GB2354811A

GB2354811A - Cover for a water tank conduit

Info

Publication number: GB2354811A
Application number: GB0018173A
Authority: GB
Inventors: David Howarth
Original assignee: ULTRA PLASTICS Ltd
Current assignee: ULTRA PLASTICS Ltd
Priority date: 1999-07-28
Filing date: 2000-07-26
Publication date: 2001-04-04
Anticipated expiration: 2020-07-26
Also published as: GB0018173D0; GB2354811B; GB9917647D0; GB2354811A8

Abstract

A cover 10 for a conduit which preferably opens into a swimming pool comprises sets of openings 12a-12d through which water may flow into or out of the pool, a peripheral rim 14 which defines the edge of a cavity 16 which is formed underneath the cover 10, and supports 18 which support a central portion of the cover 10 and which maintain the height of the cavity 16. The cover 10 may further comprise fixing holes 20 by which the cover 10 can be secured to the wall or floor of the swimming pool. The cover 10 preferably includes a solid portion not having any openings directly over the conduit opening.

Description

1 2354811 Cover for a water tank conduit This invention relates to a cover

for a conduit opening into a water tank, particularly, but not limited to a 5 cover for a conduit opening into a swimming pool.

A previous cover for a conduit of a swimming pool comprises a grille having elongate apertures, which allow the flow of water into or out of the swimming pool therethrough. This type of cover is generally fitted flush with the wall or floor of the swimming pool.

The development of these covers is hampered by the need to have small apertures to prevent users from becoming trapped in the apertures, ie the apertures are ideally small enough to prevent a person from placing a finger through the apertures. Also, the apertures must be large enough to allow a sufficient volume of water to be pumped into or out of the swimming pool. The total area of the apertures in a grate dictates the speed at which a given volume of water flows through the grate. For instance to achieve a flow rate of jM3/S through a grate with 1M2 Of openings the water must travel considerably faster than the same flow rate through a grate having 2M2 of openings.

When the apertures are small, the relatively high speed of fluid being sucked out of the pool through the grate creates a strong suction force. Serious disadvantages arise if suction force is large enough to hold a swimming pool user against the grate because of the obvious danger of drowning.

2 It is an object of the present invention to provide a cover which provides small apertures for the through flow of material whilst at the same time maintaining a low flow rate per unit area of cover.

According to one aspect of the present invention a cover for a conduit opening into a water tank comprises a body portion having a plurality of openings therein, which body portion defines a cavity which, in use, extends beyond a perimeter of a conduit to be covered, in which the openings extend over a perimeter of a conduit to be covered.

The openings may extend over substantially only those parts of the body portion which, in use, are located over a perimeter of a conduit to be covered, or are not over the conduit to be covered.

The cover may comprise a blocking portion, having substantially no openings therein, which may be located over a conduit to be covered. The openings may extend around a periphery of the blocking portion, preferably in discrete sets, which sets are preferably symmetrically arranged around the blocking portion.

The openings may be arranged in sets around the body portion. The sets may be symmetrically arranged around the body portion, preferably around a central section of the body portion.

3 The sets may comprise subsets, which may consist of a plurality of elongate openings arranged side by side. The openings may be arranged side by side substantially around the perimeter of the body portion. Where the cover is substantially circular in shape, the axis of the openings points substantially towards the centre of the circle.

The total area of the openings is preferably larger than the crosssectional area of a conduit to be covered.

Preferably the total area is at least twice as large as said crosssectional area, most preferably at least three times larger.

The body portion may include at least one cavity support portion. The or each support portion may extend from the body portion into the cavity. The or each support may be arranged, in use, to contact the periphery of a conduit to be covered. Preferably, a plurality of supports are provided, which supports are arranged, in use, to contact the periphery of a conduit to be covered at spaced locations around said periphery.

The body portion may include a peripheral rim, which may define an edge of the cavity. The rim may extend, in use, from an upper part of the body portion to a location beyond a perimeter of a conduit to be covered.

The body portion may be spaced from a conduit to be covered and a surrounding area of that conduit. Said spacing of the body portion may form the cavity.

4 The cover may include a f ixing means receiving portion. Preferably said receiving portion comprises at least one opening, most preferably a plurality of openings. The openings may be aligned with an existing fixing means 5 receiving section of a conduit to be covered.

