Abstract:
The flowmeter of the present invention is primarily used in swimming pools and is configured to deactivate a swimming pool pump when the drain in the swimming pool is blocked or covered. Swimming pool drains are often blocked or covered by the body of a swimmer. When the drain is blocked or covered, the pump creates substantial suction force that entraps the body of a swimmer against the drain. By deactivating the pump when the drain is blocked or covered, the flowmeter of the present invention serves as a safety vacuum release system that prevents entrapment of a person by the drain of the swimming pool.

Description:
BACKGROUND OF INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention is related to an apparatus and method of measuring the flow rate of water extracted from a swimming pool and utilizing said measurement to control a swimming pool pump so as to prevent the entrapment of a person by the drain of the swimming pool and to optimize the use of the pump so that the swimming pool is maintained clean without wasting energy. 
         [0003]    2. Description of Prior Art swimming pool or simply a pool is a container filled with water intended for swimming or water-based recreation. A swimming pool can be built of various sizes and either above or in the ground. A swimming pool may be for public or private use. Private swimming pools are mostly built in private residences and used for recreation and relaxation by adults, children, and even infants. Public pools are mostly built in hotels, schools, fitness centers, and parks. Public pools are mostly used for fitness, water sports, and training by people of all ages, including elderly and young children. 
         [0004]    Swimming pools present a significant risk of death and drowning, especially for young children and the elderly. In regions where private pools are common, drowning is typically a major cause of childhood fatalities. As a result, the design, construction, and maintenance of pools are fields that are highly regulated by federal, state, and local governments. 
         [0005]    Swimming pools are designed to be large containers of water with a drain, inlet connections, and a circulation system. The circulation system is driven by a large water pump that extracts water from the pool through the drain. The water that is extracted from the pool is passed through as debris collection trap and a skimmer to remove large debris such as leaves and branches. The water is then pumped back into the swimming pool through the inlet connections that are typically located around the interior wall of the pool. 
         [0006]    The drain in a swimming pool creates a significant suction caused by large volume of water being extracted from the pool through the drain by the pump. The suction can be strong enough to trap a person on the drain. When a person inadvertently places parts of their body in the vicinity of an active drain, a portion of their body may become entrapped by the chain. A drain that is completely blocked can develop a strong vacuum within a fraction of a second with suction pressure that may prevent a person entrapped by the drain to be able to break free, thus, leading to death by drowning. 
         [0007]    A drain in a large swimming pool is generally located at the bottom of the deepest section, may be 6 to 10 feet below the water surface. In smaller pools or spas, the drain is also positioned at the lowest point which may be only a few feet from the surface. Thus in the use of a smaller pool or spa, there is a considerably greater likelihood that the user will come into contact with the drain. 
         [0008]    The drains in residential swimming pools are typically small in diameter. The pumps used in pools are typically large horsepower pumps that can draw a vacuum as high as 29 inches of mercury. Thus it is possible that the body of a person, when positioned in close proximity to the drain, may be drawn down upon the surface of the drain cover to completely block the drain openings thus creating a strong vacuum that can entrap and drown a person in a few seconds. The suction pressure of this magnitude can prevent young people and some adults from pulling free from the suction of a drain that is completely blocked by the body or clothing of such person. Even if the person is able to pull free, bruises or welts may result. In at least one case, a child was drowned when his abdomen inadvertently covered and blocked the drain, whereby he was entrapped at the bottom of the pool and unable to break free. 
         [0009]    Body entrapment typically occurs when a part of a person&#39;s torso completely covers a drain. A limb entrapment refers to accidents in which a person&#39;s arm or leg is sucked into the drain of a pool. Disembowelment accidents occur where small children place their buttocks over a drain, completely covering the drain creating a seal. Injury occurs when the greatly increased suction acts to eviscerate the child when their lower intestines are sucked out of their body through their anus. 
         [0010]    Safety organizations, such as the United States Consumer Product Safety Commission (CPSC), the National Spa and Pool Institute (NPSI), and various governments have acknowledged the need for vacuum release systems that protect against swimming pool or spa drain entrapment. In fact, in 2008, the Federal Pool and Safety Act became effective and addresses this problem of body entrapment by swimming pool drains. 
