US 3815161 A
A weir for use in a swimming pool skimmer is pivotally mountable in the throat of the skimmer and has a large flat surface facing toward the entrance to the throat. The upper end of the weir is also a flat surface, the plane of which intersects the plane of the other flat surface at an angle of about 45 DEG . The weir is hollow under the angularly disposed surface and that surface terminates in a sharp edge, so that when water is drawn from the pool into the skimmer to achieve a skimming action, the water flows across the sloping surface in close and quite uniform proximity thereto regardless of the angle of inclination of the weir, and dips downwardly as it leaves the edge of the weir and enters the well of the skimmer.
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Description (OCR text may contain errors)
United States Patent 91 Baker 1111 3,815,161 [451 June ll, 1974 1 SWlMMlNG POOL SURFACE SKIMMJNG WEIR 751 lnventor: William 0. Baker, Corona Del Mar,
 Assignee: Baker Hydro Inc., Irvine, Calif.
 Filed: Apr. 16, 1973 21 Appl. No.: 351,810
 US. Cl. 4/172.17  Int. Cl E04h 3/16, E04h 3/18  Field of Search 4/172.19, 172, 172.15,
Primary Examiner-Henry K. Artis  ABSTRACT A weir for use in a swimming pool skimmer is pivotally mountable in the throat of the skimmer and has a large flat surface facing toward the entrance to the throat. The upper end of the weir is also a flat surface, the plane of which intersects the plane of the other flat surface at an angle of about 45. The weir is hollow under the angularly disposed surface and that surface terminates in a sharp edge, so that when water is drawn from the pool into the skimmer to achieve a skimming action, the water flows across the sloping surface in close and quite uniform proximity thereto regardless of the angle of inclination of the weir. and dips downwardly as it leaves the edge of the weir and enters the well of the skimmer.
18 Claims, 2 Drawing Figures SWIMMING POOL SURFACE SKIMMING WEIR BACKGROUND OF THE INVENTION The weir which is the subject of the present application is an improvement on the weirs disclosed in copending application Ser. No. 7,000 filed Jan. 30, 1970 by Brackston T. Whitaker and entitled SWIMMING POOL SURFACE SKIMMING WEIRS. Prior to the discovery of the weirs that are the subject of that application, it had been the general practice to employ, in association with the skimmers of swimming pools, weirs of uniform thickness from top to bottom with the top disposed at approximately a right angle to the inner and outer faces. The above identified co-pending application discloses several embodiments of weirs, differing from the conventional flat weir by having a flat to mildly convex surface presented toward the entrance of the throat of the skimmer and having at their upper ends various contours providing an acute angle of the intersection of the outer and inner surfaces. Such weirs were found to have improved skimming action over weirs previously known.
SUMMARY OF THE INVENTION A weir which embodies the present invention has, in common with weirs of the prior art, a broad flat surface facing outwardly from the skimmer throat toward the pool. It is biased to stand generally upright when a skimming operation is not in progress and the water in the pool is calm. In contrast with prior art weirs, however, a weir embodying the present invention does not have its top surface normal to its face, but has its top surface disposed in a plane sloping inwardly away from the poll at an angle of the order of 45 relative to the face of the weir. The free edge of the sloping surface is a thin, knife-like edge'and the weir is hollow below the sloping surface.
As is well known, when a skimmer is operated by circulating the water from the skimmer well through the filtering and water pumping equipment of the pool and back to the pool, the weir pivots inwardly until the weir has been completely submerged and water flows across its top, from the pool to the skimmer well, Generally, it is the practice to maintain a water level such that the weir will not be pivoted down into aflat position in order for water to escape over its top, but such that it will pivot to a slanting position with an acute but substantial angle between the outer face of the weir and the normal water surface level of the pool. In the case of a weir embodying the present invention, movement of the weir inwardly from an upright position through an angle of 45, would bring its sloping upper surface substantially into parallelism with the water surface in the pool in a quiescent state.
However, the water level and water velocity conditions may be such that a weir embodying the present invention may move inwardly more than 45. The junction of its outer face and upper sloping surface is then completely submerged with the upper sloping surface sloping downwardly away from the quiescent water level condition. As the water flowing through the throat approaches the junction of the outer surface and the sloping surface, it dips downwardly to follow the sloping surface with a generally uniform or mildly diminishing depth, in a swift flow which may be shallower at the point where the surface leaves the knife-like edge of the sloping surface of the weir than it is as it crosses overthe junction of the flat face of the weir and the sloping surface. It dips downward further after leaving the knife-like edge before flowing into the well of the skimmer in a configuration of surface ripples. This plunging of the water surface downwardly along the sloping upper end of the weir and dipping downwardly further. as it leaves the knife-like edge of the sloping surface of the weir produces a surface velocity of the water passing across the top of the weir that produces a greatly improved flow of surface debris into the entrance of the skimmer and thus accomplished a better skimming action than previously known weirs.
