WAI ¹ ER-SHUTOFF SYSTEM WITH A FLOW SENSING UNIT HAVING DUAL FLOW PATHS

FIELD OF THE INVENTION

The present invention relates to a comprehensive water shutoff system for homes, buildings, barns, livestock facilities, water craft etc. ("structures") and more particularly to a water shutoff system including a flow sensing unit capable of sensing relatively low levels of water flow.

BACKGROUND OF THE INVENTION

In most structures, water is supplied through one or more underground water supply lines. These water supply lines receive water from either a municipal source or a well. At the structure, a water supply line connects with a number of other water supply distribution lines that extend through the structure to various zones of the structure or individual appliances such as toilets, laundry rooms, dishwashers, bathtubs, showers, water heaters, etc.

As is appreciated, water supplied to structures is typically supplied under pressure. If a leak occurs in a distribution line or at a fixture or appliance, it is appreciated that water would continue to leak indefinitely. When the water is supplied by a well, a leak could eventually drain the well and causing the well pump to burn out. Accordingly, even small leaks can cause substantial water damage, and of course there are catastrophic water leaks that can occur at structures which are unattended and result in devastating damages and losses.

Automatic water shutoff systems are known and have been used to sense water leaks and automatically close a shutoff or control valve to prevent further leakage and damage. See, for example, the disclosures found in U.S. Patent Nos. 5,771 ,920; 5,794,653 and 6,216,727. The disclosures of these patents are expressly incorporated by reference.

There is no doubt that automatic water shutoff systems that are known serve a useful function. However, many water shutoff systems of the prior art are limited in their functionality and have not had the ability to sense a wide range of flow conditions that are problematic and the presence of water that has accumulated on a floor. One of the problems faced by designers

and ^" d'fev^iop^rδ"df "witfef shUtoff-systό'ms is that of designing a comprehensive system that is economical and which can detect both accumulating water through moisture sensors and sense very small flows as well as relatively large flows.

Therefore, there has been and continues to be a need for a water shutoff system that is practical, effective and which is not unduly expensive and which will enable a property owner to not only detect catastrophic and large leaks, but will enable the system to detect and react to small leaks by shutting off the water and sounding an audible or visual alarm while transmitting such alarm through a security system panel to a monitoring service.

SUMMARY OF THE INVENTION

The present invention entails a water shutoff system that includes a shutoff valve, a flow sensing unit, power supply with back-up battery, and a controller operatively interconnected between the flow sensing unit and the shutoff valve. The flow sensing unit includes dual flow paths and is designed such that in one mode, when a relatively low flow is passing through the flow sensing unit, this low flow will be directed through a low flow path where the water flow will be sensed or monitored. In a second mode of operation, when the water flow through the supply line increases to a selected flow rate or level, a substantial portion of the water passing through the flow sensing unit is directed through a main flow path. In either case, flow through the relatively low flow path is sensed. If one or more predetermined flow conditions are met, the shutoff valve will shut off the water in the supply line.

In one embodiment of the present invention, the main flow path is normally closed. Thus, when a relatively small flow of water passes through the flow sensing unit, that water flow will be constrained to move through the relatively low flow path, effectively bypassing the normally closed relatively high flow path. A sensor or flow sensing device associated with or actually disposed in the relatively low flow path will sense the flow of water passing therethrough and direct signals to the controller indicative of the flow passing through the relatively low flow path.

In addition, the present invention entails a method of measuring or sensing flow and closing a shutoff valve associated with a water supply line in response to one or more

preselected rrøwcieuicirøons toeWg-fnet The method entails directing water passing through a water supply line through a flow sensing unit having dual flow paths, one path for receiving relatively low flow, and the other path being for receiving relatively high flow. The method entails, in the case of one mode, directing the water flow through the relatively low flow path and sensing the flow of water therethrough. If the sensed flow condition exceeds a selected threshold, then the controller actuates a main shutoff valve, closing the same, resulting in the water passing through the supply line being shut off.

Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic illustration of the water shutoff system of the present invention.

Figure 2 is a sectional view of the flow sensing unit forming a part of the system of the present invention with the main flow path being closed.

Figure 3 is a view similar to Figure 2 but with the main flow path opened.

