GB2258484A

GB2258484A - Access cover for a paved area

Info

Publication number: GB2258484A
Application number: GB9216260A
Authority: GB
Inventors: Keith Stanley Thompson
Original assignee: Glynwed Consumer and Building Products Ltd
Current assignee: Glynwed Consumer and Building Products Ltd
Priority date: 1991-07-30
Filing date: 1992-07-30
Publication date: 1993-02-10
Anticipated expiration: 2012-07-30
Also published as: GB9116422D0; GB9216260D0; GB2258484B

Abstract

An access cover made as a casting has a rim (3) surrounding a base (5) above which pavior bricks or blocks are to be supported and on which are spaced members (7, 8) which stiffen the base and are disposed below the level at which the pavior bricks or blocks are laid for their front faces to be at or above the level of the front of the rim. Preferably the spaced members (7, 8) are ribs projecting from the base, at least some of the ribs intersecting one another and at least some of the ribs (8) being joined to the rim. The cover may be designed to fit to an existing or known type of frame or it may form part of an access cover and frame assembly, the frame (2) being adapted to be embedded in a paved area. <IMAGE>

Description

ACCESS COVER FOR A PAVED AREA This invention relates to an access cover for a paved area, which cover, for example, enables access to be gained to sewers, drains and telecommunications services.

Access covers for use in roads, pavements and similar situations are generally made as castings in a metal such as iron, although some less robust covers are made as pressings or fabrications from metal sheet. The conventional cover has an integral, substantially closed, metal top portion which forms the main closure part of the cover and is intended to lie at, or substantially at, the level of the surrounding road or other surface.

Whilst being functionally satisfactory the conventional cover is not acceptable for use in paved areas because its exposed top portion is conspicuous and detracts from the appearance of the paving.

According to a first aspect the present invention consists in an access cover which is made as a casting, is adapted to receive and locate pavior bricks or blocks and comprises a rim surrounding a base above which the pavior bricks or blocks are to be supported and which is inset from the front of the rim, and spaced members on the base which stiffen the base and are disposed below the level at which the pavior bricks or blocks are laid above the base for their front faces to be at or above the level of the front of the rim.

When used in a paved area the access cover can have pavior bricks or blocks laid in it to match, and continue the pattern of, those of the surrounding paving. All that need be exposed then of the cover is the front of the rim and any key hole or other means provided in or on the cover for lifting it from its position of use.

The cover may be designed to fit to an existing or known type frame which embeds in the paved area, or it may form part of a cover and frame assembly.

According to a second aspect of the present invention, therefore, there is provided an access cover and frame assembly comprising an access cover in accordance with the first aspect of the invention herein set forth and a frame into which the main cover is received and which is adapted to be embedded in a paved area.

The frame in the assembly may be in accordance with that of the frame assembly which is the subject of our British patent application No. 90007390.9, publication No. 2 230 037A. Thus the frame may be provided at spaced intervals around a peripheral wall of the frame with a plurality of projections which are adapted in use to co-operate with, and space from the peripheral wall, paving bricks or blocks laid adjacent to the peripheral wall in the paved area.

Preferably the supporting frame with which the cover is used is also a casting.

The cover, and the frame, may be cast from cast or ductile iron.

The cover may be square, rectangular, triangular, round or other suitable plan shape. In a triangular form the cover and its supporting frame may be in accordance with the manhole cover and frame disclosed in British patent specification 1 313 515. The triangular cover may thus have one or more separate depending support portions at vertices of the triangle on the underside of the cover, within its triangular area, each support portion having at least one bearing surface at its underside. The bearing surface slopes relatively to the general plane of the front surface of the rim and co-operates with a generally upwardly facing sloping bearing surface on the frame.These bearing surfaces on the cover and frame are so arranged as to tend to prevent relative movement between the frame and cover in the general plane of the front surface of the rim, and hence in or parallel to the general plane of the upper surface of the pavior bricks or blocks supported by the body of the cover and the surrounding paved area in which the cover is set in use.

