Abstract:
Certain exemplary embodiments of the present invention provide a lock keying system comprising: a lock cylinder comprising: a cylinder body; a plug assembly disposed in said cylinder body and comprising a plurality of pins and a one-to-one corresponding plurality of racks for relocating said plurality of pins; and a rack alignment tool receiving aperture defined by said lock cylinder; and a rack alignment tool comprising: a base plate; and a plurality of spaced elongated prongs, each prong from said plurality of prongs comprising a first longitudinal end adapted to engage a corresponding one of said plurality of racks, each prong from said plurality of prongs dimensioned lengthwise to relocate to a first predetermined position said corresponding one of said plurality of racks, said first predetermined position common to each of said plurality of racks, each prong from said plurality of prongs comprising a second longitudinal end connected to said base plate, wherein said rack alignment tool is adapted to restrain a carrier assembly comprising said plurality of racks in an unengaged position wherein said plurality of racks are unengaged with said plurality of pins. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. This abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a Continuation-in-Part of the following pending application:  
         [0002]    Ser. No. 10/256,066, (Attorney Docket No. 5645-03 (1013-006)), filed 26 Sep. 2002, and titled “Rekeyable Lock Assembly and Method of Operation”. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0003]    The invention and its wide variety of potential embodiments will be readily understood via the following detailed description of certain exemplary embodiments, with reference to the accompanying drawings in which:  
           [0004]    [0004]FIG. 1 illustrates a lock cylinder according to the present invention.  
           [0005]    [0005]FIG. 2 is an exploded view of the lock cylinder of FIG. 1.  
           [0006]    [0006]FIG. 3 is a perspective view of a plug assembly illustrating a carrier sub-assembly with a locking bar disposed in a locking position to lock the plug assembly in a lock cylinder body.  
           [0007]    [0007]FIG. 4 is a top plan view of the plug assembly of FIG. 3.  
           [0008]    [0008]FIG. 5 is a partially broken away side view of the plug assembly of FIG. 3.  
           [0009]    [0009]FIG. 6 is a partially exploded view of the plug assembly of FIG. 3.  
           [0010]    [0010]FIG. 7 is a section view through the plug assembly of FIG. 3 and a cylinder body, the section being taken transversely at one of the pins and illustrating the positioning of the pin, a rack, and the locking bar relative to each other and the cylinder body in a locked configuration.  
           [0011]    [0011]FIG. 8 is a perspective view of the plug assembly of FIG. 3 with a valid key inserted therein and illustrating the locking bar disposed in an unlocking position to allow the plug assembly to rotate in the lock cylinder body.  
           [0012]    [0012]FIG. 9 is a top plan view of the plug assembly of FIG. 8.  
           [0013]    [0013]FIG. 10 is a partially broken away side view of the plug assembly of FIG. 8.  
           [0014]    [0014]FIG. 11 is a partially exploded view of the plug assembly of FIG. 8.  
           [0015]    [0015]FIG. 12 is a section view through the plug assembly of FIG. 8 and a cylinder body, the section being taken transversely at one of the pins and illustrating the positioning of the pin, the rack, and the locking bar relative to each other and the cylinder body in an unlocked configuration.  
           [0016]    [0016]FIG. 13 is a perspective view similar to FIG. 8 but with the carrier assembly moved axially to a rekeying position.  
           [0017]    [0017]FIG. 14 is a top plan view of the plug assembly of FIG. 13.  
           [0018]    [0018]FIGS. 15 a - 15   e  are various views of a cylinder body for use in the present invention.  
           [0019]    [0019]FIGS. 16 a - 16   f  are various views of the cylinder plug body for use in the present invention.  
           [0020]    [0020]FIGS. 17 a - 17   f  are various view of the carrier for use in the present invention.  
           [0021]    [0021]FIGS. 18 a - 18   b  are views of a rack for use in the present invention.  
           [0022]    [0022]FIGS. 19 a - 19   b  are views of a spring catch for use in the present invention.  
           [0023]    [0023]FIGS. 20 a - 20   b  are views of a pin for use in the present invention.  
           [0024]    [0024]FIGS. 21 a - 21   b  are views of a locking bar for use in the present invention.  
           [0025]    [0025]FIGS. 22 a - 22   d  are views of a spring retaining cap for use in the present invention.  
           [0026]    [0026]FIG. 23 is an exploded perspective view of an alternative embodiment of the invention.  
           [0027]    [0027]FIGS. 24 a - 24   e  are views of an alternative embodiment of the lock cylinder housing.  
           [0028]    [0028]FIG. 25 is a transverse section view taken through an alternative embodiment of the present invention.  
           [0029]    [0029]FIGS. 26 a - 26   b  are views of an alternative embodiment of the spring catch.  
           [0030]    [0030]FIGS. 27 a - 27   eb  are views of an alternative embodiment of the carrier.  
           [0031]    [0031]FIGS. 28 a - 28   b  are views of an alternative embodiment of the pin.  
