US 6119720 A
A flood control device measures fluid flow into a house or building and shuts off the fluid flow if measured flow conditions indicate an overly high consumption due to a leak, break, or other abnormal condition which is present in the plumbing system of the house or building.
1. A flood control device comprising:
a housing having an inlet and an outlet;
an impeller which rotates a specified number of times for a given volume of fluid flowing into the inlet;
a detector for sensing rotation of said impeller;
an electronic circuit coupled to said detector and configured to count the number of rotations of said impeller;
a solenoid activated by said electronic circuit;
a trigger activated by said solenoid;
a spring loaded shaft releasably restrained in place by said trigger;
a rotatable shut-off valve coupled to said spring loaded shaft such that when said trigger is activated so as to release said spring loaded shaft from being restrained by said trigger, said spring loaded shaft rotates so as to close said outlet and stop fluid flow through the flood control device.
2. The flood control device of claim 1, wherein said rotatable shut-off mechanism comprises a rotating ball valve.
3. The flood control device of claim 1, wherein said rotatable shut-off mechanism comprises a ball check valve coupled to a cam.
4. The flood control device of claim 1, wherein said impeller comprises a helical axial impeller.
5. The flood control device of claim 4, wherein said impeller is removable from said housing.
6. The flood control device of claim 1, additionally comprising a digital display device.
This application is a continuation of U.S. application Ser. No. 09/036,992 entitled "Flood Control Device" and filed on Mar. 9, 1998, now U.S. Pat. No. 5,979,493, which is a continuation-in-part of U.S. application Ser. No. 08/691,569, also entitled "Flood Control Device," and filed on Aug. 2, 1996, now U.S. Pat. No. 5,782,263, which application claims priority to provisional Application No. 60/001,918, filed on Aug. 4, 1995. The disclosure of the above mentioned Flood Control Device applications are hereby incorporated by reference in their entireties.
1. Field of the Invention
The present invention relates generally to a safety device which cuts off the water supply to a house or building in the event of overly high water consumption due to a leak, break or open faucet in the plumbing of a house or building.
2. Description of the Related Art
Other than a fire, perhaps the most catastrophic type of damage which can occur to a home or other building is damage due to water leakage from a broken or badly leaking water line. Since water supply lines may run throughout a house or other building, a leak may occur in the heart of the house or other building, and may result in extensive damage both to the structure and to the contents prior to the water supply being manually shut off.
The main causes of runaway water leakage are ruptured pipes, tubes or fittings; faulty washing machine hoses, water heaters, supply lines and other plumbing equipment; rusty or aging components, electrolysis, poor installation practices, poor quality materials, frozen pipes, tubes or hoses, earthquake activity and pressure surges. With so many different factors that can create plumbing failures and runaway water leaks, one can readily realize the need for a fluid shutoff safety device. Flooding in a home or other building brings water damage resulting in extensive destruction and expense. Massive difficulties ensue in the wake of interior structural flooding as families and businesses must contend with problems including substantial loss of time, money and the home, office or other building involved.
In the prior art, there exists a number of devices which are designed to control flow and to act as a shutoff in the event of a leak. These devices generally fall into two major categories, namely the shock operated type and the flow or pressure operated type. The shock operated device is designed to shut off flow in the event of a major shock such as that of an earthquake or the like. Examples of such devices are found in Lloyd, U.S. Pat. No. 3,747,616, and Mueller, U.S. Pat. No. 3,768,497 and Pasmany, U.S. Pat. No. 4,091,831. These devices are all designed for use with gas lines and do not address the problem of breaks or leaks in the line downstream of the devices. In addition, the shock operated type of control valves do not address the problem of broken or leaking water or gas lines due to normal erosion or the possibility that someone has simply opened a faucet or line and has forgotten to close it.
The second approach, which causes a shutoff of flow in the event of an overly large flow rate or an excess pressure change across the device, is illustrated, for example, by Frager, U.S. Pat. No. 2,659,383, Bandemortelli, U.S. Pat. No. 4,522,229, and Quenin, U.S. Pat. No. 4,665,932. All three of these devices are designed primarily for industrial applications and are large, complex and expensive and therefore, inappropriate for use in a home or other relatively small building. A simpler valve control device designed to cut off the water supply to a house or building is described in U.S. Pat. No. 4,880,030 entitled "Safety Flow Control Fluid Shutoff Device." This device detects a downstream plumbing break or leak by sensing a water pressure increase within the valve. This increase in water pressure forces a piston to block the outlet of the device, thereby stopping flow through the device. It should be understood that the terms, "valve control device," "control valves" and "flood control devices or valves" as used herein, are synonymous and interchangeable.
