NL1039765C2

NL1039765C2 - A pipe connector and a method for connecting pipes by such pipe connector.

Info

Publication number: NL1039765C2
Application number: NL1039765A
Authority: NL
Inventors: Gerard Jager; Hendrik Snaathorst
Original assignee: J O A Technology Beheer B V
Priority date: 2012-08-17
Filing date: 2012-08-17
Publication date: 2014-02-18

Description

Title A pipe connector and a method for connecting pipes by such pipe connector.

5 Technical Field

The present invention relates generally to piping technology and, more specifically, to the connection of pipes of a transport line of a cut tobacco pneumatic conveying system.

10

Background of the Invention

Pneumatic conveying is widely used in the transport of various materials or products by a pneumatic fluid through transport lines or transport pipes 15 of a pneumatic conveying or transport system. Generally, the pneumatic fluid is a gas and in most cases the fluid is air.

Smooth and aligned piping connections are a critical factor in damage prevention or reduction of products transported with a relative high transport 20 velocity through a transport line. Cut tobacco, for example, is very prone to product degeneration and damage as a result of incorrect transport piping and bends in the transport line and system lay-out.

Summary 25

It is an object of the present invention to provide an advanced pipe connector for connecting pipes, such as feeding pipes of a transport line of a cut tobacco pneumatic conveying system.

30 It is a further object of the present invention to provide a method and a device for connecting pipes using the improved pipe connector.

In a first aspect, there is provided an advanced pipe connector comprising a first and second tubular flange, the first flange having an inner surface 1039765 2 forming a receiving opening for receiving an end of a first pipe and the second flange having an inner surface forming a receiving opening for receiving an end of a second pipe to be connected to the first pipe, each pipe having an outer circumferential surface and an inner circumferential surface, wherein each flange comprises at least 5 one mounting recess at its inner surface forming the receiving opening, the at least one mounting recess being arranged for receiving part of the outer surface of a pipe received in its receiving opening for mounting the pipe to the flange by radially stretching the pipe from its inners surface, and the first and second flange being arranged for being coupled to each other such that the end of a first pipe when 10 mounted in the first flange and the end of a second pipe when mounted in the second flange abuttingly connect.

The advanced pipe connector provides a smooth pipe connection having a single pipe transition at the abutting ends of the first and second pipe. The 15 connector can be quickly mounted to the ends of the pipes to be connected without welding by simply mechanically stretching each end of a pipe received in a receiving opening of a flange in outward radial direction from its inners surface. By this stretching operation, material at the outer surface of the end of the pipe received in the receiving opening of a flange will be forced into the at least one mounting recess 20 at the inner surface of the receiving opening of a flange, thereby providing a strong and reliable pipe flange mounting.

In an example of the advanced pipe connector, the at least one mounting recess comprises at least one circumferential mounting groove, providing a 25 complete circumferential mount of the pipe and flange. An even stronger and even more reliable mounting is achieved in another example of the advanced pipe connector, wherein each flange comprises two circumferential mounting grooves spaced in axial direction of the flange.

30 The dimensions of the at least one mounting recess in radial and axial direction of the flange are relative small compared to the pipe wall thickness, such that a relative small amount of material is received in the at least one mounting recess, thereby maintaining the inner surface of the pipe at the position of the at least one mounting recess as smooth as possible.

3

In a further example of the advanced pipe connector, the first and second flange comprise abutting coupling surfaces, each coupling surface being aligned with an end of the receiving opening of a flange, and when mounted in a 5 flange the end of a pipe is in alignment with the coupling surface of the flange.

The abutting coupling surfaces of the flanges ease the coupling of the flanges while connecting the pipes.

10 In another example of the advanced pipe connector the abutting coupling surface of the first flange comprises a circumferential shoulder part aligned with the end of the receiving opening and the second flange comprises a circumferential recessed part aligned with the end of the receiving opening and arranged for mating with and receiving the shoulder part in an abutting manner.

15

The mating shoulder and recessed part of the first and second flange, respectively, provide an improved alignment of the first and second pipe to be connected and thereby a reliable and smooth single pipe transition of the first and second pipe to be connected.

20

In an embodiment of the advanced pipe connector at least one of the abutting surfaces comprises a circumferential groove for receiving a sealing ring for providing a fluid tight coupling of the first and second flange, such as a well-known O-type ring for example.

