IMPROVEMENTS IN THE CONSTRUCTION OF LOCKS
Year: 1842

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MOSES
POOLE, of Lincoln's Inn, in the County of Middlesex, Gentleman, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fifteenth day of January, in the fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Moses Poole, Her especial licence, full power, sole privilege and authority,
that I, the said Moses Poole, my exors, adñiors, and assigns, or such others as
I, the said Moses Poole, my exors, adñiors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed,
the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF LOCKS," communi-
cated to mo by a certain Foreigner residing abroad; in which said Letters
Patent is contained a proviso that I, the said Moses Poole, shall cause a
particular description of the nature of the said Invention, and in what
manner the same is to be performed, to be inrolled in Her said Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, tho said
Moses Poole, do hereby declare the nature of the said Invention, and the
manner in which the same is to be performed, is particularly described and
ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked thereon
(that is to say):-
-
The first part of the Invention consists of a lock which is called "Tho
Combined Snail Wheel Lock," which name is given to it an account of
one of its principal characteristics being the causing of the key to carry round
with it any desired number of wheels formed of flat plates of metal, which 1
wheels revolve upon a centre pin, and are each of them perforated with a snail-
like or other suitably formed opening, within and upon which the bit of the
key is to act in a manner to be presently described.
In the accompanying Drawings Figure 1 is a representation of a door lock
with the cap plate. Figure 2, removed for the purpose of exhibiting the 1
interior. A is the bolt which is not to be acted upon directly by the key, but
by a pendulous lever B which works on a joint pin at B', said pin being its
fulcrum. The end B of this lever, which is made thicker than the part of it
under the bolt, is received within the space or notch C in the bolt, which it
serves to carry back and forth. D is one of the snail wheels, of which, in the 2
lock from which this Drawing was made, there are four; one of these is
represented separately in Figure 3. In this wheel a is a centre hole which
passes over the drill pin 6 of the lock; c is a snail-like excentric or othor.
suitably formed perforation, which may be alike in each of the wheels. Tho
bit of the key is to operate on the curb d, d, of the perforation, and it will be g
manifest that the point upon which it will act will be determined by the length
of that part of the bit which is brought into contact with the said eccentrio
curve.
:
Figure 4 shows the kind of key employed, e, f,.g and h, being four portions
of the bit, varying in length from each other, and intended to act upon the 3
curves d, d, of the wheels. The part i serves to connect the bit with tho
barrel, and there is a recess in the bush of the cap plate to allow this part to
turn in, without which provision the bit would be cut off. The respective
acting parts of the bit e, f, g, h, may be of any length within the compass of
the snail-like perforation, their length being governed by. accident or fancy. 3
In order to move the bolt forward by the action of the key, the end. Bo
of the
pendulous lever must be received into recesses E, which are formed on each
of, the snail wheels; and it will be evident that this cannot take place. unless
the similar recesses in each of the wheels are mado to coincided. To effect this

page_text: ·
these recesses are not made until the key is finished and allowed to act by the
projecting portions of its bit upon the respective. wheels by turning it round,
so as to carry them in the direction of the arrow, which is that for shooting
the bolt out, and in doing this the wheels will be carried to different distances;
until the last and least projecting part of the bit is brought into contact with
its corresponding wheel. The recess E is then made through all the wheels
whilst they are confined in this position, and the key therefore, when again
turned to.shoot the bolt, will always cause them to coincide, and as the wheels
aro carried round, the end of the pendulous lever B will fall into the recess, and
it will be carried forward, and with it the bolt A. The key is not allowed to
turn any further than is necessary for shooting the bolt and allowing the end
B of the lever to escape from the recesses E, there being a stop pin or
projection on the under side of the bush of the cap plate, with which pin or stop
the part of the bit comes into contact, and is thereby arrested; in order to
remove the key it must be turned back to its original position. When the
bolt is to be withdrawn the key is to be turned as in locking, until the piece-
B falls into the recesses E, and then on reversing the motion of the key the
bolt will be carried back or withdrawn by the action of the lever. The flat
side of the bit of the key coming into contact with the ends e of the snail-like
perforations causes the snail-like openings in them all to coincide as they are
turned back for the purpose of removing the key. When the wheels are
brought into the proper position for withdrawing the key, the lip or tongue
fwhich constitutes the end of a spring 9, 9, falls into notches h on the edges
of the wheels, and holds them in place until they are again acted upon by the
key. This lip is lifted from the notches by the action of that one of the wheels.
