IE54782B1

IE54782B1 - Improvement in manhole/access cover and frame assemblies

Info

Publication number: IE54782B1
Application number: IE2783/83A
Authority: IE
Original assignee: Selflevel Covers Ag
Priority date: 1982-11-27
Filing date: 1983-11-28
Publication date: 1990-01-31
Also published as: AU2173383A; AU557085B2; SE8306558L; DE3343002A1; IE832783L; NL8304078A; DK543083A; CH655532B; JPS59150832A; GB2134572B; GB8331735D0; NL192991C; DK153167B; GB2134572A; NL192991B; NO834372L; DK153167C; SE8306558D0; DK543083D0

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> [GB2134572A]

Description

la 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 dislodged or separated from the adjoining surfaces. In the course of time, however, the seals tend to stick and it is nob 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 - 2 - 3 4 7 8 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 assembly including a 5 generally rectangular frame having opposite parallel side frame members each having an inwardly facing inner wall and an inwardly projecting flange, and a generally rectangular cover to be supported within the frame and between said side frame inner walls and having opposite 10 parallel marginal lower surface portions to rest on the upper surfaces of said inwardly projecting flanges respectively, said lower surface portions of the cover and said upper surfaces of the flanges respectively having complementary formations thereon comprising a projection 15 from one surface which is engageable within a recess in the other surface when the cover is operatively positioned in the frame, the bottom wall of each recess having a sloping portion which leads into the surface in which the recess is formed, said surface extending evenly 20 away from the recess whereby, as the cover is displaced parallel to said side members of the frame, interengage-ment of the projections with the sloping bottom walls of the recesses causes the cover to be lifted with respect to the frame until the projections leave the recesses, 25 whereafter, upon continued displacement of the cover, the projections smoothly engage the surface which extends evenly away from the recess.

Thus, inter-engagement between the projections - 2a - and recesses not only serves to locate each cover in its correct operative position in the frame, but it also assists 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 - 3 - - 3 - S 4 V 8 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, 5 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 10 supporting two rectangular covers 11 (only one of which is shown), both the frame and the covers being formed from cast-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 16 and 17 respectively along the bottom of the wall 15. Spaced parallel longitudinal grooves 18 are formed in the inwardly facing surface of the wall 15 to receive a sealing compound. The ends of the side frame members 10 are formed - 4 - with laterally projecting flanges 19 whereby two side frame members may be bolted together end-to-end or to the end frame members.

Referring to Figure 2, each end frame member 5 14 or 14a comprises an upstanding wall 20, 20a from the bottom of which extends an outwardly projecting flange 21 or 21a.

It will be seen from Figure 2 that the end wall 14 slopes outwardly whereas the wall 14a slopes 10 inwardly. The flanges 19 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 15 horizontal base portion 23 and opposed upwardly extending side walls 24 which are inclined outwardly so that they will mate with the upstanding walls 15 of the side frame members 13. The marginal side portions of the cover rest on the inwardly turned flanges 16 on the side 20 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 25 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. - 5 - S 47 8 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 5 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 16 of the side frame members, is formed at 10 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 15 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 20 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 25 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 as --6- effect of breaking any fluid-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 5 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 16 alongside the recess 29 therein.

Claims

1. A manhole/access cover and frame assembly including a generally rectangular frame having opposite parallel side frame members each having an inwardly facing inner wall and an inwardly projecting flange, and a generally rectangular cover to be supported within the frame and between said side frame inner walls and having opposite parallel marginal lower surface portions to rest on the upper surfaces of said inwardly projecting flanges respectively, said lower surface portions of the cover and said upper surfaces of the flanges respectively having complementary formations thereon comprising a projection from one surface which is engageable within a recess in the other surface when the cover is operatively positioned in the frame, the bottom wall of each recess having a sloping portion which leads into the surface in which the recess is formed, said surface extending evenly away from the recess whereby, as the cover is displaced parallel to said side members of the frame, interengagement of the projections with the sloping bottom walls of the recesses causes the cover to be lifted with respect to the frame until the projections leave the recesses, whereafter, upon continued displacement of the cover, the projections smoothly engage the surface which extends evenly away from the recess.

2. A manhole/access cover as claimed in Claim 1 in which the cover has downward projections arranged to be - 8 - received in respective recesses formed in the upper surfaces of the respective associated flanges.

3. A manhole/access cover as claimed in Claim 1 or Claim 2, wherein said interengageahle projections and 5 recesses are located adjacent one end of the cover.

4. A manhole/access cover substantially as hereinbefore described by way of example with reference to and as shown in the accompanying drawings. I0 Dated this 28th day of November 1983 Dermot P Cummins & Co

5. 264 Merrion Road, Dublin 4 (subsequently 41 Lower Baggot Street, Dublin 2) Agent for the applicant