Patent Abstract:
A safety device for use in a fluid transfer and/or circulation system of the type which uses a pump to draw water from a reservoir through one or more intake lines each extending from an open end at the reservoir to the pump intake. The safety device connects to the fluid transfer/circulation system and includes a sensor, a triggering mechanism, and a vacuum breaker. When the pump is operating, the sensor monitors one or more conditions of the system. When one or more of the monitored conditions deviates outside of a normal operational range, as a result of an obstruction of any one or more of the open ends of the intake lines, the triggering mechanism triggers the vacuum breaker to eliminate negative pressure in the system by introducing air from atmosphere into the intake lines, thereby removing suction at the open ends of the intake lines. The safety device may further activate warning devices including audible and visible alarms to indicate that the system has been deactivated.

Full Description:
This application is a continuation-in-part application based on patent application Ser. No. 09/357,036 filed on Jul. 20, 1999now U.S. Pat. No. 6,171,073, which was a continuation-in-part application based on previously filed patent application Ser. No. 08/901,849 filed on Jul. 28, 1997, now U.S. Pat. No. 5,947,700 granted on Sep. 7, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a safety device for fluid transfer systems and, more particularly, to a safety device for eliminating vacuum pressure in the system in response to an obstruction of one or more open intake lines, thereby removing a suction force at the open ends of intake lines in the system. 
     2. Description of the Related Art 
     Drowning is the second leading cause of unintentional injury related deaths to children 14 years old and younger. Most drownings occur in swimming pools and hot tubs, and in many incidents (involving both adults and children) the main culprit is the water circulation system. In a typical pool, the circulation system includes a main drain suction intake line and at least one skimmer suction intake line, both of which feed into a main intake line that leads to a pump. A return line directs water flow back into the pool. 
     Most people do not feel threatened by a pool&#39;s circulation system, including the main drain intake on the bottom of the pool, and the skimmer boxes along the side of the pool. However, if a person comes into contact with any of the suction intake lines of the circulation system (at either the main drain or skimmer intakes) causing the suction intake to be covered or obstructed, the immense suction of the pump forms an instant seal between the open end of the suction intake line and the person&#39;s skin or clothing. This may result if a person places their hand over the open end of the suction intake line or, as often happens with children, a person sits down on the suction intake. In either case, the force needed to pull them free often exceeds 800 pounds. Moreover, the injuries which are inflicted in a matter of a few seconds are horrific, usually permanent and sometimes fatal. If a person, especially a child, is sucked onto the main drain suction intake on the bottom of the pool, they usually drown. 
     The only way to free a person sucked onto the intake of a circulation system of this type, without causing severe injury or dismemberment, is to eliminate the vacuum (i.e. negative pressure) in the intake between the entrapped person and the pump, to thereby remove the intense suction force at the open end of the intake line. It is helpful to disable the source of the suction by interrupting power to the pump. However, even if the pump is shut down, a vacuum can remain in the intake side of the system between the pump and the obstructed end of the suction intake line. Sometimes, a victim could still be freed with some assistance, although serious injury or death may result. Ideally, if the vacuum in the intake line can be quickly eliminated after a victim becomes stuck to the intake, the victim will be freed with little or no assistance and without injury. 
     In the most instances wherein a victim becomes stuck to an intake of a circulation system, typically in a swimming pool or hot tub, rescuers fail to realize the need to immediately shut off the pump. Instead, in a panic, people tend to go the victim and attempt prying them free. In the rare instance this is successful, the injuries are often severe and permanent. Of course, there are also instances wherein there are no other people present to come to the victim&#39;s rescue. These situations are almost always fatal. 
