BACKGROUND OF INVENTION
1. Field of Invention
The present invention is related to a padlock and, more particularly, to a padlock with double locking effects.
2. Related Prior Art
Padlocks include combination (or “numeral”) padlocks and key-operable padlocks. The combination padlocks include a numeral-wheel type and a button type. These padlocks are used in various fields. For example, Taiwanese Patent Nos. 369068 and 498918 disclose key-operable padlocks. Taiwanese Patent Nos. 32470 and 46563 disclose combination padlocks.
Deeming a trunk, a suitcase, a briefcase, a bag or the like suspicious, U.S. customs workers are authorized to break its lock or locks for security check. Such a damaged lock is a loss of a user and causes the user trouble and inconvenience.
To avoid the above-mentioned problems, the U.S. government regulates that lock manufacturers must provide the U.S. customs with a standard key for opening their locks. According to this regulation, several lock manufacturers all over the world are allowed to manufacture such locks.
It is therefore intended to provide a locking apparatus which meets the regulation of the U.S. government. Furthermore, in case a user forgets to bring his key or forgets an unlocking number, the locking apparatus provides the user with another measure for unlocking it.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
SUMMARY OF INVENTION
It is therefore the primary objective of the present invention to provide a padlock with double effects.
To achieve the primary objective of the present invention, there is provided a padlock including a lock body, a shackle and at least one locking unit. The lock body includes a first lock hole defined therein and a second lock hole defined therein. The shackle includes a first end for insertion in the first lock hole and a second end for insertion in the second lock hole. In the lock body, the locking unit is changeable between a locking position for locking the first and second ends of the shackle in the first and second lock holes, a first unlocking position for allowing the first end of the shackle to be removed from the first lock hole and a second unlocking position for allowing the second end of the shackle to be removed from the second lock hole.
The present invention can be best understood through the following description and accompanying drawings wherein:
Other objectives, advantages and features of the present invention will become apparent from the following description referring to the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
The present invention will be described by the detailed illustration of three embodiments referring to the drawings wherein:
FIG. 1 is a perspective view of a padlock according to the first embodiment of the present invention;
FIG. 2 is a top view of the padlock;
FIG. 3 is a front view of the padlock in another position than shown in FIG. 1;
FIG. 4 is a front view of the padlock in another position than shown in FIG. 3;
FIG. 5 is a perspective view of a padlock according to the second embodiment of the present invention;
FIG. 6 is a front view of the padlock in another position than shown in FIG. 5;
FIG. 7 is a front view of the padlock in another position than shown in FIG. 6;
FIG. 8 is a perspective view of a padlock according to the third embodiment of the present invention;
FIG. 9 is a front view of the padlock in another position than shown in FIG. 8;
FIG. 10 is a front view of the padlock in another position than shown in FIG. 9;
FIG. 11 is a perspective view of a first key, a second key and a locking unit of the padlock shown in FIG. 10; and
FIG. 12 is an exploded view of the locking unit shown in FIG. 11.
DETAILED DESCRIPTION OF EMBODIMENTS
Referring to FIGS. 1 through 4, according to a first embodiment of the present invention, a padlock includes a lock body 40, a shackle 42, a first combination locking unit 44 for locking a first end of the shackle 42 in the lock body 40 and a second combination locking unit 46 for locking a second end of the shackle 42 in the lock body 40. The padlock of is 11 similar to those shown in U.S. patent application Ser. No. 10/833,076 except including two combination locking units 44, 46 instead of a combination locking unit and a key-operable locking unit.
The lock body 40 is similar to the lock body shown and described in U.S. patent application Ser. No. 10/833,076. The lock body 40 includes first and second lock holes 48 and 50 defined therein as shown in FIG. 2. More details of the lock body 40 will not be provided for briefness.
The shackle 42 is similar to the shackle shown and described in U.S. patent application Ser. No. 10/833,076. The shackle 42 includes a first insert 52 secured to the first end thereof and a second insert 54 secured to the second end thereof. The first insert 52 includes a neck 56 and a head 58. The second insert 54 is structurally similar to the first insert 52 and includes a neck 60 and a head 62. More details of the shackle 42 will not be given for briefness.