The cover may be adapted for retrofitting in place of an existing cover.

The openings may have a width of less than 10mm, preferably just less than 8mm.

According to another aspect of the present invention, a method of reducing the speed of flow of water through a cover into or out of a water tank for a given flow rate comprises placing a cover over a conduit through which said water is to flow; wherein the cover comprises a body portion having a plurality of openings therein, which openings extend over a perimeter of the conduit and the body portion defines a cavity which extends beyond a perimeter of the conduit.

All of the above aspects may be combined with any of the features disclosed herein, in any combination.

A specific embodiment of the present invention will now be described, by way of example, and with reference to the accompanying drawings, in which:

Figure 1 is a schematic view of the underside of a first embodiment of a cover for a swimming pool inlet/outlet; Figure 2 is a schematic cross sectional view of the cover of figure 1 fitted to an opening in a swimming pool; Figure 3 is a schematic view of a prior art cover for an inlet/outlet, shown roughly to scale with the cover of figure 1; and

Figure 4 is a schematic view of the underside of a second embodiment of a cover for a swimming pool inlet/outlet.

A cover 10 comprises four sets of openings 12a to 12d, through which water can flow into or out of a swimming pool. The cover 10 has a peripheral rim 14 which defines the edge of a cavity 16 (see figure 2). The cover also has supports 18 to support a central portion of the cover 10 and maintain the height of the cavity 16.

The cover 10 in this example has a diameter of 1m and a thickness at the rim of 25mm. The thickness of the cover over the cavity 16 is 13mm. The cavity is formed by machining out 12mm of material from a 25mm thick disc. The supports 18 are formed by selective machining to avoid those parts.

The openings of each set have a width of just less than 8mm. However, where the cover 10 is intended to be used in shallow water, then the openings have a width of 4mm to give a greater safety margin to prevent a user from becoming trapped.

6 Each set of openings 12a to 12d is formed in two rectangular subsets of openings, which openings have a length of approximately 40cm.

The cover 10 has fixing holes 20 through which fixings are placed and secured to the wall or floor 22 of the swimming pool around the opening to be covered.

The location of the fixing holes 20 is chosen to correspond to the position of existing fixing holes for receiving a previous cover which the present cover 10 is intended to replace. In this way, the cover 10 described herein can be used as a retro fit cover.

For the sake of comparison, a prior art cover is shown in figure 3, roughly to scale with the present cover 10. The 4mm to 8mm width of the openings in the cover of figures 1 and 2 is important to deter a user from becoming trapped in the cover 10. However, it is also necessary to limit the velocity of water passing though the cover to prevent a user from being sucked on to the cover and being held there, in which position they may get into difficulty or even drown.

The prior art cover shown in figure 3 would typically have a water velocity through the apertures of greater than 1m per second. This figure is dangerously high and could easily result in a person becoming pulled onto the cover.

In order to maintain the same flow rate of water through the cover 10 described herein but reduce the velocity of 7 water flowing through the grill, it has been realised that by increasing the area from which water is drawn through the cover 10, the speed of water through a particular part of the cover is reduced.

In the example shown in figure 1 the open area of the sets of openings 12a to 12d is approximately four times the open area of the prior art cover shown in figure 3. This results in a significantly lower velocity of water flowing through the cover, even though the flow rate of water (ie the amount of water passing though the cover per unit time) is maintained. The cover described herein can provide satisfactory flow rates with a velocity of water flowing through a particular part of the cover of less than 0.5m per second.

A wide variety of shapes of cover 10 can be envisaged. In order to reduce the risk of an object blocking the openings in the cover 10, two sets of openings could be' placed 2m to 3m apart in a large cover, whilst still using the same fixings as the prior art cover shown in f igure 3. With such a large separation between sets of openings, it would be very difficult for all of the openings to be covered by an object, which should be avoided to prevent a malfunction of the pumping system. The cover need not necessarily be circular, it could be lobed, or rectangular or assume one of a variety of a polygonal or curved shapes. The number of sets of openings can also be varied to suit particular flow rates and sizes of cover.