     The imminent danger presented by fluid circulation systems of the type commonly found in swimming pools, hot tubs, and the like has been longstanding in the art. Little, if any attention has been given to providing a satisfactory solution to this deadly problem that exists in every swimming pool, hot tub, as well as all other fluid circulation systems wherein a fluid is drawn from a reservoir through one or more suction intakes by a pump. Accordingly, there has been and there remains an urgent need to provide an effective means of preventing death and injury to those otherwise unfortunate victims who become unexpectedly attached (i.e., entrapped) by suction to the intake of a fluid circulation system. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a device for use in a fluid transfer. and/or circulation system of the type including at least one pump which draws water from a reservoir through one or more intake lines each extending from an open end at the reservoir to an intake of the pump. The primary purpose of the invention is to save lives and property by alleviating the intense vacuum that builds when one or more of the suction intake ports of a pump assisted fluid circulation system becomes obstructed. The safety device includes means for sensing one or more operating conditions in the fluid transfer/circulation system (e.g., negative pressure levels, positive pressure levels, water flow rate, pump voltage and/or amperage) and means for analyzing the sensed operating conditions. When the pump is operating, the safety device continually analyzes the operating conditions of the system. If the device detects a deviation of the operating conditions outside of a normal operational range, the vacuum pressure relief means are actuated in order to eliminate negative pressure in the system, thereby removing suction at the open ends of the intake lines. The device also disables the pump, shutting it off, upon detecting the abnormal operation condition(s). In the event there is an absence of fluid movement when the pump is operating (e.g., broken pipes, reservoir dry, etc.), the device triggers the vacuum pressure relief means and disables the pump, thereby preventing damage to the system. Warning devices, including audible and visible alarms, may be provided to indicate that operation of the fluid transfer system has been interrupted. This is especially useful to alert users to the possible occurrence of an obstruction of the intake lines by a person or object and the need to inspect and reset the device prior to reactivating the fluid transfer system. Other options can also be integrated with the device, including remote audible alarms, visual indicators, a remote panic switch, and the like. 
     OBJECTS AND ADVANTAGES OF THE INVENTION 
     With the foregoing in mind, it is a primary object of the present invention to provide a safety device for use in a fluid transfer/circulation system, wherein the device is structured to eliminate negative pressure in the system upon detecting a negative pressure level being outside of a selected operational range, thereby removing suction at the open ends of the intake lines. 
     It is a further object of the present invention to provide a safety device which is particularly useful in the fluid circulation systems of swimming pools, hot tubs and the like for preventing death and injury to persons or animals which become attached (i.e., entrapped) by suction to the intake openings of the system. 
     It is still a further object of the present invention to provide a safe, reliable and relatively inexpensive safety device for easy installation to existing fluid transfer/circulation systems and which automatically adjusts to any system, each time the fluid begins to flow, thereby establishing a normal operating range of conditions for each system, and wherein the device is structured to eliminate negative pressure in the system upon detecting an operating condition being outside (high or low) of the normal operating range, thereby removing suction at the open ends of the intake lines. 
     It is still a further object of the present invention to provide a reliable, relatively inexpensive safety device for use in a fluid transfer/circulation system of the type including at least one pump which draws water from a reservoir through one or more intake lines, and wherein the device is structured to deactivate the pump(s) and to further eliminate negative pressure in the system upon detecting one or more operating conditions of the system being outside of a predetermined range. 
     It is still a further object of the present invention to provide a safety device, as described above, further including warning devices such as, but not limited to, audible and visible alarms, to indicate that the safety device has been triggered to eliminate negative pressure in the intake lines of a fluid transfer system. 
     It is still a further object of the present invention to provide a safety device, as described above, which is contained in a totally sealed, compact unit for convenient, easy installation in-line with any fluid transfer/circulation system. 
