GB2095598A - Device for cutting side connections in the lining of a pipe - Google Patents

Abstract

The invention relates to devices for cutting pipe linings 12 in order to re-establish side connections 14 to a pipeline 10 after the lining thereof by means of a flexible liner which has been impregnated with resin so as to cure hard in a lining position within the pipeline. The device has a rotary cutter 36 mounted on a head movable along the axis of the pipe, angularly about the axis of the pipe, and radially of the pipe. The device is supported on skids 18 and may be locked in position by inflation of an air bag 44. <IMAGE>

Description

SPECIFICATION Improvements relating to cutting devices This invention relates to devices for cutting pipelinings in order to re-establish side connections or "laterals" to the pipeline after the lining operation. in particular, the device is concerned with cutting away a portion of a rigid pipelining which covers the connecting aperture between a side connection or lateral and the pipeline proper, in the instance when a pipeline is lined, by means of a flexible liner which is impregnated with a thermosetting resin, which cures hard when the lining is placed and held in position lining the pipeline.

Such a lining process and the appropriate liners are known by the trade mark "INSITU FORM".

The Insituform lining process is usable for lining for example underground waste pipes or sewers, and a single liner can be used to line a pipeline of the order of 200 or 300 feet or in other words the distance between adjacent manholes. Typically, between adjacent manholes there may be as many as six to one dozen side connections leading from domestic installations, and of course these side connections must be re-established by removing the portions of the lining material covering the openings connecting the side connections and the main sewer. The present invention is concerned with a device for this purpose.

In accordance with the present invention, the device comprises a cutter unit adapted to be moved along the inside of a passageway which has been lined by the Insituform process, said cutter unit comprising a body which carries a rotary cutter head, said head being movable relative to the body in a direction which will be the direction of the pipeline when the cutter unit is in use, and also being turnable about an axis extending in the said direction, whereby the cutter head with an appropriate cutter can be made to cut the appropriate portions of the Insituform lining material, the cutter head also being mounted so as to be displaceable in a direction at right angles to said direction.

The body may be provided with means for locking the unit in any selected position in the passageway, and such means may comprise an inflatable air bag.

The body may include a displaceable part for carrying the said air bag, the said displacable part being movable to a raised position from a lowered position thereby to adapt the unit for use in pipelines applying within a wide range of diameters.

A body may be provided with skids on which it can run as it is being moved along the pipeline interior, and suitably, the unit may be adapted for pulling along the inside of the pipeline by means of a suitable chain and winch arrangement.

The cutter may comprise a small air motor and chuck for holding a cutter bit.

The means for displacing the cutter head in the direction which will be the direction of the pipeline when the cutter is in use and may comprise a hydraulic piston and cylinder device, the cylinder being defined by a portion of the cutter body.

The means for turning the cutter about an axis extending in the said direction, may comprise a hydraulic motor placed upon the cutter body, and having a displacement shaft extending through the piston of the piston cylinder device which serves to displace the cutter head axially.

The cutter head may be mounted for radial displacement by providing for a cylinder block at the end of the abovementioned piston, such cylinder containing a piston drivingly connected to the cutter head to displace same radially.

The preferred cutter unit therefore includes three hydraulically driven prime movers namely a first double acting piston cylinder for displacing the cutter unit back and forth axially, a second hydraulic piston cylinder unit for displacing the cutter unit radially, and a hydraulic motor for displacing the cutter unit angularly. The cutting bit will be preferably driven by a rotary air motor.

In the control of the cutter unit, there may be provided a portable power pack containing the hydraulic control valves and appropriate hydraulic logic, said control valves being electrically controlled from a control panel, may for example be situated in a control vehicle at ground level. The power pack and control panel are connected electrically, and the said control vehicle may be provided with a television monitor whereby a control operator in the vehicle can inspect each cutting operation whilst it is taking place inside the pipeline, if also located in the pipeline is an appropriatetelevision camera, locatable so as to view each cuttting operation. It is well known to position television cameras in pipelines for underground pipeline inspection purposes.