which is first moved by the key, the notch h in this
wheel, being bevelled off'
The spring 9, 9, repre-
in the manner shown by the dotted lines, Figure 3.
sented by dotted lines, is shewn as attached to the fulcrum end of the lever B,
but this mode-of attachment is not a point of any importance when so attached;
however, it aids in moving the bolt forward by its being brought into contact
with the offset on the under side of the bolt as it is moved forward by the lever
B. Sometimes I allow a pin upon this lever to enter a slot or mortice made
through the bolt for the purpose of moving it back and forth; this part,
however, may be arranged in various ways. Between each of the wheels
there is interposed a stationary plate F, Figures 1 and 5, by which they are
rendered independent of each other in their action.
:
**In Figure 6 I have represented the snail wheels as combined in a padlock,
the hasp or shackle of which is a revolving ring, but they may be combined
with a hasp or shackle of the ordinary kind. The snail wheels G. are similar
TT

page_text: to those already described, and are to be separated from each other by a plate
or by small washers. H is the lasp or shackle, consisting of a hoop or ring
with a picco cut out at I. This hoop revolves in a groove in the lock made to
receive it, and is represented in the Drawing as when the lock is closed; when
unlocked the ring is to be turned round by hand, so as to allow the staple to
escape at the opening I. The notch i on the periphery of the snail wheels
performs the office of the end of the lever B in the lock first described, and
when the key comes to its bearing on the respective snail perforations, the
notches in each wheel similar to i coincide, and in consequence of this, when the
plates are turned round to a suflicient distance, the end of the spring catch ¹
enters these notches, and the catch is thereby withdrawn from the notch in
the ring II, within which it is represented as being contained, and then the ring
can then be turned around until the catch arrests it by coming into contact
with the offset K in the ring, which brings the opening I without the body of
the lock. The spring L performs the office of that marked g, g, in the door
leck, its lower end entering notches m in the snail plates when they are
turned back, and thus arresting and holding them in the proper place whilst
the plates are revolving. This spring leans upon their edges and keeps them
from any accidental or irregular motion. When the plates or wheels are
turned back, and the key removed, the hoop h may be turned round, and the
catch will fall into its notch, as shown in the Drawing. I have sometimes
used a device by means of which the hoop II is made to revolve by the action
of the key, but this of course renders the action somewhat more complex; I
have also variously arranged the springs, catches, and other auxiliary parts, a
thing which can readily be done by any clever workman without varying the
general principle upon which said lock operates; I do not intend therefore, by
anything contained in the foregoing description, to limit myself to the precise
inanner which I have exhibited of arranging these parts, but to vary them as
I think proper, whilst I attain the same end by analagous means.
Having thus fully set forth the nature of the improvements in the com-
bined snail wheel lock, and shown the manner in which the same are carried
into operation, what I claim therein as new, and desire to secure by Letters
Patent are, the use and employment of said combined wheels, having in them
openings similar to those described, which wheels are to be operated upon and
carried round to different distances by projecting pieces on the bit of the key
until a notch or envity in each wheel is brought to coincide with those on the
other wheels with which it is combined, so as to admit of the opening of the
lock in the manner or upon the principle above set forth.
