AU2012200128B2 - Inpsection cover - Google Patents

Abstract

Abstract A moulded plastics inspection cover suitable for underground services such as electrical cables, communications (telephone and video) and traffic signals, comprising a one piece homogenous moulding incorporating a substantially continuous top section joined to (as part of the same moulding) a continuous or semi continuous bottom section by a periphery of substantially vertical webs formed by a plurality of side cavities entering from the edges of the cover on all or some of the sides. In

Description

EDITORIAL NOTE 2012200128

The description commences at page 2. There is no page 1 and no information missing 11. Jan, 2012 11:28

PIPERS

No, 1281 P. 5 2 2012200128 11 Jan 2012

INSPECTION COVERS

FIELD OF THE INVENTION

The invention relates to closures to underground housings having surface access openings, and more particularly to inspection covers for underground services such as electrical, communications (telephone and video) and traffic signals.

BACKGROUND OF INVENTION

An inspection cover is a removable plate forming the lid over the opening of an inspection pit, to prevent anyone from falling in and to keep unauthorized persons out. Inspection covers for pits that are 1 or more metres deep (sometimes called “manhole covers”) are generally circular in shape and are typically 50cm in diameter so that they are large enough for a man to pass through the opening when the cover has been removed.

For shallower pits the rectangular inspection covers are often used, Underground services typically those provided by the electrical and communications industries have adopted rectangular inspection covers typically of 650mm x 340mm in size, or smaller circular covers.

In each case they usually have a substantial mass, often in excess of 50kg. A major reason for an inspection cover to be manufactured at such a large weight is to prevent the inspection cover from becoming dislodged when traffic passes over it and to meet the class strength requirements. Also they are usually made from heavy materials such as concrete or more likely cast iron with in-fills of concrete. This provides the inspection cover with the necessary strength and weight to withstand the weight of traffic flow. A typical inspection cover usually consists of a tnefal base and rim with a few pick holes on top of the inspection cover that allows a hook handle to be inserted to lift it.

One problem with the design of an inspection cover is that its heavy weight prevents a worker 20J14 8NZ CAP Spec 20111109.doot COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 3 2012200128 11 Jan 2012 1. Jan. 2012 11:29

PIPERS

No. 1231 P. 6 from easily removing it for inspection of an inspection. As mentioned above a hook handle needs to be inserted to the pick holes on top of the inspection cover in order to lift it. Furthermore the current metal lids will conduct electricity in the event of a broken wire. A few attempts have been made previously to produce inspection covers from lightweight materials. However the necessary strength to meet load specifications and withstand the weight of the traffic flow could not be achieved from these lightweight materials and they have not been very successful in providing an alternative to inspection covers made from cast iron or steel. Even furthennore an inspection cover is required to meet the standards and regulations imposed by government departments or local authorities of the country where it is to be used. In Australia and New Zealand the Class B and other loading requirements for an inspection cover is the ability to withstand a load of up to 8 tonnes under specified conditions. Currently these tests use a 250mm diameter test load. To meet this requirement a cover is supported around its periphery by a frame and the specified test load is placed in the centre of the cover and the deflection of the cover is measured. Previous attempts at meeting this requirement with lightweight materials have failed.

The exception is our lightweight inspection cover described in our Australian Innovation patent 201000187 which has a metallic reinforcing spider and moulded plastic wedges attached to the spider. That arrangement is strong but requires additional labour to assemble, and is suitable for larger circular covers but not suitable for the smaller rectangular covers needed by underground services supplied by the industries providing electrical and communications services (telephone, broadband, cable TV and video) and for traffic signals. The larger circular covers are not cost effective for these applications.

OBJECT OF THE INVENTION

It is an object of the invention to provide improved inspection covers that ameliorate some of the disadvantages and limitations of the known art or at least provide the public with a useful choice. 205H8N2 CAP Spec 2011 IlOS.docx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 4 2012200128 11 Jan 2012 11. Jan. 2012 11:29

PIPERS

No. 1281 P. 1

SUMMARY OF INVENTION

In a first aspect the invention provides a moulded plastics inspection cover suitable for underground services such as electrical cables, communications (telephone and video) and traffic signals, comprising a one piece homogenous moulding incorporating a substantially continuous top section joined to (as part of the same moulding) a continuous or semi continuous bottom section by a periphery of substantially vertical webs formed by a plurality of side cavities entering from the edges of the cover on all or some of the sides.

