WO1998029230A1

WO1998029230A1 - Method and device for producing branched pipes or sheaths by extrusion, and pipes or sheaths resulting from the implementation

Info

Publication number: WO1998029230A1
Application number: PCT/FR1998/000002
Authority: WO
Inventors: Michel Flandin
Original assignee: Fm Plastics (S.A.R.L.)
Priority date: 1997-01-03
Filing date: 1998-01-02
Publication date: 1998-07-09
Also published as: AU5868198A; FR2758107A1

Abstract

The invention concerns the production, by extrusion, of branched pipes or sheaths, characterised in that, at the delivery of the die (2) of an extruder tube head, is arranged a second retractable die made up of at least two mobile parts (9A, 9B) capable of being mutually brought closer or spaced, and in that in said tube head is installed a main mandrel rod (7) with at least two dividing mandrel rods (8a, 8b) in parallel out of the main die (2) from the end of said main mandrel rod (7), said mobile parts (9A, 9B) of the supplementary die being shaped such that their being brought closer brings about a division of the cross section of the main die (2) delivery constituting two supplementary dies (10A, 10B) around the dividing mandrel rods (8a, 8b) enabling the simultaneous extrusion of two tubes (T2, T3) whereas the spacing of said mobile parts (9A, 9B) of the supplementary die eliminates the division of the cross section of the main die (2) delivery and enables the extrusion of a single tube (T1).

Description

Method and device for the execution by extrusion of branched pipes or sheaths, and the pipes or sheaths resulting from their use.

The present invention relates to a device and method for the extrusion of pipes, tubes or sheaths, provided with at least two branches or branches. It also relates to branched, flexible or rigid pipes, tubes or sheaths obtained by the use of these devices and methods, such as, for example: - flexible pipes for transporting various fluids, liquid or gaseous, or even powdery, either to route them to two or more points of use from a single supply source, or to mix products from two or more than two in a single distribution pipe sources;

- sheaths of electric cables;

- optical fiber sheaths, etc.

The conventional extrusion processes and extruders used for working with plastics make it possible to produce either a single tube or two tubes simultaneously (bi -ext rus i on but do not allow continuous production of this that is to say without stopping production or the extrusion cycle, pipes comprising two or more than two subdivisions, or conversely two pipes or more than two pipes merging into a single pipe of larger diameter.

Up to now, the realization of circuits of the aforementioned type is therefore obtained by connecting a main pipe, by means of a suitable connection, for example of the connection tee type, to two or more of two branch tubes, the these components are assembled in different ways ⁽ press fitting, screwing, gluing, etc.).

Generally, these assemblies are carried out by installers or users, so that the situation described above leads to many drawbacks, such as: - for manufacturers:

- the manufacture, by means of different molding machines, of the components of the circuits (main pipe and secondary pipes, on the one hand, and fittings, on the other hand), which lengthens the manufacturing times and increases the importance of necessary investments;

- separate storage of these different components, which complicates interventions related to this storage and the shipment of said components to resellers or users;

- for Users:

- a relatively high cost;

- problems of separate storage of components; - a time devoted to the correct and safe assembly of these components for the realization of a circuit. Similar difficulties are encountered in the sheathing of two or more of two electrical cables, or of two or more of two optical fibers, which must be enclosed in a common sheath over a portion of their length and in an individual sheath over their remaining portion.

The subject of the invention is therefore in particular a method and a device making it possible to produce, continuously, without stopping production or the extrusion cycle, branched pipes which may have various shapes, sections, thicknesses and lengths.

According to the invention, this object is achieved by a process in which there is, at the outlet of the die of the tube head of an extruder, a second erasable die consisting of at least two movable parts capable of being brought together or spaced from each other, and in that one installs in said tube head a main punch having at least two dividing punches extending parallel out of the main die from the end of said punch main, said movable parts of the additional die being shaped so that their bringing together creates a division of the exit section of the main die by constituting two additional die around the dividing punches, allowing the simultaneous extrusion of two tubes, while the separation of said movable parts of the additional die allows remove the division of the outlet section of the main die and the extrusion of a single tube.