           [0032]    [0032]FIGS. 29 a - 29   b  are views of an alternative embodiment of the rack.  
           [0033]    [0033]FIGS. 30 a - 30   b  are views of an alternative embodiment of the locking bar.  
           [0034]    [0034]FIG. 31 is a perspective view of an exemplary embodiment of a rekeying tool of the present invention.  
           [0035]    [0035]FIG. 32 is a front view of an exemplary embodiment of a rekeying tool of the present invention engaged with an exemplary embodiment of a lock cylinder of the present invention.  
           [0036]    [0036]FIG. 33 is a perspective view of an exemplary embodiment of a rekeying tool of the present invention engaged with an exemplary embodiment of a lock cylinder of the present invention.  
           [0037]    [0037]FIG. 34 is a partially exploded view of an exemplary embodiment of a rekeying tool of the present invention engaged with an exemplary embodiment of a lock cylinder of the present invention.  
           [0038]    [0038]FIG. 35 is a front perspective view of an exemplary embodiment of a cylinder body of the present invention.  
           [0039]    [0039]FIG. 36 is a rear view of an exemplary embodiment of a cylinder body of the present invention.  
           [0040]    [0040]FIG. 37 is a top view of an exemplary embodiment of a cylinder body of the present invention.  
           [0041]    [0041]FIG. 38 is a front view of an exemplary embodiment of a cylinder body of the present invention.  
           [0042]    [0042]FIG. 39 is a rear perspective view of an exemplary embodiment of a cylinder body of the present invention.  
           [0043]    [0043]FIG. 40 is a perspective view of an exemplary embodiment of a carrier dislocation tool of the present invention engaged with an exemplary embodiment of a lock cylinder of the present invention.  
           [0044]    [0044]FIG. 41 is a flow chart of an exemplary exemplary embodiment of rekeying method of the present invention.  
           [0045]    [0045]FIG. 42 is a partially exploded view of an exemplary embodiment of a keying tool of the present invention engaged with an exemplary embodiment of a lock cylinder of the present invention.  
           [0046]    [0046]FIG. 43 is a flow chart of an exemplary embodiment of keying method of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0047]    When rekeying a lock assembly having a traditional cylinder design, the user is required to remove the cylinder plug from the cylinder body and replace the appropriate pins so that a new key can be used to unlock the cylinder. This typically requires the user to remove the cylinder mechanism from the lockset and then disassemble the cylinder to some degree to remove the plug and replace the pins. This requires a working knowledge of the lockset and cylinder mechanism and is usually only performed by locksmiths or trained professionals. Additionally, the process usually employs special tools and requires the user to have access to pinning kits to interchange pins and replace components that can get lost or damaged in the rekeying process. Finally, professionals using appropriate tools can easily pick traditional cylinders.  
         [0048]    Certain exemplary embodiments of the present invention provide a rekeying system comprising: a rekeyable lock cylinder comprising: a cylinder body; a plug assembly disposed in said cylinder body and comprising a plurality of pins and a one-to-one corresponding plurality of racks for relocating said plurality of pins; and a rekeying tool receiving aperture defined by said rekeyable lock cylinder; and a rekeying tool comprising: a base plate; and a plurality of spaced elongated prongs, each prong from said plurality of prongs comprising a first longitudinal end adapted to engage a corresponding one of said plurality of racks, each prong from said plurality of prongs dimensioned lengthwise to relocate to a first predetermined position said corresponding one of said plurality of racks, said first predetermined position common to each of said plurality of racks, each prong from said plurality of prongs comprising a second longitudinal end connected to said base plate.  
         [0049]    Certain exemplary embodiments of the present invention provide a rekeying tool for a rekeyable lock cylinder comprising a cylinder body and a plug assembly disposed in the cylinder body and comprising a plurality of pins and a one-to-one corresponding plurality of racks for relocating the pins, said lock cylinder defining a tool-receiving aperture, said rekeying tool comprising: a base plate defining a first face and a second face, said first face opposing said second face; a plurality of spaced elongated prongs, each prong from said plurality of prongs comprising a concave first longitudinal end adapted to engage a corresponding one of the plurality of racks, each prong from said plurality of prongs dimensioned lengthwise to relocate to a first predetermined position the corresponding one of the plurality of racks, the first predetermined position common to each of the plurality of racks, each prong from said plurality of prongs comprising a second longitudinal end connected to said base plate; and a handle connected to said second face of said base plate.  
         [0050]    Certain exemplary embodiments of the present invention provide a method for rekeying a rekeyable lock cylinder comprising a cylinder body, and a plug assembly disposed in said cylinder body and comprising a plurality of pins and a one-to-one corresponding plurality of racks for relocating said pins, said lock cylinder defining a tool-receiving aperture, comprising the activities of: inserting a rekeying tool into the tool-receiving aperture, relocating the plurality of racks to a first predetermined level; rotating the plug assembly with respect to the cylinder body from a first position to a second position; and disengaging the plurality of racks from the plurality of pins.  
