A vehicle fluid pressure braking system is disclosed which includes brake-applying devices having separate service and parking actuators. Separate service and parking actuation circuits are provided to control actuation of the service and parking actuators, respectively. An interlocking valve is provided which prevents release of the parking actuator until a predetermined fluid pressure level is communicated to the service actuator. This interlocking valve prevents inadvertent release of the par...

The release device for multiple release compressed air brakes of railborne vehicles comprises a pressure reduction valve (12) which responds in the case of rapid brake applications and optionally of full brake applications, which in order to facilitate the brake release procedure and to accelerate the pressurization of the brake cylinder (13) feeds compressed air from the reference pressure chamber of the triple pressure control valve (2) into the brake cylinder (13). In addition, a sensor valve...

Apparatus for indicating the condition of hand brakes on railway cars and for applying and releasing railway car parking or hand brakes automatically in response to predetermined conditions including movement of a train, wayside conditioning apparatus, wayside operating mechanism, a signal controlled by an operator and performance of predetermined railway operating procedures, such as completion of an air brake test procedure. The apparatus may respond to mechanical, electrical and electronic si...

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 ac...

A piping cleaning system switches over a four-way switching valve 43 of a heat pump circuit 200 so that two transfer heat exchangers 25, 26 are operated alternately as a cooling device and a heating device, by which a cleaning refrigerant in a cleaning circuit 2 is circulated through a gas line 3 and a liquid line 5. During this cleaning operation with the cleaning refrigerant circulated, when the cleaning refrigerant runs short in amount, a solenoid valve SV3 is opened so that cleaning refriger...

A vehicle air brake system includes spring set air released parking brakes to which air is supplied through a pressure holding valve which maintains the air chambers of the parking brakes at a predetermined pressure even though the air brake system may be at operating pressures substantially lower than the predetermined pressure. When the air pressure in the air brake system falls below operational levels, the pressure holding valve responds to release the air from the parking brake chambers.

A pneumatically-operated braking system for a tractor-trailer combination incorporates a trailer control valve (4) for providing braking pressure for the trailer. The control valve (4) is adapted to be actuated by a pressure differential acting across it to limit the flow of air in the supply line (2) when a leak is present in the trailer control line (12), and the pressure differential is generated between the pressure in the supply line (2) and pressure supply from another independent source (...

A pneumatic vehicle spring parking brake pressure holding valve abruptly seals an atmospheric outlet and enables the valving of brake release air pressure to the spring parking brakes when the vehicle reservoir attains a first pressure. Parking brake release is thus enabled. In the case of loss of air pressure from the system, the pressure holding valve retains the brakes fully released until the vehicle reservoir air pressure drops to a second pressure which is lower than the first. The pressur...

An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking co...

An optical RF spectrum analyzer which is suitable for determining the reaime spectral frequency content of radar return signals. The optical RF spectrum analyzer includes a demodulator for demodulating an input RF signal to produce a time-varying voltage signal at its output, and a sample and hold circuit for sampling the time-varying voltage signal to obtain and hold a prescribed number of samples of the time-varying voltage signal during each of successive prescribed frame intervals. At the co...