Abstract:
Disclosed is a locking device, including a first locking part, having a casing and a blocking piece arranged on the casing, a second locking part, having a spring lock element which is formed spring-elastic at least in sections, and magnetic means, which act between the blocking piece of the first locking part and the second locking part and cause a magnetic force between the blocking piece of the first locking part and the second locking part. To close the locking device the first locking part can be attached onto the second locking part in a closing direction. To release the locking device the spring lock element can be slid in an opening direction directed essentially lateral to the closing direction relative to the blocking piece.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority of German Patent Application Number 10 2010 044 144.9, filed Nov. 18, 2010. 
       BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a locking device. 
         [0003]    Such a locking device has a first locking part, comprising a casing and a blocking piece arranged on the casing, a second locking part, comprising a spring lock element which is formed spring-elastic at least in sections, and magnetic means, which act between the blocking piece of the first locking part and the second locking part and cause a magnetic force between the blocking piece of the first locking part and the second locking part. To close the locking device, the first locking part is attached in a closing direction onto the second locking part, wherein the closing process, due to the magnetic force of the magnetic means between the blocking piece of the first locking part and the second locking part, is assisted magnetically. In a closing position, then, the blocking piece and the spring lock element engage with each other, so that the locking part is locked counter to the closing direction against the second locking part. The blocking piece and the spring lock element, thus, in the closing position form a positive lock counter to the closing direction, so that the blocking piece in the closing position is held lockingly on the spring lock element. To release the locking device, the spring lock element is slid in an opening direction essentially directed across to the closing direction relative to the blocking piece, to, in this manner, disengage the spring lock element and the blocking piece. 
         [0004]    In such a locking device, as it is known for example from the WO 2009/092368 A2, the closing takes place in a magnetically assisted manner, in that attaching the first locking part onto the second locking part and lockingly engaging the blocking piece with the spring lock element is assisted magnetically. To lock the locking device the first locking part is attached in the closing direction onto the second locking part and thus a locking engagement between the blocking piece and the spring lock element is established. To open, the spring lock element is moved by moving the second locking part or at least a part of the second locking part in the opening direction essentially across to the closing direction approximatively straight, so that in this manner the blocking piece disengages from the spring lock element and the first locking part can be removed from the second locking part. 
         [0005]    A locking device of this kind can be employed in various ways to connect two components to each other, wherein one of the components is connected to the first locking part and the other one of the components is connected to the second locking part and, via the engaging lock of the locking parts with each other, the components are coupled with each other in a secure, detachable manner. 
         [0006]    Locking devices of this kind in their closing position provide a secure, enduring connection of two parts to each other and can be closed in a simple manner and can be reopened in a haptically pleasant manner. The possible applications of such locking devices extend to devices of a general kind for the (detachable) connection of two components, such as locks of bags, flaps or covers, connecting devices for straps or cords or also entirely different components. 
         [0007]    In the locking device of the WO 2009/092368 A2 the blocking piece of the first locking part projects from the casing of the first locking part to be able to establish an engagement of the blocking piece of the first locking part with the spring lock element of the second locking part, but it can, thus, be unattractive and obstructive in the opened locking device. 
       SUMMARY OF THE INVENTION 
       [0008]    It is the object of the present invention to provide a locking device, in which the blocking piece in an opened position of the locking device is, if possible, not obstructing the use of a component which is connected to the first locking part. 
         [0009]    According to an exemplary embodiment of the invention it is provided that the blocking piece is arranged movably on the casing of the first locking part in such a way that in a retracted position it is enclosed at least partially in a housing chamber of the casing and in an extended position it projects from the casing in such a way that it can be brought into engagement with the spring lock element. 
         [0010]    The present invention is based on the idea to arrange the blocking piece movably on the casing of the first locking part. In a retracted position the blocking piece is largely arranged in the casing and thus does not or at least not completely project from the casing. In an opened position of the locking device the blocking piece is positioned in the retracted position and is thus not obstructing or disturbing the use of a component which is connected to the first locking part. Upon closing the locking device the blocking piece is transferred from its retracted position into the extended position and in this extended position projects from the casing in such a way that it can be brought into engagement with the spring lock element and thus can be lockingly attached onto the spring lock element for locking the first locking part with the second locking part. 