         [0051]    Certain exemplary embodiments of the present invention provide a lock keying system comprising: a lock cylinder comprising: a cylinder body; a plug assembly disposed in said cylinder body and comprising a plurality of pins and a one-to-one corresponding plurality of racks for relocating said plurality of pins; and a rack alignment tool receiving aperture defined by said lock cylinder; and a rack alignment tool comprising: a base plate; and a plurality of spaced elongated prongs, each prong from said plurality of prongs comprising a first longitudinal end adapted to engage a corresponding one of said plurality of racks, each prong from said plurality of prongs dimensioned lengthwise to relocate to a first predetermined position said corresponding one of said plurality of racks, said first predetermined position common to each of said plurality of racks, each prong from said plurality of prongs comprising a second longitudinal end connected to said base plate, wherein said rack alignment tool is adapted to restrain a carrier assembly comprising said plurality of racks in an unengaged position wherein said plurality of racks are unengaged with said plurality of pins.  
         [0052]    Certain exemplary embodiments of the present invention provide a lock keying tool for a lock cylinder comprising a cylinder body and a plug assembly disposed in the cylinder body and comprising a plurality of pins and a one-to-one corresponding plurality of racks for relocating the pins, said lock cylinder defining a tool-receiving aperture, said lock keying tool comprising: a base plate defining a first face and a second face, said first face opposing said second face; a plurality of spaced elongated prongs, each prong from said plurality of prongs comprising a concave first longitudinal end disposed on a first portion of said prong and adapted to engage a corresponding one of the plurality of racks, each prong from said plurality of prongs defining a longitudinal axis and longitudinally dimensioned to relocate to a first predetermined position the corresponding one of the plurality of racks, the first predetermined position common to each of the plurality of racks, each prong from said plurality of prongs comprising a second longitudinal end disposed on a second portion of said prong and connected to said base plate, said second portion having a wider axial cross-section than said first portion; and a handle connected to said second face of said base plate.  
         [0053]    Certain exemplary embodiments of the present invention provide a method for keying a lock cylinder comprising a cylinder body and a plug assembly disposed in said cylinder body, said plug assembly comprising a plurality of pins and a one-to-one corresponding plurality of racks for relocating said pins, said lock cylinder defining a tool-receiving aperture, comprising the activities of: while the plurality of racks are not engaged with the plurality of pins: aligning the plurality of racks to a first predetermined level; and after aligning the plurality of racks to the first predetermined level, inserting a key into the plug assembly, the plurality of pins relocated by the key; and after inserting the key into the plug assembly, engaging the plurality of racks with the plurality of pins.  
         [0054]    A lock cylinder  10  according to an exemplary embodiment of the present invention is illustrated in FIG. 1- 2 . The lock cylinder  10  includes a longitudinal axis  11 , a lock cylinder body  12 , a plug assembly  14  and a retainer  16 . In FIG. 1, the plug assembly  14  is in the home position relative to the cylinder body  12 .  
         [0055]    The lock cylinder body  12 , as seen in FIGS. 15 a - 15   e , includes a generally cylindrical body  20  having a front end  22 , a back end  24  and a cylinder wall  26  defining an interior surface  28 . The cylinder wall  26  includes an interior, locking bar-engaging groove  29  and a pair of detent recesses  30 ,  32 . The generally V-shaped locking bar-engaging groove  29  extends longitudinally along a portion of the cylinder body  12  from the front end  22 . The first detent recess  30  is disposed at the back end  24  and extends to a first depth. The second detent recess  32  is disposed adjacent the first detent recess  30  and extends to a lesser depth. A detent bore  34  extends radially through the cylinder wall  26  for receiving a detent ball  36  (FIG. 2).  
         [0056]    The plug assembly  14  includes a plug body  40 , a carrier sub-assembly  42  and a plurality of spring-loaded pins  38  (FIGS. 2 and 20 a - 20   b ). The plug body  40 , illustrated in FIGS. 16 a - 16   f , includes a plug face  44 , an intermediate portion  46  and a drive portion  50 . The plug face  44  defines a keyway opening  52 , a rekeying tool opening  54  and a pair of channels  56  extending radially outwardly for receiving anti-drilling ball bearings  60  (FIG. 2). The drive portion  50  includes an annular wall  62  with a pair of opposed projections  64  extending radially inwardly to drive a spindle or torque blade (neither shown). The drive portion  50  further includes a pair of slots  66  formed in its perimeter for receiving the retainer  16  to retain the plug body  40  in the cylinder body  12 .  
