Title:
Safety drain
Kind Code:
A1


Abstract:
Safety devices comprising axially elongated fittings having a plurality of relatively small channels extending therethrough are placed in the drain entry of drains for fluid containers such as swimming pools, wading pools, spas and the like to reduce or eliminate body entrapment, hair entanglement and the like.



Inventors:
Witte, Donald H. (Altus, OK, US)
Application Number:
10/418685
Publication Date:
09/23/2004
Filing Date:
04/18/2003
Assignee:
WITTE DONALD H.
Primary Class:
International Classes:
E04H4/12; (IPC1-7): E04H4/00
View Patent Images:
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Primary Examiner:
PHILLIPS, CHARLES E
Attorney, Agent or Firm:
Jack A. Kanz (Richardson, TX, US)
Claims:

What is claimed:



1. A drain for a fluid container comprising: (a) a first tubular conduit having an inlet end opening and an outlet with the inlet end opening adapted to drain fluid from a fluid container and the outlet communicating with a drain line; (b) a first safety fitting comprising an axially elongated body having an inlet face and an outlet face positioned within said first conduit with said inlet face substantially defining the inlet end opening of said first tubular conduit; and (c) a plurality of channels extending through said axially elongated body, each channel having an entrance opening in said inlet face and an outlet in said outlet face, wherein: (i) the length of each channel extending through said axially elongated body is at least approximately sixteen inches; and (ii) the entrance opening of each channel is shaped to prevent the entry of an object which is substantially circular in cross-section and has a cross-sectional dimension of approximately one-half inch.

2. A drain as defined in claim 1 including: (a) a second tubular conduit having an inlet end opening and an outlet with the inlet end opening adapted to drain fluid from said fluid container at a location spaced from the inlet end opening of said first tubular conduit and the outlet communicating with said drain line; (b) a second safety fitting comprising an axially elongated body having an inlet face and an outlet face positioned within said second conduit with said inlet face substantially defining the inlet end opening of said second tubular conduit; and (c) a plurality of channels extending through said axially elongated body, each channel having an entrance opening in said inlet face and an outlet in said outlet face, wherein: (i) the length of each channel extending through said axially elongated body is at least approximately sixteen inches; and (ii) the entrance opening of each channel is shaped to prevent the entry of an object which is substantially circular in cross-section and has a cross-sectional dimension of approximately one-half inch.

3. A drain as defined in claim 2 wherein: (a) said first tubular conduit and said second tubular conduit each extend substantially vertically from the bottom of said fluid container; (b) the outlet ends of said first and second tubular conduits communicate with said drain line; and (c) said drain line is positioned intermediate the bottom of said fluid container and the outlet ends of said first and second conduits and substantially equidistant from the inlet end opening of said first tubular conduit and the inlet end opening of said second tubular conduit.

4. A drain as defined in claim 2 wherein: (a) said first tubular conduit and said second tubular conduit extend from the bottom of said fluid container at an angle inclined with respect to the bottom of said fluid container; (b) the outlet ends of said first and second tubular conduits communicate with said drain line; and (c) said drain line is positioned substantially equidistant from the inlet end opening of said first tubular conduit and the inlet end opening of said second tubular conduit.

5. A safety fitting for a drain which includes a tubular conduit with an inlet end opening defining the drain inlet comprising: (a) an axially elongated body having an inlet face and an outlet face; (b) a plurality of inlet openings in said inlet face, each said inlet opening shaped to prevent entry of an object which has a cross-sectional diameter of approximately one-half inch; (c) a plurality of outlet openings in said outlet face; and (d) a plurality of individual channels extending through said elongated body, each channel having an axial length of approximately sixteen inches and connecting one of said inlet openings in said inlet face with an outlet opening in said outlet face.

6. A safety fitting as defined in claim 5 wherein said inlet openings are in the shape of arcs arranged to form concentric circles in said inlet face.

7. A safety fitting as defined in claim 5 wherein said inlet openings form substantially circular orifices in said inlet face.

8. A safety fitting as defined in claim 5 wherein said inlet face is inclined with respect to the central axis of said axially elongated body.

9. A safety fitting as defined in claim 5 wherein said inlet face lies in a plane substantially normal to the central axis of said axially elongated body.

10. A safety fitting as defined in claim 5 wherein said inlet face defines a contoured surface.

11. A safety fitting as defined in claim 5 wherein said axially elongated body is positioned within the inlet end of a tubular conduit which defines a drain inlet so that said inlet face is substantially coextensive with said drain inlet.