Control valves which detect a high rate of flow have many drawbacks. With these types of control valves, undesired shut-offs may occur because of a high rate of flow under normal service conditions due to increases of water or gas consumption during a given period or increases in population in a water main's area, for example. Furthermore, if a break occurs, a great amount of water might run away before the predetermined value of rate of flow has been reached to effectuate a valve shut-off. Control valves which are pressure sensitive are also not reliable because there are many factors that can cause a change in water pressure, which does not necessarily mean that there is an overflow of fluid. For example, in a system where water mains are connected together in any number and one of these mains breaks, the pressure head decreases swiftly not only on the broken main but also on all the other mains and the respective control valves which are connected to these mains may unnecessarily close at the same time. Also, if a pressure sensitive control valve is located in a high place and the upstream length of the main is great, the pressure differences due to gravitational forces can cause variations in the shut-off parameters, leading to possible shut-offs which are unnecessary and inconvenient to customers as well as to water supply companies.
The prior art valve control devices described above do not address the problem of a faucet which has inadvertently been left open. There is no way for these devices to distinguish this situation from everyday normal water use. Furthermore, these prior art valve control devices are unreliable in detecting gradual leaks that create gradual changes in pressure which may be undetectable by the device.
Thus, there clearly exists a need for an improved valve control device that overcomes the deficiencies of the prior art devices and reliably eliminates the potential hazard of flooding. Moreover, such a device is needed which has the capability to measure the volume of a continuous flow of fluid and shut the fluid flow off when a preset maximum volume limit has been reached. Further, an improved flood control valve is needed that can be set for different fluid volumes depending on the size of the building or home or water usage in a particular operation. This would allow a user to advantageously change the volume of fluid which is used during one session to meet the fluid consumption demands of his or her particular home or building.
In one embodiment, the invention comprises a flood control device comprising a housing having an inlet and an outlet, an impeller which rotates a specified number of times for a given volume of fluid flowing into the inlet, and a detector for sensing rotation of the impeller. Coupled to the detector is an electronic circuit which is configured to count the number of rotations of the impeller. A solenoid is activated by the electronic circuit, a trigger is activated by the solenoid, and a spring loaded shaft is releasably restrained in place by the trigger. In addition, a rotatable shut-off valve is coupled to the spring loaded shaft such that when the trigger is activated so as to release the spring loaded shaft from being restrained by the trigger, the spring loaded shaft rotates so as to close said outlet and stop fluid flow through the flood control device.
The above and other aspects, features and advantages of the present inventions will be more apparent when presented in conjunction with the following drawings wherein:
FIG. 1 is a block diagram of one embodiment of the flood control device of the present invention.
FIG. 2 is an elevational, cross-sectional, side view of an embodiment of the flood control device of the present invention.
FIG. 3 is a cross-sectional, top view of the flood control device shown in FIG. 2.
FIG. 4 shows a liquid crystal display (LCD) and corresponding membrane switches used to manually adjust the volume preset at which point the flood control device of the present invention will close.
FIG. 5 is a schematic diagram of another embodiment of the flood control device of the present invention.
FIG. 6 is a flow chart of the learning mode of the flood control device in FIG. 1.
FIG. 7A is an elevational, cross-sectional, side view of another embodiment of the flood control device of the present invention.
FIG. 7B is an elevational view of one embodiment of the coupling device which may be used in the flood control device of FIG. 7A.
FIG. 8A is a cross-sectional top view of the flood control device of FIG. 7A.
FIG. 8B is a top view of the flood control device of FIG. 7A.
FIG. 9A is an elevational, cross-sectional, side view of another embodiment of the flood control device of the present invention.
FIG. 9B is a top view of the coupling and triggering mechanism which may be utilized in the flood control device of FIG. 8A.
FIG. 9C is an elevational side view of the coupling and triggering mechanism which may be utilized in the flood control device of FIG. 8A.
FIG. 9D is a top view of the visual gauge which may be utilized in the flood control device of FIG. 8A.
The following description of the present invention is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.
