Abstract:
In the case of a connection system having a housing ( 10 ) and a nut ( 16 ) which can be arranged on the housing ( 10 ), the aim is to provide a solution by means of which it is possible to prevent the nut ( 16 ) from being released inadvertently from the housing ( 10 ). This is intended to be achieved in that the nut ( 16 ) is formed from an elastic material and latching elements ( 24 ) are formed on the nut ( 16 ), which latching elements ( 24 ) can be latched to mating latching elements ( 26 ) which are formed on the housing ( 10 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to German Patent Application Number DE 10 2011 001 079.3, entitled VERBINDUNGSSYSTEM EINES GEHÄUSES EINES STECKVERBINDERS MIT EINER MUTTER, and filed on Mar. 3, 2011, the entire contents of which is hereby incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a connection system having a housing and having a nut which can be arranged on the housing. The invention also relates to a plug connector having a connection system such as this. 
         [0004]    2. Description of the Related Art 
         [0005]    By way of example, the housing may be used to hold one or more contact elements which are connected, making contact, to one or more conductors of a cable in the housing. After the conductors in the cable have been connected to the contact elements, a nut, also referred to as a union nut, is normally screwed onto the housing, and is tightened with a specific torque. For this purpose, the nut normally has a sleeve body with an internal thread, with a hexagonal body being arranged on the sleeve body, by means of which the nut can be attached to and released from the housing. Inter alia, the nut is used to seal the housing in the area of the contact with the conductors in the inserted cable, with the contacts, against moisture and dust. Furthermore, the nut can provide strain relief for the conductors in the cable, when contact has been made. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention is based on the object of providing a solution, by means of which it is possible to prevent the nut from being inadvertently released from the housing. 
         [0007]    In the case of a connection system of the type referred to in more detail initially, this object is achieved according to the invention in that the nut is formed from an elastic material and latching elements are formed on the nut, which latching elements can be latched to mating latching elements which are formed on the housing. 
         [0008]    The problem is also solved by a plug connector comprising a connection system a housing and a nut which can be arranged on the housing, wherein the nut is formed from an elastic material and latching elements are formed on the nut, which latching elements can be latched to mating latching elements which are formed on the housing. 
         [0009]    Expedient refinements and advantageous developments of the invention are specified in the dependent claims. 
         [0010]    The embodiment according to the invention of latching elements on the nut and mating latching elements on the housing, which can be latched to one another, makes it possible to provide a secure connection between the nut and the housing, which prevents the nut being inadvertently released, in particular by hand, from the housing. When the nut is screwed onto the housing, the latching elements on the nut hook into or latch with the mating latching elements on the housing. The latching means that the nut cannot be released from the housing simply by unscrewing the nut from the thread on the housing, since the latching prevents this. The latching must therefore first of all be released, before unscrewing, by unhooking the latching elements from the mating latching elements. For this purpose, the nut is formed from an elastic material, which is elastically deformable, for example a plastic. In order to release the latching, the longitudinal side surfaces of the nut are pressed in the direction of the center axis of the nut, allowing the latching elements to be unhooked from the mating latching elements. As soon as the latching elements and the mating latching elements no longer engage in one another, the nut can be unscrewed from and/or pulled off the housing. In this case, despite its elasticity, the material of the nut is preferably designed to have a stiff shape, in such a way that the nut can be compressed by its longitudinal side surfaces only by means of a tool, which is pushed along the longitudinal side surfaces of the nut, over the outer circumferential surface of the nut, thus compressing it. 
         [0011]    According to one preferred refinement of the invention, the latching elements are arranged in an annular shape on the nut, and the mating latching elements are arranged in an annular shape on the housing. The annular arrangement is preferably provided in this case around the entire circumferential surface of the nut and of the housing, thus allowing the nut to be attached or latched to the housing particularly securely. 
