IE20210149A2

IE20210149A2 - A drain cover

Info

Publication number: IE20210149A2
Application number: IE20210149A
Authority: IE
Inventors: Francis Clark Ronald
Original assignee: Clark Steel Holdings Ltd
Priority date: 2020-08-27
Filing date: 2021-08-26
Publication date: 2022-08-31
Also published as: GB2598353A; GB202013482D0

Abstract

A manhole cover tray comprising a floor panel having peripheral walls (102a, 102b, 102c, 102d) surrounding and extending upwardly from the floor panel to provide an enclosed space for receiving a finished substrate. The peripheral walls each comprising a corner edge (104) comprising at least one finer (105) configured to interlock with a corresponding finger or fingers adjacent corner edge of an adjacent peripheral wall to form a corner of the tray.

Description

A Drain Cover Field of Invention The present invention relates to a closure for closing an opening in the ground, particularly, removable covers for closing a manhole, drain, or other in-ground inspection chamber.

Background Drains, manholes, inspection chambers, maintenance holes, and the like require covering to prevent materials or unauthorised persons from accessing or falling into the drain, manhole etc. Typically, this is achieved using a cover acting as a removable lid that sits on top of an opening to the drain, manhole etc. The opening is normally large enough for a person to pass through once the cover is removed. Such openings are often embedded in a road surface and must withstand loads caused by pedestrian footfall and/or vehicular traffic. Therefore, covers for such openings are designed to withstand these loads. Existing covers can be manufactured using steel and sometimes take the form of a tray that sits within a frame at the opening to the drain, manhole cover etc. The tray can be filled with a finishing substrate which provides a material corresponding to the surrounding surface material, such as paving blocks, bricks, or concrete for example. As such, the cover blends in to the surrounding ground surface both aesthetically and in respect of the surface texture. Some covers include lifting handles that remain exposed after the tray has been filled with material. The lifting handles enable a user to open the cover, often via use of separate hooks, to access the drain or manhole.

Typically, the tray of a cover is manufactured by welding sheets of metal together.

There exists a need to provide an improved cover and method of manufacturing a cover.

Summary According to a first aspect of the invention there is provided a manhole cover tray comprising a floor panel having peripheral walls surrounding and extending upwardly from the floor panel to provide an enclosed space for receiving a finishing substrate.

The peripheral walls each comprise a corner edge comprising at least one finger configured to interlock with a corresponding finger or fingers of an adjacent corner edge of an adjacent peripheral wall to form a corner of the tray.

Optionally, each corner edge comprises a plurality of fingers configured to interlock with a corresponding plurality of fingers located on the adjacent corner edge to join the corner edges together.

Optionally, either or both of the plurality of fingers or corresponding plurality of fingers comprises a pair of fingers.

Optionally, the plurality of fingers comprise a bending portion which extends about a bending line, the corner of the tray corresponding to the bending line.

Optionally, the adjacent peripheral walls are at right angles to each other when viewed in plan.

Optionally, the floor panel defines a plane and the corner is inclined with respect to the normal of the plane.

Optionally, the corner extends at an angle of less than 5 degrees away from the normal of the plane, and optionally, extends at an angle of 2 degrees away from the normal of the plane.

Optionally, the corner of the tray is angled outwardly from a centre of the floor panel.

Optionally, the manhole cover tray comprises a single sheet of metal.

Optionally, the corner edges extend from a single notch at a proximal end thereof, the notch providing a drainage hole for water to drain of the tray when in use.

Optionally, the manhole cover further comprises one or more handles within the tray and, optionally, the one or more handles being flush with a distal end of the peripheral walls with respect to the floor plate.

Optionally, the manhole cover further comprises one or more apertures, each of the one or more apertures crossing a fold line between the floor panel and one of the peripheral walls.

Optionally, the manhole cover further comprises at two apertures arranged on opposing peripheral walls, wherein the handles are attached to the one or more holes.

