Abstract: An electronically controllable brake system for a vehicle includes at least one service brake circuit with service brakes and a service brake control module, wherein a service-brake brake pressure can be fed to the service brakes, and the service-brake control module is designed to generate a service-brake control signal as a function of a braking specification. The service-brake brake pressure can be generated as a function of the service-brake control signal and specified to the service brakes, for the implementation of the braking specification via the at least one service brake circuit, under electrical control by the service-brake control module. The electronically controllable brake system further includes a parking brake circuit with spring-loaded brakes, wherein a parking-brake brake pressure can be fed to the spring-loaded brakes, wherein the parking-brake brake pressure can be generated as a function of the braking specification and specified to the spring-loaded brakes.

Abstract: An electronically controllable brake system, in particular electronically controllable pneumatic brake system, for a utility vehicle, in particular utility vehicle, includes: at least one service brake circuit with service brakes and a service brake control module, a service-brake pressure being feedable to the service brakes, the service-brake control module generating a service-brake control signal as a function of a braking specification, the service-brake pressure being generatable as a function of the service-brake control signal and specified to the service brakes, for implementation of the braking specification via the at least one service brake circuit, under electrical control by the service-brake control module; and a parking brake circuit with spring-loaded brakes, a parking-brake brake pressure being feedable to the spring-loaded brakes, the parking-brake brake pressure being generatable as a function of the braking specification and specified to the spring-loaded brakes, in order to implement the

Abstract: A controller on a tractor portion of an articulated vehicle includes an electrical input port adapted to receive an electrical input signal based on a command to unpark a trailer portion of the articulated vehicle and an electronic processor adapted to: receive the electrical input signal from the electrical input port; identify, based on the electrical input signal, when the command to unpark the trailer is received at the electrical input port; and based on the command to unpark the trailer, transmit an electrical output signal to an electrical output port for causing supplemental compressed air to be communicated from the tractor to the trailer for filling an air tank on the trailer using a quick-fill mode.

Abstract: A combined spring brake modulating relay valve integrates the functions of a relay valve and a modulating valve. The housing includes a valve assembly movable in response to air pressure provided to selected ports in the housing. A relay piston selectively communicates with a control port and a primary brake circuit port. A modulating piston includes surfaces selectively pressurized by the primary brake circuit port and a secondary brake circuit port. This modulates the pressure from the delivery port to thereby selectively apply the associated spring brakes if a failure is detected at the primary brake circuit port. The exhaust member selectively controls communication between the supply and delivery ports as necessary.

Abstract: A hybrid brake apparatus for a vehicle includes a hydraulic brake circuit having a first fluid circuit and a second fluid circuit connected to a master cylinder for generating hydraulic pressure in the first and a second fluid circuits, and electrically actuated brake elements controllable as a function of the hydraulic pressure in one or the other of the first and second fluid circuits. The apparatus may include a pedal feel emulator in one of the fluid circuits. The apparatus may also include a booster for amplifying pressure in the fluid circuits, a sensor for determining that the booster has failed, and control elements providing compensation for the failed booster during operation of the electrically actuated brakes while the booster is inoperative.

Abstract: A combined spring brake modulating relay valve integrates the functions of a relay valve and a modulating valve. The housing includes a valve assembly movable in response to air pressure provided to selected ports in the housing. A relay piston selectively communicates with a control port and a primary brake circuit port. A modulating piston includes surfaces selectively pressurized by the primary brake circuit port and a secondary brake circuit port. This modulates the pressure from the delivery port to thereby selectively apply the associated spring brakes if a failure is detected at the primary brake circuit port. The exhaust member selectively controls communication between the supply and delivery ports as necessary.

Abstract: A brake pipe overcharge detection scheme determines when an overcharge situation occurs followed by an interruption of the brake pipe slow pressure reduction process of the brake system assimilation. When the slow pressure reduction process is interrupted, the rail cars may be left in an overcharged state (i.e., the car braking system is charged to a pressure greater than the normal brake pipe pressure). When the brake pipe pressure is set to its normal brake-release value, the pressure of the car braking systems will be greater than the brake pipe pressure. The car braking system will interpret this positive pressure differential as a request to set the car brakes, and will therefore partially apply the car brakes. As a result, additional drag forces will be encountered by the locomotive as it moves the train, which may result in train separations, and overheating of the car brake shoes and wheels may result in cracked wheels and derailments.

Abstract: A dual mode brake system includes a first fluid actuated brake and a second spring actuated fluid released brake configured to spring actuate the first brake in the absence of receiving sufficient fluid pressure at the second brake. A first fluid control circuit variably supplies fluid to the first brake from a source of pressurized fluid. A second fluid control circuit controllably supplies fluid to the second brake from the source of pressurized fluid. The third fluid control circuit controllably supplies fluid to the second brake based on the pressure of the fluid received by the third fluid control circuit from the first fluid control circuit and the pressure of the fluid received by the third fluid control circuit from the second fluid control circuit.

