Patent Publication Number: US-9890559-B2

Title: Padlock with fully integrated dual locking mechanism with reset mechanism

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATION 
     This application claims priority under 35 USC § 119 to U.S. Provisional Patent Application No. 62/138,135, filed Mar. 25, 2015, whose entire contents are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to padlocks, in particular a padlock with a dual locking mechanism. 
     BACKGROUND OF THE INVENTION 
     Numerous padlock constructions have been developed and are widely employed to prevent unauthorized persons from gaining access to any particular item or area which has been closed and locked. Although many locks are constructed to be opened by a key, numerous combination lock constructions have been developed which are opened by knowledge of a particular combination. 
     One particular type of combination lock that has become very popular due to its ease and convenience of use is a combination lock which employs a plurality of rotatable independent dials, each of which forms one of the indicia, usually numerals or letters, which comprise the combination for releasing the lock. Typically, the combination lock has one mode or position in which the user is able to set or reset the desired combination sequence. 
     In airplane travel, new regulations and requirements allow customs officers or transit security personnel to physically break any padlock in order to gain access to luggage which is deemed suspicious. Under these new security regulations, all luggage must be scanned or inspected to prevent the transportation of potentially dangerous items or products which are deemed to be undesirable. Currently a padlock may have two separate and independent locking systems, with both locking systems independently enabling a single shackle to be released and/or lockingly engaged. In this way, by employing either a key activation zone or a combination activation zone, the padlock can be opened. The key activation zone allows security personnel to open the padlock with a master key and then re-lock the padlock in place after the inspection has been completed. 
     SUMMARY OF THE INVENTION 
     The present invention provides a dial padlock with dual locking mechanism. The padlock can be opened by a combination code or by a key-overriding mechanism. 
     One aspect of the present invention is a padlock operable in a locked mode and in an opened mode, comprising: 
     a shackle having a heel and a toe; 
     a lock housing configured to store the heel of the shackle, the lock housing comprising a top portion, a middle portion and a bottom portion, wherein the heel of the shackle can be partially released from the lock housing from a first shackle position to a second shackle position; 
     a spindle disposed inside the lock housing and arranged to provide a code locking mechanism, the code locking mechanism configured to operate the padlock in the locked mode or in the opened mode based on a combination code; 
     a plurality of clutches rotatably mounted on the cylindrical surface of the spindle; 
     a plurality of dials mounted in the middle portion of the lock housing in relationship to the clutches to form the combination code; and 
     an overriding mechanism disposed in relationship to the spindle, the overriding mechanism activatable to cause the padlock to operate in the opened mode, wherein the shackle is in the first shackle position when the padlock is operated in the locked mode, and the shackle is in the second shackle position when the padlock is operated in the opened mode, wherein each of the clutches comprises an extended outer ring having thereon a plurality of clutch slots, and each of the dials comprises an extended inner ring having thereon a plurality of teeth arranged to engage with said plurality of clutch slots of a clutch so as to control rotational movement of said clutch relative to the spindle. 
     According to an embodiment of the present invention, the heel of the shackle comprises a neck area, and said padlock further comprises a latch having a fork arranged to engage the neck area of the heel so as to prevent the shackle from moving away from the first shackle position when the padlock is operated in the locked mode. 
     According to an embodiment of the present invention, the spindle comprises a spindle channel for storing the heel, the spindle channel having a channel portion for storing part of the neck area of the heel, and the latch is disposed in relationship to the channel portion, and the spindle further comprises a cam arranged to engage the latch so as to keep the fork in an engaging relationship with the neck area of the heel. 
     According to an embodiment of the present invention, the overriding mechanism can be activated by a key, causing the cam to disengage the fork of the latch from the neck area of the heel, allowing the shackle to move from the first shackle position to the second shackle position. 
     According to an embodiment of the present invention, the bottom portion of the lock housing comprises a bottom body, and the spindle is movably mounted on the bottom body such that the spindle can be caused to move upward toward the top portion of the lock housing in a vertical movement from a first spindle position to a second spindle position, and each of the clutches has an inner surface and an extended inner ring extended from the inner surface, the extended inner ring having a ring thickness and an opening gap made on the extended inner ring through the ring thickness, and the spindle comprises a plurality of extended protrusions, each extended protrusion associated with a clutch such that the extended inner ring of the clutch prevents the spindle from moving upward when the extended protrusion is misaligned with the opening gap of the associated clutch. 
