Abstract:
This invention is to provide a method for rekeying a rekeyable lock cylinder. The first step of entire rekeying process is to insert a first user key into a keyhole of a sliding block of a plug assembly and turn the first user key to rotate the plug assembly, then a thrust is added to the first user key to move the sliding block of the plug assembly, thereby disengaging a plurality of upper locking pieces and a plurality of lower locking pieces within a plurality of lower pin sets. Next, after pulling out the first user key from the keyhole, a second user key is inserted into the keyhole of the sliding block and turned to restore the sliding block as to reengage the upper locking pieces and the lower locking pieces. Finally, the second user key is pulled out to complete the entire rekeying process. Accordingly, the present invention may provide advantages of widely lowering rekeying cost and enhancing convenience in use, because lock replacement may be completed as soon as rekeying another user key only without replacing lock cylinder.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to an operating method of lock cylinder and more particularly to a method for rekeying a rekeyable lock cylinder. 
       BACKGROUND OF THE INVENTION 
       [0002]    Lock cylinder of a conventional lock device typically is matched with a proper key so lock cylinder as well as key must be replaced in pair while replacing a lock, which results in high lock-replacing cost and inconvenient use. 
       SUMMARY 
       [0003]    An object of the present invention is to provide a method for rekeying a rekeyable lock cylinder. The first step of entire rekeying process is to insert a first user key into a keyhole of a sliding block of a plug assembly and turn the first user key to rotate the plug assembly, then a thrust is added to the first user key to move the sliding block of the plug assembly, thereby disengaging a plurality of upper locking pieces and a plurality of lower locking pieces within a plurality of lower pin sets. Next, after pulling out the first user key from the keyhole, a second user key is inserted into the keyhole of the sliding block and turned to restore the sliding block as to reengage the upper locking pieces and the lower locking pieces. Finally, the second user key is pulled out to complete the entire rekeying process. Accordingly, the present invention may provide advantages of widely lowering rekeying cost and enhancing convenience in use, because lock replacement may be completed as soon as rekeying another user key only without replacing lock cylinder. 
         [0004]    A rekeyable lock cylinder in accordance with the present invention includes a shell, a plug assembly and a plurality of pin sets. The shell has a hollow cylindrical portion and an extending protrusion formed at a lateral of the hollow cylindrical portion, and defines a central axis. Wherein the hollow cylindrical portion has an inside wall, an outside wall and a plurality of runners that communicate with the inside wall and the outside wall, the extending protrusion has a plurality of upper pin holes that communicate with the hollow cylindrical portion. The plug assembly is disposed in the hollow cylindrical portion of the shell and includes a plug body having a front section, a middle section, a driving portion, a coupling groove and a plurality of lower pin holes, and a sliding block. Wherein the coupling groove is formed at the front section and the middle section, the lower pin holes are formed at the middle section, the sliding block that is disposed in the coupling groove of the plug body and able to move parallel to the central axis of the shell has a plurality of pin-sliding grooves and a keyhole communicating with the pin-sliding grooves. Each pin set includes an upper pin and a lower pin set, wherein the upper pin is moveably disposed at one or more upper pin hole of the extending protrusion and at one or more lower pin hole of the plug body, the lower pin set is moveably disposed at one or more lower pin hole of the plug body and at one or more pin-sliding groove of the sliding block and includes an upper locking piece, a lower locking piece able to engage with the upper locking piece and a resilient member disposed between the upper locking piece and the lower locking piece. 
         [0005]    A plug assembly of a rekeyable lock cylinder in accordance with the present invention includes a plug body and a sliding block. The plug body has a front section, a middle section, a driving portion, a coupling groove and a plurality of lower pin holes, and defines a central line. The coupling groove is formed at the front section and the middle section, the lower pin holes are formed at the middle section. The sliding block that is disposed at the coupling groove of the plug body and able to move parallel to the central line has a plurality of pin-sliding grooves and a keyhole communicating with the pin-sliding grooves. 
         [0006]    A plug body of a plug assembly in accordance with the present invention has a front section, a middle section, a driving portion, a coupling groove and a plurality of lower pin holes. The coupling groove is formed at the front section and the middle section, the lower pin holes are formed at the middle section. 
         [0007]    A sliding block of a plug assembly in accordance with the present invention has a plurality of pin-sliding grooves and a keyhole communicating with the pin-sliding grooves. 
