Diaphragm valves

Claim 1

A diaphragm valve comprising first and second self-contained sub-assemblies: (a) the first sub-assembly comprising: (1) a valve body defining a flow passage and a diaphragm opening: (2) a diaphragm closing the diaphragm opening and movable between a closed position in which the diaphragm is in engagement with a seat formed in the flow passage to close the flow passage to fluid flow and an open position in which the diaphragm is spaced from the seat and the passage is open to fluid flow; (3) a diaphragm clamping member; (4) means securing the diaphragm clamping member to the valve body for clamping the periphery of the diaphragm in fluid-tight contact with the surface of the body surrounding the diaphragm opening; and (5) an operating member in engagement with the diaphragm and mounted for axial movement relative to the clamping member towards the seat to move the diaphragm towards the closed position; (b) the second sub-assembly comprising: (1) a drive assembly releasably secured to the clamping member by means separate from said securing means, the drive assembly including force means selectively operable to apply a force to the operating member towards the seat to move the diaphragm towards the closed position, said force means being separable with said drive assembly from a force applying relationship with respect to said operating member upon release of said drive assembly from said clamping member and without requiring separation of any component of either of said sub-assemblies from its respective sub-assembly and said first sub-assembly being constructed and arranged so as to be capable of remaining in its fully operable condition relative to said flow passage upon separation of said second sub-assembly from said first sub-assembly.