GB2147803A - Access cross assemblies - Google Patents

Abstract

An access cover assembly in a floor to persuit access to services therebeneath comprises a frame 10 defining an opening into which a cover 11 may be fitted, a channel 28 being formed between the frame and cover. Two clamp rings 12 and 13 are arranged to fit within the channel 28, with ring 12 held to the frame and ring 13 to the cover by means of screws 37 and 40 respectively. When the cover is fitted in the frame, screws 40 are inaccessible as they are disposed below the ring 13, and screws 37 are covered by a flange 34 on the ring 13, lying in a rebate 33 in the ring 12. The cover is fastened to the frame by further screws 43 (Figure 3). Floor-covering material 48,49 may be cut to fit around the frame and over the cover, the edges of such material being securely clamped by the rings 12 and 13. <IMAGE>

Description

SPECIFICATION Access cover assemblies This invention relates to an access cover assembly, suitable for fitting in a floor area to permit access to services therebeneath.

When a building is constructed - and particularly larger buildings other than domestic dwellings ducts are often provided beneath the floors to carry the various services around the building, such as electricity and telephone cables, and water and drainage pipes. Occasionally, it may be necessary to gain access to the services or ducts, and so at various locations it is usual to let into the floor access cover assemblies over openings to the ducts or service points. Atypical assembly of this kind has a frame adapted to be secured to the floor around an opening therein leading to the duct, and a removable cover which when fitted within the frame provides a flat surface co-planar with the general floor level.

Very often, a floor-covering material - for example, carpeting or a flexible plastics sheeting such as vinyl flooring - are laid on the floors of buildings, but such floor coverings must be cut away to define an opening surrounding an access cover assembly so as to permit the rmoval of the cover part of the assembly without the need to lift the whole of the floor covering. This leaves free edges in the covering around the opening, which edges must be attached securely to the floor so as not to present a safety hazard. Moreover, for aesthetic reasons, it is usual to affix a piece of the same floor covering over the cover part of the assembly, and again the edges thereof must most securely be attached to the cover part.The edges of the floor covering materials in the region of the cover assembly are normally affixed to the floor and cover by means of adhesives, but experience has however shown that such a technique is unable to withstand heavy service: within a relatively short period of time, the edges of the covering material, both around the frame and adjacent the edges of the cover itself, lift away and rapidly become a safety hazard.

It is a principal object of this invention to provide an access cover assembly which permits a floor covering material to be secured around the frame of the assembly and also to the cover of the assembly, in a secure and reliable manner.

Accordingly, this invention provides an access cover assembly comprising a frame defining an opening and a cover adapted to fit within the frame so as to define an upwardly-opening channel extending around the cover and disposed between the cover and the frame, there being a first clamp ring releasably securable to the frame so as to and lie within the channel and a second clamp ring releasably securable to the cover so as also to fit within the channel, the first and second clamp rings each being adapted to permit the clamping of sheet floor covering material between the clamp rings and the frame and the cover respectively.

It will be appreciated that a floor covering may safely and securely be used with the access cover assembly of this invention. The floor covering is cut in the region of the access cover assembly such that the cut edges of the main area of the floor covering overlie the frame to an extent sufficient to be located between the frame and its associated first clamp ring, whereby those cut edges may securely be held by the clamping action between the frame and first clamp ring. The piece of the covering material cut from the main area - or some other piece, if desired - is then trimmed so as to be of a size suitable to overlie the cover of the access cover assembly, with the edges thereof extending into the region between the periphery of the cover and the second clamp ring, such that those edges may securely be held by the clamping action between the cover and second clamp ring.When thus clamped, the edges of the covering material are most securely held and no reliance is placed on adhesives; as a consequence, a relatively long service life may be expected without the overall assembly becoming a safety hazard.

Most preferably, each clamp ring is held to the associated frame or cover by means of a plurality of screw-threaded fasteners spaced around the ring, whereby tightening of the fasteners serves securely to clamp the covering material between the ring and the associated part of the cover assembly. Advantageously, the assembly is configured such that the screw-threaded fasteners are not accessible once tightened and the cover of the assembly is fitted into the frame. This ensures that the clamp rings may not accidentally be loosened, so freeing the floor covering, for example when it is desired to lift the cover from the frame.

In a preferred embodiment, the cover clamp ring overlies a peripheral portion of the cover and the screw-threaded fasteners therfor extend through plain bores in said peripheral portion of the cover, upwardly into blind threaded bore in the clamp ring.

