Abstract: An isolation valve device for a hydraulic brake system of a railway vehicle including passageways via which hydraulic pressure communication is established between a pressure controller and the brake units of each truck of a railway vehicle, and diaphragm type flow control valves adapted to interrupt hydraulic pressure communication in a respective one of the passageways leading to the different truck brake units, when a pressure differential occurs therebetween, due to a ruptured brake line at one of the trucks, for example, causing a hydraulic fluid leak thereat.

Abstract: A spring-applied, hydraulic pressure released brake actuator having a modular slack adjuster assembly in which a friction ring is arranged to limit axial movement of a nut member to which a brake shoe is connected, thereby establishing a predetermined brake shoe clearance with a vehicle wheel or brake disc. A spindle that is threadedly engaged with the nut member is connected to the actuator piston by means of a cone clutch that is disengaged during a brake release in the event the return stroke of the piston exceeds the predetermined brake shoe clearance due to brake shoe wear during the preceding brake application. This disengagement of the clutch causes the spindle to be rotated relative to the nut member under the influence of a slack adjuster spring in order to compensate the piston overtravel.

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: A handbrake system for use with a truck-mounted, single-cylinder brake rigging including truss-type brake beams, there being a single handbrake pivotal lever supported intermediate its ends by a twisted transfer link that is, in turn, fixed to the brake rigging transfer lever. A fulcrum end of the handbrake lever is free to engage the bearing surface of a thrust block mounted on the brake beam at the juncture of the beam tension and strut members in order to allow the point of engagement between the fulcrum end and the bearing surface to change with rotation of the handbrake lever. In addition, the fulcrum end of the handbrake lever is arranged with two, spaced-apart arcuate segments that successively engage the bearing surface of the thrust block during rotation of the handbrake lever to change its lever ratio and, accordingly, limit the degree of rotation of the handbrake lever.

Abstract: An electromagnetic air brake control system including a module portion and an integral relay valve portion. The module portion includes a brake pipe cut-off valve. A bistable electropneumatic valve device pneumatically connected to the brake pipe cut-off valve. A pole changing relay electrically connected to an electric coil of the bistable electromagnetic device. The pole changing relay having an electric coil connected to a d.c. voltage. A quick release relay having an electric connection to the d.c. voltage and having contacts connectable to contacts of the pole changing relay. A pair of relay driver circuits supplied by a supplemental power supply for causing the electric coils of the pole changing and quick release relays to be energized and deenergized in accordance with output signals received from a command control circuit and a monitor checking circuit.

Abstract: A filter arrangement for a moisture-removal device used in compressed air systems in which an inner filter adapted to remove water from the air is encircled by an outer filter that is adapted to remove oil from the air. A space between the inner and outer filters is provided to accommodate accumulation of the filtered-out oil with a valving arrangement provided in the area of oil accumulation that is operative in response to a pressure differential when the regeneration phase of operation is initiated to concurrently discharge the accumulated oil.

Abstract: A service valve piston assembly for a freight brake control valve device in which the graduating valve is configured to cooperate with the associated slide valve to close off the application port via which auxiliary reservoir pressure acting on one side of the piston assembly feeds the brake cylinder prior to opening of the stability port via which the brake pipe pressure on the opposite side of the piston assembly is communicated with auxiliary reservoir pressure on the one side of the piston, thereby preventing the piston valve assembly from finding a quasi-lap position in which the brake cylinder continues to be pressurized.

Abstract: A brake actuator having a service brake coupled to an emergency/parking brake through a lost-motion connection that allows the service brake to be applied independently of the emergency/parking brake includes a slack adjuster, the pawl of which is withheld from engagement with the teeth of the slack adjuster ratchet wheel by an interrupter vane whenever the emergency/parking brake is actuated, to thereby disable the slack adjuster.

Abstract: An equipment carriage for locomotive air brake valve components including a box-like frame having a rear section separating parallel end sections. The frame is arranged to guidably receive, through an open front section, a group of one or more unitized valve assemblies stacked in vertical, side-by-side relationship, such that an end face adjacent the rear section engages a mating face of a respective header bar that is affixed to the frame at the rear section thereof to provide a pipe bracket to which the locomotive air lines are connected. Such an arrangement, in addition to providing optimum space utilization, permits removal of individual unitized assemblies from the frame without requiring removal of the frame itself or any of the other unitized assemblies, and without disturbing the air line connections.

