Patent Publication Number: US-2009218451-A1

Title: Cable Retention Device

Description:
TECHNICAL FIELD 
     The present invention concerns a cable retention device to hold one or more cables and take up forces exerted by or on the one or more cables. 
     PRIOR ART 
     In many contexts where cables are used the cables are exerted to relatively large forces. Often such forces has to be taken up to not harm the cables or apparatuses or the like receiving the cables. The forces exerted on the cables may be gravity, torsion (rotational), traction, pulling, “whiplash” (caused by e.g. short circuited cables) and/or vibration forces. 
     It is common to use different types of cable clamps, but ordinary cable clamps will not take up any forces. Thus, there is a high risk that the cables are harmed if exerted to relatively high forces and if the cable clamps do not yield in any substantial way. One problem being that there is no real elastic connection between the cable and a structure receiving the cable clamps. 
     In wind power stations (plants) the turbine and its wings are usually placed pivotally at the top of a tower. The turbine is pointed to the wind. Cables go inside the tower downwards from the turbine. The turbine is placed at a relatively high position, which means that the cables will be relatively long and heavy. Supports are needed to hold the cables and tension forces due to gravity should be taken up. As the turbine part is rotated due to the wind direction the cables will also be turned and there is a need to also take up these rotations, thus, giving torsion relief or dampening. If the forces are not taken up there is a great risk that the cables or the connection for the cables to different appliances are harmed. 
     The invention is not limited to use at wind power stations. It can be used in all connections where cables are exerted to forces. As indicated above it may be used for cables that are hanging, giving traction relief or dampening and also to give torsion relief or dampening. A number of cable retention devices according to the present invention may be placed at intervals along a hanging cable. The invention may also be used to absorb vibrations. If short-circuiting appears the cables often experience a whiplash effect of very high magnitude. The present invention may be used to reduce the effects of such a whiplash. The invention may also be used for cables with a horizontal extension, whereby the cable retention devices of the invention are placed at some intervals. Long horizontal cables are often present in tunnels, such as for underground trains. 
     Thus, there exist several different situations in which cables should be received in a way to take up different forces. 
     Even though the present invention is developed mainly for wind power stations a person skilled in the art realises that it may be used in many different connections. It may also be used for pipes, wires etc. instead of or together with cables. For ease of description the expression “cable” is mainly used here, but that should be construed broadly and a person skilled in the art realises that retention devices according to the present invention may also be used for pipes, wires etc. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is that forces exerted by or on a cable in any direction should be taken up. A further object is that relatively simple and yet reliable devices should be used to take up the forces. By having relatively simple devices to take up the forces costs can be kept relatively low. A further object is that the contact with the cables should be elastic, i.e. the cables should be able to move in a certain degree in relation to the fixing points of the cable retention devices. Still a further object is that in some installations it should be possible to install and uninstall one or more cables without influencing the mounting of all other cables. 
     The present invention could replace many of the different types of cable clamps or cable clips used today, as well as clamps or clips for pipes and wires. 
     The inventions is based on modules placed around each cable, and which modules are then placed inside a frame construction. The frame construction is rigid and is made of a firm material not bulging under the expected forces. The frame constructions may be made of metal, composite materials, plastics or other suitable materials. The modules inside the frame constructions are compressed in some way to give a retention force on the cables inside the modules. As the modules are placed inside the frame construction they will press on the cable under compression, as they are not free to expand outwardly. 
     According to the invention there is some elasticity or flexibility in the connection between a cable and a structure to which the cable retention device is fixed. At the same time there is a firm contact between a cable and a module, due to high friction in said contact. Furthermore, due to the elasticity of the modules the risk of damage to the cables is relatively low. In the cable clamps normally used today parts of metal will be pressed against the cables and the harder the cable clamp is tightened the greater is the risk of damaging the cable. 
     In use at for example wind power stations the cable retention devices are used for relatively heavy cables, necessitating relatively large traction relief. Thus, each cable retention device must be able to take up a substantial force. In testing cable retention devices of the present invention has proved to be able to take up more than 500 kg. 