Preferably the cover has generally rectangular perimeter defined by a reinforced peripheral portion formed by the plurality of side cavities, and wherein tire side cavities stop short of a central portion of the cover, with tire central portion of the cover having plurality of intersecting longitudinal and transverse ribs capable of transferring a central load to the reinforced peripheral portion. (Example 1)

Optionally the cover has generally rectangular perimeter, and wherein the side cavities continue into the central portion of tire cover thereby creating a continuous lower beam across the bottom of the cover.

In another embodiment the cover has generally circular perimeter, and wherein the cavities continue into the central portion of the cover thereby creating a continuous lower beam across tire bottom of the cover.

Preferably in the case of the generally circular cover each cavity extends substantially radially inwards to a central portion of the cover.

In some case tire cover may have one or more bottom cavities in its bottom section.

Preferably the peripheral portion has top and bottom faces and a plurality of ribs extending at right angles to the perimeter to create a plurality of hollow box like sections.

Preferably the cover has locking means adapted to lock it to a supporting socket. 205146N2 CAP Spec 20111 lOS.dooc COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 5 2012200128 11 Jan 2012 1. Jan. 2012 11:29

PIPERS

No. 1231 P. 8

Preferably the locking means has a rotatable slot accessible from the upper surface of the cover to enable a lifting tool to be inserted to unlock the locking means and to lift the cover off its supporting socket.

Preferably the cover is injected moulded in one piece.

Preferably some of the peripheral reinforcing ribs extend across the width of the cover and some extend across the length of the rectangular cover to create a plurality of cells where they inters eet.

Preferably the panels are made from nylon or other type of plastics material. More preferably this is a reinforced nylon. More especially a glass filled nylon.

More preferably the design of the ribs allows the inspection cover to be injection moulded in one piece.

Preferably the design of the panels includes a moulded in feature that forms part of the hold down catch system

Preferably the width of the cover between the reinforced peripheral portion is less than the diameter of the required test load so that the test load can be supported across the top of the cover by resting on the reinforced periphery at both sides of the cover, and the underside of the reinforced periphery can be supported by the test frame.

This invention may also broadly be said to consist in the parts, elements and features refen-ed to or indicated in the specification of the application, individually or collectively, and any or all collectively of any two or more of the parts, elements or features, and where specific integers are mentioned herein which have known equivalents such equivalents are deemed to be incorporated herein as if individually set forth. 20514BNZ CAP Spec 20111109.docx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 6 2012200128 11 Jan 2012 1. Jan. 2012 11:30

PIPERS

No, 1281 P. 9

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be described, by way of example only, by reference to the accompanying drawings:

Figure 1 is a diagram showing a perspective view from the underside of a first rectangular inspection cover in accordance with a first embodiment of the invention.

Figure 2 is a diagram showing perspective view from the top of an inspection cover in accordance with a first preferred embodiment of the invention.

Figure 3 is a top plan view of the inspection cover showing the section lines for the following views:

Figure 4 is a cross-sectional view of the inspection cover on line AA of Figure 3 showing the T beam section profile

Figure 5 is a cross-sectional view of the inspection cover on line B-B of Figure 3, showing the I-beam section profile.

Figure 6 is a cross-sectional view of the inspection cover on line C-C of Figure 3.

Figure 7 is a cross-sectional view of the inspection cover on line E-E of Figure 3.

Figure 8 is a bottom top plan view of the inspection cover of Figure 3.

Figure 9 is a perspective view from the top of the inspection cover positioned in a test frame and with a test load applied to its centre in accordance with the Class B test requirements.

Figure 10 is a top plan view of the inspection cover, load, and supporting frame showing the section lines for the following views:

Figure 11 is a cross-sectional view of the inspection cover and load on line F-F of Figure 10. 205148N2 CAP Spec 20111 lOVdocx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 7 2012200128 11 Jan 2012 1. Jan. 2012 11:30

PIPERS

No. 1281 P.

