FLEXIBLE HOSE, IN PARTICULAR VACUUM CLEANER HOSE, AND METHOD FOR THE PRODUCTION THEREOF

Description

TECHNICAL FIELD

[0001] The present invention relates to a flexible hose according to the preamble of claim 1. In particular, the invention relates to a flexible vacuum cleaner hose with one or more electrical conductors, as is used on a large scale in an industrial environment, in trades and in private households, and its manufacture. BACKGROUND OF THE INVENTION AND STATE OF THE ART

[0002] Vacuum cleaner hoses with integrated electrical conductors are used, for example, to electrically connect vacuum cleaners to motor-driven accessories for cleaning purposes, such as roller brushes. In the area of ​​so-called power tools, the electrical supply to an electric tool, such as a hand-held sander, can also be provided via the suction hose to extract dust and sanding particles.

[0003] Another application for suction hoses with integrated electrical conductors is in so-called central vacuum cleaners: To conveniently switch a central vacuum cleaner located in another room on or off, two electrical conductors are laid in or along a hose profile of the suction hose. These conductors are routed via a switch located in a handle of the suction hose. In a connector at an end of the suction hose facing away from the handle, the ends of the two electrical conductors contact two metal contact plates, which can be further connected to the central vacuum cleaner via spring-loaded contact pins located in a wall connection box. By pressing the switch on the handle of the suction hose, the contact is closed or opened, and the central vacuum cleaner is switched on or off.

[0004] The state of the art is not lacking in proposals for how electrical conductors can be installed in or on a flexible vacuum cleaner hose. For example, EP 0 884 019 B1 and DE 298 04 962 U1 disclose the bonding of an inner tube to the inner wall of the vacuum hose, which forms a protective sheath for cable routing.

[0005] Gluing the inner tube to the inner wall of the suction hose using, for example, hot glue only works for relatively short hose lengths. With longer hose lengths, the reliability of the bond decreases because the hot glue cools down too much during the insertion of the inner tube into the suction hose, forming a skin on the surface and no longer fusing with the adhesive partner, i.e., the inner wall of the suction hose.

[0006] For relatively long vacuum cleaner hoses, such as those commonly used in central vacuum cleaners, it is therefore necessary to connect individual hose sections of, for example, 2.5 m in length with sleeves, as is known, for example, from EP 1 262 704 B1. However, the associated effort, as well as the fact that such vacuum cleaner hoses are less flexible in one direction than in others due to the glued-in inner hose, is undesirable for some applications.

[0007] It has also been proposed to route electrical conductors along the outside of a flexible vacuum cleaner hose and to secure them, for example, using several clips, loops, tabs, or straps positioned at intervals along the hose as holders. Such a suction hose can be found, for example, in document DE 10 2013 020 687 A1. A disadvantage of this prior art is that the electrical conductor(s) form loops between the holders when the suction hose is bent, which can interfere with the user's work.

[0008] As an alternative, it is known from document EP 2 614 762 A2 to apply a supply line, in particular a power cable with three individual conductors, each with a cross-section of 2.5 mm², to the outside of a suction hose, wherein the supply line and the suction hose are loosely surrounded by an outer hose. Furthermore, it is disclosed here that the supply line can be wound spirally around the suction hose at least once, preferably with three or four turns, to achieve greater length variability. In document WO 2019 / 011591 A1 ( Fig. 4 ) it is further proposed to use a reinforcing body in the form of a wire spiral provided in a dust removal hose body of a suction hose for a vacuum cleaner as an electrically conductive component.

[0009] It is also known – see, for example, the publication DE 91 14 487 U1 – to freely route electrical cables within a suction hose. This design has been proposed primarily for extracting dust during processing, such as sanding. However, the electrical cable creates a flow obstruction and can, especially in the long hoses of central vacuum cleaners, cause clogging due to common household dirt such as hair or fibers. Such blockages are difficult to remove with such long hoses.

[0010] Furthermore, document EP 1 656 873 A2, which forms the preamble of patent claim 1, discloses a vacuum cleaner hose with a plurality of outwardly open, helical grooves, which are laterally delimited by ribs, for receiving electrical conductors, which open outwards from the groove base without constriction, and with a braided hose sheath covering the grooves and the electrical conductors inserted therein.

[0011] In this well-known vacuum cleaner hose, the braiding of the hose cover, viewed longitudinally, overlaps the corrugated profile of an inner hose formed by the grooves, which houses the electrical conductors. This gives the vacuum cleaner hose a smooth outer circumferential surface. This results in improved gliding characteristics compared to conventional hoses without a hose cover. During vacuuming, the vacuum cleaner hose does not snag on the edges of the body when gliding over wall corners, furniture, doors, workpieces, or car bodies.This reduces the effort required during suction operation, avoids sudden interruptions in the operator's movement sequence caused by entanglements, reduces noise and, last but not least, protects the edges of the body - all in all, these are desirable effects, particularly for hose use with central vacuum cleaners, which are also partly discussed in the publication WO 2019 / 011591 A1 regarding the hose sheath made of a textile braid disclosed therein.

[0012] However, a disadvantage of this state of the art is that, compared to the previously described solutions for laying electrical conductors in or on flexible vacuum cleaner hoses, the generic vacuum cleaner hose has a relatively high weight due to its helical cable routing of the electrical conductors, which is undesirable, particularly in the case of long vacuum cleaner hoses, such as those used in central vacuum cleaners.

[0013] In this context, according to the prior art, it is further considered disadvantageous in terms of cost, weight, and electrical voltage drop to arrange an electrical cable on an elastic hose in a sinusoidal, corrugated or spiral manner. Instead, a vacuum cleaner hose is proposed in which an electrical expansion cable is attached to a tubular, elastic body and extends parallel to a centerline of the body. The electrical expansion cable is attached to the tubular body in a stretched state in close proximity to one another, so that the electrical expansion cable can compress or expand between the attachment points.

[0014] More specifically, the vacuum cleaner hose disclosed in document DE 1 218 032 A comprises a tubular body made of a fabric impregnated with, for example, rubber. Regarding the manufacture and further construction, in particular the "electrical equipment" of this vacuum cleaner hose, reference is further made to Fig. 1 bis 4 This publication states the following: A reinforcing wire spiral, for example made of steel, is arranged within the tubular body. A cord, for example made of jute, is wound around the tubular body so that the turns of the cord lie between the turns of the spiral. Before the cord is wound around the tubular body, an electrical expansion cable is applied to the body so that it extends in a straight line approximately parallel to the centerline of the body. Before the cord is wound, the electrical expansion cable is stretched. The cord serves to attach the expansion cable to the tubular body at the points where the expansion cable is held between the tubular body and a turn of the cord. The tubular body is then provided with a braided sheath. The ends of the expansion cable are led out of the sheath. A plug can be attached to one end of the cable.The other end of the electrical expansion cable can be connected to a socket that is attached to one end of the hose by means of a clamp.

