Patent GB-190204650-A (GB)
Title: Improvements in Signalling Systems for Electric Railroads.
Inventor: HART ORLANDO W
Filed: 1902-02-24
Granted: 1902-06-25
Abstract: 4650. Hart, O. W. Feb. 24. Electric railways, signalling on.-Relates more especially to single-track railways, provided with sidings to enable cars travelling in opposite directions to p a s s each other. Semaphore and lamp signals are mounted in casings, preferably supported on the trolley - wire standards, at suitable intervals along the track, and particularly at the sidings, the signals at the various signal posts being operated selectively from a central station. Fig. 1 shows the arrangement and connections of the apparatus for the central station A and four signal posts, the details of the signalling-mechanism being shown only at post No. 4. The semaphore S consists of an opaque oval disc, having a central transparent red disc, and is attached to a sliding block 27. The semaphore is held in its raised position by the catch armature 30 of the electromagnet E engaging in the notch 26 in the block 27, and in this position the rod 25 closes the contacts 36, 35. The circuit of the electromagnet E is adapted to be closed at the contact s by the projection 20 on the disc 19 which is rotated through the ratchet 17 by the armature e of the electromagnet D. The position of the projection 20 on the disc 19 differs at the different signal posts. To set the signal at a particular post, the operator at the central station actuates the key k, so closing a circuit from the generator G through the electromagnet B of the indicator c, key k, line 1, lead 12, electromagnet D, lead 13, line 2, and lead 11 back to the generator. The operation of the key is repeated until the number of the signal post appears on the indicator c, the projection 20 of the particular post being then in contact with the spring s. The operator then actuates the key K, so completing the circuit K, 8, 3, 14, s, 19, 21, 36, 35, E, 15, 13, 2, 11, G, 7 through the bell d and electromagnet E, the latter releasing the catch 30 and allowing the semaphore to fall into its indicating position. The lamps L, which show red through the semaphore, are illuminated from the trolley-wire T through the lead 40 and earth connection G<1>, and can be cut out by the switch s<2>. The semaphore, in falling, releases the weighted arm 31, which is geared through the clock train M to a contact disc 33, the arm 31 causing teeth or projections on this disc to make contact with the spring 37, so completing the circuit of the bell d. The disc 33 is arranged to ring the bell a definite number of times, corresponding to the number of the signal post, to indicate that the signal has been correctly set. The operator, on receiving this return signal, releases the key K. A sounder or a paper strip recorder may be used instead of the bell. The semaphore may be re-set by the conductor or motorman by any suitable means, is, such as a pull cord passed over a pulley and connected to the disc. Telephones t are arranged in normally open bridges across the leads 1, 3, and can be connected up by switches s<3>. In the modification shown in Fig. 2, a recorder is employed at the central station, and an indication is given that the semaphore has been correctly set, and that the lamps are lighted, by an elongated tooth v on a disc n carried by the spindle of the contact disc 33. The contact 45 engaged by the tooth v is connected to the lead 21 by the armature 47 only when an electromagnet is energized. The circuit of this electromagnet includes the lamps L<2>, L<3>, and a contact 54, which is closed by the plug 50 on the semaphore when the latter falls. The lamp L<3> is cut out by the electromagnet R<2>, so long as the lamp L<2> is in order, but, in case of failure of the lamp L<2>, the electromagnet R<2> releases its amature 53, which then connects up the lamp L<3> at the back contact 52.