EP0071273B1 - Method of manufacturing a coiled flexible tube, and coiled flexible tube - Google Patents

Description

The invention relates to a method according to the preamble of claim 1 or to a coiled hose according to the preamble of claim 5.

Such hoses, which are generally manufactured with cross-sectional areas in the order of magnitude of 50 to 100 cm ² , are used for permanent installation in buildings, machines or vehicles as air, exhaust air or exhaust gas ducts. A large number of requirements are placed on these hoses, in particular they should be cheap, that is to say simple to manufacture, but at the same time they should be tensile, reasonably flexible in order to avoid special deflection pieces, and in many cases they should also be flame-retardant or even non-flammable. Furthermore, the hose should be light in weight and easy to lay.

The requirements of flame retardancy or incombustibility can essentially be met by using metal as the hose material. For example, aluminum flat channels are known, which consist of aluminum sheet which is folded into a rectangular tube and is provided with a longitudinal seam seam. Such a rigid pipe is fundamentally inferior to hoses in that it is supplied in certain lengths, causes complex transportation, is difficult and difficult to install with different tools, and the storage of various duct parts such as pipe sections, deflection pieces, transition pieces from round to flat channels etc. required.

There are also known more or less flexible bendable aluminum tubes (e.g. Rigoform tubes), which consist of coiled and corrugated aluminum sheet, the corrugations of which run in the longitudinal direction of the coiled strips and overlap one another in the edge region, as a result of which the cohesion between adjacent coils is established becomes. The corrugations can be stretched or compressed to a certain extent, which enables the laying of curves. However, the corresponding pipes are still relatively stiff, and a strong pull or a strong overextension of the outside of the curve can lead to loosening of the not very tensile connection between adjacent turns

Flame-resistant flexible hoses have also been described (US Pat. No. 2,337,374), in which the hose wall can consist essentially of an impregnated cotton fabric or an asbestos fabric. The successive layers are placed in a single overlap or multiple wrapping around the wire of a metal wire helix and wrapped around the outside with a likewise helical metal clip. This structure is also known without special reference to flame-retardant hoses (US Pat. No. 4,084,309), the circumferential clip being formed from a metal strip which is folded over the edges of the fabric surrounding the wire, whereupon this folding structure is pressed together. The production of these known structures will have to be imagined in such a way that an overlapping area of adjacent turns is formed on the outside of the wire of the wire helix and is then pressed radially inwards via this wire helix, so that the diameter of the fabric tube initially produced is reduced while at the same time outside the metal clip is placed over the overlap area with the wire now enclosed in it. When the overlap area is placed around the wire, tensile forces are exerted on the layers on both sides by reducing the distance between the adjacent wire helix windings and pulling tissue material into the resulting bead. There is therefore a risk of tears forming in the tissue. Hoses made of pure metal foil, which is relatively resistant to tearing, cannot be produced with such structures at all.

The invention has for its object to provide a simultaneously tensile, flexible, easily transportable and relocatable and if necessary with appropriate material design flame retardant or non-combustible hose, the production of which reduces the risk of cracks in the hose material.

According to the invention, the object is achieved by the invention characterized in claim 1. This creates a cohesion of adjacent connections, the production of which does not place high demands on the extensibility of the material, so that the method is particularly suitable for the production of metal foil tubes. Even with relatively easily tearing material such as pure aluminum foil, large lengths of tube can therefore be produced in continuous production, the length of which is at most limited by the fact that the tube coming out of the manufacturing device rotates according to a simpler method of manufacture; a non-rotating hose could also be wound by running a corresponding hose forming head, but this leads to a complicated construction due to the feed of the strips and the connecting tape from the respective supply reels to the rotating forming head.

While using smooth strips to form the windings, the pressure of the five-fold stratification must be very strong in order to produce a material cohesion approximating the pressure welding, it seems preferable, according to claim 2, to make the edges of the strip material on both sides thicker than the remaining surface of the strip material Unfold the shape so that the material of the adjacent turns finds a certain form-fitting hold to each other. If the strip consists of a slightly tearing material, the measure according to claim 3 may be appropriate, which enables the Strip is laid by rotation in the helix, without its free edge being subject to the risk of tearing and fraying. If necessary, the edge area on which the connecting strip is pulled can also be edged in beforehand with a hem tape.

The measure according to claim 4 has the advantage of an improved mutual hold of the material of the adjacent turns.

The method according to the invention is particularly suitable for the production of aluminum tubes in which tensile stress in the material is avoided as far as possible in view of the low tensile strength of the film material. Tin foil and copper foil for the production of completely non-flammable hoses are also suitable as metal foils. However, the method according to the invention can also advantageously be used in the processing of plastic, in particular flame-retardant plastic, and laminated metal foil. The initially circular cross section of the hose produced can be permanently deformed, e.g. B. to a rectangular shape as a flat channel or to a connector that is round on the one hand and rectangular on the other. The corresponding bending of the material does not require a great deal of force and can possibly also be carried out at the construction site.

