Patent Publication Number: US-7213425-B2

Title: Padlock having dual unlocking modes

Description:
PRIORITY STATEMENT 
   This application claims the benefit of Taiwanese Patent Application No. 93138098, filed on Dec. 9, 2004, in the U.S. Patent and Trademark Office, the disclosure of which is incorporated herein in its entirety by reference. 
   FIELD OF THE INVENTION 
   The invention relates to a padlock having dual unlocking modes that includes a combination padlock with a pushbutton that can be depressed for locking and unlocking, and a second locking mechanism to perform locking and unlocking. 
   BACKGROUND OF THE INVENTION 
   Padlocks are widely used on articles that have obvious or potential security concerns. Referring to  FIG. 1 , a conventional combination padlock  20  has dialing wheels  22  that may be turned to valid positions to unlatch a movable arm  26  by depressing a movable push button assembly  24 . 
   Some of the padlocks are equipped with dual unlocking modes and enable users to select either way to unlock according to use requirements. Reference can also be found in U.S. Pat. Nos. 4,325,240, 6,539,761, and 6,708,534. These all disclose a padlock that includes key locks that are locked and unlocked by inserting and turning a key and combination locks that are locked and unlocked by setting a combination. The key locks have the advantage of preventing the combination from being decoded, while the combination locks have the convenience of using without a key. 
   The lock equipped with two locking mechanisms is larger than the lock that has only one lock mechanism. The design of the lock profile also has limitations due to different locations and dimensions of the locking mechanisms. 
   SUMMARY OF THE INVENTION 
   In view of the aforesaid problems, the object of the invention is to provide a padlock having dual unlocking mode that includes a key-operated unlocking mode, is simply structured and easy to use. 
   The padlock according to the invention adopts a dual-unlocking design based on a combination lock shown in  FIG. 1  that can be unlocked by dialing a cipher or through a key according to requirements. 
   In order to achieve the object set forth above, the padlock having dual unlocking mode of the invention includes a lock body, a movable push button assembly, and a combination lock mechanism. 
   The lock body has an internal space and a shackle that the shackle includes a movable arm selectively locating at an opening position or a closing position. 
   The movable push button assembly is partially disposed within the internal space. The movable push button assembly has a lock cylinder with key hole for receiving a key, and a cam coupled and moving with the lock cylinder, wherein the cam presses the movable arm and the movable arm is switched between the opening position and the closing position by the movement of movable push button assembly or the rotation of the lock cylinder. 
   The combination lock mechanism includes an axle selectively pressing the movable push button assembly. 
   When the movement of the axle is restricted by the combination lock mechanism, the movable push button assembly is not allowed to be moved and the lock cylinder is allowed to be rotated. 
   The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view of a conventional combination padlock; 
       FIG. 2  is a perspective view of the padlock of the invention with the shackle in a closed state; 
       FIG. 3  is a perspective view of the padlock of the invention with the shackle in an opened state; 
       FIG. 4  is an exploded view of the padlock of the invention; 
       FIG. 5  is a sectional view of the padlock of the invention; 
       FIG. 6  is a schematic view of the invention with the combination mechanism in the unlocking state and the shackle driven by the movable push button assembly; 
       FIG. 7  is a schematic view of the invention with the combination mechanism in the locking state and the shackle driven by the key and the movable push button assembly; and 
       FIG. 8  is a sectional view of the invention with the combination mechanism in the locking state and the shackle driven by the key and the movable push button assembly. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 2 , the padlock  10  having dual unlocking modes according to the invention includes a lock body  12  that has a shackle  122  to form a closed area. The shackle  122  has a fixed arm  124  fastened to the lock body  12  and a movable arm  126  pivotally coupled on the lock body  12  that may be moved to be locating at an opening position or a closing position selectively. 
   The lock body  12  further has an internal space. A movable push button assembly  14  is partially disposed within the internal space. The movable push button assembly  14  has a force receiving portion  141  extended outside the lock body  12 . Referring to  FIG. 3 , the force receiving portion  141  of the movable push button assembly  14  can receive an external depressing force to be depressed into the lock body  12  to move the movable arm  126  locating at the opening position or the closing position. 
   In addition, the lock body  12  has a combination lock mechanism  16  on a lower half portion. The combination lock mechanism  16  includes a plurality of dialing wheels  166  exposed outside the lock body  12 . When the dialing wheels  166  are rotated to preset unlocking positions, the movable push button assembly  14  can be depressed into the lock body when the force receiving portion  141  receives an external depressing force. When any of the dialing wheels  166  is not being rotated to the preset unlocking position, it restricts the movement of the movable push button assembly  14  so the movable push button assembly  14  cannot be depressed or moved. 
   Refer to  FIG. 4  for the structure and coupling relationship of the invention. The lock body  12  has two side caps  102  and  104  that are coupled to form the internal space. The fixed arm  124  is formed in a hook shape and extended from an upper end of one side of the lock body  12 . The lock body  12  has a shaft  128  on another end to pivotally couple with the movable arm  126  so that the movable arm  126  can be coupled with the fixed arm  124  to form the closing position or the opening position with a notch. 
