Abstract:
A device for connecting two elements by shrinking a shrink tube includes a heating element and a control unit. The heating element is adapted for providing thermal or inductive energy and is further adapted such that with it a shrink tube, which can be pulled onto a connection region of two elements to be connected, can be encased along at least part of the circumference of the shrink tube. The control unit is adapted for supplying electrical energy to the heating element and furthermore is adapted such that with it the temperature of the heating element is controllable such that, by shrinking the shrink tube, the two elements are connectable.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/600,055 filed Aug. 9, 2004, the disclosure of which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The invention relates to a device for connecting two elements, an arrangement for connecting two elements, a method for producing a device for connecting two elements, and a method for connecting two elements.  
         [0003]     According to the state of the art, a shrink tube is used to establish a connection between two elements to be connected.  
         [0004]     According to the state of the art, in order to connect two elements with the use of a shrink tube, a shrink tube is pulled over a region of the abutting elements. Heat is applied to the shrink tube by means of an industrial hot-blast device or a Bunsen burner such that as a result of this the diameter of the shrink tube is reduced. The shrunk shrink tube thus contracts over the two ends of the elements and in this way forms a mechanical connection of the two elements.  
         [0005]     The use of shrink tubes for connecting elements to be connected plays a role in particular in aircraft because shrink tube connections contribute to keeping the weight of the aircraft down. Furthermore, installation and deinstallation effort is reduced (making four or at least two steel strip clamps dispensible). Moreover, keeping hitherto-used special couplers is no longer necessary for the manufacturer or for the operator.  
         [0006]     However, in an aircraft the available installation space is confined. Furthermore, an aircraft represents a temperature-sensitive environment in which the use of an open flame or some other strong heat source as used according to the state of the art for producing a shrink tube connection is critical. Moreover, there are stringent safety regulations relating to aircraft; regulations which often are not compatible with the use of a Bunsen burner or an industrial hot-blast device. Such basic conditions can also be found in other environments (railways, office blocks, etc.) in which shrink tube connections can be used.  
       SUMMARY OF THE INVENTION  
       [0007]     According to an exemplary embodiment of the invention, a device for connecting two elements, an arrangement for connecting two elements, a method for producing a device for connecting two elements, and a method for connecting two elements with the features according to the independent claims are provided.  
         [0008]     The device according to an exemplary embodiment of the invention for connecting two elements by means of shrinking a shrink tube comprises a heating element and a control unit. The heating element is adapted for providing thermal or inductive energy and is further adapted such that with it a shrink tube, which can be pulled onto a connection region of two elements to be connected, can be encased along at least part of the circumference of the shrink tube. The control unit is adapted for supplying electrical energy to the heating element, and is further adapted such that with it the temperature of the heating element can be controlled in such a way that, by means of shrinking the shrink tube, the two elements are connectable.  
         [0009]     Furthermore, according to an exemplary embodiment of the invention, an arrangement is created for connecting a first element to a second element in a connection region by means of a shrink tube, wherein said arrangement comprises a first element, a second element, a shrink tube, a heating element and a control unit. The shrink tube is pullable onto a connection region of the first element and the second element. The heating element is adapted for providing thermal or inductive energy and is further adapted such that with it the shrink tube can be encased along at least part of the circumference of the shrink tube. The control unit is adapted for supplying electrical energy to the heating element and is further adapted such that with it the temperature of the heating element can be controlled such that, by means of shrinking the shrink tube, the first element can be connected to the second element.  
         [0010]     In the method according to an exemplary embodiment of the invention for producing a device for connecting two elements by means of shrinking a shrink tube, a heating element for providing thermal or inductive energy is formed and adapted such that with it a shrink tube which can be pulled onto a connection region of two elements to be connected can be encased along at least part of the circumference of the shrink tube. A control unit is formed for supplying electrical energy to the heating element and is adapted such that with it the temperature of the heating element can be controlled such that, by means of shrinking the shrink tube, the two elements are connectable.  