• Fig. 1 eine schematische perspektivische Draufsicht auf einen aus einem einzigen Streifen und einem einzigen Verbindungsband hergestellten gewendelten Schlauch während der Herstellung;
• Fig. 2 schematische Längsschnitte durch die Materialien der Schlauchwand zur Veranschaulichung aufeinanderfolgender Verfahrensschritte der Herstellung der Verbindung zwischen benachbarten Wendelwindungen;
• Fig. 3 bis 6 schematische Querschnitte durch fertiggestellte Verbindungen verschiedener Konfiguration;
• Fig. 7 eine schematische Darstellung eines Dreh-Antriebsrads bei der Herstellung eines gewendelten Schlauchs von im Vergleich zu Fig. 1 abgewandelter Konstruktion;
• Fig. 8 eine Darstellung entsprechend Fig. 1 für eine etwas abgewandelte Durchführungsform;
• Fig. 9 einen Schnitt in einer Ebene 9-9;
• Fig. 10 einen schematischen Längsschnitt durch die Materialien der nach Fig.8 hergestellten Schlauchwand.

Further details, advantages and developments of the invention result from the subclaims and from the following description of preferred implementation and exemplary embodiments with reference to the drawing. Show it:

• Figure 1 is a schematic top perspective view of a coiled tube made from a single strip and a single connecting band during manufacture;
• 2 shows schematic longitudinal sections through the materials of the hose wall to illustrate successive method steps in the production of the connection between adjacent spiral turns;
• 3 to 6 schematic cross sections through completed connections of different configurations;
• FIG. 7 shows a schematic illustration of a rotary drive wheel in the production of a coiled hose of a construction modified in comparison to FIG. 1;
• 8 shows a representation corresponding to FIG. 1 for a somewhat modified form of implementation;
• 9 shows a section in a plane 9-9;
• 10 shows a schematic longitudinal section through the materials of the tube wall produced according to FIG. 8.

Fig. 1 shows the production of a coiled hose from a single strip to be coiled from a semi-rigid material, for example from 40 mm wide and 0.1 or 0.2 mm thick pure aluminum foil strip made of anodized aluminum, and a connecting strip made of hard aluminum with a width of 15 mm and one Thickness from 0.2 to 0.5 mm. A tube made from these materials without the use of other agents such as adhesive tape or the like is completely non-flammable and is at the same time flexible to a certain extent, since in the event of a bend the film can fold up in the bend in the bend. The number of folds is of course not very high, but such hoses, for example with a diameter of 10 cm, are generally installed once, the required bends being made, and then remain in this position for the rest of their use.

Pure aluminum foil of 0.1 or 0.2 mm thickness fulfills these requirements for flexibility with simultaneous bending stiffness, which is necessary for the cohesion of the adjacent turns. However, other metal foils of comparable stiffness and flexibility can also be used for the production of non-combustible hoses and comparable plastic foils can also be used for the production of hoses, the flammability of which does not matter.

A corresponding metal foil strip 1 is fed according to a direction of movement 2 to a spiral guide (not shown in detail) of a known type which deflects the strip 1 onto a circular path with a longitudinal component, that is to say a helical path. Before the guide is reached, edge beads 4 of the strip 1 are formed in an edge bead station 3 by turning the edge over on both sides. To achieve this effect, the edge bead station shown consists of a number of pressure rollers, some of which are driven rollers and some of which are rollers. Specifically, the strip 1 runs between two guide rollers 5, of which only the upper one is visible, while at its edges two pressure rollers 6 which set up these edges engage with their conical end face. Subsequent pressure rollers 7 fold the folded hems back down onto strip 1. In this form, the strip 1 is connected to an already produced piece of hose 8, which consists of the previous length of the strip 1, which is already wound into a spiral rotating in the direction of an arrow 9, with the aid of a connecting band 10.

After leaving the edge bead station 3, the connecting strip 10 is fed to the strip 1, in the example described in a plane perpendicular to the plane of the strip 1. This connecting band 10 first runs through a roughening station 11 and is then folded in a folding station 12 around one of the edges of the strip 1, in the example described around that edge which, when the strip 1 is later connected to the already existing tube piece 8, form its first free end becomes. In the example described, the folding takes place in such a way that approximately one third of the connecting band 10 lies on the underside, while the double width, namely two thirds of the width of the connecting band 10, runs along the upper side of the metal foil strip 1, onto which the edge bead 4 was also folded. The folding leg arranged on the underside is denoted by 13, the one running on the top is denoted overall by 14. The folding station 12 in turn already divides the folding leg 14 into two halves 15 and 16, of which the folding leg half 16 is bent slightly outwardly so that it can be gripped more easily in a later station. The arrangement of the various pressure rollers which form the folding station 12 is not difficult for the person skilled in the art after the folding program has been presented.

