AU2013101532A4 - Access covers and assemblies - Google Patents

Abstract

An access cover is provided comprising a composite core, and a resilient outer covering moulded onto the core. The access cover comprises an upper surface having a non-slip tread. The access cover comprises a 5 stepped lip at an edge of the access cover to overlap with a complimentary stepped lip of an adjacent access cover. The access covers can be hinged to a frame of a pit assembly and locked together via a locking mechanism to secure the pit. co 0( (NN C(N (N (N

Description

P/00/012 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: "ACCESS COVERS AND ASSEMBLIES" The following statement is a full description of this invention, including the best method of performing it known to me/us: 1 TITLE ACCESS COVERS AND ASSEMBLIES FIELD OF THE INVENTION 5 The present invention relates to access covers and assemblies for pits. In particular, although not exclusively, the present invention relates to lightweight access covers for utility pits. BACKGROUND OF THE INVENTION 10 Pits, such as utility pits, provide access to utilities, such as water, gas, telecommunications and/or electricity, which often run underground. Typically pit lids, also known as access covers, are provided to cover the top of the pit. The access covers provide access points for maintenance, prevent safety issues, such as people stepping or falling into the pit, and close the pit to 15 prevent damage from the surrounding environment or tampering with the utilities. Traditionally access covers are designed to bear a significant load, such as people walking, or vehicles driving over the access covers. To provide the strength to bear these loads and to assist in keeping the access 20 cover in place, access covers are usually made of heavy materials, such as metal or even concrete. One problem with heavy access covers is that they cannot easily be opened or removed to access the pit. Heavy access covers therefore provide a risk of injury to utility workers who need to lift heavy access covers regularly.

2 Manufacture of such access covers can be high and transportation of such lids to the installation site can also be problematic. While some lighter access covers have been produced, these access covers are typically not as strong as heavy access covers and can more 5 easily break when trodden on by people or driven over by vehicles. Additionally, lighter access covers can more easily be dislodged accidentally or by wind or water. Stronger lightweight access covers have been designed. However, these access covers are expensive and time consuming to produce and are 10 made via complex processes. At least some of these access covers can also be prone to corrosion, rotting, or other degeneration. Another problem with some removable access covers is that they can fall into the pit risking injury to personnel and/or damage to utilities in the pit. 15 OBJECT OF THE INVENTION It is a preferred object of the present invention to provide an improved access cover that addresses or at least ameliorates one or more of the aforementioned problems and/or provides a useful commercial alternative. 20 SUMMARY OF THE INVENTION Generally, embodiments of the present invention relate to lightweight access covers and assemblies for utility pits. In one form, although not necessarily the broadest or only form, the present invention resides in an access cover comprising: 25 a composite core; and 3 a resilient outer covering moulded onto the core. Preferably, the access cover comprises a stepped lip at an edge of the access cover to overlap with a complimentary stepped lip of an adjacent access cover. 5 Preferably, the resilient outer covering comprises a mixture of one or more of fibreglass, resins, hardeners, gel coat sealers, UV stabilizers and anti slip grit. Preferably, the access cover comprises an upper surface having a non slip tread. 10 Preferably, the non-slip tread consists of a plurality of L-shaped projections on the upper surface of the access cover. In another form, although not necessarily the broadest form, the present invention resides in a method of making an access cover comprising: shaping a composite core; and 15 moulding a resilient outer covering onto the core. In a further form, although not necessarily the broadest form, the present invention resides in a pit assembly comprising: a frame; and one or more access covers hinged to the frame, each access cover 20 comprising: a composite core; and a resilient outer covering moulded onto the core. Preferably, the pit assembly comprises a locking mechanism to lock the access covers together.

4 Further forms and/or features of the present invention will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS 5 In order that the invention may be readily understood and put into practical effect, reference will now be made to preferred embodiments of the present invention with reference to the accompanying drawings, wherein like reference numbers refer to identical elements. The drawings are provided by way of example only, wherein: 10 FIG 1 is a horizontal cross-sectional view of an access cover according to embodiments of the present invention; FIG 2 is a vertical cross-sectional view of the access cover shown in FIG 1; FIG 3 is a top perspective view of a cover assembly comprising two 15 access covers according to embodiments of the present invention; FIG 4 is an underside perspective view of the cover assembly shown in FIG 3; FIG 5 is a plan view of the cover assembly shown in FIG 3; FIG 6 is a front view of the cover assembly shown in FIG 3; and 20 FIG 7 is a side view of the cover assembly shown in FIG 3. Skilled addressees will appreciate that elements in the drawings are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the relative dimensions of some of the elements in the drawings may be distorted to help improve understanding of embodiments of 25 the present invention.

