Patent ID: 6263899
Filing Date: 2001-07-24
Classification: G05D,Y10T

Abstract:
A mixing valve comprising in combination:a hollow body having first and second inlet ports, at least one outlet port, and a valve opening;first and second inlet chambers communicating with said first and second inlet ports, said inlet chambers being spaced from one another lengthwise of said hollow body;first and second outlet chambers communicating with said at least one outlet port, said outlet chambers being spaced from one another lengthwise of said hollow body;cylinder means providing a liquid mixing chamber in said body, said cylinder means extending lengthwise of said body and including first ceramic means defining cold and hot water inlet orifices that open into said mixing chamber and communicate with said first and second inlet chambers respectively and cold and hot water transfer orifices that open into said mixing chamber and communicate with said first and second outlet chambers respectively; said inlet and transfer orifices being spaced from one another lengthwise of said mixing chamber;a porting block disposed in said liquid mixing chamber said porting block being movable axially in said mixing chamber and having an internal chamber, said porting block including second ceramic means slidably engaged with said first ceramic means, said second ceramic means defining cold and hot water inlet and cold and hot water outlet orifices that open into said internal chamber, said cold and hot water inlet and outlet orifices of said second ceramic means being spaced from one another lengthwise of said mixing chamber and disposed so as to be shifted by axial movement of said porting block into and out of varying degrees of alignment with said cold and hot water inlet and transfer orifices respectively of said first ceramic means, whereby to vary the flow of hot and cold water through said mixing chamber;a balancing piston slidably disposed in said internal chamber, said balancing piston having cold and hot water chambers, cold and hot water inlet orifices leading to said cold and hot water chambers respectively and communicating with said cold and hot water inlet orifices respectively of said second ceramic means, and cold and hot water outlet orifices leading from said cold and hot water chambers respectively and communicating with said cold and hot water outlet orifices of said second ceramic means respectively, whereby said piston will move in one direction or the other in accordance with the pressure differential of the cold and hot water supplied to its cold and hot water chambers via cold and hot water inlet orifices respectively of said first and second ceramic means; andmeans for selectively moving said porting block in one direction or the other lengthwise of said mixing chamber so as to vary the relative rates of flow of cold and hot water through said valve via said first and second ceramic means.