12. A drain for a fluid container including a first drain safety fitting having an inlet end and an outlet end with the inlet end defining a drain inlet face adapted to drain fluid from the fluid container and the outlet end communicating with a drain line, said first drain safety fitting comprising: (a) an axially elongated body having an inlet face and an outlet face; and (b) a plurality of channels extending through said axially elongated body, each channel having an entrance opening in said inlet face and an outlet in said outlet face, wherein: (i) the length of each channel extending through said axially elongated body is at least approximately sixteen inches; and (ii) the entrance opening of each channel is shaped to prevent entry of an object which is substantially circular in cross-section and has a cross-sectional dimension of approximately one-half inch.

13. A drain as defined in claim 12 wherein said inlet face is substantially co-planar with the bottom of said fluid container.

14. A drain as defined in claim 12 wherein said inlet face is not coplanar with the bottom of said fluid container.

15. A drain as defined in claim 12 wherein said inlet face is substantially hemispherical.

16. A drain as defined in claim 14 wherein at least part of said inlet face extends above the plane of the bottom surface of said fluid container.

17. A drain as defined in claim 12 wherein said inlet face defines a contoured surface.

18. A drain as defined in claim 12 including at least one open-faced groove in said inlet face extending between and connecting the entrance openings of at least two of said channels.

19. A drain as defined in claim 18 wherein said open-faced groove extends from at least one of said channels to a location on the periphery of said inlet face.

20. A drain as defined in claim 12 including a second drain safety fitting having an inlet end and an outlet end with the inlet end defining a drain inlet face spaced-apart from the drain inlet face of said first safety drain fitting adapted to drain fluid from the fluid container and the outlet end communicating with said drain line, said second drain safety fitting comprising: (a) an axially elongated body having an inlet face and an outlet face; and (b) a plurality of channels extending through said axially elongated body, each channel having an entrance opening in said inlet face and an outlet in said outlet face, wherein: (iii) the length of each channel extending through said axially elongated body is at least approximately sixteen inches; and (iv) the entrance opening of each channel is shaped to prevent the entry of an object which is substantially circular in cross-section and has a cross-sectional dimension of approximately one-half inch.

21. A drain as defined in claim 20 wherein: (a) said first drain safety fitting and said second drain safety fitting each extend substantially vertically from the bottom of said fluid container; (b) the outlet ends of said first and second tubular conduits communicate with a common drain line; and (c) said common drain line is positioned intermediate the bottom of said fluid container and the outlet ends of said first and second drain safety fittings and is substantially equidistant from the inlet end of said first drain safety fitting and the inlet end of said second drain safety fitting.

22. A drain as defined in claim 20 wherein: (a) said first drain safety fitting and said second drain safety fitting extend from the bottom of said fluid container at an angle inclined with respect to the bottom of said fluid container; (b) the outlet ends of said first and second safety drain fitting communicate with a common drain line; and (c) said common drain line is positioned substantially equidistant from the inlet end opening of said first safety drain fitting and the inlet end opening of said second safety drain fitting.

23. A safety fitting for a drain comprising: (a) an axially elongated body which defines a tubular conduit having an inlet face and an outlet face; (b) a plurality of inlet openings in said inlet face, each said inlet opening shaped to prevent entry of objects which have a predetermined cross-sectional diameter; (c) a plurality of outlet openings in said outlet face; and (d) a plurality of individual channels extending through said elongated body, each channel having an axial length of approximately sixteen inches and connecting one of said inlet openings in said inlet face with an outlet opening in said outlet face.

24. A safety fitting as defined in claim 23 wherein said inlet face is substantially hemispherical.

25. A safety fitting as defined in claim 23 including at least one open-faced transverse groove extending between and connecting the inlet openings of at least two of said channels.

26. A safety fitting as defined in claim 25 wherein said open-faced groove extends to the periphery of said inlet face.

27. A safety fitting as defined in claim 23 having at least one open-faced groove in said inlet face which extends from the inlet opening of at least one of said channels to the periphery of said inlet face.

28. A safety fitting as defined in claim 23 wherein said inlet face defines a contoured surface.

Description:

[0001] This is a continuation-in-part of application Ser. No. 10/390,460 entitled Safety Drain filed Mar. 17, 2003, now abandoned.

