AU775884B2 - Access cover assembly - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: ACCESS COVER ASSEMBLY WEBFORGE AUSTRALIA PTY LTD Applicant: The following statement is a full description of this invention, including the best method of performing it known to me: 1 WARCOf WVPCTCOcMPPC TFOMS DOC ACCESS COVER ASSEMBLY The present invention relates to access cover assemblies and in particular to such assemblies that are installed in roads, footpaths or other paved or unpaved areas, to provide access below the installation, to facilities such as to sewers, storm water drains, electrical or telephone cabling, or other below ground or floor level facilities and which further require close fitting machined lids and frames that are required to make the installation either water tight, gas tight or non-rocking. It will be convenient to describe the invention in 10 relation to this type of application, however it is to be understood that the invention is not limited thereto, but can extend to other applications, such as openings in building floors, roofs or decking.

Access covers are well known and generally comprise a metallic frame which is permanently installed in the ground, normally to a concrete foundation, 15 and a removable lid which is snugly received by the frame. The frame is normally recessed into the ground, so that the lid may be received within the frame flush with the surrounding ground level. Access cover assemblies can come in a variety of different shapes and sizes, although they are generally either round, square or rectangular. The present invention is concerned with 20 such assemblies that are either square or rectangular.

It is known to provide access cover assemblies in different configurations, as either single part, single row or multi-row assemblies. Single part assemblies comprise a frame which is arranged to receive a single lid or cover only. Such assemblies usually provide limited below ground access sufficient for a single person to pass through the frame when the lid is removed.

As such, these assemblies are only appropriate when limited access for the passage of personnel or equipment is required.

Single row assemblies provide an opening of more rectangular or elongate proportions and normally provide greater access to below ground level than a single part assembly. Like single part assemblies, single row assemblies include a frame installed in the ground, but the frame is arranged to receive a plurality of lids arranged in a row. In such an assembly, access to below the ground can be through one or more of the lids removed from the frame.

Multi-row assemblies provide the largest sized opening of all of the assemblies described herein and comprise a frame which is arranged to receive a plurality of lids both longitudinally and laterally. Again, access to below the ground is available by removal of one or more of the lids constituting the assembly.

Known single part, single row and multi row lid frames consist of individual straight elements joined by bolting. The adjacent faces of the frames 10 at each joint are unmachined, and therefore a gap is left between the adjacent faces when the frames are bolted together. To stiffen the frame, that gap is .•..normally filled with lead (because it is a metal with good flow characteristics) as a further step in the assembly and installation process. However, as lead is a soft metal, frame joints formed in the above manner are not particularly rigid.

As a consequence, if care is not taken during transportation and particularly •during installation, the shape of the frames can be distorted such that the assembly lids may not fit properly within the frame, potentially resulting in a lack of water tightness, gas tightness and/or rocking movement under traffic. This is a particular problem for multi-row assembly frame assemblies which are 20 normally much larger in area than single part or single row assemblies, as even small changes in the shape of the frame can significantly affect the proper fitting of a plurality of lids. Thus, skill is required in the assembly, transport and installation of leaded joint frames, to ensure distortion of those frames does not occur, or is at worst only minimal.

A further disadvantage in relation to known or industry standard single row and multi row cover assemblies, is that the range of frame opening sizes does not increase in regular increments and additionally, the opening sizes vary with the particular strength class of assembly which is required. This forces designers to consult complicated size charts, to select the appropriate size and strength of access cover which best suits the design application.

The lack of a regular incremental size increase particularly affects multi row cover assemblies, because they require the formation of "wall box rebates" in the concrete support structure for supporting each end of load bearing cross members. Thus, the positioning of the wall box rebates changes, depending on the size of multi cover assembly that is chosen, so that there is no consistency in the positioning of the rebates and this further complicates assembly design.

A still further disadvantage of known access cover assemblies, arises due to the use in single and multi row cover assemblies, of single part assembly style lids. In single part assemblies, the lid is supported along all four edges.

However, when such a lid is used in a single row or multi row assembly, the lids may be supported on three, but normal two sides only. Unsupported sides of a lid cause it to have a greatly reduced load bearing capacity and therefore the design of lids is required to accommodate the load bearing reduction which occurs in single row and multi row lids, resulting in a greatly over-designed lid for use in a single part assembly.