According to a second aspect of the invention there is provided a method of manufacturing a manhole cover tray, the manhole cover tray comprising a floor panel having peripheral walls surrounding and extending outwardly from the floor panel. The peripheral walls each comprise a corner edge comprising at least one finger configured to interlock with a corresponding finger or fingers of an adjacent corner edge of an adjacent peripheral wall when in an assembly state. The method comprises the steps of: obtaining a manhole cover tray blank comprising the floor panel and at least two adjacent peripheral walls in a planar configuration, wherein each peripheral wall comprises a corner edge comprising at least one finger configured to interlock with at least one corresponding finger or fingers of an adjacent corner edge of an adjacent peripheral wall when in the assembly state; a wall forming step comprising folding the at least two peripheral walls of the blank to extend outwardly from the floor panel so that a corner edge of each of the peripheral walls is aligned with a corresponding corner edge of the adjacent peripheral wall; a corner forming step comprising interlocking the at least one finger of one of the peripheral walls with the corner edge of the adjacent peripheral wall to form a corner of the manhole cover tray.

Optionally, the corner forming step includes the step of simultaneously interlocking a plurality of fingers located on one corner edge with another plurality of fingers located on another corner edge adjacent to the one corner edge.

Optionally, each plurality of fingers is a pair of fingers.

Optionally, the step of interlocking includes bending the plurality of fingers about a bending line, the corner of the tray corresponding to the bending line.

Optionally, the wall forming step comprises folding the at least two peripheral walls of the blank to an angle of less than 90 degrees with respect to a plane of the floor panel wherein the angle is optionally greater than 85 degrees, and optionally, greater than 88 degrees with respect to the plane.

Optionally, the joined peripheral walls are at right angles to each other when viewed in plan.

Optionally, the manhole cover tray blank is formed by cutting or punching a single metal sheet.

Optionally, the manhole cover tray blank comprises four adjacent peripheral walls, and during the wall forming step, the method further comprises folding the four peripheral walls of the blank, each peripheral wall comprising two opposing corner edges that are each aligned with a corresponding corner edge of a corresponding adjacent peripheral wall, and the floor panel being substantially rectangular, and during the joining step, interlocking the fingers of the peripheral walls to form four rectangular corners of the manhole cover tray.

Optionally, the method further comprises the step of forming one or more holes in the blank, each of the one or more holes crossing any folding line across which the at least two peripheral walls of the blank are folded, the one or more holes being configured to enable attachment of one or more handles within the tray.

Optionally, the method further comprises the step of attaching, via the one or more holes, one or more handles within the tray, optionally, the one or more handles extending to a plane formed by an opening of the tray.

According to a third aspect of the invention there is provided a cover assembly for a drain or manhole, the cover assembly comprising the manhole cover tray as discussed above, the cover assembly further comprising a frame for mounting to an opening of a drain or manhole, wherein the tray is configured to removeably nest within the frame thereby covering the drain or manhole.

Optionally, the cover assembly further comprises a finishing substrate within the tray and retained by the peripheral walls.

According to a fourth aspect of the invention there is provided a blank for manufacturing the manhole cover tray discussed above.

Brief description of Figures Figure 1 shows a top plan view of a blank.

Figure 2a shows a top view of a tray formed from the blank of figure 1.

Figures 2b and 2c show side views of the tray of figure 2a.

Figure 2d shows a cross-sectional view of the tray of figure 2a along line A—A.

Figures 3a and 3b show three-dimensional representations of the tray of figure 2a resting in a frame.

Figure 4 shows a top plan view of an alternative blank to that shown in figure 1.

Figure 5a shows a top view of a tray formed from the blank of figure 4.

Figures 5b and 50 show side views of the tray of figure 5a.

Detailed description With reference to figure 1, a blank 101 for forming a tray for use as a manhole/drain cover (referred to throughout as a manhole cover tray) comprises peripheral walls 102a, 102b, 1020, and 102d. The example of figure 1 shows four peripheral walls 102a-d, however there may be fewer or greater than four peripheral walls. The peripheral walls 102a-d surround a floor panel 103. Each peripheral wall 102a, 102b, 1020, and 102d includes corner edges 104. Each of the corner edges 104 includes bendable features for enabling joining with another corner edge 104. In this example, the bendable features are fingers 105. The fingers 105 may be considered to be castellations or tabs that are formed along the corner edge 104 having any shape that enables joining between edges when fingers of adjacent corner edges are bent around each other.

The floor panel 103 comprises a planar sheet which defines a plane out of which the peripheral walls 102a—d extend to define the internal space of the tray. It will be appreciated that in some examples, the tray panel may comprise one or more strengthening features such as ribs or folds, as is known in the art.

