Fire extinguisher head coupling assembly and associated plunger unit

Claim 1

IN A FIRE EXTINGUISHER HEAD ASSEMBLY DESIGNED FOR COUPLING TO A TANK AND INCLUDING A DISCHARGE PASSAGE ADAPTED TO COMMUNICATE WITH SAID TANK, THE COMBINATION COMPRISING: A PLUNGER ASSEMBLY DESIGNED FOR SLIDING MOVEMENT IN SAID HEAD ASSEMBLY; VALVE MEANS CARRIED BY SAID PLUNGER ASSEMBLY; AN ANNULAR MEMBER OF GIVEN DIAMETER EXTENDING FROM AND INTEGRALLY FORMED WITH THE LOWER END OF SAID HEAD ASSEMBLY; ANNULAR SPRING RETAINING MEANS INCLUDING AN INNER UPPER PORTION THREADINGLY COUPLED WITHIN SAID ANNULAR EXTENSION MEMBER, SAID INNER UPPER PORTION INCLUDING SPRING RETAINING MEANS HAVING A DECREASED DIAMETER PORTION; SPRING MEANS CARRIED BY SAID DECREASED DIAMETER PORTION AND POSITIONED TO BIAS SAID VALVE MEANS TOWARDS ITS SEATED POSITION IN SAID HEAD ASSEMBLY; SAID SPRING RETAINING MEAN HAVING A LOWER OUTER PORTION DISPOSED BEYOND THE FREE END OF SAID ANNULAR MEMBER, SAID LOWER OUTER PORTION HAVING A DIAMETER GREATER THAN SAID GIVEN DIAMETER; AN ANNULAR SEALING MEMBER CARRIED BY SAID LOWER OUTER PORTION FOR SEALING COOPERATION WITH THE FREE END OF SAID ANNULAR MEMBER; AND A NUT CARRIED BY SAID LOWER OUTER PORTION, SAID NUT HAVING AN UPPER AXIAL PORTION THEREOF PROTRUDING RADIALLY INWARDLY OVER SAID LOWER OUTER PORTION OF SAID SPRING RETAINING MEANS SUCH THAT SAID FREE END AND SEALING MEMBER ARE RADIALLY INTERPOSED BETWEEN SAID UPPER AXIAL PORTION OF SAID NUT AND SAID INNER UPPER PORTION OF SAID SPRING RETAINING MEANS.