Patent Publication Number: US-6988282-B2

Title: Drain cover

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application is a continuation of U.S. application, Ser. No. 10/144,212, filed on 10 May 2002 now U.S. Pat. No. 6,738,994. The parent application is hereby incorporated by reference herein in its entirety and is made a part hereof, including but not limited to those portions which specifically appear hereinafter. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to drain cover having a slot that precludes entangling or trapping a swimmer or bather. 
   2. Description of Prior Art 
   Swimming pools and hot tubs typically include circulation systems that draw water from the pool or tub at high flow rates. When swimmers and bathers frolic underwater, they risk exposing their hair, fingers, clothing, etc. to active pool drains. For example, swimming a circuit to and from a drain is a common aquatic exercise that brings the swimmer into the vicinity of the drain, particularly the head of the swimmer. Strands of hair, for example, may be entrained into the drainage flow and pass through apertures in conventional drain gratings. 
   When hair strands are drawn through drain gratings, hair entanglement may proceed by knotting or wrapping mechanisms. Hair may be drawn into the drain and then entangled behind the grating element resulting in knotting. Alternatively, hair may be drawn into the drain and then wrapped around the grating element resulting in wrapping. Each of these mechanisms is sufficiently aggressive that a bather may be trapped even in the face of heroic intervention. 
   In addition, a swimmer may become trapped against a drain if the swimmer&#39;s body comes in sufficient contact with the drain so as to form a vacuum. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is one object of this invention to provide a drain cover having a structure where no elements exist that may be trapped or wrapped by strands of hair. 
   It is another object of this invention to provide a drain cover having a structure that prevents the drain from creating a vacuum against the body of a swimmer. 
   These and other objects of this invention are addressed by a drain cover comprising one or more hollow tubes having a continuous single slot formed therein. Alternatively, the drain cover may comprise a shell having a simply connected slot formed therein. The drain cover according to this invention may be formed in a number of geometries, discussed in detail below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and features of this invention will be better understood from the following detailed description taken in conjunction with the drawings wherein: 
       FIG. 1A  shows a hair entanglement condition in a knotting mode in a prior art drain cover grate; 
       FIG. 1B  shows a hair entanglement condition in a wrapping mode in a prior art drain cover grate; 
       FIG. 2  is a side view of a drain cover according to one preferred embodiment of this invention; 
       FIG. 3  is an open end view of the drain cover shown in  FIG. 2 ; 
       FIG. 4  is a side view of a drain cover having a solid end according to one preferred embodiment of this invention; 
       FIG. 5A  is a side view of an end contouring of a drain cover according to one preferred embodiment of this invention; 
       FIG. 5B  is a side view of an end contouring of a drain cover according to one preferred embodiment of this invention; 
       FIG. 5C  is a side view of an end contouring of a drain cover according to one preferred embodiment of this invention; 
       FIG. 6  is a top view of an end contouring of a drain cover according to one preferred embodiment of this invention; 
       FIG. 7  is a top view of an end contouring of a drain cover according to one preferred embodiment of this invention; 
       FIG. 8  is a top view of a drain cover according to one preferred embodiment of this invention; 
       FIG. 9  is a top view of a drain cover according to one preferred embodiment of this invention; 
       FIG. 10  is a top view of a drain cover according to one preferred embodiment of this invention; 
       FIG. 11  is a top view of a drain cover according to one preferred embodiment of this invention; 
       FIG. 12  is a top view of a drain cover according to one preferred embodiment of this invention employing shell elements; 
       FIG. 13  is a side view of a drain cover according to one preferred embodiment of this invention employing shell elements; 
       FIG. 14  is a side view of a drain cover according to one preferred embodiment of this invention employing shell elements; and 
       FIG. 15  is a front view of the drain cover shown in  FIG. 14 . 
   

   DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
     FIGS. 2–15  show various embodiments of drain cover  10  according to this invention. Drain cover  10  is preferably used in connection with a drain for a swimming pool, whirlpool bath, hot tub and/or other environment requiring drainage of water from an environment containing swimmers and/or bathers. As such, the term “drain” is used throughout the specification and claims to include any drain used in such an environment. Similarly, the terms swimmers and bathers are used interchangeably within this specification and include any person, animal and/or object that may become tangled or trapped in or against a drain cover. 
     FIGS. 1A and 1B  show a prior art grating element and two mechanisms by which a swimmer may get his hair tangled in such grating element.  FIG. 1A  shows how two or more groups of hair may become entangled and/or knotted under a bottom edge of the grating element, thus trapping the swimmer against the drain cover.  FIG. 1B  shows how one or more groups of hair may become wrapped around the grating element thus similarly trapping the swimmer against the drain cover. 
     FIGS. 2 and 3  show drain cover  10  according to a preferred embodiment of this invention wherein hollow tube  30  includes a single continuous slot  20  formed in a sidewall of hollow tube  30 . Slot  20  may be located anywhere around the periphery of tube  30  and need not be parallel to the tube sides. Hollow tube  30  is preferably formed of plastic, such as polyvinyl chloride (PVC), and/or any other appropriate material that is durable, resistant to degradation, strong and fairly workable. Preferably, hollow tube  30  is constructed of a material that is readily available and easily manufactured, such as extruded, to keep costs of drain cover  10  to a minimum. Additionally, a manufacturing process like extrusion is associated with inexpensive dies as contrasted with expensive injection molding molds. 
   Hollow tube  30  preferably comprises a circular cross-section, but alternatively may comprise a non-circular cross-section, including elliptical, polygonal or any other appropriate cross-section known to those having ordinary skill in the art. Hollow tube  30  is preferably formed with a cross-section length and slot size suitable to use within a pool and to permit sufficient flow rate through drain cover  10  and into the drain. 
   Fitting  50  is then used to connect hollow tube  30  with respect to the drain. Fitting  50  may be an elbow joint, expansion joint or any other fitting that facilitates a secure fit between the drain and drain cover  10 . 
   According to preferred embodiments of this invention, drain cover  10  may have end  37  of hollow tube  30  either open or closed.  FIG. 3  shows hollow tube  30  having an open end  37  while  FIG. 4  shows hollow tube having a closed or sealed end  37 . 
   Fitting  50  may be positioned at one end of hollow tube  30 , such as at end  35  as shown in  FIG. 2  or alternatively may be positioned between the ends of hollow tube  30  such as shown in  FIG. 8 . Preferably, fitting  50  results in drain cover  10  wherein hollow tube  30  and slot  20  extend parallel to the bottom of the pool/spa/tub, or hugs this bottom, and/or are recessed in this bottom. 
   Drain cover  10 , generally, and hollow tube  30 , specifically, are preferably of an appropriate length so that a swimmer cannot block the intake with his body to create a vacuum, thus preventing the potential for evisceration and body entrapment. According to one preferred embodiment of this invention, drain cover  10  is 24 inches long, although other lengths are also appropriate. 
   Likewise, the configuration of slot  20 , specifically the width of slot  20 , is selected to prevent swimmers&#39; finger entrapment. According to one preferred embodiment of this invention, slot width will not exceed 8 mm or will be greater than 1 inch. 
   Should free end  37  of drain cover  10  be configured so that it cannot be sealed by the human body, the length of drain cover  10  may be adjusted solely based upon flow capacity requirements, since evisceration or body entrapment will be prevented by the configured end. Such a configuration of open end  37  may involve sculpting open end  37  with alternative end contours  40  such as shown in  FIGS. 5A–C ,  6  and  7 , designed to prevent the sealing of the open end  37  by the human body.  FIGS. 5A–C  show end  37  having alternative vertical contours to prevent sealing by the human body while  FIGS. 6 and 7  show end  37  having alternative horizontal contours. 
     FIG. 8  shows one preferred embodiment of this invention wherein drain cover  10  includes fitting  50  positioned along hollow tube  30  to form a T-configuration. The T-configuration may include unequal tube lengths on either side of fitting  50  or equal tube lengths on either side of fitting  50 . 
   According to one preferred embodiment of this invention, shown in  FIG. 9 , second hollow tube  30 ′ is positioned perpendicularly with hollow tube  30 , second hollow tube  30 ′ having a second single continuous slot  20 ′ intersecting slot  20 . Such an arrangement may be preferable when a higher flow rate is desired or if the pool geometry requires a smaller footprint of drain cover  10 . 
   According to one preferred embodiment of this invention, drain cover  10  may comprise hollow tube  30  formed in a serpentine configuration, such as shown in  FIG. 10 , with slot  20  formed in a corresponding serpentine configuration. Alternatively, hollow tube  30  may be coiled, such as shown in  FIG. 11 , with slot  20  following the curvature of hollow tube  30 . Hollow tube  30  may alternatively be formed in any other configuration suitable for the application including decorative shapes, shapes that conform with a pool geometry or any other configuration within manufacturing limitations. 
   According to another preferred embodiment of drain cover  10  shown in  FIGS. 12–15 , shell  60  is positioned over the drain. Shell  60  preferably forms a spherical section having slot  20  within shell  60 . Alternatively, shell  60  may be trapezoidal, square, rectangular, triangular, elliptical or any other suitable domed geometry. 
   Slot  20  may be curvilinear and may be located anywhere on shell  60 , provided that the location does not result in a geometry that may entangle hair. Such a slot  20 , which is mathematically defined as “simply connected” within shell  60 , will result in a geometry wherein hair, string or other element may be extended within the slot and not wrap or entangle within shell  60 . 
   Shell  60  may be arranged with ridges, ribs and/or other projections, generally referred to as projections  62  in  FIG. 12 , that cannot be encircled by hair and yet prevent sealing of drain cover  10  with a swimmer&#39;s body or extremity. 
     FIG. 12  shows a top view of shell  60  according to one preferred embodiment of this invention. As shown, shell  60  includes two opposing parts  70 ,  70 ′ divided by slot  20 . 
   As shown in  FIGS. 13 and 14 , which are side views of two preferred shell embodiments, slot  20  is formed within the profile of shell  60  thereby dividing shell  60  into two opposing parts  70 ,  70 ′. The opposing part  70  has a maximum first height H 1  measured from the fitting  50  to the tip of the domed profile along the surface which forms the slot. The other opposing part  70 ′ has a maximum second height H 2  measured from the fitting  50  to the tip of the domed profile along the surface which forms the slot. As shown in  FIGS. 14 and 15 , the two opposing parts  70 ,  70 ′ of shell  60  may be positioned at different elevations H 1  and H 2 , respectively, relative to the surface in which the drain is located. 
   Preferably, drain cover  10  according to this preferred embodiment of the invention is significantly larger than the drain. A larger shell  60  drain cover  10  will prevent body suction entrapment and/or evisceration. Shell  60  is preferably sufficiently large so as to preclude the covering of slot  20  by the body of a swimmer/bather precluding thereby the creation of a vacuum. 
   According to one preferred embodiment of this invention, the width of slot  20  within the shell embodiment  60  will not exceed 8 mm or will be greater than 1 inch. 
   While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.