GB2300663A

GB2300663A - Manhole shutters

Info

Publication number: GB2300663A
Application number: GB9609646A
Authority: GB
Inventors: Stephen Wilson
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-05-09
Filing date: 1996-05-09
Publication date: 1996-11-13
Anticipated expiration: 2016-05-09
Also published as: GB9609646D0; GB9509219D0; GB2300663B

Abstract

A method for forming a concrete channel between two or more pipe ends in a manhole base involves the use of pre-formed boat shutters 11, 16 and box shutters 15. The pipe ends are interconnected by means of the boat shutters and the box shutters are located on the boat shutters to extend the shuttering upwardly. Concrete is applied round the shuttering and the shuttering is removed once the concrete has at least partially set. The shutters may be re-used. The box shutters may include curved parts 12 which co-operate with curved boat shutters 13.

Description

INTERNAL MANHOLE SHUTTERS This invention relates to a method for forming a concrete channel between two or more pipe ends in a manhole base and to shutters which may be used in such a method.

Shutters are commonly used in the construction industry for forming concrete structures.

Concrete channels are formed at the base of manholes to carry the flow of liquids from one pipe (the inlet pipe) to at least one other pipe (the outlet pipe). Such channels must comply with building regulation specifications.

The current practice is to construct wooden shuttering for each individual channel. This is an expensive practice with regard to both materials and time.

According to the present invention there is provided a method for forming a concrete channel between two or more pipe ends in a manhole base, the method comprising the steps: (i) interconnecting said pipe ends by at least one pre-formed channel-section shutter; (ii) locating further pre-formed shutters on said channel-section shutters upwardly to extend the shuttering between said pipe ends; (iii) applying concrete around the assembled shutters; and (iv) allowing said concrete at least partially to set and removing the pre-formed shutters.

The pipe ends may be of different diameters. The pre-formed shutters include at least two channel-section shutters of different dimensions to correspond to respective pipe end diameters.

Preferably the pre-formed shutters include at least one channel-section shutter and at least one further shutter having relatively inclined transverse ends. Such shutters allow the assembled shuttering to extend between two non-aligned pipe ends. The shutters of use in the present invention may be made of any suitable material, for example, plastic or glass-reinforced plastic.

The present invention also provides a pre-formed shutter for use in the method of the invention.

In addition, the present invention provides a kit comprising a plurality of pre-formed shutters, at least one of the shutters being of channel section, and at least one of the shutters being a said further shutter.

The present invention allows smooth channels to be created in concrete by using pre-formed shutters which may be of different sizes. The shutters may be of two types, the channel-section shutters being referred to hereinafter boat shutters and the further shutters being referred to hereinafter as box shutters. The shutters may be re-used.

The boat shutters form the curved cross-section of the channel and the box shutters sit on top of the boat shutters and form the sides of the channel. The shutters may be secured releasably to each other, for instance by being bolted together or by the use of pin wedges. Each boat shutter may include a pipe extending longitudinally therethrough to carry any existing liquid flow between the inlet and outlet pipes. The channel-section shutters are made such that when joined together the pipes of adjacent shutters are aligned to enable the flow to be continuous between the pipe ends.

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 shows a typical arrangement of shutters combined to interconnect a small inlet pipe and a larger outlet pipe set at an angle to each other; Figure 2 shows both a box and a boat shutter for forming a straight section of the shuttering; Figure 3 shows angled boat and box shutters; Figure 4 shows tapered boat and box shutters; and Figure 5 shows shuttering in place between two pipe ends within a manhole.

Referring to Figure 1 of the accompanying drawings, shuttering between two pipe-ends (not shown) in a manhole base includes boat shutter 11 which is partially inserted into the outlet pipe.

Smaller boat shutter 16 is partially inserted into the inlet pipe. A tapered boat shutter 15 is joined to boat shutter 16 to accommodate the difference in diameter and invert levels of the inlet and outlet pipes. Further curved boat shutters 13 are fixed between the straight boat shutter 11 and tapered boat shutter 15 to accommodate the angle between the inlet and outlet pipes.

Appropriately sized straight box shutter 10, curved box shutters 12 and tapered box shutters 14 are fixed to the corresponding boat shutters, 11, 13, 15 to form a rigid mould for a concrete channel between the inlet and outlet pipes.

Once the concrete has been poured around the assembled shuttering and has been allowed at least partially to set, the shuttering is removed in reverse order to that of assembly in order to leave a smooth channel joining the inlet and outlet pipes.

Figures 2 to 4 show the various types of shutter in greater detail. These drawings show each boat shutter provided with longitudinally aligned holes such as 1 la and 1 lb in Figure 2, which allow liquid to enter and leave while the shuttering is in place in order to carry the existing flow of liquid between the outlet and inlet pipes. The interior of the boat shutters may be provided with a pipe extending between holes 1 la and 1 lb.

Figure 5 of the accompanying drawings shows, in plan view, shuttering in place between two pipe ends in a manhole base.

Claims

1. A method for forming a concrete channel between two or more pipe ends in a manhole base, the method comprising the steps: (i) interconnecting said pipe ends by at least one pre-formed channel section shutter; (ii) locating further pre-formed shutters on said channel-section shutters upwardly to extend the shuttering between said pipe ends; (iii) applying concrete around the assembled shutters; and (iv) allowing said concrete at least partially to set and removing pre formed shutters.

2. A method according to Claim 1 wherein the pipe ends are of different diameters, the pre-formed shutters including at least two channel-section shutters of different dimensions to correspond to the respective pipe end diameters.

3. A method according to Claim 1 or Claim 2 wherein the pre-formed shutters include at least one channel-section shutter and at least one further shutter having relatively inclined longitudinal ends whereby the assembled shuttering may extend between two non-aligned pipe ends.

4. A method according to any of the preceding Claims wherein said pre-formed shutters are made of plastic or of glass reinforced plastic.

5. A method according to any of the preceding Claims wherein the or each channel-section shutter includes a pipe extending longitudinally therethrough.

6. A method according to Claim 1 substantially as described herein.

7. A method for forming a concrete channel between two or more pipe ends in a manhole base, substantially as described with reference to the accompanying drawings.

8. A pre-formed shutter for use in the method of any of the preceding Claims.

9 A kit comprising a plurality of pre-formed shutters and for use in the method of any of the preceding Claims.