Emergency actuator for air brake system

Claim 1

EMERGENCY BRAKE ACTUATING MECHANISM FOR A MOTOR VEHICLE EQUIPPED WITH AN AIR BRAKE SYSTEM OF THE TYPE WHICH INCLUDES A SUPPLY OF COMPRESSED AIR, A BRAKE ACTUATING CAM SHAFT, A BRAKE ARM SECURED THERETO, A PRIMARY BRAKE ACTUATING AIR POT HAVING A PISTON THEREIN AND COMMUNICATING WITH THE COMPRESSED AIR SUPPLY THROUGH AN OPERATOR CONTROLLED VALVE, A PISTON ROD MOUNTED FOR LIMITED MOVEMENT BY THE PISTON OF THE PRIMARY AIR POT, POWERFUL SPRING MEANS EMERGENCY BRAKE OPERATION, AND SECONDARY AIR PRESSURE ACTUATED MEANS COMMUNICATING WITH THE COMPRESSED AIR SUPPLY AND ACTING OPPOSITELY TO SAID SPRING MEANS WITH SUFFICIENT FORCE, AT A DESIGNED OPERATING PRESSURE OF THE COMPRESSED AIR SUPPLY, TO MOVE THE SPRING MEANS TO INOPERATIVE POSITION; SAID EMERGENCY BRAKE ACTUATING MECHANISM COMPRISING (A) A SLIP-LINK ON THE FREE END OF THE PISTON ROD (B) THRUST MEANS ON THE SLIP-LINK FOR THRUST ENGAGEMENT WITH THE FREE END OF THE BRAKE ARM IN A BRAKE SETTING DIRECTION UPON CONTROLLED ACTUATION OF THE PRIMARY AIR POT FOR NORMAL BRAKE SETTING OPERATION, (C) SAID BRAKE ARM BEING MOVABLE AWAY FROM THRUST ENGAGEMENT WITH SAID THRUST MEANS ALONG SAID SLIPLINK MEMBER IN A BRAKE SETTING DIRECTION, (D) AND A TENSION MEMBER INTERCONNECTING THE FREE END OF THE BRAKE ARM TO SAID SPRING MEANS FOR BIASING THE TENSION MEMBER AND THE BRAKE ARM TO WHICH IT IS CONNECTED IN A BRAKE SETTING DIRECTION, THE LIMIT OF MOVEMENT OF THE BRAKE ARM BY THE SPRING MEANS BEING GREATER THAN ITS LIMIT OF MOVEMENT BY THE PRIMARY AIR POT, WHEREBY, UPON A DESIGNED DROP IN PRESSURE IN THE COMPRESSED AIR SUPPLY, THE SECONDARY AIR PRESSURE ACTUATED MEANS RELEASES THE SPRING MEANS, WHICH THEREUPON, BY MEANS OF THE TENSION MEMBER, BIASES THE FREE END OF THE BRAKE ARM ALONG THE SLIP-LINK AND CLEAR OF THE THRUST MEANS TO AN EMERGENCY BRAKE SETTING POSITION BEYOND THE LIMIT OF MOVEMENT OF THE BRAKE ARM AND ITS CAM SHAFT BY THE PRIMARY AIR POT.