It is an object of the present invention to provide a new access cover assembly which overcomes, or at least alleviates one or more of the above prior art disadvantages.

The present invention provides an access cover assembly including a frame and a plurality of lids for receipt within said frame, said frame being arranged for fixing to a supporting surface and including a frame section defined 20 by frame members that are assembled together to define a square or rectangular opening, each of said frame members including a wall portion and a depending lip portion which are arranged substantially perpendicular to each other, said wall portion being provided for locating an edge of said lid, while said lip portion is provided for supporting at least a major portion of the weight of 25 said lid, said frame further including at least one elongate cross-bar extending laterally across said opening defined by said frame section for supporting each edge of said lids which is unsupported by said frame members, the or each said cross-bar including a wall portion and a depending lip portion arranged substantially perpendicular to each other, for respectively locating and supporting an edge and at least a major portion of the weight of a lid in the manner of said frame members, and at least one end of the or each said crossbar being supported by said frame.

WAUlJ4AnxreiAprdMS8825-00 Amend Spoddoc 4 The cross bars of the above embodiment of the invention permit previously unsupported edges of a lid to be supported. Thus, each lid can be W :Ji eArirewYPasa825-00 Amnd SPed.doc supported on all four sides thereof and the over-design strengthening of lids as discussed in relation to the prior art, is not necessary. The use of cross-bars also permits the lids to have positively tapering edges. In the past, abutting faces of the unsupported lid edges included oppositely tapering faces, ie overlying and underlying mating faces to properly nest together.

The use of cross-bars also increases the level of water and gas tightness available in an access cover assembly of the present invention. Previously, adjacent unsupported edges of adjacent lids in single and multi row cover assemblies, may not abut, but be separated by a small gap, allowing gas and 10 water to leak therepast. However, in the arrangement according to the invention, each of the previously unsupported edges is at least supported vertically on a horizontal supporting ledge of a cross-bar and that contact provides substantial resistance to any gas or water leakage. The lid edges may also engage the cross-bar in a vertical abutment, which further increases resistance to leakage.

The cross bar or bars of the preferred embodiment preferably are releasably attached to the frame of the access cover assembly, so that they can be removed from extending across the opening defined by the frame when access through the opening of the assembly is required. The cross-bars may 20 be releasably fixed in place by suitable fasteners, however in a preferred embodiment, the frame members include recesses suitable to receive and locate one or both the ends of the cross-bars so that they may simply be lifted from the frame assembly when access through the frame opening is required.

The cross-bars span the width of the opening of the frame in single row assemblies and if that width is not too great, then installing the ends of a crossbar into recesses in opposed frame members of the assembly may be quite easily done by one person on their own. However, for frame openings of greater width, it may be difficult for a single person to place the remote end of the cross bar in the recess provided in the frame member for locating that cross-bar end, due to the weight of the cross-bar, or simply because the length of the cross-bar makes the exercise too awkward. Thus, the invention provides for the installation of a guide rail that extends between opposed recesses and 6 upon which a cross-bar can be guided to insert the remote end of the cross-bar into the relevant frame member insert. The guide rail preferably is made to have a light weight and to be easy releasable and removable from the frame opening like the cross-bars. Preferably, each end of the guide rail fits into a recess in the frame member, to locate the rail in place. Preferably, the guide rail has no load carrying responsibility, other than the load of a cross-bar during sliding and guiding movement.

The cross-bar described above is also applicable to multi-row assemblies, but in such assemblies, it is normal for the frame to include 10 intermediate members being removable structural beams, extending between adjacent rows of lids and the cross-bars in such an assembly therefore span the opening between a frame member and a beam member, or between a pair **of adjacent beam members. The beam members then can include suitable inserts for receipt of the end of a cross-bar and possibly also a guide rail.

In a further embodiment, the or each cross-bar of an assembly has a width between adjacent lids that is sufficient to be clearly noticeable if it is inadvertently not installed when the access cover itself is being installed, or when the lids and cross-bars, and guide rails if provided, are being replaced after the access opening has been opened for passage therethrough. If a 20 cross-bar is not installed, then the facing edges of adjacent lids will not be supported with a dramatic reduction in strength, and movement between adjacent lids could result, the occurrence of one or both of which would result in the disadvantages of the prior art discussed earlier.

