GB2035413A

GB2035413A - Drainage inspection chamber

Info

Publication number: GB2035413A
Application number: GB7835599A
Authority: GB
Original assignee: Reed International Ltd
Current assignee: Reed International Ltd
Priority date: 1978-09-05
Filing date: 1978-09-05
Publication date: 1980-06-18
Also published as: GB2035413B

Abstract

In a prefabricated inspection chamber of the kind having a manhole access body 1 and an integral base 3 with at least one channel extending between an inlet opening 5 and an outlet opening 6, circular openings constituting the inlet and outlet openings are provided in the side wall structure and separately formed socket members 9 for receiving inlet and outlet pipes are located in each of the openings. The socket members 9 may be located in each of the openings by a bayonet type location and then sealed in position for example by solvent welding. The chamber is of oval cross-section tapers downwardly, and is moulded in reinforced plastics. <IMAGE>

Description

SPECIFICATION Prefabricated drainage inspection chambers This invention relates to inspection chambers of prefabricated construction for use in drainage or sewerage systems and of the kind having a manhole access and a base with at least one channel in the base and extending between an inlet opening and an outlet opening. Normally there is a main channel extending across the base between a main inlet opening and an outlet opening and a number of branch channels each extending across the base from a respective inlet opening to the main channel.

According to the present invention a prefabricated inspection chamber of the kind described is formed from plastics material with a base and integral side wall structure, circular openings in the side wall structure constituting said inlet and outlet openings, and separately formed socket members for receiving inlet and outlet pipes are located in each of the openings by a bayonet type location.

To form said bayonet type location projecting pins or the like may be provided on the socket member, said pins locating in a channel formation in the peripheral wall surface of said openings. Thus the channel formations will have open ends to allow entry of the pins by an axial movement of the socket member which wiFl then be rotated about its axis to trap the pins in the channel formation. Thereafter the socket members will be sealed in position by solvent welding for example.

Advantageously the cross-section of the inspection chamber is oval and the side-wall structure tapers inwardly from the manhole access with for example about a 21/2 taper.

One construction of inspection chamber in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a perspective view of the inspection chamber, Figure 2 shows a sectional side elevation of the inspection chamber, Figure 3 shows a plan view of the base of the inspection chamber, and Figure 4 shows a perspective view of a detail.

Referring to the drawings, the inspection chamber has a main body 1 formed by moulding glass fibre reinforced plastics material. The main body 1 is oval in cross-section and tapers inwardly with about a 21/2 taper from a manhole access 2 to an integral base 3. The base 3 has a main drainage channel 4 extending across it between a main inlet opening 5 and a main outlet opening 6. It is to be noted that the channel 4 extends in the direction of the larger axis of the oval to facilitate rodding when clearing the drainage system. The base is also provided with four branch channels 7 connecting with the main channel 4 and leading from respective inlet openings 8.

Located in the openings 5, 6 and 8 are similar socket members 9. Each of these socket members 9 has in known manner a socket portion 10 fitted with an internal peripheral seal of rubber or the like for sealing with the spigot end of an inlet or outlet pipe.

Adjoining the socket portion 10 is a cylindrical extension 12 whose internal diameter is the same as that of the inlet or outlet pipe. The extension 12 is provided with pip like projections 13 which locate in a channel formation 14 in the peripheral wall surface of the opening 5, 6 or 8 into which the socket member is to be fitted.

As can best be seen from Figure 4 the channel formation 14 is partly in the wall structure of the main body 1 and partly in a block member 15 which is dropped down into a complementarily shaped recess 16 in the main body 1. This mode of assembly facilitates moulding of the main body.

The channel formation 14 has axially extending channel portions 17 which open to the outside surface of the main body 1 and connect at their inner ends with a circumferential channel 18. Thus each socket member 9 is located by an initial axial movement in which its projections 13 pass along the channel portions 17 and then by a rotational movement to trap the projections in the circumferential channel 18. Thereafter the socket members 9 are solvent welded in position.

1. A prefabricated inspection chamber of the kind having a manhole access and a base with at least one channel extending between an inlet opening and an outlet opening, the base being formed integrally with a side wall structure, wherein circular openings constituting said inlet and outlet openings are provided in said side wall structure, and separately formed socket members for receiving inlet and outlet pipes are located in each of the openings.

2. A prefabricated inspection chamber according to claim 1, wherein said socket members are located in each of the openings by a bayonet type location.

3. A prefabricated inspection chamber according to claim 1 or 2, wherein the socket members are sealed in said openings for example by solvent welding.

4. A prefabricated inspection chamber substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Prefabricated drainage inspection chambers This invention relates to inspection chambers of prefabricated construction for use in drainage or sewerage systems and of the kind having a manhole access and a base with at least one channel in the base and extending between an inlet opening and an outlet opening. Normally there is a main channel extending across the base between a main inlet opening and an outlet opening and a number of branch channels each extending across the base from a respective inlet opening to the main channel. According to the present invention a prefabricated inspection chamber of the kind described is formed from plastics material with a base and integral side wall structure, circular openings in the side wall structure constituting said inlet and outlet openings, and separately formed socket members for receiving inlet and outlet pipes are located in each of the openings by a bayonet type location. To form said bayonet type location projecting pins or the like may be provided on the socket member, said pins locating in a channel formation in the peripheral wall surface of said openings. Thus the channel formations will have open ends to allow entry of the pins by an axial movement of the socket member which wiFl then be rotated about its axis to trap the pins in the channel formation. Thereafter the socket members will be sealed in position by solvent welding for example. Advantageously the cross-section of the inspection chamber is oval and the side-wall structure tapers inwardly from the manhole access with for example about a 21/2 taper. One construction of inspection chamber in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a perspective view of the inspection chamber, Figure 2 shows a sectional side elevation of the inspection chamber, Figure 3 shows a plan view of the base of the inspection chamber, and Figure 4 shows a perspective view of a detail. Referring to the drawings, the inspection chamber has a main body 1 formed by moulding glass fibre reinforced plastics material. The main body 1 is oval in cross-section and tapers inwardly with about a 21/2 taper from a manhole access 2 to an integral base 3. The base 3 has a main drainage channel 4 extending across it between a main inlet opening 5 and a main outlet opening 6. It is to be noted that the channel 4 extends in the direction of the larger axis of the oval to facilitate rodding when clearing the drainage system. The base is also provided with four branch channels 7 connecting with the main channel 4 and leading from respective inlet openings 8. Located in the openings 5, 6 and 8 are similar socket members 9. Each of these socket members 9 has in known manner a socket portion 10 fitted with an internal peripheral seal of rubber or the like for sealing with the spigot end of an inlet or outlet pipe. Adjoining the socket portion 10 is a cylindrical extension 12 whose internal diameter is the same as that of the inlet or outlet pipe. The extension 12 is provided with pip like projections 13 which locate in a channel formation 14 in the peripheral wall surface of the opening 5, 6 or 8 into which the socket member is to be fitted. As can best be seen from Figure 4 the channel formation 14 is partly in the wall structure of the main body 1 and partly in a block member 15 which is dropped down into a complementarily shaped recess 16 in the main body 1. This mode of assembly facilitates moulding of the main body. The channel formation 14 has axially extending channel portions 17 which open to the outside surface of the main body 1 and connect at their inner ends with a circumferential channel 18. Thus each socket member 9 is located by an initial axial movement in which its projections 13 pass along the channel portions 17 and then by a rotational movement to trap the projections in the circumferential channel 18. Thereafter the socket members 9 are solvent welded in position. CLAIMS