NZ617568B2 - Flexible plastic hose and method for its manufacture - Google Patents

Abstract

Disclosed is a flexible plastic hose comprising a flexible wall made out of a plurality of laterally connected windings of a helically wound profile. The profile comprises a web part (7) with predetermined properties for providing flexibility to the hose, an upright part (61, 81) on both sides of the profile and a horizontal leg (62, 82) that extends in line with the web part and in the direction of the adjacent winding. The windings of the profile are attached to each other by means of a weld (9) located between the upright parts (61, 81) of the adjacent windings. Together, these upright parts form a helical reinforcement rib on the flexible wall of the hose with predetermined properties for providing hub strength to the hose, such that the hose is resistant to buckling, when bent, and will return to its original shape in absence of a compressive force. e profile and a horizontal leg (62, 82) that extends in line with the web part and in the direction of the adjacent winding. The windings of the profile are attached to each other by means of a weld (9) located between the upright parts (61, 81) of the adjacent windings. Together, these upright parts form a helical reinforcement rib on the flexible wall of the hose with predetermined properties for providing hub strength to the hose, such that the hose is resistant to buckling, when bent, and will return to its original shape in absence of a compressive force.

Description

Flexible plastic hose and method of cturing same Technical field This invention s to a le plastic hose comprising a flexible wall made out of a plurality of laterally connected windings of a lly wound profile.

This ion also relates to a method of manufacturing the flexible plastic hose.

Prior art US 3,910,808 describes a method to wind an extruded profile into a flexible hose which can be used for medical applications.

US 4,375,381 describes a method wherein a U—shaped profile is being wound up. The U-shaped profile is helically welded to a second hot ed profile, which is positioned on top of the end of the upright legs of two parallel profile windings.

These methods have as foremost disadvantage that the profiles need to be wound when hot, such that the axial production rate is fairly low (up to 1 — 1.5 Description of the invention lt is an object of the invention to provide a hose that can be produced at a higher production rate, or to at least provide the public with a useful choice.

This object can be reached according to the ion by means of a hose which shows all the features of the first independent claim. it is also an object of the invention to provide a method for manufacturing the hose by means of helically winding a profile, with which a higher production rate can be attained.

This object can be reached according to the invention with a method which shows all of the steps of the second independent claim.

The invention concerns a flexible plastic hose comprising a flexible wall made out of a plurality of laterally ted windings of a helically wound profile, wherein the windings of the profile are attached to each other by means of a weld, wherein the profile comprises a web part with predetermined properties for providing flexibility to the hose, and n the profile ends on both sides in an upright part. The upright parts are provided, on both sides of the e, with a horizontal leg that s in line with the web part and in the direction of the adjacent winding. The weld is located between the upright parts of nt gs and together with these upright parts forms a helical reinforcement rib on the flexible wall of the hose with predetermined properties for providing a given hub strength to the hose This means that the rib ensures that, when the hose is bent, it will not buckle, and when compressed, the hose will return to its original shape in absence of the compressive force.

The invention further concerns a method for manufacturing a flexible plastic hose, comprising the following steps: extruding a plastic profile containing a web part with predetermined properties for providing flexibility to the hose, and which ends on both sides in an upright part, helicaliy winding the profile, wherein the windings of the profile are attached to each other by means of a weld, for forming a flexible wall of the hose, wherein the upright parts are provided, on both sides of the profile, with a horizontal leg that extends in line with the web part and in the direction of the adjacent winding, and the weld is applied between the upright parts of the adjacent windings of the profile, in such a way that the weid forms, together with the upright parts, a helical rcement rib on the flexible wall of the hose with predetermined properties for providing hub strength to the hose.

Hoses of the type that have a web part alternating with a rib part are already known, as well as the predetermined properties that the web part and rib part heed to have in order to obtain the desired flexibility and hub strength.

Hence, these ermined properties require herein no further explanation.

With the hose according to the invention, it is possible to obtain higher production rates, because the extruded profile can be cooled before the helical g and hence, no extra cooling is required during or after the helical winding of the e for forming the le wall of the hose. The hot g material wili be placed n the upright parts of the adjacent profiles. The upright parts move along the weld which therefore does not come in contact with the tooling of the production facility. As a result, an axial production rate of for example 5 m/min can be obtained. Also, it turns out that the profile of the hose according to the invention shows the surprising effect that hoses can be produced with smaller internal diameters (for example 19 mm or smaller) than with the prior art profiies.