         [0008]    A lower pin set of a pin set in accordance with the present invention includes an upper locking piece, a lower locking piece and a resilient member. The lower locking piece engages with the upper locking piece, the resilient member is disposed between the upper locking piece and the lower locking piece. 
         [0009]    Shell of a rekeyable lock cylinder in accordance with the present invention has a hollow cylindrical portion and an extending protrusion formed at a lateral of the hollow cylindrical portion. The hollow cylindrical portion has an inside wall, an outside wall and a plurality of runners that communicate with the inside wall and the outside wall, the extending protrusion has a plurality of upper pin holes communicating with the hollow cylindrical portion, wherein the runners extend to the extending protrusion and communicate with the upper pin holes. 
         [0010]    A method for rekeying a rekeyable lock cylinder in accordance with the present invention includes providing a rekeyable lock cylinder that has a shell, a plug assembly and a plurality of pin sets. The plug assembly is disposed within the shell and has a plug body and a sliding block that is disposed in the plug body and axially moveable has a keyhole. Each pin set has one or more lower pin set that is moveably disposed within the plug body and at least includes an upper locking piece and a lower locking piece engaging with the upper locking piece. First, a first user key is inserted into the keyhole of the sliding block and turned to rotate the plug assembly, and then a thrust is added onto the first user key to move the sliding block as to disengage the upper locking pieces and the lower locking pieces. Next, after pulling out the first user key from the keyhole, a second user key is inserted into the keyhole of the sliding block and turned to restore the sliding block as to reengage the upper locking pieces and the lower locking pieces. Finally, the second user key is pulled out to complete the entire rekeying process. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is an exploded perspective view of a rekeyable lock cylinder in accordance with a preferred embodiment of the present invention. 
           [0012]      FIG. 2  is a perspective view of a shell in accordance with a preferred embodiment of the present invention. 
           [0013]      FIG. 3  is an assembled perspective view of the rekeyable lock cylinder in accordance with a preferred embodiment of the present invention. 
           [0014]      FIG. 4  is a perspective view of a plug body in accordance with a preferred embodiment of the present invention. 
           [0015]      FIG. 5  is a front plan view of the plug body in accordance with a preferred embodiment of the present invention. 
           [0016]      FIG. 6  is an assembled view of a sliding block and the plug body in accordance with a preferred embodiment of the present invention. 
           [0017]      FIG. 7  is a perspective view of the sliding block in accordance with a preferred embodiment of the present invention. 
           [0018]      FIG. 8  is another perspective view of the sliding block in accordance with a preferred embodiment of the present invention. 
           [0019]      FIG. 9  is an assembled side view of the sliding block and the plug body in accordance with a preferred embodiment of the present invention. 
           [0020]      FIG. 10  is an assembled view of a burglarproof member and the plug body in accordance with a preferred embodiment of the present invention. 
           [0021]      FIG. 11  is an assembled longitudinal section view of the rekeyable lock cylinder taken along line A-A of  FIG. 3 . 
           [0022]      FIG. 12  is a view of a lower pin set structure in accordance with a preferred embodiment of the present invention. 
           [0023]      FIG. 13  is a flow chart for rekeying the rekeyable lock cylinder in accordance with a preferred embodiment of the present invention. 
           [0024]      FIG. 14  is a longitudinal section view illustrating a first user key is inserted into the rekeyable lock cylinder in accordance with a preferred embodiment of the present invention. 
           [0025]      FIG. 15  is a transverse section view illustrating the rekeyable lock cylinder taken along line B-B of  FIG. 3 . 
           [0026]      FIG. 16  is a longitudinal section view illustrating the first user key is turned in 90° clockwise in accordance with a preferred embodiment of the present invention. 
           [0027]      FIG. 17  is a transverse section view illustrating the first user key is turned in 90° clockwise in accordance with a preferred embodiment of the present invention. 
           [0028]      FIG. 18  is a longitudinal section view illustrating the disengagement of the upper locking pieces and the lower locking pieces due to the moved sliding block in accordance with a preferred embodiment of the present invention. 
           [0029]      FIG. 19  is a transverse section view illustrating the disengagement of the upper locking pieces and the lower locking pieces due to the moved sliding block in accordance with a preferred embodiment of the present invention. 
           [0030]      FIG. 20  is another transverse section view illustrating the disengagement of the upper locking pieces and the lower locking pieces due to the moved sliding block in accordance with a preferred embodiment of the present invention. 
           [0031]      FIG. 21  is a longitudinal section view illustrating the first user key is pulled out in accordance with a preferred embodiment of the present invention. 
