Low pressure warning apparatus

Claim 1

A LOW PRESSURE WARNING APPARATUS COMPRISING: A HOLLOW MEMBER HAVING AN INLET ADAPTED FOR CONNECTION TO A SOURCE OF COMPRESSED GAS; A TRANSVERSE WALL SEALING ONE END OF SAID HOLLOW MEMBER AND PROVIDED WITH A LONGITUDINAL OPENING THERETHROUGH; PRESSURE ACTUATED MEANS INCLUDING A ROD JOURNALED FOR MOVEMENT THROUGH SAID OPENING AND WHICH HAS ONE END EXTENDING WITHIN THE INTERIOR OF SAID HOLLOW MEMBER, AND A PLUNGER SECURED TO AN OPPOSITE END OF SAID ROD, SAID PLUNGER INCLUDING A GAS ACCUMULATION CHAMBER AND A CHAMBER OUTLET; BIASING MEANS BIASED BETWEEN SAID HOLLOW MEMBER AND SAID ROD AND URGING SAID PRESSURE ACTUATED MEANS AGAINST THE FORCE EXERTED BY THE COMPRESSED GAS ON SAID ONE END OF SAID ROD; SAID PRESSURE ACTUATED MEANS BEING MOVABLE BETWEEN AN EXTENDED POSITION UNDER THE FORCE EXERTED BY THE COMPRESSED GAS AND A RETRACTED POSITION UNDER THE FORCE OF SAID BIASING MEANS WHEN THE PRESSURE OF THE GAS DECREASES TO A PRESELECTED LEVEL; SAID ROD HAVING AN AXIAL BORE ADJACENT SAID OPPOSITE END AND COMMUNICATING WITH SAID CHAMBER, AND SAID ROD ALSO HAVING A RESTRICTED ORIFICE PROVIDING A RESTRICTED PASSAGE BETWEEN THE INTERIOR OF SAID HOLLOW MEMBER AND SAID AXIAL BORE WHEN SAID PRESSURE ACTUATED MEANS IS IN SAID RETRACTED POSITION; MEANS SEALING SAID RESTRICTED ORIFICE FROM THE INTERIOR OF SAID HOLLOW MEMBER WHEN SAID PRESSURE ACTUATED MEANS IS IN SAID EXTENDED POSITION; AND MEANS NORMALLY CLOSING SAID CHAMBER OUTLET AND ADAPTED TO BE OPENED BY GAS PRESSURE WHEN A PREDETERMINED QUANTITY OF GAS HAS BEEN ACCUMULATED WITHIN SAID CHAMBER, WHEREBY AN AUDIBLE SIGNAL IS PRODUCED BY A CYCLIC ACCUMULATION OF GAS AND EXHAUSTION OF GAS FROM SAID CHAMBER WHEN SAID PRESSURE ACTUATED MEANS IS IN SAID RETRACTED POSITION.