Abstract: A continual type quick service valve adapted to be independently mounted on a railway car to provide local, supplemental venting of the car brake pipe pressure, as long as the brake pipe pressure continues to be reduced externally. This quick service venting of the brake pipe pressure is achieved utilizing a single piston actuated exhaust valve that is either cyclically-operated between open and closed states or is held open continuously depending upon the degree of brake application in effect. By selective tuning, the open duration of the exhaust valve can be made to exceed the duration the exhaust valve is closed during each cycle of operation or to remain open for the duration of the external brake pipe pressure reduction to achieve high operating efficiency.

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: 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 truss-type brake beam having a bent configuration in which the compression and tension members are bent on opposite sides of a strut member, so that the compression and tension member segments lie in separate planes that intersect to form an angle therebetween, the line of intersection being rectilinear. The bent configuration of the brake beam accommodates housing of a brake-cylinder in the pocket between the compression and tension members adjacent the strut member, facilitates passage of force-transmitting rods between the companion brake beams of a given truck, and permits application of brake beam actuating forces without imparting torque moments to the beam.

Abstract: A brake assurance circuit via which a magnet valve device is deenergized to exhaust brake pipe pressure independently of the locomotive brake valve device in order to apply braking any time the proper operating status of the locomotive brake valve is changed after the locomotive is underway. A pressure switch responsive to the cut-in and cut-out setting of the manual selector valve associated with the brake valve senses the locomotive status and connects one of two possible circuits to the magnet valve device in parallel with a primary circuit having a speed responsive switch. Once locomotive movement is underway, the primary circuit drops out and the effective circuits selected by the pressure switch maintains the magnet valve energized provided the selected pressure switch setting is not changed.

Abstract: A freight brake control valve device having an improved quick service function provided by suppressing premature cut off operation of the quick service limiting valve. In one embodiment of the invention, this is accomplished by connecting the quick service volume pressure to the underside of the quick service limiting valve piston during preliminary quick service to counteract the pressure pulse on the opposite side of the piston that occurs during the transition between the preliminary and secondary stages of quick service. In a second embodiment, pressure is created at the underside of the quick service limiting valve piston by dashpot action of the piston itself.

Abstract: A hydraulic power unit for a hydropneumatic brake actuator having a power piston comprising a force piston formed with a bore therein and a take-up piston operative in the force piston bore for movement relative thereto during a brake application. This relative movement is controlled by a check valve device carried with the force piston to establish or interrupt fluid pressure communication between the respective pistons and establishes a positive clearance between a brake shoe and wheel tread, for example, during a subsequent brake release.

Abstract: An optical controller device employing a single rotatable light blocking plate on opposite sides of which are mounted light emitting and light receiving elements. A pattern of openings or transparent areas arcuately arranged on different circumferences of the light blocking plate determine the passage or interruption of light and thus provide output signals according to the position of rotation of an operator's handle connected to the light blocking plate. The light emitting and receiving elements are mounted on support plates configured so that a first group of the light emitting and receiving elements and a second group of the light emitting and receiving elements are symmetrically disposed on opposite sides of a centerline of the light blocking plate.

Abstract: A single-cylinder, truck-mounted brake assembly for a railway vehicle truck in which low-cost, lightweight, truss-type brake beams are employed, with one beam having the single brake cylinder mounted thereon. Force-transfer levers pivotally-mounted to the respective brake beams at the beam-midpoint are interconnected by force-transmitting members that pass through openings in the bolster to move the brake beams into brake shoe/wheel engagement when a brake application is made. The brake rigging is set up so that the transfer lever bail imparted to the force-transmitting members is split. With respect to the force-transfer lever connected to the one force-transmitting member (brake cylinder), this has the effect of the brake cylinder piston skewing equally on opposite sides of the cylinder centerline to prevent piston seal leakage.

Abstract: A hydropneumatic brake actuator having a friction member positionable by a power piston during a brake application stroke through a lost-motion connection therewith to establish a stop to limit return movement of the power piston during a brake release and thereby provide a predetermined brake shoe clearance. The friction member comprises an elastomeric-type O-ring that can be compressed axially to varying degrees, thereby adjusting the radial force that the O-ring exerts on the piston bore.

