Abstract:
A water recirculation system is disclosed for moving water from a hot water tap to a cold water tap. The recirculation system includes a water manifold that houses a pump, solenoid, check valve and temperature switch. Water is moved between these components within the water manifold so that external piping is unnecessary.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to water recirculation systems. More specifically, this invention relates to an integrated manifold within a water recirculation system that houses a water pump, a solenoid, a check valve, and a temperature switch. 
     2. Description of the Related Art 
     As interest in water conservation has grown, many devices have been designed for home water conservation. One such class of water conservation devices are known as water recirculators. These devices address the conservation problem created by individuals that turn on their hot water faucets and run the water tap until hot water emerges. This waste of cool water down the drain has been addressed by devices that slowly and constantly recirculate water from the hot water heater into the cold water tap so that hot water is always available at the faucet. 
     For example, many devices exist that are placed underneath a sink in the home and connect the hot water tap to the cold water tap. These devices normally include a pump for moving water from the hot water tap to the cold water tap to provide instant hot water once the faucet is turned on. Some devices also include a timer so that water is only recirculated during times that people are usually present in the home. 
     One such device is described in U.S. Pat. No. 5,009,572 to Imhoff. The Imhoff device includes a hot water supply line and a cold water supply line. An electric motor pumps water from the hot water supply line to the cold water supply line by passing through a solenoid valve. A temperature sensor is provided for detecting the water temperature at the inlet port of the pump and turning on the pump once the water temperature of the hot water falls below a preset level. A series of hollow tubes is used to connect each component of the Imhoff system with other components. This series of tubes running between components makes the Imhoff device complicated to produce, expensive to maintain, and expensive to manufacture. 
     Another water recirculation system is disclosed in the U.S. Pat. No. 5,511,579 to Price. The Price system also includes a hot water inlet, cold water outlet, and recirculation pump for moving water from the hot water inlet to the cold water outlet. This system also includes a temperature switch mounted in a plastic housing for determining the temperature of water entering the recirculation device. 
     The temperature switch mounted into the plastic housing determines the temperature of water flowing from the hot water inlet. The housing also contains a port for directing the hot water away from the temperature switch and into a tube that is connected to a recirculation pump. The recirculation pump connects to another tube that runs to a solenoid switch. The solenoid switch in turn is connected to a tube that moves water to a check valve. The water passing over the check valve moves into a tube that thereafter connects to the cold water outlet. The check valve also includes a port to move water through a “back-flow” tube into the temperature switch manifold in order to recirculate a portion of the hot water back over the temperature switch. This helps prevent overheating of the water in the cold water line. 
     However, this system is expensive to manufacture because of the numerous tubes connecting the each component within the recirculation system. Thus, what is needed in the art is a recirculation system that is compact and inexpensive to manufacture in high-volume. Such a system is described below. 
     SUMMARY OF THE INVENTION 
     One embodiment of the invention is a water recirculation manifold that includes a hot water inlet; a first internal lumen connecting the hot water inlet to a first chamber, wherein the first chamber is adapted to receive a temperature switch; a second internal lumen connecting the first chamber to a second chamber, wherein the second chamber is adapted to receive a pump; and a third internal lumen connecting the second chamber to a cold water outlet. 
     Another embodiment of the invention is a fluid recirculation system that includes a hot water inlet and a manifold that has: a first internal lumen connecting the hot water inlet to a first chamber, wherein the first chamber is removably connected to a temperature switch; a second internal lumen connecting the first chamber to a second chamber, wherein the second chamber is removably connected to a pump; and a third internal lumen connecting the second chamber to a cold water outlet. 
     Yet another embodiment of the invention is a fluid recirculation system, having: a hot fluid inlet and a manifold comprising: a first internal lumen connecting the hot fluid inlet to a first chamber, wherein the first chamber is removably connected to a temperature switch; a second internal lumen connecting the first chamber to a second chamber, wherein the second chamber is removably connected to a pump; a third internal lumen connecting the second chamber to a cold fluid outlet; a third chamber connected to the second chamber and the cold fluid outlet, wherein the third chamber is removably connected to a check valve; and a fourth chamber connected to the third chamber and the cold fluid outlet, wherein the fourth chamber is adapted to receive a solenoid valve. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of one embodiment of a water recirculation manifold. 
