Eyeball fitting for increasing flow of return water to swimming pool

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BACKGROUND

Eyeball fittings are used to direct return water into a swimming pool. They have spherical exteriors so they can be turned to different angular orientations within a spherical seat in which they are held by a retainer ring. Water flows through their hollow interiors and out through a discharge opening that directs the water in a desired flow pattern within the pool.

While studying water flow through chlorinators arranged in swimming pool return lines, I discovered that the available eyeball fittings substantially constrict the water flow rate. This led to a closer examination of the eyeballs, revealing that they have hollow interiors leading to a wall at their discharge sides, with different diameter discharge openings formed in the wall. Such a construction creates substantial turbulence and significantly impedes the water flow. One brand of eyeball fitting adds an inner piece that fits within the discharge opening, reducing its size but streamlining the flow through path. This works somewhat better.

I then devised an eyeball fitting to maximize the through flow, not only making an inline chlorinator work better, but also improving the overall efficiency of the pool water filtration system. My eyeball fitting includes a more efficient eyeball that can replace the inefficient eyeballs in existing fittings, and it also includes a seat and a retainter ring combining to form a complete eyeball fitting. By increasing the water flow rate, my eyeball fitting can reduce the operating time for the pump and filter and thus reduce the energy cost of operating a pool. The larger flow rate through my eyeball fitting also directs a more vigorous steam of return water into a desired flow pattern within the pool.

SUMMARY OF THE INVENTION

My eyeball fitting includes an eyeball having a spherically shaped outside surface allowing it to be set at different angular orientations held by a retainer ring for directing return water into a swimming pool. Its opposite entrance and discharge sides have respective concentric entrance and discharge openings connected by an inside surface. The discharge opening has a sharp edge where return water leaves the eyeball and enters the swimming pool. The inside surface is smooth and even within the eyeball with no discontinuities or abrupt changes. The inside surface also curves continuously from the larger diameter entrance opening to the smaller diameter discharge opening in a curvature that gradually increases in radius as the inside surface gradually reduces in cross-sectional flow area proceeding from the entrance opening to the sharp discharge edge. A seat ring for my eyeball fitting has an internally curved entrance side leading to an exit side with a spherically shaped recess for receiving the spherical outside surface of the eyeball. The entrance side is smooth, even, and continuously curved at a gradually increasing radius of curvature proceeding from the entrance side toward the spherical recess.

DRAWINGS

FIG. 1 is a front elevational view of a preferred embodiment of my eyeball fitting mounted at an angular inclination;

FIG. 2 is a cross-sectional view of the eyeball fitting of FIG. 1, removed from its fixture and taken along the line 2--2;

FIGS. 3-5 are partially cross-sectional views of three different sizes of eyeballs for my eyeball fitting;

FIGS. 6-8 are respective front elevational views of the different size eyeballs of FIGS. 3-5;

FIG. 9 is a bar graph of test results showing how my eyeball fitting improves over prior art eyeball fittings; and

FIG. 10 is a cross-sectional view of the eyeball fitting of FIG. 1 mounted within a fixture at a discharge end of a return line.

DETAILED DESCRIPTION

My eyeball fitting 10 includes an eyeball 20 resting in seat 30 where it is held by a retainer ring 15 having thumb and finger projections 16 for screwing in threads 17. Seat ring 30 can drop into the inside of a fixture 11 ahead of retainer ring 15, and seat 30 and ring 15 can fit new and many existing return water fixtures.

The generally known environment of fixture 11, mounting eyeball fitting 10, is illustrated in FIG. 10. The output end 51 of fixture 11 has internal threads 52 in which seat ring 30 can be either screwed or removably fitted, as illustrated. Threads 17 of retainer ring 15 screw into threads 52 at output end 51 of fixture 11 to retain eyeball 20 in place and, for the illustrated arrangement, to also retain seat ring 30 against internal abutment 53. The input end 54 of fixture 11 has internal threads receiving connector 55 to which return line 56 is fastened with clamp 57. Full water flow through return line 56 passes through connector 55 and into fixture 11 where it flows through seat ring 30 and into the entrance opening 26 of eyeball 20. Many other known configurations of fixture 11 can also accommodate my eyeball fitting.

Eyeball 20 can replace existing eyeballs in conventional fittings and substantially increase the water flow rate. The combination of seat 30 and eyeball 20 further increases the water flow rate, and ball 20 and seat 30 can both be substituted in some existing fixtures. By using a suitable fixture 11, my complete eyeball fitting, including ball 20, seat ring 30, and retainer ring 15, can be mounted at the discharge end of any return line 56.

Eyeball 20 has a spherical exterior surface 24 sized to fit the spherical seats of existing eyeball fittings so that eyeball 20 can replace less efficient eyeballs. It preferably has an annular surface 23 arranged concentrically around discharge opening 21 on the discharge side of eyeball 20. Annular surface 23 is positioned to engage retainer ring 15 to limit the angular orientation of eyeball 20 as best shown in FIGS. 1 and 2.