The present invention still further provides a variable sizing system for access cover assemblies, said system including providing frames, and lids suitable for receipt within said frames, which frames are provided in a variety of square or rectangular sizes, the differences between successive assemblies sizes being a constant dimension.

The attached drawings show an example embodiment of the invention of the foregoing kind. The particularity of those drawings and the associated description does not supersede the generality of the preceding broad description of the invention.

Figure 1 is a plan view of a frame according to one embodiment of the invention.

Figure 2 is a perspective view of the frame of Figure 1.

Figure 3 shows top and underneath views of a lid according to one embodiment of the invention.

Figure 4 is an underneath perspective view of the frame shown in Figure 2.

Figure 5 is a sectional view of the corner section marked X in Figure 1.

Figure 6 is a perspective view of single row frame assembly according to a further embodiment of the invention.

Figures 7 and 8 show front and rear views of a locating member according to the invention.

Figure 9 shows a view of a frame assembly recess and guide rail according to one embodiment of the invention.

Figure 10 shows a part assembled view of a multi-row frame assembly according to the invention.

Figure 11 shows an exploded view of an installation of a multi-row frame assembly according to the invention.

Figure 12 shows a support box for a beam member according to one embodiment of the invention.

Figures 13 and 14 show a locating member according to one embodiment of the invention.

Figure 1 is a plan view from above, of a single part access cover frame.

The frame 10 comprises four frame members 11 to 14 which are connected to 25 each other at the respective ends thereof, to form a square frame suitable to receive a lid therein. A perspective view of Figure 1 is shown in Figure 2. Each of the frame members 11 to 14 includes a wall portion designated by the relevant frame member reference numeral and prime, eg. 11', 12', 13' and 14' and a lip portion designated by the relevant frame member reference numeral and double prime. The wall portions 11' to 14' and the lip portions 11" to 14" are disposed at approximately a 900 angle to each other.

W.WtmnSPDed'625-O0 SPECI c anges doc The frame 10 is arranged to neatly receive a lid of any suitable kind, such as the kind which is shown in Figure 3 (two views of which are shown, namely view from above and below). The lid 15 includes a wall portion 16 that depends downwardly (in use) from edge regions of the lid plate 17. The wall portion extends about the full periphery of the lid plate 17, slightly inboard thereof so that the lid plate extends beyond the wall portion 16, so defining a lip portion 18. The wall portion 16 of the lid 15 fits within and snugly against the inner surface 19 of the frame members 11" to 14", while the bottom edge 20 of the lid 15 rests against the upper surface 21 of the lips 11 to 14 of the frame It can be seen from Figure 2, that the inner surface 19 includes a step 22 and the wall portion 16 of the lid 15 includes a complimentary step 23 to assist in snugly nesting the lid 15 in the frame 10. The peripheral edge of the lip portion 18 rests over the upper surface of the frame member wall portions 11' to 14'.

°Olo The frame members 11 to 14 are separate members that are fixed together either at the site where the access cover assembly is to be installed, or remote from that site so that the frame can be transported as constructed to the relevant site. This latter arrangement is preferred.

Figure 4 is an inverted perspective view of the frame 10 of Figure 2 and 555005 shows a further lip 24 extending from each of the frame members 11 to 14 and 20 which includes openings 25 and ribs 26 spaced-apart along the length of each respective frame member 11 to 14. These features 25 and 26 assist in securing the frame 10 in the surface to which the access cover assembly is installed. Further discussion of these features is not required in order to describe the invention.

The connecting joint between adjacent frame members is shown in detail in Figure 5. Referring to that figure, this shows a view of the joint marked X in Figure 1. As is shown in Figure 5, the frame members 12 and 13 nest together snugly with the surfaces in contact between the members being shown in shaded lining and designated by the letter C. Those contact surfaces C are machined surfaces, so that effective contact is made between the frame members 12 and 13. A seal may also be provided between the frame 10 and 9 the lid 15 and such a seal for example, may extend between the steps 22 and 23.

