Abstract: An improved security and communication system accurately and quickly locates the position of a signaling portable radio frequency transmitter. When a portable transmitter is activated, a first signal, including identification information, is emitted. The first signal is received by any of a number of radio frequency relays, the signal is manipulated and transmitted to a central processing station as a second signal. The central processing station can, by using the second signals received, either from one or a number of relay stations, determine which relay station is closest to the portable transmitter.

Abstract: A security and communication system permits the location of signaling portable radio frequency transmitters which may be carried by individuals. If an individual signals with his portable frequency transmitter, a first signal is sent including a first individual identification code to identify the particular portable transmitter. The first signal is picked up by at least one of a plurality of radio frequency relays each positioned in a predetermined location. Such relays immediately transmit a second signal including the first identification code and also a second identification code to identify the individual relay that is transmitting the second signal. Thus the signal sent by the individual relay identifies the location and the specific identity of the particular portable radio frequency transmitter which is sending the signal.

Abstract: A remote-controlled doorbell adapted for connection across the existing doorbell in a building having a wired doorbell system. A transmitter for generating an over-the-air radio signal is coupled across the wired doorbell so that the transmitter will be actuated in response to current flowing through the wired doorbell. A remote receiver coupled to sound producing means receives the over-the-air radio signal and actuates the sound producing means when the existing doorbell is energized.

Abstract: A method and apparatus are provided for loading railroad cars coupled in motion. Prior to loading, an "empty" composite weight is obtained of the front and rear trucks of an empty selected railroad car, the rear truck of the adjacent forward railroad car with load and the front truck of the adjacent rearward railroad car. This "empty" composite weight is stored in a memory. The dynamic composite weight during loading is sensed. A desired net weight of the load (to be loaded into the selected railroad car) is selected. A total composite weight that is equal to the "empty" composite weight plus the desired net weight of the load is stored in a memory. The selected railroad car is loaded until the dynamic composite weight appears equal to the total composite weight. The actual net weight of the load is then determined by substracting the empty composite weight from the actual total composite weight.

Abstract: A system is provided for weighing freight cars coupled in motion during loading. An upstream weigh bridge is provided and is mechanically separated from a downstream weigh bridge, with a loading chute overlying one of the weigh bridges for dispensing material to the freight cars. The upstream weigh bridge has a length that is less than the distance between the rear axle of one car to be loaded and the front axle of the succeeding car.The position of the freight car under consideration is sensed and the chute is opened to load the freight car. The full draft weight of the freight car during loading is detected, taking the weight on the upstream weigh bridge into consideration. The chute is closed when the weight reaches a predetermined amount. The weight of the loaded freight car is determined after the freight car has left the upstream weigh bridge and only the weight on the downstream weigh bridge is taken into consideration.