GB2188663A

GB2188663A - Cover and frame assemblies for manholes or access holes

Info

Publication number: GB2188663A
Application number: GB08608043A
Authority: GB
Inventors: Derek Ferns
Original assignee: SELFLEVEL COVERS AG
Current assignee: SELFLEVEL COVERS AG
Priority date: 1986-04-02
Filing date: 1986-04-02
Publication date: 1987-10-07
Also published as: GB8608043D0

Abstract

Components for use in the manufacture of a manhole or access cover and frame assembly comprise L- sectioned elongate frame elements 16, and elongate L-sectioned cover elements 17 which may nest within the frame elements 16. The dimensions of first limbs 18,20 of the two elements are such that, when the elements are nested, the longitudinal free end edge surfaces 22,23 thereof are adjacent and substantially co-planar. The second limb 21 of each cover element is formed, at its free end edge, with a longitudinal flange 33 which overlies the longitudinal free end edge surface of the second limb 19 of the frame element 16 within which it is nested. In a rectangular cover and frame assembly manufactured from such components, the components may be assembled with either their first limbs or their second limbs vertical, depending on functional requirements, the latter arrangement rendering the assembly particularly unobtrusive at floor level. <IMAGE>

Description

SPECIFICATION Improvements in or relating to cover and frame assemblies The invention relates to cover and frame assemblies, and particularly to assemblies for providing access to manholes or the like, comprising a generally rectangular frame to be mounted in the surface where the manhole or access aperture is formed, which frame receives a cover comprising another rectangular frame adapted to be filled with a slab of material, such as concrete, which provides the main body of the cover.

In floor areas designed to have visual appeal as well as being utilitarian, it is desirable for the access cover and frame assembly to be as unobtrusive as possible. This is particularly the case, for example, in floor areas such as might be used in interiors, shopping precincts, shops, offices, public buildings and pedestrian walkways, where the surface is tiled, mosaiced or has some other form of decorative finish.

The present invention provides components for use in the manufacture of such a cover and frame assembly which result in the visible portions of the assemblies being narrow, and thus visually unobtrusive, and yet where the components co-operate to meet the necessary functional requirements of the assembly, particularly with regard to the provision of a fluidtight seal between the cover and frame and to the securing of the frame in position.

According to the invention, there are provided components for use in the manufacture of a cover and frame assembly, comprising an elongate frame element which is generally Lshaped in cross-section and comprises first and second limbs, and an elongate cover element which is also generally L-shaped in cross-sectiQn and comprises first and second limbs whereby the cover element may nest within the frame element with its first and second limbs overlying the first and second limbs respectively of the frame element, the dimensions of the first limbs of the two elements being such that the longitudinal free end edge surfaces thereof are adjacent and substantially coplanar when the elements are nested, and the second limb of the cover element being formed, at its free end edge, with a longitudinal flange which overlies the longitudinal free end edge surface of the second limb of the frame element when the elements are nested.

When used in the construction of an access cover and frame assembly, therefore, the components may be assembled together into the frame and cover respectively with their first limbs vertical, i.e. at right angles to the general plane of the frame and cover. In this case the adjacent, co-planar and parallel upper end edge surfaces of the components will be uppermost and will lie in the plane of the floor surface and thus form the only visible part of the assembly (assuming that the filler slab of the cover matches the main part of the floor surface).

Alternatively, the components may be assembled into the frame and cover respectively with their second limbs vertical. In this case the only part of the assembly which will be visible at the floor surface will be the surface of the aforementioned longitudinal flange on the second limb of the cover element, since this flange overlies the upper end edge surface of the corresponding limb on the frame element. In this case the assembly will be even more unobtrusive.

Preferably at least one of the limbs of the frame element is formed with at least one longitudinal sealing groove which faces the corresponding limb of the other element when the two elements are nested, whereby sealing means may be located in the groove to provide a fluid tight seal between the element.

Alternatively or additionally, one of the limbs of the cover element may be formed with at least one longitudinal sealing groove which faces the corresponding limb of the frame element when the two elements are nested.

