Diaphragm pumps for delivering liquid or gaseous media

Claim 1

A diaphragm pump comprising diaphragm means comprising an outer diaphragm and an inner diaphragm spaced from said outer diaphragm, each of said diaphragms having a spherical portion and a cylindrical portion joined to the respective spherical portion by a curved connecting portion, and a fluid filling the space between said two diaphragms; support means within said diaphragm means and having a spherical portion of a shape corresponding to the spherical portion of said inner diaphragm in substantially unstressed condition of the latter for supporting the same in said substantially unstressed condition; first passage means extending through said support means for feeding fluid against that surface of said diaphragm means which faces said support means to expand said diaphragm means, and for discharging fluid from the thus formed space between said diaphragm means and said support means; an outer housing surrounding said diaphragm means, said outer housing having an inner spherical surface having a center of curvature offset with respect to the center of curvature of said spherical portion of said support means so as to form between said inner surface and said diaphragm means, when the latter abuts said support means, a space of sickle-shaped cross-section in which said diaphragm may expand and contract; clamping means comprising a clamping ring of wedge-shaped crosssection located between the tubular portions of said diaphragms for clamping said tubular portions respectively against said outer housing and said support means; and second passage means communicating with said last-mentioned space for feeding fluid into and out of the same.