Patent GB-191115282-A (GB)
Title: Improvements in and relating to Railway Cab-signalling.
Inventor: MARTIN RICHARD HARINGTON
IPC: B61L3/04
Filed: 1911-06-30
Granted: 1912-06-27
Abstract: 15,282. Martin, R. H. June 30. Recording signals; miniature signals; track apparatus actuating signals on trains and for stopping trains. - A position-indicator is provided on an engine to show the distance from a signal at danger, the pointer being clutched to a wheel-driven mechanism by the passing over of a track contact at danger.' Combined with the indicator is a speed governor whereby an emergency signal may be given, or the train stopped, when the position and speed together constitute a danger. The position - indicator may be combined into a single instrument, with the indicator described in Specification 15,280/11. The indicator consists of a pointer A<14>, Fig. 2, moving over a dial A<15> and held by a spring A<16>. The pointer is driven from a wheel-driven gear A<9>, when connected thereto by a clutch A<1>, A<2> operated either by a spring, on the de-energization of an electro-magnet of which the circuit is broken on receipt of a danger indication, or by an arm B' pivoted at B<2> and connected by a pin B<3> to an ear B<4> on a screwed sleeve B<5>. The sleeve B<5> is moved to operate the clutch by the movement of the screwed spindle B<6> of the semaphore arm B<11> when that arm goes to danger. For putting the mechanism out of action, an arm B<16> is actuated to put out the toggle B<12>, B<13> which carries the pivot B<2>. The arm may be connected to the hand-lever pulled across the instrument face as described in the before-mentioned Specification. The danger indication is given at a fixed distance, say one mile, in front of the signal, and the dial is calibrated to work from that distance to zero. To show the distance from a number of stop signals close together, a wheel-driven wheel D', Fig. 3,- is provided with a number of spring-pressed stops D<3> adapted to be held in two or more positions by spring- pressed bolts D<5> provided with heads D<9> adapted to pass through a clip D", which can be drawn back on receipt of a danger indication to release the bolt then passing through it. The corresponding stop D<3> is then projected into the path of a spring arm D" fixed on the pointer spindle. A second danger indication projects a second stop, the distance between the stops being proportional to the distance between the signals. If then a second contact relating to the first signal be passed at ' safety ' an arm D<18> is released and reversely rotated by its spring D<19>. This arm has a bevelled end which raises the spring arm D<17> clear of the stops D<3>, thereby allowing the spring A<16> to return the pointer until the second stop is encountered, whereupon the pointer shows the distance from the second signal. The arm D<18> has a projection D<23> which contacts with the stop D<3>, and is thereby carried back to its zero position, where a cam returns the stop and a spring catch holds the arm. Alternatively, the stops may be housed in recesses open at both ends, and may be pressed inwards on receipt of a danger indication to engage the spring arm with their inner ends. In another construction, shown in Fig. 5, the wheels drive a toothed wheel T<1>, with which are adapted to engage radial arms T<6> pivoted on disks T<4> and held by pivot springs either in operative or inoperative positions. The leading arm is adapted to be engaged by a lever T<10> when a danger indication is given, to force it into engagement with the wheel T<1> to carry round the spring arm D<17>. A releasing-lever T<15>, released from its catch on receipt of a safety indication by an electro-magnet T<17>, acts as before to release the arm D", which then springs back to zero or to the next arm T<6>. An emergency stop signal may be provided by an additional spring-controlled arm arranged in the manner of the releasing-arms, but not bevelled to raise the arm D<17>. To this arm is fixed an emergency pointer preferably painted red, so that, when an electro-magnet is energized to release the arm the pointer is released and moves until engaged by the first stop, to show ' danger ' and cancel any previous signal. An audible signal may be simultaneously actuated, and the signal may be given bv the apparatus described in Specification 15,281 / 11. To stop the train, or give an emergency warning, when speed and position combined constitute a danger, a cam F<1>, Fig. 5, is connected to the pointer A<14>, and contacts with a lever F<2>, Fig. 7, which carries one end of a link F<8>, the other end of which is carried by a speed governor F<12> or other speed-registering mechanism. A rod F<14> thus partakes of the combined movements of the ends of the link F<8>, and when it rises to a certain position, closes an electric contact or opens a valve to give the signal or stop the train by opening the brake pipe. The link F<8> may be replaced by a movable slotted link so that the relative effect of the two operating movements may be varied.