US2684587A

US2684587A - Locking key retainer

Info

Publication number: US2684587A
Application number: US326946A
Authority: US
Inventors: Arnold J Fleming
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-12-19
Filing date: 1952-12-19
Publication date: 1954-07-27
Anticipated expiration: 1971-07-27

Description

y 1954 A. J. FLEMING LOCKING KEY RETAINER Filed Dec. 19, 1952 INVENTOR. /mza 27-25mm;

Patented July 27, 1954 UNITED STATES PATENT OFFICE LOCKING KEY RETAINER Arnold J. Fleming, Ithaca, N. Y.

Application December 19, 1952, Serial No. 326,946

1 Claim.

The ordinary household key and lock usually found in doors can be made a very effective means for preventing entry so long as it remains in place. However, a common trick known to thieves and burglars is to use a tool inserted into the key-hole from the outside by which the key in the lock can be turned. Using such a tool the burglar can then readily open the ordinary door, either by turning the key to unlock it or by turning the key enough to push it out and open the door with another key.

In order to prevent such entry, various key fasteners or guards have been developed in the past embodying hooks or rings fitting around the shaft of the door knob and having depending elements which can project thru the loop or handle of the ordinary household key so that it cannot be turned as long as the securing device is in place.

The present invention is an improved retainer of that general type. The principal defects of previous retainers have been that they were unduly complicated and expensive, and that they could be displaced by a burglar using a wire or by shaking the key itself. The principal object of the present invention is to provide such a safety key retainer having a minimum number of parts that can be easily manufactured so as to reduce the cost, and yet provide a device which will effectively prevent a burglar from displacing it, so that the key will continue to be securely held in the safe position in the lock.

Referring now to the drawings forming part of this specification,

Fig. l is a front view of the retainer in the open position, showing the stem and hook, the rotatable lock, and the holding pins in the guiding slots.

Fig. 2 is a view of the same device turned around so as to show its back, with the rotatable lock closed around the shaft of a door knob, and the stem extending down thru the loop or handle of an ordinary key so as to prevent its turning.

Fig. 3 is a detail front view of the rotatable lock closure element.

Fig. 4 is a side elevation of the same.

Fig. 5 is a detail rear View of the hook element and its depending stem for holding a key in place.

Fig. 6 is a side View of the same.

Similar reference numerals refer to similar parts thruout the various views.

The hook element l of the device is best seen in Fig. 1, Fig. 5 and Fig. 6 and consists of a sheet metal stamping or other thin material made in the general shape of a question mark, having a rounded head 2 and a depending stem 3 which terminates in a wedge shaped point 4. The head 2 has a slot or jaw 5 which slopes upward and is wide enough to slip over the shaft 6 of the door knob as shown in Fig. 2. The depending blade or stem 3 of the device hangs down and passes thru the loop of the handle 8 of the ordinary key in its key-hole d. So long as the stem 3 is hooked on the door knob and projects thru the handle 8 of the key, the key cannot be rotated to any considerable extent and will remain in the locking position in the door.

However, it has been found that thieves have occasionally found a way to displace various devices of the key holding type by passing a wire or small rod thru the key hole to get it under the lower end of the depending stem and toss or force it up out of the loop of the key handle. To preclude such an action, the tip t of the stem 3 is not made square or broadly rounded, but is wedge shaped. This wedge shaped end. not only assists in guiding the stem 3 thru the loop 8 of the key handle but also makes it difficult to raise the stem 3 by any wire or rod that may be used to try to lift it, since the lifter will not find a blunt surface to bear against but will tend to glance oif in one direction or the other.

Another trick used by thieves is to unhook the element I from the door knob, either by shaking the knob or by other means. To prevent this, the present device has a rotary locking head It as shown in Fig. 1 and Fig. 2 and in separate detail in Fig. 3 and Fig. 4. This rotatable locking head I0 is made of a sheet metal stamping or other thin material in the general form shown in Fig. 3 and with a tab H projecting at right angles to serve as a handle, by which the head can be rotated. This head it has a slot [2 corresponding to the slot or jaw 5 of the hook element 1 so that when the slots 5 and I2 of the two elements are placed parallel the jaw is open, and when the head Isl is rotated about the jaw is closed, and the opening left in the two elements is substantially a ring closely encircling the shaft 6 of the door knob. Fig. 1 shows the jaws open and Fig. 2 shows them closed around the door knob shaft 6.

The lock head It is guided in its rotary motion by arcuate slots is and it which may be cut in the head of the hook I, and in these slots there travel pins [6 and It having overlapping heads I! and H, these pins It and It being held in the rotary lock head I 6 by riveting or other suitable means as shown in Fig. 1 and Fig. 4. While the arcuate slots l5 and [5' are shown in the head 2 and the pins l6 and It are shown on the head [0, it will be understood that their positions could just as well be interchanged, with the slots in the rotary head I!) and the pins on the hook head 2, to produce the same efiect. These arouate guiding means insure the proper locking motion.

However, while the slots [5 and it are in general arcuate, they are provided with a special cam action at the end of the closing movement to force the pins It and It into terminal depressions 20 and 23, which act as detents to hold the movable member Iii securely at the end of its closing travel. The purpose of these detents is to hold the lock head closed against any shaking or rattling that might be used against it; in other words, to provide 'a definite resistance to unlocking the head which can only be done by considerable force applied properly to the tab 1 I.

In operation the door is first locked with the ordinary key left in the lock. Then the present device is opened and hooked on the door knob as shown in Fig. 2 with the stem 3 passing thru the loop of the handle of the door key. The rotary head it is then turned by means of the tab or handle H until the pins [6 and i6 snap down into the depressions 26 and 20 as shown in Fig. 2. This holds the device securely on the knob and thru the key handle so that it cannot be turned or shaken out. durable and can be easily manufactured.

I claim:

A looking key retainer for preventing the removal of a door key comprising in combination a hook element having a head and stem and a general contour similar to that of a question The whole device is light,

mark with an opening in one side of its head adapted to hook over the shaft of a door knob and a stem extending downward to pass thru the loop of a door key when a door is locked, said stem terminating in a downwardly extending point so that it cannot readily be lifted out of the loop by upward pressures, said hook element having a pair of concentric arcuate slots in its head on opposite sides of the opening, the upper end of the upper slot and the lower end of the lower slot each having a retaining notch extending downward toward the stem, a rotatable looking element having guiding pins in the arcuate slots of the hook so that it can rotate relative to said hook, said locking element having a slot which in one position accords with the opening in the head of the hook element and when the looking element is rotated closes said opening around the shaft of the door knob, and a handle on said locking element by which it may be rotated and by which the guiding pins may be moved into and out of the retaining notches at the ends of the slots, said notches extending downward toward the stem so that any attempt to lift stem out of the key loop will only force the guiding pins more securely into the retaining notches.

Reierences Cited in the file of this patent UNITED STATES PATENTS Number Name Date 167,674 Knight Sept. 14, 1875 250,426 Coombe Dec. 6, 1881 251,041 Gibbons Dec. 20, 1881 942,753 Ryan Dec. 7, 1909 1,307,496 Holcomb June 24, 1919