Title of Invention	"A REKEYABLE LOCK CYLINDER"
Abstract	A rekeyable lock cylinder, comprising: a cylinder body with a longitudinal axis; a locking bar disposed in the cylinder body for movement transverse to, and rotationally about, the longitudinal axis; a plug assembly disposed in the cylinder body and being rotatable between a first position and a second position, the plug assembly having a lock face with a tool receiving aperture; a plurality of pins and a corresponding plurality of racks disposed in the plug assembly, the plurality of racks being selectively engageable with the plurality of pins; and a first member coupled to the plurality of racks, the first member being moveable in response to application of a force against the first member by a tool received through the tool receiving aperture, the first member being configured to simultaneously disengage all of the plurality of racks from the plurality of pins in response to the movement of the first member.

Title of Invention

"A REKEYABLE LOCK CYLINDER"

Abstract

A rekeyable lock cylinder, comprising: a cylinder body with a longitudinal axis; a locking bar disposed in the cylinder body for movement transverse to, and rotationally about, the longitudinal axis; a plug assembly disposed in the cylinder body and being rotatable between a first position and a second position, the plug assembly having a lock face with a tool receiving aperture; a plurality of pins and a corresponding plurality of racks disposed in the plug assembly, the plurality of racks being selectively engageable with the plurality of pins; and a first member coupled to the plurality of racks, the first member being moveable in response to application of a force against the first member by a tool received through the tool receiving aperture, the first member being configured to simultaneously disengage all of the plurality of racks from the plurality of pins in response to the movement of the first member.

