Patent GB-190800098-A (GB)
Title: Improvements in and relating to Apparatus for Signalling on Railways.
Inventor: SAUNDERS LEWIS ERNEST
Filed: 1908-01-02
Granted: 1909-03-02
Abstract: 98. Saunders, L. E., Davis, H. L., and Griffiths, W. Jan. 2. Contacts, electric and mechanical; indicating route to drivers; signalling to cabins &c.-In railway signalling-apparatus using a long ramp for mechanically disclosing electrically-operated signals on the engine cab, means are provided for giving, on the engine, signals adapted to indicate whether the train is consigned to the main line or to a branch on either side. The ramps and their electric connexions to the cabin, the miniature signals, and the disclosing-means are all of the character described in Specification No. 12,008, A.D. 1907, but three home signals a, b, c and three distant miniature signals d, e, f are now provided in the engine indicator, the semaphores a, d controlling the left branch, b, e the main line, and c, f the right-hand branch, the shutter having two disclosing-slots h, i as before. Two ramps A, B are also provided at each such junction signal, and the engine carries twin contact-wheels w, x, the bearing-bars for which are carried between insulated brackets q, r. The ramps are electrically connected with the signal cabin, so that the movement of the three levers 11, 12, 13, governing the corresponding semaphore signals, to 'safety,' causes current to be sent through the ramps to a passing train to give the corresponding signal. The slides q, r are connected to a switch 8, 9, which normally makes contact with a wire 25, leading to the winding of a magnet 1 and to one winding of a double-wound magnet 2, and with a wire 26 leading to the second winding of the magnet 2 and to the magnet 3, both circuits being then earthed. The signals a, d and c, fare arranged to be put to safety by positive current passing through the ramps A, B to the magnets 1, 3 respectively, while the signals b, c are operated by negative current through either ramp to the magnet 2, for which purpose, the magnets are provided with polarized armatures. Indicators, similar to the engine indicators but without the disclosing-means, are provided in the cabins, separate indicators being provided for home' and 'distant' signals. To give a signal for the lefthand branch, the signalman pulls over the lever 11, thereby completing a circuit from the negative end of a battery 10, through wires 30, 31, 32 to earth, and from the positive side through wires 34, 35, magnet 14, and instrument 24 to earth, attracting the armature 16 and lowering the cabin miniature signal. A train on reaching the ramps then completes a circuit from the battery 10 through wires 20, armature 16, wire 37, ramp A, slide q, wire 25, and magnets 1, 2 to earth. This positive current actuates only the signals a, d of the lefthand branch. A signal for the right-hand branch is similarly given by pulling over the lever 13, and actuating the magnet 15, while the main-line signal is given by pulling over the lever 12, whereby negative current to actuate signals b, c is given, both magnets 14, 15 being in this case energized. When the magnets 14, 15 are not energized, their armatures bear against contacts 19, 21, so that both ramps A, B are in circuit, by a wire 53, with the telephone 23 in the cabin, so that the driver while over a ramp giving a 'danger' signal, may communicate with the cabin by moving the switch 8, 9 on to the contacts of his telephone 6, which movement of the switch may be effected by the lifting of the receiver. If the driver wishes to communicate when the signal is at 'clear,' he may throw over his switch and pass intermittent current through the ramp circuits, causing the signal in the instrument 24 to become unsteady and thereby call the signalman's attention.