Abstract: A backup pneumatic emergency control valve for an electro-pneumatic brake system for a railroad freight car comprising an emergency portion of a standard AB type freight brake control valve device without the service portion.

Abstract: A system and method of calibrating pressure transducers in an electro-pneumatic brake system for a railroad train in which a locomotive microprocessor generates a respective best fit curve for the train brake pipe, supply reservoir and brake cylinder pressures that approximates the actual train pressure therefore. These best fit curves are generated from the pressure transducer readings of these pressures at each car by employing an equation based on a fourth order polynomial. Each car is then provided with a theoretical reference pressure signal from the best fit curve for each of the mentioned brake pipe, supply reservoir and brake cylinder pressures, according to the position of the car in the train. The theoretical reference signal is then compared at each car with the car pressure transducer reading for the respective brake pipe, supply reservoir and brake cylinder pressures to obtain a transducer error correction factor that remains constant through a full range of pressures.

Abstract: A visual brake cylinder piston travel indicator for a railroad car having a brake cylinder device located remotely from a convenient viewing area. An indicator rod is suitably sized and configured to extend from the remote brake cylinder device to the viewing area where the brake cylinder piston travel may be determined by the relationship of the indicator rod end with respect to a reference point. At the brake cylinder device, the indicator rod is connected to the piston hollow rod by a bearing assembly that includes the hollow rod collar. The bearing assembly provides for relative rotation between the indicator rod and hollow rod, while concurrently transmitting axial movement of the piston to the indicator rod, such relative rotation being necessitated by the fact that the piston and hollow rod typically rotate during reciprocal movement between a brake application and brake release position, due to torsional forces imparted by the piston return spring.

Abstract: A fastener assembly for installing valve devices and the like on one side of a mounting plate by bolts where the bolt holes are without threads and the opposite side of the mounting face is inaccessible for holding a bolt head or nut from turning. The fastener assembly includes at least one fastener plate and a minimum of two threaded bolts affixed thereto, so that the threaded portion of the bolts projects through bolt holes in the mounting plate. A retaining washer is threaded onto the projecting bolt threads to retain the fastener plate in place while the valve device is being installed onto the projecting bolt threads on which lock nuts are subsequently screwed to secure the installation.

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 piston valve assembly in which plastic wear rings are fitted on an aluminum piston member to prevent metal-to-metal engagement between the piston member and the bore of the bushing in which the piston member is operatively disposed in order to eliminate abrasion of the piston member due to vibration in the bushing bore.

Abstract: A multi-thickness diaphragm member including clamping sections that are sized for assembly of the diaphragm in standard air brake valve devices and a flexure portion intermediate the clamping sections that forms a convolution during assembly. The thickness of the flexure portion is less than that of the clamping sections to facilitate formation of the diaphragm convolution without wrinkling, in order to alleviate progressive fatigue failure. The thin flexure portion of the diaphragm is joined with the respective clamping sections through a tapered area, which lies entirely outside of the annular space in which the diaphragm convolution forms during assembly, to thereby maximize the radius of curvature of the convolution for optimum utilization of the flexure portion in forming the convolution.

Abstract: A relay valve device for a relayed type brake system in which the compressed air of the auxiliary reservoir is connected to an equalizing reservoir instead of directly to the brake cylinder, as in a conventional system. Since the equalizing reservoir volume is fixed, as compared to the brake cylinder volume which varies with piston displacement, the equalizing reservoir volume must be greater than the final brake cylinder volume in order to obtain a full equalization pressure that matches the full service application pressure in a conventional brake system. The relay valve device employs a control piston that is subject opposingly to the equalizing reservoir pressure and the effective brake cylinder pressure delivered by the relay valve device.

Abstract: A disc brake shoe in which a relatively thin gage, low-cost metal backing plate has bonded to one face a friction brake lining and is formed on the opposite face with a plurality of straps that are adapted to engage corresponding recesses formed in a complementary thick gage metal backing plate to interlock the respective backing plates into a unitary brake shoe assembly which can be easily disassembled to permit change-out of a worn brake shoe by simply substituting a newly lined, low cost backing plate for the existing backing plate having worn lining without the need to re-claim the backing plate for re-use.