The tube head according to the invention is remarkable in that it comprises: - on the one hand, a second die arranged, in an erasable manner, at the outlet of the main die of said tube head, this additional die being constituted at least two movable parts capable of being moved towards or away from each other, said movable parts being shaped so as to create, in the approached position, a division of the outlet section of the main die and to form at least two dividing dies, and, - on the other hand, a main punch having at least two dividing punches extending, in parallel, out of the main die, from the end of said main punch.

The implementation of the method and of the device according to the invention makes it possible to produce, continuously and alternately, a monotube of any shape, size or thickness, with a chosen length and, then, without stopping production or continuous extrusion cycle of multi-tubes of any shape, size and thickness, identical or different from each other, with a chosen length, said monotube and said bitubes being connected in continuity, without the use of fittings.

It is understood that it is thus possible to manufacture, quickly and very economically, branched pipes or tubes, flexible, semi-rigid or rigid and having characteristics of shapes, dimensions, thicknesses and varied lengths, which simplifies the problems. raw material supply, - H -

manufacturing, storage, shipping and assembly.

It is also possible to sheath two or more of two electric cables or two or more of two optical fibers in a common envelope over a portion of their length and in individual envelopes over their remaining portion.

The aims, characteristics and advantages above and still others will emerge more clearly from the description which follows and from the appended drawings in which: FIG. 1 is a view in longitudinal section of the tube head produced according to the invention, the additional sector is shown in functional position.

Figure 2 is a sectional view along line 2-2 of Figure 1. Figure 3 is a view similar to Figure 1 and showing the additional die in the erased inactive position.

Figure 4 is a view similar to Figure 3 and showing the molding of a monotube. Figure 5 is a sectional view along line 5-5 of the figure.

Figure 6 is a view similar to Figure 2 and showing the simultaneous molding of two tubes.

Figure 7 is a sectional view along line 7-7 of Figure 6.

Figure 8 is a view similar to Figure 6 and showing the extrusion of a monotube following a bitube and in a situation of continuity with the latter.

FIG. 9 is a detail view, on a larger scale, and along the line 9-9 of FIG. 8.

Figure 10 is a detail view, on a larger scale and along line 10-10 of Figure 4.

Figure 11 is a front view of one of the movable parts of the additional multi outlet die. Figure 12 is a sectional view along line 12-12 of Figure 11.

Figure 13 is a partial view in cross section illustrating the distribution chamber formed in the internal face of the mobile parts of the additional die mu 11 i -so rt ie.

Figure 14 is a partial view illustrating the distal end of the punch. Figure 15 is a plan view of Figure 14.

Reference is made to said drawings to describe an interesting example, although in no way limiting, of implementation of the method and production of the extrusion device according to the invention. This device, consisting of a tube head, for example of the "straight head" type or of the "square head" type, can be installed at the outlet of an extruder such as, for example, single-screw extruder, double- screw, multi-screw extruder, or the like, of which it is not necessary to describe the various organs and the operation which are well known to those skilled in the art, familiar with the work of plastics.

Is shown in the drawings, the extrusion head body 1, the main die 2, the fixing flange 3 of the die 2 on said body 1, the e-punch por 4 fixedly mounted, in a manner known per se , inside the body 1.

The longitudinal axes 5 show the locations of the screws ensuring the blocking of the main die 2 in the axial direction, while the radial axes 6 show the locations of the pressure screws ensuring the centering of said die.

According to a characteristic arrangement of the invention, the internal member of the extrusion head consists of a main punch 7 attached to the punch holder 4 via its proximal end (considering the direction of advance of the plastic) and at least two spaced dividing punches 8a, 8b extending parallel in longitudinal direction, from the distal end of said main punch 7.

