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The mixing valve includes a plurality of flow regulating assemblies (A) each of which independently regulates the flow of one of a plurality of fluids. Each flow regulating assembly includes a pressure displaceable structure (22) which is physically displaced by changes in pressure and a movable val

The mixing valve includes a plurality of flow regulating assemblies (A) each of which independently regulates the flow of one of a plurality of fluids. Each flow regulating assembly includes a pressure displaceable structure (22) which is physically displaced by changes in pressure and a movable valving member (50) which is movable relative to a stationary valve seat (42) for adjusting the cross section of a flow path therebetween. The movable valving member is operatively connected with the pressure displaceable structure such that the cross section of the flow path varies generally in inverse proportion to the sensed pressure. A proportioning assembly (B) proportions back pressure from adjacent a mixed fluid outlet (132) between the flow regulating assemblies such that each flow regulating assembly regulates its fluid flow in accordance with the proportion of the back pressure accorded it. A mixed fluid selecting valve assembly (C) selectively connects the proportioning valve assembly with one of a plurality of mixed fluid outlets which have larger and smaller diameter sections to cause relatively low and high back pressures, hence, relatively high or low flow rates. A mixed fluid temperature control (D) monitors the temperature of the mixed fluid adjacent the mixed fluid outlet and controls the proportioning assembly to maintain the mixed fluid substantially at a selected temperature.

대표청구항 ▼

1. A fluid mixing apparatus for mixing a cooler fluid flow with a warmer fluid flow to produce a mixed fluid flow having a selectable intermediate temperature, the mixing apparatus comprising: means defining a cooler fluid inlet which is adapted to be connected with a source of the cooler fluid u

1. A fluid mixing apparatus for mixing a cooler fluid flow with a warmer fluid flow to produce a mixed fluid flow having a selectable intermediate temperature, the mixing apparatus comprising: means defining a cooler fluid inlet which is adapted to be connected with a source of the cooler fluid under pressure to receive the cooler fluid flow therefrom; a first regulating assembly operatively connected with the cooler fluid inlet means for regulating the pressure of the cooler fluid; means for defining a warmer fluid inlet which is adapted to be connected with a source of the warmer fluid under pressure to receive the warmer fluid flow therefrom; a second regulating assembly operatively connected with the warmer fluid inlet means for regulating the pressure of the warmer fluid; means for defining at least one mixed fluid outlet for discharging the mixed fluid flow, the mixed fluid flow developing a back pressure adjacent the mixed fluid outlet means; a fluid pressure proportioning valve member movably disposed between the mixed fluid outlet means and the first and second regulating assemblies for selectively proportioning the back pressure between the first and second regulating assemblies, such that the fluid pressure proportioning valve member causes the first and second regulating assemblies to control the relative flow rates of the cooler and warmer fluid flows; and, mixed fluid temperature control means for controlling a median position of the fluid pressure proportioning valve member and for causing the fluid pressure proportioning valve member to dither about the median position such that the mixed fluid substantially maintains a selected intermediate temperature. 2. The mixing apparatus as set forth in claim 1 wherein the first and second regulating assemblies include: a valve seat disposed between the inlet means and the proportioning means; and a pressure sensing means disposed between the valve seat and the proportioning means; and a movable valving member disposed adjacent the valve seat for defining a flow path with an adjustable cross section therebetween, the movable valving member being disposed between the inlet means and means defining a pilot reservoir, means defining a pilot supply aperture in fluid connection between the inlet means and the pilot reservoir means, means defining a pilot outlet aperture which is larger in cross section than the pilot supply aperture for selectively releasing fluid from the pilot reservoir means and a pilot valve for controlling fluid flow through the pilot outlet aperture means, the pilot valve being operatively connected with the pressure sensing means to vary the fluid flow through the pilot outlet aperture means in response to variations in the sensed pressure. 