GB446459A - Improvements in or relating to signalling apparatus for railway level crossings - Google Patents

Abstract

446,459. Level-crossing signals. NAAMLOOZE VENNOOTSCHAP MACHINERIEEN-EN APPARATEN FABRIEKEN MEAF, 30, Croeselaan, Utrecht, Holland. June 1, 1935, Nos. 16003 and 16004. Convention dates, Aug. 24, 1934 and Nov. 14, 1934. [Class 105] In a level-crossing signalling arrangement wherein short trackcircuit sections L, M are provided at the two ends of the stretch and in which further normally energized relays 3, 4 are included in the conductor lines to the track circuits to give a warning signal in case of breakage, these relays 3, 4 are also used for the train control of the signal and thus their contacts are kept regularly in use. The arrangement shown in the Figure has in addition to the normally energized shortsection track relays 1, 2 and control relay 3, 4, further relays 5, 6 normally de-energized but coming into action when the train reaches the short sections N, O butting on the actual crossing. A train entering at the left shunts out the relay 1 which then remains de-energized over a stick shunt circuit including its own back contact 12 and a back contact 63 of the relay 6. The signal control relay 7 is deenergized by the opening of front contact 11a of the relay 1 ; thus the warning signal is brought into operation. When the train reaches the crossing the axles on the sections N, O shunt out the relays 3, 4 and thus their back contacts 33, 43 pick up the relay 5 a front contact 52 of which energizes the relay 6 (over back contact 11b of the stick shunted relay 1). This energization of the relay 6 opens the back contact 63 in the stick shunt circuit of relay 1 which therefore now lifts its contact 11 and opens the circuit of the relay 6. A stick circuit over front contact 51 and back contact 61a maintains the relay 5 energized after the train leaves the sections N, O. The signal relay 7 is energized over the front contacts 31, 41, 21a and 11a to give the clear signal. When the leaving train reaches the end section M the relay 2 is shunted out and its back contact 21b then allows the relay 6 to be energized over front contacts 52 and 11a. The relay 6 then opens its back contact 61a to de-energize the relay 5 ; closes its front contact 62 to maintain itself energized so long as the shunted relay 2 closes the back contact 21b ; and opens the back contact 64 in the stick shunt circuit of relay 2 to allow the relay 2 to lift as soon as the section M is free of axles. The apparatus is thus returned to the normal state. Any conductor breakage which de-energizes the relays 3, 4 will give a warning signal since the front contacts 31, 41 in the line to the signal relay 7 will open. A modification is described in which only one section O is provided at the crossing, the relay 4 being connected directly thereto but the relay 3 only being connected whilst the relay 5 is energized. The arrangement operates properly both with single short vehicles and very long trains.