The connecting joint also includes in dot outline an opening 28 which extends through each of the frame members 12 and 13, to accommodate a nut and bolt fastener (not shown). The opening 28 is also shown in Figure 2. The opening could alternatively be threaded, to receive a threaded bolt.

Each of the frame members 11 to 14 includes differently shaped ends formed in the manner shown in Figure 5. Thus, one end of each frame member is formed according to the end of the frame member 12 as shown in Figure while the other end of each frame member is formed according to the end of the frame member 13 shown in the same figure. In this way, only one style of frame member needs to be produced to form the frame 10 shown in Figures 1, 2 and 4. Clearly, this simplifies manufacture and minimises production costs.

Figure 5 also shows the positive taper PT of the frame member wall portions 12' and 13'. The wall portions 16 of the lid 15 can thus have a positive or overlying taper about its full periphery, which simplifies lid manufacture and installation as well as removal from the frame. The lid can also be removed from any direction, which differs from some prior art arrangements, in which cooperating sections of the lid and the frame prevent removal of the lid in certain directions.

Figure 6 shows a single row access cover assembly 30, comprising a frame 31 and a lid 32. The frame 31 is constructed from a plurality of frame members 33 of the same kind as those shown in the earlier figures relating to the single part access cover assembly. Clearly herein resides an advantage, in that many of the same components are used in the construction of a single part assembly, as are used in the single row assembly. Therefore, the system overall, requires less components with resulting reductions in the number of patterns required for manufacturing purposes. Various other flow on advantages are clearly apparent.

The single row access cover assembly is formed in a rectangular configuration, having a width of a single end frame member and a length of three side frame members. Between each of the side frame members is a further frame member called a locating member 34 and such a member is shown in more detail in Figures 7 and 8.

Figure 7 shows a view of the locating member 34 as would be seen from the inside of the frame 31, while Figure 8 shows the same member 34 as would be seen from outside of the frame 31. The locating member 34 includes a wall portion 35 and a front lip portion 36. The member 34 further includes a rear lip 37, an opening 38, two strengthening webs 39 and a pair of rails 40. Openings 41 are provided for receipt of fasteners to connect the locating member 34 in the frame 31 and while two such openings are shown in Figures 7 and 8, alternatively, only a single opening 41 may be provided, as shown in Figure 6.

What is required, is that the locating members 34 be securely fitted to the frame 31 and any number of openings for receiving fasteners for that purpose can be provided.

The lip 36 includes a channel 42 to receive the end of a guide rail 43 (see Figures 6 and The guide rail 43 as shown is an elongate square crosssectional bar, which is preferably tubular. The channel 42 is formed to snugly receive one end of the guide rail 43 and could, for example, be formed as semi- °cylindrical, for use with a cylindrical bar. The guide rail 43 simply rests under its own weight when an end thereof is placed in the channel 42. While it is not completely clear from Figure 6, a locating member is positioned in the frame 31 to receive either end of the guide rail 43.

The guide rail 43 can be employed to assist location of a cross-bar 44 in the frame 31. A cross bar 44 can be quite heavy and it would normally require a person on either side of the frame 31 to position one in place. This is wasteful in terms of personnel time, because otherwise, the frame 31 can be installed by one person only.

The guide rail 43 has little weight and therefore can easily be placed across the frame 31 to seat in the channels 42 of respective opposed locating members 34. With a guide rail 43 in place, it is also easy to place a cross bar 44 in place, by sliding one end of the bar along the guide rail 43. Once fitted, the ends of the cross bar 44 abut against the inside face 45 of the locating member 34 (see Figure 7) and are supported on the lip 36 thereof.

11 As is shown in Figure 6, the cross bar 44 extends across the width of the frame 31. Advantageously, the cross bar 44 presents supporting surfaces on opposite faces thereof, for supporting an edge of the lid 32. Without the cross bar 44, the edge 46 of the lid 32 would otherwise be unsupported. Thus, the cross bar arrangement 44 provides for greater structural stability and load carrying capacity for the assembly The cross bar 44 advantageously has a dimension in the elongate direction of the frame 31 that is sufficient for it to be clearly noticeable if it were to be inadvertently omitted when the access cover assembly is being installed.

