GB2465434A

GB2465434A - Inspection chamber base formed using a modular mould

Info

Publication number: GB2465434A
Application number: GB0821525A
Authority: GB
Inventors: Jason Shingleton
Original assignee: Polypipe Civils Ltd
Current assignee: Polypipe Civils Ltd
Priority date: 2008-11-25
Filing date: 2008-11-25
Publication date: 2010-05-26
Anticipated expiration: 2028-11-25
Also published as: GB2465434B; GB0821525D0

Abstract

A base (1) for an inspection chamber (2) or manhole used in drainage is provided, comprising at least one element which is pre-formed from a modular tool part. The base may have a plurality of elements which may be preformed using vacuum forming using a set of interchangeable mould inserts to enable different channel configurations to be produced. Also disclosed is a base whose elements are formed from a millable material and milled to a desired shape by a computer numerically controlled (CNC) machine. The millable elements may be hollow or filled with foam and may also be coated, for example with polyurethane.

Description

INSPECTION CHAMBERS

The invention relates to inspection chambers, or manholes or access chambers.

Inspection chambers are used to gain access to underground water handling systems and usually have bases which connect up with underground pipe work. However, the flow pattern of the underground pipework can vary with the result that different base profiles or configurations are required in order to cope with the variety of pipework flow patterns or profiles.

Hitherto this has meant that a multiplicity of base patterns is made, each formed from a separate mould tool, which is expensive. There has also been a proposal for providing different base profiles by assembling parts selectively from a set of parts, but again this is time-consuming and expensive.

It is accordingly an object of the invention to seek to mitigate these disadvantages.

According to one aspect of the invention there is provided a base for an inspection chamber used in drainage, comprising at least one element which is pre-formed from a modular tool part.

According to a second aspect of the invention there is provided an inspection chamber comprising a base as hereinbefore defined.

Using the invention, it is possible to provide bespoke base parts using modular tooling for one mould tool.

There may be a plurality of elements each pre-formed using a set of interchangeable mould inserts for a single mould tool and which are selected to provide a particular element or elements for the base. This can provide a complete set of base parts using modular tooling, not a range of many base parts.

There may be a plurality of elements, each pre-formed from a millable material to a desired shape and which may be selected as a particular element or elements for the base.

The or each element may be pre-formed by a numerically controlled milling machine.

The material may comprise a polystyrene member milled to the desired shape.

Suitably, an external surface of the or each element may be coated with a coating for example the coating may comprise polyurethane. This provides an abrasion-resistant coating.

Alternatively, the or each element may be vacuum formed.

In the latter case, an interior of the or each element may be hollow. For strengthening, an originally hollow interior of the or each element may be filled with strengthening means, for example a foamed material such as a foamed resin material.

In a preferred embodiment the inspection chamber may comprise a generally cylindrical shaft, a lower end, in use, being closed by the base.

Suitably, the shaft may comprise a double walled shaft of plastic material. Preferably, an outer wall of the double-walled shaft may be corrugated.

It will be understood that the invention extends to a set of parts for forming an inspection chamber for use in a drainage system, comprising a generally cylindrical open-ended shaft and a base as hereinbefore defined assemblable at an open end thereof.

Yet further, it will be understood that the invention extends to a mould tool and a plurality of mould tool parts each adapted for use with the tool and to form a set of modular elements which can provide a base of an inspection chamber for use in a drainage system.

An inspection chamber and a base therefor are hereinafter described, by way of example, in the accompanying schematic drawing, which shows an exploded longitudinal sectional view of an inspection chamber and base.

Referring to the drawing there is shown a base 1 for an inspection chamber 2 used in drainage, comprising at least one element which is pre-formed from a modular tool part.

In the embodiment, the base element I is vacuum formed to the desired flow pattern configuration using a single mould tool and a modular tool part element for moulding a particular base element as shown with, in the embodiment, a flow channel 3.

The outer surface or flow surface 4 of the moulded element 1 may be strengthened by a strengthening, abrasion-resistant coating e.g. of polyurethane. The interior 5 may also be strengthened by being filled with a foam, for example an expanded foamed material.

The base element 1 may also be formed from a millable material such as a polystyrene block which is moulded as by being milled to the required shape by a computer-aided milling machine, which is then coated on the flow surface with a strengthening material such as a polyurethane coating.

The manhole or inspection chamber 2 is a right cylinder of plastic material which is double walled, the inner wall or skin 6 being smooth and the outer wall or skin 7 being corrugated.

To assemble, the base I is offered up to the lower end (in use) of the shaft 2 and is inserted therein, being secured as by suitable means, which could be an interference fit, on the lower end. A base or platform 8 is then offered up and secured in place over the bases to provide a stable structure, the inspection chamber being mounted on the platform.

It will therefore be understood from the foregoing that using the invention it is possible to provide using a single mould tool, which can be a vacuum moulding tool, different bases comprising elements or inserts for providing a required flow pattern at the inspection chamber 2. Thus each element or insert I of the base is bespoke, using a set of mould inserts which provide the desired flow characteristics without the need to stock a multiplicity of individual elements or inserts.

Claims

CLAIMSI. A base for an inspection chamber used in drainage, comprising at least one element which is pre-formed from a modular tool part.
2. A base according to Claim 1, there being a plurality of elements each pre-formed using a set of interchangeable mould inserts or parts for a single mould tool and which are selected to provide a particular element or elements for the base.
3. A base according to Claim 1, there being a plurality of elements, each pre-formed from a millable material to a desired shape and which are selected as a particular element or elements for the base.
4. A base according to Claim 3, the or each element being pre-formed by a numerically controlled milling machine.
5. A base according to Claim 4, the material comprising a polystyrene member milled to the desired shape.
6. A base according to Claim 5, an external surface of the or each element being coated with a coating.
7. A base according to Claim 6, the coating comprising polyurethane.
8. A base according to Claim 2, the or each element being vacuum formed.
9. A base according to Claim 8, an interior of the or each element being hollow.
10. A base according to Claim 9, an originally hollow interior of the or each element being filled with strengthening means.
11. A base according to Claim 10, the strengthening means comprising a foamed material.
12. A base for an inspection chamber, substantially as hereinbefore described with reference to the accompanying drawing.
13. An inspection chamber for use in a drainage system, comprising a base according to any preceding claim.
14, An inspection chamber according to Claim 13, comprising a generally cylindrical shaft, a lower end, in use, being closed by the base.
15. An inspection chamber according to Claim 14, the shaft comprising a double walled shaft of plastic material.
16. An inspection chamber according to Claim 15, an outer wall of the double-walled shaft being corrugated.
17. An inspection chamber for use in a drainage system, substantially as hereinbefore described with reference to the accompanying drawing.
18. A set of parts for forming an inspection chamber for use in a drainage system, comprising a generally cylindrical open-ended shaft and a base according to any of Claims I to 12 assemblable at an open end thereof
19. A mould tool and a plurality of mould tool parts each adapted for use with the tool and to form a set of modular elements which can provide a base of an inspection chamber for use in a drainage system.