Patent Publication Number: US-4548062-A

Title: Security device for preventing separation of a lock from a door

Description:
The present invention relates to a security device which is affixed to a door to prevent a lock independently mounted to the door from being separated from the door from the outside. 
     SUMMARY OF THE INVENTION 
     A plate is provided for preventing separation of an independently mounted door lock from the door from the outside. The plate is mounted inside of the door and envelops the lock. A second plate can be provided on the outside of the door and the two plates can be connected together. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a standard lock mounted on the door and enveloped by means the plate according to the invention from inside of the door; 
     FIG. 2 is a front elevation view of the plate of FIG. 1 including reinforcing ribs, with the plate mounted to the door and with the mounting nuts and lock omitted; 
     FIG. 3 is a section view taken along line 3--3 of FIG. 2 showing the plate mounted to the door by bolts and a second plate mounted outside of the door by bolts; and 
     FIG. 4 is a section view taken along lines 4--4 of FIG. 2. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The use of different devices for securing a lock against destruction of its cylinder, has caused in recent times the knocking out of the lock from a door into the apartment. This invention secures the lock against this accurrence. FIGS. 1 and 2 show a plate 1, which envelope the lock 2 and is fixed to the door 3 by means of the bolts 4, which are passed through the door. Said plate is provided with a hole 6, through which passes the head 7 of the lock for manually locking it. The plate 1 is provided with ribs or projections 8 for increasing its strength. A plate 9 can be affixed outside of the door for securing the lock against destruction of its cylinder, and plate 9 secures also the heads 5 of the bolts 4.