Abstract:
Embodiments include thermostatic valves for showers and tubs in which the temperature is regulated by a thermostatic motor/element. Both the flow from the valve and the temperature are controlled by a rotary stem. Hot and cold water is pre-mixed by passage through the coils of a return spring into a mixing chamber and a ceramic valve at the top of the mixing chamber controls flow of mixed water from the mixing chamber into an outlet chamber where fluctuations in the water temperature are eliminated before the water is conveyed to the shower or tub.

Description:
BACKGROUND OF THE INVENTION 
     Field of the invention 
       [0001]    Embodiments relate to thermostatic valves involving the mixing of fluids of dissimilar temperature in which supplies of fluids are controlled according to the temperature of the mixed fluids by a reciprocating valve. 
         [0002]    Thermostatic valves are used to control the temperature of water supplied to showers and baths. Such valves function by using a temperature sensitive regulator, often a thermostatic motor/element, to regulate the relative volumes of hot and cold water supplied to the shower or bath. Rapid variations in the temperature, pressure, or flow rate of the hot and cold water supplied to thermostatic valves may cause corresponding variations in the temperature of the water supplied to the shower or bath. Embodiments of the present disclosure minimize or eliminate such variations. 
         [0003]    The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tool and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
         [0005]    Embodiments include thermostatic valves which comprise a body with a wall, hot and cold water inlets, a cartridge assembly, a mixing chamber located within the cartridge assembly, an outlet chamber located between the cartridge assembly wall and the body wall, a thermostatic motor/element, a shuttle moved by the thermostatic motor/element in a reciprocating motion, the shuttle controlling admission of hot and cold water through ports pass a return spring into the bottom of the mixing chamber. The thermostatic motor/element and shuttle are located within the mixing chamber, a ceramic valve is located at the top of the mixing chamber and the ceramic valve controls movement of mixed water from the mixing chamber through ports in the wall of the cartridge assembly into the outlet chamber where the water temperature is stabilized. The ceramic valve is controlled by rotation of an internal valve stem and the preset relation of the shuttle to the hot and cold water ports also is controlled by the rotation of the internal valve stem. A stabilized water outlet is located at the bottom of the outlet chamber and the stabilized water outlet is connected to a shower outlet and a bath outlet. 
         [0006]    In embodiments hot and cold water flow through ports past a return spring into the bottom of the mixing chamber, through the mixing chamber, through the ceramic valve at the top of the mixing chamber into the outlet chamber, and from the bottom of the outlet chamber into the stabilized water outlet, then into the shower and bath outlets. 
         [0007]    In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. 
         [0008]    BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0009]      FIG. 1  is a side view of an embodiment thermostatic valve 
         [0010]      FIG. 2  is a partial exploded view of the embodiment thermostatic valve of  FIG. 1 . 
         [0011]      FIG. 3  is a side view of an embodiment cartridge assembly. 
         [0012]      FIG. 4  is a cross-sectional view of the cartridge assembly of  FIG. 3  taken at line  4 - 4  of  FIG. 3 . 
         [0013]      FIG. 5  is an exploded view of the cartridge assembly of  FIG. 3 . 
         [0014]      FIG. 6  is an axial cross-sectional view of an embodiment thermostatic motor/element. 
         [0015]      FIG. 7  is a perspective view of an upper ceramic valve disk. 
         [0016]      FIG. 8  is a perspective view of a lower ceramic valve disk. 
         [0017]      FIG. 9  is a schematic view showing the flow of water through an embodiment thermostatic valve. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]      FIG. 1  is a side view of an embodiment thermostatic valve  100 . Visible in  FIG. 1  is the generally cylindrical valve body  102 , body wall  103 , bonnet  118 , external valve stem  150 , hot water inlet  108 , cold water inlet  104 , tub outlet  114 , cold water check-stop port  111 , cold water supply stop  106 , cold water check-stop bonnet lock  105 , hot water check-stop port  112 , hot water supply stop  110 , and hot water check-stop bonnet nut  109 . Not shown in  FIG. 1  but directly opposite of tub outlet  114  on the back side of the tub valve is a shower outlet. 
         [0019]      FIG. 2  is a partial exploded view of the embodiment thermostatic valve  FIG. 1 . Visible in  FIG. 2  is the generally cylindrical valve body  102 , body wall  103 , cold water inlet  104 , cold water check-stop port  111  located between the cold water inlet  104  and the body  102 , hot water inlet  108 , and hot water check-stop port  112  located between the hot water inlet  108  and the body  102 . Also visible is the hot water supply stop  110  and hot water check-stop bonnet  109 . The check-stop valves allow interruption of flow of water into the thermostatic valve for maintenance purposes. The cold water check-stop port  111  is further shown in exploded view and comprises a cold water supply stop seat  115 , cold water check-stop plunger  113 , o-ring  107 , cold water supply stop  106 , o-ring to  116 , and cold water check-stop bonnet  105 . The hot water check-stop valve comprises similar parts. 
