Jan. 19, 1971 D. A. STANWOOD 1,
I SPRING LOADED WEIR FOR POOL SKIMMERS Filed Aug. 7, 1969 z Sheets-Sheet 1 INVENTOR. DAV/0 A. S74/VW000 B TM ATTORNEYS- United States Patent 3 555 574 SPRING LOADED wiuRFoR POOL SKIMMERS David A. Stanwood, West Covina, Califi, assignor t0 Swimquip, Inc., Elmonte, Calif., a corporation of California Filed Aug. 7, 1969, Ser. No. 848,154 Int. Cl. E04h 3/20 US. Cl. 4172.17 5 Claims ABSTRACT OF THE DISCLOSURE The disclosure shows a spring loaded weir in a skim tank system used in a swimming pool, through which water is circulated to a filter. The weir comprises a sheet of spring material such as leaf spring fixed at its lower edge at the bottom of the throat leading into the skim tank from the pool, and is provided at its upper free edge with a lip member which is of a density and dimension to cause it to float at the surface of the water when there is no water flowing through the tank. When water flows from the pool to the tank, as when a circulating pump is turned on, the weir is bent down so that water can flow over the lip into the tank.
This invention relates to weirs for use with skimmers of pools and has for an object to provide a simplified form of weir which will avoid the need for articulated or hinged elements.
An object is to provide such a weir which does not have moving parts other than flexure of weir material itself.
Proper cleaning of the water of a pool such as a swimming pool depends in large measure on circulating and filtering the water drawn over a skimming ledge and into a tank generally referred to as a skim tank. Due to factors such as evaporation, and splashing, followed by the refilling of the pool, the level of water in a pool is not maintained constant. In order to maintain proper flow from the surface of the pool to the filter despite changes of height of the water in the pool, floating weirs have been used.
In such arrangements, the water passing over the skimming weir is received in the tank, which supplies the inlet of a pump which does the recirculating. The floating weirs generally in use heretofore have been in the form of a rigid float plate located at the throat or entrance from the pool to the skim tank and pivotally mounted on a horizontal axis at the bottom of the throat. The dimensions of the weir are such that it can substantially close the throat at least up to the highest expected level of water in the pool. The weir is of a weight in relation to its dimensions which causes the upper or free part of the weir to float in such a manner that the upper edge protrudes above the pool water level when there is no flow of water from the pool to the tank, thereby substantially blocking communication between the tank and the pool and preventing the skimmed debris and the like collected in the tank from flowing back into the pool. When the pump is operated to circulate the water through the filter, the pump action draws water down from the skim tank, thereby reducing the water level in the tank. This causes the pressure of the higher water level in the pool to pivot the floating weir sufficiently to allow enough water to flow over the upper or free edge of the weir to supply the pump and maintain equilibrium between the pool water level and the somewhat lower level in the skim tank while the pump is operating. The floating weir thus operates to keep the level in the tank constant for any given flow rate determined by the pump.
It has been the experience that the pivoting elements of the weir have required some servicing due to occasional 3,555,574 Patented Jan. 19, 1971 sticking at the pivot and also due to the fact that some pivots have permitted enough sliding laterally of the weir to cause one side or the other of the weir to rub or jam against the side of the throat leading to the skim tank. These factors can impair the operation of the weir.
In accordance with the present invention, the abovementioned service problems of the previously used floating weirs are overcome by elimination of the need for pivoting elements, while permitting the upper edge of the weir to move upward or downward in dependence on the pool water level and the rate of pumping. Instead of using a pivoted rigid plate, there is used a flexible resilient sheet material such as leaf spring, the lower edge of which is securely fastened or wedged into a retaining means at the bottom of the throat. The spring sheet is provided at or near its upper free edge with a lip structure which rests at the water surface when the pump is not operating, and the leaf spring is stiff enough to cause at least part of the lip to emerge from the water surface when there is no water flow. Then, when the circulating pump is operated, the pressure on this resilient weir from the pool water which occurs when the water level in the skin tank drops, causes the spring sheet to flex to an extent sufficiently to enable the pool water to flow over the lip to supply the skim tank. Thus the upper edge or lip extends sufficiently above the pool water level when the pump is not operated, to prevent flow from the skim tank back to the pool, while allowing this upper edge to be flexed downwardly when the pump is operated such that enough water will flow over the weir to keep the skim tank from emptying.
A feature resides in making the lip of about the same density as the liquid, which results in desirable lip positions during periods of water flow and also during no water flow.
The foregoing and other features will be better understood from the following detailed. description and the accompanying drawing, of which:
FIG. 1 is a vertical sectional view of a skim tank shown installed at a wall of a swimming pool and provided with a spring weir according to the present invention;
FIG. 2 is a transverse sectional view taken along a plane at line 2-2 of FIG. 1; and
FIG. 3 is an enlarged vertical sectional view showing details of the weir.
