CERTAIN APPARATUS AND ARRANGEMENTS FOR AFFORDING ADDITIONAL SECURITY IN LOCKS
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, greeting, I,
CHARLES MINORS COLLETT, now residing at Hammersmith, in the County of
Middlesex, Gentleman, but late of 62, Chancery Lane, in the said County
of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Sixteenth day of April, in the tenth year of Her reign, did give
and grant unto me, the said Charles Minors Collett, my exors, admors,
and assigns, Her especial licence, full power, sole privilege and authority,
that I, the said Charles Minors Collett, my exors, admors, and assigns,
and such others as I, the said Charles Minors Collett, my exors, adiñors,
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter, during the term of years therein mentioned,
should and lawfully might make, use, exercise, and vend, within that part of
Her United Kingdom of Great Britain and Ireland called England, Her
Dominion of Wales, and Town of Berwick-upon-Tweed, and in Her Islands
of Jersey, Guernsey, Alderney, Sark, and Man, and also in all Her Colonies
and Plantations abroad, the Invention called "CERTAIN APPARATUS AND
ARRANGEMENTS FOR AFFORDING ADDITIONAL SECURITY IN LOCKS;" in which said
Letters Patent there is contained a proviso that I, the said Charles Minors
Collett, shall particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same is to be performed, by an instrument in
writing under my hand and seal, to be enrolled in Her said Majesty's High

page_text: Court of Chancery within six calendar months next and immediately after
the date of the said in part recited Letters Patent, as, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Minors Collett, 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 instrument in writing
(reference being to the letters and figures therein contained, and to the
Drawings thereunto annexed):-
One part of the said Invention consists in the application of certain
apparatus or arrangement of parts to locks to prevent the withdrawal of a
false key in the event of an attempt being made to open the lock.
Another part of the said Invention consists in the application to common
locks of a ward or wards which is or are to be placed in the space that remains
unoccupied between the bolt and plate wherein the keyhole is formed, or
between the bolt and the back plate of the lock, the object being to obtain
additional security at a trifling expence. The above-mentioned parts of the
said Invention may also be combined in one lock.
These improvements in locks are represented in the annexed Sheet of
Drawings, in which the same letters of reference are used for similar parts
wherever they occur.
Figure 1 is a front view of a portmanteau lock constructed according to the
first part of the Invention; Figure 2 exhibits the interior of the lock with the
face plate and protecting plate removed; Figure 2* is a vertical section of
the lock taken on the dotted line Z, Z, of Figure 1; Figure 3 is a front view
of the plate that carries the works for detaining the false key, and which I
term the "protecting plate;" Figures 4 and 5 are back views of the protecting
plate, shewing the works belonging thereto in different positions; Figures
6, 7, 8, are detached views (in plan and section) of the rings used for enabling
the owner of the lock to extract the false key; Figures 9 shew a plan view
and vertical section of these rings combined together; Figure 10 is a view of
the upper side, Figure 11 a view of the under side, and Figure 12 an edge
view of an excentric forming part of the detaining apparatus; Figure 16
exhibits the key belonging to the lock. A, Figure 2, is the case of the lock;
B, Figure 1, the face plate; C, Figure 8, the protecting plate secured to the
back plate of the lock by screws passing through the holes a, Figure 3; and
D, Figure 2, is the sliding bolt of the lock. The movements of the bolt D,
Figure 2, are governed by the tumblers E, Figure 2 (similar to those used in
Chubb's and other tumbler locks), which are mounted on a pin F, Figure 2,

page_text: fixed in the back plate, and projecting through a slot in the bolt D, Figure 2,
(as indicated by the dotted lines). A portion of each tumbler is cut out, and
through the openings thus formed a square pin G, Figure 2, fixed to the bolt,
projects, and while the tumblers are retained in the position shewn by the
pressure of their springs H, Figure 2, against the part 6, Figure 2, the pin G,
Figure 2 (and consequently the bolt D to which it is attached), is prevented
from moving by the projections c of the several wards. But on the intro-
duction of the key (shewn at Figure 16) the tappets or steps upon it raise the
wards into such a position that the edges of their projections c and d will
become parallel, and thus permit the pin G to pass between them into the
part of the opening in the wards when the key exerts a pressure against
the side of the notch in the lower edge of the bolt in order to force back
the same. After the bolt has been forced back the wards are returned to
their original position by the pressure of their springs.