         [0011]    To address this issue of body entrapment, suction entrapment avoidance fixtures have been developed that can be installed within the pipe of the circulation system to minimize the risk of suction entrapment injury. These suction entrapment avoidance fixtures can be very effective at releasing the suction developed under dangerous circumstances. However, all of said suction entrapment avoidance fixtures are designed to activate after suction has developed. In essence, the devices in the market are designed to eliminate any suction already developed by the entrapment of a swimmer. The inventor of the present invention is unable to identify prior art specifically designed to prevent any suction from developing. 
         [0012]    What is needed is a reliable and robust device that continuously monitors the specific parameters that can cause or exacerbate the development of dangerous suction force at the drain of a swimming pool. For example, the faster that water is extracted from the pool the greater the risk of a suction being developed. Thus, unless a safe, inexpensive, and easy method of preventing the development of dangerous suction at the drain of a swimming pool is created, the risk of people continuing to be injured or drown by entrapment at the drain of a swimming pool will persist. 
       SUMMARY OF THE INVENTION 
       [0013]    Accordingly, the present invention has been made in view of the above-mentioned disadvantages occurring in the prior art. The present invention is a swimming pool flowmeter with a rotor that rotates at a velocity that is proportional to the flow rate of water within the swimming pool drain pipe. The flow rate of the water in the drain pipe is then used to determine if the swimming pool pump must be shut-off so as to prevent and eliminate any entrapment of a body by the drain in the swimming pool. 
         [0014]    It is therefore a primary object of the present invention to detect the flow rate of the water within the drain pipe of a swimming pool. 
         [0015]    Another object of the present invention is to maintain the flow rate of the water within the drain pipe of a swimming pool within a predetermined range so as to prevent a vacuum or suction force at the drain with sufficient power to entrap a person underwater. 
         [0016]    Yet another object of the present invention is to provide a cessation of a suction force at the drain of a swimming pool immediately upon the drain becoming blocked or substantially covered. 
         [0017]    A yet further object of the present invention is to prevent the operation of the swimming pool pump when the flow rate within the drain pipe is below a predetermined range. 
         [0018]    Another object of the present invention is to maximize the efficiency of the water recirculation by keeping all the pipes fully filled with water even when the pump is turned off by means of the check valve function. 
         [0019]    Another object of the present invention is to monitor the water flow thru a see-through sight glass. 
         [0020]    The above objects and other features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail with reference to the accompanying drawings. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0021]    The accompanying drawings which are incorporated by reference herein and form part of the specification, illustrate various embodiments of the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. In the drawings, like reference numbers indicate identical or functional similar elements. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
           [0022]      FIG. 1  is a perspective view of the pool flowmeter of the present invention in its assembled state as it would be installed to the drain pipe of a swimming pool. 
           [0023]      FIG. 2  is an exploded view of the pool flowmeter of the present invention. 
           [0024]      FIGS. 3   a  and  3   b  show perspective views of the easing of the present invention. 
           [0025]      FIGS. 4   a  and  4   b  show perspective views of the front attachment of the present invention. 
           [0026]      FIG. 5   a  and  5   b  show perspective views of the back attachment of the present invention. 
           [0027]      FIGS. 6   a  and  6   b  show perspective views of the flapper of the present invention. 
           [0028]      FIG. 7  shows a perspective view of the rotor of the present invention. 
           [0029]      FIG. 9  is a cross sectional view of the pool flowmeter of the present invention installed to the drain pipe of a swimming pool. 
           [0030]      FIG. 10  is a block diagram illustrating the pool flowmeter of the present invention. 
           [0031]      FIG. 11  is a flowchart illustrating the functionality of the monitoring mechanism. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    Reference will now be made to the drawings in which various elements of the present invention will be given numerical designations and in which the invention will be discussed so as to enable one skilled in the an to make and use the present invention. 
         [0033]      FIG. 1  illustrates the functional elements that can be variously combined, to form different combinations that embody the present invention. The present invention comprises a pool flowmeter  100  with a casing  10 , a front attachment  20 , a back attachment  30 , a rotor  40 , a flow protector  50 , a control box  60 , and a display unit  70 . 