     According to an embodiment of the present invention, when the padlock is operated in the locked mode, the dials can be rotated relative to the spindle to change the combination code and the clutches are caused to rotate along with the dials, such that when the combination code matches a predetermined code, the opening gap of each of the clutches aligns with an associated extended protrusion of the spindle, allowing the spindle to move from the first spindle position to the second spindle position when the shackle is pulled upward from the first shackle position to the second shackle position, causing the padlock to operate in the opened mode. 
     According to an embodiment of the present invention, the plurality of dials form a dial stack comprising a first dial and a last dial, the last dial positioned in contact to the bottom body of the lock housing, and the top portion of the lock housing comprises a top body mounted on the first dial and a spacer fixedly mounted on the top body between the top body and the spindle, the spacer having a shackle hole dimensioned to receive the heel of the shackle, the top body comprising a locking hole and a top body hole, the locking hole dimensioned to receive the toe of the shackle, the top body hole in communication with the shackle hole of the spacer and the spindle channel of the spindle for placement of the heel of the shackle. 
     According to an embodiment of the present invention, the shackle hole of the spacer has an inner surface and an extended ring extended therefrom, the extended ring having a shackle-protrusion slot made thereon and a ring surface facing the top body, wherein the spacer has a cutout zone dimensioned to receive the spindle, allowing the spindle to move between the first spindle position and the second spindle position, and the heel of the shackle has a shackle protrusion positioned in relationship to the shackle-protrusion slot such that when the shackle is in the first shackle position, the shackle protrusion is located between the extended ring and the spindle, and when the shackle is pulled upward from the first shackle position to the second shackle position, the shackle protrusion moves through the shackle-protrusion slot so that when the spindle is in the second spindle position, the shack protrusion is located in the shackle hole between the extended ring and the top body. 
     According to an embodiment of the present invention, when the padlock is operated in the opened mode, the shackle can be rotated so as to move the toe of the shackle away from the locking hole of the top body and to move the shackle protrusion away from the shackle-protrusion slot, and when the shackle protrusion is moved away from the shackle-protrusion slot, the extended ring of the spacer prevents the shackle from moving downward. 
     According to an embodiment of the present invention, when the spindle is in the second spindle position, each of the extended protrusion of the spindle is engaged with the opening gap of one of the clutches, preventing the clutches from rotating relative to the spindle. 
     According to an embodiment of the present invention, when the spindle is in the second spindle position, the dials can be rotated relative to the clutches to change the combination code. 
     According to an embodiment of the present invention, each of the dials has an outer ring arranged for placing a plurality of symbols to form the combination code, the outer ring dimensioned to receive a clutch, and each of the dials is associated with one of the clutches to form a dial-clutch assembly, each dial-clutch assembly comprising a separation ring positioned within the outer ring of the dial, and a helical spring positioned within the outer ring between the separation spring and extended outer ring of the clutch, such that when the dial in a dial-clutch assembly is rotated relative to the clutch, the teeth of the dial are configured to push the clutch toward separating ring and to compress the helical spring so as to allow the teeth to disengage from the clutch slots. 
     According to an embodiment of the present invention, each of the teeth has a slope-like surface on both sides of the tooth and each of the clutch slots also has a slope-like surface on both side of the clutch so as to facilitate rotation of the dial relative to the clutch in a dial-clutch assembly. 
     According to present invention, the spindle further comprises a ratchet slot spaced from the extended protrusions of the spindle, the ratchet slot dimensioned to receive a ratchet plate having a plurality of tips, and the inner surface of each of the clutches has a plurality of ratchet-receiving slots arranged to engage with one of the tips of ratchet plate so as to produce a clicking sound when the clutch is rotated relative to the spindle. 