Full Text	The present application is a divisional application out of Indian Patent application number 628/DELNP/2005. The present invention relates to a rekeyable lock cylinder and a method of keying the same. The present invention relates generally to lock cylinders and particularly to lock cylinders that can be rekeyed. More particularly, the invention relates to lock cylinders that can be rekeyed without the use of a master key. Background of the Invention When rekeying a cylinder using 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. The present invention overcomes these and other disadvantages of conventional lock cylinders. The lock cylinder of the present invention operates in a transparent way that presents the familiar experience of inserting a key and rotating the key in the lock cylinder, as with current cylinders. However, in the present invention, that same familiar experience is used'to rekey the lock cylinder. Thus, the user does not require any special knowledge, training, or tools to rekey the lock cylinder of the present invention. Summary of the Invention The. present invention provides a simple means for "teaching" a lock cylinder a new key while obsoleting old keys. According to the present invention, a rekeyable lock cylinder comprises a cylinder body with a longitudinal axis and a plug assembly disposed in the cylinder body. The plug assembly includes a plug body and a carrier sub-assembly disposed adjacent the plug body. The plug assembly further includes a plurality of pins. The carrier sub-assembly is moveable parallel to the longitudinal axis of the cylinder body and includes a plurality of racks for engaging the pins. The racks disengage from the pins in response to movement of the carrier in a first direction and engage the pins in response to movement of the carrier in a second direction. The lock cylinder is in a rekeyable condition when the racks are disengaged from the pins. The present invention further includes a novel method of rekeying a rekeyable lock cylinder. According to the invention, a method of rekeying a rekeyable lock cylinder comprises the steps of providing a lock cylinder with a plug body and a lock face having a keyway and a tool-receiving aperture, inserting a first valid key in the keyway, rotating the plug body to a first position, inserting a tool in the tool-receiving aperture, removing the first valid key from the keyway, inserting a second valid key in the keyway, and rotating the plug body away from the first position. The step of inserting the tool includes the step of moving a rack out of engagement with a pin. According to one aspect of the invention, the lock cylinder includes a carrier that is moveable parallel to a longitudinal axis of the lock cylinder and the step of inserting the tool includes the step of moving the carrier. Other features and advantages will become apparent from the following description when viewed in accordance with the accompanying drawings and appended claims. Brief Description of the Drawings Figure 1 illustrates a lock cylinder according to the present invention. ' Figure 2 is an exploded view of the lock cylinder of Figure 1. Figure 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. Figure 4 is a top plan view of the plug assembly of Figure 3. Figure 5 is a partially broken away side view of the plug assembly of Figure 3. Figure 6 is a partially exploded view of the plug assembly of Figure 3.Figure-7:-is ejection vJew4hrough^heplug~assembl-y-otFJgure^3-anda 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. Figure 8 is a perspective view of the plug assembly of Figure 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. Figure 9 is a top plan view of the plug assembly of Figure 8. Figure 10 is a partially broken away side view of the plug assembly of Figure 8. Figure 11 is a partially exploded view of the plug assembly of Figure 8. Figure 12 is a section view through the plug assembly of Figure 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. Figure 13 is a perspective view similar to Figure 8 but with the carrier assembly moved axially to a rekeying position. Figure 14 is a top plan view of the plug assembly of Figure 13. Figures 15a-15e are various views of a cylinder body for use in the present invention. Figures 16a-16f are various views of the cylinder plug body for use in the present invention. Figures 17a-17f are various view of the carrier for use in the present invention. Figures 18a-18b are views of a rack for use in the present invention. Figures 19a-19b are views of a spring catch for use in the present invention. Figures 20a-20b are views of a pin for use in the present invention. Figures 21a-21b are views of a locking bar for use in the present invention. Figures 22a-22d are views of a spring retaining cap for use in the present invention. Figure 23 is an exploded perspective view of an alternative embodiment of the invention. .Figures, 24a-24e are views of alternative embodiment of the lock cylinder housing. Figure 25 is a transverse section view taken through an alternative embodiment of the present invention. Figures 26a-26b are views of an alternative embodiment of the spring catch. Figures 27a-27e/are views of an alternative embodiment of the carrier. Figures 28a-28b are views of an alternative embodiment of the pin. Figures 29a-29b are views of an alternative embodiment of the rack. Figures 30a-30b are views of an alternative embodiment of the locking bar. Detailed Description of the Drawings A lock cylinder 10 according to the present invention is illustrated in Figure 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 Figure 1, the plug assembly 14 is in the home position relative to the cylinder body 12. The lock cylinder body 12, as seen in Figures 15a-15e, 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 (Figure 2). The plug assembly 14 includes a plug body 40, a carrier sub-assembly 42 and a plurality of spring-loaded pins 38 (Figures 2 and 20a-20b). The plug body 40, illustrated in Figures 16a-16f, 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 (Figure 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 body12. 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 (Figures 2 and 22a-22d). 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 (Figure 2) extends radially inwardly from opposite the first planar surface 72. The carrier sub-assembly 42 (Figures 2, 6 and 10) includes a carrier 90 (Figures 17a-17e), a plurality of racks 92 (Figures 18a-18b), a spring catch 96 (Figures 19a-19b), a spring-loaded locking bar 94 (Figures 21a-21b), and a return spring 98 (Figure 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 surface102 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 (Figure 17c) 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 semicircular g>oove 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. Each spring-loaded pin 38 includes a pin 113 and a biasing spring 115. The pins 113, illustrated in Figures 20a-20b, are generally cylindrical with annular gear teeth 114 and a central longitudinal bore 116 for receiving biasing springs 115 (Figure 2) The Rack 92, illustrated in figure 18a-18b, 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 Figures 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 Figure 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. The spring-loaded locking bar 94, illustrated in Figures 21a-22b, 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 Figure 12. The spring-retaining cap 82, illustrated in Figures 22a-22d, 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 Figures 7 and 12. A plurality of spring alignment tips 146 extend from the lower surface 144 to engage the springs 44?r 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 (Figures 16e-16f). 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 Figure 3. The plug assembly 14 is placed in the lockcylindert>ody 12 and the tetainer-16-isiiisposed ir the slots6& 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. The properly keyed lock cylinder 10, without the key 160 inserted, is illustrated in Figures 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 Figure 4. In addition, the bullet-shaped features 78 are misaligned with the roeooges 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. The internal configuration of a lock cylinder 10 with the valid key 160 inserted therein at the home position is illustrated in Figures 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 Figures 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 Irove 111 in the racks 92, as illustrated in Figure 12, allowing the racks 92, and the carrier 90, to move parallel to the longitudinal axis of the lock cylinder 10. To rekey the lock cylinder 10, the valid key 160 is inserted into the keyway 52, as illustrated in Figures 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 Figure 14. The valid vMdkeyJs 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. An alternative embodiment 210 of the invention is illustrated in Figures 23-29. The alternative embodiment includes the same components, as illustrated in Figure 23, but several of the components have been modified. Functionally, both embodiments are the same. The modified housing 212, illustrated in Figures 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. The modified pin biasing springs 226, illustrated in Figures 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. The modified spring catch 228, illustrated in Figures 23 and 26, includes a central U-shaped portion 230 and a pair of arms 232 extending from the U-shaped portion 230. The modified carrier 236, illustrated in Figures 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 permitting4t to-move radially-outwardly4o-engage-tb.e 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. The modified pins 244, illustrated in Figures 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. The modified racks 250, illustrated in Figures 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. The modified locking bar 252, illustrated in Figures 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. The above-described 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. We claim: 1. A rekeyable lock cylinder, comprising: a cylinder body with a longitudinal axis; a locking bar disposed in the cylinder body for movement transverse to, and rotationally about, the longitudinal axis; a plug assembly disposed in the cylinder body and being rotatable between a first position and a second position, the plug assembly having a lock face with a tool receiving aperture; a plurality of pins and a corresponding plurality of racks disposed in the plug assembly, the plurality of racks being selectively engageable with the plurality of pins; and a first member coupled to the plurality of racks, the first member being moveable in response to application of a force against the first member by a tool received through the tool receiving aperture, the first member being configured to simultaneously disengage all of the plurality of racks from the plurality of pins in response to the movement of the first member. 2. The rekeyable lock cylinder as claimed in claim 1, wherein the first member is coupled to the plurality of racks by a coupling configured to facilitate a linear movement of the plurality of racks. 3. The rekeyable lock cylinder as claimed in claim 1, wherein the first member is spaced apart from the longitudinal axis of the cylinder body and is movable between a normal position and a rekeying position, wherein the plurality of pins and the corresponding plurality of racks are movable to effect rekeying in response to movement of the first member from the normal position to the rekeying position. 4. The rekeyable lock cylinder as claimed in claim 1, wherein the first member is disposed adjacent to the plug assembly, the first member being moveable between a normal position and a rekeying position, wherein the plurality of racks disengage from the plurality of pins in response to movement of the first member from the normal position to the rekeying position and the plurality of racks engage the plurality of pins in response to movement of the first member from the rekeying position to the normal position. 5. The rekeyable lock cylinder as claimed in claim 1, wherein each pin of the plurality of pins includes at least one groove and each corresponding rack of the corresponding plurality of racks includes at least one pin-engaging tooth for engaging the at least one groove. 6. A rekeyable lock cylinder, comprising: a cylinder body with a longitudinal axis; a locking bar disposed in the cylinder body for movement transverse to, and rotationally about, the longitudinal axis; a plug assembly disposed in the cylinder body and being rotatable about the longitudinal axis, the plug assembly having a lock face with a tool receiving aperture; a plurality of pins and a corresponding plurality of racks disposed in the plug assembly, the plurality of racks being configured to be engaged with the plurality of pins; and a first member coupled to the plurality of racks, the first member being configured to be moved in response to application of a force by a tool received through the tool receiving aperture to facilitate a movement of at least one of the plurality of pins and at least one of the corresponding plurality of racks to effect rekeying to a new key. 7. The rekeyable lock cylinder as claimed in claim 6, wherein the first member is detachably coupled to the plurality of racks by a coupling configured to facilitate a linear movement of the plurality of racks. 