TECHNICAL FIELD

[0001] The present invention relates to a system and method for conserving water supplied by a hot water tank and, in particular, to a method for returning unheated water to the hot water tank or to a water collection device.

BACKGROUND ART

[0002] Almost all conventional residential homes, condominiums, and apartments have water supply systems that provide both hot and cold running water to the resident or a guest. Supplied water is provided to the residence through a water line, such as from a public water station or a private well. A portion of the supplied water flows along a cold water supply line to be accessed by a user via a cold water faucet. The remaining portion of the supplied water is usually diverted to a hot water tank to be heated and made available to the user via a hot water supply line and a hot water faucet.

[0003] It has been known in the art that it is common practice for a resident of the average household to run, and thus discard, unheated water present in the hot water supply line until the unheated water has been purged and the hot water from the hot water tank is available at the hot water faucet or at a shower head, for example. As the discarded water is sent down a drain, this otherwise clean and useful water is essentially wasted. Over a period of time, the clean water that is thus discarded may amount to many hundreds of gallons of water per annum per household. Moreover, the user may continue to run the water when not being needed, such as during lathering or shampooing, so as to maintain the hot water supply at a sufficient warm temperature at the hot water faucet.

[0004] To date, there have not been satisfactory methods to conserve such wasted water. Many conscientious residents collect the water in a bucket, for example, for later use in watering plants, or for pouring into a clothes washing machine. However, this requires extra physical effort, and cannot possibly conserve all the water that is run and not used while bringing hot water to the faucet or shower head. From a practical standpoint, most residents will not concern themselves with the wastefulness of sending clean water down the drain, as the living standards in most developed countries have conditioned people to use resources as necessary without regard to conservation practices, and the lack of understanding of basic scientific and environmental principles is common among the general population.

DISCLOSURE OF THE INVENTION

[0005] In one aspect of the present invention, a water conservation system for conserving water supplied by a hot water tank having a cold water supply line attached to the hot water tank and a hot water supply line providing water from the hot water tank to a user comprises: a diverter module adapted to selectively open a diverter fluid path extending between the hot water supply line and the cold water supply line in response to an action of the user; and a return module connected to the cold water supply line, the return module adapted to return water to the hot water tank in response to the opening of the diverter fluid path.

[0006] In still another aspect of the present invention, a diverter module for use in a water conservation system comprises: a diverter housing having a substantially elliptical cross section; a diverter input gate hingedly attached to an input end of the diverter housing; a diverter output gate hingedly attached to an output end of the diverter housing; a bi-metallic cantilever spring rotatably attached to a spring pivot pin, the spring pivot pin attached to an inside surface of the diverter housing; a first connecting rod attached to the diverter input gate and to a first arm of the bi-metallic cantilever spring; and a second connecting rod attached to the diverter output gate and to a second arm of the bi-metallic cantilever spring.

[0007] The additional features and advantage of the disclosed invention is set forth in the detailed description which follows, and will be apparent to those skilled in the art from the description or recognized by practicing the invention as described, together with the claims and appended drawings.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0008] The foregoing aspects, uses, and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when viewed in conjunction with the accompanying figures, in which:

[0009] Fig. 1 is a diagrammatical illustration of a water conservation system incorporating a diverter module and a return module with a hot water tank, in accordance with the present invention;

[0010] Fig. 2 is a cross sectional illustration of a diverter module installed between a hot water delivery line and a cold water delivery line;

[0011] Fig. 3 is a cross sectional illustration of the diverter module of Fig. 2 in an open state to divert cold water in the hot water delivery line to a cold water delivery line;

[0012] Fig. 4 is a cross sectional illustration of a diverter module in a closed state to allow hot water from the hot water delivery line to flow to a hot water faucet;

[0013] Fig. 5 is an isometric cutaway diagrammatical illustration of the diverter module in the closed state of Fig. 5 showing an diverter input gate, a bi-metallic cantilever spring, and an diverter output gate, in accordance with the present invention;

[0014] Fig. 6 is a diagrammatical illustration of the return module of Fig. 2 showing a pump, a water pressure pulse sensor, a sliding fluid valve, and an electrical power source, in accordance with the present invention;

[0015] Fig. 7 is a diagrammatical illustration of the return module of Fig. 7 in the process of returning water to the hot water tank;

