Apparatus for varying the time between initiation and subsequent release of an emergency brake application

For use with a locomotive brake control apparatus having a normally charged brake pipe variations of the pressure in which pipe control the application and release of brakes on the locomotive and the cars in a train hauled thereby, a brake valve device operable to control both the supply of fluid under pressure to the brake pipe to cause a brake release and the release of fluid under pressure from the brake pipe at either a service rate or an emergency rate to respectively cause a service brake application or an emergency brake application, said brake valve device comprising a relay valve for supplying fluid under pressure to said brake pipe and a brake pipe cut-off valve operable to cut off flow of fluid under pressure from said relay valve to said brake pipe, a first reservoir of a chosen volume, and fluid pressure operated valve means including a restricted communication enabling flow of fluid under pressure between said brake pipe and said first reservoir at a service rate of brake pipe reduction whereby said first reservoir is charged from said brake pipe via said restricted communication and said valve means is operable by the fluid under pressure in said first reservoir upon the release of fluid under pressure from the brake pipe only at an emergency rate, and when so operated enables flow of fluid under pressure to said brake pipe cut-off valve to cause operation thereof to cut off flow of fluid under pressure from said relay valve to said brake pipe and also the release of fluid under pressure from said first reservoir at said service rate until the pressure in said first volume reservoir is reduced to a chosen value thereby preventing an increase of pressure in said brake pipe to cause a brake release prior to the reduction of the pressure in said first reservoir to said chosen value, wherein the improvement comprises:

• a. means for controlling the rate of reduction of the pressure in said first reservoir, and
• b. a fluid pressure operated valve device operated by fluid under pressure supplied thereto upon operation of said fluid pressure operated valve means in response to the release of fluid under pressure from said brake pipe at only an emergency rate for rendering effective said means for controlling the rate of reduction of the pressure in said first reservoir.