GB2313870A

GB2313870A - Sealing an enclosure having two doors

Info

Publication number: GB2313870A
Application number: GB9709792A
Authority: GB
Inventors: David Mcnicholas
Original assignee: Tegrel Ltd
Current assignee: Tegrel Ltd
Priority date: 1996-06-05
Filing date: 1997-05-14
Publication date: 1997-12-10
Anticipated expiration: 2017-05-14
Also published as: GB9709792D0; GB2313870B

Abstract

An enclosure 2, particularly for electrical equipment such as illuminated variable message road signs, has an opening therein closed by a pair of side-hinged doors 4, 6, a resilient gasket 10 on the enclosure extending around the opening with the edge regions of the top, bottom and hinged side of each door 4,6 in their closed positions sealingly engaging the gasket 10. A sealing strip 18 is mounted on, to extend the length of, the free edge of the first door 4, the arrangement being such that, on closure of the first door 4, the top and bottom extents of the edge region of the flee side of the first door 4 seal against the gasket 10, and, on closure of the second door 6, the edge region of the free side of the second door 6 seals against the sealing strip 18 on the first door 4 whereby the enclosure is totally sealed.

Description

ENCLOSURE This invention relates to enclosures, and more particularly to sealing means for enclosures provided with doors and containing, for example, electrical equipment.

It is established practice to provide enclosures for electrical equipment, such as illuminated, variable-message road signs, which are mounted outdoors and are subject to the elements, in particular rain.

The enclosures are provided with one or more hinged doors to permit access to the interior thereof, and it is necessary for these doors to seal the interior of the enclosure when in their closed positions. Sealing is commonly achieved by providing a peripheral sealing gasket of a resilient material on the enclosure with which the inner face of the or each door engages on closure to effect the seal.

In the case of relatively wide enclosures, the provision of a single door may be impractical in view of the size of the door and the space it would occupy in its open position - in particular the access to gantry-mounted road signs with walkways thereto would be severely limited, and could not accommodate wide doors.

It is therefore common practice to provide two doors on such a wide enclosure, and to fit a central vertical stile to the enclosure, a pair of gaskets, one for each door, being located on the enclosure with parallel side extents of each gasket being mounted on the central stile.

However, such an arrangement has distinct disadvantages in that, when unrestricted access to the enclosure is required, for example to fit large equipment therein, it is necessary to provide a removable stile to enable access, and thereafter to replace the stile prior to closing the enclosure. As the stile carries parts of the sealing gaskets, there is a possibility that these gaskets may be incorrectly replaced, which would affect the sealing of the enclosure and permit the ingress of water.

It would be desirable to be able to provide a double-door enclosure capable of providing unrestricted access thereto and in which sealing thereof was ensured on closure of said doors.

According to the present invention, there is provided an enclosure having an opening therein closed by a pair of sidehinged doors, and a resilient sealing gasket mounted on the enclosure to extend around said opening, the edge regions of the top, bottom and hinged side of each door, in its closed position, making sealing engagement with said gasket, the edge of the free side of a first of said doors carrying a sealing strip extending the length of the door, the arrangement being such that, on closure of said first door, the top and bottom extents of the edge region of the free side of the first door make sealing engagement with the gasket on the enclosure, and, on closure of the second door, the edge region of the free side of said second door makes sealing engagement with said sealing strip on the first door, whereby the enclosure is totally sealed.

In a preferred embodiment of the invention, the edge region of the free side of the first door is of shallow channel shape, conveniently truncated V-shape, in transverse section, the sealing gasket being correspondingly recessed at the regions of contact by the top and bottom extents of said edge region of the free side of the first door, the sealing strip being mounted to the free edge of said free side of the first door to extend outwardly of said door at a shallow angle thereto, typically of the order of 30* to the plane of the first door.

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. 1 is an isometric view of an enclosure according to the invention with its doors partially open; Fig. 2 is a horizontal section through the region of the enclosure circled in Fig. 1 with the left-hand door closed; Fig. 3 is a horizontal section through the overlapping region of the doors with both doors closed, and Fig. 4 shows part of the internal locking arrangement for the left-hand door.

Referring to the drawings, there is shown a metal enclosure indicated generally at 2, for example of stainless steel, for housing electrical equipment such as illuminated, variablemessage road signs, the open rear face of the enclosure 2 being closed by means of a pair of hinged doors 4,6.

A flange 8 projects outwardly from the rear face of the enclosure 2 to surround the opening therein, a peripheral sealing gasket 10 being carried by said flange 8.

The edge region of the free side of the door 4 is of shallow channel-shape in transverse section as best seen in Figs. 2 and 3, said section more particularly being of truncated V-shape including sidewalls 12,14 extending at angles of the order of 30 with the plane of the door 4, and a base portion 16 extending parallel with the plane of the door 4.

The free edge of the sidewall 14 carries a sealing strip 18 which is a friction push-fit thereon and extends the length of the free side of the door 4. In the open position of the door 4, the sealing strip forms a continuation of the sidewall 14 and projects rearwardly and outwardly of the plane of the door 4.

