Abstract:
A dual changeable combination lock comprises a housing in which are disposed internal and external toothed wheels each engaging with or disengaging from each dial, wherein the internal toothed wheels can control the shackle and the external toothed wheels can control the switch button. Besides providing the combination changing function of a common combination lock, the above lock can provide another set of separately and independently set changeable numbers by the interaction between the button and the external toothed wheels.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    (a) Field of the Invention 
         [0002]    The present invention relates to a dual changeable combination lock, and more particularly to a combination lock that has the dual changeable functions. 
         [0003]    (b) Description of the Prior Art 
         [0004]    A conventional combination lock is based on driving the internal toothed wheels by the dials, as shown in U.S. Pat. No. 4,733,548, wherein the internal toothed wheels can control the movement of the shackle, and the lock opening combination of the dials can be changed by the engagement and disengagement of the internal toothed wheels with the dials. 
         [0005]    However, the conventional combination lock has only one set of lock opening combination and cannot provide another set of lock opening is combination. Therefore, there is a need for improvement. 
       SUMMARY OF THE INVENTION 
       [0006]    The primary object of the present invention is to provide a dual changeable combination lock in which are disposed internal toothed wheels and external toothed wheels each engaging with each dial, wherein the internal toothed wheels can control the movement of the shackle, and the external toothed wheels can control the motion of the switch button, and two sets of separately and independently set lock opening combinations are provided by the engagement and disengagement of the internal and external toothed wheels with the dials. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a sectional view of a first embodiment of the present invention in a locking position. 
           [0008]      FIG. 1-1  is atop view of  FIG. 1 . 
           [0009]      FIG. 1-2  is a top view of a first embodiment of the present invention when reaching a first correct opening combination. 
           [0010]      FIG. 1-3  is a sectional view of a first embodiment of the present invention when reaching a first correct opening combination and pulling out the shackle. 
           [0011]      FIG. 2  is a sectional view of a first embodiment of the present invention when reaching a second correct opening combination. 
           [0012]      FIG. 2-1  is a top view of  FIG. 2 . 
           [0013]      FIG. 3  is a schematic sectional view of a first embodiment of the present invention before changing the combination numbers. 
           [0014]      FIG. 3-1  is a sectional view of a first embodiment of the present invention when a new first correct opening combination can be set. 
           [0015]      FIG. 4  is a schematic sectional view of a first embodiment of the present invention when changing to a new second open combination in a second manner. 
           [0016]      FIG. 5  is a front view of a second embodiment of the present invention in a full locking position. 
           [0017]      FIG. 6  is a sectional view of a second embodiment of the present invention when reaching a first correct opening combination. 
           [0018]      FIG. 6-1  is a top view of  FIG. 6 . 
           [0019]      FIG. 6-2  is a side view of  FIG. 6 . 
           [0020]      FIG. 7  is a sectional view of a second embodiment of the present invention when locking a first opening combination and opening a second opening combination. 
           [0021]      FIG. 7-1  is a top view of  FIG. 7 . 
           [0022]      FIG. 7-2  is a side view of  FIG. 7. 5   
           [0023]      FIG. 7-3  is a side view of  FIG. 7  when opening the box cover. 
           [0024]      FIG. 8  is a sectional view of a third embodiment of the present invention in a full locking position. 
           [0025]      FIG. 9  is a sectional view of a third embodiment of the present invention when reaching a first correct opening combination. 
           [0026]      FIG. 10  is a sectional view of a third embodiment of the present invention when a new first opening combination can be set. 
           [0027]      FIG. 11  is a sectional view of a third embodiment of the present invention when reaching a second correct opening combination. 
           [0028]      FIG. 12  is a sectional view of a third embodiment of the present invention is when changing to a new second opening combination of a second correct opening combination. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    A combination lock according to present invention comprises: a housing  10  and a plurality of dials  40 , all the dials  40  being arranged in a single row, each of the dials  40  being capable of rotating with respect to the housing  10 , the dials  40  having two opening combinations, the two opening combinations being able to be mutually independent and changed into new opening combinations respectively, and the two new opening combinations also being able to be mutually independent. 
         [0030]    In a first embodiment of the present invention: Referring to FIGS.  1  and  1 - 1 , a combination lock according to the present invention in a locking position comprises: a housing  10 , a shackle  20 , a button  30 , a plurality of dials  40 , a plurality of internal toothed wheels  50  and a plurality of external toothed wheels  60 , wherein the internal teeth  42  of the dials  40  mutually engage with the external teeth  52  of the internal toothed wheels  50 , the external teeth  41  mutually engage with the external toothed wheels  60 , the shackle  20  has thereon protrusions  21  which is not aligned with the notches  51  of the internal toothed wheels  50 , and the button  30  has thereon a sleeve  31  for sleeving on the shackle  20  and has therein insert blocks  32  for passing through the notches  61  of the external toothed wheels  60 ; 
         [0031]    The sleeve  31  on the button  30  is sleeved on the shackle  20  and the insert blocks  32  within the button  30  are not aligned with the notches  61  of is the external toothed wheels  60  so that the button  30  cannot be pushed downwardly and the lock is locked. 
         [0032]    Referring to  FIG. 1-2 , the dials  40  reach a first correct opening combination, and the protrusions  21  of the shackle  20  are aligned with the notches  51  of the internal toothed wheels  50 . Referring to  FIG. 1-3 , the shackle  20  can be pulled out of the housing  10 . 