         [0011]    Transferring the blocking piece from the retracted position into the extended position best takes place automatically by the effect of the magnetic means, which act between the blocking piece and the second locking part in a magnetic manner. When the first locking part is attached onto the second locking part, the magnetic means create a magnetic force between the blocking piece on the first locking part and the second locking part and transfer the blocking piece from its retracted position into the extended position, so that the blocking piece engages mechanically with the spring lock element and the locking device can in this manner be locked. 
         [0012]    The magnetic means can for example be formed by two (permanent) magnets, one of which is arranged on the blocking piece and the other on the second locking part. It is also conceivable, however, to provide on the one of blocking piece and second locking part a magnet and on the other of blocking piece and second locking part a magnetic anchor made of ferromagnetic material, for example iron. 
         [0013]    Advantageously the magnetic means are dimensioned in such a way that upon attaching the first locking part onto the second locking part the blocking piece is held in the extended position to lockingly engage the blocking piece with the spring lock element. The background is here that upon attaching the blocking piece onto the spring lock element the blocking piece pushes aside the spring lock element in an elastic manner, to bring the blocking piece with a catch section into a positive-locking engagement with a corresponding catch section on the spring lock element. The force required to push away the spring lock element should herein be smaller than the magnetic force of the magnetic means, so that upon the locking engagement the blocking piece is held in its extended position and is not pushed into its retracted position due to the force required to establish the locking engagement. 
         [0014]    To automatically return the blocking piece into its retracted position after the opening of the locking device, it can be provided to pre-stress the blocking piece against the casing of the first locking part in the direction of the retracted position. For this purpose separate magnetic pre-stressing means can be provided, which act between the blocking piece and the casing of the first locking part and exert a magnetic force on the blocking piece in the direction of the retracted position. This magnetic force should herein, at least when the first locking part is brought sufficiently close enough to the second locking part, be smaller than the magnetic force of the magnetic means acting between the blocking piece and the second locking part, so that these magnetic means, upon attaching the first locking part onto the second locking part, can transfer the blocking piece into its extended position in a reliable manner. 
         [0015]    The pre-stressing can also be caused by a mechanical spring, which acts between the blocking piece and the casing of the first locking part and returns the blocking piece into its retracted position after the opening of the locking device. 
         [0016]    An adjustment element can be provided on the second locking part, mounted slidable on a casing of the second locking part along the opening direction. The spring lock element is arranged on this adjustment element, so that by actuating the adjustment element the spring lock element can be moved relative to the blocking piece of the first locking part. In the closing position the spring lock element engages with the blocking piece, so that the first locking part is held on the second locking part. To open the locking device the adjustment element can then be actuated in such a way that the spring lock element is moved relative to the blocking piece and disengages from the blocking piece. 
         [0017]    This adjustment element can for example be formed as a kind of sledge and be mounted on the casing of the second locking part, wherein the adjustment element is adjustable relative to the casing in the direction of the opening direction, and by actuating the adjustment element the spring lock element is moved relative to the casing. Opening the locking device thus takes place not by a movement of the second locking part altogether, but by actuating the adjustment element of the second locking part, on account of which the engagement between the blocking piece and the spring lock element is released and the first locking part can be taken out from the second locking part. 
         [0018]    The magnetic means in this case advantageously act between the blocking piece of the first locking part and the adjustment element of the second locking part, so that the magnetic means also exert a force on the adjustment element in such a way that the adjustment element, due to the magnetic force between the blocking piece and the adjustment element, upon attaching the first locking part onto the second locking part is adjusted in such a position, in which the blocking piece can be brought into engagement with the spring lock element. 
         [0019]    The spring lock element advantageously extends in a circumferential direction around the closing direction and is, for example, formed as a strip, which is elastic at least in sections and bent around the closing direction, on which a catch section is arranged for the locking engagement with a corresponding catch section on the blocking piece. In the closing position the spring lock element encompasses the blocking piece in the circumferential direction at least in sections, so that the blocking piece is held on the spring lock element by this encompassing. 
         [0020]    The spring lock element is in sections opened circumferentially in the opening direction, so that the blocking piece can be released from the encompassing with the spring lock element by a relative movement between the spring lock element and the blocking piece. 
