Patent GB-338401-A (GB)
Title: Brake-shoe with electro-mechanical control for the braking of waggons of shunting tracks
IPC: B61K7/02
Filed: 1929-12-11
Abstract: 338,401. Deloison, F. Jan. 7, 1929, [Convention date]. Skid-brakes.-In apparatus for braking railway wagons comprising a brake shoe which is mounted by a wheel of the wagon and slides along the track rail until it is removed from beneath the wheel by a def rail, the shoe is attached to a whereby it is positioned, by a which is released by the engagement of the wheel with the shoe. The cable is driven by an electric motor controlled from a distant a device for indicating the position of the shoe is provided. The shoe comprises a a sole plate 1 upon which the w a stop piece 2 for the wheel. The block 6 slides on the track rail 3 and upon a guide rail 4. An endless cable 7 running over pulleys 8, 9 one of which is driven by an electric motor 11 is adapted to be temporarily attached to the shoe by a spring plunger 15 which presses the cable against a bottom plate 22. The plunger 15 can be raised to release the shoe from the cable by a lever 20 on the shoe adapted to be engaged by the wheel. By closing the circuit of the motor 11 from the control station, the shoe may be traversed from its siding track 3<1> to any desired position on the main track rail 3, its movement in this direction being limited, however, by engagement with a track switch 26 which breaks the motor circuit. In the braking operation the wheel mounts the shoe, engages the lever 20 to release the shoe from the cable and pushes it along until it is' withdrawn by the siding 3<1> while the wheel runs on the track rail 5. The wheel engages a switch 24 which closes the motor circuit when it runs on to the rail 5 causing the shoe to travel along the siding 3<1> until it engages a switch 25 which breaks' the motor circuit. The device for indicating the position of the shoe when setting it for braking comprises a three-phase motor 28, Fig. 5, which is run simultaneously with the cable-driving motor 11. The shaft of this motor carries an index and a pair of drums 82, 83 each provided with a conducting ring broken by a non-conducting sector. The drums are engaged by pairs of contacts 84 - - 87. When after the shoe has been set to the desired position the circuit of the two motors is broken by the control switch, a reverse circuit for the indicator motor, which includes the contacts 84 - - 87 in two of the phase circuits, is closed, this circuit being automatically broken when one of the drum contacts 85, 87 of each pair comes on to the non- conducting sector of the drum, thereby bringing the index to the zero position. The circuit arrangement for the two motors 11, 28 comprises a relay 30 and a relay 29 having a pair of armature arms 46, 88, one of which is closed on its contacts when the other is open. When the switch 31 in the control station is closed to set the brake shoe in operative position on the track, the relay 29 is energized from the source phases B, C and the relay arm 46 engages its contacts. The circuits of the motors 11, 28 are thus completed the source phase A being directly connected to the phases a, a<1> of the two motors and the source phases B, C being connected to the motor phases b, c, b<1>, c<1> through the relay contacts 54, 66. The relay is de-energized to stop the motor by opening either the switch 31 or the limit track switch 26. The closing of the relay arm 88 on its contacts, however, completes a reverse circuit for the indicator motor 28 by interchanging the phases b<1>, c<1>, the circuits including the relay contacts 91, 97 and the drum switches 82, 83 on the motor shaft. The motor runs until these phase circuits are broken by the drum switches at the zero position of the index. The driving motor may be reversed to bring the brake shoe on to the siding 3<1> either by depressing the hand control switch 33 or by the closing of the track switch 24 by the wheel. In either case, the relay 30 is energized by the sources B, C and interchanges the phases b, c of the motor. The circuit of the relay 30 when its circuit is closed by the track switch 24 also completes its own circuit by the contact 125 so that it remains closed after the wheel has released the switch and until the circuit is broken by the engagement of the shoe with the track switch 25 at the end of its travel.