GB2064703A

GB2064703A - Unblocking and repairing conduits

Info

Publication number: GB2064703A
Application number: GB8037773A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-11-22
Filing date: 1980-11-24
Publication date: 1981-06-17

Abstract

For dislodging blockages in e.g. sewers, an apparatus comprises a plastics bag 10 inflatable 12 and deflatable 16 via a pipe 11 from a pressurised air supply to engage and hold fast with the inside surface of said sewer 9. A pipe 14 passes through the bag 10 to introduce pressurized air to dislodge the blockage 8. A series of spaced flexible, elastic, plastics hoops 13 are attached to the bag 10 and are flared to grip the pipe 9. For blocking an opened sewer under repair whilst allowing fluid flow to continue two bags (10' Fig. 3, not shown) penetrated by a pipe (7) to carry the fluid and each of similar configuration to that 10 described above are inflated in respective sewer ends. Instead of a bag 2 alternatives are described: (1) 2 circular plates whose axial separation is screw- threadedly adjustable and separated by a sleeve that expands/contracts when the plates are moved together/apart and (2) an inflatable tyre on a wheel. <IMAGE>

Description

SPECIFICATION Apparatus for dislodging blockages in sewers This invention relates to apparatus for use with sewers, waste pipes or the like (hereinafter in the specification and claims referred to simply as "sewers") and particularly for disdislodging blockages in sewers, but access is required to a location below a sewer necessitating the sewer to be broken for access to be gained, the apparatus can be used to block off each open side of the sewer while enabling flow of material in the sewer to be maintained.

According to one aspect of the present invention, there is provided, for dislodging blockages in sewers, apparatus insertable in the non-expanded condition into a blocked sewer from an access opening upstream of the blockage then to be expanded to engage and hold fast with the inside surface of said sewer, and a pipe passing through the device to exhaust pressurised air at the downstream side of the device to dislodge the blockage, whereafter the device is decreased in bulk to release same from the inside surface of the sewer and enable withdrawal thereof through said access opening.

According to a second aspect of the present invention, there is provided, for dislodging blockages in sewers, apparatus comprising a bag inflatable to cylindrical form, and insertable in the deflated condition into a blocked sewer from an access opening upstream of the blockage then to be inflated via a tube from a pressurised air supply to peripherally engage and hold fast with the inside surface of said sewer, and a pipe passing through the bag to exhaust pressurised air at the downstream end of the bag to dislodge the blockage, whereafter the bag is deflated to release same from the inside surface of the sewer and enable withdrawal thereof through said access opening.

Preferably, a series of spaced hoops of flexible elastic material gird the bag and are flared in the direction opposite to that in which the pipe exhausts the hoops serving, when the bag is inflated, to enhance adherence between the bag and the inside surface of the sewer.

According to a third aspect of the present invention, there is provided apparatus for use with sewers to be broken comprising two circumferentially-expansible devices insertable in the non-expanded condition one into each open end of the sewer when broken from said broken access opening and then expanded to engage and hold fast with the inside surface of said sewer, and a pipe interconnecting and passing through both devices to allow flow of material in the sewer to be maintained for the duration of the necessitied breakage, whereafter the devices are each decreased in bulk to release same from the inside surface of the sewer and enable withdrawal thereof through said broken access opening.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:~ Figures 1 and 2 show diagrammatic side elevations in part section of one embodiment of an apparatus for dislodging a blockage respectively, both in operative positions in a sewer which is shown in longitudinal section; and Figure 2 is a diagrammatic side elevation of a second embodiment of an apparatus for use with a sewer in the operative position in a sewer.

In a first embodiment, apparatus for dislodging blockages in sewers comprises an inflatable bag 10, cylindrical when inflated, connected via a pipe 11 to a pressurised air supply (not shown), a valve 12 being interposed in pipe 11 to control flow of air therethrough. A pipe 14, supplied with pressurised air via a valve 15 passes through the bag 10 end-to-end to exhaust the pressurised air beyond the end of the bag 10 downstream from the supply. The joints between the pipes 11 and 14 and the bag 10 are air-tight. A series of spaced hoops 13 of flexible elastic material gird the bag 10. The hoops 13 are of plastics material and are flared in the direction opposite to that in which the pipe 14 exhausts.

The The hoops 13 are attached to the bag so that they do not separate from the bag 10 when it is deflated. The air supply for both pipe 14 and pipe 11 are from the same source, namely a compressor (not shown), air being fed therefrom through pipe 20 to both pipe 11 and pipe 14 via a T-piece 17 having a shut-off valve 19 in the stem thereof. Pipe 11 has a valve 16 exhausting to atmosphere.

A bag 10 of the apparatus above-described is is inserted in a deflated state into a blocked sewer 9 through an access opening nearest to the blockage and upstream of the blockage 8.

