivery passage to an exhaust. The delivery passage is for supplying air to a brake shoe application device. The invention has a feedback space having pressure connection to the delivery passage. A portion of the common displaceable actuator is located within the feedback space, as is a positioner for the common displaceable actuator. The positioner has at least three force and displacement communication portions. The first communicates a first force and a first displacement with the common displaceable actuator. The invention has a pressure defining member which defines pressure by its position. It communicates a second force and a second displacement with the second one of the force and displacement communication portions.

Abstract: In a locomotive braking system, an independent brake control circuit uses second control signal(s) to adjust pressure in a first reservoir. A microprocessor derives the second control signal(s) based on at least a first control signal indicative of brake handle position and first feedback indicative of first reservoir pressure. One pneumatic relay adjusts pressure in a 20 pipe based on first reservoir pressure. An automatic brake control circuit uses third control signal(s) to adjust pressure in a second reservoir. The microprocessor derives the third control signal(s) based on at least second feedback indicative of second reservoir pressure and third feedback indicative of pressure in a 20 pipe. Another pneumatic relay controls pressure in a brake cylinder based on whichever of at least the 20 pipe and the second reservoir delivers a highest pressure. A new system for backup control of the 20 pipe includes the microprocessor and a timer.

Abstract: An electropneumatic brake control valve unit capable of operating at the interface of the emergency brake portion or the service brake portion of a standard brake control valve as a retrofit unit or operating as a stand alone electropneumatic unit. The unit includes electric valves responsive to electrical signals and sensed brake pipe pressures to operate pneumatic valves to control the brake cylinder. The pneumatic valves are also operable independent of the electric control valves so as to allow braking with the electrical controls off or disabled. The unit can operate in combination with a complete brake control valve or with either or none of its emergency and service portions.

Abstract: In an electric vehicle in which regenerative braking is performed in preference to hydraulic braking, an uncomfortable vibration generated due to a sudden variation in the load of a motor, is prevented at the start of the regenerative braking. At the start of the braking, the regenerative braking force is gradually increased from a previously set regenerative initial value to a demanded braking force rather than being increased quickly to the demanded braking force, thereby preventing the generation of the vibration. A deficiency in the braking force during this time is compensated for with the hydraulic braking force. When the demanded braking force exceeds a regenerative acceptable value, the regenerative braking force does not exceed the acceptable value, and a deficiency of braking force thereafter is compensated for with the hydraulic braking force.

Abstract: Method and apparatus for providing a filtered signal which indicates of a flow of fluid to a fluid pressure communication conduit, the flow being dependent upon the pressure of fluid in a chamber. The pressure in the chamber is controlled by one or more pressure adjusting valves. The invention provides for receiving into a data processing module one or more valve signals indicating open states of the pressure adjusting valve or valves, and also a flowrate signal from a flowrate sensor, which represents the real instantaneous flowrate, and it is this signal which needs to be filtered to remove transients. The invention provides for choosing between a first processing mode and a second processing mode for the flowrate signal. The first processing mode is used when the second processing mode is not in effect, and when neither of the valve signals indicates an open valve. The second processing mode is activated a valve signal indicates an open valve.

Abstract: Data processing system for calculating the flowrate of air from a pressurized reservoir to an air pressure communication line. A pressure sensor is connected to the reservoir to provide an analog signal indicating pressure, which is converted into a digital pressure signal. The system also has a sensor connected to pressure ports upstream and downstream of an orifice, located between the reservoir and the air pressure communication line. This provides an analog differential pressure signal which is converted into a digital differential pressure signal, which is processed to obtain a first digital flowrate signal. This is combined with the digital pressure signal to obtain a flowrate correction value, from which a revised flowrate value is obtained. This revised flowrate value may be sent to an operator of the system, to a control system, or to an alarm system.

Abstract: A process and device for starting a motor vehicle having a braking system in which a brake force is at least partially supplied by at least brake energy storage devices. Prior to starting a motor vehicle, the vehicle is initially switched into a non-drivable state in which the vehicle is disabled from movement. A charging state of each brake energy storage device may be checked to ensure an adequate charging state. If the charging state of at least one of the brake energy storage devices is greater than or equal to a predetermined minimum charging state, the vehicle may be switched into a drivable state and, thus, operable by the driver.

Abstract: A plurality of electrical fluid pressure control valves or a plurality of groups each comprised of a plurality of electrical fluid pressure control valves are operatively associated with respective power supply replays. The electrical fluid pressure control valves and a plurality of electrical switch valves are connected in parallel to a power source. A plurality of failure sensors are associated with the respective electrical fluid pressure control valves or the respective groups so as to detect whether an electrical system failure in any one of the electrical fluid pressure control valves or the groups occurs. If occurs, failure control unit is operable to control a corresponding one of the power supply relays so as to cause a corresponding one of the electrical switch valves to selectively connect a corresponding one of the wheel cylinders to a master cylinder.

