AU756128B2 - Improved access cover support frame and members - Google Patents

Description

M-'UI 185/91 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: IMPROVED ACCESS COVER SUPPORT FRAME AND MEMBERS The following statement is a full description of this invention, including the best method of performing it known to us IP Australia Documents received on:- 0 1 APR 1999

CD

Batch No: 1 IMPROVED ACCESS COVER SUPPORT FRAME AND MEMBERS Field of Invention The present invention relates to an improved access cover supporting frame and parts thereof. Throughout this specification the term "access cover" will be used to identify any type of access cover, manhole cover and pit cover or any comparable structure.

Background Access covers and their frames are commonly found in roads, sidewalks, floors of buildings and the like to cover drains, sewers, inspection and maintenance ports. There are a considerable number of types of access covers, dependent on their intended use, cost and ascetics. They can vary in shape, style and materials used. An access cover, in use, is usually located within a *frame, the frame providing a defined location for the access cover and also a fixed support for the access cover. The access cover and frame are generally 15 positioned so as to be flush with the level of the surrounding area.

One of the more popular access covers and frames are Gatic® brand access covers and frames. Amongst the commonly sold products are cellular :access covers and frames. These products have been in use for quite a number of years and can be found in roads and walkways. There has been little change in the design over time, primarily because the design has remained safe, economical to manufacture and reliable even with modern traffic conditions. It has, however, been found by experience over many years that if the access cover arrangement is to fail over time, it is likely that the support frame or its surrounding concrete apron will fail before the cover.

The cellular access covers typically have a cast iron (or ductile iron) skeleton having a plurality of upwardly open cells. The cells of the skeleton are normally filled with concrete, usually during installation. This process gives a final product with the best attributes of both the concrete and iron. The frame is installed by placing the frame into a rebate which has been cast in situ and packing up the frame to align the top of the frame with the level of the surrounding area. The frame itself is typically also cast as a skeleton frame in an annular configuration with inner and outer legs, an annular ledge on the 2 inner leg on which the access cover is adapted to sit and top web generally at the level of the top of the access cover when it is positioned in the frame, the top web joining the upper zones of the inner and outer legs. A hollow zone is therefore formed between the inner and outer legs. The lower leg regions of the frame are adapted to sit in the cast rebate where they may be packed to the correct level as discussed above. The annular shape of the frame may be square, rectangular, circular, oval or any other shape corresponding to the outline shape of the access cover.

One significant problem associated with the existing frames of the aforementioned type is that it is difficult to fill the hollow zone within the frame with a concrete slurry during installation. The filling of the cast iron cells in the cover is relatively easy to do and is usually quickly performed on site. However, the cellular frame must also be filled with concrete and this is a more difficult to thoroughly do on site. A further problem is that the outer wall of existing frames 15 is generally continuous such that concrete surrounding the frame outwardly of it does not tie into concrete within the frame more or less providing a potential fault line at the outer wall concrete interface zone.

A still further problem with the existing access frames is that on occasion it is desirable to tie concrete reinforcing steel from a surrounding apron into the 20 frame. This can be difficult or impossible to do with existing access frames.

It is the principle objective of the present invention to overcome one or more of the problems of the prior art as described above. It is a preferred objective of the present invention to provide a means which will facilitate filling of access cover frames with concrete slurry during installation. Any such means should ideally not affect the load carrying ability of the access frame and cover.

Furthermore, it is a preferred objective of the present invention to provide a means for assisting the tying of reinforcing steel from a surrounding apron into the access cover frame. Finally, it is a preferred objective of the present invention to provide an access cover frame which is economical to manufacture and easier to place.

One or more of the above objectives may be addressed by the invention described below.

DESCRIPTION OF INVENTION In accordance with this invention there is provided a support frame having at least one support frame member having an outer downwardly facing flange, an inner downwardly facing flange including support means adapted to support an access cover, an upper web connecting said outer flange to said inner flange, characterised in that the outer flange has a least one aperture or recess which will allow concrete slurry to pass therethrough.

The invention also relates to a support frame member for supporting an access cover, said support frame member including an outer downwardly facing flange, an inner downwardly facing flange formation including support means adapted to support a said access cover, and an upper web connecting said outer flange to said inner flange formation, said support frame member being characterised in that the outer flange has aperture means which will allow S: concrete slurry to pass therethrough.

