Abstract:
The present disclosure relates to a cable insertion ( 1 ) for connecting a cable ( 7 ) to a housing ( 10 ). The cable insertion ( 1 ) includes a connection device ( 2 ) having a cantilever-like element ( 14 ) having a mounting fixture ( 11 ) on the front end thereof for mounting a mating part ( 3 ) attached to a jacket ( 12 ) of the cable ( 7 ). A securing means ( 4 ) secures the fixture.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a 35 U.S.C. §371 National Phase conversion of PCT/EP2008/068138, filed Dec. 22, 2008, which claims benefit of Swiss Application No. 232/08, filed Feb. 16, 2008, the disclosure of which is incorporated herein by reference. The PCT International Application was published in the German language. 
     BACKGROUND 
     1. Field of the Disclosure 
     The present disclosure relates to the field of cable entries for cables into housings, in particular optical cables, according to the preamble of the independent patent claims. 
     2. Related Art 
     Cable entries for inserting cables into housings are known from the prior art, which at the same time are used as strain relief or for kink protection. Typical representatives of this generic type have a cap with an opening which is surrounded by a thread. The opening is normally suitable for holding a chuck, which can be drawn in by a cap nut which interacts with the thread. These solutions are not suitable for situations in which cables must be connected to plugs. In general, the cable entries that are known from the prior art are used at the same time for electrical shielding, and/or for electrically conductive connection of an outer conductor to a housing. 
     The cable entries which are known from the prior art are not suitable, or are suitable only to a restricted extent, for use with optical waveguides (glass fibers). In contrast to conventional cable entries, optical waveguides result in particular requirements since they are typically delivered prefabricated with one or more plugs provided. The cable entry should therefore also offer the capability to hold a cable with plugs. Complex plug-like apparatuses are known in which the connectors for the optical waveguide are firmly integrated in an outer housing. These have a very complicated design and are therefore very costly. In general, they also cannot easily be fitted. 
     A further problem frequently occurs when a multicore cable having a corresponding number of plugs must be connected to a mating piece. For example, in adverse conditions, a fitter frequently has to connect a cable in a very confined space above his head or in confined spatial conditions, with only one hand available in this case. 
     The cable entries known from the prior art are not suitable for this purpose. 
     SUMMARY 
     One object of the invention is to provide an apparatus for connecting a cable to a housing. A further object of the invention is to provide an apparatus for connecting a cable which is provided with one or more plugs to a housing. 
     The object is achieved by the cable entry defined in the independent patent claims. 
     One embodiment of a cable entry according to the invention has a connecting apparatus similar to a cantilever arm, to which at least one cable can be attached by means of a cable sheath or an interlocking mating piece. The connecting apparatus has a base with an opening, which is suitable for holding a cable, or a cable with one or more plugs. In general, the base has attachment means, for example in the form of screw holes, by means of which the base can be fitted to a housing. A holding apparatus is arranged a certain distance in front, coaxially or at an angle, and/or arranged laterally offset with respect to the opening, and is used to hold the mating piece. 
     The holding apparatus is used for (interlocking) connection of one or more mating pieces which are fitted to a cable sheath. Good results are achieved by the mating piece having an undercut which, for example, is formed by a groove by means of which the mating piece can be inserted from the side into a slotted end plate. The mating piece can be secured with respect to the end plate by a securing element, such that it does not fall out. 
     The end plate is typically located at the front end of a cantilever arm which is fitted such that it projects from the base. The cantilever arm is preferably designed to be skeletal, or is designed such that the cable can be introduced into the opening without any major impediment, or the plug can be operatively connected to a corresponding mating piece. The cantilever arm may consist of one or more webs or, for example, may be in the form of a half shell. Depending on the field of application, the connecting apparatus consists of one or more parts which are produced from metal or from plastic, for example by injection molding. If required, the cantilever arm can also be elastically deformable or can be provided with a joint such that it is appropriately aligned with the cable when pulled obliquely, and is used for kink protection. In certain fields of application, the joint can also be used as a fitting aid, because it improves the accessibility to the opening in the base plate. If required, the joint can be designed such that it can be split, such that the connecting apparatus can be broken down into two parts, with one on the cable side and the other on the housing side. In the extreme, the cantilever arm is arranged on the cable side and is attached to a corresponding connecting piece on the side of the base plate when being fitted. 
     One advantage of the described cable entry is that the connection of the cable sheath (mechanical strain relief) is separated from the operative connection of the cable or the connection of the plug, respectively. 