[0015] Unlike the vacuum cleaner hose disclosed in the generic prior art according to EP 1 656 873 A2, the vacuum cleaner hose according to DE 1 218 032 A does not have a corrugated inner tube. Rather, the tubular body is forced into shape between the internally supporting wire spiral and the externally constricting cord, which simultaneously serves to secure the electrical expansion cable at defined, spaced-apart points on the tubular body. Such a structure with a plurality of components is not only relatively complex, including in terms of manufacturing, but also still has a relatively high weight. This leads to a certain "bulkiness" of the vacuum cleaner hose, which is undesirable for certain applications, due to the integrated wire spiral and poor recyclability.

[0016] With regard to the electrical expansion cable of the vacuum cleaner hose according to the document DE 1 218 032 A, it should also be noted that there is shown a two-wire power cable that is thick in relation to the wall thickness of the hose or the braiding, similar to a loudspeaker cable, which protrudes unsightly from the rest of the vacuum cleaner hose under the braiding or leads to an elongated bulge on the hose circumference (cf. the Fig. 3 und 4 This bead can impede the movement of the hose, for example, if it is pulled over an edge or rolled around its longitudinal axis. According to the description, such expansion cables can be extended by at least 200 percent of their original length. However, technical details of these particularly stretchable cables are not described here.

[0017] A further disadvantage of this prior art is that the electrical expansion cable has to be stretched considerably, i.e. in the described application by at least 33% of its normal length, before it is attached to the tubular body by means of the cord in order to be able to not only extend but also compress between the attachment points. This is not only complex to manufacture, but can also result in the finished vacuum cleaner hose always having a certain pre-stretching or pre-curvature in the unloaded state, which can be undesirable, for example, in the specific application of a central vacuum cleaner. In the previously known design, this can of course be counteracted to a certain extent by making the central reinforcing spiral stronger, although this is detrimental to the flexibility of the vacuum cleaner hose.

[0018] Furthermore, a data communication cable and a method for producing such a cable are known from WO 2020 / 139199 A1. This data communication cable comprises a set of elongated bodies, each formed from an elastic material and having an unstretched free length, and, for each of the elongated bodies, a set of conductive wires arranged along the elongated body such that each conductive wire is stretchable to more than the free length of the elongated body. At least one conductive wire is configured for communicating data between electronic devices. Furthermore, the conductive wires are extendable in response to an extension of the elongated body, such that the extended data communication cable remains usable for data communication between the electronic devices.

[0019] In a specific embodiment of this data communication cable, the conductive wires are arranged in a sinusoidal, wave-like, or serpentine pattern along the respective elongated body. Any use of such data communication cables in connection with flexible vacuum cleaner hoses is not disclosed in this prior art.

[0020] Finally, DE 25 47 901 A1 discloses a flexible hose for vacuum cleaners or the like, having at least one electrical cable arranged thereon, provided with an elastic insulating sheath. The electrical cable is guided along the inner surface of the hose and is designed as a flat cable, which is attached to the inner surface of the hose by a flat side; more precisely, its insulating sheath is glued or welded to the inner surface of the hose several times at spaced-apart locations along its length. TASK

[0021] Compared to the described prior art, the invention is based on the object of designing a flexible hose, in particular a vacuum cleaner hose, with an inner tube, a sheath, and at least one electrical conductor in such a way that the problems mentioned above with regard to the prior art are addressed and, in particular, long "electrified" hoses with a comparatively low weight and the aforementioned operating properties, particularly desirable for use in central vacuum cleaners, can be produced cost-effectively. The object of the invention further includes specifying a method for producing such a flexible hose provided with at least one electrical conductor, which enables the simplest, quickest, and most cost-effective production or partial assembly of the hose with the at least one electrical conductor in large quantities. PRESENTATION OF THE INVENTION

[0022] These objects are achieved by a flexible hose, in particular a vacuum cleaner hose, having the features of patent claim 1 and a method for producing a flexible hose having the method steps of patent claim 11. Advantageous embodiments of the invention are the subject of the dependent patent claims.

[0023] In a flexible hose, in particular a vacuum cleaner hose, which has a corrugated profile - ie correspondingly pre-shaped - inner hose, which defines with an inner side a cavity for conveying media along a longitudinal axis of the hose, is surrounded on an outer side by a substantially smooth sheath and is provided with a connecting piece at at least one of its two ends, wherein an electrical conductor is arranged radially between the inner hose and the sheath, which extends from one end to the other end of the inner hose and ends in the connecting piece for establishing electrical contact; according to the invention, the electrical conductor is formed by an elastic, ieIn this context, a flat conductor arrangement is formed which can be stretched and compressed against - albeit small - restoring forces and which extends essentially without prestress and is electrically insulated parallel to the longitudinal axis along the hose and is held on the wave-shaped profile of the inner hose by the sheath.

[0024] In other words, the electrical conductor—unlike in the generic prior art—is not wrapped around the inner tube or laid primarily in the circumferential direction of the inner tube. Rather, the electrical conductor extends essentially without prestress directly in the longitudinal direction of the inventive tube, parallel to the longitudinal axis along the tube. As a result, the electrical conductor is significantly shorter than in the aforementioned prior art, resulting in a correspondingly lower weight and lower cost of the tube.

[0025] By designing the electrical conductor as an "elastic"—as opposed to (essentially) "rigid"—flat conductor arrangement, there is no need for the electrical conductor, viewed longitudinally through the flexible hose, to follow the wave-like profile of the inner hose. Rather, the elastic flat conductor arrangement can bridge the depressions of the wave-like profile on the outer side of the inner hose while resting on the elevations of the wave-like profile. Nevertheless, due to its elastic properties, the flat conductor arrangement is capable of following bends and / or elongations of the flexible hose without offering significant resistance.

[0026] Depending on the bending direction, the elastic flat conductor arrangement experiences stretching or compression between the protrusions of the inner hose's wave-shaped profile. The same applies to compression or tension in the hose's longitudinal direction. Since the elastic flat conductor arrangement is inserted between the inner hose and the sheathing essentially without prestress, the hose is advantageously free from constraining forces caused by the elastic flat conductor arrangement, which would prestress or prebend the hose.