         [0011]     Furthermore, according to an exemplary embodiment of the invention, a method for connecting two elements by means of shrinking a shrink tube is provided, in which method a shrink tube is pulled onto a connection region of two elements to be connected, along at least part of its circumference the pulled-on shrink tube is encased by a heating element, and by means of the heating element thermal or inductive energy is supplied to the shrink tube, wherein the temperature of the heating element is controlled such that, by means of shrinking the shrink tube, the two elements are connected.  
         [0012]     According to an exemplary embodiment of the invention, furthermore, a shrink tube is used along at least part of the heating element encasing its circumference to provide thermal or inductive energy for shrinking the shrink tube for connecting two elements onto which in a connection region the shrink tube is pulled.  
         [0013]     One exemplary aspect of the invention may be seen in that a shrink tube for connecting two elements is supplied in a targeted way with a defined quantity of heat required for shrinking, in that the shrink tube is directly encased by a heating element for providing the thermal or inductive energy required for shrinking. For instance, the shrink tube is brought into direct contact with the heating element such that heat transfer/introduction can take place by means of heat conduction and/or heat radiation and/or heat convection. In other words, the heat source and the shrink tube may be arranged so as to be directly spatially adjacent such that according to an exemplary embodiment of the invention the efficiency when supplying thermal or inductive energy for shrinking the shrink tube may be significantly improved. Because the heat transfer is spatially more localised, and the quantity of heat to be provided overall may be reduced as a result of increased efficiency during heat transfer when compared to the state of the art, the shrink tube connection according to an exemplary embodiment of the invention can be used even in critical, spatially confined, temperature-sensitive environments, for example in an aircraft. The solution according to an exemplary embodiment of the invention also meets stringent safety regulations because the quantity of heat emitted to the surroundings may be reduced, and an open fire (as is the case with the use of a Bunsen burner) or a spatially non-confined flow of hot air (as is the case with the use of an industrial hot-blast device) may be avoided.  
         [0014]     Application of the invention may be therefore particularly advantageous in such scenarios in which due to confined installation space or stringent safety requirements (for example in an aircraft, in which a naked flame must at all costs be avoided, or in which the temperature sensitivity of the surroundings are to be taken into account) shrinking the shrink tube into place by means of an open heat source is problematic.  
         [0015]     The term “shrink tube” may relate in particular to a tube made from a thermoplastic material, which tube contracts due to the effect of heat. In other words, the diameter of the shrink tube is irreversibly reduced under the effect of heat such that the shrunk shrink tube engages the two elements to be connected and thus establishes a connection between the elements.  
         [0016]     According to an exemplary embodiment of the invention, a shrink tube connection for connecting two elements even in confined and temperature-sensitive environments is provided.  
         [0017]     Concretely, the heating element of the invention can be implemented as a heating sleeve for shrinking into place a shrink tube connection. In this way a secure lightweight connection between two elements can be implemented by means of a targeted supply of thermal or inductive energy, wherein the overall energy quantity arising and any undesired heating up of the environment are reduced.  
         [0018]     Two elements to be connected (for example two pipe ends to be connected or two cable ends to be connected), onto which elements the shrink tube is pulled, can be positioned such that the shrink tube is aligned by means of markings (for example colour markings) on the elements to be connected. A heating element (for example a heating mat) covers the shrink tube in a predefinable connection region, of sufficiently large size, of the elements to be connected. For instance, the heating element envelops the shrink tube over its entire circumference. As an alternative it is possible that the heating element envelops the shrink tube only along part of its circumference (for example half the circumference or a quarter of the circumference), for example with the use of a heating element with an essentially U-shaped profile, into which the shrink tube can be inserted. Additional elements may be provided, for example a temperature sensor for determining the temperature of the heating element or of the shrink tube, or hook and fleece tapes for attaching a heating mat placed around the shrink tube.  
