| 摘要 |
<p>WAYSIDE SIGNALING SYSTEM FOR RAILROAD CAB SIGNALS AND SPEED CONTROL A transmitter and a receiver are located at each junction location between adjoining track sections along a stretch of track for transmitting and receiving cab signal or speed control commands through wire loops laid in a preselected pattern parallel to and between the rails of each section. Train carried apparatus is selectively reponsive to the speed commands and to the pattern of the wire loops to control the movement of the train in the established direction through the stretch. A distinct directional frequency is transmitted from the selected entrance end of the stretch, when a train movement is desired, and is repeated at each wayside location through the wire loops to the exit end. The directional frequency reception at each location activates a filter output to selectively enable gating elements to connect the associated transmitter and receiver to the adjoining section loops in accordance with the desired traffic direction. The speed command transmission is selected in accordance with the advance traffic conditions. If the immediate advance section is occupied by a train, a restricted speed command is transmitted in the principal loop of the approach section but no command is applied to a second loop at the exit end which causes the train to halt prior to entering the next section. This prevents the overrun of sections by a following train and the inadvertent reception of a higher speed command intended for the preceding train.</p> |
