TEMENTS IN THE CONSTRUCTION OF LOCKS
Year: 1854

page_text: LETTERS PATENT to John Tann, of Minerva Terrace, Hackney Road, in
the County of Middlesex, Patent Lock Manufacturer, for the Invention
TEMENTS IN THE CONSTRUCTION OF LOCKS."
Sealed the 29th August 1854, and dated the 2nd March 1854.
PROVISIONAL SPECIFICATION left by the said John Tann at the Office
of the Commissioners of Patents, with his Petition, on the 2nd March
1854.
. I, JOHN TANN, of Minerva Terrace, Hackney Road, in the County of
Middlesex, Patent Lock Manufacturer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF LOCAL" to be as
follows:
This Invention consists in an improved mode of constructing certain parts
of locks, for the purpose of rendering such instruments more secure than the
locks as heretofore constructed, and in known and common use; and this
Invention relates more particularly to those descriptions of locks known and
distinguished as "tumbler locks." The mode heretofore practised in con-
structing locks of the most modern, and, up to the present time, allowed to be
of the most improved construction, namely, those known as Hobbs's patent, has
been to make the "stump," or that part which is employed to hold the bolt of
the lock (when shot outwards) in such a position as to prevent or to render
difficult the drawing back of such said bolt with any pick or instrument other
than the key designed and specially intended to be employed for such purpose:

page_text: and further, a peculiar feature in the construction of the aforesaid locks has
been to arrange and dispose the aforesaid stump with respect to the other parts
of the lock in such manner as that it is independent of the bolt of the lock,
instead of being affixed to such said bolt, as heretofore generally practised in
the construction of locks, and particularly those known and distinguished as
Barron's, Chubb's, and other patent locks; and the object and intention of
making such said stump independent of the bolt has been to take the end
pressure off the bolt, and thereby to render ineffectual any attempt to force
back the bolt for the purpose of causing the aforesaid stump to press against
the tumblers of the lock, and by which such said tumblers would hang, and
thereby facilitate the raising thereof, and the ultimate unlocking or picking of
the lock by instruments other than the key thereof. Now, it is to be parti-
cularly understood, that the principle of construction of this Invention consists
in, and is entirely dependent upon, and will only act, so as to afford additional
security to the lock when end pressure is exerted upon the bolt, instead of the
pressure being required to be taken off the bolt, as before stated, with reference
to Hobbs's locks; and this I effect by constructing locks in the following
manner, that is to say:-I employ a bolt, in which a stump is fixed, which
works in the "gates" of the several tumblers in the manner commonly prac-
tised, excepting that (for the purposes of this Invention) I construct and
arrange that tumbler which is in immediate contact with the bolt (and which
I call a locking or holding tumbler) in such manner, that this tumbler only
receives the pressure from the stump of the bolt, by which I take off the
pressure from the other tumblers, and thus prevent them from hanging when
raised by any instrument other than the key of the lock; and I employ a
separate spring acting upon the tail end of the said locking or holding tumbler,
for the purpose of raising the front end of such said tumbler when the other
tumblers are raised by the action of the key thereon, and when there is no end
pressure upon the bolt, observing that the aforesaid locking or holding tumbler,
by being acted upon by the aforesaid spring only, is entirely self-acting, and is
not in any way operated upon by the key of the lock; and it is only when end
pressure is exerted upon the bolt (as commonly practised in picking locks),
that this tumbler becomes locked or held, and does not therefore rise with the
other tumblers, and the locking or holding of this one tumbler in particular
arises from the pressure of the stump against the edge of the gate of this
tumbler being greater than the pressure of the spring upon the tail end of such
said tumbler. Thus it will be seen, that so long as the end pressure remains
upon the bolt of the lock, such bolt cannot be drawn back, but immediately such
pressure is removed the spring acts, and the locking or holding tumbler then