[0027] Advantageously—in addition to the advantages of coated hoses already mentioned at the beginning—according to the invention, the hose's coating also serves to hold the elastic flat conductor arrangement to the inner hose, more precisely to its wave-shaped profile on the outer side of the inner hose. Depending on the materials used, this should not fundamentally preclude the use of an additional adhesive or similar material between the elastic flat conductor arrangement and the outer side of the inner hose and / or an inner side of the coating, provided that this adhesive does not noticeably impair the elasticity of the flat conductor arrangement.

[0028] Due to its design as an elastic flat conductor arrangement, the electrical conductor is not excessively "thick," thus not leading to a significant local increase in diameter at the coated hose. The word "flat" in the term "flat conductor arrangement" thus actually refers to a design of the conductor arrangement in which the length and width dimensions of the conductor arrangement are significantly greater than its thickness. While the length of the conductor arrangement is readily derived from the desired overall length of the flexible hose, a "significantly greater width dimension compared to the thickness dimension" in the elastic flat conductor arrangement according to the invention means a width along the hose circumference that is at least ten times larger than the thickness perpendicular to the longitudinal axis of the hose.In a preferred embodiment of the hose according to the invention, the ratio of width to thickness of the elastic flat conductor arrangement is approximately in a range between 15 to 1 and 40 to 1, more preferably between 20 to 1 and 30 to 1.

[0029] Furthermore, since the elastic flat conductor assembly is attached to the outside of the inner hose and is not somehow integrated into the inner hose, it is advantageously relatively easy to remove the elastic flat conductor assembly of a hose to be disposed of from the rest of the hose for recycling purposes.

[0030] Last but not least, the inventive design of the flexible hose advantageously allows for a (at least) two-stage process during its production, in which the inner hose with its wave-shaped profile on the outside is first produced, before this "basic hose" is "refined" in a second step by applying and attaching the elastic flat conductor arrangement with regard to the desired electrical properties of the hose. As a result of this modular design of the hose, it is possible to produce hoses from a kind of modular system, depending on the desired or required configuration, with different elastic flat conductor arrangements. These can differ, for example, in the number of individual conductors installed (e.g., 1, 2, 3, or 4 individual conductors) and / or according to the power to be transmitted in the respective effective cable cross-section. This ensures high flexibility in hose production and also offers cost advantages.

[0031] Preferably, the elastic flat conductor arrangement is secured to the wave-shaped profile of the inner tube—if necessary, solely—by pressing the elastic flat conductor arrangement against elevations of the wave-shaped profile by means of the sheathing. In the radial direction relative to the longitudinal axis of the tube, this creates a positive fit for the elastic flat conductor arrangement, which is sandwiched or inserted between the inner tube and the sheathing, and which counteracts any radial movement of the elastic flat conductor arrangement.

[0032] However, in a direction along the longitudinal axis of the hose or transversely thereto, i.e. viewed in the circumferential direction of the hose, there is a frictional connection for the elastic flat conductor arrangement which prevents any longitudinal or transverse displacement of the elastic flat conductor arrangement above the inner hose or below the sheathing. Between the individual contact points of the elastic flat conductor arrangement to the inner hose, namely at its elevations, or to the sheathing, the flat conductor arrangement can then lengthen or compress due to its elastically deformable design in accordance with an axial deformation and / or a bending of the hose, as already mentioned. For this purpose, the elastic flat conductor arrangement can have an elastic extensibility of between 25% and 75% in the longitudinal direction, e.g. 50% in a specific application, depending on the application.

[0033] To increase the force or frictional connection between the elastic flat conductor arrangement and the inner tube or the sheathing of the tube, the elastic flat conductor arrangement, or at least a portion thereof, can be further provided with a rubber coating, which can be accomplished with little effort. If the elastic flat conductor arrangement comprises, for example, a knitted or braided fabric, such a (partial) rubber coating can be created, for example, by incorporating or braiding in a rubberized thread.

[0034] In principle, it is conceivable that the essentially smooth sheathing of the hose consists of one or more elastic bands that are elastically wound around the already wave-shaped inner hose—with the elastic flat conductor arrangement beneath the band(s). The sheathing can also be circularly knitted on a circular knitting machine from, for example, textured polyamide threads or similar materials around the inner hose with the elastic flat conductor arrangement on top.

[0035] In contrast, a preferred design of the hose is one in which the sheath is formed by braiding the inner hose from monofilament and / or multifilament plastic threads. Such a braid advantageously provides a firm mechanical hold for the elastic flat conductor arrangement, yet still allows for a slight expansion of the sheath, for example, to allow the ends of the elastic flat conductor arrangement to be gripped with pliers or the like during final assembly of the hose, allowing the elastic flat conductor arrangement to be pulled slightly out of its position between the inner hose and the sheath for contacting in the connector.When, in connection with the present invention, a covering of the inner tube is mentioned, this primarily refers to tubes braided with round monofilaments, flat monofilaments, plied monofilaments and / or multifilaments, wherein the monofilament or multifilament threads of the braiding may even be flocked with short fibers made of a thermoplastic, as disclosed in the document EP 2 363 210 A2.

[0036] The braiding of the inner tube with monofilament and / or multifilament plastic threads not only serves as a preferred vehicle for holding the elastic flat conductor arrangement to the wave-shaped profile of the inner tube. Due to the supporting effect of the braid, braided hoses also exhibit better mechanical properties than conventional hoses. For example, kinking occurs later in a braided hose than in a conventional hose. If the hose is not braided too tightly, it is more flexible than a conventional hose because it can be bent and twisted more freely until it kinked. In terms of an improved appearance, braided hoses also offer the possibility of a more flexible external appearance than conventional hoses.

[0037] To ensure that the supporting braid improves the hose's flexibility rather than impairing it, the braid must be loosely applied to the hose and not braided as tightly as possible. This allows the braid to be compressed during the hose's bending until the edges of the parallel threads touch each other. Only then does a significant counterforce build up, counteracting the bending movement. If the braid is braided too tightly and tightly, for example, the braided hose no longer has the significantly improved flexibility of a standard hose, but may even exhibit stiffer behavior.

[0038] The braid must therefore not be applied too tightly and tightly to the hose and / or compressed too much on the hose. The properties of the braid vary depending on whether monofilaments, multifilaments, or a mixture of both threads are braided. In a hose loosely braided only with monofilaments, i.e. relatively thick individual fibers, coverage gaps will inevitably occur in the braid. A maximum coverage of the hose circumference of approximately 80% can be achieved here. If a hose braided in this way is bent, the threads of the braid that slide over one another shift, and with them the coverage gaps. Nevertheless, this braid is also suitable for holding the elastic flat conductor arrangement to the wave-shaped profile of the inner hose.