DESCRIPTION OF THE DRAWINGS For a complete understanding of the invention, reference may be had to the following detailed description to be interpreted in the light of the accompanying drawings wherein:
FIG. 1 is a vertical sectional view of the skimmer of a swimming pool having installed therein a weir in accordance with thepresent invention, the weir being partly broken away and shown in section; and
FIG. 2 is a perspective view of the weir shown in FIG. 1, viewing the weir from the inside.
Referring now to the drawings and particularly to FIG. 1, the reference numeral 10 designates the wall of a swimming pool and in accordance with a common practice the wall is topped by a coping 12. An opening is provided in the wall of the swimming pool below the coping l2 and in location which includes the usual level 13 of water that is maintained in the pool. Into this opening is installed the swimming pool skimmer, designated generally by the reference numeral 14. The skimmer 14 may comprise, according to previously known design, a housing 16 and a throat 18 which communicates with the swimming pool at the normal water surface level. The throat 18 is defined by side walls 20 and upper and lower walls 22 and 24 respectively. Access to the housing 16 is gained through an opening at the top-which is fitted with a cover 26 to permit removal of a strainer 28 which is provided to prevent the entry of large solid objects into-the pump and filtering system for the pool (not shown) through a conduit 30. A main drain conduit 32 is shown as connecting to the well 33 of the housing 16. These elements and combinations are known in the prior art, and a great many variations made be made depending upon the particular requirement.
Inside the throat 18 of the skimmer and near its entrance a weir, designated generally by the reference numeral 40, is pivotally mounted on the lower wall 24 of the skimmer 18 by means of pivots 42.
Referring now to FIG. 2, in addition to FIG. 1, the weir 40 is a hollow shell and a preferred embodiment thereof is molded of plastic. There are a number of types of plastic which are suitable for the purpose, an example being an ABS resin which is usually a mixture of styrene-acrylonitrile copolymer with acrylonitrilebutadiene rubber. These are thermoplastic resins with high impact strength, high heat distortion strength, and are resistant to action of most solvents, oils and chemicals. The weir could, of course, be fabricated from metal, but it needs to have a high resistance to corrosion in view of the usage in the swimming pool of chemicals, such as chlorine and an acid to counteract bacteria and the formation of algae.
As mentioned previously, the weir 40 is in the form of a hollow shell and its outside, the side that is presented toward the swimming pool when the weir is mounted in the throat 18 of the skimmer, is comprised of three panels,-namely a major panel 44 and two minor panels 46 and 48. The panels 46 and 48 may be considered as extensions of the major panel 44 and may be integral therewith, blending or merging into one another in a curvature 50 of relatively short radius. End panels 52 bridge the end of the minor panels 46 and 48 and complete the shell, so that from the inside the weir has a generally rectangular configuration. The width of the weir from one end panel 52 to the other is only slightly less thanthe width of the skimmer throat to permit free pivoting of the weir, while extending across substantially the entire throat width.
lnteriorly, the weir 40 may be provided with stiffening or reinforcing walls 54 extending across from one end panel 52 to the other and it may be further reinforced by gussets 56 joining the lower reinforcing wall 54 to the inside surface of the minor panel 48 and by gussets 58 joining the upper reinforcing wall 54 to the inside surface of the minor panel 46. It will be understood that all of the reinforcing components 54, 56 and 58 may be integral parts of a weir produced by a molding process.
The hinge pins 42 at the lower ends of the side walls 52 of the weir 40 may also be integral with those side walls and formed by molding. It follows from this that the side walls 20 of the throat 18 of the skimmer will be provided with cylindrical sockets (not shown) to receive the hinge pins 42. As indicated by the reference numeral 60 in FIG. 2 the minor panel 48 of the weir may be slotted adjacent to the locations of the hinge pins 42 on the end panels 52 so that'the hinge pins 42 are carried by a yieldable portion of the end plates 52, the end plates being thin enough to be flexible so that the hinge pins 42 may be snapped into the sockets provided in the walls 22 of the weir to receive the hinge pins 42. In order to impart buoyancy to the weir 40, which in turn will bias the weir toward an upright position in the throat entrance when there is water in the entrance to the throat at the usual surface level of the swimming pool, a block 62 of material having a specific gravity less than that of water, such as expanded polystyrene is fitted into the interior of the weir in the space bounded by the end plates 52 and the reinforcing walls 54. As specifically shown in FIG. 2, the two reinforcing gussets 58 and the two inner ones of the four gusstes 56 may have attached thereto, in spaced relation to the outer surfaces of the walls 58, flange segments 64 which receive and frictionally retain right angled clips 66 which overlie the exposed surface of the block 62 of polystyrene and retain it in the weir..
