Patent ID: 8240522

Claim:
A dual function liquid dispensing apparatus comprising: a) a housing defining multiple compartments aligned on parallel axes; b) constant flow valves arranged in said compartments, said constant flow valves comprising: (i) barrier walls extending across said axes to subdivide said compartments into head sections and base sections; (ii) ports in said barrier walls; (iii) modulating assemblies internally subdividing said base sections into liquid chambers and spring chambers, said modulating assemblies having throttle pins projecting along said axes and through said ports into said head sections, and having flexible diaphragms supporting said modulating assemblies for movement in opposite directions along said axes; (iv) springs in said spring chambers, said springs being responsive to inlet liquid pressures in said head sections below threshold levels to maintain said modulating assemblies in closed positions against said barrier walls and to thereby prevent liquid flow from said head sections via said ports into said liquid chambers, said springs being yieldably responsive to inlet liquid pressures in said head sections above said threshold levels to thereby accommodate movement of said modulating assemblies to open positions away from said barrier walls, with an accompanying liquid flow from said head sections via said ports into said liquid chambers, and with said throttle pins serving to modulate the size of the flow paths through said ports as an inverse function of variations in said inlet liquid pressures above said threshold levels, whereby the pressures and flow rates of the liquids delivered to said liquid chambers are maintained at a substantially constant levels; c) inlets in said housing for connecting said head sections to external liquid sources; d) outlets in said housing for connecting said liquid chambers to a common nozzle; e) closure means acting independently of said springs for maintaining each said modulating assemblies in said closed positions when said inlet liquid pressures are both above and below said threshold levels; and f) operating means for deactivating said closure means to thereby free said modulating assemblies for movement to said open positions in response to liquid inlet pressures in said head sections above said threshold levels.