It should be understood at the outset that although the flood control valve of the present invention will be described in the context of water flow in the water lines and plumbing of houses and buildings, the flood control device of the present invention may also be utilized to provide control valves in other areas such as gas lines or systems in which the flow of gas must be regulated. The principles of operation of the flood control valve of the present invention not only provide a means for preventing water damage due to broken, leaking or open water lines, but can also prevent, or at least lessen, the dangerous conditions which result from broken, leaking or open gas lines.
It is a primary function of a flood control valve to prevent water damage to a house or building in which a plumbing line, faucet, or other water source is broken, leaking or inadvertently left open. To this end, the flood control valve of the present invention operates on the principle of metering and measuring the volume of fluid delivered in a continuous steady flow. Such a flood control valve is extremely reliable because the measurement of the volume of a continuous flow is relatively easy and accurate when compared to measuring flow rate changes and pressure changes as in the prior art devices. It is easy to envision the utility that such a reliable flood control valve can provide, for example, in an earthquake situation when there may be many broken lines. By selectively shutting off certain water mains and/or lines, the flood control device of the present invention can close those mains and lines which are wasting water and causing flooding, while keeping open operational water mains and/or lines for use by firefighters or other emergency personnel. By closing off the broken mains and lines, the flood control valve of the present invention ensures that there will be adequate water pressure in the interconnected mains and lines for use by firefighters and other emergency personnel. Historically, inadequate water pressure resulting from broken water mains and lines has posed significant problems for firefighters in their battle against fires which typically arise in the aftermath of a serious earthquake. It should also be noted that the flood control valve of the present invention may be strategically located in the plumbing system of a house or building to shut-off only certain, specified lines. For example, by placing the flood control device downstream of a fire-sprinkler system, the flood control device will not be affected by the consumption of water by the sprinkler system in the event of a fire.
In addition to its primary function of preventing flooding in a house or building, the flood control valve of the present invention may also be used as a water conservation device. By shutting off the flow of fluid after a predetermined volume of fluid has been measured flowing through the device, the flood control device can effectively curtail the waste of water by broken or leaking pipes or by users who unnecessarily use excess amounts of water. It is readily apparent that such a flood control device would be of tremendous value in states such as California or Arizona, for example, where fresh water is scarce and its conservation is a major concern to their respective populations.
FIG. 1 shows a schematic diagram of a flood control valve 100 which includes an inlet 101 that may be connected to any incoming water source, such as a water main. The inlet 101 is typically of cylindrical design and of standard shape to mate with standard water lines for home or business use. Additionally, the inlet 101 may be either internally or externally threaded in order to meet the particular requirements of a given application. It is to be understood, however, that the shape, size and mating characteristics of the inlet 101 may be varied in order to achieve connectivity with any type of water supply line. Flood control device 100 further includes an outlet 109 which is connected to the plumbing system of a house or building. Similar to the inlet 101, the outlet 109 may have any shape, size and mating characteristics in order to achieve connectivity with any type of plumbing line, pipe or faucet of a house or building.
Between inlet 101 and outlet 109, and within a housing 111, the flood control valve 100 further includes a flow detector 103, a controller 105 and a shut-off mechanism 107. The flow detector 103 serves the function of measuring the volume, or quantity, of fluid which has continuously passed through the flood control valve 100. When a preset volume of fluid has been detected by flow detector 103, the controller 105 will activate the shut-off mechanism 107 which then shuts off either the inlet 101 or the outlet 109, thereby stopping any further flow of fluid through flood control valve 100.
Referring to FIG. 2, a flood control device 200 which operates in accordance with the present invention is shown. As fluid flows into inlet 211, the volume of fluid is measured by an electronic circuit 203 that counts revolutions of an axial or centrifugal impeller 213. In the preferred embodiment, an axial impeller 213 is used and a predetermined number of revolutions of the axial impeller 213 represents a gallon of fluid. The continuous flow of fluid counts up on an electronic counter 202 of electronic circuit 203, toward a preset (selected) volume of flow, which may be stored in electronic circuit 203.
