LockS UPON A NEW CONSTRUCTION
Year: 1784

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
BRAMAH, of Piccadilly, in the County of Middlesex, Cabinet Maker, send
greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thir Third day of April, in the twenty-fourth year of His
reign, did give and grant unto me, the said Joseph Bramah, His special
licence, full power, sole priviledge and authority, that I, the said Joseph
Bramah, my executors, administrators, and assigns, should and lawfully might,
during the term of years therein expressed, make, use, exercise, and vend,
throughout that part of His Majesty's Kingdom of Great Britain called
England, the Dominion of Wales, and Town of Berwick-upon-Tweed, my
invented "LockS UPON A NEW CONSTRUCTION;" in which said recited Letters
Patent is contained a proviso obliging me, the said Joseph Bramah, by 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 four calendar months next
after the date of the said recited Letters Patent, as in and by the said
Letters Patent, and the Statute in that behalf made, relation being thereunto
had, may more at large appear.
NOW KNOW YE, that in compliance with the said proviso, and in
pursuance of the said Statute, I, the said Joseph Bramah, do hereby declare

page_text: that my said Invention is composed and made in manner following (that is
to say):-
The principle of all locks hitherto known or in public use is too well under-
stood to require any particular description here; yet it may not be improper to
observe on what ideas their security was always founded, and likewise how
far such principle may tend to render them perfect or effectual, by which may
be obtained some comparative information necessary to shew or explain the
advantages and superior utility of this my said Invention. The means hitherto
adopted for the security of all locks are the inserting or fixing between the
keyhole and the bolt a greater or a lesser number of wheels or wards, which said
wheels or wards may be crossed or interwoven in such manner as to render
the communication between the keyhole and the bolt as irregular and crooked
as possible, in order to prevent the said bolt from being removed by any coun-
terfeit application when the key is absent, the bitt of which said key is so
cut or shaped as to form a compleat tally with the said wheels and wards, and
is thereby capable of producing the required effect when applied for the
purpose of moving the bolt. Now the insufficiency of this method of rendering
locks a perfect security is as follows, (viz.)-Notwithstanding the said wheels
and wards may be variously placed and disposed, yet they cannot by any
means become sufficient to answer the intended purpose; owing to their being
always left fixed in the lock, their form and disposition can be easily obtained by
impression, so that notwithstanding they may prevent the use or effect of pick-
locks, yet the making a perfect or skeleton key is always extremely practi-
cable; and 'farther, the variations capable of being made in the disposition of
the said wheels or wards,.and the form of the key's bitt, is not sufficient to
produce the required number of locks without having great quantities exactly
alike, and their keys capable of opening each other reciprocally, from which
they become a very imperfect security, as any ill-disposed person may, by .fur-
nishing himself with a number of old keys, be enabled to open almost all the
common locks in the kingdom with as little difficulty as if he had in his
possession the key belonging to each lock. To remedy these said objections
by discovering some principle or method whereby the success of pick-
locks, false keys, and all other counterfeit means of opening locks may be
infallibly prevented, has been the ultimate design of this my said Invention,
and may be effected in manner following (viz.), instead of introducing (for the
security of the bolt and other moveable parts of the lock) a number of wards
and wheels, I have found out and invented a much more simple and effectual
means of rendering the said bolt and other parts intirely immoveable without
the absolute application of the real key; by those said means the effects of

page_text: pick-locks, the practicability of obtaining the form of the key, and the having
number of the said keys alike, is intirely avoided by having a greater or lesser
number of moveable parts, such as levers, sliders, &c., so adapted and placed
in the lock so as to require each of them a separate and distinct change in
their situation or position before the bolt and other parts of the lock on which
its safety depends can be set at liberty or moved. These said levers, sliders, or
other moveables, by the assistance of an elastic graviating or other power,
have the property of maintaining or restoring their given position or situa-
tion after it may have been destroyed by any forcible application for that
purpose; from this said property the said levers, sliders, or other moveables are
rendered capable of receiving (as it were) any impression or required change
in their position or situation correspondent to the cause which produces such
said charge, and are also thereby always restored to their former state or
rosting situation when the said cause is withdrawn, so that the opening these
my said invented locks is as difficult as it would be to determine what kind
of impression had been made in any fluid when the cause of such said impres
sion was wholly unknown, or to determine the seperate magnitudes of any given
number of unequal substances without being permitted to see them, or to coun-
terfeit the tally of a banker's check without having either part in possession.
The form of these said levers, sliders, or other moveables, and also the manner
of fixing them in the lock, may be varied without end without altering or losing
any of the intended properties or advantages, as the principal merits and efficacy
of my said Invention does no ways depend thereon, but intirely depends on the
said levers, sliders, and other moveable parts being so fixed or disposed as to
prevent the bolt or other part of the lock on which its safety depends from
being moved without the said levers, sliders, or other moveables first receiving
cach of them a seperate and distinct change in their position or situation, by a
key or other contrivance for that purpose, which being pushed or pressed in a
progressive direction, without revolution, against some part of each of the
said levers, sliders, &c., occasions them to change their positions in manner
exactly correspondent to the part of the key so applied, and the said part being
formed with a number of irregular surfaces equal to the number of levers,
sliders, &c. against which it is pushed or pressed, causes them to move at
different times, and to different distances from their original situation, and the
said key, by having a stop or some mark whereby to limit or determine the
length of its push against the said levers, sliders, &c., puts a period to each of
their motions, notwithstanding they are at liberty to move farther, but are
prevented by the resistance of a spring, gravity, or other power always endea-