         [0034]    The casing  10  is cylindrical in shape having a front flange  11  and a back flange  12 . A ring  13  is centrally located within the casing  10  and held in place by a plurality of supports  14  that form an attachment between the casing  10  and the ring  13  as shown in  FIGS. 3   a  and  3   b.  Additionally, the top of the casing  10  has a platform  15  with a protrusion  16  as shown in  FIGS. 3   a  and  3   b,  and to which the control box  60  is attached. 
         [0035]    The front attachment  20  is annular in shape having a plurality of prongs  21  that protrude radially outward as shown  FIGS. 4   a  and  4   b.  Each prong  21  is adjacent to the first end  23  of the front attachment  20  and has a hole  22 , as shown in  FIGS. 4   a  and  4   b.  The back attachment  30  mirrors the front attachment  20  in size and shape. Thus, the back attachment  30  is also annular in shape having a plurality of prongs  31  that protrude radially outward as shown in  FIGS. 5   a  and  5   b.  Each prong  31  is adjacent to the first end  to the first end  33  of the back attachment and has a hole  32 , as shown in  FIGS. 4   a  and  4   b.  However, the front attachment  20  differs from the back attachment  30  in that it has a flow protector  50  inserted through the first end  23  as shown in  FIGS. 4   a  and  5   a.    
         [0036]    The flow protector  50  has a predominantly fiat disc  57  with a hinge  55  attached to a frame  51  that forms a seal seat  52 . It is preferred that the hinge  55  be located at the top portion of the flat disc  57  so that the bottom portion can swing, as shown in  FIGS. 6   a  and  6   b.  The flow protector  50  is configured with a flat disc  57  that swings on the hinge  55  off the seal seat  52  to allow forward flow of water. However, when the flow of the water ceases or reverses direction, the flat disc  57  swings back on to the seal seat  52  so as to block the reverse flow of water. 
         [0037]    In the preferred embodiment, the rotor  40  comprises a hub  41  with a shaft  42  that is coaxially extending outward from opposite sides of the hub  41 . In addition, a plurality of blades  45  are embeddedly fixed to the hub  41 , as shown in  FIG. 7 . It is preferred that the blades  45  be made out of plastic material with a piece of magnetic material embedded therein. Otherwise, the blades  45  can be made purely out of magnetic material. The pool flowmeter  100  of the present invention is configured for installation to a drain pipe  210  of a swimming pool  200 . The drain pipe  210  extends from a drain  230  to a pump  240  and back to the swimming pool  200 . The pool flowmeter  100  of the present invention is installed to the drain pipe  210  so that it may measure the flow of water being drawn by the pump  240  from the swimming pool  200 . Installation of the pool flowmeter  100  of the present invention is as follows: First, the drain pipe  210  is split, or cut at the desired location for the pool flowmeter  100 . Second, the front attachment  20  and the back attachment  30  are each attached with an adhesive to each cut end of the drain pipe  210  as shown in  FIG. 9 . Third, the shaft  42  of the rotor  40  is fitted into the ring  13  so that the rotor  40  is thereby free to rotate or to be displaced within the casing  10 . It is preferred that a bearing be used to facilitate rotation. With the rotor  40  in place, the casing  10  is placed in between the front attachment  20  and the back attachment  30  that are attached to the drain pipe  210 . Placement of the casing  10  is such that the front flange  11  abuts the front attachment  20  and the back flange  12  abuts the back attachment  30  as shown in  FIGS. 1 and 9 . Finally, a plurality of long bolts  29   a  are inserted through the holes  22  in the front attachment  20  and then through the holes  32  in the back attachment  30 . A nut  29   b  is then attached to each long bolt  29   a  so that the front attachment  20 , the back attachment  30 , and the casing  10  are held securely together as shown in  FIGS. 1 and 9 . The preferred embodiment of the present invention incorporates a rubber o-ring or gasket  99  between the front flange  11  and the front attachment  20  and between the back flange  12  and the back attachment  30 . The rubber o-ring or gasket creates a seal so as to prevent any water from leaking out of the drain pipe  210  or the pool flowmeter  100  of the present invention. 
