Abstract: A brake system is provided for a multi-platform railroad car in which a single microprocessor is employed to control the car brakes. In one embodiment, a single electro-pneumatic control unit provides a common brake pressure to the brakes of each truck in accordance with the truck design net brake ratio and load weight of whichever truck requires the lowest brake pressure. In a second embodiment of the invention, the brakes on separate truck sets are provided with different common brake pressures by employing separate electro-pneumatic control units for each truck set under control of the microprocessor. In such an arrangement, the different common brake pressure on one truck set can be increased to make-up at least a portion of a brake deficit on another truck set due to light car loads associated with the other truck set in order to meet or at least closely approach the commanded net braking ratio for the entire multi-platform car.

Abstract: A regulating valve device is provided for utilization with an end-of-train unit in order to reduce a train brake pipe pressure from the rear end in accordance with a pressure reduction initiated at the locomotive on the front end. A stepping motor under control of a microprocessor controls the compression of a spring to establish a target pressure corresponding to a pressure command signal transmitted from the locomotive to the end-of-train unit. The service exhaust valve device regulates the brake pipe pressure to the target pressure corresponding to the spring compression set by the stepping motor and includes an arrangement for overriding the motor control in the event of a fault condition that prevents the motor from resetting the spring to its initial compression when it is desired to recharge the brake pipe to release a brake application.

Abstract: A combined automatic pneumatic and electro-pneumatic brake system for a railroad freight car in which a conventional type ABD control valve device is modified to incorporate a solenoid valve portion at a mounting face from which the manual release valve portion has been removed and where existing passages in the control valve may be accessed in order to utilize the existing car control valve device with only a minimum of modification.

Abstract: For use with control valves having test ports via which various pressures may be accessed in performing an automatic single car brake test, there is provided a test plate via which such control valves may be conditioned to obtain faster charging of the brake equipment when performing the brake test with a manual single car tester. The test plate interconnects the test ports such that the test pressure supplied to the car brake pipe charges the brake equipment in by-pass of the charging choke in the control valve.

Abstract: A pneumatic receptacle adapted to receive a pneumatic connector head of a test device is mounted in a universal location remote from the brake control valve of a railroad freight car. The remotely mounted receptacle may be located on the railroad car body, for example, and is communicated with access ports associated with the control valve via hoses or conduits. In locating the receptacle on the car body, hook-up of the test device can be accomplished conveniently and in a safe manner by railroad personnel in the course of conducting a single car test to check the condition of the car brakes, regardless of the control valve location.

Abstract: A portable, single-car test unit for a railway freight brake control valve for manually executing pressure manipulations to evaluate the operating conditions of the control valve. The pipe bracket portion is connected to a brake pipe, an auxiliary reservoir, an emergency reservoir, a brake cylinder retaining valve and a brake cylinder each being connected to a respective fluid passageway. The test unit accesses the fluid passageways at access ports, respectively connected to each passageway. Valves are utilized in the test unit to manipulate the pressure in the fluid passageways and pressure gauges measure fluid pressure in the passageways. An operator records each pressure measurement and calculates and stores the differences between selected pairs of the pressure measurements as well as elapsed time data for the measurements.

Abstract: An electro-pneumatic brake control system for a railroad car including application and release solenoid valves having a fail-safe configuration in which full emergency brake pressure is delivered in the event of a power loss due to a train break-in-two for example. The present invention discloses a pressure limiting valve for the purpose of limiting the maximum pressure capable of being delivered in accordance with the existing car load weight sensed by an electric load sensor at the time a bower loss is experienced.

Abstract: A microprocessor based electro-pneumatic brake system for a railroad car including an emergency backup having load control apparatus under control of the microprocessor and arranged to maintain a load setting consistent with the microprocessor control in the event a power failure or malfunction renders the microprocessor inoperable.

Abstract: An improved railway brake shoe member characterized by logitudinally tapered sidewalls of the brake shoe that provide adaptive response to braking under conditions of mis-alignment between the brake shoe member and the tread of a railway car wheel by facilitating wear-in of the mis-aligned brake shoe, thereby assuring brake shoe/wheel tread engagement and accordingly alleviating degradation of braking efficiency and undesirable thermal inputs to the wheel flange that otherwise results from such brake shoe mis-alignment.

Abstract: A brake shoe locking key is provided with a retention tab that is saw-tooth shaped and extends across the entire width of the key shank. The retention tab is upraised from the shank more than the correspondingly-shaped serrations typically formed on the bottom of the key and is thus more effective in engaging the brake head as an initial detent to prevent the key from backing out of the keyhole in the brake head when a loose fitting key fails to retain its locking position. In addition, the retention tab is adapted to engage the keybridge at the orifice through which the key passes in order to provide a further detent to prevent a loose key from backing completely out of its locking connection between the brake head and brake shoe, in the event the first detent fails to engage.