Figure 10 shows a multi-row access cover assembly 50, while Figure 11 shows a schematic view of the assembly 50 and a concrete pit 51 for receiving **the frame 52 of the assembly 50. Referring first to Figure 10, the assembly includes a plurality of frame members 53 of the same kind as that shown in the earlier figures relating to the single part and single row assemblies. The assembly 50 is of a width twice of the single row assembly 30, while its length is the same. The increase in width of the multi-row assembly over the single row assembly results in a single major structural departure from the single row assembly. That departure comprises the use of a joist beam 54 extending lengthwise of the assembly The beam 54 is an I beam construction, although other cross-sectional configurations could be employed, such as a box beam for example. The beam 54 is of continuous construction and is shown in a sectional form in Figure for illustrative purposes only. The ends of the beam 54 are supported in a beam support box 55 which is shown in Figures 10 and 11 and also in Figure 12 in more detail.

Referring to Figure 12, the support box 55 includes a rear wall 56, side walls 57 and a floor 58. The box 55 is welded or otherwise attached to either end of opposed frame members 53, while a locating member 59 is positioned intermediate the respective frame members.

The locating member 59 is shown in detail in Figures 13 and 14 which show rear and front views of the member 59 respectively. It is apparent that the member 59 differs from the locating member 34 principally by the absence of a front lip equivalent to the lip 36 of the member 34. This allows the box to sit close against the rear wall 61 of a recess 60 formed in the concrete pit 51.

The support box 55 rests against the floor of the recess 60 and therefore the weight of the beam 54 is taken by the concrete pit 51. The box 55 is provided for locating purposes only and not to actually support the weight of the beam 54.

The beam 54 supports a plurality of joist bars 62 which are shown fixed by bolts to the joist beam 54. Intermediate each of the joist bars 62 is a locating member 63. Each locating member 63 includes a channel of the same kind as the channel 42 of the locating member 34, to receive one end of a guide rail 43 and a cross bar 44.

The arrangement of the single row assembly 30 and the multi row assembly 50, is such as to support a plurality of removable lids 34 over an access opening of any suitable size. In both assemblies, the lids 34 and the structures supporting those lids over the access opening are completely removable to provide full access through the opening. In this respect, each of the cross bars, the guide rails and the joist beam are removable from over the .access opening. In each case, it is possible to remove only a selection of lids *.*along with the supporting structure supporting those lids, or the entire structure may be removed. In respect of the multi row assembly, the beam 54 will generally have to be removed fully, but if access through the assembly is only required on one side of the beam, then the beam need not be removed.

As shown in Figure 11, the frame 52 is supported in a concrete pit 51 which is cast on site. The frame 52 is fixed to the pit 51 by a further casting of concrete, so as to permanently fix the frame in place. When the frame 52 is properly fixed to the pit 51, the removable components can be fixed thereto.

The concrete pit 51 is only shown in respect of the multi-row assembly 50, but the same structure applies for both the single part and single row assemblies.

The single row and multi-row assemblies advantageously are available to be constructed in constant incremental size increases. That is, the length of a single row assembly or the length and width of a multi-row assembly can be chosen on the basis of a sizing system that varies by standard size increments.

13 At present, applicant has developed a base assembly which has a square dimension of 465mm x 465mm, and the system provides for incremental increases in either of these dimensions, by 150mm increments, greatly simplifying the task of installation design.

The invention as described offers advantages over prior art arrangements, such as quicker and more simplified installation of access cover assemblies, which is partly due to increased frame rigidity by the absence of a need to employ leaded joints and uniform load carrying capacity. Other advantages will be apparent to those skilled in the art.

The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be S°understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.

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Claims (18)

1. An access cover assembly including a frame and a plurality of lids for receipt within said frame, said frame being arranged for fixing to a supporting surface and including a frame section defined by a plurality of frame members that are assembled together to define a square or rectangular opening, each of said frame members including a wall portion and a depending lip portion which are arranged substantially perpendicular to each other, said wall portion being provided for locating an edge of said lid, while said lip portion is provided for supporting at least a major portion of the weight of said lid, said frame further including at least one elongate cross-bar extending laterally across said opening defined by said frame section for supporting each edge of said lids which is unsupported by said frame members, the or each said cross-bar including a wall portion and a depending lip portion arranged substantially perpendicular to each other, for respectively locating and supporting an edge and at least a major portion of the weight of a lid in the manner of said frame members, and at least one end of the or each said cross-bar being supported by said frame. o *oo *0 W ksha=%pewASM2SM0 SPECJ dnwues oc

2. An access cover assembly according to claim 1, opposite ends of each of said frame members including planar, machined mating surfaces and in an assembled condition of said frame, said frame members being connected together by abutting surface to surface engagement of said machine mating surfaces.

