CERTAIN IMPROVEMENTS ON LOCKS APPLICABLE TO DOORS AND TO OTHER PURPOSES
Year: 1820

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MALLET, of Marlborough Street, Dublin; Locksmith, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth did.
by His Letters Patent under the Great Seal of that part of the United
Kingdom of Great Britain and Ireland called England, bearing date at
Westminster, the Fourteenth day of December, in the first year of His
reign, give and grant unto me, the said William Mallet, my exors, admors,
and assigns, His especial licence, full power, sole privilege and authority,
that I, the said William Mallet, my exors, admors, and assigns, during the
term of years therein mentioned, should and lawfully might make, use,
exercise, and vend, within England aforesaid, my Invention of " CERTAIN
IMPROVEMENTS ON LOCKS APPLICABLE TO DOORS AND TO OTHER PURPOSES;" in
which said Letters Patent there is contained a proviso that if I, the said William
Mallet, shall not particularly describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, and cause the same to be inrolled in His
Majesty's High Court of Chancery within two calendar months next and
immediately after the date of the said Letters Patent, that, then the said
Letters Patent, and all liberties and advantages whatsoever thereby granted.
shall utterly cease, determine, and become void, as in and by the same,
relation being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Mallet, do hereby declare that the nature of my said Invention, and

page_text: the manner in which the same is to be performed, are particularly described
and ascertained in and by the Drawings hereunto annexed, and the follow-
ing description thereof (that is to say):
No. 1 is the interior perspective view of the lock, the cap or cover being
removed to exhibit its parts. A, A, coloured yellow, is the plate by which it is
attached to the door, &c. B, B, tinted grey, is the bolt represented as shot
out or locked, as part thereof being before the plate of the lock. On said
bolt are screwed or otherwise fastened. the barricadoed guider C, C, coloured
blue, the guide stud D, which keeps the sliding guards E, E, E, coloured
red, when moving in a parallel line with little friction, and F the spring
center pin split about half down the height it rises from the bolt, into which
split the end of the spring fastens and round which it plays. The barricadoed
guider C, the guide stud D, and center fixed pin F being attached to the
bolt, are here mentioned with it, and are more particularly referred to and
described hereafter. The sliding guards E, E, E, of which there may be a
greater or less number, move forward and backward with the bolt in locking
or unlocking the door, chest, box, &c., to which the lock may be attached, but
are not attached to it; they slide freely to the heights they are required to rise
through the apertures in the barricadoed guider C, C, and the guide stud D,
by means of mortices cut in them, as shewn. G is a stud rivetted to the
plate of the lock, which keeps the bolt locked or unlocked by standing behind
the sliding guards when the bolt is shot out or locked, and the notch H, when
.the bolt is withdrawn or unlocked. I is a guard stud (also rivetted to the
plate), between which and G the sliding guards must pass with great nicety in
locking and unlocking. There is a small projection J at the back of the
sliding guards, which, when they are all raised to the height wished by the
manufacturer, keeps the lines or surfaces of them which are exposed to the
action of the key or any other instrument by which the lock might be
attempted to be picked, in the same plane with each other, higher, but parallel
with the surface of the barricadoed guider, or in a variety of planes differing
from the projecting parts a, a, a, on the front of the key No. 8, as required.
The use of this arrangement is to prevent any indication of the corresponding
projections of the key, which, if they were not thus stopped, could be acquired
by rising them. L, No. 1, is the moveable collar, coloured green, playing in
circular holes, into which it is fitted, in the cap and plate of the lock. The
part of the collar at the letter of reference (viz¹) L, is the entire breadth o
depth, and it prevents, therefore, the plates from being crushed together, while
its outer diameter is so large that its periphery comes nearly into contact with
the bolt, barricadoed guider, and sliding guards in their passage occupying the

