An in-toilet leak detector is disclosed, as are communication systems for reporting toilet leaks. The leak detector comprises an inlet that receives water from the toilet's fill tube and diverts it through a flow tube. A capacitive sensor is located between the inlet and an opening of the flow tube from which water flows into the overflow tube of the toilet tank. A housing is connected to the flow tube and the inlet and contains a controller and other electronics, including one or more transceivers. The leak detector measures the duration of water flow and establishes an alert if the water flow is shorter or longer in duration than a calibrated normal duration. The transceivers connect the leak detector to a computer network, and leak alerts are communicated to a server or servers so that they can be forwarded directly to those responsible for fixing the toilets.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Generally speaking, the invention relates to water flow detection, and more specifically, to an in-toilet leak detector.

2. Description of Related Art

Wasting water has enormous practical, financial, and environmental consequences. Undetected leaks in plumbing fixtures, like toilets, are one of the most insidious sources of wasted water. Especially in a commercial establishment, like a hotel, a few leaking toilets can seriously increase water costs. Beyond mere wastage, a leak can be a harbinger of a larger problem that will require a larger repair effort and possibly cause more damage if it is not caught.

U.S. Pat. No. 6,802,084 to Ghertner et al. discloses a toilet tank leak detection and reporting system. The system uses a flow sensor placed in the toilet tank. The system senses water flow based on the resistance of the flowing water, and includes a timing module. If the water flows for a shorter or longer time than usual, the system activates an alarm. While an embodiment of this patent's leak detection system has been sold successfully for a number of years, there are certain drawbacks. For example, while the sensor is within the toilet, the electronics for the system are placed outside of the toilet bowl, leaving the leads for the contacts exposed.

SUMMARY OF THE INVENTION

One aspect of the invention relates to an in-toilet leak detector. The leak detector is constructed and arranged to remain entirely within a toilet tank. In the leak detector, an inlet is connected to the fill tube of the toilet tank and diverts water downwardly, through a flow tube that empties out into the overflow tube of the toilet tank, thus filling the toilet bowl. Within the leak detector between the inlet and the outlet opening of the flow tube is a sensor. In some embodiments, the sensor may be a capacitive sensor with one electrode along the interior of the flow pathway between the inlet and the flow tube and the other electrode positioned around the exterior of the flow tube. A housing is connected to the inlet and flow tube, and contains a controller for the leak detector, as well as one or more transceivers and other input-output components. When water flows into the tank after a flush, the leak detector detects the water flow and the controller times it. If the duration of water flow is over or under a calibrated time, an alert is established.

Another aspect of the invention relates to systems for reporting toilet leak alerts. The system comprises one or more leak detectors of the type described above, each of which has transceivers adapted to connect it wirelessly in or to a computer network. When leak alerts are established by the one or more leak detectors, they may be transmitted over a computer network, such as the Internet, to a server or servers that handle them. The alerts may be communicated via an e-mail or SMS gateway directly to individuals responsible for handling the maintenance of the leaking toilet.

Other aspects, features, and advantages of the invention will be set forth in the description that follows.

DETAILED DESCRIPTION

FIG. 1is a perspective view of a toilet10with the lid of the toilet tank12removed to show the placement of an in-toilet leak detector, generally indicated at14, according to one embodiment of the invention.FIG. 2is a top plan view illustrating the placement of the leak detector14in more detail.

As shown inFIGS. 1 and 2, the fill valve assembly16of the toilet is unmodified, and terminates in a fill tube18, through which water flows to fill the toilet bowl13. Instead of ending in a spigot that allows water to flow into the overflow tube20of the tank12, as it would in a typical toilet, the fill tube18attaches to the intake22of the leak detector14. Water flowing from the fill tube18is diverted through a flow tube24of the leak detector14, which is positioned over the overflow tube20of the tank12, and exits downwardly into the overflow tube20of the tank12. When water flows within the flow tube24of the leak detector14, it is detected by the leak detector14. The duration of the water flow during each flush of the toilet is used to determine whether or not there is a leak within the toilet.

FIG. 3is a side elevational view of the leak detector14in isolation. As shown inFIGS. 1-3, the leak detector14has a housing26, which contains the electronics and control elements for the leak detector14. In the illustrated embodiment, the housing26is elliptical in overall shape and has a relatively low profile. Of course, the shape of the housing26is not critical as long as the housing26has a relatively low profile and does not interfere with the lid of the toilet tank12or other components. Preferably, the housing26is made of a plastic or another water-resistant material polymeric material, like high-density polyethylene (HDPE), acrylonitrile-butadiene-styrene (ABS) plastic, and other such materials. Typically, the housing26has upper and lower halves28,30that are sealed with a rubber boot or gasket32. The rubber of the rubber boot or gasket32may be, for example, a thermoplastic elastomer. The degree to which the housing26is water-tight will vary from embodiment to embodiment; it is sufficient in most circumstances if the housing26resists moisture and splashes and can remain within the toilet tank12for a long period of time. The housing26has two buttons34,36and an indicator light38whose purpose will be explained in greater detail below. While buttons34,36are used in the illustrated embodiment, other types of controls may be used in other embodiments, including membrane switches.