The main punch 7 is housed inside the main die 2, while the dividing punches 8a, 8b extend out of said die, in the direction of outside.

According to another characteristic arrangement of the invention, a second die 9A-9B is disposed at the outlet of the main die 2. This additional die consists of at least two movable parts 9A, 9B, capable of being brought closer or apart l 'from one another, said parts being shaped so as to create, in the approaching and joining position, a division of the outlet section of the main die and to form at least two dividing dies 10A, 10B.

The two movable parts 9A, 9B of the erasable multi-die can advantageously be identical, as illustrated in the drawings.

According to the example illustrated, an erasable multi-thread is shown consisting of a two-thread allowing the simultaneous extrusion of two tubes T1, T2, but it is emphasized that the moving parts 9A, 9B could be shaped so as to constitute when they are joined, more than two dividing dies, for example three or more dividing dies, the punch assembly comprising, of course, in this case, a corresponding number of dividing punches.

According to the example shown, the outlet section of the assembly: main die 2-main punch 7 has an oblong shape, while the outlet section of the divider die assemblies 10A, 10B-divider punches 8a, 8b is circular. It is obvious, however, that these outlet sections could have other shapes, while the outlet sections of the multi-die may be identical or not.

The outlet end 2a of the main die 2 and the internal face of the movable parts 9A, 9B of the multi-thread 9A-9B are arranged in a complementary manner, so as to allow precise guidance of said movable parts, when they move closer together. or erasure.

For example, the distal end 2a of the main die 2 has laterally guide surfaces opposite parallels 11, oriented perpendicular to the axis of said die. On the other hand, the mobile parts 9A, 9B have in their flat internal face applied against the external face 2b of the distal end 2a of the main die 2, a recess 12 opening onto the junction edge of said mobile parts, said recess ent being delimited, laterally, by parallel guide surfaces 13. The distance separating the guide surfaces 11 from the distal end of the main die is substantially equal to the distance separating the guide surfaces 13 from the moving parts 9A, 9B, so that the latter can slide without excessive play, on said distal end.

Means are provided for holding the flat bottom 12a of the recess 12 of the movable parts 9A, 9B, pressed against the outer flat face 2b of the distal end 2a of the main die 2.

These means are, for example, constituted by oblong slots 14 opening into the bottom of the recess 12 of the movable parts 9A, 9B, the major axis of these oblong slots being oriented perpendicular to the junction edge 9a of said movable portions. Screws shown by the axis lines 15, which are screwed into longitudinal threads provided in the main die and passing through the oblong slots 14 allow the movable parts 9A, 9B to be pressed against the main die, while allowing the reciprocating movements and of law of said moving parts.

The alternating movement of the mobile parts 9A, 9B of the multi-die 10A-10B can be ensured by hydraulic, pneumatic, mechanical, or electromechanical devices, such as, for example, small jacks ⁽ shown by the centerlines and arrows 16), these devices being able to be controlled manually or by automatic progr am ab.

The jacks 16 or other devices ensuring the translational movements of the mobile parts 9A, 9B of the multi-die 10A-10B can be made integral with these last by screwing, said by ies mo iles comprising, in their central part, a blind thread 17 opening in their edge 9b parallel to their junction edge 9a, this thread being oriented perpendicular to said edge. This method of assembly and the fixing of the mobile parts 9A, 9B on the die 2 by means of the screws 15, allow a removable mounting of said mobile parts on the extrusion head.

It is thus possible to replace, conveniently and quickly, a multi-die by another having, for example, a different extrusion profile.

