GB260841A - Apparatus for automatically opening and closing barriers at level crossings of railways - Google Patents

Abstract

260,841. Rizzi, G., and Cerutti, F. March 15, 1926. Operating and controlling gates and barriers hydraulically and pneumatically, and by treadles and the like; indicating and signalling operation of gates and barriers. - Each barrier 1 at a level crossing of a railway track is subjected to the action of a pair of ram pistons 3, 11 Fig. 1, the piston 3 being operated by a treadle - operated compressor 6 to close (or open) the barrier, the piston 11 being operated to release the barrier, so that it can close (or open), by means of a treadle-operated piston 14' positioned on the other side of the barrier. When the treadle 7 is pressed down by the train it causes fluid pressure to pass through the conduit 5 into the cylinder 2. The piston 3 then moves upwardly and closes the barrier through a rod 4. The barrier is secured in the horizontal position by a pawl 8 engaging with a lever 9. After passing the gate the train depresses the treadle 15<1> and pressure fluid lifts the piston 11 and releases the pawl 8. As the counterweight 13 falls to open the barrier pressure fluid is driven from the cylinder 2 into the compressor 6. The process is repeated when the train approaches the gate in the opposite direction and operates the compressors 6<1>, 14. In a modified construction, the barrier is secured in the open position and the first treadle causes its release, when it closes by gravity. The second treadle when depressed restores the gate to its open position. In other forms, the cylinders are provided with overflow receptacles. In the compressor shown in Fig. b, the treadle 15, when depressed, moves the piston 20 through a lever 17, pawl 18 and toothed pistonrod 19, a second pawl 21 preventing the return of the piston. A cam-surface 22 at the end of the piston-rod lifts the pawls when the piston reaches its inner dead point, the pawls being moved laterally by a spring on to the smooth side of the piston-rod to allow the piston to be returned. An expansion chamber may be arranged between the compressor and the piston operating the barrier. In order to avoid the shock caused by the depression of a pedal by a vehicle wheel the arrangement shown in Fig. 11 is employed. A side rail 30 is connected with an arm 31 supported by a spring 32 and pressed against the rail by a spring 32<1>, and the arm is pivotally connected to a rod 33 adapted to operate the compressor through lever mechanism. A stop pin 39 positioned on one side of the rod 33, as shown, provides for the operation of the compressor only when the train is moving in the direction of the arrow F. The movement and position of the barrier may be suitably indicated by a bell or signalling device.