[0039] However, with a braid made of stretchable and compressible multifilaments, i.e., fiber bundles or a hybrid braid made of monofilaments and multifilaments – which is also well suited for securing the elastic flat conductor arrangement on the inner hose – the hose circumference can be braided completely, creating a fabric-like surface. Due to the stretchable multifilaments, such braids adhere to the outer radius of the bent hose when the hose is bent and compress to the inner radius of the bent hose without forming gaps. However, excessive compression of the braid on the hose can also lead to undesirable hose stiffening or bulging. The specialist should take all of this into account when attaching the elastic flat conductor arrangement to the undulating profile of the inner hose using a braid.

[0040] In a preferred embodiment of the flexible hose, it can further be provided that the elastic flat conductor arrangement has at least one stranded cable which, viewed in the longitudinal direction of the flat conductor arrangement, runs in a serpentine or zigzag shape and is held in place by threads which, in the manner of a knitted fabric, form thread loops around the stranded cable which are intertwined to form stitches. Due to the serpentine or zigzag shape of the stranded cable, which as such has only a low elastic stretchability in the axial direction, the elastic flat conductor arrangement has good extensibility. The serpentine or zigzag shape of the stranded cable is stretched or compressed in its wavy or triangular shape, depending on whether the elastic flat conductor arrangement is subjected to tension or compression in the axial direction.Meanwhile, the threads intertwined into meshes, which extend around the stranded cable or enclose it, ensure the necessary cohesion in the elastic flat conductor arrangement.

[0041] If the flexible hose in a "minimal" electrical configuration only has an elastic flat conductor arrangement with a single stranded wire, it is conceivable, for example, that the hose could be used in an environment where the hose's electrical conductor is intended to provide a - possibly additional - grounding connection for an electrical accessory or power tool connected to a vacuum cleaner. However, the flat conductor arrangement will usually have two or more stranded wires (e.g., three or four stranded wires) in order to be used, as mentioned above, for the electrical supply of an accessory or power tool and / or switching functions, depending on the electrical requirements of the respective application.

[0042] Particularly with a view to achieving the narrowest possible design of the elastic flat conductor arrangement, it is preferred in such a case if the elastic flat conductor arrangement has at least two stranded conductors that, viewed transversely to the flat conductor arrangement, run in a similarly serpentine or zigzag shape with an axial spacing from one another. Thus, the individual stranded conductors can be arranged closely spaced from one another, with "parallel" serpentine or zigzag shapes, without the stranded conductors touching or interfering with each other during stretching or compressing their respective wave or triangular shape.

[0043] Furthermore, the or each stranded wire of the elastic flat conductor arrangement can preferably comprise a plurality of individual metallic wires and at least one plastic thread for strain relief. This makes it easy to reinforce the respective stranded wire or to protect it against tearing.

[0044] In principle, it is possible to insulate the entire elastic flat conductor arrangement so that it extends parallel to the longitudinal axis of the hose in an electrically insulated manner, for example by encasing the entire arrangement in an electrically insulating, elastically deformable plastic foam. However, particularly with regard to low weight and the smallest possible installation space, it is preferred if the at least one stranded conductor of the elastic flat conductor arrangement is provided with extruded insulation or lacquer insulation. This also allows for greater longitudinal extensibility of the entire arrangement.

[0045] In a preferred embodiment of the hose, the threads of the knitted fabric of the flat conductor arrangement can also be at least partially elastic, whereby the threads of the knitted fabric can, for example, comprise a mixture of polyester or polyamide fibers with elastane fibers. These fibers, when readily available, exhibit high heat resistance and are advantageously flame-retardant. In principle, however, it is also conceivable to hold the individual components in the elastic flat conductor arrangement together by means of a knitted fabric made of relatively rigid threads that are interlaced somewhat more loosely or loosely into stitches, so that the necessary deformation work can be performed by the individual thread loops of the knitted fabric.

[0046] It is further preferred if the connecting piece has a contact region to which the elastic flat conductor arrangement is electrically connected, wherein the contact region can in particular have at least one slip ring. For example, in the case of a central vacuum cleaner, the rotatability of the hose relative to a stationary, electrified connection box can be easily ensured by means of spring-loaded contact pins assigned to the slip ring(s), or a connection of such a hose without any rotational angle orientation of the connecting piece to the connection box. It will be apparent to a person skilled in the art that a mobile vacuum cleaner and / or a terminal device can also be provided with such a connection box. The elastic flat conductor arrangement can of course also be arranged at one end of the hose in a handle or the like.end with a switch over which the electrical conductor is looped, depending on the intended use of the suitably "electrified", flexible hose.

[0047] In terms of the method, the present invention provides a method for producing a flexible hose, which comprises at least the following three method steps a) to c): a) forming an inner hose which, with an inner side around a longitudinal axis, delimits a cavity and has a profiling at least on one outer side which, viewed in section, has a wave shape with elevations and depressions; b) applying an elastic flat conductor arrangement to the outer side of the inner hose in a substantially prestress-free manner, such that the elastic flat conductor arrangement runs along the longitudinal axis and transversely to the elevations and depressions of the profiling; and c) fastening the elastic flat conductor arrangement to the outer side of the inner hose by applying a sheath to the wave-shaped profiling.

[0048] An important aspect here is the separation of the process steps a) forming the inner tube on the one hand, and b) applying and c) attaching the elastic flat conductor arrangement to the outside of the inner tube on the other. This separation of the process steps offers the advantage that, in a modular system, an inner tube of the same basic type can be further refined according to the respective electrical wiring requirements by applying / attaching the elastic flat conductor arrangement, or not, if this is not necessary or desired.

[0049] It is also possible to further electrically equip an inner hose of the same basic type according to the respective requirements or wishes by applying / attaching various elastic flat conductor arrangements, which differ, for example, in the number and / or cross-section of the individual conductors, their dimensions and / or their elasticity.

[0050] This separation of process steps a) on the one hand and b) or c) on the other hand also leads to recycling advantages, because the elastic flat conductor arrangement subsequently applied / attached to the outside of the inner hose can generally be removed more easily when the hose is disposed of than a conductor that is an integral part of the inner hose or is incorporated into the inner hose.