page_text: rises, and I protect this tumbler from being acted upon by a pick or other like
instrument, by forming a rebate upon the bolt of the lock below the edge of
said tumbler, and I also place a shield beneath the under edges of most of the
other tumblers, so as to present obstruction to the introduction of a pick or
other like instrument. And I declare this Invention to consist in so con-
structing certain parts of locks as that I render available the end pressure
upon the bolt for the purpose of attaining greater security in locks than
heretofore; whereas the principle of construction of the modern locks, before
mentioned, consists in removing the pressure from the bolt for the purpose of
affording such security.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Tann in the Great Seal Patent Office on the 2nd
September 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TANN, of Minerva Terrace, Hackney Road, in the County of Middlesex,
Patent Lock Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of March, in the year of our Lord One
thousand eight hundred and fifty-four, in the seventeenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said John Tann, Her special licence that I, the said John Tann, my executors,
administrators, and assigns, or such others as I, the said John Tann, my execu-
tors, 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 THE CONSTRUCTION OF LOCKS," upon the
condition (amongst others) that I, the said John Tann, by an instrument in
writing under my hand and seal, 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 Tann, 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):-

page_text: My Invention consists in an improved mode of constructing certain parts of
locks, for the purpose of rendering such instruments more secure than locks as
heretofore constructed, and in known and common use, and this Invention
relates more particularly to those descriptions of locks known and distinguished
as tumbler locks. And I would remark, that the mode heretofore practised of
constructing locks of the most improved construction, namely, those known and
distinguished as Hobbs's patent locks, has been to make the stump, or that
part which is employed for holding the bolt of the lock when shot outwards,
occupy such a position as to prevent or render difficult the drawing back of
such said bolt with any pick or instrument other than the key designed and
specially intended to be used for such purpose. And a peculiar feature in my
said Invention is, the arranging and disposing of the aforesaid stump, or that
part which first takes the pressure from the bolt with respect to the other parts
of the lock, so that the said stump is entirely independent of the bolt of the
lock, instead of being affixed to such said bolt, as heretofore generally practised
in the construction of locks, and particularly those known and distinguished as
Barron's, Chubb's, and other patent locks of a similar character. And the
object and intention of my said Invention, as regards the making of the said
stump independent of the bolt of the lock, is, for the purpose of taking the end
pressure of the bolt off the lock, and thereby to render ineffectual any attempt
to force back the bolt for the purpose of causing the main stump to press
against the tumblers of the lock, and by which such said tumblers would hang,
and thereby facilitate the raising thereof, and the ultimate unlocking or
picking of the lock by instruments other than the key thereof. Now, it is to
be particularly understood, that the principle of construction of my said Inven-
tion consists in, and is entirely, dependent upon, and will only act, so as to afford
additional security to the lock when end pressure is exerted upon the bolt,
instead of the pressure being required to be taken off the bolt, as before stated,
with reference to Hobbs's locks, and this I effect by constructing locks in the
following manner, that is to say:-I employ a bolt, in which a main stump is
fixed, which works in the gates of the several tumblers in the manner commonly
practised, excepting that, for the purposes of my said Invention, I construct and
arrange that tumbler, which is in immediate contact with the bolt of the
lock (and which I call a locking or holding tumbler,) in such manner, that this
tumbler alone receives the pressure from the bolt of the lock, as shewn in the
Drawing, by which I take off the pressure of the main stump upon the other
tumblers, and thus prevent them from hanging, when raised by any instrument
other than the key of the lock; and I employ a separate spring acting upon the
tail end of the before-mentioned locking or holding tumbler, for the purpose of