     FIG. 2 is a flow diagram illustrating the flow of fluids through a manifold block of the invention. 
     FIG. 3 is a transparent perspective view of one embodiment of a manifold block of the invention. 
     FIG. 4 is a bottom view of one embodiment of a manifold block of the invention. 
     FIG. 5 is a top view of one embodiment of a manifold block of the invention. 
     FIG. 6 is a right side view of one embodiment of a manifold block of the invention. 
     FIG. 7 is a front view of one embodiment of a manifold block of the invention. 
     FIG. 8 is a rear view of one embodiment of a manifold block of the invention. 
     FIG. 9 is a top view of an alternate embodiment of a manifold block of the invention. 
     FIG. 10 is a side view of an alternate embodiment of a manifold block of the invention. 
     FIG. 11 is a cross-sectional view of an alternate embodiment of a manifold block of the invention taken along line II of FIG.  10 . 
    
    
     DETAILED DESCRIPTION 
     Embodiments of the invention relate to water recirculation systems that provide instant hot water at the faucet. A hot water supply line runs from a remotely located supply source, such as a water heater, to an inlet port of the recirculation system. After passing through the inlet port, the hot water enters an integrated water manifold. Within the manifold are mounting areas for a temperature sensor, water pump, check valve, and solenoid. 
     The temperature sensor is in electrical contact with the water pump and solenoid valve so that the pump and solenoid are only activated when the water temperature at the inlet drops below a predetermined temperature. When the system is activated by a low temperature reading at the inlet, the pump begins pulling water from the inlet and pushing water out the outlet of the integrated manifold. The outlet of the manifold is connected to the cold water line in the house so that the water recirculates back into the cold water line. 
     As will be discussed more specifically below, a check valve is positioned within the integrated manifold to provide a unidirectional water flow so that once the water pump stops, water does not flow in the reverse direction through main channels of the manifold and only a controlled amount of water can return to the hot water line via the backflow line. The check valve consists of a ball which is spring loaded into closed position. However, it should be noted that other well known types of check valves are anticipated to function in a similar manner and be within the scope of the invention. 
     Also located in the integrated manifold is a solenoid consisting of a diaphragm, pin, and spring. When electrically disengaged, the pin deploys and closes the diaphragm which prevents hot water from continuing to the cold water line. It should be noted that the design allows water to flow in the reverse direction, into the backflow channel, while the solenoid is disengaged. However, water is prevented from entering other portions of the manifold by the check valve. 
     FIG. 1 is an exploded view of one embodiment of a water recirculation system  10 . A rectangular manifold block  20  is shown having a hot water inlet  25 , mounting channels  26 ,  27  and a cold water outlet  30 . As will be described below, hot water from a household hot water system enters the manifold block  20  through the hot water inlet  25 . Normally, the hot water inlet  25  is connected through a tube or pipe (not shown) to a hot water valve under a sink. 
     Similarly, hot water that enters through the hot water inlet  25  exits from the manifold block  20  through the cold water outlet  30 . Normally, the cold water outlet  30  is connected through a tube pipe (not shown) to a cold water valve located under a sink. 
     The manifold block  20  also has a top  35  that includes an opening  40  for mounting a temperature switch  45 . As will be described below, water that is drawn into the manifold block  20  through the hot water inlet  25  contacts the temperature switch  45  through a lumen  48 . Also included on the top  35  is an orifice  50  for mounting a solenoid assembly  55  to the manifold block  20 . The solenoid assembly  55  includes a body  60 , solenoid plate  62 , plunger  64 , spring  68 , pin  70 , and flexible diaphragm  75 . When the solenoid assembly  55  is electrically activated, the pin  70  is forced upward into the flexible diaphragm  75 . The flexible diaphragm  75  then bends away from the manifold block  20  to allow the flow of cold water through the manifold block  20  until hot water opens the temperature switch, which disengages the pump and solenoid. This will be described in more detail below. 
     The manifold block  20  has a right side  80  that has an orifice  84  for mounting a check valve assembly  88 . The check valve assembly  88  includes a ball  90 , spring  94 , and mounting screw  96 . Preferably, the ball  90  is a ⅝″ outer diameter delrin ball which fits snugly into the orifice  84 . When engaged, the mounting screw  96  fits into the orifice  84  to engage the ball  90  within the manifold block  20 . The check valve assembly  88  allows water to only flow in the direction from the hot water inlet  25  to the cold water outlet  30 . 
