Abstract: An access plate mounted between the pipe bracket portion and either the service portion or the emergency portion of a railway freight brake control valve. Passageways are provided through the access plate, each passageway terminating in a respective access port along an end of the access plate. Openings extend through opposed sides of the access plate, intersecting respective access plate passageways. The openings on each side are sized and positioned to sealingly align with openings of the pipe bracket portion and either the emergency portion or the service portion. The openings on the pipe bracket portion, emergency portion and service portion connect to passageways communicating to the brake pipe, the brake cylinder retaining valve, the brake cylinder, the emergency reservoir and the auxiliary reservoir. A housing may be attached to the pipe bracket portion to connect to the access ports, such housing preferably having a valve means for preventing the escape of fluid pressure therefrom.

Abstract: A full function skid control valve assembly for use in an air brake system which provides for brake control utilizing a compact single assembly. The system provides for the maintenance of certain minimum operating pressures so that, when the air pressure within the vehicle brake system falls below predetermined levels, the valve assembly automatically partially or entirely exhausts the air pressure sometimes causing the spring parking brakes to engage. Once the air pressure within the brake system returns to predetermined levels, the valve assembly will allow a reservoir to be charged and the spring brakes to be deactuated. During operation, the assembly provides control of the service brakes while preventing undesired skid conditions.

Abstract: An operating brake valve for an electrically and pneumatically actuated braking system in a motor vehicle has a movable thrust piece (2) arranged within a housing (1) and a balance piston (4) actuated via a graduated spring (3), whereby a combined inlet/exhaust valve (7, 9, 10) is arranged downstream of the balanced piston. A position sensor (20) is provided which can be actuated via a push rod (17) connected to the thrust piece (2). A stop valve (29) is located in the connecting line (26) to the reservoir (12) or in the control line (15) coming from the balance chamber, whereby an electrically controlled solenoid valve (40) is provided for actuating the stop valve and, in the nonexcited state, for relieving the valve body of the stop valve (29) opposite to its closing direction.

Abstract: A fluid pressure responsive valve includes a valve member mounted on a guide pin slidably carried by a piston. A valve guide is engaged by one side of the valve element, and the piston engages the opposite side. The piston controls the valve member. The valve guide acts as a stop for a check valve element that controls communication through the inlet port, and also guides and supports the spring controlling the check valve element.

Abstract: Control valve assemblies for regulating the parking/emergency spring brakes of a tractor trailer air brake system which include valve components for insuring that the spring brakes are not released until pressurization of the system's service reservoir is achieved and which components are operable to exhaust the spring brakes to atmosphere upon the failure of the supply pressures within the system to thereby automatically apply the spring brakes. In one embodiment, the valve components permit pressure to be supplied to release the spring brakes under circumstances when it is not possible to pressurize the service reservoir.

Abstract: A valve assembly for use in conjunction with spring applied, air release parking brakes of the character found in heavy-duty truck-trailers which, in a single valve housing provides system pressure protection, prevents compounding application of the brakes and performs the parking brake release function in an expedicious and highly reliable manner.

Abstract: A relay valve for a fluid pressure braking system includes a relay piston and a load piston which is responsive to the pressure at the inlet port of the relay valve to exert a biasing force on the relay piston loading the latter against the inlet/exhaust valve. The biasing force is opposed by fluid pressure at the inlet port acting across the effective area of the inlet/exhaust valve. The biasing force is greater than the spring force holding the inlet/exhaust valve closed, so that the valve responds immediately to pressure signals transmitted through the control port of the relay valve.

Abstract: Within a single envelope or housing, this full-function valve integrates all of the emergency and service requirements of a tandem axle air brake system for heavy duty truck semi-trailers, thereby decreasing complexity and cost and enhancing safety, reliability and operating capability while also satisfying applicable Federal Regulations. The housing encloses a spring brake valve module, a relay valve module and a biased one-way pressure protection valve, all interconnected to meet operating requirements, while preventing non-intentional spring brake engagement, foreclosing trailer movement without adequate service brake capability and optionally providing anti-compounding protection.