page_text: vouring to restore them to their original situation, so that the motion of each
lever, &c. seperately depends on the heighth or depth of that surface of the key
against which it falls, so that a perfect tally is formed similar to any impres
sion made in a soft body by the forcible application of any harder one, which
said hard body represents the essential part of the key, and may be of any
determinate shape, formed by rule on by accident, and the moving the bolt or
other parts of the lock, whereby it may be opened, intirely depends on the
positive motion of the said levers, sliders, &c., as any one of them would, by
being pushed the least degree too much or too little, intirely prevent the bolt
&c. from being moved or set at liberty; and as the whole of the said levers,
sliders, &c. are restored to their resting situation when the key is withdrawn,
by the properties or powers above mentioned, the said tally or impression is
then totally destroyed, and consequently the opening of the lock is then left
wholly dependant on chance whilst the said key is absent, as there is no rule
whatever, nor imagination founded on certainty, that may in the least degree
tend to assist in discovering the required position or situation of each or any
of the said levers, sliders, or other moveables, whereby the form of the key, on
the part of the said key necessary to the opening of the lock, might be ascer
tained. Now, admitting that no lock on this said principle can be picked,
or the form of the key obtained, their further security then depends on the
number of different keys that may be made without having any two of them
alike, which number, I trust, will appear indeterminate from the following
demonstration, (viz.) :—
Let us suppose the number of levers, sliders, or other moveables, by which
the lock is kept shut, to consist of twelve, all of which must receive a different
and distinct change in their position or situation the application of the key,
and each of them likewise capable of receiving more or less than its due,
either of which would be sufficient to prevent the intended effect; it remains,
therefore, that to estimate the number producible may thus be attempted,
(viz.) Let the denominations of these levers, &c. be represented by twelve
arithmetical progressionals; we find that the ultimate number of changes that
may be made in their place or situation is four hundred and seventy-nine
million one thousand five hundred, and by adding one more to that number
of levers, &c., would then be capable of receiving a number of charges
equal to six thousand two hundred and twenty-seven million nineteen
thousand five hundred, and so on progressively, by the addition of others in
like manner, to infinity. From this it appears that one lock, consisting of
thirteen of the said levers, sliders, or other moveable parts, may (by changing

page_text: their places only, without any difference in motion or size,) be made to require
the said immense number of keys by which the said lock could only be opened
under all its variations. Wherefore it likewise appears, that the same number
of locks may be made consisting of the same parts without the smallest dif-
ference whatsoever, and by varying the places of such said parts, would require
each of them a separate key, and not one out of the whole number above
mentioned capable of opening any lock except that particular lock to which
it belongs. Now, it must be observed that the number of different locks
above stated are produced by thirteen moveables, (to wit,) levers, sliders, &c.,
which having all a distinct difference in their required motions, determines
their denominations or names without any relation being had to the separate
value or positive motion of each, which said motion may be given at discretion;
so that it plainly appears, that the number producible from a like number of
levers, &c. is far from terminating here, as their motions, and the difference in
proportion one to another, may be varied without end, and are to be added to
the former; it is therefore very obvious from this demonstration, that a much
less number of tho said lovers, sliders, or other moveables, will be found suf-
ficient to produce any required number of tho said locks without having any
of their keys to pass cach other. These said levers, sliders, or other move-
ables above mentioned, may be adopted and applied to all sorts of discretionary
fastenings whatever, such as bolts, bars, turn-buckles, &c.
The Figures or Drawings hereunder written, or hereunto annexed, togetber
with the demonstration or description therewith given, will more fully shew
the true nature and intent of this my said Invention.
In witness whereof, I have hereunto set my hand and seal, this Twenty-
first day of August, in the year of our Lord One thousand seven