[0002] This invention relates to drain systems. More particularly, it relates to safety devices for drains for fluid containers such as swimming pools, wading pools, spas and the like which reduce or eliminate entrapment, hair entanglement and the like in such drain systems.

[0003] The popularity of therapeutic and recreational water pools such as swimming pools, wading pools, spas, hot tubs, whirlpool baths, etc., has been plagued by accidental user entrapment by submerged drains. Since body and hair entrapment in drain and/or re-circulation systems can cause serious physical injuries and/or death, various drain systems have been designed to minimize drain entrapment hazards. Grated drain covers with grate openings designed to prevent entry or passage therethrough of most human body parts can somewhat minimize the likelihood of drain entrapment, particularly when used with multiple spaced-apart drain entries connecting to a common drain line to effectively eliminate entrapment caused by substantially blocking a single drain entry. However, when hair is permitted to extend through a grate opening and into a line of flowing water, the hair tends to become entangled on the downstream side of the grate. Thus, a person whose hair is permitted to pass through a drain grate into the drain line can become physically trapped without blocking the drain opening. Since such hair entanglement does not necessarily substantially impede water flow though the entrapping drain, spaced-apart drain openings and other systems relying on pressure or flow variations in the affected drain cannot detect or prevent hair entrapment and cannot provide means for releasing the trapped victim.

[0004] In accordance with the present invention, hair entanglement and associated bodily entrapment in water pool drain systems is effectively prevented by providing the drain entry with an elongated fitting which divides the drain entry into a plurality of smaller inlets sized and shaped to prevent entry of large objects. Each of the smaller inlets communicates directly with a channel of substantially the same cross-sectional size and shape having a downstream length of approximately sixteen (16) inches or more (approximately 40 cm. or more). The elongated fitting thus provides a plurality of elongated channels of relatively small diameter extending downstream from the drain entry grate which prevent hair which enters the drain from becoming entangled downstream from the drain entry grate. Other features and advantages of the invention will become more readily understood from the following detailed description taken in connection with the appended claims and attached drawing in which:

[0005] FIG. 1 is an elevational view, partially in section, of a pool drain installation employing safety drain fittings in accordance with one embodiment of the invention;

[0006] FIG. 1A is a fragmentary elevational view, partially in section, of the drain installation of FIG. 1 taken through line 1A-1A;

[0007] FIG. 2 is a top plan view of the safety drain fitting shown partially in section FIG. 1;

[0008] FIG. 3 is a fragmentary sectional view taken through line 3-3 of the safety drain fitting shown in FIG. 2;

[0009] FIG. 4 is a top plan view of an alternative embodiment of a safety drain fitting of the invention;

[0010] FIG. 5 is an elevational view, partially in section, of an alternative drain installation employing the principles of the invention;

[0011] FIG. 6 is an enlarged fragmentary sectional view of the safety drain fitting illustrated in the drain installation of FIG. 5;

[0012] FIG. 7 is a fragmentary side elevational view, partially in section, of an alternative embodiment of the safety drain fitting illustrated in FIG. 2;

[0013] FIG. 8 is a top perspective view of an alternative embodiment of the safety drain fitting illustrated in FIG. 4; and

[0014] FIG. 8A is a fragmentary sectional view taken through line 8A-8A of the safety fitting of FIG. 8.

[0015] The drawing is incorporated into and forms part of the disclosure of this specification to illustrate exemplary embodiments of the invention. Throughout the several views of drawing like reference numerals designate corresponding elements. The figures are not to scale but are intended to disclose the inventive concepts by illustration. It will be recognized that the principles of the invention may be utilized and embodied in many and various forms. In order to demonstrate these principles, the invention is described herein by reference to specific preferred embodiments. The invention, however, is not limited to the forms illustrated and described. Furthermore, the invention is not limited to use in connection with water pools but may find utility in other similar applications involving flow of fluids from a container into an outlet line through a drain or the like.

[0016] For purposes of this disclosure, the term “drain” is used to mean any method, system or apparatus by which a fluid is moved from a container to an outlet line across a pressure gradient. Thus “drain” may be used to refer to gravity systems wherein fluid flows from a container into an outlet by gravity as well as systems wherein a pressure gradient is induced by increasing the relative pressure in the container or reducing the relative pressure in the outlet line with a pump or the like.