         [0020]    Also visible in  FIG. 2  is a cartridge assembly  119  with an internal valve stem  158  which will be described in further detail below. An external valve stem  150  extends from and interacts with the internal valve stem  158 . The external valve stem  150  extends through the bonnet  118  and a handle (not shown in  FIG. 2 ) is attached to the external valve stem  150 . Rotation of the handle causes rotation of the external valve stem  150  and rotation of the internal valve stem  158 . This arrangement allows a non-rising relationship between the handle and the thermostatic shower valve. Rotation of the handle does not result in transverse movement of the external valve stem and attached handle in the plane perpendicular to the plane of rotation. 
         [0021]    Also visible in  FIG. 2  is a external valve stem o-ring  159  and a bonnet o-ring  157 . A bonnet  118  covers the top of the thermostatic valve. A lower limit stop  156  and upper limit stop  152  interact with the bonnet limit stop  154  and limits the extent of rotation of the external valve stem  150 . A retaining ring  153  secures the stop rings in place. 
         [0022]      FIG. 3  is a side view of the cartridge assembly  119 . The cartridge assembly comprises a cartridge base  124  surmounted by a cartridge bonnet  120 . The internal valve stem  158  extends from the top of the cartridge bonnet  120 . 
         [0023]      FIG. 4  is a cross-sectional view of the cartridge assembly  119  of  FIG. 3  taken at line  4 - 4  of  FIG. 3 . Visible in  FIG. 4  is the cartridge base  124  with cartridge base wall  125 . Attached by threads to the top of the cartridge base wall  125  is cartridge bonnet  120 . Mixed water ports  168  are arrayed about the cartridge base wall  125 . The internal stem  158  extends from the top of the cartridge assembly. Internal stem threads  162  on the outer surface of the internal stem interact with cartridge bonnet internal threads  121  on the inner surface of the cartridge bonnet wall  117 . Rotation of the internal stem  158  causes longitudinal translation of the internal stem with reference to the cartridge assembly. A cylindrical slotted ceramic drive  123  transmits the rotation of the internal valve stem to the upper ceramic valve disk  146 . 
         [0024]    A overload spring  126  bears on and urges downward a overload spring adapter  148  which receives the top of a thermostatic motor/element. A cylindrical upper ceramic valve disk  146  interacts with a cylindrical lower ceramic valve disk  144  to form a ceramic disk valve  143  which controls passage of water through the thermostatic valve. A return spring  137  urges upward a shuttle  128  against a thermostatic motor/element  136 . The shuttle  128  has on the upper circumference a shuttle cold water seat  129  and on the lower circumference a shuttle hot water seat  127 . The shuttle cold water seat  129  controls the flow of cold water through the cold water port  133  down past the inner side of the shuttle and past the cylindrical mixing chamber wall  122  to the bottom of the mixing chamber wall where the cold water mixes with hot water in the return spring chamber  164  containing the return spring  137 . The mixed water then flows into the mixing chamber  142 . The hot water seat  127  controls flow of hot water through the hot water port  131  where it passes into the return spring chamber  164  containing the return spring  137 , mixes with cold water, and passes into the mixing chamber  142 . The passage of hot and cold water past the shuttle  128  and through the coils of the return spring  137  provides very efficient mixing of the hot and cold water. The thermostatic motor/element is surrounded by the mixing chamber  142  and is exposed to the flow of mixed hot and cold water. 
         [0025]      FIG. 5  is a partial exploded view of an embodiment cartridge assembly  119  showing the relationships between some of the components. Visible in  FIG. 5  is the cartridge base  124  with the hot and cold water inlet screens  139  and inlet o-rings  141  which cover the hot and cold water ports at the bottom of the cartridge base  124 . Also visible is the return spring  137 , lower shuttle o-ring  134 , shuttle  128 , shuttle cold water lip  129 , shuttle hot water lip  127 , and ceramic drive  123 . The thermostatic motor/element  136  and upper shuttle o-ring  135  are also visible. The cartridge bonnet  120  is shown along with the internal valve stem  158  at the top of the cartridge bonnet. 
