Patent Application
20050283900
1. Field of the Invention
The present invention relates to circulation systems for hydrotherapy tubs, spas or pools, and more particularly to a novel safety suction inlet for use with a circulation system that incorporates both an internal gate and external cover to avoid potential hazards including body, hair or other foreign object entrapment or entanglement, should the external cover be removed.
2. Description of the Prior Art
It is generally known that water is recirculated under high pressure in hydrotherapy tubs, spas and pools. A pump draws water from the interior of a tub or spa through an inlet and forces the water through one or more jets or nozzles that, after mixing the water with air, inject the water under pressure back into the interior of the tub or spa. Because the system uses high pressure to recirculate the water, there is a danger that an object such as a body part or hair may become entrapped or entangled in the inlet, leading to potentially serious consequences inluding serious injury or death by drowning.
While most people are unaware of the potential danger of the circulation system, if one comes in direct contact with any of the suction inlets of the hydrotherapy tub, spa or pool, the suction force will immediately form a seal between the inlet and the individual's skin, or clothing. In addition, the individual's hair may become entangled in the suction inlet. If either of these should occur, the force needed to dislodge the body, hair, or other object can exceed 500 pounds. In addition, in the case of a portion of the body or hair, serious injuries can be inflicted almost instantaneously, up to and including death by drowning.
Once an object, such as a part of the body, becomes entrapped in the suction inlet of the circulation system, the only way to dislodge the object is to interrupt or disable the suction system. One way to do this is to interrupt the electrical power to the pump; however, even if the power is removed the suction between the intake of the pump and the obstructed suction inlet could remain for a short period of time. Thus, a way is needed to quickly remove the vacuum condition between the obstructed suction inlet and the intake of the pump, so that the object can be freed without damage or injury.
In order to reduce or eliminate the chance of occurence of such accidents, several solutions for preventing an object from becoming entrapped in the suction inlet have been proposed. One approach is to sense the blockage and quickly reduce the vacuum between the suction inlet and the system pump. For example, floats or electromagnetic switches for detecting and reacting to potential blockages have been used; however, these solutions may be mechanically and/or electrically complicated.
In order to relieve the vacuum condition between an obstructed suction inlet and the intake of a pump, U.S. Pat. No. 4,602,391 to Shepard discloses a dynamically balanced suction relief pump. A controlled amount of water under pressure is supplied from a pump to an air inlet duct to maintain a water level in a column under normal operating conditions. A check valve keeps water from spilling from the column and maintains water in the column unless a blockage occurs, in which case the water level drops and air enters the system to cavitate the pump, thereby relieving the vacuum between the obstructed suction inlet and the intake of the pump. However, the system disclosed by Shepard is relatively complex and does not include any additional safety features to prevent blockage of the suction inlet.
A different, and much more serious safety concern, is entanglement which can occur if a portion of hair is drawn into the suction inlet. If hair becomes entangled in the suction inlet the individual's head will be held under the water and, unless the entanglement is released immediately, will result in death by drowning. Relieving the vacuum condition will generally not release entangled hair, since the hair will be twisted and knotted behind the suction inlet.
Thus, in another approach to reducing the chance of a foreign object becoming entrapped or entangled in the suction inlet, an external grate or cover is used to directly cover the suction inlet. This physically prevents an object (particularly hair) from being entangled inside the suction inlet and, further, prevents an efficient seal from being formed between the object and the inlet. However, if the external grate or cover is removed there will be no protection against the object becoming entrapped or entangled in the suction inlet, which can result in serious injury or death as described above. Thus, the American Society of Mechanical Engineers has established the ASME/ANSI A112.19.8M (1987) testing standard for suction inlets to be used with swimming pools, wading pools, spas, hot tubs and whirlpool bathtub appliances.
The ASME/ANSI suction testing standard requires that the external suction cover be secured mechanically and requires a special tool for removal of the external suction cover (i.e., slotted screws are not permitted; star/Phillips screw heads are permitted). The intent is to make removal of the external suction cover difficult to minimize the likelihood that the whirlpool/spa will be operated without the cover in place.
If an individual's hair becomes entangled in an external or one piece suction cover, in order to permit them to remove themselves from the water and avoid drowning they either need to pull the hair out of their scalp, cut their hair, immediately pump all the water out of the tub or spa, or remove the external suction cover using the required tool. It is extremely unlikely that any of the above can be accomplished in time.