Also, it turns out that the profile of the hose according to the invention shows the surprising effect that the total weight of the hose can be reduced.

Also, it is le with the profile of the hose according to the invention to make hoses of which the inside is substantially smooth, that is to say that there are almost no ridges or s that will open up when the hose is bent or pulled and in which dirt ofthe medium transported through the hose can accumulate.

In preferred embodiments of the hose ing to the invention, the upright parts on one side or on both sides of the profile are provided with a horizontal leg. which extends in line with the web part and in the direction of the adjacent winding. These horizontal legs form spacers which creates a weil~defined area n the upright parts, provided for orating the weld.

In preferred embodiments of the hose according to the ion, the t parts are folded towards each other at the top, in such a way that they substantially completely enclose the weld. ably, the folding of the up- right parts occurs in the production process after the application of the weld- ing material. However, the upright parts can also be formed in this manner in the extrusion step. in preferred embodiments of the hose according to the invention, the upright parts comprise protrusions directed towards the adjacent winding in such a way that these protrusions overlap. These protrusions ensure a larger contact area between the welding material and the profile windings, in such a way that the connection of two adjacent gs by means of the weld can be reinforced.

In preferred embodiments of the invention, one or more electrical con- ductors/cables are incorporated into the rib part (in the upright parts, in the weld or between upright parts and the weld) and/or the web part. These can be heating wires, but also communication iines, temperature-sensitive wires, signalling wires etc.

One of the advantages of the technique according to the invention is that it is simpler to incorporate such conductors/cables into the web part. Ex~ isting production methods according to the prior art use a hot wound profile.

However, it is rather difficult to check and secure the position of the conduc— tors/cables in the heated web part when these are heiically wound whilst hot.

Hence, the plastic material of the web part is in the semi-liquid stage and has little strength to keep the wires in place.

According to the ion, the e can be cooled down after extru» sion to a temperature below the ing temperature of the used plastic material(s). Therefore, it is possible, for example, to extrude the profile in a straight way t g it in a water tank. The web part with the electri— cal (or other) wires will then be cooled down and will fixate the wires in the web in a specific position. Only when the profile is sufficiently cooled down (for example maximum 60 00, depending on the plastic material) and the wires are fixated in the web part, the profile will be helically wound.

Short description of the drawings The invention shall now be explained in more detail by means of the description below and the added drawings.

Figure 1 and 2 show cross sections of a part of a hose according to the prior art.

Figure 3 and 4 show cross ns of a part of a hose according to a first preferred ment of the invention.

Figure 5 and 6 show cross sections of a part of a hose according to the second preferred embodiment of the invention.

Figure 7-17 show cross sections of a part of a hose according to alter- native ments of the invention.

Embodiments of the invention Hereafter, the present ion will be described by means of specific embodiments and with nce to certain drawings, yet the invention is not limited thereto and will only be defined by the claims. The drawings provided here are merely schematic representations and are not limiting. In the draw- ings, dimensions of certain parts can be shown ed, which means that the parts involved are not depicted on scale, and this merely for illustrative purposes. The dimensions en the relative dimensions do not necessarily cor- respond with the practical embodiments of the invention.

Furthermore, certain terms such as “first“, “second”, ” and the like will be used in the description and claims to make a distinction between simi~ lar elements and are not necessarily meant to indicate a sequential or chron- ological order. The terms in question are interchangeable in the conditions appropriate therefore, and the embodiments of the invention may work in other sequences than those that are illustrated or described here.

Furthermore, terms such as “top", “bottom”, “above”, “under”, and the like in the description and in the claims are used for descriptive purposes and not necessarily to indicate ve positions. The said terms used are inter- changeable in the conditions appropriate therefore, and the embodiments of the invention may work in other orientations than described or rated here.