15 The support frame may comprise a number of support frame members, preferably frame members of the type described above, with all of the frame members arranged in such a manner as to form a support frame for an access cover.

The support frame itself may be an integral unit or it may be assembled from a number of individual support frame members or portions. For example a S: square or rectangular support frame may be assembled using four linear frame members which are fitted together to form a complete support frame.

will be understood that the greater the number of recesses and/or apertures in the outer flange of the frame member the easier it will be to fill the frame member with concrete slurry. It would normally be expected that the presence of recesses and/or apertures in the outer flange of a frame member would unduly weaken the frame member such that the overall support frame and thereon would have a significantly reduced load carrying ability. However, it was found that significant portions of the outer flange of each frame member may be removed without unduly affecting the overall load carrying ability of the frame and cover, particularly when an internally reinforced frame member is used.

A preferred aspect is the inclusion of internal reinforcement in the frame member, whereby the frame member is internally reinforced by having internal 4 webbing extending downwardly from the upper webbing and which connects at least a portion of the inner surface of outer flange to at least a portion the inner surface of the inner flange.

It is preferable that the inventive frame member is further characterised in that the upper web has at least one aperture (preferably a plurality) which will allow concrete slurry to pass therethrough. This further facilitates the filling of the frame member with concrete slurry. Ideally, the frame member is also internally reinforced and that the reinforcement is of the type described earlier and is so arranged with the apertures in the upper webbing to form cells. Each cell comprises an aperture, wherein the aperture is bordered by the outer and inner flanges and by the internal reinforcement It is preferable that the outer flange of the frame member has a plurality of recesses or apertures therein. It is preferable that only recesses are present in the outer flange, that is openings that open onto the bottom edge of the outer 15 flange. It is also preferred that each recess or aperture in the outer flange is located such that the load carrying ability of the support frame and the cover S'used therewith will not be unduly affected.

:The inner flange of the frame member must be adapted to support an access cover. One common method of supporting the access cover is to include 20 in the inner flange a ledge portion, wherein the ledge portion is itself adapted to support the access cover.

Further preferred features and aspects of the present invention will become apparent from the following description of the preferred embodiment illustrated in the accompanying drawings, in which Figure 1 is a perspective view of a known cellular support frame and access cover; Figure 2 is a perspective view of the known cellular support frame and access cover of Figure 1 grouted into a cast rebate; Figure 3 is a perspective view of a cellular support frame, according to a preferred embodiment of the present invention; Figure 4 is a top plan view of a cellular support frame member, according to a preferred embodiment of the present invention; Figure 5 is a side elevation view of the cellular support frame member as shown in Figure 4; Figure 6 is a section view taken on line A-A of Figure 4; and Figure 7 is an end view of a cellular support frame member as shown in Figure 4.

Referring to Figure 1 (prior art), the access cover 1 comprises an iron framework or skeleton 2. The skeleton forms a series of cells. The cover fits into the hole bordered by the support frame 3. The support frame 3 includes an inner flange 5, an outer flange 6 and an upper web 7 connecting the flanges together. The inner flange 5 has a ledge 8 upon which the access cover 1 will sit when fitted. The upper web 7 contains apertures 9 through which concrete slurry is poured to fill the void formed between the upper web and inner and outer flanges. Both the access cover 1 and the support frame members 4 have a cellular arrangement 15 Referring to Figure 2 (prior art), the access cover 1 and frame 3 is shown installed with a concrete slurry filling the cells in the cover 1. The support frame 3 is grouted into the rebate and concrete 11 has been poured into the apertures 9 to fill the frame 4.

Figure 3 shows a support frame 4 of the present invention. The support 20 frame 4 has an inner flange 5, an outer flange 6, an upper web 7, a ledge 8 and 0 apertures 9 similar to the prior art frame. The outer flange 6 is shown as having three recesses 12. In use the void space in the support frames is at least partially filled with concrete slurry which passes through the recesses 12 when the rebate around the frame 4 is filled with concrete slurry. In this manner, a direct tying of concrete outwardly of the frame is achieved to concrete inwardly of the frame thereby avoiding potential fault lines at the interface of the outer flange 6 and the concrete mass outwardly thereof. Moreover, the recess 12 allows the possibility of tying reinforcing wire or rod material from the concrete outwardly of the flange 6 to the zone within the frame inwardly of the flange 6.

