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BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to locks and more particularly, to a padlock having a storage chamber. 
         [0003]    2. Description of the Related Art 
         [0004]    In recent years, number wheel-controlled padlocks having an internal storage chamber are widely accepted by consumers because the padlocks have the advantage of being capable of storing keys, memo pad and other small personal items. A conventional number wheel-controlled padlock generally comprises a casing that includes a bottom shell and a cover shell pivotally connected to the bottom shell and defining with the bottom shell a storage chamber for keeping personal small items. The number wheel-controlled padlock further comprises a shackle, and a combination lock unit for locking/unlocking the shackle, controlling the opening of the casing. When the user rotated the number wheels of the combination lock unit to show a predetermined sequence of numbers, the shackle is unlocked and movable relative to the casing to an unlocked position for allowing removal of the padlock from the attached object. At this time, the cover shell is allowed to be opened from the bottom shell so that the user can put personal items in the storage chamber or take storage items out of the storage chamber. 
         [0005]    According to the aforesaid prior design, the padlock is inconvenient to use. When the user wishes to store an item in the storage chamber of the casing or to take one storage item out of the storage chamber, the user must unlock the shackle prior to opening the casing. Further, because the combination lock unit is adapted to lock/unlock the shackle and the casing at the same time, the mechanical design thereof is relatively complicated. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention has been accomplished in view of the above-noted circumstances. It is one object of the present invention to provide a padlock having a storage chamber, which controls locking/unlocking of the casing and the shackle separately. 
         [0007]    To achieve this object of the present invention, a padlock comprises a casing, a shackle, a latch, a constraint member and a combination lock unit. The casing has a bottom shell provided with a first through hole and a second through hole, and a cover shell pivotally connected to the bottom shell. The shackle has a shackle body and a hook connected to shackle body and provided with an end. The shackle body is inserted through the first through hole of the bottom shell and movable relative to the bottom shell between a first position where the hook is inserted through the second through hole of bottom shell and the end of the hook suspends inside the bottom shell, and a second position where the end of the hook is located outside the bottom shell. The latch is mounted in the bottom shell and movable between an engagement position where the latch engages the end of the hook to stop the shackle body of the shackle from moving away from the first position toward the second position when the shackle body of the shackle is in the first position and a release position where the latch is disengaged from the distal end of the hook for allowing the shackle body of the shackle to be moved from the first position toward the second position. The constraint member has a hook portion and is mounted in the cover shell. The constraint member is movable between a locked position where the hook portion of the constraint member is hooked on one of the shackle and the latch to prohibit biasing of the cover shell relative to the bottom shell and an unlocked position where the hook portion of the constraint member is kept away from the one of the shackle and the latch for allowing the cover shell to be biased relative to the bottom shell. The combination lock unit is mounted in the cover shell for controlling the constraint member to determine whether the constraint is moveable between the locked position and the unlocked position. 
         [0008]    As stated above, the padlock uses the latch to control locking and unlocking of the shackle and the combination lock unit to control locking and unlocking of the casing. Thus, the casing of the padlock can be separately opened without opening the shackle, facilitating storing person items in the casing or removal of the storage items from the casing. 
         [0009]    Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
           [0011]      FIG. 1  is a perspective view of a padlock in accordance with a preferred embodiment of the present invention; 
           [0012]      FIG. 2  is an exploded view of the padlock in accordance with the preferred embodiment of the present invention; 
           [0013]      FIG. 3  is a perspective view of the constraint member according to the preferred embodiment of the present invention; 
           [0014]      FIG. 4  is a schematic drawing showing that the cover shell is covered on the bottom shell, the constraint member is positioned at the locked position, and the two hook portions of the constraint member are respectively hooked on the shackle body of the shackle and the protruding rod of the latch; 
           [0015]      FIG. 5  is a schematic drawing showing that the shackle body of the shackle and the protruding rod of the latch are forced to push the hook portions of the constraint member such that the constraint member is moved toward the unlocked position during opening of the cover shell from the bottom shell; 
           [0016]      FIG. 6  is a schematic drawing showing that the constraint member is positioned at the locked position, and the notches of the number wheels are aligned in line and respectively aimed at the protruding blocks of the constraint member; 
           [0017]      FIG. 7  is a schematic drawing showing that the constraint member is positioned at the unlocked position and the protruding blocks of the constraint member are moved into the notches of the number wheels; 
           [0018]      FIG. 8  is a schematic drawing showing that the cover shell is opened from the bottom shell, the latch is positioned at the engagement position, and the shackle body of the shackle is positioned at the first position, and 
           [0019]      FIG. 9  is a schematic drawing showing that the cover shell is opened from the bottom shell, the latch is positioned at the release position, and the shackle body of the shackle is positioned at the second position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    Referring to  FIGS. 1-3 , a padlock  10  in accordance with a preferred embodiment of the present invention is shown comprising a casing  20 , a shackle  30 , a latch  40 , a constraint member  50  and a combination lock unit  60 . 