Abstract: A dual capacity empty/load changeover valve for a railway freight car in which a piston-operated check valve controls the supply of compressed air delivered from the auxilary reservoir to the brake cylinder via the car control valve. The check valve is connected to a balance piston having equal opposing pressure areas, one of which is subject to the air supplied to the brake cylinder under all conditions of car loading. The opposing pressure area of the balance piston is pressurized in a load condition and depressurized in an empty condition, thereby establishing a proportional mode of brake control during empty car braking. A proportioning spring acts on the balance piston to establish the brake cylinder pressure at which the check valve becomes operative to proportion the air supplied to the brake cylinder.

Abstract: A tread brake unit including a spring actuated compensating mechanism for maintaining the brake unit piston stroke constant. A roller associated with the compensating mechanism is adapted to ride along an operating surface of a lever arm that rotates according to the degree of piston stroke. The profile of this operating surface regulates the roller movement to prevent the stressing of operating springs in the compensating mechanism from exceeding a maximum value corresponding to their fatigue limit.

Abstract: A low brake pipe pressure detecting circuit for a railway train is provided in conjunction with a conventional vent valve device typically associated with the locomotive brake valve device to exhaust the train brake pipe pressure and thereby effect an emergency brake application. Conventional pneumatic pilot valve devices are interconnected with the vent valve device to actuate the vent valve device only for a limited duration following which the pilot valves are automatically reset to effect closure of the vent valve device preparatory to recharging brake pipe pressure to obtain a subsequent brake release.

Abstract: A vent valve device having a pair of diaphragm-type piston members forming a pilot chamber therebetween. The one piston controls a vent valve via which brake pipe pressure is vented locally, while the other piston controls a pilot valve a control venting of the pilot chamber. A breather choke between the pilot chamber on one side of the other piston and a control chamber on the opposite side establishes a predetermined pressure differential thereacross only when brake pipe pressure supplied to the pilot chamber is reduced at an emergency rate to thereby actuate the other piston to a position opening the pilot valve. In addition, this other piston operates a cut-off valve to isolate the pilot chamber from brake pipe pressure so that the pilot valve quickly exhausts pilot chamber pressure.

Abstract: A freight brake control valve device for a railway vehicle having a service piston slide valve arranged with a detent to latch the service piston in preliminary quick service position until such time as the application pressure differential acting on the piston exceeds a predetermined value.

Abstract: An actuating cylinder having a fluid pressure operated piston member connected by a friction member to a push rod to which a brake shoe, or the like, may be attached as the output member. A force transfer lever is arranged between the piston and push rod to transmit the piston force to the output member with mechanical advantage only after the friction connection is overcome by resistance at the push rod, such as occurs by engagement of the brake shoe with the wheel of a railway vehicle.

Abstract: A force transfer mechanism including a force lever through which an input force is transmitted to an output member with mechanical advantage only after the output member encounters sufficient resistance to overcome a friction connection between an input member and the output member indicative of the input member having moved from a retracted position to an operative position. The resultant movement of the input member relative to the output member in the absence of the frictional connection therebetween allows the input member to engage the end of force lever that is normally spaced-apart therefrom and to accordingly drive the output member with a force corresponding to the input force multiplied by the ratio of the force lever only in the operative position of the input member.

Abstract: A diaphragm for a diaphragm-type piston characterized by an S-shaped or ogee-like profile approximating a theoretical model that is substantially free of distortion in a selected position of the piston assembly in which a convolution is formed in the annular space between the diaphragm piston and the body in which the piston operates. Being molded without a convolution, the diaphragm lends itself well to maintaining a reinforcing fabric centrally embedded within the diaphragm proper, while at the same time being substantially distortion-free in a selected position of the piston assembly.

Abstract: An operators's brake valve device for a railway locomotive that is adapted to provide brake pipe recharging in a holding position of the brake valve handle in which the release of brake cylinder pressure is cut off by a release magnet valve device that, in conjunction with an appliction magnet valve device, provides electro-pneumatic control of the train brakes. These magnet valves are controlled electrically via pneumatically piloted electrical switches that receive discrete pressure signals according to the different positions of the brake valve handle.

Abstract: A diaphragm piston assembly in which an annular ring member is provided, preferably at the outer clamping periphery of the diaphragm between the underside of the diaphragm and body, to exert a force on the diaphragm in the direction of the cover that clamps the diaphragm to the body, thereby encouraging the diaphragm convolution to assume a disposition in a preferred direction corresponding to the direction in which the convolution is predisposed by the inherent "spring effect" of the diaphragm.

Abstract: An unloader device for controlling the output of a hydraulic pump, for example, in a constant pressure-type motor vehicle braking circuit. Delivery to hydraulic accumulators in the circuit is halted by a resilient seal defining an annulus forming part of the inlet fluid flow path to the pump and to which the pump delivery pressure is applied to expand the seal in the sense to close the annulus, by a valve operable when the delivery pressure reaches a predetermined value.