25

In the example of the advanced pipe connector comprising the mating shoulder and recess abutting surfaces, the part of the abutting coupling surface of the first flange beyond the shoulder part comprises the circumferential groove for receiving the sealing ring and part of the abutting coupling surface of the 30 second flange beyond the recessed part is substantially flat, the grooved part and the substantially flat part having dimensions for compressing the sealing ring when the first and the second flange are coupled.

4 A person skilled in the art will appreciate that the first and second tubular flange may be coupled to each other by a variety of coupling means, such as nuts and bolts, rivets and the like.

5 Adhering to the fast manner of mounting a flange and a pipe, in an example of the advanced pipe connector each tubular flange at an outer surface thereof opposite the abutting coupling surface has a substantially inwardly tapered shape in radial outward direction, and the pipe connector comprises a substantially V-shaped clamping ring for receiving the edges for coupling the flanges in a 10 clamping manner.

The clamping ring can be very easily and quickly applied and provides clamping force for holding the first and second flange along their outer entire circumference. To even enhance the speed of coupling, in an embodiment the 15 clamping ring is comprised of two halves, each halve having at each end fastening means for fastening the halves for coupling the flanges in a clamping manner. Suitable fastening means are, for example, nut and bolt connections and snap connections.

20 In a second aspect there is provided a method for connecting an end of a first pipe to an end of a second pipe by a pipe connector comprising a first and second tubular flange, the first flange having an inner surface forming a receiving opening for receiving the end of the first pipe and the second flange having an inner surface forming a receiving opening for receiving the end of the second pipe 25 to be connected to the first pipe, each pipe having an outer circumferential surface and an inner circumferential surface, wherein each flange comprises at least one mounting recess at the inner surface forming the receiving opening, the method comprising the steps of: - receiving an end of the first pipe in the receiving opening of the 30 first flange, - mounting the first pipe to the first flange by radially stretching the first pipe from its inner surface at the end received in the receiving opening such that the at least one mounting recess of the first pipe receives part of the outer surface of the first pipe, 5 - receiving an end of the second pipe in the receiving opening of the second flange, - mounting the second pipe to the second flange by radially stretching the second pipe from its inner surface at the end received in the receiving 5 opening such that the at least one mounting recess of the second pipe receives part of the outer surface of the second pipe, and - coupling the first and second mounted flange to each other such that the end of the first pipe mounted in the first flange and the end of a second pipe mounted in the second flange abuttingly connect.

10

In an example of the method above, the stretching is performed by inserting a rolling unit into the pipe from its end to be mounted to the flange, the rolling unit comprises a plurality of circumferentially distributed axially rotatable conically shaped rollers extending in axial direction of the pipe and the rollers being 15 displaceable in radial direction of the pipe, wherein the rollers are rotated in circumferential direction of and pushed against the inner circumferential surface of the pipe. Viewed from their end to be inserted in the pipe, the diameter of the rollers slightly increases.

20 The stretching is performed such that a smooth inner circumferential surface of the pipe at its end received in a receiving opening of a flange is achieved while sufficient material at the outer surface of a pipe is received in the at least one mounting recess of a flange. As a result of the stretching by the conical rollers, the inner diameter of the pipe may slightly increase when viewed towards its end to be 25 mounted in the flange.

In the example of the advanced pipe connector of which the first and second flange comprise abutting coupling surfaces, each coupling surface being 30 aligned with an end of the receiving opening of a flange, a pipe to be mounted to a flange is received in the receiving opening of the flange such that the end of the pipe is in alignment with the coupling surface of the flange.

6

The advanced pipe connector and method are in particular suitable for connecting feeding pipes of a transport line of a cut tobacco pneumatic conveying system constructed of aluminium or stainless steel. The first and second flange of the advanced pipe connector may be constructed from metal such as aluminium or 5 stainless steel.

The above-mentioned and other features and advantages of the invention are illustrated in the following description with reference to the enclosed drawings which are provided by way of illustration only and which are not limitative to 10 the present invention.

Brief description of the Drawings

Fig. 1 shows, in a schematic and illustrative manner, an example of 15 a pneumatic conveying system, such as cut tobacco pneumatic conveying system.

Fig. 2 shows, in a schematic, perspective and illustrative manner, an example of a first and second pipe connected by an example of the pipe connector according to the invention (not to scale).

Fig. 3 shows, in a schematic and illustrative manner, a partly cross 20 section in longitudinal direction of the pipes and pipe connector along the line Ill-Ill in Fig. 2, with a broken away part.

Fig. 4 shows, in a schematic and illustrative manner, detail of the cross section of the pipes and pipe connector shown in Fig. 3 on an enlarged scale.

Fig. 5 shows, in a schematic, perspective and illustrative manner, an 25 example of a rolling unit (not to scale).