The fingers may be provided by polygonal projections, rectangular in the example shown, (when viewed in plan) which extend from the corner edge. The fingers may be interspersed and defined by notches. The fingers and notches may be have a similar width such that they can engage with corresponding notches and fingers of the opposing corner edge. The corner edges may be provided with any number of fingers and corresponding notches. The minimum number of fingers is one on each of the corner edges such that there is at least one finger and at least one corresponding notch to receiving the opposing finger. The maximum number of fingers will be application specific and determined by the depth of the tray and the retaining strength required from each of the fingers.

The fingers may project from an edge of the peripheral wall which originates from the fold line which defines the peripheral wall. It will be appreciated that the spacing of the fingers from the base of the peripheral wall will be different along each of the opposing walls such that they can engage with each other during manufacture.

The blank 101 may include one or more holes 106 for attaching a handle during a future stage of manufacture. The holes 106 may extend across a folding line 107 along which the peripheral walls 102a-d can be folded. Therefore, the holes may provide an attachment point for the handle on both of the resulting peripheral wall 102a-d that is formed by the foldable portion 102b, 102d and, the floor panel 103.

To form the manhole cover tray, the peripheral walls 102a, 102b, 1020, and 102d are folded along the folding lines 107. All of the peripheral walls 102a-d may be folded out of the plane of the floor panel 103 (Le. towards or away from the viewer from the viewpoint of figure 1). After the folding is complete, the peripheral walls 102a-d enclose the floor panel 103 so as to define an interior space in which a finishing substrate may be located and retained. Corner edges 104 of adjacent peripheral walls 102a-d become aligned to each other.

Adjacent peripheral walls, such as peripheral walls 102a and 102b are joined together by interlocking fingers 105 that are located on the edges of the peripheral walls 102a,b that are aligned to each other. The interlocking fingers 105 can be considered to be bendable fastening tabs/castellations that, once bent to be interlocked, remain in place in an interlocked position. In other words, the fingers 105 of each corner edge 104 are bent to clasp an adjacent corner edge with the fingers being interdigitated (i.e. interleaved). Typically, metals such as steel are utilised for the blank because they are sufficiently ductile to remain in place and not spring back after bending. As an example, the blank may be formed from a bendable steel metal sheet having a thickness in the region of 1.5 to 6 mm. The described folding and joining process can be undertaken by a metal bending machine advantageously without the use of screws, rivets, or other fastening hardware orjoining methods such as welding.

Figures 2a-2d show a manhole cover tray 202 that has been formed after the peripheral walls 102a, 102b, 1020, 102d have been folded, and also, after the corner edges 104 have been joined together. in the shown example, the fingers 105 join adjacent peripheral walls (e.g. peripheral walls 102a and 102b) together by being bent about a bending line corresponding to the corner 201 formed by two adjacent (folded) peripheral walls. Therefore, the fingers 105 of adjacent peripheral walls 102a, 102b, 1020, 102d interlock with each other and secure the peripheral walls (i.e. walls) at a particular angle depending on the geometry of the corner edges of the peripheral walls.

In the shown example, the internal angle B between the floor panel and the profile of a tray wall (see figure 2c) is greater than 90 degrees. In one example, the internal angle is 91.5 degrees, however the internal angle may be as great as 94.5 degrees or 95 degrees or any angle in between. Other angles will be possible. Therefore, the tray of the shown example can be considered to be shaped as an (inverted) pyramidal frustum with the opening of the tray corresponding to a surface that is normally considered to be the base of the pyramidal frustum and the sides of the tray corresponding to slanted sides of a pyramidal frustum. This shape advantageously enables the tray to be placed within a frame and adequately secured in place in order to minimise any unwanted material/liquid ingress past the sides of the cover when it is in—situ. It also allows the tray to be located with greater ease and provides a greater clearance for the fingers which are folded around the corner and sit proud of the external surface of the peripheral walls. It will be appreciated that the internal angles provided above will relate folding angles of 88.5 degrees, 85.5 degrees and 85 degrees with respect to the plane of the floor panel. For example, folding the flat sheet which pattern for the panel through 88.5 degrees will provide the tray with an internal angle of 91.5 degrees. it will be appreciated that, although the internal angle is discussed above, the folding angle will typically relate to the external angle which extends between the plane of the wall and the exterior of the peripheral wall. As such, the folding angle may be between 85 degrees and 90 degrees with respect to the plane of the floor plate.