[0016] Fig. 8 is a diagrammatical illustration of an alternative water conservation system incorporating a diverter module functioning to divert cold water from the hot water delivery line to a water collection device via a drain pipe, in accordance with the present invention;

[0017] Fig. 9 is a cross sectional illustration of the diverter module of Fig. 9 installed between a hot water delivery line and the drain pipe;

[0018] Fig. 10 is a cross sectional illustration of the diverter module of Fig. 10 in an open state to divert cold water in the hot water delivery line to the drain pipe;

[0019] Fig. 1 1 is a cross sectional illustration of a diverter module of Fig. 10 in a closed state to allow hot water from the hot water delivery line to flow to a hot water faucet; and

[0020] Fig. 12 is an isometric cutaway diagrammatical illustration of the diverter module in the closed state of Fig. 13 showing an diverter input gate, a bi-metallic cantilever spring, and an diverter output gate, in accordance with the present invention.

MODES FOR CARRYING OUT THE INVENTION

[0021] There is shown in Figure 1 a water conservation system 10 for conserving water supplied by a hot water tank 12, in accordance with the present invention. The water conservation system 10 may be attached to a conventional main water supply line 14 with supply water flow 26 available to the hot water tank 12. A hot water supply line 16 provides hot water to a hot water faucet 36 from the hot water tank 12. A cold water supply line 18 provides cold water to a cold water faucet 38 from the main water supply line 14. In an exemplary embodiment, the water conservation system 10 includes two innovative modules. The first module is a diverter module 20 connected to both the hot water supply line 16 and the cold water supply line 18. The second module is a return module 30 installed in a parallel configuration across the cold water supply line 18.

[0022] Installation of the diverter module 20 into the water conservation system 10 requires the attachment of a diverter input end 22 of the diverter module 20 to the hot water supply line 16 such that the water flowing in the hot water supply line 16 is in selective fluid communication with the diverter module 20. Installation of the diverter module 20 also requires the attachment of a diverter output end 24 to the cold water supply line 18 such that the water present in the diverter module 20 is in selective fluid communication with the cold water supply line 18. It should be understood that the connection between the diverter module 20 and the hot water supply line 16 may be achieved by any practical plumbing configuration known in the relevant art.

[0023] Installation of the return module 30 into the water conservation system 10 requires a first fluid attachment of an input water line 32 of the return module 30 to the cold water supply line 18, and a second fluid attachment of an output water line 34 to the cold water supply line 18, the two attachments being achieved by any practical plumbing configuration known in the relevant art. The diverter module 20 and the return module 30 are major components of a water system upgrade kit 40 that is configured for convenient installation into a conventional plumbing system for the purpose of achieving water conservation, in accordance with the present invention. The water conservation system 10 functions by diverting unheated water from the hot water faucet 36 into the diverter module 20, as indicated by arrows 21 , 23 and back to the hot water tank 12 through the return module 30, as indicated by arrows 25, 27.

[0024] There is shown in Figure 2 a cross-sectional view of the diverter module 20. In a typical installation, the diverter module 20 is configured for attachment between the cold water supply line 18 and the hot water supply line 16, without requiring cutting completely through either water line for the installation of a tee connector, for example. The diverter module 20 is shown in an equilibrium position, which occurs when there has been no recent request for hot water at the hot water faucet 36.

[0025] In the configuration shown, the diverter module 20 includes a cylindrical diverter housing 50 having a substantially elliptical cross-sectional shape. The diverter housing 50 is typically fabricated from a metal, such as copper, having essentially the same coefficient of expansion as the supply line material, also typically copper or a copper alloy. Accordingly, the diverter module 20 may be attached using welded or soldered seams 42 and 44, as is well-known in the relevant art. For residential water systems in which a plastic or a composite material is used for conveying fluids, the diverter housing 50 may be plastic or a composite, so as to allow attachment with chemical compounds or epoxies.

[0026] A bi-metallic cantilever spring 52 is secured to the inside of the diverter housing 50 by mounting onto a spring pivot pin 54. The bi-metallic cantilever spring 52 is free to rotate about the spring pivot pin 54. In the embodiment shown, the bimetallic cantilever spring 52 is substantially S-shaped, but the spring can be

alternatively configured in a C-shape (not shown) and still function in a similar manner. A first link pin 66 is provided at the end of a first spring cantilever arm 56, and second link pin 68 is provided at the end of a second spring cantilever arm 58. An input connecting rod 72 is secured to the first link pin 66, and an output connecting rod 74 is secured to the second link pin 68.