         [0021]    To attach the blocking piece onto the spring lock element to lock the first locking part relative to the second locking part, the blocking piece is thus attached onto the spring lock element in the closing direction and herein pushes aside the spring lock element in an elastic manner in the direction of an expanding across to the closing direction, so that the spring lock element engages lockingly with the blocking piece and encompasses the blocking piece in a locking engagement position along the circumferential direction. To release, the spring lock element is then moved in the opening direction relative to the blocking piece, so that the blocking piece disengages from the spring lock element by a relative movement across to the closing direction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The idea underlying the invention shall subsequently be further explained with the help of the exemplary embodiments illustrated in the figures. In the figures: 
           [0023]      FIG. 1  shows an exploded view of a locking device; 
           [0024]      FIG. 2  shows an exploded view of the locking device according to  FIG. 1 , viewed from a different perspective; 
           [0025]      FIG. 3A  shows a top view of the locking device prior to closing; 
           [0026]      FIG. 3B  shows a sectional view of the arrangement according to  FIG. 3A  along the line A-A; 
           [0027]      FIG. 4A  shows a top view of the locking device prior to closing; 
           [0028]      FIG. 4B  shows a sectional view of the arrangement according to  FIG. 4A  along the line A-A; 
           [0029]      FIG. 5A  shows a top view of the locking device in a closing position; 
           [0030]      FIG. 5B  shows a sectional view of the arrangement according to  FIG. 5A  along the line A-A; 
           [0031]      FIG. 6A  shows a top view of the locking device in the unlocked state; 
           [0032]      FIG. 6B  shows a sectional view of the arrangement according to  FIG. 6A  along the line A-A; 
           [0033]      FIG. 7  shows an exploded view of a further exemplary embodiment of a locking device; 
           [0034]      FIG. 8  shows an exploded view of the locking device according to  FIG. 7 , viewed from a different perspective; 
           [0035]      FIG. 9A  shows a top view of the locking device prior to closing; 
           [0036]      FIG. 9B  shows a sectional view of the arrangement according to  FIG. 9A  along the line A-A; 
           [0037]      FIG. 10A  shows a top view of the locking device prior to closing; 
           [0038]      FIG. 10B  shows a sectional view of the arrangement according to  FIG. 10A  along the line A-A; 
           [0039]      FIG. 11A  shows a top view of the locking device in the closing position; 
           [0040]      FIG. 11B  shows a sectional view of the arrangement according to  FIG. 11A  along the line A-A; 
           [0041]      FIG. 12A  shows a top view of the locking device in the unlocked state and 
           [0042]      FIG. 12B  shows a sectional view of the arrangement according to  FIG. 12A  along the line A-A. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0043]    A first exemplary embodiment of a locking device  1 , illustrated in  FIGS. 1 to 6 , has a first locking part  2  and a second locking part  3 , which in an opened position exist separately from each other, which, to close, can be attached onto each other in a closing direction X and are locked with each other in a closing position. 
         [0044]    The first locking part  2  comprises a casing  21  with a casing section  210 , enclosing a housing chamber  213 . In this housing chamber  213  a blocking piece  22  is arranged slidable. 
         [0045]    The second locking part  3  comprises a casing  31 , onto which a casing part  32  is attached. A holding section  330  is arranged on the casing  31 , which holds a spring lock element  34  torque-proof on a housing opening  310  of the casing  31 . 
         [0046]    Upon using the locking device  1  for example for the closing of a bag, a section of a bag cover can be held tucked between the casing  31  and the casing part  32 . 
         [0047]    The blocking piece  22 , arranged on the casing  21  of the first locking part  2 , and the spring lock element  34 , arranged on the casing  31  of the second locking part  3  serve for the mechanical locking of the first locking part  2  with the second locking part  3  in a closing position. The blocking piece  22  and the spring lock element  34  for this purpose each have one or multiple catch sections  222  or  340 , which, for the locking of the first locking part  2  with the second locking part  3 , can be brought into locking engagement with each other and in the closing position cause a positive-locking connection of the blocking piece  22  to the spring lock element  34 . 
         [0048]    The first locking part  2  can be attached in a closing direction X onto the second locking part  3 , to transfer the locking device  1  into its closing position, as shall yet be subsequently explained in detail with the help of  FIGS. 3 to 6 . The spring lock element  34  herein extends along a circumferential direction U around the closing direction X and is in sections opened circumferentially by an opening  341 . This has the effect that the blocking piece  22  can on the one hand in a comparably simple manner without great effort be attached in the closing direction X onto the spring lock element  34 , in that the blocking piece  22  with its catch section  222  (circulating the blocking piece  22  circumferentially) is attached in the closing direction X onto the catch section  340  of the spring lock element  34  and hereby expands the spring lock element  34  across to the closing direction X, so that the catch section  222  of the blocking piece  22  lockingly engages with the catch section  340  of the spring lock element  34 . 