   The movable push button assembly  14  is partially disposed in the internal space on one side of the lock body  12 , and includes an outer barrel  142 , a lock cylinder  144  and a cam  146 . The outer barrel  142  has a round cavity  1422  to house the lock cylinder  144 . The round cavity  1422  has a wedge trough  1424 . The lock cylinder  144  has a plurality of latch plates  1442  extended from the surface to be wedged in the wedge trough  1424 . Hence the lock cylinder  144  and the outer barrel  142  may be latched through the latch plates  1442  and the wedge trough  1424 , and moved together into the lock body  12 . The lock cylinder  144  also has a key hole  1444  on an outer end surface for receiving a key K to retract the latch plates  1442  into the lock cylinder  144  so that the lock cylinder  144  may be rotated to a selected angle in the round cavity  1422  by the key K. 
   The cam  146  is coupled and moving synchronously with the lock cylinder  144 . It also presses the movable arm  126 . So that the movable arm  126  is moved to be locating at the opening position or the closing position by the movement of cam  146  of the movable push button assembly  14 . The cam  146  has a sliding trough  1462  coupling with a guiding member  1446  of the lock cylinder  144 . Besides coupling, the cam  146  and the lock cylinder  144  can also slide relative to each other in the direction of the sliding trough  1462 . 
   Moreover, the movable arm  126  has a coupling member  1262  extended outwards. The cam  146  has a latch trough  1464  and a guiding surface  1466  in contact with the coupling member  1262 . So that the cam  146  and the movable arm  126  are coupled and in contact with each other and may move synchronously. 
   Referring to  FIG. 4 , the movable push button assembly  14  is partially disposed in the internal space of the lock body  12 , the cam  146  and the movable arm  126  are coupled and in contact with each other, and the distal end of the coupling member  1262  is latched in the latch trough  1464 . When the movable push button assembly  14  receives an external force and is depressed into the lock body  12 , the movable arm  126  is also moved to the opening position as shown in  FIG. 5 . In addition, the movable arm  126  may also be moved by inserting a key K into the key hole  1444  and retracting the latch plates  1442  to release the coupling relationship between the lock cylinder  144  and the outer barrel  142 , and by turning the key K 90 degrees as shown by the arrow to rotate the lock cylinder  144  so that the guiding surface  1466  guides the movable arm  126  to the opening position. 
   Therefore, the movable arm  126  can be moved by depressing and moving the movable push button assembly  14 , and can also be moved by turning the key K inserting into movable push button assembly  14  to form dual unlocking modes. 
   Referring to  FIG. 5 , the combination lock mechanism  16  on the lock body  12 , besides the dialing wheels  166 , further includes an axle  162  and an elastic member  164 . The axle  162  has a head  1622  of a larger diameter on one end. The elastic member  164  is coupled on a stem  1624  and pushes the axle  162 . The head  1622  presses a lower end of the movable push button assembly  14  in normal conditions. 
   The dialing wheels  166  are coupled on the stem  1624  and restrict the movement of the axle  162  by their positions after rotation. That is, the movement of the axle  162  is determined by the relative rotation positions of the dial wheels  166 . When all the dial wheels  166  are rotated to a unlocking position that the axle  162  is not restricted by the combination lock mechanism  16 , the movable push button assembly  14  is in an unlocking state and allowed to be moved into the lock body  12  by an external force as shown in  FIG. 6 . On the other hand, when any of the dial wheels  166  is not being rotated to the unlocking position that the axle  162  is restricted by the combination lock mechanism  16  in a locking state, the movable push button assembly  14  is restricted and is not allowed to be moved. The movable arm  126  is fixed to maintain the shackle  122  in the closed position. 
   While the movable push button assembly  14  is in a locking state that the movable arm  126  cannot be moved by depressing movable push button assembly  14 , as shown in  FIGS. 7 and 8 , the lock cylinder  144  and the cam  146  is allowed to be rotated with the key K, in which the guiding surface  1466  guides the coupling member  1262  of the movable arm  126  to allow the movable arm  126  to be moved to the opening position. 
   The outer barrel  142  of the movable push button assembly  14  may be dispensed with. The round cavity  1422  and the wedge trough  1424  are formed directly on the lock body  12 . The lock body  12  encases the lock cylinder  144 . The movable push button assembly  14  includes the lock cylinder  144  and the cam  146 . 
   In addition, as shown in the drawings, the movable push button assembly  14  and the movable arm  12  may be located on two sides of the lock body  12 . Then the movable push button assembly  14  may be depressed or rotated without interfering with the shackle  122 . Moreover, to prevent contamination the movable push button assembly  14  may have a cover  18  to cover the key hole  1444  (as shown in  FIG. 4 ). The cover is removed and opened only when the padlock  10  has to be unlocked by the key to unlatch the movable arm  126  of the shackle  122 . 
   In summary, the padlock having dual unlocking modes of the invention can release the movable push button assembly  14  by rotating the dialing wheels, and it can also be unlocked with a key. By integrating the key driven lock cylinder  144  with the movable push button assembly  14 , the size of the padlock  10  is increased very little. The limitation on the profile of the padlock  10  also is minimized. 
   While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.