Abstract:
An automatic compensating valve, e.g., for individual shower and tub/shower combination fixtures, has a valve body defining cold and hot water inlet flow passageways, a mixing chamber, a mixed temperate water outlet flow passageway, and an axial bore. The valve includes a plunger that defines, with other elements of the valve, a first orifice for communication of the cold water inlet with said mixing chamber and a second orifice for communication of hot water inlet with mixing chamber. The plunger is mounted within a mixing subassembly for axial movement within the bore, including in response to temperature of water within the mixing chamber to vary the ratio of flow of cold water through the first orifice to flow of hot water through the second orifice. The first orifice and the second orifice are arranged for flow of water transverse to axial movement of the plunger within the bore. The valve further includes a wax motor mounted axially within the bore for positioning of the plunger in response to temperature of water within the mixing chamber.

Description:
TECHNICAL FIELD  
       [0001]     This application claims benefit from U.S. Provisional Patent Application No. 60/526,710, filed Dec. 2, 2003, the complete disclosure of which is incorporated herein by reference.  
         [0002]     This invention relates to water flow control valves, and more particularly to automatic compensating valves. 
     
    
     BACKGROUND  
       [0003]     It has been known to provide point of supply valves for controlling water temperature with changes in supply temperature and pressure. It is also known to provide point of use thermostatic control valves and combination valves.  
       SUMMARY  
       [0004]     According to one aspect of the invention, an automatic compensating valve, e.g. for individual shower and tub/shower combination fixtures, comprises: a valve body defining a cold water inlet flow passageway, a hot water inlet flow passageway, a mixing chamber, a mixed temperate water outlet flow passageway, and an axial bore; a plunger defining, with other elements of the valve, a first orifice for communication of the cold water inlet with the mixing chamber and a second orifice for communication of the hot water inlet with the mixing chamber, the plunger being mounted within a mixing subassembly for axial movement within the bore, including in response to temperature of water within the mixing chamber to vary the ratio of flow of cold water through the first orifice to flow of hot water through the second orifice, the first orifice and the second orifice being arranged for flow of water transverse to axial movement of the plunger within the bore; and a wax motor mounted axially within the bore for positioning of the plunger in response to temperature of water within the mixing chamber.  
         [0005]     Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The automatic compensating valve further comprises a spring biasing the plunger towards a relatively greater ratio of flow of hot water to flow of cold water into the mixing chamber. The automatic compensating valve further comprises a spring biasing the wax motor and the plunger towards a relatively greater ratio of flow of cold water to flow of hot water into the mixing chamber. The plunger is positioned upon opening for initial preferential flow of cold water into the mixing chamber. The automatic compensating valve further comprises a poppet check and shutoff valve assembly in each of the cold water inlet flow passageway and the hot water inlet flow passageway. The automatic compensating valve further comprises the mixing subassembly disposed axially within the bore and a stem subassembly disposed axially within the bore. The stem subassembly and the mixing subassembly are accessible from the face of the valve. The automatic compensating valve is configured for use at individual shower and tub/shower combination fixtures.  
         [0006]     The invention thus provides an automatic compensating valve, e.g. for individual shower and tub/shower combination fixtures, that automatically mixes hot and cold water at the point of use, to provide and maintain blended water within a specified temperature range. The wax element or thermostatic motor responds quickly to compensate for temperature fluctuations induced by changes in water temperatures and for changes in water pressure. In the event of loss of cold water feed, the thermostatic motor reacts rapidly to shut off, or at least to virtually shut off, hot water flow. Also, the valve opens in cold water position, thereby to ensure maximum bather safety and comfort. Furthermore, the hot water and cold water flows are delivered radially into the mixing chamber, thus to avoid unwanted pressure effects on the control of flow, e.g. as often experienced with more typical axial feed. Finally, all of the valve components are accessible from the front of the valve, e.g. for less complicated repair and/or replacement.  
         [0007]     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0008]      FIG. 1  is a bottom section view of an automatic compensating valve of the invention, e.g. for individual shower and tub/shower combination fixtures.  
         [0009]      FIG. 2  is an exploded perspective view of the automatic compensating valve of  FIG. 1 .  
         [0010]      FIG. 3  is a top plan view of the valve body of the automatic compensating valve of  FIG. 1 ; while  FIG. 3A  is a front section view of the valve body, taken at the line  3 A- 3 A of  FIG. 3 .  
         [0011]      FIG. 4  is a front view of the check poppet of the poppet check and shutoff valve assemblies of the automatic compensating valve of  FIG. 1 ; while  FIG. 4A  is a side section view of the check poppet, taken at the line  4 A- 4 A of  FIG. 4 .  