The central regions of the upper and lower extents of the flange 8 on the enclosure 2 are recessed to conform with the channel section of the edge region of the free side of the door 4, as seen at 20 in Fig. 1, the gasket 10 thereon in said central regions therefore being correspondingly shaped to receive therein, in sealing engagement, the upper and lower extents of the edge region of the free side of the door 4.

Thus, on closure of the door 4, the inner face thereof seals against the associated half of the gasket 10, with the upper and lower extents of the edge region of the free side of the door 4 sealing against the recessed central regions of the gasket 10 as seen in Fig. 2 but with the sealing strip 18 extending at an angle to the main extent of the gasket 10.

On subsequent closure of the door 6, the inner face thereof seals against the associated other half of the gasket 10 with the inner face of the edge region of the free side thereof sealing against the strip 18, as seen in Fig. 3, which is displaced by the door 6 from a position extending at an angle to the plane of the door 4 to a position extending parallel with the common plane of the doors 4,6. Furthermore, the door 6 in its closed position urges the upper and lower extents of the strip 18 into sealing engagement with the upper and lower extents of the gasket 10 as seen in Fig. 2.

Thus it will be appreciated that the provision of the gasket 10 and strip 18 in the manner described ensures total sealing of the open rear face of the enclosure 2 on closure of the doors 4,6.

The door 4 is provided with an internally operated locking system part of which is shown in Fig. 4. The system is mounted on the inner face of the base portion 16 of the channel section edge region of the free side of the door 4, and includes a pivotal handle 20 mounted on a fixed plate 22, rotation of the handle moving parallel bars 24,26 upwardly and downwardly respectively into co-operating locking engagement with the upper and lower regions of the enclosure 2.

Subsequent to closing the door 4, and prior to closing the door 6, the two-point locking system on the door 4 is actuated to retain the door 4 in its closed position in sealing engagement with the gasket 10.

The door 6 is provided with an externally operated locking system (not shown) similar to that of the door 4 in that it includes a pair of parallel bars internally of the door 6 for locking engagement with the upper and lower regions of the enclosure 2, said bars being actuated by means of a pivotal handle located externally of the door 6. The locking system for the door 6 further includes a cam plate internally of the door 6 which, on rotation of the handle to actuate the bars, engages with the plate 22 to provide three point locking of the door 6.

Thus, subsequent to closure of the door 6 and on actuation of the locking system associated therewith, the door 6 is retained in its closed position in sealing engagement with the gasket 10 and with the sealing strip 18.

It will be appreciated that the described arrangement enables unrestricted access to the enclosure 2 when the doors 4,6 are open, there being no central stile to impede said access, while the doors 4,6, in their closed positions, make sealing engagement with the enclosure and with each other to prevent the ingress of moisture and the like into the enclosure and without the requirement for a central stile.

Clearly the precise configurations of the edge region of the free side of the door 4, the central regions of the upper and lower extents of the gasket 10, and the sealing strip 18 can be varied from those described and illustrated without departing from the scope of the invention.

Typical enclosures to which the invention is applicable may be from 700 mm to 2200 mm high and from 1000 mm to 1500 mm wide, while the described sealing arrangement can readily satisfy the requirements for Degree of Protection IPX6 as specified in BS EN 60529:1992 "Degrees of protection provided by enclosure (IP Code)".

Claims

1. An enclosure having an opening therein closed by a pair of side-hinged doors, and a resilient sealing gasket mounted on the enclosure to extend around said opening, the edge regions of the top, bottom and hinged side of each door, in its closed position, making sealing engagement with said gasket, the edge of the free side of a first of said doors carrying a sealing strip extending the length of the door, the arrangement being such that, on closure of said first door, the top and bottom extents of the edge region of the free side of the first door make sealing engagement with the gasket on the enclosure, and, on closure of the second door, the edge region of the free side of said second door makes sealing engagement with said sealing strip on the first door, whereby the enclosure is totally sealed.

2. An enclosure as claimed in claim 1 in which the edge region of the free side of the first door is of shallow channel shape in transverse section, the sealing gasket being correspondingly recessed at the regions of contact by the top and bottom extents of said edge region of the free side of the first door, the sealing strip being mounted to the free edge of said free side of the first door to extend outwardly of said door at a shallow angle thereto.

3. An enclosure as claimed in claim 2 in which the edge region of the free side of the first door is of truncated V-shape in transverse section.

4. An enclosure as claimed in claim 2 or claim 3 in which the shallow angle is of the order of 30 to the plane of the first door.

5. An enclosure as claimed in any one of claims 1 to 4 in which the first door includes an internally operated locking mechanism thereon co-operating with the interior of the enclosure to retain the first door in a closed position, the second door being provided with an externally operated locking mechanism thereon co-operating with the interior of the enclosure to retain the second door in a closed position.

6. An enclosure as claimed in claim 5 in which the locking mechanism of the second door co-operates with the locking mechanism of the first door internally of the enclosure to supplement the retention of the second door in its closed position.

7. An enclosure substantially as described with reference to and as illustrated by the accompanying drawings.