Figure 4 is a perspective view of a portion of the flow sensor that forms a part of the flow sensing unit.

Figure 5 is a plain view of the bottom side of the flow sensor component shown in Figure 4.

Figure 6 is a fragmentary exploded view of the flow sensor that forms a part of the flow sensing unit.

Figure 7 is a schematic illustration showing an alternative embodiment for the water shutoff system.

Figures 8 and 9 are fragmentary sectional views illustrating the movement of a poppet valve that is utilized in the system shown in the Figure 7 embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENT

With further reference to the drawings, the water shutoff system of the present invention is shown therein and indicated generally by the numeral 10. As will be appreciated from subsequent portions of the disclosure, the water shutoff system 10 is designed to sense water flow through a supply line into a structure and upon sensing and determining that one or more certain flow conditions exist, the water shutoff system is operative to shut the water supply off to the structure.

With reference to Figure 1 , and the shutoff system 10, the system includes a shutoff valve 12. Shutoff valve 12 is movable between opened and closed positions and is generally connected so as to be aligned with an inlet water supply. By actuating the shutoff valve 12 and causing the same to assume a closed position, the shutoff valve 12 is operative to close the water supply line 20. In order to actuate the shutoff valve 12, there is provided an actuator 13

12. Various types of actuators can be utilized. It is contemplated that in one embodiment, an electric motor will be provided and coupled to the shutoff valve 12 by a shaft. This means, of course, that the actuation of the electric motor would result in the shutoff valve being moved, for example, from an open position to a closed position.

Water shutoff system 10 has the capability of sensing the flow of water into the structure or through a portion of the structure. Accordingly, forming a part of the water shutoff system 10 is a flow sensing unit indicated generally by the numeral 14. Subsequently herein, a more detailed discussion of the flow sensing unit 14 will be forthcoming.

Operatively connected between the flow sensing unit 14 and the valve actuator 13 is a controller 16, such as a programmable logic controller. The controller provides the primary user interface to the system to allow user to change various feature settings. As will be appreciated from subsequent portions of the disclosure, electric signals will be directed from flow sensing unit 14 to the controller 16 with the electric signals being indicative of flow conditions sensed by the flow sensing unit 14. Controller 16 is, in turn, operative to control the actuator 13 which in turn controls the shutoff valve 12.

A control panel 18 is also provided. Control panel 18 can be hard wired to the controller 16 or can communicate therewith through conventional wireless means.

The particular structure of the water shutoff system 10 can vary. For example, the shutoff valve 12, actuator 13, and flow sensing unit 14 may form a part of a single assembly. As such the water shutoff valve 12 and actuator 13 could be installed in a water supply line 20 such that water flowing in the water supply line would be constrained to pass through the water shutoff valve 12 and the flow sensing unit 14. Thereafter water exiting the flow sensing unit 14 would continue through the water supply line 20 to a point where any number of distribution water lines would lead to various zones of the structure such as bathrooms, kitchen, laundry room, etc. or specific appliances such as a water heater, water softener, or irrigation system.

Now turning to a discussion of the flow sensing unit 14, flow sensing unit 14 is particularly designed to sense relatively low water flow. In order to achieve this design objective, as will be discussed below, flow sensing unit 14 is sometimes referred to as a dual path flow sensing unit 14. By dual path it is meant that the flow sensing unit 14 includes two or

more sep'arate ^α τιow"patns tHrougirWhich the incoming water can flow as it passes through the flow sensing unit.

With reference to the flow sensing unit 14 shown in Figures 1-6, there are two flow paths provided for therein. First, there is what is referred to as a main flow path and this is indicated generally by the numeral 100. Secondly, there is a relatively low flow path, and that path is indicated generally by the numeral 102. When there is sufficient water pressure in water supply line 20, there will be flow through both the main flow path 100 and the relatively low flow path 102. In this case the flow rate of water (oz./min. or gal./min.) in the main flow path 100 will be greater than the flow rate of water in the relatively low flow path 102. Hence, flow path 102 is referred to as a relatively low flow path because the flow therein, in circumstances where there is flow in path 100, is relatively low compared to the flow rate of water in flow path 100. Hence, the main flow path 100 can be appropriately termed a relatively high flow path.