     According to the present invention, the extended inner ring of each of the clutches further comprises a plurality of faulty notches made through a part of the ring thickness, the faulty notches spaced from the opening gap, such that when the extended protrusion of spindle is misaligned with the opening gap of the associated clutch, the extended protrusion of the spindle is in contact to one the faulty notches on the associated clutch. 
     According to an embodiment of the present invention, the bottom body comprises a plurality of screw holes, the spindle has a cylindrical surface and a plurality of screw passing slots on the cylindrical surface, and the spacer further comprises a plurality of screw receiving holes, and the lock housing further comprises screws arranged to fasten the spacer to the screw holes on the bottom body via the screw receiving holes of the spacer through the screw passing slots of the spindle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  shows a cross sectional side view of the padlock in a locked mode. 
         FIG. 1B  shows a cross sectional bottom view of the padlock of  FIG. 1A . 
         FIGS. 2A and 2B  show different views of a dial. 
         FIGS. 3A and 3B  show different views of a clutch. 
         FIG. 4  is an isometric view of the shackle. 
         FIG. 5  is an isometric view of the latch. 
         FIG. 6  is an isometric view of the ratchet plate. 
         FIG. 7  is an isometric view of the cover plate. 
         FIGS. 8A and 8B  are different views of the spacer. 
         FIGS. 9A and 9B  are different views of the bottom body. 
         FIGS. 10A and 10B  are different views of the top body. 
         FIG. 11  is an isometric view of the cylinder. 
         FIG. 12  is an isometric view of the cam. 
         FIGS. 13A and 13B  are different views of one half of the spindle. 
         FIGS. 14A and 14B  are different views of another half of the spindle. 
         FIG. 15A  is a cross sectional view of a dial-clutch assembly when the teeth of the dial are engaged in the wave-slots of the clutch. 
         FIG. 15B  is an exploded cross sectional view of the dial-clutch assembly. 
         FIG. 15C  is a cross sectional view of a dial-clutch assembly when the teeth of the dial are disengaged from the wave-slots of the clutch. 
         FIG. 16A  shows a cross sectional side view of the padlock opened by a matching combination code. 
         FIG. 16B  shows a cross sectional bottom view of the padlock of  FIG. 16A . 
         FIG. 17A  shows a cross sectional side view of the padlock opened by a key. 
         FIG. 17B  shows a cross sectional bottom view of the padlock of  FIG. 17A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As seen in  FIGS. 1A-5, 13A-14B , the present invention is directed to a dial padlock with dual locking mechanism, which is encased in a lock housing. The padlock  10  can be opened by a combination code and by a key operating mechanism. The lock housing has three portions: a top portion, a middle portion and a bottom portion. The top portion includes a top body  150 ; the middle portion includes a stack of dials  40  and clutches  50 ; and the bottom portion includes a bottom body  130 . The lock housing is configured to store the long leg  71  (heel) of shackle  70 . The dual locking mechanism includes a spindle  60 . The spindle  60  is located inside the lock housing to provide a code locking mechanism in order to keep the padlock in the locked mode based on a combination code. The spindle  60  has a substantially cylindrical surface  6001  and a plurality of extended protrusions  61  extended from the cylindrical surface  6001 . The code locking system is controlled by dials  40  which cause the rotational movement of the clutches  50 . When all dials  40  are turned to the preset lock-open combination, all the clutches are turned such that the opening gap  51  of each clutch  50  aligns with an extended protrusion  61  of the spindle  60 . The opening gap  51  is made through the thickness of an extended inner ring  58  of clutch  50 . The alignment between the opening gaps  51  and the extended protrusions  61  allows the user to pull the spindle  60  upward (away from the bottom portion of the lock housing) to place the padlock  10  in an opened mode. The spindle  60  has a spindle channel  6002  for placing the long-leg  71  of shackle  70  in the lock housing. The spindle channel  6002  has a lower channel portion  6003  with a stop wall  69 . The long leg  71  of shackle  70  has a neck area  73  with an upper surface  72  and a lower surface  76 . The neck area  73  of the long leg  71  is partially located in the lower channel portion  6003  of spindle  60  with the end of the long leg  71  of shackle  70  being located in the proximity of the bottom of the lower channel portion  6003 . The spindle  60  has a latch channel  62  made into part of the lower channel  6003 . The latch channel  62  is dimensioned for placing a latch  80  between the upper surface  72  and lower surface  76  of the neck area  73  of shackle  70 . The latch  80  has a fork  82 . 
