Patent GB-329661-A (GB)
Title: Apparatus for preventing the passing of danger signals on railways
IPC: B61L3/04
Filed: 1929-01-17
Abstract: 329,661. Schmidt, F. K. Jan. 17, 1929. Track apparatus actuating signals on trains and for stopping trains.-The train carries a number of flexible contacts bars operated in predetermined sequence by track contacts operable, for example, in conjunction with the usual track signals so that the operation of the final bar in the series on over-running a danger signal, releases a spring (not shown) or otherwise operates to give a signal or apply the brakes. Signals may also be given by the operation of an intermediate bar in the series, for example a warning signal on passing a distant signal at danger, the brake being applied by the final bar operation at the home danger signal. The flexible bars 6 - - 9 are clamped at 10 in bracket 12 mounted on a wheel axle 11 and prevented from rotating by a pin 12<x> engaging a socket 12<xx> on the vehicle body, the lower ends of the bars being adapted to engage track contacts 2 - - 5 (shown diagrammatically, Fig. 1) which can be raised or otherwise moved to operative position when necessary. The track contacts are suitably staggered and spaced along the track to give the required sequence, which as described is a successive operation of the bars 6 - - 9, and are of such length that each bar is retained flexed as in Fig. 7 until operation of the next succeeding bar is initiated. Each bracket 12 carries a casing containing a depending pivoted member 20 and a cranked lever 13-15, the lower end of the depending arm having a roller engaged by thecorresponding flexible contact bar. As shown, the pivoted members and levers are duplicated to provide for running in either direction. Between bars 6 - - 9 are pivoted normally horizontal locking levers 17-19 (biassed to normal position by gravity or springs) the left end of each bar (Fig. 1) resting on the horizontal arm of the corresponding lever 13-15, the right hand end being positioned in front of member 20 of the succeeding bar to prevent its swinging movement. Member 20 of the first-operated bar 6, and the cranked lever of the last-operated bar 9 are omitted as unnecessary. Members 20 are so disposed, when held by the locking bars, as to prevent flexure of the contact bars about their upper end supports 10. In operation, on overrunning raised contacts 2-5 at a danger signal, bar 6 is flexed by contact 2 thus moving lever 13 to raise the left-hand end of the bar 17, the right-hand end of which is depressed to release member 20 of bar 7. Bar 7 is then operated by contact 3 to effect a similar movement of lever 14 and bar 18, thus releasing member 20 of bar 8. Operation of bar 8 similarly releases bar 9, the operation of which by contact 5 gives a signal or applies brakes by suitable means, such as therelease of a compression spring, not shown. This compression spring may be moved to the stressed operative condition only when necessary, as by a member connected to the driver's control lever. Alternatively the stressing may be effected automatically when the locomotive is under steam &c., the steam &c. being admitted to operate a piston, which stresses the spring and is thenretained by a catch released to apply the brakes, the piston also controlling a steam-supply valve, the valve being opened to supply steam when the piston and spring are released, and closed when the piston occupies its spring-stressing position.