8. The rekeyable lock cylinder as claimed in claim 6, wherein the first member is moveable in a direction generally along the longitudinal axis of the cylinder body between a normal position and a rekeying position, wherein the plurality of pins and the corresponding plurality of racks are movable to effect rekeying in response to movement of the first member from the normal position to the rekeying position. 9. The rekeyable lock cylinder as claimed in claim 6, wherein each pin of the plurality of pins includes at least one groove and each corresponding rack of the corresponding plurality of racks includes at least one pin-engaging tooth for engaging the at least one groove. 10. A rekeyable lock cylinder, comprising: a cylinder body with a longitudinal axis and having a locking-bar engaging groove; a locking bar disposed in the cylinder body for movement transverse to, and rotationally about, the longitudinal axis, the locking bar being configured to be selectively received in the locking-bar engaging groove of the cylinder body; a plug assembly disposed in the cylinder body and being rotatable relative to the cylinder body, the plug assembly having a lock face with a key slot and a tool receiving aperture; a plurality of pins and a corresponding plurality of racks disposed in the plug assembly, the plurality of racks being configured for engagement with the plurality of pins, and wherein a coupling couples the plurality of pins to the locking bar; and a first member coupled to the plurality of racks, the first member being moveable in response to application of a force against the first member by a tool received through the tool receiving aperture, the first member being configured-to simultaneously disengage all of the plurality of racks from the plurality of pins in response to the movement of the first member. 11. The rekeyable lock cylinder as claimed in claim 10, wherein the first member is disposed adjacent to the plug assembly, the first member being moveable between a normal position and a rekeying position, wherein the plurality of racks disengage from the plurality of pins in response to movement of the first member from the normal position to the rekeying position and the plurality of racks engage the plurality of pins in response to movement of the first member from the rekeying position to the normal position. 12. The rekeyable lock cylinder as claimed in claim 10, wherein each pin of the plurality of pins includes at least one groove and each corresponding rack of the corresponding plurality of racks includes at least one pin-engaging tooth for engaging the at least one groove. 13. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plurality of pins disposed in the cylinder body; and a carrier sub-assembly disposed in the cylinder body and including a carrier and a plurality of racks for engaging the pins, the carrier sub-assembly being moveable parallel to the longitudinal axis of the cylinder body between a first position and a second position to disengage the racks from the pins. 14. The lock cylinder as claimed in claim 13 further comprising a plug assembly containing the plurality of pins, the carrier sub-assembly containing the plurality of racks for engaging the plurality of pins. 15. The lock cylinder as claimed in claim 13 wherein the racks disengage from the pins in response to movement of the carrier from the first position to the second position and engage the pins in response to movement of the carrier from the second position to the first position, the lock cylinder being in a rekeyable condition when the carrier is in the second position. 16. The lock cylinder as claimed in claim 13 wherein each pin includes at least one gear tooth. 17. The lock cylinder as claimed in claim 13 wherein each of the plurality of pins includes a hollow cup-shaped body. 18. The lock cylinder as claimed in claim 13 further comprising a plurality of springs, the plurality of springs having a non-constant diameter. 19. The lock cylinder as claimed in claim 13 wherein the pins are cup-shaped and configured to receive the plurality of springs. 20. The lock cylinder as claimed in claim 13 wherein a spring catch for retaining the carrier in the second position. 21. The lock cylinder as claimed in claim 20 wherein the spring catch includes a U-shaped center portion and a pair of arms extending from the center portion. 22. The lock cylinder as claimed in claim 21 wherein the carrier sub-assembly further includes a spring-catch recess, the recess including a guide configured to receive the U-shaped center portion of the spring catch and a pair of anchors configured to engage the pair of arms. 23. The lock cylinder as claimed in claim 20 wherein the cylinder body includes a groove for receiving the spring catch when the carrier sub-assembly is in the second position. 24. The lock cylinder as claimed in claim 20 wherein the spring catch moves from an engaging position, wherein the spring catch retains the carrier sub-assembly in the second position, to a disengaged position in response to rotation of the carrier sub-assembly in the cylinder body. 25. The lock cylinder as claimed in claim 13 wherein each rack includes at least one locking bar-receiving groove and a plurality of pin-engaging gear teeth and each pin includes at least one gear tooth for engaging the rack between two of the plurality of pin-engaging gear teeth. 26. The lock cylinder as claimed in claim 13 wherein the carrier sub-assembly further includes a carrier having a plurality of rack-receiving slots and a locking bar recess. 27. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plug assembly including a plurality of racks selectively engageable with a plurality of pins; and means for changing the lock cylinder between a rekeying condition and an operating condition, the means for changing being configured to move the plurality of racks in the cylinder body parallel to, transversely to, and rotationally about the longitudinal axis of the cylinder body to disengage the racks from the pins. 28. The lock cylinder as claimed in claim 27 wherein the means for changing includes means for preventing rotational movement of the racks and pins about the longitudinal axis. 29. The lock cylinder as claimed in claim 28 wherein the means for preventing includes means for locking the plug assembly against rotation in the cylinder body. 30. The lock cylinder as claimed in claim 27 wherein the means for changing includes a carrier movable between a first position and a second position and means for biasing the carrier toward the first position. 31. The lock cylinder as claimed in claim 30 wherein the plug assembly includes the carrier configured to engage the plurality of racks, the racks being engaged with the pins when the carrier is in the first position and disengaged from the pins when the carrier is in the second position. 32. The lock cylinder as claimed in claim 30 wherein the means for changing includes means for engaging the cylinder body to retain the carrier in the second position. 33. The lock cylinder as claimed in claim 32 wherein the means for engaging is configured to disengage from the cylinder body in response to rotation of the plug assembly in the cylinder body. 34. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plurality of pins disposed in the cylinder body; and a plurality of racks for engaging the plurality of pins, the racks being configured to disengage from the pins in response to movement in the cylinder body parallel to, transversely to, and rotationally about the longitudinal axis. 35. The lock cylinder as claimed in claim 34 further including a plug body having a locking bar movable between a locked position and an unlocked position, wherein the plug body is rotatable in the cylinder body to a rekeying position when the locking bar is in the unlocked position and the racks can be disengaged from the pins in the rekeying position. 36. The lock cylinder as claimed in claim 34 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks. 37. The lock cylinder as claimed in claim 36 wherein a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter. 38. The lock cylinder as claimed in claim 37 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring. 39. A rekeyable lock cylinder comprising: a plug body having a longitudinal axis and a plurality of pins; and a plurality of racks disposed to engage the pins, the racks being disengaged from the pins in response to movement of the racks transversely to, rotationally about and parallel to the longitudinal axis. 40. The lock cylinder as claimed in claim 39 wherein a carrier having a plurality of slots for receiving the racks, the carrier being movable longitudinally between a first position and a second position, the racks being engaged with the pins in the first position and disengaged from the pins in the second position. 41. The lack cylinder as claimed in claim 40 wherein the carrier is rotated about the longitudinal axis from a home position to the first position and longitudinally from the first position to the second position. 42. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plurality of pins; and a plurality of racks for engaging the plurality of pins, the racks being movable parallel to, transversely to, and rotationally about the longitudinal axis to disengage from the pins. 43. The lock cylinder as claimed in claim 42 wherein a carrier configured to carry the plurality of racks and a plug with a face having a keyway and a rekeying tool-receiving aperture, the carrier being movable parallel to the longitudinal axis in response to insertion of a rekeying tool into the rekeying tool-receiving aperture. 44. The lock cylinder as claimed in claim 43 wherein a locking bar movable between a locking position and an unlocking position, wherein the carrier is rotatable in the cylinder body to a rekeying position when the locking bar is in an unlocking position and is movable longitudinally when the carrier is in the rekeying position. 45. The lock cylinder as claimed in claim 42 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks. 46. The lack cylinder as claimed in claim 42 wherein a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter. 47. The lock cylinder as claimed in claim 46 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring. 48. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plug body disposed in the cylinder body and having a face with a keyway and a tool-receiving aperture; a carrier disposed in the plug body; and a first valid key configured to be received in the keyway, the plug body being rotatable between a first position and a rekeying position when the first valid key is disposed in the keyway, the carrier moving longitudinally in response to the insertion of a rekeying tool into the tool-receiving aperture, the first valid key being removable from the plug body after the tool is inserted in the tool-receiving aperture. 49. A lock cylinder having a keyway, comprising: a first plurality of guide channels; a plurality of cup-shaped pins movably disposed within the first plurality of guide channels, each cup-shaped pin of the plurality of cup-shaped pins being located to extend across the keyway, and each cup-shaped pin of the plurality of cup-shaped pins having an engagement protrusion, the first plurality of guide channels being configured to conform to the shape of the plurality of cup-shaped pins to allow movement of the plurality of cup-shaped pins in a first direction toward the keyway while restraining movement in all directions transverse to the first direction; a plurality of biasing springs positioned to bias the plurality of cup-shaped pins in the first direction toward the keyway; a second plurality of guide channels; and a plurality of racks movably disposed in the second plurality of guide channels, each rack of the plurality of racks having at least one engagement groove to selectively receive the engagement protrusion of a respective cup-shaped pin. 50. The lock cylinder as claimed in claim 49, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and each biasing spring of the plurality of biasing springs has a non-constant diameter. 51. The lock cylinder as claimed in claim 49, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and wherein each biasing spring of the plurality of biasing springs has a coil portion of reduced diameter that engages the depression. 52. The lock cylinder as claimed in claim 49, wherein each guide channel of the first plurality of guide channels has a sidewall opening defining a pair of retention supports, and wherein the pair of retention supports restrains movement of a respective cup-shaped pin in a respective guide channel in a direction transverse to the keyway. 53. The lock cylinder as claimed in claim 49, wherein each guide channel of the first plurality of guide channels is formed as a cylinder having an axial sidewall slot. 54. The lock cylinder as claimed in claim 49, wherein a cylinder body, and a locking bar disposed within the cylinder body, and wherein each rack of the plurality of racks has at least one locking bar groove to selectively receive the locking bar. 55. The lock cylinder as claimed in claim 49, wherein each guide channel of the first plurality of guide channels is configured to restrain movement of a respective cup-shaped pin in a respective guide channel in directions transverse to the keyway toward and away from the plurality of racks. 