     In the combination-open mode and in the locked mode, the fork  82  of latch  80  always engages the lower surface  76  of the neck area  73  of shackle  70 . The latch  80  is placed inside a latch channel  62  of spindle  60 . As such, the shackle  70  and the spindle  60  are pulled up and pushed down together. 
     In the key-open mode, the lower surface  76  of the neck area  73  of shackle  70  and the stop wall  69  in the lower channel portion  6003  limit the upward movement of shackle  70 . 
     An advantage of the padlock, according to the present invention, is the reset mechanism. Once the user has opened the padlock by a combination code, the user can turn the dials  40  to set a new combination with or without rotating the shackle  70 . As seen below, when the padlock  10  is in the locked mode, the clutches  50  are disengaged from the spindle  60  and, therefore, move easily along with the dials  40  in a rotation movement relative to spindle  60 . However, when the padlock  10  is in the reset mode, the clutches  50  are engaged with the spindle  60  and the clutches  50  are prevented from rotating when the dials  40  are turned. Thus, the user must use a stronger force to turn the dials in the reset mode than the force to turn the dials in the locked mode. 
     Another feature of this lock is the anti-peek function. As shown in  FIGS. 2A and 2B , each dial  40  has an extended inner ring  43  with a ring surface  44 , and an outer ring  47  with a bottom surface  45 . As the dials  40  are stacked one upon another, the extended inner ring  43  of the lower dial  40  is placed inside the lower end of outer ring  47  of the dial  40  directly above, with the bottom surface  45  of the lower dial  40  contacting the top surface  49  of the upper dial  40 . The last dial  40  is also placed over the contact surface  132  of bottom body  130 . In addition, the top body  150  of padlock  10  is fastened to the bottom body  130  via a spacer  110 , limiting the vertical (upward and downward) movement of the dials  40 . The stacking of the dials  40  blocks the view of the internal mechanism of the lock, making picking the lock difficult. 
     Finally, another advantage of this padlock is to allow a traveler to use the combination mechanism during a trip and allow the TSA officer to inspect the luggage by using the key operating mechanism. 
     Placement of Dials, Clutches, Clutch Springs and Separation Rings ( FIGS. 1A-3B, 15A and 15B ) 
     As seen in  FIG. 15A , each of the dials  40  is associated with a different one of the clutches  50  to form a dial-clutch assembly  200 . As seen in  FIGS. 2A-2B , the outer ring  47  of each dial  40  has a cylindrical outer surface with numerals or symbols  48  to form a combination code. The outer ring  47  has a bottom surface  45  and a top surface  49 . The extended inner ring  43  of dial  40  joins the outer ring  47  at the top surface  49 . The inner ring  43  has a ring surface  44  and a plurality of teeth  41  within the cylindrical inner surface of the outer ring  47 . As seen in  FIG. 3A-3B , the clutch  50  has a cylindrical body with an inner surface  56  and an outer surface  5001 . The clutch  50  has an extended outer ring  57  extended from the outer surface  5001  and an extended inner ring  58  extended from the inner surface  56 . The lower side of the extended outer ring  57  has a lower surface  59 . The upper side of the extended outer ring  57  has a plurality of wave-slots  53  formed thereon. The wave-slots  53  of each clutch  50  are dimensioned to receive the teeth  41  of an associated dial  40 . The clutch  50  has a plurality of ratchet receiving slots  52  formed on the inner surface  56 . The extended inner ring  58  has a thickness. The extended inner ring  58  has an opening gap  51  formed thereon through the thickness. The extended inner ring  58  also has a plurality of faulty notches  55  made on a part of the thickness. 