     In one embodiment, the cable entry has a connecting apparatus. The connecting apparatus has a base plate for attaching the connecting apparatus to a housing, an opening for passing a cable through the base plate, and a cantilever arm which projects from the base plate and at whose opposite end a holding apparatus is arranged, which is suitable for holding one or more mating pieces which are fitted to one or more cables. The cantilever arm can be designed to be skeletal, such that the mating piece can be operatively connected to the connecting apparatus before the cable is connected. Good results are achieved if the cantilever arm is in the form of a half shell. The cantilever arm can be used as a (temporary) holder/fitting aid for a transceiver. The holding apparatus may be in the form of a slotted end plate. If required, a twisting protection means can be formed between the mating piece and the holding apparatus, and prevents inadvertent twisting of the cable with respect to the connecting apparatus. 
     The cable entry according to the invention is suitable, inter alia, for use in mobile radio installations, for a so-called Radio Remote Head (RRH). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail with reference to the embodiment which is illustrated in the following figures, in which: 
         FIG. 1  shows a cable entry in the fitted state, with a cable and a housing; 
         FIG. 2  shows the cable entry shown in  FIG. 1 , partially sectioned; 
         FIG. 3  shows the cable entry shown in  FIG. 1 , in the broken-down state; 
         FIG. 4  shows the process of fitting a cable to the cable entry shown in  FIG. 1 ; 
         FIG. 5  shows a further embodiment of a cable entry. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  shows a perspective illustration of a cable entry  1  according to the invention, viewed obliquely from above, in the fitted state.  FIG. 2  shows the cable entry  1  shown in  FIG. 1 , in the form of a partially sectioned illustration, such that the interior can be seen.  FIG. 3  shows a perspective illustration, obliquely from above, of the cable entry  1  in the disassembled state and broken down into individual parts. Mutually corresponding parts are provided with the same reference symbols. 
     As can best be seen form  FIG. 3 , a cable entry  1  according to the invention generally consists of a connecting apparatus  2 , a mating piece  3  and a securing element  4 . The connecting apparatus  2  has a base  5  (base plate) with an opening  6  which is suitable, for example, for holding a cable  7 , or a cable  7  with one or more plugs  8 . The illustrated embodiment shows an optical connector (LC connector) which is used for connecting glass fibers  7  to a transceiver  17  (cf.  FIG. 2 ). The base  5  generally has attachment means, for example in the form of screw holes  9 , by means of which the base  5  can be fitted to a housing  10 . At least one holding apparatus  11  is positioned in front of the opening, coaxially or at an angle or laterally offset with respect to the opening  6 , respectively. In the illustrated embodiment, the holding apparatus  11  is arranged coaxially with respect to the opening  6 , and at a distance from the latter on a cantilever arm  14  which is in this case in the form of a half shell. In the illustrated embodiment, the cantilever arm  14  is designed such that the transceiver  17  can be pulled out of the housing  10  through the opening  6  for connection of the plugs  8  (cf.  FIG. 4   b ). Depending on the field of application and the purpose, other refinements of the cantilever arm  14  are possible, for example with only one or more webs. The illustrated embodiment offers the advantage that the plug  8  can be connected in the area of the opening  6  without any impediment. This would be impossible if the cantilever arm were closed all round. 
     The holding apparatus  11  is used for interlocking connection of one or more mating pieces  3  which are fitted to a cable sheath  12  (assembly process cf.  FIG. 4 ). Good results are achieved by the mating piece being in the form of a mushroom, or being designed with an undercut or a groove  13 , such that it can be latched into a correspondingly designed holding apparatus  11 , and can be secured against pulling. For example, the mating piece  3  can be designed to be thicker in a spherical shape at least in places, in order to allow it to be latched into a correspondingly designed socket (holding apparatus)  11 , thus resulting in a certain amount of lateral mobility. The mating piece  3  in the illustrated embodiment is manufactured from a comparatively elastic plastic. The mating piece  3  is used on the one hand for transporting tensile forces from the cable sheath  12  to the connecting apparatus  2 , and on the other hand for kink protection. 
     In the illustrated embodiment, the holding apparatus  11  is in the form of a slotted end plate  11  with a side opening  18  into which the mating piece  3  can be hooked at the side, with the groove  13 . This refinement and the interlock that it results in prevent inadvertent twisting of the cable  7  with respect to the connecting apparatus  2 . For this purpose, at the front end, the mating piece  3  has two mutually opposite parallel flanks  19  (cf.  FIG. 3 ) which, in the assembled state (cf.  FIG. 4   b ), correspond in an interlocking manner with corresponding opposing surfaces  20  in the area of the cantilever arm  14 . Other options for twisting protection means are possible. 
     The apparatus is secured by the securing element  4 , which in this case is in the form of a sleeve being pushed over the mating piece  3  and the cantilever arm  14 , and being screwed to a thread  15  in the area of the base plate. Other securing means are possible. Seals  16  in the form of O-rings close the interior of the cable entry  1  from external influences in the area of the thread  15  and of the end plate  11 . 
       FIG. 4  schematically illustrates the process of fitting a cable  7 , which is provided with a mating piece  3 , to a connecting apparatus  2 , attached to the housing  10  by means of the base plate  5 . The cantilever arm  14  projects approximately at right angles from the housing  10 . 
