GB2227045A

GB2227045A - Cistern lids

Info

Publication number: GB2227045A
Application number: GB8929198A
Authority: GB
Inventors: Douglas Robert Macka Rodgerson
Original assignee: Elsy & Gibbons Ltd
Current assignee: Elsy & Gibbons Ltd
Priority date: 1989-01-12
Filing date: 1989-12-27
Publication date: 1990-07-18
Anticipated expiration: 2009-12-27
Also published as: GB8929198D0; GB8900639D0; GB2227045B

Abstract

A cistern, such as a feed cistern for a hot water storage system, or a hot or cold water storage cistern, comprises a water-containing body portion (2) having a substantially rectangular aperture (6) formed in the top wall (4) thereof, and a strip sealing member (8) mounted in, to surround, the aperture (6) and to make sealing contact with the top wall (4). The sealing member (8) is provided with an inwardly-open groove (12) therearound and the cistern is completed by a substantially rectangular lid member (14) including a peripheral lip portion (16) which is received in the groove (12) to make sealing contact therewith. <IMAGE>

Description

IMPROVED CISTERN This invention relates to cisterns such as feed cisterns for hot water storage systems, and hot or cold water storage cisterns.

Feed cisterns and hot or cold water storage cisterns commonly comprise open-topped containers of, for example, copper or plastics material the contents of which, because of the open-topped nature of the cisterns, are prone to contamination by dust, insects and the like.

Clearly this is an unhygienic situation and it would be desirable to be able to provide a cistern less prone to contamination than heretofore and capable of satisfying Water Bylaw 30 (2) as well as new British Standards that are in the course of preparation for cisterns which would comply with Byelaw 30 (2).

According to the present invention, there is provided a cistern comprising a water-containing body portion including a top wall defining therein a substantially rectangular aperture, a strip sealing member mounted in, to surround, said aperture to make sealing contact with said top wall, said sealing member being provided with an inwardly-open groove therearound, and a substantially rectangular lid member including a peripheral lip portion adapted to be received within said groove in the sealing member to make sealing contact therewith.

The lid member is preferably of a substantially rigid plastics material such as polypropylene capable of slight flexure whereby the peripheral lip portion thereof can be snapped into said inwardly-open groove in the sealing member.

Conveniently the sealing member, which may be of extruded silicon rubber, further includes an outwardly-open groove therein below said inwardly-open groove and adapted to receive the inner edge region of the top wall defining said aperture, the mouth of said outwardly-open groove being of a depth less than the thickness of the top wall of the body portion and the mouth of the inwardly-open groove being of a depth less than the thickness of the peripheral lip portion of the lid member whereby said sealing member makes sealing contact with both said top wall and said lid member.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig..l is a perspective view of part of a cold water feed cistern according to the invention; Fig. 2 shows the components of the cistern of Fig. 1 in exploded form, and Fig. 3 is a vertical section through the cistern of Fig. 1 on the line A-A.

Referring to the drawings there is shown a cold water feed cistern comprising a substantially rectangular section body portion 2 of sheet copper and including a top wall 4 in which is cut a substantially rectangular aperture 6 the corners of which are rounded as best seen in Fig. 2.

The cistern further comprises a length of extruded silicon rubber the ends of which are joined to form a continuous loop seal 8. An outwardly-open slot or groove 10 is formed in and around the outer face of the seal 8, the depth of the mouth of said slot 10 being slightly less than the thickness of the top wall 4 of the tank portion 2.

Thus the seal 8 can be located in the aperture 6 with the peripheral region of the top wall 4 defining said aperture 6 being received within the slot 10 whereby the seal 8 makes sealing engagement with the upper and lower faces of the top wall 4 as best seen in Fig. 3.

A further slot or groove 12 is formed in the seal 8, said slot 12 being inwardly-open and extending around the inner face of the seal 8 and being located above the slot 10 for reasons which will become apparent.