[0017] When fluid flows from a container into an outlet drain a pressure differential is developed at the drain entry. When the fluid is a relatively dense liquid such as water, the total pressure exerted on a body blocking the drain is proportional to the cross-sectional area of the drain and thus can be quite substantial. Similarly, where a suction pump is used to withdraw fluid from the container, or where the container is itself pressurized, a relatively large pressure differential can exist across the outlet drain opening.

[0018] Many water pools, such as swimming pools, wading pools, spas, etc., employ a drain system in which the water is withdrawn at or near the bottom of the pool for re-circulation and/or removal. Because of the pressure differential across the drain inlet, a body which blocks the drain inlet can become trapped at the drain inlet, particularly where a suction pump or the like is employed to withdraw the water. Five (5) potentially serious hazards are commonly associated with such drains:

[0019] (i) Evisceration/disembowelment which can occur when negative pressure is applied directly to the intestines of the victim through an unprotected drain inlet.

[0020] (ii) Body suction entrapment which can occur when negative pressure is applied to a large portion of the victim's body or large limbs, sealing the body against the drain inlet and resulting in entrapment against the drain inlet.

[0021] (iii) Mechanical entrapment which can occur when a limb, such as a finger or toe, is caught in a small opening of a drain inlet or drain cover grate.

[0022] (iv) Limb entrapment which can occur when a limb is inserted into an opening of a drain inlet, resulting in mechanical entrapment or swelling. This most frequently occurs when a drain cover or grate is inadvertently removed or otherwise missing.

[0023] (v) Hair entanglement which occurs when long hair becomes snagged, knotted or entangled with a drain cover grate or the like. Heretofore, all five major entrapment hazards could not be addressed with a single solution.

[0024] In order to minimize the likelihood of body suction entrapment, it has become common practice to employ at least two spaced-apart drain inlets communicating with a common drain line. The drain inlets are preferably placed at locations separated by a distance sufficient to preclude a human body from blocking both inlets simultaneously. Thus, if a body inadvertently blocks flow through one of the inlets, flow is diverted to the other inlet and the pressure differential across the blocked drain inlet, depending on the mass, flow rate, etc., of the water in the conduit connecting the blocked drain inlet to the common drain line, is rapidly substantially reduced. The body thus is not trapped against the blocked inlet by a large pressure differential.

[0025] FIG. 1 illustrates a spaced-apart drain inlet system in which the bottom 10 of a container such as a pool or the like has a first drain inlet 11 and a second drain inlet 12 communicating with a common drain line 13. It will be appreciated that in the drain arrangement of FIG. 1, if either first drain inlet 11 or second drain inlet 12 is blocked, flow through the other drain inlet will continue; the pressure differential across the blocked drain inlet will be minimized; and the blocking body will not be trapped against the drain inlet by a large pressure differential. It will be recognized, however, that spaced-apart drain inlets may still present evisceration/disembowelment hazards if the conduit connecting the spaced-apart drain inlets contains a large mass of moving liquid. Even though blocking of one drain inlet does not block flow through the entire system, the inertia of a large mass of moving water abruptly stopped by blockage of a drain inlet can temporarily create a large pressure differential (suction) at the blocked drain inlet. Accordingly, the spaced-apart drain inlets are usually separated by a distance of only a few feet and the size of interconnecting conduit limited so that pressure can be rapidly equalized across the blocked drain inlet without overcoming a large suction surge caused by the inertia of a large mass of moving water in the conduit connecting the blocked inlet to the common drain line.

[0026] To prevent entry of large bodies into the drain system, drain inlets are ordinarily protected by a grate. In order to minimize mechanical entrapment of human body parts in grates used in such drain inlets, grates used for swimming pools, etc., are ordinarily designed to comply with applicable regulations and standards. Most current regulations applicable to swimming pools require that the grate openings be sized and shaped so that a dowel of predetermined diameter cannot pass through the grate. The diameter of the dowel used for this measurement is determined by ASTM or ASME standards and is usually three-eighths inch or one-half inch. Accordingly, the size and shape of such grate openings described hereinafter as one-half inch is intended to describe the current applicable regulations or standards prescribed by ASTM or ASME. While such grates affectively prevent most mechanical entrapment hazards, such grates are frequently accidentally or inadvertently removed or not replaced after maintenance, cleaning or the like. In such instances, the drain inlet with a missing grate presents a serious mechanical entrapment hazard.