         [0057]    The intermediate portion  46  includes a main portion  70  formed as a cylinder section and having a first longitudinal planar surface  72  and a plurality of channels  74  for receiving the spring-loaded pins  38 . The channels  74  extend transversely to the longitudinal axis of the plug body  40  and parallel to the planar surface  72 . A second planar surface  76  extends perpendicular to the first planar surface  72  and defines a recess  80  for receiving a retaining cap  82  (FIGS. 2 and 22 a - 22   d ). The channels  74  extend from the second planar surface  76  partially through the plug body  40 , with the sidewalls of the channels open to the first planar surface  72 . The first planar surface  72  further includes a plurality of bullet-shaped, rack-engaging features  78 . A bore  86  for receiving a spring-loaded detent ball  36  (FIG. 2) extends radially inwardly from opposite the first planar surface  72 .  
         [0058]    The carrier sub-assembly  42  (FIGS. 2, 6 and  10 ) includes a carrier  90  (FIGS. 17 a - 17   e ), a plurality of racks  92  (FIGS. 18 a - 18   b ), a spring catch  96  (FIGS. 19 a - 19   b ), a spring-loaded locking bar  94  (FIGS. 21 a - 21   b ), and a return spring  98  (FIG. 2). The carrier  90  includes a body  100  in the form of a cylinder section that is complementary to the main portion  70  of the plug body  40 , such that the carrier  90  and the main portion  70  combine to form a cylinder that fits inside the lock cylinder body  12 . The carrier  90  includes a curved surface  102  and a flat surface  104 . The curved surface  102  includes a locking bar recess  106  and a spring catch recess  108 . The locking bar recess  106  further includes a pair of return spring-receiving bores  109  (FIG. 17 c ) for receiving the locking bar return springs. The flat surface  104  includes a plurality of parallel rack-receiving slots  102  extending perpendicular to the longitudinal axis of the carrier. A semi-circular groove  111  extends along the flat surface  104  parallel to the longitudinal axis of the carrier  90 . The back end of the carrier  90  includes a recess  112  for receiving the return spring  98 .  
         [0059]    Each spring-loaded pin  38  includes a pin  113  and a biasing spring  115 . The pins  113 , illustrated in FIGS. 20 a - 20   b , are generally cylindrical with annular gear teeth  114  and a central longitudinal bore  116  for receiving biasing springs  115  (FIG. 2). The racks  92 , illustrated in FIGS. 18 a - 18   b , include a pin-engaging surface  118  having a plurality of gear teeth  122  configured to engage the annular gear teeth  114  on the pins  113 , as illustrated in FIGS. 7 and 12, and a semi-circular recess  124  for engaging the bullet-shaped, rack-engaging features  78  on the planar surface  72 , as illustrated in FIG. 12. The racks  92  further include a second surface  126  that includes a plurality of anti-pick grooves  128  and a pair of locking bar-engaging grooves  132 .  
         [0060]    The spring-loaded locking bar  94 , illustrated in FIGS. 21 a - 22   b , is sized and configured to fit in the locking bar recess  106  in the carrier  90  and includes a triangular edge  134  configured to fit in the V-shaped locking bar-engaging groove  29 . Opposite the triangular edge  134 , the locking bar  94  includes a pair of longitudinally extending gear teeth  136  configured to engage the locking bar-engaging grooves  132  formed in the racks  92 , as illustrated in FIG. 12.  
         [0061]    The spring-retaining cap  82 , illustrated in FIGS. 22 a - 22   d , includes a curvilinear portion  140  having an upper surface  142  and a lower surface  144 . The thickness of the curvilinear portion  140  is set to allow the curvilinear portion  140  to fit in the recess  80  with the upper surface  142  flush with the intermediate portion  46  of the plug body  40 , as illustrated in FIGS. 7 and 12. A plurality of spring alignment tips  146  extend from the lower surface  144  to engage the springs  148 . In addition, a pair of cap retaining tips  152  extend from the lower surface  144  to engage alignment openings  154  formed in the plug body  40  (FIGS. 16 e - 16   f ).  
         [0062]    To assemble the lock cylinder  10 , the pins  113  and spring  115  are disposed in the channels  74  of the plug body  40 . The spring-retaining cap  82  is placed in the recess  80 , with the cap retaining tips  152  disposed in the alignment openings  154  and the spring alignment tips  146  engaged with the springs  115 . The carrier sub-assembly  42  is assembled by placing the racks  92  into the slots  102  and the spring-loaded locking bar  94  into the locking bar recess  106 , with the gear teeth  136  engaging the locking bar-engaging grooves  132  formed in the racks  92 . The spring catch  96  is disposed in the spring catch recess  108  of the carrier  90 . A valid key  160  is inserted into the keyway  52 , the return spring  98  is compressed into the return spring recess  112 , and the carrier sub-assembly is placed adjacent the plug body  40 , as illustrated in FIG. 3. The plug assembly  14  is placed in the lock cylinder body  12  and the retainer  16  is disposed in the slots  66  formed in the plug body  40  to retain the plug assembly  14  in the cylinder body  12 . The lock cylinder  10  is now keyed to the valid key  160 .  
