Patent Publication Number: US-2022213716-A1

Title: Rekeyable lock with small increments

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/165,456, filed on Mar. 24, 2021. 
     The present application is also a continuation-in-part of U.S. patent application Ser. No. 16/527,188, filed on Jul. 31, 2019, which claims priority to and the benefit of U.S. Provisional Application No. 62/712,369, filed on Jul. 31, 2018. 
     To the extent appropriate a claim for priority is made to each of the above listed applications. Additionally, the disclosure of each of the above listed applications is hereby incorporated by reference herein in their entireties. 
    
    
     BACKGROUND 
     Lock cylinders that can be rekeyed without removal of the cylinder plug are known. These types of locks are highly beneficial to consumers because the locks can be easily rekeyed without calling a locksmith. Sizes and tolerances of engaging components within the lock become smaller to allow an increased variation in the bitting of keys. This also creates an increase in stress on the small components. Therefore, there is a need for a rekeyable lock that increases the variation in the bitting of keys recognized by the lock while maximizing strength of the small components. 
     SUMMARY 
     This disclosure relates generally to locks; in particular, this disclosure relates to a lock with a rekeyable lock cylinder. According to one aspect of the present disclosure, a rekeyable lock cylinder is provided that maximizes a number of bitting positions for use in unlocking the lock cylinder. By maximizing a number of bitting positions, for example seven or more bitting positions, the number of bitting combinations of a key used with the lock cylinder is increased. This maximizes security of the lock cylinder. 
     According to one aspect, this disclosure provides a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. The rekeyable lock cylinder includes a locking bar movable between a locked position and an unlocked position. When in the locked position, the locking bar is positioned within the groove of the cylinder body to block rotation of the plug assembly with respect to the cylinder body. When in the unlocked position, the locking bar is spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body The rekeyable lock cylinder includes a key follower disposed in the plug assembly. The key follower includes a rack engagement feature that is a post. The rekeyable lock cylinder includes a rack disposed in the plug assembly. The rack includes a key follower engagement feature that is a slot. The rack engagement feature of the key follower and the key follower engagement feature of the rack are engaged to facilitate simultaneous movement of the key follower and the rack. The rack controls movement of the locking bar between the locked and unlocked positions. The rack is selectively disengageable from the key follower when moving in a direction parallel to the longitudinal axis of the plug assembly. The rekeyable lock cylinder includes the slot of the rack extending at least partially through, and bounded by, the rack. The slot has a first side and a second side that extend parallel with one another along a portion of the length of the rack. The slot has a series of engagement grooves that are arranged along the first side of the slot. The slot also includes a linear aperture arranged along the second side of the slot, immediately adjacent the series of engagement grooves. The post of the key follower has a projection that is engageable with at least one of the series of engagement grooves of the slot when the post is received in the slot. The post of the key follower includes a fin engageable with the linear aperture of the slot when the post is received in the slot. 
     According to another aspect, this disclosure provides a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. The plug includes a plurality of key follower recesses aligned along the longitudinal axis. The plurality of key follower recesses of the plug assembly each have a rectangular cross-section. The rekeyable lock cylinder includes a plurality of key followers that each have a portion positioned within each of the plurality of key follower recesses of the plug assembly. Each of the plurality of key followers corresponds with a rack and each rack is selectively disengageable from the corresponding key follower to facilitate rekeying between different keys. The portion of each of plurality of key followers positioned within each of the plurality of key follower recesses has a rectangular cross-section. The rekeyable lock cylinder includes a locking bar movable between a locked position engaged with the groove of the cylinder body for blocking rotation of the plug assembly with respect to the cylinder body and an unlocked position spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body. Each rack controls movement of the locking bar between the locked and unlocked positions. Each of the plurality of key followers is formed to define a post. Each rack is formed to include a slot that extends at least partially through and bounded by the rack. The post is received in the slot such that complementary engagement surfaces of the post and slot engage with one another to block movement of the plurality key followers relative to the racks. 
     According to another aspect, this disclosure provides a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. The rekeyable lock cylinder includes a key follower and a corresponding rack disposed in the plug assembly. The rack is selectively disengageable from the key follower to facilitate rekeying between different keys. The key follower is formed to define a post having a first projection and a second projection. The first and second projections are vertically aligned within one another and perpendicular to the longitudinal axis of the cylinder body. The first and the second projections have a first length and a second length, respectively. The first and second lengths are parallel to the longitudinal axis of the cylinder body. The first length is greater than the second length. The rekeyable lock cylinder includes a locking bar movable between a locked position engaged with the groove of the cylinder body for blocking rotation of the plug assembly with respect to the cylinder body and an unlocked position spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body. The rack controls movement of the locking bar between the locked and unlocked positions. The rack has a plurality of key follower post recesses. The post of the key follower is received in a pair of the plurality of key follower post recesses of the rack to block movement of the key follower relative to the rack. 
     A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings are illustrative of particular embodiments of the present disclosure and therefore do not limit the scope of the present disclosure. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present disclosure will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements. 
         FIG. 1  is a perspective view of an example lock cylinder according to an embodiment of this disclosure. 
         FIG. 2  is an exploded view of the example lock cylinder shown in  FIG. 1 . 
         FIG. 3  is a perspective cross-sectional view along line  3 - 3  of  FIG. 1  showing, among other things, the key followers engaged with the racks. 
         FIG. 4  is a perspective view of an example of a key follower according to an embodiment of this disclosure. 
         FIG. 5  is a perspective view of an example rack according to an embodiment of this disclosure associated with the example key follower shown in  FIG. 4 . 
         FIG. 6  is a front view of the rack of  FIG. 5 . 
         FIG. 7  is a side view of the rack of  FIG. 5 . 
         FIGS. 8-11  are perspective views of the key follower of  FIG. 4  and rack of  FIG. 4  mating. 
         FIG. 12  is a cross-sectional view of a portion of the key follower of  FIG. 4  positioned within the rack of  FIG. 5 . 
         FIG. 13  is a cross-sectional view of the example lock cylinder shown in  FIG. 1  showing the locking bar engaged with the rack in a first unlocking position. 
         FIG. 14  is a cross-sectional view of the example lock cylinder shown in  FIG. 1  showing the locking bar engaged with the rack in a first locked position. 
         FIG. 15  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 16  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 15 . 
         FIG. 17  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 18  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 17 . 
         FIG. 19  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 20  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 19 . 
         FIG. 21  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 22  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 21 . 
         FIG. 23  is a front view of the rack of  FIG. 22 . 
         FIG. 24  is a side view of the rack of  FIG. 22 . 
         FIGS. 25-27  are perspective views of the key follower of  FIG. 21  and rack of  FIG. 22  mating. 
         FIG. 28  is a cross-sectional view of a portion of the key follower of  FIG. 21  positioned within the rack of  FIG. 22 . 
         FIG. 29  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 30  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 29 . 
         FIG. 31  is a perspective view of the rack of  FIG. 30 . 
         FIG. 32  is a top view of the key follower of  FIG. 29  engaged with the rack of  FIG. 30 . 
