GB467215A - Improvements relating to drivers' brake control devices for electro-pneumatically controlled fluid pressure braking apparatus - Google Patents

Abstract

467,215. Fluid - pressure brakes. KERSHAW, A. G., SIMMONS, A. W., LEECH, K. H., and WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Dec. 14, 1935, No. 34782. [Class 103 (i)] In a self-lapping driver's control device for an electropneumatically controlled brake system wherein a floating lever is connected to the hand lever, to the electric contacts of the valves and to an abutment subject to the brake cylinder pressure an arm 5 on the shaft 2 of the hand lever 1 is connected by link 7 to the floating lever 9 which is connected by link 11 to a lever 13 on a fixed pivot 15. The upper arm of the lever 13 carries on a member 17 contacts for engagement with contacts 18 connected respectively to the holding or release valve and the application valve respectively. The lever 9 is pivoted also to a rod 21 slidable in the rod 22 of a piston 23 subject to brake cylinder pressure through passage 26 and to the pressure of a spring 28. A spring 36 is interposed between collars 29, 30 slidable both on the rod 21 and within the piston rod 22. Normally, as shown, one contact 18 is engaged to energize the holding valve which is thus open to release the brake. Initial movement of the handle 1 effects a rapid movement of the member 17 by reason of the inequality of the arms of the lever 13 to deenergize the holding valve and energize the application valve, the lever 9 turning on the pivot 19. The lever 13 then abuts on a stop and with continued movement of the hand lever, the lever 9 turns on pivot 10 withdrawing the rod 21 through the piston rod 22 and compressing the spring 36. The piston 23 under the action of the cylinder pressure follows up the rod 21 until the rods 21, 22 are in the original relative position and further movement of the piston is then transmitted through the spring 36 to the rod 21 turning the lever 9 on the pivot 8 to reverse the movement of the member 17 to a position in which both contacts 18 are disengaged and both valves closed. The cylinder pressure established is thus dependent upon the extent of movement of the hand lever. Graduated release of the brake is similarly effected. The shaft 2 may carry a rotary valve which may for instance effect the release of fluid from an automatic brake pipe to effect an emergency application of the brakes or may control connections to a driver's valve to permit pneumatic control as an alternative to electric control of the brakes.