         [0063]    The properly keyed lock cylinder  10 , without the key  160  inserted, is illustrated in FIGS.  4 - 7 . The pins  113  are biased to the bottom of the channels  74  and, based on the cut of the key  160 , the racks  92  are disposed at various positions in the slots  102  of the carrier  90 . In this configuration, the locking bar  94  extends from the carrier  90  to engage the groove  29  in the cylinder body  12  to prevent the plug assembly  14  from rotating in the cylinder body  12  and the racks  92  engage the pins  113 , as illustrated in FIG. 4. In addition, the bullet-shaped features  78  are misaligned with the recesses  111  in the racks  92  and therefore interfere with movement of the racks  92  parallel to the longitudinal axis of the lock cylinder  10 , preventing the lock cylinder  10  from being rekeyed.  
         [0064]    The internal configuration of a lock cylinder  10  with the valid key  160  inserted therein at the home position is illustrated in FIGS.  8 - 12 . In this configuration, the locking bar  94  is free to cam out of the groove  29  in the cylinder body  12 , as depicted in FIGS. 8, 9 and  12 . The bits of the key  160  lift the pins  113  in the channels  74  and thereby re-position the racks  92  in the slots  102 . When repositioned, the racks  92  are disposed to align the locking bar-engaging grooves  132  with the extended gear teeth  136  on the locking bar  94 . The locking bar  94  is free to cam out of the groove  29  as the key  160  is rotated. At the same time, the bullet-shaped features  78  are aligned with the recesses  111  in the racks  92 , as illustrated in FIG. 12, allowing the racks  92 , and the carrier  90 , to move parallel to the longitudinal axis of the lock cylinder  10 .  
         [0065]    To rekey the lock cylinder  10 , the valid key  160  is inserted into the keyway  52 , as illustrated in FIGS.  13 - 14  and rotated approximately 45° counterclockwise from the home position until the spring catch  96  moves into the second detent recess  32  formed in the cylinder body  12 . A paperclip or other pointed device  162  is inserted into the tool opening  54  and pushed against the carrier  90  to move the carrier  90  parallel to the longitudinal axis of the lock cylinder  10  until the spring catch  96  moves into the first detent recess  30 , and the pointed device  162  is removed. With the spring catch  96  disposed in the first detent recess  30 , the racks  92  are disengaged from the pins  113 , as illustrated in FIG. 14. The valid key  160  is removed and a second valid key is inserted and rotated clockwise to release the spring catch  96 . As the spring catch  96  leaves the first detent recess  30 , the carrier  90  is biased toward the plug face  44  by the return spring  98 , causing the racks  92  to re-engage the pins  113 . At this point, the lock cylinder  10  is keyed to the second valid key and the first valid key  160  no longer operates the lock cylinder  10 . The lock cylinder  10  can be rekeyed to fit a third valid key by replacing the first and second valid keys in the above procedures with the second and third valid keys, respectively.  
         [0066]    An alternative embodiment  210  of an exemplary embodiment of the present invention is illustrated in FIGS.  23 - 29 . The alternative embodiment includes the same components, as illustrated in FIG. 23, but several of the components have been modified. Functionally, both embodiments are the same.  
         [0067]    The modified housing  212 , illustrated in FIGS. 23 and 24, includes a plurality of apertures  214  running longitudinally along the bottom thereof and a pair of vertical grooves  216 ,  218  formed in the housing sidewall. In addition, the sidewall includes a removable side panel  220 . The rectangular holes  214  are positioned to allow the use of a manual override tool. The center groove  216  includes an aperture  222  extending through the housing sidewall. The aperture  222  allows a user to move the locking bar during a manual override operation. The side panel  220  provides access for performing certain operations while changing the master key of the lock cylinder.  
         [0068]    The modified pin biasing springs  226 , illustrated in FIGS. 23 and 25, include a non-constant diameter, with the last few coils at each end of the springs  226  having a reduced diameter. The tapering allows for a greater spring force in a smaller physical height.  
         [0069]    The modified spring catch  228 , illustrated in FIGS. 23 and 26, includes a central U-shaped portion  230  and a pair of arms  232  extending from the U-shaped portion  230 .  
         [0070]    The modified carrier  236 , illustrated in FIGS. 23 and 27, includes means for retaining the spring catch  228  in the spring catch recess  238 . In the illustrated embodiment, this includes a guide  240  projecting outwardly in the center of the spring catch recess  238  and a pair of anchors  242  radially offset from the guide  240 . The guide  240  prevents the spring catch  228  from moving transversely in the recess  238  while permitting it to move radially outwardly to engage the housing  12 ,  212  as described above. The anchors  242  engage the arms  232  of the spring catch  228  and prevent the arms  232  from splaying outwardly, thereby directing the compressive force of the spring catch  228  to extend the U-shaped portion  230  outwardly to engage the housing  12 ,  212 .  
         [0071]    The modified pins  244 , illustrated in FIGS. 23 and 28, include a single gear tooth  246  instead of the plurality of gear teeth of the pins  113  described above. The single gear tooth  246 , which preferably includes beveled sides  248 , provides for a smoother engagement with the racks during the rekeying process.  
