Abstract:
A key blank, key and master keying system for a twisting tumbler sidebar lock of the type where the sidebar is blocked or unblocked by a selectively positioned longitudinally extending slider, has a key blank with a slider contacting surface on a rib on the blank below the bitting area at one of a plurality of selected predetermined locations. A key with skew cut bittings can be cut on the blank and the blank can be configured with the slider contacting surface at different predetermined locations. The slider contact area on the rib of the key blank can be divided into two horizontal portions at different predetermined locations and the slider itself can have contact surfaces also positioned at different predetermined locations so that a number of different master keying variations are possible.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    The present application is a continuation-in-part of U.S. application Ser. No. 09/981,801 filed Oct. 19, 2001, which in turn is a continuation-in-part of U.S. application Ser. No. 09/776,929 filed Feb. 6, 2001, now abandoned. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to improvements in key and key blank configurations for use with twisting tumbler/sidebar-slider controlled cylinder locks of the type disclosed in the parent applications, and a master keying system therefor.  
           [0004]    2. Description of the Background Art  
           [0005]    Keys to operate locks with rotating reciprocating (twisting) tumblers are conventionally bitted on the upper portion of the key blade with skew cut bittings. The skew cuts operate in combination with chisel pointed spring loaded tumbler pins to position the pins at the correct location to operate the cylinder. This type of lock is known as a Medeco lock made by Medeco Security Locks, Inc. of Salem, Va. Medeco cylinders of this type are well-known and their construction and operation is disclosed, for example, in U.S. Pat. Nos. 3,499,302 (Spain et al.) and U.S. Pat. No. 3,722,240 (Spain et al.). Other and later patents, for example, describing the Medeco locks are U.S. Pat. No. 4,635,455 (Oliver), U.S. Pat. No. 4,732,022 (Oliver), U.S. Pat. No. 5,289,709 (Field), U.S. Pat. No. 5,419,168 (Field) and U.S. Pat. No. 5,570,601 (Field).  
           [0006]    The first generation of twisting tumbler locks, for example, rotating pin tumblers with skew cut keys manufactured by Medeco Security Locks, Inc., utilized variations in the pins to establish a master keying system. This technique is well-known in the lock industry.  
           [0007]    The second generation of Medeco locks was sold under the trademark BIAXTAL and expanded on the master keying capabilities of the original Medeco products by off-setting the key bittings along the blade of the key and providing pins with different offset tips. This construction and technique is disclosed, for example, in U.S. Pat. Nos. 4,635,445 (Oliver) and 4,732,022 (Oliver).  
         SUMMARY OF THE INVENTION  
         [0008]    The ability of a locksmith or lock manufacture to configure lock cylinders to operate in master keying systems is quite important in the lock industry. The present invention provides additional benefits in increased master keying which is primarily attributed to the uniquely formed key blank and key operating with a third level locking slider for the Medeco lock as disclosed in U.S. application Ser. No. 09/981,801, which is incorporated herein by reference.  
           [0009]    The key of the present invention has a conventional bitting area and, on the side of the key blade, a rib that projects horizontally from a longitudinal axis of the key. The rib of the present invention is provided with a front end to contact a slider that moves axially within the cylinder. By varying the structure, configuration and placement of the front end of the rib and the slider contact surface, a unique master keying system has been developed whereby each lock can be operated by its own key and groups of locks can be operated by a master key. In other words, new master keying systems are disclosed using a unique technique which requires a rib on the side of the key blank to interact with a uniquely configured sliding member in the cylinder. The sliding member functions to block the operation of the cylinder until the key correctly positions the slider as explained in U.S. application Ser. No. 09/981,801.  