         [0049]    To open, the spring lock element  34  is slid in an opening direction Y, essentially directed across to the closing direction X, relative to the blocking piece  22  so that the blocking piece  22  is led through the circumferential opening  341  on the spring lock element  34  and disengages from the spring lock element  34 . 
         [0050]      FIGS. 3A and 3B  show the locking device  1  prior to the closing of the locking device  1 . In this state the blocking piece  22  is retracted into the housing chamber  213  of the casing  21  and is thus positioned in a retracted state in which it does not project outwards from the casing  21 . A magnet  212  is arranged on a housing opening  214  of the casing section  210  (see  FIG. 1 ), which stands magnetically attracting opposite to a magnet  223  of the blocking piece  22  (see  FIG. 3B ). On account of the magnetic force between the magnets  212 ,  223 , the blocking piece  22  is in the opened position of the locking device  1  at first held in its retracted position. 
         [0051]    When, as illustrated in  FIGS. 4A and 4B , the first locking part  2  is in the closing direction X brought close to the second locking part  3 , the blocking piece  22  is transferred from its retracted position into an extended position, as illustrated in  FIG. 4B . This takes place in an automatic manner due to a magnetic force between the magnet  223 , arranged on the blocking piece  22 , and a magnet  331 , arranged on the holding section  330  on the casing  31  of the second locking part  3 . 
         [0052]    In the extended position the blocking piece  22  extends through an opening  211  on the casing  21  and projects outwards from the casing  21 . The blocking piece  22  in this case lies against the edge section of the opening  211 , which confines the housing chamber  213  in the closing direction X, so that an end position for the extended position is defined by the edge of the opening  211 . 
         [0053]    The magnets  223 ,  331  realize magnetic means for creating a magnetic force between the blocking piece  22  and the second locking part  3  and fulfil two kinds of functions. For one thing, the magnetic means  223 ,  331  have the effect that the blocking piece  22 , upon attaching the first locking part  2  onto the second locking part  3 , is transferred from its retracted position (see  FIG. 3B ) into its extended position (see  FIG. 4B ). For another, the magnetic means  223 ,  331  create a magnetic force, which magnetically assists in the closing of the locking device  1  and pulls the blocking piece  22  into engagement with the spring lock element  34 , so that the mechanical locking engagement of the blocking piece  22  with the spring lock element  34  can be established in a largely automatic manner, when the magnets  223 ,  331  are suitably dimensioned. 
         [0054]    The magnetic means in the form of the magnets  223 ,  331  are dimensioned in such a way, that upon attaching the blocking piece  22  onto the spring lock element  34  the blocking piece  22  is not returned into its retracted position, but the catch section  222  of the blocking piece  22  engages with the catch section  340  of the spring lock element  34  and for this purpose can push aside the spring lock element  34  in the direction of an expanding. 
         [0055]      FIGS. 5A and 5B  show the locking device  1  in its closing position, in which the catch sections  222 ,  340  of the blocking piece  22  and of the spring lock element  34  lockingly engage with each other, so that via the engagement of the blocking piece  22  with the spring lock element  34  the first locking part  2  is held on the second locking part  3  in a mechanically locking manner. 
         [0056]    To open the locking device  1  the blocking piece  22  and the spring lock element  34  are slid relative to each other along the opening direction Y, as illustrated in  FIGS. 6A and 6B . For this purpose, the second locking part  3 , along with the spring lock element  34 , is moved in the opening direction Y relative to the first locking part  2  with the blocking piece  22  arranged on it, so that the blocking piece  22  passes through the circumferential opening  341  on the spring lock element  34  and disengages from the spring lock element  34 . 
         [0057]    In the unlocked state, illustrated in  FIGS. 6A and 6B , the first locking part  2  is no longer held on the second locking part  3 , so that the locking parts  2 ,  3  can be taken away from each other. 
