WO2016005851A1

WO2016005851A1 - Device for the insertion of flexible sheaths

Info

Publication number: WO2016005851A1
Application number: PCT/IB2015/054813
Authority: WO
Inventors: Francesco Paolo Criffo'
Original assignee: In.Tec. S.R.L.
Priority date: 2014-07-08
Filing date: 2015-06-26
Publication date: 2016-01-14

Abstract

A device (1) for the insertion of flexible sheaths suitable to repair a pipe (1a) by inserting inside the pipe a covering sheath (10), is provided for; the device (1) comprises an inlet cross-section (3a) of the covering sheath (10) in the inner chamber (2a); an inner chamber (2a); an outlet cross-section (4a) of the covering sheath (10) from the inner chamber (2a) to connect an inside out end of the covering sheath (10) to; an attachment (5) for a compressor suitable to put said inner chamber (2a) and at least said inside-out end of said covering sheath (10) in overpressure; and deformable restriction means (6) of the inlet cross-section (3a) partially overlapped with the inlet cross-section (3a) and placed in the inner chamber (2a) so as to come into contact with the covering sheath (10) when the inner chamber (2a) is in overpressure making said inner chamber (2a) airtight.

Description

D E S C R I PT I O N

DEVICE FOR THE INSERTION OF FLEXIBLE SHEATHS

The present invention relates to a device for the insertion of flexible sheaths of the type described in the preamble of the first claim.

As known, to repair pipes one of the solutions most frequently adopted involves the insertion in the pipe to be repaired of a covering sheath consisting of a layer impermeable to the passage of fluids; and of a layer impregnated with a resin suitable to solidify and to come into contact with the inner surface of the pipe.

To insert the covering sheath inside the pipe, specific devices are used also called extruders or inversion tubes.

The inversion tubes consist of a casing defining an inner chamber; a winder for the sheath placed inside the chamber; an outlet channel of the sheath from the inner chamber; and an inlet channel for the pressurised air into the inner chamber.

The functioning of the inversion tubes and, therefore, the repair process of a pipe provides that the sheath is turned inside out placing the layer impregnated with resin on the outside and the impermeable layer on the inside.

The sheath is sealed at one end and a vacuum is created by placing the inner volume defined by the impermeable layer in depression.

Meanwhile, the components constituting the resin are mixed and the sheath is impregnated with said resin and passed through a calender which flattens it and adjusts the thickness, making it uniform.

At this point the sheath is inserted in the inversion tube, in particular in the inner chamber and, then wound on the winder placing one end at the mouth of the outlet channel. This end is then turned inside out on the outlet channel, placing the impermeable layer on the inside and the impregnated layer on the outside and firmly connected to the outside of the mouth of the outlet channel.

At this point the outlet pipe is arranged adjacent to the mouth of the pipe to be repaired; a compressor is connected to the inner chamber of the inversion tube. The latter is put into overpressure by said compressor.

Such increase in pressure in the chamber causes a pressure increase in the portion of the sheath adjacent to the mouth of the outlet channel and, thus pushes the sheath to unwind and come out of the inner chamber into the pipe.

This action causes the sheath, coming out of the outlet channel, to turn inside out bringing the impregnated layer into contact, thanks to the internal pressure of the sheath, with the inner surface of the pipe.

Lastly, the resin solidifies locking the sheath in contact with the inner surface of the pipe.

The prior art mentioned above has several significant drawbacks.

The first major drawbacks are the slowness and complexity of the repair process due to the need to wind the entire sheath in the inversion tube.

Another drawback is that the resin, when the sheath is wound on the winder, tends to solidify more quickly

To solve said drawbacks inversion tubes have been made which comprise sealing elements so as to include only a portion of sheath. Similar inversion pipes are described in the patent documents: US-A-2005 / 098,909; US-A-2003209823; US-

B-4685983 and NL-A-2003599

However these inversion pipes only work if the depression is very high and not with low depressions. In this situation the technical purpose of the present invention is to devise a device for the insertion of flexible sheaths able to substantially overcome the inconveniences mentioned above.

Within said technical task one important object of the invention is to obtain a device for the insertion of flexible sheaths which permits the fast and simple repair of pipes, and characterised by the use of compact equipment which functions even at low pressures.