I will now describe the second part of the Invention, which relates to an

page_text: improved lock which I denominate the Clam Shell Padlock, and which is
particularly applicable to mail and other travelling bags, but it may, also: be
used for other purposes. The distinguishing features of this lock are:-Tho
manner in which I construct or form the shell or case within which the key
operates upon what I call the spring hooks; the manner in which I form
these spring hooks No. 1; and also the way in which I connect the bow or
hasp with the shell or case without the employment of a joint pin. The shell
or case consists of two plates or pieces of metal only; which are struck up in
the same die, and are therefore exactly alike in form.
Figure 1 represents one of these plates, which, when laid upon and rivetted
to a corresponding plate, forms the shell, the edges of which are 'curved or
rounded.
Figure 2 shows the interior of the lock, the key-hole plate, Figure 1, being
removed. It is the bow or hasp which is embraced at its joint part by the sides
of the shell, and is thereby held in place, tlie part which enters the notch at a
serving as the fulcrum upon which it turns; it is thus left solid, not requiring
to be perforated for a joint pin. B is one of the spring hooks, with a fixed or
permanent hook or head; C is one of the spring tails with a detached hook or
head B, b. Of these I generally employ from four to six, placed one above the
other, but any desired number may be used. I usually cut each of these
spring hooks or spring tails out of a single plate, with a slit b, b, along it, so as
to constitute the part c, c, c, a spring, which admits the catch of the hasp to
come under the hook when the hasp is shut or pushed in, and holds it there
until it is released by the key; and when the key forces the hook or catch part
d back, it will cause the upper end of the spring to bear against the inclined
portion e of the catch of the hasp, and will cause the hasp to fly out as soon as
it is relieved from the action of the hook or catch part of the spring hooks.
The side of the key bits (which may be of different lengths) when turned to
open the lock bears against the lips e, e, e, of the spring hooks when they have
those lips, as in Figures 4 and 5, and only lifts them when they have no such
lips, as shewn in Figure 3, in which case the said detached heads are pierced
with a hole, as shown at f, Figure 3; and when the fixed heads are used in
combination with them, a hole is also pierced through them, as shown at f,
Figure 5, through which hole a small wire passes to connect them together,
and make them move together when drawn back by the key, to each of which
they are adapted and fitted in a way well understood by locksmiths. When the
key is not acting upon the spring books, or the hasp is not being pushed in so
as to be held by the catch, there is no tension whatever on the spring c, c, but
it is quite free, exerting no pressure whatever on the catch.

page_text: Having thus fully described the construction and operation of the improved
mail bag padlock, what I claim therein as constituting the Invention is,―
First, the forming of the shell or case of two pieces of plate metal, raised and
adapted to each other in the manner set forth. I do not claim the raising of
metal by means of dies, this being a well known process; but I limit my
claim to the manner in which I have adapted the raised plates to the forming
of the shell of a padlock, instead of making it by casting or by joining a rim
ou to wrought metal; as by the adaptation I have not only improved the form,
but have given additional strength, and that at a diminished cost.
Secondly, I claim the manner of combining the bow or hasp of the lock
with the shell of the lock, without the use of a joint pin, as herein fully set
forth.
Thirdly, I claim the manner of forming and using the spring hooks, whether
with fixed or detached heads, as described, the springs being so arranged as
to be brought into action by the shutting of the hasp, and by the turning of
the key, and causing of the hasp to fly out by the pressure of the springs
against the inclined point of the catch.
It will be manifest that variations may be made in the manner of forming
and arranging the respective parts of the lock herein described, and I do not
intend therefore to limit myself 'in this respect. The springs may be made in
separato pieces and attached to the spring hooks, and the hooks may be made
in different forms detached from the springs or spring tails, and these detached
hends made without lips may be used in connexion with those having heads or
hooks, being connected together by a. wire passing through them, or by any
other method, so that they all shall be drawn by the key, and other changes
may be introduced in other parts whilst the instrument will remain substan-
tially the same, producing the like results by analageous means.