Fig. 6 shows, in a schematic and illustrative manner, in cross section, detail of a pipe/flange mount obtained by using the rolling unit of Fig. 5.

30 Detailed description

Figure 1 shows, in a schematic and illustrative embodiment, an example of a device 10 for feeding cut tobacco from a delivery unit 12-1 to a tobacco processing device 13, such as a cigarette maker, by a pneumatic conveying system 7 11. The cut tobacco, or in general fibrous material, is transported from the cut tobacco delivery unit 12-1 to the tobacco processing device 13 via an intermediate transport line 14, also called a feed line of the pneumatic conveying system 11.

5 The device 10 typically comprises a plurality of cut tobacco delivery units 12-1, 12-2, ..., 12-n (n £ 1) each containing, for example, a different blend of cut-tobacco. For selecting a particular delivery unit 12-1, 12-2..... 12-n a so-called blend selector 15 is provided. The blend selector 15 comprises a plurality of inputs 16- 1, 16-2, ..., 16-m (m > 1) that each connect to a respective output 17-1, 17-2, ..., 10 17-m of the blend selector 15. In the example shown, delivery unit 12-1 connects via a feed line 18-1 to input 16-1 of the blend selector 15. At the corresponding output 17- 1 of the blend selector 15 the feed line 14 to the cut-tobacco processing device 13 connects, such that cut-tobacco from the delivery unit 12-1 is transported to the cut-tobacco processing device 13.

15

For producing tobacco products by the tobacco processing device 13 having a different blend, a respective one of the other delivery units 12-2.....12-n has to be connected, with its feed line 18-x (x=2, .... n), to input 16-1 of the blend selector 15, of course by first disconnecting the feed line 18-1.

20 A particular delivery unit 12-1, 12-2, .... 12-n may comprise several feed lines 19-x, 20-x, etc. (x=1, 2.....n) for connecting the respective delivery unit to a respective (other) input 16-1, 16-2..... 16-n of the blend selector 15, at each output 17-2, ..., 17-n of which, by a respective pneumatic conveying system, a 25 further cut-tobacco processing device may connect.

In the example shown, the pneumatic conveying system 11, at the end of the transport line 14, comprises a unit 21, such as a fan or equivalent device for creating a low pressure or vacuum in the transport line 14. To prevent entrance of 30 dust or other substances of cut-tobacco from the transport line 14 into the unit 21, a dust filter 22 is provided in front of the unit 21, when viewed in the material transport direction, schematically indicated by arrows 24.

o δ

In the embodiment shown, the unit 21 is operative for a plurality of cut-tobacco processing devices 13, via a plurality of pneumatic conveying systems 11, the transport lines 14 of which are collected by a line collector unit 23 which collects, for example, six transport lines 14.

5

Tobacco transport in the transport line 14 is operated according to a demand driven start-stop process. For providing an amount of tobacco for processing by the cut-tobacco processing device 13, a so-called air lock 25 is incorporated in the transport line 14 at the cut-tobacco processing device 13. Behind 10 the air-lock 25, when viewed in the transport direction 24, a valve 26 is included in the transport line 14. This valve 26, also called maker valve, is operated by the cut-tobacco processing device 13, such as a cigarette maker. The maker valve 26 operates for closing and opening of the transport line 14, i.e. for stopping and starting the material transport there through.

15

For controlling the pneumatic fluid flow in the transport line 14, a fluid flow control unit 27, for example in the form of at least one flow control valve such as a servo motor driven pressure regulator-reducer, is incorporated in the transport line 14 between the maker valve 16 and the line collector unit 23. The fluid 20 flow control unit 27 is operated by a control system 28.

Reference numerals 29, 30 and 31 indicate devices of the control system 28 for determining physical parameters, such as velocity or speed of the material and pneumatic fluid transport in the transport line 14 at a position in front of 25 the cut-tobacco processing device 13, when viewed in the transport direction 24. The values measured by any of the devices 29, 30 and 31 are provided to a digital processing device or electronic processor or computer 32. The processing device 32 is suitably programmed for processing the input received from the devices 29, 30, 31 for controlling the material transport in the feeding line 14 by suitably operating the 30 fluid flow control unit 27.

Servo motor driven pressure regulator-reducer valves and velocity determining or measurement devices, as such, are known to the skilled person and commercially available. The latter may include direct velocity or speed measurement 9 devices or indirect velocity or speed measurement devices such as pressure and pressure difference measurement devices measuring pressure of the pneumatic fluid at several positions in and along the transport line, from which the particular velocities can be determined. Measurement data in both analogue and/or digital form 5 may be processed.