3. An access cover assembly according to claim 1 or 2, opposite ends of the or each said cross-bar including planar machined mating surfaces and in an assembled condition of said frame, said frame section including at least one planar machined mating surface for surface to surface abutting engagement with a said mating surface of the or each said cross-bar.

4. An access cover assembly according to claim 3, the or each said cross- bar extending across said opening defined by said frame section such that each end of the or each said cross-bar is supported by said frame section, said frame section including a machined mating surface for surface to surface abutting engagement with each end of the or each said cross-bar.

5. An access cover assembly according to any one of the preceding claims each of said lids including a positively tapered peripheral edge, while said depending wall portion of each of said frame members and the or each said cross-bar has a complimentary negative taper for snug nesting between said lids and said frame. 25

6. An access cover assembly according to anyone of the preceding claims, the or each said cross-bar being releasable from said frame for removal from extending across said frame section opening as necessary.

7. An access cover assembly according to claim 6, the or each end of the or each said cross-bar being respectively received within a machined recess in said frame section which locates the or each said cross-bar end, but which permits the or each said cross-bar end to be lifted out of said recess for removal from said frame. w. on Spea'6625-0 SPECI cdanges oc 16

8. An access cover assembly according to any one of the preceding claims, said frame including at least one elongate guide rail extending across said frame opening for guiding the installation of a cross-bar in said frame.

9. An access cover assembly according to claim 8, the or each said guide rail being releasable from said frame for removal from extending across said frame section opening as necessary.

An access cover assembly according to claim 9, one or each end of the or each said guide rail being located in a respective recess in said frame section, which recess locates said guide rail end, but which permits said guide rail end to be lifted out of said recesses for removal from said frame.

11. An access cover assembly according to any one of the preceding claims, said frame including a beam member extending across said frame opening perpendicular to the direction of extent of the or each said cross-bar, the or each said cross-bar extending between said frame section and said beam member, said beam member including a wall portion and a depending lip portion which are arranged substantially perpendicular to each other, said wall portion being provided for locating an edge of a said lid, while said lip portion is provided for supporting at least a major portion of the weight of a said lid. o

12. An access cover assembly according to claim 11, said beam member including a recess for locating the end of the or each said cross-bar, which 25 recess locates the cross-bar end, but which permits said cross-bar end to be lifted out of said recess for removal from said frame.

13. An access cover assembly according to claim 11 or 12, said frame including a guide rail extending across said frame section opening between said frame section and said beam member for guiding the installation of a cross-bar between said frame section and said beam member. W- an Speow625-O0 SPECI cdwes.oc 17

14. An access cover assembly according to any one of claims 11 to 13, said frame including a plurality of beam members in parallel extending across said frame section opening, at least one elongate cross-bar extending between adjacent said beam members.

An access cover assembly according to claim 14, guide rails extending between adjacent said beam members across said frame section opening for guiding the installation of a cross-bar between said beam members.

16. An access cover assembly according to any one of claims 11 to 15, said beam members including a load bearing beam which bridges said frame section opening and a cap supported on said load bearing beam, said cap including said wall portion and said depending lip portion of said beam member.

17. An access cover assembly according to any one of claims 12 to 16, the ends of said beam member being supported in an open beam box fixed to said frame section.

18. An access cover assembly according to claims 2 or 3 or any one of 20 claims 4 to 17, when dependent on claim 2 or 3, said frame members being fixed together through said machined mating surfaces, by fastening means. DATED: 1 June 2004 PHILLIPS ORMONDE FITZPATRICK :6 Attorneys for: i 25 WEBFORGE AUSTR LIA PTY LTD .0 *0 W:Wron\Speo66625-00 SPECl chunes.ooc