Attention is now directed particularly to the minor panels 46 and 48, the planes of which, with that of the major panel 44, form the outer face of the weir. The slope of the minor panel 48 relative to that of the major panel 44 has the principal purpose of providing clearance at the bottom of the weir for pivotal mounting adjacent to the flange 72, but the angle between the planes of these two surfaces is not particularly critical.
On the otherhand, it is important that the angle of the plane of the minor panel 46 of the face of the weir relative to the plane of the major panel 44 be such as to position the minor panel 46 substantially horizontal or preferably very slightly inclined downward toward the housing 16 when the weir is in operation as shown in FIG. 1. Preferably the downward inclination should not exceed about It has been found that, in the preferred embodiment, this is. accomplished when the angle between the planes of the minor panel 46 and the major panel 44 is generally'in the neighborhood of 45. Another significant aspect of the geometry of the weir is that the free edge of the minor panel 46 of the weir 40- is tapered to approximately knife edge thinness forming at the free edge a lip 74. A further aspect of the geometry of the weir is that, interiorly, between the inner surface of the minor panel 46 and the upper strenghtening wall 54, the weir is hollow. These features impart to the preferred embodiment of the weir the capability of the weir to perform in a superior manner in a skimming operation.
FIG. 1 displays in phantom the normal position of the weir 40 when the circulating pump is off. The weir then issubstantially upright and prevents debris from floating back out of the housing 16 into the pool. FIG. 1 shows in solid lines a typical water surface condition in relation to the weir when the skimmer is in operation. The circulating equipment of the pool draws water out of the skimmer well 33 through the conduit 30, thereby causing the weir to move pivotally in a clockwise direction until it is beneath the surface of the pool water. Water from the pool then continuously flows over the weir and through the well 33. In normal operation the major panel 44 is submerged and the minor panel 46 is slightly submerged just below the water surface, and is horizontal, or preferably slightly inclined downward as shown. In this condition beginning at a point approximately above or slightly in advance of the arcuate surface 50 by which the major panel 44 and the minor 46 merge into one another the water begins to slope downwardly and it follows generally or slightly approaches the surface of the minor panel 46 so that the depth of water passing over the minor panel 46 where it leaves the lip 74 is less than the depth at the point that it passes over the arcuate junction between the two surfaces. The sloping of the water surface downwardly in general conformity with or approaching the surface of the minor panel 46 is indicated at in FIG. I. As the water leaves the lip 74 it dips downwardly appreciably as indicated at 92 and the remainder'of the water surface in the skimmer is comprised of ripples such as 94 which may have purely randum locations.
Without intending to be bound by any particular explanation it is theorized that because the free edge of the minor surface 46 of the weir is a sharp knife-like edge and because inside the inner surface of the minor panel 46 the weir is hollow, the rapid flow of water off the lip 74 creates a suction inside or just beneath the hollow formed by the inner surface of the minor panel 46 and the upper surface of the upper reinforcing wall 54 by drawing water from this area. It is further theorized that this suction results in a circulation of water over an extended distance and a path having a closed geometrical configuration, as, for example, generally oval, beneath the hollow in the upper end of the weir 40, as represented by the dotted lines 96 the direction of the circulation being indicated by the several arrow points. Because the direction of the circulation at the left of the lip 74 is in an upward direction it would appear that there may be sufficient velocity in this flow for some of the water to impinge upon the inner surface of the minor panel 46 of the weir 40. It has been observed that the weir constructed in the manner set forth herein is more stable than any heretofore known, the stability being evidence by a lessening in the tendency of the weir to oscillate or otherwise follow disturbances of the water in the pool itself. It is thought that this stability is achieved by a neutralizing or counterbalancing in part of the water pressure on the face of the weir 40 by the circulatory pressure beneath the minor panel 46 of the weir.
Another observed advantage of the weir embodying the invention is a lessening in the tendency for the formation of a vortex or whirlpool in the well 33 of the skimmer. It is well known that when liquids drain rapidly from basins such draining is frequently accompanied by the formation of a vortex or whirlpool and there is a tendency for air to be drawn into the vortex and be carried along with the liquid being drained off. Such air, trapped in the water being drawn into the circulatory system of a swimming pool, may be detrimental to the operation of the pumping equipment, and avoidance of a vortex is desirable. Again, not wishing to be bound by any particular explanation, it is theorized that the circulation of water beneath the lip 74 indicated by the dotted line path 96 has a markedinhibiting effect upon the formation of a vortex in the pit of the skimmer.