         [0072]    The modified racks  250 , illustrated in FIGS. 23 and 29, include beveled gear teeth to improve the engagement with the pins during the rekeying process. In addition, the pair of locking bar-engaging grooves  132  in the racks  92  are replaced with a single locking bar-engaging groove  251 .  
         [0073]    The modified locking bar  252 , illustrated in FIGS. 23 and 30, is thinner than locking bar  94  and replaces the pair of gear teeth  136  with a single gear tooth  256  and rounds out the triangular edge  134 . The thinner design reduces any rocking of the locking bar  252  in the locking bar recess  106 .  
         [0074]    [0074]FIG. 31 is a perspective view of an exemplary embodiment of a manual override or rekeying tool  310 , which can comprise a base  312  having, for example, a elongated approximately annular segment or elongated approximately toroidal segment shape. Attached to base  312  can be a plurality of prongs  314  each having, for example, an elongated approximately rectangular shape. Each of prongs  314  can be approximately perpendicularly attached to an inner surface  313  of base  312 , and can have an end  316 , that can have any shape that engages the a corresponding one of the plurality of racks  340  (shown in FIG. 34) of plug assembly  320 , such as for example, a concave shape. To an outer surface  315  of base  312  can be attached a handle  318 , having, for example, an elongated approximately rectangular shape. A longitudinal axis of handle  318  can be approximately perpendicular to and/or approximately parallel to a longitudinal axis of base  312 . In an alternative embodiment (not shown), base  312  can have an elongated approximately rectangular shape, or any other shape, provided that base  312  serves to limit an insertion depth of rekeying tool  310  into the lock cylinder. As yet another alternative, another feature of tool  310  can limit its insertion depth.  
         [0075]    [0075]FIG. 32 is a front view, and FIG. 33 is a perspective view, of an exemplary embodiment of a rekeying tool  310  of the present invention engaged with an embodiment of a lock cylinder  350  of the present invention. Referring to FIGS. 32 and 33, rekeying tool  310  can be inserted into lock cylinder  350  along a direction, or such that handle  318  is, parallel to a keyway  323  defined through a plug face  322  of plug assembly  320 . Base  312  can be configured to approximately conform to an outer surface of cylinder assembly  330 .  
         [0076]    [0076]FIG. 34 is a partially exploded view of an exemplary embodiment of a rekeying tool  310  of the present invention engaged with an embodiment of a lock cylinder  350  of the present invention. Note that prongs  314  can engage with, and/or align to a common level, racks  340 .  
         [0077]    [0077]FIG. 35 is a front perspective view, FIG. 36 is a rear view, FIG. 37 is a side view, FIG. 38 is a front view, FIG. 39 is a rear perspective view, of an exemplary embodiment of a cylinder body  330  of the present invention. Referring to FIGS.  34 - 39 , cylinder body  330  can define a plurality of rekeying tool apertures  332  that can allow rekeying tool  310  to access the plurality of racks of plug assembly  320 . Cylinder body  330  can also define a locking bar release tool aperture  335  via which a locking bar release tool  360  (shown in FIG. 40) can access and/or dislocate a locking bar  94  (shown at least in FIGS. 2, 3,  7 ,  8 ,  12 , and  21 A) from engaging with locking bar recess  337  of cylinder body  330 .  
         [0078]    [0078]FIG. 40 is a perspective view of an exemplary embodiment of a locking bar release tool  360  of the present invention engaged with an exemplary embodiment of a lock cylinder  350  of the present invention. Locking bar engagement tool  360 , which can be as simple as a paperclip, can be inserted through locking bar engagement tool aperture  335  defined in cylinder body  330 , such that locking bar  94  (shown at least in FIGS. 2, 4,  7 ,  8 ,  12 , and  21 A) can engage with racks  92  to align, restrict, and/or limit travel of, pins  113 .  
         [0079]    [0079]FIG. 41 is a flow chart of an exemplary embodiment of rekeying method  410  of the present invention. At activity  412 , a rekeying tool can be inserted through one or more apertures of the cylinder body, such that the prongs of the rekeying tool engage the racks of the plug assembly. The insertion depth of the rekeying tool can be limited by the geometry of the rekeying tool, such as a shape of the base of the rekeying tool or a prong length, and/or the geometry of the cylinder body and/or plug assembly. For example, if the cylinder body has a elongated circular exterior, an interior and/or contact surface of the base of the rekeying tool can be shaped as an elongated annular segment, the inner radius of that segment approximately matching an outer radius of the cylinder body.  