         [0019]     By means of a thermal energy source it is then possible to supply heat directly to the shrink tube, for example by implementing temperature control according to the specifications of the shrink tube or of a diameter parameter, if required with the use of time control, as a result of which the shrinking process is initiated and controlled or regulated. Once a desired shrinkage temperature has been achieved and this shrinkage temperature has been maintained for a specified period of time, the supply of energy can be terminated. A high-quality, secure and pressure-proof connection between the two elements (for example a pipe connection) may then been formed with little expenditure of energy. The heating sleeve can then be removed from the device and can be employed in some other position.  
         [0020]     The control unit, which is electrically coupled to the heating element, can control the time-related and/or space-related temperature gradient on the shrink tube. A control routing used to this purpose can be adapted specifically to the particular shrink tube used or to the particular elements to be connected that are used. The control modalities (for example control algorithm or regulating algorithm, materials parameter or diameter parameter) of the control unit can be predefined so as to be fixed in the control unit or they can be set by the user by means of a user interface on the control unit and can thus be adjusted flexibly to the requirements of each individual case.  
         [0021]     According to an exemplary embodiment of the invention, the control system can be implemented either by means of a computer program, i.e. by means of software, or by means of one or several special electronic circuits (for example on a printed circuit board or as a monolithically integrated circuit), i.e. in hardware, or in any desired hybrid form, i.e. by means of software components and hardware components, which algorithms take into account the materials characteristics of the shrink tube used, as well as its diameter. In this case a control unit is provided.  
         [0022]     Exemplary improvements of the invention are stated in the dependent claims.  
         [0023]     Below, embodiments of the device according to an exemplary embodiment of the invention are described. These embodiments also apply to the arrangement according to an exemplary embodiment of the invention, to the methods according to an exemplary embodiment of the invention as well as to the use according to an exemplary embodiment of the invention.  
         [0024]     The device can comprise a carrier body on which and/or in which the heating element is arranged. The heating element can either be embedded in the carrier body or applied to the surface of said carrier body. Embedding provides safe protection of the heating element against damage because the heating element is surrounded by the material of the carrier body. Attachment of the heating element to the carrier body ensures particularly good heat transfer between the heating element and the shrink tube.  
         [0025]     The heating element and the carrier body can be a heating mat which is designed to be wrapped around the shrink tube. According to this embodiment, the heating mat can be mechanically flexible or bendable such that the heating mat can be wrapped around the shrink tube or around part of the shrink tube so as to establish good thermal contact. Concretely, such a heating mat or heating sleeve is an electrical heater, for instance comprising integrated thermal insulation. Such a heating sleeve can be made from a textile material and can comprise a heating surface, an electrically insulated heating line, thermal insulation and a robust outer casing. If such a heating sleeve is wrapped around a shrink tube, the heating sleeve can be fixed by means of an attachment device (for example a hook and loop fastener) such that the heating sleeve securely and steadily surrounds the shrink tube. Such an attachment device should be able to be detachable quickly such that after shrinking of the shrink tube the heating sleeve is removable and can be used immediately for establishing another shrink connection.  
         [0026]     According to an exemplary embodiment of the invention, the materials for such a heating sleeve can be selected based on the conditions of use (in particular the materials and geometric parameters of the shrink tube and the elements to be connected). For example silicon, textile glass or textile quartz glass can be used as materials for the carrier body.  
         [0027]     As an alternative to the described embodiment, the heating element and the carrier body can comprise two (or more) shell elements which are adapted to be placed around a shrink tube. For example, the heating element and the carrier body can comprise two semi-cylindrical shells, which are for example attached to each other by means of a hinge. The semi-cylindrical shells can be placed around the shrink tube and can subsequently be brought into direct contact with shrink tube, for example in that the hinge connection is closed. In this way particularly robust carrier bodies can be used. Furthermore, according to this embodiment, the installation effort for attachment of the device around a shrink tube to be shrunk is very modest.  