56. A lock cylinder, comprising: a cylinder body; a plug body rotatably disposed in the cylinder body, the plug body having a keyway; a plurality of guide channels, each guide channel of the plurality of guide channels having a sidewall opening defining a pair of retention supports; a plurality of cup-shaped pins movably coupled to the plug body, each cup-shaped pin of the plurality of cup-shaped pins being located in a respective guide channel of the plurality of guide channels, wherein each pair of retention supports cooperates with its respective guide channel to restrain movement of a respective cup-shaped pin in the respective guide channel in a direction transverse to the keyway, and each cup-shaped pin of the plurality of cup-shaped pins has an engagement protrusion that extends into the sidewall opening of the respective guide channel; and a plurality of racks movably coupled to the plug body, each rack of the plurality of racks having at least one engagement groove to selectively receive the engagement protrusion of the respective cup-shaped pin. 57. The lock cylinder as claimed in claim 56, wherein each guide channel of the plurality of guide channels is a circular cylinder having an axial sidewall slot. 58. The lock cylinder as claimed in claim 56, wherein a plurality of biasing springs, and each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, each biasing spring biasing a respective cup-shaped pin toward the keyway. 59. The lock cylinder as claimed in claim 58, wherein each biasing spring of the plurality of biasing springs has a non-constant diameter. 60. The lock cylinder as claimed in claim 58, wherein each biasing spring of the plurality of biasing springs has a coil portion of reduced diameter at each end of the biasing spring. 61. The lock cylinder as claimed in claim 56, as claimed in a locking bar disposed within the cylinder body, and wherein each rack of the plurality of racks has at least one locking bar groove to selectively receive the locking bar. 62. A lock cylinder, comprising: a cylinder body; a plug body rotatably disposed in the cylinder body, the plug body having a keyway; a plurality of guide channels, each guide channel of the plurality of guide channels having a slotted sidewall opening; a plurality of cup-shaped pins movably disposed within the plurality of guide channels, each guide channel of the plurality of guide channels being configured to conform to the shape of a respective cup-shaped pin of the plurality of cup-shaped pins to restrain movement of the respective cup-shaped pin in the respective guide channel in a direction transverse to the keyway, and each cup-shaped pin of the plurality of cup-shaped pins having an engagement protrusion that extends into the slotted sidewall opening of the respective guide channel; and a plurality of racks movably coupled to the plug body, each rack of the plurality of racks having at least one engagement groove to selectively receive the engagement protrusion of the respective cup-shaped pin. 63. The lock cylinder as claimed in claim 62, wherein a plurality of biasing springs positioned to bias the plurality of cup-shaped pins in a direction toward the keyway, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and each biasing spring of the plurality of biasing springs has a non-constant diameter. 64. The lock cylinder as claimed in claim 62, wherein a plurality of biasing springs positioned to bias the plurality of cup-shaped pins in a direction toward the keyway, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and wherein each biasing spring of the plurality of biasing springs has a coil portion of reduced diameter that engages the depression. 65. The lock cylinder as claimed in claim 62, wherein each slotted sidewall opening defines a pair of retention supports, and wherein the pair of retention supports restrains movement of a respective cup-shaped pin in a respective guide channel in a direction transverse to the keyway. 66. The lock cylinder as claimed in claim 62, wherein each guide channel of the plurality of guide channels is configured to conform to the shape of a respective cup-shaped pin of the plurality of cup-shaped pins to restrain movement of the respective cup-shaped pin in the respective guide channel in all directions transverse to the keyway. 67. A rekeyable lock cylinder comprising: a lock cylinder housing; a plug body disposed in the lock cylinder housing and having a longitudinal axis, the plug body being rotatable about the longitudinal axis between a home position and a rekeying position; at least one rack disposed in the plug body; and at least one pin disposed in the plug body, the at least one rack being configured to engage the at least one pin, one of the at least one rack and the at least one pin being moveable relative to the other parallel to the longitudinal axis from a first position to a second position to move the one of the at least one rack and the at least one pin out of contact with the other and from the second position to the first position to move the one of the at least one rack and the at least one pin into contact with the other. 68. The lock cylinder as claimed in claim 67 wherein the plug body comprises a carrier moveable parallel to the longitudinal axis, the movement of the carrier moving the one of the at least one rack and the at least one pin out of contact with the other. 69. The lock cylinder as claimed in claim 67 wherein a plug face having a rekeying opening configured to receive a rekeying tool. 70. The lock cylinder as claimed in claim 67 wherein plug body includes a rekeying tool opening and a rekeying tool, the rekeying tool opening includes a first opening portion and a second opening portion, and the rekeying tool includes a first tool portion disposed in the first opening portion and a second tool portion disposed in the second opening portion. 71. The lock cylinder as claimed in claim 68 wherein the at least one rack disengages from the at least one pin in response to movement of the carrier from the first position to the second position and engages the at least one pin in response to movement of the carrier from the second position to the first position, the lock cylinder being in a rekeyable condition when the carrier is in the second position. 72. The lock cylinder as claimed in claim 67 wherein the at least one pin includes a hollow cup-shaped body. 73. The lock cylinder as claimed in claim 72 wherein the at least one pin is configured to receive a spring. 74. The lock cylinder as claimed in claim 67 wherein means for retaining the one of the at least one rack and the at least one pin in the second position. 75. The lock cylinder as claimed in claim 74 wherein the means for retaining includes a spring catch. 76. The lock cylinder as claimed in claim 74 wherein the means for retaining further includes a recess in the cylinder housing for receiving a spring catch when the one of the at least one rack and the at least one pin is in the second position. 77. The lock cylinder as claimed in claim 74 wherein the means for retaining is configured to release the one of the at least one rack and the at least one pin to return to the first position in response to rotation of the plug body in the cylinder housing. 78. The lock cylinder as claimed in claim 67 wherein the at least one rack includes at least one locking bar-receiving groove and a plurality of pin-engaging gear teeth and the at least one pin includes at least one gear tooth for engaging the at least one rack between two of the plurality of pin-engaging gear teeth. 79. The lock cylinder as claimed in claim 67 wherein the plug body further includes a body portion and a carrier, the at least one rack being disposed in the carrier and the at least one pin disposed in the body portion, the carrier being movable longitudinally relative to the body portion to move the at least one rack and the at least one pin into and out of contact. 80. The lock cylinder as claimed in claim 67 wherein the at least one rack is movable in a direction transverse to the longitudinal axis in the first position and is restricted from such transverse movement in the second position. 81. The lock cylinder as claimed in claim 69 wherein a rekeying tool having an integral push button extending through the plug face. 82. A rekeyable lock cylinder comprising: a lock cylinder housing having a longitudinal axis; a plug body disposed in the lock cylinder housing for rotation between a home position and a rekeying position; a carrier disposed in the lock cylinder housing, the carrier being movable longitudinally relative to the plug body; a plurality of pins disposed in the plug body; a plurality of racks disposed in the carrier for engaging the plurality of pins, the racks being movable between a first position and a second position relative to the plurality of pins, the racks being movable by the pins upon insertion of a first valid key into the plug body when the racks are in the first position; and means for preventing movement of the racks transverse to the longitudinal axis in the second position, the lock cylinder being, in a rekeyable condition in the second position. 83. The lock cylinder as claimed in claim 82 wherein a locking bar movable between a locking condition and an unlocking condition, wherein the plug body is rotatable in the cylinder housing to the rekeying position when the locking bar is in the unlocking condition and the racks can be disengaged from the pins in the rekeying position. 84. The lock cylinder as claimed in claim 82 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks. 85. The lock cylinder as claimed in claim 84 wherein a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter. 86. The lock cylinder as claimed in claim 85 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring. 87. A rekeyable lock cylinder comprising: a lock cylinder housing; a plug body having a longitudinal axis and a plurality of pins, the plug body being rotatable in the lock cylinder housing between a home position and a rekeying position; and a plurality of racks disposed to engage the plurality of pins, the plurality of racks being moveable parallel to the longitudinal axis to disengage from, and reengage, the plurality of pins, and transversely to the longitudinal axis and rotationally about the longitudinal axis in engagement with the plurality of pins. 88. The lock cylinder as claimed in claim 87 wherein the plug body further includes a carrier having a plurality of slots for receiving the racks, the carrier being movable longitudinally between a first position and a second position, the plurality of racks being engaged with the plurality of pins in the first position and disengaged from the plurality of pins in the second position. 89. The lock cylinder as claimed in claim 88 wherein the carrier is rotated about the longitudinal axis from the home position to the first position and longitudinally from the first position to the second position. 90. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a carrier disposed in the cylinder body for movement parallel to and rotationally about the longitudinal axis; a plurality of pins disposed in the cylinder body; and a plurality of racks disposed in the cylinder body for engaging the plurality of pins, the racks being movable longitudinally to disengage from the pins in response to movement of a rekeying tool. 91. The lock cylinder as claimed in claim 90 wherein the carrier is configured to carry the plurality of racks. 92. The lock cylinder as claimed in claim 91 wherein a locking bar movable between a locking position and an unlocking position, wherein the carrier is rotatable in the cylinder body to a rekeying position when the locking bar is in an unlocking position. 93. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plug body disposed for rotational movement in the cylinder body and having a face with a keyway and a tool-receiving aperture; a carrier disposed adjacent the plug body; and a first valid key configured to be received in the keyway, the plug body being rotatable between a first position and rekeying position when the first valid key is disposed in the keyway, the carrier moving longitudinally in response to the movement of a rekeying tool in the tool-receiving aperture, the first valid key being removable from the plug body after the tool is inserted in the tool-receiving aperture. 94. A rekeyable lock cylinder comprising: a cylinder body with a longitudinal axis; a plug body disposed in the cylinder body for rotational movement between a home position and a second position, the plug body including a plug face with a keyway and a tool-receiving aperture; a carrier disposed in the cylinder body adjacent the plug body for rotation with the plug body between the home position and the second position, the carrier being moveable longitudinally between an initial position relative to the plug body and a rekeying position when the plug body is in the second position; means coupled to the carrier for retaining the carrier in the rekeying position; a plurality of pins disposed in the plug body for transverse movement in response to insertion of a first valid key in the keyway; a plurality of racks disposed in the carrier for longitudinal movement with the carrier in response to movement of a rekeying tool in the tool-receiving aperture when the plug body is in the second position; and means for retaining the racks in a common transverse alignment relative to the plug body when the carrier is in the rekeying position, the first valid key being removable when the carrier is in the rekeying position and obsoleted in response to rotation of the plug body to the home position with a second valid key in the keyway. 95. The lock cylinder as claimed in claim 94 wherein the rekeying tool includes an integral push button extending at least partially outwardly from the plug face. 96. The lock cylinder as claimed in claim 95 wherein the plug body includes means to obsolete the first valid key in response to partial movement of the plug body from the second position to the home position with the second valid key in the