Preferably at least one of the limbs of the frame element is formed with a longitudinal groove adapted to receive retaining means for engagement by a retaining element passed through an aperture in the corresponding limb of the cover element when the elements are nested so as thereby to retain the elements in the nested position. Preferably the groove is located between two of the aforementioned sealing grooves so that the presence of the retaining element does not interfere with the fluid-tight seal.

The outer surface of at least one limb of the cover element may be inclined with respect to the inner surface of the corresponding limb of the frame element, when the two elements are nested, so that the surfaces are furthest apart adjacent the junction between the first and second limbs. Thus, if the limb having the inclined surface is vertical this will facilitate upward removal of the cover from the frame, in use, since the clearance between the cover elements and the corresponding frame elements will increase as the cover is lifted.

The inner surface of at least one of the limbs of the cover element and/or the outer surface of at least one of the limbs of the frame element is preferably provided with formations extending away from said surface for keying the surface to a settable material applied thereto. In the case of the frame element this will key the frame into concrete or similar material in which it is set, and, in the case of the cover element, this will locate within the cover frame a filler slab of concrete or the like which forms the main body of the cover.

The invention includes within its scope a cover and frame assembly when constructed using components of any of the kinds referred to above.

The following is a more detailed description of one embodiment of the invention, by way of example, reference being made to the accompanying drawings in which: Figure 1 is a vertical section through a cover and frame assembly constructed using components according to the invention, and Figure 2 is a similar section through an alternative cover and frame assembly using the same components but in a different manner.

Referring to Figure 1, the assembly comprises a rectangular outer frame 10, set in concrete or similar settable material 11 surrounding a rectangular manhole or other access aperture 12, and a cover 13 comprising a rectangular frame 14 surrounding a filler slab 15 which may also be of concrete or similar settable material.

The rectangular outer frame 10 is formed from four frame elements 16 secured together at their corners by any suitable means, and the frame 14 of the cover is similarly formed from four cover frame elements 17.

The elements 16 and 17 may be of constant cross-section in which case they may be formed by extrusion, drawing, hot rolling or any other suitable process depending on the material from which they are made. This material may, for example, be aluminium or plastics or any other suitable material.

As will be seen from Figure 1, each frame element is generally L-shaped in cross-section and, in use, the elements are nested as shown. Each outer frame element 16 comprises a vertical first limb 18 and a horizontal second limb 19. Similarly each cover frame element 17 comprises a vertical first limb 20 and a horizontal second limb 21.

The upper free end edge surfaces 22 and 23 of the first limbs of the elements respectively lie at the ground surface and thus constitute the only visible parts of the outer and cover frames. The two surfaces, as seen in Figure 1, are co-planar.

The outer surface of the limb 18 of the outer frame element 16 is integrally formed with projecting formations 24 which are shaped to key the frame element to the concrete 11 and, similarly, the inner surface of the limb 20 of the cover frame element is formed with formations 25 to key their cover element to the concrete or similar material 15.

Similar keying formations 26 are formed on the lower horizontal limb of the cover frame element 20.

To provide an effective seal between the cover and frame, the lower limb 21 of each cover frame element is formed with a longitu dinal groove 27 to receive sealing means and the corresponding limb of each outer frame element 19 is also formed with grooves 28 and 29 to receive sealing means. The sealing means may be of any conventional form such as a grease-type sealing material or a resilient sealing strip such as a generally D-sectioned neoprene tube received in the grooves.

There may be located in the groove 29 a retaining block (not shown) formed with a threaded hole to receive the threaded end of a retaining bolt (also not shown) which passes through a suitably located aperture in the cover filler and frame element. This enables the cover to be secured in position if required.

The retaining block may be slid to the appropriate position along the groove 29.

The vertical limb 20 of each cover frame element is formed on its outer surface with a generally circular cross-section longitudinal groove 30 which receives a similarly shaped portion of a resilient sealing strip 31. The sealing strip 31 has a limb which projects away from the cover frame element for resilient engagement with the adjacent surface of the limb 18 of the corresponding outer frame element.

