Patent GB-375456-A (GB)
Title: Improvements in or relating to single line railway systems
IPC: B61L23/24
Filed: 1931-04-02
Abstract: 375,456. Staff and like systems for controlling traffic on railways. TYER & CO., Ltd., PUNTER, J. W., Ashwin Street, Dalston, London, and TATTERSALL, A. E., Hayton House, Acomb, Yorkshire. April 2, 1931, No. 10097. [Class 105.] In a staff or like system for controlling traffic on railways an occupation authority for working parties comprises a key G and a pair of contact plugs I, J connected by a short length of conductor cable H. At each end of the section and at intermediate points are located plug boxes K<1> .. to retain one plug J while the other plug I and the key G are to be inserted in key boxes E<1>, E<2> at each end of the section or in a key box F carried by the working party trolley, Fig. 2, which by reason of the shortness of the cable H must therefore be removed from the rails. The occupationauthority may be released, when the staff instruments are normal, on the receipt of the appropriate polarity current from the far station over line wire 17 which actuates a polarized relay L to close its contact 15 whereby a locking relay D is energized to permit movement of a rotary switch C past the position 2 to position 4 in which a battery B<2> is now applied to the plug-box line 26. The circuit to the locking relay D is from battery B<1>, wire 25, contact 15, contact 22 which is closed only when the staff instruments are normal, contacts 9, 10 bridged with the rotary switch C in position 2, wire 20 to relay D and back to the battery over wire 19. The plug boxes K<1> retain the plug J by a hooked armature engaging a pin j on the plug. The key boxes El, E<2>, F retain the key G by a magnet detent m which engages a shoulder on a disc N on the keyoperated barrel g. The barrel also acts to move a lever o ; the lever o and magnet detent m when lifted open the contacts 40, 42 respectively. Accordingly, with the switch C in position 4 and with the pushbutton 35 depressed to close contact 34 the battery B<2> will energize the key-box magnet M to lift the detent m and allow the barrel g to be turned to permit withdrawal of the key G ; the movement of the barrel g allows the lever o to drop and therefore the contact 40 closes to complete a circuit from key-box battery B<3> to the plug-box magnet P whereby the armature hook is withdrawn to release the plug J. The plug I is freely inserted in its socket and accordingly the key G and the plugs I, J with the cable H are released for the occupation authority. To return the system to staff working the key G is inserted in a key box and turned so that the magnet detent m drops to lock the barrel g and to close contact 42 whereby battery B<3> is applied to the plug-box line 26 and on turning the rotary switch C to position 3 a relay R is energized to close its contact 50 and so to close the circuit of batterv Bl to the locking magnet D which now permits the switch C to be moved to position 1 and the system is now normal. The occupation authority may be released by magneto-generated oscillatory current applied to the line wire 17, the occupation wire 26 then being omitted and blocking condensers being inserted in the connections to the plug boxes K<1> .. to prevent a release operation by the staff instrument direct current.