     In the description below expressions such as “bottom”, “side”, “vertical” and possible further similar expressions are used for ease of description and often with reference to directions shown in the attached Figs. In use the devices of the present invention may be placed in any orientation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained further below by way of examples and with reference to the enclosed drawings. In the drawings: 
         FIG. 1  is a perspective view of a cable retention device according to the present invention attached to a cable ladder or cable rack; 
         FIG. 2  is a plan view of the cable retention device of  FIG. 1 ; 
         FIG. 3  is a perspective view of parts of the cable retention device of previous Figs. in a not assembled condition; 
         FIG. 4  is a perspective view of an alternative embodiment of a cable retention device according to the present invention; 
         FIG. 5  is a perspective view of a third embodiment of a cable retention device according to the present invention; 
         FIG. 6  is a perspective view of a fourth embodiment of a cable retention device according to the present invention; 
         FIG. 7  is a plan view of the cable retention device of  FIG. 6 ; 
         FIG. 8  is a perspective view of a fifth embodiment of a cable retention device according to the present invention; 
         FIG. 9  is a plan view of a detail of the cable retention device of  FIG. 8 ; 
         FIG. 10  is a perspective view of a cable retention device according to the present invention, illustrating a supplement; 
         FIG. 11  is a perspective view of a sixth embodiment of a cable retention device according to the present invention; 
         FIG. 12  is a perspective view of a seventh embodiment of a cable retention device according to the present invention; 
         FIG. 13  is a perspective view of a part of the cable retention device of  FIG. 12 ; 
         FIG. 14  is a perspective view of an eight embodiment of a cable retention device according to the present invention; 
         FIG. 15  is a perspective view of a ninth embodiment of a cable retention device according to the present invention; 
         FIG. 16  is a perspective view of a first example of a module to be received in the cable retention devices of the present invention; 
         FIG. 17  is a plan view of a second example of a module to be received in the cable retention devices of the present invention; 
         FIG. 18  is a cross sectional view taken along the line A-A of  FIG. 17 ; 
         FIG. 19  is a plan view of a third example of a module to be received in the cable retention devices of the present invention; 
         FIG. 20  is a cross sectional view taken along the line B-B of  FIG. 19 ; 
         FIG. 21  is a side view of a tenth embodiment of a cable retention device according to the present invention; and 
         FIG. 22  is a side view an eleventh embodiment of a cable retention device according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the embodiment of  FIG. 1  two frame constructions  1  are shown, inside which a number of modules are received. The modules are to receive a cable  2  each. In the shown example one of the frames receive one cable  2  and the other frame two cables  2 . The number of cables received in each frame  1  may vary and normally most of the modules will have a cable  2 . In the various examples below cable retention devices are shown having different numbers of columns and receiving different numbers of modules. A person skilled in the art realises that the numbers of columns and modules may vary as well as the dimensions of the columns and modules. However, the dimensions of co-operating modules and columns are adapted to each other. 
     Each frame construction  1  comprises a number of plates  3 ,  4 ,  7  placed aligned one over the other. Thus, there will one outer plate  3 ,  4  at each end and a number of intermediate plates  7 . In the shown example of  FIGS. 1 and 2  there is only one intermediate plate  7 , but a person skilled in the art realises that the number of intermediate plates may be any number from zero and upwards. In the example of  FIG. 3  there is no intermediate plate. Between the plates  3 ,  4 ,  7  a number of modules are received, which modules are formed of two module halves  6 . In this example the module halves  6  are fixed to the plates  3 ,  4 ,  7 , preferably with an adhesive. The fixation may also be accomplished by means of Velcro, nailing, riveting or a composite moulding technique. The outer plates  3 ,  4  have module halves  6  on only one side, while the intermediate plates  7  have module halves  6  on two sides. Thus, in assembled condition one or more rows of modules are formed between the plates  3 ,  4 ,  7 . At the ends of each row of modules a support plate  5  is arranged to hold to the modules together and to support compression of the modules. In this example the support plates  5  are fixed to a module half  6  at each end of the row of modules. In other embodiments the support plates  5  are fixed to or are parts of the plates  3 ,  4 ,  7 . The plates  3 ,  4 ,  7  are fixed to each other by means of rods  8 , which rods are threaded, at least partly to co-operate with nuts  9 . The rods  8  are received in grooves  10  at the ends of the plates  3 ,  4 ,  7 . The grooves  10  at the ends of the plates  3 ,  4 ,  7  are open outwardly in such a way that the rods  8  may be inserted in the grooves  10 . In other embodiments circular openings replace one or both grooves  10  of each plate. 