The cistern is completed by a substantially rectangular lid indicated generally at 14 of a substantially rigid yet flexible plastics material suchaspolypropylene. The lid 14 includes a peripheral lip portion 16 the corners of which are rounded, said lip portion 16 being adapted to be received in the slot 12 in the seal 8 as most clearly seen in Fig. 3.

More particularly, the depth of the mouth of the slot 12 is slightly less than the thickness of the lip portion 16, and the seal 8 and lid 14 can be flexed to enable the lip portion 16 to be received in the slot 12 whereby the seal 8 makes sealing engagement with the upper and lower faces of the lip portion 16.

Thus it will be appreciated that the body portion 2 is effectively sealed by the lid 14 by virtue of the positive pressure exerted by the seal 8 on the top wall 4 of the tank portion and the lip portion 16 of the lid 14 and whereby no dust or- insects can penetrate past the edge of the lid 14 into the interior of the cistern.

The outside dimension of the lid 14, and more particularly of the lip portion 16, are slightly greater than the equivalent dimensions of the aperture 6 in the top wall 4 so that the lid 14 cannot inadvertently be pushed through the aperture and into the cistern on the application of excessive pressure to the top of the lid 14.

It will be noted from Fig. 3 that the slots 10 and 12 each include an innermost volume 10a, 12a respectively clear of the edge of the assocziated component 4,16 received therein.

These clearances within the slots 10,12 are such as to accommodate any distortion, expansion, misalignment or the like of the top wall 4 and lid 14 of the cistern that might occur and whereby the seal between these components is maintained.

Water Byelaw 30 (2), as well as requiring a cistern to exclude light and insects therefrom, further requires that the cistern is not airtight. In order to satisfy this requirement, the lid 14 is provided with a hole 18 in which is sealingly located a breather assembly (not shown).

The breather assembly itself incorporates a filter providing communication between the interior of the body portion 2 and atmosphere.

Although described in relation to a cold water feed cistern, the invention has application to hot and cold water storage cisterns.

In the case of a hot water storage cistern, the nonairtight nature of the otherwise sealed cistern is achieved by venting the hot water storage cistern through the associated cold water supply cistern which is itself vented to the atmosphere.

Modifications and variations from the described arrangement may be made without departing from the scope of the invention. For example, the body portion 2 may be of a plastics material, while the lid 14 may be of metal and may be rigid, the resilience of the seal 8 being such as to permit insertion of the lip portion 16 of the lid 14 into the slot 12 whereby the lid 14 adopts its operative position best seen in Fig. 3. Other modifications and variations will be apparent to those skilled in the art.

Claims

1. A cistern comprising a water-containing body portion including a top wall defining therein a substantially rectangular aperture, a strip sealing member mounted in, to surround, said aperture to make sealing contact with said top wall, said sealing member being provided with an inwardly-open groove therearound, and a substantially rectangular lid member including a peripheral lip portion received within said grove in the sealing member to make sealing contact therewith.

2. A cistern as claimed in claim 1 in which the lid member is of a substantially rigid plastics material capable of flexure whereby the peripheral lip portion thereof can be snapped into said inwardly-open groove in the sealing member.

3. A cistern as claimed in claim 1 or claim 2 in which the sealing member is further provided with an outwardly-open groove therein below said inwardly-open groove and receiving the inner edge region of the top wall defining said aperture, the mouth of said outwardly-open groove being of a depth less than the thickness of the top wall of the body portion and the mouth of the inwardlyopen groove being of a depth less than the thickness of the peripheral lip portion of the lid member whereby said sealing member makes sealing contact with both said top wall and said lid member.

4. A cistern as claimed in claim 3 in which the sealing member is of extruded silicon rubber.

5. A cistern as claimed in claim 3 or claim 4 in which the inwardly-open groove and the outwardly-open groove each include volumes therein internally of the innermost edge region of the associated component received therein.

6. A cistern as claimed in any one of claims 1 to 5 in which the outside dimensions of the lid member are slightly greater than the equivalent dimensions of the aperture in the top wall of the body portion.

7. A cistern substantially as described with reference to and as illustrated by the accompanying drawings.