[0051] Because, according to process step b), the elastic flat conductor arrangement is applied to the outside of the inner tube along the longitudinal axis and transversely to the elevations and depressions of the wave-shaped profile, essentially without prestressing – in this respect, exactly the opposite of the procedure in the generic prior art, where the conductors are laid transversely to the longitudinal axis and along the profile depressions – only a simple axial relative movement between the inner tube and the elastic flat conductor arrangement is required during the application of the elastic flat conductor arrangement. The application of the elastic flat conductor arrangement can thus be carried out as quickly as possible for a predetermined tube length with minimal use of conductor material. The complex winding of long and correspondingly heavy conductors around the longitudinal axis of the inner tube is eliminated.

[0052] Process step c) also contributes to the rapid and cost-effective production of a flexible (electrical) hose in mass production. This is because the elastic flat conductor arrangement is fixed on / at the corrugated profile of the inner hose and the flexible hose is provided with a sheath on the outside of the inner hose in a single process step.

[0053] In principle, the inner tube can be formed, for example, by blow molding a suitable plastic material, whereby the wave-shaped profile on the outer side of the inner tube can be created by a corresponding grooved or grooved design of the molded parts or halves of the blow mold. In contrast, it is preferred if, in step a) of forming the inner tube, a profile is first extruded from a plastic material, after which the profile is wound helically to form the inner tube—single-thread or multi-thread, depending on the respective specifications—with adjacent turns of the profile being connected to one another in a media-tight manner.The advantages of such a wound inner hose compared to a blow-molded inner hose are, in particular, that the inner hose can be designed with a substantially smooth inner surface and thus low flow losses and only low noise during operation, and that higher suction capacities can be achieved due to the good dimensional stability and recovery capacity of the inner hose.

[0054] Preferably, the adjacent turns of the profile are joined together in a media-tight manner using a hot-melt adhesive. This ensures reliable, fast, and cost-effective production of the inner tube. However, other connection options, possibly using other adhesives, or, for example, creating a material bond between the individual profile turns using laser welding or similar, are also conceivable.

[0055] Steps b) of applying and c) of (finally) securing the elastic flat conductor arrangement to the outside of the inner tube by applying the sheathing to the undulating profile of the inner tube can also, in principle, be carried out sequentially, particularly if, during the application of the elastic flat conductor arrangement, a (pre-)fixing to the raised portions of the profile is already carried out using an adhesive (e.g., glue or adhesive tape). However, particularly with a view to achieving the fastest and most efficient production possible, it is preferred if steps b) of applying and c) of securing the elastic flat conductor arrangement to the outside of the inner tube are carried out simultaneously.

[0056] In a preferred, specific embodiment of the method for producing the flexible hose with regard to the above-described embodiment of the flexible hose, the wave-shaped profile of the inner hose can finally be braided with monofilament and / or multifilament plastic threads to form the sheath, wherein the elastic flat conductor arrangement is applied to the outside of the inner hose essentially without pretension at the braiding point, so that after the braiding point, the braided plastic threads press the elastic flat conductor arrangement against the elevations of the wave-shaped profile of the inner hose. The elastic flat conductor arrangement can be supplied in a simple manner, for example, from a spool or reel having a core onto which the elastic flat conductor arrangement is wound.

[0057] Further features, properties and advantages of the flexible hose according to the invention and the method for its production will become apparent to the person skilled in the art from the following description of a preferred embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The invention will now be explained in more detail using a preferred embodiment with reference to the accompanying, partially schematic drawings, in which identical or corresponding parts or sections are provided with the same reference numerals. In the drawings: Fig. 1 a simply interrupted plan view of a flexible hose according to the invention, namely a vacuum cleaner hose, which is provided with a connecting piece on both sides and between which a - in Fig. 1 illustrated in detail - has a sheath in the form of a braiding of an inner tube; Fig. 2 a single interrupted longitudinal section view of the flexible hose according to Fig. 1 ; Fig. 3 an enlarged view of detail III in Fig. 2 in a central area of ​​the flexible hose according to Fig. 1 , which shows an elastic flat conductor arrangement inserted between the wave-shaped profiled inner tube and the sheath of the flexible hose; Fig. 4 a sectional view of the flexible hose according to Fig. 1 according to the section line IV-IV in Fig. 1 ; Fig. 5 a 4-fold broken side view of the flexible hose according to Fig. 1 in an S-shaped bent state, with the sheath shown broken away to illustrate how the elastic flat conductor arrangement can follow an elastic deformation of the inner tube; Fig. 6 a plan view of the flexible tube according to Fig. 1 looking along arrow VI in Fig. 5 , wherein the sheath is shown broken away to illustrate how the elastic flat conductor arrangement is stretched along an outer curve of the inner tube; Fig. 7 is a plan view, broken up and down, of the flexible tube according to Fig. 1 looking along arrow VII in Fig. 5 , wherein the sheath is omitted to illustrate how the elastic flat conductor arrangement is compressed along an inner curve of the inner tube; Fig. 8 a plan view of the flexible tube according to Fig. 1 , wherein the sheath is shown broken away to illustrate how the elastic flat conductor arrangement extends undeformed along the hose axis on the inner hose when the hose is not bent; Fig. 9 a perspective view of the flexible hose according to Fig. 1 , diagonally from above / left side, with a view of the hose connection piece at its Fig. 9 right end; and Fig. 10 is an exploded perspective view of the flexible hose according to Fig. 1 from diagonally above / left side, especially to illustrate how the elastic flat conductor arrangement is electrically connected to contact areas in the connector. DETAILED DESCRIPTION OF THE EMBODIMENT

[0059] In the figures, a vacuum cleaner hose is generally designated by reference numeral 10 as an example of a flexible hose. The hose 10 has a corrugated inner tube 12, ie a correspondingly pre-profiled inner tube 12, which defines with an inner side 14 a hollow space 16 for conveying media along a longitudinal axis 18 of the hose 10. On an outer side 20, the hose 10 is surrounded by a substantially smooth sheath 22, which in the illustrated embodiment is a braiding of monofilament and / or multifilament plastic threads. According to the Fig. 1 und 2 the hose 10 is further provided at at least one of its two ends 24, 26 - here at both ends 24, 26 - with a connecting piece 28, which in the illustrated embodiment is designed as a plug-in connection.