The following arrangement of parts constitutes the detaining apparatus, the
application of which to a lock forms the subject of the first part of the
Invention. I is an excentric the shape of which is clearly shewn at Figures
10, 11, and 12; the boss g on its front side fits into a corresponding recess in
the protecting plate C, and the front side of the excentric is kept in close
contact with the hinder side of the plate C by the spring J, which presses
against the end of the tubular portion of the excentric. The excentric has
a keyhole formed in it so that when a key is introduced into the lock it will
enter the keyhole of the excentric, and on being turned will carry the excentric
round with it, and thereby bring the other parts of the detaining apparatus
into action in the manner to be presently described. K is a hooked piece of
metal mounted on a pin or stud L which is capable of moving to and fro
within a slot formed in the plate C; the large end or head of the pin or stud L
fits into a curved shoulder formed at the upper end of a lever M; this lever is
capable of turning on a pivot N at its lower end, but is kept in a perpen-
dicular position by a spring O pressing against it. Near the middle of the
lever M is a small projection i, the use of which will be hereafter explained.
A tendency to descend is imparted to the hooked piece K by its spring p, but
it is prevented from descending too far by the fixed stud q, and also by the
edge of the excentric I. R is a peculiarly-shaped piece of metal which is
attached to the plate C by the screw S; this screw passes through a slot in the
piece R so as to admit of the latter moving freely backwards and forwards
horizontally, the other end of the piece R being prevented from descending
below a certain point by the fixed stud T. On the front side of the protecting
plate is a boss U in which a keyhole is made; this boss is encircled by three.

page_text: rings V, V, V, (shewn separately at Figures 6, 7, and 8, and combined
together at Figures 9 as they would appear when surrounding the boss,) and
the boss and rings project through a circular opening in the face plate of the
lock, as represented at Figure 1. Each ring is formed with a ledge or rim j
whereby it is retained in its proper position and prevented from falling
through the circular opening in the face plate B. In each ledge or rim is a
notch k, the position of which, when the ledges or rims are hidden by the
face plate, is indicated by the small pin 7; these notches are each of a suitable
size to receive the projection i upon the lever M, so that when the notches are
all caused to coincide, the projection i can enter into them in case the lever M
should be pushed forward, which forward movement of the lever M cannot
otherwise take place by reason of its projection i pressing against the outer
edge of the several ledges or rims. The action of the different parts is as
follows: Supposing the lock at the commencement of the description to be
in an unlocked state, the parts of the detaining apparatus being in the positions
shewn at Figure 4, and the keyhole of the excentric I coinciding with the
keyhole in the boss U, the key is introduced and turned round in the direction
of the arrow, carrying the excentric with it. By this means the projection m
of the excentric will be brought into contact with the end of the piece R (as
represented by the dotted lines in Figure 4), and push the piece R forward
into the position shewn at Figure 5, while at the same time the tumblers E
are raised and the bolt D is shot forward by the tappet or step on the key.