Additional concrete slurry may need be poured into hollow zone 20 via the apertures 9 to thoroughly fill the support frame members.

6 Reference will now be made to Figures 4, 5, 6 and 7. In Figure 4, the inner flange 5, the outer flange 6, the upper web 7, ledge 8, apertures 9 and recesses 12 can all be clearly seen. In addition there are grooves 15 located at either end of the support frame member. In Figure 5, a side view (from the outer flange side) shows the recesses 12 in more detail. Figure 5 also indicates by the dotted lines the location of internal reinforcement webs 13 and 14. The internal reinforcement webs are located in the void space formed between the upper web and inner and outer flanges. The reinforcement web extends from the upper web 7 downwards and connects to a portion of both of the inner and outer flanges 5,6.

The reinforcement webs 13,14 are located in such a manner with each aperture 9 so as to form a cellular structure in the support frame member. Figure 6 shows a section view along line A-A of Figure 5 and shows the reinforcement webs 13 and So14. Figure 7 shows an end view of the support frame member. The end view shows the groove 15 containing apertures 16. When assembling a support frame 15 of the above described type, four frame members are fixed temporarily around a o cover member to obtain the closest fit between the cover member and the frame members. The frame members are configured at their end zones to create a butt joint between two end zones at each corner. Thereafter bolts are passed through *•*the apertures 16 into the end zone of the adjacent frame member to fix the frame together. Preferably a reasonably large gap is left between the end zones which is then filled with a filling material such as molten lead. The process is such as to minimise and if possible create an interference fit between the support frame and the cover member.

It will be understood that whilst the support frame shown in the drawings is of a square configuration, the support frame could be in any desired shape including circular, rectangular or oval.

Claims (13)

1. A support frame member for supporting an access cover, said support frame member including an outer downwardly facing flange, an inner downwardly facing flange formation including support means adapted to support a said access cover, and an upper web connecting said outer flange to said inner flange formation, said support frame member being characterised in that the outer flange has aperture means which will allow concrete slurry to pass therethrough.

2. The support frame member as defined in claim 1 characterised in that the outer flange has a plurality of apertures forming said aperture means.

3. The support frame member as defined in claim 1 or 2 characterised in that the support frame member is internally reinforced by having internal webbing extending downwardly from the upper web and which connects at least a portion of an inner surface of the outer flange to at least a portion of an inner surface of the inner flange formation.

4. The support frame member as defined in any one claims 1 to 3 characterised in that the upper web has at least one aperture which will allow concrete slurry to pass therethrough.

5. The support frame member as defined in claim 1 or 2 characterised in that the support frame member is internally reinforced by having internal webbing extending downwardly from the upper web and which connects at least a portion of an inner surface of the outer flange to at least a portion of an inner surface of the inner flange formation and the upper web of the frame member has a plurality of apertures and further characterised in that the internal reinforcement is so arranged so that each aperture in the upper web forms a cell.

6. The support frame member as defined in any one of claims 1 to characterised in that said inner flange has a ledge portion forming said support ,ans adapted to support an access cover. 8

7. The support frame member as defined in any one of claims 1 to 6 characterised in that the support frame member is formed from cast iron.

8. The support frame member as defined in claim 7 characterised in that the support frame member is formed from ductile cast iron.

9. A support frame for an access cover having at least one support frame member as defined in any one of claims 1 to 8. The support frame as defined in claim 9 wherein additional support frame members are present and said additional support frame members are as defined in any one of claims 1 to 8.

11. The support frame as defined in claim 9 or 10 wherein the support frame is an integral unit. *o

12. The support frame member as defined in any one of claims 1 to 8 or the support frame as defined in any one of claims 9 to 11 filled with concrete. o

13. A support frame for access covers as defined in claim 9 substantially as aoo. hereinbefore described with reference to the accompanying drawings. ooooo

14. A support frame member as defined in any one of claims 1 to 8 substantially as hereinbefore described with reference to the accompanying drawings. DATED this 7th day of November 2002 FARNELL THOMAS LIMITED WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA P6200AU00.DOC