Discharge opening 21 can vary in size as shown in FIGS. 3-8; but at any size, discharge opening 21 has a sharp discharge edge 22 where return water leaves eyeball 20 and enters a swimming pool. Any rounding, beveling, or irregularity reducing the sharpness of edge 22, as is common with prior art eyeball fittings, causes turbulence and reduces the through flow rate.

Entrance opening 26 on the entrance side of eyeball 20 is concentric with discharge opening 21 and has a diameter preferably as large as the pipe 56 leading to the eyeball fitting to accommodate maximum input flow. Since most pool return lines have an inside diameter of 11/2 inches, entrance opening 26 is preferably 11/2 inches in diameter, which is substantially larger than entrance openings of prior art eyeballs at about 11/8 inches. Entrance opening 26 is also larger than discharge opening 21.

Inside surface 25 smoothly and evenly curves from entrance opening 26 to discharge opening 21. It has a high surface finish and no discontinuities or abrupt changes, so that it minimizes turbulence in the flowing water.

Inside surface 25 is also continuously curved from entrance opening 26 to discharge opening 21, and the curvature of inside surface 25 has a radius that gradually increases as surface 25 gradually reduces in cross-sectional flow area proceeding from entrance opening 26 to sharp discharge edge 22. Making the radius of curvature increase continuosuly from entrance opening 26 to discharge edge 22 makes inside surface 25 curve continuously all the way to discharge edge 22. Specific radii of curvature of inside surface 25 vary, depending on the size of discharge opening 21, because entrance opening 26 is preferably always sized to the 11/2 inch maximum for receiving water inflow. As shown in FIGS. 3-5, this makes the minimum radii of curvature at the eyeball entrance openings smaller for eyeballs with smaller discharge openings and larger for eyeballs with larger discharge openings. Although curvature radii vary for different sizes of discharge openings 21, the radius of curvature for each size of inside surface 25 gradually increases from larger diameter entrance opening 26 to smaller diameter discharge edge 22.

Hollow regions 40 extend inward from the discharge side of eyeball 20 between discharge edge 22 and annular surface 23 for all eyeballs 20 that have smaller discharge openings than the maximum opening illustrated in FIG. 2. Radial spokes 41 extend across hollow regions 40, which extend to different depths, depending on the size of discharge region 21 for each eyeball 20. Hollows 40 reduce the amount of resin required, lighten the weight, and speed up the molding of eyeballs 20.

Seat ring 30 preferably has a cylindrical outside surface 31 sized to fit into many existing return line fixtures 11 used in constructing swimming pool return lines. Its entrance opening 36 on its entrance side is preferably somewhat larger than entrance opening 26 for eyeball 20. Internal surface 35 leads from entrance opening 36 to an exit side 32 having a spherically shaped recess 33 with a diameter smaller than entrance opening 36. Spherical exterior surface 24 of eyeball 20 fits within spherical recess 33 in seat 30, within which eyeball 20 is movable to varying angular orientations.

Internal surface 35 at the entrance side of seat ring 30 is smooth, even, and continuously curved at a gradually increasing radius of curvature and a gradually diminishing cross-sectional area proceeding from entrance opening 36 to spherical recess 33. The curvature of internal surface 35 is shaped for smoothly joining and continuing into the curvature of inside surface 25 of eyeball 20 having a maximum size discharge opening 21 set at a maximum angular orientation in seat 30 as shown in FIG. 2. This smoothly and continuously joins the curvatures of seat surface 35 and eyeball surface 25 along the inside of the bend that through flowing water follows in curving toward the angular orientation of discharge opening 21. The inside of the water flow bend is the most important surface to keep smooth and even, as the outside of the water flow bend naturally allows more flow room. For eyeballs 20 with smaller discharge openings 21, the curvatures of seat surface 35 and eyeball surface 25 do not flow continuously together as shown in FIG. 2.

I have extensively tested the comparative performance of my eyeball fitting and prior art eyeball fittings, using test arrangements having conventional swimming pool pumps and filters and realistically simulated return lines. My eyeball fitting consistently outperforms prior art fittings by producing larger gallons per minute flow rates as shown in FIG. 9 for each standard size of eyeball. Measurement of the electric current drawn by the pump confirms the higher flow rates of my eyeball fittings by indicating more efficient pumping. Pressure measurements also confirm higher flow rates through my eyeball fittings by indicating lower back pressures at the pump, filter, and return line.

Increased flow rate through my eyeball fittings benefits pool operation in several ways. The pump is more efficient and moves more water for the energy input. Filtration is also more efficient because of cycling the pool water through the filter at a faster rate. The higher filtration flow rate can reduce the duty cycle and the energy cost of operating the pool because the pump and filter can run for a shorter time interval each day. Automatic chlorinators in pool return lines also work more efficiently at high flow rates to ensure proper chlorination. Finally, a larger flow rate through an eyeball fitting directs a more vigorous return water jet for swirling the pool water.

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