           [0032]      FIG. 22  is a transverse section view illustrating the first user key is pulled out in accordance with a preferred embodiment of the present invention. 
           [0033]      FIG. 23  is another transverse section view illustrating the first user key is pulled out in accordance with a preferred embodiment of the present invention. 
           [0034]      FIG. 24  is a longitudinal section view illustrating a second user key is inserted into the rekeyable lock cylinder in accordance with a preferred embodiment of the present invention. 
           [0035]      FIG. 25  is a transverse section view illustrating the second user key is inserted into the rekeyable lock cylinder in accordance with a preferred embodiment of the present invention. 
           [0036]      FIG. 26  is another transverse section view illustrating the second user key is inserted into the rekeyable lock cylinder in accordance with a preferred embodiment of the present invention. 
           [0037]      FIG. 27  is a longitudinal section view illustrating the second user key is turned counterclockwise in accordance with a preferred embodiment of the present invention. 
           [0038]      FIG. 28  is a transverse section view illustrating the second user key is turned counterclockwise in accordance with a preferred embodiment of the present invention. 
           [0039]      FIG. 29  is a longitudinal section view illustrating the second user key is turned in 90° counterclockwise in accordance with a preferred embodiment of the present invention. 
           [0040]      FIG. 30  is a transverse section view illustrating the second user key is turned in 90° counterclockwise in accordance with a preferred embodiment of the present invention. 
           [0041]      FIG. 31  is another transverse section view illustrating the second user key is turned in 90° counterclockwise in accordance with a preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]    A rekeyable lock cylinder in accordance with a preferred embodiment of the present invention, as shown in  FIGS. 1 and 2 , includes a shell  10 , a plug assembly  20  and a plurality of pin sets  30 . The shell  10  has a hollow cylindrical portion  11  and an extending protrusion  12  formed at a lateral of the hollow cylindrical portion  11 , and defines a central axis  10   a.  The hollow cylindrical portion  11  has an inside wall  11   a,  an outside wall  11   b,  an ending surface  11   c,  a plurality of runners  111  communicating with the inside wall  11   a  and the outside wall  11   b,  a burglarproof slot  112 , a first slot  113 , a second slot  114  and an accommodating gap  115  recessed on the ending surface  11   c.  The burglarproof slot  112 , the first slot  113  and the second slot  114  are formed at the inside wall  11   a,  the first slot  113  is adjacent to the ending surface  11   c  and the second slot  114  is located below the accommodating gap  115 . In this embodiment, the first slot  113  and the second slot  114  are in parallel and disposed alternately. The accommodating gap  115  is formed at one end of the hollow cylindrical portion  11 . The extending protrusion  12  has a plurality of upper pin holes  12   a  that communicate with the hollow cylindrical portion  11 . In this embodiment, the runners  111  of the hollow cylindrical portion  11  extend to the extending protrusion  12  and communicates with the upper pin holes  12   a  of the extending protrusion  12 . 
         [0043]    As shown in  FIGS. 1 ,  3 ,  4  and  5 , the plug assembly  20  is disposed within the hollow cylindrical portion  11  of the shell  10  and includes a plug body  21 , a sliding block  22 , a limit member  23  and a burglarproof member  24 . The plug body  21  has a front section  21   a,  a middle section  21   b,  a driving portion  21   c,  a coupling groove  211 , a plurality of lower pin holes  212 , one or more opening  213  and an axial groove  214 , and defines a central line  20   a.  The central line  20   a  is parallel to and overlapped onto the central axis  10   a  of the shell  10 . The coupling groove  211  is formed at the front section  21   a  and the middle section  21   b.  The lower pin holes  212  are formed at the middle section  21   b  and have an extending slide groove  212   a.  The opening  213  is formed at the middle section  21   b  and communicates with one or more lower pin hole  212 . The axial groove  214  is formed at the front section  21   a.  As shown in  FIGS. 1 and 6 , the sliding block  22  is disposed at the coupling groove  211  of the plug body  21  and able to axially move parallel to the central axis  10   a  of the shell  10  or the central line  20   a.  As shown in  FIGS. 1 ,  6 ,  7  and  8 , the sliding block  22  has a first end  22   a,  a second end  22   b,  a join surface  22   c,  a plurality of pin-sliding grooves  221 , a keyhole  222  and a cavity  223 . The first end  22   a  has a flange  224  that corresponds to the accommodating gap  115  of the hollow cylindrical portion  11  of the shell  10 , and an insertion slot  225  is recessed at the second end  22   b.  The join surface  22   c  faces the opening  213  of the plug body  21 . In this embodiment, the keyhole  222  communicates with the first end  22   a,  the second end  22   b  and the pin-sliding grooves  221 . Otherwise, in another embodiment, while the key is relatively short, the keyhole  222  merely needs to communicate with the first end  22   a  and the pin-sliding grooves  221 , and which corresponds to the axial groove  214  of the plug body  21 . The pin-sliding grooves  221  are located below the lower pin holes  212  of the plug body  21 . 
