Patent ID: 9127779
Filing Date: 2015-09-08
Classification: F01P,F16K,G05D

Abstract:
1. A frictionless, pressure-balanced proportioning valve assembly for low-power, electrically-operated, thermostatic mixing valves, comprising: a. a housing having a first water inlet, a second water inlet, an intermediate mixed-water outlet, a spool bore formed in said housing, being in flow communication with said first and second water inlets, said spool bore having a generally central, widened portion being in flow communication with said intermediate mixed-water outlet; b. a spool, having first and second widened end-portions and a central, widened disk portion, wherein said spool is guided in said spool bore, by said first and second widened end-portions, said central, widened disk portion having a narrower axial width than said spool bore central, widened portion, said spool being loosely axially movable within said spool bore with said central, widened disk portion traveling in said spool bore central, widened portion between two opposing seats, thereby defining a peripheral flow gap between said central, widened disk portion and said seats, wherein said central, widened disk portion separates said spool bore into a first tubular water inlet chamber and a second tubular water inlet chamber; c. first and second elastic diaphragm seals each one respectively disposed at each end of said spool and said housing, so as to seal said spool against said housing, said elastic diaphragm seals being configured by effective area equalization, for pressure balancing of said first tubular water inlet chamber between said first elastic diaphragm seal and said disk portion, and pressure balancing of said second tubular water inlet chamber between said second elastic diaphragm seal and said disk portion; d. a temperature sensor exposed to a mixed-water outlet pathway, for generating an electronic signal readable by an electronic circuit and in relation to the temperature of water in said mixed-water outlet pathway; and e. an attached drive means, energized by a low-power electric motor, coupled with said spool so as to cause axial displacement of said spool in accordance with said electronic signal, wherein said axial displacement of said spool proportionally mixes flow from said first and second water inlets into said intermediate mixed-water outlet.