page_text: space of ward with more effect, and at less expence, and therefore rendering it
difficult, if not impossible, to introduce the pick locks in general. use to
operate on the sliding guards to open the lock. M, coloured brown, is the
outer rim of the lock, which meets the bolt and the barricadoed guider at
each extremity, and when the cap or cover N is on prevents damp and dust
from rusting or impeding the action of the spring and works. No. 2 and 3
represent a geometrical plan and section of the bolt and barricadoed guiders,
with a dotted line on No. 2 representing the form and situation of the spring.
The grooves O and P are slits or passages through which the studs G and I
pass, as seen in No. 1 and No. 9. e is the barricadoed guider in both plan
and section No. 2 and 3. Q, No. 2, are holes for rivets or screws to attach
it to the bolt; R, R, in No. 3, are screws supposed to be used for that purpose.
The barricadoed guider may be made of separate plates, with the mortices
S, S; S, left, or solid, with said mortices cut out, which mortices must be cut
of proper size for the lower parts of the sliding guards referred to below to
move through easily. No. 4 is one of the sliding guards; they are of one
thickness throughout, viz, the thickness of the apertures S, S, S, in the barri-
cadoed guider. The parts T, T, T, T, of the sliding guards slide through the
mortices of the barricadoed guider S, S, S, and when they are fixed in their
respective places, they, with the barricadoed guider and the bottom plate of the
bolt form one undeviating line, plane, or flat surface, which may be so engraved,
punched, &c., as to render it very difficult to discover where the sliding guards
are situated, or how many are used in the lock. No. 5 is a view, and No. 6
is a section of the moveable collar U, U. No. 5, the outer diameter of the
moveable collar, comes nearly in contact with the bolt, barricadoed guider,
and sliding guards, as described before and shewn in No. 1. V, V, is the
part playing in the plate and cap of the lock; the internal circle is the part
the key moves in. W, W, No. 6, is the part of the moveable collar, the
breadth of the key fitting between the cap and plate, and preventing them
from being crushed together, as before described. No. 7 is a plan of the spring
displayed before it is turned to the required form as at X. It is cut or split
up in so many divisions as there are sliding guards, each division of which acts
on its separate sliding guard, and is a little hollowed where it acts to retain its
proper position on the sliding guard, which is rounded with a corresponding
form for it to fit on; the solid end of the spring at Y has a square notch cut
down on it which passes down on the solid part of the screw F, No. 1, and
the parts from Z to Z of this spring fitting into the split head of said screw I
holds it firmly in its place to act with proper effect on the sliding guards. X
is the form of the spring shewn also at Nos. 1 and 2.
It is evident this

page_text: spring, by being divided as before described, possess the advantages of many
springs in one, and at the cheapest rate. From the above description, and from
the form of the key No. 8, I apprehend it will be easy to conceive the manner
in which the key must act on the lock, viz, the key being placed in the move-
able collar is turned round until the projecting parts of it a, a, a, come in
contact with the sliding guards at K, No.-1, which are risen by it to their
proper heights between the studs (G and I, No. 1); the longest projecting part
of the key in turning round strikes or presses against the barricadoed guider,
and shoots the bolt, when the springs, acting on the sliding guards, force them
down into the level plane, from whence they had been previously raised by the
key. In No. 9 I have given another perspective representation of my lock
with the key in it, and the bolt half way in its passages. This will shew still
clearer the manner in which the sliding guards move, as well as its whole
action; the letters of reference are the same as in No. 1. In No. 10 I have
given the view of the lock with cap on, which will explain it to the most
unexperienced. In this view will be seen a small notch a, into which falls a
lever bolt b, for the purpose of preventing the collar L from being turned
round, see also No. 5 and 6. When the key is introduced and passed through
the collar it presses the reverse end of the lever and brings the bolt out of the
notch, by which the collar is enabled to turn round. This is an additional
security to the lock, for which I have obtained the said Patent, as it is obvious
that without lifting this lever the collar could not be passed round so as to get
at the sliding guards; but this additional security I do not consider as abso-
lutely necessary, but may be either adopted or omitted at the option of the
manufacturer. I think it proper to observe that I do not confine myself to
the exact form or shape of the sliding guards, barricadoed guiders, or move-
able collars, nor the precise situation of studs used for the purpose in G and I,
No. 1 and 9, represented; but according to the variation of circumstances,
adopt other shapes, still retaining the principle, which may be easily conceived
by the mechanist. But to be explicit to all, I observe that with respect to the
sliding guards, they may be made as in No. 11, with the studs situated in
relation to them as at b and c, and the barricadoed guider may be in two
distinct pieces, especially in the smaller kind of locks, with grooves
cut at No. 12 or 13. Here the sliding guards occupy the whole space
without bars in the barricadoed guiders; and they are shewn with different
colours, blue and yellow, to admit the whole depth of the key being obliged
to act on them. This plan is useful where tlie locks are required to be
made thin; the center pin of the key and the corresponding hole in the move-
able collar may be square, triangular, or any form desired. The studs also, G.