[0027] Since conventional grates are designed to prevent passage of a solid body which has a diameter greater than about one-half inch, long hair can easily be drawn into the drain system through conventional grates. Most such conventional grates have an axial length (thickness) in the direction of water flow of less than about one-half inch. Thus, long hair passing through the grate can (and does) often extend through the grate and into the drain line. Flowing water passing over the hair tends to entangle the hair downstream from the grate. The hair thus becomes knotted and tied to the grate and the body to which the hair is attached (such as a person's head) becomes attached to the grate without blocking water flow. Accordingly, such catastrophic entrapment is not precluded by spaced-apart drain inlets or other systems which react to pressure or flow variations in the drain system.

[0028] In accordance with the present invention, the conventional grate is replaced by (or used in connection with) a drain safety fitting 15 which comprises an axially elongated body having an inlet face 16 and an outlet face 18 with a plurality of channels 17 extending axially through the body from the inlet face 16 to the outlet face 18. As illustrated in FIGS. 1-3, the safety fitting 15 is positioned within a drain conduit 14 (the entry end of which defines the drain inlet) and has a cross-sectional size and shape coextensive with the cross-sectional entry opening of the drain inlets 11, 12. The inlet face 16 thus forms the drain entry grate (or may be fitted directly downstream from a conventional drain entry grate) and serves to prevent the passage of large solid bodies into the drain system.

[0029] As illustrated in FIGS. 1, 3 and 7, a plurality of channels 17 extends axially through the body of the safety fitting 15 from the inlet face 16 to the outlet face 18. In the preferred embodiment, the axial length of the safety fitting 15 from the inlet face 16 to the outlet face 18 is approximately sixteen (16) inches and the channel openings in the inlet face 16 are shaped to prevent the passage of a one-half inch dowel therethrough (or a three-eights inch diameter dowel, depending on the applicable ASTM, ASME or other standards or regulations). Accordingly, the inlet face 16 of safety fitting 15 may provide the function of a drain grate. However, since the axial length of the channels 17 is approximately sixteen (16) inches or more, hair drawn into each channel 17 is confined therein and cannot become entangled with hair in adjacent channels. Therefore, hair passing through the drain grate cannot become entangled on the downstream side of the drain grate unless the hair is substantially longer than the axial length of channels 17.

[0030] It will be recognized that installation of axially elongated safety fittings 15 which extend a substantial distance below the bottom of a pool, etc., can become expensive and tedious when they connect with a common drain line positioned a distance substantially below the bottom of a pool. Much of the difficulty of such installations can be overcome by using the drain installation arrangement illustrated in FIGS. 1 and 1A.

[0031] As shown in FIG. 1, the spaced-apart drain conduits 14 extend vertically from the bottom 10 of the pool. If the axial length of the safety fitting 15 is sixteen (16) inches, the length of each drain conduit 14 must be at least sixteen (16) inches. To avoid burying the common drain line 13 at an unnecessary depth, drain conduits 14 are each joined to a reducing elbow 19 which is connected to a centrally positioned riser 20 through lines 21 and tee 22. The riser 20 is connected to common drain line 13 at a point substantially equidistant from first and second drain inlets 11, 12 using conduits of substantially matching size and length. Accordingly, substantially equal pressure differentials will be developed across first and second drain inlets 11, 12. However, if one drain inlet is blocked, flow will continue through the other. Since flow through the unblocked inlet is unrestricted, the pressure differential across the blocked inlet is rapidly reduced, thereby avoiding entrapment of a body blocking only one of the drain inlets 11, 12. In this arrangement, only the area immediately below the drain inlets 11, 12 need be excavated to permit connection to a common drain line 13 placed at a relatively shallow depth.

[0032] Substantially elongated safety fittings 15 may also be employed in the alternative arrangement illustrated in FIGS. 5 and 6. In this arrangement the drain conduits 14 are positioned to incline from the bottom 10 of the container toward a common drain line 13. By placing the drain conduits 14 in an inclined position, the vertical depth of the common drain line 13 may be reduced without reducing the axial length of the safety fittings 15. To accommodate placement of the safety fitting 15 in the inclined drain lines 14, the inlet face 16 may, of course, be inclined with respect to the axial length of the safety fittings 15 so that the inlet face 16 is positioned substantially at the inlet end opening of drain conduits 14. To maintain the desired axial length of each of the channels 17, the outlet face 18 should be similarly inclined as illustrated in FIG. 6. Use of inclined drain conduits 14 as illustrated in FIG. 5 also reduces the length of conduit 14 connecting the drain inlet to the common drain line 13. Since the length of drain line 14 is reduced, and part of its volume is occupied by elongated safety fitting 15, the mass of water contained in drain line 14 is substantially reduced, thus minimizing the inertia suction caused by abrupt blockage of the drain inlet.