         [0080]    At activity  413 , the rekeying tool can relocate the plurality of racks, such that the racks are aligned at a common level. For example, each rack can have a reference point, and full insertion of the rekeying tool can cause each reference point to align along a line parallel to an axis of the cylinder body and/or the plug assembly. As another example, referring to FIG. 12, each of the bullet-shaped features  78  can be aligned with the recesses  111  in the racks  92 , allowing the racks  92 , and the carrier  90 , to move parallel to the longitudinal axis of the lock cylinder  10 . Referring to FIGS. 12 and 40, with the racks  92  aligned, a locking bar engagement tool  360  can be inserted into a locking bar engagement tool aperture  335  in the cylinder body  330  to cause the locking bar  94  to engage with cut-outs in the racks  92 , thereby preventing relative movement among the racks, and consequently, relative movement between the pins  113  engaged with the racks  92 .  
         [0081]    At activity  414 , with the racks thus “locked” by the locking bar  94 , the rekeying tool can be removed from the lock assembly. Then, the plug assembly can be rotated within the cylinder body to a learn position. This rotation can occur without requiring the use of a valid key, and preferably occurs with use of any key. Referring to FIGS. 13 and 14, as the plug assembly is rotated approximately 45 degrees to approximately 90 degrees counterclockwise the locking bar is retained in engagement with the racks.  
         [0082]    At activity  415 , with the plug assembly in the learn mode, the racks can be disengaged from the pins by pushing the racks away from the pins. Referring to FIGS. 13 and 14, a carrier relocation tool, such as a paperclip or other pointed device  162 , can be inserted into the tool opening  54  and pushed against the carrier  90  to move the carrier  90  parallel to the longitudinal axis of the lock cylinder  10  until the spring catch  96  moves into the first detent recess  30 , and the pointed device  162  is removed. With the spring catch  96  disposed in the first detent recess  30 , carrier  90  is locked in place by the spring catch  96 , the racks  92  are disengaged from the pins  113 , and the racks  92  are locked in place by the bullet-shaped features  78  (shown in FIG. 6).  
         [0083]    At activity  416 , a new key can be inserted into the keyway of the plug assembly. As the new key is inserted, the pins can ride up and down the ramps of the key. Once the key is fully inserted, the pin heights can correlate to the new key.  
         [0084]    At activity  417 , the racks can be re-engaged with the pins. Referring to FIGS. 13 and 14, the new key can be rotated clockwise to release the spring catch  96 . As the spring catch  96  leaves the first detent recess  30 , the carrier  90  is biased toward the plug face  44  by the return spring  98 , causing the racks  92  to re-engage the pins  113 . At this point, the lock cylinder  10  is keyed to the new key (i.e., the “new” key) and any previously valid key  160  no longer operates the lock cylinder  10 . Thus, the new key can be learned by rotating the plug assembly away from the learn position.  
         [0085]    Thus, via the rekeying tool, without requiring a valid key, the lock assembly can be placed into a learn mode, in which it can read and conform to a profile of a new key, without removing the plug assembly from the cylinder body.  
         [0086]    [0086]FIG. 42 is a partially exploded view of an exemplary embodiment of a keying tool  420  of the present invention engaged with an exemplary embodiment of a lock cylinder  10  of the present invention. Keying tool  420  can be used to configure a lock cylinder to suit any appropriate key cut (occasionally a.k.a. “bit spacing”), including a competitor&#39;s key cut.  
         [0087]    Keying tool  420  can be substantially identical to rekeying tool  310  (shown in FIG. 31), except that keying tool  420  can comprise a carrier retainer  427 , that is shaped and/or dimensioned to at least partially fill its corresponding tool aperture  332  in cylinder body  330  (shown in FIG. 39), for instance while longitudinal ends  426  of keying tool&#39;s prongs  424  are engaged in rack apertures  103  (shown in FIG. 17A) in a dislocated carrier assembly  42  (shown at least in FIGS. 2, 4,  14 ).  
         [0088]    Thereby, referring to FIGS. 2 and 42, keying tool  420  can prevent the dislocated carrier assembly  42  whose racks  92  are unengaged (possibly because they have not yet been inserted into carrier assembly  42 ) with their corresponding pins  113 , from moving with respect to cylinder body  12  and/or from returning to its original position. That is, via insertion of keying tool  420  into a lock cylinder  10 , a carrier assembly  42  that has been moved from a “normal” position to a “dislocated” position can be retained in place with respect to the cylinder body  12 , thereby allowing racks  92  that are inserted into the carrier assembly  42  to remain unengaged from pins  113  until the carrier retainer portion  427  of keying tool  420  is removed from, and/or no longer at least partially fills, its corresponding aperture in cylinder body  12 , and/or until keying tool  420  is removed from the lock cylinder  10 . Keying tool  420  can also align the inserted racks  92  and/or a feature on the inserted racks  92  to a predetermined level.  