     The module halves  6  are normally made of a compressible material and/or have compressible parts. As the cable retention device is assembled the modules are to be compressed, whereby each module will be pressed against a possible cable  2  received in the middle of the module. Thereby there will be a firm contact, due to high friction, between cable and module. At the same time an elastic connection will be formed between each cable  2  and the structure to which the cable retention device is fixed. 
     In use a number of cables  2  are placed in the cable retention device, whereby each cable is received in one module each. When all the cables  2  have been placed in one module half  6  each, the module halves are brought together forming rows of modules. Then rods  8  are placed in the grooves  10  of all plates  3 ,  4 ,  7  of the cable retention device. For every plate  3 ,  4 ,  7  one nut  9  is arranged one each rod  8 . The nuts  9  at the ends of each rod  8  are placed outside the plates  3 ,  4 , while the nuts  9  at the other plates  7  may be placed on any side of the plate  7 . By tightening the nuts  9  the modules will be compressed. 
     In  FIG. 1  the cable retention device is shown attached to a cable ladder, by means of clamping to the side rails of the cable ladder. This is only one example of attachment of a cable retention device according to the present invention to a structure. 
     The cable retention device of  FIG. 4  has two outer plates  11 ,  12 , i.e. plates placed at opposite ends of the cable retention device. It also has an intermediate plate  13 . All three plates  11 ,  12 ,  13  are placed one above the other at a distance when the cable retention device is assembled. Module halves  6  are attached to the plates  11 ,  12 ,  13 . The outer plates  11 ,  12  have module halves  6  on only one side, while the intermediate plate  13  has module halves  6  on both sides. In the same way as described above the plates  11 ,  12 ,  13  of the cable retention device are held together by means of threaded rods  8  and nuts  9  received on the rods  8 . In this example each plate  11 ,  12 ,  13  has a one circular hole at one end and a groove  15  at the other end. The rods are received in the openings and grooves  15  of the plates  11 ,  12 ,  13 . The groove  15  of each plate is open at one long side, whereby each plate can be turned in and out of contact by one rod  8 . Thus, each plate  11 ,  12 ,  13  is pivotally connected to the rest of the cable retention device. Hereby the mounting and dismounting of the cables are made easier by twisting the plates  11 ,  12 ,  13  relative each other at the same time as the parts of the cable retention device are held together by the rod  8  received in the circular openings of the plates  11 ,  12 ,  13 . The module halves  6  on the plates  11 ,  12 ,  13  are arranged in row and between support plates  14  extending at right angles from the plates  11 ,  12 ,  13 . The module halves  6  may either be glued to the plates  11 ,  12 ,  13  or held at the plates by being pressed in between the support plates  14  or a combination of the two. Alternatively the module halves  6  are composite moulded to the plates  11 ,  12 ,  13  and the support plates  14 . In the assembled condition gaps are formed between the support plates  14  of opposing plates  11 ,  12 ,  13 . These gaps represent the maximal possible compression of the modules and that a correct compression is achieved when the gaps are closed. 