       FIG. 4   a  shows the cable  7  with the mating piece  3  obliquely above the cantilever arm  14  with the end plate  11 . The securing element  4 , which is in the form of a sleeve, is arranged behind the mating piece  3 . In  FIG. 4   b , the mating piece  3  is operatively connected to the holding apparatus  2 , by the groove  13  being latched into the opening  18  in the end plate  11 , which is slotted at the side. The two plugs  8  are located obliquely above this, before being operatively connected to the transceiver  17 , which is pulled out of the housing  10  through the opening  6 . The cantilever arm  14  is in the form of a half shell and is in this case used as an opposing bearing (holder). In  FIG. 4   c , the plugs  8  are operatively connected to the transceiver  17 , and the transceiver  17  is pushed back again into the housing  10 , through the opening  6 . In  FIG. 4   d , the securing means  4  is pushed in the x direction over the connecting apparatus  2 , and is screwed to the thread  15  in the area of the opening  6 . Seals  16  seal the apparatus against external influences. 
       FIG. 5  shows a further embodiment of a cable entry  1 , in which the cantilever arm is on the cable side and is operatively connected during the fitting process to a corresponding connecting piece on the side of the base plate.  FIG. 5   a  shows the cable entry  1  in the fitted state, obliquely from above.  FIG. 5   b  shows the cable entry in the disassembled state, and  FIG. 5   c  shows a section illustration through the fitted cable entry  1  as shown in  FIG. 5   a , in such a way that the interior can be seen better. 
     The cable entry  1  consists of a connecting apparatus  2 , a mating piece  3  and a securing element  4 . The connecting apparatus  2  has a base  5  (base plate) with an opening  6  which is suitable for holding a cable  7  with one or more plugs  8 . In the illustrated embodiment, a cantilever arm  14  can be split, with the longer part in this case being arranged on the cable side. In the illustrated embodiment, the cantilever arm  14  has two webs  21  which each have an attachment element  22 , which in this case is in the form of a hammer, at the front end. The connecting apparatus  2  has two depressions  23  which, in the fitted state (cf.  FIG. 5   c ), correspond with the attachment elements  22  which are in the form of hammers. The webs  21  are designed to be sprung such that the elements  22  which are in the form of hammers can be snapped into the opposite depressions  23 . The illustrated embodiment is distinguished by a slimline design which can be produced easily. Other embodiments of the attachment elements are possible. For example, they may be in form of corresponding heels, which can be operatively connected in the lateral direction, from above or from underneath. Another possibility is for the attachment elements to be in the form of a bayonet fitting or thread. Depending on the field of application, the cantilever arm  14  can be connected firmly, or such that it can be split, to the cable  7  or to the mating piece  3 . Once the attachment elements  22 , which are in the form of hammers, have been snapped into the depressions  23  and the plugs  8  have been connected, the securing element  4  which is in the form of a sleeve is pushed over the cantilever arm  14  and is screwed to a thread  15  on the connecting apparatus  2  (cf.  FIGS. 5   a  and  5   c ). The securing element  4 , which is in the form of a sleeve, can be designed such that, at least in certain spatial directions, it absorbs a large proportion of the forces which occur and contributes to the robustness of the cable entry, for example in the event of forces in the lateral direction (lateral tension). 
     The depressions  23  can be arranged internally or externally. The webs  21  and the securing element  4  prevent inadvertent twisting of the cable, and provide relief for the cable against bending moments and tension. Seals  16  can be provided between the mating piece  3  and the securing element  4 , and the securing element  4  and the connecting apparatus  2 , sealing the cable entry  1  against environmental influences. If required, the cantilever arm  14  can be designed to be elastic or movable to a defined extent. Depending on the field of application, the cantilever arm  14  or the securing element  4  can be attached to the connecting apparatus  2  in a different manner. For example, it is possible to connect the cantilever arm  14  to the connecting apparatus  2  via a screw thread. By way of example, the securing element  4  can be operatively connected to the connecting apparatus  2  via a snap-action connection. 
     REFERENCE SYMBOLS 
     
         
           1  Cable entry 
           2  Connecting apparatus 
           3  Mating piece 
           4  Securing element 
           5  Base (base plate) 
           6  Opening 
           7  Cable 
           8  Plug 
           9  Screw holes 
           10  Housing 
           11  Holding apparatus (slotted end plate) 
           12  Sheath 
           13  Groove 
           14  Cantilever arm 
           15  Thread 
           16  Seal 
           17  Optical mating piece (transceiver) 
           18  Opening in the end plate 
           19  Flanks (mating piece  3 ) 
           20  Opposing surface 
           21  Web (cantilever arm) 
           22  Attachment element in the form of a hammer 
           23  Depression for holding an attachment element in the form of a hammer