The joining edges 9a of the movable parts 9A, 9B of the additional multi-die, have notches 10a, 10b separated by a dividing wall 18 and arranged symmetrically, so that when said edges are in contact, circumscribed openings are obtained constituting the dividing threads 10A, 10B of said multi-die, in the center of which the dividing punches 8a, 8b are placed, respectively. The joining edge 9a of each movable part 9A, 9B, may include a tooth 20 and a cavity 21 with sloping surfaces, arranged on either side of the notches 10a, 10b, so as to cooperate with the cavity and the tooth, respectively, of the other movable part, in order to perfect the centering of said movable parts, at their junction. A plastic distribution chamber is provided between the outlet section of the main die 2 and the inlet of the di ous dies 10A, 10B of the multi-die. For example, the dividing wall 18 is shaped so that a space 19 is formed between its internal edge and the part 7a of the end of the main punch 7 which is between the dividing punches 8a, 8b. For this purpose, the internal edge of the dividing wall 18 has a concave surface 18a, while the edge of the part 7a is tapered, and is placed at a distance from the concavity 18a of the wall 18, so that the space 19 constitutes a distribution chamber upstream of the dies 10A, 10B of the multi-die. It is understood that when the multi-die is open in the standby position (movable parts 9A, 9B distant from one another), the outlet section of the extrusion head corresponds to The outlet section of the assembly: main punch 7-main die 2, so that only this assembly works and produces a single tube or monotube T1 (Figures 4, 5 and 10).

On the other hand, when the multi-die is closed in the working position (mobile parts 9A, 9B placed in contact with one another), the exit section of the extrusion head is formed by the exit sections of the assemblies: divider punches 8a, 8b - divider dies 10A, 10B, so that two tubes T2, T3 or bitubes, are extruded simultaneously ⁽ Figures 6, 7 and 9). It is thus possible to manufacture, continuously and alternately, a tube or monotube T1 of any shape, size, thickness, or length and, then, without stopping the production or the extrusion cycle, two or more than two tubes or bitubes T2, T3, ..., which can have various shapes, dimensions, thicknesses and lengths, and so on, the monotubes T 1 and the successive bitubes T2, T3 communicating with each other.

The product leaving the extrusion head is cut to form branched tubes or pipes, depending on the destination of the latter which also fall within the scope of the present invention.

It is understood that the device and the method of the invention make it possible to manufacture flexible, semi-rigid or rigid pipes, using any material which can be brought into a viscosity state allowing them to be shaped by extrusion, such as Most thermoplastic materials.

In the description and claims of this patent application, the words "tubes" and "pipes" should be considered as the equivalent of the term

"sheath", because, as indicated previously, the method and the device of the invention can be implemented to carry out the sheathing of two or more of two cables electrical or two or more of two optical fibers to be enclosed in a common sheath over a portion of their length and in individual sheaths on their rest portion. More generally, still, the method and the device according to the invention can be used to carry out the sheathing, continuously, of conduits, electrical conductors, optical fibers or other filiform product, of similar or different nature, which must be contained in a common sheath over a portion of their length and in individual sheaths over their remaining portion, such as, for example:

- air ducts;

- water pipes; - the electric cables ;

- light guides (optical fibers)

- etc.

For this, the main punch 7 and, above all, the dividing punches 8a, 8b are provided with aial channels for the passage and movement of conduits, electrical cables, optical fibers or the like, and these are cut from a reel or other feed systems, mounted on the extrusion machine, through said channels, at the same time as the common sheath T1 or individual sheaths T2, T3, of plastic material is extruded.

Claims

1. - Process for the execution, by extrusion, of branched pipes or sheaths, characterized in that there is, at the outlet of the die ⁽ 2) of the tube head of an extruder, a second erasable die consisting of at least two movable parts ⁽ 9A, 9B) able to be brought close or apart from each other, and in that one installs, in said tube head a main punch (7) having at least two dividing punches (8a, 8b) extending parallel out of the main die (2) from the end of said main punch (7), said movable parts ⁽ 9A, 9B) of the additional die being shaped so that Their bringing together creates a di ision of the exit section of the main die (2) by constituting two additional threads (10A, 10B) around the dividing punches (8a, 8b), allowing the simultaneous extrusion of two tubes ( T2, T3), while the spacing of said movable parts (9A, 9B ) of the additional die eliminates the division of the outlet section of the main die (2) and the extrusion of a single tube (T1).

