Abstract:
A drain for swimming pools, spas, whirlpool baths, etc., includes a plurality of first orifices in communication with corresponding serpentine passageways to minimize hair or a body part from covering and entering the first orifices to a degree sufficient to entrap a bather. A plurality of second orifices independent of the first orifices and in fluid communication with one another through a peripheral passageway provide a flow of water from the peripheral passageway into the serpentine passageways to create an alternate water inflow path and reduce the pressure differential and possible entrapment that might occur should a body part or hair come in contact with or enter the first orifices. Moreover, a plurality of ridges are attendant the first orifices to reduce the likelihood of direct contact with the first orifices by a body part or hair.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to drains for swimming pools, spas and whirlpool baths and, more particularly, to a drain for reducing the likelihood of entrapment of a person&#39;s hair and body parts. 
     2. Description of the Related Art 
     Typically, a suction outlet or drain used in a pool or spa is located at the bottom or in a wall of such pool, spa or bath. The drain provides an outflow of water into a suction line connected to a suction pump. A debris trap or the like may be disposed between the suction line and the pump to collect large sized debris. Usually, the outflow from the pump passes through a filter and is ultimately returned to the pool, spa or bath. 
     The suction attendant the drain may be significant, which poses a danger to a user of or a bather in the pool, spa or bath. Should the drain be covered by a body part, the force of the suction acting on such body part may be sufficient to prevent the person from extricating himself/herself and drowning may occur or significant injury may result. Often, the hair of a bather may be drawn into the drain and become tangled about elements of the drain or wrapped about itself to the extent that extrication may be impossible. Again, the consequences may include drowning. Because of these hazards to users of a pool, spa or bath, various efforts have been undertaken to preclude such entrapment. 
     In 1923, Booraem disclosed in U.S. Pat. No. 1,454,310 a rudimentary grating covering a drain for the purpose of protecting a bather from the hazards associated with limb entrapment. The grate also served the function of screening debris to keep it out of the suction line and other downstream elements. 
     As spas and whirlpool bathtubs became more widely used, the bathers were usually in much closer proximity to an active drain for longer periods of time. This resulted in hair entrapment injuries as well as drowning. The increase of injuries of this type and related drownings dictated the evolvement of drains with more effective features to prevent hair entrapment. A resulting improvement of the drain was that of using a cover with small orifices to reduce the likelihood of hair passage therethrough. However, when a large volume of hair was proximate the apertures, the resulting differential pressure was often sufficient to draw hairs through the small orifices. After the hair passed through the orifices, it often wrapped about itself and effectively prevented withdrawal of the hair. An improvement to the use of such small orifices is disclosed in a 1998 patent to Perry, Et al., U.S. Pat. No. 5,799,399 which taught the use of internal guide vanes to reduce turbulent flow of the water and thereby reduce tangling of hair passing through the orifices. Guide vanes reduced the likelihood of hair entanglement, but the problem was still present, especially when the orifices were essentially covered by hair. 
     Another approach to prevent hair entanglement is disclosed by Nelson in U.S. Pat. No. 5,978,981 wherein a plurality of elongated flow channels are provided which are of sufficient length that hair cannot reach the end of the channels where it might tangle. Since some bathers have very long hair, the channels had to be of extended length to prevent entanglement of such hair. This necessitated a large drain cover which was difficult to manufacture. It also required significant space to accommodate the channels which space was often impractical or impossible in many typical locations. 
     U.S. Pat. No. 6,088,842, issued to Barnett discloses another approach by providing a plurality of protrusions positioned to form a grating arrangement with a single opening. The protrusions are shaped to facilitate the removal of tangled hair. This apparatus may work well for limited volumes of hair exposed to limited flow rates. However, most modern suction pumps have significant flow capabilities well above the level required to create turbulent flow behind the protrusions. Such turbulence can and will tangle hair making it difficult or impossible to pull the hair back through the openings. 
     To address the hazard of entrapment a body part due to the pressure differential across a drain cover when it is blocked by the body part, certain standards have been promulgated by the National Spa and Pool Institute. In particular, such standards prohibit the use of a single point suction on small drain covers that can be completely blocked by a bather. The most widespread solution and compliance with the standards involves the use of two drains in fluid communication with one another through a common suction line. When such arrangement is used, complete blockage of one drain will not result in significant pressure differential across the blocked drain as the suction force is relieved by flow through the second drain. Thus, removal of the body part from the affected drain was usually possible. 