         FIG. 33  is a cross sectional view of the key follower of  FIG. 29  engaged with the rack of  FIG. 30  along line A-A in  FIG. 32 . 
         FIG. 34  is a bottom view of the key follower of  FIG. 29  engaged with the rack of  FIG. 30 . 
         FIG. 35  is a cross-sectional view of the key follower of  FIG. 29  engaged with the rack of  FIG. 30  along line B-B in  FIG. 34 . 
         FIG. 36  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 37  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 36 . 
         FIG. 38  is a side view of the key follower of  FIG. 36  engaged with the rack of  FIG. 37 . 
         FIG. 39  is a cross-sectional view of the key follower of  FIG. 36  engaged with the rack of  FIG. 37  along line C-C in  FIG. 38 . 
         FIG. 40  is a side view of the key follower of  FIG. 36  engaged with the rack of  FIG. 37 . 
         FIG. 41  is a cross-sectional view of the key follower of  FIG. 36  engaged with the rack of  FIG. 37  along line D-D in  FIG. 40 . 
         FIG. 42  is a cross-sectional view of the key follower of  FIG. 36  engaged with the rack of  FIG. 37  along line E-E in  FIG. 40 . 
         FIG. 43  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 44  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 43 . 
         FIG. 45  is a side view of the key follower of  FIG. 43  engaged with the rack of  FIG. 44 . 
         FIG. 46  is a cross-sectional view of the key follower of  FIG. 43  engaged with the rack of  FIG. 44  along line F-F in  FIG. 45 . 
         FIG. 47  is a side view of the key follower of  FIG. 43  engaged with the rack of  FIG. 44 . 
         FIG. 48  is a cross-sectional view of the key follower of  FIG. 43  engaged with the rack of  FIG. 44  along line G-G in  FIG. 44 . 
         FIG. 49  is a cross-sectional view of the key follower of  FIG. 43  engaged with the rack of  FIG. 344  along line H-H in  FIG. 40 . 
         FIG. 50  is a perspective view of another example of a key follower according to an embodiment of this disclosure. 
         FIG. 51  is a perspective view of another example of a rack according to an embodiment of this disclosure associated with the key follower of  FIG. 51 . 
         FIG. 52  is a side view of the key follower of  FIG. 50  engaged with the rack of  FIG. 51 . 
         FIG. 53  is a cross-sectional view of the key follower of  FIG. 50  engaged with the rack of  FIG. 51  along line I-I in  FIG. 52 . 
         FIG. 54  is a side view of the key follower of  FIG. 50  engaged with the rack of  FIG. 51 . 
         FIG. 55  is a cross-sectional view of the key follower of  FIG. 50  engaged with the rack of  FIG. 51  along line J-J in  FIG. 54 . 
         FIG. 56  is a cross-sectional view of the key follower of  FIG. 50  engaged with the rack of  FIG. 51  along line K-K in  FIG. 54 . 
         FIG. 57  is a perspective view of the key follower of  FIG. 50  engaged and the rack of  FIG. 51  and positioned within a plug body. 
         FIG. 58  is a perspective cross sectional view of the plug body, the key follower, and the rack of  FIG. 57 . 
         FIG. 59  is a perspective view of the key follower of  FIG. 50  and the rack of  FIG. 51  both positioned outside of the plug body of  FIG. 57 . 
     
    
    
     DETAILED DESCRIPTION 
     The figures and descriptions provided herein may have been simplified to illustrate aspects that are relevant for a clear understanding of the herein described devices, systems, and methods, while eliminating, for the purpose of clarity, other aspects that may be found in typical devices, systems, and methods. Those of ordinary skill may recognize that other elements and/or operations may be desirable and/or necessary to implement the devices, systems, and methods described herein. Because such elements and operations are well known in the art, and because they do not facilitate a better understanding of the present disclosure, a discussion of such elements and operations may not be provided herein. However, the present disclosure is deemed to inherently include all such elements, variations, and modifications to the described aspects that would be known to those of ordinary skill in the art. 
     References in the specification to “one embodiment,” “an embodiment,” “an illustrative embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may or may not necessarily include that particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other examples whether or not explicitly described. Additionally, it should be appreciated that items included in a list in the form of “at least one A, B, and C” can mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C). Similarly, items listed in the form of “at least one of A, B, or C” can mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C). 
     In the drawings, some structural or method features may be shown in specific arrangements and/or orderings. However, it should be appreciated that such specific arrangements and/or orderings may not be required. Rather, in some examples, such features may be arranged in a different manner and/or order than shown in the illustrative figures. Additionally, the inclusion of a structural or method feature in a particular figure is not meant to imply that such feature is required in all examples and, in some examples, may not be included or may be combined with other features. 
     This disclosure relates to a rekeyable lock cylinder that can be rekeyed without removal of the cylinder plug. The operation for rekeying the lock cylinder is similar to that described in U.S. Pat. No. 10,612,271, which is hereby incorporated by reference. While the rekeying operation operates similarly, the present lock cylinder includes pin-rack engagement features that maximize a number of bitting positions in the lock while maintaining strength. Examples of a rekeyable lock cylinder and methods of manufacturing of the same are described in U.S. Provisional Patent Application No. 63/165,517, filed on Mar. 24, 2021, entitled “DRILL RESISTANT LOCK CYLINDER AND METHOD OF MANUFACTURING” (Attorney Docket No. 17986.426USP1), the disclosure of which is hereby incorporated by reference in its entirety. 
     An illustrative lock cylinder  10 , according to an embodiment of the present disclosure, is illustrated in  FIGS. 1 and 2 . The lock cylinder  10  includes a cylinder body  14  and a plug assembly  16 . A retainer clip  18  ( FIG. 2 ) couples together the cylinder body  14  with the plug assembly  16 . 
     The cylinder body  14 , as best seen in  FIG. 2 , illustratively 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  30  (best seen in  FIGS. 3, 13, and 14 ). In some examples, the locking bar engaging groove  30  has a generally rectangular-shaped cross-section and extends longitudinally along a portion of the cylinder body  14 , typically from the front end  22 . 
     The plug assembly  16  includes a plug body  32 , a carrier subassembly  34 , and a plurality of key followers  38  (also known as pins). The plug body  32  illustratively includes a plug face  36 , an intermediate portion  40 , and a drive portion  42 . The plug face  36  defines a keyway opening  44  and a rekeying tool opening  46 . In some examples, the plug face  36  further defines a pair of channels extending radially outwardly for receiving anti-drilling ball bearings. The drive portion  42  is configured to drive a torque blade  51 , which could be coupled with a latch assembly (not shown). The drive portion  42  further includes a pair of slots  52  formed in its perimeter and a central groove  54  for receiving the retainer clip  18  to retain the plug body  32  in the cylinder body  14 . 
     The intermediate portion  40  includes a main portion  56  formed as a cylinder section and having a plurality of channels  58  for receiving the key followers  38 . The channels  58  illustratively extend transversely to the longitudinal axis of the plug body  32 . A retaining cap  64  is received in a recess  62  to trap the key followers  38  inside the plug body  32 . The channels  58  extend partially through the plug body  32 , with the sidewalls of the channels open to a planar surface  66 . The planar surface  66  illustratively includes a plurality of bullet-shaped, rack-engaging features  68  that block rekeying of the lock cylinder  10  if racks  72  are not aligned to unlock the lock cylinder  10  (e.g., if a valid key is not inserted into the lock cylinder  10 ). 