     In the example of  FIG. 5  a cable retention device is shown arranged with an attachment plate  16 , which attachment plate is intended for fixation to a part of a structure. The cable retention device has one bottom plate  17 , a number of side plates  18  extending at right angle from the bottom plate  17  and at a distance from each other. Thus, columns are formed between the side plates  18 . At the end of each formed column opposite the bottom plate  17  a compression plate  19  connected to an upper plate  20  are arranged. The compression plate  19  is received in such a way that it my slide inside the formed column, while the upper plate  20  is fixed to the side plates  18 . In the shown example the upper plates  20  are received in dovetails of the side plates  18 . A screw  21  and nut  22  is arranged for each pair of upper plate  20  and compression plate  19 . Each screw  21  goes through a circular opening in one upper plate  20  and the free end of the screw is to abut a compression plate  19 . The modules inside the cable retention device are compressed in that each compression plate  19  is pressed against the modules of respective column. The nut  22  is arranged on the outside of the upper plate  20  to lock the screw  19  in a desired position. 
     In use modules are to be received in the columns of the cable retention device and to keep the modules in place inside the columns stops  23 ,  24  are arranged on the side plates  18 . The stops  18 ,  19  project slightly over the edge of the side plates  18  and each has a length that is such that modules placed inside the columns of the cable retention device cannot be lifted out of the cable retention device, but have to be inserted and taken out by sliding via one column end after release of the upper plate  20  and compression plate  19 . The stops  23 ,  24  have a length adapted to the dimensions of the modules. The stops  23 ,  24  may be fixed to the side plates  18  in any suitable way such as by means of screws, rivets, soldering, welding, gluing or composite moulding. The stops  23 ,  24  may also be integrated parts of the side plates  18 . 
     The cable retention device of  FIGS. 6 and 7  resembles the cable retention device shown in  FIG. 5 . The main differences being that a single upper plate  25  replaces the several upper plates  20  of  FIG. 5 . Thus, also this cable retention device has a bottom plate  17 , a number of side plates  18  and compression plates  19   a . In this example the compression plate  19   a  has protruding edges resting on the sides of the side plates  18  forming the compartment in which the compression plate  19   a  slides. Screws  21  and nuts  22  are arranged to control the positions of the compression plates  19   a . Furthermore, stops  23 ,  24  are arranged in the same way as described above to keep the modules in place inside the columns of the cable retention device. Said stops  23 ,  24  are only shown in  FIG. 7 . The single upper plate  25  is fixed to the side plates  18  by means of a number of screws  26 . 
     The main difference in handling the cable retention devices of  FIGS. 6 and 7  compared to the cable retention device of  FIG. 5  is that to mount or dismount a cable the compression of all columns has to be released. In the example of  FIG. 5  only the compression of that column in which the cable is to be mounted and dismounted has to be released. Thereby, it is possible to keep some cables in position when other cables are removed or inserted. 
     In  FIGS. 8 and 9  a further example of a cable retention device is shown, which resembles the cable retention devices shown in  FIGS. 5-7 . The only difference in relation to the example of  FIG. 5  is the form of the upper plates  27  and the way said upper plates  27  are fixed to the side plates  18 . Each upper plate  27  has two protruding parts  29  on two of its opposing sides, which protruding parts  29  all are arranged at different position and whereby a cut-out  30  is formed on each side between two protruding parts  29 . The protruding parts  29  of one upper plate  27  will fit into cut-outs  30  of an adjacent upper plate  27 . In the centre of each upper plate  27  a circular opening  31  is formed to receive a screw  21  to control the position of a compression plate  19   a  in co-operation with a nut  22  in the same way as described above. In each protruding part  29  of each upper plate  27  a circular opening  32  is formed to receive a screw  28 . By means of the screws  28  the upper plates  27  are fixed to the side plates  18  of the cable retention device. Although not explicitly shown stops  23 ,  24  are normally also arranged in the embodiment of  FIG. 8 , to keep the modules in place inside respective column. 