Main flow path 100 extends through a housing 104. Housing 104 includes an inlet end 106 and an outlet end 108. Exterior threads 110 are provided about an inlet portion. Secured on the outlet end of the housing 104 is a pipe coupling 210. By disconnecting the coupling 210, access can be gained to the interior of housing 104 upstream of the coupling 210.

Disposed within the housing 104 upstream of the coupling 210 and aligned with the main flow path 100 is a normally closed valve indicated generally by the numeral 112. Various valve designs can be used. Valve 112 includes a housing indicated generally by the numeral 114. Housing 114 includes a front or upstream section 114A. Spaced downstream from the front portion 114A is a downstream section 114B. Connecting the front or upstream portion 114A with the downstream portion or section 114B is a series of connectors or ribs 114C. See Figures 2 and 3. Valve 112 includes a stopper 116 that is movable back and forth in the housing 114. Stopper 116 is biased to assume a normally closed position shown in Figure 2. In the normally closed position stopper 116 seats against an O-ring (not shown) formed in the housing 114, and prevents flow from flowing past and downstream the valve 112. Extending downstream from the stopper 116 is a stem 118. Stem 118 is confined within an area of the housing that holds and guides the stem as the stem moves fore and aft as viewed in Figures 2 and 3. A spring 120 is disposed around the stem 118 and extends between the downstream

seαtiσrv i 14ts ^i| a'ntf'tne"'neaα"ortne ⁱⁱ stσpper 116. Hence, spring 120 biases the stopper 116 towards a closed position. In other words, stopper 116 is biased upstream to seat against an O- ring that forms a sealed interface between the housing 114 and the stopper 116. On the inlet side of the valve 112 there is provided an O-ring 124 that provides a sealed interface between the housing 104 and the inlet side of the valve 112. Hence, when valve 112 assumes its normally closed position, the stopper 116 along with the O-ring 124 will prevent water from flowing completely through the housing 104 and the main flow path 100. It is appreciated that the spring 120 can be sized to allow a certain flow of water through the low flow path 102 before opening to permit water to flow through the main flow path 100. Thus, the flow rate of water through the low flow path 102 can be controlled or adjusted by varying the strength of the spring 120.

Housing 104 includes a number of bypass outlets. In particular, on the upstream side of the valve 112 there is provided a bypass outlet 130. In similar fashion, on the downstream side of the valve 112 there is provided a bypass inlet 132. Bypass outlet 130 and bypass inlet 132 form a part of the relatively low flow path 102.

Continuing to refer to the flow sensing unit 14, there is provided a flow sensor, indicated generally by the numeral 140, mounted to the housing 104 of the main flow path 100. Flow sensor 140 includes a housing that comprises a base indicated generally by the numeral 140A and a communications module indicated generally by the numeral 14OB. First, with respect to the base 140A, the same includes a flange 142 that is designed to abut and fit tightly adjacent a flattened surface of the housing 104. Flange 142 is secured by bolts or other suitable fasteners to the housing 104. Extending upwardly from the flange 142 is a cylindrical portion 144. As will be appreciated from subsequent portions of the disclosure, the cylindrical portion 144 includes an open interior area that houses or forms a flow measuring chamber. Formed atop the cylindrical portion 144 is flange 146. The housing structure that forms the flow sensor 140 can be constructed of various suitable materials. In one embodiment, the housing structure, and particularly the base 140A and parts of the communication module 140B, can be formed of a molded plastic material.

•NOW viewing tHe' lntδrioWihø' cylindrical portion 144 of the flow sensor 140, and as particularly seen in Figure 6, there is provided an interior annular ledge 148 that extends adjacent the interior wall of the cylindrical portion 144. Annular ledge 148 extends entirely around the inside of the cylindrical portion 144. Extending across the interior portion of the cylindrical portion 144 is a pair of cross members 150. Cross members 150 are spaced apart and each include an indented seat 150A. This is particularly shown in Figure 6. Disposed on each side of the cross members 150 is a debris cavity 152. As will be appreciated from subsequent portions of the disclosure, as water passes through the interior portion of the base 140A, from time to time debris may be found entrained in the flow of water and the two debris cavities 152 are positioned with respect to the flow of water through the base 140 such that debris can fall or drop from the stream of water flow into one of the debris cavities 152.