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

Abstract: An electro-pneumatic brake system for a railroad freight car is integrated with the existing pneumatic freight brake system by utilizing the air stored in the emergency reservoir to supply brake cylinder pressure via the exhaust passage of the pneumatic control valve, which is maintained in release position during electro-pneumatic brake operation. The electro-pneumatic brake system fails to a release mode, so that the brakes on an individual car that experiences a power loss do not apply. In the case of a power loss in the electro-pneumatic system, due to a train break-in-two, the pneumatic brake system is automatically operated by the consequent loss of brake pipe pressure to provide a back-up brake, while at the same time interrupting the control valve exhaust path via which the electro-pneumatic brake is communicated with the brake cylinder.

Abstract: An improved disc brake pad backing plate assemblage of the dovetail type wherein dovetail end strength for resisting deformation is increased by the use of a special secondary backing plate member in conjunction with a primary backing plate member having a dovetail for mating engagement with the dovetail groove in a disc brake holder. The resultant absence of dovetail end deformation facilitates removal of the disc brake pad from the mating dovetail groove.

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 railway car vent valve device having a nullifier valve that is selectively operable to disable the vent valve device during a single car test procedure in which the service stability of the car control valve is checked. The nullifier valve is automatically reset when the car brake pipe pressure drops below a predetermined value, such as occurs when the single car test apparatus is disconnected from the car brake pipe following completion of the single car test procedure.

Abstract: A constant tensioning device in the form of an elastic member interposed in the handbrake chain between a railway car handwheel and a handbrake lever of the railway car brake apparatus for maintaining tension in the handbrake chain in accordance with the applied handbrake force, irrespective of such shifting of the railway car relative to its truck, as would otherwise cause slack to develop in the handbrake chain and thereby cause an undesired loss of handbrake force.

Abstract: A spool type valve arrangement in which a booster spring is employed to overcome static friction of the spool valve O-rings and thereby assure prompt actuation of the spool valve member. The arrangement is such that the booster spring is only active through a limited distance of travel from release position toward application position, this limited distance of spool valve travel being selected so as to occur prior to any transition of the port connections controlled by the spool valve. In this manner, the spool valve return spring force need not be increased in order to reset the spool valve sufficiently to reestablish the original spool valve port connections.

Abstract: A microprocessor-based locomotive brake control system having an electropneumatic brake pipe pressure regulating circuit via which a train brake pipe pressure is controlled and a normally closed charging cut-off valve between the brake pipe regulating circuit anad the brake pipe. The charging cut-off valve is electropneumatically controlled in order to effect opening of the normally closed charging cut-off valve on a controlling locomotive. An arrangement is provided for maintaining the charging cut-off valve open when electric power is lost on a controlling locomotive, while providing for closure of the charging cut-off valve on a non-controlling locomotive irrespective of the presence or absence of electric power.

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: An empty/load changeover valve device for a railway car having a proportioning valve including a valve member via which brake cylinder pressure is supplied and released and a balance piston to which the valve member is connected. The balance piston has equal opposing pressure areas both of which are subject to brake pressure in the "load" setting of the changeover valve device, one of the pressure areas being vented in the "empty" setting, thereby establishing either a non-proportioning mode of brake control or a proportioning mode of brake control. In the "empty" setting, brake supply pressure is connected to an equalizing reservoir. A regulating valve is provided to interrupt this connection until the brake supply pressure reaches a predetermined value, thereby preventing the other pressure area of the balance piston from being unloaded sufficiently to cause an inadvertent opening of the check valve member and a consequent drop in brake cylinder pressure.

Abstract: A hinge assembly for a manual or automatic air brake valve test fixture that includes a secondary test plate to which a valve device to be tested is mounted from a front load position and then rotated to its usual side location for clamping to the primary test plate, thereby relieving the tester of physical strain encountered heretofore in mounting the valve in a side load position. The hinge assembly is spring-loaded to obtain even, face-to-face engagement of the mating surfaces of the primary and secondary test plates and thereby assure the integrity of the pressure seal therebetween.