As will be appreciated by those skilled in the art, a number of other control mechanisms may be provided at the pneumatic conveying system 11, such as valves for releasing pneumatic fluid from the material delivery unit 12, the 10 transport line 14, safety valves, and the like (not shown).

In operation, the unit 21 is operative to create a low-pressure or vacuum in the transport line 14, such that cut-tobacco and air is introduced into the transport line 14, from the material delivery unit 12-1, and transported to the cut-15 tobacco processing device 13. By the air-lock 25 cut-tobacco from the transport line 14 is received and collected. Once the cut-tobacco processing device 13 requires an amount of cut-tobacco, it closes the maker valve 26 and the cut-tobacco 33 is released from the air-lock 25 and delivered to the cut-tobacco processing device 13, after which the maker valve 26 is opened again. The amount of cut-tobacco 20 delivered and the flow mode of the fibrous material in the transport line 14 are typically achieved by controlling the pneumatic fluid in the transport line 14 from the control system 28 operating the flow control unit 27.

In the case of cut tobacco as the fibrous material to be conveyed, 25 the pneumatic conveying system 11 is generally operated by air as the pneumatic fluid for conveying the cut tobacco. Typical values of the material velocity in the transport line are in the range of about 15-19 m/s and of the fluid velocity in the range of about 17-23 m/s.

30 For tobacco conveying, for example, in practice transport pipes with a length in the range of about 50 - 500 m are used, having an internal diameter in the range of about 80 - 150 mm. It will be appreciated that such lengths of pipe are not manufactured in one piece and need to be constructed by connecting pipes of 10 standard lengths, for example. In practice, pipe lengths of about 200 m are fairly standard.

Fig. 2 shows, in a schematic, perspective and illustrative manner, 5 part of first pipe 35 and part of second pipe 40, such as circle cylindrical transport pipes of the transport line 14 of a feeding system of the type shown in Figure 1. The first pipe 35 and second pipe 40 connect to each other by a pipe connector 50 in accordance with an example of the invention. The first pipe 35 comprises an inner circumferential surface 36 and an outer circumferential surface 37. The second pipe 10 40 likewise comprises an inner circumferential surface 41 and an outer circumferential surface 42. The pipe connector 50 comprises a first tubular flange 51 and a second tubular flange 52, which are coupled to each other by a clamping ring 53. The first 51 and second flange 52 each define a receiving opening 54, 55 for receiving an end of the first pipe 35 and second pipe 40, respectively.

15

For clarification purposes, a cylindrical (r, Θ, z) coordinate system is indicated, wherein r represents the radial direction, Θ represents the azimuthal or angular or circumferential direction and z represents the axial or longitudinal direction of a pipe 35, 40 and the pipe connector 50.

20

In the cross sectional view of Fig. 3, for clarification purposes, part of the first pipe 35 and the second pipe 40 at the pipe connector 50 is shown broken away. In the example shown, the first flange 51 at the inner surface 56 forming the receiving opening 54 comprises two mounting recesses in the form of two mounting 25 grooves 57, 58 that extend in circumferential direction Θ of the first flange 51. The two mounting grooves 57, 58 are spaced over a distance in axial direction z of the first flange 51. The second flange 52, in the same manner as the first flange 51, at the inner surface 59 defining the receiving opening 55 comprises two mounting recesses in the form of two mounting grooves 60, 61 that extend in circumferential 30 direction Θ of the second flange 52. The two mounting grooves 60, 61 are spaced over a distance in axial direction z of the second flange 52.

It will be appreciated that instead of two mounting grooves 57, 58 and 60, 61 each flange 51, 52 may have just one or more than two mounting 11 grooves. Further, the mounting grooves 57, 58 and 60, 61 need not necessarily be continuously in radial direction Θ of a flange 51, 52. A mounting recess or groove in an inner surface 56, 59 of a flange 51, 52 and distributed in circumferential direction Θ thereof, may have any shape or form suitable for receiving part of the outer 5 circumference 37, 42 of a pipe 35, 40, respectively.

The first flange 51 and second flange 52, in the example shown, comprise circumferential coupling surfaces 62, 63, respectively. The coupling surface 62 of the first flange 51 is formed as a circumferential shoulder part 64 10 aligned with the end 65 of the receiving opening 54. The coupling surface 63 of the second flange 52 is formed as a circumferential recessed part 66 aligned with the end 67 of the receiving opening 55 and arranged for mating with and receiving the shoulder part 64 in an abutting manner when the first flange 51 and the second flange 52 are coupled to each other, as shown.