I will now describe the third part of the Invention, which relates to a lock
which I denominate a Combination Lock.. In constructing it I form a number
of horizontal tumblers, rarely employing fewer than six, and sometimes use as
many as twenty; and as they are so constructed that their relative positions
may be changed at pleasure by the use of the key in locking, the mutation
of twenty such tumblers will give more than a million of changes, the key
being also so made that the bit of the key shall consist of as many parts
combined together as there are tumblers employed in the lock, each of which
bits are made to correspond with the respective tumblers which they are to lift:
In the improved lock the bits of the key are not made to operate, as has been
usually done, directly upon the lower edges of the respective sliding horizontal
tumblers, but I use in combination with them à corresponding number of

page_text: auxiliary tumblers and these may be horizontal, or upright, or vertical, upon
which the key is to operate directly, and the upper edges of these auxiliary:
tumblers bearing against the lower edges of the sliding horizontal tumblers
with which they correspond, the whole are lifted by the bits of the key. The
lower edges of my 'auxiliary tumblers, where the key acts upon them, I hollow
out in such a manner as to form within each of them a cavity or arch, which
I denominate the belly of the tumbler; and at the upper part of this arch, in
each of the tumblers, I form a small secondary arch, consisting of a small
secondary belly, and from this circumstance I denominate the interior of the
árch the double belly. By this peculiarity in their form the key is made to act
upon said auxiliary or upright tumblers, and through them upon the sliding
horizontal tumblers, in a manner which renders the operation of this lock much
more secure; certain, and accurate than a lock made without such provision...
In the accompanying Drawing, Figure 1 represents the interior of the lock,
the cap plate being removed for the purpose of exhibiting it; the rim of
the lock is shown at a, a, a. A, A, is the outer. or upper tumbler in this
position of the lock. This outer tumbler works on a round stump 6, which
is. rivetted or otherwise firmly attached to the plate of the lock at the rear
end or tail of the bolt. One of the tumblers below that, marked A, A,
is shown in Figure 2,' and this is represented with a slot or opening G
through it, instead of the round hole through A, A,' all the tumblers
excepting that one being furnished-with such a slot. This is for the purposo
of allowing the said tumblers to slide back and forth on the stump b, for
a purpose which will presently appear. F is a stump affixed into the tail
or thin part of the bolt, its shape being such as is shown in the Drawing, or it
may be fitted into a mortice in the said tail of the bolt by a tenon on the lower
end of the said stump F, and a corresponding tenon on the upper end of the
said stump, fitted into a similar mortice in a plate projecting over the said
stump from the head of the bolt, in which case the stump is allowed to move
freely backwards and forwards in the said two mortices about one eighth of an
inch. d is a stump rivetted or otherwise affixed to the plate of the lock above
the tail of the bolt. These stumps may be made of iron, steel, or other suit-
able material. The tumblers I usually form of alternate plates of iron and
brass, these dissimilar metals being much less liable to adhesion than those
which are similar. The tumblers have notches, or racks as they are some-
times. called by locksmiths, at their fore ends, as shewn at H, which notches
are adapted to the stump F, Figure 1, allowing the said stump to pass out of
or into said notches or racks as the bolt is moved back and forth by the key
when the tumblers are properly lifted, but which notches are so constructed as
.:

page_text: to hold fast on the said stump F by means of the weight of one end of such
tumbler when not lifted by the key, and to be drawn out by it along with the
bolt, the slots G on tho tumblers allowing of such sliding motion on the round
stump b. The said tumblers have also a fin or projection J.formed on their
upper edges by the two notches c and c. This projection or fin is so situated or
placed as to be immediately behind the stump d, Figure 1, when the tumblers
are placed in the lock with the bolt thrown back, and immediately before the
stump d, when the bolt is thrown out, and the tumblers thrown out with it, as
herein-before described. The use of said fin is to prevent the bolt being thrown
back by the said fin striking against tho stump d when the tumblers are lifted
after being drawn out with the bolt. In the several tumblers of one lock all
the mouths of the notches H are placed at different heights, so that the several
tumblers shall require to be lifted to different heights or distances to allow
the bolt stump F to pass into or out of the several notches.