3. A fluid mixing apparatus for mixing a cooler fluid flow with a warmer fluid flow to produce a mixed fluid flow having a selectable intermediate temperature, the mixing apparatus comprising: means defining a cooler fluid inlet which is adapted to be connected with a source of the cooler fluid under pressure to receive the cooler fluid flow therefrom; a first regulating assembly operatively connected with the cooler fluid inlet means for regulating the pressure of the cooler fluid; means for defining a warmer fluid inlet which is adapted to be connected with a source of the warmer fluid under pressure to receive the warmer fluid flow therefrom; a second regulating assembly operatively connected with the warmer fluid inlet means for regulating the pressure of the warmer fluid; means for defining at least one mixed fluid outlet for discharging the mixed fluid flow, the mixed fluid flow developing a back pressure adjacent the mixed fluid outlet means; a fluid pressure proportioning valve member disposed between the mixed fluid outlet means and the first and second regulating assemblies for selectively proportioning the back pressure between the first and second regulating assemblies, such that the fluid pressure proportioning valve member causes the first and second regulating assemblies to control the relative flow rates of the cooler and warmer fluid flows; a solenoid coil and armature for controlling movement of the fluid pressure proportioning valve member; temperature sensing means for sensing mixed fluid temperature and producing a sensed temperature single indicative of the sensed temperature, the temperature sensing means being disposed adjacent mixed fluid flow outlet means to sense the temperature of the mixed fluid flow; temperature selection means for producing a selected temperature signal indicative of the selected temperature; an error means for determining an error between the actual and sensed temperatures, the error means being operatively connected with the temperature sensing and selection means; and a proportioning control means for producing a unipolar pulse train for controlling the fluid pressure proportioning valve member in accordance with the error between the sensed and selected signals, the proportioning control means being operatively connected with the solenoid coil and the error means. 4. The mixing apparatus as set forth in claim 3 wherein the proportioning control means controls at least one of a width and an amplitude of each pulse in the pulse train. 5. A fluid mixing apparatus for mixing a cooler fluid flow with a warmer fluid flow to produce a mixed fluid flow having a selectable intermediate temperature, the mixing apparatus comprising: means defining a cooler fluid inlet which is adapted to be connected with a source of the cooler fluid under pressure to receive the cooler fluid flow therefrom; a first regulating assembly operatively connected with the cooler fluid inlet means for regulating the pressure of the cooler fluid; means for defining a warmer fluid inlet which is adapted to be connected with a source of the warmer fluid under pressure to receive the warmer fluid flow therefrom; a second regulating assembly operatively connected with the warmer fluid inlet means for regulating the pressure of the warmer fluid; means for defining at least one mixed fluid outlet for discharging the mixed fluid flow, the mixed fluid flow developing a back pressure adjacent the mixed fluid outlet means; fluid pressure proportioning valve means disposed between the mixed fluid outlet means and the first and second regulating assemblies for selectively proportioning the back pressure between the first and second regulating assemblies such that the fluid pressure proportioning means causes the first and second regulating assemblies to control the relative flow rates of the cooler and warmer fluid flows, the fluid pressure proportioning means including: a first proportioning valve seat in fluid communication with the first regulating assembly, a second proportioning valve seat in fluid communication with the second regulating assembly, a proportioning valve member disposed for movement relative to the first and second proportioning valve seats, and a proportioning valve coil for controlling the relative movement of the proportioning valve member; and, mixed fluid temperature control means for controlling the fluid pressure proportioning means, the mixed fluid temperature control means including: temperature sensing means for sensing mixed fluid temperature and producing a sensed temperature signal indicative of the sensed temperature, the temperature sensing means being disposed adjacent mixed fluid flow outlet means to sense the temperature of the mixed fluid flow, temperature selection means for producing a selected temperature signal indicative of the selected temperature, an error means for determing an error between the actual and sensed temperatures, the error means being operatively connected with the temperature sensing and selection means, a proportioning control means for producing a control signal for controlling the pressure proportioning means in accordance with the error between the sensed and selected signals, the control signal having a variable DC component and an AC component, the DC component controlling a median position of the proportioning valve member and the AC component controlling dithering of the proportioning valve member. 