         [0021]    The casing  20  comprises a bottom shell  21  and a cover shell  23 , which has its one side, namely, the bottom side pivotally connected to one side, namely, the bottom side of the bottom shell  21  by a pivot pin  22  and biasable relative to the bottom shell  21  to close or open the bottom shell  21 . The cover shell  23  defines therein a storage chamber  23   a  for keeping the user&#39;s small personal items such as keys, memo pad and etc. The bottom shell  21  comprises a first through hole  21   a  and a second through hole  21   b  on the other side, namely, the top side thereof in communication with inside space, an upper stop block  21   c  and a lower stop block  21   d  arranged on the inside at one lateral side, namely, the right side, the upper stop block  21   c  having a through hole  21   e  in axial alignment with the first through hole  21   a , an elongated latch accommodation chamber  21   f  located on the top side and provided with an opening  21   g  facing downwardly. The cover shell  23  comprises three view holes  23   b  and three button holes  23   c  cut through the inner and outer walls thereof and arranged in a staggered manner on the middle near the top side, a locating frame  23   d  located on the inner wall in a predetermined shape adjacent to the top side and defining a combination lock unit accommodation chamber  23   e  and a constraint member accommodation chamber  23   f.    
         [0022]    The shackle  30  comprises a shackle body  31 , a hook  33  pivotally connected to one end of the shackle body  31  by a pin  32 , a transparent flexible plastic sleeve  34  sleeved onto the shackle body  31  and the hook  33 . The hook  33  is provided at a free end thereof with a first locating notch  33   a  and a second locating notch  33   b  spaced from each other. The shackle body  31  is inserted through the first through hole  21   a  and the through hole  21   e  of the upper stop block  21   c  into the inside of the bottom shell  21 , and movable relative to the bottom shell  21  between a first position P 1  (see  FIG. 8 ) and a second position P 2  (see  FIG. 9 ). When the shackle body  31  is moved to the first position P 1 , the free end of the hook  33  passes through the second through hole  21   b  and is suspended inside the bottom shell  21 . When the shackle body  31  is moved to the second position P 2 , the free end of the hook  33  is moved out of the second through hole  21   b  to the outside of the bottom shell  21 . Further, the free end of the shackle body  31  is mounted with a stop pin  31   a . As shown in  FIG. 9 , when the shackle body  31  is moved upwards relative to the bottom shell  21 , the stop pin  31   a  will be stopped at the upper stop block  21   c  to keep the shackle body  31  in the upper limit position, i.e., the second position P 2 , avoiding falling of the shackle body  31  out of the bottom shell  21 . Further, as shown in  FIG. 8 , when the shackle body  31  is moved downwards relative to the bottom shell  21 , the free end of the shackle body  31  is stopped against the lower stop block  21   d  to keep the shackle body  31  in the lower limit position, i.e., the first position P 1 . 