page_text: and I, may be placed opposite each other, or otherwise. But any of the
above uses of my Invention, and all other possible combinations of them, if
practised by others, I should deem equally an infringement of my patent right,
and every mechanist will see that the principles above described are applicable
to every description of lock for doors, &c. &c.
The above will, I trust, render clear to every mechanic the parts of my new-
invented lock, and the manner of its operation in locking and unlocking.
With respect to the materials of which it can be composed, they may be of
any metal or metallic substance used in the construction of locks. The
moveable collars may be of wrought or cast iron, steel, or brass, &c. The
sliding guards may be of any of the same metals, &c., but if of brass or other
soft metal, I recommend their being faced with steel where the key acts, to
prevent injury from wear. In fact, those conversant with making locks, and
all other mechanics, will know the proper materials of which to compose the
different parts.
Having thus described its component parts and operation, it remains for me
to state the relative qualities of my patent lock when compared with all others
in existence. These I consider to be, first, superior strength; secondly,
superior security; and, thirdly, its being more simple in its construction, con-
sequently cheaper and less liable to be put out of order than others. Its
superior strength results from the moveable collar, which cannot, like all
other locks having pipes rivetted in the plates, be moved out of its position;
neither, like them, can it be bent or broken so as to prevent the introduction
of the proper key; it also preserves the sides from being closed together on
each other, and is, of course, infinately stronger than the wards introduced into
ordinary locks, whose situation it occupies in that now under description; it
also serves as a defence to the sliding guards, barricadoed guide, and bolt.
The sliding guards also, it is evident, could not be injured, as they can only be
slid back, but will instantly, by the action of their spring, return to their
places, and with the barricadoed guider form a solid mass between the plates
of the lock, which is not at all liable to injury from violence, and less than any
other lock from time. Its superior security consists in the sliding guards
having all their fronts exposed to the action of false keys, picklocks, &c., lying
in the same plane; and they must be all raised with the greatest accuracy to
their respective required heights in order to move the bolt; as the moveable
collar intercepts the sight of them it is impossible to know whether they are
all acted on or not, and it is self-evident no judgment can be formed as to the
heights to which they are respectively to be raised. The chances, therefore,
are infinate against their being all raised and at the same time to their proper

page_text: heights. If any of these sliding guards are raised too high it must neces-
sarily come in contact with and catch against the stud (I, No. 1); on the
contrary, if not raised sufficiently high, it will be held by the stud (G, No. 1);
in either case the bolt can neither be moved forward or backward; and it is
impossible for human judgment to form any idea of the cause of obstruction.
This is individual security from picking; it is evident also that a general one
from locks being made like each other is equally impossible, for the number of
sliding guards, and of the length of the bit of the key which acts on them, may
be varied beyond arithmetical calculation, even ad infinitum. Its simplicity,
and consequent cheapness, and the little liability of being put out of order,
result from its form, from the moveable collar occupying the place of expensive
wards, from the barricadoed guider and sliding guards projecting the spring, &c.,
so that neither dirt or violence can injure or impede them or it. In addition
to these advantages it presents this very essential one, that should the key be
lost or stolen a complete variation may be effected in the lock by the transpo-
sition of the sliding guards, so that the original key would not pass it, and
these variations can be repeatedly made by similar transpositions, varying from
these preceding according to the number of sliding guards, which, with the
addition of lengthening or shortening them, renders this form of variation
with a single lock almost infinite.
In witness whereof, I, the said William Mallet, have hereunto set my
hand and seal, this Seventh day of February, in the year of our Lord
One thousand eight hundred and twenty-one.