The technical purpose and specified aims are achieved by a device for the insertion of flexible sheaths as claimed in the appended Claim 1 . Preferred embodiments are described in the dependent claims.

The characteristics and advantages of the invention are clearly evident from the following detailed description of a preferred embodiment thereof, with reference to the accompanying drawings, in which:

Fig. 1 shows a median cross-section of the device for the insertion of flexible sheaths according to the invention;

Fig. 2a shows a cross-section of a detail of a device for the insertion of flexible sheaths according to the invention including a sheath and in a first position;

Fig. 2b is the cross-section in Fig. 2a in a second position,

Fig. 3 shows a detail of the device for the insertion of flexible sheaths according to the invention in perspective; and

Fig. 4 shows a detail of the device for the insertion of flexible sheaths according to the invention.

Herein, the measures, values, shapes and geometric references (such as perpendicularity and parallelism), when used with words like "about" or other similar terms such as "approximately" or "substantially", are to be understood as except for measurement errors or inaccuracies due to production and/or manufacturing errors,

With reference to said drawings, reference numeral 1 globally denotes the device for the insertion of flexible sheaths according to the invention.

It is suitable to be used to repair a pipe by inserting inside said pipe a covering sheath 10.

The covering sheath 10, as known to a person skilled in the art, is a flexible tube preferably thermo-plasticized on one side and, therefore, comprises an impermeable side and an absorbent side impregnated with resin which when processing is completed will come into contact with the inner wall of the pipe to be repaired.

The device for the insertion of flexible sheaths 1 comprises a casing 2 defining an inner chamber 2a suitable to receive the covering sheath 10; an inlet 3, defining an inlet aperture 3a of the covering sheath 10 into the inner chamber 2a; an outlet 4 defining an outlet aperture 4a of the sheath 10 from the inner chamber 2a; at least one attachment 5 for a compressor suitable to put said inner chamber 2a in overpressure, i.e. to define, in the inner chamber 2a, a pressure greater than atmospheric pressure; and restriction means 6 of the inlet cross-section 3a arranged at the inlet cross-section 3a; and, optionally, a support structure suitable to rest on the ground, arranging the casing 3 raised above the ground.

The casing 2 and, thus, the inner chamber 2a define a longitudinal axis 2b suitable to be positioned, when the device for the insertion of flexible sheaths 1 is in use, in any position relative to the ground. The casing 2 comprises a central body 21 substantially defining the inner chamber 2a and comprises one or more attachments 22 by means of which to connect the support structure to the casing 2, and one or more portholes 23 suitable to enable the user to see inside the hollow body 21 .

The inlet 3 and the outlet 4 are arranged on opposite faces of the casing 2 and in particular at the bases of the central body 21 which forms most of the casing 2. The inlet aperture 3a thus has an extension perpendicular to the longitudinal direction 2b and preferably extends mainly in a transverse direction 2c, lying on the plane perpendicular to the longitudinal direction 2b. In fact it is preferably oblong in shape and very elongated The inlet aperture 3a is in fact suitable to receive the sheath 10 following its calendering, thus to receive a sheath of reduced dimensions.

The restriction means 6 superpose said inlet aperture 3a.

The restriction means 6 are deformable, preferably elastically, so that, as described in detail below, the overpressure of the inner chamber 2a deforms the restriction means 6 causing a restriction, or better a cancellation, of the free cross- section of the inlet aperture 3a crossed by the covering sheath 10. These are shown in detail in Figs. 2a, 2b and 3.

In particular, the restriction means 6 define, at rest, an aperture of a lesser extension than the size of said inlet aperture 3a. More specifically, the restriction means 6 define, at rest, an aperture of a substantially zero extension. Such restriction means 6 are however deformable and thus allow the entry of the covering sheath 10.

More specifically, the inlet 3 comprises a rigid plate 31 firmly connected to the casing 2 by releasable fastening means 34, such as screws and the like, so that the restriction means 6 are accessible for maintenance or replacement or otherwise. The plate 31 is further connected by means of a gasket 33 to the casing 2, which guarantees the airtight seal of the internal volume 2a of the device 1 and defines the outermost portion of the inlet aperture 3a and having said slot- shape, of a greater area than the area of the sheath 10 after calendering The inlet 3 then comprises a contouring 32 consisting of a preferably cylindrical rigid wall facing the inside of the casing 2 and suitable to continue the outermost portion of the inlet aperture 3a. The contouring 32 is preferably in one piece with the plate 31 .

