Patent GB-190409858-A (GB)
Title: Improvement in and relating to Staff Systems and Apparatus for Controlling Traffic on Single Line Railways.
Inventor: SMITH EDWARD WYTHE
Filed: 1904-04-29
Granted: 1904-07-28
Abstract: 9858. Smith, E. W. April 29. Controlling traffic on railways, staff systems for; signalling-instruments.-Modifications in the Webb and Thompson electric staff and disc instruments for the purpose of preventing improper insertion or withdrawal of a staff from an instrument, indicating the condition of the block sections, and cutting out an intermediate cabin at will are shown in Figs. 1, 2, 4, 8, 10, and 12. Small staffs A, Fig. 12, are employed, having the usual rings 70, 71, 72, 73 for actuating the disc-locking pawls, spaced differently for each section and with further means for preventing the placing of a staff in an instrument to which it does not belong, consisting of a fifth ring 70<a> which passes between one of the discs and the side of the case, also of notches at the side of the staff entrance 1, Fig. 1, through which these rings must pass, and of enlargements 41 ... 45 on the staff which engage with grooves in the usual notches B, Fig. 10, of the discs. The staffs are inserted in the opening 1, and pass down the curved passage 2 to the compartments 4 of the magazine 3, operating as they do so the disc mechanism, consisting of five discs on the spindle 6, mechanical and electric locking-pawls on the spindle 7, and a safety lever on spindle 10. The locking-disc 21, Fig. 2, is controlled by the signalman of the cabin in advance, who energizes the electromagnets 22 to release. These magnets, of which the pole-pieces are seen at 22<a>, 22<b>, Fig. 4, are carried by the vertical arms of the lever 9 and, together with permanent magnets 23, 23<a>, 23<b> similarly supported, they form a field in which an armature 24, 25 can rotate from its normal position to that shown, in which the movement of lever 9 by a disc would cause the hooks 27, 29 to engage, whereby the levers 9, 8 would move together and the projection 8<a> clear the edge of, and unlock, the disc 21. A pin 18 on the lever 8 engages in a slot on the safety lever 15, and cannot escape therefrom unless motion of the lever has brought the pin opposite the gap 19 between the jaws 16, 17, return movement of the lever being always secured by pins 30 on the locking-disc engaging the projection 31. The arms 16', 20 on the disc 9 and lever 15 respectively also lock together, and a link 32 attached to the latter operates the cam 33 and thus the lever 34 for the communicator switch interchanging the line and earth connections upon withdrawing or replacing a staff. Normally, projections on the locking-pawls and levers engage the recesses in the discs, but are thrown out of gear by the insertion or withdrawal of a staff. To cut out an intermediate cabin, the two staffs, one for each of the short sections ending there, are placed in the two drawers 74, 76, Fig. 8, which can then be. pushed well to the left, the ends 85 of the pawls 84 having been lifted by the rings 70 ... 73 on the staff so that the shoulders 86 do not lock the drawers. By this movement, the L-shaped pieces 83 have been released, and the central drawer 75 may now be drawn to the right in order to remove the long-section staff, the other drawers being simultaneously locked by the pieces 83. Fig. 10 shows the indicating-mechanism in which the poles 46, 47 of an electromagnet and those 48, 49 of a permanent magnet form a field for the armature 50 carried on the arms 51 centrally pivoted. Flags 53, 54, 56 are thus brought to windows 55, 57 and co-operate with fixed wording thereon to give the required indications. The flag 60 is pivoted at 61 and mechanically operated on the withdrawal of a staff by pins 69 carried by the disc 35, the lever 66 and piece 62 acting on the tail 64 so as to bring the flag downwards in front of flag 53, depressing, by means of projections 65<a>, 51<a>, the armature until the window 53 is reached. The four signals thus shown are " train in section," "train on line going," " train on line coming," " line-clear." A system of making the connections between the line - wire, earth, generator, bell, signalling-key, the electromagnets of the locking and indicating mechanism, and also the commutator switch is provided.