[0027] In an exemplary embodiment, the spring cantilever arms 56, 58 are fabricated from two or more layers of different metals and metal alloys to form a bimetallic layer pair. The two metals or metal alloys each have a different coefficient of thermal expansion, as is understood in the relevant art. Accordingly, as the ambient temperature inside the diverter housing 50 is increased, the spring cantilever arms 56, 58 will tend to bend inwardly, with the link pins 66, 68 moving towards the spring pivot pin 54.

[0028] The diverter module 20 also includes a diverter input gate 80 and a diverter output gate 90. Both the diverter input gate 80 and the diverter output gate 90 have specified planar elliptical shapes. As explained in greater detail below, the planar elliptical shapes enable the diverter input gate 80 and the diverter output gate 90 to block water flow through the diverter housing 50 when the diverter input gate 80 and the diverter output gate 90 are completely closed. Also, the planar elliptical shapes enable the diverter input gate 80 and the diverter output gate 90 to also block water flow through the hot water supply line 16 and the cold water supply line 18, respectively, when the diverter input gate 80 and the diverter output gate 90 are completely opened from the diverter housing 50.

[0029] The diverter input gate 80 includes an input gate base 82 attached to an inner housing surface 46 of the diverter housing 50. In the exemplary embodiment shown, the input gate base 82 is connected to an input gate closure 84 by a first hinge 86. This configuration allows for the input gate closure 84 to rotate into and out of the diverter housing 50 as needed. This configuration also allows for the input gate closure 84 to rotate into and out of the hot water supply line 16 as needed. In an alternative embodiment (not shown), either or both of the diverter input gates 80, 90 may be fabricated from a plastic material, and include a straight grooved region to enable bending without a hinge. [0030] The diverter output gate 90 includes a fixed, output gate base 92 connected to a output gate closure 94 by a second hinge 96. The output gate closure 94 can be rotated into and out of the interior of the diverter housing 50. An output gate detent 48 and an output gate stop 78 are provided on the inner housing surface 46 near the output gate closure 94, as shown. The output gate stop 78 serves to prevent the output gate closure 94 from rotating further into the interior of the diverter housing 50. The output gate detent 48 is provided to frictionally secure the output gate closure 94 in a closed position until forced into an open position by the output connecting rod 74. An input gate stop 76 serves to prevent the input gate closure 84 from rotating into the interior of the diverter housing 50.

[0031] The input connecting rod 72 connects the first link pin 66 on the first spring cantilever arm 56 to a first attachment link 88 on the input gate closure 84 of the diverter input gate 80. The first attachment link 88 allows the input connecting rod 72 to rotate relative to the input gate closure 84. The output connecting rod 74 connects the second link pin 68 on the second spring cantilever arm 58 to a second attachment link 98 on the output gate closure 94 of the diverter output gate 90. The second attachment link 98 allows the output connecting rod 74 to rotate relative to the output gate closure 94.

[0032] With the diverter module 20 in the equilibrium mode of Figure 2, the user may turn on the hot water faucet 36, shown in Figure 1 . This action causes an initial flow of unheated water in the hot water supply line 16, indicated by arrow 51. This initial fluid flow forces the input gate closure 84 into an open position, as shown in Figure 3, and closes off the hot water supply line 16 at the diverter module 20.

Opening the input gate closure 84 also causes the input connecting rod 72 to rotate the bi-metallic cantilever spring 52 counterclockwise, to the configuration shown. This action forces the output connecting rod 74 to open the output gate closure 94.

[0033] The input gate closure 84 has an elliptical shape precisely conforming to the elliptical shape of the inside surface of the hot water supply line 16 when intersected by a plane oriented at the same angle as the fully-opened input gate closure 84. The unheated water flowing from the hot water tank 12, indicated by a low reading on a thermometer symbol 106, is thus forced to flow through the diverter module 20 rather than flowing from the hot water faucet 36. In accordance with the present invention, this unheated water is returned to the hot water heater 12 rather than being wasted at the hot water faucet 36.