5 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention relate to access covers and assemblies for pits, such as utility pits. However, embodiments of the present 5 invention can be used in other applications where a strong, lightweight lid or cover is required, which may require variations to the embodiments of the present invention described herein, but will nonetheless fall within the scope of the present invention as claimed. FIGS 1 and 2 are horizontal and vertical cross-sectional views of an 10 access cover 100 according to embodiments of the present invention. The access cover 100 comprises a core 110 that is strong and lightweight. In this embodiment, the core 110 is planar and has a honeycomb structure. In alternative embodiments, the core 110 can have other structures, such as other isotropic and/or open-cell structures and/or be non-planar. 15 The core can be made of a composite material, particularly an artificial composite material, or another strong, lightweight, stable, non-biodegradable material. The composite material can be a resin composite, a fibre composite and/or a fiber-reinforced polymer, or another strong, lightweight composite material.. In some embodiments, the core 110 is made of a material known 20 as LV Core from LV Composites Toowoomba, Australia. A resilient outer covering 120 is moulded onto the core 110. The resilient outer covering 120 can comprise a mixture of one or more of fibreglass, resins, hardeners, gel coat sealers, UV stabilizers and anti-slip grit. FIGS 3 and 4 show a top and an underside perspective view of a cover 25 assembly 200 according to embodiments of the present invention. The cover 6 assembly 200 comprises a first access cover 210 coupled to a second access cover 220. The first and second access covers 210, 220 can be the access cover 100 shown in FIGS 1 and 2. The first access cover 210 and the second access cover 220 each 5 comprise a stepped lip 212, 222. The stepped lip 212 of the first access cover 210 has a complimentary shape to the stepped lip 222 of the second access cover 220 to enable the first access cover 210 and second access cover 220 to be coupled together such that an upper stepped lip 212 of the first access cover 210 abuts on top of a lower stepped lip 222 of the adjacent second 10 access cover 220. The first access cover 210 and second access cover 220 are coupled together such that lips 214, 224 provide a rim around the cover assembly 200 to engage a frame of a pit assembly. Each lip 214, 224 comprises one or more rectangular recesses 216, 226 at an end of the access cover to enable 15 the first access cover 210 and/or the second access cover 220 to coupled to the frame of the pit assembly and/or to be hinged to the frame of the pit assembly. The first access cover 210 comprises a locking mechanism 230 for securing the first access cover 210 to the second access cover 220. As such, 20 the first access cover 210 and the second access cover 220 can be coupled to and/or hinged to the frame of the pit assembly and then locked together to secure the pit. An upper surface of each access cover 210, 220 has a non-slip tread 218, 228. Each non-slip tread 218, 228 consists of a plurality of L-shaped 25 projections in the upper surface of the access cover 210, 220.

7 FIG 5 is a plan view of the cover assembly 200 shown in FIGS 3 and 4. The L-shaped projections of the non-slip tread 218, 228 are arranged in a series of broken zigzag patterns across the upper surface of each access cover 210, 220. 5 FIG 6 is a front view of the cover assembly 200 shown in FIGS 3, 4 and 5. The stepped lip 212 of the first access cover 210 sits above the stepped lip 222 of the second access cover 220 when the access covers 210, 220 are coupled together. The base 213 of the stepped lip 212 is higher than the base 215 of the lip 214 on the first access cover 210. 10 FIG 7 is a side view of the cover assembly 200 shown in FIGS 3-6 showing rectangular recesses 216, 226 and non-slip tread 218, 228. According to another form, the present invention resides in a method of making an access cover, for example, the access cover 100. The method comprises shaping a strong, lightweight composite core to the shape required 15 for the access cover. The can be performed by any known technique suitable for the material of the core. The method comprises moulding a resilient outer covering onto the strong, lightweight composite core using known suitable moulding techniques. In another form, the present invention resides in a pit assembly 20 comprising a frame and one or more access covers as previously described herein. The access covers can each be hinged to the frame to enable the access covers to be opened and closed whilst remaining coupled to the frame. The pit assembly can comprise a locking mechanism to lock the access covers together and secure the pit.

8 Embodiments of the present invention provide a strong, lightweight access cover that is easy, quick and cost effective to produce. The light weight core 110 of the access cover makes it safer, easier and quicker to install and significantly reduces the risk of injury to utility workers compare 5 with prior art heavy covers. The locking mechanism 230 enables the access cover to be secured to prevent tampering with the services in the pit. The locking mechanism 230 and the rectangular recesses 216, 226 in the lip of the access cover provide a tight seal to minimize the ingress of water and debris and prevent the access cover from being accidentally dislodged. The non-slip 10 tread 218, 228 on the upper surface of the access cover makes the access cover safer to install in places where people may walk on the access cover. The strong, light weight, composite core is waterproof and will not corrode, rot or degenerate. Threads, services and fittings can be cast into the core without significantly affecting the strength of the core or the access 15 cover. The core is isotropic which provides strength to the access cover in all directions. Hinging of the access covers to the frame of the pit assembly prevents the access covers from falling into the pit and provides a more user-friendly pit assembly. 20 In this specification, the terms "comprise", "comprises", "comprising" or similar terms are intended to mean a non-exclusive inclusion, such that a system, method or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

9 The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge. Throughout the specification the aim has been to describe the 5 preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. It is to be appreciated by those of skill in the art that various modifications and changes can be made in the particular embodiments exemplified without departing from the scope of the present invention. 10

Claims (5)

1. An access cover comprising: a composite core; and 5 a resilient outer covering moulded onto the core.

2. The access cover of claim 1, wherein the access cover comprises a stepped lip at an edge of the access cover to overlap with a complimentary stepped lip of an adjacent access cover. 10

3. The access cover of claim 1 or 2, wherein the access cover comprises an upper surface having a non-slip tread.

4. A method of making an access cover comprising: 15 shaping a composite core; and moulding a resilient outer covering onto the core.

5. A pit assembly comprising: a frame; and 20 one or more access covers hinged to the frame, each access cover comprising: a composite core; and a resilient outer covering moulded onto the core.