In the illustrated embodiment, a depending clip40with a generally vertically-oriented slot is attached to the underside of the housing26. The clip40is sized and arranged to allow the leak detector14to clip on to the overflow tube20so that the flow tube24of the leak detector14empties into the overflow tube20, as shown inFIGS. 1 and 2.

FIG. 4is a partially sectional elevational view of the leak detector14, illustrating water flow in and through the leak detector14. As shown, the intake22has a barbed nipple42that receives and retains the fill tube18of the toilet10. Water from the fill tube18enters the intake22and passes through a metal block44, which diverts it downward, through and ultimately out of the flow tube24to fill the toilet bowl13.

As shown inFIG. 3, a conductive metal ring or band46is wrapped around the exterior of the flow tube24toward its bottom. The metal block44and the metal ring46are arranged so that they are not in direct electrical contact with one another—the metal block44is on the inside of the flow tube24and the metal ring46is on the outside. Thus, the metal ring46, which may be copper or brass, never directly contacts the water flowing through the flow tube24. However, as they are positioned, the two parts44,46are separated by a dielectric—air and plastic when no water is flowing, and a combination of air, water, and plastic when water is flowing. Therefore, the two parts44,46have a variable capacitance, depending on whether or not water is flowing. In order to determine whether water is flowing, the leak detector14measures the capacitance between the metal block44and the metal ring46. Of course, the metal block44and metal ring46are not the only components that may be used to sense capacitance. For example, a brass tube may be used along the interior of the flow tube24instead of the metal block44. Additionally, a brass tube may extend from the bottom of the metal block44to a point just above the metal band46, and the water may drain through that tube, instead of into the flow tube24itself. Additionally, as can be seen inFIG. 4, the flow tube24or metal block44includes a drain hole45that primarily serves to prevent a vacuum from forming within the flow tube24.

The metal ring46is typically electrically insulated along its exterior, so that water droplets and splashes will not cause an electrical short or a false reading. This can be done quickly and inexpensively by shrink-wrapping the metal ring46with an appropriate plastic. However, in other embodiments, the metal ring46could be overmolded, so that it is covered with a thicker layer of molded plastic or rubber and is not visible from the exterior of the leak detector14. Any exposed surfaces of the metal block44that might cause errant readings may also be coated or passivated in any known manner.

While the illustrated embodiment emphasizes measurement of capacitance as an indicator of flow, as those of skill in the art will understand, embodiments of the invention may measure any characteristic of an electric circuit that includes the metal block44and the metal ring46and depends directly or indirectly on whether water is flowing between the two electrodes44,46. This may include measurements of the time-dependent characteristics of resistor-capacitor (RC), inductor-capacitor (LC) or resistor-inductor-capacitor (RLC) circuits that include the metal block44and the metal ring46.

As was described briefly above, the housing26contains the control electronics for the leak detector14. Typically, one or more printed circuit boards with the control electronics would be mounted within the housing.FIG. 5is a schematic diagram of the control electronics, generally indicated at100.

The control electronics100include a central unit, such as a processor102. In other embodiments, the central unit may be an application-specific integrated circuit or any other type of integrated circuit capable of performing the functions described here. As one example, the processor102may be a PIC18F46J50 microprocessor from Microchip Technology, Inc. of Chandler, Ariz., U.S.A.

Coupled to the processor102are a number of components: a memory104, a read-only memory (ROM)106, one or more transceivers108,110, and, optionally, a speaker114. As shown, the processor102is connected to the metal block44and metal band46through a sensor circuit116; to the indicator light38, which may comprise one or more light-emitting diodes (LEDs)118,120, each of a different color; and to the two buttons34,36through appropriate circuitry. A power source112is also provided. The power source112would typically be a battery.

The memory104would typically be a FLASH memory, or any other type of memory that can be used to temporarily store instructions and data. The ROM106, which may be an electrically eraseable programmable ROM (an EEPROM), typically contains software for the processor102that enables it to execute the tasks necessary to detect leaks using the components of the leak detector14.