[0060] As will be described in more detail below, an electrical conductor 30 is arranged radially between the inner tube 12 and the sheath 22, which extends from one end 24 to the other end 26 of the inner tube 12 and terminates in the connecting piece 28 for establishing electrical contact, as shown in Fig. 10. According to essential features of the tube 10, the electrical conductor 30 is formed by an elastic flat conductor arrangement 32 which extends essentially without prestress and electrically insulated parallel to the longitudinal axis 18 along the tube 10. In this position, the elastic flat conductor arrangement 32 is held at least by the sheath 22 on the undulating profile 34 of the inner tube 12.

[0061] Shown in the Fig. 1 und 2 only the hose sections near the ends 24, 26 of the hose 10, which can be several meters long depending on the intended use. For central vacuum cleaners, for example, hose lengths between 6 and 15 meters are quite common. In the illustrated embodiment, the connectors 28 at both ends 24, 26 of the hose 10 are designed identically as plug-in connectors. Other end pieces - e.g., a handle with one (or more) switch(es) on one side and a plug-in connector on the other side, or a combination of a plug-in connector here and a connection box there, etc. - are of course also conceivable, depending on the respective application requirements.

[0062] The wave-shaped profile 34 of the inner tube 12 is in section along the longitudinal axis 18 of the tube 10 in the Fig. 2 and 3can be seen. Accordingly, the profiling 34, seen in section, has a wave shape with alternating elevations 36 or wave crests and depressions 38 or wave troughs on the outside. In the illustrated embodiment, the elevations 36 and depressions 38 run in a single-threaded manner - or alternatively, multiple-threaded, not shown here - helically as seen in the circumferential direction of the inner tube 12. This is explained by the fact that this is a wound inner tube 12, i.e. an inner tube 12 whose wall is formed from a profile 39 wound helically around the longitudinal axis 18, wherein adjacent turns of the profile 39 are connected to one another in a media-tight manner.

[0063] The profile 39 of the inner tube 12 shown here as an example has two areas in cross section, namely one in Fig. 3 right-hand area, the cross-section of which essentially has the shape of the letter U in "square" writing and which forms the outer recesses 38 of the profiling 34 on the wound inner tube 12, and one in Fig. 3 left-hand area, which, viewed in cross-section, essentially has the shape of a horizontal letter C or a letter tilted clockwise by approximately 90° and forms the outer elevations 36 of the profiling 34 on the wound inner tube 12. As in Fig. 3 As can be clearly seen, the C-shaped region of a turn of the profile 39 is virtually "hooked" over the right leg of the U-shaped region of an adjacent turn of the profile 39, so that a short profile overlap is created there along the longitudinal axis 18. In the area of ​​this profile overlap, a hot-melt adhesive 40, for example, is provided for the media-tight connection of the adjacent turns of the profile 39, forming a helical circumferential seam. On the inner side 14 of the inner tube 12, the U-shaped regions of the profile 39 form a substantially smooth inner surface 42 of the tube 10, which is only interrupted by a narrow spiral groove 44 formed between the individual turns of the profile 39, as best shown in Fig. 3 can be seen.

[0064] In the illustrated embodiment, the profile 39 of the inner tube 12 is extruded from a plastic material, such as polyethylene (PE), polypropylene (PP), or an ethylene-vinyl acetate copolymer (EVAC). As for the hot-melt adhesive 40, this can also be made of a plastic material, such as PE or EVAC.

[0065] As the detail below in Fig. 1 As illustrated, in the illustrated embodiment, the sheath 22 of the hose 10 is a braiding of the inner hose 12 made of monofilament and / or multifilament plastic threads, as already briefly mentioned, which can be made of a thermoplastic such as polyamide (PA) or PE, for example. When the hose 10 is bent on the tension side, the multifilament threads lie flat against the inner hose 12 and compressed on the compression side of the inner hose 12 transversely to the thread and thus also towards the wall of the inner hose 12, so that the braiding 22 always lies against the wall. With a particularly advantageous mixing ratio of 50% multifilament threads to 50% monofilament threads, the braided surface of the hose 10 also always remains closed.

[0066] According to the Fig. 3 und 4 The elastic flat conductor arrangement 32, which is shown exaggeratedly thick in the sections of the drawings for illustrative purposes, is pressed by means of the braiding 22 onto the elevations 36 of the wave-shaped profile 34. In these contact areas, the elastic flat conductor arrangement 32 is thus held in a form-fitting manner between the inner hose 12 and the braiding 22 in the radial direction of the hose 10, while the pressing force directed radially with respect to the longitudinal axis 18 of the hose 10 ensures a force-fitting, i.e. friction-fitting, fixing in the longitudinal and circumferential directions of the hose 10.

[0067] Axially between these contact areas, the flat conductor arrangement 32 can, due to its elastic design, reversibly lengthen or compress in accordance with the deformation of the flexible hose 10 under the prevailing bending, torsional and / or tensile / compressive forces. This is shown in the Fig. 5 (below) and 6 for the case of elongation when bending the hose 10 and in the Fig. 5 (above) and 7 for the case of compression when bending the hose 10.

[0068] Further details of the elastic flat conductor arrangement 32 are particularly Fig. 6 bis 8 and 10 (bottom left). Accordingly, the elastic flat conductor arrangement 32 has at least one, in the illustrated embodiment two flexible stranded wires 46, 48. In the example shown, each of the stranded wires 46, 48 runs in a zigzag shape (alternatively serpentine) when viewed in the longitudinal direction of the flat conductor arrangement 32, in such a way that the stranded wires 46, 48 run equally zigzag (or serpentine) when viewed transversely to the flat conductor arrangement 32 with an axial spacing from one another, as best shown in Fig. 6 can be seen. The respective stranded wire 46, 48 is held in its course by threads 50, which form thread loops around the respective stranded wire 46, 48 in the manner of a knitted fabric, which loops are intertwined to form stitches.

[0069] The individual threads 50 of the knitted fabric shown here are at least partially elastic and can, for example, comprise a mixture of polyester or polyamide fibers with elastane fibers. It will be apparent to a person skilled in the art that, after the elastic flat conductor arrangement 32 is arranged on the outer side 20 of the inner tube 12, viewed in its longitudinal direction, in alignment with the longitudinal axis 18 of the tube 10 (cf. Fig. 2 and 8 ), the threads 50 of the knitted fabric on or in the tube 10 have an elastic elongation - e.g. in the "outer curve" according to the Fig. 5 (below) and 6 - or an elastic compression - approximately in the "inner curve" according to the Fig. 5 (top) and 7 - allow the respective stranded conductors 46, 48 to extend in their zigzag (or serpentine) configuration. To further increase the frictional engagement of the elastic flat conductor arrangement 32 in its sandwich position between the elevations 36 of the wave-shaped profile 34 of the inner tube 12 and the sheath 22, the flat conductor arrangement 32 can be provided with a (partial) rubber coating, for example by providing corresponding threads 50 in the knitted fabric of the flat conductor arrangement 32.