2. - Method according to claim 1, used for the continuous sheathing of at least two filiform elements, of similar nature or not, such as, for example, air conduits, water conduits, electric cables, optical fibers , to be enclosed in a common sheath over a portion of their length and in individual sheaths on their remaining portion, characterized in that the latter are passed through axial channels formed in the dividing punches (8a, 8b) at the same time as the extrusion of the common sheath (T1) or of the individual sheaths (T2, T3) of plastic material is carried out.

3. - Device for the execution, by extrusion, of branched pipes or sheaths, comprising a tube head consisting of a punch (7) and a die (2), characterized in that Said tube head also includes:

- On the one hand, a second die disposed, in an erasable manner, at the exit of the main die from said tube head, this additional die consisting of at least two movable parts (9A, 9B) capable of being brought together or distant from each other, said movable parts (9A, 9B) being shaped so as to create, in the approaching position, a division of the outlet section of the main die (2b) and to form at least two die dividers (10A, 10B), and,

- On the other hand, at least two dividing punches (8a, 8b) extending, in parallel, out of the main die (2) from the end of said main punch (7).

4. - Device according to claim 3, characterized in that the end (2a) of the main die (2) and the internal face of the movable parts (9A, 9B) of the multi-thread (10A-10B) are arranged so complementary, so as to allow the latter to be guided during their moving in and out.

5. - Disposi if according to one of claims 3 or 4, characterized in that the extrusion head comprises means (14, 15) for pressing the movable parts (9A, 9B) of the multi-thread (10A-10B ) against The outer flat face (2b) of the outlet end (2a) of the main die (2).

6. - Device according to any one of claims 3 to 5, characterized in that it comprises means (16) ensuring the movements of approximation and é é gment of the moving parts (9A, 9B) of the multi-die ( 10A-10B), these means being, for example, constituted by jacks (16) connecting said movable parts (9A, 9B) to a fixed member (3) of the extrusion head.

7. - Device according to any one of claims 3 to 6, characterized in that the movable parts (9A, 9B) of the multi-thread (10A, 10B) are removably mounted on the extrusion head.

8. - Device according to any one of claims 3 to 7, characterized in that a distribution chamber (19) is formed between the outlet section of the main die (2) and the entries of the d-sighting dies (10A , 10B) of the multi-thread (10A-10B).

9. - Device according to claim 8, characterized in that the notches (10a, 10b) constituting the dividing dies When the movable parts (9A, 9B) of the multi-thread are brought together in the junction position, are separated by a wall (18 ) whose internal edge has a concave surface (18a), and in that the edge of the part (7a) of the end of the main piston (7) comprised between the dividing punches (8a, 8b) has a tapered profile and is located at a distance from the concave surface (18a) of said wall (18).

10. - Device according to any one of claims 3 to 9, characterized in that the joining edge (9a) of each movable part (9A, 9B) of the multi-die (10A-10B) comprises a tooth (20) and a cavity (21) with sloping surfaces, arranged on either side of the notches (10a, 10b) formed in said junction edge, so as to cooperate with the cavity and the tooth, respectively, of the other movable part, in order to perfect the centering of said mobile parts (9A, 9B) during their junction.

11. - Device according to any one of claims 3 to 10, for the sheathing of at least two filiform elements, of similar nature or not, such as, for example, water conduits, air conduits, electric cables , optical fibers, to be enclosed in a common sheath (T1) over a portion of their length and in individual sheaths (T2, T3) on their remaining portion, characterized in that the dividing punches (8a, 8b) are provided with axial channels for the passage and movement of said elements

12. - Branched pipe or sheath, having a monotube (T1) and at least two bitubes (T2, T3) or branches, characterized in that it is obtained by the implementation of the method according to claim 1, or obtained by the implementation of the device according to any one of claims 3 to 11.