Pneumatically actuated fastener driving device with improved sleeve valve for controlling the pressure beneath the drive piston

Abstract

Abstract A PNEUMATICALLY ACTUATED FASTENER DRIVING DEVICE HAVING A CONVENTIONAL PLENUM CHAMBER AIR RETURN SYSTEM AND A SLEEVE VALVE MECHANISM NORMALLY BIASED INTO AN INOPERATIVE POSITION PERMITTING UNRESTRICTED EXHAUST FLOW OF AIR OUTWARDLY OF THE LOWER END OF THE DRIVE CYLINDER THROUGH ENLARGED EXHAUST PORTS DURING THE DRIVE STROKE OF THE DRIVE PISTON AND FASTENER DRIVING ELEMENT, THE SLEEVE VALVE MECHANISM BEING OPERATIVE IN RESPONSE TO THE CHARGING OF THE PLENUM CHAMBER WITH RETURN AIR AT A PREDETERMINED PRESSURE TO MOVE INTO AN OPERATIVE POSITION CLOSING OFF THE UNRESTRICTED FLOW THROUGH THE EXHAUST PORTS AND COMMUNICATING THE RETURN AIR WITH THE DRIVE CYLINDER TO EFFECT THE RETURN STROKE OF THE DRIVE PISTON AND FASTENER DRIVING ELEMENT, THE VALVE MECHANISM BEING OPERABLE IN RESPONSE TO A PREDETERMINED DECREASE IN THE PRESSURE OF THE AIR IN THE PLENUM CHAMBER DUE TO EXPANSION INTO THE DRIVE CYLINDER DURING THE RETURN STROKE AND TO CONTROLLED DISSIPATION TO ATMOSPHERE THROUGH A SEPARATE PATH TO MOVE BACK INTO ITS NORMALLY BIASED INOPERATIVE POSITION AT OR NEAR THE END OF THE RETURN STROKE SO AS TO BE PROPERLY CONDITIONED FOR THE NEXT DRIVE STROKE. D R A W I N G

Inventors

• 👤 Connor R O

Bibliographic Details