     These and other objects and advantages of the present invention are more readily apparent with reference to the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a schematic block diagram of the primary components of the safety device in accordance with a first preferred embodiment of the present invention; 
     FIG. 2 is an elevational view, in partial section, illustrating a typical fluid circulation system for circulating fluid in a reservoir, such as a swimming pool, hot tub or the like, showing the safety device of the embodiment of FIG. 1 installed in-line on a main suction intake line of the system, between the intake of the system&#39;s pump and suction intake openings in the swimming pool; 
     FIG. 3 is a schematic block diagram of the primary components of the safety device in accordance with several other preferred embodiments of the present invention, wherein the sensor may be a positive pressure sensor, a negative pressure (i.e., vacuum pressure) sensor, a fluid flow meter, a voltage meter, or an amperage meter; 
     FIG. 4 is an elevational view, in partial section, similar to the view of FIG. 2, wherein the safety device includes a positive pressure sensor installed in-line with the return line of the fluid circulation system, on an output side of the pump, in accordance with another embodiment of the invention; 
     FIG. 5 is an elevational view, in partial section, similar to the views of FIGS. 2 and 4, wherein the safety device of the present invention is shown in accordance with yet another embodiment thereof, wherein a sensor is connected to the pump for measuring the voltage and/or the amperage drawn by the pump during operation thereof; 
     FIG. 6 is an elevational view, in partial section, similar to the views of FIGS. 2,  4  and  5 , showing the safety device in yet another embodiment thereof, wherein a fluid flow meter is installed in-line with the intake line, between the intake of the system&#39;s pump and the suction intake openings in the swimming pool or other fluid reservoir; 
     FIG. 7 is a cross-sectional view of yet another embodiment of the safety device of the present invention; and 
     FIG. 8 is an elevational view, in partial section, showing the safety device of the embodiment of FIG. 7 installed in-line on a main suction intake line of a fluid circulation system, between the intake of the system&#39;s pump and suction intake openings in the swimming pool or other fluid reservoir. 
    
    
     Like reference numerals refer to like parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is directed to a fluid vacuum safety device for use in a pump assisted fluid circulation system for the purposes of alleviating an intense vacuum that builds in the system when one or more of the suction intake ports of the circulation system become obstructed. 
     Referring to FIGS. 2,  4 - 6  and  8 , a typical fluid circulation system of the type commonly found in swimming pools and hot tubs is shown. A reservoir of water W is contained within a structure having side walls  2  and a bottom  4 . A main drain  6  having a drain cover grating is provided on the bottom  4 . At least one skimmer box  8  is provided along one or more of the side walls  2  at the water surface level SL. A drain suction intake line  10  leads from the main drain  6  to a main suction intake line  20 . A skimmer suction intake line  12  has an open end  13  is the skimmer box  8  which is maintained below the water surface level SL. The skimmer suction intake line  12  feeds into the main intake line  20 . The main intake line  20  is directed to a pump  24  which may have a screen trap  26  connected to the main intake line  20 , just prior to the intake of the pump  24 . A main output line  28  leads to a filter  30 . One or more return lines  32  extend from the filter  30  back to the water reservoir W to return water that is circulation through the system back to the reservoir W. 
     FIG. 2 shows the fluid vacuum safety device  50  in accordance with one embodiment thereof installed in-line along the main suction intake line  20  of the circulation system, prior to the intake of the pump  24  and screen trap  26 . If an object or person is caused to be sucked onto one of the open ends of the suction intakes, such as the open end  13  of the simmer suction intake  12 , the drain plate  7  or, if the drain plate is removed, the drain suction intake line  10  at the main drain  6 , a vacuum will instantly develop throughout the intake lines, including the main suction intake line  20 . The fluid vacuum safety device  50  is designed to react to this situation to immediately eliminate the vacuum in the system and, accordingly, the suction force at the open ends of each of the suction intake lines, including the skimmer suction intake  13  and the main drain intake  6 . Upon reaching a predetermined vacuum level, which happens quite rapidly when one of the intakes becomes obstructed, the fluid vacuum safety device  50  causes air from atmosphere to be rapidly introduced into the main intake line  20  and throughout the other intake lines, thereby removing all suction force at the open suction intake ends  13  and  6  in the reservoir W. The air introduced into the system interrupts the prime of the pump  24 , thereby eliminating any further source of suction. 