[0070] As for the individual electrical conductors of the elastic flat conductor arrangement 32, each of the stranded wires 46, 48 comprises a plurality of individual metallic wires, as indicated in Fig. 10 at the bottom left by reference numeral 52 by splicing at the wire ends. Between the individual metallic wires, the respective stranded wires 46, 48 can also have one or more plastic threads for strain relief. In the illustrated embodiment, the individual wires of the respective stranded wires 46, 48 are enamel-insulated for electrical insulation. Alternatively or additionally, the respective stranded wires can also be provided with extruded plastic insulation (not shown in the figures).

[0071] Fig. 10 shows further details of a possible connecting piece 28 at the end 26 of the hose 10. In the exemplary embodiment shown here, the connecting piece 28 has a contact region 54 which is electrically connected to the elastic flat conductor arrangement 32 and which has two slip rings 56. The two slip rings 56 of the contact region 54 are attached at an axial distance from one another to a sleeve-shaped slip ring carrier 58 made of plastic which, according to Fig. 10, is provided with screw projections 60 on its inner circumferential surface. In the assembled state of the connecting piece 28, the slip ring carrier 58 is screwed with its screw projections 60 onto the inner hose 12, more precisely onto its helically extending outer recesses 38, whereby the slip ring carrier 58 clamps the sheath 22 onto the inner hose 12.

[0072] In this position, the slip ring carrier 58 is further fixed to the inner hose 12 by means of a collar sleeve 62, which is pressed into the inner hose 12 in a force-fitting manner to such an extent that an annular collar 64 formed on the collar sleeve 62 comes to rest against a shoulder 66 (see Fig. 10) on the inner circumference of the slip ring carrier 58. In this case, projections 68 provided on the outside of the annular collar 64 of the collar sleeve 62 engage in associated windows 70 in the slip ring carrier 58, so that rotation of the slip ring carrier 58 about the longitudinal axis 18 of the hose 10 is no longer possible.

[0073] On the slip rings 56, in particular according to the Fig. 1 , 9and 10 solder lugs 72, 74 are provided, to which the stranded wires 46, 48 of the elastic flat conductor arrangement 32 are soldered, as indicated by dashed lines in Fig. 10, in order to electrically contact the contact area 54 of the respective connecting piece 28 with the elastic flat conductor arrangement 32. An elastomeric ring seal 78, which is slipped onto an end-side ring extension 76 of the collar sleeve 62, finally completes the respective connecting piece 28 of the flexible hose 10. During operation of the hose 10, this ring seal 78 serves to seal between the connecting piece 28 and an associated junction box (not shown).

[0074] A method for producing the flexible hose 10 described so far generally comprises the following three method steps a) to c): In a first step a), an inner hose 12 is formed, which defines a cavity 16 with an inner side 14 around a longitudinal axis 18 and has a profile 34 on at least one outer side 20 which, viewed in section, has a wave shape with elevations 36 and depressions 38. The "base hose" produced so far is, in principle, already ready for use, i.e., if no special requirements are placed on it with regard to electrical equipment or a sheathing or braiding, this base hose can be assembled by cutting to length and providing it with suitable connecting pieces.

[0075] Only in a subsequent step b) does the above-described elastic flat conductor arrangement 32, when requirements are placed on the hose 10 with regard to its electrical equipment, take place, essentially without prestress, on the outer side 20 of the inner hose 12, so that the elastic flat conductor arrangement 32 runs along the longitudinal axis 18 and transversely to the elevations 36 and depressions 38 of the profiling 34. In other words, in this step, the hose 10 is provided with the desired electrical conductor 30, which, due to its design as an elastic flat conductor arrangement 32, is able to readily follow deformations of the hose 10, as already described above. Since the elastic flat conductor arrangement 32 runs along the inner hose 12, the (conductor) material used and consequently also the hose weight are minimized compared to previously known solutions.

[0076] Finally, in order to maintain this "electrified" state during further processing and later use of the hose 10, in a further step c), the elastic flat conductor arrangement 32 is attached to the outer side 20 of the inner hose 12 by applying a sheath 22 to the wave-shaped profile 34 of the inner hose 12. This attachment can, as already mentioned above, be achieved by braiding the outer side 20 of the inner hose 12, if necessary with the aid of an additional adhesive (adhesive or adhesive tape) on and / or under the elastic flat conductor arrangement 32, particularly in the region of the elevations 36 of the wave-shaped profile 34 of the inner hose 12.

[0077] Preferred substeps of step a) of forming the inner tube 12 include, as already mentioned above, a first substep in which a profile 39 is extruded from a plastic material. Subsequently, in a further substep, the profile 39 is wound helically to form the inner tube 12, with adjacent turns of the profile 39 being joined together in a media-tight manner, e.g., by means of the hot-melt adhesive 40, as is known per se.

[0078] With a view to particularly fast and efficient mass production of "electrified" flexible hoses 10, it is particularly preferred if steps b) of applying and c) of attaching the elastic flat conductor arrangement 32 to the outer side 20 of the inner tube 12 are carried out simultaneously. This can be done, in particular, by braiding the wave-shaped profile 34 of the inner tube 12 with monofilament and / or multifilament plastic threads to form the sheath 22, as is also known per se. However, this braiding is then carried out with the special feature that the elastic flat conductor arrangement 32 is applied to the outer side 20 of the inner tube 12 essentially without pretension at the braiding point, so that after the braiding point, the braided plastic threads press the elastic flat conductor arrangement 32 against the elevations 36 of the wave-shaped profile 34 of the inner tube 12.

[0079] It will be apparent to those skilled in the art that, in this way, virtually any length of inner hose 12 can be "electrified" and provided with a sheath 22 within the scope of "continuous production." Once the desired hose length has been reached, the braided inner hose 12, equipped with the elastic flat conductor arrangement 32, must then be appropriately cut to length before the hose 10 can be further assembled with the desired connectors 28.

[0080] For example, should the Fig. 1, 2 , 9and 10 are to be attached to the end 24 and / or 26 of the hose 10 as sketched, the elastic flat conductor arrangement 32 or at least its stranded wires 46, 48 must be pulled slightly out of their position between the inner hose 12 and the sheath 22 during or after cutting to length, as indicated in the top left of Fig. 10. The electrical conductors can then be stripped and soldered to the soldering lugs 72, 74 of the slip rings 56 on the slip ring carrier 58 screwed onto the inner hose 12, whereupon the connecting piece 28 can be fully assembled as already mentioned above.