Abstract: A brake pressure control valve for regulating the braking pressure in the trailer brake system of a tractor-trailer vehicle, so as to develop the trailer brake pressure to a preset level ahead of the braking pressure in the tractor brake system during a pilot phase of brake operation. The preset level of this advance trailer brake pressure can be selected by an adjustable member that forms a part of the auxiliary valving that controls the point at which the pilot phase of operation is terminated. A limit stop is cooperatively arranged with this adjustable member in order to provide a means for limiting the point beyond which the auxiliary valving is activated, to thereby prevent the advance trailer brake pressure from exceeding a specified safe maximum value.

Abstract: A variable load brake control equipment for a road/rail type vehicle comprising variable load brake apparatus located between the auxiliary reservoir and a supplemental volume reservoir in the supply line upstream of the vehicle control valve device. During braking, the auxiliary reservoir pressure and the supplemental volume reservoir pressure combine to provide an unmodulated buildup of brake pressure until the brake pressure reaches a value that varies as a function of the vehicle load. At this point, the variable load valve device operates to isolate the auxiliary reservoir, so that a continued buildup of brake pressure is modulated by reason of the fact that the supplemental volume reservoir alone supplies braking pressure.

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 handbrake arrangement for a single cylinder, truck-mounted, railway car brake assembly comprising a lever system mounted on the body of the single brake cylinder, which is, in turn, mounted on one of a pair of truck brake beams. The lever system is connected to the handbrake chain, so that operation of the handwheel effects relative movement between the brake cylinder body and brake cylinder push rod. This results in the truck brake beams being spread apart into braking position in the same manner as occurs during a pneumatic brake application, via the respective brake beam, transfer levers and force-transmitting connecting rods that extend between the brake beams.

Abstract: A freight brake control valve device in which the emergency piston slide valve is arranged to incorporate, in conjunction with the conventional service stability function provided thereby, an accelerated service application function in which a continuous local venting of brake pipe pressure is provided to hasten propagation of service rates of brake pipe reduction. A preliminary flow restrictor in one flow path and a primary flow restrictor in a parallel flow path control the quick-action chamber "breathing" rate such that the emergency piston is stabilized against movement to emergency position, as long as the brake pipe pressure reduction does not exceed a service rate. Following a service application, the preliminary flow restrictor has the further function of maintaining "breathing" until after the local reduction of brake pipe pressure is cut off, thereby assuring positive movement of the emergency piston to its service lap position.

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 railway car braking system employing a pneumatic brake to supplement the primary electric brake is provided with a feedback signal corresponding to the effectiveness of the electric brake. This feedback signal is compared with the brake command signal to derive a deficiency signal, in accordance with which the pneumatic brake is applied. A detector senses a change in the deficiency signal in decreasing sense for applying a correction factor to the deficiency signal, thereby compensating for hysteresis typically associated with the various valves in the pneumatic brake system, in order to obtain consistent pneumatic braking for a given deficiency signal during both an increase and a decrease of the pneumtic braking level.

Abstract: An anti-locking braking control system in which each one of at least two wheels of an axle provides a speed signal for use by a respective control channel of an electronic control unit having "modified individual wheel control" logic. A pair of control valves are connected in series to regulate the respective wheel brake pressure to obtain a "select-low wheel control" mode, the "individual wheel control" logic of the control channels assuring that the series-connected control valves are operated synchronously when reapplication of braking pressure is called for by a respective control channel.

Abstract: A hydraulic brake actuator including a hydraulic parking brake that can be applied by mechanically locking up either a normal service brake application or a hand pump operated brake application. The lock-up mechanism includes a friction collar that surrounds the piston push rod and a hand pump actuated locking member that surrounds the friction collar. The friction collar and locking member have complementary conical surfaces that are engageable when hydraulic hand pump pressure is applied to a piston face of the locking member to wedge the friction member into pressure engagement with the piston push rod, as a means of locking up the push rod to obtain a parking brake. The locking member also includes a plurality of spring-like fingers that project axially from the periphery of the locking member and are provided with latching tabs adapted to enter a recess in the body to prevent return-movement of the locking member when the hydraulic hand pump operation is terminated.