Patent GB-1274714-A (GB)
Title: Improvements in and relating to train brake coupling systems
IPC: B61G7/00
Filed: 1969-06-12
Abstract: 1,274,714. Train brake-line couplings. DRESSER INDUSTRIES Inc. 12 June, 1969 [9 July, 1968], No. 29931/69. Heading B7T. [Also in Division F2] A coupling system for a train brake line 7 having air brakes and mechanical couplers comprises an air operated brake line valve 18 in the line 7 for opening and closing an end of the line 7 and an air-operated control valve 19 connected between the brake line valve and its source of operating air, such that when the mechanical coupler, is coupled to or intentionally uncoupled from an adjoining coupler the brake line valve automatically opens or closes respectively, but should accidental uncoupling occur the brake line valve is held open to exhaust the brake line and cause application of the brakes. The brakes are applied in the absence and released in the presence of pressurized air in the brake line 7, which has an air coupler 6 at its end and a portion 14 within the train car. The system comprises a piping circuit 37 of pressurized air tapped from the brake line 7, the valves 18, 19, primary and secondary coupling valves 34, 51 and an uncoupling valve 35. On coupling two couplers and linking the air couplers 6 the primary coupling valve 34 is actuated to supply a self-produced puff of air to the head 57 of the valve member 56 of the secondary coupling valve 51 to move the member so that the valve inlet and outlet ports 53, 54 are interconnected to supply pressurized air to the coupling head 29 of the valve 19 to move its member 28 for pressurized air to pass, through ports 26, 25 to the line valve 18, moving the line valve member 21 against its spring 22 and allow air in the line 14 through to the coupler 6. On intentional uncoupling, loss of air through the coupler 6 is. prevented by actuation of the uncoupling valve 35 to interconnect its inlet and outlet ports 67, 66 and pass pressurized air through the valve 35 via a line 40 to the head 58 of valve member 56 to stop the air supply from the outlet port and to the head 30 of valve 19 to move its member 28 to connect the port 25 to exhaust 27 and release the air from the member 21 which returns under the action of its spring 22 to close the valve and the line 14. The line 40 is extended to an air coupler 74 for mating with a similar coupler on the adjacent car and an intentional uncoupling, air applied through the valve 35 is bled away through the coupler 74; this and the release of a plunger 36 in the valve 34 reset the system for the next coupling operation. On accidental uncoupling air will escape causing application of the brakes,. the line 18 remaining open as it is only closable by exhausting the air from head 23 of its member 24 by operating the uncoupling valve 35, with non-return valves 42 preventing such exhaust through the lines 14, 7. A spring ball 33 and detent keep the valve member 28 in position. The valve 34 and coupler 74 are mounted directly on the mechanical coupler with actuation of the valves occurring automatically with manual connection of the mechanical couplers, with the uncoupling valve connected to a lock operating rod 3 of the mechanical coupler. A lost motion connection (71) prevents unintended actuation of the uncoupling valve 35 by forces arising from the motion of the train on the operating rod 3. In a modification (Fig. 8, not shown) the two coupling valves are replaced by a single valve (75) with a differential piston.