Pipe profile

Abstract

The invention relates to a double tube profile comprising an outer tube and an inner tube arranged in the outer tube with its longitudinal central axis parallel to the longitudinal central axis of the outer tube, wherein the inner tube has a substantially circular cross-section perpendicular to its longitudinal central axis and the outer tube has a cross-section deviating from a circular cross-section perpendicular to its longitudinal central axis.

Description

[0001] The present invention relates to a tubular profile, a method for producing a connection by means of a tubular profile and the use of a tubular profile for producing a connection between a first component having the tubular profile or consisting of it and a second component by means of a connecting means.

[0002] Numerous different joining techniques for connecting components are known from a wide variety of technical fields. For most applications, a connection that is as simple and cost-effective as possible, yet still stable, is desired.

[0003] One of these prior art joining techniques is a connection using square tube profiles, in which tubes with a square cross-section perpendicular to their longitudinal center axis are inserted into suitable holders and, if necessary, secured in this position using suitable connecting materials or methods. Such square tube profiles, made from a wide variety of materials, are used millions of times in technical structures in both stationary and mobile applications.

[0004] The plug-in connection of a square tube profile in a bracket can be secured using suitable methods such as welding, soldering, or gluing. Alternatively, the connection between the bracket and the profile can also be achieved by form-fitting, with the square tube profile being manufactured to fit precisely into the bracket's socket. Another alternative is the use of costly and complexly manufactured fitting parts, such as milled or laser-cut parts.

[0005] However, clamp / screw connections of standardized tubular profiles are also widely used, in which each tubular profile is fixed in the holder by means of a screw. This technology is particularly cost-effective and also versatile, as the tubular profile can basically be fixed in any position in the holder, and is used, for example, in construction and furniture manufacturing as well as in automotive engineering. A disadvantage of this prior art solution, however, is that the plug / screw connections are usually oversized and the screw connection for fastening the profile is only one-directional. Even tightly screwed square tubular profiles can therefore move within the connection when the necessary leverage is applied and, in the worst case, can even come loose due to constantly repeated movements.

[0006] With screw clamps in the end area of ​​square tube profiles known from the prior art, this can also lead to undesirable deformation of the side surface of the square tube profile, which is subject to the screw connection, causing it to be pushed in "ramp-like" toward the end of the profile, rendering the connection unstable, especially if it is subject to movement or leverage. To avoid this, particularly stable and thick-walled profiles are used in the prior art, which, however, also have the disadvantages of being heavy and expensive. Object of the invention

[0007] It is the object of the present invention to provide an alternative pipe profile which overcomes the aforementioned disadvantages known from the prior art and is characterized in particular by a high stability of a clamp / screw connection produced with the pipe profile. General description of the invention

[0008] The invention solves this problem with the features of the claims and in particular with a double tube profile which comprises or consists of an outer tube and an inner tube arranged in the outer tube with its longitudinal center axis parallel to the longitudinal center axis of the outer tube, wherein the inner tube has a substantially circular cross-section perpendicular to its longitudinal center axis and the outer tube has a cross-section deviating from a circular cross-section perpendicular to its longitudinal center axis.

[0009] For the purposes of the present invention, an "outer pipe" is understood to mean a pipe in which - at least in sections - another pipe (the inner pipe) is arranged. Accordingly, an "inner pipe" is understood to mean a pipe that is arranged within a surrounding pipe.

[0010] For the purposes of the invention, a “double tube profile” is understood to mean an arrangement of two tubes, of which a first tube is arranged at least in sections in a second tube.

[0011] According to a preferred embodiment, the outer tube has a square or substantially square cross-section perpendicular to its longitudinal center axis, wherein the term "substantially" here is intended to mean only minimal deviations from a square cross-section, e.g. within the framework of manufacturing tolerances. In this embodiment, in which the outer tube has a square cross-section perpendicular to its longitudinal center axis, the double tube profile according to the invention can also be referred to as a square tube profile. In contrast to square tube profiles known from the prior art, however, in the square tube profile according to the invention an inner tube with a circular or substantially circular cross-section perpendicular to its longitudinal center axis is arranged in the outer tube with a square cross-section perpendicular to its longitudinal center axis.Here too, the term “essentially” refers to only minimal deviations from a circular cross-section, e.g. within the scope of manufacturing tolerances.

