Pneumatic device to brake or unbrake a trailer

Claim 1

APPARATUS OF THE CHARACTER DESCRIBED FOR PNEUMATICALLY APPLYING AND RELEASING THE BRAKES OF A TRAILER COMPRISING AN AUTOMATIC RELAY VALVE, SAID AUTOMATIC RELAY VALVE INCLUDING A HOUSING, SERVICE PISTON MEANS SLIDABLY MOUNTED WITHIN THE HOUSING, A SERVICE BRAKE LINE CONNECTED TO THE HOUSING FOR SUPPLYING COMPRESSED AIR THERETO FOR ACTUATING THE SERVICE PISTON MEANS, A FIRST PORT FORMED IN THE HOUSING PLACING THE AUTOMATIC RELAY VALVE IN COMMUNICATION WITH THE ATMOSPHERE, A SECOND PORT FORMED IN THE HOUSING CONNECTING THE TRAILER BRAKING SECTIONS TO THE AUTOMATIC RELAY VALVE, A THIRD PORT FORMED IN THE HOUSING CONNECTING THE COMPRESSED AIR RESERVOIR TO THE AUTOMATIC RELAY VALVE, DOUBLE-ACTING VALVE MEANS INCLUDING AN INLET AND AN EXHAUST VALVE POSITIONED WITHIN THE HOUSING ADAPTED TO BE ACTUATED BY THE SERVICE PISTON MEANS WHEREBY, WHEN THE INLET VALVE IS IN OPEN POSITION, COMPRESSED AIR IS FED TO THE TRAILER BRAKING SECTIONS FROM THE TRAILER COMPRESSED AIR RESERVOIR AND WHEN THE EXHAUST VALVE IS IN OPEN POSITION, COMPRESSED AIR IS EXHAUSTED FROM THE BRAKING SECTIONS TO THE ATMOSPHERE, AN EMERGENCY RELAY PISTON SLIDABLY MOUNTED WITHIN THE HOUSING AND HAVING ONE FACE FORMING AN OPERATING CHAMBER WITH ONE END OF THE HOUSING AND AN OPPOSITE FACE DEFINING AN AIR PRESSURE CHAMBER, AN EMERGENCY AIR LINE CONNECTED TO THE PRESSURE CHAMBER FOR SUPPLYING FLUID PRESSURE TO THE OPPOSITE FACE OF THE EMERGENCY RELAY PISTON, A CONDUIT CONNECTED BETWEEN THE TRAILER AIR RESERVOIR PORT AND THE OPERATING CHAMBER FOR SUPPLYING FLUID PRESSURE TO THE ONE FACE OF THE PISTON, ROD MEANS CARRIED BY THE EMERGENCY RELAY PISTON FOR ACTUATING THE SERVICE PISTON MEANS, WHEREBY THE EMERGENCY RELAY PISTON IS RECIPROCABLE WITHIN THE HOUSING TO THEREBY ACTUATE THE INLET AND EXHAUST VALVE MEANS FOR PLACING THE COMPRESSED AIR RESERVOIR PORT IN COMMUNICATION WITH THE PORT CONNECTED TO THE BRAKING SECTION OF THE TRAILER AND FOR PLACING THE PORT CONNECTED TO THE TRAILER BRAKING SECTIONS IN COMMUNICATION WITH THE PORT CONNECTED TO THE ATMOSPHERE, IN COMBINATION WITH A TRAILER MANUAL BRAKE RELEASE DEVICE AND BRAKING DEVICE INLCUDING AN AUXILIARY CYLINDER POSITIONED WITHIN THE OPERATING CHAMBER OF THE AUTOMATIC RELAY VALVE AND COMMUNICATING WITH SAID EMERGENCY AIR LINE, AN AUXILIARY PISOTN RECIPROCBLE IN SAID CYLINDER, A ROD FIXED TO SAID AUXILIARY PISTON AND HAVING ONE PORTION EXTENDING IN SAID OPERATING CHAMBER AND AN OPPOSITE PORTION PROTRUDING EXTERIORLY OF SAID HOUSING TO DEFINE AN EXTERNAL CONTROL EXTREMITY, AN AUXILIARY VALVE IN SAID OPERATING CHAMBER OPENING AND CLOSING COMMUNICATION BETWEEN SAID OPRATING CHAMBER AND SAID TRAILER SIR RESERVOIR PORT, RESILIENT MEANS URGING SAID AUXILIARY VALVE TOWARD ITS CLOSED POSITION, SAID AUXILIARY VALVE BEING POSITIONED AGAINST SAID RESILIENT MEANS TO ITS OPENED POSITION BY END PRESSURE OF THE ONE PORTION OF SAID ROD, MEANS ESTABLISHING COMMUNICATION BETWEEN SAID AUXILIARY CYLINDER AND SAID PRESSURE CHAMBER TO AUTOMATICALLY ACTUATE SAID AUXILIARY PISTON IN RESPONSE TO A PREDETERMINED PRESSUE IN SAID PRESSURE CHAMBER WHEREBY SAID ROD IS MOVED WITH SAID AUXILIARY PISTON TO POSITION SAID AUXILIARY VALVE IN ITS OPENED POSITION IN RESPONSE TO COMPRESSED AIR FLOWING INTO SAID PRESSURE CHAMBER, AND DETENT MEANS FOR RETAINING SAID ROD IN A PLURALITY OF POSITIONS CORRESPONDING TO THE OPENED AND CLOSED POSITIONS OF SAID AUXILIARY VALVE.