     The carrier subassembly  34  includes a carrier  70 , a plurality of racks  72 , a spring catch  75 , a locking bar  74 , a pair of clips  76  for holding corresponding biasing members  78  against the locking bar  74  to urge the locking bar  74  against the racks  72 , and a return spring  80 . The carrier  70  includes a body  82  in the form of a cylinder section that is complementary to the main portion  56  of the plug body  32 , such that the carrier  70  and the main portion  56  combine to form a cylinder that fits inside the cylinder body  14 . The carrier  70  includes a curved surface  84  and a flat surface  86 . The curved surface  84  includes a locking bar slot  88 , a spring catch recess  90 , and a pair of clip receiving recesses  100  for receiving the clips  76 . The locking bar slot  88  illustratively includes a pair of biasing member-receiving bores  92  for receiving the biasing members  78 . In the embodiment shown, the locking bar  74  includes a corresponding pair of recessed areas  96  for receiving the biasing members  78 . The flat surface  86  of the carrier  70  includes a plurality of parallel rack-receiving slots  94  extending perpendicular to a longitudinal axis of the carrier  70 . 
     The spring-loaded locking bar  74  is sized and configured to fit in the locking bar slot  88  in the carrier  70 . The locking bar  74  illustratively includes a blocking portion  98  that is received in the locking bar engaging groove  30  in the cylinder body  14  when in a locked position (as shown in  FIG. 14 ) and extends out of the locking bar engaging groove  30  when in an unlocked position ( FIGS. 3 and 13 ). Opposite the squared-off edge of the blocking portion  98 , the locking bar  74  includes a flange  102  configured to engage locking bar engaging grooves  104  formed in the racks  72  ( FIG. 13 ). In the depicted examples, the flange  102  is generally triangular shaped and sized so that when the locking bar  74  is in the unlocked position, the flange  102  is positioned entirely within the locking bar engaging grooves  104  of the racks  72 . As such, in some examples, the locking bar engaging grooves  104  of the racks  72  are larger than the flange  102 . Biasing members  78  urge the blocking portion  98  out of the groove  30  in the cylinder body  14  toward the racks  72 . 
     A pin-rack engagement feature  50  provides strong engagement between the key followers  38  and the rack  72  while allowing a plurality of bitting positions. One example of a pin-rack engagement feature  50 , according to an embodiment of the present disclosure, is shown in  FIGS. 3, 4, and 5 . The pin-rack engagement feature  50  includes a rack engagement feature of the key follower  38  that is configured to engage with a key follower engagement feature of the rack  72 . In the depicted example, the rack engagement feature is a post  31  and the key follower engagement feature is a slot  71 . Complementary engagement surfaces of the post  31  and slot  71  engage with one another to block movement of the key followers relative to the racks  72 . In some examples, the slot  71  provides engagement support around the post  31 , specifically on opposing sides of the post  31 . 
     Reducing size allows the lock to distinguish between additional bitting positions to increase the number of possible bitting sequences or patterns on keys used in lock cylinder  10  compared to the rekeyable lock cylinder described in U.S. Pat. No. 10,612,271, which increases security. The term “bitting position” is intended to mean a depth of a key cut in a bitting sequence of a key. The “bitting position” is typically identified by a digit or letter that indicates a depth of a key cut. The number of bitting positions (i.e., depths of key cuts) that can be recognized by lock cylinders differ. For example, the lock cylinder described in U.S. Pat. No. 10,612,271 is capable of recognizing six different bitting positions. This can be seen by the six gear teeth grooves in the racks illustratively shown in that application that receive the tooth of the key followers, which allows six positions of the key followers relative to the racks. The six positions of the racks relative to the key followers correspond with six bitting positions available for the lock cylinder illustratively described in that application. Due to tolerances in machining and structural rigidity of the racks, it is not feasible to increase the number of gear teeth in the racks to increase the number of bitting positions that are recognized by the lock cylinder described in that application. 
     The pin-rack engagement feature  50 , illustratively described herein, increases the number of bitting positions recognized by the lock cylinder  10 . In the depicted example, there are twelve grooves  73  available in the racks  72  that can be engaged by the post  31  of the key followers  38 . Each consecutive groove  73  is spaced from one another by an increment distance I (as shown in  FIG. 5 ), which is equal to the incremental distance separating each consecutive bitting position on a key. Accordingly, there are twelve bitting positions recognized by the lock cylinder  10  in the embodiment shown. Of course, one skilled in the art should appreciate that the lock cylinder  10  is shown for illustrative purposes, and could potentially include more or less grooves  73  to adjust the number of bitting positions recognized by the lock cylinder  10 . By increasing the possible bitting positions available, such as seven or more for example, this increases the number of possible combinations for the bitting sequences to unlock the lock cylinder  10 , thereby increasing security. 
     In the illustrative embodiment, as shown in  FIG. 4 , the post  31  includes three offset barrels  33  arranged in a triangular pattern. In some examples, each post  31  includes two offset barrels  33  arranged in a linear pattern. In some examples, each post  31  can have barrels  33  arranged in multiple linear patterns. For example, the linear patterns of the barrels  33  can be offset from one another by a half of a key cut increment to increase engagement with the rack  72 . Each barrel  33  defines a semi-cylindrical outer surface. In some examples, cones are arranged at the ends of barrels  33  to guide insertion of the post  31  into the slot  71 . 
     As seen in  FIGS. 5-7 , the slot  71  includes a series of semi-cylindrical grooves  73 . A series of grooves  73  extends along either side of the slot  71  and are offset from one another to correspond to the pattern of barrels  33 . The grooves  73  of each rack  72  include a first set of grooves  77 , positioned closest to the key followers  38 , and a second set of grooves  79  opposite from the first set of grooves  77  in the slot  71 . In some examples, as shown in  FIG. 7 , the second set of grooves  79  can have a length G that is greater than a comparable length of the first set of grooves  77 . In the illustrative embodiment, the slot  71  extends through and is bounded on all sides by the rack  72 , as shown in  FIG. 5 . In some examples, the slot  71  does not extend through the entire rack  72 . 
     The semi-cylindrical surfaces of the barrels  33  and semi-cylindrical grooves  73  increase the contact surface area of the pin-rack engagement feature  50 . In the depicted example, as shown in  FIG. 12 , when mated, a single barrel  33  interfaces with a single groove of the second set of grooves  79 . Further, in the depicted example, when mated, a pair of barrels  33  interfaces with a pair of grooves of the first set of grooves  77 . Specifically, in the depicted example, the post  31  of each key follower  38  interfaces with both sets of grooves  77 ,  79  of each slot  71  of each rack  72  to further strengthen and stabilize the pin-rack engagement feature  50 . In some examples, depending on the thickness of the rack  72  and the lengths of the posts  31 , the post  31  does not extend entirely through the slot  71 . The post  31  only need to interface, and interlock, with the slot  71  to ensure that the rack  72  and key followers  38  move together. Such an interfacing arrangement maintains strength of the pin-rack engagement feature  50  even as sizes of the components are reduced. It is considered within the scope of the present disclosure, that the key followers  38  can have a variety of different numbers of barrels  33  that interface with a variety of different numbers of either the first or second set of grooves  77 ,  79 . 