         [0023]    The latch  40  comprises a latch body  42  and a protruding rod  44  perpendicularly outwardly extending from a middle part of the latch body  42 . The latch body  42  has one end beveled, forming an engagement end  42   a . The other end of the latch body  42  is configured to provide a spring mounting rod  42   b . The latch  40  is mounted in the latch accommodation chamber  21   f  of the bottom shell  21  and movable between an engagement position P 3  (see  FIG. 8 ) and a release position (see  FIG. 9 ). Further, the protruding rod  44  is inserted through the opening  21   g  of the latch accommodation chamber  21   f  and exposed to the inside of the bottom shell  21 . Further, a spring member  46  is mounted in the latch accommodation chamber  21   f . The spring member  46  has its one end sleeved onto the spring mounting rod  42   b  of the latch body  42  and stopped against a part of the latch body  42 , and its other end stopped against an inside wall of the latch accommodation chamber  21   f . Thus, the spring member  46  imparts a spring force to the latch  40 , keeping the latch  40  in the engagement position P 3  normally. Further, when the latch  40  is forced by an external force to move from the engagement position P 3  toward the release position P 4 , for example, when the user holds the protruding rod  44  to move the latch  40  from the engagement position P 3  toward the release position P 4 , the spring member  46  is compressed (see  FIG. 9 ). When the applied force is released from the latch  40 , the spring member  46  imparts a return force to the latch  40  to move the latch  40  back to the engagement position P 3 . Further, a cover plate  48  is affixed to the inner wall of the top side of the bottom shell  21  by screws  49  to close the latch accommodation chamber  21   f , avoiding falling of the latch  40  and the spring member  46  out of the latch accommodation chamber  21   f.    
         [0024]    Referring to  FIG. 3 , the constraint member  50  is a single piece block member having substantially a rectangular shape. The constraint member  50  comprises a block body  50   a . The block body  50   a  has a first hook portion  50   b  and a second hook portion  50   c  disposed at the top side thereof and spaced from each other at a predetermined distance, three protruding blocks  50   d  spaced on the back side thereof and a spring mounting rod  50   e  located on one end thereof. The constraint member  50  is mounted in the constraint member accommodation chamber  23   f  of the cover shell  23  and movable between a locked position P 5  (see  FIG. 4  and  FIG. 6 ) and an unlocked position P 6  (see  FIG. 5  and  FIG. 7 ). A spring member  52  is mounted in the constraint member accommodation chamber  23   f . The spring member  52  has its one end sleeved onto the spring mounting rod  50   e  and stopped against a part of the block body  50   a  and its other end stopped against the cover shell  23 . Thus, the spring member  52  imparts a pressure to the constraint member  50 , keeping the constraint member  50  in the locked position P 5  normally. 
         [0025]    The combination lock unit  60  is mounted in the combination lock unit accommodation chamber  23   e  and adapted to control the constraint member  50 , deciding whether or not to allow movement of the constraint member  50  between the locked position P 5  and the unlocked position P 6 . The combination lock unit  60  comprises a metal rack  61  mounted inside the combination lock unit accommodation chamber  23   e , a shaft  62  mounted on the rack  61 , three number wheels  63  rotatably mounted on the shaft  62 , three ratchet wheels  64  rotatably mounted on the shaft  62 , three ratchet wheel driving units  65 , a shifting lever  66  connected to one end of the shaft  62  and a combination lock unit guard plate  67 . 
         [0026]    Each number wheel  63  comprises a wheel body  63   a  and a ring  63   b  mounted on the wheel body  63   a  inscribed with a series of numerals (not shown) on the periphery. The wheel body  63   a  has a notch  63   c  on one side edge thereof at a predetermined location. When the number wheels  63  are rotated to show a predetermined sequence of numbers, the notches  63   c  of the wheel bodies  63   a  of the number wheels  63  are aligned in line and respectively aimed at the protruding blocks  50   d  of the constraint member  50  (see  FIG. 6 ), allowing the protruding blocks  50   d  to be moved into the notches  63   c.    
         [0027]    The ratchet wheels  64  are respectively affixed to the number wheels  63  at one side so that rotating one ratchet wheel  64  causes the associated number wheel  63  to be rotated. 