           [0010]    U.S. application Ser. No. 09/981,801 discloses variations of the front end of the rib that contacts the slider whereby the front ends are slopped at an angle or stepped in a vertical plane. The present invention provides variations in the depths of the front end of the slider along a horizontal plane of the key. Further, the present invention improves on the invention of U.S. application Ser. No. 09/981,801 in that the structure of the fore end of the rib on the key and the structure of the mating contact area on the slider and the cylinder are configured so that there are spaced horizontal areas which can then be used to significantly increase the master keying capabilities.  
           [0011]    The above and other features and advantages of the present invention will be further understood from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings wherein like reference numerals are used throughout the various views to designate like parts. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 a  is a side elevation view of a key blank according to the present invention.  
         [0013]    [0013]FIG. 1 b  is a sectional view taken along line A-A of the key blank of FIG. 1 a.    
         [0014]    [0014]FIG. 1 c  is a bottom plan view of the key blank of FIG. 1 a.    
         [0015]    [0015]FIG. 2 a  is a side elevation view of another configuration of a key blank according to the present invention.  
         [0016]    [0016]FIG. 2 b  is a sectional view taken along line B-B of the key blank in FIG. 2 a.    
         [0017]    [0017]FIG. 2 c  is a bottom plan view of the key blank of FIG. 2 a.    
         [0018]    [0018]FIG. 3 a  is a side elevation view of yet another configuration of a key blank according to the present invention.  
         [0019]    [0019]FIG. 3 b  is a sectional view taken along line C-C of the key blank of FIG. 3 a.    
         [0020]    [0020]FIG. 3 c  is a bottom plan view of the key blank of FIG. 3 a.    
         [0021]    [0021]FIG. 4 a  is a side elevation view of a key blank with a different configuration of contact surfaces on a slider contacting rib according to the present invention.  
         [0022]    [0022]FIG. 4 b  is a sectional view taken along line D-D of the key blank of FIG. 4 a.    
         [0023]    [0023]FIG. 4 c  is a bottom plan view of the key blank of FIG. 4 a.    
         [0024]    [0024]FIG. 5 a  is a side elevation view of another key blank with a different configuration of contact surfaces on a slider contacting rib according to the present invention.  
         [0025]    [0025]FIG. 5 b  is a sectional view taken along line E-E of the key blank of FIG. 5 a.    
         [0026]    [0026]FIG. 5 c  is a bottom plan view of the key blank of FIG. 5 a.    
         [0027]    [0027]FIG. 6 a  is a side elevation view of yet another key blank with a different configuration of contact surfaces on a slider contacting rib according to the present invention.  
         [0028]    [0028]FIG. 6 b  is a sectional view taken along line F-F of the key blank of FIG. 6 a.    
         [0029]    [0029]FIG. 6 c  is a bottom plan view of the key blank of FIG. 6 a.    
         [0030]    [0030]FIG. 7 is a bottom plan view of a slider illustrating one of the many possible key contact variations.  
         [0031]    [0031]FIG. 8 is a perspective view of the slider shown in FIG. 7.  
         [0032]    [0032]FIG. 9 is a perspective view of a slider similar to FIG. 8 but shown with a different configuration of key rib contact surfaces.  
         [0033]    [0033]FIG. 10 is a perspective view of a slider showing yet another configuration of key rib contact surfaces.  
         [0034]    [0034]FIG. 11 a  is a side elevation view of a cylinder lock illustrating the operation of a properly configured key blank according to the present invention.  
         [0035]    [0035]FIG. 11 b  is a sectional view taken along line G-G of the arrangement shown in FIG. 11 a.    
         [0036]    [0036]FIG. 11 c  is a bottom plan view of the arrangement shown in FIG. 11 a.    
         [0037]    [0037]FIG. 12 a  is a side elevation view of another cylinder lock illustrating the operation of a properly configured key blank according to the present invention.  
         [0038]    [0038]FIG. 12 b  is a sectional view taken along line H-H of the arrangement shown in FIG. 12 a.    
         [0039]    [0039]FIG. 12 c  is a bottom plan view of the arrangement shown in FIG. 12 a.    
