Abstract:
Embodiment thermostatic valves are protected against damage to the wax motor from the leakage of hot water into the valve when the hot water inlet is closed. Embodiments include an improved temperature motive means with fewer parts than conventional valves and with an improved sealing relation between the wax motor/shuttle and the water ports.

Description:
BACKGROUND OF THE INVENTION 
       [0001]      1 . Field of the invention 
         [0002]    Embodiments include thermostatic mixing valves which mix fluids of dissimilar temperatures with temperature motive means and with a reciprocating valve. 
         [0003]    Conventional thermostatic mixing valves have a wax motor or other temperature responsive device which is attached to the shuttle or reciprocating valve. Occasionally with such valves there is a leakage of hot water into the mixing chamber even though the hot water port has been closed by the shuttle. If the valve has no provisions for this scenario, the wax motor is unable to expand, which causes damage to the wax motor and may make the thermostatic valve ineffective. Conventional arrangements to avoid this issue can be seen in U.S. Pat. Nos. 6,726,110; 7,913,926; and 6,315,210. Embodiments of the present disclosure have wax motors and shuttles arranged in a new configuration in which the motors are not attached to the shuttles, thus avoiding such damage to the thermostatic valve when the motor is in an overload condition. 
         [0004]    In addition, embodiment valves have fewer parts than conventional valves, thereby simplifying manufacture, increasing reliability, and reducing costs, as well as allowing better control of the temperature of the mixed water from the valve through improvement of the sealing effect of the shuttle within the valve. 
         [0005]    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 
       [0006]    Embodiments include a thermostatic mixing valve which comprises a body with a mixing chamber. A cold water path comprises a cold water inlet, cold water conduit, a circumferential cold water port, and a circumferential cold water seat on the upper edge of the cold water port, the cold water port and cold water seat located on the wall of the mixing chamber. A hot water path comprises a hot water inlet, hot water conduit, a circumferential hot water port, and a circumferential hot water seat located on the lower edge of the hot water port, the hot water port and hot water seat located on the wall of the mixing chamber below the cold water port and cold water seat. A mixed water path comprises a mixing chamber and a mixed water outlet. There is shuttle with on its upper circumference a cold water lip and on its lower circumference a hot water lip. The shuttle has a lumen with a shoulder, and the shoulder has an upper surface and a lower surface. A cylindrical wax motor comprising a wax motor stem and a wax motor body, the body having a shoulder with an upper surface and a lower surface, is inserted into the shuttle lumen with the wax motor shoulder upper surface in contact with the shuttle shoulder lower surface and the wax motor not connected to the shuttle. A shuttle spring is in contact with the shuttle shoulder upper surface and biases the shuttle toward the wax motor body. A wax motor spring is in contact with the wax motor shoulder lower surface and biases the wax motor body toward the shuttle. 
         [0007]    Embodiments include the temperature motive means of a thermostatic mixing valve which comprises a tubular shuttle having a lumen and a shoulder on the lumen, and a cylindrical wax motor having a shoulder. The wax motor is located within the shuttle lumen with the motor shoulder in contact with the shuttle shoulder, and the motor and the shuttle are not connected to each other. 
         [0008]    Embodiments include the temperature motive means of a thermostatic mixing valve which comprises a tubular shuttle having a cold water seat and a hot water seat on the outer surface of the shuttle, the shuttle having a lumen with a shoulder within the lumen, and the shuttle shoulder has an upper surface and a lower surface. The shuttle shoulder upper surface is capable of being biased downward in the mixing valve by a shuttle spring. There is a cylindrical wax motor with a shoulder on the circumference of the wax motor and the wax motor shoulder has an upper surface and a lower surface. The wax motor lower surface is capable of being biased upward in the mixing valve by a wax motor spring. The wax motor is capable of being inserted into the shuttle lumen with the wax motor shoulder upper surface in contact with the shuttle lumen lower surface and the wax motor is not connected to the shuttle. 
         [0009]    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. 
         [0010]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0011]      FIG. 1  is a cross-sectional view of an embodiment thermostatic mixer valve. 
           [0012]      FIG. 2  is an exploded cross-sectional view of an embodiment thermostatic mixer valve. 
           [0013]      FIG. 3  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve with exaggerated elements with flow of both hot and cold water through the valve. 