         [0044]    In this embodiment as shown in  FIGS. 1 and 9 , the limit member  23  being a pillar is disposed at the cavity  223  of the sliding block  22  and preferably there is a reducing portion  23   a  at one end of the limit member  23 . Besides, as shown in  FIGS. 1 and 8 , the plug assembly  20  further includes on or more thrust member  26 , the cavity  223  of the sliding block  22  has a bottom  223   a  and on or more positioning groove  223   b  recessing at the bottom  223   a,  and the thrust member  26  may be disposed within the positioning groove  223   b  of the bottom  223   a  in order to push the limit member  23 . As shown in  FIGS. 1 and 10 , the burglarproof member  24  substantially employs steel ball in this embodiment and is disposed at the opening  213  of the plug body  21 . 
         [0045]    As shown in  FIGS. 1 ,  11  and  12 , each pin set  30  includes an upper pin  31  and a lower pin set  32 , wherein the upper pin  31  is moveably disposed at one or more upper pin hole  12   a  of the extending protrusion  12  of the shell  10  and one or more lower pin hole  212  of the plug body  21 , the lower pin set  32  is moveably disposed within one or more lower pin hole  212  of the plug body  21  and one or more pin-sliding groove  221  of the sliding block  22 . In this embodiment, the lower pin set  32  is substantially height-adjustable pin including an upper locking piece  321 , a lower locking piece  322  able to engage with the upper locking piece  321  and a resilient member  323  disposed between the upper locking piece  321  and the lower locking piece  322 . In this embodiment, the resilient member  323  is a spring and the upper locking piece  321  has a rib  3211 , an upper tooth portion  3212  and an upper fixing portion  3213 . The rib  3211 , which forms a relieving groove  3211   a,  is moveably disposed at the extending slide groove  212   a  of the lower pin hole  212  and capable of guiding the upper locking piece  321  to move longitudinally as well as preventing the upper locking piece  321  from transversely moving. The upper tooth portion  3212  is formed at the rib  3211  and has a first tooth interval S 1 , the upper fixing portion  3213  has an upper pillar  3213   a,  and the lower locking piece  322  includes a lower tooth portion  3221  having a second tooth interval S 2  and a lower fixing portion  3222  having a lower pillar  3222   a.  In this embodiment as shown in  FIG. 12 , the upper tooth portion  3212  of the upper locking piece  321  engages with the lower tooth portion  3221  of the lower locking piece  322  and the first tooth interval S 1  is greater than the second tooth interval S 2  or may be equal in another embodiment. Moreover, two ends of the resilient member  323  are practically fixed at the upper fixing portion  3213  and the lower fixing portion  3222  respectively, preferably at the upper pillar  3213   a  of the upper fixing portion  3213  and the lower pillar  3222   a  of the lower fixing portion  3222  respectively. 
         [0046]    In this embodiment as shown in  FIG. 11 , while the rekeyable lock cylinder is not inserted by a proper key, the cavity  223  of the sliding block  22  corresponds to the first slot  113  of the hollow cylindrical portion  11  and the limit member  23  is pushed by the thrust member  26  to enter into the first slot  113  of the hollow cylindrical portion  11 . Besides, the opening  213  of the plug body  21  corresponds to the burglarproof slot  112  of the hollow cylindrical portion  11  that catches the burglarproof member  24 . Therefore, in addition to that the plug body  20  cannot be turned because the upper pin  31  of the pin set  30  is lower than the turning interface, the burglarproof member  24  is also caught by the burglarproof slot  112 , so it is able to effectively prevent the burglary from unlocking by impacting lock to rotate the plug body  20  in this embodiment. 
