Deformable diaphragm apparatus

Claim 1

FILLING AND ISOLATING APPARATUS FOR A HYDRAULIC SYSTEM COMPRISING A FLUID RESERVOIR VESSEL HAVING AN OUTPUT PORT IN COMMUNICATION WITH SAID HYDRAULIC SYSTEM, A DEFORMABLE DIAPHRAGM ADAPTED TO FIT WITHIN THE BODY OF SAID VESSEL AND TO EXERT PRESSURE ON THE FLUID IN SAID VESSEL, A REMOVABLE COVER FOR THE TOP OF SAID VESSEL, SAID COVER BEING PROVIDED WITH A CENTRAL APERTURE EXTENDING THERETHROUGH, SAID DIAPHRAGM COMPRISING A BELLOWS HAVING AN OPEN END AND A CLOSED END, SAID OPEN END HAVING AND OUTWARDLY EXTENDING FLANGE ADAPTED TO BE RETAINED IN HERMETIC SEALED RELATION BETWEEN THE LIP OF SAID VESSEL AND THE INSIDE OF SAID COVER, A ROD FASTENED TO THE INSIDE OF THE CLOSED END OF SAID BELLOWS, SAID ROD ADAPTED TO EXTEND THROUGH THE APERTURE IN SAID COVER, A SLOT IN SAID ROD RUNNING IN A DIRECTION NORMAL TO THE LONGITUDINAL AXIS OF SAID ROD, AND RESTRAINING MEANS ADAPTED TO BE FITTED WITHIN SAID SLOT AFTER SAID ROD HAS BEEN PARTIALLY DRAWN THROUGH SAID COVER IN A DIRECTION OPPOSITE FROM THE INTERIOR OF SAID VESSEL, WHEREBY TO TEMPORARILY MAINTAIN SAID DIAPHRAGM IN DEFORMED POSITION AGAINST THE INSIDE PORTION OF SAID COVER WHEN SAID COVER IS REMOVED FROM SAID VESSEL SO THAT THE VOLUME OF FLUID WHICH MAY BE INTRODUCED INTO SAID VESSEL IS SUBJECT TO MINIMUM DISPLACEMENT BY SAID DIAPHRAGM AFTER SUCH INTRODUCTION AND THE REPLACEMENT OF SAID COVER OVER SAID VESSEL.