IMPROVEMENTS IN LATCHES OR FASTENINGS” FOR DOORS, CASEMENTS, AND SHUTTERS
Year: 1875

page_text: LETTERS PATENT to John Browning, of 63, Strand, London, Optician,
for the Invention of "IMPROVEMENTS IN LATCHES OR FASTENINGS” FOR
DOORS, CASEMENTS, AND SHUTTERS."
Sealed the 29th June 1875, and dated the 2nd January 1875.
•
PROVISIONAL SPECIFICATION left by the said John Browning at the
Office of the Commissioners of Patents, with his Petition, on the
2nd January 1875.
I, JOHN BROWNING, of 63, Strand, London, Optician, do hereby
5 declare the nature of the said Invention for " IMPROVEMENTS IN LATCHES
Or Fastenings FOR DOORS, CASEMents, and ShuttERS,” to be as follows :—
This Invention of improvements in latches or fastenings for doors,
casements, and shutters consists in a latch intended to prevent the opening
of the door, casement, or shutter by persons from the outside, as can
now be very easily done with the common latch by means of any instru-
ment, such as a knife blade or a very thin piece of steel.

page_text: My Invention consists of a plate of metal, preferably (though not
essential) having the form of a long sided triangle. At the small end it
is provided with a knob or handle at one-third of the length. From this
small end is a diagonal slot or openning forming an angle of about 45°
with one of the long sides of the triangle in a direction from the small
end to the longer end of the triangle. Within this slot a pin with a
large headed projection works freely the head-over and on to the face of
the metal triangle. This pin either by a plate or other suitable fastenning
is firmly secured to the door jamb or other part to which the corre-
sponding door, casement, or shutter is to be fastened. The metal triangle
moves freely upon this pin, and when unsupported hangs down free from
being struck by the movement of the door casement or shutter. When
used as a fastener the door or other article is closed and the latch is
raised by the knob and rotated on the pin till the large end of the
triangle projects over the door and rests upon another pin with a pro-
jecting head securely fixed to the door. A slot is cut in the triangle to
-allow the small portion of the pin to enter within the slot and allow the
triangle to drop three or four diameters of the small diameter of
the pin, where the triangle now rests, and prevents the door being
opened in that position of the latch. The slot in the triangle is also
continued from its upper part backwards and nearly parallel with the
lower side of the triangle for five or six diameters of the small part of
the pin. In this, which I call the third slot, and in the previously
described diagonal first slot, consists the peculiarity of the Invention,
for it will be evident that if any attempt is made from the outside upon
the latch through the chink to lift it the small end being the lightest is
forced against the pin in the diagonal slot, and by the action of the pin
upon this slot the latch is forced horizontally forward. The latch then
in its third slot slides on to the pin fixed on the door, and as this slot
has no outlet in that direction the latch is more firmly fixed than before.
As a farther precaution this third slot may be carried downward about
one or two diameters of the pin, and then the latch locking into this 4th
slot can have no further movement horizontally, and greater security
⚫ is given against any attempts at lifting it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Browning in the Great Seal Patent Office
on the 1st July 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BROWNING, of 63, Strand, London, Optician, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of January, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Browning, Her
special license that I, the said John Browning, my executors, admi-
nistrators, and assigns, or such others as I, the said John Browning,
my executors, administrators, and assigns, should at any time agree with,
and no others; from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN LATCHES OR FASTENINGS FOR DOORS, CASEMENTS; AND
SHUTTERS," upon the condition (amongst others) that I, the said John
Browning, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Browning, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention of improvements in latches or fastenings for doors,
casements, and shutters consists in a latch intended to prevent the
opening of the door, casement, or shutter by persons from the outside,
as can now be done with the common latch by means of any instrument,
such as a knife blade or a very thin piece of steel.
I will describe the Invention by the aid of the accompanying Sheet .of
Drawings forming part of this Specification, and in which Figure 1 is a

page_text: -
view of the latch as it would appear fixed on the door or shutters;
Figure 2, horizontal view of same.
Figure 3, plan of the latch removed.
Figures 4 and 5, the plates to be attached to the shutters, with the
pins by which the latch is retained in place; Figures 6 and 7, horizontal
view of Figures 4 and 5; and Figure 8, modification of the latch.
'The like letters indicate the like parts in all the Figures.
In Figure 1 the two parts b and 6' are attached by screws to the
shutters, one on the right and one on the left, or is attached to the
door post, 6' to the door, or vice versa, and if necessary the parts may be
reversed, as in right and left-handed latches. The part being attached
by screws or other suitable means to one part of the shutter so that the
division line of the shutters clears it, as indicated by the dotted line 8, 8,
it will be seen that the latch a is free to rotate round the pin c in the
slot a'. The plate with its pin c' is now fixed to the corresponding
half of the shutter to be secured, and it is placed so that the notch a² of
the plate a when the latter is rotated shall just fall upon the pin c³, the
head of the pin then prevents the shutter being pushed open from the
outside. If any attempt is now made from the outside to open the
shutters by lifting the latch by a knife blade for instance on the line of
division of the shutters, say, on the line s, a, the small and lightest end
of the latch being lifted, is driven by the pin c and the action of the
slot a¹ towards the right-hand (looking at the Drawing, Figure 1), and
the horizontal part of the latch a³ is then driven under the pin c¹ and
the lifting of the latch prevented.
The principle of the Invention rests in the free play of the latch at
the small end in the diagonal slot, the preponderating weight of the free
end projecting beyond the chink or opening between the shutters or door,
by which the latch can be tampered with and the horizontal portion of
the latch brought under the pin to prevent the lifting of the latch.
Within these principles it is obvious several changes of form may be
made without departing from the spirit of the Invention..
One modification of the latch described is as follows, see Figure 8,
wherein the two slots a¹ and a² are intended to be parallel with each
other, and to be adjusted to fasten or enter upon the pin c³ only when
the pin c is exactly in the middle of the slot a', thus increasing the
difficulties of adjusting the latch to a point at which it can be lifted..

page_text: Having now described and particularly set forth the nature of the
Invention, as well as the best means I am acquainted with for putting
the same into practice, I would have it understood that what I claim is
a latch, as herein described, with a diagonal slot working on a fixed pin
and locking into a pin on the corresponding half of a shutter or other
article to be fastened, so adjusted as to drive the latch horizontally when
tampered with, and to lock so as to prevent the latch being lifted, sub-
stantially as described.
In witness whereof, I, the said John Browning, have hereunto
set my hand and seal, this Thirtieth day of June, in the
year of our Lord One thousand eight hundred and seventy-
five.