         [0012]    The latching elements are preferably arranged on the outer circumferential surface of the nut. The latching elements are therefore preferably formed on a different surface of the nut than the thread or the internal thread of the nut, by means of which the nut is screwed onto the housing or the thread on the housing. The arrangement of the latching elements and of the thread on different surfaces allows the thread and the latching elements to be operated independently of one another, without them influencing one another. 
         [0013]    Provision is preferably furthermore made for an annular element to be formed on an outer circumferential surface of the housing, with the mating latching elements being arranged on an inner surface of the annular element. The provision of an additional annular element, on which the mating latching elements are arranged, makes it possible to prevent the mating latching elements from being arranged in the area of the thread, in particular of the external thread, on the housing, via which the nut is screwed onto the housing. This makes it possible to prevent the thread which is arranged on the housing and the mating latching elements which are arranged on the housing from influencing one another when the nut is being attached to or released from the housing. In this case, the annular element is preferably arranged underneath the thread which is formed on the housing, in the direction in which the nut is attached to the housing. The annular element preferably at the same time forms a step or collar which is circumferential around the outer circumferential surface of the thread, on which the nut can rest when attached to the housing, and can thus be supported. This makes it possible to further improve the attachment of the nut to the housing. 
         [0014]    Furthermore, the latching elements and the mating latching elements are preferably in the form of wedges, at least in sections. The configuration of the latching elements and of the mating latching elements in the form of wedges is preferably designed such that, when the nut is rotated in order to attach the nut to the housing, the latching elements can slide over the mating latching elements, in that the flanks or longitudinal side surfaces of the wedge-shaped latching elements and mating latching elements, which are provided with a gradient &gt;0°, can slide on one another. As soon as the rotation direction of the nut is changed from screwing the nut onto the housing to an opposite rotation direction for unscrewing the nut from the housing, the latching elements are hooked to the mating latching elements, in that the end surfaces, which are straight, of the wedge-shaped latching elements and mating latching elements abut against one another, thus preventing them from sliding on one another. This allows the nut to be attached to the housing without major effort, while at the same time preventing the nut being inadvertently released or unscrewed from the housing. 
         [0015]    According to a further preferred refinement of the invention, at least two operating elements for holding a tool are arranged on the outer circumferential surface of the nut. The formation of operating elements on the nut makes it possible to simplify the compression of the nut on its longitudinal side surfaces in order to release the latching, in that the tool presses onto the operating elements in order to release the latching, thus allowing the longitudinal side surfaces or the outer circumferential surface of the nut to be compressed in the direction of its center axis, without a large amount of force being applied. The operating elements are preferably in the form of blocks or boxes, and are arranged distributed in a circular shape around the outer circumferential surface, which runs on the longitudinal side, of the nut. In this case, six operating elements are preferably arranged on the outer circumferential surface, thus allowing the latching to be released via the operating elements, for example by means of a hexagonal wrench. 
         [0016]    The operating elements are preferably connected to one another in pairs, such that two operating elements which are arranged alongside one another are connected to one another, for example via a web. The connection of the operating elements in pairs makes it possible to reduce the force which has to be applied by a tool to the operating elements. Furthermore, the robustness and wear resistance of the operating elements is improved. 
         [0017]    In order to make it easier to push a tool onto the operating elements for operation of the operating elements, it is preferable for the operating elements to have an operating surface with a gradient &gt;0°. The operating surface is that surface via which operating elements are operated by means of the tool. The gradient of the operating surface in this case increases in the direction of the attachment direction of the nut. The operating element or the operating surface of the operating element is therefore preferably conical. 
