Patent GB-452493-A (GB)
Title: Improvements in railway level-crossing operating and signalling systems
IPC: B61L29/22
Filed: 1934-11-19
Abstract: 452,493. Operating barriers. FRYBA, J., 107, Ceskomoravska Street, Prague. Nov. 19, 1934, Nos. 33223 and 33224. Void [Abridged as open to inspection under Sect. 91 of the Acts, May 18, 1935]. [Class 65 (i)] [See also Group XXX] A level-crossing barrier is operated together with preliminary audible and visible signals by track contacts operating a locking-up relay 1 which energizes a mercury - switch relay 5 whereby a solenoid 7 is energized to release a latch 10 from a weight-driven disc and to release the locked-up relay by closing a contact energizing a release winding 4. The movement of the disc mechanically operates a bell hammer and a contact sector and a contact bar respectively light up signal lamps and, after a certain movement, energize a switch device S<1> for closing the circuit to the motor for lowering the barrier. The completion of the barrier movement opens the circuit at a gate-operated switch P which now prepares a circuit to a switch device S<2> for the motor circuit for the raising of the barrier which occurs when a track contact at the crossing completes the circuit to the switch device S<2>. Normally de-energized and normally energized arrangements using track contact apparatus responsive only to the passage of the first or last wheel and above a certain speed are described. The counter-balance weights of the barrier are arranged so that in both positions of the barrier they assist the starting movement. The barrier is raised at a higher rate by the battery including additional cells for this movement. Fig. 2 shows an arrangement for a single track with traffic in each direction. An approaching train at a track contact A briefly energizes, from a control battery 53, a relay 1 the contact 2, 3 of which is mechanically locked up and actuates a mercury switch 5, 6 by which a solenoid 7 is energized to remove a latch 10 from a weight-driven disc 11. The solenoid also closes a contact 9 whereby a winding 4 is energized to release the mechanically locked-up contact 2, 3. A contact sector 49 on the disc 11 lights lamps 46 and later a contact 12 bridges two contacts 13 to energize over a back contact 15 the winding 14 of a switch device S<1> for the motor. The winding 14 continues energized, but with reduced current, over its front contact 16 and a resistance r<1>. The motor 20 is energized over front contacts 17, 18 from the partial section 30 of a power battery. When the barrier is completely lowered a switch P is actuated so opening a contact 28 to break the stick circuit of the winding 14 to stop the motor ; the closure of the contact f maintains the lamps 46 alight and the closure of the contact 29 prepares for the pick up of the switch device S<2> for the raising of the barrier when the track contact C at the level crossing is actuated. The raising movement of the barrier is effected at a greater speed by including the section 31 as well as the section 30 of the power battery. The lowering movement re-winds the disc 11 by a cable connection and the disc is held by the latch engaging a tooth e. The leaving train actuates a track contact B which briefly lifts the latch 10 as before described but the disc 11 only moves slightly because the latch at once drops and engages a second tooth d ; thus the barrier is not lowered by a leaving train but the disc is now in readiness to be released by a train approaching either side of the crossing. For a double track with traffic in both directions on each track the arrangement shown in Fig. 3 may be used. An entering train at track contact A energizes, over a back contact 50, the locking-up relay 1 and, in parallel therewith, a relay 51. The relay 1 causes the lowering of the barrier as previously described. The closure of the front contact 55 of the relay 51 forms a stick circuit for a holding winding 54 therefor so that the various contacts remain attracted ; a relay 58 is energized in parallel with the winding 54. When the train reaches the crossing C track contacts 60, 57 are respectively briefly closed and opened ; the contact 60 energizes a relay 61 the contacts of which are then maintained attracted by a holding winding 63 energized over front stick contact 64; the opening of contact 57 de-energizes the relay 58 which closes its back contact 59 whereby the switch S<2> is energized for the raising of the barrier, the circuit to the switch S<2> being from the control battery 53 over a contact 22 closed only when the barrier is fully lowered and a back contact 79 (corresponding to the back contact 59) associated with the other track. Thus as soon as the crossing has been passed the carrier is raised. The leaving train at track contact B energizes over front contacts 67, 65 a relay 68 which by opening its back contacts 56, 66 breaks the stick circuits of the windings 54, 63 so that the relays 51, 61 are now in their normal de-energized state closing their back contacts such as 50 in readiness for operation by a further train. In this arrangement only a single operation of the solenoid latch is required. Should a train be on the second track when a train on the first track reaches the crossing and drops the contact 59 of the relay 58 the switch S<2> will not be picked up since the contact 79 will be open. A simpler arrangement, Fig. 4 (not shown), for traffic in either direction on each of two tracks uses directional track contacts at each approach side and last-wheel track contacts at the actual crossings.