What is claimed is:
1. In a swimming pool surface skimmer of the type which includes a skimmer throat for receiving water from the swimming pool, and a skimmer weir assembly in said throat for moving as the water level in the swimming pool changes, the improvement wherein the weir assembly comprises:
a pivotally mounted body exposing a first surface facing toward the entrance to said throat and a second substantially flat surface forming the upper end of the weir and disposed in a plane intersecting the plane of said first surface in an acute angle such that in operation said second substantially flat surface is nearly parallel to the surface of the flowing water at the point of passage of the water across said second surface.
2. A swimming pool skimmer as defined in claim 1 wherein:
under the circumstance that the deflection of the weir body by the flow of water is sufficient to dispose said second substantially flat surface ina slightly downwardly sloping attitude relative to the surface level of water in the pool the flow of water across said second substantially flat surface is correspondingly downward thereby maintaining said near parallelism.
3. A swimming pool skimmer as defined in claim 1 wherein:
any observable departure from parallelism between said second substantially flat surface and the surface of the water flowing across it is convergence of the planes of second surface and the water surface in the direction of the flow of the water.
4. A swimming pool skimmer in accordance with claim 1 wherein:
said pivotally mounted body has associated therewith means for buoyantly biasing the body to seek a vertical position.
5. A swimming pool skimmer in accordance with claim 4 wherein:
said biasing means is a removably attached mass of expanded polystyrene. 6. A swimming pool skimmer in accordance with claim 1 wherein:
the first surface is substantially flat and the angle of intersection of the planes of said first and second substantially flat surfaces is approximately 45.
7. A swimming pool skimmer in accordance with claim 1 wherein:
the free edge of said second surface is a sharp knifelike edge.
8. A swimming pool skimmer in accordance with claim 7 wherein:
an open cavity is disposed immediately below said second surface.
9. In a swimming pool surface skimmer of the type which includes a housing, a skimmer throat for fluid communication between the housing interior and the swimming pool, and a skimmer weir assembly in said throat for moving as the water level in the swimming pool changes, the improvement wherein the weir assembly comprises:
a pivotally mounted body exposing a first surface facing toward the entrance to said throat and a second substantially flat surface forming the upper end of the weir and disposed in a plane intersecting the plane of said first surface in an acute angle with its free edge being generally a sharp edge so that in skimming operation said second substantially flat surface and the surface of the flowing water at the point of passage of the water across said second surface are substantially parallel and the water surface dips substantially after leaving the sharp edge.
10. A swimming pool as defined in claim 9 wherein the portion of the weir body exposing said second surface requires only sufficient thickness to impart stiffness and has its inner surface exposed to the water between the inner surface of the weir and the bottom of the throat.
11. A swimming pool skimmer in accordance with claim 10 wherein said second substantially flat surface and its companion inner surface intersect substantially in a knife edge.
12. A swimming pool skimmer in accordance with claim 9 wherein:
said weir body has side plates associated with the portions exposing said first and second surfaces and thereby provides an open cavity facing away from the skimmer throat.
13. A weir for use in the throat of the skimmer of a swimming pool which comprises:
a plurality of panels of stiff sheet material interassociated so as to provide a major panel to face outwardly of the throat of the skimmer and a minor panel intersecting the major panel in an acute angle; and
means for pivotally mounting said weir in said skimmer throat at the end of said major panel which is remote from said minor panel so that said minor panel is uppermost and can emerge above the surface of the water in the skimmer; and
, I means for biasing said weir in a direction to cause it to seek a vertical altitude. 14. A weir in accordance with claim 13 wherein:
when said weir is mounted in the skimmer throat the minor panel is slightly inclined away from the entrance to the throat.
15. A weir in accordance with claim 13 wherein the surfaces of said panels intersect in an angle of approximately 45.
16. A weir in accordance with claim 13 wherein:
side panels are associated with the major and minor panels to form an open cavity facing away from the entrance to the skimmer throat.
17. A weir in accordance with claim 16 having mounted in said cavity means for buoyantly biasing said weir to seek an upright position extending above the water level.
18. A weir for use in the throat of the skimmer of a swimming pool which comprises:
a plurality of panels of stiff sheet material interassociated so as to provide a major panel to face outwardly of the throat of the skimmer and a minor panel intersecting the major panel in an angle of the order of 45;
side panels associated with the major and minor panels to form with said major and minor panels an open cavity;
means mounted in said cavity for buoyantly biasing said weir to seek an upright position; and
means for pivotally mounting said weir in said skimmer throat with said minor panel uppermost and said cavity facing away from the entrance to the throat of the skimmer.