When the counter 202 or electronic circuit 203 indicates that the flow has reached the preset number of gallons (revolutions) the electronic circuit 203 activates a solenoid 207 which in turn activates a trigger 239. The activation of trigger 239 closes outlet 227 to stop all flow of the fluid through the flood control device 200 as will be explained in more detail below. The flood control device 200 remains closed until it is manually re-opened by re-cocking a cocking lever 237, which functions as a release mechanism. The functioning of the cocking lever 237 will be described in further detail below. If at any time the flow of fluid is stopped before reaching the preset volume limit, the electronic counting mechanism 202 of electronic circuit 203 resets itself to zero. The electronic circuit 203 is of relatively simple design and includes a counter 202, a memory 204 for storing the values of the preset maximum volume at which the flood control device 200 will shut off fluid flow, a logic circuit 206 for determining when the preset maximum volume limit has been reached and a switch 208 which transfers power form a power source, e.g., a battery pack, to a trigger mechanism such as solenoid 207 which will be described in further detail below. The memory 204 and logic circuit 206 also keep track of whether there is a continuous flow of water. If there is a break or lapse in the flow of water, memory 204 and logic circuit 206 will detect this and reset electronic counter 202 to zero. This function will be described in greater detail below.
A constant flow of fluid through the flood control valve 200 causes the helical axial impeller 213 to turn, even at very low flow rates. The impeller is of very low mass and mounted on either end on small, low resistance bearings 219 which are housed in axial impeller cartridge 215. In the preferred embodiment, axial impeller cartridge is removable so that it may be cleaned or replaced as necessary to ensure proper operation of the flood control valve 200. The material used to construct the impeller 213 should displace the same weight as the fluid being transferred. When this is achieved, the friction within the bearings is reduced since the impeller is neither floating nor sinking, either of which would place a radial load on the impeller bearings 219. In the preferred embodiment, helical axial impeller 213 may be made from a suitable plastic or nylon material having a mass which achieves neutral radial loading when immersed in water.
The impeller 213 has, located on one or several of its vanes, one or more indicator masses 217, preferably of a metal or magnetic material, which can be detected as they pass a proximity sensing device 205, as the impeller is turned by the flow of fluid. The proximity sensing device 205 can be a magnetic reed switch, a "hall effect," eddy current, or optical detector, all of which are well-known in the art Use of this type of proximity device allows the detection of fluid flow without penetrating the pressure vessel of the fluid line with shafts, wires, or other devices that move, require seals, and represent potential leaks. Resistance on the impeller is minimal or nonexistent, allowing detection at very low flow rates.
As fluid flow turns the impeller 213, the proximity sensing device 205 sends a pulsing electronic signal to the electronic circuit 203. Electronic counter 202 includes a clock that measures the duration between successive pulses. Memory 204 records this pulse duration and logic circuit 206 determines a specified time as a function of this pulse duration, e.g., 2x pulse duration, which, if exceeded, indicates a break in the flow of fluid. The electronic counter 202 of electronic circuit 203 counts only pulses that are no more than the specified length of time apart. As long as the duration of time between pulses is no more than the specified length of time, the counter 202 continues to log pulses. Whenever the specified length of time is exceeded, the counter 202 resets to zero. Thus, only continuous flow through the flood control valve is measured, so that normal operation of faucets, toilets, etc. will not release the valve but an abnormally long continuous flow win.
In a preferred embodiment, when a specific number of pulses (i.e. 200 pulses=5 gal.) is reached, the electronic circuit 203 closes switch 208 and activates a solenoid 207 having a plunger 243 within the solenoid 207. In one embodiment, the specific number of pulses is set manually. In another embodiment of the invention, the specific number of pulses is determined by the electronic circuit 203 during a learning mode. The learning mode is described in more detail with reference to FIG. 6. When current is applied to solenoid 207, the plunger 243 is forced upward thereby activating a trigger mechanism 239 which holds the cocking lever 237 in place. The solenoid 207 and corresponding plunger 243 operate under the well-known principles of electromagnetic induction and such devices are well-known in the art and commercially available. When the trigger 239 releases the cocking lever 237, the cocking lever 237 rotates axially about cam shaft 229 which is attached to the cocking lever 237, which in turn rotates a cam 225. The cocking lever 237 is rotated by means of a drive spring 233 which is held in a coiled position when the cocking lever 237 is in the cocked position. Upon release of the cocking lever 237 by the trigger mechanism 239, the drive spring 233 uncoils thereby rotating the cocking lever 237, the cam shaft 229 and the cam 225. At this point, the cam 225 is in the closed position.