         [0012]      FIG. 5  is a front view of the check sleeve of the poppet and shutoff valve assemblies of the automatic compensating valve of  FIG. 1 ; while  FIG. 5A  is a top view of the check sleeve; and  FIG. 5B  is a side section view of the check sleeve, taken at the line  5 B- 5 B of  FIG. 5 .  
         [0013]      FIG. 6  is a front view of the check stem of the poppet check and shutoff valve assemblies of the automatic compensating valve of  FIG. 1 ; while  FIG. 6A  is a top view of the check stem; and  FIG. 6B  is a side section view of the check stem, taken at the line  6 B- 6 B of  FIG. 6 .  
         [0014]      FIG. 7  is an exploded view of the stem subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 7A  is a front view of the stem subassembly of  FIG. 7 ; and  FIG. 7B  is a side section view of the stem subassembly, taken at the line  7 B- 7 B of  FIG. 7A .  
         [0015]      FIG. 8  is a top perspective view of the base element of the mixing subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 8A  is a bottom perspective view of the base element of  FIG. 8 ;  FIG. 8B  is a top view of the base element of  FIG. 8 ;  FIG. 8C  is a bottom view of the base element of  FIG. 8 ;  FIG. 8D  is a side view of the base element of  FIG. 8 ;  FIG. 8E  is a front view of the base element of  FIG. 8D ;  FIG. 8F  is a side section view of the base element, taken at the line  8 F- 8 F of  FIG. 8E ; and  FIG. 8G  is a front section view of the base element, taken at the line  8 G- 8 G of  FIG. 8D .  
         [0016]      FIG. 9  is a top perspective view of the sleeve of the mixing subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 9A  is a top view of the sleeve of  FIG. 9 ;  FIG. 9B  is a side view of the sleeve of  FIG. 9 ; and  FIG. 9C  is a bottom view of the sleeve of  FIG. 9 .  
         [0017]      FIG. 10  is a side view of the seat cage of the mixing subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 10A  is a top view of the seat cage of  FIG. 10 ; and  FIG. 10B  is a side section view of the seat cage, taken at the line  10 B- 10 B of  FIG. 10A .  
         [0018]      FIG. 11  is a top perspective view of the plunger of the mixing subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 11A  is a top view of the plunger of  FIG. 11 ;  FIG. 11B  is a side view of the plunger of  FIG. 11 ;  FIG. 11C  is a bottom view of the plunger of  FIG. 11 ;  FIG. 11D  is a side section view of the plunger, taken at the line  11 D- 11 D of  FIG. 11C ; and  FIG. 11E  is an oblique side section view of the plunger, taken at the line  11 E- 11 E of  FIG. 11A .  
         [0019]      FIG. 12  is a perspective view of the stem of the stem subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 12A  is a front view of the stem of  FIG. 12 ;  FIG. 12B  is a top view of the stem of  FIG. 12 ;  FIG. 12C  is a bottom view of the stem of  FIG. 12 ; and  FIG. 12D  is a side section view of the stem, taken at the line  12 D- 12 D of  FIG. 12A .  
         [0020]      FIG. 13  is a perspective view of the overload insert of the stem subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 13A  is a front view of the overload insert of  FIG. 13 ;  FIG. 13B  is a bottom view of the overload insert of  FIG. 13 ; and  FIG. 13C  is a side section view of the overload insert, taken at the line  13 C- 13 C of  FIG. 13B .  
         [0021]      FIG. 14  is a perspective view of the overload stop of the stem subassembly of the automatic compensating valve of  FIG. 1 ; while  FIG. 14A  is a side view of the overload stop of  FIG. 14 ;  FIG. 14B  is a top view of the overload stop of  FIG. 1 ; and  FIG. 14C  is a side section view of the overload stop, taken at the line  14 C- 14 C of  FIG. 14B .  
         [0022]      FIG. 15  is a perspective view of the cartridge nut of the automatic compensating valve of  FIG. 1 ; while  FIG. 15A  is a top view of the cartridge nut of  FIG. 15 ;  FIG. 15B  is a front view of the cartridge nut of  FIG. 15 ;  FIG. 15C  is a bottom view of the cartridge nut of  FIG. 15 ;  FIG. 15D  is a side section view of the cartridge nut, taken at the line  15 D- 15 D of  FIG. 15B ; and  FIG. 15E  is an oblique side section view of the cartridge nut, taken at the line  15 E- 15 E of  FIG. 15C .  