The bolt D and the parts connected therewith are now in the situation shewn
at Figure 2. By the above movement of the piece R the hooked end of the
piece K which was previously retained in the depression n of the piece R is
released, and descending presses upon the periphery of the excentric I, which
is turned until its keyhole corresponds with the keyhole in the boss U, and
then the key is withdrawn. If a false key be now introduced and turned in
the direction of the arrow in Figure 2, it will come in contact with the
projection on the lower part of the bolt D, which will prevent it from
moving any further in that direction. If the key be now turned in the
direction of the dotted arrow (which dotted arrow is also seen in Figures 4
and 5, it will carry the projection m of the excentric I past the hooked end
of the piece K, until the tappets or steps of the key come in contact with the
tumblers E, which will prevent its further progress. If the key be now
turned in the reverse direction for the purpose of withdrawing it from the
lock, the projection m of the excentric will be caught by the hooked end of
the piece K, and the farther movement of the key effectually prevented; the
key will consequently be securely retained until released by the owner of the

page_text: lock. To release the key the three rings V, V, V, must be moved round
until their notches coincide, which will be the case when the three pins 1, 1, 1,
range in the same line as at Figures 9; if the key be then somewhat forcibly
turned in the direction last-above mentioned, the projection m of the excentric
will draw forward the hooked piece K and lever M (the projection i of the
latter entering the notches of the rings V¹, V³, V³), until the piece K and
excentric I have arrived at the position indicated by the dotted lines in
Figure 5, when the projection of the excentric will escape from under the
hooked end of the piece K, and the excentric can then be turned till its key-
hole coincides with the keyhole in the boss U; the key may now be withdrawn
from the lock. When the tumblers E are raised and the bolt D drawn back
by means of the right key, the shoulder p of the bolt comes in contact
with the shoulder 9 of the piece R and forces it back, and the small
inclined end of the piece R pressing against the inclined end of the
piece K causes the same to rise upwards in opposition to its spring P,
until the hooked portion of the piece K rests in the depression formed
in the piece R, the parts of the detaining apparatus will then be in the
positions shewn at Figure 4. In order to simplify the above description the
pins of the rings V₁, V³, V³, are shewn directly above or in a line with the
centre of the notch in each ring; but in practice the positions of the pins
with regard to the notches will be varied in each lock. Thus, in one lock
the pins may be so situated that by turning the rings until the pin of the
ring V is opposite the number 3 on the boss U, the pin of the ring V oppo-
site 7 on that boss, and the pin of the ring Vs opposite 10, the notches will
be caused to coincide with each other, and the false key can then be released;
and in another lock the pins may be so situated that to produce the same
effect the rings must be turned until their pins are respectively opposite the
numbers 1, 5, and 8 on the boss U, so that no person but the owner of the
lock, who is aware of the proper numbers, can release the false key; and
although three rings are shewn in the Drawing, two, four, or more rings
may be used. In applying the first part of the Invention to a drawer lock
the depth of the rings V, V, V³, must be increased, as exhibited at Figure 12*,
which is a vertical section taken through the centre of a drawer lock, the parts
between the protecting plate and the back of the lock being omitted in this
Figure.
The mode of applying the detaining apparatus to a more simple kind of
luck than the preceding one is shewn at Figure 13, which exhibits the inte-
rior of an ordinary lock, the key plate being removed. A is the case of the
lock; D is the bolt, which is furnished with a spring D at the back, as is
usual in locks of this description. J is the spring that presses against the

page_text: tubular portion of the excentric as above described. The "protecting plate"
applied to this lock is exactly the same as that represented at Figures 3, 4,
and 5. It is secured to the back plate of the lock by screws passing through
the holes a; and as the bolt D, Figure 13, is not formed with a shoulder p
like the bolt D, Figure 2, a pin p is fixed in the required position, in order
to act upon the shoulder q of the piece R (when the bolt is shot back), and
bring the parts of the detaining apparatus into the positions shewn at Figure 4.
The actions of the different parts are precisely the same as those above
mentioned.
The other part of the said Invention, videlicet, the application to common
locks of a tumbler or tumblers which is or are to be placed in the space
that remains unoccupied between the bolt and the plate wherein the keyhole
is formed, or between the bolt and the back plate of the lock, is shewn at
Figure 14. This lock is constructed in the same manner as that represented
at Figure 13. A is the case of the lock; D, the bolt; and D¹ its spring.