With a fixed internal gate combined with an external (removable) safety cover, the suction inlet could be rated and tested to the above ASME/ASNI standard with the external safety cover removed. Instead of requiring a special tool, the external safety cover could be attached so it could be removed with a light pull. Further, if the external safety cover were used in conjunction with a circulation system that cavitates or turns off the pump when the individual's hair is entangled on the external safety cover, they would be able to simply pull the external safety cover off with minimal effort and stand up once the pump either cavitated or was shut off.
Accordingly, there is a need for a safety suction inlet for use with circulation systems for hydrotherapy tubs, spas or pools incorporating both a fixed internal gate and a removable external safety cover to avoid potential hazards including body, hair or other foreign object entrapment or entanglement, should the external safety cover be removed.
The present invention is directed to a safety suction inlet for use with circulation systems for hydrotherapy tubs, spas or pools, and more particularly to a safety suction inlet incorporating both a fixed internal gate and a removable external safety cover to avoid potential hazards including body, hair or other foreign object entrapment or entanglement, should the external cover be removed.
In a first embodiment of the present invention, the safety suction inlet includes both a fixed internal gate and a removable external safety cover. The internal gate is permanently positioned within the body of the safety suction inlet just beneath the external suction cover. The internal gate is positioned such that it provides a secondary point of safety in the event that the external suction cover becomes removed or otherwise dislodged from the safety suction inlet. The internal gate thus prevents an object from becoming entrapped or entangled in the safety suction inlet even if the external suction cover is removed.
In a second embodiment of the present invention, the safety suction inlet may be combined with a conventional circulation system in order to reduce the chance of an object becoming entrapped or entangled in the suction inlet of the system.
In a third embodiment of the present invention, the safety suction inlet may be combined with a safety circulation system having a cavitation tee connected to a vent in contact with ambient air. A column of water is maintained in the vent above the cavitation tee until such time that the safety suction inlet becomes blocked. When the safety suction inlet is blocked, the column of water above the cavitation tee and inside the atmospheric vent reduces to a level that causes air to enter the system and cavitation of the pump to occur, thereby relieving the vacuum between the cavitation tee and the safety suction inlet and releasing the object causing the blockage.
In a fourth embodiment of the present invention, the circulation system further includes a focused inlet connected to the cavitation tee that allows rapid cavitation in the event that the safety suction inlet becomes blocked. The focused inlet includes a small orifice placed at the face of the safety suction inlet having a diameter that can be adjusted to alter the sensitivity of the cavitation effect.
In each of the third or fourth embodiments of the present invention, the cavitation tee may be located remotely away from the safety suction inlet, thereby providing for convenient installation and maintenance.
In a fifth embodiment of the present invention, the safety suction inlet includes a fixed internal gate, a removable external safety cover, and a plurality of raised tabs. As with the first embodiment, in the fifth embodiment the internal gate is positioned within the body of the safety suction inlet just beneath the external suction cover. Likewise, the internal gate is positioned to provide a secondary point of safety in the event that the external suction cover becomes removed or otherwise dislodged from the safety suction inlet. In this embodiment, the addition of the plurality of raised tabs prevents an object from forming a seal with the safety suction inlet body, thereby reducing the possibility of an object becoming entrapped. Similarly, the fixed internal gate prevents an object from becoming entrapped or entangled in the safety suction inlet even if the external suction cover is removed.
In a sixth embodiment of the present invention, the internal gate is fixed to a flow element that attaches to the back of a conventional suction inlet. The combination of the flow element and the conventional suction inlet perform exactly the same function as the safety suction element having the fixed internal gate. As with the other embodiments, the internal gate provides a secondary point of safety in the event that the external suction cover becomes lost or otherwise dislodged from the safety suction inlet. The internal gate thus prevents an object from becoming entrapped or entangled in the safety suction inlet even if the external suction cover is removed.
In a seventh embodiment of the present invention, a plurality of rods or other projections oriented within a flow element, such as an elbow, prevents an object from becoming entangled in the safety suction inlet. The combination of the flow element and the conventional suction inlet performs exactly the same function as the safety suction element having the fixed internal gate.