     A recirculation pump  98  mounts to the lower surface of the manifold block  20  through O-ring seal  99 . As shown, the recirculation pump  98  includes a series of blades  105  that spin to force water through the manifold block  20 . 
     Also shown is a plug  110  that fits within an opening  112  on the right side  80  of the manifold block  20 . The plug  110  closes the opening  112  that is created during the process of drilling the inner lumens of the manifold block  20 . 
     FIG. 2 is an operational diagram of the manifold block  20 . As shown, water enters the hot water inlet  25  and flows through an inlet lumen  118  to the temperature switch  45 . When the temperature of water at the hot water inlet  25  drops below a predetermined threshold, the temperature switch  45  activates the water recirculation pump  98  and solenoid. Water from the hot water inlet  25  then flows inside a lumen  120  to the recirculation pump  98 . From the recirculation pump  98 , the water flows through a lumen  122  to the check valve  88 . As shown, the check valve  88  prevents water from flowing in the opposite direction within the lumen  122 , towards the recirculation pump  98 . 
     Once water from the hot water inlet  25  has passed the check valve  88 , it flows into a lumen  124  and to the solenoid assembly  55 . At this point, the water path is divided into a large lumen  126  and a smaller backflow line  130 . Water flowing through the large lumen  126  exits the cold water outlet  30 , whereas water entering the backflow line  130  is returned to the temperature switch  45 . 
     Referring to FIG. 3, a perspective phantom-line view of one embodiment of the invention is illustrated. The manifold block  20  includes a hot water inlet  25  that allows hot water to enter the inlet lumen  118  and flow to a temperature switch chamber  135  that is adapted to mount with the temperature switch  45 . The temperature switch chamber  135  has an opening to the lumen  120  that allows water to flow to a pump chamber  139 . The pump chamber is shaped to fit the upper portion of a water pump so that the pump can mount directly into the pump chamber  139  without modification. Although in one embodiment of the invention, the pump is mounted to the manifold by screws, it should be noted that other means of mounting the pump to the manifold are contemplated. For example, the inner cylindrical walls of the pump chamber can be scored with screw threads so that the recirculation pump  98  can be easily screw threaded into the pump chamber  139 . 
     The pump chamber  139  connects through the lumen  122  to a cylindrical check valve chamber  140 . As can be envisioned, the check valve chamber  140  is formed to snugly fit the ball  90  and spring  94  (FIG.  1 ). The check valve chamber  140  connects to the vertical lumen  124  that terminates at a solenoid chamber  144 . Thus, water that flows through the check valve  88  moves through the vertical lumen  124  to the solenoid chamber  144 . 
     The solenoid chamber  144  includes three orifices: a cold water orifice  158 , a check valve orifice  159  and a backflow orifice  165 . The cold water orifice  158  connects the solenoid chamber  144  to the lumen  126  and cold water outlet  30 . The check valve orifice  159  connects to the check valve chamber  140  and the backflow orifice  165  connects the solenoid chamber  144  to the backflow line  130 . 
     FIG. 4 is a bottom view of the manifold block  20 , and illustrates the pump chamber  139  in the bottom of the manifold block  20 . As shown, the pump chamber  139  connects the recirculation pump  98  to the manifold block  20 . 
     Referring now to FIG. 5, a top view of the manifold block  20  is provided. The opening  40  in the top  35  is illustrated along with the inner lumen  48  within the opening  40  that defines the temperatures switch chamber  135 . In addition, the opening  50  for the solenoid assembly  55  is illustrated. The opening  50  defines the solenoid chamber  144  within the manifold block  20 . 
     As shown, the temperature switch chamber  135  includes access to the lumen  120 . In addition the solenoid chamber  144  is shown in FIG. 5, including the cold water orifice  158  and the backflow orifice  165 . The opening  159  is also shown in the opening  50  for the solenoid assembly  55 . The opening  159  provides a passage way from the check valve assembly  88  to the solenoid chamber  144 . 
     FIG. 6 provides a view of the right side of the manifold block  20  and shows the opening  84  and opening  112 . 