Two triangular covers in accordance with the first aspect of the present invention may be used with a square or rectangular supporting frame. The covers may be of right-angled isosceles triangular shape. The covers and their supporting frame may form a cover and frame assembly in accordance with the assembly which is the subject of British patent No. 2 116 611. Each cover has an edge formation which, at least when the cover is received in, and supported solely by, the frame is urged into frictional engagement with a corresponding edge surface of the frame. Both covers have sides which lie adjacent to one another in use, lifting formations being provided adjacent to those sides.As the covers are lifted using the lifting formations the said sides are caused to be drawn together, thereby releasing each edge formation from frictional engagement with the corresponding edge surface of the frame and facilitating removal of the covers from the frame.

The spaced members stiffening the base of the or each cover in accordance with the first aspect of the present invention may comprise ribs projecting from the base. At least some of the ribs may intersect and at least some of the ribs may be joined to the rim.

Preferably the ribs project from the base to a height such that their upper surfaces are at or just below the level to which sand mortar or other bedding material for the pavior bricks or blocks is laid on the base.

Typically they extend for about half the height of the rim.

An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings, in which, Figure 1 is a partial plan view of an access cover in accordance with the present invention and a supporting frame; and Figures 2, 3, 4 and 5 are sections respectively on lines 2-2, 3-3, 4-4 and 5-5 of Figure 1.

The access cover 1 shown in Figure 1 of the drawings is one of a pair of similar right-angled isosceles triangular shape which fit into a square frame 2. Each cover 1 and the frame 2 is made as a casting in ductile iron. The covers are designed to have pavior bricks or blocks of standard dimensions bedded in them.

Each cover 1 has an upstanding rim 3 surrounding an inset base 5. The base 5 is imperforate and has a triangular upwardly-stepped portion 6 at each of the two corners which are at opposite ends of the hypotenuse side of the cover. Formed integrally with the base 5 are stiffening ribs 7, 8 which stiffen the base. Some of the ribs 7, 8 are also integrally joined to the rim 3. The ribs 7, 8 project from the base to a height which is a little less than half the height of the rim 3. Their height is such that they extend to a level above the base at or just below the level to which sand, mortar or other bedding material will be laid in the cover for the pavior bricks or blocks to be bedded in the cover with their upper surfaces at or just above the level of the front, i.e. top, surface of the rim.Some of the ribs, 7, extend parallel to the hypotenuse side of the cover and others of the ribs, 8, extend perpendicularly to that side. Some of the ribs 7, 8 intersect one another. The ribs 7, 8 define pockets 9 on the base 5.

Mid-way along each of the two shorter sides of the cover is a lifting box 10 which is integrally joined to the base 5 and adjacent parts of the rim 4, and extends for the height of the rim. Each lifting box 10 contains a lifting keyhole 11 in an upper wall 12 and a prising slot 13 at the edge of that wall adjacent to the rim.

Each of the two stepped triangular portions 6 of the base 5 has at its underside, extending lengthwise of and directly below the rim along the hypotenuse side of the cover, a depending bearing rib 14, Figure 4.

The bearing rib 14 has a chamfered under-surface 15 which is inclined downwardly and inwardly from the adjacent outer wall surface of the rim, at an angle of approximately 300 to the horizontal. The dependency of each bearing rib 14 is less than the upward stepping of the respective triangular portion 6 from the main body of the base 5.