The shut off mechanism can be either a gate valve, a rotating ball valve, or a ball check valve. The preferred shut off mechanism is the ball check valve type as shown in FIG. 2. This valve consists of a ball 223 placed in a ball chamber 220 which is in the flowpath of the fluid. The cam 225 controlled by shaft 229 and cocking lever 237 holds the ball 223 out of a seat 224. The seat 224 and cam 225 are downstream from the ball 223. When the cam 225 is rotated to the position which releases the ball 223, the ball 223 moves into the seat 224, shutting off all fluid flow through the flood control valve. A ball spring 218 can be used to ensure seating of the ball 223 at very low flow rates. This allows shutting down of fluid flow even from a pinhole leak.
The outlet 227 remains in the closed position until the cocking lever 237 is manually placed in the cocked position and fluid flow is restored. As the cocking lever 237 is moved to the cocked position, the cam 225 pushes the ball 223 out of its seat 224 to the open position. Longitudinal movement of the ball 223 in and out of the seat 224 is guaranteed by three ball guide ribs 221, equally placed around the ball chamber 220. Spring loading of the cocking lever 237 causes it to move to the closed position when it is released by triggering mechanism 239. Packing seal 231, or otherwise known as stem packing, is preferably used around the cam shaft, since it penetrates the liquid pressure chamber. Packing seal 231 ensures a water-tight seal so that leaks in the flood control valve 200 are prevented.
The electronic circuit 203 which counts the rotations of helical axial impeller 213, is of simple design which may be implemented by one of ordinary skill in the electronic circuitry field. In the preferred embodiment, electronic circuit 203 is an application specific integrated circuit (ASIC) chip which is compact in size and possesses low power requirements. The electronic counter 202, memory 204 and switch 208 of electronic circuit 203 may be standard components which are well-known in the art. Logic circuit 206 of electronic circuit 203 is also of relatively simple design and in one embodiment, may be a comparator which compares pulse signals and makes a determination as a result of the comparison. Such a logic circuit may be implemented by one of ordinary skill in the electronic circuitry art.
The power to drive the electronic circuitry 203 and the solenoid 207 may be provided by solar cell charged batteries; a power supply transformer plugged into a wall outlet in which the power supply drives the circuit board and keeps a backup battery charged; or a long-life battery pack 235, preferably of the lithium type, as shown in FIG. 2, that drives the circuit for three to five years, or more, and if available, with a low battery aural warning. The long life battery pack 235 with a low power drain electronic circuit is the preferred power source.
Optionally, as shown in FIG. 2, the flood control valve 200 may also include one or more permanent magnets 245 attached to axial impeller 213. When the axial impeller 213 begins to rotate, the permanent magnets 245 successively pass a coil generator 247, thereby inducing current to flow in the coil of the coil generator 247. As the axial impeller 213 spins faster, the induced current increases. This current may be used to charge the long-life battery pack 235.
A top view of flood control valve 200 is shown in FIG. 3. From FIG. 3 one can see the relative positions of cam 225 and ball 223 in their open and closed positions.
FIG. 4 shows a LCD display 400 which may be utilized to indicate the maximum volume of continuous fluid flow, e.g., 12 gallons, at which point the flood control device 200 will shut off. Membrane push button switches 401, 403 allow the user to set the desired maximum volume allowed before the valve will shut off flow, by scrolling up or down. In the preferred embodiment, to conserve energy, the display is normally off, and is activated by pushing one of the membrane push buttons 401, 403. After 20 seconds, the display turns off. The LCD display 400 along with corresponding membrane switches 401, 403, may be coupled to electronic circuit 203 (FIG. 2) of flood control device 200, so that a preset volume limit may be adjusted and stored into electronic circuit 203. Additionally, the LCD display 400 may provide a bypass setting in which the flood control device 200 may be bypassed altogether when it is desired or necessary to continuously consume a large volume of water, e.g., filling a swimming pool. In the bypass mode, the flood control device 200 may be bypassed through a bypass pipe (not shown) or simply never trigger the shut-off mechanism to shut-off fluid flow. Such LCD displays are well-known in the art and are commercially available. Similarly, membrane push button switches 401 and 403 are also well-known in the art and are commercially available. The LCD may also include a leaning mode push button 406. The learning mode push button 406 may be used to enter and exit a learning mode. During the learning mode, the electronic circuit 203 monitors volume flow through the flood control device 200, and stores information concerning the maximum volume which flowed through the valve between flow stopped conditions. The maximum volume detected during the learning mode is used by the flood control device 200 in a standard mode to determine when too much liquid has flowed through the flood control device 200. This feature is described in more detail below with reference to FIG. 6.