     Referring now to FIG. 1, the principal components of the fluid vacuum safety device  50  are shown in block diagram form. Specifically, the principal components of the fluid vacuum safety device  50  include a sensor circuit  120 A which senses the vacuum pressure level in the fluid circulation system. The output of the sensor circuit  120 A is applied to an analyzer/control circuit  130  that allows selective setting (programming) of a particular negative pressure range (a predetermined high and low vacuum pressure level) which thereby defines a trip point (high or low) or emergency condition in the system. The output of the analyzer/control circuit  130  controls operational relays or contactors  150  to interrupt power to the pump  24  and triggers a vacuum breaker  170  upon detecting the trip point. In the preferred embodiment, the analyzer/control  130  is a programmable microprocessor and vacuum breaker  170  is a solenoid controlled valve. A power supply  160  furnishes voltage for the circuitry. The sensor  120 A utilizes a strain gauge to sense the vacuum in the pump return line  20 . The sensor  120 A converts vacuum pressure to voltage readings. Changes in voltage readings correspond directly to vacuum pressure level changes in the system. The voltage readings are amplified in the sensor and sent to the analyzer/control  130  for processing. 
     Referring to FIG. 3, the principal components of the fluid vacuum safety device are shown in block diagram form in accordance with several additional embodiments thereof. Specifically, the sensor  120  shown in FIG. 3, may include any of a number of different sensors for measuring operating conditions in the swimming pool. In addition to the negative pressure sensor for sensing vacuum pressure level in the fluid circulation system, as described in connection with FIGS. 1 and 2, the sensor  120  may include a positive pressure sensor, a fluid flow meter, a voltage meter/regulator, and/or an amperage meter. The sensor  120 , in accordance with the various embodiments represented by FIG. 3, communicates with the analyzer/control circuit  130  that allows selective setting “programming” of one or more particular operating conditions (e.g., vacuum pressure, positive pressure, water flow rate, pump voltage level and/or pump amperage level) which thereby defines a trip point (high or low) or emergency condition in the system. In several of the embodiments, the analyzer/control  130  is a programmable microprocessor and the vacuum breaker  170  is a solenoid controlled valve. When the analyzer/control  130  determines that the sensed one or more operating conditions, as sensed by the sensor  120 , have deviated outside of a normal operational range (i.e., beyond the trip point), the analyzer/control  130  triggers actuation of the vacuum breaker  170  to introduce air from atmosphere into the intake line  20  of the fluid circulation system, thereby eliminating vacuum in the intake lines and further eliminating suction at the open intake ends  6 ,  13  within the reservoir W. 
     Referring to FIG. 4, the safety device  50  is shown installed in accordance with one preferred embodiment, wherein the safety device  50  includes a positive pressure sensor  120 B installed in-line along the return line  32 , between the output side of the pump  24  and the reservoir W. In this particular embodiment, the positive pressure sensor  120 B is structured to measure the positive pressure in the return line  32  when the pump  24  is operating. A normal operational positive pressure range is established and is maintained in memory in the analyzer/control  130 . In the event the positive pressure measured in the return line  32  deviates outside of a normal operational range, the analyzer/control  130  triggers the vacuum breaker  170  to introduce air into the main intake line  20 . The analyzer/control  130  is also structured to interrupt power to the pump  24  to thereby terminate operation of the pump  24 . 
     Referring to FIG. 5, the safety device  50  is shown in yet another embodiment of the invention, wherein the sensor  120 C is adapted to read voltage and/or amperage levels of the pump during operation thereof. A normal voltage and/or amperage operating range for the pump is determined and is stored in the microprocessor memory of the analyzer/control  130 . Should the voltage and/or amperage level drawn by the pump  24  deviate outside of the normal operational range, the analyzer/control  130  will trigger actuation of the vacuum breaker  170  to introduce air from atmosphere into the return line  20 , thereby relieving suction at the open intakes  13  and  6  within the reservoir W. 
     Referring to FIG. 6, the safety device  50  is shown installed in a fluid circulation system of a swimming pool, in yet another embodiment of the invention, wherein a fluid flow meter  120 D is installed in-line on the main intake line  20  of the system. The fluid flow meter  120 D is another type of sensor contemplated within the spirit and scope of the invention. In this particular embodiment, the analyzer/control  130  is programmed to store a normal operational range of water flow rates of water traveling through the main intake line  20  leading to the intake of the pump  24  when the system is operating normally. Should the water flow rate deviate outside a normal operational range, as sensed by the fluid flow meter  120 D, the analyzer/control  130  triggers actuation of the vacuum breaker  170  to introduce air into the intake lines, thereby relieving suction at the open ends  6 ,  13  within the reservoir W. 