     In some examples, barrels  33  and grooves  73  are formed to define complimentary non-circular geometric profiles, such as triangular or rectangular for example. In some examples, the racks  72  can include anti-picking grooves  81  at a side  83  of the rack  72  where the locking bar engaging grooves  104  are defined. Such grooves provide feedback when they are engaged by the locking bar  74 , such feedback can mimic that feedback received with the locking bar  74  when positioned within the locking bar engaging grooves  104 . 
     To rekey the lock cylinder  10 , a valid key  43  is inserted into the keyway opening  44  and rotated. A tool (not shown) is inserted into the tool opening  46  and pushed against the carrier  70  to move the carrier  70  parallel to the longitudinal axis of the lock cylinder  10  until the spring catch  75  moves into a detent recess of the cylinder body  14 . Moving the carrier  70  withdraws the posts  31  of the key followers  38  from the mating slots  71  of the racks  72  in a longitudinal direction, parallel with the longitudinal axis of the lock cylinder  10 . The valid key is then removed and a second key (with different bitting from the first key) is inserted and rotated to release the spring catch  75 . As the spring catch  75  leaves the detent recess of the cylinder body  14 , the carrier  70  is biased toward the plug face  36  by the return spring  80 , causing the posts  31  to insert, and interface with, into the slots  71  in a longitudinal direction, parallel with the longitudinal axis of the lock cylinder  10 . This longitudinal movement of the posts  31  of the key followers  38  into the slots  71  of the racks  72  is shown in  FIGS. 8-11 . In some examples, as mentioned above, the key followers  38  and/or racks  72  can include features (e.g., a cone, rounded surfaces, etc.) that help guide the engagement of the posts  31  into the slots  71  and corresponding grooves  73 . At this point, the lock cylinder  10  is keyed to the second (valid) key and the first key no longer operates the lock cylinder  10 . In some examples, each post  31  can include stiffening rib and each slot  71  of the rack  72  can include a corresponding recess to accommodate stiffening rib. 
     As the number of bitting positions increases, the incremental distance between each bitting position decreases or becomes smaller. A stack up of tolerances from the engagement of multiple components can cause variations in the relative position of the locking bar engaging grooves  104  formed in the racks  72  during operation of lock cylinder  10 . As shown in  FIGS. 13 and 14 , the locking bar engaging grooves  104  of each rack  72  are wider than the flange  102  of the locking bar  74 . Thus, the locking bar  74  can have multiple positions within the locking bar engaging grooves  104  of the rack  72 , including at least one valid position where the locking bar  74  is in the unlocked position. 
       FIG. 13  shows an example where the locking bar  74  is positioned within the locking bar engaging groove  104  of the rack  72  while the blocking portion  98  is removed from the locking bar engaging groove  30  of the cylinder body  14 , thereby positioning the locking bar in the unlocked position.  FIG. 14  shows an example where the locking bar  74  can be positioned within the locking bar engaging groove  104  of the rack  72  while the blocking portion  98  of locking bar  74  remains positioned within the locking bar engaging groove  30  of the cylinder body  14 , thereby maintaining a locked locking bar position. As the racks  72  move with the key followers  38 , the locking bar  74  contacts the side  83  of the rack  72  outside of the locking bar engaging groove  104  and remains in the locked position. In some examples, the locking bar  74  travels over the anti-picking grooves  81  as the racks  72  move. 
     Another example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 15 and 16 . The pin-rack engagement feature includes a post  331  of spring-loaded pins  338  engaged with a mating slot  371  of racks  372 . Complementary engagement surfaces of the post  331  and the slot  371  engage with one another to block movement of the spring-loaded pins  338  relative to the racks  372 . As shown in  FIG. 15 , each post  331  includes a barrel  333  and a stiffening rib  337 . The barrel  333  defines a semi-cylindrical outer surface. In some examples, a cone  335  is arranged at the ends of the barrels  333  to guide insertion of post  331  into slot  371 . As seen in  FIG. 16 , the mating slot  371  includes a series of semi-cylindrical grooves  373 . A series of grooves  373  extends along either side of mating slot  371 . A recess  375  is positioned at one end of the slot  371  to accommodate the stiffening rib  337 . The semi-cylindrical surfaces of the barrel  333  and semi-cylindrical grooves  373  maximize a contact surface area of the pin-rack engagement feature. In some examples, the barrels  333  and the grooves  373  are formed to define complimentary non-circular geometric profiles, such as triangular or rectangular for example. In the illustrative embodiment, the slot  371  extends through and is bounded on all sides by the rack  372  as shown in  FIG. 16 . In some examples, the slot  371  does not extend through the entire rack  372 . The slot  371  is generally positioned on an opposite side of the rack  372  from the respective locking bar engaging groove  304  of that rack. 
     Another example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 17 and 18 . The pin-rack engagement feature includes a post  431  of spring-loaded pins  438  engaged with a mating slot  471  of racks  472 . Complementary engagement surfaces of the post  431  and the slot  471  engage with one another to block movement of the spring-loaded pins  438  relative to the racks  472 . As shown in  FIG. 17 , each post  431  includes a pair of barrels  433 . Each barrel  433  defines a semi-cylindrical outer surface. In some examples, a cone  435  is arranged at the end of each of the barrels  433  to guide insertion of posts  431  into slot  471 . As seen in  FIG. 18 , the mating slot  471  includes a series of semi-cylindrical grooves  473 . A series of grooves  473  extends along either side of mating slot  471 . The semi-cylindrical surfaces of each barrel  433  and semi-cylindrical grooves  473  maximize a contact surface area of the pin-rack engagement feature. In some examples, the barrels  433  and the grooves  473  are formed to define complimentary non-circular geometric profiles, such as triangular or rectangular for example. In the illustrative embodiment, the slot  471  extends through and is bounded on all sides by the rack  472  as shown in  FIG. 18 . In some examples, the slot  471  does not extend through the entire rack  472 . The slot  471  is generally positioned on an opposite side of the rack  472  from the respective locking bar engaging groove  404  of that rack. 
     Another example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 19 and 20 . The pin-rack engagement feature includes a post  531  of spring-loaded pins  538  engaged with a mating slot  571  of racks  572 . Complementary engagement surfaces of the post  531  and the slot  571  engage with one another to block movement of the spring-loaded pins  538  relative to the racks  572 . As shown in  FIG. 19 , each post  531  includes a pair of vertically stacked of barrels  533 . Each barrel  533  defines a semi-cylindrical outer surface. In some examples, a cone  535  is arranged at the end of each of the barrels  533  to guide insertion of posts  531  into slot  571 . As seen in  FIG. 20 , the mating slot  571  includes a series of semi-cylindrical grooves  573 . A series of grooves  573  extends along either side of mating slot  571 . The semi-cylindrical surfaces of each barrel  533  and semi-cylindrical grooves  573  maximize a contact surface area of the pin-rack engagement feature. In some examples, the barrels  533  and the grooves  573  are formed to define complimentary non-circular geometric profiles, such as triangular or rectangular for example. In the illustrative embodiment, the slot  571  extends through and is bounded on all sides by the rack  572  as shown in  FIG. 20 . In some examples, the slot  571  does not extend through the entire rack  572 . The slot  571  is generally positioned on an opposite side of the rack  572  from the respective locking bar engaging groove  504  of that rack. 
