Mixing valve

Abstract

A mixing valve (10) includes a valve body (12) having a hot fluid inlet (14), a cold fluid inlet (16), a mixed fluid outlet (18), and a cavity (20) in the valve body (12) between the inlets (14, 16) and the outlet (18). Mixing valve (10) includes a liner (30, 130, 230, 430, 530, 630, 730, 830) positioned in valve body (12) and a valve member (40, 140, 240, 340, 440, 540, 640, 740, 840) movable therein between a first position restricting the flow of hot fluid and a second position. Liner (30, 130, 230, 430, 530, 630, 730, 830) includes a downstream valve seat (74, 174, 274, 474, 574, 674, 774) that, when engaged by valve member (40, 140, 240, 340, 440, 540, 640, 740, 840), restricts flow of hot fluid past valve member (40, 140, 240, 340, 440, 540, 640, 740, 840).

1 - 45 . (canceled) 
     
     
         46 . A mixing valve comprising
 a valve body providing a first fluid inlet, a second fluid inlet, a mixed fluid outlet, and a cavity defined by at least one internal wall, the cavity being in communication with the inlets and the outlet, and   a valve member movable along a central axis in the cavity between a position restricting flow from at least one of the fluid inlets and a position permitting flow through both of the inlets, the valve member including a central region and a plurality of spaced apart mixing fins each extending from the central region and including a surface that is non-parallel to the axis to facilitate mixing of the first and second fluids.   
     
     
         47 . The mixing valve of  claim 46 , wherein each fin includes a generally radially outwardly facing front, a left side and an opposite right side each extending between the front and the valve member, the surface extending between a bottom edge of each of the left and right sides, the bottom edge of one of the left and the right sides being axially upstream of the bottom edge of the other side. 
     
     
         48 . The mixing valve of  claim 46 , wherein the surface of each mixing fin is perpendicular to the axis. 
     
     
         49 . The mixing valve of  claim 46 , wherein the surface of each mixing fin faces radially inwardly and axially upstream. 
     
     
         50 . A mixing valve comprising
 a valve body providing a first fluid inlet, a second fluid inlet, a mixed fluid outlet, and a cavity having a longitudinal axis, the cavity defined by at least one internal wall, and the cavity being in communication with the inlets and the outlet,   a first valve seat extending from the at least one internal wall,   a second valve seat extending from the at least one internal wall, and   a piston in the cavity and movable along the axis, the piston including a piston bore extending longitudinally therethrough and having a first piston end, a second piston end, a middle region between the ends, an engagement surface at the first piston end bordering the piston bore and engaging the first seat to block flow of the first fluid through the piston bore, a failure shutoff surface at the second piston end movable to engage the second valve seat, the first fluid entering the piston bore between the first valve seat and the engagement surface, the piston formed to include a slot therein positioned axially closer to the engagement surface than to the failure shutoff surface to facilitate mixing of the first and second fluids.   
     
     
         51 . The mixing valve of  claim 50 , further comprising a liner including the first and second valve seats. 
     
     
         52 . The mixing valve of  claim 50 , wherein the piston includes a plurality of spaced apart surfaces non-parallel to the axis and arranged to at least partially face the direction of flow of fluid through the piston bore to encourage turbulent flow through the piston. 
     
     
         53 . The mixing valve of  claim 52 , wherein the plurality of surfaces is perpendicular to the axis through the cavity. 
     
     
         54 . The mixing valve of  claim 52 , wherein at least a portion of at least one of the plurality of surfaces is sloped, having a radially extending component and an axially extending component. 
     
     
         55 . A piston for use in a fluid mixing valve, the piston comprising:
 a main body region and   a plurality of spaced apart fins extending from the main body region, at least a portion of the fins configured to lie non-parallel to the direction of flow of at least one fluid through the valve.   
     
     
         56 . The piston of  claim 55 , wherein each fin includes a surface generally perpendicular to the axis. 
     
     
         57 . The valve member of  claim 55 , wherein the only connection between each of the plurality of fins is the main body region. 
     
     
         58 . The valve member of  claim 55 , wherein an axis extends longitudinally through the piston, each of the plurality of fins includes a surface nonparallel to the axis, a front region, a left side and an opposite right side, each side extending between the front region and the main body region, the surface extending between a bottom edge of each of the left and right sides, the bottom edge of one of the left and the right sides being axially upstream of the bottom edge of the other side. 
     
     
         59 . The valve member of  claim 58 , wherein each of the plurality of fins includes a radially outwardly facing front surface, and the only connection between each of the plurality of structures is the main body region.