Abstract:
A profiled key for use in an associated cylinder lock provided with a rotatable key plug having a longitudinal keyway. The key has a substantially flat key blade with a longitudinally extending profile groove at a side surface thereof and at least one local recess adjacent to said profile groove. The local recess constitutes a locally expanded portion of said profile groove, and the locally expanded portion of the profile groove has a cross-section with two opposite, non-symmetrical side walls. The local reces will accommodate a blocking element in the lock, and permit full insertion of the key blade into the keyway.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a key for use in an associated cylinder provided with a rotatable key plug having a longitudinial keyway. The key blade has a substantially flat key blade and a longitudinally extending profile groove. The key is especially adapted for use in a lock having a blocking element, which is movable elevationally so as to prevent the insertion of an incorrectly cut key blade into the keyway. 
         [0002]    The key of the present invention is part of an inventive concept of a lock and key combination, which is the subject of a separate patent application being filed in parallel with the present application. 
         [0003]    The contents of the parallel application mentioned above is incorporated in this disclosure by refernce. 
         [0004]    Similar lock and key combinations are generally known, e.g. from the U.S. Pat. No. 5,715,717 (Widén). The profile groove or grooves in the key will provide great possibilities to vary the cross-sectional profile of the key, which is a great advantage. 
       OBJECT OF THE INVENTION 
       [0005]    The object of the present invention is to provide a key, cooperating with a blocking mechanism in the lock and providing an increased number of profile varieties. 
       SUMMARY OF THE INVENTION 
       [0006]    According to the present invention, this object is achieved by providing a key having a substantially flat key blade and being characterized in that said substantially flat key blade has a longitudinally extending profile groove at at least one side surface thereof, said profile groove is provided with an inner, longitudinally straight portion corresponding to the outermost portion of a profile rib in said longitudinal key way of the key plug, said substantially flat key blade also has at least one local recess adjacent to said profile groove, said at least one local recess constitutes a locally expanded portion of said profile groove, and said locally expanded portion of the profile groove has a cross-section with two opposite, non-symmetrical side walls. 
         [0007]    As will be explained below, the locally expanded portion of the profile groove will accomodate a blocking element arranged in the associated lock, upon moving the blocking element from an initial position to a second position enabling full insertion of the key blade into the lock. In case a differently cut key blade is inserted, i.e. a key blade without a local recess adjacent to the profile groove, the blocking element of the lock will stop the key blade from being fully inserted into the keyway. 
         [0008]    The key may be configured in various ways, in accordance with the dependent claims and as explained further below with reference to the appended drawings. 
     
    
     
       SHORT DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1   a  shows, in a side view, a cylinder lock, with a key blade inserted therein; 
           [0010]      FIG. 1   b  shows the cylinder lock and key combination of  FIG. 1   a  in a perspective view; 
           [0011]      FIG. 1   c  shows the lock and key combination of  FIG. 1   a  in a perspective, exploded view, illustrating a locking mechanism above the keyway of the lock and the key blade according to the invention; 
           [0012]      FIG. 1   d  shows a cross-section along the line Id-Id in  FIG. 1   a  also illustrating a blocking element arranged in the key plug of the lock; 
           [0013]      FIG. 1   e  shows a cross-section as in  FIG. 1   d,  but without a key; 
           [0014]      FIG. 1   f  shows a cross-section along the line  1   f - 1   f  in  FIG. 1   a;    
           [0015]      FIGS. 2   a,    2   k  show schematically in perspective views how the key blade interacts with the blocking element of the lock ( FIG. 2   b  at a larger scale); 
           [0016]      FIGS. 3   a  and  3   b  show the key blade of  FIGS. 2   a,    2   b  in a side view ( FIG. 2   b  at a larger scale); 
           [0017]      FIG. 4  shows, in a side view, a key blade anid a blocking element located closer to the entrance of the keyway; 
           [0018]      FIGS. 5 and 6  show the blocking element and the key blade of  FIG. 4  in a cross-sectional view and an end view, respectively. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    In  FIGS. 1   a,    1   b,    1   c,    1   d,    1   e,    1   f  there is shown a cylinder lock and key combination having conventional upper and lower tumbler pins  1 ,  2  in a linear row ( FIG. 1   c ) cooperating with an upper edge of the inserted key blade, the upper edge having a corresponding numiber of recess cuts  11 ,  12 ,  13 ,  14 ,  15 ,  16  at various levels. Deep inside the keyway of the lock, not very far from the tip of the inserted key blade, there is a blocking element  20 , which is movable elevationally (up and down) at the side of the keyway. 