         [0028]    The ratchet wheel driving units  65  are respectively mounted in the rack  61  corresponding to the ratchet wheels  64 , each comprising a driving rod (not shown), a pawl  65   a  and a button  65   b . Pressing the driving rod causes the driving rod to push and rotate the associated ratchet wheel  64 , and therefore the associated number wheel  63  is rotated with the ratchet wheel  64 . The pawl  65   a  engages the associated ratchet wheel  64 , stopping the associated ratchet wheel  64  in position. Each button  65   b  is affixed to the associated driving rod, and inserted through one button hole  23   c  of the cover shell  23  and exposed to the outside of the cover shell  23  for pressing by the user. The user can see the number exposed by the respective number wheel  63  through one view hole  23   b.    
         [0029]    The relationship among the number wheels  63 , ratchet wheels  64 , ratchet wheel driving units  65  and shifting lever  66  of the combination lock unit  60  and their operation principle are obvious to any person skilled in the art, and therefore no further detailed description in this regard is necessarily presented hereunder. 
         [0030]    The combination lock unit guard plate  67  is fixedly fastened to the locating frame  23   d  inside the cover shell  23  by screws  67   a  to prohibit falling of the constraint member  50 , the spring member  52  and the combination lock unit  60  out of the locating frame  23   d . The combination lock unit guard plate  67  has a first locating hole  67   b  and a second locating hole  67   c . When the constraint member  50  is in the locked position P 5 , the first hook portion  50   b  and second hook portion  50   c  of the constraint member  50  respectively extend to the first locating hole  67   b  and the second locating hole  67   c  (see  FIG. 8 ). When the constraint member  50  is in the unlocked position P 6 , the first hook portion  50   b  and second hook portion  50   c  of the constraint member  50  are respectively concealed inside the combination lock unit guard plate  67  (see  FIG. 5 ). 
         [0031]    After understanding of the structure of the component parts of the padlock  10  and their relationship, the operation and effects of the padlock  10  are outlined hereinafter with reference to  FIGS. 4-9 , 
         [0032]    When the padlock  10  is locked (see  FIG. 1 ), i.e., when the shackle  30  is in the first position P 1 , the cover shell  23  is closed on the bottom shell  21  and the number wheels  63  are rotated to a number combination that does not open the lock, as shown in  FIG. 4 , the shackle body  31  of the shackle  30  and the protruding rod  44  of the latch  40  are respectively received in the first locating hole  67   b  and second locating hole  67   c  of the combination lock unit guard plate  67  and hooked in place by the first hook portion  50   b  and second hook portion  50   c  of the constraint member  50  (in the locked position P 5 ), and at this time, the protruding blocks  50   d  of the constraint member  50  are respectively stopped against the wheel bodies  63   a  of the number wheels  63 , therefore the constraint member  50  is held in the locked position P 5  and prohibited from movement toward the unlocked position P 6 , keeping the padlock  10  in the locked status. 
         [0033]    When wanting to unlock the padlock  10 , the user can press the respective buttons  65   b  to move the respective number wheels  63  to the position where the number wheels  63  show a predetermined sequence of numbers. At this time, the notches  63   c  of the number wheels  63  are aligned in line and respectively aimed at the protruding blocks  50   d  of the constraint member  50  (see  FIG. 6 ). Thereafter, the user can pull the cover shell  23  outwards from bottom shell  21 . At this time, the shackle body  31  of the shackle  30  and the protruding rod  44  of the latch  40  are moved away from the first locating hole  67   b  and the second locating hole  67   c  respectively and forced against the first hook portion  50   b  and second hook portion  50   c  of the constraint member  50  to move the constraint member  50  from the locked position P 5  to the unlocked position P 6  (see  FIG. 5 ). At this time, the protruding blocks  50   d  of the constraint member  50  are respectively moved into the notches  63   c  of the number wheels  63  (see  FIG. 7 ). Thus, the first hook portion  50   b  and the second hook portion  50   c  can be moved away from the shackle body  31  of the shackle  30  and the protruding rod  44  of the latch  40  so that the cover shell  23  can be continuously turned outwards from the bottom shell  21  to open the storage chamber  23   a  (see  FIG. 8 ). 