The term "comprising" and derivative terms, as they are used in the claims, should not be interpreted as limited to the means that are mentioned fter; the term does not exclude other elements or steps. The term should be interpreted as a specification of the mentioned properties, integers, steps, or ents that are referred to, without excluding the presence or the on of additional properties, integers, steps, or components, or groups f. The scope of an expression such as “a device comprising means A and B” is therefore not only restricted to devices that merely consist of ents A and B. On the other hand, what is meant is that, as far as the present invention is concerned, the only relevant components are A and Figure 1 and 2 respectively show a cross section of an extruded plas— tic profile and two adjacent windings of a hose according to the prior art. The extruded profile comprises an upright part 1, a flat web part 2 and an inverted U-shaped part 3, which forms the rib part of the hose. The weld 4 is applied in this classic embodiment between the upright part 1 and the hanging part 5 and the rib part 3.

Figure 3 and 4 tively show a cross section of an extruded plas- tic material e and two adjacent windings of a hose according to the first embodiment of the invention. The extruded profile comprises on both sides an inverted T—shaped part 6, 8, and in the middle a flat web part 7. The in- verted T-shaped part 6, 8 shows an upright part 61, 81 and a horizontal leg 62, 82 in line with the web part 7. These horizontal legs 62, 82 of the adja- cent gs are facing each other and therefore create a distance between the upright parts 61, 81, such that a space is created which is substantially completely filled with welding material 9. The welding material 9 is therefore nearly entirely located between the t parts 61, 81. The upright parts 61, 81, together with the weld 9, form a reinforcement rib with a helical course along the hose.

The hose of figure 3 and 4 is ctured by successively: extruding the profile, cooling down the profile, winding the cooled profile for obtaining the adjacent windings that make up the exterior of the hose, and applying the g material between the upright parts. The welding material is heated to a temperature above the softening temperature (semi—liquid phase), for ex- ample 150 to 270 0C, depending on the used plastic materials.

Figure 5 and 6 respectively show a cross section of an extruded plas- tic e and two adjacent windings of a hose according to a second embod» iment of the invention. The extruded profile is equivalent to that of figure 3 and 4 and comprises two inverted T-shaped parts 16, 18 with in between a web part 17. The inverted T-shaped parts 16, 18 of the adjacent windings are folded towards each other on the top, in such a way that they substantially completely enclose the weiding material 19. In this way, a hose is ed which looks well finished on the outside. The g can be done after the application of the welding al 19 between the upright parts 16, 18. On the other hand, the profile can also be extruded in this shape, in which the weld needle which is used to apply the weld, will then be positioned under the surface of the hanging part when inserting the profile in the winding de- vice.

The embodiment according to figure 7 is substantially equivalent to that of figure 5 and 6. The difference is that the inverted T~parts 16, 18 com- prise two electricai conductors 20, 21.

The embodiment according to figure 8 is substantially lent to that of figure 7. The difference is that the electrical conductors 22, 23 are in- tegrated into web part 17.

In the embodiment according to figure 9, two electrical conductors 24, are integrated into the welding al 19. in alternative embodiments, the conductors may also be installed be- tween the t parts and the weld.

In the embodiment of figure 10 and 11, the upright parts 26, 28 on both sides of web part 27 comprise protrusions 29, 3O directed towards the nt winding and in such a way that these protrusions 29, 30 overlap each other. These protrusions ensure a larger contact area between welding material 31 and the upright parts 26, 28 of the profile windings, in such a way that the adhesion of the two nt windings by means of weld 31 can be reinforced. in the ment of figure 12 and 13 the extruded profile is - lent to that of figure 5 and 6 and comprises two inverted T—shaped parts 32, 34 with in between a web part 33. The inverted T—shaped parts 32, 34 of the adjacent windings are folded s each other at the top and overlap each other in such a way that the g material 35 is completely enclosed. Be— cause of this, a hose is provided that looks well finished on the outside. The folding can be done after the application of the welding material 35 between the upright parts 32, 34. On the other hand, the profile can also be extruded in this shape, in which the weld needle which is used to apply the weld, will then be positioned under the surface of the g part when inserting the profile in the g device.

In the embodiment of figure 14, the web part 36 shows an unfoldable part that is provided to be unfolded when an axial tensile force is exerted on~ to the hose, such as to provide an tion of the hose.

In the embodiment of figure 15 and 16, web part 37, 38 shows collaps- ible parts, respectively directed inwards or outwards, which are movabie be- tween two stable positions: a folded position ( as depicted in figure 15 and 16) and a extended position (not depicted). Such folding parts with two stable positions are known from the hinge parts of straws, but can also be applied to this type of hose.