Abstract: A pipe bracket for use in a freight brake control valve on a railway freight vehicle is provided. Four access ports are preferably provided on a first side of the pipe bracket. The freight car piping, including a brake pipe, brake cylinder line, emergency reservoir line and an auxiliary reservoir line are connected to a second side of the pipe bracket. The freight brake control valve further includes an service portion coupled with a third side of the pipe bracket and an emergency portion coupled with a fourth side of the pipe bracket. A plurality of passageways are included within the pipe bracket for providing fluid communication from the freight car piping to the service portion and the emergency portion. The access ports are preferably connected to each of the passageways within the pipe bracket to permit testing of the fluid pressures within the passageways.

Abstract: A brake source select system for selecting one of a plurality of sources of pressurized hydraulic fluid for use in actuating a brake system. The brake source select system (10) includes a primary, secondary and reserve source (20, 22 and 24) of pressurized hydraulic fluid connected in fluid communication respectively to a primary selector valve (32), a secondary selector valve (96) and a reserve selector valve (102). Pressurized hydraulic fluid from the primary source (20) is applied to deselect ports (94 and 100) on the secondary and reserve selector valves, causing those valves to block fluid flow from their associated sources to the brake system, so long as the primary source is operative.

Abstract: A fluid pressure braking system includes pressure sensors in each of the supply and service reservoirs and in the supply line to the trailer. The system includes an air compressor which is loaded and unloaded in response to variations in the pressure level in the supply reservoir by actuation of a solenoid valve by an electronic control module which is responsive to the pressure sensors. The system includes spring brakes which are controlled by the control module through actuation of solenoid valves. The control module is similarly responsive to supply line pressure and the pressure level in the supply line to control a solenoid valve which controls communication through the supply line.

Abstract: An emergency auxiliary pressurizing system for a vehicle braking system includes a portable container having clean high-pressure pneumatic fluid therein and connected by conduit means to the vehicle braking system with the conduit having a pneumatic pressure-reducing valve and a relief valve therein with a switch valve for controlling the connection to the braking system.

Abstract: A protection valve device for a spring parking brake control system has a pipe bracket for connection in a normally pressurized brake pipe, the pipe bracket having connected thereto a protection valve, a charging reset valve and a charging check valve. The protection valve has a chamber at one side of a piston normally pressurized by pressure at a spring parking brake cylinder port and monitors the spring parking brake cylinder pressure to vent fluid from the brake pipe to automatically cause an emergency brake application if such pressure indicates a spring parking brake is applied. The charging reset valve prevents the venting of brake pipe fluid during charging of the brake pipe and spring parking brake system.

Abstract: A railroad air brake system for truck mounted air brakes includes an ABDW valve and auxiliary and emergency reservoirs with pipe connections therebetween. There is a brake pipe and a connection between the brake pipe and the ABDW valve. Truck mounted brake cylinders are located at each truck and a brake cylinder pipe connects the brake cylinders with the ABDW valve. A brake cylinder pressure maintaining valve is connected to the brake pipe, brake cylinder pipe and volume reservoir, as well as to the emergency reservoir. The brake cylinder pressure maintaining valve operates to provide air from the volume reservoir to the brake cylinder pipe and thus the brake cylinders when pressure in the brake cylinder pipe drops below a predetermined level, thus insuring a minimum brake application pressure, regardless of the piston travel of the brake cylinders.

Abstract: A brake actuating system especially useful for applying the brakes of a towed vehicle concurrently with application of braking pressure in the towing vehicle is provided which includes a variable valve means interconnected to the towed vehicle's conventional type hydraulic brakes. The variable valve means controls the pressure applied to the brakes of the towed vehicle in response to variable electric current which is supplied via a variable current source which is interconnected to the brakes of the towing vehicle. Also provided, is a breakaway safety device which upon physical separation of the towed vehicle from the towing vehicle causes hydraulic pressure to be supplied automatically to the hydraulic brakes of the towed vehicle.

Abstract: In a proportioning type control valve device in which a piston valve assemblage is actuated to service position in accordance with a differential between brake pipe and control reservoir pressures on opposite sides of an actuating piston abutment forming a part of the piston valve assemblage, there is provided on the control reservoir side of the piston abutment a bellows device that is normally held under compression by the presence of control reservoir fluid pressure so as to be normally disengaged from the piston and engageable therewith only in the absence of control reservoir pressure to serve as the reference against which reductions in brake pipe pressure are measured to establish the actuating force on the piston abutment. When disengaged from the piston abutment under the influence of the control reservoir pressure, the bellows holds a control spring housed within the bellows under compression.