15

Part of the coupling surface 62 of the first flange 51 radially outward from the shoulder part 64 comprises a circumferential groove 68 for receiving a sealing ring 69 and part of the coupling surface 63 of the second flange 52 radially outward from the recessed part 66 is substantially flat. The shoulder part 64 and the 20 recessed part 66 have dimensions in axial z direction for compressing the sealing ring 69 when the first 51 and the second flange 52 are coupled. The sealing ring 69 provides a fluid tight, i.e. a gas tight coupling of the first 51 and second flange 52.

By aligning the end 38 of the first pipe 35 with the end 65 of the 25 receiving opening 54 of the first flange 51, and by aligning the end 43 of the second pipe 40 with the end 67 of the receiving opening 55 of the second flange 52 and mounting the pipes 35, 40 to a particular flange 51, 52, respectively, the mating shoulder part 64 and recessed part 66 provide that, in the coupled state of the flanges 51, 52, wherein the coupling surfaces of the shoulder part 64 and the 30 recessed part abut, the pipe ends 38 and 43 also abut and align in axial z direction. This provides a single pipe transition 70 at the abutting ends 38, 43 of the first 35 and second pipe 40.

12

Those skilled in the art will appreciate that the coupling surfaces 62 and 63 may be flat over their entire surface or may have any suitable other mating shape. The coupling surfaces 62, 63 may be shaped and dimensioned not to abut when the flanges are coupled, however in such case the pipe ends 38, 43 have to 5 extend beyond the end 65, 67 of their receiving opening 54, 55 to provide a single pipe transition 70 such that the ends 38, 43 of the first 35 and second pipe 40 abut when the flanges are coupled.

The flanges 51, 52 may be coupled by nuts and bolts or the like at 10 part thereof extending in radial r direction outside the outer circumferential surfaces 37, 42 of the pipes 35, 40. In the example shown, each tubular flange 51, 52 at an outer surface 71, 72 thereof opposite their respective abutting coupling surface 62, 63 has a shape which substantially inwardly tapers in axial z direction when viewed in radial outward direction r, i.e. in the direction of their outer edge 73, 74. The 15 flanges 51, 52 are clamped by a substantially V-shaped clamping ring 53 receiving the edges 73, 74 and exerts a clamping force in axial z direction to keep the flanges 51, 52 tightly coupled to each other.

The clamping ring 53 may be formed in a non-closed one piece, and 20 such that in clamped position, the open ends are fastened to each other by a nut and bolt connection or a snapping hook and eye connection, or the like. In another example of the pipe connector, the clamping ring 53 is comprised of two halves, each halve having at each end fastening means for fastening the halves for coupling the flanges 51, 52 in a clamping manner.

25

For mounting the first pipe 35 to the first flange 51, the end 38 of the first pipe 35 is inserted in the receiving opening 54 of the first flange 51, such that the end 38 of the pipe 35 aligns with the end 65 of the receiving opening 54. The first pipe 35, i.e. the part thereof received in the first flange 51, is now stretched by a 30 mechanical force from the inner surface 36 of the pipe in outward radial r direction, such that the mounting grooves 57, 58 of the flange 51 are completely or partly filled by part 75, 76 of the outer circumferential surface 37 of the first pipe 35. This provides a strong pipe/flange mount, as schematically shown in Figure 4, which 13 shows the encircled detail IV of the cross section of the pipes and pipe connector in Figure 3 on an enlarged scale.

In Figure 4, the wall thickness of the pipe is indicated by t, the depth 5 and width of a circumferential groove 57, 58 are indicated by d and w, respectively. The dimensions d, w of a groove 57, 58 are relatively small compared to the pipe wall thickness t, such that a relative small amount of material 75, 76 is received in a groove 57, 58 respectively, thereby maintaining the inner surface 36 of the pipe 35 at the position of the grooves 57, 58 as smooth as possible as a result of the stretching 10 performed.

In a like manner, for mounting the second pipe 40 to the second flange 52, the end 43 of the second pipe 40 is inserted in the receiving opening 55 of the second flange 51, such that the end 43 of the pipe 40 aligns with the end 67 of 15 the receiving opening 55. The second pipe 40, i.e. the part thereof received in the second flange 52, is now stretched by a mechanical force from the inner surface 41 of the pipe in outward radial r direction, such that the mounting grooves 60, 61 of the flange 52 are completely or partly filled by part of the outer circumferential surface 42 of the second pipe 40.