         [0034]    After the storage chamber  23   a  is opened, the user can hold the protruding rod  44  of the latch  40  and move the latch  40  from the engagement position P 3  to the release position P 4  to disengage the engagement end  42   a  from the second locating notch  33   b  of the hook  33 . At this time, the user can pull the shackle  30  outwards to shift the shackle body  31  from the first position P 1  to the second position P 2  and to have the free end of the hook  33  be moved out of the bottom shell  21 , thereby opening the shackle  30 . Thereafter, the user can release the latch  40  to let the latch  40  be returned by the spring member  46  to the engagement position P 3 . 
         [0035]    When wanting to lock the shackle  30  again after the shackle  30  has been opened, the user can push the shackle  30  from the second position P 2  toward the first position P 1 , at this time the free end of the hook  33  is moved into the second through hole  21   b  of the bottom shell  21  forced against the engagement end  42   a  of the latch  40 , moving the latch  40  from the engagement position P 3  toward the release position P 4  for allowing the free end of the hook  33  to be continuously moved to the deep inside of the bottom shell  21  to the first position P 1  where the shackle  30  is stopped in place. Thereafter, the latch  40  will be returned by the spring member  46  to the engagement position P 3  where the engagement end  42   a  is forced into engagement with the first locating notch  33   b  of the hook  33  to lock the shackle  30 . 
         [0036]    When closing the cover shell  23  on the bottom shell  21  at this time, the first hook portion  50   b  and second hook portion  50   c  of the constraint member  50  are moved with the constraint member  50  away from the first locating hole  67   b  and second locating hole  67   c  of the combination lock unit guard plate  67  by the actuation of the shackle body  31  and the protruding rod  44  toward the unlocked position P 6  until the shackle body  31  and the protruding rod  44  have been fully received in the first locating hole  67   b  and the second locating hole  67   c . At this moment, the constraint member  50  will be pushed back to the locked position P 5  by the spring member  52  to make the first hook portion  50   b  and the second hook portion  50   c  hook on the shackle body  31  and the protruding rod  44  respectively. Thereafter, the user can press the buttons  65   b  to rotate the number wheels  63  to show a different sequence of numbers not to open the lock, and therefore the cover shell  23  and the bottom shell  21  are locked and cannot be opened. 
         [0037]    As stated above, the padlock  10  has functions for allowing the casing  20  and the shackle  30  to be separately opened or locked. The user can press the buttons  65   b  to rotate the number wheels  63  to show the predetermined sequence of numbers for allowing opening of the cover shell  23 . After opened the cover shell  23 , the user can hold the protruding rod  44  of the latch  40  and move the latch  40  to the release position P 4  to unlock the shackle  30 , i.e., the casing  20  of the padlock  10  can be separately opened without opening the shackle  30 , facilitating access to storage items. 
         [0038]    In the aforesaid preferred embodiment, the constrain member  50  is made having one first hook portion  50   b  and one second hook portion  50   c  for hooking the shackle body  31  of the shackle  30  and the protruding rod  44  of the latch  40  respectively, enhancing locking stability. However, in actual practice, the constraint member  50  can be designed having only one hook portion, for example, having only the first hook portion  50   b  or the second hook portion  50   c  for hooking the shackle body  31  of the shackle  30  or the protruding rod  44  of the latch  40 , achieving the same effect of locking the cover shell  23  to the bottom shell  21 . Further, in the aforesaid preferred embodiment, the combination lock unit  60  comprises a ratchet wheel driving unit  65  for allowing the user to rotate the number wheels  63  by pressing the associated buttons  65   b . However, this combination lock design is not a limitation, for example, the ratchet wheels  64  and the ratchet wheel driving unit  65  can be omitted and the number wheels  63  can be exposed to the outside of the cover shell  23  for rotation by the user directly to lock or unlock the combination lock unit  60   
         [0039]    Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.

Summary:
A padlock includes a casing having a bottom shell and a cover shell pivoted with each other, a shackle movably mounted in the bottom shell, a constraint member movably mounted in the cover shell and having a hook portion for hooking the shackle to lock the cover shell and the bottom shell, and a combination lock unit mounted in the cover shell for controlling the constraint member to determine whether the constraint member is allowable to move away from the shackle.