Abstract: An automatic retainer valve includes a body defining a piston passageway and at least one piston positioned within the piston passageway, a brake pipe and reference volume in fluid communication with a first end of the valve, a brake cylinder in fluid communication with a second end of the valve, and an exhaust port defined in the body and positioned between the first and second ends of the valve. Pressurized fluid may be vented from the brake cylinder via the exhaust port upon a brake cylinder pressure exceeding a reference volume pressure. The brake cylinder pressure may push the at least one piston towards the first end of the valve until the brake cylinder pressure equalizes with the reference volume pressure.

Abstract: A system reliably communicates brake commands from a master controller on a lead locomotive to the brake equipment on each rail vehicle of a freight train. The system includes a mechanism for detecting whether the brake commands are being successfully communicated over a communications channel that is normally used to convey such commands from the master controller to the brake equipment on each rail vehicle. The system also includes on each rail vehicle a mechanism for communicating the brake commands that is independent of the communications channel. The mechanism for communicating conveys the brake commands from the lead locomotive to the rail vehicles only when the mechanism for detecting determines that communication over the communications channel has failed. The system further includes on each rail vehicle a mechanism for receiving the brake commands from the lead locomotive via the mechanism for communicating.

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 pilot mechanism for improving operation of various functions of the pneumatic brake of a train. The mechanism includes solenoid valves, controllable by either a radio/battery mode of operation or a train wire system mode of operation. The solenoid valves can be interposed in various passages in fluid communication with passages of a conventional ABD control valve, as modified to enable operation of the invention, to permit substantially immediate venting of air in those passages to atmosphere.

Abstract: A microprocessor-based, electropneumatic brake control system for a locomotive having a pneumatic back-up control valve which includes a quick release valve for maintaining a release condition of the control valve during dynamic braking. An arrangement is provided to prevent the control valve from applying during a trainline-initiated emergency application prior to the dynamic brake becoming ineffective following dynamic brake knockout, in order to avoid the possibility of a wheel skid.

Abstract: A quick service limiting valve device for a freight brake control valve employing a primary valve in a fluid flow path via which brake pipe air is connected to the brake cylinder during a secondary phase of quick service to propagate the brake pipe reduction signal until the brake cylinder pressure acting on the limiting valve control piston effects closure of the primary valve to terminate the quick service flow of brake pipe air to the brake cylinder when a predetermined brake cylinder limit pressure is realized. A secondary valve is arranged to interrupt the brake pipe to brake cylinder flow path downstream of the primary valve in the event leakage at the primary valve causes the pressure acting on the quick service limiting valve control piston to exceed the predetermined limit pressure.

Abstract: A valve assembly for use with spring-set air-release vehicle parking brakes comprises a particular arrangement of conventional components providing desired spring brake operational characteristics heretofore requiring costly, complex specially-designed units. The valve assembly typically employs a plurality of interconnected check valves in combination with pressure protection and quick release valves to provide the desired characteristics. These include a system whereby at startup pressurized air from the tractor fills the trailer reservoir tanks and the spring brake chambers simultaneously. The valve assembly also assures that if during tractor-trailer operation the supply air from the tractor is severed or otherwise lost, service brake air in the trailer reservoir tanks is retained at a sufficient pressure to provide adequate service brake operation.

Abstract: A piston valve assembly for a freight brake control valve device in which axial displacement of a piston member is provided relative to its slide valve in response to slide valve friction creating excessive resistance to movement of the piston assembly from lap to release position. This relative movement between the piston member and slide valve causes a graduating valve that is carried fast with the piston member to open a release insuring passage in the slide valve and thereby exhaust auxiliary reservoir pressure from one side of the piston member. Accordingly, a relatively high pressure differential is created across the piston member to quickly overcome the slide valve resistance and assure prompt movement of the piston valve assembly and thereby obtain brake release without delay.