[0033] It should be recognized that the cross-sectional geometry of the inlet end openings of the channels 17 in the safety fitting 15 is not limited to any particular configuration. The major requirement is only that each opening will not permit entry of a dowel of the diameter prescribed by applicable regulations and standards for drain grates. Accordingly, various configurations of the inlet openings in conduits 17 may be utilized, depending on the method of manufacture, materials used, etc. For example, the inlet face 16 may take the configuration of a conventional concentric drain grate as shown in FIG. 4. In this embodiment, each channel 17 (and its associated inlet end opening) takes the shape of a segmented arc so that the channels 17 are arranged as segments of concentric circles. Alternatively, the inlet end openings can be in the form of closely spaced substantially rectangular or circular (including such geometries as pentagonal, hexagonal, etc.) openings. So long as the length of each channel 17 extending through the elongated body of the safety fitting 15 is approximately sixteen (16) inches and the inlet opening of each channel 17 is shaped to prevent entry of an object which is substantially circular in cross-section and has a cross-sectional dimension of one-half inch, the safety fitting 15 will provide the grate structure required for pool drains and prevent entanglement of hair and the like extending downstream from the entry face of the grate.

[0034] Body suction entrapment occurs when the victim's body (or a large limb) forms a seal against and therefore obstructs essentially all flow through a drain inlet. The inlet face 16 of the fitting 15 of the invention, however, may be configured to reduce the likelihood of complete blockage and thus reduce the likelihood of body suction entrapment. For example, the inlet face 16 of the safety fitting 15 may be contoured so that the inlet face is non-planar. A contoured inlet face is less likely to be blocked by a human body or body part because it is difficult to form a complete seal against a contoured surface. As illustrated in FIG. 7, the inlet face 16 of the safety fitting 15 may be dome-shaped (substantially hemispherical) or otherwise configured and positioned within the drain inlet 11, 12 so that all or a portion of the inlet face 16 projects above the floor surface of the bottom 10 of the pool or other container. When so configured and positioned, the inlets to channels 17 are somewhat inclined with respect to the surface of bottom 10 and positioned at various elevations with respect to the surface of bottom 10. Accordingly, complete simultaneous blockage sufficient to seal all inlets to channels 17 is less likely to occur, reducing the likelihood of body suction entrapment.

[0035] Transverse open-faced grooves 30 or the like as shown in FIG. 8 and FIG. 8A may also be formed in the inlet face 16 to form a contoured surface. Grooves 30 are preferably at least as deep as they are wide and preferably extend from peripheral edge to peripheral edge (not necessarily the full diameter) of the inlet face 16. Grooves 30 also connect the inlet orifices of at least two channels 17. Such grooves 30 thus provide lateral paths for fluid flow from various locations adjacent the periphery of the inlet face 16 which are below the major plane of the surface of inlet face 16. Such lateral paths thus prevent total blockage and sealing of the entire drain inlet unless the full area of the inlet face 16 is completely obstructed.

[0036] It should be noted that lateral grooves 30 may be formed in the inlet face of safety fitting 15 regardless of the configuration or shape of the inlets to channels 17 and regardless of whether the inlet face 16 is flat, domed or any other configuration. Furthermore, if the peripheral edge of safety fitting 15 is slightly elevated with respect to the floor surface of bottom 10, the grooves 30 extending to the peripheral edge provide a lateral or side entry path, thereby further reducing the likelihood that a body can form a seal over the entire inlet face 16.

[0037] Various other surface shapes may be utilized to form contoured surfaces. For example, the inlet face 16 may have a central dome surrounded by a circular depression or may have asymmetrical depressions and/or raised portions. Accordingly, for purposes of this disclosure the term “contoured surface” means any surface which is not substantially planar.

[0038] Various methods and materials may be used to fabricate the safety fittings of the invention. For example, the elongated body of the fitting 15 may be machined from a unitary piece of metal, plastic stock or other material. It may be formed as a unitary piece (or multiple fitted pieces) by molding or extrusion. Where the elongated body is formed by extrusion, the walls of the individual channels 17 may be relatively thin without degrading structural integrity when the channels 17 define closely packed geometric shapes such as the hexagonal shapes shown in FIG. 2. Obviously, other geometric shapes may be used as desired.

