Respiratory assister

Claim 1

A RESPIRATORY ASSISTOR HAVING A PORTABLE CASING IN WHICH ARE HOUSED THE PARTS OF A PNEUMATICALLY SELF-CONTAINED ASSEMBLY INCLUDING FAN MEANS FOR GENERATING A STREAM OF AIR UNDER PRESSURE ABOVE ATMOSPHERIC, AND MOTOR MEANS FOR DRIVING THE FAN MEANS, THE ASSEMBLY COMPRISING A PATIENT''S DELIVERY DEVICE, CONDUIT MEANS FOR CONNECTING THE FAN MEANS WITH THE PATIENT''S DELIVERY DEVICE, A MAIN CONTROL VALVE DISPOSED IN THE CONDUIT MEANS, AN EXHAUST PORT FOR CONNECTING THE CONDUIT MEANS TO ATMOSPHERE AT A POINT BETWEEN THE MAIN CONTROL VALVE AND THE PATIENT''S DELIVERY DEVICE, AN EXHAUST PORT VALVE RESPONSIVE TO EXPIRATION BY THE PATIENT TO OPEN THE EXHAUST PORT, A FLUID PRESSURE DEVICE FOR URGING THE EXHAUST VALVE TOWARD CLOSED POSITION DURING INSPIRATION BY THE PATIENT AND INCLUDING A FLUID PRESSURE CONTROL LINE HAVING A POINT OF CONNECTION WITH THE CONDUIT MEANS BETWEEN THE MAIN VALVE AND THE EXHAUST PORT, A CHECK VALVE IN THE CONDUIT MEANS BETWEEN SAID CONNECTION POINT AND TO EXHAUST PORT, SAID CHECK VALVE BEING ORIENTED TO PERMIT AIR FLOW IN THE DIRECTION FROM THE FAN TOWARD THE PATIENT''S DELIVERY DEVICE AND TO PREVENT AIR FLOW IN THE OPPOSITE DIRECTION, CONTROL MECHANISM FOR THE MAIN CONTROL VALVE INCLUDING A FIRST DIAPHRAGM MOVEABLE TO A CONTROL POSITION IN RESPONSE TO A BUILD-UP OF PRESSURE IN THE CONDUIT MEANS BE TWEEN THE CHECK VALVE AND THE PATIENT''S DELIVERY DEVICE A SECOND DIAPHRAGM MOVABLE TO A CONTROL POSITION IN RESPONSE TO A BUILD-UP OF PRESSURE IN THE CONDUIT MEANS BETWEEN THE CHECK VALVE AND THE PATIENT''S DELIVERY DEVICE TO CLOSE THE MAIN VALVE, A PNEUMATIC CONNECTION BETWEEN SAID DIAPHRAGMS AND THE CONDUIT MEANS, MEANS INTERCONNECTING SAID DIAPHRAGMS AND SAID MAIN CONTROL VALVE FOR OPENING THE MAIN VALVE WHEN THE FIRST DIAPHRAGM MOVES TO ITS CONTROL POSITION AND FOR CLOSING THE MAIN VALVE WHEN THE SECOND DIAPHRAGM MOVES TO ITS CONTROL POSITION, A PORT FOR VENTING THE FLUID PRESSURE CONTROL LINE; AND MEANS ASSOCIATED WITH THE MAIN VALVE TO OPEN THE PORT UPON CLOSURE OF THE MAIN VALVE AND TO CLOSE THE PORT UPON OPENING OF THE MAIN VALVE.