GB2078813A - Water Trap - Google Patents

Abstract

A water trap comprises a cylindrical container 7 into which depends a skirt 6 formed at the lower end of a frusto-conical funnel 5. The container 7 is supported by webs extending radially inwardly from an outer sleeve 4. The lower edge of skirt 6 is spaced a distance h below the upper edge of the container 7 so that liquid only flows to the outlet when the container 7 is full, by overflowing the rim of the container. <IMAGE>

Description

SPECIFICATION Water Trap The present invention relates to a water trap.

Where water enters, for example, a drain, it is frequently desired to place a water trap to keep the interior of the drain isolated from the exterior to prevent smells and discourage insects and so forth. A common form of water trap is a so called "S" bend as found on hand basins. Although simple in construction it occupies a fairly large amount of space as its width is at least three times the outer diameter of the pipe. Also it is difficult to make its inlet and outlet ends coaxial with one another.

According to the present invention we provide a water trap comprising a liquid inlet comprising a skirt which depends into a container so that when the container is full of liquid it overflows and empties via an outlet.

Preferably the inlet comprises a frusto-conical funnel having a part-cylindrical skirt attached to its lower, smaller diameter end, the skirt depending in to a coaxial cylindrical container. In such a construction, the funnel and container may be supported by an outer, coaxial sleeve which, in cooperation with the outer wall of the container, defines one or more outlet passages for the liquid, the container suitably being supported by webs extending radially inwardly from the outer sleeve.

The entire functional parts of the trap can thus be contained within the outer sleeve which enables a compact yet simple construction to be achieved with coaxial inlet and outlet liquid flow. In such a form, the trap can readily be made as a self contained unit so that it can be used in applications where it is difficult to accommodate a conventional S-bend trap. Two such applications where it is difficult to use an S-bend trap and where the illustrated embodiment of the present invention can readily be used are in inlets to out-of-door drains and also in drains from the floors of showers. In both cases a simple bore can be made to interconnect the desired drain inlet with the drain proper and an interconnecting pipe and a trap can be inserted in the bore in a coaxial reiationship with one another.

The invention will be further described with reference to the accompanying drawings, in which Fig. 1 is a longitudinal section through one embodiment of water trap according to the present invention; Fig. 2 is a plan view of the water trap of Fig. 1; Fig. 3 is a transverse cross-sectional view of the water trap of Fig. 1, rotated through 450 with respect to the plane of Fig. 1; and Fig. 4 is a longitudinal section of another embodiment of water trap according to the invention.

The water trap 1 in Figure 1 comprises a main body part 2 and a top 3. The body part 2 comprises an outer cylindrical portion 4 the upper rim of which merges with a frusto-conical funnel part 5 disposed interiorly of the wall 4 and merging at its lower, smaller diameter end with a depending cylindrical skirt 6.

Also disposed within the body part 2 is a cylindrical container 7 which is fixed to the outer wall 4 by means of four webs 8 (Fig. 3) equiangularly spaced around the axis of body part 2 and which comprises a cylindrical wall 9 and a planar bottom wall 10, the lower surface of which, for convenience of construction, is coplanar with the lower edge of the wall 4.

As can clearly be seen from Fig. 1 ,the upper edge of the wall 9 is spaced vertically above the lower edge of the wall 6 bya distance h.

When liquid runs down the funnel 8, it collects in the container 9 until it oveflows. Clearly, when the flow of liquid into the funnel 5 is interrupted, the level of liquid in the container 9 cannot be much below its lower edge. That the liquid level is then below the lower edge of container 9 is due to the momentum of the liquid passing through the trap.

Liquid from the container 9 exits the trap via the outlet openings 11 (Fig. 3).

The top 3 of the trap comprises a skirt 12 which is threadedly or otherwise fixedly engaged with the body part 2, a grating 13 and a radially outwardly directed flange 14 which serves to locate the trap 1 in the aperture in which, in use, it is placed.

As can be seen from Figure 3, the walls 4, 6 and 9 are all of circular cross-section and coaxial with one another and with the funnel 5.

Figure 4 shows a further version of the trap 1 in which the radially outwardly directed flange 14 is integral with the body 2 while the grating 13 is a separate item and rests on an internal annular shoulder 1 6 radially inwardly of the flange 14.

The funnel 5 and cylindrical wall 6 are formed integrally with one another and as a separate item from the body 2 and grating 13, the funnel 5 being provided at its upper, wider end with a radially outwardly directed flange which rests on a further annular shoulder 1 7 below the shoulder 1 6. This construction facilitates access to the container 9 to unable material e.g. silts, leaves and the like to be removed from it. In alternative versions of the trap, the funnel 5 could be integral with the body 2 as in Figure 1 but with a separate grate as in Figure 4, or the grate 13 could be as shown n in Figure 4 and have the funnel fixed to it.

The height h in Figure 1 and various other dimensions of the container 9 funnel 5 and so forth should be chosen such that some liquid always remains in the container 9 at least up to the level of the lower edge of the cylindrical wall 6 so that the desired trap effect is achieved. Thus, for example, account should be taken of the likely evaporation rate of liquid from the container 9 as compared with the likely frequency of its being filled. Also, the trap dimensions should be chosen such that the container 9 will not be emptied (after the flow of liquid into the funnel 5 has ceased) by siphonic action.

Claims (9)

Claims

1. A water trap having a liquid inlet and a liquid outlet the liquid inlet comprising a skirt which depends into a container so that when the container is full of liquid it overflows and empties via the outlet.

2. A water trap according to Claim 1 wherein the skirt is in the form of a funnel.

3. A water trap according to Claim 1 or 2 wherein the inlet comprises a vertical frustoconical funnel having said skirt attached to its lower end, the skirt being cylindrical and wherein the container is cylindrical and coaxial with the funnel and skirt.

4. A water trap according to Claim 3 wherein the funnel and container are supported by an outer, coaxial sleeve which, in cooperation with the outer wall of the container, defines one or more outlet passages for the liquid.

5. A water trap according to Claim 4 wherein the container is supported by webs extending radially inwardly from the outer sleeve.

6. A container according to Claim 4 or 5 wherein the funnel rests on the outer sleeve.

7. A water trap according to Claim 4 or 5 wherein the funnel is formed integrally with the outer sleeve.

8. A water trap according to any one of Claims 2 to 7 wherein the funnel is covered by a grating.

9. A water trap constructed and arranged substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 3 or Figure 4 of the accompanying drawings.