page_text: raising the front end of such said tumbler when the other tumblers are raised
by the action of the key thereon, and also when there is no end pressure
exerted upon the bolt, observing, that the aforesaid locking or holding tumbler,
by being acted upon by the aforesaid spring only, is entirely self-acting, and is
not in any way operated upon by the key of the lock, and it is only when end
pressure is exerted upon the bolt (as commonly practised in picking locks),
that this self-acting tumbler becomes locked or held, and does not therefore
rise with the other tumblers, and the locking or holding of this one tumbler in
particular arises from the pressure of the main stump against the edge of the
gate of this tumbler being greater than the pressure of the spring upon the tail
end of such said tumbler. Thus it will be seen, that so long as the end pressure
remains upon the bolt of the lock such bolt cannot be drawn back, but
immediately such said pressure is removed, the spring acting upon the tail end
of the before-mentioned locking or holding tumbler causes the opposite end
thereof to rise and disengage itself from the bolt which previously held it. And
I protect such self-acting tumbler from being operated upon by a pick or
other like instrument, by forming a rebate upon the bolt below the edge of
such said tumbler, and I place a shield beneath the under edges of most of
the other tumblers. I also affix on the outside of the face or cap plate of the
lock, and over the keyhole thereof, a cylindrical-shaped cap, on the inside of
which a solid piece of metal with a keyhole in it is capable of being moved
round by the bit of the key, for the purpose of closing the keyhole, and
thereby preventing the introduction of a second instrument into the body of
the lock for lifting the tumblers, supposing that end pressure on the bolt had
been obtained.
In order to explain my said Invention as completely as possible, I now
proceed to describe the best means I am acquainted with for carrying the
same into practical effect, reference being had to the illustrative Drawings
hereunto annexed, and to the numeral figures and letters of reference marked
thereon respectively, as follows:-
DESCRIPTION OF THE DRAWINGS.
At Sheet 1, Figure 1 is a front view of a lock, constructed according to my
said Invention for an iron safe, and exhibited drawn half the real size of the
lock, the front or face plate thereof being removed, so as to expose to view
the arrangement of the working parts of the lock, the bolt of which is shewn
shot out or locked. Figure 2 exhibits the said lock with four of the tumblers
removed, thereby exposing to view the detector tumbler. Figure 3 exhibits

page_text: self-acting tumbler. Figures 4, 5, 6, 7, are detached parts, herein-after par-
ticularly described and referred to. Figure 8 shews another mode of con-
structing locks according to my said Invention, with the self-acting tumblers.
At Sheet 2, Figure 9 is a front view of another form of lock, constructed
according to my said Invention, the face plate thereof being removed, so as to
expose to view the arrangement of the working parts of the lock, the bolt
whereof is shown shot out. Figure 10 shews the said lock with all the
tumblers removed, excepting the self-acting tumbler, herein-after referred to.
Figure 11 is a front view of another form of lock, constructed according to
my said Invention, the face plate thereof being removed, so as to expose to
view the arrangement of the working parts of the lock, the bolt thereof being
exhibited as shot out or locked. Figure 12 is the above lock without the first
four tumblers, which are removed for the purpose of exposing the position of
the detector tumbler when at rest, as also the relative position of certain other
parts with which the said tumbler is connected. Figure 13 shews the same
parts of the above lock as are exhibited at Figure 12, but with the detector
tumbler in action, and as it would appear when end pressure was applied to
the bolt of such said lock. Figure 14 is the above lock with all the tumblers
removed, so as to expose the bolt and self-acting lever, herein-after referred to.
Figure 15 is the bolt of the lastly above-mentioned lock, shewn detached from
the other parts of the lock.
At Sheet 1, Figures 16, 17, 18, 19, 20, shew several views of a novel key-
hole guard, constructed according to my said Invention. Figure 16 shews a
front elevation of a lock with the said keyhole guard applied thereto. Figure 17
is a transverse section through the line A, B, at Figure 16 of the guard cap
applied to the front plate of the lock. Figure 18 shews the inside of the
said cap detached from the face plate of the lock. Figure 19 shews the solid
guard detached from the guard cap. Figure 20 shews the guard placed
within the cap, and as it would appear before being fixed to the face plate of
the lock.
At each of the foregoing Figures of each Sheet of Drawings I employ similar
letters of reference to denote corresponding parts, in so far as such parts
appear or can be seen at each of the figures respectively, and in so far as
regards those figures only which are necessary to the explanation of each
separate form of construction of lock, unless otherwise stated, as herein-after
mentioned.
At Figures 1 to 7 inclusive, of Sheet 1, A, A, is the case of the lock; B,
the bolt; C, the self-acting tumbler before mentioned. a, b, c, d, are seven
lever tumblers, which are operated upon by the key shown at Figure 4, which