It is to be noted how the contouring 32 defines a sliding channel for the sheath 10 entering the inner chamber 2a with appropriately, an almost constant cross-section the same as the inlet cross-section 3a. Preferably, said sliding channel has an extension axis substantially parallel and, more preferably substantially coinciding with the longitudinal axis 2b.

Furthermore, the inlet 3 comprises an inlet portion 35 (Fig. 4), preferably substantially prismatic and preferably in polymeric material that includes an internal cavity 36 for the passage of the sheath 10 and of the restriction means 6. Said prismatic portion connects by means of the fastening means 34 and the gaskets 33 to the plate 31 and to the central body 21 . The latter then comprises a second slot 21 a, similar to the first aperture 3a, which forms a continuous passage with the internal cavity 36 and with said first aperture 3a.

The compressor attachment 5 is of the known type and the device 1 further comprises a connection for a pressure gauge 5a, also, in itself, known.

The restriction means 6 preferably comprise a flexible membrane 60 suitable to come into contact with the covering sheath 10 by elastic deformation. It is preferably made of airtight material. In detail, the membrane 60 is made of flexible polymeric material, in particular it is coated, more particularly PVC coated on both sides or otherwise.

The flexible membrane 60 preferably comprises a first portion 61 connected to the outer portion of the contouring 32, appropriately by gluing, and a second portion 62 protruding from the contouring 32, preferably by a length practically equal to the height of the contouring, away from the plate 31 .

Said second portion 62 is the innermost portion of the inlet aperture 3a. Said second portion 62 is also suitable to restrict, and preferably substantially cancel, in the rest configuration, the area of the inlet aperture 3a Consequently the opposite end to the plate 31 of the flexible membrane 60 is substantially closed, although deformable to allow the passage of the sheath 10.

Suitably, gluing points or other similar solutions are present at the end of the second portion 62 designed to connect to each other, at the corners of the means 6 distal from the axis 2b, opposite edges so as to restrict the elastic deformation of the means 6 during the passage of the covering sheath 10.

The restriction means 6 further comprise two rotatable walls 63 substantially consisting of two rigid walls arranged along the walls in the transverse direction 2c of the aperture 3a of the contouring 32.

Said walls 63 are preferably constrained, appropriately exclusively, to the outer sides of the flexible membrane 60 by a weak bond, preferably by gluing along a segment extending in the transverse direction 2c which substantially forms a rotational hinge in said transverse direction 2c.

Said connection of the walls 63 to the membrane 60 is appropriately the only connection of said walls 63 which are therefore not mutually connected, so as to allow a better closure of said flexible membrane 60. Moreover, preferably the rotatable walls 63 have a length, in said transverse direction 2c, less than or equal to the length, in the same direction, of the contouring 32 and the flexible membrane 60.

Said walls 63 preferably have a section consisting of two segments mutually angled so that the portions of the walls 63 which surround the second portion 62 of the membrane 60 converge towards the centre of the aperture 3a The two walls 63 are preferably rotatable around an axis arranged parallel to the walls of the aperture 3a having the greatest extension. This rotation is achieved appropriately by gluing the walls to the membrane 60 along a line parallel to the aperture 3a and to the walls of the aperture 3a having the greatest extension.

The rotatable walls 63 thus help the membrane 60 to remain in a closed position when not subject to external stress. They are also preferably rigid with respect to the membrane 60 and preferably not rigid in an absolute sense and are in a rigid but deformable polymer, such as PVC and the like. Alternatively they are rigid even in an absolute sense, for example in metal.

Joined to the casing 2, the device for the insertion of flexible sheaths 1 has at least one attachment 5 suitable to permit a compressor to be in fluidic through connection with the inner chamber 2a defining a slightly inclined insertion axis with respect to the barycentric main extension axis 2b.

The outlet 4 is substantially a cylindrical portion coaxial with the cylindrical body 21 and with a reduced cross-section compared to said cylindrical body 21 and has a diameter of predetermined dimensions which allows the connection of the sheath thereto.