[0012] As an alternative to a square cross-section, the outer tube of the double tube profile according to the invention can also have an octagonal cross-section perpendicular to its longitudinal central axis.

[0013] Optionally, the inner tube arranged in the outer tube extends over the entire length or only over part of the length of the outer tube.

[0014] A particular advantage of the double tube profile according to the invention is that when the double tube profile is arranged in a holder and fixed in the holder by means of a connecting means, in particular a screw, a stable connection can be created between the double tube profile and the holder. This is because, unlike profiles known from the prior art, which are only fastened in a holder in one direction with a screw, in the double tube profile according to the invention, the inner tube is pressed into an oval shape in the area of ​​the screw connection by one-sided pressure on a surface of the outer tube. This in turn deforms the outer tube and is pressed into the holder by the pressure exerted on the one hand by the connecting means and on the other hand by the deformed inner tube.The outer tube is compressed on one side by the engagement with the connecting means and "swells" on the opposite side and on the sides in between, so that the outer tube is not pressed against an inner wall of the holder in just one direction as in the prior art, but is pressed against an inner wall of the holder in three directions. This "expansion clamp" enables an extremely firm hold of the double tube profile according to the invention in the holder. As a result, the connection of the double tube profile and the holder by means of a connecting means, unlike a prior art arrangement of square tube profiles in a holder, does not wobble and is removable, but is secure and secure.

[0015] According to an advantageous embodiment, the double-profile pipe according to the invention has an opening in the outer pipe through which the inner pipe can be contacted by a connecting means or can engage with it. In this way, the connecting means can exert direct pressure on the inner pipe arranged in the outer pipe.

[0016] According to the invention, the outer tube and the inner tube of the double tube profile according to the invention can consist of the same or different material, wherein the material for the outer tube and for the inner tube is preferably each independently selected from the group comprising plastic, metal, metal alloys, natural fibers, carbon fibers and mixtures thereof.

[0017] In embodiments where the outer tube and inner tube are made of the same material, the strength of the inner tube is preferably equal to or greater than the strength of the outer tube. To this end, the wall thickness of the inner tube is, in particular, equal to or greater than the wall thickness of the outer tube to ensure the necessary pressure distribution.

[0018] In embodiments where the outer tube and inner tube are not made of the same material, the ratio of the wall thicknesses of the inner tube and outer tube can also be different, with the strength of the inner tube being greater than the strength of the outer tube. For example, according to one embodiment, the inner tube is made of steel, while the outer tube is made of plastic or aluminum.

[0019] In general, it is preferred that the outer diameter of the inner tube of the double tube profile according to the invention corresponds to an inner diameter of the outer tube, ie the clear inner width of the outer tube, in each case perpendicular to the longitudinal center axis of the outer or inner tube.

[0020] The invention further relates to a method for producing a connection by means of a double pipe profile, which comprises the following steps: - Providing a double tube profile comprising an outer tube and an inner tube arranged in the outer tube with its longitudinal center axis parallel to the longitudinal center axis of the outer tube, wherein the inner tube has a substantially circular cross-section perpendicular to its longitudinal center axis and the outer tube has a cross-section deviating from a circular cross-section perpendicular to its longitudinal center axis; - Arranging the double tube profile in a holder; - Fixing the double tube profile in the holder by engaging a connecting means, in particular a screw, with the double tube profile through an opening in the holder.

[0021] The double tube profile provided in the method according to the invention can have all the features of the double tube profile according to the invention described above, in particular - the outer tube has a substantially square or octagonal cross-section perpendicular to its longitudinal central axis; - the inner tube arranged in the outer tube extends over the entire length or only over part of the length of the outer tube; - the outer tube has an opening through which the inner tube can be contacted by a connecting means or can engage with it; - the outer tube may be made of the same or different material as the inner tube, wherein the material for the outer tube and for the inner tube is preferably each independently selected from the group comprising plastic, metal, metal alloys, natural fibers, carbon fibers and mixtures thereof; - the outer diameter of the inner pipe corresponds to the inner diameter of the outer pipe; and / or - the strength of the inner tube must be equal to or greater than the strength of the outer tube.

[0022] According to a preferred embodiment of the method according to the invention, the double tube profile provided therein has an opening in the outer tube and the connecting means is brought into engagement with the double tube profile through an opening in the holder in that the connecting means contacts the inner tube through the opening in the outer tube.