         [0028]     In the device, the heating element can be adapted such that with it a shrink tube that can be pulled onto a connection region of two elements to be connected can be encased along the entire circumference of the shrink tube. This embodiment provides particularly good heat exchange between the shrink tube and the heating element because the shrink tube is entirely surrounded by the thermal or inductive energy source, i.e. by the heating element.  
         [0029]     The heating element can for example be implemented as a meander-shaped heating wire. With this configuration a large quantity of heat can be provided in a confined space. A spiral-shaped geometry is also possible.  
         [0030]     The control unit/regulating unit can be designed such that it controls/regulates the temperature of the heating element based on at least one material parameter of a shrink tube to be shrunk. The required quantity of heat or an advantageous temperature gradient for the shrinking process of a shrink tube, among other things depends on the material. For example a radiation cross-linked polyolefin, Kynar™, Viton™ or Teflon™ can be used in a shrink tube.  
         [0031]     Furthermore, the control unit or regulating unit can be designed such that it controls and/or regulates the temperature of the heating element based on at least one geometry parameter of a shrink tube to be shrunk, for example its length, its diameter, or wall thickness. The quantity of heat to be supplied or an advantageous time-related temperature gradient on the heating element, among other things depends on the diameter of the shrink tube, its length, and on the elements (pipes, cables, wires, etc.) onto which it is to be shrunk. By means of adapting the temperature cycle, the shrinking-on process can be optimised.  
         [0032]     Furthermore, the control unit/regulating unit can be adapted in such a way that it controls/regulates a temperature-time gradient of the heating element. In this way a temperature cycle (heating—shrinking at a constant temperature—cooling) can in a targeted way be attuned to the materials used or to the elements to be connected.  
         [0033]     The control unit may be a regulating unit to which an actual temperature (i.e. a measured present temperature) of the heating element can be supplied and which, based on the actual temperature, regulates or sets a desired temperature of the heating element. In other words, the control unit according to an exemplary embodiment of the invention can also comprise a regulating mechanism. This means that the quantity of heat produced by the heating element is readjusted on the basis of an acquired actual temperature of the heating element. In this way the supply of too much or too little thermal or inductive energy to a shrink tube can be corrected.  
         [0034]     The device can comprise a temperature sensor for determining the actual temperature of the heating element, which temperature is to be supplied to the regulating unit. Such a temperature sensor can for example be a Pt100 resistance thermometer.  
         [0035]     Below, embodiments of the arrangement according to an exemplary embodiment of the invention are described. These embodiments also apply to the device according to an exemplary embodiment of the invention, the methods according to an exemplary embodiment of the invention, and to the use according to an exemplary embodiment of the invention.  
         [0036]     In the arrangement the first element can be a first pipe and the second element can be a second pipe. Thus, according to an exemplary embodiment of the invention, a high-quality pipe connection between two end regions of a pipe to be connected can be implemented with locally well-defined heat transfer.  
         [0037]     As an alternative, the first element can be a first cable (for example a wire with an insulation cover) and the second element can be a second cable (for example a wire with an insulation cover). It is thus for example possible to envelop two cable ends stripped of insulation, i.e. two bared wire ends, with a cylindrical shrink tube, and subsequently by means of targeted heat transfer to simultaneously interconnect the two wires mechanically and such that they are electrically conductive, and to provide electrical insulation to them. In this case the shrunk shrink tube is simultaneously a connection element and an electrical insulation element. Connection of the wires by means of the shrink tube can optionally, for example, be supported in that the wires in a border region comprise a means that strengthens the connection (for example a solder such as soldering tin). The heat transfer for shrinking the shrink tube can then also be used for melting the soldering tin.  
         [0038]     The first element can comprise a first alignment mark, and/or the second element can comprise a second alignment mark, wherein by means of the first alignment mark and/or the second alignment mark the shrink tube to be pulled on can be aligned on the first element and on the second element. Such an alignment mark on at least one of the two elements to be connected can be used for adapting the relative position of the first element in relation to the second element so as to achieve a high-quality good connection between the two elements.  