     In each of the dial-clutch assembly  200 , the teeth  41  of the dial  40  are arranged to engage with the wave-slots  53  of the clutch  50 . A separation ring  190  is placed below the clutch  50  within the inner surface of the outer ring  47  of dial  40 , near the bottom surface  45 . A helical clutch spring  180  is placed in the space between the lower surface  59  of clutch  50  and the separation ring  190 . As seen in  FIG. 3B , each of the wave-slots  53  has slope-like surfaces  54  on both sides of the wave-slot  53 . As seen in  FIG. 2B , each of the teeth  41  also has slope-like surfaces  46  on both sides of the tooth  41  so as to facilitate the turning of the dial  40  relative to the clutch  50  in the reset mode, for example. In the padlock  10 , the dial-clutch assemblies  200  are stacked one upon another to form the middle portion of the lock housing, between the top portion and the bottom portion of the lock housing. 
     Placement of Spindle, Dial-Clutch Assemblies, Bottom Body and Cover Plate ( FIGS. 1A-1B, 6 and 13A-14B ) 
     The spindle  60  is made up to two parts: one part is depicted in  FIGS. 13A and 13B ; and the other part is depicted in  FIGS. 14A and 14B . The two parts are fastened together with rivets  231 ,  232  on one another inserted into mating holes on the other part after the heel or long-leg  71  of the shackle  70  has been placed in the spindle channel  6002 . The spindle  60  has a ratchet slot  67  to receive a ratchet plate  90  ( FIG. 6 ). The ratchet plate  90  has a plurality of tips  91  arranged to engage with the ratchet receiving slots  52  of clutches  50  so as to produce a clicking sound or feeling when a clutch  50  is rotated relative to the spindle  60 . After the ratchet plate  90  is placed in the ratchet slot  67  of the spindle  60 , a cover plate  100  with holes  102  is fastened to the top portion  68  of spindle  60  through rivets  63 . As such, the ratchet plate  90  is fixedly mounted on the spindle  60 . 
     The spindle  60  is placed inside the lock housing. In particular, the upper part of the spindle  60  resides inside the stack of dials  40  and clutches  50  and the lower part resides in the bottom portion of the lock housing. The bottom end  64  of the spindle  60  has a curved slot  65  on each half of the spindle. The bottom body  130  of the bottom portion has two curved members  131  to be placed in the curved slots  65 . The bottom body  130  also has a protrusion-receiving slot  135  to receive the lower part of the bottom extended protrusion  61 . Because of the restriction of the protrusion-receiving slot  135  of bottom body  130  on the bottom extended protrusion  61  of spindle  60  and the restriction of the curved slots  65  of spindle  60  on the curved members  131  of bottom body  130 , the spindle  60  can only have vertical movement but no rotational movement relative to the lock housing. 
     Placement of Spindle, Spacer, Top Body, Dials, Clutches and Bottom Body ( FIGS. 1A-3B, 8A-10B and 13B ) 
     The spindle  60  has two screw passing slots  66 . After the spindle  60  is placed inside the stack of dials  40  and clutches  50  and on the bottom body  130 , a spacer  110  is placed on top of the stack of dials  40 . The spacer  110  has two (can be one or more than two) holes  111  to allow screws  140  to thread onto the threaded holes  134  of the bottom body  130  after passing through the screw passing slots  66  of spindle  60 . The screw passing slots  66  allow the screws  140  to be fastened to the bottom body  130  without interfering the vertical movement of spindle  60  relative to the lock housing—i.e., relative to the stack of dials  40  and clutches  50 . The spacer  110  also has a shackle hole  118  dimensioned to receive the long leg  71  of shackle  70 . 
     When the lock is in the locked mode and a user aligns the dials  40  to the indicating line  154 / 133  ( FIGS. 9A and 10A ) according to the combination code, the opening gaps  51  of clutches  50  align with the extended protrusions  61  of spindle  60 . The user can pull the shackle  70  upward together with the spindle  60 . The spacer  110  has a cutout zone  113  to allow the spindle  60  to move upward until the top  68  of spindle  60  contacts the edge  114  of cutout zone  113 . The short leg  74  (toe) of shackle  70  is now released from the locking hole  151  of top body  150 . The top body  150  has a screw hole  152  below the locking hole  151  to allow a screw  120  to thread onto a screw hole  117  of spacer  110  for fastening the top body  150  to the spacer  110 . As such, the top body  150  cannot be pulled away from spacer  110 . The top body  150  also has a top body hole  153  in communication with the shackle hole  118  of spacer  110  and the spindle channel  6002  of spindle  60 . 