Figure 12 is a cross-sectional view of the inspection cover and load on line G-G of Figure 10, showing the box section at the periphery of the cover and its relationship to the 250mm diameter test load and the supporting test frame.

Figure 13 is a diagram showing a perspective view from the underside of a circular inspection cover in accordance with a second embodiment of the invention.

Figure 14 is a diagram showing perspective view from the top of an inspection cover in accordance with the second embodiment of the invention.

Figure 15 is a top plan view of the circular inspection cover.

Figure 16 is an underside plan view of the circular inspection cover.

Figure 17 is a side view of the circular inspection cover.

Figure 18 is a top plan view of a second rectangular inspection cover in accordance with a third embodiment of this invention.

Figure 19 is a side view of the second rectangular inspection cover.

Figure 20 is an underside plan view of the second rectangular inspection cover.

Figure 21 is a diagram showing perspective view from the top of the second rectangular inspection cover.

Figure 22 is a diagram showing perspective view from the underside of the second rectangular inspection cover. 205148NZ CAP Spec 20111109.docx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 8 2012200128 11 Jan 2012 11. Jan. 2012 11:30

PIPERS

No. 1281 P. 11

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description will describe the invention in relation to preferred embodiments of the invention, namely an inspection cover, The invention is in no way limited to these preferred embodiments as they are purely to exemplify the invention only and that possible variations and modifications would be readily apparent without departing from the scope of the invention.

As will be seen from the three examples each cover is formed as a one piece homogenous moulding incorporating a continuous top section joined to (as part of the same moulding) a continuous or semi continuous bottom section by a periphery of vertical webs formed by a plurality of cavities entering from the edges of the cover on all or some of the sides. In the case of a circular collar these would be entering radially.

These cavities can be to a lesser or greater depth creating either an edge box section with a conventional lattice type center area (Example 1). Or the cavities can continue into the center line thereby creating a continuous lower beam across the bottom of the lid. (Example 3).

One option of the invention is create cavities in from the bottom surface of the lid to enable the side moulding cores that form the cavity, to have significant draft for easy extraction during the moulding cycle. (Example 3).

The cover of this invention is preferably moulded in plastic by injection moulding but could be made by any other process using any plastics material.

Example 1 A preferred inspection cover 1, is substantially rectangular in shape, and in this example has been moulded, so as to be 650mm long and 340 mm wide. Figure 1 shows the underside of the cover 1, and shows a plur ality of reinforcing nbs (6 and 7).

The cover has a top surface 2, a reinforced peripheral portion 3 and a main portion 4. 20S14 8NZ CAP Spec 201111 OSTdocx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 1. Jan. 2012 11:30

No, 1281 P. 12 9 2012200128 11 Jan 2012

The main portion 4 has a plurality of longitudinal ribs 6, and a plurality of transverse ribs 7.

Some of the longitudinal ribs 6, and some of the transverse ribs 7, extend the length and breadth of the cover, and intersect to form cells 8. These intersecting ribs taper towards the centre of the inspection cover (see below and in particular figures 11 and 12), so that loads are transmitted towards the reinforced periphery of the cover.

Figures 3 to 8 show various cross sectional views, showing the longitudinal T-beam profiles of libs 6 and 7 (in cross section in Figure 4) which are designed to transfer a central load to the peripheral portion. Figure 6 is a cross sectional view on line C-C and passes through a transverse rib 7 looking towards one of the locking fittings 13.

Optionally the ribs 6 and the ribs 7 are curved as shown so that they are shallower towards the centre of the cover and deeper towards the perimeter of the cover. In some cases the ribs will be of uniform death across the length and breadth of the cover.

The peripheral portion 3 is an apertured hollow box section having a plurality of ribs 17 at right angles to the perimeter. These ribs are connected together by a circumferential plate 5 which also has a circumferential flange 15 extending perpendicular to the plate. Typical spacing between the ribs at the periphery is 75mm. The ribs and the top and bottom plates at the peripheiy create a series of I-beams to reinforce the peripheral portion.

The design of the cover with its open cells 8 and apertured hollow box section at the peripheiy and allow cover to be injection moulded in one operation.

Figure 5 shows the I-beam profile of the peripheral portion in cross section on line B-B of Figure 3. This I-beam arrangement is at right angles to the peripheral edge to provide a strong perimeter.

