Failure warning apparatus for oil pressure brake

Claim 1

A failure warning apparatus for a fluid pressure brake comprising brake switch means responsive to the actuation of the brake pedal of the fluid pressure brake for closing and opening an energizing circuit path in accordance therewith, latch-in relay means having a plurality of circuit making members and a latch-in relay coil for energization via the energizing circuit path of said brake switch means for controlling the movement of said plurality of circuit making members between first and second circuit positions, an abnormal pressure detecting switch means responsive to the failure of the fluid pressure brake for providing an energizing circuit path for said latch-in relay coil, said brake switch means, said latch-in relay means and said abnormal pressure detecting switch means being connected in series with each other, a warning means energized by one of said plural circuit making members in one of the first and second positions thereof providing an energizing circuit path therefor, said latch-in relay coil being responsive to the initial closing of the energizing circuit by said brake switch means and the detection of the failure of the fluid pressure brake by said abnormal pressure detecting switch means for moving said plural circuit making members from one of the first and second position to the other position thereof for enabling energization of said warning means, and circuit means for completing an energizing circuit for controlling said latch-in relay coil to cause movement of said circuit making members for de-energizing said warning means after correction of the failure of the fluid pressure brake.