     Locked Mode ( FIGS. 1A-3B, 4, 5, 9A, 11 and 12 ) 
     So long as at least one of the clutches  50  is not aligned with an extended protrusion  61  of spindle  60 , the spindle  60  cannot be moved upward. Furthermore, because the fork  82  of latch  80  is engaged with the lower surface  76  of the neck area  73  of long leg  7 , the shackle  70  cannot be pulled upward. As seen in  FIG. 5 , the latch  80  has a slot  81  spaced from the fork  82 . As seen in  FIGS. 1A, 1B, 11 and 11B , the padlock  10  has a cylinder  160  placed inside the spindle  60 . The cylinder  160  has two extended protrusions  161  on top of cylinder  160 . A cam  170  having two holes  172  is placed on top of cylinder  160  so that the cam  70  is turned along with the cylinder  160 . The cam  170  has an extended pin  171  arranged to engage with the slot  81  of latch  80 . If the cam  170  cannot be turned, the latch  80  is in a locked position. As such, the fork  82  of latch  80  prevents the shackle  70  from being pulled upward to release the short leg  74  from the locking hole  150  of top body  150 . 
     Each of the clutches  50  has one or more faulty notches  55  made on the extended inner ring  58 . When the extended protrusion  61  of spindle  60  is not aligned with the opening gap  51  of an associated clutch  50 , the extended protrusion  61  of spindle  60  is in contact to one of the faulty notches  55  of the associated clutch  50 . The faulty notches  55  make the lock harder to pick. Furthermore, the bottom body  130  has an extended ring  136  extended from the contact surface  132 , and the extended inner ring  43  of the last dial  40  is placed in the exterior of extended ring  136 , rendering it difficult to peek into the internal mechanism of padlock  10 . 
     Unlocked by Combination Code ( FIGS. 2A-3B, 8A-10B, 16A and 16B ) 
     To unlock the padlock  10  by the combination code, the user must align the dials  40  to the indicating line  154 / 133  of top body  150  and bottom body  130 . When the dials  40  are turned, the clutches  50  are also turned as the teeth  41  of dials  40  are engaged with the wave-slots  53  of clutches  50 . When all the dials  40  align to the lock open code, the opening gaps  51  of all the clutches  50  align with the extended protrusions  61  of spindle  60 . The user can pull the shackle  70  upward along with the spindle  60  until the top  68  of spindle  80  hits the edge  114  of the cutout zone  113  of spacer  110 . The upward movement of the spindle  60  causes each of the extended protrusions  61  to be engaged with the opening gap  51  of the associated clutch  50 . The engagement prevents the clutches  50  from rotating relative to the spindle  60 . The short leg  74  of shackle  70  is now released from locking hole  151  of top body  150 , and the protrusion  75  of shackle  70  also moves out of the shackle-protrusion slot  115  of spacer  110  and into the shackle hole  118  between the top body  150  and the ring surface  116  of a ring  119 . The shackle-protrusion slot  115  is made on the ring  119 , which is extended from the inner surface of the shackle hole  118 . As the short leg  74  of shackle  70  is released, the shackle  70  can rotate freely while the protrusion  75  of shackle  70  contacts the ring surface  116  of spacer  110 . The ring surface  116  prevents the shackle  70  from being pushed downward so long as the short leg  74  of shackle  70  is not aligned with the locking hole  151  of top body  150 . In the unlocked or open mode of padlock  10 , the extended protrusions  61  of spindle  60  are always engaged with the opening gaps  51  of clutches  50 . When the clutches  50  are stationary with the spindle  60 , the user may reset the combination code. While the spindle  60  is in the upward position, the lower portion of the extended protrusion  61  is still engaged with the protrusion receiving slot  135  of bottom body  130 , and the curved members  131  of bottom body  130  are still engaged with the curved slots  65  of spindle  60 . This engagement prevents any rotational movement of the spindle  60  relative to the lock housing. 
