Modular telephone jack lock

A lock designed specifically to lock up a plug-in socket of a modular type telephone; the lock including a jack that snap locks into the socket, a key-operated bolt for unlocking the jack therefrom, and an integral clamp for selectively clamping around the extension cord extending from a telephone desk set for securing the same from theft.

BACKGROUND OF THE INVENTION 
This invention relates generally to telephone accessories, and more 
particularly to the recently developed, modular type telephones that have 
a single jack for plugging into a single opening of a wall-mounted socket. 
It is well known that considerable misuse of a telephone occurs, especially 
in business firms where unauthorized persons use the company telephones 
for making their own personal telephone calls so that the firm is obliged 
to pay for them. This situation is objectionable and is therefore in need 
of an improvement. 
SUMMARY OF THE INVENTION 
Therefore it is a principal object of the present invention, to provide a 
lock for locking up the conventional wall-mounted socket, installed by a 
telephone company, so as to prevent a telephone hand set or desk set from 
being plugged therein for telephone use. 
Another object is to provide a lock which additionally serves to protect an 
unplugged desk set from being stolen from a premises by means of clamping 
the desk set extension cord thereto. 
Yet a further object is to provide a lock that is key-operated so as to be 
for personal use, and which is small in size so that when the lock is not 
in use, it may be carried in a person's pocket. 
Further objects of the invention will appear as the description proceeds. 
To the accomplishment of the above and related objects, this invention may 
be embodied in the form illustrated in the accompanying drawings, 
attention being called to the fact, however, that the drawings are 
illustrative only, and that changes may be made in the specific 
construction illustrated and described within the scope of the appended 
claims.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
Referring now to the drawing in greater detail, the reference numeral 10 
represents a modular telephone jack lock according to the present 
invention, wherein there is a hard plastic case 11 from a rear side of 
which a plug 12 extends for insertion into a plug-in opening 13 of a 
conventional, wall-mounted socket 14 of a modern modular type telephone, 
wherein a single plug in a single opening provides connection of a desk 
set 15 with a telephone company system. 
The plug 12 includes a leaf spring component 16 having corners 17 that lock 
behind corners 18 of the socket opening 13 so that when inserted, the plug 
snap-fits therein and automatically locks thereto. A lock mechanism 19 
with pins 20 inside the case, is operated by a removable key 21 so as to 
rotate a bolt 22 of the lock and depress the leaf spring component so that 
the corners thereof clear the corners of the socket opening in order to 
permit removal of the lock 10 from the socket. 
In the present invention, a clamp 23 is pivotally secured by a hinge 24 to 
the case and is pivotable against a rear side thereof so that a 
semi-cylindrical notch 25 of the clamp aligns with a semi-cylindrical 
notch 26 transversely across a rear side of the case so that they together 
form a cylindrical hole 27 in which an extension cord 28 of the desk set 
may be placed for securement against theft of the desk set. After the 
extension cord is thus seated and the clamp pivoted down against the case 
rear side, two screws 29 may be inserted through clearance holes 30 in the 
clamp and into threaded holes 31 in the case so as to capture the 
extension cord safely and prevent theft thereof. It also should be 
particularly noted that the screws are inaccessible for removal due to the 
abutting of the face of the socket when the lock 10 is mounted in the 
socket. 
Thus there is provided a lock which prevents a plug 32 on an extension cord 
of a desk set from being plugged into a socket opening 13 by unauthorized 
persons and also prevents a desk set from being carried away. 
FIG. 3 shows the application of the present invention for an externally 
mounted plug-in opening 13' that is upon the top of a wall socket 14'. The 
hard plastic case 11' in this use of the invention is similarly provided 
with a plug 12' having a leaf spring component 16' extending downwardly 
and perpendicularly to the plastic case 11'. The leaf spring 16' has 
corners 17' for locking engagement with corners 18' of the opening 13' in 
a manner similar to that described above. 
While certain novel features of this invention have been shown and 
described and are pointed out in the annexed claims, it will be understood 
that various omissions, substitutions and changes in the forms and details 
of the device illustrated and in its operation can be made by those 
skilled in the art without departing from the spirit of the invention.