Seamless pressure responsive diaphragm installation

Claim 1

A pressure responsive diaphragm installation comprising: a rigid housing member forming a generally rectangular cavity having a bottom, upright sides, and corners at the intersections thereof together defining a pressure chamber, said housing member further having a flange portion extending about the periphery of said cavity; a diaphragm of a flexible material, said diaphragm constructed by: folding the peripheral edge region of a flat rectangular sheet of said material upward from a center region along bottom folds spaced from the peripheral edge thereof a distance equal to the depth of the sides of said housing member cavity combined with the width of the flange portion thereof; forming upright corners at each corner of said flat rectangular sheet to be interfit with said housing member cavity, by folding said material along a pair of corner folds at each corner extending from the intersection of each bottom fold and each aligned with a respective one of the bottom folds; gathering a tapered loop of excess material inwardly at each corner as said sides are raised up by folding along said bottom folds; folding a top section of each of the sides outwardly along respective flange folds to form a flange portion along each side configured to overlie said housing member flange portion; and forming a pleat on either side of each corner in said flange portion by folding along a pair of transverse flange folds to allow the top of the gathered loop of material at each corner to lie flat across said corner in the form of a tab curving from the loop of excess material, whereby seamless diaphragm corners are provided; and a rigid clamping member shaped to overlie said housing member and diaphragm flange portions, whereby enabling sealing of said diaphragm flange portion against said housing flange portion.