The station 12 is shown in the course of the supply of the strip 1 to the tube piece 8, but it could also lie on the free front edge thereof. Likewise, if the function is essentially the same, it is possible for the station to engage on the opposite edge of the strip 1 and / or for the width ratio of the folding legs 13 and 14 to be reversed.

The strip 1 is now connected to the already existing hose section 8 as the foremost turn, in that the edge of the strip 1 not shown with the connecting strip 10, shown on the right in the strip 1 in FIG. 1, with a certain overlap area on the inside to the previously free edge the last turn of the strip 1 in the tube piece 8. This edge is the one that has been folded over a certain length beforehand with the connecting strip 10, the folding leg half 16 projecting inwards. The kink between the folding leg halves 15 and 16 abruptly represents the limit of the overlap between the strip material of the successive turns. The tangential approach and application of the material of the following strip 1 on the inside takes place according to FIG. 1 at a location 17 hidden by the upper tube wall.

In a closing station 19 that follows, the folding leg half 16 is folded around the edge of the strip, which has laid itself in the angle between the folding leg halves 15 and 16, and the stratification 13-1,4-15-1,4-16 thus created becomes broad or pressed together along lines. A line pressure can cause the edge beads 4 not to be completely flat-rolled, but to press the connecting band 10 sufficiently firmly onto the material of the strip 1 to give a firm connection between the successive turns.

In the event that the folding station 12 is in comparison to the embodiment according to FIG. 1 on the opposite edge of the strip 1, this is applied to the last turn so that its free edge is in the angle between the folding leg halves 15 and 16 on the incoming strip sets. This can be particularly advantageous if the intended overlap is relatively large and thus the folding leg 16 is wide, since in this case the station 19 can be provided immediately at the point 17 when the strip 1 enters the tube rotation and it does so in terms of inside or outside protruding folding leg half 16 are no difficulties which can arise in the circular arrangement due to tensile or compressive stresses in this leg due to the changed diameter compared to the hose jacket surface.

1 shows station 19 only a distance far after the winding overlap has been established. In fact, this station 19 is expediently arranged directly at the meeting point 17 even with the connecting band 10 running around the end of the hose section.

Fig. 2 shows successive processing steps in the manufacture of the hose. In a stage a, the strip 1 and the connecting band 10 are still immediately in the state in which they were unwound from the respective supply spools. In stage b, the strip 1 is already provided with edge beads 4 and the connecting band 11 is already in the state of being folded, the kink between the folding legs 13 and 14 being already visible. Stage c shows the folding leg 14 again divided into its folding leg halves 15 and 16 by a kink. In stage d the free edge of the incoming strip 1 or the end turn of the tube piece 8 already produced is placed on the folding leg half 15, and in stage e the folding leg half 16 is in turn folded down onto this edge of the strip 1.

FIG. 3 shows a schematic representation of the connection location of adjacent turns in a representation similar to FIG. 2e, wherein arrows 21 also indicate pressing directions. In Fig. 3, the strips 1 are not provided with edge beads 4, the pressure according to the arrows 21 must be very strong here in order to achieve a firm connection of the materials.

4, the edge beads 4 are present. The pressing (arrows 21) takes place along a line parallel to the edge beads, as a result of which the cross-sectionally approximately S-shaped configuration of the connecting band 10 has a compressed strip in the central region, the thickness of which is practically the sum of the thicknesses of the material layers.

Fig. 5 shows another form of edge processing of the strip 1. This is a bending of the edge or a flanging. With a pressing in the region of this bend or this flanging, the result is that the bent edge of the strip 1 hooks onto the connecting band 10.

6 finally illustrates a modified edge bead formation, namely on both sides in a different direction.

FIG. 7 shows the closing station 19 in a schematic cross section for the case of a hose constructed from two flexible strips, in which an inner spiral and an outer spiral alternate. The station 19 extends over two pressing points at a distance of one spiral step, which, using rollers, presses the helically running connecting lines between the strip material of successive turns in two steps Perform ten, of which the first essentially folds over the folding leg half 16 and the second carries out the pressing along two lines.

8, the edge that lies opposite the edge covered with the connecting band 10 is bordered by a special seam band 25. The seam band 25 is a thin film strip, which is first brought up in a plane perpendicular to the feed plane of the strip 1 and is bent around the edge of the strip 1. The strip edge is thus well protected and does not tend to fray, even if the thin metal foil tears easily. At the connecting rib running in a screw line around the finished hose, the material is thus in seven layers, since in addition to the five layers described earlier, the two layers formed by the U-legs of the hem band 25 are added. In a manner not shown, the opposite edge could also be hemmed analogously before the connecting strip is put on, in particular if the connecting strip is only applied after a certain circumferential angle in the screw area.