page_text: is very similar in its construction to the keys as heretofore employed in lever
tumbler locks. The tumbler c, shewn detached at Figure 5, is a detector
tumbler of the ordinary kind, and the tumbler d, which is the bottom tumbler,
is formed with a curtain d', shewn at Figure 6, for the purpose of protecting
those tumblers which are above it. The construction of the self-acting lever
tumbler C, shewn detached at Figure 7, and the mode of arranging the same
with respect to the tumblers a, b, c, d, and bolt B of the lock, is as follows:-
There is a pin e securely fixed to the back plate of the lock, and upon this pin
the tumbler is placed and connected by a hole at F, Figure 7, upon which it
vibrates, upon receiving pressure from the spring g and comb spring D, the
lever C being connected to the several tumblers a, b, c, d, by a pin h securely
fixed into the lever C, as shewn at Figure 7, said pin passing through slots i
formed in each of the aforesaid tumblers and bolt, as exhibited at Figures 1, 2, 3.
k is a stump of the ordinary kind, securely fixed to the bolt B of the lock.
The dotted lines marked l, m, at Figure 3, represent rebates; that marked
being fixed to or formed upon the back plate of the lock, and that marked m
being formed upon the back of the bolt of the lock. The use of these
rebates is to protect the self-acting tumbler C from being acted upon by a
pick, and I protect the pin h from the action of a picking instrument by
affixing a guard E to the ease of the lock, as exhibited at Figures 1, 2, 3,
and I form notches in each of the tumblers, marked severally a, b, c, d, into
which the guard E takes, and thus enables the tumblers to rise without
uncovering the guard E. The action of this lock is as follows:-Assuming
the several parts to be in a locked position, as exhibited at Figure 1, in
order to unlock them, the tumblers a, b, c, d, are raised by the steps formed on
the "bit" of the key, so as to bring the gatings of the several tumblers into a
line with the stump k, and hold them in that position whilst the key throws
back the bolt, the pin h of the self-acting tumbler C, rising with the other
tumblers by reason of there being no end pressure upon the bolt B, and
the pressure from the comb spring D being also removed from the pin h,
allows the spring g to exert its elastic force upon the self-acting tumbler C,
and by thus disengaging the pin h from the slot i in the bolt, the said bolt is
now free to be moved back or unlocked by the action of the key thereon.
But supposing end pressure to be exerted upon the bolt B for the purpose
5 of picking or opening the lock by any instrument other than the key
thereof, the effect of such pressure is to hold the pin h within the slot i
in the bolt, and thus to remove the pressure of the stump k from the
tumblers a, b, c, d; and by these means I prevent the said tumblers from
hanging, when raised by any instrument other than the key, and thus afford

page_text: additional security to the lock. Figure 8 shows another form of construction
of lock, as also another mode of arranging the self-acting lever C, before
mentioned, and exhibited at Figure 7. It will be seen, upon referring to
Figure 8, that the self-acting lever C has its fulcrum upon a pin h, placed
beneath the edge of the bolt B of the lock; one end of the lever C takes
into a notch formed in the edge of the bolt, as exhibited, whilst the
opposite end X of the said lever is kept in forced contact with the bellies
of the several tumblers a, b, c, d, by pressure from the spring g. In
other respects this lock is similar to that exhibited at Figure 1, and
has similar letters of reference placed upon such of the corresponding
parts as are employed and appear at Fig. 8. The operations of this last-
mentioned lock are as follows:-Upon raising the several tumblers by the
action of the key thereon, until the gatings therein are brought opposite
to the stump of the lock, the end of the self-acting lever C will follow
the said tumblers, and thus disengage the other end of the said lever
from the bolt B, and allow the said bolt to be shot back or unlocked by
continuing to turn the key. But supposing a pick or instrument other than
the said key to be employed to open the lock, it will appear evident, that
unless the lever C is disengaged from the notch in the bolt precisely at the
same time that the gatings of the several tumblers are brought opposite to the
stump k, the bolt B cannot be drawn back or unlocked; and I propose, as an
additional security to the lock, to so adjust the stump within the notches in
the tumblers as that the said stump does not touch the sides of such said
notches when the bolt is locked, and I so arrange the hooked end of the
lever C in the notch in the bolt as that it alone receives any end pressure that
may be exerted upon the bolt, and thus I prevent the hanging of the tumblers,
and offer still further obstruction to the picking of the lock.
Another mode of constructing locks according to my said Invention is
exhibited at Sheet 2 of the annexed Drawings, as follows:-Instead of
arranging the self-acting lever C so that any end pressure upon the bolt C
is transferred to a pin fixed therein as at h, Figures 1, 2, 3, of Sheet 1, I form
a gating in the self-acting lever, as exhibited detached at Figure 10%,
Sheet 2, and at the opposite end of the said lever to that upon which
the spring operates, I affix a pin a, upon which the front part of the
several tumblers a, b, c, d, rest. The effect of thus arranging the self-acting
lever C is as follows:-It will appear evident, that upon raising the
tumblers a, b, c, d, with the key of the lock, and supposing there is no
end pressure exerted upon the bolt as the said tumblers are raised, the pin
a will follow the same, and thus disengage the part y of the lever C from the