With the shut-off valve 19 and valve 12 open, and valves 15 and 16 closed the bag 10 is inflated in order that its circumference peripherally engages and holds fast against the inside surface of the sewer 9. The hoops 1 3 serve, when the bag 10 is inflated and the hoops strengthened thereby to afford greater adherence between the bag 10 and the inside surface of the sewer 9. Valve 12 is closed and valve 15 is opened to pass pressurised air into the space between the downstream end of the bag 10 and the blockage 8. With the bag 10 held fast in the sewer 9, the pressure of the air increases and dislodges the blockage 8 from the sewer's inside surface to enable the blockage possibly disintegrated to be carried away with the liquid in the sewer. The bag is of synthetic plastics material.To remove the bag, valve 15 is closed and valve 16 is opened for the air in the bag 10 to exhaust to atmosphere.

The apparatus can also be used to remove a blockage in a waste pipe and Fig. 2 shows this use in respect of a toilet, the parts of the apparatus being numeralled as bag 5, pipe 4 to inflate or deflate the bag 5 with shut-off valve 3 and pipe 2 to pass aire to the downstream of the bag 5 when inflated. In this case, a hand pump 1 is used to (a) inflate bag 5 by being connected to the outer end of pipe 4 and (b) to create pressurised air for passing to the downstream end of the bag 5 by being connected (as shown) to pipe 2.

Hoops may be used on the bag 5 if required.

In a second embodiment, as shown in Fig.

3 apparatus for use with sewers to be broken for access to be gained therebelow comprises two circumferentialiy-expandible devices, namely inflatable bags 10' interconnected by pipe 7 passing there between and through both bags 10'. Pipe 111 is provided to inflate the bag 10' through T-junction 6. Pipe 20' and valves 19' and 16' are provided to serve the same purposes as in the first embodiment.

When the top part of the sewer 9 is broken, the bags 10' are placed one in each open end of the sewer at the broken access openings.

The bags 10' are inflated by compressed air being fed thereinto through open valve 19' and pipe 11 ' with valve 16' closed. The bags operate in the same manner as in the first embodiment to close off the pipe. Pipe 7 allows any fluid in the sewer 9 to flow therealong from one side of the break to the other side thereby allowing the sewer still to be used while workmen can gain access to the area below the sewer by removing the remainder of said sewer. After the workmen have finished, a bottom part of a replacement sewer to connect bolt open ends can be located, the bags deflated by closing valve 1 91 opening valve 1 61 and the bags are then removed thereby allowing a top part of said sewer to be located to close off the sewer.

In a modification, the bag 10 is replaced by a device (not shown) comprising two circular plates held in axial registry one with the other and spaced apart by an expandible sleeve in air-tight association with both. Screw-threaded means are provided axially of the plates to bring the plates closer together or move them further apart, respectively to expand the sleeve outwardly into peripheral engagement with the inside wall surface of the sewer, or to return the sleeve to its normal state in which it is not in engagement with the inside wall surface of the sewer. The pipe 14 passes through and between the plates.

In a further modification, the bag 10 is replaced by two similar devices (not shown) each comprising a wheel having an inflatable tyre, the wheels being solid and mounted in spaced relation on a shaft. In this modification the tube 11 feeds pressurised air into each tyre such that the tyres engage and hold fast to the inside surface of the sewer. The pipe 14 passes through and between the wheels.

The apparatus above-described is advantageous over conventional apparatus for dislodging blockages in sewers since there is no possibility of leaving part of the apparatus in the sewer as is sometimes the experience with rods.

Claims

1. Apparatus for dislodging blockages in sewers comprising a circu mferentially-expansi- ble device insertable in the non-expanded condition into a blocked sewer from an access opening upstream of the blockage then to be expanded to engage and hold fast with the inside surface of said sewer, and a pipe passing through the device to exhaust pressurised air at the downstream side of the device to dislodge the blockage, whereafter the device is decreased in bulk to release same from the inside surface of the sewer and enable withdrawal thereof through said access opening.

2. Apparatus for dislodging blockages in sewers comprising a bag inflatable to cylindrical form, and insertable in the deflated condition into a blocked sewer from an access opening upstream of the blockage then to be inflated via a tube from a pressurised air supply to peripherally engage and hold fast with the inside surface of said sewer, -and a pipe passing through the bag to exhaust pressurised air at the downstream end of the bag to dislodge the blockage, whereafter the bag is deflated to release same from the inside surface of the sewer and enable withdrawal thereof through said access opening.

3. Apparatus as claimed in Claim 1 or 2, wherein a series of spaced hoops of flexible elastic material gird the bag and are flared in the direction opposite to that in which the pipe exhausts the hoops serving, when the bag is inflated, to enhance adherence between the bag and the inside surface of the sewer.

4. Apparatus for use with sewers comprising two circumferentially-expansible devices insertable in the non-expanded condition one into each open end of the sewer when broken from said broken access opening and then expanded to engage and hold fast with the inside surface of said sewer, and a pipe interconnecting and passing through both devices to allow flow of material in the sewer to be maintained for the duration of the necessitied breakage, whereafter the devices are each decreased in bulk to release same from the inside surface of the sewer and enable withdrawal thereof through said broken access opening.

5. Apparatus for dislodging blockages in sewers substantially as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings.

6. Apparatus for use with sewers substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.