The use of a spring loaded weir in accordance with the present invention is illustrated in FIGS. 1 and 2 of the drawing, which shows a skimming system somewhat like FIGS. 1 and 2 of W. 0. Baker US. Pat. No. 3,306,448, issued Feb. 28, 1967, for Automatic Skim Tank and System," except that in FIGS. 1 and 2 of the present application, the spring loaded weir is substituted for the rigid floating weir shown in the Baker patent. It should be understood that the system of the Baker patent is referred to only as an example of how the leaf spring weir can be used; the weir can be used in other arrangements than that of the Baker patent.
In FIG. 1 there is illustrated a swimming pool wall 10 having a vertical surface 11 exposed to the water in the pool. The skim tank 12 is preferably im bedded adjacent to or in the wall 10, and is adapted to receive water withdrawn from the upper surface of the pool.
In the present example, the tank 12 comprises two companion upper and lower hollow parts 13 and 14. the lower tank part 14 has an upper opening defined by an annular angle flange 15. The upper part has a lower opening defined by circular walls received within the angle flange 15.
The upper open end of the tank part 13 telescopes within a frame 16 that is carefully set in the decking 17 adjoining the top of the swimming pool wall 10. A removable cover 18 seated upon the frame 16 provides access to the interior of the tank 12 as may be required.
The upper tank part 13 has an intermediate horizontally extending branch"'19 beneaththe decking 17 and projecting toward the swimming pool surface 11. The branch 19 registers with an opening 20 in the swimming pool wall 10. Throughthe opening 20, the surface water of the swimming pool may pass to the branch portion 19 and thence to the tank 12 proper. The branch or throat 19 mounts a skimming weir 21 of spring material that meters the flow of water into the tank in accordance with the level of water 22 therein. As the level 22 descends, the flexible rectangular sheet of the weir 21 flexes more and becomes somewhat more convex causing the upper part 44 of the lip to drop downward to a level somewhat below the pool water level 23 sufficient to permit the flow of pool water over the weir lip and down to the lower level 22 in the tank, which occurs when the circulating pump is in operation.
When the circulating pump is not in operation the level in the tank will be the same as the level 23 in the pool for there will always be communication between the pool water and the tank even when there is no pumping. Under this condition there is no pressure applied against the weir from the pool side so that the weir assumes a relatively unfiexed or less flexed condition as shown by the dotted line 210 which allows the weir lip 44 to protrude somewhat above the pool water level as shown by the dotted lines, Owing to the fact that the clearance spaces between the sidewalls of the weir 21 and the vertical walls of the throat are very small, no substantial amount of debris or other undesired material which may be in the tank when the circulating motor is shut off will flow from the tank back through the throat into the pool water.
The circulating pump (not shown) withdraws water from the tank 12. For this purpose, the bottom of the lower tank portion 14 has a fitting 24 cooperable with a conduit 25 that leads to the pump inlet.
When the water level 22 in the tank drops significantly, a portion of the tank adjoining the fitting 24 must be sealed to prevent the pump from sucking air. For this purpose, the tank 12 has an integral partition 26 extending across the bottom of the tank. A separate chamber 27 is thus defined about the outlet 25. The chamber 27 has two sources of supply. One is the water flowing into the tank 12 over the skimming weir 21. Access is provided via an opening 28 in the partition wall. This opening 28 is surrounded by a raised valve seat 29 for purposes presently to appear. The second source of supply is an equalizer line 30 that extends from a fitting 31 in the bottom of the tank 12 to the wall surface 11. Communication between the equalizer line 30 and the chamber 27 is normally closed by a check valve 32 of any suitable form, and that requires a predetermined pressure differential to cause it to open. The equalizer line 30 opens in the swimming pool wall 11 at a place normally substantially below the lowest usual level of the water in the swimming pool.
A buoyant ball closure 33 above the seat 29 may close the opening 28, but only if the level 22 drops critically. Hence the chamber 27 is normally supplied by the water passing over the weir 21. i
A removable basket 37 having a rim resting on the angle flange 15 provides a guide properly positioning the ball closure 33 for cooperation with seat 29 should thelevel 22 drop critically. Thus the bottom of the basket 38 has an inwardly or upwardly offset portion 138 that defines a cage above the seat 29 and within which the ball 33 can reciprocate. Normally the ball 33 rises to the top of the cage. At the top center of the cage is an apertured boss 39 which guides a stem 40 attached to the ball 33.
