Diaphragm support

Claim 1

A DIAPHRAGM ASSEMBLY FOR INSTALLATION IN A HOUSING, SAID ASSEMBLY COMPRISING A FLUID IMPERVIOUS FLEXIBLE DIAPHRAGM IN THE FORM OF AN ELONGATE SLEEVE HAVING AN OPEN END AND A CLOSED END, THE OPEN END BEING ADAPTED TO BE SECURED PERIPHERALLY IN AND TO THE WALL OF THE HOUSING TO PARTITION THE HOUSING INTO TWO CHAMBERS, A FRUSTOCONICAL SPRING COMPRISING A PLURALITY OF TURNS, FORMED FROM A FLAT STRIP OF RESILIENT MATERIAL AND DISPOSED AT ONE SIDE OF AND COAXIAL WITH THE SAID SLEEVE, THE FLAT SURFACES OF THE STRIP BEING SUBSTANTIALLY PARALLEL TO THE AXIS OF SAID SPRING, EACH TURN BEING IN SLIDING ENGAGEMENT WITH ADJACENT TURNS, THE APICAL END OF THE FRUSTOCONICAL SPRING OPPOSING THE SAID CLOSED END OF THE SLEEVE, BEARING MEANS COMPRISING TWO MEMBERS, ONE COMPRISING A PLATE WITH A RECESS THEREIN SECURED TO SAID APICAL END OF THE SPRING AND THE OTHER COMPRISING A PLATE WITH A BOSS PROJECTING THEREFROM SECURED TO SAID OPENED END OF THE SLEEVE, SAID BEARING MEANS PROVIDING ROTATIONAL MOVEMENT BETWEEN SAID APICAL END OF THE SPRING AND SAID OPPOSED END OF THE DIAPHRAGM WHILE PREVENTING RELATIVE RADIAL DISPLACEMENT THEREOF, AND SAID SLEEVE LENGTH BEING SUCH AS TO FORM A DEEP ROLLING LOOP OUTWARDLY OF THE SPRING WHEN THE SPRING IS IN AN EXTENDED POSITION.