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You are an expert at summarizing long articles. Proceed to summarize the following text: 
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims priority under 35 U.S.C. 119 from Taiwan Patent Application No. 102210381 filed on Jun. 3, 2013, which is hereby specifically incorporated herein by this reference thereto. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a combination-identifiable padlock, especially to a padlock with combination lock cylinder and a key lock cylinder. 
     2. Description of the Prior Arts 
     Padlocks are common used small locks to easily lock objects such as bicycles, cabinets, suitcases and so on. Combination lock cylinders are usually used in the padlocks to perform locking and unlocking. If the user forgets the combination, the conventional padlock can only be broken to be unlocked and the broken conventional padlock cannot be reused. Therefore, some of the conventional padlocks have both a combination lock cylinder and a key lock cylinder. When the user forgets the combination, the user can still use a key to unlock the conventional padlock. 
     However, even the user can unlock the conventional padlock by the key when the combination is forgotten, the forgotten combination is still unknown. Then the conventional padlock is only able to be unlocked by the key while the combination lock cylinder is no longer operable since the combination is unidentified. Therefore, even the conventional padlock can be unlocked by the key, the conventional padlock still lose partial function after the combination is forgotten. 
     To overcome the shortcomings, the present invention provides a combination-identifiable padlock to mitigate or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     The main objective of the present invention is to provide a combination-identifiable padlock. The combination-identifiable padlock has a shell, a combination lock cylinder, a key lock cylinder and an identification assembly. The combination lock cylinder, the key lock cylinder and the identification assembly are mounted in the shell. When the correct key is inserted, the key lock cylinder is rotatable to actuate the identification assembly and combination lock cylinder is actuated to identify the combination. Therefore, the combination is retrievable to avoid the combination lock cylinder to become unusable when the combination is forgotten. 
     Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a combination-identifiable padlock in accordance with the present invention; 
         FIG. 2  is a partially exploded perspective view of the combination-identifiable padlock in  FIG. 1 ; 
         FIG. 3  is an exploded perspective view of the combination-identifiable padlock in  FIG. 1 ; 
         FIG. 4  is another exploded perspective view of the combination-identifiable padlock in  FIG. 1 ; 
         FIG. 5  is a partially perspective view of the combination-identifiable padlock; 
         FIG. 6  is another partially perspective view of the combination-identifiable padlock in  FIG. 1 ; 
         FIG. 7  is an operational perspective view of the combination-identifiable padlock in  FIG. 1 , shown unlocked with combination lock cylinder; 
         FIG. 8  is an operational perspective view of the combination-identifiable padlock in  FIG. 1 , shown unlocked with key lock cylinder; 
         FIGS. 9 and 10  are operational end views in partial section of the combination-identifiable padlock in  FIG. 1 , showing the inactive panel located at original position; 
         FIGS. 11 and 12  are operational end views in partial section of the combination-identifiable padlock in  FIG. 1 , showing the inactive panel reaching out; 
         FIGS. 13 and 14  are operational end views in partial section of the combination-identifiable padlock in  FIG. 1 , showing the operations to change the key lock cylinder; and 
         FIG. 15  is another partially exploded perspective view of the combination-identifiable padlock in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 and 2 , a combination-identifiable padlock in accordance with the present invention comprises a shell  10 , a combination lock cylinder  20 , a key lock cylinder  30  and an identification assembly  40 . 
     With reference to  FIGS. 2 to 4 , the shell  10  has a front shell  101  and a rear shell  102  connected to each other by multiple pins  103  and multiple mounting holes  104 . The pins  103  may be riveted to fasten the front and rear shells  101 ,  102 . The shell  10  has a first room  11 , a second room  12  and a third room  13 . The third room  13  is defined between the first and second rooms  11 ,  12 . A partition  14  is formed between the second and third rooms  12 ,  13 . The front shell  101  has multiple through holes  111  formed therethrough and communicating with the first room  11 . The rear shell  102  has multiple receiving recesses  112  formed therein and communicating with the third room  13 . Each receiving recess  112  corresponds to one of the through holes  111  on the front shell  101 . The front shell  101  has a sliding slot  121  formed therein and communicating with the second room  12 . The front shell  101  has a positioning hole  122  formed therethrough and located in the sliding slot  121 . A rod hole  15  is formed through a top of the shell  10  and communicates with the first room  11 . A lock hole  16  is formed through the top of the shell  10  and communicates with the second room  12 . An opening  17  is formed through the rear shell  102  and communicates with the lock hole  16 . 
     The combination lock cylinder  20  is mounted in the first room  11  of the shell  10  and comprises multiple external wheels  21 , multiple internal wheels  22 , a lock rod  23  and a resilient element  24 . Each external wheel  21  is mounted through a corresponding through hole  111  of the front shell  101  and is mounted in a corresponding receiving recess  112  of the rear shell  102 . Each internal wheel  22  is mounted in a corresponding external wheel  21  and has an identification hole  221  formed through a sidewall thereof. The lock rod  23  is mounted through the internal wheels  22  and has an outer end. The outer end of the lock rod  23  is mounted through the rod hole  15  of the shell  10  and has a curved part  16  extending into the lock hole  16  of the shell  16 . The resilient element  24  abuts a bottom end of the lock rod  23 . The cooperation between the external wheels  21 , the internal wheels  22  and the lock rod  23  results in locking and unlocking the combination lock cylinder  20 . The other detailed structure of the combination lock cylinder  20  is well known by a person skilled in the art so that is not described here. 