         [0040]    [0040]FIG. 13 a  is a side elevation view of a slider controlled lock illustrating the operation of an improperly configured key blank according to the present invention.  
         [0041]    [0041]FIG. 13 b  is a sectional view taken along line I-I of the arrangement shown in FIG. 13 a.    
         [0042]    [0042]FIG. 13 c  is a bottom plan view of the arrangement shown in FIG. 13 a.    
         [0043]    [0043]FIG. 14 a  is a side elevation view of a further key blank according to the present invention with a particular surface rib contact.  
         [0044]    [0044]FIG. 14 b  is a sectional view taken along line J-J of the key blank of FIG. 14 a.    
         [0045]    [0045]FIG. 14 c  is a bottom plan view of the key blank of FIG. 14 a.    
         [0046]    [0046]FIG. 15 a  illustrates a Medeco BIAXIAL® key incorporating the slider contact rib according to the present invention.  
         [0047]    [0047]FIG. 15 b  is a sectional view taken along line K-K of the key of FIG. 15 a.    
         [0048]    [0048]FIG. 15 c  is a bottom plan view of the key of FIG. 15 a.    
         [0049]    [0049]FIG. 16 a  illustrates an original Medeco key incorporating the slider contact rib according to the present invention.  
         [0050]    [0050]FIG. 16 b  is a sectional view taken along line L-L of the key of FIG. 16 a.    
         [0051]    [0051]FIG. 16 c  is a bottom plan view of the key of FIG. 16 a.   
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0052]    With reference to FIGS. 1 a - c , a key blank  10  is comprised of a key head or key bow  101 , a key blade portion  103  extending from the key bow  101  as is conventional, and a key stop  102 . The key stop  102  limits the insertion of a key into a lock cylinder plug. The key blade  103  is divided vertically into two areas, the top area is a skewed cut bitting area  104  and the bottom area is a slider contact rib area  105 .  
         [0053]    Variations in the key blank  10  are achieved in part by the length of a slider contact rib  106 . These variations are measured longitudinally from the key stop  102  to a fore end  107  of the slider contact rib  106 . On the key blank  10 , as illustrated in FIGS. 1 a - c , the fore end  107  of the slider contact rib  106  is positioned at predetermined location  1 .  
         [0054]    [0054]FIGS. 2 a - c  show a similarly configured key blank  20  with a key stop  202  and a fore end  207  of a slider contact rib  206  which is positioned at predetermined location  2 .  
         [0055]    With reference to FIGS. 3 a - c , a key blank  30  similar to the key blanks described above has a key stop  302  and a slider contact rib  306  with a fore end  307  positioned at predetermined location  3 .  
         [0056]    [0056]FIGS. 4 a - c  show a key blank  40  having a key stop  402  and a slider contact rib  406 . The slider contact rib  406  has two separate fore end portions: an inner part  407  and an outer part  408 . As can be seen, the inner part  407  of the fore end is positioned at predetermined location  1  while the outer part  408  of the fore end is positioned at predetermined location  6 .  
         [0057]    With regard to FIG. 5, a key blank  50  is of similar configuration having a key stop  502  and a slider contact rib  506  with an inner part  507  of a fore end positioned at predetermined location  2  and an outer part  508  of the fore end positioned at predetermined location  6 .  
         [0058]    Similarly, the key blank  60  illustrated in FIG. 6 has a key stop  602 . A fore end of a slider contact rib  606  has two portions: an inner part  607  and an outer part  608 . The inner part  607  of the fore end is positioned at predetermined location  3  and the outer part  608  of the fore end is positioned at predetermined location  6 .  
         [0059]    With reference to FIGS.14 a - c , a key blank  4000  has a key stop  4002  and a slider contact rib  4006 . The slider contact rib  4006  has two contact end portions  4007  and  4008 . The contact end portion  4007  is at a predetermined position  1  and the contact end portion  4008  is at a predetermined position  3 .  