Figure 3 is the key without any bits on it, the end or key pin being square,
and marked K, and having a nut L screwed on the extreme end of it, which
nut is round and forms part of the key pin, and corresponds in diameter
with the round shoulder M of the said key pin from whence the key pin
originates.
Figures 4, 5, 6, 7, 8, 9, are the bits, with a square hole in each, fitted to the
square part of the key pin, so as to be put on and taken off at pleasure. One
of the bits, Figure 9, is to be placed on one end of the square part of the key
pin K, and always to remain there when the key is used, in order to lift one of
the tumblers, videlicet, the top one which has a round hole in the back end, like
a common or ordinary tumbler, and consequently must always be lifted. One
other bit to each key, Figure 4, is made thicker and stronger than the others;
it is to be placed on the other end of the square part of the key pin, and is
intended to work against the talents of the bolt to move the bolt out or in.
The other or intervening bits, Figures 5, 6, 7, 8, are numbered as in the
plate, and are intended to lift or raise the before-described sliding horizontal or
changeable tumblers. These bits are of differents lengths, each one adapted to
a different tumbler, being longer or shorter, as the corresponding tumbler on
which it acts requires to be lifted more or less to allow the bolt stump F to
pass out of or into the notch II, and each one numbered to correspond with its
respective tumbler, in order to shew its relative place on the key, the numbers
usually commencing at the shoulder of the key pin as a matter of con-
venience. I sometimes mark these bits with characters or hieroglyphics..
Figures 10, 11, 12, 13, are rings or blanks fitted to the square part of the
key pin, of the same, diameter as the nut and shoulder of the key pin, and of

page_text: the same thickness as the number of changeable bits. One of these rings is
to be put upon the key pin to fill up the space wher a bit is taken off.
Figure 14 is a table of combinations or changes to shew the different forms
of which the key is susceptible, and to assist the operator in remembering the
key he uses in locking by reference to the register number. Each combination
is numbered in the marginal column, which numbers I call register numbers.
The number of changes in a lock will of course depend upon the number of
sliding horizontal or changeable tumblers it contains, and their corresponding
numbered bits.
In Figure 1, C is the uppermost of the auxiliary tumblers which are to
slide up and down between the checks ff. descending by their own gravity
when not acted upon by the key. The upper tumbler C acts upon the lower
edge of the tumbler A, and vertical tumblers. below it upon the respective
horizontal tumblers with which they correspond. The horizontal tumblers
arc, under this arrangement, curved or formed with an obtuse angle, as shewn
at A, to adapt them to being lifted by and operating against the upper ends of
the vertical tumblers C. The upper tumbler in the series C represented as
straight on its upper edge, but that immediately blow it has not its upper
edge in a line with, but is made to project above it, as shewn by the dotted
lines a, a; and the lower edge of the tumbler against which it acts is cut away
and so formed as to correspond with the tumbler by which it is to be lifted, as
shewn by the dotted lines b, b. The object of this device is to prevent the
possibility of one of the upright tumblers acting upon a horizontal tumbler
upon which it ought not to act, which might otherwise result from a slight
deviation in either of the series. What is said of the first two tumblers
appertains to the whole series, that is to say, each successive pair is made
to break joints with those pairs in their immediate vicinity. Although
in the improved lock herein described I do not make the lower edges
of the sliding horizontal tumblers to coincide with each other, so as when
down and not acted upon by the key to be all in one line or plane, I yet
preserve the same principle of action by making the upright or vertical
auxiliary tumblers C, when not lifted by the key, to coincide with each other
in the hollow or belly part D, D, upon which the bits of the key are to operate,
so that with a key having a single bit in the ordinary form, said tumblers
would be all lifted to the same height. Upright tumblers, having the bits of
the key operating within them in what is called the belly part, have been used,
but I form these tumblers, as above remarked, with what I call a double belly,
or double concavity, there being a smaller concavity, hollow, or belly E at the