         [0038]    Once the casing  10 , front attachment  20 , and back attachment  30  are properly installed to the drain pipe  210  of a swimming pool  200 , the pump  240  of the swimming pool  200  is activated to extract water from the swimming, pool  200  through the drain pipe  210 . Forces created by the water flowing through the drain pipe  210  cause the rotor  40  to rotate or to be displaced within the casing  10  and cause the flat disc  57  of the flow protector  50  to swing on the hinge  55  off the seal seat  52  to allow forward flow of the water. 
         [0039]    In essence, the water flowing within the drain pipe  210  from the drain  230  is intercepted by the blades  45  thus promoting the rotation or displacement of the rotor  44  The rate of rotation or displacement of the rotor  40  will be proportional to the flow rate of water in the drain pipe  210 . Thus, the greater the flow rate of the water in the drain pipe  210  the faster the rotor  40  rotates or displaces. 
         [0040]    A hall sensor  17  is placed inside the protrusion  16  in the platform  15  of the casing  10  as shown in G.  9 . When the rotor  40  is properly positioned in the casing  10  as shown in  FIG. 9 , the hall sensor  17  is directly above the blades  45  of the rotor  40 . Thus, the hail sensor  17  is able to sense the magnetic properties of the rotor  40  as it rotates or displaces directly underneath the hall sensor  17 . As the rotor  40  is rotated or displaced by the water flow within the drain pipe  210 , the hall sensor  17  detects the rate at which the rotor  40  is rotated or displaced. The hall sensor  17  then converts the rate of rotation or displacement of the rotor  40  into a corresponding signal  91  having a frequency corresponding to the rate of rotation of the rotor  40 . The rate of rotation or displacement of the rotor  40  is correlated to the flow rate of the water in the drain pipe  210  and communicated to a display unit  70  via cables. 
         [0041]    However, the rotor  40  only rotates or displaces when water flows within the drain pipe  210 . Water flows within the drain pipe  210  only when the pump  240  is activated to extract water from the swimming pool  200  through the drain  230 . Furthermore, the flow protector  50  has a spring  56  that pushes the flat disc  57  against the seal seat  52 . When the pump  240  is turned on, it has to be set with sufficient power output to create a minimum flow rate of water within the drain pipe  210  that overcomes the resistive force of the spring  56  so that the flat disc  57  swings on the hinge  55  and off the seal seat  52  to allow water to flow through. This ensures that any water flow within the drain pipe  210  exceeds a predetermined rate as set by the resistive force of the spring  56 . The flow protector  50  also ensures that water in the drain pipe  210  will not flow in the reverse direction. 
         [0042]    It is important that the water flow in the drain pipe  210  exceed the predetermined rate in the forward direction so as to preserve the accuracy and operating life of the pump  240  and of the pool flowmeter  100  of the present invention. Allowing the pump  240  or the pool flowmeter  100  to operate with low water flow can result in excessive wear and heat that cause damage. The damage is caused when the rotor  40  or the impeller in the pump  240  churn low volumes of water. This can increase the temperature of the water due to friction to the point that it flashes into vapor. The vapor can then interrupt the cooling of the pump  240  and pool flowmeter  100  causing excessive wear and heat. 
         [0043]    The flow rate of the water in the drain pipe  210  can drop outside the operating range when the drain  230  is blocked or covered. When this occurs, the blockage of the drain  230  limits or prevents the amount of water from the swimming pool from entering the drain pipe  210  resulting in a low water flow rate. But a dangerous situation arises when the drain  230  is blocked or covered by the body of a swimmer. Such results in the dangerous body entrapment issues previously discussed. When the body of a swimmer blocks or covers the drain  230 , a substantial suction force is created by the pump  240  as it tries to extract water from the swimming pool  200 . The suction force can often be great enough that the swimmer is unable to break free without injury or even death. Despite the source of the blockage, the pool flowmeter  100  of the present invention can detect such a potential danger by sensing the sudden drop in flow rate of the water in the drain pipe  210  while the pump  240  is running. When the flow rate drops below the acceptable operating levels, the pool flowmeter  100  of the present invention sends a corresponding signal to the display unit  70  and/or to the pump  240 . 
