Pressure vessel with improved diaphragm mounting

Claim 1

A pressure vessel comprising: (a) first and second vessel shells 3, 2 and with said shells having cylindrical side walls 5, 4, open mouths and closed ends 7, 6, (b) a flexible resilient diaphragm 12 disposed within said vessel and separating the latter into variable volume chambers, said diaphragm having a peripheral edge portion, (c) the cylindrical wall 5 of said first vessel shell 3 having a radially outwardly extending offset 17 merging into an exterior bulge 19 forming an interior peripheral groove 20 within which said edge portion of said diaphragm is disposed, (d) a radially inwardly tapered wall 21 extending from said bulge 17 and with said tapered wall merging into an axially extending cylindrical shell end portion 23 having a peripheral edge 24, (e) the cylindrical wall 4 of said second vessel shell 2 having a first radially inwardly extending offset 25 forming an abutment 26 engaged by said peripheral edge 24 of said first shell 3 to form a joint between said shells, (f) a second radially inwardly extending offset 28 on said second shell 2 and spaced axially from said first inwardly extending offset 25, (g) wall means 29 disposed between said first and second offsets and with said wall means press-fittingly engaging said axially extending shell end portion 23, (h) a further axially extending cylindrical wall 30 extending from said second inwardly extending offset 28 on the side of said last-named offset remote from said wall means 29, said further wall 30 being disposed generally radially opposite of said groove 20 and engaging said peripheral edge portion of said diaphragm 12, (i) one side of the periphery of said diaphragm 12 being generally flat to provide a face 15 engaged by said further cylindrical wall 30, (j) the other side of the periphery of said diaphragm 12 being provided with a projection 16 disposed in said groove 20, (k) and a radially inwardly tapered diaphragm protecting lip 32 forming the end of said further cylindrical wall 30, (l) said radially outwardly extending offset forming an interior shoulder 18, (m) said second radially inwardly extending offset 28 being disposed axially between said joint and the area 22 of merging of the said tapered wall 21 into said cylindrical shell end portion 23, (n) said diaphragm extending freely outwardly from said groove 20 and between said interior shoulder 18 and said tapered lip 32, (o) said radially inwardly tapered wall 21 on said first vessel shell 3 comprising, during assembly, inclined ramp means along which said peripheral edge portion of said diaphragm 12 rides for tightening into said groove 20, (p) the said peripheral edge of said diaphragm 12 being confined by said radially outwardly extending offset 17, said groove 20, said inwardly tapered wall 21, said shell end portion 23, said second radially inwardly extending offset 28, and said further cylindrical wall 30.