Portable door lock

A portable door lock has a relatively-thin sheet-metal locking strap that fits between the door and the jamb. The strap has a fixed bolt on one end that is received in the recessed keeper in the jamb, with the door in the open position. The door is closed over the strap; and a locking dog pivotably mounted on the other end of the strap, is pivoted towards the door such that the dog partially overlaps the strap, and such that the outer face of the dog engages the inner side of the door, thereby preventing the door from being opened from the outside. The outer face of the dog may be arcuately formed to accommodate different door thicknesses within a given range, and the outer arcuate face may have a frictional layer for non-slip purposes and to prevent any marring of the door finish. A retainer may be provided over the dog and the strap to retain the portable door lock in its locking position.

The present invention constitutes a portable door lock, and more 
particularly, to a portable door lock that may be used in the home or when 
traveling. 
BACKGROUND OF THE INVENTION 
In the prior art of which I am aware, various door locks and alarms have 
been disclosed which are intended to safeguard the occupants of a room or 
a home. These prior art devices are usually heavy and cumbersome, 
difficult to understand and manipulate, and/or costly to manufacture or 
service. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to alleviate the 
disadvantages and deficiencies of the prior art by providing a portable 
door lock which is simple and effective, yet economical to manufacture, 
thereby facilitating its widespread marketing and distribution. 
It is another object of the present invention to provide a portable door 
lock which is readily understood, easy to install, and accommodates either 
right or left handed doors. 
It is yet another object of the present invention to provide a portable 
door lock in the form of a complete integral unit, such that there are no 
keys, separate chains or other loose pieces that may become lost or 
mislaid. 
It is a further object of the present invention to provide a portable door 
lock that, once installed, may be removed quickly and easily, which is 
especially important in the event of an emergency. 
In accordance with the teachings of the present invention, there is 
illustrated and described herein a preferred embodiment of the portable 
door lock, in which a relatively-thin locking strap is adapted to be 
fitted between a door and its cooperating jamb. The strap has first and 
second end portions, and bolt means are carried on the first end portion 
of the strap. The bolt means is adapted to be received within a recess in 
the keeper on the jamb when the door is in its open position. A locking 
dog or brace is pivotably mounted on the second end portion of the strap 
about an axis which is transverse to the plane of the strap. The dog has 
an unlocked position in which it is normally pivoted away from the strap 
when the door is in its open position. After the door is closed over the 
strap, such that the conventinal bolt on the door is retracted, the dog 
may be pivoted towards the strap and into its locking position such that 
the dog overlaps the strap, and such that the dog engages the inner side 
of the door, thereby preventing the door from being opened from its outer 
side. To release the lock, the dog is simply pivoted away from the strap, 
such that the door may be opened and the portable door lock removed. 
In accordance with the further teachings of the present invention, the dog 
has an arcuate face outwardly of its pivotable mounting on the strap. This 
arcuate face engages the inner side of the door and will accommodate doors 
of various thickness. A frictional surface is provided on the arcuate face 
of the dog, so as to provide a non-slip locking position of the dog, yet 
without marring the finish on the inner side of the door. A retainer is 
also provided to maintain the dog in its locking position and prevent it 
from separating relative to the strap. 
These and other objects of the present invention will become apparent from 
a reading of the following specification taken in conjunction with the 
enclosed drawings.

GENERAL DESCRIPTION OF A PREFERRED EMBODIMENT 
With reference to FIGS. 1-5, the portable door lock 10 comprises a locking 
plate or strap 11 and a pivotal locking dog or brace 12. The strap has a 
first end portion 13 and a second end portion 14. A fixed bolt means 15 is 
carried in the front end portion of the strap. Preferably, the bolt means 
is a solid piece which is brazed to the strap and has a configuration 
similar to the conventional bolt on the door. The second end portion of 
the strap is pivoted to the dog by a rivet 16 or other suitable means. The 
dog has an outer arcuate face 17 which is preferably covered with a rubber 
or other frictional layer 18. Preferably, the strap is formed from 
relatively-thin slightly-flexible sheet metal, while the dog is 
substantially thicker than the strap and is preferably formed from an 
aluminum plate. 
The door 19 is of the conventional design and is provided with a 
retractable bolt 20 that is part of the conventional knob (not shown), and 
the door cooperates with a conventional jamb 21. The jamb has a keeper 22 
provided with a recess 23 for normally receiving the bolt in the door. 
In operation, the strap 11 is positioned between the door and jamb, when 
the door is in its open position as shown in FIG. 3, such that the bolt 
means 15 in the strap 11 is received within the recess 23 in the keeper on 
the jamb. The door is then closed over the strap, as shown in FIG. 4, such 
that the conventional bolt in the door is retracted within the door. The 
dog 12 is then pivoted towards the door such that the dog partially 
overlaps the strap as shown in FIG. 5, and such that the outer face of the 
dog engages the inner side 24 of the door, thereby preventing the door 
from being opened from its outer side 25. This is the locking position of 
the portable door lock of the present invention. 
In this locking position, the frictional layer 18 on the arcuate face 17 of 
the locking dog 12 will prevent the dog from slipping up or down, or 
sideways, and will protect the finish of the inner side of the door 
against an undesired marring. 
To release the portable door lock, the dog 12 is simply pivoted away from 
the strap 11 and moved back towards its position shown in FIG. 3. The door 
may then be opened and the portable door lock removed. This is especially 
important in the event an emergency occurs and a quick exit is imperative. 
FIGS. 6-8 illustrate schematically the portable door lock in its locking 
position with respect to three different-sized doors. FIG. 6 is for a 
11/2" door; FIG. 7 for a 13/4" door, and FIG. 8 for a 2" door. The design 
of the dog, and more particularly its arcuate face, will accommodate these 
different door thicknesses within a given range covering most 
applications. Moreover, it will be appreciated that the illustrations of 
FIGS. 6-8 are exemplary only, and that any size door within a given range 
may be locked securely with the portable door lock of the present 
invention. 
It will also be appreciated that the portable door lock of the present 
invention is reversible from the position shown in the drawings, that is, 
it may be used with either right or left-handed doors. 
The portable door lock of the present invention is a complete integral 
unit; there are no keys, separate chains or other loose pieces that may 
become lost or mislaid, and this is another important feature of the 
present invention. 
FIGS. 9 and 10 illustrate an alternate embodiment, wherein the strap 
11.sup.1 has a lanced-out tab 26 to simulate the bolt means 15 of the FIG. 
1 embodiment. 
FIGS. 11 and 12 illustrate another alternate embodiment, wherein a 
retaining means is provided over the strap and the dog. Preferably, the 
retaining means comprises a U-shaped wire-formed retainer 27 having one 
end pivotably received in a hole 28 in the dog. The retainer is wrapped 
around the dog and has its other, free end 29 spread sufficiently from the 
face of the dog to receive the strap therebetween. The retainer prevents 
the dog from slipping up or down or sideways relative to the strap. 
The portable door lock of the present invention is simple, effective and 
reliable; may be manufactured economically from readily available 
materials; and may be readily understood and installed without requiring 
extensive skill or instruction. These are significant advantages 
heretofore not available. 
Obviously, many modifications may be made without departing from the basic 
spirit of the present invention. Accordingly, within the scope of the 
appended claims, the invention may be practiced other than specifically 
described herein.