     The key lock cylinder  30  is mounted in the second room  12  of the shell  10 . The key lock cylinder  30  is unlocked with a key to be rotated. The key lock cylinder  30  has a stop  31 , a top end and a notch  34 . The stop  31  is formed on an outer wall of the key lock cylinder  30 . The top end of the key lock cylinder  30  is hollow, extends out of the lock hole  16  of the shell  10  and is mounted around the curved part  231  of the lock rod  23 . The notch  34  is formed transversely through the top end of the key lock cylinder  30 . A positioning pin  32  and a resilient element  33  are mounted transversely in the key lock cylinder  30 . The positioning pin  32  is mounted slidably in the sliding slot  121  to keep the key lock cylinder  30  from pulling out of the shell  10 . The resilient element  33  presses against the positioning pin  32  to abut an inner wall of the shell  10 . The other detailed structure of the key lock cylinder  30  is well known by a person skilled in the art so that is not described here. 
     With further reference to  FIGS. 5 and 6 , the identification assembly  40  is mounted in the third room  13  of the shell  10  and comprises an actuating panel  41 , a resilient element  42  and an inactive panel  43 . The actuating panel  41  has a first side  411  facing the combination lock cylinder  20  and a second side  412  facing the key lock cylinder  30 . A shallow recess  413  is formed on the first side  411 . A protrusion  414  is formed on the second side  412 . A mounting tag  415  is formed on an edge of the actuating panel  41 . The resilient element  42  is mounted in the shallow recess  413  and is clamped between the actuating panel  41  and the partition  14 . The inactive panel  43  is connected securely to the actuating panel  41 . The inactive panel  43  may have a fastening hole  432  mounted securely around the mounting tag  415  to connect the inactive panel  43  securely to the actuating panel  41 . Multiple resilient pawls  431  are formed on a side of the inactive panel  43 , selectively protrude into the first room  11  of the shell  10  and selectively engage respectively with the identification holes  221  of the internal wheels  22 . 
     With further reference to  FIG. 7 , the padlock as described may be unlocked via the combination lock cylinder  20 . The curved part  231  of the lock rod  23  is sprung out of the top ends of the shell  10  and the key lock cylinder  30  so that the lock rod  23  is rotated freely and the padlock as described is unlocked. With further reference to  FIG. 8 , the padlock as described may be unlocked via the key lock cylinder  30 . The user rotates the key lock cylinder  30  through the key until the notch  34  of the key lock cylinder  30  communicates with the opening  17  of the shell  10 . Then the curved part  231  of the lock rod  23  can be rotated out of the shell  10  through the notch  34  and the opening  17  to unlock the padlock as described. 
     With reference to  FIGS. 9 and 10 , generally, the stop  31  on the key lock cylinder  30  does not abut the protrusion  414  on the actuating panel  41  so that the resilient pawls  431  of the inactive panel  43  do not interfere the internal wheels  22 . No matter the internal wheels  22  are rotated at any angles, the resilient pawls  431  of the inactive panel  43  do not engage the identification holes  221  of the internal wheels  22 . 
     With reference to  FIGS. 11 and 12 , when the user wants to retrieve the forgotten combination, the key is inserted to rotate the key lock cylinder  30 . When the stop  31  of the key lock cylinder  30  abuts the protrusion  414  of the actuating panel  41 , the actuating panel  41  is pressed to tilt so that forces the inactive panel  43  to move toward the combination lock cylinder  20 . Then the resilient pawls  431  abut against the outer walls of the internal wheels  22  because of the resilience. The external wheels  21  and the internal wheels  22  are rotated to retrieve the forgotten combination. When the identification hole  221  of each internal wheel  22  aligns with the corresponding resilient pawl  431 , the resilience forces the corresponding resilient pawl  431  to pivot to engage the identification hole  221 . Then the internal wheels  22  and the external wheels  21  are held and cannot be rotated, and the combination lock cylinder  20  is unlocked. At this time, the external wheels  21  show the correct combination so that the combination is retrieved. When the combination is retrieved, the key lock cylinder  30  is rotated back to be locked. Then the stop  31  leaves the protrusion  414  so that the resilient element  42  pushes the actuating panel  41  to move back. Thus, the inactive panel  43  is also pulled back to the original position. 
     Generally, the positioning pin  32  is mounted in the sliding slot  121  to keep the key lock cylinder  30  from pulling out of the shell  10 . However, the key lock cylinder  30  may need to be changed regularly for safety reason. With reference to  FIGS. 13 to 15 , when the key lock cylinder  30  needs to be changed, the key is inserted into and rotates the key lock cylinder  30 . When the positioning pin  32  aligns with the positioning hole  122  of the shell  10 , the resilient element  32  forces the positioning pin  32  to engage the positioning hole  122 . Then the user put a tool  50  into the positioning hole  122  so that the positioning pin  32  is pressed to leave the sliding slot  121 . Therefore, the key lock cylinder  30  can be pulled out of the shell  10  to be replaced. 
     The padlock as described has following advantages. With the identification assembly  40 , the user easily retrieves the forgotten combination simply by inserting the correct key and rotating the wheels  21 ,  22 . Therefore, combination lock cylinder  20  does not lose its function forever since the combination is retrievable. Further, the key lock cylinder  30  can be changed regularly for safety reasons. 
     Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Summary:
A combination-identifiable padlock has a shell, a combination lock cylinder, a key lock cylinder and an identification assembly. The combination lock cylinder, the key lock cylinder and the identification assembly are mounted in the shell. When the correct key is inserted, the key lock cylinder is rotatable to actuate the identification assembly and combination lock cylinder is actuated to identify the combination. Therefore, the combination is retrievable to avoid the combination lock cylinder to become unusable when the combination is forgotten.