SUNDRY VERY VALUABLE AND IM- PORTANT IMPROVEMENTS ON A LOCK FOR DOORS, CABINETS, AND OTHER THINGS ON WHICH LOCKS ARE USED
Year: 1798

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, JOSEPH
BRAMAH, of Piccadilly, in the County of Middlesex, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Third day of May, in the thirty-eighth year of His reign,
give and grant unto me, the said Joseph Bramah, His especial licence that I,
the said Joseph Bramah, during the term of years therein mentioned, should and
lawfully might use, exercise, and vend, within England, Wales, and the Town
of Berwick-upon-Tweed, my Invention of "SUNDRY VERY VALUABLE AND IM-
PORTANT IMPROVEMENTS ON A LOCK FOR DOORS, CABINETS, AND OTHER THINGS ON
WHICH LOCKS ARE USED," and for which, in the year One thousand seven
hundred and eighty-four, I obtained His Majesty's Royal Letters Patent,
and also in the keys by which the same are locked and unlocked; in which
said Letters Patent there is contained a proviso obliging me, the said Joseph
Bramah, by an instrument in writing under my hand and seal, to cause a
particular description of the nature of my said Invention, and in what manner
the same is to be performed, to be inrolled in His Majesty's High Court of
Chancery within one calendar month after the date of the said recited
Letters Patent, as in and by the same (relation being thereunto had) may
more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Joseph Bramah, do hereby declare that my said improvements do consist,
and are to be understood as follows, that is to say:-
The practice of granting Patents for subsequent improvements in the
objects of former ones has long been common; and among the number of
Patents granted there are comparatively few which can be called original,
so that it is difficult to say, in many instances, where the boundary of one
ends and where that of another begins; but nothing of this kind can per-
plex the present case; for I believe it will be universally allowed that the
principle comprehended in my former Patent is premordial, and the dis
covery of it new, and as I am confident that that principle is competent to
perfect security, as far as principle is concerned in the production of a
safe lock, I profess not to add anything thereto whereby to pretend any
greater security on the score of principle; but I here declare, that the real
object of this my second Patent is, to obviate and remove objections which
render all kinds of locks which are opened by a key eventually unsafe,
viz: when the key belonging to any lock is out of the possession of its
owner it may be counterfeited, and the simplicity of its application being
within the reach of every capacity, the office of the lock is suspended until
the key is again in the possession of its owner. A remedy for these two
objections I propose to effect in two ways in locks, on the principle for which
1 before had a Patent, viz :-
First, by making the keys capable of varied arrangements similar to the
locks, which may be done by causing the key to consist of as many separate
parts as there are sliders in the locks, so that the varied projections of the
surface which act on the sliders, to bring them to their proper station, may be
arranged by the owner, conformable to the disposition of the sliders in his lock,
and which lock he may arrange differently at pleasure.
Secondly, by so adapting the locks that a system may be introduced which
will admit of an universal graduated standard instrument, very simple in its
nature, and capable of being applied with effect by none but its owner in the
act of opening the lock, which act shall at all times depend on a secret that
may exist only in the mind of every respective owner, except he chuse to com-
municate it to others, and which shall operate with regard to opening the locks
on the precise principle of the sign and countersign in military operations,
namely, to admit some to certain privileges and exclude others. For this
purpose, let us suppose a cylinder or frame in which the sliders (also called
guards) are fixed, to be prepared in the usual way, and the number of sliders
to amount to twenty-four. In the first place, I propose to open the slit or

page_text: groove in which each slider moves out to the front of the lock, at a greater
distance in some cases from the center of the frame than the usual diameter
of the keyhole, so as to render the exterior.end or point of each slider on
which the key acts seperately accessible, so that by any instrument which will
pass into the said slit, and fall in contact with the end of the slider, each of
them may be forced from its resting station to any given distance within the
latitude of variation allowed for the whole twenty-four sliders, then the spring,
which in the old lock replaces the sliders after the operation of the key, being
removed, each slider will always remain in the station which the instrument
employed to give it motion leaves it, whether that motion be excessive or
deficient, for the purpose of opening or permitting the motion of the bolt:
Now, suppose the distance of variation in the motion of these twenty-four
sliders to be limited to one inch, their relative variations will then be one
twenty-fourth part of an inch each, or the notches in each slider will require
the sliders to move conformable to these variations before they will all
fall, coincident with the edge of the guard plate. These notches and the
respective sliders shall be denominated A, B, C, D, E, &c., up to twenty-
four, and then suppose them placed in the frame under any arrangement the
owner may think proper to select from the infinite variety they are capable of,
and by a method actuated by the hand or otherwise, each slider is brought
into its resting station, that is to say, so that all of them shall appear from
the front of the lock with an equal projection. The lock is then immovable
until each slider receives from without a distinct change in its station. For
this office a key must be prepared, which will bring each slider into its
proper station by a separate action on only one at a time, instead of perform-
ing the whole at once as the key now does. This instrument, which I call a
key, or rather an index, may be of steel, iron, or any other metal, or even
wood, and must be made of a size capable of entering the slits or grooves in
the frame, so as to fall in contact with the sliders, and capable of pushing
them back one at a time as aforesaid, to the distance of one inch. Then
suppose that this inch is divided into twenty-four gradations, and each of them
marked A, B, C, D, E, and so on, to twenty-four, this instrument being then
put into the hands of the person who arranged the order of the sliders in
setting in the frame (and which can at any time be re-arranged) he will be
able, by his knowledge of the particular situation of each letter (beginning at
any fixed points), to give each slider its regular motion by pushing down A
wherever it may be placed in the frame to the letter A upon this index, and in
the same way B, C, D, and all the rest, wherever they are respectively placed;
and when this is performed the lock will open by a partial revolution of

page_text: the slider frame, or by sliding the said frame in some instances, and by
leaving it stationary in others, and causing the guard plate to move instead of
the frame, as there are a number of methods by which the effect may be pro-
duced; but I rest not on any precise method of accomplishing the end, but on
the end itself, which has been amply described above.
Now, as the above clearly shews the true object of the Patent to which
it is annexed, and as the article itself must be of public circulation, the
methods I now describe, and hereafter may adopt in producing this effect,
cannot be hid from the public eye; therefore to attempt any minute specification
would be useless, as no guarantee can be necessary on the behalf of the public,
when they must, at the commencement of their right, be in possession of the
thing itself, with all the improvements that fourteen years' practice can suggest;
and as 'practice only can evince the most complete means of producing the
afore-mentioned effect, I again repeat, that I intend this Patent shall protect
my right to the Invention or Discovery of the object I have above stated, in
any manner I shall find most effectual, in producing it at all times, during the
term of years expressed in my said Patent.
In witness whereof, I, the said Joseph Bramah, have hereunto set my
hand and seal, this Second day of June, in the year of our Lord One
thousand seven hundred and ninety-eight.
Inrolled the same Second day of June, in the year above written.