         [0039]     The first alignment mark and/or the second alignment mark can be a visually perceptible mark, a mark that is perceptible in a tactile sense, or a mechanical mark. A visual alignment mark can for example be a colour mark on the elements to be connected, for example a circumferential visible line provided on the first element and/or on the second element and which indicates optimum positioning of the two elements to be connected in that the two end regions of the shrink tube coincide with the colour marks with optimum positioning of the shrink tube pulled into place. The alignment mark can also be a scratch mark, in other words a mechanical indentation in one of the elements to be connected. An abutment mark is also possible, in other words a mechanical end stop for the pulled-on shrink tube on one of the elements to be connected.  
         [0040]     Below, one embodiment of the method for connecting two elements is described. This embodiment also applies to the device according to an exemplary embodiment of the invention, the arrangement according to an exemplary embodiment of the invention, the method according to an exemplary embodiment of the invention for producing the device, and to the use according to an exemplary embodiment of the invention.  
         [0041]     According to this embodiment, regulating (or controlling) the temperature of the heating element involves increasing the temperature from a starting temperature to a predefinable target temperature; maintaining the target temperature for a predefinable maintenance time; and reducing the temperature from the target temperature to the starting temperature. By predefining such a temperature cycle with predefinable parameters the shrinking process can be optimised. In this way a stable shrink tube connection is achieved with little heat transfer.  
         [0042]     Below, one embodiment of the use according to an exemplary embodiment of the invention is described. This embodiment also applies to the device according to an exemplary embodiment of the invention, the arrangement according to an exemplary embodiment of the invention, and the methods according to an exemplary embodiment of the invention.  
         [0043]     Shrinking shrink tubes by means of a defined supply of thermal or inductive energy to the shrink tube, with the use of a heating element enveloping said shrink tube for connecting two elements, can be carried out particularly advantageously in an aircraft. In an aircraft a shrink connection can be used as a reliable and weight-reducing connection between two elements, namely particularly advantageously when implementing such a shrink connection with the spatially exact supply, according to an exemplary embodiment of the invention, of thermal or inductive energy to a shrink tube to be shrunk, without there being any danger of overheating in a temperature-sensitive environment, or any danger of a fire breaking out.  
         [0044]     Embodiments of the invention are shown in the figures and are explained in further detail below. 
     
    
     DETAILED DESCRIPTION  
       [0045]     The following are shown:  
         [0046]      FIG. 1 a  lateral view of an arrangement for connecting two pipes, according to a preferred embodiment of the invention;  
         [0047]      FIG. 2 a  cross-sectional view, along sectional line I-I′ shown in  FIG. 1 , of the arrangement for connecting two pipes, according to the preferred embodiment of the invention;  
         [0048]      FIG. 3 a  lateral view of an arrangement for connecting two cables, according to another embodiment of the invention;  
         [0049]      FIG. 4 a  device for connecting two elements, according to one embodiment of the invention; and  
         [0050]      FIG. 5 a  device for connecting two elements, according to another embodiment of the invention.  
     
    
       [0051]     Identical or similar components in various figures have identical reference numbers.  
         [0052]     The representations in the figures are schematically and not to scale.  
         [0053]     Furthermore, with reference to  FIGS. 1 and 2 , an arrangement  100  for connecting a first pipe  101  to a second pipe  102  by means of shrinking a polyolefin shrink tube  103 , according to a preferred embodiment of the invention is described.  