         [0023]      FIG. 16  is a perspective view of the bonnet of the automatic compensating valve of  FIG. 1 ; while  FIG. 16A  is a top view of the bonnet of  FIG. 16 ;  FIG. 16B  is a front view of the bonnet of  FIG. 16 ;  FIG. 16C  is a bottom view of the bonnet of  FIG. 16 ; and  FIG. 16D  is a side section view of the bonnet, taken at the line  16 D- 16 D of  FIG. 16B .  
         [0024]      FIG. 17  is a perspective view of the high temperature stop of the automatic compensating valve of  FIG. 1 ; while  FIG. 17A  is a top view of the high temperature stop of  FIG. 17 ;  FIG. 17B  is a side view of the high temperature stop of  FIG. 17 ; and  FIG. 17C  is a side section view of the high temperature stop, taken at the line  17 C- 17 C of  FIG. 17A .  
         [0025]      FIG. 18  is top section view of the automatic compensating valve of  FIG. 1  shown in closed position, with no flow of water.  
         [0026]      FIG. 19  is top section view of the automatic compensating valve of  FIG. 1  show in partially open position for flow of mixed temperate water, e.g. at 105° F.  
         [0027]      FIG. 20  is top section view of the automatic compensating valve of  FIG. 1  shown in partially open position for flow of mixed hot water, e.g. at 140° F.  
         [0028]      FIG. 21  is a front view of a wax element of the automatic compensating valve of  FIG. 1 .  
         [0029]      FIG. 22  is a plot of stroke versus temperature for the wax element of  FIG. 21  in the automatic compensating valve of  FIG. 1 . 
     
    
       [0030]     Like reference symbols in the various drawings indicate like elements.  
       DETAILED DESCRIPTION  
       [0031]     Referring to  FIGS. 1 and 2 , an automatic compensating valve  10  of the invention, e.g. for individual shower and tub/shower combination fixtures, has a body  12  ( FIGS. 3 and 3 A), e.g. formed of cast bronze, defining a cold water inlet flow passageway  14 , a hot water inlet flow passageway  16 , a bore  18 , and a mixed temperate water outlet passageway  20 . The cold and hot water inlets  15 ,  17 , respectively are configured for sweat fitting to cold and hot water supply piping, respectively. The mixed water outlets  21 ,  21   a  are configured for sweat fitting to supply piping for delivering blended mixed water to the tub spout and/or to the shower head.  
         [0032]     Disposed in the cold water inlet flow passageway  14  and in the hot water inlet flow passageway  16  are poppet check and shutoff valve assemblies  22 ,  24 . Referring also to  FIGS. 4-4A ,  5 - 5 B and  6 - 6 B, each poppet check and shutoff valve assembly  22 ,  24  consists of a disc plunger  26 , formed, e.g., of BUNA-N (acrylonitrile-butadiene) copolymer (70 to 75 durometer), mounted to a check poppet  28  and urged by a spring  30  toward sealing contact with an opposed seat  32  defined by the valve body  12 . The check poppet  28  is mounted to a check stem  38 , which is disposed in threaded engagement with a check sleeve  34 . The check sleeve in turn is disposed in threaded engagement in an aperture  36  defined by the valve body  12 , in each of the hot water and cold water inlet flow passageways  14 ,  16 , respectively. The check stem  38  is axially adjustable relative to the check sleeve  34 , as described more fully below. O-rings  40 ,  42  (e.g., EPDM (ethylene-propylene-diene copolymer), 70 durometer) provide sealing between the body  12  and the check sleeve  34  and between the check sleeve  34  and the check stem  38 , respectively. Under normal inlet flow pressure, the disc plunger  26  and check poppet  28  are urged from the seat  32  to allow flow of cold water and flow of hot water, respectively, into the control valve bore  18 . If inlet flow is lost, and/or a backflow condition develops, the disc plungers  26  are urged by the respective springs  30  into sealing contact with the opposed seats  32  defined by the body to resist flow through the passageway  14 ,  16 . When it is desired to cease flow, e.g. for maintenance of the control valve, check stem  38  can be rotated in threaded engagement with check sleeve  36 , e.g. by engagement of a screwdriver blade in slot  44 , to bring the disc plunger  26  into sealing contact with the opposed valve seat  32 , thereby to reduce or completely cease flow. The check poppet  28 , check sleeve  34  and check stem  38  are all formed of suitable material, e.g. C36000 brass.  