     While single-point suction is prohibited by most construction standards and codes, such is not always the case. Even when it is, installers are frequently unaware of the requirement or simply feel that it is not necessary based on their personal experience. It is therefore of import to provide a suction outlet or drain which self-limits the water flow and localized velocities to a level below that required to entangle or entrap hair. Additionally, it would be beneficial to minimize the amount of differential pressure that may come in contact with a bather by dispersing the inlet orifices over a large area to reduce the likelihood of complete blockage. 
     It is therefore a primary object of the present invention to provide a drain for a pool, a spa or a whirlpool bath that reduces the likelihood of entry of hair through the inlet orifices. 
     Another object of the present invention is to provide a drain for a pool, spa or bath which includes secondary inlet orifices to prevent a pressure differential across the drain in the event of partial or complete blockage of the primary inlet orifices. 
     Still another object of the present invention is to provide inlet orifices having mechanical features for reducing the likelihood of passage of hair therethrough. 
     Yet another object of the present invention is to provide a drain for a pool, spa or bath that reduces the likelihood of entanglement of any hair that may inadvertently enter through the inlet orifices. 
     A further object of the present invention is to provide a drain for a pool, spa or bath that has a limited water flow rate through each of a plurality of inlet orifices relative to the water flow rate of the suction line connected to the drain. 
     A yet further object of the present invention is to provide passageways extending from inlet orifices to segregate any hair entering therein and prevent entanglement. 
     A still further object of the present invention is to provide a method for reducing the likelihood of entrapment of hair in a drain for a pool, spa or whirlpool bath. 
     These and other objects of the present invention to those skilled in the art as the description thereof proceeds. 
     BRIEF SUMMARY OF THE INVENTION 
     An anti-hair entrapment drain includes a cover having a central impervious surface generally coincident with an underlying suction line. A plurality of laterally extending first orifices extend from the impervious surface to provide primary water inlets. The water is channeled through passageways defined by adjacent walls extending radially inwardly to an aperture in an underlying plate, which aperture is in fluid communication with the suction line. A second set of orifices, generally radially coincident with the first set of orifices, are in fluid communication with one another through a peripheral passageway. The peripheral passageway is also in communication with the passageways extending from the first set of orifices. The water inflowing through the passageways enters the suction line through a bulkhead fitting. The drain may be attached to the shell of a fiberglass pool or spa with a collar threadedly engaging a threaded section of the bulkhead fitting extending through an aperture in the shell. The drain may be attached to the liner of a pool or spa by capturing the liner between the plate and the bulkhead fitting. The cover and plate, absent the bulkhead fitting of the drain may be detachably attached to a ring mounted in the wall or the bottom of a swimming pool or spa and encircling or adjacent an existing suction line. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be described with greater specificity and clarity with reference to the following drawings in which: 
         FIG. 1  is an exploded view of the major components of the anti-entrapment drain; 
         FIG. 2  is a partially cutaway perspective view of the drain; 
         FIG. 2A  is a cross-sectional view of the drain; 
         FIG. 3  illustrates a partly cutaway view of a cover mounted upon a plate; 
         FIG. 4  illustrates the underside of the cover; 
         FIG. 4A  is a detailed view taken within circle  4 A shown in  FIG. 3 ; 
         FIG. 5  illustrates the plate useable in conjunction with a fiberglass wall or bottom or vinyl-lined wall or bottom of a pool, spa or whirlpool bath; 
         FIG. 6  illustrates a top view of the cover; 
         FIG. 7  illustrates a bottom view of the cover; 
         FIG. 8  illustrates a plate usable in conjunction with a pool, spa or bath of cementitious material; 
         FIG. 9  illustrates a mounting ring used in conjunction with the plate shown in  FIG. 8 ; 
         FIG. 10  illustrates a plate useable to retrofit the present drain in an existing pool, spa or bath; and 
         FIG. 11  illustrates a collar for threaded engagement with the bulkhead fitting. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , there is shown an exploded view of a drain  10  for use in a swimming pool, spa or whirlpool bath. The drain is connected to a suction line, representatively identified by numeral  12 , which conveys water to a suction pump. The water flowing to the suction pump may pass through a debris trap to collect large sized debris. The water outflow from the suction pump may pass through a filter and into a return line for return to the pool, spa or whirlpool bath. 