         [0058]    By taking out the first locking part  2  from the second locking part  3 , moreover, the magnets  223 ,  331  on the blocking piece  22  or on the casing  31  are removed from each other, so that the magnetic force between these magnets  223 ,  331  is weakened. When the first locking part  2  is sufficiently far enough removed from the second locking part  3 , the magnetic force of the magnets  212 ,  223 , acting between the casing  21  of the first locking part  2  and the blocking piece  22 , exceeds the magnetic force of the magnets  223 ,  331 , so that due to the magnetic force between the magnets  212 ,  223  the blocking piece  22  is pulled towards the magnet  212  on the casing section  210  of the casing  21  of the first locking part  2  and with that is transferred into its retracted position (see  FIG. 3B ). 
         [0059]    In the retracted position, as has been said before, the blocking piece  22  then does not, or at least not obstructively, project outwards from the casing  21 , so that the blocking piece  22  is not obstructing the handling of a component, which the first locking part  2  is connected to, and, moreover, is not affecting the aesthetic overall impression of this component (e.g. when used on a handbag or the like). 
         [0060]      FIGS. 7 to 12  show a further exemplary embodiment of a locking device  1 , which essentially differs from the exemplary embodiment according to  FIGS. 1 to 6  in that on a casing  21  of a first locking part  2  two blocking pieces  22   a,    22   b  and on a casing  31  of a second locking part  3  two spring lock elements  34   a,    34   b  are provided and thus a double mechanical locking of the locking parts  2 ,  3  with each other can be established. The same reference signs as before are subsequently assigned to components with the same function, as far as this seems useful. 
         [0061]    The first locking part  2  has two blocking pieces  22   a,    22   b,  which are arranged on a casing section  210  of the casing  21 , each in a housing chamber  213   a,    213   b  respectively. Each blocking piece  22   a,    22   b  has a catch section  222   a,    222   b  and supports a magnet  223   a ,  223   b.    
         [0062]    A magnet  212   a,    212   b  is arranged on each of the housing openings  214   a,    214   b  of the casing section  210 , which said magnet  212   a,    212   b  closes the housing chamber  213   a ,  213   b  on the rear side (i.e. towards a side turned away from the other, second locking part  3  in the closing position) (compare  FIG. 7 ). 
         [0063]    The second locking part  3  has a casing  31 , onto which a casing part  32  is attached. On the casing part  32 , which is rigidly connected to the casing  31 , an adjustment element  33  is arranged, which on the one hand supports two spring lock elements  34   a,    34   b  on holding sections  330   a,    330   b  in a torque-proof manner and which is, on the other hand, connected to magnets  331   a,    331   b  via housing openings  232   a,    232   b.    
         [0064]    The adjustment element  33  is held slidable along the opening direction Y on the casing part  32  via positive-locking elements  320  and can be slid along longitudinal guiding sections  323  relative to the casing part  32  (see  FIG. 8 ). End positions of the adjustment element  33  are defined along the opening direction Y on the one hand by a stop section  321  and on the other hand by stops  322 , which are lying in recesses  333  on the adjustment element  33 . 
         [0065]      FIGS. 9A and 9B  show the locking device  1  in a state prior to closing. In this state the blocking pieces  22   a,    22   b  of the first locking part  2  are retracted into the housing chambers  213   a,    213   b  on the casing section  210  and do not or at least not obstructively project outwards beyond the casing  21 . When, analogous to the preceding description for the exemplary embodiment according to  FIGS. 1 to 6 , the first locking part  2  is brought close to the second locking part  3 , the magnetic forces between the magnets  223   a,    223   b,    231   a,    231   b  on the blocking pieces  22   a,    22   b  on the one hand and on the adjustment element  33  on the other hand have the effect that the blocking pieces  22   a ,  22   b  are transferred from their retracted position into an extended position illustrated in  FIGS. 10A and 10B . 
         [0066]    In the extended position the blocking pieces  22   a,    22   b  each extend through the opening  211   a,    211   b  on the casing  211  respectively and project outwards from the casing  21  in the direction of the second locking part  3 . 
         [0067]    In this extended position the blocking pieces  22   a,    22   b  can be inserted in housing openings  310   a,    310   b  on the casing  31  of the second locking part  3 , to be brought into locking engagement with the spring lock elements  34   a,    34   b.  In the locked state, corresponding to the closing position of the locking device  1  and illustrated in  FIGS. 11A and 11B , the catch sections  222   a,    222   b  of the blocking pieces  22   a,    22   b  then engage with the catch sections  340   a,    340   b  of the spring lock elements  34   a,    34   b,  so that via this engagement the first locking part  2  is held in an engaging, positive-locking manner on the second locking part  3 . 