     A still further example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 21 and 22 . The pin-rack engagement feature includes a post  631  of pins  638  engaged with a mating slot  671  of racks  672 . Complementary engagement surfaces of the post  631  and the slot  671  engage with one another to block movement of the spring-loaded pins  638  relative to the racks  672 . 
     As shown in  FIG. 21 , each post  631  includes set of ridges  633  configured to integrate with the slot  671 . The ridges  633  may also be said to be formed from a plurality of barrels, as discussed above. As seen in  FIG. 22 , the mating slot  671  includes a series of semi-cylindrical grooves  673 . The grooves  673  extends along either side of the mating slot  671 . The ridges  633  of the post  631  and semi-cylindrical groove  673  maximize a contact surface area of the pin-rack engagement feature. In some examples, the post  631  and the grooves  673  are formed to define complimentary non-circular geometric profiles, such as triangular or rectangular for example. In the illustrative embodiment, the slot  671  extends through and is bounded on all sides by the rack  672  as shown in  FIG. 22 . In some examples, the slot  671  does not extend through the entire rack  672 . 
     As seen in  FIGS. 22-24 , the slot  671  includes a series of semi-cylindrical grooves  673 . The series of grooves  673  extends along either side of the slot  671  and are offset from one another to correspond to the pattern of ridges  633 . The grooves  673  of each rack  672  include a first set of grooves  677 , positioned closest to the key followers (e.g., pins  638 ), and a second set of grooves  679  opposite from the first set of grooves  677  in the slot  671 . In some examples, as shown in  FIG. 24 , the second set of grooves  679  can have a length G that is greater than a comparable length of the first set of grooves  677 . In the illustrative embodiment, the slot  671  extends through and is bounded on all sides by the rack  672 , as shown in  FIG. 22 . In some examples, the slot  671  does not extend through the entire rack  672 . The slot  671  is generally positioned on an opposite side of the rack  672  from the respective locking bar engaging groove  604  of that rack. 
     In the example sequence shown in  FIGS. 25-27  showing engagement between a pin  638  and rack  672 , the semi-cylindrical surfaces of the ridges  633  and semi-cylindrical grooves  673  increase the contact surface area of the pin-rack engagement feature. In the depicted example, as shown in  FIG. 27 , when mated, a single barrel  33  interfaces with a single groove of the second set of grooves  79 . Further, in the depicted example, when mated, the ridges  633  interface with a pair of grooves of the first set of grooves  677 , as well as grooves  679 . 
     Specifically, in the depicted example, the post  631  of each key follower  638  interfaces with both sets of grooves  677 ,  679  of each slot  671  of each rack  672  to further strengthen and stabilize the pin-rack engagement feature. In some examples, depending on the thickness of the rack  672  and the lengths of the posts  631 , the post  631  does not extend entirely through the slot  671 . The post  631  only need to interface, and interlock, with the slot  671  to ensure that the rack  672  and key followers (e.g., pins  638 ) move together. Such an interfacing arrangement maintains strength of the pin-rack engagement feature even as sizes of the components are reduced. It is considered within the scope of the present disclosure, that the key followers  638  can have a variety of different sizes or shapes that interface with a variety of different numbers of either the first or second set of grooves  677 ,  679 . In particular, with respect to the embodiment shown, to accommodate the additional number of barrels  633  while maintaining a constant number of possible relative positions between the pin  638  and rack  672 , a corresponding increase in a number of grooves  673  within the slot  671  are provided relative to the number of grooves  573  within the slot  571  seen in  FIG. 19 . As compared to the embodiments discussed previously, the increased pin size increases a strength of the post  631 , particularly in the vertical direction. This improves the overall strength of the lock cylinder, in avoiding damage in response to objects being inserted into a keyway opening, such as keyway opening  244 . 
     The features of one spring-loaded pin  38 ,  338 ,  438 ,  538  or rack  72 ,  372 ,  472 ,  572  can be used in any other spring-loaded pin  38 ,  338 ,  438 ,  538  or rack  72 ,  372 ,  472 ,  572 . Spring-loaded pins  38 ,  338 ,  438 ,  538  can include more or less posts  31 ,  331 ,  431 ,  531  and racks  72 ,  372 ,  472 ,  572  can include more or less grooves  73 ,  373 ,  473 ,  573 . 
     Another example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 29-35 . The pin-rack engagement feature includes a post  731  of a spring-loaded pin  738  engaged with a mating slot  771  of racks  772 . Complementary engagement surfaces of the post  731  and the slot  771  engage with one another to block movement of the spring-loaded pin  738  relative to the racks  772 . 
     As shown in  FIG. 29 , the spring-loaded pin  738  has a generally cylindrical shape. However, it is considered within the scope of the present disclosure that the spring-loaded pin  738  could have a variety of shapes depending on the shape of the recess in which it is positioned within the cylinder plug. In the depicted example, the post  731  of the spring-loaded pin  738  includes a first projection  733  and a second projection  735 . In some examples, the first and second projections  733 ,  735  are vertically aligned with one another. In some examples, the first and second projections  733 ,  735  are vertically aligned with one another perpendicular to the longitudinal axis of the cylinder body. In some examples, the first projection  733  and the second projection  735  are wedge shaped and can include rounded edges to facilitate insertion into the slot  771 . 
     As shown in  FIGS. 30 and 31 , the mating slot  771  of the rack  772  includes a series of key follower post recesses  773 . In some examples, the key follower post recesses  773  are open at a vertical side  774 . In some examples, the vertical side  774  is perpendicular to the longitudinal axis of the lock cylinder  10 . The first and second projections  733 ,  735  of the post  731  of the spring-loaded pin  738  and the series of key follower post recesses  773  of the slot  771  of the rack  772  maximize a contact surface area of the pin-rack engagement feature. In some examples, the vertical side  774  is adjacent the spring-loaded pin  738  when complementary engagement surfaces of the post  731  and the slot  771  engage with one another. 
       FIG. 32  shows a top view of the spring-loaded pin  738 , and  FIG. 33  shows a cross-sectional view along line A-A in  FIG. 32  with the post  731  engaged in the slot  771 . As shown, the first and second projections  733 ,  735  of the post  731  have a first length L 1  and a second length L 2 , respectively. The first and second lengths L 1 , L 2  are measured parallel to the longitudinal axis of the lock cylinder  10 . In some examples, the first length L 1  is greater than the second length L 2 . In some examples, the first length L 1  is less than the second length L 2 . In some examples, the first length L 1  is equal to the second length L 2 . 