Abstract: A method and apparatus for effecting double-acting braking for a wheel or a set of wheels permitting compensation of failures of at least one of the braking circuits of a double-acting braking arrangement of the type comprising at least two sets of braking members and two braking circuits for each brake. A single control action achieved by a single actuating member acts simultaneously on the two braking circuits of each of the brakes and in the case of a failure of one of the two braking circuits resulting in a drop in pressure in the failed braking circuit and consequently in a reduction of the braking torque applied by the brake, the remaining circuit has its pressure increased whereby the braking torque is automatically increased by a predetermined value. For this purpose the control action is applied simultaneously to two relays having at least two operating pressure levels, each relay acting on one of the two sets of braking members via the two braking circuits.

Abstract: There is provided a brake system for a vehicle train which includes a tractor and a trailer, a source of high pressure air connected through an air control line to a pneumatic brake with the air control line in the tractor being connected to a fast-acting pressure switch which is activated by a higher pressure and a slow-acting pressure switch which is activated by a lower pressure, and with the fast-acting pressure switch operatively connected to open a valve to supply high pressure air directly to the trailer brake, and with said low pressure switch operatively connected to open the circuit which includes the fast-acting pressure switch.

Abstract: The usual brake cylinder in a conventional freight car brake apparatus is replaced by a novel cylinder that embodies a pair of pistons and a spring of sufficient strength to effect a hand brake application. Conventional brake applications and releases are effected accordingly as the usual brake control valve effects the supply of fluid under pressure to and the release thereof from one of the two pistons which are connected to a common piston rod through which force is transmitted to brake applying brake shoes. The second piston is subjected on one side to the force of the spring and on the other side selectively to brake pipe pressure or pressure in a hand brake release reservoir that is charged from the brake pipe to a higher pressure by an air-driven air booster operated by air from the brake pipe. Thus, the spring is enabled to effect a hand brake application in the absence of fluid under pressure acting on the other side of the second piston.

Abstract: In a vehicle brake system of the type employing both spring and service brake actuators, fluid which is discharged from the spring brake actuators at the initiation of spring brake application is exhausted through selected service brake actuators to effect at least a momentary service brake application. Since spring brakes normally respond relatively slowly as compared to service brakes, service brake application can be effected prior to spring brake application, and brake response time is reduced. The service brake actuators selected to receive exhausted spring brake fluid can be arranged to brake vehicle wheels which have no associated spring brake actuators, whereby emergency braking capability can be provided on vehicle wheels which have no spring brake actuators.

Abstract: A hydraulic modulator which is positioned in a hydraulic brake pressure circuit forming a part of a brake system. The modulator uses power steering pump output fluid under normal conditions. When actuated, the relatively free flowing, low pressure fluid is restricted to build up pressure, causing the modulator to seal the modulating chamber from the supply pressure portion of the rear brake system and then open the rear brake apply conduit to a displacement-increasing modulating chamber. The rate of displacement increase is controlled by a release restriction through which trapped pressurized fluid from the power steering pump is controllably released to the pump reservoir. Upon deactivation of the modulator, the displacement is decreased and rear brake pressure is reapplied.

Abstract: A control system for a spring-applied service brake which can also be used as a parking brake. Pressure from the vehicle hydraulic system is normally used to release the brakes. In the event of a loss of the primary pressure from the hydraulic system, the control system switches automatically to use of secondary pressure from the vehicle compressed air system to release the brakes, while maintaining the ability of the operator to apply the brakes by normal operation of the service and parking brake controls.

Abstract: A multi-axle vehicle brake system includes an air receiving portion, a valve portion, an air storage portion and a brake portion. The air receiving portion receives air from a supply source. The valve portion is connected to the air receiving portion. The storage portion includes a plurality of storage reservoirs connected for receiving air from and communicating air to the valve portion. The brake portion includes service and parking brake actuating chambers mounted on each end of each axle. Certain ones of the service brake actuating chambers are connected for receiving air from one of the storage reservoirs. Others of the service brake actuating chambers are connected for receiving air from another of the storage reservoirs. Each of the parking brake actuating chambers are connected for receiving air from either of the storage reservoirs.

Abstract: A full-power hydraulic braking system comprises two independently-powered service circuits serving separate sets of brakes, a common pedal-actuated dual brake valve controlling operation of said circuits, a spring brake actuator fed from both service circuits through separate lines and, in each of said lines, a pressure responsive protection valve operable in the event of a failure in either service circuit to cut off the spring brake actuator from that service and ensure continued operation of said actuator from the other service circuit.