E is the tumbler (shewn separately in side and edge view at Figures 15),
which is mounted on a pin F fixed in the back plate of the lock beneath the
bolt; H is the spring that acts on the tumbler; and G is the square pin
affixed to the bolt, and working in the opening of the tumbler. The action
of the tumbler, and the parts in connection therewith, will be readily under-
stood on referring to the commencement of this Specification. At Figure 14
the spring J and pin p are also shewn, in order to point out how both parts
of the said Invention may be applied to one lock. From the above descrip-
tion it will be evident that the alterations requisite to be made in a common
lock,
for the purpose of applying either part of the said Invention, will be of
the most simple kind, as, in order to apply the detaining apparatus, nothing
more will be requisite than to fix the pin p on the bolt D, and secure the
spring J to the back plate of the lock. If the tumbler is to be applied, the
square pin G must be attached to the bolt, and the pin F and spring H fixed
in their proper positions either to the back plate or the key plate of the lock;
for I would remark, with respect to this second part of the said Invention,
that, as in some common locks the unoccupied space is between the bolt and
the key plate, and in other locks it is between the bolt and the back plate, so
the situation of the tumbler or tumblers will vary accordingly. Other arrange-
ments of apparatus may be used in place of the rings V1, V2, V3, (described
under the first of the Invention) for the purpose of releasing a false key after it
has been caught by the detaining apparatus.
In Sheet II. of the accompanying Drawings Figure 1 is a front view
of a lock, with one arrangement of releasing apparatus applied thereto;
Figures 2, 3, 4, 5, 6, and 7 exhibit detached views of certain parts of the

page_text: apparatus. In the preceding part of this Specification it was stated that the
false key, after having been caught by the detaining apparatus, could not be
released by any person but the owner of the lock (or the person who is
acquainted with the different positions which the studs 1, 1, 1, of the rings
V, V, V, should be placed in to effect that object); for the rings V¹,
V³, V³, presenting the plain edges of their rims j, j, j, to the projection i
of the lever M, prevent that lever and the hooked piece K from moving
forward, as before described. Now, four or any other number of sliders V,
shewn separately at Figures 2, 3, 4, 5, are substituted for the rings
V, V, Vs. These sliders work between small clips or guides (indicated by
the dotted lines W in Figure 1) fixed to the front plate B of the lock, and
their front ends are kept in contact with that plate by small springs acting on
their back ends. In that side of each slider which is opposite the projection
of the lever M, there is a small notch k. These notches are formed at
different distances from the ends of their respective sliders, as shewn in the
side view, Figure 6, so that it will be necessary to move them through different
degrees of space, in order that their notches may correspond (as represented
at Figure 7) and form one recess suitable for receiving the projection of the
lever M. A rectangular opening is made in the plate B, in front of the
sliders, so as to admit of the sliders being acted on by the key shewn at
Figure 8, which is formed with suitable steps for adjusting the sliders in such
manner that the false key may be released. Another mode of effecting this
object by means of sliders is represented at Figures 9, 10, 11, 12, and 13.
Figure 9 is a front view of the lock, and Figure 10 is a front view of the
sliders; Figures 11 and 12 are side views, and Figure 13 is an end view of
the sliders. Notches are made in the side of the sliders as in the least-
described apparatus; but the sliders now move vertically (between the guides
r, r, represented by dotted lines) instead of horizontally. The notches are
caused to coincide and form one recess for receiving the projection of the lever
M, by moving the sliders, by means of the stud or pin fixed in each, instead
of using a key for that purpose, as in the preceding arrangement. To facili-
tate the adjustment of the sliders, a row of figures, letters, or dots may be
engraved on the plate B, at the side of the rectangular opening through
which the ends of the sliders are seen. Other apparatus or combinations of
parts may be applied to the detaining apparatus described under the first part
of the Invention, for the purpose of raising the hooked piece K, and thus
releasing a false key when the same has been caught.
Four different arrangements of releasing apparatus are exhibited at
Figures 14, 15, 16, 17, and 18. When any one of these is used, the boss U

page_text: and the rings V, V, Vs, are dispensed with. The lever M is likewise removed,
and the hooked piece K turns on a pin fixed in the plate C. This arrange-
ment admits of the plate C being employed as the front plate of the lock (in
order to diminish the thickness of the lock) by forming it, as indicated by the
dotted lines C¹, in Figures 14 and 15, (Figure 14 being a back view, and
Figure 15 an edge view of the plate C,) so that it will cover all the moving
parts of the lock, the front extremity of the bolt being made somewhat
thinner, in order that it may work behind the plate C, and at the same time
act upon the shoulder 9 of the piece R. The hooked piece K is formed with
a descending arm K', the lower end of which is to be acted on by a suit-
able ȧrm or bolt, for the purpose of raising the piece K, and thus releasing
the false key. The arrangement employed for giving motion to the piece K
in a small lock of the kind commonly termed the Bramah lock, are as
follows: The front end of the barrel u, Figure 15, of the small lock, fits into
a boss C³, formed on the back of the plate C, and the annular plate v, which
enters partly into the barrel u, is screwed to the boss. To the hinder end of
the barrel the nib or bent arm w is fixed, the extremity of which projects
beneath the end of the arm K', so that on the barrel being turned, it will
raise that arm, and consequently the hooked piece K. Now, supposing a false
key to be introduced through the keyhole of the plate C (represented by
dotted lines in Figure 14), and through the keyhole of the excentric I, and
turned in the direction of the arrow (carrying the excentric with it, so that
the projection m will pass the hooked end of the piece K) until the key is
stopped by the wards or tumblers, the person who has introduced the key
will turn it in the reverse direction for the purpose of withdrawing it from the
lock; but when the key has arrived at the position shewn in Figure 14, the
projection m of the excentric will be caught by the hooked end of the piece K,
and thus the key will be effectually retained. The owner of the lock can
release the false key by introducing a suitable key into the barrel u of the
small Bramah look, and turning the barrel until its bent arm w has raised
the piece K sufficiently to admit of the excentric I turning until its keyhole
coincides with the keyhole in the plate C, and then the false key can be
drawn out. Figure 16 exhibits another mode of raising the piece K, in order
to release the false key. In this case a bolt D, similar to those used in common
locks, is substituted for the Bramah lock; and when this bolt is shot forward,
by means of a suitable key, its bevilled end acting beneath the end of the
arm K¹ elevates the piece K. In Figure 17 another arrangement is shown in
which a bolt D is also used; but instead of it being acted on by a key, it is
connected by a wire or rod a with a secret spring in the side of the box or

page_text: other article to which the lock is applied. One end of the wire a is securely
attached to the bolt, and the other end terminates in a disc a¹, which is con-
tained in a suitable recess in the side of the box, and is covered with wood,
leather, or other material, so as to present a similar appearance to other por-
tions of the surface. When this disc is pressed into the recess, the bevilled
end of the bolt D is forced beneath the end of the arm K, and on the
pressure being removed, it is caused to return to its original position by the
action of the helical spring y contained in the chamber z. Any other kind of
spring may be employed in place of the helical spring. If preferred, when a
secret spring is used, the position of the bolt D may be changed from the lower
part to the upper part of the plate C, and its bevilled end caused to act
beneath the under side of the piece K, (see Figure 18,) which must be made
of a suitable shape for that purpose. By this means the arm K' is rendered
unnecessary.
Another part of this Invention consists in certain improvements in the con-
struction of Bramah locks, and in the application to a Bramah lock of the
detaining apparatus for the purpose of catching any false key that may be
introduced into the lock. Bramah locks have been hitherto made with a boss
or cap upon the front plate to receive the end of the barrel containing the
sliders, as indicated by the dotted lines B' in Figure 19, which represents a
vertical section of a Bramah lock. This projecting boss or cap has been
found objectionable in some applications of the Bramah lock; and great care
is required to form a circular opening of exactly the proper size and position
for receiving the boss or cap, or through which it is intended to protrude.