FIG. 5 shows another schematic diagram of the flood control valve of the present invention. Flood control valve 500 includes an inlet 501 which receives fluid from a water source external to the house or building being protected, e.g., a water main. A counter wheel 503, located within flood control valve 500, rotates a specified number of times for a given volume of fluid flowing into inlet 501. A counter 505, coupled to counter wheel 503, measures the volume of fluid, e.g., gallons, continuously flowing through the valve 500 by counting the number of rotations of counter wheel 503. The counter 505 may be a mechanical or electronic counter either of which are well-known in the art. A controller 507, coupled to the counter 505, monitors the counter 505 and when a preset volume of fluid has been measured, the controller 507 will activate a gate driver 513 to close a gate 515, shutting off the outlet 517. If the fluid flow stops before the preset volume limit is reached, the counter 505 resets to zero. Therefore, only a continuous flow of fluid which reaches the preset volume will be detected as a break, leak, or opening in the pipes or faucet.
The controller 507 may be of mechanical design which advances a mechanical trigger which in turn activates the gate driver 513 when the preset volume of fluid has been reached. Alternatively, the controller 507 may be an electronic circuit which electronically activates the gate driver 513 when the preset volume of fluid has been reached. The gate driver 513 may alternatively be of mechanical design, such as a spring-loaded type which releases shut-off gate 515 when activated by the controller 505. However, it should be understood that the counter wheel 503, counter 505, controller 507, gate driver 513 and gate 515 are not limited to the above descriptions thereof which are merely exemplary. Other embodiments of the components above will be readily apparent to those of ordinary skill in the art and are within the scope of the present invention.
The flood control valve 500 also includes a reset button 511, coupled to controller 507, which will open the gate 515 and reset the counter 505 to a value of zero. The flood control valve 500 also includes a bypass pipe 519 through which fluid flow will be directed upon activation of a bypass switch 509. In the bypass mode, flood control valve 500 simply becomes a connecting valve or pipe through which fluid may flow.
As mentioned above, one advantageous aspect of the present invention includes a learning mode for the flood control device. FIG. 6 is a flow chart illustrating one embodiment of this learning process. The process is described herein as applied to the valve of FIGS. 2-4 but the same principles may be applied to the valves of FIGS. 7A through 9D as well. Referring now to FIG. 6, at a state 550, the electronic circuit 203 receives a request to enter the learning mode. Typically, the request to enter the leaning mode is initiated by the user pressing the learning mode button 406. Moving to a state 552, the learning circuit 203 sets two variables NEW-- COUNT and MAXIMUM-- GALLONS equal to zero in preparation for recording the maximum volume flow through the flood control device 200 between flow stopped conditions. For each period of fluid flow, the variable NEW-- COUNT represents the volume of fluid that passed through the flood control device 200 during that interval. The variable NEW-- COUNT is reinitialized to zero at or prior to the beginning of each continuous flow interval. The electronic circuit 203 uses the variable MAXIMUM-- GALLONS to define the maximum continuous fluid flow through the flood control device 200 during the learning process. The variable MAXMUM-- GALLONS will thus be equal to the highest value of NEW-- COUNT which was obtained while the valve was in learning mode.
Next, at a state 554, the electronic circuit 203 increments NEW-- COUNT for each gallon of water which flows through the valve until water flow stops. Moving to a decision state 556, the electronic circuit 203 evaluates whether the value of NEW-- COUNT is greater than the value of MAXIMUM-- GALLONS. If the variable NEW-- COUNT is less than the variable MAXIMUM-- GALLONS, the electronic circuit 203 proceeds to the decision state 560. Otherwise, if the variable NEW-- COUNT is greater than the variable MAXIMUM-- GALLONS, the electronic circuit 203 sets the variable MAXIMUM-- GALLONS equal to NEW-- COUNT at a state 558. During the first iteration of this loop, the value of NEW-- COUNT will be greater than the value of MAXIMUM-- GALLONS since the variable MAXIMUM-- GALLONS was set to zero in the state 554.
Referring again to decision state 560, if the variable NEW-- COUNT was not greater than the maximum value, or after setting the MAXIMUM-- GALLONS equal to NEW-- COUNT in state 558, the electronic circuit 203 determines whether the learning period has ended. In one embodiment of the invention, the learning period ends if the user pushes the learning button 406 a second time. In another embodiment, the learning period ends after a predetermined amount of time. In yet another embodiment of the invention, the length of the learning mode is input by the user through the use of the pushbuttons 401 and 403. It will be appreciated that the learning period could be of essentially any length, although it is preferable to allow sufficient time to observe normal high fluid usage periods. For many installations, 3-30 days is often suitable.