         [0068]    To open the locking device  1 , the adjustment element  33  is moved, along with the spring lock elements  34   a,    34   b  arranged on it, in the opening direction Y relative to the blocking pieces  22   a,    22   b,  as illustrated in  FIGS. 12A ,  12 B. The blocking pieces  22   a,    22   b  are thus moved through circumferential openings  341   a,    341   b  of the spring lock elements  34   a,    34   b  and disengage from the spring lock elements  34   a,    34   b,  so that the lock between the first locking part  2  and the second locking part  3  is terminated and the blocking pieces  22   a,    22   b  can be taken out of the housing openings  310   a,    310   b  of the casing  31  of the second locking part  3 , to remove the first locking part  2  from the second locking part  3 . 
         [0069]    As illustrated in  FIG. 12B , the adjustment element  33  in the unlocked state lies against the stop section  321  of the casing part  32 . This stop section  321  therefore defines an end position for the unlocked state, in which the engagement between the spring lock elements  34   a,    34   b  and the blocking pieces  22   a,    22   b  is terminated. 
         [0070]    Analogous to the preceding description for the exemplary embodiment according to  FIGS. 1 to 6 , in the exemplary embodiment according to  FIGS. 7 to 12  the blocking pieces are also pre-stressed via magnetic pre-stressing means in the direction of their retracted position against the casing  21 . For this purpose, the magnets  223   a,    223   b  on the blocking pieces  22   a,    22   b  stand attracting opposite to the magnets  212   a,    212   b  on the casing section  210 , so that, when the first locking part  2  is taken out from the second locking part  3 , the blocking pieces  22   a,    22   b  are returned into their retracted position according to  FIG. 9B  due to this magnetic returning force. 
         [0071]    Instead of magnetic pre-stressing means in the form of the magnet  212  in the embodiment according to  FIGS. 1 to 6  or the magnets  212   a,    212   b  in the embodiment according to  FIGS. 7 to 12 , a mechanical spring  224  can also be employed, which acts between the blocking piece  22  or the blocking pieces  22   a,    22   b  and the casing section  210 , as schematically illustrated in  FIG. 12B  for the blocking piece  22   b.  Such a spring  224  causes a mechanical return force, which causes a return of the blocking piece  22  or of the blocking pieces  22   a,    22   b  into the retracted position, as soon as the returning force exceeds the magnetic force of the magnetic means between the blocking piece  22  and the second locking part  3  or the blocking pieces  22   a,    22   b  and the second locking part  3 . 
         [0072]    A locking device of the described kind can for example be employed
       for buttons for clothing;   for belt buckles (advantage: upon looping in a retracted blocking piece does not get caught on trouser loops);   for a connection of two pieces of luggage or of modular carrier boxes;   for a coupling of a piece of luggage or a transport box with a loading area of a vehicle (advantage: heavy boxes do not have to be lifted in order to be unlocked or raised over a multitude of blocking pieces spread out on the loading area);   for toys, e.g. for the coupling of a toy train.       
 
       LIST OF REFERENCE SIGNS 
       [0000]    
       
           1  Locking device 
           2  Locking part 
           21  Casing 
           210  Casing section 
           211 ,  211   a,    211   b  Opening 
           212 ,  212   a,    212   b  Magnet 
           213 ,  213   a,    213   b  Housing chamber 
           214 ,  214   a,    214   b  Housing opening 
           22 ,  22   a,    22   b  Blocking piece 
           222 ,  222   a,    222   b  Catch section 
           223 ,  223   a,    223   b  Magnet 
           224  Spring 
           3  Locking part 
           31  Casing 
           310 ,  310   a,    310   b  Housing opening 
           32  Casing part 
           320  Positive-locking elements 
           321  Stop section 
           322  Stops 
           323  Longitudinal guiding section 
           33  Adjustment element 
           330 ,  330   a,    330   b  Holding portion 
           331 ,  331   a,    331   b  Magnet 
           332 ,  332   a,    332   b  Housing opening 
           333  Recesses 
           34 ,  34   a,    34   b  Spring lock element 
           340 ,  340   a,    340   b  Catch section 
           341 ,  341   a,    341   b  Opening 
           35  Housing opening 
         B Direction of movement 
         U Circumferential direction 
         X Closing direction 
         Y Opening direction