upper sides of each of the large hollow or belly in each of these tumblers., The

page_text: design of this second belly or hollow is to suspend the lifting action of the
respective bits which operate upon the tumblers during the time in which the
thick bit is acting upon the bolt to shoot it out or to withdraw it in unlocking,
whilst, as heretofore constructed, the horizontal tumblers have been kept in
motion, either rising or falling, during the whole time of the uioving of the
bolt; and hence it becomes necessary to mako provision for this continuous
upward or downward motion of the tumblers by cutting away or giving an
inclination to the side of the bolt stump F, in order to admit of its passing
through the notches or openings EI in the fore ends of the horizontal tumblers,
or otherwise it was requisite to give such form to said openings as would pro-
duve a like result. By entering the second belly E, which takes place at the
instant the tumblers aro lifted to their proper height for the bolt stump to
enter the notches H in the tumblers, the action of the bits of the key is sus-
pended, and so continues until the motion of the bolt has ceased, the horizontal
tumblers resting upon the upper side of the bolt stump during that period.
The bolt stump may consequently be made square, or nearly so, and may have.
its upper and lower sides in close contact with the openings in the tumblers
during its whole passage.
To give notice, should any attempt be mado to pick the lock, I adapt
a detector thereto, which I construct in the following manner :-S, Figure 1,
is a lever which works upon a round stump T, and shewn in its proper
place in the lock, extending forwards beyond the fore ends of the tumblers
when in their natural position, and having a bar U attached to the end
of it, which bar is at right angles with the lover, and extends from the plate
to the cap, directly across the upper edges of the tumblers, when they are
drawn out by the bolt. There is also attached to this lever a wire or rod
opposite to the dotted circle g, which projects through tho plate of the lock,
and works freely when the lever is lifted or depressed in a curved groove h
made for that purpose. The lever is retained in whatever position it is left,
cither up or down, by a spring i, which presses upon the back end of it. This
lever, with its fixturas, is what I have called a Detector, and its uso is to show
whether a false key or other improper instrument has been introduced into the
keyhole and the tumblers lifted. Should one or more of the tumblers be
drawn out with the bolt when the lock is locked, such tumbler or tumblers
will pass underneath the bar U of the lever S, Figure 1; and if either of the
tumblers so drawn out are then lifted, the bar and lever will also be lifted and
remain in that position, which will be detected by the rod or wire 9, which
passes through the aforesaid curved groove in the plate of the lock; the lover
may then bo returned to its former position by depressing the wire or rod g...

page_text: Having thus fully described the nature of the improvements, and set forth the
manner in which the same operates, what I claim therein, and desire to secure
by Letters Patent is, the combining of the upright or vertical tumblers C
with the horizontal tumblers A, A, in such manner as that the latter shall be
lifted by the former instead of the bits of the key, the said upright tumblers C
being so formed as to have their arches or bellies to coincide with each other
in the manner set forth when not acted upon by the bits of the key, and so as
not to give a true impression or indication of the different lengths of the several
key bits through the keyhole. I claim the forming of the second belly or con-
cavity E in each of the auxiliary tumblers, said concavity being so situated
as to receive the respective bits of the key at the instant the bolt stump F
enters the openings in the ends of the horizontal tumblers, and thus suspend-
ing the action of said bits during the time of the moving of the bolt, in the
manner set forth. I claim, in combination with a lock furn with hori-
zontal and vertical tumblers, constructed as herein described, the formation of
the openings or slots G in the horizontal tumblers, by which said tumblers
are subject to two distinct motions, that is, the ordinary one of being lifted by
the key, or of sliding forward on the stump b, in the manner and for the
purpose set forth, and the moveable stump F, by which all the tumblers are
brought into action to resist the pressure when the force is applied to move
back the bolt.