In this way, the cover clamp ring fasteners are accessible only when the cover has been removed from the frame. The inner periphery of the frame clamp ring in this preferred embodiment is provided with a rebate, the screw-threaded fasteners extending through plain bores in the region of the rebate of the ring, downwardly into threaded bores in the frame. By providing on the cover clamp ring an outwardly-projecting flange which will lie in the rebate of the frame clamp ring when the cover is fitted in the frame, the flange will cover the screwthreaded fasteners associated with the frame clamp ring and so prevent access thereto other than when the cover has been removed from the frame.

Preferably, an air-tight seal is provided between the cover and the frame. This advantageously comprises a pair of resilient seal rings, one located in a groove in the cover and co-operating with a seal rib provided on the frame, and the other located in a groove in the frame and co-operating with a seal rib provided in the cover.

The overall shape of the access cover of this assembly may take any required form. For example, the cover could be circular, or essentially square or rectangular, though in the latter case it is preferred for the corners to be rounded.

By way of example only, one specific embodiment of access cover assembly of this invention will now be described in detail, reference being made to the accompanying drawings, in which: Figure lisa plan view of a corner region of the access cover assembly which is constructed in accordance with this invention, showing the assem buy with the cover fitted in the frame and a sheet flooring material being held thereby; Figure 2 is a part sectional view of the cover assembly of Figure 1, taken on line Il-Il marked on that Figure; and Figure 3 is a part sectional view of the cover assembly of Figure 1, but taken on line Ill-Ill marked on that Figure.

The cover assembly of this invention comprises a frame 10 adapted to be let into a floor and a cover 11 adapted to fit within the opening defined by the frame, there being clamp rings 12 and 13 associated with the frame 10 and cover 11 respectively. The frame 10 is suitably configured to permit the positioning thereof in a floor around an opening in the floor giving access to a duct or service point beneath the floor, the frame typically being cemented into the floor at the time of laying of the floor itself. As will be appreciated from Figures 2 and 3, the frame 10 has a major base region 14 from which upstands a shoulder 15 extending around the frame, which base region 14 and shoulder 15 provide a location for the cover 11 fitted into the frame.From the shoulder 15 there is a land 16 lying generally parallel to the base region 14, a clamp face 17 leading upwardly and sloping outwardly (of the frame) from the land 16.

Projecting downwardly from the outer part of the clamp face 17 is a peripheral leg 18 having a flange 19 formed at the free, lower end thereof. Formed in the base region 14 is a groove 20, the innermost part of the base region 14 being provided with an upstanding lip 21, as will be appreciated from a consideration of Figures 2 and 3.

The major area 22 of the removable cover 11 is flat, but around the periphery ofthat major area 22 is a downwardly projecting portion 23, adapted to bear on the base region 14 of the frame 10 and to fit within the recess defined by the shoulder 15. In this way, the position of the cover 11 is accurately determined within the opening defined by the frame 10. The lower face of the portion 23 is formed with a groove 24 extending around the entire periphery of the cover, there being a pair of lips 25 also extending peripherally around the groove 24, one to each side thereof. The upper surface of the portion 23 of the cover 11 defines a peripheral land 26, there being a clamp face 27 extending upwardly and inwardly (of the cover) from the land 26, which face 27 leads to the upper surface of the cover 11.

When the cover 11, as described above, is fitted within the frame 10, also as described above, there is a flat-bottomed V-shaped channel 28 extending around the entire periphery of the cover 11, defined by the clamp faces 17 and 27 and the lands 16 and 26. In this channel 28 there are located two clamp rings 12 and 13, ring 12 being associated with the frame 10 and ring 13 with the cover 11. Ring 12 defines a clamp face 31 disposed to lie adjacent and co-operate with clamp face 17 of the frame, whereas ring 13 defines a clamp face 32 arranged to lie adjacent and co-operate with clamp face 27 of the cover 11. Clamp ring 12 has a rebate 33 extending around the entire inner periphery thereof, whereas clamp ring 13 has a projecting flange 34 which, when the assembly is completed and the cover fitted within the frame, is located in the rebate 33 to overlie part of the clamp ring 12.

A series of screw-threaded bores 35 is provided around the frame 10, each bore extending perpendicularly into the frame downwardly from the land 16.

The clamp ring 12 is provided with similarly disposed countersunk plain bores 36, whereby the ring 12 may be secured to the frame 10 by means of a like number of screws 37 located in the bores 36 and threaded into the bores 35. Similarly, a series of screw-threaded bores is provided around the clamp ring 13, each bore extending into the ring from the lower face thereof. The land 26 of the cover is provided with similarly disposed countersunk plain bores 39, whereby the clamp ring 13 may be secured to the cover 11 by means of screws 40 extending through bores 39 and threaded into the bores 38.