Abstract: An improved freight brake emergency valve device having improved stability against undesired emergency brake applications, without loss of emergency sensitivity. Flow regulator in the form of a valve and choke combination or a choke itself is employed between the quick action chamber and the chamber normally subject to quick action chamber pressure on the side of the emergency piston opposite brake pipe pressure. This has the effect of momentarily reducing the volume of quick action chamber pressure in order to achieve an intensified pressure reduction in response to initial deflection of the piston member sufficient to counteract a momentary, spurious brake pipe pressure fluctuation.

Abstract: An improved freight brake emergency valve device providing improved stability against undesired emergency brake applications without degradation of emergency sensitivity. This is achieved, in one aspect of the invention, by introducing a spring force on the emergency piston as the piston approaches emergency position to thereby retard the piston momentum suffiently to allow a random brake pipe pressure fluctuation to dissipate. In another aspect of the invention, a choke and check valve are arranged to create a dashpot effect to retard piston momentum resulting from a random brake pipe pressure fluctuation.

Abstract: The acceleration apparatus for connection with a pilot operated compressed-air brake comprises a tap-off valve which vents the main air line or conduit at the beginning of the braking procedure. This tap-off valve is opened by an actuator or actuating mechanism via a disengageable intermediary member. By employing a rotationally symmetrical plunger or push rod which is pivoted into the operative position thereof by a spring and deflected by an interrupter piston, the construction of the disengageable intermediary member can be substantially simplified. The plunger or push rod possesses at the one end thereof a cam or pin and a substantially conical surface.

Abstract: A modulation valve device for governing pressure in a brake pipe has coaxial accelerating and releasing valves provided wherein accelerated application and release pistons are dovetailed together to reduce the size and the weight of the modulating device.

Abstract: An improved freight brake emergency valve providing improved stability against undesired emergency brake applications without degradation of emergency sensitiveity by increasing the "breathing" range of travel of the emergency piston to allow a momentary random brake pipe pressure fluctuation to dissipate, and by providing a volumetric chamber between the quick action chamber "breather" port connection at the slide valve/seat interface and the "breather" choke in order to obtain a momentary fast reduction of quick action chamber pressure to counteract a brake pipe pressure fluctuation during pressure equalization between the quick action chamber and the added volumetric chamber.

Abstract: A freight brake control valve device having an improved quick service function achieved by providing an additional volume upstream of the quick service limiting valve with which the brake pipe fluid under pressure is equalized during the second stage of quick service to achieve an intensified secondary quick service reduction of brake pipe pressure. Further, a smooth and continuous local reduction of brake pipe pressure occurs without any time lag at the time of transition from preliminary to secondary stage quick service. In a first embodiment of the invention, an exhaust passage separate from the brake cylinder exhaust passage is provided to assure venting of this additional volume in the event the brake cylinder retainer valve is set up. In a second embodiment, the additional volume is vented via the brake cylinder exhaust passage.

Abstract: A freight brake control valve device having an improved quick service function achieved by utilizing a common quick service volume during secondary quick service as well as preliminary quick service, in order to achieve an intensified secondary quick service reduction of brake pipe pressure. Further, a continuing local reduction of break pipe pressure is obtained without any time lag during transition from preliminary to secondary stage quick service. In a first embodiment of the invention, an exhaust passage separate from the brake cylinder exhaust passage is provided to assure venting of the preliminary quick service volume in the event the brake cylinder retainer valve is set up. In a second embodiment, the additional volume is vented via the brake cylinder exhaust passage.

Abstract: A freight brake control valve device in which the emergency piston is arranged to operate a pair of slide valves having lost motion therebetween to provide a continuous, local reduction in the brake pipe pressure in response to initial actuation of the emergency piston when a service rate of brake pipe pressure reduction is made, in order to quickly propagate a brake pipe pressure reduction wave along the train and accordingly provide an accelerated application of the train brakes. This accelerated application function in response to a service rate of brake pipe pressure reduction is achieved during movement of the emergency piston toward emergency position, during which movement, the quick-action chamber "breathing" function also occurs, the latter being presently incorporated in the emergency piston slide valve to stabilize the emergency piston following initial actuation thereof, so as to prevent further actuation of the emergency piston to emergency position.