Any of the first, fourth, fifth, sixth or seventh embodiments of the present invention may be used with a conventional or safety circulation system. Further, the external suction cover may be removably fixed to the suction inlet, thereby adding an additional level of protection against an object becoming entangled in the suction inlet.
Further features and advantages of the present invention will be appreciated by a review of the following detailed description of the preferred embodiments taken in conjunction with the following drawings.
The present invention may be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein like numerals denote like elements and in which:
The following exemplary discussion focuses on a novel safety suction inlet for use with circulation systems for hydrotherapy tubs, spas or pools, and more particularly to a safety suction inlet incorporating both a fixed internal gate and a removable external safety cover to avoid potential hazards including body, hair or other foreign object entrapment or entanglement, should the external cover be removed.
Referring to
Referring now to
Referring to external safety cover 210,
Although safety suction inlet 200 is shown with threaded mounting portion 206, other mounting mechanisms including press fit, adhesive, or o-ring are possible and are intended to fall within the scope of the present invention. The use of such mounting methods will be apparent to those skilled in the art.
Continuing with
Return path 406 is connected to an output of pump 402 and serves to return water to the interior of the hydrotherapy tub, spa or pool. As with circulation path 404, return path 406 may be comprised of multiple components, such as pipes, elbows, threaded fittings, and other conventional components (again, not individually shown).
Conventional circulation system 400 operates as follows. During normal operation, water is drawn from the hydrotherapy tub, spa or pool through safety suction inlet 200 and circulation path 404 by pump 402 and back to the hydrotherapy tub, spa or pool through return path 406. In
Referring now to
Safety suction inlet 200 and suction cover 210 are located in the interior of a hydrotherapy tub, spa or pool (partial wall 516 shown) and serve to channel water into safety suction circulation system 500. Safety suction inlet 200 is connected to an intake of pump 502 through primary circulation path 504 and, in parallel, through secondary circulation path 506. As will be apparent to those skilled in the art, both primary circulation path 504 and secondary circulation path 506 may be comprised of multiple components, such as pipes, elbows, threaded fittings, and other conventional components (not individually shown).
Return path 514 is connected to an output of pump 502 and serves to return water to the interior of the hydrotherapy tub, spa or pool. As with primary circulation path 504 and secondary circulation path 506, return path 514 may be comprised of multiple components, such as pipes, elbows, threaded fittings, and other conventional components (again, not individually shown). Air vent 510 connects secondary circulation path 506 to ambient air through cavitation tee 508 and is oriented vertically to maintain a column of water above its end under normal operating conditions.
Safety suction circulation system 500 operates as follows. During normal operation, water is drawn from hydrotherapy tub, spa or pool through safety suction inlet 200 and primary circulation path 504 by pump 502 and back to the hydrotherapy tub or spa through return path 514. In
If safety suction inlet 200 becomes blocked, the flow through primary circulation path 504 is immediately stopped, and air is drawn through air vent 510 into secondary circulation path 506. The air flow continues into pump 502, breaks the priming of the system and causes pump 502 to cavitate, thereby reducing the vacuum in primary circulation path 504. This allows the object that is blocking safety suction inlet 200 to be released. In
The description of safety suction circulation system 500 describes one conventional method for relieving the vacuum in the suction line. As will be obvious to those skilled in the art, a number of other methods exist for relieving the vacuum, including electrical disablement, column of water, check valve without a column of water, multiple suction fittings, and combinations thereof. Safety suction inlet 200 of the present invention may be used in combination with each of these methods to reduce the danger of hair entanglement that could lead to serious injury or death by drowning.
Referring now to
Continuing with
In
Any embodiments of
The foregoing description includes what are at present considered to be preferred embodiments of the invention. However, it will be readily apparent to those skilled in the art that various changes and modifications may be made to the embodiments without departing from the spirit and scope of the invention. For example, the specific shape and dimensions of suction inlet 200 or internal safety gate 204, or the hole size or pattern of the latter, may be changed. Alternatively, the precise number of components and physical layout of conventional circulation system 400 or safety suction circulation system 500 may vary according to the specific application. In addition, external safety cover 210 may be removably attached to safety suction inlet 200 in a variety of ways. Accordingly, it is intended that such changes and modifications fall within the spirit and scope of the invention, and that the invention be limited only by the following claims.