         [0060]    A Medeco BIAXIAL® lock can be modified to utilize the slider contact rib on a key blank of the present invention. FIG. 15 a  illustrates the Medeco BIAXIAL® key incorporating the slider contact rib on the side of the key. Referring to FIGS. 15 a - c , a key  5000  has a stop  5002  and a slider contact rib  5007 .  
         [0061]    An original Medeco cylinder lock can also be modified to utilize the slider contact rib on a key blank of the present invention. FIG. 16 a  illustrates the original cylinder Medeco key incorporating the slider contact rib on the side of the key. Referring to FIGS. 16 a - c , a key  6000  has a stop  6002  and a slider contact rib  6007 .  
         [0062]    With regard to FIGS. 7 and 8, a slider  70  has at least one projection  707  on its top surface that must be precisely positioned before the lock cylinder can open, as explained in the above-referenced application. On the bottom edge of the slider  70  is a key contact rib  708  that contains contact areas that mate with a slider contact rib on a key. On the slider  70 , contact area  713  is configured to a predetermined location  3  so that the contact area  713  mates with a fore end of the slider contact rib on the key. The other contact area  721  is configured to a predetermined location  1  and has a contact surface to mate with a fore end of the slider contact rib on the key.  
         [0063]    [0063]FIG. 9 shows another embodiment of a slider  71  which has a slider body  709  and a key contact rib  708 ′ that contains contact areas  712 ,  721 . The contact areas  712 ,  721  mate with a slider contact rib on a key, and are configured to two predetermined locations. The contact area  712  closest to the slider body  709  is configured to predetermined location  2  for mating with a fore end of the slider contact rib on the key. The contact area  721  farthest from the slider body  709  is configured to predetermined location  1  for mating with a fore end of the slider contact rib on the key.  
         [0064]    With regard to FIG. 10, a further slider configuration is shown. A slider  72  contains contact areas  711 ,  721  that mate with a slider contact rib on a key. Similarly, the contact areas  711 ,  721  are configured to two predetermined locations. The contact area  711  closest to the slider body  709  is configured to predetermined location  1  for mating with the fore end of the slider contact rib on the key. The contact area  721  furthest away from the slider body  709  is also configured to predetermined location  1  for mating with a fore end of the slider contact rib on the key.  
         [0065]    The operation of the key for locking/unlocking a cylinder lock or locks with rotating reciprocating (twisting) tumblers will now be described with reference to FIGS.  11 - 13 . As illustrated in FIGS. 11 a - c , a lock cylinder plug  90  contains tumbler pin holes  91  to house Medeco-type chisel pointed rotatable tumbler pins (not shown). Contained within the lock cylinder plug  90  is a sidebar  80  with sidebar legs  81  as is known in the art of Medeco locks. The sidebar  80  has at least one notch  82  to receive the corresponding projection  707  on the slider  70  (FIGS.  7 - 10 ) when the key correctly positions the slider  70 . The slider  70  fits into a cavity  93  in the lock cylinder plug  90  and is biased by a spring (not shown) towards a face  92  of the lock cylinder plug  90 . When the key  30 , illustrated in FIGS. 3 a - c , for example, is inserted into the lock cylinder plug  90 , the contact area  713  on the slider  70  mates with the fore end  307  on the key to correctly position the slider  70  within the lock cylinder plug  90 .  
         [0066]    As illustrated in FIGS. 12 a - c , the lock cylinder plug  90  containing slider  70  can also be operated, for example, with the key  40 , as illustrated in FIGS. 4 a - c . The slider contact rib  406  on the key  40  is provided with the inner part  407  of the fore end and the outer part  408  of the fore end. The inner part  407  of the fore end is positioned at predetermined location  1  and the outer part  408  of the fore end is positioned at predetermined location  6 . The inner part  407  of the fore end mates with the contact area  721  on the slider  70  and positions the slider  70  in a correct operating location. The outer part  408  of the fore end is sufficiently clear of the contact area  713  on the slider  70  and does not mate with the contact area  713 .  