         [0020]    The blocking element, and its interaction with the inserted key blade, will be better understood from  FIG. 1   d.  Here, the cylindrical housing of the lock is denoted  30 , having an upright housing part  31  accomodating the upper locking pins  1 ,  2  mentioned above and a cylindrical bore  32 , in which a cylindrical key plug  33  is rotatably journalled. 
         [0021]    The key plug  33  has a central keyway  34  extending lonigitudinally along the axis of the cylindrical bore  32  and a central plane A extending through the cylindrical axis and the upper housing portion  31 . In a longitudinal row in this plane A, there are a number of cylindrical holes (not visible in  FIG. 1   d ) each accotmmodating one of the lower locking pins  2 . In  FIGS. 1   d  and  1   e,  the profile of the keyway  50  and the corresponding key blade  60  are clearly visible. The keyway  50  is oriented along the central plane A. It has a lower, rather wide portion  50   a,  and an upper, relatively narrow portion  50   b.  The upper and lower portions of the keyway have side walls  50   c  and  50   d  lying in a common plane in parallel to the central plane A (to the right thereof in  FIG. 3 ). At the other lateral side, the upper keyway portion  50   b  has a side wall  50   e,  whereas the lower part of the keyway has a side wall  50   f,  the latter being located further away from the central plane A than the upper side wall  50   e.    
         [0022]    On the right hand side of the keyway, there is a longitudinal, profiled rib  51  extending along the key plug. The profile rib  51  has a base portion  52  (concealed by the blocking element  20  in  FIG. 1   d ) and an end portion  53  provided with a downwardly directed tongue  54 . 
         [0023]    On the left hand side, the keyway has two longitudinal ribs  55  and  56  at the lower portiion of the keyway. 
         [0024]    The key blade  60  (see  FIG. 1   d ), according to the present invention, has a profile shape which is substantially supplementary to the keyway  50 . Accordingly, the key  60  has a lower base portion  60   a,  which is relatively wide, and an upper portion  60   b,  which is relatively narrow. 
         [0025]    At the right hand side (as seen in  FIG. 1   d ) the key blade has a longitudinally extending groove  61  with an outer portion  62 , and an inner, undercut portion  63 . The profile groove  60  has a bottom wall  64  and an opposite side wall  65 , which is inclined and faces the bottom wall  64  and also forms the inside wall of a ridge  66  extending along the key blade  60 . 
         [0026]    As will be evident from  FIG. 1   d,  the profile groove  61  accomodates the longitudinally extending profile rib  51 , including the downwardly directed tongue  54  in the undercut portion of the groove  61 . 
         [0027]    On the left hand side, the key blade  60  has two longitudinal grooves  67  and  68  corresponding to the profile ribs  55 ,  54 . 
         [0028]    As appears from  FIG. 1   f,  the outer portion  62  of the profile groove  61 , and the corresponding base portion  52  of the profile rib  50  has a slanted upper wall  69  and slanted surface  59 , respectively. 
         [0029]    Now, since the sectional profile of the key blade  60  corresponds to the cross-sectional profile of the keyway  50 , the key blade  60  can be inserted partially or fully into the keyway, as is known in the art. Of course, only key blades being cut with the particular profile of the keyway may be fully inserted into the keyway. 
         [0030]    In order to allow for further variations of the exact profile of the keyway, there is provided, according to the present invention, a blocking element  20  (as mentioned above) which can be regarded as a movable profile portion. 
         [0031]    Generally, the blocking elemeut has a profile section, which corresponds to the longitudinally extending groove  61  in the key blade. However, in the region of the outer portion  62  of the groove  61 , it is somewhat larger, in a direction parallel to the central plane A. So, it does not fit into the profile groove of the keyway along the full length thereof. 
         [0032]    However, according to the present invention, the key blade  60  is provided with a local recess  70  which constitutes a locally expanded portion of the profile groove  62  and is wide enough to accomfliiiodate the uppermost portion of the blocking element  20 , as will be explained more fully below. 