[0081] A flexible hose, particularly a vacuum cleaner hose, has a wave-shaped inner tube, which defines a hollow space for conveying media along a longitudinal axis on its inner side, is surrounded on its outer side by a substantially smooth sheath, and is provided with a connector at at least one of its two ends. Radially arranged between the inner tube and the sheath is an electrical conductor, which extends from one end of the inner tube to the other end and terminates in the connector for establishing electrical contact.The electrical conductor is formed by an elastic flat conductor arrangement that extends parallel to the longitudinal axis of the hose in an electrically insulated manner and is held to the undulating profile of the inner hose at least by the sheathing. This allows particularly long, lightweight hoses equipped with electrical conductors to be produced cost-effectively. Furthermore, a method for producing such a hose in large quantities is proposed. LIST OF REFERENCE SYMBOLS

[0082] 10Hose 12Inner hose 14Inside 16Cavity 18Longitudinal axis 20Outside 22Sheathing, braiding 24End 26End 28Connector 30Electrical conductor 32Elastic flat conductor arrangement 34Wavy profiling 36Elevation 38Recess 39Profile 40Hot melt adhesive 42Inner surface 44Spiral groove 46Stranded wire 48Stranded wire 50Threads 52Splicing 54Contact area 56Slip ring 58Slip ring carrier 60Screw projection 62Collar sleeve 64Ring collar 66Step 68Protrusion 70Window 72Solder tag 74Solder tag 76Ring extension 78Ring seal

Claims

1. Flexible hose (10), particularly vacuum cleaner hose, with an inner hose (12) which is profiled for itself in wave shape and by an inner side (14) bounds a cavity (16) for the conveying of media along a longitudinal axis (18) of the hose (10) and which is surrounded at an outer side (20) by a substantially smooth sheathing (22) and provided at at least one of its two ends (24, 26) with a connecting member (28), wherein an electrical conductor (30) extending from one end (24) to the other end (26) of the inner hose (12) and ending in the connecting member (28) for electrical contact-making is arranged radially between the inner hose (12) and the sheathing (22), characterized in that the electrical conductor (30) is formed by a resilient flat conductor arrangement (32) which extends along the hose (10) parallel to the longitudinal axis (18) substantially without pre-stress and with electrical insulation and which is held on the wave-shaped profiling (34) of the inner hose (12) by the sheathing (22).

2. Flexible hose (10) according to claim 1, characterized in that the resilient flat conductor arrangement (32) is pressed against elevations (36) of the wave-shaped profiling (34) by the sheathing (22).

3. Flexible hose (10) according to claim 1 or 2, characterized in that the resilient flat conductor arrangement (32) is provided with a rubberization.

4. Flexible hose (10) according to any one of the preceding claims, characterized in that the sheathing (22) is a braiding of monofilamentary and / or multifilamentary plastics material threads.

5. Flexible hose (10) according to any one of the preceding claims, characterized in that the resilient flat conductor arrangement (32) comprises at least one strand line (46, 48), which extends in loop shape or zigzag shape as seen in longitudinal direction of the flat conductor arrangement (32) and is held in its course by threads (50) which in the manner of a knitted fabric form thread loops about the strand line (46, 48), that are looped into stitches.

6. Flexible hose (10) according to claim 5, characterized in that the resilient flat conductor arrangement (32) comprises at least two strand lines (46, 48) which extend at a mutual axial spacing equally in loop shape or zigzag shape as seen transversely to the flat conductor arrangement (32).

7. Flexible hose (10) according to claim 5 or 6, characterized in that the strand line (46, 48) of the resilient flat conductor arrangement (32) comprises a plurality of metallic individual wires and at least one plastics material thread for tension relief.

8. Flexible hose (10) according to any one of claims 5 to 7, characterized in that the strand line (46, 48) of the resilient flat conductor arrangement (32) is provided with an extruded insulation or is lacquer-insulated.

9. Flexible hose (10) according to any one of claims 5 to 8, characterized in that the threads (50) of the knitted fabric are resilient at least in part, wherein the threads (50) of the knitted fabric preferably comprise a mixture of polyester or polyamide fibers with elastane fibers.

10. Flexible hose (10) according to any one of the preceding claims, characterized in that the connecting member (28) has a contact region (54) with which the resilient flat conductor arrangement (32) is electrically connected, wherein the contact region (54) preferably comprises at least one slip ring (56).

11. Method of producing a flexible hose (10) according to any one of the preceding claims, characterized by the following method steps: a) forming an inner hose (12), which by an inner side (14) bounds a cavity (16) around a longitudinal axis (18) and has at least at an outer side (20) a profiling (34) which as seen in section has a wave shape with elevations (36) and depressions (38), b) mounting of a resilient flat conductor arrangement (32) on the outer side (20) of the inner hose (12) substantially free of pre-stress so that the resilient flat conductor arrangement (32) extends along the longitudinal axis (18) and transversely to the elevations (36) and depressions (38) of the profiling (34) and c) securing the resilient flat conductor arrangement (32) to the outer side (20) of the inner hose (12) by mounting a sheathing (22) on the wave-shaped profiling (34).

12. Method of producing a flexible hose (10) according to claim 11, characterized in that in the step a) of forming the inner hose (12) initially a profile (39) of a plastics material is extruded and then the profile (39) is helically wound to form the inner hose (12), wherein adjacent windings of the profile (39) are media-tightly connected together.

13. Method of producing a flexible hose (10) according to claim 12, characterized in that the adjacent windings of the profile (39) are media-tightly connected together by a hot-melt adhesive (40).

14. Method of producing a flexible hose (10) according to any one of claims 11 to 13, characterized in that the steps b) of mounting and c) of securing the resilient flat conductor arrangement (32) on and to the outer side (20) of the inner hose (12) are carried out at the same time.

15. Method of producing a flexible hose (10) according to any one of claims 11 to 14, characterized in that for formation of the sheathing (22) the wave-shaped profiling (34) of the inner hose (12) is braided by monofilamentary and / or multifilamentary plastics material threads, wherein the resilient flat conductor arrangement (32) is laid on the outer side (20) of the inner hose (12) substantially without pre-stress at the braiding point so that after the braiding point the braided plastics material threads press the resilient flat conductor arrangement (32) against the elevations (36) of the wave-shaped profiling (34) of the inner hose (12).