Fluid dispensing valve having a deformable diaphragm

Claim 1

A liquid-dispensing diaphragm valve comprising a valve casing defining a conduit having an interior wall, one end of which is in communication with the interior of a container for liquid and the other end of which is in communication with an aperture constituting a valve seat; a deformable, resilient, substantially conical diaphragm having an apex and accommodated within said conduit and having, extending abouts its base, an annular skirt having means to prevent rotation thereof and which fits into said conduit so that said diaphragm is disposed in a plane normal to the longitudinal axis of said conduit and further having a boss-like valve element with its base on said apex and projecting axially therefrom, said valve element being adapted to sealingly engage with said valve seat when the valve is in the closed position, said diaphragm being provided with at least one opening therethrough immediately adjacent the base of the valve element; said valve seat being an aperture located centrally in a cap member disposed in a plane parallel to that of said diaphragm and rotatably engageable with an outlet port of said conduit, said diaphragm having at least two protuberances circumferentially spaced apart and projecting outwardly from said apex and parallel to said valve element but to a lesser axial extent than said valve element wherein said protuberances are radially spaced between the interior wall of the conduit and the valve element, said protuberances having at their distal ends camming surfaces, each having a tooth-like profile, the plane of each of said camming surfaces being at an acute angle to the axis of the valve element; said cap member having at least two circumferentially spaced apart annular, inclined, inwardly-directed camming surfaces surrounding said central aperture, radially spaced between the interior wall of the conduit and the valve element and co-acting with the camming surfaces of said diaphragm protuberances; the arrangement being such that rotation of said cap member causes the annular camming surfaces of the said cap member to slidably move over the co-acting camming surfaces of said diaphragm to thereby displace said valve element from said valve seat, against the biasing force of said resilient diaphragm, and thus to provide a number of openings defined between the circumferentially spaced apart co-acting camming surfaces; thereby allowing liquid to flow from the interior of said container into said conduit, through said at least one opening in said diaphragm, through the defined openings between caming surfaces and out through said valve seat for discharge therefrom.