[0023] Regardless of whether the double tube profile provided in the method according to the invention has an opening in the outer tube and the connecting means can contact and engage the inner tube through this opening, or whether the double tube profile has no opening in the outer tube and the connecting means therefore contacts and engages the outer tube, the engagement of the connecting means with the inner tube or the outer tube preferably includes a deformation of the inner tube arranged in the outer tube in that it is compressed in a first dimension and expands in a second dimension.In this way, the inner tube and the surrounding outer tube are pressed against a wall of the bracket opposite the connecting element by the pressure exerted by the connecting element. Because the pressure causes the inner tube to deform and expand in the second dimension, the inner tube and the surrounding outer tube are also pressed against the side walls of the bracket. This pressure of the double tube profile against three walls of the surrounding bracket ensures high stability and resistance to pull-off of the connection.

[0024] Finally, the invention also relates to the use of a double tube profile according to the invention for producing a connection between a first component having the double tube profile or consisting of it and a second component by means of a connecting means, such as a screw. Detailed description of the invention

[0025] The invention will now be described in more detail by means of embodiments and with reference to the figures, which schematically - in the Fig. 1 shows a perspective view of a first embodiment of a double tube profile according to the invention; - in the Fig. 2 shows a sectional view of a square tube profile known from the prior art arranged in a holder; - in the Fig. 3 shows a sectional view of a double tube profile according to the invention arranged in a holder; - in the Fig. 4 shows a perspective view of another embodiment of a double tube profile according to the invention; - in the Fig. 5 shows a further embodiment of a double tube profile according to the invention in a sectional view.

[0026] In the Fig. Figure 1 schematically shows a perspective view of a double tube profile 1 according to the invention. This consists of an outer tube 2 and an inner tube 3, wherein the outer tube 2 has a square cross-section perpendicular to its longitudinal center axis, and the inner tube 3 has a circular cross-section perpendicular to its longitudinal center axis. In the embodiment shown, the inner tube 3 extends over the entire length of the outer tube 2, and the outer diameter of the inner tube 3 corresponds to the inner diameter of the outer tube 2.

[0027] The Fig. Figure 2 schematically shows, in partial figure a), a first sectional view of a square tube profile known from the prior art, which is arranged in a holder 5 and fixed by means of a screw as a connecting means 6. Partial figure b) shows the square tube profile arranged in the holder 5 in a further sectional view, along line AA of partial figure a).

[0028] In contrast to the double tube profile according to the invention, the square tube profile known from the prior art comprises only a single tube, which, due to the similar or identical geometry to the outer tube of a double tube profile 1 according to the invention, is also identified by the reference numeral 2 and referred to as the outer tube. Partial figure a) shows how the outer tube 2 deforms when engaged with a connecting means 6. The sectional view shown in part figure b) along the line AA from part figure a) shows the "ramp formation" frequently observed in the prior art, particularly when the profile is brought into engagement with the connecting means 6 in the end region of the outer tube 2. Here, the connecting means 6 presses on the side surface of the square tube profile on which the screw connection acts, so that the square tube profile is pressed in like a ramp.This makes the connection very unstable, especially if there is any movement or leverage acting on it.

[0029] The Fig. Figure 3 schematically shows, in partial figure a), a first sectional view of a double-tube profile 1 according to the invention, which is arranged in a holder 5 and fixed by means of a screw as a connecting means 6. Partial figure b) shows the double-tube profile 1 arranged in the holder 5 in a further sectional view, along line BB of partial figure a).

[0030] As can be seen, the inner tube 3 is only located in the area of ​​the screw connection, i.e. at the point where the double tube profile 1 engages with the connecting means 6, and in a surrounding area in the outer tube 2. Where the connecting means 6 engages with the double tube profile 1, the outer tube 2 is pressed in with a square cross-section (perpendicular to its longitudinal center axis), and the inner tube 3 is also compressed in a direction perpendicular to its longitudinal center axis, so that the cross-section of the inner tube 3, which originally had a circular cross-section, is oval in this area perpendicular to its longitudinal center axis. However, unlike what is known from the prior art, the outer tube 2 does not form a ramp due to the inner tube 3 arranged therein, but is only pressed in in the area of ​​the screw connection.

[0031] By compressing the inner tube 3 in a first direction, the diameter of the inner tube is increased in a second direction perpendicular to this first direction, i.e., the inner tube expands in this second direction and presses against the holder 5 in which the double tube profile 1 is arranged. In this way, the double tube profile 1 according to the invention is pressed against the holder 5 in three directions by the pressure of the connecting means 6, exerting a kind of spreading effect therein, by which it is firmly and securely fixed in the holder.

