Apparatus for locating a malfunctioning brake control valve on train

In a railroad train which has an air brake pipe extending the length of the train, and wherein each car is equipped with a brake control valve for venting said brake pipe when required for an emergency operation, and which brake control valve can vent said brake pipe when mulfunctioning,

• means for determining the difference in time (t.sub.1 - t.sub.2) required for the air pressure change in a vented brake pipe to travel from a venting malfunctioning brake control valve to the front end of said train and to the back end of said train whereby the location of said malfunctioning brake control valve can be determined from the formula X = L/2 -465 (t.sub.1 - t.sub.2), where L is the length of the train, and
• X is the distance of the malfunctioning brake control valve from the end of the train at which the pressure change in the vented brake pipe arrives first, comprising,
• a pressure change actuated means at the head end and at the rear end of said train coupled to said brake pipe for respectively transmitting a first and a second radiofrequency signal when actuated by receiving a pressure change through said brake pipe from a malfunctioning brake control valve,
• means for receiving said transmitted first and second signals at one end of said train, and
• means to which said first and second signals are applied by said means for receiving for indicating the difference in time, (t.sub.1 - t.sub.2), which was required for the air pressure change caused by a malfunction brake control valve to travel through said brake pipe to said respective pressure change actuated means at said head end and at said rear end of said train.

In a railroad train which has an air brake pipe extending the length of the train, and wherein each car is equipped with a brake control valve for venting said brake pipe when required for an emergency operation, and which brake control valve can vent said brake pipe when malfunctioning, means for determining the location of said malfunctioning brake control valve comprising

• a pressure change actuated means at the head end and at the rear end of said train, coupled to said brake pipe for respectively transmitting a first and second signal when actuated by receiving a pressure change through said brake pipe from a malfunctioning brake control valve,
• means for receiving said first and second signals at one end of said train,
• first and second counter means to which said received first and second signals are respectively applied to enable them to commence counting upon the application of said respective signals,
• means for driving said counter means at a rate of 465 bits per second when they are enabled to count whereby their count difference is an indication in feet of the distance of said malfunctioning brake control valve from the center of the train in the direction of the one of said pressure actuated means which was actuated first.