GB2134572A

GB2134572A - Removing manhole covers

Info

Publication number: GB2134572A
Application number: GB08331735A
Authority: GB
Inventors: Derek Ferns
Original assignee: SELFLEVEL COVERS AG
Current assignee: SELFLEVEL COVERS AG
Priority date: 1982-11-27
Filing date: 1983-11-28
Publication date: 1984-08-15
Also published as: DK543083A; GB8331735D0; NL192991C; CH655532B; AU2173383A; SE8306558D0; NL8304078A; DK153167B; AU557085B2; DK153167C; IE832783L; DK543083D0; SE8306558L; IE54782B1; JPS59150832A; NO834372L; NL192991B; DE3343002A1; GB2134572B

Abstract

In a manhole/access cover and frame assembly wherein two or more rectangular covers 11 are supported in a frame 10 having internally-flanged side members on which the covers rest, each cover 11 is formed with a pair of downward corner projections 28 which locate in respective recesses 29 in the upper surface of the associated frame flange. The base of each recess 29 is sloped whereby when the cover is slid horizontally, for removal, it is lifted slightly as the projections 28 ride up the recesses 29, so breaking any seal. <IMAGE>

Description

SPECIFICATION Improvement in manhole/access-cover and frame assemblies The invention relates to manhole/access cover and frame assemblies. The invention is particularly applicable to assemblies where both the cover-and frame are formed from..cast-iron, but it is not limited to such assemblies.

In order to ensure-an air and water tight joint between the cover and its frame, provision is often made to accommodate sealing .compound or other sealing arrangements. When:the cover is to.be removed, the sealing .compound or equivalent must be displodged or separated from the adjoining surfaces. -In the co.urse of time, however, the seals tend to stick and it is not unusual for an operator to experience some difficulty in removing the cover.

Where two or more covers are fitted adjacent to one .another, it is sometimes.easier, after removing the first cover, to slide an adjacent cover laterally than to lift it. However, this.does not necessarily dislodge or separate the seals, or all of them.

It is the object of the invention to provide a manhole/access cover and frame assembly in which removal of the cover is facilitated.

According to the invention there is provided a manhole/access cover and frame assernbly comprising two or more generally rectangular covers supported side-by-side within .a generally rectangular frame including side frame members having inner walls which engage opposite stretches of the outer peripheral walls of the covers, the side frame members aíso having inwardly projecting flanges, on the upper surfaces of which rest the opposite marginal portions of said covers, marginal edges of each cover and the associated flanges having respective elements of projection and recess combinations, the projections engaging in the recesses when the cover is operatively positioned in the frame.

Preferably each said recess has a sloping bottom wall which is engageable by said projection so that as the cover is slid along the frame, from said operative position, interengagement of the projection with the sloping bottom wall lifts the cover with respect to the frame.

Thus, inter-engagement between the projections.and recesses not only serves to locate each cover in -its correct operative position in the frame, but it may also be-arranged to assist in removal of the cover by slightly lifting the cover as the cover is removed by sliding it along the frame.

The following is a detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawings in which: Figure 1 is a plan view of a manhole/access cover and frame assembly having-two covers, only one of which is shown in the drawing, Figure.2 -is a vertical section along the line 2-2 of Figure 1, Figure 3 is a vertical section along the line 3-3 of Figure 1,and Figures 4, .and 6 are more detailed views of one of the: projections on the cover.

-Referring to the drawings, the manhole cover and frame -assembly comprises a rectangular frame 1 0supporting two rectangular covers 11 (only one of which is shown), both the frame and the covers being formed fromcast-iron. The central:portions of the covers may be formed with recessed areas 12 to receive a concrete filling.

Although the frame 10 may be integrally formed in one piece, it is preferably formed from a number of separately formed elongate side members 13 and end members 14 bolted together.

At best seen in Figure 3, each side frame member 13 comprises an upstanding outwardly sloping wall 15 and inwardly and outwardly projecting flanges 1 6 and 1 7 respectively along the bottom of the wall 1 5. Spaced parallel longitudinal grooves 1 8 are formed in the inwardly facing surface of the wall 15 to receive a seaiing compound. The ends of the side frame members 10 are formed with laterally projecting flanges 19 whereby two sidle frame members may be bolted together end-to-end or to the end frame members.