       FIG. 34  shows a bottom view of the spring-loaded pin  738 , and  FIG. 35  shows a cross-sectional view along line B-B in  FIG. 34  with the post  731  engaged in the slot  771 . 
     Another example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 36-42 . The pin-rack engagement feature includes a post  831  of a spring-loaded pin  838  engaged with a mating slot  871  of racks  872 . Complementary engagement surfaces of the post  831  and the slot  871  engage with one another to block movement of the spring-loaded pin  838  relative to the racks  872 . 
     As shown in  FIG. 36 , the spring-loaded pin  838  has a generally cylindrical shape. However, it is considered within the scope of the present disclosure that the spring-loaded pin  838  could have a variety of shapes depending on the shape of the recess in which it is positioned within the cylinder plug. 
     In the depicted example, the post  831  of the spring-loaded pin  838  includes a projection  833  and a fin  835 . In the depicted example, the projection  833  is positioned on the fin  835 . In some examples, the projection  833  has linear slides. In some examples, the projection  833  has a semi-cylindrical profile. In some examples, the fin  835  has linear slides and a rectangular shape. In some examples, the fin  835  has rounded edges. 
     As shown in  FIG. 37 , the mating slot  871  of the rack  872  extends at least partially through, and is bounded by, the rack  872 . The slot  871  has a first side  875  and a second side  877  that extend parallel with one another along a portion of the length of the rack  872 . The slot  871  includes a series of engagement grooves  879  (shown in  FIG. 38 ) arranged along the first side  875  of the slot  871 . The slot  871  also includes a linear aperture  891  (shown in  FIG. 38 ) arranged along the second side  877  of the slot  871 , immediately adjacent the series of engagement grooves  879 . In some examples, each of the series of engagement grooves  879  is semi-cylindrical. In some examples, the linear aperture  891  is partially rectangular. In some examples, each of the series of engagement grooves  879  mirrors the profile of the projection  833  of the post  831  of the pin  838 , and the linear aperture  891  is sized and shaped to receive the fin  835  of the post  831  of the pin  838 . 
       FIG. 38  shows a side view of the spring-loaded pin  838  and the rack  872  engaged with one another.  FIG. 39  shows a cross-sectional view along line C-C in  FIG. 38  with the post  831  engaged in the slot  871 . 
     The pin  838  and the rack  872  have an interfacing path IP along which the rack  872  and pin  838  engage and disengage with one another. In some examples, the rack  872  moves in and out of engagement with the pin  838 . In some examples, the interfacing path IP is parallel with the longitudinal axis of the of the cylinder body. In some examples, the fin  835  extends in the same direction as the interfacing path IP. 
     As shown in  FIG. 39 , the first side  875  of the slot  871  has a first depth D 1  measured parallel to the longitudinal axis of the cylinder body  14 , and the second side  877  of the slot has a second depth D 2 , measured parallel to the longitudinal axis of the cylinder body  14 . In some examples, the first depth D 1  is greater than the second depth D 2 . As shown, the first side  875  of the slot  871  receives the projection  833  and the second side  877  of the slot  871  receives the fin  835 . In some examples, the fin  835  extends through, and past, the slot  871  when the post  831  is received in the slot  871 . In some examples, the fin  835  extends further through the slot  871  than the projection  833 . 
       FIG. 40  shows an end view of the spring-loaded pin  838  and the rack  872  engaged with one another.  FIG. 41  shows a cross-sectional view along line D-D in  FIG. 40 , and  FIG. 42  shows a cross-sectional view along line E-E in  FIG. 40 . 
     Another example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 43-49 . The pin-rack engagement feature includes a post  931  of a spring-loaded pin  938  engaged with a mating slot  971  of racks  972 . Complementary engagement surfaces of the post  931  and the slot  971  engage with one another to block movement of the spring-loaded pin  938  relative to the racks  972 . The pin-rack engagement feature shown in  FIGS. 43-49  is substantially similar to the pin-rack engagement feature shown in  FIGS. 36-42 . Specifically, the pin  938  includes the post  931  that has a fin  935  and three projections  933 ,  934 ,  936  positioned on the side of the fin  935 . Projections  933 ,  934 ,  936  are configured to mate with grooves  979  of a first side  975  of the slot  971  of the rack  972 . In some examples, the post  931  can include at least two projections. In some examples, the post  931  can include more than three projections. The fin  935  of the post  931  of the pin  938  is configured to be received by a linear aperture  991  of a second side  977  of the slot  971  of the rack  972 . 
       FIG. 45  shows a side view of the spring-loaded pin  938  and the rack  972  engaged with one another.  FIG. 46  shows a cross-sectional view along line F-F in  FIG. 45  with the post  931  engaged in the slot  971 .  FIG. 47  shows an end view of the spring-loaded pin  938  and the rack  972  engaged with one another.  FIG. 48  shows a cross-sectional view along line G-G in  FIG. 47 , and  FIG. 49  shows a cross-sectional view along line H-H in  FIG. 47 . 
     Another example of a pin-rack engagement feature according to an embodiment of the present disclosure is shown in  FIGS. 50-56 .  FIG. 53  shows a cross-sectional view along line I-I in  FIG. 52 .  FIG. 55  shows a cross-sectional view along line J-J in  FIG. 54 .  FIG. 56  shows a cross-sectional view along line K-K in  FIG. 54 . The pin-rack engagement feature includes a post  1031  of a spring-loaded pin  1038  engaged with a mating slot  1071  of racks  1072 . Complementary engagement surfaces of the post  1031  and the slot  1071  engage with one another to block movement of the spring-loaded pin  1038  relative to the racks  1072 . The pin-rack engagement feature shown in  FIGS. 50-56  is substantially similar to the pin-rack engagement feature described above. Specifically, the pin  1038  includes the post  1031  that has a fin  1035  and a projection  1033  positioned on a side of the fin  1035 . The projection is configured to mate with grooves  1079  of a first side  1075  of the slot  1071  of the rack  1072 . In some examples, the post  1031  can include at least two projections. The fin  1035  of the post  1031  of the pin  1038  is configured to be received by a linear aperture  1091  of a second side  1077  of the slot  1071  of the rack  1072 . 
     The pin  1038  includes a main body  1039 , from which the post  1031  extends. In some examples, the main body  1039  is configured to be received in a plug body. In some examples, the main body  1039  can receive a spring therein. In the depicted example, the main body  1039  has a rectangular transverse cross section. In some examples, the main body has a circular cross section. It is considered within the scope of the present disclosure, that the main body  1039  can have a variety of different cross sections that match the profile of the recess of the plug assembly in which the pin  1038  is positioned. 
       FIGS. 57 and 58  show a plug body  1001  that has a longitudinal axis X. The plug body  1001  includes a front face  1003 , a rear face  1005 , and a plug main body  1007  extending between the front and rear faces  1003 ,  1005 . The plug body  1001  further includes a series of key follower recesses  1009  aligned in the plug main body  1007  between the front and rear faces  1003 ,  1005 . As shown in  FIGS. 57 and 58 , the pin  1038  is coupled to the rack  1072  and the main body  1039  of the pin  1038  is positioned within a key follower recess  1009 .  FIG. 59  shows the pin  1038  and the rack  1072  removed from the plug body  1001 . 