Full Text

The present application is a divisional application out of Indian Patent application number 628/DELNP/2005.
The present invention relates to a rekeyable lock cylinder and a method of keying the same.
The present invention relates generally to lock cylinders and particularly to lock cylinders that can be rekeyed. More particularly, the invention relates to lock cylinders that can be rekeyed without the use of a master key.
Background of the Invention
When rekeying a cylinder using 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.
The present invention overcomes these and other disadvantages of conventional lock cylinders. The lock cylinder of the present invention operates in a transparent way that presents the familiar experience of inserting a key and rotating the key in the lock cylinder, as with current cylinders. However, in the present invention, that same familiar experience is used'to rekey the lock cylinder. Thus, the user does not require any special knowledge, training, or tools to rekey the lock cylinder of the present invention.
Summary of the Invention
The. present invention provides a simple means for "teaching" a lock cylinder a new key while obsoleting old keys. According to the present invention, a rekeyable lock cylinder comprises a cylinder body with a longitudinal axis and a plug assembly disposed in the cylinder body. The plug assembly includes a plug body and a carrier sub-assembly disposed adjacent the plug body. The plug assembly further includes a plurality of pins. The carrier sub-assembly is
moveable parallel to the longitudinal axis of the cylinder body and includes a plurality of racks for engaging the pins. The racks disengage from the pins in response to movement of the carrier in a first direction and engage the pins in response to movement of the carrier in a second direction. The lock cylinder is in a rekeyable condition when the racks are disengaged from the pins.
The present invention further includes a novel method of rekeying a rekeyable lock cylinder. According to the invention, a method of rekeying a rekeyable lock cylinder comprises the steps of providing a lock cylinder with a plug body and a lock face having a keyway and a tool-receiving aperture, inserting a first valid key in the keyway, rotating the plug body to a first position, inserting a tool in the tool-receiving aperture, removing the first valid key from the keyway, inserting a second valid key in the keyway, and rotating the plug body away from the first position. The step of inserting the tool includes the step of moving a rack out of engagement with a pin.
According to one aspect of the invention, the lock cylinder includes a carrier that is moveable parallel to a longitudinal axis of the lock cylinder and the step of inserting the tool includes the step of moving the carrier.
Other features and advantages will become apparent from the following description when viewed in accordance with the accompanying drawings and appended claims.
Brief Description of the Drawings
Figure 1 illustrates a lock cylinder according to the present invention. ' Figure 2 is an exploded view of the lock cylinder of Figure 1.
Figure 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.
Figure 4 is a top plan view of the plug assembly of Figure 3.
Figure 5 is a partially broken away side view of the plug assembly of Figure 3.
Figure 6 is a partially exploded view of the plug assembly of Figure 3.Figure-7:-is ejection vJew4hrough^heplug~assembl-y-otFJgure^3-anda
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.
Figure 8 is a perspective view of the plug assembly of Figure 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. Figure 9 is a top plan view of the plug assembly of Figure 8. Figure 10 is a partially broken away side view of the plug assembly of Figure 8.
Figure 11 is a partially exploded view of the plug assembly of Figure 8. Figure 12 is a section view through the plug assembly of Figure 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.
Figure 13 is a perspective view similar to Figure 8 but with the carrier assembly moved axially to a rekeying position.
Figure 14 is a top plan view of the plug assembly of Figure 13. Figures 15a-15e are various views of a cylinder body for use in the present invention.
Figures 16a-16f are various views of the cylinder plug body for use in the present invention.
Figures 17a-17f are various view of the carrier for use in the present invention.
Figures 18a-18b are views of a rack for use in the present invention. Figures 19a-19b are views of a spring catch for use in the present invention. Figures 20a-20b are views of a pin for use in the present invention. Figures 21a-21b are views of a locking bar for use in the present invention. Figures 22a-22d are views of a spring retaining cap for use in the present invention.
Figure 23 is an exploded perspective view of an alternative embodiment of the invention.
.Figures, 24a-24e are views of alternative embodiment of the lock cylinder
housing.

Figure 25 is a transverse section view taken through an alternative embodiment of the present invention.
Figures 26a-26b are views of an alternative embodiment of the spring catch. Figures 27a-27e/are views of an alternative embodiment of the carrier. Figures 28a-28b are views of an alternative embodiment of the pin. Figures 29a-29b are views of an alternative embodiment of the rack. Figures 30a-30b are views of an alternative embodiment of the locking bar.
Detailed Description of the Drawings
A lock cylinder 10 according to the present invention is illustrated in Figure 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 Figure 1, the plug assembly 14 is in the home position relative to the cylinder body 12.
The lock cylinder body 12, as seen in Figures 15a-15e, 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 (Figure 2).
The plug assembly 14 includes a plug body 40, a carrier sub-assembly 42 and a plurality of spring-loaded pins 38 (Figures 2 and 20a-20b). The plug body 40, illustrated in Figures 16a-16f, 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 (Figure 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 body12.

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 (Figures 2 and 22a-22d). 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 (Figure 2) extends radially inwardly from opposite the first planar surface 72.
The carrier sub-assembly 42 (Figures 2, 6 and 10) includes a carrier 90 (Figures 17a-17e), a plurality of racks 92 (Figures 18a-18b), a spring catch 96 (Figures 19a-19b), a spring-loaded locking bar 94 (Figures 21a-21b), and a return spring 98 (Figure 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 surface102 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 (Figure 17c) 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 semicircular g>oove 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.
Each spring-loaded pin 38 includes a pin 113 and a biasing spring 115. The
pins 113, illustrated in Figures 20a-20b, are generally cylindrical with annular
gear teeth 114 and a central longitudinal bore 116 for receiving biasing springs
115 (Figure 2) The Rack 92, illustrated in figure 18a-18b, 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 Figures 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 Figure 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.
The spring-loaded locking bar 94, illustrated in Figures 21a-22b, 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 Figure 12. The spring-retaining cap 82, illustrated in Figures 22a-22d, 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 Figures 7 and 12. A plurality of spring alignment tips 146 extend from the lower surface 144 to engage the springs 44?r 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 (Figures 16e-16f).
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 Figure 3. The plug assembly 14 is placed in the lockcylindert>ody 12 and the tetainer-16-isiiisposed ir the slots6& 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.

The properly keyed lock cylinder 10, without the key 160 inserted, is illustrated in Figures 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 Figure 4. In addition, the bullet-shaped features 78
are misaligned with the roeooges 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.
The internal configuration of a lock cylinder 10 with the valid key 160 inserted therein at the home position is illustrated in Figures 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 Figures 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 Irove 111 in the racks 92, as illustrated in Figure 12, allowing the racks 92, and the carrier 90, to move parallel to the longitudinal axis of the lock cylinder 10.
To rekey the lock cylinder 10, the valid key 160 is inserted into the keyway 52, as illustrated in Figures 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 Figure 14. The valid
vMdkeyJs 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.
An alternative embodiment 210 of the invention is illustrated in Figures 23-29. The alternative embodiment includes the same components, as illustrated in Figure 23, but several of the components have been modified. Functionally, both embodiments are the same.
The modified housing 212, illustrated in Figures 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.
The modified pin biasing springs 226, illustrated in Figures 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.
The modified spring catch 228, illustrated in Figures 23 and 26, includes a central U-shaped portion 230 and a pair of arms 232 extending from the U-shaped portion 230.
The modified carrier 236, illustrated in Figures 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 permitting4t to-move radially-outwardly4o-engage-tb.e
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.
The modified pins 244, illustrated in Figures 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.
The modified racks 250, illustrated in Figures 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.
The modified locking bar 252, illustrated in Figures 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.
The above-described 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.