The square frame 2 has sides of inverted T-section providing an upstanding frame rim 16 and a base flange 17 The height of the frame rim is greater than the height of the rim 3 of each of the covers 1. An inner side surface 18 of the frame rim 16 is slightly outwardly inclined upwardly. The base flange 17 is asymmetrically disposed relative to the frame rim so that a major portion 17' of the flange extends outwardly around the frame. Inside each of two diagonally opposite corners of its square shape the frame has a flat triangular supporting web 19, at the bottom of the frame rim 16, of a thickness corresponding to the difference in height of the frame rim 16 and the rims 3 of the covers.At the inside of each of the other two diagonally opposite corners of the frame there is a seat 20 of prism shape extending from the corner in a direction towards the centre of the frame from a position at the bottom of the adjacent frame rim 16. The seat 20 presents two relatively inclined, upwardly facing, bearing surfaces 21 which meet at a central apex 22 extending horizontally on the diagonal of the square frame. Each bearing surface 21 is adapted to co-operate with the chamfered under-surface 15 of a respective one of the bearing ribs 14 of one of the covers 1 and is complementally inclined to the under-surface. The apex 22 is spaced below the upper edges of the frame rim 16 by a distance corresponding substantially to the distance that the upper side edge of the chamfered under-surface 15 of each bearing rib 14 is spaced below the front surface of the rim 3 of each cover 1.

Spaced along its four sides the frame rim 16 has on a perpendicular outer surface 23 small spacer projections 24 which co-operate with pavior bricks or blocks set around the frame when it is in use in a paved area to space them from the frame.

Similar spacer projections 25 are formed on an inner surface of the rim 3 of each cover for spacing from the rim pavior bricks or blocks set in the cover.

For the pavior bricks or blocks to be set in the covers sand, mortar or other bedding material is laid in each of the covers to a level at or just above the level of the tops of the stiffening ribs 7, 8. The pavior bricks or blocks can be arranged so that they match and continue the pattern of the pavior bricks or blocks in the surrounding paved area in which the access cover is located for use.

When the covers are fitted into the frame 2 the right-angled corner of the base of each cover seats on one of the supporting webs 19 of the frame, and the bearing ribs 14 at its other two corners co-operate with respective bearing surfaces 21 of the seats 20 of the frame. The three-position support given to each cover by the frame, and the co-operation between the inclined surfaces of the bearing ribs and bearing surfaces, ensures that the covers are stably supported and are restrained from movement relative to the frame in the general plane of the upper surface of the rims of the covers.

The inclined inner side surface 18 of the frame rim co-operates with the two shorter sides of each of the covers to urge the covers towards one another as they are fitted into the frame. This inhibits lifting of the covers from the frame under loads imposed on them, as by traffic passing over them, when they are in use.

Claims

1. An access cover which is made as a casting, is adapted to receive and locate pavior bricks or blocks and comprises a rim surrounding a base above which the pavior bricks or blocks are to be supported and which is inset from the front of the rim, and spaced members on the base which stiffen the base and are disposed below the level at which the pavior bricks or blocks are laid above the base for their front faces to be at or above the level of the front of the rim.

2. An access cover according to claim 1 wherein the spaced members are ribs projecting from the base.

3. An access cover according to claim 2 wherein at least some of the ribs intersect.

4. An access cover according to claim 2 or claim 3 wherein at least some of the ribs are joined to the rim.

5. An access cover according to any of claims 2 to 4 wherein the ribs project from the base to a height such that their upper surfaces are at or just below the level to which bedding material for the pavior bricks or blocks is required to be laid on the base to receive the pavior bricks or blocks.

6. An access cover according to claims 3 and 4, or claim 5 as dependent from claims 3 and 4, which is of generally right-angled triangular shape in plan and has some of the ribs extending parallel to the hypotenuse side of the triangular shape and some of the ribs extending perpendicularly to that side.

7. An access cover and frame assembly comprising an access cover as claimed in any preceding claim and a frame into which the access cover is received and which is adapted to be embedded in a paved area.

8. An assembly according to claim 7 wherein the access cover and frame are of generally triangular shape in plan.

9. An assembly according to claim 7 wherein the frame is of generally rectangular or square shape in plan and there is a second access cover in accordance with the access cover as claimed in any of claims 1 to 6, the two access covers each being of generally triangular shape in plan such that assembled together in a pre-determined orientation their triangular shapes in plan combine to form a generally rectangular or square shape in plan complementary to and able to be received into the rectangular or square shape of the frame.

10. An access cover substantially as described herein with reference to the accompanying drawings.

11. An access cover and frame assembly substantially as described herein with reference to the accompanying drawings.