     Each key follower recess  1009  has an open top and receives a pin  1038  therein. In operation, the pin  1038  moves axially up and down in the recess  1009  as the pin  1038  follows the bitting of a key that is inserted into the plug body  1001 . 
     In the depicted examples, each of the plurality of key followers recesses  1009  has a rectangular cross-section. It is considered within the scope of the present disclosure that each of the key followers recesses  1009  can have a variety of cross sections. In some examples, all of the key follower recesses  1009  have the same cross section. In some examples, all of the key follower recesses  1009  have different cross sections. In some examples, the key follower recesses  1009  each have a cross section that matches that of a pin positioned therein. In some examples, the key follower recesses  1009  each have a cross section that does not match that of a pin positioned therein. In some examples, the key follower recesses  1009  each have cross section that limits rotation of a pin within the key follower recess  1009 . In some examples, at least one of the key follower recesses  1009  has a circular cross section and the pin  1038  has a rectangular cross section. In some examples, at least one of the key follower recesses  1009  has a polygonal cross section. 
     EXAMPLES 
     Illustrative examples of the lock cylinder disclosed herein are provided below. An embodiment of the lock cylinder may include any one or more, and any combination of, the examples described below. 
     Example 1 is a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. A key follower and a corresponding rack are disposed in the plug assembly, with the rack being selectively disengageable from the key follower to facilitate rekeying between different keys. A locking bar is movable between a locked position engaged with the groove of the cylinder body for blocking rotation of the plug assembly with respect to the cylinder body and an unlocked position spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body. The rack controls movement of the locking bar between the locked and unlocked positions. The key follower is formed to define a post and the rack is formed to include a slot extending at least partially through and bounded by the rack. The post is received in the slot such that complementary engagement surfaces of the post and slot engage with one another to block movement of the key follower relative to the rack. 
     In Example 2, the subject matter of Example 1 is further configured such that the post is formed to define at least a semi-cylindrical outer surface and the slot includes a series of semi-cylindrical grooves. The semi-cylindrical outer surface of the post engages with at least one of the semi-cylindrical grooves of the slot when the post is received in the slot. 
     In Example 3, the subject matter of Example 2 is further configured such that the post includes a barrel defining the at least one semi-cylindrical surface. 
     In Example 4, the subject matter of Example 3 is further configured such that the slot further includes a recess for receiving the at least one semi-cylindrical surface. 
     In Example 5, the subject matter of Example 2 is further configured such that the post includes two barrels defining the at least one semi-cylindrical surface. 
     In Example 6, the subject matter of Example 5 is further configured such that the barrels are offset from one another in a linear pattern. 
     In Example 7, the subject matter of Example 2 is further configured such that the post includes three barrels defining the at least one semi-cylindrical surface. 
     In Example 8, the subject matter of Example 7 is further configured such that the barrels are offset from one another in a triangular pattern. 
     In Example 9, the subject matter of Example 8 is further configured such that a first series of semi-cylindrical grooves are arranged along a first side of the slot and a second series of semi-cylindrical grooves are arranged along a second side of the slot. The first series of semi-cylindrical grooves is offset from the second series of semi-cylindrical grooves. 
     Example 10 is a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. A key follower and a corresponding rack are disposed in the plug assembly. A locking bar is movable between a locked position engaged with the groove of the cylinder body for blocking rotation of the plug assembly with respect to the cylinder body and an unlocked position spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body. The rack controls movement of the locking bar between the locked and unlocked positions. The key follower is engaged with the rack by an engagement feature. The rack is selectively disengageable from the key follower to facilitate rekeying between different keys. The engagement feature allows at least seven different positions of the key follower relative to the rack to allow at least seven different bitting positions in the rekeyable lock cylinder. 
     In Example 11, the subject matter of Example 10 is further configured such that the engagement feature includes a post and a slot, the post being formed to define at least a semi-cylindrical outer surface. The slot includes a series of semi-cylindrical grooves, and the semi-cylindrical outer surface of the post engages with at least one of the semi-cylindrical grooves of the slot when the post is received in the slot. 
     In Example 12, the subject matter of Example 10 is further configured such that the post includes two barrels defining the at least semi-cylindrical surface. 
     In Example 13, the subject matter of Example 12 is further configured such that the barrels are offset from one another in a linear pattern. 
     In Example 14, the subject matter of Example 11 is further configured such that a first series of semi-cylindrical grooves is arranged along a first side of the slot and a second series of semi-cylindrical grooves is arranged along a second side of the slot, and wherein the first series of semi-cylindrical grooves is offset from the second series of semi-cylindrical grooves. 
     Example 15 is a rekeyable lock cylinder. The rekeyable lock cylinder includes a cylinder body with a longitudinal axis and is formed to define a groove. The rekeyable lock cylinder includes a plug assembly disposed in the cylinder body and rotatable about the longitudinal axis. The rekeyable lock cylinder includes a locking bar movable between a locked position and an unlocked position. When in the locked position, the locking bar is positioned within the groove of the cylinder body to block rotation of the plug assembly with respect to the cylinder body. When in the unlocked position, the locking bar is spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body. The rekeyable lock cylinder includes a key follower disposed in the plug assembly and the key follower includes a rack engagement feature. The rekeyable lock cylinder includes a rack disposed in the plug assembly and the rack includes a key follower engagement feature. The rack engagement feature of the key follower and the key follower engagement feature of the rack are engaged to facilitate simultaneous movement of the key follower and the rack. The rack controls movement of the locking bar between the locked and unlocked positions. At least one of the rack engagement feature of the key follower and the key follower engagement feature of the rack is a projection and at least one of the rack engagement feature of key follower and the key follower engagement feature of the rack is a slot. The rack is selectively disengageable from the key follower when moving in a direction parallel to the longitudinal axis of the plug assembly. 
     In Example 16, the subject matter of Example 15 is further configured such that the rack engagement feature of the key follower and the key follower engagement feature of the rack allow at least seven different positions of the key follower relative to the rack. 
     In Example 17, the subject matter of Example 15 is further configured such that the projection is formed to define at least a semi-cylindrical outer surface. The slot includes a series of semi-cylindrical grooves, and the semi-cylindrical outer surface of the post engages with at least one of the semi-cylindrical grooves of the slot when the post is received in the slot. 
     In Example 18, the subject matter of Example 17 is further configured such that the projection includes two barrels defining the at least semi-cylindrical surface. 
     In Example 19, the subject matter of Example 18 is further configured such that the barrels are offset from one another in a linear pattern. 
     In Example 20, the subject matter of Example 15 is further configured such that a first series of semi-cylindrical grooves is arranged along a first side of the slot of the at least one of the rack engagement feature of the key follower and the key follower engagement feature of the rack, and a second series of semi-cylindrical grooves is arranged along a second side of the slot. The first series of semi-cylindrical grooves is offset from the second series of semi-cylindrical grooves. 