     In  FIG. 10  a U-shaped cover  33  is illustrated. The cover  33  is fixed to the cable retention device by means of screws  34  at the outer side plates  18 . The cover  33  has openings to receive the compression screws  21 . The cover  33  covers the compression plates  19  and the upper plates  20 ,  25 ,  27 . The cover  33  may be combined with any of the cable retention devices described above and will give some protection against dust, dirt etc. deteriorating the repeated function of the screw  21  and nuts  22 . Furthermore, the cover  33  aids in keeping the upper plates  20 , received by dovetail joints with the side plates  18  of  FIG. 5 , in the correct position in e.g. vibrating environments. 
     In the embodiment of  FIG. 11  a cable retention device is arranged with an attachment plate  35 , which attachment plate  35  is to be attached to a suitable structure. Alternatively, the cable retention device may be welded, bolted or cast directly to the structure. The shown cable retention device has two compartments each receiving a number of modules, a number of partitions and a compression unit in the form of a compression wedge  36 . The compression wedge  36  has parts that slid relative each other along inclined contact surfaces, by means of screws  37 . By the sliding the outer dimension of the compression wedge  36  is altered and the modules will be compressed. In the shown example the screws  37  have two counter-directed threads, which means that the compression of the compression wedge can be regulated from one side. 
     In  FIGS. 12 and 13  a further alternative cable retention device is shown. It is formed of two generally U-shaped frame parts  39 ,  40 . Inside each frame part  39 ,  40  modules are received. In the middle of the cable retention device two blocks  41  of a compressible material are arranged. Each block has two through openings  44  for receiving screws that goes between long sides of the two frame parts  39 ,  40 . The blocks  41  are shown with protruding edges  43 , between which the modules are to be received. The frame parts  39 ,  40  are assembled in such a way that they form an inner rectangular space, in which the modules and the blocks  41  are received. Furthermore, due to the dimensions of the compressible blocks  41   a  small gap  45  is formed on two opposing sides between the frame parts  39 ,  40  before compression. The gaps  45  give the maximal possible compression and the correct compression when the gaps are closed. In use the compressible blocks  41  will be compressed in that nuts  42  received on the screws are tightened, whereby the compressible blocks  41  will expand in directions in right angle to the screws and compress the modules. 
     In  FIG. 14  a further example of a cable retention device  46  according to the present invention is shown. The cable retention device  46  has a bottom plate  47  and a number of side plates  48 , extending at right angles from the bottom plate  47 . Normally the side plates  48  are attached to the bottom plate  47  by welding, even though soldering, gluing, attachment means or moulding may be used. An upper plate  49  is fixed to the side plates  48  by means of screws  50  at the ends of the side plates  48  opposite the bottom plate  47 . The screws  50  are shown as socket head cap screws in this example. A person skilled in the art realises that any suitable type of screw may be use in this example as well as the other examples described here. A number of compartments are formed between the bottom plate  47 , the side plates  48  and the upper plate  49 . Modules are to be received inside the compartments formed. The cable retention device  46  of this example has a peripheral flange  51  for attachment to a structure. The compression of the modules of this cable retention device  46  is given in that the outer dimensions of the modules received in one compartment are slightly larger than the available space inside the compartment. Thereby, the modules will be compressed as the upper plate  49  is fixed to the side plates  48  by means of the screws  50 . 
     In  FIG. 15  a further example for a cable retention device according to the present invention is shown. The cable retention device of this example mainly corresponds with the cable retention devices of  FIGS. 2-4 . The only main difference being that a single U-shaped rod  53  replaces the two rods at each side of the cable retention device. The U-shaped rod  53  forms an arc at one side of the cable retention device that may be used as a clamping device. In the example of  FIG. 15  the cable retention device is clamped to a structure part  54 , which is a rod going from the top to the bottom of a tower of a wind power station. A number of cable retention devices may be placed at regular intervals of said structure part  54 . 