         [0054]     As shown in  FIG. 1 , the arrangement  100  comprises a first pipe  101  and a second pipe  102  which are to be connected in a connection region  111  (mechanically abutting or for mechanical end coupling &lt;pipes can oscillate&gt;with a gap). The arrangement  100  further comprises a polyolefin shrink tube  103  which by way of the connection region  111  of the first pipe  101  is connected to the second pipe  102 . Furthermore, a meandering heating wire  104  with a high value of relative ohmic resistance is provided (on which heating wire  104  thus an adequate quantity of ohmic heat can be released when an electric current flows through it). The heating wire  104  provides thermal energy for shrinking the polyolefin shrink tube  103  and is arranged such that with it the polyolefin shrink tube  103  is completely encased. Furthermore, a sleeve  105 , i.e. a bendable carrier material, is provided, with the heating wire  104  arranged on the inside of said sleeve  105 . The sleeve  105  encases the polyolefin shrink tube  103  such that good thermal coupling, for instance direct thermal contact, i.e. mechanical contact, is established between the heating wire  104  and the polyolefin shrink tube  103 . A hook-tape closure  106  ensures that an end region of the sleeve  105 , which end region comprises a hook-tape closure  106 , is firmly attachable to a central section of the sleeve  105 , comprising a fleece tape. In other words, by overlapping the hook-tape closure  106  with a fleece tape, stable fixing of the sleeve  105  becomes possible.  
         [0055]     Furthermore,  FIG. 1  shows a first colour mark  109  on the first pipe  101  and a second colour mark  110  on the second pipe  102 . When the pipes  101 ,  102  are shifted together such that the polyolefin shrink tube  103  covers the connection region  111 , then spatial correspondence of the colour marks  109 ,  110  with the marginal sections of the hollow cylindrical polyolefin shrink tube  103  or with the sleeve  105  indicates that the two steel pipes  101 ,  102  are optimally aligned in relation to each other for establishing a shrink tube connection.  
         [0056]     By means of a cable  107 , the heating wire  104  is electrically coupled to a control circuit  108 .  
         [0057]     The control circuit  108  comprises a monolithically integrated circuit in which a control program for controlling or regulating the time gradient of the temperature on the heating wire  104  is stored. By means of a user interface, a user can enter parameters for a connection to be established (material and dimensions of the polyolefin shrink tube  103 ; material and dimensions of the pipes  101 ,  102  to be connected; required strength of a connection to be established; etc.) Based on these parameters, the program, in the integrated circuit of the control circuit  108 , controls and regulates the temperature gradient on the heating wire  104  in such a way that optimal shrinkage of the polyolefin shrink tube  103  becomes possible such that a permanent and stable connection between the first pipe  101  and the second pipe  102  is established. For this purpose the circuit  108  provides electrical energy in a regulable quantity to the heating wire  104  by way of the cable  107 , which electrical energy is convertible in the heating wire to ohmic or inductive heat and is thus convertible to thermal energy. The circuit  108  therefore also fulfils the function of an electrical energy source.  
         [0058]     After a user has entered shrink connection parameters by means of a user interface, the circuit  108 , based on these shrink connection parameters, supplies electrical energy to the heating wire  104 , which energy due to (desirable) ohmic losses in the heating wire  104  is converted to thermal energy. Due to good spatial and thermal coupling between the heating wire  104  and the polyolefin shrink tube  103  this thermal energy is transferred to said shrink tube  103 . As a result of this a defined quantity of heat is provided to the polyolefin shrink tube  103 , which leads to shrinkage of the shrink tube  103 . In this way a stable connection between the first pipe  101  and the second pipe  102  is established.  
         [0059]      FIG. 2  shows a cross-sectional view of the arrangement  100  along a line I-I′ shown in  FIG. 1 .  
         [0060]     Below, with reference to  FIG. 3 , an arrangement  300  according to another embodiment of the invention is described.  