           [0014]      FIG. 4  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve with exaggerated elements with flow of hot water only through the valve. 
           [0015]      FIG. 5  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve with exaggerated elements with flow of cold water only through the valve. 
           [0016]      FIG. 6  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve with exaggerated elements with flow of cold water only through the valve under conditions of excessive hot water in the thermostatic valve. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]      FIG. 1  is a cross-sectional view of an embodiment thermostatic mixer valve  100 . The valve includes a cruciform or cross-shaped body  102  with a hot water inlet  104  and a cold water inlet  108  on opposed arms, and a bonnet  122  with a temperature adjustment stem  126  at the top of the valve and a mixed water outlet  106  at the bottom of the valve. A cylindrical mixing chamber  105  extends from the mixed water outlet  106  to the bottom of the bonnet  122 . 
         [0018]    An optional hot water check valve  110 , optional filter  107 , and optional retaining ring  109  is located adjacent to the hot water inlet  104 . A hot water path  114  comprises the hot water inlet  104 , hot water conduit  121 , hot water port  111  and hot water seat  115 . Both the hot water port  111  and the hot water seat  115  extend about the circumference of the mixing chamber  105 . The hot water seat  115  is located on the bottom of the hot water port  111  and the seat extends slightly into the mixing chamber  105 . 
         [0019]    An optional cold water check valve  112 , optional filter  107 , and optional retaining ring  109  is located adjacent to the cold water inlet  108 . A cold water path  116  comprises the cold water inlet  108 , cold water conduit  125 , cold water port  113  and cold water seat  117 . Both the cold water port  113  and the cold water seat  117  extend about the circumference of the mixing chamber  105 . The cold water seat  117  is located on the bottom of the cold water port  113 . 
         [0020]    The cold water port  113  is located above the hot water port  111  on the wall of the mixing chamber  105 . 
         [0021]    A bonnet  122  is attached to the top of the body  102  by complementary threads  129  in the top of the body  105  and threads  127  in the sides of the bonnet  122 . A bonnet bore  144  penetrates the bonnet  122 . A bonnet ledge  143  is on the inner surface of the bore  144 . A temperature adjustment stem  126  extends through the bonnet bore  144  and is attached by stem threads  128  to internal bonnet threads  123 . Rotation of the temperature adjustment stem  126  causes the stem to advance into or retract from the mixing chamber  105 . A locking nut  124  secures the temperature adjustment stem in the desired position. 
         [0022]    In embodiments, the temperature motive means  131  includes a wax motor  130 , shuttle  138 , shuttle spring  120 , and motor spring  118 . 
         [0023]    The wax motor  130  consists of a wax motor stem  136  and wax motor body  134  with a shoulder  132  about the circumference of the body. The shoulder  132  has a wax motor shoulder upper surface  133  and a wax motor shoulder lower surface  135 . 
         [0024]    The shuttle  138  has a cylindrical shape with a shoulder  137  on the lumen with a shoulder upper surface  141  and a shoulder lower surface  139 . A shuttle cold water lip  140  is on the upper edge of the cylindrical shuttle  138 . A shuttle hot water lip  142  is on the lower edge of the cylindrical shuttle  138 . The shuttle cold water lip  140  interacts with the cold water seat  117  to close the cold water port  113 . The shuttle hot water lip  142  interacts with the hot water seat  115  to close the hot water port  111 . 
         [0025]    The shuttle  138  is inserted into the mixing chamber  105 . The wax motor  130  is located within the shuttle  138  lumen with the wax motor shoulder upper surface  133  in contact with the shuttle shoulder lower surface  139 . The wax motor stem  136  is in contact with the temperature adjustment stem  126 . A motor spring  118  is supported at one end by a motor spring retaining rib  119  at the mixed water outlet  106  and the other end is in contact with the wax motor shoulder lower surface  135 . The motor spring  118  biases the wax motor  130  upward toward the temperature adjustment stem  126 . The shuttle spring  120  is supported at one end by the bonnet ledge  143  and the other end of the spring  120  bears on the shuttle shoulder upper surface  141 . The shuttle spring  120  biases the shuttle  138  downward toward the mixed water outlet  106 . 