A non-intercellular seal material ring 41 is 5 located in the groove 20 in the frame, and a similar non-intercellular seal material ring 42 is located in the groove 24 of the cover. When the cover is fitted into the frame, an air-tight seal is formed by the seal rings 41 and 42, co-operating with the lips 21 and 25, respectively. The cover may then be secured in position by means of countersunk screws 43 extending downwardly through holes 44 and 45 provided in the clamp ring 13 and land 26 of the cover respectively, and threaded into aligned bores 46 provided in the base region 14 of the frame, though screws 43 may pass freely through holes 45, those holes are tapped, to permit eyebolts or the like to be passed through holes 44 and threadingly engaged in the holes 45, to facilitate lifting of the cover once screws 43 have been removed.Holes 44 are thus of a sufficient diameter to permit an eyebolt to pass therethrough.

The frame may be made from two or more peripherally-extending sections, bolted together; for this purpose apertured lugs 47 are provided to receive the bolts.

It will be appreciated that prior to assembly of the cover 11 into the frame 10, access may be had to the screws 37 associated with the frame clamp ring 12 and also to the screws 40 of the cover clamp ring 13, to permit tightening of those clamp rings to the associated frame or cover. In this way, a sheet flooring material 48 suitably cut to size to lie around the frame may have its free edges securely clamped between the clamp face 17 of the frame and clamp face 31 of the frame clamp ring 12. Similarly, the free edges of a piece of sheet flooring material 49 cut to a suitable size to overlie the cover 11, may have its free edge securely clamped between the clamp face 27 of the cover and the clamp face 32 of the cover clamp ring 13. Once the edges of the sheet flooring material have been clamped in this way, the cover may be fitted into the opening defined by the frame and the screws 43 offered into position and tightened, so as to secure the cover within the frame and effect an air-tight seal between these two components. The screws 37 and 40 associated with the clamping rings, are not then accessible. Subsequently, should it be required to gain access through the cover assembly, the screws 43 are released and the cover lifted; the screws 37 and 40 are not accessible and so the sheet flooring material cannot accidentally be released from its clamped state. The access cover assembly of this invention thus provides a safe and reliable means for the securement of the free edges of sheet flooring material to the frame and the cover of the assembly.

Claims (9)

1. An access cover assembly comprising a frame defining an opening and a cover adapted to fit within the frame so as to define an upwardly-opening channel extending around the cover and disposed between the cover and the frame, there being a first clamp ring releasably securable to the frame so as to lie within the channel and a second clamp ring releasably securable to the cover so as also to lie within the channel, the first and second clamp rings each being adapted to permit the clamping of sheet floor covering material between the clamp rings and the frame and the cover respectively.

2. An access cover assembly according to claim 1,wherein each clamp ring is held to the respective associated frame or cover by means of a plurality of screw-threaded fasteners spaced around the ring, whereby tightening of the fasteners serves securely to clamp any covering material provided, between the ring and the associated part of the cover assembly.

3. An access cover assembly according to claim 2, wherein the screw-threaded fasteners are not accessible once tightened to cause their respective rings to effect a clamping action and the cover of the assembly is fitted into the frame.

4. An access cover assembly according to claim 3, wherein the cover clamp ring overlies a peripheral portion of the cover and the screw-threaded fasteners therefor extend through the plain bores in said peripheral portion of the cover, upwardly into blind threaded bores in the clamp ring.

5. An access cover assembly, according to claim 3 or claim 4, wherein the inner periphery of the frame clamp ring is provided with a rebate, the frame clamp ring screw-threaded fasteners extending through plain bores in the region of the rebate of the ring, downwardly into threaded bores in the frame.

6. An access cover assembly according to claim 5, wherein the cover clamp ring is provided with an outwardly-projecting flange which will lie in the rebate of the frame clamp ring when the cover is fitted in the frame, whereby the flange covers the screw-threaded fasteners associated with the frame clamp ring and so prevents access thereto other than when the cover has been removed from the frame.

7. An access cover assembly according to any of the preceding claims, wherein an air-tight seal is provided between the cover and the frame.

8. An access cover assembly according to claim 7, wherein the air-tight seal comprises a pair of resilient seal rings, one located in a groove in the cover and co-operating with a seal rib provided on the frame, and the other located in a groove in the frame and co-operating with a seal rib provided in the cover.

9. An access cover assembly substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.