Additionally, there may be a microphone on the camera unit, for detecting the sound of cutting so that the control operator as well as viewing the cutting operation can listen to the cutting operation, for control purposes, because when the cutting bit strikes a material of a different consistency there will be a change in the cutting frequency and hence the cutting sound, and the operator can move the cutter accordingly for the effective cutting of the laterals.

The control panel will be provided with appropriate joy sticks and control mechanisms to enable to the operator manually to control the cutting operation for each lateral or side connection, but it is envisaged that this operation can be effected automatically.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a sectional elevation showing the cutter unit inside a pipeline; Figure 2 is an end view of the cutter unit to illustrate the capability of the cutter head to be moved angularly; Figure 3 is a sectional elevation illustrating diagrammatically how the angular adjustment shaft passes through the main piston; Figure 4 illustrates the hydraulic and pneumatic connections to the cutter unit; Figure 5 illustrates an end view of a portable power pack used with the cutter unit; Figure 6 and 7 illustrate a front view and side view of a control panel which is used with the cutter unit; and Figure 8 illustrates in perspective elevation how the cutter of the cutting unit removes a portion of lining material to re-establish a side connection.

Referring to the drawings, an underground pipline such as a sewer 10 has been lined according to the Insituform lining process, with an Insituform lining 12, which is hard lining material comprising basically cured synthetic resin in which is embedded a strengthening absorbent material such as a synthetic felt. The purpose of the lining 12 is, as is known, to rehabilitate the pipe 10. Fig. 1 shows that there is connected to pipe 10 a lateral or side connecting pipe 14, and the connecting aperture has been covered with the lining 12. The lining must therefore be cut in the region of the connecting aperture in order to re-establish the side connection.

The present invention is concerned with a cutting device for the re-establishing of side connections such as the one illustrated by reference numeral 14, and the cutting unit of the embodiment illustrated in Fig. 1 comprises a square section elongated body 16 which rests on skids 18 for the support and movement of the body along the inside of the pipe 10 by means of pulling cables or chains 20. The body 16 defines an internal hydraulic cylinder 22 containing a main piston 24. This piston and cylinder arrangement 22, 24 is double acting, and at the projecting end of piston 24 there is a cylinder block 26 provided internally with a hydraulic cylinder 28 containing a piston 30. The piston 30 is simple acting and the cylinder contains a return spring to return the piston to an inwards position when the pressure of the fluid in the cylinder 28 is removed.The piston 30 is connected to a cutter unit by means of a bracket 32, the bracket 32 releasably supporting an assembly comprising an air motor 34 and a cutting bit 36. A rotary adjustment hydraulic motor 38 is carried at one end of the body 16, and a shaft 40 connected to motor 38 (see Fig. 3) extends through piston 24 and is connected to the block 26 so that the block 26 can be angularly adjusted, as illustrated by arrow 42 in Fig. 2, thereby to adjust the position of the cutting assembly 34, 36.

With the arrangement described, it will be appreciated that the cutting assembly 34, 36 can; (i) be moved axially of the pipe 10 by means of the piston and cylinder arrangement 22, 24; (ii) be moved radially of the pipe 10 by means of the piston and cylinder arrangement 28, 20; and (iii) can be moved angularly of the pipe 10 to the extent indicated by arrow 42 in Fig. 2, which in fact is 270 , by means of the motor 38.This in fact makes the assembly, 34, 36 universally adjustable, within the physical limits of the system, within the pipe 10 for the effective cutting out of the side connections, such as 14.

For locking the cutting unit in any particularly position in the pipe 10, whilst cutting is taking place, there is provided an inflatable bag 44 on the top of the body 16. In fact, the bag 44 is provided on an inverted U-shaped frame member 46 which embraces body 16 as shown clearly in Fig. 2, the member 46 being linked to the body 16 by means of pins 48 carried by the body and U-shaped slots 50 in the sides of the frame member 46. By this arrangement, the frame member 46 can be moved to an upper elevated position as shown in dotted lines in Fig. 2, thereby to increase the effective height of the body, and thereby to enable the unit to be used in pipes of larger diameter.Similarly, the skids 18 are interchangeable with other skids having longer legs, or shorter legs, thereby to adjust the effective position which the unit will take in the pipe 10, in order to suit the side connections being re-established.