The control electronics100may include any number of transceivers108,110, each of which would typically be a complete radio system for communicating via a particular radio communication protocol. These transceivers108,110would allow the leak detector14to communicate with other information systems, as will be described below in more detail. Communication protocols that may be used by the leak detector14include traditional WiFi (IEEE 802.11a/b/g/n), Bluetooth, and other protocols like ZigBee or MiWi point-to-point communication protocols (IEEE 802.15.4). ZigBee and MiWi may be particularly suitable in some embodiments, as they are low-power protocols. With point-to-point communication protocols, longer-range communications are handled through “mesh networks” of similar devices. In some cases, a leak detector14may also have a conventional input-output data port, such as a universal serial bus (USB) port, so that it can be connected directly to a computer by a hardwired connection for diagnostic or other purposes. Of course, if such a port in the housing26is provided, it would typically be well covered by a waterproof cover. In addition to the transceivers108,110, the indicator light38with its LEDs118,120, the speaker114(if one is present) and the buttons34,36are used for input and output.

The functions of the processor102are detailed with respect toFIG. 6, a high-level flow diagram of a method, generally indicated at200, for detecting leaks using the leak detector14. Method200begins at task202and continues with task204. In task204, a decision task, the processor102determines whether the leak detector14has been calibrated.

As was described briefly above, the leak detector14uses a capacitance measurement to determine when water is flowing into the toilet12. If a water flow is detected, that water flow is timed. If the flow is too short or too long, that indicates that a leak is present. In order to have a baseline for comparison, if a calibration has not been set (task204: NO), the user can place the leak detector14in a calibration mode and then flush the toilet12. Method200then continues with task206, the leak detector14times the duration of the flush, and that duration is stored in task208. In some embodiments, calibration mode may require several flushes, and the duration that is stored may be the median, mean, or some other statistic describing what the baseline duration of flow should be. Of course, collecting this data may not be necessary in all embodiments; instead, the leak detector14may be pre-programmed with a baseline flush duration, or the user may be able to select a baseline flow duration depending on the model of the toilet. If calibration data exists (task204: YES), control of method200passes to task210.

While task204is shown at the beginning of method200for clarity in illustration and explanation, in actuality, the leak detector14may be calibrated or recalibrated at any time by placing the detector14into calibration mode. This would typically be done by pressing one of the buttons34,36, or a sequence of the buttons34,36. The processor102may light one of the LEDs118,120to acknowledge that the leak detector14is in calibration mode. Method200continues with task210.

Task210, another decision task, asks whether setup is necessary. In addition to calibration for leak detection, the leak detector14is most advantageously configured to communicate through a computer network to one or more computers. If the setup necessary to allow that communication has not been done (task210: NO), method200continues with task212, and that setup is performed.

In task212, setup options that may need to be configured include the internet protocol (IP) address of the leak detector14, the IP address of its gateway or repeater, point-to-point protocol options, and other conventional network parameters, depending on the protocols by which the leak detector14is to communicate. This may be done either using the buttons34,36on the housing26itself, or through a communication interface provided by the network (as will be described below). Like the calibration of task204, the setup of task210may be performed, or reset, at any time using the buttons34,36on the housing. For example, the user may simultaneously depress both buttons34,36to cause the leak detector14to reset its network settings. In one case, if the leak detector14is using Bluetooth, depressing both buttons may cause the leak detector14to become discoverable for Bluetooth pairing, and task212may involve Bluetooth pairing. Method200continues with task214.

Once the leak detector is interfaced and calibrated, it may enter a low-power “sleep” mode to minimize power consumption until a toilet flush is detected. In addition to flushes, depressing a specified button36,38may bring the leak detector14out of sleep mode and cause it to display its status via the indicator light38. When a toilet flush is detected (task214: YES), method200continues with task216and the processor102times the duration of water flow. If no flush is detected (task214: NO), method200continues with task250and returns.

After task216, method200continues with task218, another decision task. In task218, if the flow is shorter than the calibrated baseline, method200continues with task220and a short flow alarm is established. If there is no short flow (task218: NO), method200continues with task222, in which the processor102determines whether or not the flow was too long. If the flow was too long (task222: YES), a long flow alert is established in task224. If the flow was not too long, and thus, the flush was normal (task222: NO), method200returns at task250.

Thus, the leak detector14is capable of distinguishing two different leak conditions: flow that is too short, and flow that is too long. The conditions described above are simplified. In some embodiments, the leak detector14may follow the same basic method as described above. However, instead of establishing an alarm based on the duration of a single flush, the leak detector14may establish an alarm only if X number of flushes of the last Y total flushes were over or under the baseline water flow time. For example, an alarm may only be established if three out of the last12flushes consistently showed a long duration flow or a short duration flow. In that case, the method would include the additional step of storing the flow time after task216, and the decision tasks218and222would be based on the last Y total flushes.