     Referring to FIGS. 7 and 8, yet another embodiment of the safety device  50  is shown, in accordance with a purely mechanical embodiment thereof. Specifically, the safety device  50  in the embodiment of FIGS. 7 and 8 includes a base unit  52  defined primarily by an inverted T-section formed of PVC and having a main through passage  54  defined along the bottom of the inverted T and having opposite open ends  55 ,  55 ′ which connect in-line to the main intake line  20 , as seen in FIG.  8 . During normal operating conditions, water flow will travel in a direction of the arrow  56  and through conduit  54  towards the pump  24 . The inverted T section of the base unit  52  further includes an upwardly extending vent port  60  extending upwardly from the through passage  54 , in fluid communication therewith, to a top end  62 . The open top end  62  is surrounded by an annular flange  64  having an O-ring seal  67  fitted to a top face of the flange  64 . 
     A membrane  70  rests on the O-ring  67  in covering relation to the open top  62  of the vent port  60 . The membrane  70  may be structured of a frangible material, such as a glass or plastic film which is structured to break in response to a predetermined negative pressure level. Specifically, the thickness of the central zone  74  of the frangible membrane  70  may be determined in accordance with the shattering or disintegrating characteristics of the membrane material. More particularly, the thickness of the central zone  74  of the frangible membrane  70  may be gauged according to the desired predetermined vacuum pressure level at which the frangible membrane is caused to implode and disintegrate. 
     Alternatively, the membrane  70  may be structured and disposed to move or collapse, such as against a spring force, to introduce air into the through passage  54  and main intake line  20 , in response to a vacuum pressure level within the intake line  20  deviating beyond a predetermined maximum level. 
     Once the membrane  70  is caused to disintegrate, move or otherwise uncover the open top end  62  of the vent port, air from atmosphere is able to quickly enter through the open top to fill the intake lines of the fluid circulation system (as indicated by the arrow  76 ) thereby eliminating the vacuum in the system and relieving suction at the open intake end within the reservoir W. 
     The membrane  70  is maintained in place, in covering relation to the open end  62 , by a fitting  80  having a lower annular face  82  which opposes the flange  64 , sandwiching the rim  72  of the membrane  70  therebetween, as seen in FIG.  7 . The O-ring  67  absorbs pressure to prevent the membrane  70  from cracking as the fitting  80  is advanced and tightened towards the flange  64  and against the rim  72  of the membrane  70 . A female coupling  84  is provided to facilitate attachment of the fitting  80  to the base unit  52 , enabling threaded advancement and withdraw of the fitting  80  relative to the flange  64  and the membrane  70 . Threads  85  about the outer periphery of the fitting  80  intermesh with corresponding threads  86  on the inner face of the female coupling  84 . An inwardly directed flange  87  on the lower open end of the female coupling  84  engages the under side of the flange  64  of the vent port. The fitting  80  further includes a flat ledge  88  which proceeds inward to a reduced diameter extension  89 . The fitting  80  is open at both the opposite ends and has a larger diameter between the annular face  82  compared to a top open end  90 . The ledge  88  on the fitting is provided with a plurality of air inlet holes  94  which extend from the top ledge  88  through the thickness of the fitting  80  to provide air flow communication between the exterior atmosphere and an inner chamber  96  above the frangible membrane  70 . When the membrane  70  is caused to uncover the open end  62  of the vent port  60 , air from atmosphere enters through the inlet holes  94  and through the top opening  62  of the vent port  60  and throughout the suction intake lines of the system to eliminate vacuum therein. A cap  102  is fitted to the reduced diameter extension  89  to cover the open top end  90 . 
     While the instant invention has been shown and described in accordance with preferred embodiments thereof, it is recognized that variations, modifications and changes may be made to the instant disclosure without departing from the spirit and scope of the invention, as set forth in the following claims and within the doctrine of equivalents.

Technology Classification (CPC): 0