Referring to Figure 2, each end frame member 14 or 1 4a comprises an upstanding wall 20, 20a from the bottom of which extends an outwardly projecting flange 21 or 21 a.

It will .be seen from Figure 2 that the end wall 14 slopes outwardly whereas the wall 1 4a slopes inwardly. The flanges 1 9 on the ends of the side frame members 13 are inclined in a corresponding manner so that they will mate with flanges 22 and 22a respectively on the ends of the end frame members.

As best seen in Figure 3, each cover 11 has a horizontal base portion 23 and opposed upwardly extending side walls 24 which are inclined outwardly so that they will mate with the upstanding walls 1 5 of the side frame members 13. The marginal side portions of the cover rest on the inwardly turned flanges 1 6 on the side frame members.

Referring to Figure 2, one end wall 25 of the cover 11 is inclined outwardly and the opposite end wall 25a is inclined inwardly so that the end walls will mate respectively with the inclined walls 20 and.20a on the end frame members. The angles of inclination of the walls are the same so that the outwardly inclined end wall of each cover 11 will mate with the abutting inwardly inclined end wall of the adjacent cover.

Reinforcing flanges 26 project downwardly from the underside of the base portion 23 of the cover 11 in conventional manner.

Key sockets 27 (Figure 1) are provided in the upper surface of each cover 11 for the insertion of keys to permit removal of the cover from the frame.

Referring to Figure 2, each of the opposed marginal side portions of the cover 11 , which rest on the flanges 1 6 of the side frame members, is formed at the end adjacent the inwardly inclined wall 25a with a downwardly extending projection 28 which, when the cover is fitted in its operative position, locates within a recess 29 in the flange 16. The recesses 29 which will be engaged by the downward projections on the manhole cover which is not shown are visible in Figure 1.

As shown in Figure 2, the bottom walls of the recesses 29 are sloped. The engagement of the projections 28 with the recesses 29 assists in locating each cover accurately with respect to the frame. Furthermore, in an assembly where a plurality of covers are arranged side-by-side, after the first cover has been removed by lifting the remaining covers are normally removed by sliding them along the side frame members as well as lifting them. Since the bottom walls of the recesses 29 are sloped, the engagement of the projections 28 with the sloping bottom walls, as each cover is slid along the side frame, has the effect of lifting one end of the cover slightly and this assists its removal. For example, it will have the effect of breaking any fiuid-tight seal which has been made around the periphery of the cover.

Figures 4 to 6 show one of the projections 28 in greater detail. Figure 4 is a vertical section through one end of the cover 11, Figure 5 is an underplan view and Figure 6 is an end view. It will be seen that alongside the projection 28 may be provided a smaller projection 30 which bears on the surface of the associated flange 1 6 alongside the recess 29 therein.

Claims

1. A manhole/access cover and frame assembly comprising two or more generally rectangular covers supported side-by-side within a generally rectangular frame including side frame members having inner walls which engage opposite stretches of the outer peripheral walls of the covers, the side frame members also having inwardly projecting flanges on the upper surfaces of which rest the opposite marginal portions of said covers, marginal edges of each cover and the associated flanges having respective elements of projection and recess combinations, the projections engaging in the recesses when the cover is operatively positioned in the frame.

2. A manhole/access cover as claimed in claim 1 in which the cover has downward projections arranged to be received in respective recesses formed in the upper surfaces of the respective associated flanges.

3. A manhole/access cover as claimed in either of claims 1 and 2 in which each recess has a sloping bottom wall which is engageable by said projection, so that as the cover is slid along the frame, from said operative position, interengagement of the projection with the sloping bottom wall lifts the cover with respect to the frame.

4. A manhole/access cover as claimed in any one of the preceding claims in which each cover has projections or recesses in each of its corners.

5. A manhole/access cover substantially as hereinbefore described by way of example with reference to and as shown in the accompanying drawings.