         [0033]    Referring to FIGS.  2  and  2 - 1 , when the lock reaches a second correct opening combination, the notches  61  of the external toothed wheels  60  are aligned with the insert blocks  32  of the button  30 . At this time, the button  30  and the sleeve  31  are pushed downwardly, and the insert blocks  32  of the button  30  can pass through the notches  61  of the external toothed wheels  60  and compress the spring  11  at their lower ends so that the shackle  20  disengage from the sleeve  31  of the button  30  and the lock is opened. 
         [0034]    Referring to FIGS.  3  and  3 - 1 , the first opening combination of the present invention is changed into a new opening combination. The locked shackle  20  in  FIG. 1  is pulled out and then rotates at 90°. The shackle  20  is pressed downwardly and the protrusions  21  of the shackle  20  can press the internal toothed wheels  50  to move downwardly and contract the spring  12  so that the external teeth  52  of the internal toothed wheels  50  disengage from the internal teeth  42  of the dials  40  and then the dials  40  are rotated to change to a new open combination. When the force applied to the shackle  20  is cancelled, the spring  12  will push the internal toothed wheels  50  upwardly to engage with the dials  40 , thus obtaining a new first opening combination. 
         [0035]    Referring to  FIG. 4 , the second opening combination of the present invention is changed into a new opening combination. When the dials  40  show the opening combination, a sharp object is pushing the changeable switch  13  to move the external toothed wheels  60  upwardly and compress the return spring  14  thereabove so that the external toothed wheels  60  disengage from the external teeth  41  of the dials  40 . Because the notches  61  of the external toothed wheels  60  are locked by the insert blocks  32  of the button  30 , the external toothed wheels cannot rotate. At this time, the dials  40  are rotated to change the combination numbers. When the sharp object that applies force to the changeable switch  13  is removed, the return spring  14  will push the external toothed wheels  60  downwardly to engage with the external teeth  41  of the dials  40 , thus obtaining a new second opening combination. 
         [0036]    In summarization of the foregoing description, the new first opening combination and the new second opening combination can be mutually independent. The internal toothed wheels  50  and the external toothed wheels  60  each can disengage from the dials  40  so as to change the respective new opening combinations. 
         [0037]    In a second embodiment of the present invention: Referring to  FIG. 5 , the housing  10  of the combination lock according to the present invention is provided with a box  70 . The shackle  20  extends into the housing  10  into a locking state. The button  30  beside the box  70  is located at the upper position and the box  70  is in a locking state. 
         [0038]    Referring to FIGS.  6  and  6 - 1  and  6 - 2 , the dials  40  reach a first correct opening combination, and the shackle  20  can be pulled out to open the lock. 
         [0039]    Referring to FIGS.  7  and  7 - 1  and  7 - 2  and  7 - 3 , when the shackle  20  is in a locking state, the button  30  is pushed downwardly and the snap fitting  33  of the button  30  is not buckled with the buckling block  711  on the box cover  71  of the box  70  so that the box cover  71  at the front edge of the box  70  can be opened around the axis  712  as a center of the bottom to receive keys or belongings. 
         [0040]    In a third embodiment of the present invention: Referring to  FIG. 8 , a lock for a computer has two L-shaped shackles  22 ,  23  locking the lock hole B 1  of a to be locked article B, and the two shackles  22 ,  23  are shaft coupled at their lower ends to pressing blocks  221 ,  231  respectively, wherein one pressing block  221  is propped at its lower portion against the back up plate  241  on the upper portion of the lock rod  24 , the other pressing block  231  is propped against the upper portion of the switch button  30 , a changeable switch  242  is provided at the bottom of the housing  10 . 
         [0041]    Referring to  FIG. 9 , the dials  40  use a first opening combination to open the lock, and the pressing block  231  is pressed downwardly to compress the spring  25  and move the lock rod  24  downwardly so that the shackle  23  can be tilted to disengage from the lock hole B 1  of the article B and then the lock is opened. Referring to  FIG. 10 , the dials  40  show the first opening combination. If it is desired to change the combination numbers, a sharp object is pushing the changeable switch  242  to drive the internal toothed wheels  50  to move upwardly and the external teeth  52  of the internal toothed wheels  50  disengage from the internal teeth  42  of the dials  40 . Accordingly, the dials  40  can be rotated to change to a new combination numbers. 
         [0042]    Referring to  FIG. 11 , the dials  40  use a second opening combination to open the lock, and the pressing block  221  presses down on the button  30  and compresses the spring  11  so that the shackle  22  can be tilted to disengage from the lock hole B 1  of the article B and then the lock is opened. Referring to  FIG. 12 , the dials  40  are at the second opening combination. If it is desired to change the combination numbers, a sharp object is pushing the changeable switch  13  to move the external toothed wheels  60  upwardly and compress the return spring  14  thereabove so that the external toothed wheels  60  disengage from the external teeth  41  of the dials  40 . Because the notches  61  of the external toothed wheels  60  are locked by the insert blocks  32  of the button  30 , the external toothed wheels cannot rotate. Accordingly, the dials  40  can be rotated to change to a new combination numbers. 
         [0043]    As is apparent from the foregoing, the present invention provides a dual changeable combination lock, in the housing of which are disposed internal and external toothed wheels each capable of engaging with or disengaging from each dial to provide two sets of changeable numbers. The above two sets of numbers can be separately set and mutually independent, so it is impossible to predict another set of combination from one set of combination. Various structures can be derived from the button to be adapted to different functions.