GB2398593A

GB2398593A - Cover assembly for an inspection chamber, manhole etc.

Info

Publication number: GB2398593A
Application number: GB0303732A
Authority: GB
Inventors: Ronald Francis Clark
Original assignee: CLARKSTEEL HOLDINGS Ltd
Current assignee: CLARKSTEEL HOLDINGS Ltd
Priority date: 2003-02-19
Filing date: 2003-02-19
Publication date: 2004-08-25
Anticipated expiration: 2023-02-19
Also published as: GB2398593B; GB0303732D0

Abstract

The cover assembly, primarily for use with non-man-entry inspection chambers, includes a cover 10, a frame 11 for receiving the cover and an adaptor 12 designed to be received by the frame so that it defines an opening that is smaller than that defined by the frame. The cover, frame and adaptor preferably all have the same shape with the adaptor having an outer and inner portions joined together by a frangible section so that the inner portion can be removed to vary the size of the opening through the assembly. The assembly elements are preferably all formed from plastic material and the adaptor may include spaced apart strengthening ribs. The adaptor may include a substantially horizontal flange which is received in a groove in the frame and/or the adaptor may snap-fit in the frame.

Description

A COVER ASSEMBLY

This invention relates to a cover assembly for an inspection chamber, manhole or the like.

Inspection chambers are designed for non man entry and at 450 mm diameter are limited to a 1.2 metres maximum depth for safety reasons. Ever more crowded developments mean that often deeper inspection chambers are required. These are now allowed provided the entry hole is only 300 or 350 mm diameter (dependent on final depth). This is intended to prevent all accidental entry but can require added inspection chamber inventory at site.

According to the present invention, there is provided a cover assembly for an inspection chamber, manhole or the like, comprising a cover, a frame for receiving the cover and an adaptor for location alongside or below the frame, the adaptor defining an opening smaller than the opening defined by the frame.

Preferred and/or optional features of the invention are set forth in claims 2 to 7, inclusive.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of one embodiment of a cover assembly according to the present invention, Figure 2 is a plan view of the assembly shown in Figure 1, Figure 3 is a fragmentary section taken along the line III- III of Figure 2, Figure 4 is a plan view of the adaptor of the assembly, Figure 5 is an underneath view of the adaptor of the assembly, Figure 6 is a section taken along the line VI-VI of Figure 5, Figure 7 is a section taken along the line VII-VII of Figure 5, and Figure 8 is an exploded perspective view of another embodiment of a cover assembly according to the present invention, and Figure 9 is a fragmentary sectional view of the cover shown in Figure 8.

Referring now to Figures I to 7 of the drawings, there is shown therein a cover assembly for an inspection chamber, comprising a cover lo, a frame 11 and an adaptor 12.

The cover 10 is circular in plan and has a reduced-slip pattern 13 on its upper surface.

The frame 11 is of annular shape and comprises a horizontally extending flange 14, inner and outer upstanding annular flanges 15 and 16, respectively, defining therebetween an annular groove 17 for receiving a depending annular lip 18 on the cover 10 and inner and outer depending annular lips 19 and 20, respectively, defining an annular groove 21 therebetween.

The frame 11 has a plurality of angularly spaced apart triangular reinforcing ribs 22 between the horizontal flange 14 and the outer upstanding flange 16.

The cover 10, frame 11 and adaptor 12 are typically, but not necessarily, of plastics material, e.g. polypropylene.

The adaptor 12 is of annular shape and comprises an upper outwardly extending, annular, horizontal flange 23, an annular flange 24 depending from the inner edge of the flange 23, a further annular horizontal flange 25 extending radially inwardly from the depending flange 24 intermediate the upper and lower ends thereof and a downwardly inclined reduction flange 26 extending downwardly and inwardly from the outer edge of the further horizontal flange 25.

The reduction flange 26 comprises outer and inner portions 26_ and 26_ joined by a frangible section 27 enabling the inner portion 26_ of the reduction flange to be easily broken or cut away.

As best shown in Figures 5 and 7, the underside of the adaptor 12 has a plurality of angularly spaced apart radially extending reinforcing webs 28 which extend over the length of the horizontal flange 25 and the outer portion 26_ of the reduction flange 26.

In use, the upper horizontal flange of the adaptor 12 seats in the groove 21 on the underside of the frame 11 and on the top rim of the inspection chamber (not shown). The adaptor, whether having both reduction flange portions 26_ and 26b or just the outer portion 26_, serves to reduce the size of the opening through the cover assembly as compared with the size of the opening defined by the frame 11.

Typically, the inner diameter of the inner portion 26_ is 300 mm and the inner diameter of the outer portion is 350 mm, whereas the diameter of the opening in s the frame is typically 450 mm.

Figures 8 and 9 of the drawings show an alternative assembly in which the adaptor 12' is snap-fittable within the frame 11'. As best shown in Figure 9, the horizontal flange 23' of the adaptor 12' sits on the upper edge of the upstanding flange 15' of the frame 11' and the adaptor 12' has a plurality of angularly spaced clips 29 which are snap-fittable under the depending annular lip 19' of the frame 11'. The lower edges of the clips 29 are angled in order to allow the adaptor 12' to be inserted into the frame 11'. In this case, the adaptor 12' is located alongside the frame 11'.

The adaptors can be supplied with new inspection chamber cover assemblies. They can also be retro-fitted to existing inspection chamber cover assemblies. The assemblies may also contain inserts or pilot holes to enable such security fittings as may be required to meet building regulations with regard to security and safety.

The cover, frame and adaptor of the cover assemblies described above are all circular when viewed in plan, but other shapes are possible although, in most cases, the cover, frame and adaptor of each assembly will be of similar shape.

The embodiments described above are given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention as defined by the appended claims. For example, the invention is not only applicable to inspection chambers but also to manholes and other access chambers.

Claims

A cover assembly for an inspection chamber, manhole or the like, comprising a cover, a frame for receiving the cover and an adaptor for location below or alongside the frame, the adaptor defining an opening smaller than the opening defined by the frame.
2. A cover assembly as claimed in claim 1, wherein the cover, the frame and the adaptor are all of similar shape when viewed in plan.
3. A cover assembly as claimed in claim 1 or claim 2, wherein the adaptor has an outer portion and an inner portion joined to the outer portion by a frangible section so that the inner portion can be removed to vary the size of the opening through the assembly.
4. A cover assembly as claimed in any one of the preceding claims, wherein the cover, the frame and the adaptor are of plastics material.
5. A cover assembly as claimed in any one of the preceding claims, wherein the adaptor has a plurality of spaced apart strengthening ribs.
6. A cover assembly as claimed in any one of the preceding claims, wherein the frame has two spaced apart, endless or substantially endless, depending lips defining a groove therebetween and wherein the adaptor has an in use horizontal or substantially horizontal flange which in use seats in the said groove.
7. A cover assembly as claimed in any one of the claims 1 to 5, wherein the adaptor is snap-fittable in the frame.
8. A cover assembly as claimed in any one of the preceding claims, in the form of a manhole cover assembly.
9. A cover assembly substantially as hereinbefore described with reference to Figures I to 7, or Figures 8 and 9 of the accompanying drawings.