[0032] In the Fig. Figure 4 shows a perspective view of another embodiment of a double tube profile 1 according to the invention. The cross sections of the inner tube 3 and the outer tube 2 are square and circular, respectively, according to the preferred embodiment (each perpendicular to the longitudinal center axis of the tubes). In contrast to the Fig. 1, in this embodiment the outer tube 2 has an opening 4. Through this opening a connecting means 6 (in Fig. 4 not shown, cf. Fig. 3) directly contact and engage the inner tube 3 running inside the outer tube 2. As a result, the pressure is exerted directly on the inner tube 3, and not only indirectly through the connecting means 6. In this embodiment, the positive fit between the connecting means 6 and the opening 4 in the outer tube 2 achieves even better pull-off security while maintaining the pressure distribution through the oval deformation of the inner tube 3.

[0033] The inner tube 3 can be arranged in the outer tube 2 only in the end region of the double tube profile 1, in which the opening 4 is also located, or alternatively can extend over the entire length of the outer tube 2.

[0034] In the Fig.Figure 5 shows a perspective sectional view of a further embodiment of a double tube profile 1 according to the invention, in which the inner tube 3 has a circular cross-section perpendicular to its longitudinal center axis and the outer tube 2 has an octagonal cross-section perpendicular to its longitudinal center axis. In this embodiment too, upon engagement with a connecting means 6 (not shown), the clamping / spreading action described above occurs, ie the inner tube 3 is compressed in a first direction perpendicular to its longitudinal center axis and expands in a second direction perpendicular to the first direction, whereby it presses with the surrounding outer tube 2 against the walls of a holder 5 (not shown).

[0035] The features of the invention disclosed in the above description, in the examples and figures as well as in the claims may be essential both individually and in any combination for the realization of the invention in its various embodiments. List of reference symbols: 1 double tube profile 2 outer tube 3 inner tube 4 Opening in the outer tube 5 Bracket 6 connecting devices

Claims

[1] Double tube profile (1), comprising an outer tube (2) and an inner tube (3) arranged in the outer tube (2) with its longitudinal center axis parallel to the longitudinal center axis of the outer tube (2), wherein the inner tube (3) has a substantially circular cross-section perpendicular to its longitudinal center axis and the outer tube (2) has a cross-section deviating from a circular cross-section perpendicular to its longitudinal center axis. [2] Double tube profile according to claim 1, characterized by that the outer tube (2) has a substantially square or octagonal cross-section perpendicular to its longitudinal central axis. [3] Double tube profile according to claim 1 or claim 2, characterized by that the inner tube (3) arranged in the outer tube (2) extends over the entire length or only over part of the length of the outer tube (2). [4] Double tube profile according to one of the preceding claims, characterized bythat the outer tube (2) has an opening (4) through which the inner tube (3) can be contacted by a connecting means or can engage with it. [5] Double tube profile according to one of the preceding claims, characterized by that the outer tube (2) and the inner tube (3) consist of the same or different material, wherein the material for the outer tube (2) and for the inner tube (3) is preferably each independently selected from the group comprising plastic, metal, metal alloys, natural fibers, carbon fibers and mixtures thereof. [6] Double tube profile according to one of the preceding claims, characterized by that the outer diameter of the inner tube (3) corresponds to an inner diameter of the outer tube (2). [7] Double tube profile (1) according to one of the preceding claims, characterized by that the strength of the inner tube is equal to or greater than the strength of the outer tube. [8] Method for producing a connection by means of a double pipe profile (1) according to one of the preceding claims, the method comprising the following steps: - Providing the double tube profile (1) according to one of the preceding claims; - arranging the double tube profile (1) in a holder (5); - Fixing the double tube profile (1) in the holder (5) by engaging a connecting means (6) with the double tube profile (1) through an opening in the holder (5). [9] Method according to claim 8, characterized by that the connecting means (6) is brought into engagement with the double tube profile (1) through an opening in the holder (5) in that the connecting means (6) contacts the inner tube (3) through an opening (4) in the outer tube (2). [10] Use of a double tube profile (1) according to one of claims 1 to 7 for producing a connection between a first component having the double tube profile (1) and a second component by means of a connecting means (6).

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