Abstract: A microprocessor based brake pipe pressure control system for one or more cars of a railroad train wherein the local exhaust of each car brake pipe pressure, under control of an electro-pneumatic valve, is individually regulated such that the gradient of the resultant train brake pipe pressure closely approximates the natural brake pipe pressure gradient for any given brake pipe pressure reduction.

Abstract: A composition type brake shoe for a railroad car in which the backing plate keybridge is filled with composition brake lining material to reinforce the keybridge. A recess formed in the braking face of the brake lining extends beyond the keybridge so that a relatively thin area of brake lining is formed between the recess and backing plate outboard of the keybridge opening, and to which thin section area cracks that may develop in the brake lining are encouraged to migrate in order to redirect backing plate flexure away from the critical keybridge area to a stronger area of the backing plate.

Abstract: An electro-pneumatic brake control system for a railroad car including application and release solenoid valves having a fail-safe configuration in which full emergency brake pressure is delivered in the event of a power loss due to a train break-in-two for example. The present invention discloses a pressure limiting valve for the purpose of limiting the maximum pressure capable of being delivered in accordance with the existing car load weight sensed by an electric load sensor at the time a power loss is experienced.

Abstract: A brake shoe key of the spring-type for affixing a brake shoe to a brake head, the key being formed from a flat strip of spring metal including a shank portion having a generally curvilinear profile and a head portion that is integral with the shank portion and is characterized by an open-loop configuration to provide a space in which a pry bar may be inserted, the open-loop configuration being formed by a stop leg that is outturned from one face of the shank and a pry leg that is spaced-apart from the stop leg on the opposite side thereof from the shank.

Abstract: A test connector for connecting an air brake test device to access ports of an air brake control valve device where such access ports are normally closed by check valves. A plurality of actuator devices corresponding in number to the access ports are provided in the test connector to unseat the check valves and conduct test air to the test device via central passages in the actuators. The actuators are piston operated in response to a pilot pressure received from a source of compressed air remote from the connector.

Abstract: A microprocessor based brake control system for a railroad car, wherein the car brake cylinder pressure is regulated in accordance with the specific design net braking ratio of the car and the actual car load weight in order to achieve consistent levels of retardation on the cars throughout the length of a train irrespective of such variables as design net braking ratio that otherwise influence car retardation. The actual level of retardation is increased on partially loaded or empty cars so that those cars share in the braking of a train. This is especially useful during grade braking.

Abstract: A remote handle operating mechanism for a cut-out cock located on the back side of a pipe bracket on which the service and emergency portions of a railroad brake control valve device are mounted at the front side thereof. A push-pull rod extends from the cut-out cock actuating lever via an opening in a detent bracket to the front of the pipe bracket to facilitate operation of the cut-out cock. A locking rod affixed to the push-pull rod co-acts with the detent bracket to latch the push-pull rod in either one of two positions corresponding to the open and closed positions of the cut-out cock to prevent inadvertent operation of the cut-out cock.

Abstract: A piston valve assembly in which a piston member is outfitted with a plastic insulator between the metal piston member and a cover with which the piston member is otherwise engageable in one case and between the metal piston member and a valve actuator stem with which the piston member is otherwise engageable in another case, thereby preventing metal-to-metal contact therebetween and consequent metallic abrasion and pulverization.

Abstract: A pipe bracket portion of a freight brake control valve having an improved filter arrangement. The pipe bracket portion has a first side with a service portion and an emergency portion mounted thereto. The pipe bracket portion has a second side with a brake pipe, a brake cylinder, a emergency reservoir and an auxiliary reservoir thereto. The pipe bracket portion is provided with a cavity designed for containing a generally cylindrical filter therein. A retaining nut secures the filter in the cavity and provides a seal between the outer circumference of one end of the cylindrical filter and the pipe bracket portion. A first cavity portion and a second cavity portion are thus formed within the cavity in which the first cavity portion houses the cylindrical filter, and the second cavity portion has at least one radial port for delivering air.

Abstract: A test connector for connecting an air brake test device to access ports provided on an air brake control valve device where such access ports are normally closed by check valves is disclosed. In one embodiment, a plurality of stem operators project into the access ports without opening the check valves therein when the test connector is installed in position on the control valve device. A handle is provided to effect rotation of an eccentric shaft on which the stem operators are connected to unseat the check valves and thereby access air at the respective access ports when it is desired to initiate testing following installation of the test connector. In an alternate embodiment, a plurality of test probes pivotally mounted on the test connector body enter the access ports and unseat the check valves in the course of installing the test connector in position on the control valve. In both embodiments, the stem operators/test probes are self-aligning to facilitate installation of the test connector.