         [0018]    According to a further advantageous refinement of the invention, the nut has an inner ring and an outer ring, which is arranged parallel to the inner ring and on which the latching elements are formed, with the outer ring being formed at a distance from the inner ring. The thread of the nut is preferably formed on the inner ring. The formation of an outer ring and of an inner ring allows the latching elements and, if appropriate, the operating elements to be arranged physically separately from the thread on the nut. The arrangement at a distance results in a gap being formed between the inner ring and the outer ring. The gap means that the elasticity of the nut can be increased, particularly in the area of the toothed elements and, if appropriate, of the operating elements which are arranged on the outer ring, thus making it possible to simplify the release of the latching of the latching elements to the mating latching elements by means of a tool, since, because of the gap, less force need be applied to compress the nut in the direction of its center axis, with the outer ring being deformed via the gap in the direction of the inner ring. Simultaneous deformation of the inner ring and therefore of the nut thread formed on the inner ring can therefore be prevented. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The invention will be explained in more detail in the following text on the basis of one preferred embodiment, and with reference to the attached drawings, in which: 
           [0020]      FIG. 1  shows a schematic illustration of a housing of a connection system according to the invention, 
           [0021]      FIG. 2  shows a schematic detailed illustration of mating latching elements which are formed on the housing, 
           [0022]      FIG. 3  shows a schematic illustration of a nut of a connection system according to the invention, and 
           [0023]      FIG. 4  shows a schematic illustration of a connection system according to the invention having a housing as shown in  FIG. 1  and having a nut as shown in  FIG. 3 , and having a tool, fitted to the nut, in order to release the nut. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]      FIG. 1  schematically illustrates a housing  10 , for example a housing of a plug connector. The housing  10  is cylindrical with an internal area  12  for holding, for example, contact elements, which are not shown here, for making contact with conductors in a cable, which is not shown here. On its outer circumferential surface, the housing  10  has a thread  14  to which a nut  16 , as shown in  FIG. 3 , can be attached by screwing it on. Furthermore, an annular element  18  in the form of an attachment or collar is integrally formed on the outer circumferential surface of the housing  10 , with the annular element  18  projecting from the outer circumferential surface of the housing  10  and completely surrounding the outer circumferential surface, such that the annular element  18  forms a type of collar or step. The annular element  18  is formed underneath the thread  14  in the attachment direction  20  of the nut  16  on the housing  10 , such that the nut  16  can rest on the annular element  18  when it is attached to housing  10 , as is shown in  FIG. 4 . The annular element  18  has a circumferential outer edge  22 , with mating latching elements  26 , which engage in latching elements  24  that are formed on the nut  16 , being formed on the inner surface, which faces in the direction of the thread  14 , of the edge  22  of the annular element  18 . The latching elements  24  and the mating latching elements  26  are in the form of latching teeth. A plurality of mating latching elements  26  which are arranged alongside one another are formed in an annular shape over the entire circumferential inner surface of the edge  22  of the annular element  18 , with the mating latching elements  26  being in the form of wedges, at least in sections. 
         [0025]      FIG. 2  shows a detailed illustration of the mating latching elements  26  of the housing  10 , in this case showing that the mating latching elements  26  each have a first section  60  and a second section  62 , with the second section  62  being in the form of a wedge, that is to say the longitudinal side surfaces  36  of the mating latching elements  26  are provided with a gradient &gt;0°. The first section  60 , or the longitudinal side surface of the first section  60 , is in contrast formed with a gradient =0°. The latching is created as soon as the corresponding latching element  24  on the nut  16  has been passed over the first section  60  and then over the second section  62 , and latches on the end surface  40  of the mating latching element  26  on the second section  62 . The latching elements  24  of the nut  16  preferably likewise each have a first section with a longitudinal side surface with a gradient =0° and a second section, arranged following this, with a wedge-shaped longitudinal side surface with a gradient &gt;0°. The formation of a first section  60  such as this in addition to the second section  62  makes it possible to lengthen the sliding movement of the latching elements  24  along the mating latching elements  26  before latching. 