We claim:
1. A rekeyable lock cylinder, comprising:
a cylinder body with a longitudinal axis;
a locking bar disposed in the cylinder body for movement transverse to, and rotationally about, the longitudinal axis;
a plug assembly disposed in the cylinder body and being rotatable between a first position and a second position, the plug assembly having a lock face with a tool receiving aperture;
a plurality of pins and a corresponding plurality of racks disposed in the plug assembly, the plurality of racks being selectively engageable with the plurality of pins; and
a first member coupled to the plurality of racks, the first member being moveable in response to application of a force against the first member by a tool received through the tool receiving aperture, the first member being configured to simultaneously disengage all of the plurality of racks from the plurality of pins in response to the movement of the first member.
2. The rekeyable lock cylinder as claimed in claim 1, wherein the first member is coupled to the plurality of racks by a coupling configured to facilitate a linear movement of the plurality of racks.
3. The rekeyable lock cylinder as claimed in claim 1, wherein the first member is spaced apart from the longitudinal axis of the cylinder body and is movable between a normal position and a rekeying position, wherein the plurality of pins
and the corresponding plurality of racks are movable to effect rekeying in response to movement of the first member from the normal position to the rekeying position.
4. The rekeyable lock cylinder as claimed in claim 1, wherein the first member is disposed adjacent to the plug assembly, the first member being moveable between a normal position and a rekeying position, wherein the plurality of racks disengage from the plurality of pins in response to movement of the first member from the normal position to the rekeying position and the plurality of racks engage the plurality of pins in response to movement of the first member from the rekeying position to the normal position.
5. The rekeyable lock cylinder as claimed in claim 1, wherein each pin of the plurality of pins includes at least one groove and each corresponding rack of the corresponding plurality of racks includes at least one pin-engaging tooth for engaging the at least one groove.
6. A rekeyable lock cylinder, comprising:
a cylinder body with a longitudinal axis;
a locking bar disposed in the cylinder body for movement transverse to, and rotationally about, the longitudinal axis; a plug assembly disposed in the cylinder body and being rotatable about the longitudinal axis, the plug assembly having a lock face with a tool receiving aperture;
a plurality of pins and a corresponding plurality of racks disposed in the plug assembly,
the plurality of racks being configured to be engaged with the plurality of pins; and
a first member coupled to the plurality of racks, the first member being configured to be moved in response to application of a force by a tool received through the tool receiving aperture to facilitate a movement of at least one of the plurality of pins and at least one of the corresponding plurality of racks to effect rekeying to a new key.
7. The rekeyable lock cylinder as claimed in claim 6, wherein the first member is detachably coupled to the plurality of racks by a coupling configured to facilitate a linear movement of the plurality of racks.
8. The rekeyable lock cylinder as claimed in claim 6, wherein the first member is moveable in a direction generally along the longitudinal axis of the cylinder body between a normal position and a rekeying position, wherein the plurality of pins and the corresponding plurality of racks are movable to effect rekeying in response to movement of the first member from the normal position to the rekeying position.
9. The rekeyable lock cylinder as claimed in claim 6, wherein each pin of the plurality of pins includes at least one groove and each corresponding rack of the corresponding plurality of racks includes at least one pin-engaging tooth for engaging the at least one groove.
10. A rekeyable lock cylinder, comprising:
a cylinder body with a longitudinal axis and having a locking-bar engaging groove;
a locking bar disposed in the cylinder body for movement transverse to,
and rotationally about, the longitudinal axis, the locking bar being configured to be selectively received in the locking-bar engaging groove of the cylinder body;
a plug assembly disposed in the cylinder body and being rotatable relative to the cylinder body, the plug assembly having a lock face with a key slot and a tool receiving aperture;
a plurality of pins and a corresponding plurality of racks disposed in the plug assembly, the plurality of racks being configured for engagement with the plurality of pins, and wherein a coupling couples the plurality of pins to the locking bar; and
a first member coupled to the plurality of racks, the first member being moveable in response to application of a force against the first member by a tool received through the tool receiving aperture, the first member being configured-to simultaneously disengage all of the plurality of racks from the plurality of pins in response to the movement of the first member.
11. The rekeyable lock cylinder as claimed in claim 10, wherein the first member is disposed adjacent to the plug assembly, the first member being moveable between a normal position and a rekeying position, wherein the plurality of racks disengage from the plurality of pins in response to movement of the first member from the normal position to the rekeying position and the plurality of racks engage the plurality of pins in response to movement of the first member from the rekeying position to the normal position.
12. The rekeyable lock cylinder as claimed in claim 10, wherein each pin of the plurality of pins includes at least one groove and each corresponding rack of the corresponding plurality of racks includes at least one pin-engaging tooth for engaging the at least one groove.
13. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a plurality of pins disposed in the cylinder body; and
a carrier sub-assembly disposed in the cylinder body and including a carrier and a plurality of racks for engaging the pins, the carrier sub-assembly being moveable parallel to the longitudinal axis of the cylinder body between a first position and a second position to disengage the racks from the pins.
14. The lock cylinder as claimed in claim 13 further comprising a plug assembly containing the plurality of pins, the carrier sub-assembly containing the plurality of racks for engaging the plurality of pins.
15. The lock cylinder as claimed in claim 13 wherein the racks disengage from the pins in response to movement of the carrier from the first position to the second position and engage the pins in response to movement of the carrier from the second position to the first position, the lock cylinder being in a rekeyable condition when the carrier is in the second position.
16. The lock cylinder as claimed in claim 13 wherein each pin includes at least one gear tooth.
17. The lock cylinder as claimed in claim 13 wherein each of the plurality of pins includes a hollow cup-shaped body.
18. The lock cylinder as claimed in claim 13 further comprising a plurality of springs, the plurality of springs having a non-constant diameter.
19. The lock cylinder as claimed in claim 13 wherein the pins are cup-shaped and configured to receive the plurality of springs.
20. The lock cylinder as claimed in claim 13 wherein a spring catch for retaining the carrier in the second position.
21. The lock cylinder as claimed in claim 20 wherein the spring catch includes a U-shaped center portion and a pair of arms extending from the center portion.
22. The lock cylinder as claimed in claim 21 wherein the carrier sub-assembly further includes a spring-catch recess, the recess including a guide configured to receive the U-shaped center portion of the spring catch and a pair of anchors configured to engage the pair of arms.
23. The lock cylinder as claimed in claim 20 wherein the cylinder body includes a groove for receiving the spring catch when the carrier sub-assembly is in the second position.
24. The lock cylinder as claimed in claim 20 wherein the spring catch moves from an engaging position, wherein the spring catch retains the carrier sub-assembly in the second position, to a disengaged position in response to rotation of the carrier sub-assembly in the cylinder body.
25. The lock cylinder as claimed in claim 13 wherein each rack includes at least one locking bar-receiving groove and a plurality of pin-engaging gear teeth and each pin includes at least one gear tooth for engaging the rack between two of the plurality of pin-engaging gear teeth.
26. The lock cylinder as claimed in claim 13 wherein the carrier sub-assembly further includes a carrier having a plurality of rack-receiving slots and a locking bar recess.
27. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a plug assembly including a plurality of racks selectively engageable with a plurality of pins; and
means for changing the lock cylinder between a rekeying condition and an operating condition, the means for changing being configured to move the plurality of racks in the cylinder body parallel to, transversely to, and rotationally about the longitudinal axis of the cylinder body to disengage the racks from the pins.
28. The lock cylinder as claimed in claim 27 wherein the means for changing includes means for preventing rotational movement of the racks and pins about the longitudinal axis.
29. The lock cylinder as claimed in claim 28 wherein the means for preventing includes means for locking the plug assembly against rotation in the cylinder body.
30. The lock cylinder as claimed in claim 27 wherein the means for changing includes a carrier movable between a first position and a second position and means for biasing the carrier toward the first position.
31. The lock cylinder as claimed in claim 30 wherein the plug assembly includes the carrier configured to engage the plurality of racks, the racks being engaged with the pins when the carrier is in the first position and disengaged from the pins when the carrier is in the second position.
32. The lock cylinder as claimed in claim 30 wherein the means for changing includes means for engaging the cylinder body to retain the carrier in the second position.
33. The lock cylinder as claimed in claim 32 wherein the means for engaging is configured to disengage from the cylinder body in response to rotation of the plug assembly in the cylinder body.
34. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a plurality of pins disposed in the cylinder body; and
a plurality of racks for engaging the plurality of pins, the racks being configured to disengage from the pins in response to movement in the cylinder body parallel to, transversely to, and rotationally about the longitudinal axis.
35. The lock cylinder as claimed in claim 34 further including a plug body having a locking bar movable between a locked position and an unlocked position, wherein the plug body is rotatable in the cylinder body to a rekeying position when the locking bar is in the unlocked position and the racks can be disengaged from the pins in the rekeying position.
36. The lock cylinder as claimed in claim 34 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks.
37. The lock cylinder as claimed in claim 36 wherein a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter.
38. The lock cylinder as claimed in claim 37 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring.
39. A rekeyable lock cylinder comprising:
a plug body having a longitudinal axis and a plurality of pins; and
a plurality of racks disposed to engage the pins, the racks being disengaged from the pins in response to movement of the racks transversely to, rotationally about and parallel to the longitudinal axis.
40. The lock cylinder as claimed in claim 39 wherein a carrier having a plurality of slots for receiving the racks, the carrier being movable longitudinally between a first position and a second position, the racks being engaged with the pins in the first position and disengaged from the pins in the second position.
41. The lack cylinder as claimed in claim 40 wherein the carrier is rotated about the longitudinal axis from a home position to the first position and longitudinally from the first position to the second position.
42. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a plurality of pins; and
a plurality of racks for engaging the plurality of pins, the racks being movable parallel to, transversely to, and rotationally about the longitudinal axis to disengage from the pins.
43. The lock cylinder as claimed in claim 42 wherein a carrier configured to carry the plurality of racks and a plug with a face having a keyway and a rekeying tool-receiving aperture, the carrier being movable parallel to the longitudinal axis in response to insertion of a rekeying tool into the rekeying tool-receiving aperture.
44. The lock cylinder as claimed in claim 43 wherein a locking bar movable between a locking position and an unlocking position, wherein the carrier is rotatable in the cylinder body to a rekeying position when the locking bar is in an unlocking position and is movable longitudinally when the carrier is in the rekeying position.
45. The lock cylinder as claimed in claim 42 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks.
46. The lack cylinder as claimed in claim 42 wherein a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter.
47. The lock cylinder as claimed in claim 46 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring.
48. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a plug body disposed in the cylinder body and having a face with a keyway and a tool-receiving aperture;
a carrier disposed in the plug body; and
a first valid key configured to be received in the keyway, the plug body being rotatable between a first position and a rekeying position when the first valid key is disposed in the keyway, the carrier moving longitudinally in response to the insertion of a rekeying tool into the tool-receiving aperture, the first valid key being removable from the plug body after the tool is inserted in the tool-receiving aperture.
49. A lock cylinder having a keyway, comprising: a first plurality of guide channels;
a plurality of cup-shaped pins movably disposed within the first plurality of guide channels, each cup-shaped pin of the plurality of cup-shaped pins being located to extend across the keyway, and each cup-shaped pin of the plurality of cup-shaped pins having an engagement protrusion, the first plurality of guide channels being configured to conform to the shape of the plurality of cup-shaped pins to allow movement of the plurality of cup-shaped pins in a first direction toward the keyway while restraining movement in all directions transverse to the first direction;
a plurality of biasing springs positioned to bias the plurality of cup-shaped pins in the first direction toward the keyway;
a second plurality of guide channels; and
a plurality of racks movably disposed in the second plurality of guide channels, each rack of the plurality of racks having at least one engagement groove to selectively receive the engagement protrusion of a respective cup-shaped pin.
50. The lock cylinder as claimed in claim 49, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and each biasing spring of the plurality of biasing springs has a non-constant diameter.