Abstract: The preferred embodiment of the invention is a brake system comprised of a primary source of air under pressure, and independent secondary source of air under pressure, a primary relay, a secondary relay valve, a device for actuating the service brakes, a device for actuating the park brakes and a control device, and a plurality of brake assemblies. The primary relay receives air under pressure only from the primary source and the secondary relay receives air under pressure only from the secondary source, but the other components are so arranges as to achieve complete system redundancy in operation at the source level, the brake level, the hose level, and at the actuation level.

Abstract: An air brake control system for use in truck trailers, including tandem trailers, having at each axle compressed-air spring brakes and service brakes with each trailer being coupled to receive compressed air through an emergency (supply) gladhand and to receive service brake signals through a service (control) gladhand and which includes an integrated brake valve system for each trailer within a common valve housing.

Abstract: Method and apparatus for compensating for transient effects in pneumatically operated air brake system for a railway vehicle. A look up table or experimentally determined second order correction values is stored in a memory. Based on the magnitude of a previous application of the brakes, a correction value is selected from the look up table having a magnitude to compensate for transient errors in the system. The correction value is then diminished by fixed decrements at fixed intervals. Upon a subsequent application of the brakes, the diminished correction value is used to adjust the pressure communicated to braking mechanisms located on the train cars.

Abstract: A pressurized fluid control module is provided for a tractor-trailer brake system to effect the appropriate braking function.

Abstract: A trailer braking system for a towing vehicle has a trailer braking valve (26) is fed with a pressurized air supply which is modulated by the opening of the valve, as controlled by a first control pressure regulated by a trailer braking controller (24) in accordance with braking demand signals, to produce a trailer braking pressure. In order that a trailer braking pressure may be generated even if the above trailer braking valve control fails, the valve is supplied with a second control pressure independently of the first, and which is also capable of operating the trailer braking valve (26). In a preferred embodiment, the second control pressure is supplied from a braking line of the towing vehicle, such that the "back up" control pressure is a function of the towing vehicle braking.

Abstract: An electrically-controlled motor vehicle brake system, which responds to fluid pressure supplied from a common source. The system includes an electronic control system to process information and issue brake commands. A brake cylinder, to apply and release brake pressure on each respective wheel brake, receives pressure from at least one solenoid valve, connected to receive pressure from the source. The pressure is communicated to the brake cylinder of each respective wheel brake upon receipt of a control signal from the control system. A brake power selector includes both a pedal-operated brake valve, connected on an input side to receive pressure from the source, and connected on an output side to a ventilation portion of the solenoid valve for modulating the brake pressure, and an electrical frequency selector is connected to provide an input signal to the electronic control system upon actuation by an operator of such vehicle during a brake application.

Abstract: A braking system for railroad freight trains and a novel relay valve for use in the system are disclosed. The relay valve permits the brake system to be configured so that the requirement for expensive control valves is minimized. The novel relay valve is interposed between the control valve and a number of brake cylinders. Upon a signal from the control valve, the relay valve delivers brake air to the cylinders from a pre-charged reservoir or other source. The novel relay valve includes primary and secondary flow valves to cause air to be delivered to the brakes in a controlled manner. An exhaust valve arrangement in the relay valve permits the brakes to be released.

Abstract: An integrated pressure exhaust valve and pneumatic coupling is used on a truck trailer for bringing air brake pressure from a tractor to the truck trailer. A gladhand coupling moiety is used for quick connection with an identical coupling moiety on the air pressure hose from the tractor. A check valve mechanism is incorporated in the body of the trailer coupling moiety for permitting air flow to the brakes when pressure from the tractor is greater than pressure in the trailer brake lines, and for permitting air flow from the brake lines to the atmosphere when pressure from the tractor is decreased. The integrated pressure exhaust valve and pneumatic coupling moiety can be mounted on the front of the trailer where it is found that pressure exhaust valve placement is most effective.