     Reset Mode ( FIGS. 2A-3B, 8A-8B, 13A-13B, 15A-15C and 16A ) 
     When the lock is in the opened mode, the extended protrusions  61  of spindle  60  are engaged with the opening gaps  51  of clutches  50 , preventing the clutches  50  from rotating relative to the spindle  60  and the lock housing. The user can rotate the dials  40  to reset the combination code. The dials  40  can only be rotated without the clutches  50 , requiring the teeth  41  of each dial  41  to be moved out of the engaged wave-slots  53  of an associated clutch  50  until different wave-slots are engaged. This is possible only by pushing the associated clutch  50  downward against the urging force of a clutch spring  180  while a dial  40  is rotated. The downward movement of the clutch  50  compresses the clutch spring  180  as shown in  FIG. 15C . The user must use a stronger force to rotate the dials while resetting the combination code. According to an embodiment of the present invention, each tooth  41  has a slope-like surface  46  on each side of the tooth  41  and each wave-slot  53  has a slope-like surface  54  on each side of the wave-slot. These slope-like surfaces make disengaging the teeth  41  from the wave-slots  53  easier. 
     In a padlock  10  where 10 digits on each dial  40  are used to set a combination code, there are ten teeth  41  on each dial  40  and ten wave-slots  53  on each clutch  50 . Typically the user rotates each of the dials  40  one digit at a time until the desired combination aligns with the indicating line  154 / 133  of top body  150  and bottom body  130 . To give the user a better grip on the dials  40 , each dial  40  also has ten ribs  42  separating the ten digits. As seen in  FIG. 15A , the separation ring  190  in each dial-clutch assembly  200  helps isolate the rotation of one dial  40  from another dial  40 . 
     After resetting, the user rotates the shackle  70  so that its short leg  74  aligns with the locking hole  151  of top body  150  so that the protrusion  75  of shackle  70  also aligns with the shackle-protrusion slot  115  of space  110 . The shackle  70  can be pushed down to engage the short leg  74  of shackle  70  with the locking hole  151  of top body  150 . As the extended protrusions  61  of spindle  60  become disengaged with the opening gaps  51  of the clutches  50 , the user can rotate the dials  40  along with the clutches  50  to place the lock in the locked mode. 
     Unlocked by Key Operating Mechanism ( FIGS. 3A-5, 11, 12, 13A-13B, 17A and 17B ) 
     The key operating mechanism is controlled by a wafer tumbler cylinder  160 , the cam  170  and the latch  80 . The cylinder  160  has two extended protrusions  161 . The cam  170  has two holes  172  to receive the extended protrusions  161  of cylinder  160 . The cam  170  also has an extended pin  171  arranged to engage the slot  81  of latch  80  which is placed inside the latch channel  62  of spindle  60 . As a correct key  300  is inserted into the cylinder  160 , the turn of the key  300  causes the cylinder  160  and the cam  170  to turn. As the cam  170  turns, the extended pin  171  of cam  170  drags the latch  80  sideward in a horizontal movement to move the fork  82  away from the lower channel portion  6003 . The fork  82  of latch  80  is also disengaged from the lower surface  76  of the neck area  73  of shackle  70 . As such, there is no blockage on the neck area  73  of shackle  70 . However, the spindle  60  has no vertical movement because at least one of the opening gaps  51  of the clutches  50  is misaligned with the extended protrusions  61  of spindle  60 . The shackle  70  can be pulled upward without the spindle  60  until the lower surface  76  of the neck area  73  hits the stop wall  69  of the lower channel portion  6003  of spindle  60 . The short leg  74  of shackle  70  is thus released from the locking hole  151  of top body  150 . Since the clutches  50  are not engaged with the spindle  60 , the clutches  50  can be caused to turn along with the dials  40  even when the padlock  10  is unlocked by the correct key  300 . 
     The present invention provides a dual locking padlock wherein the lock body, the cylinder, the clutches, the dials and the spindle are concentric to a center line. 
     Although the present invention has been described with respect to one or more embodiments thereof, it will be understood by those skilled in the art that the foregoing and various other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention.