Derailment emergency valve

Apparatus for emergency braking of a railway car which includes two parts, one part being an elongated wheel truck and the other part being a car frame, the wheel truck being provided with at least one axle for rotatably supporting a train wheel and having a fluid pressurized brakeline in a wheel braking system, and the wheel truck resiliently supporting said car frame, the improvement comprising:

• an elongated tubular break-away valve member;
• means for connecting said member in fluid tight relation to said pressurized brake line whereby the fluid pressure is maintained in said line and in said member;
• means for rigidly attaching said member at one point thereon to one of said parts, said member extending substantially horizontally on and having a portion extending beyond said point of attachment, a peripheral groove in said member adjacent to said point of attachment, a flexible, substantially inextensible cable having one end attached at a first connection point to said extended portion and the other end attached at a second connection point to the other of said parts;
• said cable being dimensioned so that during a predetermined separation of said car frame and truck tensional force is produced in said cable causing said valve member to break-away;
• said first and second points being on a line substantially vertically and normal to the longitudinal axis of said member so that when said car frame and truck are in relatively separated positions corresponding to an emergency condition, said cable is tensioned and said force is exerted substantially normal to the longitudinal axis of said member to maximize the break-away force on said member at said groove thus providing fluid escape from said line when rupture occurs to reduce the pressure in said line sufficiently to actuate wheel braking during emergency conditions.