         [0026]      FIG. 3  schematically illustrates a nut  16  according to the invention. The nut  16  is formed from an elastic material and has an inner ring  28  and an outer ring  30 , which is parallel to the inner ring  28 , with the inner ring  28  being arranged at a distance from the outer ring  30 , such that a gap  32  is formed between the inner ring  28  and the outer ring  30 . The latching elements  24  for securely latching the nut  16  to the housing  10  are formed on the outer circumferential surface of the nut  16 , to be precise on the outer circumferential surface of the outer ring  30 , with the latching elements  24  being arranged in an annular shape alongside one another, in the same way as the mating latching elements  26  on the housing  10 , and being in the form of wedges, at least in sections. The configuration of the latching elements  24  and of the mating latching elements  26  in the form of wedges at least in sections is designed such that, when the nut is rotated in order to attach the nut  16  to the housing, the latching elements  24  can slide over the mating latching elements  26 , in that the flanks or longitudinal side surfaces  34 ,  36  of the wedge-shaped latching elements  24  and mating latching elements  26 , which are provided with a gradient &gt;0°, can slide on one another. As soon as the rotation direction of the nut  16  is changed from screwing the nut  16  onto the housing  10  to an opposite rotation direction in order to unscrew or release the nut  16  from the housing  10 , the latching elements  24  hook onto the mating latching elements  26 , by the straight end surfaces  38 ,  40  of the wedge-shaped latching elements  24  and mating latching elements  26  abutting against one another, and thus preventing them from sliding on one another. 
         [0027]    Furthermore, six operating elements  42  are arranged in an annular shape around the outer circumferential surface of the nut  16 , on the outer circumferential surface of the nut  16 , to be precise on the outer circumferential surface of the outer ring  30 , with two operating elements  42  in each case being connected to one another in pairs via a web  44 . The operating elements  42  have an operating surface  46  which faces away from the nut  16  and to which a tool can be fitted in order to release the nut  16  from the housing  10 , as is shown in  FIG. 4 . The operating surface  46  is conical, that is to say it has a gradient &gt;0° from a first end  48  toward a second end  50 , which is adjacent to the latching elements  24 , as a result of which the gradient of the operating surface  46  increases from the first end  48  toward the second end  50 . This makes it easier to push a tool  52  on in the pushing-on direction  54 , since the operating surfaces  46  act as a type of guide for the tool  52 . 
         [0028]    As is also shown in  FIG. 3 , a partial thread  56  is formed on the inner surface of the inner ring  28 , extending only over a small segment of the inner surface of the inner ring  28 . The thread  14  on the housing  10  has a cutout  58 , which is designed to correspond to the size of the partial thread  56 , as a result of which, when the nut  16  is attached to the housing  10 , the nut  16  need not be screwed on over the entire thread section of the thread  14 , but can be plugged on and the nut  16  just has to be rotated through a turn of &lt;180°, in order to be attached to the housing  10 . This allows the nut  16  to be attached to the housing  10  considerably more easily and quickly. 
         [0029]      FIG. 4  shows a connection system according to the invention, in which a nut  16 , as shown in  FIG. 2 , is attached to a housing  10 , as shown in  FIG. 1 . In order to release the nut  16 , which has been attached to the housing  10 , a tool  52  in the form of a hexagonal wrench is pushed onto the operating surface  46  of the operating elements  42 . When the tool  52  is pushed on in the pushing-on direction  54 , the outer ring  30  of the nut  16  is compressed together with the latching elements  24  arranged thereon, in the direction of the inner ring  28 , that is to say in the direction of the center of the nut  16 , as a result of which the latching elements  24  can be released from being latched to the mating latching elements  26  on the housing  10 , and can be unlatched, thus subsequently allowing the nut  16  to be unscrewed from and pulled off the housing  10 . 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
         Housing  10   
         Internal area  12   
         Thread  14   
         Nut  16   
         Annular element  18   
         Attachment direction  20   
         Edge  22   
         Latching elements  24   
         Mating latching elements  26   
         Inner ring  28   
         Outer ring  30   
         Gap  32   
         Longitudinal side surface  34   
         Longitudinal side surface  36   
         End surface  38   
         End surface  40   
         Operating element  42   
         Web  44   
         Operating surface  46   
         First end  48   
         Second End  50   
         Tool  52   
         Pushing-on direction  54   
         Thread  56   
         Cutout  58   
         First section  60   
         Second section  62