The outer surface of the vertical limb 20 of each cover frame element, facing the corresponding outer frame element, is inclined as indicated at 32. This ensures that the clearance between the cover and frame increases as the cover is lifted, thus facilitating its removal from the frame.

The inner end of the horizontal second limb 21 of each cover frame element is formed with a downwardly extending flange 33. Figure 2 shows an alternative arrangement where both the outer frame components and the cover frame components are turned through 90 before being assembled together to form the outer frame and cover frame respectively so that, in this construction, the second limbs 19 and 20 are vertical and the flange 33 on the cover frame is uppermost.

It will be seen that in this construction the flange 33 overlies the upper end surface 34 of the now vertical limb 19 of each frame element so that the flange 33 forms the only part of the assembly which is visible at the ground surface. Such an arrangement provides an extremely unobtrusive frame for the assembly while at the same time providing all the necessary functions of the frame, such as the provision of fluid-tight seals and adequate keying to the surrounding material and cover slab respectively.

In the arrangement shown in Figure 1, the vertical limb 18 of the outer frame element 16 may be extended vertically downwards to the level of the bottom of the formation defining the groove 29. This provides greater stability for the frame element when it is stood, in the orientation shown, on a flat surface during assembly of the outer frame from the four frame elements.

Claims

1. Components for use in the manufacture of a cover and frame assembly, inciuding an elongate frame element which is generally Lshaped in cross-section and comprises first and second limbs, and an elongate cover element which is also generally L-shaped in cross-section and comprises first and second limbs whereby the cover element may nest within the frame element with its first and second limbs overlying the first and second limbs respectively of the frame element, the dimensions of the first limbs of the two elements being such that the longitudinal free end edge surfaces thereof are adjacent and substantially co-planar when the elements are nested, and the second limb of the cover element being formed, at its free end edge, with a longitudinal flange which overlies the longitu dinal free end edge surface of the second limb of the frame element when the elements are nested.

2. Components according to Claim 1, wherein at least one of the limbs of the frame element is formed with at least one longitudi nal sealing groove which faces the corresponding limb of the cover element when the two elements are nested, whereby sealing means may be located in the groove to provide a fluid tight seal between the elements.

3. Components according to Claim 1 or Claim 2, wherein one of the limbs of the cover element is formed with at least one longitudinal sealing groove which faces the corresponding limb of the frame element when the two elements are nested.

4. Components according to any of Claims 1 to 3, wherein at least one of the limbs of the frame element is formed with a longitudinal groove adapted to receive retaining means for engagement by a retaining element passed through an aperture in the corresponding limb of the cover element when the elements are nested so as thereby to retain the elements in the nested position.

5. Components according to Claim 3 and Claim 4, wherein said groove is located between two of the aforementioned sealing grooves so that the presence of the retaining element does not interfere with the fluid-tight seal.

6. Components according to any of Claims 1 to 5, wherein the outer surface of at least one limb of the cover element is inclined with respect to the inner surface of the corresponding limb of the frame element, when the two elements are nested, so that the surfaces are furthest apart adjacent the junction between the first and second limbs.

7. Components according to any of Claims 1 to 6, wherein the inner surface of at least one of the limbs of the cover element is provided with formations extending away from said surface for keying the surface to a settable material applied thereto.

8. Components according to any of Claims 1 to 7, wherein the outer surface of at least one of the limbs of the frame element is provided with formations extending away from said surface for keying the surface to a settable material applied thereto.

9. Components for use in the manufacture of a cover and frame assembly, substantially as hereinbefore described with reference to the accompanying drawings.

10. Components for use in the manufacture of a cover and frame assembly, according to any of Claims 1 to 9, and comprising four of said frame elements of such length that they may be assembled together to form a rectangular frame, and four of said cover elements of such length that they may be assembled together to form the peripheral portion of a rectangular cover which will nest within the rectangular frame formed by the frame elements.

11. A cover and frame assembly when constructed from components according to Claim 10, said four frame elements being assembled together to form a rectangular frame and said four cover elements being assembled together to form the peripheral portion of a rectangular cover which will nest within said rectangular frame.