This inspection cover also includes a pair of apertures 12, to assist in locking and/or lifting the cover. The underside of the apertures 12 are shown in figure 1. They may also include rotatable locking means 13 shown in Figures 1 and 2 having a slot 14 on the upper side enabling the a T-shaped lifting tool (or other a flat blade tool) to be inserted and to thereby rotate the locking 205148NZ CAP Spec 2011 [ 109.docx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 10 2012200128 11 Jan 2012 1. Jan. 2012 11:31

PIPERS

No. 1281 P. 13 tongue 15 through 90 degrees to engage or disengage a complementary receptor on the socket which receives and supports the cover in use. The T-shaped portion can then be used as a lifting handle to lift he cover out of its socket, The locking tongue 15 when in the locked position helps to prevent the cover being lifted off by flooding.

This top surface may also have provision for a none slip tread pattern, as shown in figure 2, and may also have provision for the insertion of words 11 moulded into this cover, for example by providing a pair of mould inserts, in the injection moulding tooling, so that the words can be varied depending upon the supplier's name, the industry application (electrical or gas for example) or nature of the items to be inspected.

Example 2 - Figures 13 to 17:

In this example the cover is a circular cover with eight radial side cavities extending towards an octagonal central portion.

Looking at the top views in this Example it is noted that the locks are not shown in this example (as they are in Example 1 with reference to the apertures 12), as locking systems can vary in number and design but a cover as shown in this example would typically have some sort of locking means which could be as simple as being bolted down (which usually happens now with waste water covers).

Figure 13 shows the circular cover 22 with bottom surface 24. Radial side cavities 26 are defined by ribs 25 which extend from the outer rim 28 of the cover to the central octagonal portion 27.

Figure 14 shows the top surface 23 of the cover 22. The top surface 23 as seen in Figure 15 is essentially uniform in texture comprising a pattern of intersecting grooves which provide a nonslip tread pattern. It will be appreciated that various patterns may be applied without deviating from the scope of tire invention.

Figure 16 illustrates the radial side cavities 26 and the truncated configuration the ribs 25 create extending outwardly from the central octagonal portion 27 to the outer rim 28 of the circular 20SHSN2. CAP Spec 2011 UOgi.docx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 11 2012200128 11 Jan 2012 1. Jan. 2012 11:31

No. 1281 P. 14 cover.

Figures 17 shows a number of T-beam profiles of ribs 25 which are designed to transfer a central load to tire peripheral portion or outer rim 28.

Example 3 - Figures 18 to 22:

In this example the cover is a rectangular cover with three bottom cavities and sixteen tapered side cavities. The side cavities are separated by a series of central ribs extending along the centre line of the cover, thereby creating a series of reinforcing I-beams across the cover.

Looking at the top views in this Example it is noted that the locks are not shown in this example (as they are in Example 1 with reference to the apertures 12), as locking systems can vary in number and design but a cover as shown in this example would typically have some sort of locking means which could be as simple as being bolted down (which usually happens now with waste water covers).

Figures 18 and 21 show the top surface 31 of tire rectangular cover 30. The top surface 31 is essentially uniform in texture comprising a pattern of intersecting grooves which provide a nonslip tread pattern. It will be appreciated that various patterns may be applied without deviating from the scope of the invention.

Figures 19 shows a number of I-beam profiles of ribs 33 which are designed to transfer a central load to the peripheral portion when the cover is supported on a frame in a similar fashion to that described with Example 1.

Figures 20 and 21 illustrate tire three bottom cavities 34 formed by ribs 36 which extend obliquely from the central rib 37. Also shown are ribs 33 extending perpendicularly from central rib 37 to the peripheral portion 38 of the cover 30. Additionally ribs 39 extend from the central rib 37 to each respective comer of the rectangular cover 30. Ribs 33, 36, 37 and 39 collectively form a series of sixteen tapered side cavities 35, 205148N2 CAP Spec 201 111OS.docx COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 12 2012200128 11 Jan 2012 1. Jan. 2012 11:31

No. 1281 P. 15 ADVANTAGES:

The inspection cover provides a lightweight more cost effective alternative to standard type of inspection covers made from cast iron or concrete, or our earlier spider frame circular cover. The lighter weight of less than lOkgs (and in the most cases of less than 5kgs) makes the inspection cover more versatile than existing covers.