page_text: stump k, and allow the said stump to be free to pass through the gatings
of the several tumblers, and the bolt to be drawn back or unlocked. But
assuming a pick or instrument other than the key to be employed for opening
the lock and end pressure to be exerted upon the bolt thereof before lifting the
tumblers, the stump k, coming into contact with the part y of the self-acting
lever C, will be resisted thereby, and thus prevent the spring g from having
any effect thereon; at the same time, the pressure of the stump being entirely
borne by the self-acting lever C, the tumblers a, b, c, d, when lifted, cannot
therefore possibly hang, by which the security of the lock is. considerably
enhanced.
The two other modes of constructing locks according to my said Inven-
tion, as exhibited at Figures 9, 10, 11, 12, 13, 14, 15, of Sheet 2, are as
follows: As regards the lock exhibited at Figures 9 and 10, the peculiar
feature is, causing the self-acting lever tumblers C to take the pressure from
the stump of the bolt of the lock, so as to prevent the other tumblers from
hanging; and also the peculiar mode exhibited at Figure 10, of arranging the
said lever, so that that part which holds the stump has to be moved downwards
to disengage it therefrom; and to effect this, the gatings in the tumblers must
all be raised into a line with the stump, so as to relieve the pressure from the
pin x in the lever c, said lever being protected from the action of a picking
instrument by forming a rebate + on the bolt, as exhibited; in other respects, the
action of this lock is similar to that before described and exhibited at Figures
1, 2, 3, of Sheet 1, and has similar letters of reference placed upon correspond-
ing parts. And as regards the construction of the lock exhibited at Figures
12, 13, 14, 15, it is as follows:-It will be seen, upon referring to Figure 14,
that each end of the self-acting lever C is formed with hooks, said hooks taking
alternately into notches a, b, formed in the edge of the bolt B, the construction
of which is shown more clearly at Figure 15. The bolt B is also furnished
with a lever or talon B', attached to the said
fulcrum of the said lever or talon; d is a spring
and employed for keeping the lever B¹ down when out of use; h is the stump,
fixed to the bolt Bin the usual way; said stump passes through a hole formed
in the lever B', as exhibited at Figure 14, and there is a slot e formed in the
said lever and bolt through which passes an ordinary guide pin i, said pin
being the fulcrum of the tumblers a, b, c, d; a notch f is also formed in the
lever or talon B', to enable this end of the said lever to rise, when acted upon
by
bolt by a pin c, which is the
fixed to the bolt of the lock,
a pick or instrument other than the key of the lock. I further affix a pin
k to the lever B¹, which pin takes into the gating of the detector tumbler, and
likewise into that tumbler which is next to it; and instead of causing the key