If the electronic circuit 203 determines that the learning period has not ended, at step 562 the electronic circuit 203 sets the variable NEW-- COUNT equal to zero in preparation for evaluating the next continuous volume flow of liquid and the electronic circuit 203 returns to a state 554 to continue recording and evaluating the maximum volume flow. Otherwise, if the end of the learning period is reached, at a state 564 the electronic circuit 203 optionally displays the new MAXIMUM-- GALLONS to the user via the LCD display 400. Next, at state 566, the electronic circuit 203 ends the learning mode, and the value of the variable MAXIMUM-- GALLONS is retained in memory.
During a standard mode of normal operation, the electronic circuit 203 uses the variable MAXIMUM-- GALLONS which was calculated in the learning mode in a manner analogous to the preset limit described above. In one embodiment of the invention, the electronic circuit 203 uses the volume of liquid represented by MAXIMUM-- GALLONS as the maximum amount of volume that can continuously flow through the flood control device 200 before the flood control device 200 shuts off the volume flow. In another embodiment of the invention, the flood control device uses the volume of liquid represented by MAXIMUM-- GALLONS to calculate a higher shut-off volume by multiplying the measured MAXIMUM-- GALLONS by a scaling factor of greater than 1. By using a higher volume of liquid as the shut-off event, a measure of fault tolerance is incorporated into the learning mode, if for some reason, the volume flow throughout the learning period was too low.
One embodiment of a flood control device 200 according to the present invention thus provides a learning mode which can monitor the maximum usage of the liquid flowing through the flood control device over a selected time period. The flood control device 200 uses this measurement to allow normal and everyday use of the liquid. However, if an excessive continuous volume flow in relation to the maximum volume flow is detected, the flood control device advantageously disables the flow.
FIG. 7A shows a purely mechanical implementation of a flood control valve 600. In accordance with the present invention, flood control valve 600 also operates on the principle of metering and measuring the volume of fluid in a continuous flow. A steady flow of fluid moves a trigger mechanism 619 toward a release mechanism 623 to release a shut off gate 633 when a preset maximum volume limit has been reached. If flow stops prior to the limit being reached, the trigger mechanism 619 is reset and made ready for the next flow cycle. The flood control valve 600 is designed to be installed on the main flow line to a residence or other building.
Operation of flood control valve 600 is started when fluid flows into inlet 601 and through a helical screw 603, located at the center of the valve 600, causing the helical screw 603 to rotate. For each rotation of the screw 603, a fixed volume of fluid moves through the valve. A screw shaft 605, driven by the helical screw 603, is connected to a coupling device 615 via a pair of 45° bevel gears 607, 609. As shown in FIGS. 7A and 7B, bevel gear 607 is connected to screw shaft 605 and bevel gear 609 is connected to a drive shaft 613 which drives coupling device 615. The coupling device 615 serves the function of advancing the trigger mechanism 619 during constant flow conditions and allowing it to reset once flow stops.
As shown in FIG. 7B, the coupling device 615 is coupled to drive shaft 613 by means of spring elements 653 which are connected to a pair of semi-circular "pads" 655, or contact pads 655, located within a "drum" formed within the output drive shaft 651. When water is flowing, the driving force imparted by the water turns the input drive shaft 613 and presses the contact pads 655 tightly against the driven drum surface of the output drive shaft 651. In this way, power is transferred across the coupling device 615 to advance the trigger mechanism 619 while compressing or "winding up" a spring element (not shown) attached to the output drive shaft 651 of the coupling device 615.
The trigger mechanism 619 is moved along a rotary belt 617 which moves as the output drive shaft 651 of coupling device 615 rotates. When the flow of water stops, the force pressing the contact pads 655 against the driven drum surface of output drive shaft 651 goes away and the spring (not shown) which is attached to the output drive shaft 651 begins to unwind. In this way, the output drive shaft 651 begins to rotate in the opposite direction and the trigger mechanism 619 returns to its original position. Very little resistance is offered by the contact pads 655 when the drum is rotating in the "unwinding" direction because this motion tends to compress the spring elements 653 on which the contact pads 655 are mounted.