By being capable of detecting two different types of errant flow conditions, the leak detector14can also assist the user in diagnosing the root cause of the leak. For example, a short duration flow can indicate a leaking flapper valve. A long duration flow can indicate, for example, a bad flush valve, a bad fill valve, or a float arm that is stuck in place, to name a few possible causes. In some cases, the leak detector14may also be configured and programmed to report a certain level of inconsistency in flushes (e.g., a certain number of short flushes and a certain number of long flushes in the same period or window). Additionally, although method200asks whether the flush duration is greater or less than a baseline calibrated duration, other embodiments may use other metrics. For example, method200may instead ask whether the duration of flow is more than one or two standard deviations greater or less than a calibrated flow time or a calibrated mean flow time. If this is done, separate alarms may be established depending on the severity of the leak. Other statistics and metrics will be apparent to those of skill in the art.

Tasks220and224of method200involve establishing an alert that there is either a long flow or a short flow leak. In embodiments of the invention, establishing an alert can involve different types of actions, depending on how the leak detector14is configured. In many or most embodiments, establishing an alert can refer to creating a visual alarm using the LEDs118,120, typically with a different light pattern to distinguish between different types of alerts. Establishing an alert can also refer to using a speaker114, if one is installed, to create an auditory alert. However, it may be more effective simply to report the leak condition to a responsible individual, and embodiments of the invention can be configured to do just that.

FIG. 7is an illustration of a broader system, generally indicated at300, in which one or several leak detectors14may be networked together to report alerts and, more generally, to be accessed and controlled remotely. Depending on the types of transceivers108,110installed in the leak detectors14, the system300may use a variety of protocols (e.g., Wifi, ZigBee, MiWi, Bluetooth) for communication.FIG. 7actually illustrates communication schemes for two different kinds of communication protocols.

In a first communication scheme, as shown by the solid arrows302,304,306,308, each of the leak detectors14may have its own IP address and may communicate directly with a router or gateway320. This would typically be the case if the communication protocol is WiFi.

A second communication scheme is shown by the dotted-line arrows310,312,314,316,318,319. In this scheme, a point-to-point communication protocol like MiWi or ZigBee is used. One or more of the leak detectors14may serve as a repeater, or the leak detectors14may be connected together in a mesh network to relay signals from one leak detector14to the next. However, the individual leak detectors14in this scheme typically would not have IP addresses of their own. Instead, one or more of the leak detectors14communicates with a repeater323that does have an IP address, or another type of address, identifier, or credential needed to communicate with an outside network. As shown inFIG. 7, the repeater323communicates with the router or gateway320.

In either communication scheme, the router or gateway320communicates with a communication network321, such as the Internet, although in some embodiments, the communication network321may be a private network that uses transmission control protocol/internet protocol (TCP/IP) and other common Internet protocols but does not interface with the broader Internet, or does so only selectively through a firewall.

The system that receives and processes signals from the leak detectors14may differ from embodiment to embodiment. In the illustrated embodiment, alerts and signals from the leak detectors14are sent through an e-mail or simple message service (SMS; text message) gateway so that they can be sent as e-mails or SMS text messages to a device324monitored by a responsible individual326, group of individuals, or department, such as a maintenance department. Thus, if a particular leak detector14creates an alert because of a leak, that alert can be sent, in e-mail or SMS form, directly to the individual responsible for fixing it. Of course, e-mail and SMS are only two examples of communication methods that may be used; in other embodiments, different forms of communication may be used.

In some embodiments, alerts and other data from the leak detectors14may also be sent to a work tracking system328that allows the individual326, or the organization for which he or she works, to track the status of the various alerts that are received, to schedule particular workers to repair particular toilets, and to track the status of those repair jobs. A work tracking system328would typically be a server, such as a Web server, that provides an interface individuals and organizations can use, typically through the communication network322. In addition to its work tracking functions, the work tracker328may allow broader data logging and analysis functions. For example, water consumption data may be calculated from the flow duration data collected by the leak detectors14, and the system328may be able to provide aggregate water consumption data for a toilet10or group of toilets10.

The system300also allows individuals326to access the individual leak detectors14for configuration and diagnostic purposes. In that case, the individual processors102of the leak detectors14may be configured to act as Web servers that use a protocol like hypertext transfer protocol (HTTP) to provide an online interface that can be used to configure the leak detectors14. In some embodiments, the systems322,328may be used to configure several leak detectors14at once. For example, if several toilets10are of the same model and are in similar locations in the same building, it may not be necessary to configure the leak detectors14individually. Instead, an individual326may provide configuration information, including a baseline flow duration, for several leak detectors14at once.

While the above description focuses on detection of leaks, the leak detectors14may be used for broader water conservation purposes irrespective of whether or not a leak exists. For example, instead of detecting leaks, the flow timing capabilities of a leak detector14may be used to determine, quantitatively or qualitatively, how much water a particular toilet10is using. In that case, if the goal is reducing water consumption, the leak detector14could establish an alert if a toilet's consumption is over a threshold level.

While the invention has been described with respect to certain embodiments, the description is intended to be exemplary, rather than limiting. Modifications and changes may be made within the scope of the invention, which is determined by the appended claims.