TECHNICAL FIELD

The present invention relates to a water pipe tool insertion device. More specifically, the invention relates to a water pipe tool insertion device for inserting a tool into a pressurised water pipe.

BACKGROUND

In all towns and cities with modern infrastructure, water is distributed to buildings and other sites of water consumption via pressurised water pipes. Such pressurised water pipes may have a pressure of between 2 and 8 bar, although the normal pressure in locations with private or public waterworks is between 4 and 6 bar. The pressurised water pipes are usually buried underground. The water pipes may be made of copper, cast iron, asbestos cement, cement or plastic materials such as PVC (polyvinyl chloride) or polyethylene. There are several work operations where there is a need to insert a tool into a pressurised water pipe, for example, inspection by camera, cleaning by means of a flushing device, detection of the position of water pipes using a signal-emitting unit (as preparation for digging up water pipes etc.), leakage sealing, leakage detection using microphones, opening of tapping, pipe thawing and the like.

When such operations are to be carried out today, a gate or cock at a higher level, typically a valve in the distribution network, is closed. Thus, the water supply in all water pipes in a fairly large area, for example, a housing estate or urban quarter, is shut off. The work operation is subsequently carried out in the water pipes in question in the shut-off area, i.e., that the work operation is carried out on water pipes with no pressure.

Normally it is necessary to give the households in the areas that are to be shut off an advance warning, which means that the work operations must be planned in good time. JP 10221257 A teaches a self-propelling tool for inspection of a water pipe. JP

2009244419 teaches a cable-laying device for laying a cable in a pipe.

US 5084764 teaches a method of inspecting a water pipe while the pipe is full of water. An inspection tool is inserted into the water pipe through a chamber and a drogue is used to pull the tool forward in the water pipe while cable/lines trail behind the tool. This tool thus requires that water pressure or water flow in the water pipe is changed. In practice, a separate water pump must be used here to drive the inspection tool forward.

It is an object of the present invention to provide a water pipe tool insertion device for inserting a tool into a pressurised water pipe without it being necessary to shut off the water supply to the area in which the pipe is located. Furthermore, it is an object that the device should be flexible in that several types of tool should be capable of being used with the water pipe tool insertion device. It is a further object that the device should be easy to use and that it should be capable of being used without contaminating the water in the water pipe.

SUMMARY OF THE INVENTION

The present invention relates to a water pipe tool insertion device for inserting a tool into a pressurised water pipe, the device comprising:

- an outer housing;

- a first chamber provided in the outer housing in which the tool can be placed, the first chamber comprising a connector for fluid-tight connection to the water pipe;

- a second chamber provided in the outer housing;

- an insertion guide with a first end adapted to be connected to the tool when the tool has been placed in the first chamber, characterised in that the insertion guide extends from the tool through a first duct between the first chamber and the second chamber, through the second chamber and then out through a second duct in the second chamber; wherein the first end of the insertion guide is adapted to be inserted into the pressurised water pipe in that the insertion guide is pushed in a direction from the second duct to the first duct in the second chamber.

In an aspect, a pressure-reducing fluid passage is formed between the insertion guide and the internal surface of the first duct.

In an aspect, the second chamber comprises a draw-off means.

In an aspect, the first duct comprises a first gasket means for reducing the amount of fluid that is allowed to pass through the first duct.

In an aspect, the second duct comprises a second gasket means for reducing the amount of fluid that is allowed to pass through the second duct.

In an aspect, the insertion guide is a flexible steel rod, a cable or the like.

In an aspect, the first chamber comprises a draw-off cock.

In an aspect, the device further comprises: a disinfection chamber provided in the outer housing; wherein the insertion guide extends from the second chamber through the second duct and through the disinfection chamber and then out through a third duct in the disinfection chamber.