         [0089]    Keying tool  420  can comprise a base  422  having, for example, an elongated annular segment or elongated toroidal segment shape. Attached to base  422  can be a plurality of prongs  424  each having, for example, an elongated approximately rectangular shape. Each of prongs  424  can be approximately perpendicularly attached to an inner surface  423  of base  422 , and can have, for example, a concavely shaped end  426 . To an outer surface  425  of base  422  can be attached a handle  428 , having, for example, an elongated rectangular shape. A longitudinal axis of handle  428  can be approximately perpendicular to and/or approximately parallel to a longitudinal axis of base  422 . In an alternative embodiment (not shown), base  422  can have an elongated rectangular shape, or any other shape, provided that base  422  serves to limit an insertion depth of keying tool  420  into the lock cylinder. As yet another alternative, another feature of tool  420 , such as carrier retainer  427 , can limit its insertion depth.  
         [0090]    Each carrier retainer  427  can be adjacent, contiguous, and/or integral with a prong  424 , and can have, for example, an elongated rectangular shape. The length of each carrier retainer  427  can be less than its corresponding prong  424 . A combined width of each prong/carrier retainer, as measured in a direction parallel to the longitudinal axis of the plug body and/or along a line where the prong and carrier retainer combination attach to base  422 , can be greater than a width of the prong  424 . Referring to FIGS.  34 - 39 , the orientation and width of at least one prong and carrier retainer combination can be sufficient to substantially fill at least the width of its corresponding rekeying tool aperture  332  in cylinder body  330 , thereby preventing a dislocated carrier assembly  42  (shown at least in FIGS. 2, 4,  14 ) from returning to its original position.  
         [0091]    As shown in FIGS. 28A and 28B, pin  244  can comprise standardized dimensions and shape, and can comprise a single tooth  246 , located in a standard position. As shown in FIGS. 29A and 29B, rack  250  can have a tooth profile that meshes with pin  246 , and having a spacing that corresponds to depth increments (occasionally a.k.a. “bit spacing”) of the key cut. The tooth spacing of rack  250  can be customized to a particular manufacturer, brand, or model of key and/or lock assembly. For example, Schlage keys and locksets tend to have an 11 mil key cut increment, while Kwikset tends to use a 15 mil key cut increment. Thus, a rack  250  that is intended for use with a Schlage key could have an 11 mil tooth spacing, and a rack  250  that is intended for use with a Kwikset key could have a 15 mil tooth spacing.  
         [0092]    Alternatively, either of two standard racks could be selected to correspond to a particular key cut depth. For example, assuming that Kwikset tends to use a 15 mil key cut increment, a first standard Kwikset rack A could have one or more tooth engagements zones (e.g., valleys) at, for instance, 15 mils, 45 mils, and 75 mils, as measured from a convenient location, such as one end of the rack. A second standard Kwikset rack B could have valleys at 30 mils, 60 mils, and 90 mils. Depending on the depth of a particular key&#39;s cut for a given pin, the appropriate rack could be chosen. So if a key had a cut depth of 60 mils, a rack B could be selected and used for the corresponding pin.  
         [0093]    [0093]FIG. 43 is a flow chart of an exemplary embodiment of keying method  430  of the present invention.  
         [0094]    At activity  432 , the rack carrier can be pushed away from the pins, such that it moves from a “normal” position to a “dislocated” position. This can be accomplished by inserting a carrier relocation tool, such as a paperclip, into a carrier relocation tool aperture found in a front face of the plug, such that the tool engages and pushes the carrier backward. With the carrier dislocated, a keying tool and/or rack alignment tool, such as that shown in FIG. 42, can be inserted into apertures in the cylinder body. Because the keying tool can retain the carrier in the dislocated position, the carrier relocation tool can now be removed.  
         [0095]    The insertion depth of the keying tool can be limited by the geometry of the keying tool, such as a shape of the base of the keying tool or a prong length, and/or the geometry of the cylinder body and/or plug assembly. For example, if the cylinder body has a elongated circular exterior, an interior and/or contact surface of the base of the keying tool can be shaped as an elongated annular segment, the inner radius of that segment approximately matching an outer radius of the cylinder body.  
         [0096]    At activity  433 , the racks can be selected, potentially to correspond to a manufacturer, brand, and/or model of key and/or lock assembly, and/or to correspond to a key cut. The selected racks can be inserted into their respective slots of the carrier assembly. At activity  434 , the keying tool can align the inserted racks.  
         [0097]    At activity  435 , a key can be inserted into the keyway of the plug assembly. As the key is inserted, the pins can ride up and down the ramps of the key to land and/or align with flats of the key. Once the key is fully inserted, the heights of the pins and/or the pin teeth can correlate to the profile of the key.  
         [0098]    At activities  436  and  437 , the racks can be engaged with the pins by removing the keying tool, such that the carrier spring biases and/or relocates the carrier back into its “normal” position.  
         [0099]    At activity  438 , the key can be learned by rotating the plug assembly away from the learn position.  
         [0100]    Thus, via the keying tool, the lock assembly can be assembled to conform to a profile of a key, without removing the plug assembly from the cylinder body.  
         [0101]    The above-described exemplary embodiments, of course, are not to be construed as limiting the breadth of the present invention. Modifications and other alternative constructions will be apparent that are within the spirit and scope of the invention as defined in the appended claims.