The first and second combination locking units 44 and 46 are structurally similar to the combination locking unit shown in U.S. patent application Ser. No. 10/833,076. The first and second combination locking units 44 and 46 are disposed in the lock body 40. The first combination locking unit 44 can be switched between a locking position and an unlocking position. The second combination locking unit 46 can be switched between a locking and an unlocking position regardless of the first combination locking unit 44. More details of the first and second combination locking units 44 and 46 will not be given for briefness.
Referring to FIG. 3, when turned to a first unlocking number, the first combination locking unit 44 is switched to the unlocking position from the locking position. Thus, the first insert 52 can be removed from the first lock hole 48. Therefore, the shackle 42 is unlocked.
Referring to FIG. 4, when turned to a second unlocking number, the second combination locking unit 46 is switched to the unlocking position from the locking position. Thus, the second insert 54 can be removed from the second lock hole 50. Therefore, the shackle 42 is unlocked.
The first unlocking number can be determined and known only by a user of the padlock. The second unlocking number can be determined only by a manufacturer of the padlock and known by customs workers as well as the manufacturer.
Referring to FIGS. 5 through 7, there is shown a padlock according to a second embodiment of the present invention. The second embodiment is similar to the first embodiment except including a first key-operable locking unit 64 and a second key-operable locking unit 66 instead of the first combination locking unit 44 and the second combination locking unit 46, respectively. The first and second key-operable locking units 64 and 66 are structurally similar to the key-operable locking unit shown in U.S. patent application Ser. No. 10/833,076. The first and second key-operable locking units 64 and 66 are disposed in the lock body 40. The first key-operable locking unit 64 can be switched between a locking position and an unlocking position. The second key-operable locking unit 66 can be switched between a locking and an unlocking position regardless of the first combination locking unit 64. More details of the first and second key-operable locking units 64 and 66 will not be given for briefness.
Referring to FIGS. 5 and 6, a first key 68 is inserted and turned in the first key-operable locking unit 64 so that the first key-operable locking unit 64 is switched to the unlocking position from the locking position. Thus, the first insert 52 can be removed from the first lock hole 48. Therefore, the shackle 42 is unlocked.
Referring to FIGS. 5 and 7, a second key 70 is inserted and turned in the first key-operable locking unit 66 so that the second key-operable locking unit 66 is switched to the unlocking position from the locking position. Thus, the second insert 54 can be removed from the second lock hole 50. Hence, the shackle 42 is unlocked.
The first key 68 is held by a user of the padlock. The second key 70 is handed to the customs workers.
Referring to FIGS. 8 through 12, there is shown a padlock according to a third embodiment of the present invention. The third embodiment is similar to the second embodiment except including a single key-operable locking unit 72 instead of the first and second key-operable locking units 64 and 66 of the second embodiment. The key-operable locking unit 72 is similar to the key-operable locking unit shown and described in U.S. patent application Ser. No. 11/603,029. The key-operable locking unit 72 can be used by with the first and second keys 68 and 70. That is, either the first key 68 or the second key 70 can be used to turn the key-operable locking unit 72 between a locking position and an unlocking position. More details of the key-operable locking unit 72 will not be given for briefness.
Referring to FIG. 9, the first key 68 is inserted and turned in the key-operable locking unit 72 so that the key-operable locking unit 72 is switched to the unlocking position from the locking position. Thus, the first insert 52 can be removed from the first lock hole 48. Therefore, the shackle 42 is unlocked.
Referring to FIG. 10, the second key 70 is inserted and turned in the key-operable locking unit 72 so that the key-operable locking unit 72 is switched to the unlocking position from the locking position. Thus, the second insert 54 can be removed from the second lock hole 50. Hence, the shackle 42 is unlocked.
The first key 68 is held by a user of the padlock. The second key 70 is handed to the customs workers.
In FIGS. 11 and 12, the key-operable locking unit 72 includes a lock core which comprises a cylinder 1, a shaft 2, a plurality of driving members 3 and a plurality of springs 4. As shown in FIG. 12, the cylinder 1 defines a chamber 10 for receiving the shaft 2, and the shaft 2 defines a keyhole 20 comprising a first slot 21, a second slot 22 in communication with the first slot 21, and a third slot 23 in communication with the first slot 21. Furthermore, the first and second slots 21, 22 receive the first key 68, and the first and third slots 21, 23 receive the second key 70. More details of the key-operable locking unit 72 will not be given for briefness as described in U.S. patent application Ser. No. 11/603,029.
The present invention includes been described by the detailed illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.