page_text: of this lock to operate direct upon the bolt of the lock, I make it to act upon
the lever or talon B', which is suitably formed for that purpose, as exhibited at
Figure 14, and I form a rebate 1, (shewn by dotted lines at Figure 14,) upon the
back plate A of the lock, and fix guards m and n thereto, as shown, to protect
the bolt and self-acting lever from being acted upon by a pick. The operations
of this lock are as follows:-When acted upon by the key thereof, the effect is
to raise the tumblers to the proper height, and by thus relieving the pressure
of the comb spring D from the pin 2, the self-acting lever C by the elastic force
of the spring g will rise, and become disengaged from the notch a in the bolt,
and thus allow the bolt to be pushed back and unlocked by the action of the
key upon the lever or talon B'. But, assuming a pick or instrument other
than the key of the lock to be employed for opening the same, the following
difficulties present themselves:-Firstly, that of raising all the tumblers to
the proper height, in consequence of the self-acting lever C taking the end
pressure from the bolt instead of its being taken by the stump h. Secondly,
upon pressure being accidentally applied to the lever or talon B', or to those
tumblers which are situated at each side of the detector, the effect of raising
the same will be either to force the pin k of the lever B₁ against the detector
tumbler, or to force the said tumblers against the pin of the detector, and thus
to detect the lock; or should the lock not be detected, but the several tumblers
only raised too high, the effect would be to throw the hooked end * of the
lever C into the notch 6 on the bolt, and thus prevent the bolt from being
pushed back or unlocked, and thus it will be seen that by combining the self-
acting lever C and lever or talon B¹ with the tumblers and bolt of the lock, in
the manner above stated, unless such several parts are operated upon in the
same manner as when using the key of the lock, the opening of the said lock
cannot be effected.
And as regards the construction of the keyhole guard before mentioned,
and exhibited at Figures 16 to 21 inclusive of Sheet 1, it is as follows:-
A is a metal cap, formed with a keyhole a and projecting pieces b, b, b, for
connecting such said cap to the face plate of a lock, which should have
corresponding holes formed therein for rivetting the said cap thereto; B is
the keyhole guard, shewn detached at Figure 19, same being formed of a
solid piece of metal, having a keyhole 6 made through it. C is a spring fixed
to the said guard, as exhibited at Figures 19 and 20; this spring takes into
V shaped notches c, c, formed in the cap A, as exhibited at Figures 18 and 21,
and is employed for arresting the guard B, when the keyhole 6 is brought
opposite either to that keyhole which is in the face plate of the lock, so as to
allow the bit of the key to enter the same, or to the keyhole in the cap A, so

page_text: as to allow the bit of the key to be removed from the cap; and I would here
rémark, that the peculiar feature of novelty in the said guard consists in forming
the keyhole which is in the face plate of the lock at right angles, or nearly so.
to the keyhole which is in the cap of the guard, as exhibited at Figures 16
and 21, but the said keyhole, if desirable, may be at any other angle with
respect to the keyhole in the cap. The action of this guard is as follows:-
When the key is out of the lock, the keyhole in the guard B is opposite
to the keyhole in the cap A. In order therefore to open the lock, the
key has to be inserted into the guard, and the guard turned round by the bit
of the key until the keyhole in the guard comes opposite to the keyhole in
the face plate of the lock, and such turning round of the guard bas the effect
of covering the keyhole in the guard cap A; thus it will be seen that the key-
holes in the face plate of the lock and the guard cap, not being opposite to
cach other, can never both be uncovered at the same time, and thus I
prevent
or render impossible the introduction of such a picking instrument as would
effect the opening of the lock. And this keyhole guard may also be applied
with equal advantage to any of the locks in known and common use, and will
be found to add considerably to the security thereof.
Having now described the nature and object of my said Invention of Im-
provements in the Construction of Locks, and in what manner the same is to
be and may be performed, I would remark, in conclusion, that what I claim is,
the novel mode, above described, of constructing tumbler locks, by combining
together the several parts thereof in the manner and for the purposes set forth
and represented by the illustrative drawings hereunto annexed, as constituting
improvements in the construction of such said locks.
In witness whereof, I, the said John Tann, have hereunto set my
hand and seal, the Second day of September, in the year of our Lord
One thousand eight hundred and fifty-four.
Witness,
ALEX PRINCE,
Patent Agent,
4, Trafalgar Square,
Charing Cross.
JOHN TANN. (L.S.)