         [0026]      FIG. 6  is an axial cross-sectional view of an embodiment thermostatic motor/element. Visible in  FIG. 6  is the thermostatic motor/element body  138  with a thermostatic motor/element body shoulder  163 . A thermostatic motor/element stem  140  extends from the top of the thermostatic motor/element. 
         [0027]      FIG. 7  is a perspective view of a cylindrical upper ceramic valve disk  146 . The disk is pierced by a hole  147 . 
         [0028]      FIG. 8  is a perspective view of a cylindrical lower ceramic valve disk  144 . The disk is pierced by an arcuate cut  145 . 
         [0029]      FIG. 9  is a schematic view showing the flow of water through an embodiment thermostatic valve. The flow of cold water  130  enters through the cold water inlet and passes through a cold water port into the return spring chamber  164 . Similarly the flow of hot water  132  is through the hot water inlet and enters the return spring chamber  164  through the hot water port. Passage through the hot and cold water ports is controlled by the reciprocal motion of the shuttle  128  which is motivated by the thermostatic motor/element and the return spring. Hot and cold water entering the valve is partially mixed by passage through the coils of the return spring in the return spring chamber  164 . The partially-mixed water proceeds with additional mixing to the top of the mixing chamber  144  which surrounds the thermostatic motor/element. Flow of mixed water is controlled by ceramic disk valve  143 . After passing through the mixed water ports the mixed water proceeds downward through the cylindrical outlet chamber  149  which surrounds the outside of the mixed water chamber  142 . Water emerging from the outlet chamber  149  is termed tempered water. Tempered water is highly stabilized and uniform in temperature. At the bottom of the outlet chamber  149  the tempered water enters the tub outlet  114  or shower outlet, (not shown in  FIG. 9 ). 
         [0030]    In operation of embodiments, as in  FIGS. 1 and 4 , cold water flows into the cold water inlet  104  to the cylindrical cold water port  133 , past the return spring  137  in the return spring chamber  164 , and into the mixing chamber  142  which surrounds the thermostatic motor/element  136 . Hot water flows into the hot water inlet  108  to the cylindrical hot water port  131 , past the return spring  137  in the return spring chamber  164 , and into the mixing chamber  142 . The cold water port  133  is located above the hot water port  131 . Flow of cold water through the cold water port  133  is controlled by the shuttle cold water seat  129  located on the upper edge of the cylindrical shuttle  128 . Flow of hot water through the hot water port  131  is controlled by the shuttle hot water seat  127  located on the bottom edge of the cylindrical shuttle  128 . 
         [0031]    In embodiments, the predetermined location of the shuttle  128  determines the temperature of the water in the mixing chamber  142 . This establishes the thermostatic character of the valve, that is, the temperature of the water emerging from the valve into the tub or shower is constant, despite variations in the temperature or pressure of the hot or cold water supply. 
         [0032]    If, for example, the water in the mixing chamber  142  is hotter than the predetermined temperature, expansion of the thermostatic motor/element forces the shuttle down, thereby reducing the flow through or closing the hot water port  131  and simultaneously increasing the flow through or opening the cold water port  133 . Conversely, if the water in the mixing chamber  142  is colder than the predetermined temperature, contraction of the thermostatic motor/element allows the return spring  137  to force the shuttle up, thereby reducing the flow through or closing the cold water port  133  and simultaneously increasing the flow through or opening the hot water port  131 . 
         [0033]    The predetermined temperature is set by moving the shuttle  128  up and down in the mixing chamber  142 . Rotation of the external valve stem  150  causes rotation of the internal valve stem  158 . Since the internal valve stem  158  has a threaded connection to the cartridge bonnet  120  via the internal stem threads  162  and the cartridge bonnet internal threads  121 , rotation of the internal valve stem causes the internal valve stem to move up and down within the mixing chamber  142 . The thermostatic motor/element  136  is urged against overload spring adapter  148  by return spring  137 . Since shuttle  128  is fixedly attached to the thermostatic motor/element body  138 , rotation of the external valve stem  150  causes reciprocal movement of the shuttle  128  up and down within the mixing chamber  142 . Such movement sets the desired temperature of the water which emerges from the thermostatic valve. 
         [0034]    Rotation of the external valve stem  150  not only controls the preset temperature of water from the valve, but also controls the flow of water from the thermostatic valve by means of the ceramic valve  143 . Ceramic valve  143  is located at the top of mixing chamber  142 . When the ceramic valve is open flow of mixed water from mixing chamber  142  through mixed water ports  168  in the cartridge base wall  125  into the outlet chamber  149  occurs. The temperature of the water is stabilized in the outlet chamber  149  and the now stabilized water subsequently flows into the tub  116  and shower outlets. 