In all shown embodiments of the invention, the rib part has predeter- mined properties, more in particular choice of material and strength, prede- termined for the provision of a certain hub strength to the hose. [n all shown embodiments of the invention the web part has predeter- mined properties, more in particular choice of material and wall ess, predetermined forthe provision of a n flexibility to the hose.

The materials for the web part could be: PE, PP, PVC, ter, PU, or other known plastic materials.

The materials for the upright parts of the profile could be: PE, PP, pol- yester, PU, or other known plastic materials.

The welding materiai needs to be compatible with the material used for the upright legs of the U—profiie. Therefore the weld can, for example, com— prise a coating of the same material.

In the above, the invention was illustrated for the sake of simplicity on the basis of a single profile that is helically wound. it is also possible, accord- ing to the ion, to g more than one profile next to each other in order to obtain a hose according to the invention with a multiple winding pitch, wherein the adjacent es need not necessarily to have the same shape with regard to their cross section. In the latter case, each e can either be welded separately, or multiple profiles can be extruded as a whole.

In this manner, it is for example possible for a hose with a pitch of three pro- files, that the three profiles are connected with three different welds. But it is also possible to extrude all three different profiles as one profile, and to con- nect this profile with one weld.

In the above, g of the profiles according to the invention was described as welding by extrusion of a welding material. However, it is also possible to connect the profiles to each other by means of another method (ex. hot air, laser, iation, ...). in further embodiments according to the invention, it is possible to em- bed an electrical conductor/cable in the web part or rib part, which is con- nected to a sensor, which is, for example, located near a coupling element at an end of the hose and which is provided in order to measure, for e, ature, humidity, or other parameters of the medium transported through the hose.

In embodiments according to the invention, it is possible to provide a tube on the inside of the flexible wall (which is formed by the concatenated profiles), that extends in the longitudinal direction of the hose and which is provided to transport a second medium, or to absorb a stress relief, or to in~ corporate an electrical conductor/cable, or for other purposes. in embodiments according to the invention, it is possible to provide an electrical conductor/cable on the inside of the flexible wall (which is formed by the concatenated profiles), for example a resistance wire with a helical uration course to heat the medium inside the hose.

In embodiments according to the invention, it is possible to provide a wire or cable (for example an electrical conductor/cable, signalling wire or ) on the outside of the flexible wall (which is formed by the concatenat— ed profiles) that is kept in piace around the flexible wall by means of a jacket, which is applied around the outside for example by means of extrusion.

In the embodiment of figure 17, the profile for manufacturing the hose is achieved in a different manner. The hose comprises the web part 47, the welding material 49, as well as the t parts 48 at the ends of the profile.

As is the case with all the other embodiments mentioned herein, the profile is manufactured by co—extrusion of two materials 47 and 46, 48 (or more). in alternative embodiments, it is possibie to manufacture both the web parts as well as the upright parts from the same material.

In these embodiments, the web parts 47 of the adjacent windings touch or practically touch each other. The reinforcement ribs, which are formed by the upright parts 46 and 48 and the weiding material 49 that is ap- plied in between, will substantially be placed on top of the web parts 47. The g material 49 can be d entireiy between the upright parts 46, 48 as is shown and possibly also be applied n web parts 47, but in alter- native embodiments, for example solely between the parts facing each other at the top and at the bottom of the upright parts 46, 48 such that a holiow rib is formed.

The advantage of this construction with a rib on top of the web parts is that a hose with a smoother inside can be obtained. in addition, in case the web part is manufactured of a conductive material and the adjacent web parts are laterally in contact with each other, it is possible to obtain an im- proved electrical conductivity of the hose than in case the web parts are not in contact with each other (in that case, the conduction of the electrical cur— rent occurs helically, such that the length of the conducting track and the overall resistance increases proportionally to the ference and the number of windings).

As with the other herein described embodiments, electrical wires can be incorporated in this profile at different ated iocations, or a hollow space can be ed in the profile. d of an electrical wire, a rein— forcement wire can also be provided (for example in metal or a hard plastic material, such as in the case of stretchable .