Between the inlet and the outlet 3 and 4, a support plate 9 is preferably arranged suitable to support the sliding of the covering sheath 10 along the inner chamber 2a and preferably made of steel. The support plate 9 is substantially a single surface with the first aperture 3a, the inner cavity 36 and with the second slot 21a. Additionally, the device for the insertion of flexible sheaths 1 comprises at least one pushing system 8 by means of which to push, in addition to the overpressure, the covering sheath 10 into the pipe 1 a.

The pushing system 8 comprises a vice 81 housed in the chamber 2a and suitable to clamp the covering sheath 10; a handle 82 suitable to move the vice 81 and, thus, the covering sheath 10 along a thrust axis preferably almost parallel to the longitudinal axis 2b; and, placed outside the casing 2, a control mechanism 83 of the pushing system 8, suitable to control the vice 81 and thus to open and close it. The vice 81 comprises a fixed portion 81a integral with the handle 82 and a movable portion 81 b, the fixed portion 81 a further defines a through section for the sheath 10

The movable portion 81 b is suitable to be moved with respect to the fixed portion 81 a defining, for the vice 81 , a spaced position in which the jaws 81 a and 81 b are mutually spaced apart so that the sheath 10 is free to slide between them in the through section; and a gripping position in which the movable jaw 81 b is moved towards the fixed jaw 81 a clamping the sheath 10 between said jaws 81 a and 81 b. The movable jaw 81 b is hinged to the handle 82 so as to rotate around an axis substantially perpendicular to the longitudinal axis 2a.

The handle 82 is a section, suitable to slide relative to the casing 2.

The control mechanism 83 comprises a movable handle, connected to the vice 81 , and in particular to the movable portion 81 b, by means of concentric rods, cables or the like, and suitable to translate the same between said gripping and spaced positions. The functioning of the device for the insertion of flexible sheaths, described above in a structural sense, is as follows.

Initially, the impermeable layer of the covering sheath 10 is on the outside and the absorbent layer on the inside. The operator closes one end of the covering sheath 10 so as to put it in depression, impregnates the absorbent layer with the resin and subjects said sheath 10 to calendering.

After completing said actions, the operator places the device 1 and, to be precise, the outlet 4 next to the pipe to be repaired, connects a compressor 5 to the attachment 5 and begins to insert the sheath 10 through the inlet cross-section 3a, deforming the restriction means 6, in the chamber 2a, as shown in Fig. 2a.

In particular, the operator introduces into the device 1 one end of the sheath, makes it slide firstly inside the internal cavity 36 of the inlet portion 36 and along the second slot 21 a of the support plate 9 and then inside the through section of the vice 81 and, lastly, makes it come out from the outlet cross-section 4a.

Once the free end comes out of the outlet cross-section 4a, it is turned inside out placing the impermeable layer inside the absorbent layer The upturned end of the covering sheath is then firmly connected, for example by means of hose clips, to the outer surface of the outlet 4, as shown in Fig. 1.

At this point, the operator actuates the compressor which, by introducing air into the inner chamber through the attachment 5, places said inner chamber 2a in overpressure. The folded back end thus begins to come out from the outlet cross- section 4a entering the pipe 1 a.

At the same time, the overpressure of the inner chamber 2a, thanks to the advantageous arrangement of the restriction means 6 and to their deformability, deforms the same, further closing, and substantially in an airtight manner, said restriction means 6, and thus the inlet cross-section 3a, as shown in Fig. 2b.

In particular, the overpressure inside the inner chamber 2a, further closes the second portion 62 against the sheath 10 making the inner chamber 2a substantially airtight. Furthermore the rotatable walls 63, in conditions of overpressure, rotate, approaching each other and further closing the inlet cross- section 3a.

The overpressure thus has a single escape route towards the outlet cross-section 4a and thus performs the unwinding of the sheath 10 in the desired direction.

Moreover, if for example on account of a non-straight segment of the pipe 1 a, the sheath 10 cannot move forward, the operator uses the pushing system 8.

In particular, the operator, by moving the movable handle relative to the movable member 82, brings the vice 81 into the gripping position, controls the sliding of the handle 82 and, thus, of the sheath 10 along the axis 2b up to surpassing the non- straight portion of pipe 1 a, and then acts on the movable handle to bring the vice 81 back into a spaced position.

The invention achieves important advantages.

In fact, the device for the insertion of flexible sheaths 1 allows a rapid continuous inversion process even with low pressures of about 0.2 - 0.3 kg. In particular it is not necessary to wind the sheath 10 inside a chamber, as was the case in the prior art, but the sheath 10 itself flows continuously inside the device.