     Example 21 is a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. The rekeyable lock cylinder includes a locking bar movable between a locked position and an unlocked position. When in the locked position, the locking bar is positioned within the groove of the cylinder body to block rotation of the plug assembly with respect to the cylinder body. When in the unlocked position, the locking bar is spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body The rekeyable lock cylinder includes a key follower disposed in the plug assembly. The key follower includes a rack engagement feature that is a post. The rekeyable lock cylinder includes a rack disposed in the plug assembly. The rack includes a key follower engagement feature that is a slot. The rack engagement feature of the key follower and the key follower engagement feature of the rack are engaged to facilitate simultaneous movement of the key follower and the rack. The rack controls movement of the locking bar between the locked and unlocked positions. The rack is selectively disengageable from the key follower when moving in a direction parallel to the longitudinal axis of the plug assembly. The rekeyable lock cylinder includes the slot of the rack extending at least partially through, and bounded by, the rack. The slot has a first side and a second side that extend parallel with one another along a portion of the length of the rack. The slot has a series of engagement grooves that are arranged along the first side of the slot. The slot also includes a linear aperture arranged along the second side of the slot, immediately adjacent the series of engagement grooves. The post of the key follower has a projection that is engageable with at least one of the series of engagement grooves of the slot when the post is received in the slot. The post of the key follower includes a fin engageable with the linear aperture of the slot when the post is received in the slot. 
     In Example 22, the subject matter of Example 21 is further configured such that the key follower is disposed within a key follower recess of the plug, and the key follower recess of the plug has a rectangular cross-section. 
     In Example 23, the subject matter of Example 21 is further configured such that the key follower is disposed within a key follower recess of the plug, and the key follower recess of the plug has a circular cross-section. 
     In Example 24, the subject matter of Example 21 is further configured such that the post includes at least two projections each defining a profile that matches that of one of the series of engagement grooves of the slot. 
     In Example 25, the subject matter of Example 21 is further configured such that the rack and the key follower have an interfacing path along which the rack and the key follower engage and disengage with one another. The interfacing path is parallel with the longitudinal axis of the cylinder body and the fin of the post extends in the direction of movement of the rack. 
     In Example 26, the subject matter of Example 21 is further configured such that the fin of the post extends through and past the linear aperture of the slot when the post is received in the slot. 
     In Example 27, the subject matter of Example 21 is further configured such that the fin extends further through the slot than the projection when the post is received in the slot. 
     In Example 28, the subject matter of Example 21 is further configured such that the projection is positioned on the fin. 
     In Example 29, the subject matter of Example 21 is further configured such that the first side of the slot has a first depth measured parallel to the longitudinal axis of the cylinder body and the second side of the slot having a second depth measured parallel to the longitudinal axis of the cylinder body, the first depth is greater than the second depth. 
     In Example 30, the subject matter of Example 21 is further configured such that the rack engagement feature of the key follower and the key follower engagement feature of the rack allow at least seven different positions of the key follower relative to the rack. 
     In Example 31, the subject matter of Example 21 is further configured such that the series of engagement grooves are semi-cylindrical. 
     In Example 32, the subject matter of Example 21 is further configured such that the linear aperture is partially rectangular. 
     Example 33 is a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. The plug includes a plurality of key follower recesses aligned along the longitudinal axis. The plurality of key follower recesses of the plug assembly each have a rectangular cross-section. The rekeyable lock cylinder includes a plurality of key followers that each have a portion positioned within each of the plurality of key follower recesses of the plug assembly. Each of the plurality of key followers corresponds with a rack and each rack is selectively disengageable from the corresponding key follower to facilitate rekeying between different keys. The portion of each of plurality of key followers positioned within each of the plurality of key follower recesses has a rectangular cross-section. The rekeyable lock cylinder includes a locking bar movable between a locked position engaged with the groove of the cylinder body for blocking rotation of the plug assembly with respect to the cylinder body and an unlocked position spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body. Each rack controls movement of the locking bar between the locked and unlocked positions. Each of the plurality of key followers is formed to define a post. Each rack is formed to include a slot that extends at least partially through and bounded by the rack. The post is received in the slot such that complementary engagement surfaces of the post and slot engage with one another to block movement of the plurality key followers relative to the racks. 
     In Example 34, the subject matter of Example 33 is further configured such that the post of the plurality of key followers and the slot of the racks allow at least seven different positions of each key follower relative to each rack. 
     In Example 35, the subject matter of Example 33 is further configured such that a first side of each slot has a first depth measured parallel to the longitudinal axis of the cylinder body and the second side of each slot has a second depth measured parallel to the longitudinal axis of the cylinder body, wherein the first depth is greater than the second depth. 
     In Example 36, the subject matter of Example 33 is further configured such that each slot has a first side and a second side extending parallel with one another along a portion of a length of each rack, each slot including: a series of engagement grooves being arranged along the first side of the slot; and a linear aperture arranged along the second side of the slot, immediately adjacent the series of engagement grooves. Each post of the plurality of key followers including: a projection engageable with at least one of the series of engagement grooves of the slot when the post is received in the slot; and a fin engageable with the linear aperture of the slot when the post is received in the slot. 
     Example 37 is a rekeyable lock cylinder with a cylinder body and a plug assembly disposed in the cylinder body. The cylinder body has a longitudinal axis and is formed to define a groove. The plug assembly is rotatable about the longitudinal axis. The rekeyable lock cylinder includes a key follower and a corresponding rack disposed in the plug assembly. The rack is selectively disengageable from the key follower to facilitate rekeying between different keys. The key follower is formed to define a post having a first projection and a second projection. The first and second projections are vertically aligned within one another and perpendicular to the longitudinal axis of the cylinder body. The first and the second projections have a first length and a second length, respectively. The first and second lengths are parallel to the longitudinal axis of the cylinder body. The first length is greater than the second length. The rekeyable lock cylinder includes a locking bar movable between a locked position engaged with the groove of the cylinder body for blocking rotation of the plug assembly with respect to the cylinder body and an unlocked position spaced apart from the groove of the cylinder body to allow rotation of the plug assembly with respect to the cylinder body. The rack controls movement of the locking bar between the locked and unlocked positions. The rack has a plurality of key follower post recesses. The post of the key follower is received in a pair of the plurality of key follower post recesses of the rack to block movement of the key follower relative to the rack. 
     In Example 38, the subject matter of Example 37 is further configured such that the plurality of key follower post recesses are open at a vertical side adjacent the key follower, the vertical side is perpendicular to the longitudinal axis of the plug assembly. 
     In Example 39, the subject matter of Example 37 is further configured such that the post of the key follower and the plurality of key follower post recesses of the rack allow at least seven different positions of the key follower relative to the rack. 
     In Example 40, the subject matter of Example 37 is further configured such that at least one of the first and second projections is wedge-shaped. 
     In Example 41, the subject matter of Example 37 is further configured such that the key follower is disposed within a key follower recess of the plug assembly, and wherein the key follower recess of the plug assembly has a rectangular cross-section. 
     In Example 42, the subject matter of Example 37 is further configured such that each of the plurality of key follower post recesses are sized and shaped to receive the first projection or the second projection of the post. 
     The various embodiments described above are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.