         [0033]    In order to secure a well-defined mobility of the blocking elemnent  20 , it is integrated with or firmly connected to a body  23 , which is guided for elevational movement in parallel to the central plane A of the key way in a substantially cylindrical cavity  24  at the side of the keyway, in parallel to the central plane A. Thus, the body  23  is guided for movement up and down in the cylindrical cavity  24 , so that the integrated or connected blocking element  20  is also movable up and down. 
         [0034]    The blocking element  20  may protrude partially or fully into the profile groove  61 , in a cut-out portion of the profile rib  51 . 
         [0035]    The interaction between the blockling element and the key blade is illustrated in  FIGS. 2   a,    2   b,    3   a,    3   b.  Initially, when the keyway  50  is empty (see  FIG. 1   e ), the blocking element  20  will be positioned in its lowermost position, because of the action of a compression spring  26  in the cavity  24  ( FIG. 1   d ). In the embodiment of  FIGS. 2   a,    2   b,    2   a,    2   b,  the profile groove  61  of the key blade  60  has no undercut portion, but this will not make any difference to the interaction between the key blade and the blocking element  20 . 
         [0036]    When the key blade  60  is inserted into the keyway  50 , a lower, first portion  21  of the blocking elemeent  20  will make contact with a ramp surface  75  near the tip end of the key blade. By way of this contact, the blocking element  20  will move upwards and take the position shown in  FIGS. 1   d  and  7   b.  Here, the upper, second portion  22  of the blocking element  20  will be accommodated in the above-mentioned recess  70 , which is locally cut out in this particular part of the keyway, so the width of the profile groove is effectively widened in this region. 
         [0037]    Without such a recess  70 , the blocking element would be jammed between the ramp surface  75  and the upper, slanted wall  69  of the longitudinal profile groove. 
         [0038]    In the embodiment shown in  FIGS. 2   a  and  2   b,  the blocking pin  20  is located deep inside the keyway near the tip end of the key blade upon full insertion of the key blade into the keyway. The first or lower projecting portion  21  of the blocking elemnent  20  contacts a machined, slightly recessed surface  76  ( FIG. 3   b ) adjacent to the lower side wall of the profile groove (in this embodinment there is no undercut portion), whereas the upper or second projecting portion  22  of the blocking element  20  is accomnmodated in the local recess  70 . This recess  70  is confined to the region of the fully inserted key blade in the vicinity of the blocking element  20 . In  FIGS. 4 ,  5 ,  6 , the blocking element  20  is located closer to the entrance of the keyway, so when the key blade is fully inserted into the keyway, the blocking element  20  is far away from the tip end of key blade. In order to accomlmodate the whole cross-section of the blocking element  20 , the lower part of the key blade material next to the groove  61  is taken away. Thus, the ridge portion  66  is cut away from the tip end of the key blade up to the location of the blocking element, leaving a lower side wall  77 , except for a portion near the tip end of the key blade. In this case, of course, the local upper recess, accommodating the second or upper projecting portion  22  of the blocking elenment  20  is located so as to start, with some overlap, where the lower side wall  77  and an adjoining inclined or ramp surface  78  ends. The overlap length should correspond or slightly exceed the dimension of the blocking element  20  in the longitudinal direction of the key plug. 
         [0039]    The upper, slanted wall portion of the recess  70  has an angle corresponding to the second projecting portion  22  of the blocking element  20 . 
         [0040]    As will be seen from  FIG. 4 , the key blade is provided with a second local recess  70  near the tip end, just like the key blade shown in  FIGS. 8   a  and  8   b.  Therefore, the key blade of  FIG. 10  will cooperate also with a blocking element  20  arranged deep inside the keyway, like the one shown in  FIG. 2   b.    
         [0041]    Accordingly, by havinig two or more blocking elements distributed longitudinally along the keyway, it is possible to provide a hierarchic system with master keys that open all individual locks having blocking pins at various locations. 
         [0042]    The blocking element in the lock may be urged to move up and down only by interaction with the profile groove and its adjoining recesses above and below the groove, without any spring acting on the body in the side cavity. Thus, the blocking element will then be positively guided by the upper and lower side walls of the partially expanded profile groove.