The Web part 47 can be produced, for example, in a TPE material. The rib (upright parts 46, 48 and g material 49) can be produced, for exam- ple, in a PP material. However, multiple other ations of materials are possible. Web part and rib may have different shapes. The dimensions of the web part and the rib can be changed and adapted to give the hose certain properties: a more flexible hose, 3 more rigid hose, many or few turns per unit length, predetermined hub strength and so on.

Claims (23)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. Flexible plastic hose comprising a flexible wall made out of a plurality of laterally connected windings of a helically wound profile, wherein the windings of the profile are attached to each other by means of a weld, wherein the profile ses a web part with predetermined properties for providing flexibility to the hose, wherein the profile ends on both sides in an upright part, wherein the upright parts are provided, on both sides of the profile, with a horizontal leg that extends in iine with the web part and in the ion of the adjacent winding, and wherein the weld is located n the upright parts of adjacent windings and 10 together with these upright parts forms a helical reinforcement rib on the flexible wall of the hose with predetermined properties for providing hub strength to the hose.

2. Flexible plastic hose according to claim 1, wherein the t parts comprise protrusions, directed towards the adjacent winding and in such a way 15 that they overlap each other.

3. Flexible piastic hose ing to any one of the us claims, n the upright parts of the adjacent windings are folded towards each other at the top and ntially completely enclose the weld.

4. le plastic hose according to claim 3, wherein the upright parts of the 20 nt windings overlap each other at the top.

5. Flexible plastic hose according to any one of the previous claims, wherein the profile is essentially U-shaped.

6. Flexible plastic hose according to any one of the previous claims, wherein the upright parts of the profile have an inverted T-shape.

7. Flexible c hose according to any one of the previous claims, wherein the profile is symmetrical.

8. le plastic hose according to any one of the previous claims, wherein the flexible wall has an inside diameter of 10 to 19 mm.

9. Flexible plastic hose according to any one of the previous claims, wherein one or more electrical conductors or cabies is/are embedded in the reinforcement rib.

10. Flexible plastic hose according to any one of the previous claims, wherein one or more electrical tors or cables is/are embedded in the web part. 10

11. Flexible plastic hose according to any one of the previous claims, wherein the web part comprises an unfoldable part that is provided to be unfolded when an axial tensile force is exerted onto the hose, such as to provide an elongation of the hose.

12. Flexible plastic hose according to any one of the previous claims, wherein 15 the web part comprises collapsible parts.

13. le plastic hose ing to any one of the previous claims, wherein the upright parts and the weld are manufactured from compatible materials.

14. Flexible plastic hose ing to any one of the us ciaims, wherein the upright parts and the weld are manufactured from the same material. 20

15. Flexible plastic hose according to any one of the previous , wherein the web parts of adjacent windings of the hose are laterally in contact with each other.

16. Flexible plastic hose according to claim 15, n the web parts are ctured from a conductive material.

17. Method for cturing a flexible c hose, comprising the following steps: extruding a plastic profile containing a web part with predetermined properties for providing flexibility to the hose, and which ends on both sides in an upright part, heiicaily winding the profile, wherein the windings of the profile are attached to each other by means of a weld, for forming a flexible wall of the hose, 1O wherein the t parts are provided, on both sides of the profile, with a horizontal leg that extends in line with the web part and in the ion of the adjacent winding, and wherein the weld is appiied between the upright parts of the adjacent windings of the profile, in such a way that the weld forms, together with the 15 upright parts, a helical reinforcement rib on the flexible wall of the hose with predetermined properties for providing hub strength to the hose.

‘18. Method according to claim 17, wherein the profile is cooled between the ion and the helically winding.

19. Method ing to claim 18, wherein the profile is cooled in a water 20 tank.

20. Method according to any one of the claims 17 to 19, wherein the e is extruded at a temperature above the melting temperature ofthe plastic material or materials of which the profile is made, and wherein the profile is cooled to a temperature below the softening temperature of these plastic material or 25 materials, before helically winding the profile.

21. Flexible plastic hose when manufactured by the method of any one of claims 17 to 20.

22. Flexible plastic hose substantially as herein described with reference to any embodiment shown in s 3 to 17 of the accompanying drawings.

23. Method for manufacturing a flexible plastic hose, the method substantially as herein described with reference to any embodiment shown in