Abstract: A relay valve device which is actuated by the presence of a control signal pressure to a higher pressure supply into a consumer circuit than when the control signal pressure is not present. The relay valve device includes a first control surface and a second control surface, and includes a shut-off device disposed in the feed line of the control pressure to the second control surface. The shut-off device is opened when the control signal pressure is present and is closed when the control signal pressure is not present, and also causes the second control surface to be connected with atmosphere.

Abstract: A parking brake control device has a differential area shuttle valve which has an outlet connected to a brake actuator and a larger area of a poppet directed to an inlet connected to a control valve for applying a parking brake pressure and a smaller area of the poppet facing a second inlet connected to a service brake pressure such that in the event of simultaneous application of parking brake and service brake pressures the shuttle valve will be moved to close off the inlet to the service brake pressure while introducing park brake pressure to the brake cylinder.

Abstract: A pressure-medium brake system, which comprises multiple circuits and has associated with each brake cylinder or group of brake cylinders relay valves which are controllable by a control medium. Depending on the number of brake circuits and the kind of the respective control medium, the relay valves are provided with several, possibly different, control chambers. This results in an overlapping control which insures that each relay valve can even be controlled in the event that a control circuit has been lost. The brake system is preferably used in utility vehicles equipped with air brakes.

Abstract: A brake control system for a railway vehicle having separately operated independent and automatic brake controls for controlling brake pressure via a double check valve and a multi-piston relay valve, wherein an adjustable regulating valve is set to exhaust the independent brake control pressure acting on one piston of the multi-piston relay valve when the relay valve delivery pressure (brake cylinder pressure) exceeds a predetermined value, to thereby limit the maximum brake cylinder pressure attainable from the combined independent and automatic brake controls unless the automatic brake pressure exceeds that predetermined value.

Abstract: The invention provides a parking brake system for automotive or delivery type vehicles, golf carts, etc. that applies the emergency or parking brake automatically after the engine is turned off or if other pre-determined conditions are met, such as, but not limited to, the driver leaving the seat or hydraulic brake failure.Several other pre-determined conditions can be integrated into the system to stop or retard the release of the parking brake such as door not properly closed, seat belt not properly in use, etc.An electronic time delay pack can be incorporated with a seat switch to allow for driver bounce on rough terrain.A one-way check valve is connected between the intake manifold and the actuator. This check valve opens fully when the engine is running and allows the vacuum to compress the actuator and release the parking brake. The check valve closes when the engine is turned off and the check valve retards the sudden return of atmospheric pressure to the actuator, thus preventing lock-up at speed.

Abstract: An electro-pneumatic brake system with a pressure control valve switched ahead of the brake cylinders is proposed, which connects the brake cylinders either with outside air or with a storage tank. The pressure control valve is directly operable by an electro-magnet or, in the case of its loss, by an operating piston and is formed as a double-seat valve with large flow-through diameters. It can be combined with stop valves in order to make possible a multichannel pressure control. The compressed brake system is intended for use in motor vehicles, especially in utility vehicles.

Abstract: In an air pressure proportioning variable load valve for a vehicle compressed air braking system the operating mechanism for a self-lapping valve assembly includes a fluid pressure responsive piston arrangement which is operable above a given fluid pressure (PI) to adjust the position of the self-lapping valve arrangement relative to a variable area pressure responsive assembly whereby the rising output pressure corresponds initially to rising input port pressure up to the given pressure (P1) followed by progressive adjustment before proportioning by virtue of relative areas of the variable area assembly.