         [0033]     Disposed within the bore  18  of the valve body  12  are a mixing subassembly  46 , and a stem subassembly  48  ( FIGS. 7-7B ). The mixing subassembly  46  consists of generally cylindrical base element  50  ( FIGS. 8-8G ) positioned within the bore  18  of valve body  12 . The base element  50 , formed, e.g., of acetal resin, e.g. as available under the trademark DELRIN® 500, Natural (acetal thermoplastic polymer), from E.I. du Pont de Nemours and Company, Inc. of Wilmington, Del., or other suitable ANSI/NSF Standard  61  listed material, has a cylindrical side wall  52  upstanding from a bottom wall  54 . The bottom wall defines a pair of orifices  56 ,  58  disposed in registration with a cold water inlet  57  (from cold water inlet flow passageway  14 ) and a hot water inlet  59  (from hot water inlet flow passageway  16 ) in the bottom surface  62  of the bore  18  in valve body  12 . O-rings  60  (e.g., EPDM (70 durometer)) provide sealing about the inlets at the interface between the opposed surfaces of the base element bottom wall  54  and the bottom surface  62  of the valve body bore  18 . Annular region  64 , defined by the inner wall of the bore  18  about the cylindrical side wall  52  of the base element  50 , is disposed in communication with the mixed temperate water outlet  65  to the mixed temperate water outlet flow passageway  20  in the bottom surface  62  of valve body  12  for flow of mixed water to the tub or shower.  
         [0034]     A sleeve  66  ( FIGS. 9-9C ), also formed, e.g., of DELRIN® 500, Natural, is positioned within the base element  50 , resting upon the bottom wall  54  of the base element, with its circumferential outer surface  68  disposed in sealing relationship with opposed inner side wall surfaces of the base element, sealed by o-ring  70  (e.g., EPDM (70 durometer)). The sleeve  66  is secured in position, engaged with the bottom wall  54  of the base element  50 , by seat cage  72  ( FIGS. 10-10B ), formed, e.g., of C36000 brass, with o-ring  74  (e.g., EPDM (70 durometer)) providing sealing between the circumferential outer surface  76  of the seat cage  72  and the opposed inner surface  78  of the cylindrical side wall  52  of the base element  50 . A plunger  80  ( FIGS. 11-11E ), formed, e.g., of DELRIN® 500, Natural, is disposed within sleeve  66  and mounted for axial movement between engagement with the bottom wall  54  of the base element  50  and engagement with the shoulders  82  of the seat cage  72 , with a spring  84  biasing the plunger upwards, towards engagement with shoulders  82 . An o-ring  86  (e.g., EPDM (70 durometer)) provides sealing between the circumferential outer surface of the plunger  80  and the opposed inner surface  88  of the sleeve  66 .  
         [0035]     The stem subassembly  48  ( FIGS. 7-7B ) consists of stem  90  ( FIGS. 12-12D ) defining an elongated axial bore  92  containing spring  94  at its closed, upper end, engaged with overload insert  96  ( FIGS. 13-13C ). The spring  94  and overload insert  96  are secured within the tip region of the axial bore  92  by overload stop  98  ( FIGS. 14-14C ), which is pressed into the axial bore of the stem and into engagement with shoulder  108  defined by the inner wall  110  of the stem  90 . The stem  90 , overload insert  96  and overload stop  98  are formed, e.g., of C36000 brass. Referring also to  FIG. 21 , wax element  100  (of known construction that responds to changes over a range of temperature by increasing or decreasing in length according to a predetermined profile ( FIG. 22 )) is disposed with a first, upper end  102  engaged within the overload insert  96  and an opposite, lower end  104  engaged in plunger  80 .  
         [0036]     The axial position of stem subassembly  48  within the bore  18  of valve body  12  is adjusted by rotation of the stem  90 , which causes the stem to rotate in engagement with the fixed cartridge nut  116  ( FIGS. 15-15E ), formed, e.g., of DELRIN® 500, Natural. The mixing subassembly  46  and the stem subassembly  48  are secured within the bore  18  of valve body  12  by bonnet  118  ( FIGS. 16-16D ), disposed in threaded engagement with the valve body. O-ring  120  (e.g., EPDM (70 durometer)) and o-rings  122 ,  124  (e.g., BUNA copolymer (70±5 durometer)) provide sealing between the bonnet  118  and the valve body  18  and between the bonnet  118  and the stem  90 , respectively. High temperature stop  126  ( FIGS. 17-17C ), formed, e.g., of C36000 brass, disposed in threaded engagement with bonnet  118 , is axially adjustable for setting a predetermined limit upon axial movement of the stem  90 .  
         [0037]     Shut-off gasket  128 , formed, e.g., of EPDM (65 to 75 durometer), is mounted upon the upper surface of the seat cage  72 , positioned for sealing engagement by an opposed valve surface  130  of the stem  90 .  