Formed in the bottom of the cylindrical portion 144 is an inlet 154 and an outlet 156. Outlet 156 has a larger cross section than inlet 154. This tends to assure that the outlet 156 will not cause an undue restriction on the flow of water through the flow sensor 140.

Positioned between the two cross members 150 is an inclined ramp 158. This is illustrated in Figure 6. Inclined ramp 158 can be straight or slightly curved or arcuate and is inclined from the inlet side of the area shown in Figure 6 to the outlet side. That is, the lower end portion of the ramp 158 terminates adjacent the outlet 156. In some cases sand particles, suspended solids, and other small debris may be entrained in the water flow passing through the flow sensor 140. Often sand and such debris will drop down onto the ramp 158. The presence and orientation as well as the location of the ramp facilitates the movement of sand and debris towards and through the outlet 156 and from the flow sensor 140.

Mounted between the cross members 150 is a paddle wheel 160. As used herein, the term "paddle wheel" means a rotating device having projections that project outwardly such as blades, vanes, propellers, etc. Paddle wheel 160 includes an axle 16OA that projects through the center of the paddle wheel. Axle 160A is designed to project onto and rest on the seats 150A that form a part of the cross members 150. Hence, the paddle wheel 160 extends generally between the two cross members 150 and during the rotation of the paddle wheel 150 it follows that a portion thereof will turn adjacent the inside walls of the two cross members 150.

in TRe'emDoaimenit'sncfwn'iTsrem'; tπetlow measuring device comprises in part the paddle wheel 160. It is appreciated that other flow measuring devices can be utilized. As will be appreciated from subsequent portions of the disclosure, as water moves through the relatively low flow path and through the flow sensor 140, the water will engage and impact the blades of the paddle wheel 160 and will cause the same to rotate.

Formed within the flow sensor 140 is a measuring chamber 162. The measuring chamber 162 is that area within the flow sensor 140 that surrounds the paddle wheel 160. That is the measuring chamber extends upwardly and around the space occupied by the paddle wheel 160 such that when water enters the inlet 152, the water will be constrained to engage the blades of the paddle wheel 160 and cause the same to rotate and at the same time will move around the axis of the paddle wheel.

Formed in the inside of the cylindrical portion 144 of the flow sensor 140 is a series of slots 164. See Figure 6. As will be appreciated from subsequent portions of the disclosure, slots 164 function to receive portions of the communications module 140B. This effectively secures and orients communication module 140B within the interior of the cylindrical portion 144 of the flow sensor.

Figure 5 illustrates the underside of flange 142 of the flow sensor 140. Inlet 154 and outlet 156 is shown formed through the flange 142. Adjacent both the inlet 154 and outlet 156 is an indented or recessed area that in the case of the embodiment shown in Figure 5 assumes the shape of a teardrop. Adjacent inlet 154, this recessed or indented area forms a relatively small intermediate chamber 200. See Figures 2 and 3. This intermediate chamber 200 which is formed by the flange 142 and adjacent surface of the housing 104 is small compared to the volume of the measuring chamber 162. However, it should be appreciated that the size or volume of this intermediate chamber 200 can vary. In like fashion, the indented or recessed area that extends adjacent outlet 156 forms another intermediate chamber 202. An O-ring 204 extends around each of the intermediate chambers 200 and 202 and the opening that forms the inlet 154 or the outlet 156. A series of feet 206 are disposed on the bottom of the flange 142 and engage and rest on the flattened surface of the housing 104 that receives the flow sensor 140. It is appreciated that when the flow sensor 140 is bolted or otherwise secured to

thdmattehed 'sMafeeW'the^ouising TO4 that ^he inlet 154 will align with the outlet 130 formed in the housing 104 of the main flow path. Likewise, outlet 156 formed in the flow sensor 140 will align with inlet 132 formed in the upper portion, as viewed in Figure 2, of the housing 104.

