Pressure balancing spool mixing valve

Abstract

There is herein described a single handle pressure balancing spool valve for mixing user-adjustable hot and cold water flow to a fixture such as a shower or tub and to adjust the rate of mixed water flow. A rotatable disc with hot and cold intake openings and an outlet opening are provided which control the degree of covering on the inlet ports of the valve. Pressure balancing of inlet pressure is provided within the valve by means of a piston-cylinder assembly to compensate for fluctuations in water inlet pressure to avoid scalding of the user.

1 . A single control pressure balancing spool mixing valve comprising: an upper single control cartridge and a lower pressure control housing, said cartridge and housing being joined together axially;
 said control cartridge including an operating spindle extending axially therein and being rotatable about its longitudinal axis;   a pivot pin extending through said spindle intermediate the ends of the spindle, whereby said spindle can pivot about said pin;   said pressure control housing having a hot water inlet, a cold water inlet, and a mixed water outlet;   moveable disc means adopted to proportion the amount of hot and cold water flowing through the valve to said mixed water outlet, said means being operatively connected to one end of said spindle for rotation therewith;   said moveable disc having a recess on one surface thereof to receive said one end of said spindle, whereby movement of said spindle about said pin will cause lateral movement of said moveable disc;   means on said moveable disc to control the volume of mixed water flow as a result of the pivoting of the spindle and the moveable disc;   pressure balance means within said housing and in communicate with both the hot and cold water inlets to sense and compensate for any fluctuation in the pressure of either the hot or cold water.   
   
   
       2 . The valve as defined in  claim 1 , wherein said pressure balance means comprises a pair of oppositely facing side housings, each having a generally cylindrical recess, a cylinder received within said recesses, and a piston slidable within said cylinder, one of said side housings being in fluid communication with inflowing hot water and the other being in communication with inflowing cold water. 
   
   
       3 . The valve as defined in  claim 2 , wherein the cylinder and the piston are formed on stainless steel. 
   
   
       4 . The valve as defined in  claim 1 , and further including an operating handle secured to the other end of said spindle for rotating and pivoting the same to control the temperature and flow rate of water to said outlet. 
   
   
       5 . The valve as defined in  claim 1 , wherein said moveable disc means is rotatable upon rotation of said spindle. 
   
   
       6 . The valve as defined in  claim 5 , and further including a keyhole-shaped recess on its lower face, and a fixed disc having openings in communication with the hot and cold water inlets and said outlet, said moveable disc upon rotation with respect to said fixed disc varies the proportional amount of hot and cold water flowing to said outlet. 
   
   
       7 . The valve as defined in  claim 5 , wherein said openings in said fixed disc for the hot and cold water are arcuate in shape. 
   
   
       8 . The valve as defined in  claim 7 , wherein said opening in said fixed disc for the mixed water outlet is generally circular in shape.