Abstract: A freight brake control valve device in which the emergency piston slide valve is arranged to provide continuous, periodic, local reductions in the brake pipe pressure in response to initial actuation of the emergency piston when a service rate of brake pipe pressure reduction is made, in order to quickly propagate a brake pipe pressure reduction wave along the train and accordingly provide an accelerated application of the train brakes. This accelerated application function in response to a service rate of brake pipe pressure reduction is achieved concurrently with the quick action chamber "breathing" function, the latter being presently incorporated in the emergency piston slide valve to stabilize the emergency piston following initial actuation thereof, so as to prevent further actuation of the emergency piston to emergency position.

Abstract: A pulsating brake accelerating device for an indirectly operating air brake for rail vehicles has a pulsator (12), which is attached to the brake pipe (BP) via a jet (23). The pulsator (12) forms a mixed pressure from two pressures. One of the pressures is formed by the pressure of the brake pipe (BP) via a jet (23) and the other pressure is formed by pressure from a control chamber (QAC) via another jet. At every braking level the pulsator (12) drains mixed pressure pulses off into the atmosphere, while at the same time the brake pipe pressure and the control chamber pressure is lowered via the mixed pressure pulsator (12). The mixed pressure can consist of two valves (14, 15). The control element (4) of the brake accelerator unit can be the emergency brake piston, which monitors several valves, one of which is the pulsator-excitation valve (8).

Abstract: Brake control valve system for rail vehicle air brake, comprising an emergency brake piston (7) having a first piston chamber (9) loaded by the quick action chamber with a much greater volume than its second piston chamber (8) loaded by the brake line. The effective pressure surfaces of the service brake piston and emergency brake piston are substantially identical. The emergency brake piston controls a first quick action exhaust valve (15) for venting smaller amounts of quick action air per unit of time, as well as a valve device (14) containing a second quick action exhaust for venting larger amounts of quick action air. Valve device (14) is pneumatically connected to the control piston (19) of a high pressure/emergency exhaust valve system (16) which operates only upon emergency braking. Piston (19) contains a nozzle (22) through which pressure remaining in the quick action chamber (10) during emergency braking is evacuated in a predetermined time.

Abstract: A control valve arrangement adapted to produce and maintain a pilot signal comprises a number of standard modules. The basic element has two standard modules, each of which includes a diaphragm-controlled on-off valve. An input signal is applied to a first valve against a reference pressure such that when the valve is on, a signal is generated and held as a pilot pressure. A second valve responds to a fall in input signal pressure to cancel out pilot pressure. The two valves together constitute a bistable operator. A particular use of this operator is in a railway braking system in which the first valve is used as an application valve and the second valve is used as a release valve. A third module may be used as a pilot pressure-maintaining valve. The pneumatically-operated diaphragm assembly shown in FIG. 1, comprises three modules, 1, 2 and 3. Module 1 is the brake application module, module 2 is the release module and module 3 is an optional pilot pressure-maintaining module.

Abstract: A pulsating brake accelerating device for an indirectly operating air brake for rail vehicles has a pulsator (12), which is attached to the brake pipe (BP) via a jet (23). The pulsator (12) forms a mixed pressure from two pressures. One of the pressures is formed by the pressure of the brake pipe (BP) via a jet (23) and the other pressure is formed by pressure from a control chamber (QAC) via another jet. At every braking level the pulsator (12) drains mixed pressure pulses off into the atmosphere, while at the same time the brake pipe pressure and the control chamber pressure is lowered via the mixed pressure pulsator (12). The mixed pressure can consist of two valves (14, 15). The control element (4) of the brake accelerator unit can be the emergency brake piston, which monitors several valves, one of which is the pulsator-excitation valve (8).