Should the water drop substantially below the level 22, and say, to the level 22, the weir 21 has obviously lost control, and the tank is about to be emptied. The ball 33 will drop in place before the level reaches the seat 29 and the opening 28 will be sealed before any air enters the chamber 27. The pump suction will maintain 4 the ball 33 seated, and at the same timewill open the equalizer line 30 by exerting the requisite force upon the check valve 32. The pump is now supplied entirely by the equalizer line 30, and the demands of the pump are met. 1
It is also possible to use the equalizer line 30 for attachment of a vacuum cleaner. In such circumstances, it would of course be necessary to close the opening 28- into the chamber 27, even if the level 22 is high. For this purpose, the closure 33 can be pushed toward the. seat. To accomplish this, the stem 40 has a handle 41 accessible upon opening the cover 18. When the closure 33 is pushed against the seat 29, the pump suction, of course, maintains it in such a position. Optionally, the closure 33 may be caused to engage the seat 29 by starving the tank 12. This" can be accomplished by manually tilting the weir 21 upwardly so as to cut off flow into the tank. The closure 33 will then seat in the manner previously described.
In order to restore normal operation, the pump must be shut down. The closure 33 will then pop up if there is adequate water in the tank 12. The pump can then be restarted.
The flexible weir sheet 21, rectangular in shape when unfiexed, dimensioned to fit nicely between the vertical side walls of the throat and to be accommodated between the bottom and top walls of the throat, is held at its forward or upstream end by a wedge arrangement. For this purpose, the bottom 19 is provided near its upstream end with a depending notch arrangement 45 having a vertical internal wall 46 and an oblique internal wall 47 facing the vertical wall, providing space for a wedge member 48 having a vertical wall 49 and an oblique wall 50 which fits into the slot. The wedge member 48 has a horizontal portion 51 which extends in the upstream direction to abut against a lip 52 extending upwardly for a short distance from the bottom of the throat.
To fix the leaf spring 21 to the throat, the lowerforward horizontal edge of the member 21 is placed within the slot of member 45 and bound between wall 46 of'the slot and 49 of the wedge. The wedge is then forced downwardly to bind this forward edge of member 21 which is done by tightening down on screws 53 passing through member 51 of the wedge and threaded into the bottom portion of throat 19 at position 54. A 'number of these screws spaced apart alongthe horizontal member 51 will serve to bind the spring member effectively.
The lip member 44 of the weir is preferably constructed so that it will have a weight approximately equal to the weight of the water which it displaces. For this purpose it is provided with an internal chamber 55 completely enclosed on all sides by an enclosure 56 comprising an upper enclosure member 57 and a bottom member 58 adapted to be sealed to the upper member 57 as by suitable adhesive or fasteners (not shown). The arrangement is such that the upper downstream end of leaf spring member 21 is securely held between the members 57 and 58. 7
When there is no filling within the enclosed chamber 55 the weight of water displaced by the weir lip 44 may be greater than the weight of the lip structure. Accordingly, it will ordinarily be desirable to place a filling of material within chamber 55 sufficient to bring the density of the weir lip plus the filling up toabout-the density of the water displacement. This filling material may comprise either water itself or some other material, and for the purpose of retaining the filling within the chamber there is provided a plug 59 to seal the material within the chamber after it is placed-there.
For the material of the leaf'spring it is preferred to use a stainless steel which should be about .008 -inch in thickness for a free leaf-spring length of about four inches between the bottom clamp and the lip member. A fourinch length of leaf spring would be about the right length for an ordinary skimmer throat having a height of about 7 /2 inches. The material of the weir sheet is not necessarily limited to steel, as other leaf spring materials may be found satisfactory, for example, a spring sheet made of plastic.
It will be recognized that by the use of the flexible resilient weir according to the present invention, servicing or breakage due to moving parts such as hinge members is avoided.
What is claimed is:
1. A spring loaded weir for attachment at the throat of a skim tank of a pool comprising a sheet of leaf spring material adapted to be secured to the bottom of the throat so that the sheet extends substantially from one side to the other of the throat and a lip member attached to the free upper edge of the sheet, the lip memher having a density such that when there is no flow of liquid through the tank, at least the upper part of the lip member is above the level of liquid in the pool and when there is liquid flow through the tank the force of the flow flexes the leaf spring, lowering the lip so that the liquid flow passes over it.
2. A spring loaded weir according to claim 1 in which the lip member is of a density approximately equal to that of the liquid which it displaces.
3. A flexible weir according to claim 1 in combination with attaching means at the bottom of the throat for attaching the bottom edge of the sheet to the throat.
References Cited UNITED STATES PATENTS 3,067,879 12/1962 Baker 210-69X 3,087,335 4/1963 Cavenah 210-169UX 3,125,513 3/1964 Johnson 210-169 3,169,920 2/1965 Payne 210-169 3,173,865 3/1965 Bosico 210-169 3,306,448 2/1967 Baker 210-121 3,314,543 4/1967 Nash 4-172.17X 3,316,934 5/1967 Sower 210-169X WILLIAM F. ODEA, Primary Examiner H. K. ARTIS, Assistant Examiner US. Cl. X.R.