Abstract: This disclosure relates to an improved fail-safe electronic filter circuit including a common-emitter transistor amplifier having a feedback path. The feedback path includes an R-C twin-T network which is imperfectly nulled to only provide regeneration at a preselected frequency. An emitter-follower circuit operates to isolate the series resistance branch of the R-C twin-T network from the collector of the transistor amplifier so that an output signal is only available during the presence of a signal having the preselected frequency and in the absence of a critical component or circuit failure.

Abstract: This invention relates to a brake shoe and brake head assembly wherein a brake head for carrying one type of brake shoe may be modified to enable securing thereto and removing therefrom other types of brake shoes without removing the brake head from a brake lever on which the brake head is pivotally mounted.

Abstract: The present invention concerns automatic fluid brake devices in which the fill and discharge of the brake cylinder or cylinders of the equipment are controlled by a device functioning as a distributing valve in relation to pressure variations in the brake pipe.In the aforementioned automatic braking devices generally used for rail vehicles, and commonly known as distributors, the brake cylinder pressure obtained during the braking process is a function of the pressure in the brake pipe.The present invention concerns distributors of the graduated release type, in which brake release is not only initiated via pressure increase in the brake pipe, but it is entirely a function of the pressure increase in this brake pipe.More specifically, the present invention concerns the type of graduated release distributor in which the discharge is adjustable, and the brake is inexhaustible regardless of the manner in which the valve is manipulated by the engine driver to carry out braking or brake release.

Abstract: This disclosure relates to a predictor for determining the coefficient of friction existing between the rotating wheels of moving railway vehicles and the brake shoes of a pair of brake elements prior to the humping operation in a classification. One of the brake elements is slidably mounted to move longitudinally relative to the track rail when engaged by the rotating wheels of the railway vehicle. The kinetic energy or force imparted to the slidable brake element is transposed in fluid pressure by a pressurized responsive transducer. The fluid pressure is sensed by a measuring device which activates an alarm when the wheels of the railway vehicle are dirty or contaminated by unctuous material to permit the vehicle to be diverted to a sidetrack for special handling.

Abstract: Combination fluid pressure and electric operable trip cock emergency brake apparatus for use with railway vehicles including a trip cock device having a fluid pressure portion and an electrical portion, both operable concurrently, when a trip lever thereon is actuated by a trip arm located on the roadway, for providing concurrent fluid pressure and electrical pilot signals to cause operation of a common control switch which in turn, when so operated, actuates propulsion and brake control devices to cause propulsion power to be cut off and an emergency brake application to be effected concurrently. The fluid pressure and electric portions of the trip cock device complement each other to insure that one or the other, if not both, will effect the desired results in an emergency situation.

Abstract: This invention relates to a molded fluid circuit plate which is used in a circuit module that distributes fluid under pressure to a plurality of logic control valve devices that may be removably secured to the circuit module. This molded fluid circuit plate constitutes a slab that has formed in either one or both of its sides, or has extending therethrough, a plurality of polygonal chambers, each chamber being separated from the adjacent chambers disposed thereabout by a plurality of partitions. When the chambers are formed in one or both sides of the circuit plate, one edge of each partition is integral with and severable from the corresponding side of the circuit plate.

Abstract: This invention relates to a disc brake apparatus wherein a plurality of brake shoes, that transmit braking force to a plurality of rotating discs, when worn to their minimum allowable thickness, may be replaced with new brake shoes, without disassembly of the disc brake apparatus, by unlocking, rotating through an angle of one hundred and eighty degrees, and thereafter relocking a plurality of pivotally mounted arms each of which may have attached to and detached from its respective ends a worn brake shoe and a new brake shoe, the rotation of each arm moving a new brake shoe to the position formerly occupied by a worn brake shoe thereby enabling the new brake shoe to transmit a braking force to the rotating disc formerly braked by the worn brake shoe.

Abstract: A brake control valve device for a use with tandem or tractor-trailer type vehicles employing dual brake systems with the source of operating fluid supplied at a relatively higher pressure than that required for operating the brakes. The respective valve elements of the valve device for controlling supply and exhaust of operating pressure to and from the respective brake circuits are mechanically actuated through a manually actuated pressure graduating piston (for the first brake circuit) and a fluid pressure responsive relay piston (for the second brake circuit), the dimensions of the relay piston being limited to less than normal for conserving space, but being provided with an adjusting mechanism for adjusting the fluid pressure responsive operating range thereof for compensating for the smaller dimension and synchronizing the relative serial operation of the dual brake circuits.

Abstract: Apparatus on each vehicle in a train, for effecting a release of an emergency brake application upon a complete stop of the train, comprises a fluid pressure operated brake pipe vent valve device that is supplied with fluid under pressure from a quick action chamber when the emergency brake application is effected, a release valve device operable upon the release of fluid under pressure therefrom to vent fluid under pressure from the brake pipe vent valve device to atmosphere to cause closing of the brake pipe vent valve thereby enabling recharging of the brake pipe to effect a release of the prior emergency brake application, and a speed responsive device for supplying fluid to the release valve device at a pressure proportional to the speed of the train.