Abstract: A service brake accelerator for indirect compressed-air brakes on railway vehicles includes a control piston which is loaded by the pressure in the main airpipe against the pressure in a reference pressure chamber and which controls a shutoff valve between the main airpipe and a piston chamber, a first outlet valve for the main airpipe and a second outlet valve for the piston chamber. Through appropriate dimensioning of the valve strokes (a,b), upon movement of the control piston out of its rest position the shutoff valve is closed first, and simultaneously or later the first outlet valve is opened and only subsequently the second outlet valve is opened. A valve piston arranged coaxially with the control piston is loaded by the pressure in the piston chamber and the force of a spring.On its other side, the valve piston is acted upon by the reference pressure over a partial area, but with the air vent valve open it is acted upon by the reference pressure over its entire area.

Abstract: A brake accelerator is operable sequentially upon each successive braking stage over the service application range of brake line pressure reductions and is employed with a single release brake control valve of an indirectly acting compressed air brake for railway vehicles. The control valve has a service brake portion and an emergency brake portion provided with a emergency brake piston one side of which is subjected to brake line pressure and the other side is subjected to auxiliary chamber pressure . The accelerator has a main piston which operates an inlet valve to connect the accelerator to the brake line. The main piston which is also subjected on one side to brake line pressure and the other side to auxiliary chamber pressure is moved to a service position upon an application of the brakes to open the inlet valve and connect a control piston with the brake line such that the control piston is subjected on both sides to brake line pressure.

Abstract: This invention relates to a railway vehicle continual quick service valve device that embodies two abutments normally subject on their respective opposite sides of the pressure in a train brake pipe and in a control chamber. Upon a reduction of brake pipe pressure on one side of these abutments, one abutment operates a valve to release fluid under pressure from the brake pipe and the brake pipe side of the other abutment to atmosphere whereupon this other abutment operates a valve that releases fluid under pressure from the control chamber and the control chamber side of both abutments to atmosphere. These abutments then operate their respective valves to cut off venting of fluid under pressure from the brake pipe and the control chamber to atmosphere. If the reduction of brake pipe pressure on the one side of the one abutment continues, the abovedescribed cycle reoccurs so long as fluid under pressure is released from the brake pipe.

Abstract: This invention relates to a railway vehicle continual quick service valve device that embodies two abutments normally subject on their respective opposite sides of the pressure in a train brake pipe and in a control chamber. Upon a reduction of brake pipe pressure on one side of these abutments, one abutment operates a valve to release fluid under pressure from the brake pipe and the brake pipe side of the other abutment to atmosphere whereupon this other abutment operates a valve that releases fluid under pressure from the control chamber and the control chamber side of both abutments to atmosphere. These abutments then operate their respective valves to cut off venting of fluid under pressure from the brake pipe and the control chamber to atmosphere. If the reduction of brake pipe pressure on the one side of the one abutment continues, the above-described cycle reoccurs so long as fluid under pressure is released from the brake pipe.

Abstract: A brake accelerator has a control chamber connected through a throttle orifice to a brake line. The brake system includes a control valve in which is an emergency brake piston one side of which is subjected to brake line pressure and the other side of which is subjected to pressure in the control chamber. The emergency brake piston, as a function of a pressure drop in the brake line, opens a brake line outlet valve so that air flows from the brake line through an inlet valve. The inlet valve is held by a control piston in its open position at the start of a pressure drop in the brake line and the air is flowed into a chamber to form a control pressure.

Abstract: An upgraded railway freight car brake control valve device comprises a novel emergency valve portion that embodies therein a minimum number of simple and inexpensive poppet valves, one of which is a double seated valve, that replaces yet performs the same functions heretofore performed by more expensive slide type valves which slide valves, and the flat seats upon which they slide as they are shifted from one position to another, in their manufacture require a considerable amount of accurate machining thus increasing the cost of the valve device of which they are an important part.