Flow sensor 140 includes the communication module 140B, which when coupled to the base 140A extends outwardly or upwardly from the base 140A. The function of the communication module 140B is to sense and count the number of revolutions made by the paddle wheel 160 and to direct the resulting data or information to the controller 16 which determines the flow or flow rate through the flow sensor 140 for any given period of time. Structurally, the communication module 140B includes a housing 170 that is designed to be inserted and fitted into the cylindrical portion 144 of the base 140A. See Figure 6. A series of keys or protrusions 142 are spaced to coincide with slots 164. This permits the communication module 140B to be appropriately positioned within the base 140A. As seen in Figure 6, the housing 170 includes a top 174. Defined below the top 174 is a cavity 176 that forms a part of the measuring chamber 162. Cavity 176 is sized to encompass an upper portion of the paddle wheel 160 when the paddle wheel is supported on the seats 15OA. Extending from the top portion of the communication module 140B is a cable 178 that carries data or other information from the communication module 140B to the controller 16. An O-ring 180 extends around the lower periphery of the housing 170 so as to form a sealed relationship between the lower portion of the communication module 140B and the annular ledge 148 disposed in the cylindrical portion 144.

Communication module 140B can utilize various known technologies to sense and measure flow. More particularly, there are numerous conventional means for counting the revolutions or portions of revolutions made by the paddle wheel 160. For example, the communication module 150 may direct a light beam or other signal through the plane of the paddle wheel 160 and effectively count the breaks in the light beam caused by the blades or vanes of the paddle wheel 160. Resulting data or information is directed to the controller 16 which would in turn calculate the flow for a particular time interval. Details of the communication module 140B are not dealt here in detail because such is not per se material to the present invention and because such flow measuring devices are well known and appreciated in the art.

However," it can Wfiόted WaWfIoW Sensor of this type is made by Kobold Messring GmbH of Germany, such as Model DPL or DPM, and would be appropriate for the type of applications envisioned for the present invention.

As seen in Figures 2 and 3, the main flow path 100 of the flow sensing unit 14 extends horizontally through the housing 104. The relatively low flow path 102 extends from the housing 104, through parts of the flow sensor 140 and back into housing 104. In particular, with respect to the embodiment illustrated herein, the relatively low flow path begins with outlet 130 formed in housing 104. Water will enter outlet 130, and as viewed in Figure 2, will move upwardly to the intermediate chamber 200. There the water will turn at an angle and move through the teardrop shaped chamber 200 to the inlet 154 of the measuring chamber 162. From there the water will flow generally upwardly, as viewed in Figure 2, through the inlet 154. Note that inlet 154 is disposed on one side of the measuring chamber 162. As water exits the inlet 154, the water will follow the direction of the arrows shown in the measuring chamber 162 of Figures 2 and 3. That is, the water will flow upwardly and around the top portion of the measuring chamber 162, and in the process will turn and drive the paddle wheel 160. As the water turns and moves downwardly it will enter the outlet 156. When the water exits the outlet 156 it will enter the other intermediate chamber 202 and will move therethrough after which the water will turn at another angle and be directed downwardly through the inlet 132 formed in the housing 104 of the main flow path 100. This describes the relatively low flow path. Note that the relatively low flow path essentially bypasses the valve 112. In describing the relatively low flow path, terms such as "upward," "downward," etc. have been used, but have been used to simply describe the relatively low flow path 102 in terms of its orientation in Figure 2. The flow sensor 140 can be positioned in any orientation on the housing 104. That is, the flow sensor 140 can project downwardly from the housing or out from any side or at any angle with respect to the housing 104.

Control panel 18 communicates with the controller 16 through either a hard wire connection or wireless means. One or more control panels 18 can be utilized per shutoff valve. Conversely, one control panel/controller can communicate with multiple shutoff valves. Preferably such control panels can be positioned near the entry/exit doors of the structure, and

in suctMs»«ilJty ^' robfiV'b'asterfient, kitchen, and bathroom. Control panel 18 is used as the primary user interface to change program settings and to activate or deactivate the water shutoff system 10. Each control panel contains a plurality of functionality accessed through keys that have access to controller via a carbon pill interface. These function keys may include an "Emergency Shut Off" key, providing the user immediate water shutoff on demand, a "Home mode" key placing the system into the Home mode, an "Away mode" key, placing the system into the Away mode, a "Bypass" key temporarily overriding the system timer for a variable period of time, a "Program" key allowing the user to change the system timer and detectable flow rate parameters, a "Disable" key allowing the user to silence the alarm, a "Reset" key to allow the system to return to the home mode from an alarm mode, and an interface that allows controller to communicate with security systems and external appliances such as a water softener and or irrigation system to allow them to run for extended periods of time without changing the home or away timer. These are known as "permission based" uses and are not limited to those appliances cited. Further, any one of the control panels can contain an audible or visual alarm.