However, the symmetrical location of the sets of openings around the original opening is seen as beneficial to I 8 prevent water being drawn through one set of openings in preference to another set further from the opening in the swimming pool, by taking a path of least resistance.

Referring to figure 4, a second embodiment of the cover 10 is shown in which the openings are arranged in a continuous array 12e around the perimeter of the peripheral rim 14. Each opening of the array is generally elongate and is 7Smm long and 7.5mm wide and the elongate axis of each opening points towards the centre of the cover 10. Such an arrangement of openings in the cover 10 also decreases the likelihood of blockage by an object. It should be appreciated that the precise dimensions of the openings and the separation therebetween may be altered as long as they are arranged generally side by side around the peripheral rim 14.

The peripheral rim 14 need not necessarily contact the wall or floor 22 of the swimming pool, as long as any gap therebetween is less than the chosen 4/8mm.

When the cover 10 is fitted in shallow wateri as well as having narrower openings, the surface of the cover may have a non-slip coating, to deter accidents.

The cover 10 described herein can be retro fitted to an existing swimming pool, without even removing the water of the swimming pool, which removal can be a costly and time consuming procedure. It is only necessary to know the spacing of and size of the existing fixings for an existing cover in a swimming pool. The location of the 9 fixing poles 20 could even by decided on site. In this way, a standard shape of cover 10 could be manufactured and taken to a chosen site, with any final adjustment to the cover being made at the site for instance for holes 5 for the fixings to be drilled.

Where the cover is to be fitted to an opening close to the edge of a pool, the cover may be semi circular in shape.

The cover disclosed herein has significant advantages over the prior art covers mentioned because it provides a cover with sufficiently small single openings to deter trapping of an individual whilst also providing sufficient area of openings to provide low velocities through the cover to reduce the risk of a person being sucked onto the grate.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the, features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or, all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features: and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims

1. A cover for a conduit opening into a water tank comprises a body portion having a plurality of openings therein, which body portion defines a cavity which, in use, extends beyond a perimeter of a conduit to be covered, in which the openings extend over a perimeter of a conduit to be covered.

2. A cover according to claim 1, wherein the openings extend over substantially only those parts of the body portion which, in use, are located over a perimeter of a conduit to be covered, or are not over the conduit to be 15 covered.

3. A cover according to either claim 1 or claim 2, wherein the cover comprises a blocking portion, having substantially no openings therein, which is located over a conduit to be covered.

4. A cover according to claim 3, wherein the openings extend around a periphery of the blocking portion, in discrete sets, which sets are symmetrically arranged 25 around the blocking portion.

S. A cover according to any preceding claim, wherein the openings are arranged in sets around the body portion.

12 6. A cover according to claim 5, wherein the sets comprise subsets, which consist of a plurality of elongate openings arranged side by side.

7. A cover according to any preceding claim, wherein the openings are arranged side by side substantially around the perimeter of the body portion.

8. A cover according to any preceding claim, wherein the total area of the openings is larger than the crosssectional area of a conduit to be covered.

9. A cover according to any preceding claim, wherein the body portion includes at least one cavity support portion.

10. A cover according to claim 9, wherein the or each support portion extends from the body portion into the cavity.

11. A cover according to claims 9 or 10, wherein the or each support is arranged, in use, to contact the periphery of a conduit to be covered. 12. A cover according to any preceding claim, wherein the body portion includes a peripheral rim, which defines an edge of the cavity.

13. A cover according to any preceding claim, wherein the cover includes a fixing means receiving portion.

13 14.. A cover according to claim 13, wherein said receiving portion comprises at least one opening.

15. A cover according to claim 14, wherein the openings are aligned with an existing fixing means receiving section of a conduit to be covered.

16. A method of reducing the speed of flow of water through a cover into or out of a water tank for a given flow rate comprises placing a cover over a conduit through which said water is to flow; wherein the cover comprises a body portion having a plurality of openings therein, which openings extend over a perimeter of the conduit and the body portion defines a cavity which extends beyond a perimeter of the conduit.

17. A cover for a conduit opening into a water tank substantially as herein described with reference to the accompanying drawings.

18. A method of reducing the speed of flow of water through a cover into or out of a water tank substantially as described herein with reference to the accompanying drawings.