     In the example of  FIG. 21  the cable retention device of the present invention has the form of a number of frames  65  placed side-by side on a plate  68 . The frames  65  resemble arches, but with rectangular shape and have flanges directed outwardly and perpendicular from the sides of the frame at the open end of the archlike frame. Each flange has an opening to receive a bolt  69 , which bolt also goes through an opening of the plate  68 . Normally, the opening of the plate is threaded but in other embodiments the fixation is given by means of bolts and nuts. Depending of the needs of a specific installation the number of frames  65  received on the plate  68  varies. Of course in such cases the length of the plate  68  will be adapted to the number of frames  65  received. Inside the frame modules of different sizes may be received. In the example shown in  FIG. 21  modules, formed of two module halves  66 , and intended for one large cable each are combined with modules, formed of two module halves  67 , and intended for two smaller cables each. The outer dimensions of the combination of modules received in each frame  65  are somewhat bigger than the inner dimension of the frame  65 . Thus, the modules will be compressed when the frames  65  are fixed to the plate  68 , which will give a retention force on any cables received inside the modules. Thus, as indicated in this example it is possible to arrange a combined retention device for a large number of cables of different diameters. To adapt the embodiment to different situations the number of frames  65  and the size of the modules inside the frames may be varied. 
     In  FIG. 22  a further example of a cable retention device according the present invention is shown. In this example the frame construction has the form of a cable clamp formed of two clamp parts  70 ,  71 . A first clamp part  70  is formed for attachment to a specific structure. A second clamp part  71  is formed for fixation to the first clamp part  70 . Each clamp part  70 ,  71  has a rounded portion in which a module half  72  is received. In this case the module halves  72  are glued to respective clamp part  70 ,  71 . Each module half  72  has the form of a generally semicircular set of peelable layers or sheets. The two module halves  72  will form a full circle when compressed by the clamp parts  70 ,  71  being fixed to each other. The peelable sheets adhere strong enough to each other to stick together but loose enough to be peeled off by hand. Normally a module support  73  is placed at each end of each module half  72  to give a proper positioning. In use the first clamp part  70  is fixed to some kind of structure. The module halves  72  are adapted to the dimension of the cable to be received by peeling off a suitable number of layers. With the cable placed inside the module halves  70  the second clamp part  71  is fixed to the first clamp part  70 , by means of bolts, bolts and nuts or other suitable fixation means. To give retention force on the cable the outer dimension of the cable should be somewhat bigger than the inside dimension of the module formed, which is controlled by the number of sheets peeled off. A person skilled in the art realises that the form of the first clamp part may vary as long as it has a rounded part for cooperation with the second clamp part in forming the cable retention device. 
     A person skilled in the art realises that the cable retention device of the present invention may be varied in many different ways. Parts shown in one example may, if possible, replace parts of other shown examples. However, in all embodiments a number of compressible modules to receive cables are placed inside of some kind of frame construction and the modules inside the frame construction are compressed, either by means inside the frame construction or by assembling the frame construction. 
     The modules of the cable retention device may have different designs. As long as they give a firm contact between module and cable, at the same time as there is an elastic or flexible connection between cable and structure, to which the cable retention device is attached. 
     In  FIGS. 16-20  three different designs of modules are shown. The module shown in  FIG. 16  is formed of two module halves  55 , forming an opening when assembled. In the opening a centre core  57  is received. Normally the centre core  57  adheres slightly to one of the module halves  55  in such a way that the centre core  57  can be loosened by hand. Thus, a gentle adhesive may be used. Furthermore, on the inside of the module halves  55  a number of sheets  56  are arranged. The sheets  56  are arranged to adhere to each other but in such a way that the sheets  56  may be peeled off one at the time by hand. In use the number of sheets  56  peeled off is adapted to the diameter of the cable to be received inside the module. Thus, a module of this kind may be used for cables of varying diameter. If not all modules in a cable retention device are to receive a cable at assembly the centre core  57  is kept in place between the module halves  55 . If at some later stage a cable is to be received the centre core  57  is taken away and a number of sheets  56  are peeled off, whereby the number of sheets  56  peeled off depends on the diameter of the cable. 
