Locking device for protecting door lock

Abstract

A locking device includes a housing having a retaining hole for retaining a door lock, and a combination lock set. When the combination lock set is unlocked, a latch of the combination lock set is disengageable from a retaining portion of the housing such that a front shell of the housing is pivotable away from a rear shell of the housing, thereby opening an accommodation chamber defining between the front shell and the rear shell. As a result, the door lock is exposed outside for allowing a key to be inserted into a key hole thereof. When the combination lock set is locked, the latch is firmly engaged with the retaining portion such that the front shell is locked on the rear shell, causing the door lock to be hidden in the accommodation chamber.

1 . A locking device comprising:
 a housing having a front shell and a rear shell pivotally connected with the front shell to define an accommodation chamber therebetween and provided with a retaining portion and a retaining hole for retaining a door lock; and   a combination lock set mounted to the front shell of the housing and received in the accommodation chamber, the combination lock set having a plurality of wheels, a latch engageable with the retaining portion of the rear shell, and a movable plate controlled by the wheels to be moveable between a first position where the latch is disengageable from the retaining portion of the rear shell such that the front shell is pivotally moveable away from the rear shell for allowing the door lock to be exposed outside when the wheels show a correct number permutation, and a second position where the latch is blocked by the moveable plate and engageable with the retaining portion of the rear shell such that the front shell is locked on the rear shell for enabling the door lock to be hidden in the accommodation chamber when the wheels show a wrong number permutation.   
   
   
       2 . The locking device as claimed in  claim 1 , wherein the latch of the combination lock set has an insertion end engagable with an insertion groove of the retaining portion of the rear shell of the housing. 
   
   
       3 . The locking device as claimed in  claim 1 , further comprising a shackle having a pivotal portion that is axially moveable and pivotable relative to the housing, and a hook portion that is integrally connected with the pivotal portion and provided with a free end insertable into the housing by means of an axial movement of the pivotal portion, and a recess at the free end, a retaining plate fastened to the rear shell of the housing, and a switch movably mounted to the retaining plate and provided with a retaining end engageable with the recess of the hook portion of the shackle. 
   
   
       4 . The locking device as claimed in  claim 3 , wherein the switch is movably mounted to an elongated groove of the retaining plate and provided with a tab and a retaining block with the retaining end. 
   
   
       5 . The locking device as claimed in  claim 1 , further comprising a protecting cover fitted to a rear side of the rear shell of the housing.