The use of a blank and corner edges via the described bending method enables rapid and easy manufacture of trays for use as manhole/drain covers. Normally, such covers are manufactured from tough materials such as steel in order that they can withstand relatively heavy loads from above that are caused by pedestrians or heavy vehicles.

Use of welding to manufacture such trays has shortcomings by being more labour intensive and having reduced accuracy for obtaining a shape of a tray corresponding to precise specifications necessary for the tray to fit within a frame. The described tray that is manufactured by bending and interlocking portions of a blank enable quick and precise manufacture, because the dimensions of the assembled manhole cover tray are largely defined by the geometry of the blank. Typically the blank is machine cut or stamped based on predefined moulds. Using these methods, the manufacturing method is quicker, and, there is less scope for geometrical variation in the finished tray that could be caused by human error. Further advantages of the described method include the avoidance of additional fastener hardware such as screws/rivets. The resulting corners are found to be sufficiently strong and permanent for a tray used as a manhole drain cover.

In the examples of the figures, the peripheral walls are shaped such that, once folded, the floor area is substantially rectangular. However, it would be appreciated that it is possible to manufacture trays of different shapes using the concepts described herein.

The fingers are folded around the external surface of the peripheral wall such that the outward movement of a first peripheral wall is prohibited by the fingers of the adjacent peripheral wall. With reference to figure 3a, there is a close—up of a joined corner of a tray as described above, as viewed from inside the tray. it can be seen that the joined corner and edge along folding line 107 advantageously leave minimal irregular protrusions or material inside the tray. The inside of the tray is therefore geometrically regular and it is easier to place surface material such as bricks or paving stones inside the tray in order that the cover matches surrounding ground material when placed in— situ.

With reference to figure 3b, the tray 202 is sitting in a frame 302. As discussed above, where the tray is shaped as an (inverted) pyramidal frustum, or any other shape that is tapered towards the floor panel of the tray, the tray is able to rest within the frame via the angled walls of the tray. In use, the frame is normally situated around the outer edge of a manhole, drain or other maintenance inspection hole in the ground. The tray 202 is normally filed with ground material and then placed in the frame to act as a cover over the hole.

With continued reference to figure 3b, there is shown handles 301. These typically comprise slots (not shown) within which a user can insert a key or other tool for lifting up the tray to expose the opening to the drain or manhole. Normally, the handles are the only significantly visible part of the tray once it is placed in-situ in the ground and filled with ground material (not shown). The handles may extend from the base, (is. the floor panel) towards the distal edge of the walls so as to be flush with the upper edge of the tray and any finishing substrate located therein in use.

Figures 4 and 5 indicate an alternative construction to that described above, with the reference numerals referring to the same features described above. It can be observed from these figures that the corner edges 104 have an alternative geometry to the example of figure 1. in particular, the base of the corner edges are provided with a notch 108 from which the adjacent corner edges extend. The corner notch may ease folding of the corner walls and provide one or more drainage holes. With reference to figures 5a and 5c, holes 106 are included in both the floor panel 103 and wall 102d.

As used herein, the term “manhole cover tray” may relate to a cover tray utilised for covering other types of ground hole such as drains.

Claims

CLAIMS:

1. A manhole cover tray comprising a floor panel having peripheral walls surrounding and extending upwardly from the floor panel to provide an enclosed space for receiving a finishing substrate, the peripheral walls each comprising a corner edge comprising at least one finger configured to interlock with a corresponding finger or fingers of an adjacent corner edge of an adjacent peripheral wall to form a corner of the tray.

2. A manhole cover tray according to claim 1, wherein each corner edge comprises a plurality of fingers configured to interlock with a corresponding plurality of fingers located on the adjacent corner edge to join the corner edges together.

3. A manhole cover tray according to claim 2, wherein either or both of the plurality of fingers or corresponding plurality of fingers comprises a pair of fingers.

4. A manhole cover tray according to claims 2 or 3, wherein the plurality of fingers comprise a bending portion which extends about a bending line, the corner of the tray corresponding to the bending line.

5. A manhole cover tray according to claim 4, wherein the adjacent peripheral walls are at right angles to each other when viewed in plan.

6. A manhole cover tray according to any of claims 2 to 5 wherein the floor panel defines a plane and the corner is inclined with respect to the normal of the plane.