     The module halves  55  are made of a rubber material giving an elastic connection between cable and structure. The rubber material may be EPDM or any other rubber material e.g. NR, SBR, NBR, EPM) giving an elastic connection. Due to the elastic contact forces in different directions are taken up. The forces may be axial, radial, torsional or vibrations. 
     The modules of  FIGS. 17 and 18  are also made of two module halves  58 , forming a central opening when the two halves  58  are assembled and mounted in a cable retention device. Also in this embodiment a centre core may be received inside the formed module, which core is taken away when a cable is to be received. On the inside of each module half  58  a number of radial grooves  59 ,  60  are arranged. In the shown embodiment every second groove  59  is formed to receive a land of a possible centre core (not shown), having four lands having a cross section with straight angles. Thus, the grooves  59  receiving the lands of the centre core have also a cross section with straight angles. The centre core is kept in place by co-operation between the lands of the centre core and the grooves  59  of the module halves  58  adapted to the form of the lands. The other grooves  60  may have any cross section but flanges  61  should be formed between the grooves  59 ,  60 . In the shown example the grooves  60  have a rounded form in cross section. In embodiments where no centre core is to be received the grooves  59 ,  60  may all have the same shape. The flanges  61  are to be pressed against a cable received inside the module, whereby the flanges  61  will give after and be folded. Thus, the foldable flanges  61  means that also in this case there will be an elastic connection between cable and structure, whereby forces can be taken up in said elastic connection. Hereby the elastic connection can be said to be given by the geometric design. If the modules are made of an elastic material, this will also contribute to the elastic connection. A person skilled in the art realises that this geometric design may have many different shapes. These modules are either made of an elastic rubber, such as EPDM, or a plastic. 
     The modules of  FIGS. 19 and 20  are formed of two halves  62 , which form a central opening when assembled and mounted inside a cable retention device. In the central opening a centre core may be received. The possible centre core is normally lightly adhered to one or both module halves  62  by means of an adhesive. The purpose of the adherence is only to keep the centre core in place and should be weak enough to be broken by hand when a cable is to be received. On the inside of the module halves  62  there are raised parts  63 , having a radius adapted to the cable to be received. The raised parts  63  adapted to the cable to be received is placed at least at each end of each module half  62  and in the middle of the module half  62 . Between the raised parts  63  adapted to the cable are lowered parts  64 , having a cross section with straight angles, i.e. the walls of said lowered parts  64  are parallel with the outer surfaces of the module half  62 . When a cable is received inside the module inside a cable retention device, it will be compressed at the raised parts  63  adapted to the diameter of the cable. At the same time the cable will be able to expand somewhat in the lowered parts  64  between the raised parts  63  adapted to the cable. The elastic contact may be enhanced in that the module halves  14  are made of a rubber material, such as EPDM. In some embodiments the modules are made of a plastic. By the design of the modules the cables are held at three areas inside each module with an open space in-between. This type of module is especially suitable to take up tension forces, i.e. forces in the axial direction of the cable. 
     Irrespectively of which kind of modules that are used the diameter of the central opening, formed when two module halves are brought together, should be slightly smaller than the diameter of the cable to be received, in a non-compressed condition. 
     As indicated above each module may be furnished with a centre core, but it is not absolutely necessary. The centre cores are beneficial in order to hinder modules not receiving any cables from collapsing when compressed. 
     The cable retention devices of the present invention are attached to a structure in any suitable way. The type of attachment suitable depends on the structure to which the cable retention device should be attached. The attachment may have the form of screws, bolts, pins, clips, rivets, arcs and/or clamps or may be done by welding, soldering, gluing or casting. 
     As indicated above the present invention is mainly developed for receiving relatively large cables, for example at wind power stations, which means that they should be able to carry relatively large loads. In some instances each cable retention device should be able to carry loads of at least 150 kg, preferably at least 300 kg and most preferred at least 500 kg. The cable retention devices of the present invention are designed to handle such loads but at the same time the cable retention devices of the present invention may be used with cables of much lower weights.