The shut-off gate 633 is located perpendicular to the flow at the entrance, or inlet, to the valve 600. It extends above and below the flow with flow passing through a hole in its center. The gate 633 is spring loaded by means of spring 629 and held in a cocked position by a releasing mechanism. The releasing mechanism consists of a rack 631 and pinion 625 with the rectangular cross section rack 631 spring loaded, by means of spring 621, as the latch in the shut-off gate 633. The pinion 625 has a lever which, when actuated by the linear motion of the trigger 619, will move rack 631, thereby releasing the shut-off gate 633.
As shown in FIGS. 8A and 8B, the pinion 625 is attached to a moveable structure 623 which may be adjusted linearly to change the maximum allowable flow setting. The pinion 625 and its structure 623 may be moved to an off position which raises the pinion above the rack preventing their contact and thus disengaging the triggering mechanism.
When the maximum flow limit has been exceeded, the shut-off gate 633 is released and flow is stopped. In its latched position, a portion of the shut-off gate 633 extends through the flow control valve casing. The downward motion of the shut-off gate 633 exposes a greater amount of the shut-off gate 633, equal to the vertical displacement of the gate 633. Resetting the gate 633 is simply accomplished by pressing up on the shut-off gate 633 and returning it to its latched position.
Referring to FIG. 9A, another embodiment of a flood control valve 800 of the present invention is shown. Similar to the flood control valve 600 of FIGS. 7A and 7B, the flood control valve 800 operates on the principle of metering and measuring the volume of fluid in a continuous flow. Operation of flood control valve 800 is started when fluid flows into inlet 801, through a helical screw 803, located at the center of the valve 800, causing the helical screw 803 to rotate. For each rotation of the screw 803, a fixed volume of fluid moves through the valve. A screw shaft 805, driven by the helical screw 803, is coupled to a rotation gear 813 via a pair of 45 degree bevel gears 807, 809. As shown in FIG. 9A, bevel gear 807 is connected to screw shaft 805 and bevel gear 809 is connected to a drive shaft 811 which drives the rotation gear 813 by means of a second 45 degree bevel gear 812 (FIG. 9B) which is coupled to rotation gear 813.
Referring to FIG. 9B, as fluid flow causes rotation gear 813 to rotate, a coupling device 815 begins rotating as a result of the movement of rotation gear 813. The coupling device 815 is similar to the coupling device 615 of FIGS. 7A and 7B which is described above and need not be further described here. As coupling device 815 begins rotating, drive shaft 817, coupled to coupling device 815 also begins rotating thereby rotating a worm gear 819 which is coupled to a drive gear 821. As shown in FIG. 9B, as worm gear 819 begins rotating, drive gear 821 is caused to rotate clockwise, thereby moving a usage indicator 823. Below drive gear 821 a triggering gear 825 is located on the same radial axis as drive gear 821.
Referring to FIG. 9C, as drive gear 821 rotates clockwise, a moving latch 827 moves toward a trigger point 824 which is attached to triggering gear 825. When the moving latch 827 contacts the triggering point 824, triggering gear 825 also begins rotating clockwise thereby rotating a spring loaded trigger arm 835 which is mechanically coupled to triggering gear 825 in gear like fashion. When spring loaded trigger arm 835 is moved by triggering gear 825 a gate latch 839 is moved toward the right thereby releasing a gate 843 to close the inlet 801 of the flood control valve 800. If fluid flow stops before the preset limit has been reached, coupling device 815 will disengage drive shaft 817 and a torsional spring 837 will begin rotating the drive gear 821 counterclockwise thereby resetting the usage indicator 823 to its original position. As explained above coupling device 815 is similar to the coupling device 615 of FIGS. 7A and 7B. Coupling device 815 includes spring elements, contact pads, and an output drive shaft which is similar to those elements as described in relation to coupling device 615 above.
As shown in FIGS. 9A and 9C, the flood control device 800 also includes a setting knob 831 which may be pulled up to set the knob to disengage the flood control valve and thereby operate the valve in a bypass mode. By pressing down on setting knob 831, the setting knob 831 may be turned to set the maximum volume at which the flood control valve will shut off fluid flow. FIG. 9D shows a top view of a gauge design by which a user can set the setting knob 831 to a desired volume setting.
While the above detailed description has shown, described, and pointed out fundamental novel features of the invention as applied to various embodiments, it will be understood that various omissions and substitutions and changes in the form and details of the system illustrated may be made by those skilled in the art, without departing from the intent of the invention. The scope of the invention is indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.