         [0047]    As shown in  FIG. 13 , the method for rekeying the rekeyable lock cylinder will be described in detail as follows. First, a rekeyable lock cylinder is provided referring to the step  400 , and then a first user key  50  is inserted into the keyhole  222  of the sliding block  22  referring to the step  410 . In this embodiment as shown in  FIGS. 14 and 15 , the first user key  50  pushes the lower pin set  32  upwardly moving and being aligned with the turning interface. Meanwhile, the receiving groove  3211   a  of the rib  3211  of the upper locking piece  321 , the burglarproof member  24 , the opening  213  and the burglarproof slot  112  are corresponding to one another to further relieve the catching state of the burglarproof member  24  and the burglarproof slot  112  of the hollow cylindrical portion  11 , which allows the upper pin  31  of the pin set  30  to be elevated by the lower pin set  32  and aligned with the turning interface. Next, the first user key  50  is turned to rotate the plug body  20  to a predetermined degree referring to step  420 , in this embodiment, the first user key  50  is clockwise turned about 90°. As shown in  FIGS. 16 and 17 , since the cavity  223  of the sliding block  22  corresponds to the second slot  114  of the hollow cylindrical portion  11  and the limit member  23  is pushed by the thrust member  26 , one end of the limit member  23  will enter into the second slot  114  of the hollow cylindrical portion  11 . Meanwhile, the reducing portion  23   a  of the limit member  23  will be blocked at the inside wall  11   a  without entering the second slot  114 . The burglarproof member  24  practically touches the upper pin  31  in this embodiment. Besides, in this embodiment, the plug assembly  20  further includes a restoring member  27  that is disposed between the second end  22   b  of the sliding block  22  and the driving portion  21   c  of the plug body  21  and is preferably disposed in an insertion slot  225  of the sliding block  22  and touches the driving portion  21   c  of the plug body  21 . Next, referring to step  430 , pushing the first user key  50  that allows the sliding block  22  of the plug assembly  20  to axially move from an original position X 1  to a rekeying position X 2  so as to disengage each of the upper locking pieces  321  and each of the lower locking pieces  322 . In this embodiment as shown in  FIGS. 18 ,  19  and  20 , the sliding block  22  moves in an interval D, which simultaneously pushes the lower locking pieces  322  of the lower pin sets  32  moving in an interval D resulting in disengagement of the lower locking pieces  322  and the upper locking pieces  321 , as well as makes the reducing portion  23   a  of the limit member  23  move in an interval D to enter into the second slot  114  of the hollow cylindrical portion  11 . Meanwhile, the limit member  23  completely enters into and is caught by the second slot  114 , thus the sliding block  22  is limited at the rekeying position X 2  via the limit member  23 . In this embodiment, for the purpose that the sliding block  22  can move smoothly, the flange  224  of the sliding block  22  may correspond to the accommodating gap  115  of the hollow cylindrical portion  11  of the shell  10  that provides an accommodating space for allowing the sliding block  22  to move. Next, the first user key  50  is pulled out from the keyhole  222  referring to step  440 . In this embodiment as shown in  FIGS. 21 ,  22  and  23 , while the first user key  50  is pulled out from the keyhole  222 , a downward movement to the lowermost position happens to the lower locking pieces  322  of the lower pin sets  32  due to the tension action of the resilient members  323 . Then, a second user key  60  is inserted into the keyhole  222  of the sliding block  22  referring to step  450 . In this embodiment as shown in  FIGS. 24 ,  25  and  26 , the lower locking pieces  322  of the lower pin sets  32  will readjust profile for matching different bitting profile with respect to the second user key  60 . Next, the second user key  60  is turned to restore the sliding block  22  back to original position X 1  referring to step  460 . In this embodiment, the second user key  60  is counterclockwise turned about 90° so as to move each of the upper locking pieces  321  back to engage with each of the lower locking pieces  322  respectively. As shown in  FIGS. 27 ,  28 ,  29 ,  30  and  31 , while the second user key  60  is turned, the limit member  23  moves to the inside wall  11   a  of the hollow cylindrical portion  11  escaping from and relieving caught state by the second slot  114 . Meanwhile, the sliding block  32  and the lower locking pieces  322  of the lower pin sets  32  are pushed by the restoring member  27  to restore, and the lower locking pieces  322  reengages with the upper locking pieces  321 . Finally, the second user key  60  is pulled out from the keyhole  222  to complete the entire rekeying process. 
         [0048]    While the present invention has been particularly illustrated and described in detail with respect to the preferred embodiments thereof, it will be clearly understood by those skilled in the art that various changed in form and details may be made without departing from the spirit and scope of the present invention.