20

For completing the pipe connection, both pipe/flange mounts are coupled to each other by the clamping ring 53 such that the end 38 of the first pipe 35 mounted in the first flange 51 and the end 43 of the second pipe 40 mounted in the second flange 54 abuttingly connect.

25

Figure 5 shows in a schematic, perspective and illustrative manner, not to scale, an example of a rolling unit 80 for use with the method according to the invention. The rolling unit 80 comprises a tubular body 81 having a plurality of circumferentially distributed conically shaped rollers 82 extending in axial z direction 30 of the tubular body 80. The rollers 82 are displaceable in radial r direction of the tubular body 81. The tubular body 81 is supported by a frame 84 and comprises a drive unit 83 for moving the tubular body 80 in axial z direction thereof and for rotating the rollers 82 in circumferential Θ direction of and displacing the rollers in radial r direction of the tubular body 81.

14

In an example, stretching is performed by inserting the rolling unit 80 into a pipe 35, 40 from the end 38, 43 thereof when received in the receiving opening 54, 55 of a flange 51, 52. The rollers 82 of the rolling unit 80 are rotated in 5 circumferential Θ direction of and at the same time pushed against the inner circumferential surface 36, 41 of the respective pipe 35, 40 by a mechanical force directed in outward radial r direction. The diameter of the rollers 82 increases in the direction towards the drive unit 83, i.e. in the direction away from the end of the rollers 82 to be inserted in a pipe.

10

As schematically indicated in Figure 6, which shows a pipe/flange mount comparable to Figure 5, as a result of the stretching operation by the conical rollers 82 of the rolling unit 80, the inner diameter of the first pipe 35 in the vicinity of the grooves 57, 58 slightly increases towards the end 38 of the pipe, i.e a reduced 15 wall thickness t of the pipe.

Although not explicitly shown, as a result of the stretching operation, by the conical rollers 82 of the rolling unit 80, the inner diameter of the second pipe 40 in the vicinity of the grooves 60, 61 slightly increases towards the end 43 of the 20 second pipe 40 in a like manner as shown in Figure 6 with respect to the first pipe 35.

The invention may be practiced otherwise than as specifically described herein, and the above mentioned embodiments and examples are merely 25 intended as an illustration to the skilled reader.

1 03 97 65

Claims

1. Pijpverbinder, omvattende een eerste en tweede buisvormige flens, welke eerste flens een binnenvlak heeft dat een opneemopening vormt voor het opnemen van 5 een einde van een eerste pijp en de tweede flens een binnenvlak heeft dat een opneemopening vormt voor het opnemen van een einde van een met de eerste pijp te verbinden tweede pijp, waarbij elke pijp een buitenomtreksvlak en een binnenomtreksvlak, heeft waarin elke flens ten minste één montage-uitsparing omvat aan het binnenvlak dat de opneemopening vormt, welke ten minste ene montage-uitsparing is ingericht voor het 10 opnemen van een deel van het buitenvlak van een in de opneemopening opgenomen pijp voor het aan de flens monteren van de pijp door het vanaf zijn binnenvlak radiaal rekken van de pijp, en de eerste en tweede flens zijn ingericht om met elkaar te worden gekoppeld zodanig dat het einde van een eerste pijp indien gemonteerd in de eerste flens en het einde van een tweede pijp indien gemonteerd in de tweede flens stotend 15 aansluiten.1. Pipe connector, comprising a first and second tubular flange, which first flange has an inner surface that forms a receiving opening for receiving an end of a first pipe and the second flange has an inner surface that forms a receiving opening for receiving an end of a second pipe to be connected to the first pipe, wherein each pipe has an outer peripheral surface and an inner peripheral surface, wherein each flange comprises at least one mounting recess on the inner surface that forms the receiving opening, which at least one mounting recess is adapted to 10 receiving a part of the outer surface of a pipe received in the receiving opening for mounting the pipe on the flange by radially stretching the pipe from its inner surface, and the first and second flange are adapted to be coupled to each other such that the end of a first pipe when mounted in the first flange and the end of a second pipe when mounted in the second flange Connect up to 15.

2. Pijpverbinder volgens conclusie 1, waarin de ten minste ene montage-uitsparing ten minste één omtreksmontagegroef omvat.The pipe connector of claim 1, wherein the at least one mounting recess comprises at least one peripheral mounting groove.

3. Pijpverbinder volgens conclusie 2, waarin elke flens ten minste twee in axiale richting van de flens uiteengelegen omtreksmontagegroeven omvat.The pipe connector of claim 2, wherein each flange comprises at least two circumferential mounting grooves spaced apart in the axial direction of the flange.