In an aspect, a second end of the insertion guide is provided outside the housing. DETAILED DESCRIPTION

Embodiments of the invention will now be described with reference to the attached drawings, wherein:

Figure 1 illustrates a cross-section of a first embodiment of the invention;

Figure 2 illustrates a cross-section of a second embodiment of the invention;

Figure 3 illustrates a cross-section of a third embodiment of the invention;

Figure 4 illustrates the use of the third embodiment of the invention in a pressurised water pipe.

Reference is now made to Figure 1. This figure shows a water pipe tool insertion device 1 for inserting a tool 2 into a pressurised pipe 3. In Fig. 1 only the end of the water pipe 3 is schematically illustrated.

The tool 2 may be a measuring device, an inspection camera, a signal transmitting device, a signal receiving device, a flushing tool or other tool used to carry out work operations in a water pipe. Some typical examples of such work operations are mentioned in the introduction above. Such tools are considered to be known to the skilled person in the field.

The water pipe 3 is an ordinary pressurised water pipe comprising a connection interface in the form of a water pipe connector 3b. The water pipe connector 3b may be a part of a main stopcock 3c (illustrated in Fig. 4). The water pipe connector 3b and the main stopcock 3c are considered to be known to the skilled person in the field and will not be described in detail here. A common type of water pipe connector 3b comprises an external threaded portion (not shown). It should nevertheless be noted that the present invention is not limited to a specific type of water pipe connector 3b.

The water pipe tool insertion device 1 comprises an outer housing 10, a first chamber 15 provided in the outer housing 10, a second chamber 20 provided in the outer housing 10 and an insertion guide 30.

The housing 10 may be provided as one body with a plurality of chambers 15, 20, or the housing 10 may be provided as a plurality of chambers having separate housings that are joined together into one housing.

The first chamber 15 is provided for placing the tool 2 during connection of the device 1 to the pressurised water pipe 3. The first chamber 15 therefore has preferably the same cross-sectional shape and the same diameter as the water pipe connector 3b. A first duct 40 is provided between the first chamber 15 and the second chamber 20. The first duct 40 is dimensioned to allow the insertion guide 30 to pass through the duct 40.

Fig. 1 shows that the second chamber 20 comprises a draw-off means 21. The draw-off means 21 is a draw-off duct in the second chamber 20 to allow water to run out freely from the second chamber 20. In the illustrated embodiment, the draw-off means 21 is a draw-off nipple with external threads. A collecting means (not shown) can be placed under the draw-off means 21 to collect water that is forced out through the duct 40, alternatively a water hose can be connected to the draw-off means 21 so that the water is passed to a drain or the like. The duct 40 is shaped to conform to the insertion guide 30 for reducing the amount of fluid that is allowed to pass through the first duct 40 past the insertion guide 30. A pressure-reducing fluid passage is thus formed between the insertion guide (30) and the internal surface of the first duct (40). This can be done in that the internal shape and size of the duct 40 is adapted to the external shape of the guide 30. Furthermore, the first duct 40 may comprise a first gasket means 41 for further reduction of the amount of fluid that is allowed to pass through the first duct 40 past the insertion guide 30.

This means that when the device 1 is connected to the pressurised water pipe 3, water from the water pipe 3 will fill the first chamber 15. Because of the pressure-reducing fluid passage, the first duct 40 will not be 100% fluid-tight and some water will thus be forced out through the duct 40 past the insertion guide 30 and out into the second chamber 20 due to the pressure in the first chamber 15. Although some water will enter the second chamber 20, the pressure of the fluid here will be lower than in the first chamber 15. Normally, the pressure in the second chamber 20 will be equal to atmospheric pressure. A second duct 50 is provided in the second chamber 20. The second duct 50 is dimensioned to allow the insertion guide 30 to pass through the duct 50.