Abstract: An electronic anti-skid brake control system for regulating an individual wheel brake pressure independently of an operator controlled brake valve device in such a manner that when a predetermined brake pressure difference between a skidding and non-skidding wheel arises, the higher wheel brake pressure of the non-skidding wheel is reduced. Pressure transducers produce an electrial signal representative of each wheel brake pressure. These signals are connected to different inputs of a pair of differential amplifiers, which algebraically sum the signals to provide different polarity output signals according to the difference in wheel brake pressure. These difference signals are then compared at operational amplifiers with a predetermined bias signal that establishes the differential pressure at which at least one operational amplifier is operated to control modulator valve means associated with the non-skidding wheel.

Abstract: This invention relates to a cycling-type continual quick service valve device which embodies therein a quick service valve means that comprises two valves each operatively connected to an abutment subject to fluid under pressure supplied from a train brake pipe through a first restriction to a chamber on one side thereof and subject to fluid under pressure supplied from the brake pipe to a chamber at the opposite side and to a quick service chamber via two restrictions arranged in parallel and in series with a third restriction, the sizes of these three restrictions being such that the rate of flow of fluid under pressure therethrough is less than the rate of flow through the first restriction. A check valve is arranged in series with one of the two parallel arranged restrictions so as to prevent flow therethrough in the direction from the chamber at the opposite side of the abutment to the brake pipe.

Abstract: This invention relates to a fluid pressure operated disc brake assembly that includes a tandem-arranged spring-applied fluid-pressure-related brake operating unit and an automatic slack adjuster mechanism which is actuated by a pair of springs to so compensate for wear of a disc brake rotor and/or brake shoes therefor that the brake shoes, while the brakes are released, are constantly lightly pressed against the brake rotor notwithstanding prior wear of the shoes and/or the rotor.

Abstract: A frequency selective filter is connected between the track transformer and phase selective unit at the receiving end of a coded phase selective track circuit to reject interfering signals of propulsion current frequency. The series L-C filter comprises a capacitor and a two-winding reactor coil with a resistor permanently connected in series between the two windings. Each winding is tapped to allow a selection of the filter inductance to match track circuit impedance, including impedance bonds and ballast resistance. Taps for short track circuits include the second winding and the resistor to improve signal to noise ratio. Energy for short interlocking track circuits is of a higher frequency, and a special tap on the first winding is selected to enable filter tuning at this other frequency for train detection since basic frequency is still used during code off-time for cab signal control.

Abstract: When the deceleration of a vehicle wheel exceeds a certain chosen value, a wheel-slip-responsive means causes operation of a valve to close communication between a hydraulic master cylinder and a hydraulic brake-applying cylinder and connect this brake applying cylinder to a volume chamber to thereby release the braking force on the wheel until this wheel accelerates back to an angular velocity that corresponds to the linear velocity of the vehicle.

Abstract: Apparatus for varying the time between the initiation and subsequent release of an emergency brake application on a locomotive and train of cars hauled thereby comprises either fluid pressure operated valve means operable, by fluid under pressure supplied for causing knockout of the locomotive power supply, to establish communication between two reservoirs, separably charged from the train brake pipe, whereby substantially all of the fluid under pressure must be released from both reservoirs to atmosphere via a first restricted communication prior to the release of an emergency application thereby increasing the time between initiating the emergency application and the subsequent release, or fluid pressure operated valve means operably responsively to power knockout to establish another restricted communication between a single reservoir and atmosphere whereby substantially all of the fluid under pressure must be released from the single reservoir to atmosphere via the two restricted communications simultaneo

Abstract: This invention relates to locomotive brake control apparatus operable responsively to a reduction of the pressure in a train brake pipe as a result of train separation at a location in the train remote from the locomotive to cause cut off of the locomotive power supply, cut out of dynamic brakes, sanding of the rails, and a service brake application on the entire train.

Abstract: Apparatus for protecting reversible engines against damage during reversal of engine rotation notwithstanding that such reversal is initiated remotely by the operator by a single movement of the control handle without regard of the engine speed at the time such reversal is initiated, said apparatus including means for automatically cutting off engine throttle, determining the engine speed and direction of rotation at time reversal operation is initiated, and delaying, if necessary, restarting of the engine in the desired direction of rotation until rotation in the prior direction has been reduced to a safe speed for effecting such rotational reversal.

Abstract: This disclosure relates to a solid-state voltage controlled oscillating circuit arrangement employing a differential type of integrated circuit operational amplifier and a transistorized output amplifier. The operational amplifier includes an inverting input coupled to a source of reference potential and a noninverting input coupled to an input signal source. The operational amplifier is provided with hysteresis for causing a dead band zone to occur until the signal on the noninverting input exceeds a predetermined value so that the operational amplifier toggles and produces output signal pulses having a frequency which is proportional to the amplitude of the input signal applied to the noninverting input. The output signal pulses are amplified by a transistorized output amplifier.

Abstract: This disclosure relates to a vital type of an optoelectronic phase inverting circuit arrangement employing a plurality of cascaded photon coupled isolators. Each of the photon coupled isolators includes a light emitting diode and an associated light responsive transistor. A source of periodic input signals is coupled to the photon coupled isolators so that electrical energy is converted to light energy by the light emitting diodes to control the conductive conditions of the respective light responsive transistors whereby the periodic input signals are inverted 180.degree. barring the presence of a critical component or circuit failure.

Abstract: This disclosure relates to a gripping type of railroad car retarder or a section of railway trackway having the running rail composed of vibrational dampening material for absorbing and dissipating vibrational energy imparted to the wheels of railway vehicles by the slip-slide action occurring between the brake shoes and the sides of the vehicle wheels or between the running rails and vehicle wheels for preventing the development of wheel screeching sounds.