Controller 16 is communicatively connected with the control panel 18. Further, controller 16 is communicatively connected with the flow sensing unit 14 as well as the valve actuator 13. In use, the flow sensing unit 14 senses flow through the flow sensing unit and particularly flow through the low flow path 100 and generates an electrical signal that is indicative of flow. This information or data concerning the water flow through the flow sensing unit 14 is supplied or directed to the system controller 16. System controller 16, as noted above, is electrically interconnected with the actuator 13 for the shutoff valve 12. When the system controller 16 elects to close the shutoff valve 12, it follows that an electrical actuating signal will be sent to the valve actuator 13 which in turn will actuate the shutoff valve 12 and close the same. Conversely, when the system controller 16 opens the shutoff valve 12, an electrical signal will be sent from the controller 16 to the valve actuator 13, which in turn will open the shutoff valve 12.

System controller 16 is powered by a power supply that is derived from the structure being served. A battery back-up is charged by the power supply. Should power from the house

or B ¹ ϋil ^l din^-faff; ^ι ' ¹ pd^6P1is ^r imτt1^tiratefiy ^iλ iSupplied to the system controller 16 by the back-up battery. Upon restoration of power derived from the structure being served the back-up battery is charged to return to its labeled power.

The water shutoff system discussed above primarily operates in two modes which are referred to as the "Home" mode and the "Away" mode. The selection of the modes can be made at any one of the control panels 18 by pressing either the "Home" function key or the "Away" function key. In the away mode, the system will allow uninterrupted water flow to occur for a selected period of time before shutting off water to the entire household or building. The selected time period can be inputted via the control panel 18. Of course, various time periods can be selected, but in one embodiment, it is contemplated that a 30 second time period would accommodate normal uses in a household such as the use of an automatic ice maker. The system is similarly programmed to a home mode when the structure is occupied. In the home mode, the selected period of time may be, for example, 30 minutes. Further, the system can be programmed to automatically assume the away mode under various conditions. For example, if the system senses no water flow for an extended period of time, the same can be programmed to automatically switch from the home mode to the away mode. Also, a motion sensor 17 can be installed and operatively associated with the controller 16 to switch the system from away mode to home mode. Various types of motion sensor 17 can be used. For example, an optical sensor, such as the type used by garage door systems, that directs an infrared beam through an area of the building or structure can be utilized. Additionally, other commercially available motion sensors such as an ultrasonic Doplar shift sensor can be used.

Motion sensor 17 is employed to sense motion or occupancy in a home, building or structure. It is particularly beneficial when used in a system such as disclosed herein where the controller 16 is operative in two modes, the home mode and the away mode. In this case, when the controller is set in the away mode and the motion sensor 17 senses motion within the home, building or structure, the controller 16 upon receiving a signal from the motion sensor will automatically switch from the away mode to the home mode. The motion sensor 17 can be hardwired into the controller 16 or can communicate with the controller wirelessly.

^,, ir« one _' emKociim'errt ¹ ; tnβ'warør snutoff system 10 will base its operation on sensing flow for a selected period of time. In this case, the flow condition that is programmed to trigger the actuation of the shutoff valve 12 is simply the combination of uninterrupted water flow over a certain period of time. It should be appreciated that the volume of flow, that is flow rate, could be sensed and the system could be programmed to trigger the actuation of the shutoff valve 12 in response to flow rate or a combination of flow rate and a selected period of time. As used herein the terms "flow" and "flow rate" are interchangeable. They both refer to a certain quantity of water per unit of time, such as ounces or gallons per minute.