51. The lock cylinder as claimed in claim 49, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and wherein each biasing spring of the plurality of biasing springs has a coil portion of reduced diameter that engages the depression.
52. The lock cylinder as claimed in claim 49, wherein each guide channel of the first plurality of guide channels has a sidewall opening defining a pair of retention supports, and wherein the pair of retention supports restrains movement of a respective cup-shaped pin in a respective guide channel in a direction transverse to the keyway.
53. The lock cylinder as claimed in claim 49, wherein each guide channel of the first plurality of guide channels is formed as a cylinder having an axial sidewall slot.
54. The lock cylinder as claimed in claim 49, wherein a cylinder body, and a locking bar disposed within the cylinder body, and wherein each rack of the plurality of racks has at least one locking bar groove to selectively receive the locking bar.
55. The lock cylinder as claimed in claim 49, wherein each guide channel of the first plurality of guide channels is configured to restrain movement of a
respective cup-shaped pin in a respective guide channel in directions transverse to the keyway toward and away from the plurality of racks.
56. A lock cylinder, comprising:
a cylinder body;
a plug body rotatably disposed in the cylinder body, the plug body having a keyway;
a plurality of guide channels, each guide channel of the plurality of guide channels having a sidewall opening defining a pair of retention supports;
a plurality of cup-shaped pins movably coupled to the plug body, each cup-shaped pin of the plurality of cup-shaped pins being located in a respective guide channel of the plurality of guide channels, wherein each pair of retention supports cooperates with its respective guide channel to restrain movement of a respective cup-shaped pin in the respective guide channel in a direction transverse to the keyway, and each cup-shaped pin of the plurality of cup-shaped pins has an engagement protrusion that extends into the sidewall opening of the respective guide channel; and
a plurality of racks movably coupled to the plug body, each rack of the plurality of racks having at least one engagement groove to selectively receive the engagement protrusion of the respective cup-shaped pin.
57. The lock cylinder as claimed in claim 56, wherein each guide channel of the
plurality of guide channels is a circular cylinder having an axial sidewall slot.
58. The lock cylinder as claimed in claim 56, wherein a plurality of biasing springs, and each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, each biasing spring biasing a respective cup-shaped pin toward the keyway.
59. The lock cylinder as claimed in claim 58, wherein each biasing spring of the plurality of biasing springs has a non-constant diameter.
60. The lock cylinder as claimed in claim 58, wherein each biasing spring of the plurality of biasing springs has a coil portion of reduced diameter at each end of the biasing spring.
61. The lock cylinder as claimed in claim 56, as claimed in a locking bar disposed within the cylinder body, and wherein each rack of the plurality of racks has at least one locking bar groove to selectively receive the locking bar.
62. A lock cylinder, comprising:
a cylinder body; a plug body rotatably disposed in the cylinder body, the plug body having a keyway;
a plurality of guide channels, each guide channel of the plurality of guide channels having a slotted sidewall opening;
a plurality of cup-shaped pins movably disposed within the plurality of guide channels, each guide channel of the plurality of guide channels being configured to conform to the shape of a respective cup-shaped pin of the
plurality of cup-shaped pins to restrain movement of the respective cup-shaped pin in the respective guide channel in a direction transverse to the keyway, and each cup-shaped pin of the plurality of cup-shaped pins having an engagement protrusion that extends into the slotted sidewall opening of the respective guide channel; and
a plurality of racks movably coupled to the plug body, each rack of the plurality of racks having at least one engagement groove to selectively receive the engagement protrusion of the respective cup-shaped pin.
63. The lock cylinder as claimed in claim 62, wherein a plurality of biasing springs positioned to bias the plurality of cup-shaped pins in a direction toward the keyway, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and each biasing spring of the plurality of biasing springs has a non-constant diameter.
64. The lock cylinder as claimed in claim 62, wherein a plurality of biasing springs positioned to bias the plurality of cup-shaped pins in a direction toward the keyway, wherein each cup-shaped pin of the plurality of cup-shaped pins has a depression to receive an end portion of a respective biasing spring of the plurality of biasing springs, and wherein each biasing spring of the plurality of biasing springs has a coil portion of reduced diameter that engages the depression.
65. The lock cylinder as claimed in claim 62, wherein each slotted sidewall opening defines a pair of retention supports, and wherein the pair of retention supports restrains movement of a respective cup-shaped pin in a respective guide channel in a direction transverse to the keyway.
66. The lock cylinder as claimed in claim 62, wherein each guide channel of the plurality of guide channels is configured to conform to the shape of a respective cup-shaped pin of the plurality of cup-shaped pins to restrain movement of the respective cup-shaped pin in the respective guide channel in all directions transverse to the keyway.
67. A rekeyable lock cylinder comprising:
a lock cylinder housing;
a plug body disposed in the lock cylinder housing and having a longitudinal axis, the plug body being rotatable about the longitudinal axis between a home position and a rekeying position; at least one rack disposed in the plug body; and
at least one pin disposed in the plug body, the at least one rack being configured to engage the at least one pin, one of the at least one rack and the at least one pin being moveable relative to the other parallel to the longitudinal axis from a first position to a second position to move the one of the at least one rack and the at least one pin out of contact with the other and from the second position to the first position to move the one of the at least one rack and the at least one pin into contact with the other.
68. The lock cylinder as claimed in claim 67 wherein the plug body comprises a
carrier moveable parallel to the longitudinal axis, the movement of the carrier
moving the one of the at least one rack and the at least one pin out of contact
with the other.
69. The lock cylinder as claimed in claim 67 wherein a plug face having a rekeying opening configured to receive a rekeying tool.
70. The lock cylinder as claimed in claim 67 wherein plug body includes a rekeying tool opening and a rekeying tool, the rekeying tool opening includes a first opening portion and a second opening portion, and the rekeying tool includes a first tool portion disposed in the first opening portion and a second tool portion disposed in the second opening portion.
71. The lock cylinder as claimed in claim 68 wherein the at least one rack disengages from the at least one pin in response to movement of the carrier from the first position to the second position and engages the at least one pin in response to movement of the carrier from the second position to the first position, the lock cylinder being in a rekeyable condition when the carrier is in the second position.
72. The lock cylinder as claimed in claim 67 wherein the at least one pin includes a hollow cup-shaped body.
73. The lock cylinder as claimed in claim 72 wherein the at least one pin is configured to receive a spring.
74. The lock cylinder as claimed in claim 67 wherein means for retaining the one of the at least one rack and the at least one pin in the second position.
75. The lock cylinder as claimed in claim 74 wherein the means for retaining includes a spring catch.
76. The lock cylinder as claimed in claim 74 wherein the means for retaining further includes a recess in the cylinder housing for receiving a spring catch when the one of the at least one rack and the at least one pin is in the second position.
77. The lock cylinder as claimed in claim 74 wherein the means for retaining is configured to release the one of the at least one rack and the at least one pin to return to the first position in response to rotation of the plug body in the cylinder housing.
78. The lock cylinder as claimed in claim 67 wherein the at least one rack includes at least one locking bar-receiving groove and a plurality of pin-engaging gear teeth and the at least one pin includes at least one gear tooth for engaging the at least one rack between two of the plurality of pin-engaging gear teeth.
79. The lock cylinder as claimed in claim 67 wherein the plug body further includes a body portion and a carrier, the at least one rack being disposed in the carrier and the at least one pin disposed in the body portion, the carrier being movable longitudinally relative to the body portion to move the at least one rack and the at least one pin into and out of contact.
80. The lock cylinder as claimed in claim 67 wherein the at least one rack is movable in a direction transverse to the longitudinal axis in the first position and is restricted from such transverse movement in the second position.
81. The lock cylinder as claimed in claim 69 wherein a rekeying tool having an integral push button extending through the plug face.
82. A rekeyable lock cylinder comprising:
a lock cylinder housing having a longitudinal axis;
a plug body disposed in the lock cylinder housing for rotation between a home position and a rekeying position;
a carrier disposed in the lock cylinder housing, the carrier being movable longitudinally relative to the plug body;
a plurality of pins disposed in the plug body;
a plurality of racks disposed in the carrier for engaging the plurality of pins, the racks being movable between a first position and a second position relative to the plurality of pins, the racks being movable by the pins upon insertion of a first valid key into the plug body when the racks are in the first position; and
means for preventing movement of the racks transverse to the longitudinal axis in the second position, the lock cylinder being, in a rekeyable condition in the second position.
83. The lock cylinder as claimed in claim 82 wherein a locking bar movable between a locking condition and an unlocking condition, wherein the plug body is rotatable in the cylinder housing to the rekeying position when the locking bar is in the unlocking condition and the racks can be disengaged from the pins in the rekeying position.
84. The lock cylinder as claimed in claim 82 wherein each pin includes at least one gear tooth for engaging one of the plurality of racks.
85. The lock cylinder as claimed in claim 84 wherein a biasing spring disposed against each of the plurality of pins, each biasing spring having a non-constant diameter.
86. The lock cylinder as claimed in claim 85 wherein each of the plurality of pins includes a cup-shaped body for receiving the biasing spring.
87. A rekeyable lock cylinder comprising:
a lock cylinder housing;
a plug body having a longitudinal axis and a plurality of pins, the plug body being rotatable in the lock cylinder housing between a home position and a rekeying position; and
a plurality of racks disposed to engage the plurality of pins, the plurality of racks being moveable parallel to the longitudinal axis to disengage from, and reengage, the plurality of pins, and transversely to the longitudinal axis and rotationally about the longitudinal axis in engagement with the plurality of pins.
88. The lock cylinder as claimed in claim 87 wherein the plug body further includes a carrier having a plurality of slots for receiving the racks, the carrier being movable longitudinally between a first position and a second position, the plurality of racks being engaged with the plurality of pins in the first position and disengaged from the plurality of pins in the second position.
89. The lock cylinder as claimed in claim 88 wherein the carrier is rotated about the longitudinal axis from the home position to the first position and longitudinally from the first position to the second position.
90. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a carrier disposed in the cylinder body for movement parallel to and rotationally about the longitudinal axis;
a plurality of pins disposed in the cylinder body; and
a plurality of racks disposed in the cylinder body for engaging the plurality of pins, the racks being movable longitudinally to disengage from the pins in response to movement of a rekeying tool.
91. The lock cylinder as claimed in claim 90 wherein the carrier is configured to carry the plurality of racks.
92. The lock cylinder as claimed in claim 91 wherein a locking bar movable between a locking position and an unlocking position, wherein the carrier is rotatable in the cylinder body to a rekeying position when the locking bar is in an unlocking position.
93. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a plug body disposed for rotational movement in the cylinder body and having a face with a keyway and a tool-receiving aperture;
a carrier disposed adjacent the plug body; and
a first valid key configured to be received in the keyway, the plug body being rotatable between a first position and rekeying position when the first valid key is disposed in the keyway, the carrier moving longitudinally in response to the movement of a rekeying tool in the tool-receiving aperture, the first valid key being removable from the plug body after the tool is inserted in the tool-receiving aperture.
94. A rekeyable lock cylinder comprising:
a cylinder body with a longitudinal axis;
a plug body disposed in the cylinder body for rotational movement between a home position and a second position, the plug body including a plug face with a keyway and a tool-receiving aperture;
a carrier disposed in the cylinder body adjacent the plug body for rotation with the plug body between the home position and the second position, the carrier being moveable longitudinally between an initial position relative to the plug body and a rekeying position when the plug body is in the second position;
means coupled to the carrier for retaining the carrier in the rekeying position;
a plurality of pins disposed in the plug body for transverse movement in response to insertion of a first valid key in the keyway;
a plurality of racks disposed in the carrier for longitudinal movement with the
carrier in response to movement of a rekeying tool in the tool-receiving aperture
when the plug body is in the second position; and
means for retaining the racks in a common transverse alignment relative to the plug body when the carrier is in the rekeying position, the first valid key being removable when the carrier is in the rekeying position and obsoleted in response to rotation of the plug body to the home position with a second valid key in the keyway.
95. The lock cylinder as claimed in claim 94 wherein the rekeying tool includes an
integral push button extending at least partially outwardly from the plug face.
96. The lock cylinder as claimed in claim 95 wherein the plug body includes means to obsolete the first valid key in response to partial movement of the plug body from the second position to the home position with the second valid key in the