         [0061]     The arrangement  300  is used to connect a first electrical cable  301  to a second electrical cable  302 . As shown in  FIG. 3 , the first cable  301  comprises a copper core  301   a  and an insulation jacket  301   b,  which envelops the copper core  301   a,  for electrically insulating the copper core  301   a.  The second cable  302  comprises a copper core  302   a  and an insulation jacket  302   b  made from an electrically insulating material, which insulation jacket  302   b  envelops the copper core  302   a.  In a connection region  111  to be established, the first cable  301  and the second cable  302  are stripped of insulation. In other words, in this abutting region the insulation jacket  301   b  has been removed from the copper core  301   a,  and the insulation jacket  302   b  has been removed from the copper core  302   a.  The two cables  301 ,  302  thus abut each other. A Teflon shrink tube  303  has been pulled onto the stripped region of the first cable  301  and of the second cable  302 . A heating mat  304 , in other words a textile carrier material with a heating wire (not shown) provided therein, is provided which completely envelops the Teflon shrink tube. The heating wire of the heating mat  304  is connected to a circuit  108  by way of a cable  107 .  
         [0062]     By way of providing electrical energy from the circuit  108  to the heating wire of the heating mat  304 , a defined quantity of thermal energy is supplied to the Teflon shrink tube  303  such that said Teflon shrink tube  303  shrinks, and produces a mechanical and electrical connection between the first wire  301  and the second wire  302 . Since in the region stripped of the insulation the copper core  301   a  abuts the copper core  302   a,  the shrink tube  303 , which tightly envelops the cables  301 ,  302 , in the shrunk state establishes a mechanical and electrical connection.  
         [0063]     Below, with reference to  FIG. 4 a  device  400  for connecting two elements by means of shrinking a shrink tube according to one embodiment of the invention is described.  
         [0064]     The arrangement  400  again comprises a circuit  108  which is coupled to a heating element  404  by means of cables  107 . The heating element  404  comprises a first semi-cylindrical heating element shell  401  and a second semi-cylindrical heating element shell  402 , which are coupled by means of a hinge  403 . By opening the hinge  403 , temporarily an opening can be established between the two semi-cylindrical heating element shells  401 ,  402 , which opening is sufficient in size to insert a hollow-cylindrical shrink tube into the heating element  404 . Then the hinge  403  is closed such that complete enveloping of the heating element  404  by the shrink tube is possible. The heating element  404  comprises the robust solid body shells  401 ,  402  and a heating wire (the latter not shown in  FIG. 4 ).  
         [0065]     Below, with reference to  FIG. 5 , a device  500  for connecting two elements by means of shrinking a shrink tube according to another embodiment of the invention is described.  
         [0066]     The device  500  comprises a circuit  108  which is electrically coupled to a heating wire  502  by way of cables  107 . The heating wire  502  is embedded in a textile sleeve  501 . In an end region of the textile sleeve  501  a hook-tape closure  503  is provided.  
         [0067]     To operate the device  500  for connecting two elements, the two elements are arranged so as to abut and are enveloped by a shrink tube. Then the sleeve  501  is wrapped around the shrink tube, wherein the textile sleeve  501  is fixed by means of the hook-tape closure  503 . The circuit  108  provides electrical energy to the heating wire  502 , wherein the heating wire  502  provides such an amount of energy to the shrink tube that said shrink tube shrinks and establishes a firm connection between the elements.  
         [0068]     It should be noted that the term “comprising” does not exclude other elements or steps and the “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined.  
       List of Reference Numbers  
       [0000]    
       
           100  Arrangement  
           101  First pipe  
           102  Second pipe  
           103  Polyolefin shrink tube  
           104  Heating wire  
           105  Sleeve  
           106  Hook-tape closure  
           107  Cable  
           108  Circuit  
           109  First colour mark  
           110  Second colour mark  
           111  Connection region  
           300  Arrangement  
           301  First cable  
           301   a  Copper core  
           301   b  Insulation jacket  
           302  Second cable  
           302   a  Copper core  
           302   b  Insulation jacket  
           303  Teflon shrink tube  
           304  Heating mat  
           400  Device  
           401  First semi-cylindrical heating element shell  
           402  Second semi-cylindrical heating element shell  
           403  Hinge  
           404  Heating element  
           500  Device  
           501  Textile sleeve  
           502  Heating wire  
           503  Hook-tape closure