Water shutoff system 10 also has the ability to sense the presence of accumulated water at various locations in a structure, and in response to sensing such accumulated water the system is operative to actuate the shutoff valve 12 and to stop the flow of water through line 20. As seen in Figure 1 , the system 10 includes one or more moisture sensors 21 distributed strategically throughout a home, building or structure. The flow sensors 21 would be placed closely adjacent the location of appliances, for example, where leaks could possibly occur. For example, a flow sensor can be placed underneath or adjacent a water heater, a washing machine, a refrigerator, a dishwasher, etc. In addition, the moisture sensors can be attached to baseboards and just slightly above the floor, or can even be placed underneath carpeted areas.

Details of the moisture sensors 21 are dealt with herein in detail because such is not per se material to the present invention and further, moisture sensors are commercially available and known and appreciated by those skilled in the art. For example, moistures sensors are available from the General Electric company. Moisture sensors 21 can communicate wirelessly with the controller 16 or can be hardwired to the controller 16.

As noted above, various types of moisture sensors can be utilized. One popular type of moisture sensor includes a pair of spaced apart electrodes or sensors. When accumulated water puddles or forms around the electrodes or sensors, the accumulated water which is a very good conductor, causes the circuit to be completed between the electrodes or sensors and a signal generated by the moisture sensor and directed therefrom through hardwiring or wirelessly via a transmitter to the controller 16. As noted above, various types of moisture sensors can be utilized. In some cases the moisture sensor 21 can be secured to a tether and disposed

unαemeaτn an'appiiaπce TOT "example'. The tether can form a part of a hardwire or could lead to a remote transmitter which would be operative to direct a signal to the controller 16 in response to the moisture sensor sensing accumulated water.

Thus, the water shutoff system 10 of the present invention has the ability to actuate shutoff valve 12 in response to sensed flow through the flow sensor 14 or in response to accumulated water sensed by one or more of the moisture sensors 21. This is a significant advantage inasmuch as moisture sensors 21 alone will not detect all of the potential leaks that can occur in a structure, and there are cases and situations where sensing the flow will not, at least immediately, detect all of the potential leaks that can occur in a structure.

Turning to Figures 7-9, another embodiment for the water shutoff system 10 of the present invention is shown therein. In this embodiment, the flow sensing unit 14 includes a housing 22. Formed in the housing 22 is an inlet 24. Inlet 24 is designed to be communicatively connected, directly or indirectly, to the water supply line 20. In the embodiment illustrated in Figure 7, on the upstream side of the flow sensing unit 16, the shutoff valve 12 is connected in the water supply line 20. Alternatively, the shutoff valve 12 could be connected on the downstream side of the flow sensing unit 14. In any event, inlet 24 is open to a flow path that is referred to herein as the main flow path or relatively high flow path 26. In the case of the particular embodiment shown in Figure 7, the main flow path 26 is generally centrally located. As illustrated, water entering the main flow path 26 from inlet 24 will continue generally straight through the flow sensing unit 14. In the embodiment illustrated, the main flow path 26 is formed by an elongated central bore formed in a housing structure.

Also formed in flow sensing unit 14 is a relatively low flow path 28. Relatively low flow path 28 essentially bypasses or extends around the relatively high flow path 26. Again, this is illustrated in Figure 7 of the drawings. Associated with the relatively low flow path 28 is a flow sensor 30. Flow sensor 30 functions to sense flow through the flow sensing unit 14 and particularly flow through the relatively low flow path 28. Flow sensor 30 can be of various commercial types. In one embodiment flow sensor 30 may comprise a differential pressure flow sensor. By sensing or measuring different pressure across the flow sensor 30, an indication of both flow and flow rate can be achieved. As discussed herein, the water shutoff system 10 is

de&tgfaed to ^' s'e'ήle'-t ^' Kii pire^FidS' of ^f έi ^:t telatively low flow rate of water through the flow sensing unit 14. In one embodiment, a flow sensor 30 is selected which has the capability of sensing flows as low as 0.5 oz./min.