         [0038]     Referring to  FIGS. 18-20  (in which the automatic compensating valve of the invention, e.g. for individual shower and tub/shower combination fixtures, is shown in top view, i.e. in reverse position from the bottom views of  FIGS. 1 and 2 ), the valve  10  is shown with an actuator knob  132  fastened, e.g. by set screw  133 , to the stem  90 , and a face cover plate  134 .  
         [0039]     In  FIG. 18 , the valve  10  is shown in closed position, with the lower valve surface  130  of the stem  90  engaged upon the shutoff gasket  128  mounted to the upper surface of the seat cage  72  to resist flow through the valve. The poppet check and shutoff valve assemblies  22 ,  24  are also shown in closed position. The plunger  80 , urged by spring  94  acting through overload insert  96 , overload stop  98 , and wax element  100 , is seated against the bottom wall  54  of the base element  50 , restricting flow of hot water from the hot water inlet flow passageway  16  into the water mixing region  136 . In this position, the plunger  80  is spaced from engagement with the seat cage  72 , thereby to permit initial flow of cold water when the valve is opened.  
         [0040]     Referring next to  FIG. 19 , the valve  10  is shown in opening position, e.g., for outlet of blended water at 105° F. The actuator knob  132  has been rotated (arrow, R) to cause the stem subassembly  48  to rotate and move axially (arrow, A). Axial movement of the stem subassembly  48  removes the lower valve surface  130  of the stem  90  from engagement upon the shutoff gasket  128  mounted to the upper surface of the seat cage  72  to permit flow of water from the mixing chamber  136  toward the mixed temperate water outlet passageway  20 . Initial flow of cold water into the mixing chamber causes the wax element  100  to decrease in overall length, which, in combination with axial movement of the stem subassembly  48 , permits the spring  84  to move the plunger  80  away from engagement against the bottom wall  54  of the base element  50 , thereby to permit flow of hot water from the hot water inlet flow passageway  16  into the water mixing region  136 . In this position, the plunger  80  also remains spaced from engagement with the seat cage  72 , thereby to permit continuing, but relatively reduced, flow of cold water into the mixing region  136 , where it is mixed with the hot water before flowing as temperate mixed water toward the mixed temperate water outlet  20 . Assuming inlet flow of cold water at 60° F. and inlet flow of hot water at 140° F., maximum outlet flow occurs at approximately 80° F. outlet temperature.  
         [0041]     Referring next to  FIG. 20 , with further rotation of the actuator knob  132  (arrow, R), the valve  10  is shown in full open position, e.g., for outlet of blended water at 140° F. Rotation and axial movement of the stem subassembly  48  (arrow, A) spaces the lower valve surface  130  of the stem  90  further from engagement upon the shutoff gasket  128  mounted to the upper surface of the seat cage  72 , thereby increasing the temperature of water flowing from the mixing chamber  136  toward the mixed temperate water outlet passageway  20 , without further increase in flow volume. The axially-spaced position of the stem subassembly  48  permits the spring  84  to move the plunger further away from engagement against the bottom wall  54  of the base element  50 , and into engagement with the seat cage  72 , thereby to permit flow of a greater proportion of hot water from the hot water inlet flow passageway  16  into the water mixing region  136  while permitting no, or only a still further relatively reduced, flow of cold water into the mixing region  136 .  
         [0042]     Referring still, by way of example, to  FIG. 20 , as mentioned above, the flow of hot water and the flow of cold water past the plunger  80  and into the blended water mixing chamber  136  is generally radial, i.e. transverse to the axis, V, of the bore  18  ( FIG. 3 ) of the valve body  12 . As a result, adverse effects of axially-directed water pressure on the axial movement and positioning of the components of the mixing subassembly  46  and the stem subassembly  48  are minimized or avoided, thereby providing more consistent valve performance.  
         [0043]     Again referring to  FIG. 20 , the range of axial movement permitted for the stem subassembly  48  (arrow, A) is restricted by engagement of outer shoulder  109  of the stem  90  with the high temperature stop  126 . The position of the high temperature stop is adjustable by rotation of the stop in threaded engagement with the bonnet  118 , and typically is set by a plumbing technician during installation.  
         [0044]     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, referring to  FIG. 20 , over expansion of the wax element  100 , e.g. due to high water temperature within the mixing region, may cause further expansion of the wax element  100 , which, acting against the spring  84 , urges the plunger  80  towards a position restricting flow of additional hot water into the mixing chamber  136 . Accordingly, other embodiments are within the scope of the following claims.