     FIG. 7 is an illustration of the front view of the manifold block  20  showing the hot water inlet  25  and cold water outlet  30 . In addition, a pair of mounting channels  26 ,  27  are shown that traverse the interior surface of the manifold block  20  and emerge out the opposite side. The mounting holes  26 ,  27  are used to mount the manifold block  20  to a housing (not shown). 
     FIG. 8 provides an illustration of the rear of the manifold block  20 . The mounting holes  26 ,  27  are illustrated as protruding through the rear of the manifold block  20 . 
     Other Embodiments 
     FIG. 9 provides a top view illustration of another embodiment of a preferred water recirculation manifold  300 . As illustrated, this manifold is also adapted to mate with a hot water supply line (not shown) through a hot water inlet port  304 . The hot water inlet port  304  communicates through an internal lumen  306  with a temperature probe chamber  310 . As illustrated in FIG. 9, a temperature probe  312  is shown mounted into the temperature probe chamber  310 . 
     As can be envisioned, water that enters the recirculation manifold  300  from the hot water inlet  304  is directed over the temperature probe  312  by passing into the temperature probe chamber  310 . In addition, the manifold  300  provides a hot water outlet port  314  which is adapted to mate with a hot water output line that connects to a hot water faucet (not shown). Water can travel from the inlet  304 , across the lumen  306 , and out the outlet  314  when the hot water faucet is opened. 
     The temperature probe chamber  310  communicates with a check valve chamber  320 , which is shown with a ball and spring system  324 . The ball and spring system  324  is biased to that water can enter from the temperature probe chamber  310 , but water cannot exit in the opposite direction. 
     Once water has passed through the check valve chamber  320 , it is directed downward, into a pump chamber  326  that houses an electrical pump (not shown). When activated, the pump will move water from the hot water inlet  304  towards the pump chamber  326 . The water is then expelled from the pump chamber  326  to a solenoid valve chamber  330 . As explained more specifically with reference to FIG. 10, the solenoid chamber  330  has an inlet and an outlet. 
     Water from the pump chamber  326  flows into the solenoid chamber inlet, and then back out the solenoid chamber outlet. In use, a solenoid, similar to solenoid  60  (FIG.  1 ), is mounted into the solenoid chamber  330 . When electrically disengaged, the solenoid prevents water from flowing through the solenoid chamber and out a cold water supply port  334 . 
     A cold water outlet port  335  connects to a cold water faucet (not shown) through a lumen  337  to the cold water supply port  334  so that cold water is sent to the cold water faucet. 
     A detailed view of the solenoid chamber  330  is presented in FIG. 10, which illustrates an inlet, port  340  and outlet port  350 . It should be realized that when the solenoid is in place, it will electrically control the flow of water from the inlet port  340  to the outlet port  350 . 
     FIG. 11 is a cross sectional view of the recirculation manifold  300  that shows the path  360  of water flowing through the system if the pump is activated. As indicated, in this embodiment, the water flows into the inlet  304 . The water then moves through the internal lumen  306  to the temperature probe chamber  310 . From the temperature probe chamber  310 , the water flows into the check valve chamber  320  before descending into the pump chamber  326 . 
     If the pump is active, it will move water from the pump chamber  326  to the solenoid input  340  and then to the cold water supply port  334 . In this manner, the water is re-circulated from the hot water inlet  304  to the cold water supply port  334 . 
     A backflow line  375  is located between the pump chamber  326  and the lumen  306  so that a small amount of cold water can flow back to the temperature probe chamber  310  when the hot water faucet is open. Because of the lower pressure created by opening the hot water faucet, cold water is moved from the cold water supply, through the solenoid chamber and into the pump chamber  326 . Because the backflow line connects the pump chamber  326  with the lumen  306 , the checkvalve  320  is bypassed. Thus, a small amount of cold water can be returned to the temperature probe to provide the advantages discussed above. 
     It should be understood that the scope of the invention is not limited to water recirculation manifolds. Other embodiments, such as water recirculation systems that incorporate the manifold block  20  are contemplated. The contemplated water recirculation system could have, for example, an outer housing that encloses the manifold block  20 . In addition, a timer could be incorporated into the system so that it only becomes activated during certain hours. In that manner the system would not recirculate water unnecessarily during times when no one is at home. 
     While particular embodiments of the invention have been described in detail, it will be apparent to those skilled in the art that these embodiments are exemplary rather than limiting, and the true scope of the invention is defined by the claims that follow.