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: An upgraded railway freight car brake control valve device comprises a novel emergency valve portion that embodies therein a plurality of simple and inexpensive poppet valves and a spool-type valve which valves replace yet perform the same functions heretofore performed by more expensive slide-type valves which slide valves, and the flat seats upon which they slide as they are shifted from one position to another, in their manufacture require a considerable amount of accurate machining thus increasing the cost of the brake control valve device of which they are an important part.

Abstract: A brake accelerator for drawing off air from the brake line of an air brake system for railway vehicles has a piston one side of which is subjected to air pressure in the brake line and the other side is subjected to a control pressure in an expansion chamber connected to the brake line through a throttle opening. A first valve is in a connection between the brake line and a pressure accumulation chamber connected to the atmosphere through a second throttle opening. The first valve is actuated by the first piston when the control pressure exerted on the first piston is predominant. A second valve opens subsequently to the first valve and is located in a connection leading from the expansion chamber through a throttle opening to the atmosphere. The second valve is actuated by a second piston loaded by the pressure in the pressure accumulation chamber in the direction to open the second valve against the force of a spring urging the second valve into its closed position.

Abstract: An upgraded railway freight car brake control valve device comprises a novel emergency valve portion that embodies therein a plurality of simple and inexpensive poppet valves that replace yet perform the same functions heretofore performed by more expensive slide type valves which slide valves, and the flat seats upon which they slide as they are shifted from one position to another, in their manufacture require a considerable amount of accurate machining thus increasing the cost of the valve device of which they are an important part.

Abstract: An inexpensive emergency valve device embodies a first movable abutment, subject on its respective opposite sides to the pressures in a brake pipe and a quick action chamber, that, upon a service rate of reduction of brake pipe pressure, unseats a poppet valve from one of two valve seats between which it is disposed so that, while unseated from both valve seats, fluid can flow at a service rate from the quick action chamber, one side of the first abutment and both sides of a second abutment, operatively connected to a combined emergency and brake pipe vent valve to atmosphere so long as brake pipe pressure is reduced at a service rate thereby preventing an emergency brake application.

Abstract: An improved simplified emergency brake valve device including a relay valve portion responsive to brake pipe pressure reduction at an emergency rate for actuating a logic valve portion which, in turn, when actuated, causes operation of a vent valve portion via which the brake pipe is opened to atmosphere for effecting reduction of brake pipe pressure at an emergency rate at the succeeding car in the train, thereby propogating such reduction of brake pipe pressure throughout the train for effecting an emergency brake application thereon.

Abstract: A fluid brake control system is disclosed having an improved quick service and accelerated release control device having valves operable when rendered effective to locally reduce the brake pipe pressure to accelerate a brake application signal through a train and at other times to apply fluid to the brake pipe for accelerating the release of brakes of a train. The control device comprises a housing containing a fluid pressure differential operated abutment subject to actuation from a normal position by differences in pressure between respective brake pipe and reference fluid pressure chambers on opposite sides of the abutment. Two quick service valves of the ball poppet type are provided on one side of the abutment that are spring biased in the direction of the abutment against their valve seats to normally closed positions and have operating push rods longitudinally disposed between the associated ball poppet valves and one side of the abutment.

Abstract: A fluid brake control system is disclosed having an improved quick service and accelerated release control device having valves operable when rendered effective to locally reduce the brake pipe pressure to accelerate a brake application signal through a train and at other times to apply fluid to the brake pipe for accelerating the release of brakes of a train. The control device comprises a housing containing a fluid pressure differential operated abutment subject to actuation from a normal position by differences in pressure between respective brake pipe and reference fluid pressure chambers on opposite sides of the abutment. Two quick service valves of the ball poppet type are provided on one side of the abutment that are spring biased in the direction of the abutment against their valve seats to normally closed positions and have operating push rods longitudinally disposed between the associated ball poppet valves and one side of the abutment.