Abstract: A dual brake valve assembly for use in fluid pressure-operated vehicle braking systems embodying two independent braking circuits comprises a housing provided with sets of primary and secondary ports associated respectively with the two braking circuits and each consisting of a supply port for connection to a source of fluid under pressure and a delivery port for connection to a brake actuator, an exhaust, and two co-axial primary and secondary valves which are operative, when actuated, to isolate the delivery ports from the exhaust and connect them to the respective supply ports. A primary piston operates the primary valve directly and acts through the primary valve and a secondary piston to operate the secondary valve. The secondary piston is provided with passages through which the respective supply and delivery ports of each set are placed in communication when the respective primary and secondary valves are operated.

Abstract: This invention relates to a brake pressure control valve and, more particularly, to a tractor-trailer control valve which includes a differential pressure surface relay piston that on one hand is acted upon by the control pressure from a control chamber and on the other hand by modulated pressure from a working chamber. The brake pressure control valve includes a first combination inlet and outlet valve which works together with the relay piston whereby the working chamber can be pressurized and vented via the first inlet and outlet valves. An auxiliary control chamber which is defined by the differential surfaces of the relay piston is connectable either to the working chamber or to the control chamber via second inlet and outlet valves. The pressure control surface of the relay piston is located opposite the working surface that is acted upon by control pressure in the control chamber. The pressure control surface can be enlarged by the pressure surface of the auxiliary control chamber.

Abstract: The invention relates to an improvement in a valve for a tractor air brake system for changing the pressure delivered to air brakes on a tractor rear axle during "bob tail" operation and particularly to a valve wherein the ratio is changed by communication of control pressure to a second control surface in accordance with the presence of trailer emergency pressure. The improved ratio control valve enables fluid pressure communication to both control surfaces of the ratio valve until a predetermined input pressure is reached so that the "crack-open" input pressure for both the "trailer-connected" and the "bob tail" modes of operation will be the same. Further in accordance with the invention, a blend-back valve is provided which is biased by the available fluid pressure in the tractor reservoir tank so that the maximum available tractor reservoir pressure may always be applied to the tractor rear axle brakes even when the trailer is operating in the "bob tail" mode.

Abstract: A pressure reducing valve is constricted with a stepped piston affording a pressure responsive area on one side responsive to the pressure at an output port and a smaller pressure responsive area on the other side, contained between the seals of the two piston diameters and responsive to the pressure at an input port, the piston carrying a self lapping valve assembly connected via a passage to the smaller area for controlling the pressure at the output port in relation to that at the input port.

Abstract: A valve for a tractor air brake system for changing the pressure delivered to air brakes on the rear axle depending on whether the trailor is attached or whether the tractor is operating in the "bob tail" mode. According to the invention, a rear axle ratio control valve provides an automatic selection of input to output ratio in accordance with the presence or absence of trailor emergency pressure. In the ratio control valve, service brake control pressure always acts against a first effective area of a piston for providing a first ratio of input to output. A second effective area of the piston receives pressure with the presence of the trailer emergency so that the ratio of pressure delivered from the valve will be changed. Further in accordance with the invention, a blend-back valve operates at a higher, predetermined pressure range, even when the pressure communication is closed by the absence of the emergency pressure to enable the valve to deliver the maximum pressure at high input pressure.

Abstract: An air brake system for a vehicle having front service and parking brakes, and rear service and parking brakes, includes separate front service, rear service and parking air systems. In the event of a failure in either service air system, normal operation of the service brake control will automatically operate the parking brakes associated with the failed service brakes.

Abstract: A control valve having relay and proportioning pistons has an intermediate piston which controls air pressure access to a blind flow chamber. At a relatively low value of control air pressure, the intermediate piston is shuttled into a position which closes and traps the existing value of control air pressure in the blind flow chamber. The trapped constant value of air pressure in the blind flow chamber operates on a larger area piston whose force is added to the forces derived from further increases in control air pressure to provide a first region of output air pressure having incremental increases smaller than the input. When the input air pressure reaches a certain value, a second region of output air pressure is reached where further increases in input air pressure cause metered addition to the air pressure in the blind flow chamber and thus produces incremental output increases greater than incremental input increases.