In addition, and as an option, the flow sensing unit 14 may include a third flow path 32. A flow sensor 34, similar to sensor 30, is associated with or disposed in the third flow path 32. The purpose of the third flow path 32 and the sensor 34 is for validation purposes. That is, if the primary sensor 30 becomes defective, then the validation sensor 34 will indicate such. In other words, if there is water flow through the flow sensing unit 14, in the case of this embodiment, there would be flow through both the flow paths 26 and 32. If perchance sensor 34 was indicating flow, but sensor 30 was not indicating flow, then that would suggest or indicate that primary sensor 30 is defective.

In one embodiment, the main flow path 26 is normally closed. That is, in cases where there is low flow or a low pressure differential across the main flow path 26, then main flow path 26 is closed and the existing water flow moves through the relatively low flow path 28 and if used, the optional third flow path 32, which happens to be a relatively low flow path also as compared to the main flow path 26. To maintain the relatively high flow path 26 normally closed, there is provided a poppet valve 40. Poppet valve 40 is movable between open and closed positions. See Figures 8 and 9. Flow sensing unit 14 includes a seat that the poppet valve 40 rests against when in the closed position, as shown in Figure 8. Various means can be employed to maintain the poppet valve 40 normally closed. For example, a spring mechanism can be used. In one embodiment of the present invention, poppet valve 40 is a magnetically actuated valve. That is, the flow sensing unit 14 utilizes a series of magnets to hold or position the poppet valve 40 in the closed position. As shown in the drawings, associated with the poppet valve 40 is a pair of magnets 42. Further, disposed within the body of the flow sensing unit 14 is a second pair of magnets 44. Under normal conditions, the magnets 42 and 44 attract each other and pull the poppet valve 40 to a closed position. Magnets 42 and 44 are particularly sized to hold the poppet valve closed until a selected pressure differential exists across the poppet valve. When this occurs, the pressure differential will be sufficient to separate the magnets 42 in the poppet valve from the magnets 44 in the

Doαy'bf the' flbw"Sensihg uriitr "FhuVpoppet valve 40 can be urged from its seat permitting water to flow from the inlet 24 of the flow sensing unit 14 into and through the main flow path 26.

As illustrated in Figure 7, the water supply line 20 extends from the flow sensing unit 14 to a series of water distribution lines 46 that extend throughout the home or a building to service various zones bathrooms, laundry room, kitchen and other rooms and appliances that require water.

It will be appreciated that the poppet valve 40 will be held in its closed position by magnets 42 and 44. When there is little or no water flow through the supply line 20, it follows that the pressure on opposite sides of the poppet valve 42 will be generally equal. The low flow path 26 will remain open to equalize pressure upstream and downstream from the poppet valve 40. When a downstream valve or valves is open to allow a flow of water through the water supply line 2O ₁ the pressure downstream of the poppet valve 40 will be reduced. The pressure upstream and downstream of the poppet valve will attempt to equalize through the open flow path or paths, which in one embodiment would simply be the low flow path 28, or in an alternative embodiment, the low flow path 28 and the third low flow path 32. In this case, flow of water would bypass the main flow path 26.

Under high flow conditions, one or more downstream water valves are open to allow a relatively high flow of water through the water supply line 20. Pressure downstream of the poppet valve 40 will be reduced more rapidly. The pressure upstream and downstream of the poppet valve 40 cannot equalize through the low flow paths 28 and 32 sufficiently. A greater pressure differential is created and the upstream pressure will overcome or overpower the magnetic forces (or in the case of a spring the spring forces) holding the poppet valve 40 in the closed position. The poppet valve 40 will be forced off its seat and the high flow path 26 will be open and water will flow therethrough. See Figure 9.

There are many advantages to the water shutoff system 10 of the present invention. One of the more important advantages is the ability of the water shutoff system 10 to detect discharged water through moisture sensors, sense or measure relatively low flow rates, flow rates on the order for example, of 0.5 oz./min. This permits the water shutoff system to control not only catastrophic leaks, but leaks that may be deemed slow and persistent leaks which

nonetheless households and buildings. Further, with the programmable controller 16, one can adjust and account for nuisance leaks that might result from an ongoing leaky faucet or toilet tank that present no risk to the structure. That is, these types of leaks can be accounted for and the controller set to sense a slow and persistent leak that exceeds a known leak.

The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.