[0034] This water flow from the hot water tank 12 forces the input gate closure 84 against the inside of the hot water supply line 16. While the input gate closure 84 remains at this angular orientation, effectively closing off flow to the hot water faucet 36, the unheated water is diverted into the diverter module 20, as indicated by arrow 53. It can be appreciated that the movements of the bi-metallic cantilever spring 52, the input connecting rod 72, and the output connecting rod 74 function to maintain both the diverter input gate 80 and the diverter output gate 90 in open positions relative to the diverter housing 50. This action enables the unheated water to flow through the diverter module 20 into the cold water supply line 18, as indicated by arrow 55.

[0035] It should be understood that the essentially simultaneous actions of the input gate closure 84 closing off the hot water supply line 16 and the output gate closure 94 closing off the cold water supply line 18 result in a water pressure pulse in the cold water supply line 18. This water pressure pulse is detected by the return module 70, shown in Figure 6, as explained in greater detail below.

[0036] The diverter module 20 remains in the open mode of Figure 3 until the remaining unheated water in the hot water supply line 16 has passed through the diverter module 20 and the temperature of the water flowing through the diverter module 20 has risen to a temperature expected from the hot water tank 12. As explained above, the first spring cantilever arm 56 and the second spring cantilever arm 58 of the bi-metallic cantilever spring 52 comprise bi-metallic layers. As the temperature of the water present inside the diverter housing 50 increases, the first spring cantilever arm 56 and the second spring cantilever arm 58 experience decreases in the respective radii of curvature, as shown in the changes between Figure 3 and Figure 4. This bending action causes the distance between the link pins 66, 68 to decrease and causes the bi-metallic cantilever spring 52 to rotate on the spring pivot pin 54. These movements place the connecting rods 72, 74 under tension. Note that the temperature of the water present in the diverter housing 50 has risen to the temperature expected from the hot water tank 12, as indicated by a high reading on the thermometer symbol 106.

[0037] The connecting rod tension forces cause the input gate closure 84 and the output gate closure 94 to completely shut, as also seen in Figure 5. Note also that the gate stops 76 and 78 are essential features on the diverter housing 50, and are necessary to insure that the diverter module 20 is properly closed when hot water becomes available at the hot water faucet 36. When the diverter module 20 is in the closed mode, the water collected in the diverter housing 50 tends to remain hot because of the surrounding metal and thermal mass. This heat serves to maintain the small radiuses of curvature in the spring cantilever arms 56, 58. This, in turn, insures that the input gate closure 84 and the output gate closure 94 remain closed and allow the hot water from the hot water tank 12 to keep flowing to the hot water faucet 36.

[0038] The continued hot water flow adjacent the diverter module 20 further insures that the water contained in the diverter housing 50 remains hot until after the hot water faucet 36 is closed. With the diverter module 20 in the closed mode, the water conservation system 10 functions as a conventional residential water system. That is, hot water continues to be available at the hot water faucet 36, and cold water is again available at the cold water faucet 38.

[0039] Figure 6 provides a diagrammatical illustration of components in the return module 30. The input water line 32 is in fluid communication with a pump 1 10. As explained above, the pump 1 10 functions to assist the return of unheated water to the hot water tank 12. Accordingly, the pump 1 10 is activated when the unheated water is diverted to the diverter module 20, shown in Figure 1 . Activation of the pump 1 10 is provided by an ON signal' sent by a water pressure pulse sensor 1 12. The ON signal is generated when the water pressure pulse sensor 1 12 detects the essentially simultaneous actions of the input gate closure 84 closing off the hot water supply line 16 and the output gate closure 94 closing off the cold water supply line 18 that produce a water pressure pulse.

[0040] Before the user turns on the hot water faucet 36 to obtain hot water, the supply water flow 26 is available to the user via the cold water supply lines 14, 18. When a water pressure pulse 1 16 is received at the water pressure pulse sensor 1 12, via the input water line 32 and a fluid port 1 18, as shown in Figure 7, a diaphragm 122 in the water pressure pulse sensor 1 12 flexes and turns on an electrical switch 124. The electrical switch 124 closes an electrical power circuit 126 to provide electrical power from an electrical power source 128 to the pump 1 10.

[0041] As the pump 1 10 powers up, cold water in the cold water supply line 18 is diverted into the input water line 32, as indicated by arrow 132. The flow of the water in the input water line 32 and through the output water line 34 cause a retractable fluid valve 130 to slide inside the output water line 34 and partially into the cold water supply line 18. The unheated water being returned to the hot water tank 12 flows into an input port opening 134, through the retractable fluid valve 130, through a valve output port opening 136 , and into the cold water supply line 18, as indicated by arrow 138.