The locking tongue also helps to prevent the cover being lifted off by flooding.

It can be easily be removed and put back in place by a single worker saving time and money when inspection is required.

By moulding the inspection cover in one piece it is easy to include inserts in the mould to vary the surface pattern, or more importantly to include wording to identify the owner or the services - e.g. “electrical” or “Telco” or water” or “gas”.

VARIATIONS

The size and shape can be varied, as can the percentage of or nature of the reinforcement. We have found that 30% glass filled nylon provides a lightweight but strong cover which in this design is able to meet the Class B test requirements.

Preferably the top cover is of uniform thickness but the top surface 2 may vary in thickness across its length and breadth, to assist in transferring loads to the reinforced peripheral portion.

The cover is designed to be injection moulded but other moulding or fabricating techniques could be used.

Although the lock down feature has not been shown in Examples 2 or 3, the same style of lock down (or lifting) apertures 12 (as shown and described in Example 1) can be provided in these circular and rectangular covers, or other types of locking can be provided, which could be as simple as a provision for being bolted down. 205148NZ CAP Spec 20111109.<Jwsi COMS ID No: ARCS-351928 Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11 11. Jan. 2012 11:31

No. 1281 P. 16 2012200128 11 Jan 2012 13 Throughout the description of this specification, the word “comprise” and variations of that word such as “comprising” and “comprises”, are not intended to exclude other additives, components, integers or steps. It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is hereinbefore described.ABSTRACT OF THE DISCLOSURE A lightweight rectangular inspection cover can be injected moulded in one piece from glass filled nylon. It has a substantially continuous top section joined to ( as part of the same moulding ) a substantially continuous or semi continuous bottom section by a plurality of substantially vertical webs formed by a plurality of cavities entering from the edges of the cover on all or some of the sides. In the case of a circular cover these would be entering radially. 20514SN2 CAP Spec 20111109, doex COMS ID No: ARCS-351928

Received by IP Australia: Time (H:m) 09:34 Date (Y-M-d) 2012-01-11

Claims (9)

1. CLAIMS:

   1. A moulded plastics inspection cover suitable for underground services such as electrical cables, communications (telephone and video) and traffic signals, comprising a one piece homogenous moulding incorporating a substantially continuous top section joined to (as part of the same moulding) a continuous or semi continuous bottom section by a periphery of substantially vertical webs formed by a plurality of side cavities entering from the edges of the cover on all or some of the sides.
2. 2. A moulded plastics inspection cover as claimed in claim 1, wherein the cover has generally rectangular perimeter defined by a reinforced peripheral portion formed by the plurality of side cavities, and wherein the side cavities stop short of a central portion of the cover, with the central portion of the cover having plurality of intersecting longitudinal and transverse ribs capable of transferring a central load to the reinforced peripheral portion.
3. 3. A moulded plastics inspection cover as claimed in claim 1, wherein the cover has generally rectangular perimeter, and wherein the side cavities continue into the central portion of the cover thereby creating a continuous lower beam across the bottom of the cover.
4. 4. A moulded plastics inspection cover as claimed in claim 1, wherein the cover has generally circular perimeter, and wherein the cavities continue into the central portion of the cover thereby creating a continuous lower beam across the bottom of the cover.
5. 5. A moulded plastics inspection cover as claimed in claim 4, wherein each cavity extends substantially radially inwards to a central portion of the cover.
6. 6. A moulded plastics inspection cover as claimed in any one of the preceding claims, wherein the bottom section has one or more bottom cavities.
7. 7. A moulded plastics inspection cover as claimed in any one of the preceding claims, wherein the cover has locking means adapted to lock it to a supporting socket.
8. 8. A moulded plastics inspection cover as claimed in claim 7, wherein the locking means has a rotatable slot accessible from the upper surface of the cover to enable a lifting tool to be inserted to unlock the locking means and to lift the cover off its supporting socket.
9. 9. A moulded plastics inspection cover as claimed in any one of the preceding claims, wherein the cover is injected moulded in one piece from glass filled nylon.