Abstract: An electrically actuated relay valve or adaptive braking modulator for a vehicle fluid pressure braking system includes a housing having a fluid pressure inlet, a pair of vents communicating with the ambient atmosphere, and a brake application effecting mechanism. The inlet communicates with a chamber defined within the modulator, amd this chamber is in turn communicated to the brake application effecting mechanism. An electrically actuated valve controls communication from the inlet into the chamber, and is shiftable from a first condition permitting substantially uninhibited communication from the inlet to the chamber to a second condition communicating the chamber to one of the vents when an incipient skidding condition is detected. A pressure differential responsive valve element controls communication between the chamber, the brake application effecting mechanism, and the other vent.

Abstract: Multiway pneumatic valve comprising supply inlet and a plurality of separate outlets connected to the inlet by separate circuits.Third and fourth circuits are respectively in series with first and second circuits. Calibrated diaphragms are exposed at their periphery to the supply pressure and in their central portion to the pressure in the tank which they control. If a tank fails, the corresponding diaphragm isolates this tank. Flaps each comprising a loose strip isolate the whole tank system in the case of a supply failure.The valve can be applied to any gas distribution problem and more particularly to pneumatic brake circuits.

Abstract: Disclosed is a positive-pressure air brake system for a highway tractor and trailer combination in which the conventional mode of tractor-to-trailer control line connection is avoided and supplanted by a sub-system in which the trailer control line pressures are developed from the tractor supply line rather than its control line through a valve assembly which responds to tractor control line pressures in relay fashion to dispense brake-operating pressures to the control line of the trailer. This valve assembly is further disclosed as having mechanism for sensing differences in the pressures of the tractor and the trailer control lines, e.g., a difference resulting from the rupture of the trailer control line, to close off the air supply to the trailer and thus bring about emergency application of the trailer brakes without any material loss of pressure in either the supply or control lines of the tractor brake system.

Abstract: A tractor protection valve for use in the air brake system of a tractor-trailer vehicle combination to protect and maintain the braking system of the tractor includes a housing having tractor supply and control ports, trailer supply and control ports, and a pair of exhaust ports. The housing has a chamber with the exhaust ports being positioned at opposite ends of the chamber. First and second spring-biased pistons are axially movable in the chamber to control communication between the ports.

Abstract: A brake control valve device for a use with tandem or tractor-trailer type vehicles employing dual brake systems with the source of operating fluid supplied at a relatively higher pressure than that required for operating the brakes. The respective valve elements of the valve device for controlling supply and exhaust of operating pressure to and from the respective brake circuits are mechanically actuated through a manually actuated pressure graduating piston (for the first brake circuit) and a fluid pressure responsive relay piston (for the second brake circuit), the dimensions of the relay piston being limited to less than normal for conserving space, but being provided with an adjusting mechanism for adjusting the fluid pressure responsive operating range thereof for compensating for the smaller dimension and synchronizing the relative serial operation of the dual brake circuits.

Abstract: A vehicle with at least front and rear sets of brakes includes a pair of brake control valves for normally communicating a source of pressurized fluid to individually control the brakes, a counterpart pair of inversion valves for normally supplying air piloting pressure to the brake control valves, and a retarding valve system communicating a source of pressurized air at one value to one inversion valve and at a proportionately lower pressure to the other inversion valve so that one set of brakes absorbs less energy than the other set of brakes in a retarding mode. The brake control system also includes a service brake valve actuatable to delivery equal pressure to both inversion valves for absorbing equal energy in both sets of brakes in an overriding manner with respect to the retarding valve system.

Abstract: A fluid pressure braking system for an articulated vehicle. The system includes valving which senses a failure in the brake service line connection between the tractor and trailer portions of the vehicle. If a failure in the service line connection is detected, the valving closes communication between the tractor and trailer portions of the vehicle and causes actuation of the trailer emergency brakes. When the brakes of the vehicle are released, the valving automatically resets itself to release the trailer emergency brakes.