Since the pressure in the second chamber 20 is low or approximately atmospheric pressure, water will not be forced out through the second duct 50. Nevertheless, to avoid introducing contaminants into the water pipe together with the guide 30, it is preferred that also the second duct 50 is shaped to conform to the insertion guide 30. Furthermore, the second duct 50 may also comprise a gasket means, in the figures indicated by means of the reference numeral 51. This will optionally contribute as secondary protection against water leaks, as the second gasket means 51 will reduce the amount of fluid that is allowed to pass through the second duct 50 past the insertion guide 30. In the figures, it is shown that the first chamber 15 comprises a connector 11 for fluid- tight connection to the water pipe 3. In Fig. 2 it is shown that the connector 11 comprises an internal threaded portion adapted to the aforementioned external threaded portion of the water pipe connector 3b. Fig. 2 also shows that a gasket 12 is provided for preventing leaks at the connection of the connector 11 to the water pipe 3. The connector 11 may of course have other types of connection interface depending on the water pipe connector 3b to which it is to be connected.

The insertion guide 30 has a first end 31 adapted to be connected to the tool 2 when the tool 2 has been placed in the first chamber 15. From the tool 2, the insertion guide 30 extends through the first duct 40 between the first chamber 15 and the second chamber 20, through the second chamber 20 and then out through the second duct 50 in the second chamber 20. In the embodiments shown in Figs. 1 and 2, the insertion guide has been passed out to outside the housing 10 through the second duct 50 and a second end opposite the first end 31 is indicated in Figs. 1 and 2. The second end 32 of the insertion guide 30 is thus located outside the housing 10.

The insertion guide 30 is adapted for inserting the tool 2 into the pressurised water pipe 3 by moving the insertion guide 30 relative to the housing 10. The insertion guide 30 may thus slide relative to the ducts 40, 50, and by pulling or pushing the insertion guide 30, the tool 2 is moved respectively out of or into the water pipe 3.

The insertion guide 30 may be a flexible steel rod, a cable or the like. If the tool 2 is a battery-operated signal transmitter, a flexible steel rod can be used. If the tool 2 is a camera, a signal transmitting, relatively rigid cable will normally be used. If the tool 2 is a flushing head, a water-carrying guide will have to be used. The insertion guide 30 will typically be stored in a coiled state on a drum or the like.

Reference is now made to Fig. 3. In this figure it is shown that the first chamber 15 comprises a draw-off cock 16. If a flushing operation is to be carried out in the water pipe in order to clean it, or where the water pipe is wholly or partially blocked and the blocked area of the pipe is to be unblocked, it is desirable that the particles loosened during the operation should be removed from the water pipe 3. This can be done by opening the draw-off cock 16. The pressure in the water pipe 3 will thus pass the contaminated water and particles out through the draw-off cock 16. Normally, this will mean that a large amount of water will be passed out through the draw-off cock 16 and this water must therefore be passed to a drain or the like. Nevertheless, the result is obtained that the particles are not spread to other parts of the water pipe 3.

Fig. 3 also shows that the device 1 further comprises a third chamber, hereafter called a disinfection chamber 70, provided in the outer housing 10. A third duct 80 is provided in the disinfection chamber 70. The third duct 80 is dimensioned to allow the insertion guide 30 to pass through the third duct 80. The disinfection chamber 70 is, during use of the device 1, filled with disinfectant fluid that disinfects the guide 30 before it is passed into the water pipe 3.

The insertion guide 30 is in this embodiment passed on from the second chamber 20 through the second duct 50 and through the disinfection chamber 70 and out through a third duct 80 in the disinfection chamber 70. The insertion guide 30 here has been passed out to outside the housing 10 through the third duct 80. In this case, too, the second end 32 of the insertion guide 30 is located outside the housing 10. The insertion guide 30 will in this embodiment be capable of being stored in coiled state on a closed drum containing disinfectant fluid. Owing to the fact that the guide 30 is passed through the disinfection chamber 70, there will be some leakage of disinfectant fluid. The disinfection chamber therefore comprises a filling duct to allow topping-up of disinfectant in the chamber 70.

An alternative embodiment is a device 1 where the first chamber 15 comprises a draw-off cock 16, but where there is no disinfection chamber. Yet another alternative embodiment is a device 1 with a disinfection chamber, but with no draw-off cock 16 in the first chamber 15.