In the spiral guide (FIG. 1), in the area of the first turn or the first turns of the tube piece 8, the strip material is guided through a plurality of guides arranged in a circle in order to carry out its concentricity. The piece of hose 8 runs on a guide bed in the direction of an arrow 22 in accordance with the production speed and later becomes a rectangular cross section by spinning rollers 23, of which a pair or several pairs with axes are arranged tangentially to the piece of hose 8 in two mutually perpendicular directions pressed to be usable for a fire-proof flat duct ventilation system. The pressure rollers 23 can also act on the hose in a separate operation after the hose produced has been separated from the helical guide according to FIG. 1, in order to avoid constructive difficulties which result from the rotation of the hose about its longitudinal axis during its winding. If the tube produced is pushed only a little way through the pairs of pressure rollers 23, a transition piece is created between the round and flat channels.

As a further supplementary processing of the hose produced, it can also be perforated on the side and changed with a throat, creating a branch piece. The materials described for the aluminum foil strip and the aluminum connecting tape can be knurled out and expanded without great difficulty like a homogeneous film tube wall.

Claims (6)

1. Process for manufacturing a strip-wound hose comprising the steps of:

placing at least on foil strip (1) in a helical form with turns thereof placed one after the other, said at least one strip being supplied from a supply of strip to a piece (8) of strip-wound hose, produced at an earlier time and turning about the longitudinal axis thereof, an joining said strip to said piece of hose for increasing length of same, the strip material of adjacent turns being made to mutually overlap along the margins and the adjacent turns along these margins being joined together upon supplying a connection band (10) so as to give a mechanical connection between one such turn and the next turn thereto, said supplied connection band, upon being folded, being so placed that at the position of such overlap it engages said margin zones for fixing the overlapping margin zone in relation to the other of said overlapping margin zones, characterized by the following consecutive steps of:

a) folding the connection band (10) about one of the lengthways edges of said strip (1) supplied for joining to said produced piece of hose in such a way that a fold leg (14) of the connection band on an upper side and a fold leg (13) on a lower side of the strip is moved along with the strip for forming a three-layer structure made up of the one layer of the strip material between two layers of the connection band,

b) placing the margin zone that is to be overlapped ot the strip on a free margin zone of the end turn of the piece (8) of hose produced earlier in such a way that one of the two materials selected from: said strip and said end turn, is placed on one (14) of the fold legs of the connection band (10) that is seated on the other of said materials, over part (15) of the breadth of this fold leg, which placing is carried out at the beginning of, or during bending to become round, of the strip (1), and of or during the overlapping placement of the strip material of the end turn upon forming of the next turn, whereafter part of the length (16) of this fold leg (14), that thus is partly covered over, is kept uncovered and on such covered part (15) of the connection band (10) there is a four-layer structure, that is made up of the connection band, strip material of the one turn, connection band and strip material of the next turn,

c) the uncovered part (16) of the fold leg (14) is folded down about the lengthways edge of the placed strip material, such folding taking place so that said uncovered part is placed on said strip material with the production of a five-layer structure made up of the connection band, strip material of one turn, connection band, strip material of the next turn and connection band,

d) this five-layer structure so produced is acted upon by a pressing force in a direction normal to the plane of the strip material and the material of the connection band for the purpose of producing a strong connection structure of the materials.

2. The process as claimed in claim 1, characterized in that before bending the connection band (10) about the strip margins the same are bent upwardly.

3. The process as claimed in claim 1 or 2, characterized in that that margin zone of the strip (1) that is opposite to the connection band (10) fixed on the strip, is covered with an edging tape (25) before the strip has started moving in a helical path.

4. The process as claimed in any of claims 1 to 3, characterized in that the surface of the connection band 610) and/or the surface of the edging tape (25) is beforehand roughened in zones (at 11) in which it is to come into contact with the material of the strip (1).

5. A strip-wound hose made up of at least one metal foil strip (1) placed in turns, said foil strip turns overlapping with the adjacent turns and with a connection band (10) along a margin zone, characterized in that said strip or strips (1) has bend zones (4) along the margins thereof, said bend zones being turned up out of the general plane of said strip, the overlapping margin zones being tucked from opposite sides into pockets formed at both sides of said connection band (10) which is wound together with the strip and is placed about the margin zones thereof in a S-like configuration in a lengthways section of the hose, said connection band together with the tucked-in margin zones having been pressed in a radial direction with respect to the hose along lines running in the round-the-hose direction.

6. The hose as claimed in claim 5, characterized in that an edging tape (25) of U-like cross section is placed on one of the margin zones of said strip (1), said margin zone being taken up in one of said pockets of said connection band.

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