4. Pijpverbinder volgens een van de voorgaande conclusies, waarin de eerste en tweede flens stootkoppelvlakken omvatten, waarbij elk koppelvlak is uitgelijnd met een einde van de opneemopening van een flens, en indien gemonteerd in een flens het einde van een pijp opgelijnd is met het koppelvlak van de flens.A pipe connector according to any one of the preceding claims, wherein the first and second flange comprise abutment coupling surfaces, wherein each coupling surface is aligned with an end of the receiving opening of a flange, and when mounted in a flange the end of a pipe is aligned with the coupling surface of the flange.

5. Pijpverbinder volgens conclusie 4, waarin ten minste één van de 25 stootvlakken een omtreksgroef omvat voor het opnemen van een afdichtring voor het verschaffen van een fluïdumdichte koppeling van de eerste en tweede flens.5. Pipe connector as claimed in claim 4, wherein at least one of the abutment surfaces comprises a circumferential groove for receiving a sealing ring for providing a fluid-tight coupling of the first and second flange.

6. Pijpverbinder volgens conclusie 4 of 5, waarin het stootkoppelvlak van de eerste flens een omtreksschouderdeel omvat opgelijnd met het einde van de opneemopening en de tweede flens een omtreksuitsparingsdeel omvat opgelijnd met het 30 einde van de opneemopening en ingericht om te passen op en voor het op stotende wijze opnemen van het schouderdeel.6. Pipe connector as claimed in claim 4 or 5, wherein the abutment coupling surface of the first flange comprises a circumferential shoulder part aligned with the end of the receiving opening and the second flange comprises a circumferential recess part aligned with the end of the receiving opening and adapted to fit on and in front of the shock absorbing of the shoulder part.

7. Pijpverbinder volgens conclusie 6 en in afhankelijkheid van conclusie 5, waarin een deel van het stootkoppelvlak van de eerste flens voorbij het schouderdeel de 1039765 omtreksgroef voor het opnemen van de afdichtring omvat en een deel van het stootkoppelvlak van de tweede flens voorbij het uitsparingsdeel in hoofdzaak vlak is, waarbij het groefdeel en het in hoofdzaak vlakke deel afmetingen hebben om de afdichtring samen te drukken indien de eerste en tweede flens zijn gekoppeld.Pipe connector according to claim 6 and in dependence on claim 5, wherein a part of the abutment surface of the first flange beyond the shoulder part comprises the circumferential groove for receiving the sealing ring and a part of the abutment surface of the second flange beyond the recess part in is substantially flat, the groove part and the substantially flat part having dimensions to compress the sealing ring when the first and second flange are coupled.

8. Pijpverbinder volgens conclusie 4, 5, 6 of 7, waarin elke buisvormige flens aan een buitenvlak hiervan tegenover het stootkoppelvlak een in hoofdzaak naar binnen afnemende vorm in radiale buitenwaartse richting heeft, en de pijpverbinder een in hoofdzaak V-vormige klemring omvat voor het opnemen van de randen voor het op klemmende wijze koppelen van de flenzen.8. Pipe connector as claimed in claim 4, 5, 6 or 7, wherein each tubular flange has an essentially inwardly decreasing shape in radial outward direction on an outer surface thereof opposite the impact coupling face, and the pipe connector comprises a substantially V-shaped clamping ring for receiving the edges for clampingly connecting the flanges.

9. Pijpverbinder volgens conclusie 8, waarin de klemring twee helften omvat, waarbij elke helft aan elk einde bevestigingsmiddelen heeft voor het bevestigen van de helften voor het op klemmende wijze koppelen van de flenzen.The pipe connector of claim 8, wherein the clamping ring comprises two halves, each half having fastening means at each end for fastening the halves for clampingly connecting the flanges.

