US1367813A - Guard for door-locks - Google Patents

Description

C. M. HATCHER.

GUARD FOR DOOR LOCKS.

APPLICATION men AUG-I8. I919.

Patenfed Feb. 8, 1921.

UNITED STATES I PATENT OFFICE.

GUARD FOR DOOR-LOCKS.

Application filed August 18, 1919.

To all whom 2'2? m a-g concern:

Be it known that I, CHARLES M. HATOHER, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Guards for Door-Locks, of which the following is a specification.

This invention relates to improvements in guards for door locks and more particularly to a device for preventing the removal of the key therefrom or its being turned from the outside.

The principal object of the invention is to provide a simple and effective guard for accomplishing the results above outlined and one which is readily attached to the door and is applicable to all forms of lock employing having a key with a ringed end.

With these and other objects in view the invention consists of certain novel features of form and structure herein illustrated and more specifically pointed out in the appended claims.

Reference being had to the drawing formin a part of the specification:

igure 1 is a view in perspective of a door.

Fig. 2 is a view in front elevation of one member of my device.

Fig. 3 is a view in front elevation of the companion piece.

Fig. 4 is a view in section on the line 4-4 Fig. 1.

Referring to corresponding parts in the several views by the same numerals of reference, 1 denotes a door having the usual type of mortise lock 2, the latch 3 of which is operated by turning a knob at, while the bolt 5 is operated by a key 6.

On the surfaces of the door are attached escutcheon plates 7 having an opening 8 for the key, and an opening for the shank 9 of the knob. The above mentioned parts are of the usual construction and require no detailed description.

The device which comprises my invention is denoted generallyby 10 and comprises two pieces 11 and 12 which are slidable one in the other. The outer member 11 comprises a rectangular plate 13 having its side edges bent back on itself as shown at 14 to form grooves for slidably holding the other plate. Plate 13 has an elongated opening 15 which is adapted to embrace the shank 9 and on its lower end has an ofiset Specification of Letters Patent.

Patented Feb. 8, 1921.

Serial No. 318,398.

tongue 16 which engages the opening in the key 6. On the upper end of this plate there is provided a curved lip 17 which serves as a handle for moving the plate.

The inner member 12 comprises a rectangular plate 16 having its sides folded back as shown at 22 to form smooth edges for engagement with the grooves formed on plate 13. In the center of plate 16 there is formed a circular opening 17 the diameter of which just admits the knob shank 9. Adjacent the lower end of the plate there is cut an elongated slot 18, the width of which is just suiiicient to allow the key stem to turn therein, and the length of which permits the ring of the key to be passed therethrough. The upper end of this plate has an extension 19 which projects above the escutcheon plate 7 and has a hole 20 through which is passed a screw 21 for attaching the plate to the door.

The guard is attached to the inside of the door with the knob extending through openings 15 and 17. wThus attached the member 11 may be moved up and down on member 12 within the limits of opening 15. The key is placed in the lock by first inserting the ring end through slot 18 from the side adjacent the door. This is necessary as the shoulder on the key adjacent the bit will not ordinarily pass through the slot. The key bit is then entered into the lock and turned until the bolt 5 is extended. The ring of the key is turned until horizontal or partly so and then the plate 11 pushed downwardly to cause the finger 16 to enter the opening in the keyring.

Now if the door is closed it will be apparent that to open it the bolt must be retracted which can only be done by turning key 6 or by forcing it out and using another or a skeleton key. But the key cannot be turned from the appointed side of the door, due to the tongue 16 extending through the opening in the key. This prevents the bolt from being retracted and furthermore prevents the key from being turned so that it may be pushed out of the key hole and a skeleton key used. Furthermore plate 11" cannot be lifted by a tool inserted through the keyhole as the inner plate prevents the possibility of the tool securing an effective hold on the plate.

I claim as new and wish to cover by Letters patent 1. A device of the character described comprising in combination with a door lock having an escutcheon plate, a key and a shanked knob, a plate having an opening for said knob shank and a slot for said key, a tongue on said plate extending past 3 the top of said escutcheon plate, means for at taching said tongue to the door, a member slidable on said plate and having a slot embracing said knob shank, a tongue on the' lower end of said member for engaging said key to prevent turning thereof.

2. A device of the character described comprising in combination with a door lock having a key and a shanked knob, a plate having an opening for said knob shank and a slot for said key, a member slidably mounted on said plate and having a slot embracing said knob shank, and a tongue extending from the lower end of said member to engage said key and prevent the turning thereof.

'3. A device of the character described comprising in combination with a door lock having a key and a shanked knob, a plate having one end rigidly held with respect to said door, said'plate having an opening for said knob shank and a slot for said key, a member slidably mounted on said plate and having a slot embracing said knob shank, and a tongue extending from the lower end of said member to engage said key and prevent the turning thereof.

In testimony whereof I afiix my si nature.

CHARLES M. HATC ER.

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