         [0044]    The pool flowmeter  100  of the present invention is configured with means of communicating with the pump  240 . The communication can be accomplished directly through a wire that is connected between the pool flowmeter  100  and the pump  240 . The communication can also be accomplished through a wireless communication such as Bluetooth, wifi, or a network between a first communication device  85  located within the pool flowmeter  100  and a second communication device  86  connected to the pump  240 . The pump  240  shuts off or deactivates immediately upon receiving said signal from the pool flowmeter  100  when the flow rate of the water in the drain pipe  210  is below a predetermined rate. Thus, when the flow rate of the water in the drain pipe  210  is below a predetermined rate, the pool flowmeter  100  sends a signal to the pump  240  to deactivate or shut off. 
         [0045]    The communication between the pool flowmeter  100  and the pump  240  takes place through a number of steps and components each of which are discussed below. The hall sensor  17  collects information of the rate of rotation or displacement of the rotor  40 . The hall sensor  17  then transmits a signal  91  to a data manager  82  located within the pool flowmeter  100 . The signal  91  correlates to the current rate of rotation or displacement of the rotor  40 . The data manager  82  is configured to receive said signal  91 , to convert it to the corresponding flow rate of the water in the drain pipe  210 , and to monitor the flow rate over time by processing multiple signals  91 . The data manager  82  can be implemented in software, hardware, or a combination thereof. In the preferred embodiment, the data manager  82  is implemented in software and stored in computer memory within the pool flowmeter  100 . 
         [0046]    The data manager  82  is preferably configured to maintain a database  82   a  of flow rate data which includes the flow rate information as well as any other desirable information. For example, the data manager can be configured to include the flow rate at particular times, the length of time that water has been flowing through the drain pipe  210  continuously, and/or the average flow rate over a particular time period. The data stored in the data manager  82  may include other desirable information not mentioned, herein without departing from the principles of the present invention. 
         [0047]    Referring to  FIG. 10 , the data manager  82  is configured to include a monitoring mechanism  83 . The functionality of the monitoring mechanism  83  is depicted in  FIG. 11 . As shown by blocks in the flowchart of  FIG. 11 , the monitoring mechanism  83  is configured to receive data from the hall sensor  17 , to convert it to flow rate data, and to compare the data with predefined preference data stored in a flow rate data storage unit  84 . Preference data, as used herein, is data that defines the preferred parameters indicating when to deactivate or shut-off the pump  240 . 
         [0048]    Once the monitoring mechanism  83  determines that the pump  240  needs to be deactivated or shut-oft, the data manager  82  is designed to communicate a message to the pump  240  via a network and communication devices  85  and  86 . The data manager  82  is designed to transmit the message as signal  92  to the first communication device  85  which communicates the message with a network  90  via signal  93 . The network  90  then communicates the message to the second communications device  86  via signal  94 . The second communication device  86  then communicates the message to a switch  89  via signal  95 . The switch  89  is configured to deactivate or shut-off the power to the pump  240  upon receiving signal  95 . 
         [0049]    Although the preferred embodiment utilizes a network  90  to communicate a notification message to the switch  89 , one ordinarily skilled in the art should realize that other configurations are possible. For example, various types of networks can be utilized or utilization of networks can be completely circumvented by configuring the first communication device  85  to communicate directly with the second communication device  86  through a wire or other wireless means. Any embodiment capable of communicating data between the data manager  82  and the switch  89  should be suitable for implementing the principles of the present invention. 
         [0050]    The determination by the monitoring mechanism  83  that the pump  240  needs to be deactivated or shut-off takes place through a number of steps each of which are discussed below. The monitoring mechanism  83  makes a determination that a potential blockage of the drain  230  may have occurred when the water flow rate in the drain pipe  210  drops below a predetermined rate. In essence, if the rate of rotation or displacement of the rotor  40  drops below a predetermined value, then the monitoring mechanism determines that a blockage of the drain  230  may have occurred. However, rather than sending the message to deactivate or shut-off the pump  240  immediately, it waits and continuously measures the water flow rate or the rate of displacement of the rotor for a first predetermined period of time. In the preferred embodiment, said first predetermined, period of time is half of one second. Thus, for half of one second after the water flow rate drops below a predetermined rate, the monitoring mechanism  83  receives and analyzes the data from the hall sensor  17  continuously. If the water flow rate remains below the predetermined rate for the entirety of the first predetermined period of time, then the monitoring mechanism  83  determines that the pump  240  must be deactivated or shut-off. 