Documents:

711-DELNP-2007-Abstract-(01-05-2012).pdf

711-delnp-2007-abstract.pdf

711-delnp-2007-Assignment-(06-01-2014).pdf

711-DELNP-2007-Claims-(01-05-2012).pdf

711-DELNP-2007-Claims-151214.pdf

711-delnp-2007-claims.pdf

711-DELNP-2007-Correspondence Others-(01-05-2012).pdf

711-delnp-2007-Correspondence Others-(06-01-2014).pdf

711-delnp-2007-Correspondence Others-(31-07-2012).pdf

711-DELNP-2007-Correspondence-151214.pdf

711-delnp-2007-correspondence-others 1.pdf

711-delnp-2007-correspondence-others.pdf

711-DELNP-2007-Description (Complete)-(01-05-2012).pdf

711-delnp-2007-description (complete).pdf

711-DELNP-2007-Description(Complete)-151214.pdf

711-DELNP-2007-Drawing-151214.pdf

711-DELNP-2007-Drawings-(01-05-2012).pdf

711-delnp-2007-drawings.pdf

711-DELNP-2007-Form 1-151214.pdf

711-DELNP-2007-Form 2(Title Page)-151214.pdf

711-DELNP-2007-Form-1-(01-05-2012).pdf

711-delnp-2007-form-1.pdf

711-DELNP-2007-Form-13-(01-05-2012).pdf

711-delnp-2007-form-18.pdf

711-delnp-2007-Form-2-(06-01-2014).pdf

711-delnp-2007-form-2.pdf

711-DELNP-2007-Form-3-(01-05-2012).pdf

711-delnp-2007-form-3.pdf

711-delnp-2007-form-5.pdf

711-DELNP-2007-GPA-(01-05-2012).pdf

711-delnp-2007-GPA-(06-01-2014).pdf

711-DELNP-2007-Other Patent Document-151214.pdf

711-DELNP-2007-OTHERS-151214.pdf

711-DELNP-2007-Petition-137-(01-05-2012).pdf

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Patent Number

264488

Indian Patent Application Number

711/DELNP/2007

PG Journal Number

01/2015

Publication Date

02-Jan-2015

Grant Date

31-Dec-2014

Date of Filing

25-Jan-2007

Name of Patentee

KWIKSET CORPORATION

Applicant Address

19701 Da Vinci,Lake Forest,CA 92610,USA

Inventors:

#	Inventor's Name	Inventor's Address
1	STEVEN ARMSTRONG	901 SEDONA LANE, ANAHEIM, CA 92808, U.S.A.
2	GERALD B. CHONG	18805 LEESBURY WAY, ROWLAND HEIGHTS, CA 91748, U.S.A.

PCT International Classification Number

E05B 29/00

PCT International Application Number

PCT/US2003/029732

PCT International Filing date

2003-09-22

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10/256,066	2002-09-26	U.S.A.