         [0026]      FIG. 2  is an exploded cross-sectional view of an embodiment thermostatic mixer valve. Visible in  FIG. 2  are the body  102  with hot water inlet  104 , mixed water outlet  106 , cold water inlet  108 . Also visible is the optional hot water check-valve  110  and optional cold water check valve  112 , and the optional filters  107  and retainer rings  109  as well as the optional hot water check valve O-ring  148  and the optional cold water check valve O-ring  149 . 
         [0027]    Also visible is the motor spring  118  which fits into the bottom of the mixing chamber  105  and is held in place by the motor spring retaining rib  119 . 
         [0028]    The wax motor  130  is shown with wax motor body  134 , wax motor shoulder  132  with a wax motor shoulder lower surface  139  and wax motor shoulder upper surface  141  and wax motor stem  136 . 
         [0029]    The shuttle  138  is shown with shuttle cold water lip  140 , shuttle hot water lip  142 , shuttle shoulder  137 , shuttle shoulder lower surface  139 , shuttle shoulder upper surface  141  and shuttle O-ring  147 . 
         [0030]    Also visible is the shuttle spring  120 , whose upper end rests on the bonnet ledge  143  and lower end on the shuttle shoulder upper surface  141 . 
         [0031]    Also visible is the bonnet  122  with bonnet O-ring  146 . Also visible is the temperature adjusting stem  126  with stem threads  128  which interact with bonnet threads  123  and the stem O-ring  145 . 
         [0032]    A locking nut  124  at the top of the thermostatic valve secures the position of the temperature adjusting stem  126 . 
         [0033]      FIG. 3  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve with exaggerated elements in a position with flow of both hot and cold water through the valve. 
         [0034]    Visible in  FIG. 3  are the elements temperature adjustment stem  126 , cold water port  113 , cold water seat  117 , hot water port  111 , hot water seat  115 , motor spring retaining rib  119 , and mixed water outlet  106 . 
         [0035]    Also visible are the elements of the temperature motive means  131  consisting of wax motor  130  with wax motor stem  136 , wax motor body  134 , wax motor shoulder  132 , wax motor shoulder upper surface  133 , wax motor shoulder lower surface; shuttle  138  with cold water lip  140 , hot water lip  142 , shoulder lower surface  139 ; shuttle spring  120 , and motor spring  118 . 
         [0036]    In operation, the clockwise rotation of the temperature adjustment stem advances the shuttle and moves the shuttle downward, and correspondingly reduces the temperature of the water from the thermostatic valve. The position of the shuttle controls the relative flow of water from the hot and cold ports. The position of the shuttle  138 , and thus the temperature of mixed water from the thermostatic valve, can be controlled or pre-set by setting the shuttle position by advancing or retracting the temperature adjustment stem  126  into or out of the mixing chamber  105 . Moving of the shuttle  138  down compresses the wax motor spring  118 . Moving the shuttle  138  up compresses the shuttle spring  120 . In embodiments, clockwise rotation of the temperature adjustment stem advances the shuttle, moves the shuttle downward, and correspondingly reduces the temperature of the water from the thermostatic valve. Clockwise rotation of the temperature adjustment stem retracts the shuttle, moves the shuttle upward, and correspondingly increases the temperature of the water from the thermostatic valve. 
         [0037]    The position of the shuttle  138  is maintained in equilibrium by the interaction of the shuttle spring  120  and the wax motor spring  118  on the shuttle  138  and wax motor  130 , respectively. The shuttle spring bears on one end against the bonnet ledge  143  and on the other end against the shuttle shoulder upper surface  141 . The shuttle shoulder lower surface  139  is thusly pressed into contact with the wax motor shoulder upper surface  133 . The wax motor  130  is urged upward by the wax motor spring  118  which presses on the wax motor shoulder lower surface  135  at one end and is restrained at the other end by the motor spring retaining rib  119 . 
         [0038]    Changes in the temperature or pressure of incoming hot or cold water causes a responds from the temperature motive means  131  which restores the preset temperature. 
         [0039]    If the hot or cold input water becomes colder the wax motor stem  136  retracts and the shoulder  132  of the wax motor body  134  moves upward, the wax motor spring  118  expands, and the shuttle spring  120  is compressed. Movement of the shuttle  138  upward reduces the opening size of the cold water port  113  and, if continued, closes the cold water port  113  through contact of the shuttle cold water lip  140  and the cold water seat  117  located on the top edge of the cold water port  113 . Simultaneously, movement of the shuttle  138  upward increases the opening size of the hot water port  111  and, if continued, completely opens the hot water port  111 . Thus the position of the shuttle is controlled by the wax motor and the temperature of water emerging from the thermostatic mixer is returned to the preset value. 