         [0051]    Once the monitoring mechanism  83  determines that the pump  240  needs to be deactivated or shut-off, the switch  89  deactivates or shuts-off the power to the pump  240  by disconnecting the power source to the pump  240 . The switch  89  is then left in the deactivated position for a second predetermined period of time. In the preferred embodiment of the present invention, the second predetermined period of time is three minutes. Thus, when the monitoring mechanism  83  determines that the pump  240  must be deactivated or shut-off, the switch  89  is deactivated and is configured to remain deactivated for a period of three minutes. In other words, when the monitoring mechanism  83  determines that the pump  240  needs to be deactivated or shut-off, the switch  89  is killed or turned off for the duration of the second predetermined period of time, thus, inhibiting the pump  240  from being activated or turned on either automatically or manually. However, when the second predetermined period of time expires, the switch  89  is turned back on, thus, allowing the pump  240  to be capable of being activated or turned on. 
         [0052]    The switch  89  and the second communication device  86  are electrically connected to one another and remotely located from the flowmeter  100  inside a housing  110 . The switch  89  is also electrically connected to the power source of the pump  240 . Thus, when the switch  89  is in the activated position, then the power source is connected to the pump  240 . But, when the switch  89  is in the deactivated position, then the power source is disconnected from the pump  240 . In other words, when the switch  89  is activated, then the pump  240  is capable of being powered. On the other hand, when the switch  89  is deactivate, then the pump  240  is disconnected from the power source and is incapable of being powered. In the preferred embodiment of the present invention, the switch  89  is a mechanical relay switch. 
         [0053]    The display unit  70  comprises a digital display that is electrically connected to the data manager  82 . The display unit  70  is configured to display information related to the flow rate of the water inside the drain pipe  210  with alphanumeric characters. The display unit  70  is encapsulated within a display case  71 . The display case  71  has a clear window  72  through which the display unit  70  can be seen, in addition, the display case  71  has a stem  73  through which wires from the display unit  70  to the data manager  82  are passed. The lowermost section of the stem  73  has a plurality of pegs  74  that are attached to a base  75 . The attachment of the pegs  74  to the base  75  is such that allows the display case  71  to be angled within a 90 degree range, from an upright vertical position to a downward facing horizontal position. This allows the display unit.  70  to be flipped down when it is unused so as to protected from damage from the sunlight and other elements. Similarly, the display unit  70  can be flipped up to a vertical upright position so that its alphanumeric display can be seen and read by the user when needed. 
         [0054]    The base  75  is rotatably attached to the control box  60 , as shown in  FIGS. 1 and 2 . The rotatable attachment allows the display unit  70  to be rotated relative to the control box  60  so that it can be positioned in the most visible position for the user to read or see it with ease. A stopper  76  protrudes from the control box  60  so as to prevent, the display unit  70  from rotating a full 360 degrees. Allowing the display unit  70  to rotate beyond 360 degrees would promote the entanglement of the wires between the display unit  70  and the data manager  82 . 
         [0055]    In the preferred embodiment of the present invention, the casing  10  is manufactured out of a clear plastic material. The preferred use of a clear material allows the user visual access to the water flowing within the drain pipe  210 . 
         [0056]    Although the preferred embodiment utilizes a rotor  40  having blades  45  and that rotates, one ordinarily skilled in the art should realize that other configurations are possible. An alternative embodiment could utilize a pad against which the water flowing through the drain pipe  210  pushes. The pressure from the water flow then displaces said pad. The displacement of said pad is detected by the hall sensor  17  in the same manner that it detects the rotational displacement of the rotor  40  of the preferred embodiment. A second alternative embodiment could utilize a pressure sensing device such as a pilot tube that measures the pressure differential within the drain pipe  210  so that such measurements can be correlated to the flow rate of the water within the drain pipe  210 . 
         [0057]    It is understood that the described embodiment of the present invention is illustrative only, and that modifications thereof may occur to those skilled in the art. Accordingly, this invention is not to be regarded as limited to the embodiments disclosed, but to be limited only as defined by the appended claims therein.