Fig. 4 illustrates the various hydraulic coupling connections to the hydraulic prime movers 22, 24; 28, 30; and 38, and also to the air driven units 34 and 44. These various pipes, which are flexible hoses, are grouped into a single core cable 52 which is coupled to the power pack unit 54 shown in Fig. 5.

This unit 54 is portable and is coupled by an electrical cable 56 to a control panel 58 which may for example be located in a control vehicle having a television monitor whereby in conjunction with the use of a camera in the pipeline 10 the cutting operation can be viewed and controlled.

The unit 54 shown in Fig. 5 is provided with a hydraulic pump 60 which supplies hydraulic fluid to and receives exhausted hydraulic fluid from a control valve unit 62 having six coupling points respectively connected to the six hydraulic pipes leading to the cutter unit. The unit 62 contains electrically operated control valves which are controlled from the unit 58 in a manner to be described.

The unit 54 furthermore is adapted to receive air under pressure from a compressor through a connection 64, to filter the air in a filter 66, and to lubricate the air in a lubricator 68.

In order to use the cutter, the operator positions the cutter in the pipeline using the T.V. camera and monitor as necessary until the cutter head 34, 36 is in a suitable position. He then locks the cutter unit by inflating the bag 44 by positoning the control switch 70 on panel 58. He then, by positioning switch 72, starts the cutter bit motor 34 which, in the example described rotates the bit 36 at 2,500 rpm. He controls the motion of the cutter head 34, 36 by means of two jot stick levers 74 and 76 on panel 58. At the same time he views the cutting operation on the television monitor and finally he listens to be cutting operation through ear phones connected to a microphone located in the pipeline adjacent for example the television carmera.

The joy stick 74 controls the radial displacement of the cutter bit 36 in that if the joy stick is moved in the direction of arrow A, the bit 36 moves outwards, and if the joice stick 34 is moved downwards in the direction of arrow B, the cutter bit is moved radially inwards.

The joy stick 76 is an eight position joy stick. Positions 1 and 2 move the cutter head 34, 36 axially back and forward along the pipe 10, the positions 3 and 4 serve for rotating the cutter head in opposite directions in the pipe 36 and the intermediate positions 5 and 6 and 7 and 8 give simultaneous rotation and axial displacement of the cutter 34 and 36, whereby completely universal control of the cutter bit 36 is possible to enable it to cut such as the lateral connection 14 as shown clearly in Fig. 8. Reference numeral 78 in Fig. 6 illustrates a volume control knob whereby the operator can control the volume of the cutting noise.

The units of the control pack 54 are selected so that the cutter can be arranged to cut automatically rather than the operator having to watch and listen and control the operation manually, and this automatic cutting can be achieved by programming the unit 54, to give it a memory. For example, the unit can be taken into the pipe 10 before it is lined and the cutter unit 34 moved around the side connection 14 in a simulated cutting action so that the unit will store the movements and will effect the movement automatically according to this programme after the lining operation and upon replacing of the cutter unit in the pipeline, much in the same fashion as is adopted for programming automatic robots which are used extensively in the automative industry.

The device according to the invention is effective and fundamentally simple. It is entirely hydraulic and pneumatic and therefore the dangers involved in positioning electrical equipment underground are eliminated.

All of the components may be constructed of anti-corrosive material, such as stainless steel, to enable the effective subsequent washing and cleaning of the cutting unit after use.

The unit may be made sufficiently small to be capable of being used in a six inch pipeline.

Claims (1)

1. A cutting device comprising a cutter unit adapted to be moved along the inside of a passageway which has been lined by the Insituform process, said cutter unit comprising a body which carries a rotary cutter head, said head being movable relative to the body in a direction which will be the direction of the pipeline when the cutter unit is in use, and also being turnable about an axis extending in the said direction, whereby the cutter head with an appropriate cutter can be made to cut the appropriate portions of the Insituform lining material, the cutter head also being mounted so as to be displaceable in a direction at right angles to said direction.