         [0035]    The cylindrical ceramic valve  143  is comprised of stationary lower ceramic valve disk  144  and a cylindrical upper ceramic valve disk  146 . The upper disk is mounted coaxially with the external valve stem  150  and is attached via the internal valve stem  158 , internal stem  160 , and ceramic drive  123  so that rotation of the external valve stem  150  causes rotation of the upper ceramic valve disk  146 . Rotation of the external valve stem  150  is constrained by the interaction of lower limit stop  156 , upper limit stop  152 , and bonnet limit stop  154  on the valve bonnet  118  so that the external valve stem  150  may be rotated clockwise and counterclockwise over a range of less than 360°. The ceramic valve  143  is mounted so that at the clockwise stop the upper ceramic valve hole  147  of the upper ceramic valve disk  146  is located over a solid portion of the lower valve ceramic disk  144 . Flow through the ceramic valve  143  is blocked when the external valve stem  150  is at the clockwise stop. Rotation of the external valve stem  150  in a counter clockwise direction results in the placement of the upper ceramic valve hole  147  of the upper ceramic valve disk  146  over the arcuate lower ceramic valve slot  145  of the lower ceramic valve disk  144 . This allows mixed water from the mixing chamber  142  to flow at a constant rate into the outer chamber  149  and subsequently out of the thermostatic valve. The ceramic valve  143  remains open as the upper ceramic valve hole  147  is moved over the length of the arcuate lower ceramic valve slot  145  and remains open when the external valve stem  150  is rotated to the counterclockwise stop. Since the area of the upper ceramic valve hole  147  controls the rate of flow of water through the ceramic valve  143 , the rate of flow through the ceramic valve  143  is constant over the range of movement of the upper ceramic valve hole  147  in the mobile upper ceramic valve disk  146  over the lower ceramic valve slot  145  in the stationary lower ceramic valve disk  144 . 
         [0036]    Rotation of the external valve stem  150  in a counterclockwise direction turns on and allows the flow of cold water through the thermostatic valve  100 . Continued rotation of the external valve stem  150  in a counterclockwise direction increases the temperature of the water through the thermostatic valve  100  until the maximum temperature is reached at the counterclockwise stop. 
         [0037]    Embodiments therefore have the advantage of providing water for the tub or shower at a predetermined temperature, despite variations in the temperature, pressure, or flow rate of the hot and cold water supply. The temperature of the water eventually used in a tub or shower is stabilized by means of passage through the return spring, through a mixing chamber, and through a outlet chamber. 
         [0038]    Embodiments include thermostatic valves which comprise, in combination, a valve body with connections to hot and cold water supplies, connections to tub and shower facilities, and means for connection of a knob to a cartridge assembly, and a cartridge assembly with thermostatic means for controlling water temperature and flow from the thermostatic valve. Cartridge assemblies easily may be removed from the body, thereby facilitating the repair or replacement of defective elements as needed. Since components of the cartridge assembly require maintenance and replacement much more often than do components of the body, the provision of a removable cartridge assembly greatly reduces the time, expense, and down-time required in maintenance over the lifetime of the thermostatic valve. 
         [0039]    Embodiments are manufactured of suitable hard, non-porous, strong materials such as bronze, steel, stainless steel, and iron. Embodiment thermostatic motor/elements are manufactured of paraffin wax with molecules of a narrow range of carbon chain lengths, allowing expansion and retraction of the thermostatic motor/element stem within a predetermined temperature range. Embodiment ceramic valves are manufactured of suitable hard, durable ceramics such as alumina oxide ceramics. 
         [0040]    Embodiments have the disclosed internal/external stem arrangement which provides significant advantages in comparison with conventional valves. This arrangement eliminates a pinch point when closing which has the potential of injury to the fingers of users. It reduces the potential of water getting between the handle and the shower wall. It makes possible an inexpensive anti-ligature handle and eschutcheon for institutional use. Finally, this arrangement eliminates a compression shut-off found in conventional valves which is capable of being over-tightened, causing difficulty in opening the valves. 
         [0041]    Embodiments incorporate ceramic shut-off valves which have the advantages of requiring only low torque to operate and having a very long operational life. Low-torque operation is important for showers which comply with the American Disabilities Act and in anti-ligature applications. 
         [0042]    Embodiments which include the disclosed shuttle and return spring configuration promote better mixing of the hot and cold waters than conventional configurations. 
         [0043]    While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. The applicant or applicants have attempted to disclose all the embodiments of the invention that could be reasonably foreseen. There may be unforeseeable insubstantial modifications that remain as equivalents.