         [0040]    Conversely, if the hot or cold input water becomes hotter the wax motor stem  136  extends and the shoulder  132  of the wax motor body  134  moves downward, the wax motor spring  118  is compressed, and the shuttle spring  120  is expanded, providing the motivation to move the shuttle  138  downward. Movement of the shuttle  138  downward increases the opening size of the cold water port  113  and, if continued, completely opens the cold water port  113 . Simultaneously, movement of the shuttle  138  downward decreases the opening size of the hot water port  111  and, if continued, completely closes the hot water port  111  through contact of the shuttle hot water lip  142  and the hot water seat  115  located on the lower edge of the hot water port  111 . Thus the position of the shuttle is controlled by the wax motor and the temperature of water emerging from the thermostatic mixer is returned to the preset value. 
         [0041]      FIG. 4  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve with exaggerated elements with flow of hot water only through the valve. The elements shown in  FIG. 4  are the same as those in  FIG. 3 . In  FIG. 4  the temperature of the incoming hot and or cold water had dropped below the preset value. The wax motor stem  136  has retracted and also is urged upward by the wax motor spring  118 . The wax motor shoulder upper surface  133  presses against the shuttle shoulder lower surface  139  and moves the shuttle  138  upward, with compression of the shuttle spring  120 . The upward movement of the shuttle  138  closes the cold water port  113  by contact of the shuttle cold water lip  140  with the cold water seat  115 . In addition, upward movement of the shuttle  138  opens the hot water port  111 . 
         [0042]      FIG. 5  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve. The elements shown in  FIG. 5  are the same as those in  FIG. 3 . In  FIG. 5  the temperature of the incoming hot and or cold water had risen above the preset value. The wax motor stem  136  has expanded and also is urged downward by the shuttle spring  118 . The shuttle shoulder lower surface  139  presses against the wax motor shoulder upper surface  133  and moves the shuttle  138  downward, with compression of the wax motor spring  118 . The downward movement of the shuttle  138  opens the cold water port  113 . In addition, downward movement of the shuttle  138  closes the hot water port  111  by contact of the shuttle how water lip  142  with the hot water seat  115 . A slight protrusion of the hot water seat  115  into the mixing chamber  105  prevents movement of the shuttle hot water lip  142  beyond the hot water seat  115 . 
         [0043]      FIG. 6  is a diagrammatic cross-sectional view of an embodiment thermostatic mixer valve with exaggerated elements with flow of cold water only through the valve under conditions of excessive hot water in the thermostatic valve . The elements shown in  FIG. 6  are the same as those in  FIG. 3 . The conditions in  FIG. 6  are the same as for  FIG. 5 . A slight protrusion of the hot water seat  115  into the mixing chamber  105  prevents movement of the shuttle hot water lip  142  beyond the hot water seat  115 . In addition, despite the fact that the hot water port  111  has been closed there has been either leakage of hot water from the hot water port  111  into the mixing chamber  105  or the temperature of the cold water supply has increased. This infusion of hot water has caused the wax motor body  134  to expand, separating the contact between the shuttle shoulder lower surface  139  and the wax motor shoulder upper surface  133 , and compressing the wax motor spring  118 . 
         [0044]    The fact that the wax motor  130  is not attached to the shuttle  138  allows accommodation of excessive expansion of the wax motor  130  without damage to the wax motor  130  or shuttle  138  and allows unimpaired functioning of the thermostatic valve when normal conditions are restored. 
         [0045]    Embodiments therefore can remain functional despite conditions which cause irreparable damage without the need of a preloaded spring assembly. 
         [0046]    Embodiments of the non-wax motor elements are manufactured of suitable hard, non-porous, strong materials such as bronze, steel, stainless steel, and iron. Embodiment wax motors are manufactured of paraffin wax with molecules of a narrow range of carbon chain lengths, allowing expansion and retraction of the wax motor stem within a predetermined temperature range. 
         [0047]    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.