     Referring jointly to  FIGS. 1 ,  2 ,  2 A,  3  and  4 , details of the drain will be described. Suction line  12  is attached to a bulkhead fitting  14 , which bulkhead fitting includes a central outlet  16  in fluid communication with the suction line. The bulkhead fitting includes external threads  18  for threaded engagement with a collar  20 . If the drain is to be used in conjunction with a fiberglass pool, spa or whirlpool bath having a shell  22 , the lower body of the bulkhead fitting is in penetrable engagement with an aperture  24  in the shell. The bulkhead fitting is secured with the shell by collar  20  and a gasket  26  is disposed above the shell and below the annular flange of the bulkhead fitting to ensure a water tight fit. A plate  28  is secured to bulkhead fitting  14  by a plurality of attachment means, such as screws  30 . 
     If drain  10  is to be used in conjunction with the liner of a pool, spa or bath such as liner  32 , shown in dashed lines, the liner would be placed on top of bulkhead fitting  14  and secured by attachment means, such as screws  30 , penetrably engaging plate  28 , liner  32  and in threaded engagement with the bulkhead fitting. A pair of gaskets  35 ,  36  may be placed on either side of the liner to ensure a water tight fit. Obviously, the material of the liner corresponding with the size of central outlet  16 , would be cutaway after installation. 
     Cover  40  is secured to plate  28  by attachment means, such as screws  42 . The cover includes a central impervious surface  44  generally coincident with opening  46  in plate  28  and central outlet  16  in bulkhead fitting  14 . A plurality of slots or first orifices  48  extend radially from surface  44  and serve as inlets to the water flowing into drain  10 . 
     Internal threads  50  in bulkhead fitting  14  are used for the purpose of threadedly receiving a plug to test the integrity of the suction line during installation and/or subsequent replacement or repair. These threads have no other purpose with respect to operation of drain  10 . 
     Referring jointly to  FIGS. 3 ,  4 ,  4 A,  5 ,  6  and  7 , details of plate  28  and cover  40  and their operative interrelationships will be described in detail. Cover  40  has a central impervious surface  44  generally centered in the cover. This surface is essentially vertically coincident with central outlet  16  disposed in bulkhead fitting  14 . Thereby, direct flow of water through the cover into the central outlet is prevented. A plurality of slots, primarily referred to as first inlet orifices  48 , extend essentially radially from surface  44  around the cover. As shown in cross section in  FIG. 4A , first inlet orifices  48  are defined by pairs of walls  60  the upper edge of which includes a cap  62 . The space between adjacent caps defines the width of first inlet orifices  48 . It has been learned that by maintaining upper edges  64 ,  66  of each of caps  62  sharp edged and the lower edges rounded, a strand of hair is less likely to pass thereacross and into the first orifice. A ridge  68  extends upwardly from each of caps  62 . The purpose of this ridge is to reduce the likelihood of a body part or hair coming in direct contact with the first orifice. Without such contact, it is unlikely that water flow through the first orifice will be blocked by a body part and it is further unlikely that hair will be drawn through the first orifice. By having upper side  69  of each ridge rounded, as illustrated, a body part or hair(s) is more likely to slide thereacross and not be drawn into an adjacent first orifice. 
     As particularly illustrated in  FIG. 3 , the depth (vertical dimension) of walls  60  increases radially inwardly. Commensurate therewith, the spacing between the walls decreases in the radial inward direction. By appropriate dimensioning, the cross-sectional area between adjacent walls increases radially inwardly and the flow rate therebetween is reduced to further reduce the likelihood of hair being drawn radially inwardly between the walls. 
     As particularly shown in  FIG. 4 , outlet orifice  70 , as defined between adjacent walls  60 , has a greater vertical dimension than width. To further discourage passage of hair through the outlet orifice, the inner edge of each wall is terminated by an abutment  72 . This abutment is generally arrow shaped in cross section, as illustrated in  FIGS. 4 and 7 . Such arrow shape presents a vertical side  74  extending from opposed walls of the outlet orifice and each side is terminated by a sharp edge to restrain sliding movement of hair therepast. 
     Plate  28  includes a plurality of depressions  76 , as particularly shown in  FIGS. 3 and 5 . Each of depressions  76  corresponds with the lower edge of one of walls  60 . Thereby, the lower edge of each wall is nested and sections of plate  28  define the bottom surface of the passageways through cover  40  from first inlet orifice  48  to the outlet orifice  70 . 