[0039] It should be recognized that the conduits 14 in which the safety drain fittings 15 are placed may be of any desired cross-sectional geometry and may be uniquely designed to accept variously shaped safety drain fittings. Since the safety drain fittings 15 are intended to be positioned at the drain entry, conduits 14 may be designed to accept and support the safety fittings 15 so that the inlet face 16 is submerged. For example, although the drain inlets 11, 12 are illustrated as substantially coplanar with the bottom 10 of the container. It will be recognized, however, that the drain inlets (and thus the inlet face 16 of fitting 15) need not be positioned horizontally or at the bottom of the container. The drain inlet may, for example, be aligned vertically (or at any other orientation) and positioned in a wall, step or other submerged surface of the container. Regardless of the orientation of the submerged drain inlet, the safety fitting 15 performs the function of a conventional grate and the need for conventional grates is eliminated. As shown in FIGS. 1-3, the inlet face may be in a plane normal to the central axis of the axially elongated body. Alternatively, where the axially elongated body is positioned in a conduit 14 which is inclined with respect to the bottom 10 of the container as shown in FIGS. 5-6, the inlet face 16 may be inclined with respect to the central axis of the elongated body so that the inlet face 16 lies in a plane substantially parallel with the plane of the bottom of the container. In either configuration, the inlet face 16 of the fitting 15 may be domed, grooved or otherwise contoured as described above to reduce the likelihood of body suction entrapment and may be elevated above (or below) the supporting wall of the container to reduce the likelihood of a single body sealing the entire entry to the drain.

[0040] Since the safety fitting 15 is approximately sixteen (16) inches long, it is unlikely that the safety fitting can be accidentally removed. Furthermore, since the channels 17 are approximately sixteen inches long, mechanical entrapment resulting from catching a finger or toe in the inlet face is highly unlikely. Accordingly, use of the safety fitting of the invention virtually eliminates the likelihood of either type of mechanical entrapment as well as hair entanglement.

[0041] It should be recognized that safety fitting 15 need not be fitted within a separate drain conduit 14 but may itself form the drain conduit 14. For example, safety fitting 15 may be extruded (or otherwise formed) as a unitary body which is permanently secured in the wall or bottom of a pool or the like so that the inlet face 16 forms and defines the drain inlet. The opposite end of the safety fitting 15 may then be joined directly to conduit 14 so that outlet face 18 is positioned within the drain conduit 14. In this arrangement, the safety fitting 15 is permanently secured to the supporting wall and forms part of the drain conduit 14. Accordingly, since the fitting 15 is permanently mounted in the container wall or bottom and inlet face 16 defines the drain inlet and forms the drain inlet grate, the submerged drain inlet grate can never be accidentally or inadvertently removed to expose an ungrated drain opening.

[0042] From the foregoing it will be recognized that the principles of the invention may be employed to completely eliminate the possibility of hair entanglement and limb entrapment. The likelihood of mechanical entrapment is also minimized by appropriate selection of inlet orifice size and configuration. Since contoured surfaces such as lateral open-faced grooves greatly reduce the likelihood of sealing the entire face of a drain inlet and the safety fitting itself reduces the mass of liquid forming suction inertia when one of a pair of spaced-apart drain inlets is blocked, the likelihood of evisceration resulting from drain blockage is greatly reduced. Furthermore, the safety fitting of the invention and drain installations disclosed may be readily used to retrofit existing pools without major construction expense.

[0043] The size and open areas of the inlet face 16 of the safety fittings 15 will obviously affect rates of flow through the safety fittings and pressure differentials thereacross. However, the preferred size, orientation and open area of each safety fitting may be readily calculated to be compatible with flow lines, pump capacities and other system variables using known standard fluid dynamics and engineering principles.

[0044] While the invention is primarily designed to provide means for preventing hair entanglement and other entrapment in drains for water pools and the like, it will be apparent from the foregoing that the principles of the invention may find utility in other applications. It is to be understood, therefore, that even though numerous characteristics and advantages of the invention have been set forth in the foregoing description together with details of the structure and function of the invention, this disclosure is to be considered illustrative only. Various changes and modifications may be made in detail, especially in matters of shape, size, arrangement and combination of parts, without departing from the spirit and scope of the invention as defined by the appended claims.