Patent GB-189716651-A (GB)
Title: Improvements in Controlling and Working Railway Signals and Points.
Inventor: TIMMIS ILLIUS AUGUSTUS
Filed: 1897-07-13
Granted: 1898-07-09
Abstract: 16,651. Timmis, I. A. July 13. Controlling and locking signals ; interlocking ; signalling between trains systems, automatic safety and locking bars; indicators and repeaters, point and signal; electric railways, signalling on.-Relates to means for controlling and operating electrically-worked signals, points, ground discs, &c. Reference is made to Specifications No. 5718, A.D. 1883, No. 7827, A.D. 1891, and No. 21,496, A.D. 1893, which describe means for electrically operating signals, points, &c., automatically and otherwise, and means for reducing the main operating-circuit to a lower holding-circuit after the operation has been effected. The present invention consists in the employment of a track circuit for controlling the operations. In the arrangement shown in Fig. 1, the track is divided into insulated sections K, K<1>, each of which is electrically connected to a battery b and an electromagnet m When the section is clear, the magnet m is energized and holds its armature l so as to complete the main signalling- circuit C between the contacts t. Then, when the signal lever L is put over, it connects the contacts t<1>, and so completes the circuit C through the magnet M, so lowering the signal S. The lowering- current is then reduced to a holding-current as described in the prior Specifications. The circuit C also includes a magnet M<1>, which holds the lever L over until the circuit is broken. Should a train or vehicle enter the section, it short-circuit, the battery band de-energizes the magnet m, which then releases the armature l and breaks the circuit C. This de-energizes the magnets M, M<1>, so that the signal goes to 'danger,' and the lever L returns to its normal position. The signal cannot be again lowered so long as the section is occupied. The magnet m may be arranged to switch in another circuit to operate the armature l. In the arrangement shown in Fig. 2, the track circuit includes two magnets m, m', the armatures l, l<1> of which close the circuit C between the contacts t<2>, t. The armature l is also provided with a projection which, when the signal is lowered, engages under and supports the signal-operating rod, the movement of the armature to the magnet m also breaking the circuit C at t<2>. When a train enters the section, the magnets m, m<1> are de-energized and allow the signal to return to 'danger.' In this arrangement, the signalman cannot put the signal to 'danger' when it has once been lowered, and it is stated that, for this reason, the arrangement is more suitable for automatic signalling. In a modification, which allows the signalman full control, the magnet m' and armature l<1> are omitted, and the magnet M<1> is comprised in the track circuit C'. In automatic signalling, the signal arm, when it is put to ' danger' by the shortcircuiting of the track circuit, actuates a switch which closes the main lowering-circuit of the signal or signals in the rear. A modification is also described which provides for one or more clear sections, as well as a signal at 'danger,' in the rear of the train. When the track is used to convey another current of electricity, as in some electric railways, the signalling-currents are conveyed by separate conductors. Points &c. are electrically interlocked with the signals, so that they cannot be operated, or even unlocked, until the signals which control them are put to 'danger,' and signals cannot be lowered until all the points controlled by them are properly set and locked. When a locking-bar is not employed, the movement of the point-lever closes a circuit through a magnet which withdraws the point-locking bolt, and the bolt then closes a circuit through a magnet which sets the points. The movement of the points breaks the first circuit and releases the locking bolt, which then re-locks the points ; these latter movements also close contacts which complete the main signalling and repeater circuits. The apparatus is duplicated in so far as is necessary for the operation of the points in both directions. When a locking-bar is employed, the locking-bolt is not directly connected to the magnet which operates it, but indirectly through a system of levers and the locking-bar.