     As particularly illustrated in  FIGS. 2 ,  2 A,  3  and  4 , cover  40  includes second orifices  78 . A peripheral wall  80  segregates first orifices  48  from the second orifices. Such wall, in combination with the part of cover  40  radially external to the wall in combination with plate  28  defines an annular or peripheral passageway  82  placing all second orifices in fluid communication with one another. As particularly noted in  FIG. 4 , studs  84  are formed as part of wall  80  but extend downwardly therefrom. The space between adjacent studs, the lower edges of wall  80  and plate  22  defines an aperture to provide fluid communication between peripheral passageway  82  and the passageways between adjacent walls  60 . It may be noted that the location of second orifices  78  is in a downwardly sloping section of cover  40 . 
     The primary purpose for embodying the second orifices is that of providing an alternate water flow path to central outlet  16  in the event most of first orifices  48  become covered by a body part or a mass of hair. Thereby, the pressure differential attendant the first orifices is maintained relatively benign to permit a bather to extricate himself/herself from the drain. 
     As particularly shown in  FIGS. 3 ,  5 ,  6  and  7 , walls  60  and depressions  76  are serpentine in configuration. It has been learned that the resulting convoluted configuration of the passageways formed thereby further reduces the likelihood of hair being drawn into and through the passageways. This result is due in part to the fact that most wet hair is relatively straight and therefore will tend to bridge rather than flow into each of the first orifices. As noted in  FIG. 3 , ridges  68  are similarly serpentine in configuration. 
     As discussed above with particular reference to  FIGS. 1 and 2A , capability for mounting drain  10  in a fiberglass pool, spa or whirlpool bath has been described. Similarly, the capability for mounting drain  10  in a liner pool or spa has been described. Referring jointly to  FIGS. 8 and 9 , there is shown the structure necessary to mount drain  10  in new construction of a pool, spa or whirlpool bath formed of cementitious material. Ring  90  includes an annular band  92  and a circular wall  94  extending upwardly therefrom. Prior to setting of the cementitious material, ring  90  would be pressed thereinto and the cementitious material would be troweled upon band  92  and adjacent the outer surface of wall  94 . Upon setting of the cementitious material, the ring would be firmly locked in place. Under certain circumstances, it may be preferable to similarly lock the ring in the plaster coating usually forming the finished surface of a pool, spa or whirlpool bath. In either event, the ring would be captured and permanently retained in place. 
     The ring includes an interior annular band  96  for supporting plate  98  (similar to plate  28 ). The plate includes a plurality of apertures  100  for penetrably receiving attachment means, such as screws, bolts, or the like, and threadedly engaging holes  102  and underlying bosses  104  in ring  90 . A key  106  in the ring corresponds with a keyway  108  in the plate to maintain orientation of the plate with respect to the ring. The plate further includes holes  110  and corresponding bosses  112  for penetrably and threadedly receiving attachment means, such as screws  42  (shown in  FIG. 1 ) for securing cover  40  to plate  98 . Outlet  114  is coincident with a stub of a suction line lodged within and extending through the cementitious material forming the pool, spa or whirlpool bath and is ultimately connected to a suction pump as described above. A pair of cross members  116 ,  118  may extend across outlet  114  as shown. As illustrated, plate  98  includes depressions  76  and this plate serves the same operative functions as plate  26  described above. 
     In existing pools having a drain not embodying the anti-entrapment features of the present invention, it may be advantageous and preferable to install drain  10  described herein. Referring to  FIG. 10 , there is illustrated a plate  120  which is useful for this purpose. This plate is similar to plates  28  and  98 , shown in  FIGS. 5 and 8 , with certain modifications. Keyway  108  is not necessary and therefore has been omitted. It is presumed that plate  120  will be placed adjacent the inlet to an existing suction line. Accordingly, outlet  114  would be placed coincident with such inlet. A plurality of elongated apertures  122  may disposed at various locations in plate  120 . The purpose of these apertures is that of permitting bolts, screws or other attachment means to penetrably engage these apertures and into engagement with the underlying plaster and/or cementitious material to retain plate  120  in place. After installation, cover  40  (see  FIG. 1 ) is attached by attachment means such as screws  42  extending through the cover and into threaded engagement with holes  110  and underlying bosses  112 . 
     Referring to  FIG. 11 , there is illustrated in detail collar  20 . Although the collar includes a hexagonal section  130 , most workmen do not carry a wrench of sufficient size to engage the hexagonal section. For such instances, nubbins are formed at the intersection of each face of the hexagonal section. Each of these nubbins includes notches  134 ,  136  disposed on either side. These notches permit a workman to tighten the collar by placing an implement, such as a screwdriver, therein and striking it to impart a rotational force to the collar. Thus, the collar can be more than hand tightened very easily using conventional tools and a bit of manual force.