10. Werkwijze voor het verbinden van een einde van een eerste pijp met een einde van een tweede pijp door een pijpverbinder omvattende een eerste en tweede 15 buisvormige flens, welke eerste flens een binnenvlak heeft dat een opneemopening vormt voor het opnemen van het einde van de eerste pijp en de tweede flens een binnenvlak heeft dat een opneemopening vormt voor het opnemen van het einde van de met de eerste pijp te verbinden tweede pijp, waarbij elke pijp een buitenomtreksvlak en een binnenomtreksvlak heeft, waarin elke flens ten minste één montage-uitsparing omvat aan 20 het binnenvlak dat de opneemopening vormt, welke werkwijze de stappen omvat van het: - opnemen van een einde van de eerste pijp in de opneemopening van de eerste flens, - monteren van de eerste pijp aan de eerste flens door het vanaf zijn binnenvlak nabij het einde radiaal rekken van de eerste pijp zodanig dat de ten minste 25 ene montage-uitsparing van de eerste pijp een deel opneemt van het buitenvlak van de eerste pijp, - opnemen van een einde van de tweede pijp in de opneemopening van de tweede flens, - monteren van de tweede pijp aan de tweede flens door het vanaf zijn 30 binnenvlak nabij het einde radiaal rekken van de tweede pijp zodanig dat de ten minste ene montage-uitsparing van de tweede pijp een deel opneemt van het buitenvlak van de tweede pijp, en - met elkaar koppelen van de eerste en de tweede gemonteerde flens zodanig dat het in de eerste flens gemonteerde einde van de eerste pijp en het in de tweede flens gemonteerde einde van een tweede pijp stotend aansluiten.10. Method for connecting an end of a first pipe to an end of a second pipe by a pipe connector comprising a first and second tubular flange, which first flange has an inner surface which forms a receiving opening for receiving the end of the first pipe and the second flange has an inner surface which forms a receiving opening for receiving the end of the second pipe to be connected to the first pipe, wherein each pipe has an outer peripheral surface and an inner peripheral surface, wherein each flange comprises at least one mounting recess on the inner surface which forms the receiving opening, which method comprises the steps of: - receiving an end of the first pipe in the receiving opening of the first flange, - mounting the first pipe on the first flange by approaching it from its inner surface radially stretching the first pipe at the end such that the at least one mounting recess of the first pipe receives a portion of the outer surface of the first pipe, - receiving an end of the second pipe in the receiving opening of the second flange, - mounting the second pipe on the second flange by radially stretching the second pipe from its inner surface near the end such that the at least one mounting recess of the second pipe receives a part of the outer surface of the second pipe, and - coupling the first and second mounted flanges together such that the end of the first pipe mounted in the first flange and the end of the first pipe mounted in the second flange-mounted end of a second pipe.

11. Werkwijze volgens conclusie 10, waarin het rekken wordt uitgevoerd door 5 het in de pijp vanaf het in de flens te monteren einde inbrengen van een roleenheid, welke roleenheid een veelheid langs de omtrek verdeeld axiaal draaibare conisch gevormde rollen omvat welke zich in axiale richting van de pijp uitstrekken en welke rollen in radiale richting van de pijp verplaatsbaar zijn, waarin de rollen in omtreksrichting worden geroteerd en tegen het binnenomtreksvlak van de pijp worden gedrukt.11. Method as claimed in claim 10, wherein the stretching is carried out by introducing into the pipe a roller unit from the end to be mounted in the flange, which roller unit comprises a plurality of circumferentially axially rotatable conically shaped rollers which extend in axial direction extend from the pipe and which rollers are movable in radial direction of the pipe, wherein the rollers are rotated in circumferential direction and are pressed against the inner peripheral surface of the pipe.

12. Werkwijze volgens conclusie 10 of 11, waarin het rekken zodanig wordt uitgevoerd dat nabij het einde van de pijp een glad binnenomtreksvlak wordt verkregen.A method according to claim 10 or 11, wherein the stretching is performed such that a smooth inner peripheral surface is obtained near the end of the pipe.

13. Werkwijze volgens conclusie 10, 11 of 12, waarin de eerste en tweede flens stootkoppelvlakken omvatten, waarbij elk koppelvlak met een einde van de opneemopening van een flens is uitgelijnd, waarin een aan een flens te monteren pijp 15 zodanig in de opneemopening van de flens wordt opgenomen dat het einde van de pijp is uitgelijnd met het koppelvlak van de flens.13. Method as claimed in claim 10, 11 or 12, wherein the first and second flange comprise abutment coupling surfaces, wherein each coupling surface is aligned with an end of the receiving opening of a flange, wherein a pipe 15 to be mounted on a flange is positioned in the receiving opening of the flange. flange it is included that the end of the pipe is aligned with the coupling face of the flange.

14. Werkwijze volgens conclusie 10, 11, 12 of 13, waarin de eerste en tweede pijp toevoerpijpen van een transportlijn van een pneumatisch transportsysteem voor gesneden tabak zijn. 20 1039765A method according to claim 10, 11, 12 or 13, wherein the first and second pipes are feed pipes of a conveyor line of a pneumatic conveyor system for cut tobacco. 20 1039765