Patent GB-189707474-A (GB)
Title: Improvements in Railway Signalling Apparatus.
Inventor: NEWSOM JOSEPH NEWBY
Filed: 1897-03-23
Granted: 1897-07-10
Abstract: 7474. Newsom, J. N. March 23. Semaphore &c. signals; lamp signals; fog and audible signals; signalling-instruments ; indicators and repeaters, signal.-Relates to means for operating railway signals from the ordinary telegraph instruments. The apparatus shown in Fig. 2 comprises a motor 59, which is driven by the electromagnet 62, and is adapted to wind up a clock spring enclosed in the case 56. This spring, through a train of gearing, drives the pawl-wheel 115, Figs. 19 and 20, mounted in the case 124. The pawl arms 118 are mounted, as shown in Fig. 19, so as to be capable of vertical movement with respect to the wheel 115 which carries them. Above the casing of this apparatus are mounted the call bells 13, the electromagnet 26 of which is connected in series with the electromagnet 232, Fig. 31, which controls the semaphore operating-mechanism. On the semaphore post 6 are mounted a red or 'danger' arm 206 and a white or 'safety' arm 208, and these arms are connected by chain and sprocket-wheel gearing, so that when one is raised the other is lowered, and vice versÔ. The arm 206 also carries the spectacle frame 209, which is duplicated on the other side of the lantern 203, so that the lamp signals are shown in both directions. The signals are moved to safety,' i.e., the arm 208 is raised and the arm 206 lowered, by the operator pulling the cord 239. When, however, the magnet 232 is energized, its armature releases the arm 231, which is geared to the quadrant 227 on the spindle 221, and permits the parts to return by gravity to 'danger.' When the motor 59 is started, the pawl. wheel 115 rotates without action ; but if the telegraph sounder 3 be operated, the forked arm 147 connected to the sounder actuates two pivoted dogs within the pawl case, and deflects the pawl arms 118 above or below the segment 128 within the pawl case, as shown in Fig. 28. Thus, when the particular call for the station is received on the sounder, the arms 118, Fig. 28, are selected so that, on the completion of the call, the pawl form 179 (which is notched to correspond with that particular call) drops over the upper pawls and stops the rotation of the pawl-wheel. This movement also releases the lever 149, which drops into engagement with a balance-wheel on the clock mechanism so as to prevent strain on the pawl-wheel. When the pawl-wheel is stopped, the motor circuit is broken, and the circuit through the magnets 26, 232 is completed, so sounding the call bell and releasing the semaphore arms so that they return to 'danger.' When the semaphore has gone to 'danger,' the bell continues to ring until a cam 47, on a shaft driven through ratchet gearing by the bell armature, releases the spring-controlled hammer 53. This hammer, when released, strikes the lever 171, which operates the lever 149 to release the clock mechanism. This operation also breaks the bell circuit and stops the bell. By means of contactbrushes 249, 251, Fig. 31, which are arranged so as to be electrically connected by a notched segment on the quadrant 227, the movement of the semaphore to danger' is caused to repeat the station call on the telegraph sounder, the segment being notched similarly to the pawl form 179, Fig. 28.