7. A manhole cover tray according to claim 6, wherein the corner extends at an angle of less than 5 degrees away from the normal of the plane, and optionally, extends at an angle of 2 degrees away from the normal of the plane.

8. A manhole cover tray according to claim 6 or 7, wherein the corner of the tray is angled outwardly from a centre of the floor panel.

9. A manhole cover tray according to any preceding claim, wherein the manhole cover tray comprises a single sheet of metal. 1O 12

10. A manhole cover tray according to any of preceding claim, wherein the corner edges extend from a single notch at a proximal end thereof, the notch providing a drainage hole for water to drain of the tray when in use.

11. A manhole cover tray according to any preceding claim further comprising one or more handles within the tray and, optionally, the one or more handles being flush with a distal end of the peripheral walls with respect to the floor plate.

12. A manhole cover tray according to any preceding claim further comprising one or more apertures, each of the one or more apertures crossing a fold line between the floor panel and one of the peripheral walls.

13. A manhole cover tray according to claim 12, comprising at two apertures arranged on opposing peripheral walls, wherein the handles are attached to the one or more holes.

14. A method of manufacturing a manhole cover tray, the manhole cover tray comprising a floor panel having peripheral walls surrounding and extending outwardly from the floor panel, the peripheral walls each comprising a corner edge comprising at least one finger configured to interlock with a corresponding finger or fingers of an adjacent corner edge of an adjacent peripheral wall when in an assembly state, the method comprising the steps of: obtaining a manhole cover tray blank comprising the floor panel and at least two adjacent peripheral walls in a planar configuration, wherein each peripheral wall comprises a corner edge comprising at least one finger configured to interlock with at least one corresponding finger or fingers of an adjacent corner edge of an adjacent peripheral wall when in the assembly state; a wall forming step comprising folding the at least two peripheral walls of the blank to extend outwardly from the floor panel so that a corner edge of each of the peripheral walls is aligned with a corresponding corner edge of the adjacent peripheral wall; a corner forming step comprising interlocking the at least one finger of one of the peripheral walls with the corner edge of the adjacent peripheral wall to form a corner of the manhole cover tray. 1O 13

15. The method according to claim 14 wherein the corner forming step includes the step of simultaneously interlocking a plurality of fingers located on one corner edge with another plurality of fingers located on another corner edge adjacent to the one corner edge.

16. The method according to claim 15, wherein each plurality of fingers is a pair of fingers.

17. The method according to claims 15 or 16, wherein the step of interlocking includes bending the plurality of fingers about a bending line, the corner of the tray corresponding to the bending line.

18. The method according to claim 17, wherein the wall forming step comprises folding the at least two peripheral walls of the blank to an angle of less than 90 degrees with respect to a plane of the floor panel and, optionally greater than 85 degrees, and optionally, greater than 88 degrees with respect to the plane.

19. The method according to any preceding claim, wherein the joined peripheral walls are at right angles to each other when viewed in plan.

20. The method according to any preceding claim, wherein, the manhole cover tray blank is formed by cutting or punching a single metal sheet.

21. The method according to any preceding claim wherein the manhole cover tray blank comprises four adjacent peripheral walls, and during the wall forming step, folding the four peripheral walls of the blank, each peripheral wall comprising two opposing corner edges that are each aligned with a corresponding corner edge of a corresponding adjacent peripheral wall, and the floor panel being substantially rectangular, and during the joining step, interlocking the fingers of the peripheral walls to form four rectangular corners of the manhole cover tray.

22. The method according to any preceding claim, further comprising the step of forming one or more holes in the blank, each of the one or more holes crossing any 1O folding line across which the at least two peripheral walls of the blank are folded, the one or more holes being configured to enable attachment of one or more handles within the tray and, optionally, attaching via the one or more holes, one or more handles within the tray, wherein the one or more handles extend to a plane formed by an opening of the tray.

23. A cover assembly for a drain or manhole, the cover assembly comprising the manhole cover tray of any of claims 1 to 13, the cover assembly further comprising a frame for mounting to an opening of a drain or manhole, wherein the tray is configured to removeably nest within the frame thereby covering the drain or manhole.

24. A cover assembly according to claim 23, further comprising a finishing substrate within the tray and retained by the peripheral walls.

25. A blank for manufacturing the manhole cover tray of any of claims 1 to 13. FF. GORMAN & CO.