6. A fluid mixing apparatus for mixing a first fluid flow with a second fluid flow to produce a mixed fluid flow, the mixing apparatus comprising: means for supplying a first fluid through a first port at a first pressure; means for supplying a second fluid through a second port at a second pressure; a proportioning valve member movably disposed between the first and second ports; a proportioning valve controller for controlling movement of the proportioning valve member relative to the first and second ports, the proportioning valve controller (a) controlling a median position of the proportioning valve member and (b) causing the proportioning valve member to dither about the median position; and, a control means for causing the proportioning valve controller to adjust the proportioning valve member median position to adjust the proportion of the first and second fluids. 7. The mixing apparatus as set forth in claim 6 wherein the first fluid supplying means includes: means defining a first fluid inlet which is adapted to be connected with a source of the first fluid under pressure to receive the first fluid therefrom; a first regulating assembly operatively connected with the first fluid inlet means for regulating the pressure of the first fluid. 8. The mixing apparatus as set forth in claim 7 wherein the second fluid supplying means includes: means for defining a second fluid inlet which is adapted to be connected with a source of the second fluid under pressure to receive the second fluid therefrom; a second regulating assembly operatively connected with the second fluid inlet means for regulating the pressure of the second fluid. 9. The mixing apparatus as set forth in claim 8 wherein each of the first and second regulating assemblies includes: a pressure sensing means for sensing pressure adjacent the fluid pressure proportioning means and an adjustable valving means for selectively varying the cross section of a flow path disposed between the inlet means and the proportioning means, the adjustable valving means being operatively connected with the pressure sensing means such that the flow path cross section is variable to the sensed pressure generally constant. 10. The mixing apparatus as set forth in claim 9 further including a damping chamber disposed between the pressure sensing means of the first and second regulating assemblies, the damping chamber limiting the speed at which the pressure sensing means respond to changes in pressure, whereby the damping chamber inhibits sudden pressure changes from throwing the first and second regulating assemblies into oscillating or rapidly changing modes. 11. The mixing apparatus as set forth in claim 9 wherein said pressure sensing means includes a displaceable structure which is physically displaced in response to changes in sensed pressure. 12. The mixing apparatus as set forth in claim 11 wherein the adjustable valving means includes a stationary valve seat and a movable valving member which is movable relative to the valve seat to adjust the cross section of the flow path therebetween, the movable valving member being operatively connected with the displaceable structure for movement generally in response to movement thereof. 13. The mixing apparatus as set forth in claim 12 further a valve member biasing means operatively connected with the movable valving member. 14. The mixing apparatus as set forth in claim 12 wherein the movable valving member includes a valving diaphragm having a first face disposed adjacent the inlet and a second face disposed adjacent means for defining a pilot reservoir, the valving diaphragm having at least one aperture therethrough for permitting fluid communication between the inlet means and the pilot reservoir means. 15. The mixing apparatus as set forth in claim 14 further including a pilot valve for selectively opening and closing a pilot outlet aperture from the pilot reservoir means, the pilot valve being operatively connected with said pressure sensing means such that the pilot valve means increases the opening of the pilot outlet aperture in response to a drop in the sensed pressure. 16. The mixing apparatus as set forth in claim 15 further including a spring operatively connected with the movable valving member and the pilot valve which tends to bias the pilot valve means to its open position and tends to bias the movable valving member toward the valve seat. 17. The mixing apparatus as set forth in claim 8 further including: means for defining at least one mixed fluid outlet for discharging the mixed fluid flow, the mixed fluid flow developing a back pressure adjacent the mixed fluid outlet means. 18. The mixing apparatus as set forth in claim 17 further including mixed fluid flow rate adjusting means for selectively adjusting the back pressure, whereby the mixed fluid flow rate is selectively varied. 19. The mixing apparatus as set forth in claim 18 wherein the mixed fluid flow rate adjusting means includes means for defining a first mixed fluid outlet and a second mixed fluid outlet, the first and second mixed fluid outlet means having segments with different cross section flow paths therein such that each mixed fluid outlet means develops a different back pressure, and flow rate control valve means for selectively connecting the first and second ports with the first and second mixed fluid outlet means.