US3081616A

US3081616A - Safety lock

Info

Publication number: US3081616A
Application number: US77429A
Authority: US
Inventors: Albert E Mintz
Original assignee: DOCK AND DOCK
Current assignee: DOCK AND DOCK
Priority date: 1960-12-21
Filing date: 1960-12-21
Publication date: 1963-03-19
Anticipated expiration: 1980-03-19

Description

March 19, 1963 A. E. MINTZ 3,081,616

SAFETY LOCK Filed Dec. 21, 1960 26 I IPI l Al berf E. Minrz INVENTOR j/wym 2 ATTORNEY hired drama This invention relates to safety locks and more specifically, it relates to safety locks of the door chain type which may be locked and unlocked on one side of a door by a person without a key and which may be locked and unlocked on the other side by an authorized person with a key.

In my co-pending application, Serial No. 718,035, filed February 27, 1958, and which matured December 27, 1960, into Patent No. 2,966,053, of which this is a continuation-in-part, there is disclosed a casing attached to a door frame and a chain releasably mounted to the inside of a door. The chain had a locking plug at the opposite end which was connected to the casing and required a key to separate it therefrom. The chain was of such length that the door could be partially opened to the extent that a key could be passed through from the outside to unlock and remove the plug from the casing.

The safety lock comprising the present invention is similar in principle to that of my co-pending application except that in the present instance the locking plug remains connected to the casing on the door frame and the locking arrangement secures the chain to the plug or permits separation therefrom as desired. The locking mechanism includes a chain receiving means which is held in locked position by a retention portion positioned in an opening in the casing. In one form this permits the use of an ordinary padlock to be used as the plug to which the chain may be attached and detached. Since this makes the plug readily available from commercial sources at prices much less than the cost of special locking plugs, the price of the present safety lock becomes quite competitive with conventional door chains that does not have the advantage of permitting opening from the outside by a person with a key.

FIGURE 1 is a perspective view of the safety lock of the door chain type as viewed from the side of the door to which it is mounted, and

FIGURE 2 is a vertical cross-sectional view of the casing.

Referring now to FIGURE 1, there is shown a fragmentary portion of a door and door frame 11. The door has a knob 12, and the usual door locks which are not shown in the drawing.

In the preferred embodiment of the invention a door chain 13 is shown attached at one end 14 to the slide part 15 which engages a slot 16 in a standard chain bracket 17 secured to the door .10. The length of the chain 13 is such that with the other end 18 afiixed to the door frame 1 1, the slide part 15 cannot be released from the bracket 16 until the door 14} is substantially fully closed.

The chain end 18 is afiixed to door frame 11 through the frame mounted casing 19 having an inverted padlock 2% contained therein. End 18 of the chain is shown engaging the padlock loop 21. The casing '19 is open at the top to permit insertion of a key into the lock of the padlock to release the padlock loop 21 so that the end 18 of the chain may be readily removed.

It should now be apparent that the unlocking of the padlock and freeing of the end 18 of the chain may be easily accomplished from the other side of the door by opening the door within the limits prescribed by the chain, and then inserting the proper key in the con- 3,681,615 Patented Mar. 19, 1963 veniently located keyhole of the padlock at the upper end of the casing. Likewise, upon leaving the house, the chain end may be readily placed over the padlock loop and the loop snapped shut by a person on the outside, so that the opening of the door will again be restricted by the chain.

It also should be apparent that with the padlock 20 locked, the slide part 15 and bracket '17 function in the manner of conventional door chain locks, permitting a person on the inside to lock and unlock the door as desired without resorting to using a key in the padlock.

It will be understood that the invention is not to be considered as limited to the use of a slide and bracket at the other end of the chain since the end 14 of the chain could be secured to the door in a fixed position if desired. The use of the slide and bracket, however, provides greater convenience for the householder by making it possible to release that end of the chain in the conventional manner. Also, if desired, the casing could be secured instead to the door with the other end of the chain fastened to the door frame. H

In FIGURE 2, the casing 19 is shown in cross-section to better show the attachment of the padlock 20. Here an opening 22 extends through the casing 19 and is adapted to receive the padlock 20 with the padlock loop 21 extending downwardly and to permit insertion of the key 23 at the top. The casing is thus preferably about the same length as the body of the padlock.

As shown, the axis of the opening 22 preferably slants inwardly at the bottom toward mounting plate 24. This provides more clearance from the wall for rotating the key 23 and slants the padlock loop 21 somewhat nearer the mounting plate. This provides an unusual advantage in that when the loop 21 is opened, the weight of the chain 13 being slightly off center toward the free end 25 causes it to turn toward the door to facilitate easy removal of the end of the chain therefrom.

The padlock may be retained in the casing by some means such as retainer screw 26 inserted through an opening 27 in the mounting plate 24 and into a small recess 28 in the body of the padlock 20. The mounting plate may be attached to the door frame by means of screws 29, 36, one of which is not perpendicular to the plate 24 for greater fastening security.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims:

What is claimed is:

1. A safety lock comprising a chain with means for attachment to the inside of a door, a padlock releasably connected to said chain, a door frame mounted casing having an opening therein for receiving the body of said padlock in inverted position, means retaining said padlock in said opening, said chain being of such length as to permit the door to be partially opened to permit insertion from outside the door of a key into said padlock to free said chain therefrom when said door, chain, padlock and casing are connected.

2. A safety lock comprising a chain with means for attachment to the inside of a door, a padlock releasably connected to said chain, a door frame mounted casing having an opening therein for receiving the body of said padlock in inverted position, said opening being slightly slanted to position said padlock non-vertical, means retaining said padlock in said opening, said chain being of such length as to permit the door to be partially opened to permit insertion from outside the door of an unlocking means into said padlock to free said chain from the 3 loop of said padlock when said door, chain, padlock and casing are connected.

References Cited in the file of this patent 23 UNITED STATES PATENTS 5 21844 2,816,431 Harney Dec. 17, 1957 22,135

2,881,611 Callegari Apr. 14, 1959 354, 47 2,966,053 Mintz Dec. 27, 1960 42- FOREIGN PATENTS Germany Jan. 27, 1903 Great Britain July 22, 1911 Great Britain Mar. 15, 19 12 Great Britain Mar. 13, 19 13 Great Britain Oct. 7, 19 11 Great Britain Aug. 13, 1931

Claims

2. A SAFETY LOCK COMPRISING A CHAIN WITH MEANS FOR ATTACHMENT TO THE INSIDE OF A DOOR, A PADLOCK RELEASABLY CONNECTED TO SAID CHAIN, A DOOR FRAME MOUNTED CASING HAVING AN OPENING THEREIN FOR RECEIVING THE BODY OF SAID PADLOCK IN INVERTED POSITION, SAID OPENING BEING SLIGHTLY SLANTED TO POSITION SAID PADLOCK NON-VERTICAL, MEANS RETAINING SAID PADLOCK IN SAID OPENING, SAID CHAIN BEING OF SUCH LENGTH AS TO PERMIT THE DOOR TO BE PARTIALLY OPENED TO PERMIT INSERTION FROM OUTSIDE THE DOOR OF AN UNLOCKING MEANS INTO SAID PADLOCK TO FREE SAID CHAIN FROM THE LOOP OF SAID PADLOCK WHEN SAID DOOR, CHAIN, PADLOCK AND CASING ARE CONNECTED.