Patent GB-190415061-A (GB)
Title: Improvements in or relating to Signalling Apparatus for Railways and the like.
Inventor: THOMPSON WILLIAM PHILLIPS
Filed: 1904-07-05
Granted: 1905-03-02
Abstract: 15,061. Thompson, W. P., [Weatherby Electric and manufacturing Co.]. July 5. Automatic systems; semaphore signals; lamp signals; contacts, electric; controlling signals; signalling approach. of trains; crossing-gate signals; electric railways and tramways, signalling on. - An automatic electric absolute block system is described for a single-line electric railway with an overhead trolley wire and turn-outs between the blocks. Each car actuates a special electric switch either in the main wire, or in the turn-out wire at the entrance to each block, thus actuating special semaphore disc and lamp signals through a special controlling-mechanism. Slight modifications render the system applicable for double lines. Fig. 1 shows the connections for three stations. Two sets of controlling-mechanism, one for each direction of travel, are comprised in each case, each set comprising a pair of electromagnets D, D', Fig. 4, with armatures e, e<1>, each pivoted on a shaft e<2> normally raised by a weighted arm e<4>. Between the magnets D, D<1> is a drum G with a ratchet flange g at each end engaged by a pivoted pawl g<3> on an arm e' when the electromagnets are energized. Stops g<4> limit the movement of the pawl g<3>, and a stop pin g<5> on the arm e' allows movement of one tooth only at a time, while a spring detent x prevents casual movement. The drum surface is broken by an insulating-strip g<9>. Brushes h in contact with the drums are connected to the trolley wire A, Fig. 1, while the electromagnets D, D<1>, F, F<1> are connected in pairs through a resistance to earth plates h<6> or the track rails, and are also connected through wires L, M, L', M<1> to switches N, N', arranged in the trolley wire A and in the turn-out wire at each station. The trolley-wire switch N, Fig. 5, is contained in a casing N<3> clamped between the usual guy-wire insulator n<3> and the hunger ear n by a screwed bolt n<5>. Arms o depend from each projecting-end of a rock-shaft n<8> within the case, and bend inwards, almost meeting beneath the trolley wire A. The trolley wheel of a car moving in either direction actuates these arms o, and the shaft n<8> causes an attached shoe P to connect two springs p<1> and so to close a circuit between the attached wires L', M', or between the wires L', M<3>, through two springs p<3>. These springs are insulatedly mounted on standards connected by two cross-pieces, between which two horizontal friction discs are journalled, to prevent overswinging of the shoe P after actuation, by engaging a rod P' attached to the rock-shaft n<8>. Similarly, each turn-out wire switch N', Fig. 1, completes the circuit between the wires L, M, or between the wires L<3>, M'. The disc semaphore signal mechanism, Fig. 11, is shown duplicated for a single line, and is contained within a cylindrical case Q. One of the hinged circular doors is shown open in the Figure. Each disc semaphore R is visible through a circular window in the upper part of the door, and moves by means of a sleeve on a pin fixed to the door, being actuated by an arm r' moving against a pin r<6> fixed in one hole of two concentric rings of holes in a disc r<3> attached to the sleeve. Adjustable weights s, s<1> on arms fixed to the sleeve restore the disc by gravity to its normal position. The adjustable position of the pin r<6>, together with the adjustable weights s, s<1>, allows regulation of the sensitiveness. The arm r' is attached to the pivoted armature t of the controlling-magnet T. A pair of electric incandescent or other lamps u illuminates each window, exhibiting a red light when a red-glass disc R is interposed. A porcelain or frosted-glass screen separates the pairs of lamps. The lamps and electromagnets are connected to the drums G, G<1>, Fig. 1, a fuse being interposed in the circuit together with an earthed lightning-arrester strip. Two green caution-signal electric incandescent lamps or semaphores are contained within a casing W, Fig. 11, on the case Q divided to contain a lamp in each half. These lamps are contained in the same circuit with the corresponding lamps u at the stations to the left and right on block-system principles. If cars moving from right to left omit the turn-outs, and vice versÔ, a car passing from the block B<2>, Fig. 1, to the block B' connects the springs p, p<1> of the trolley switch N, so connecting the trolley wire with the wires L', M<1>. The current alone the wire M<1> energizes the magnet F<1> at the station C', and through the ratchet moves the drum G<1> one tooth, so moving its insulating-strip into contact with the brushes h and breaking the circuit containing the magnet T at the station C', its semaphore disc R being then released and the lamps cut out, thus clearing the block B'. At the same time, the current in the wire L' similarly sets the signal at the station. According to the number of teeth in the ratchet drum G, Fig. 4, the number of cars successively entering any section in the same direction may be varied. When the maximum number of cars has passed, a pin on the drum engages the bracket g<7>, and the drum must then be oppositely rotated by oppositely-travelling cars. To reverse a car, the trolley is lowered while the car drifts past a switch, which it actuates when returning. Hand-switches may replace the automatic switches N, N'. An audible signal, such as a bell, may be included in the semaphore-signal circuit for use at crossings and bridges, and the audible signal may replace the visual signal. The system may be employed to indicate the approach of a car at curves or street corners.