page_text: into the bottom of each notch, so that the motion of the bar or bolt G is thereby
totally prevented till these sliders are moved some way or other to give it
liberty, which must be done from their ends at I, I, as no other part of them is
meant to be exposed for the purpose; them which ends at I, I, always have an
equal projection when the bar G is set fast. Now we will suppose each of
these sliders capable of being pushed upwards towards A, B, &c. to any deter-
mined distance, and when each of them has exactly received its due motion,
the bar G is set at liberty, so as to slide backwards or forwards as required.
Now, in order to determine the separate and distinct motion that shall be given
to each, we will suppose the part H to be made, which part serves to repre-
sent a key, and the ends 1, 2, 3, 4, 5, 6, are cut of different lengths, either by
rule or by chance, so that when pushed against the ends of the sliders at I, I,
will cause each of them to be slided up at different times and to different dis-
tances from I, I, in a form exactly correspondent to the ends of the part H;
when they have thus received their correspondent position, and their ends at
I, I, form a compleat tally with the part H, by making a notch in each slider at
1, 2, 3, &c., in a line with the bar G, the said bar will then have liberty to be
slided backwards and forwards without obstruction, and when brought into its
original situation, and the part I withdrawn, the sliders A, B, C, &c. will
then fall down into their notches and fasten it as usual, and their ends at I, I,
will be restored perfectly even as before, and not the least trace left of the
position required in them to set the bar G at liberty; it depends therefore
intirely on chance, when the part II or key is absent, see Specification. The
construction of the Fig. 1 is thus adapted for the more easy conveying the
truc ideas of this Invention. These sliders A, B, C, &c. may also be made so
as to have their required motion or position given them without the use of H,
by having sundry changeable marks graduated on the edge or other part of
each of them exposed for that purpose, as at 0, 0, certain of which are to be
brought in contract, or in a line, before the notches 1, 2, 3, &c. will be opposite
to each other or the bar G moved; and the said marks or gradations
required may be distinguished by figures, characters, &c. and the secret will
serve as a key to such as are in possession thereof. (For the changes producible
in this number of sliders or other moveables, see Specification).
Fig. 2 is meant only to represent in what manner sliders may most con-
A is a frame or barrell that moves
veniently be applied in locks of all sorts.
the bolt by its turning, in which barrel or frame is fixed eight or any other
number of sliders. B is a thin plate fixed in the lock, through which the barrel
or frame A passos, and is prevented from turning for the purpose of moving the

page_text: bolt by the projecting parts of the sliders that moves in the fixed plate B till
the notches in each of them is, by the application of the correspondent part of
the key, pushed into contract or in a line with the plate A at the end of each
slider. In the billenderical parts, c, c, c, &c. is fixed a spiral spring, which
always restores them after the key is withdrawn, similar to A, B, C, &c. by
their own gravity in Fig. 1.
Fig. 3 represents a method of fixing any number of levers for the security
of the part that moves the bolt, which part is B, and is fixed to the levers
C, C, &c. as in the section. A, A, A, is the plate and other fixed parts of the
lock; D is the drill pin on which the key is applied; e is the spring that
restores the levers after having been pressed down by the key; the notches in
the head of each lever are made by the rules already described. An endless
variety of other modes may be adopted of placing levers, sliders, or other
moveable parts, in order to effect the above purposes without in the least
degree deviating from or losing any of the essential properties arising from the
ideas of this Invention. A, Fig. 4, represents a lock that locks on both sides;
B is the bolt; C is the cover plate in which the projecting parts of the sliders
move for the purpose of securing the bolt; e, e, &c. are the sliders; D is the
barrel or frame represented in Fig. 8, in which the sliders are fixed F, F, and
are the cillenderical parts in which the spiral springs act; G is the key-hole,
which is bored through the center of D, as shewn in the section, into which
hole the edges of the sliders project, in order that the end of the key may
fall against them when pushed forward in the hole G; H is a part joined to
the barrel or frame D, and acts as a key's bitt to move the bolt when D is
turned round for that purpose; I is the section where the barrel, sliders, &c. is
marked the same as in the plan; K, K, the 'key, from both sides, on which
there is a small stump at L, that fall into a notch or slit in the barrel D,
in order that D may be turned round with the key for the purpose of
moving the bolt, and also by its turning under the cap M, the key is prevented
from being pushed out by the springs whilst it is revolving. To move the
bolt the end of the key is formed with different surfaces, which gives the sliders
different motions, see Specification, and brings the notches in the sliders, when
pushed down to its stop, exactly in a line with the cover plate C, which notches
being the size of the thickness of the said plate, permits the barrel D to
make a revolution if required; and it appears from this section, that as the
sliders e, e, &c. may be each of them be pushed as far as the bottom of the
slit or grove n, n, in which they move, that the whole of the notches in sliders
are liable to be pushed too far as well as too little, both of which would
prevent the barrel D from being turned, or the bolt B from being moved.

page_text: AND BE IT REMEMBERED, that on the Twenty-first day of August, in
the year above mentioned, the said Joseph Bramah came before our said Lord
the King in His Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained and specified, in form above men-
tioned. And also the Specification aforesaid was stampt according to the
tenor of the Statute made in the sixth year of the reign of Their Majesties
King William and Queen Mary of England, and so forth.