Abstract: An electronic fail safe circuit ensures that if there is a microprocessor failure during a brake application, this failure does not result in a release of the brakes. This is accomplished by the fail safe circuit forcing the appropriate solenoids to the self-regulating valve's hold state for a certain amount of time. This, in combination with the self regulating valve, accomplishes the desired outcome of a minimum disruption in the brake application and, specifically, prevention of an erroneous brake release. To further enhance the reliability of the system, a dual battery power supply is used. Each battery is tested prior to doing a brake application. Each battery has to pass the test, i.e., each battery individually must have enough charge to complete the brake application, before the brake application is undertaken.

Abstract: A microprocessor controlled valve system is used with an EOT unit on a railcar remote from the locomotive of the train. The system includes a pressure transducer, a microprocessor unit, a valve device, a motor drive and a pneumatic drive. The microprocessor unit receives from the transducer an electrical signal indicative of actual brake pipe pressure and from the locomotive a brake command signal indicative of desired brake pipe pressure. The microprocessor unit issues a drive signal when the brake command signal requires a service brake application and an actuating signal when the brake command signal requires an emergency brake application. The valve device defines an elongated bore, a primary passage, a branch passage, an exhaust passage and an elongated valve body able to move reciprocatingly in the bore according to the operation of the drives. The primary and branch passages communicate with the brake pipe, and all of the passages communicate with the bore.

Abstract: In a microprocessor-controlled electro-pneumatic brake control system for a railway train, pressure in the brake cylinder is maintained despite the loss of pressure in the "20 pipe" brake line, or failure of a key relay valve that controls pressure to that brake line. Feedback signals derived from the "20 pipe" brake line when found to be inappropriate after a predetermined amount of time are substituted for by brake command signals generated by the brake controller.

Abstract: An hydraulic braking system is disclosed which comprises a fluid source and brake actuators, wherein a first master control valve is provided to supply substantially equal pressures to all brake actuators and additional control valves are provided to regulate pressures applied to respective ones of said brake actuators. The first control valve and the additional control valves are provided in series between the fluid source and the brake actuators so that operation of the master control valve allows equal hydraulic pressures to be applied to each actuator while the additional control valves allow individual brake regulation and in an emergency operation of the master control valve allows for automatic operation of all the actuators.

Abstract: An EOT unit on a railcar is equipped with a microprocessor controlled regulating valve system to control pressure within the brake pipe. The system includes a microprocessor unit, a pressure transducer, a regulating valve device and an electropneumatic control mechanism. The microprocessor receives from the transducer an electrical signal indicative of actual brake pipe pressure and from the locomotive a brake command signal indicative of desired brake pipe pressure. The microprocessor issues electrical control signals to the mechanism when the brake command signal requires either a service brake application or an emergency brake application. The regulating valve device defines a primary passage, a branch passage, an exhaust passage, and an elongated valve bore in which a diaphragm operated piston is located above an elongated valve stem. The valve stem features two valves with the first located between the primary and exhaust passages and the second between the exhaust and branch passages.

Abstract: The invention relates to a method for providing controlled braking of a motor vehicle and a brake system for carrying out the method. The brake system includes a central unit and brake actuators for each wheel of the motor vehicle. The brake actuators are connected to the central unit. In the central unit, a relative braking-force distribution key is computed at time intervals and is transmitted to the brake actuators. With a braking operation, the absolute braking force for the braking operation is computed in each brake actuator from the corresponding component of the relative braking-force distribution key.

Abstract: A vehicle brake includes a compact module having an inlet port connected to the return-to-sump line of a hydraulic operating system on the vehicle. The module includes a path to a filter mounted on the module for filtering the operating system fluid and a poppet valve for bypassing a clogged filter. Passages in the module direct most of the return line fluid through a poppet valve which develops a source of back pressure substantially lower that system operating pressure in a cavity in the module and returns the fluid to an outlet connected to sump. A portion of the fluid in the cavity is communicated via a charge port in the module to a hydrostatic system to replenish leakage and shuttle flow in the hydrostatic system and to prevent cavitation. The source of back pressure in the module is selectively connected to spring-applied, pressure-released brakes through a four-way solenoid valve housed by the module.

Abstract: A control method for a manual back-up electro-hydraulic braking system in which the rear service brakes of the vehicle are intentionally operated in a manual back-up mode under specified non-failure operating conditions to conserve electrical energy. The manual back-up mode for the rear service brakes is initiated if braking is commenced while the vehicle speed is below a near-zero threshold speed. If braking is commenced above the threshold speed, the manual back-up mode for the rear service brakes is initiated when the vehicle speed falls below the threshold and the pressure command for the rear brakes has been substantially constant for at least a predetermined time. In this case, the rear manual back-up mode is initiated by reducing the rear brake pressure command to the rear boost units at a controlled rate until the rear brake pressure reaches the manually developed pressure, and then entering the manual back-up mode.