This advantage results in a faster procedure. It is also made possible in particular by the restriction means 6 which allow the overpressure to escape only in the desired direction, i.e. from the outlet cross-section 4a. Moreover, the continuous process causes the sheath with the resin not to be amassed wound in the chamber In these conditions, typical of the prior art, there is a more rapid solidification of the resin, given that when the resin is amassed in one single area the solidification thereof is faster,

The device for the insertion of flexible sheaths 1 is thus simple, economical, lightweight, and compact compared to the prior inversion tubes.

Lastly, the pushing system 8 allows the sheath 10 to tackle and nimbly traverse any section of the pipe to be repaired.

Variations may be made to the invention without departing from the scope of the inventive concept described in the independent claims and in the relative technical equivalents. In said sphere all the details may be replaced with equivalent elements and the materials, shapes and dimensions may be as desired.

Claims

C L A I M S

1. Device ( 1 ) for the insertion of flexible sheaths suitable to repair a duct (1 a) by inserting inside said duct (1 a) a covering sheath ( 10); said device (1 ) comprising:

- a casing defining an inner chamber (2a);

- an outlet aperture (4a) of said covering sheath ( 10) from said inner chamber (2a) to constrain a turned-up end of said covering sheath ( 10) to;

- at least one attachment (5) for a compressor suitable to put said inner chamber (2a) and at least said turned-up end of said covering sheath (10) in overpressure;

- an inlet aperture (3a) of said covering sheath ( 10) in said inner chamber (2a);

- deformable restriction means (6) of said inlet aperture (3a) placed at said inlet aperture (3a);

- said restriction means (6) being placed inside said inner chamber (2a) so as to come into contact with said covering sheath (10) when said inner chamber (2a) is in overpressure thus making said inner chamber (2a) substantially air-tight and comprising a flexible membrane (60) impermeable to the passage of fluid and suitable to come into contact with said covering sheath (10) by elastic deformation,

- characterised in that

- said restriction means (6) comprise rotatable walls (63), rigid in relation to said membrane (60), suitable to keep said membrane (60) in a closed position when not subject to external stresses,

- and in that said rotatable walls (63) are connected solely to said flexible membrane (60) and are not mutually connected.

2. Device (1 ) according to claim 1 , wherein said of restriction means (6) define, at rest, an aperture of a lesser extension than the size of said inlet aperture

(3a).

3. Device ( 1 ) according to claim 2, wherein said restriction means (6) define, at rest, an aperture having a nil extension.

4. Device (1 ) according to one or more of the previous claims, wherein said elastic membrane is made of flexible polymer material.

5. Device ( 1 ) according to one or more of the previous claims, comprising a plate (31 ) defining the outermost portion of said inlet section (3a) and a contouring (32), in a single piece with said plate, consisting of a rigid wall facing the inside of the casing (2) and suitable to continue the outermost portion of the inlet aperture (3a).

6. Device (1 ) according to one or more of the previous claims, in which said flexible membrane (60) preferably comprises a first portion (61 ) connected to the outer portion of said contouring (32) and a second portion (62) protruding from said contouring (32), away from the plate (31 ).

7. Device ( 1 ) according to claim 8, wherein said rotatable walls (63) are connected exclusively to said flexible membrane (60) and are not mutually connected.

8. Device (1 ) according to claim 8 or 9, wherein said rotatable walls (63) have a length, in said transversal direction (2c), less than or equal to the length, in the same direction, of the contouring (32) and the flexible membrane (60).

9. Device ( 1 ) according to one or more of the previous claims, comprising an inlet (3), defining said inlet aperture (3a), comprising a plate (31 ), defining the outer part of said inlet aperture (3a), an inlet portion (35) including an inner cavity (36) for the passage of said covering sheath ( 10) and of said restriction means (6), connected via releasable connection means (34) and gaskets (33) to said plate and to said central body (21 ).

10. Device (1 ) according to one or more of the previous claims, comprising a support plate (9) suitable to support the sliding of the covering sheath (10) along said inner chamber (2a).

11. Device (1 ) according to one or more of the previous claims, comprising a vice (81 ) housed in said inner chamber (2a) and suitable to clamp to said covering sheath (10); a handle (82) suitable to move said vice (81 ).