[0042] It should be understood that the outer surface of the retractable fluid valve 130 closely conforms to the size and shape of the inside surface of the output water line 34. This congruity allows the retractable fluid valve 130 to freely slide within the output water line 34 in response to the water flow produced by the pump 1 10. The retractable fluid valve 130 functions to (i) block the water supply 26 when the retractable fluid valve 130 is moved into the cold water supply line 18, and (ii) direct unheated water flow from the diverter module 20 through the pump 1 10 to the hot water tank 12.

[0043] When the diverter module 20 closes and prevents the continued flow of water to the return module 30, an increased working load is placed on the pump 1 10. The pump 1 10 is configured to shut down under this condition. This action causes the retractable fluid valve 130 to return to an equilibrium position out of the cold water supply line 18 and into the output water line 34, as shown in Figure 6. This movement is enabled by the retractable fluid valve 130 being urged into the output water line 34 by an elastic component 142, such as a spring. When the retractable fluid valve 130 moves out of the cold water supply line 18 and returns to the position shown in Figure 6, the water supply 26 returns to the cold water supply line 18.

[0044] At some time after the user has closed the hot water faucet 36, the temperature of the water in the diverter housing 50 returns to ambient temperature. The temperature of the bi-metallic cantilever spring 52 likewise returns to ambient temperature. The curvature of the first spring cantilever arm 52 and of the second spring cantilever arm 54 return to the configuration of the diverter module 20 in the equilibrium mode shown in Figure 2.

[0045] There is shown in Figure 8 an exemplary embodiment of an alternative water conservation system 150 for conserving water supplied by the hot water tank 12, in accordance with the present invention. The hot water supply line 16 provides hot water to the hot water faucet 36 from the hot water tank 12. A diverter module 160 is installed between the hot water supply line 16 and a cold water drain line 152. The cold water drain line 152 conveys unheated water from the hot water tank 12 to a collection device (not shown), as indicated by arrows 154 and 156. The collection device may comprise a tank or other watertight container. When hot water from the hot water tank 12 reaches the diverter module 160, the hot water is conveyed to the hot water faucet 36 in a manner similar to the operation of the water conservation system 10 described above. [0046] The interior components of the diverter module 160 are shown in Figure 9. The diverter module 160 includes a cylindrical diverter housing 170 having a substantially elliptical cross-sectional shape. The diverter module 160 further includes a bi-metallic cantilever spring 162 secured to the inside of the diverter housing 170 by rotatably mounted onto a spring pivot pin 164. An input connecting rod 172 and an output connecting rod 174 are secured to the bi-metallic cantilever spring 162 in a manner similar to the assembly configuration of the diverter module 20, described above.

[0047] When a user opens the hot water faucet 36, the unheated water, represented by the thermometer symbol 106, is routed through the diverter module 170, as indicated by arrow 182, forcing an input gate closure 184 against the inside of the hot water supply line 16, as shown in Figure 10. Likewise, an output gate closure 186 is forced against the inside of the cold water drain line 152 so as to direct the water flow towards the collection device, as indicated by arrow 188.

[0048] When hot water is present in the diverter housing 170, represented by the thermometer symbol 106 in Figure 1 1 , the input gate closure 184 and the output gate closure 186 remain closed, as also shown in Figure 12, and hot water in the hot water supply line 16 is allowed to flow to the hot water faucet 36, as indicated by arrow 192 in Figure 1 1 . An output gate detent 194, shown in Figure 12, may be provided on an inside surface of the diverter housing 170 to retain the output gate closure 186 in a closed position while the water contained in the diverter housing 170 remains hot.

[0049] It is to be understood that the description herein is only exemplary of the invention, and is intended to provide an overview for the understanding of the nature and character of the disclosed water conservation system. The accompanying drawings are included to provide a further understanding of various features and embodiments of the method and devices of the invention which, together with their description serve to explain the principles and operation of the invention. INDUSTRIAL APPLICABILITY

The present invention provides a system and method for conserving water supplied by a hot water tank by returning unheated water to the hot water tank or to a water collection device rather than allowing the unheated water to be otherwise disposed of.