         [0067]    As illustrated in FIGS. 13  a - c , the lock cylinder plug  90  containing slider  70  cannot be operated, for example, with the key  20  (FIGS. 2 a - c ). The fore end  207  of the slider contact rib  206  is positioned at predetermined location  2 . When the key  20  is inserted into the lock cylinder plug  90 , the key contact rib  713  on the slider  70  mates with the fore end  207  of the slider contact rib  206 . The slider  70  moves so far away from the face  92  of the lock cylinder plug  90  that the projection  707  will not fit within the notch  82  on the sidebar  80 .  
         [0068]    When a key with the unique slider contact rib as disclosed herein is inserted into a lock cylinder plug containing the unique slider described in the aforementioned application, the first contact surface on the slider contact rib to mate with the key contact surface on the slider will position the slider in the lock cylinder plug. However, if the key  4000  (FIGS. 14 a - c ), for example, is used in a lock cylinder containing the slider  70 , both surfaces  4007 ,  4008  will mate with contact areas  712 ,  721  simultaneously, and thus, both surfaces  4007 ,  4008  will position the slider  70 .  
         [0069]    By positioning the slider contact rib on the key blank to six predetermined locations and dividing the slider contact rib into two horizontal contact surfaces, it is possible to configure 21 (twenty one) different key blanks to fit into one keyway of a cylinder lock.  
         [0070]    A key blank could be configured into any one of the following 21 possibilities by identifying the inner part or innermost horizontal contact surface as  1   a ,  2   a ,  3   a ,  4   a ,  5   a  and  6   a , and the outer part or outermost horizontal contact surface as  1   b ,  2   b ,  3   b ,  4   b ,  5   b  and  6   b:   
         [0071]    [0071] 1   b - 1   a   
         [0072]    [0072] 2   b - 1   a   
         [0073]    [0073] 2   b - 2   a   
         [0074]    [0074] 3   b - 1   a    
         [0075]    [0075] 3   b - 2   a    
         [0076]    [0076] 3   b - 3   a   
         [0077]    [0077] 4   b - 1   a    
         [0078]    [0078] 4   b - 2   a    
         [0079]    [0079] 4   b - 3   a    
         [0080]    [0080] 4   b - 4   a   
         [0081]    [0081] 5   b - 1   a    
         [0082]    [0082] 5   b - 2   a    
         [0083]    [0083] 5   b - 3   a    
         [0084]    [0084] 5   b - 4   a    
         [0085]    [0085] 5   b - 5   a   
         [0086]    [0086] 6   b - 1   a    
         [0087]    [0087] 6   b - 2   a    
         [0088]    [0088] 6   b - 3   a    
         [0089]    [0089] 6   b - 4   a    
         [0090]    [0090] 6   b - 5   a    
         [0091]    [0091] 6   b - 6   a   
         [0092]    Similarly, sliders of cylinder locks can be configured into the same 21 different arrangements.  
         [0093]    A lock containing a  3   b - 1   a  slider can be operated by keys with the following configurations: 
         [0094]    [0094] 3   b - 1   a    
         [0095]    [0095] 3   b - 2   a    
         [0096]    [0096] 3   b - 3   a    
         [0097]    [0097] 4   b - 1   a    
         [0098]    [0098] 5   b - 1   a    
         [0099]    [0099] 6   b - 1   a    
         [0100]    With the above key blank and slider configurations, and the existing Medeco master keying techniques, a much larger and more complex master keying system can be provided than that previously known and available.  
         [0101]    Although the present invention has been described with reference to the particular embodiments disclosed, it is understood that these embodiments are merely illustrative of the application and principles of the invention. Numerous other configurations can be made and other arrangements can be devised without departing from the spirit and scope of the invention as defined in the appended claims.