Abstract: An internal safety shutoff and operating valve includes a housing defining a valve seat and a cylinder. A piston slidable in the cylinder includes a valve closure member engageable with the seat for closing the valve. A spring biases the piston toward the closed position, and an actuating assembly moves the piston against the spring to the open position. One set of main ports communicates with the valve seat between the valve seat and the cylinder, and the other set of main ports communicates with the opposite side of the valve seat. Pressure forces on the piston are balanced by a passage in the piston intercommunicating the cylinder with one set of main ports. In order to prevent leakage between the piston and the cylinder wall to the other set of ports, a seal assembly including a groove in the piston wall and a seal ring in the groove is provided. The groove includes rounded inner corners, and the seal ring is provided with inner and outer grooves interconnected by passageways.

Abstract: An air conditioning system for a railway vehicle operable from an applied high voltage direct current, which system includes an alternating current induction motor driving a variable speed, helical screw-type refrigerant compressor. A variable frequency AC drive circuit is provided to power the motor from the high voltage direct current. The output frequency of the drive circuit is varied according to the cooling demand of the vehicle.

Abstract: A pot-type burner is equipped with baffle plates for establishing recirculation zones within the burner for efficiently mixing air and gas in a conventional manner. The burner construction is improved by removing the combustion ring, and in its stead adding an annular dome. This initiates sonic pulsations, sustained within a heat exchanger housing which has critical dimensions relative to the burner parts. The pulsations produce improved combustion.

Abstract: A check assembly using compressible fluid for linearly dampening the closing movement of a door includes a cylindrical, hollow housing having a cavity defined therein with first and second ends. Slidably mounted within the cavity and attached to the door is a piston of substantially the same cross-sectional area as the cavity. The piston has flap-type, relief check valves allowing free passage of compressible fluid through the piston only during motion of the piston in the door opening mode. The check assembly further includes longitudinal grooves fabricated circumferentially around the cavity and of a dimension such that the seal of the piston against the cavity wall is broken at different points during movement of the piston allowing compressible fluid to flow from one side of the piston to the other. Finally, the check assembly includes a fluid bypass continuously communicating compressible fluid from one end of the cavity to the other thereby defining a closed loop system.

Abstract: A lamp out detection circuit is provided for a buoy lamp changer. The circuit includes an modified Hartley transistor oscillator which is tuned to operate at a preselected frequency. A typical lamp flasher applies power to the lamp and the lamp out circuit, simultaneously. If a normal lamp is in operation, a current pulse is inductively coupled to the oscillator in a manner suppressing sustained oscillation. Should the filament of an incircuit lamp fail or become electrically non conductive, the lack of inductive coupling to the oscillator would permit sustained oscillation which results in generation of a pulse signal. Time delay means are provided to ensure that the pulse signal is not intermittent. Further indexing through a time delay is provided to permit the lamp changer to rotate a new lamp into an operating position before further monitoring of faults occurs. Means are provided to prevent rotation of the turret after the last lamp has failed.

Abstract: A relay has an abutment mounted adjacent its armature for movement therewith. A spring-biased tapered pin engages the abutment when the relay is energized. This causes the relay to maintain a latched, first switch state. An electromagnetic releaser is then energized which displaces the pin thus freeing the armature. A spring returns the armature to an unlatched position whereby the relay is set to a second switch state.

Abstract: A hot water generator capable of producing a maximum rate of water temperature increase without generation of vapors including a heat exchanger in the form of an annularly shaped helical coil through which the water to be heated is pumped and which is connected to a piping system including a load and a combustor for rapidly providing increased combustion which is controlled in response to the temperature of the water at the outlet of the coil so that the heater can produce a maximum rate of water temperature rise without causing boiling and generating vapors in the coil. The method concerns the shock testing of piping components by producing nearly theoretical maximum heat flux rate very quickly.

Abstract: A tape recorder module vehicle operation data, on-board. The module is removed from the vehicle and data is played back at a ground station. A telecommunication link exists with a remote data processing system for processing the played back data.