Now the object of the improvement constituting this part of the Invention
is to get rid of the boss or cap in order that the front plate of the lock may be
made perfectly flat, similar to the front plate of an ordinary lock. This is
effected by causing the hind end of the barrel u to protrude through a circular
opening in the back plate or case A, Figure 19, and fixing the annular plate
v to the inner side of the back plate, by which means the foremost end of the
barrel will be moved so far back that it will not project beyond the edge of the
case A, and therefore a flat front plate B with a keyhole formed therein may
be applied to the case A. s, a, are the sliders which work in separate recesses
in the barrel ; their hind ends pass through notches formed in the inner
edge of the annular plate v, for the purpose of allowing them to slide endways,
but preventing them from moving round with the barrel u except they be
forced back to such distances as will bring their respectivo notches (which are
formed at different distances from the extremities of the different sliders)
exactly oppoite to the inner edge of the annular plate v. The sliders are at

page_text: all times pressed towards the foremost end of the barrel by a helical spring t¹
coiled around the centre pin t, and acting against a small ring or plate
splaced behind the hooked ends of the sliders; but when it is desired to shoot
or draw back the bolt D the key is introduced, and the sliders are forced back
to the requisite distances by suitable slits of different lengths formed for that
purpose at the extremity of the pipe of the key; then the key being turned,
the barrel u and sliders s will be carried round by a small nib or projection on
the side of the key pipe which has entered a keyhole formed in the foremost
end of the barrel, and thus the short arm or projection u¹ on the exterior of
the barrel u will be caused to act in a notch in the lower edge of the bolt D,
and move the same backwards or forwards, as the case may be. It is evident
that the security of this lock against being fraudulently opened results from
the notches of the sliders being situated at different distances from the
extremities of the same, and therefore increased security will be obtained if the
positions of the notches be varied to a greater extent. This can only be
accomplished by using longer sliders and a barrel of increased length, which.
in the ordinary Bramah locks would render it necessary for the front plate to
have a longer boss or cap; but by a modification of the last improvement
a longer barrel may be used, and still a flat front plate be retained.
Figure 20 is a vertical section of a lock suitably constructed for effecting
this object. It will be seen that the principal difference between this lock and
the one shewn at Figure 19 consists in the back plate A being made with a
boss A', to the end of which the annular plate v is fastened; this arrangement
admits of a longer barrel and longer sliders being employed, the projection
being transferred from the front to the back of the lock, where its presence is
but slightly if at all objectionable.
•
Figure 21 is a front view, and Figure 22 a vertical section of a Bramah
lock constructed according to the last improvement, but having the front plate.
thereof (which is in this instance marked C) furnished with detaining apparatus
arranged as described under the fourth part of this Invention, so as to dispense
with the boss U, rings V1, V2, Vs, and lever M; and in this case the detaining
apparatus consists simply of the excentric I, the hooked piece K with its arm
K, and the piece R, and the means used for raising the same.
The action of the different parts of the Bramah lock and of the detaining
apparatus having been fully described in the previous portion of this Specifica-
tion, it will be unnecessary to repeat the same here. There is one circum-
stance, however, that requires particular attention; that is, that the keyhole
of the Bramah barrel and the short arm u', which moves the bolt D, must be
so situated that the keyhole of the barrel will not coincide with the keyhole

page_text: in the front plate when the bolt D is in its forward position, but that if a false
key be introduced through the keyhole in the front plate it must be turned so
far round before it can enter the keyhole of the barrel as will suffice to carry
the projection of the excentric I beneath the hooked piece K, which will pre-
vent the return of the key until it is released by the owner of the lock, as
before mentioned; and the false key is prevented from continuing its onward
movement and carrying round the excentric until the keyhole of the latter
coincides with the keyhole in the front plate (when the key could of course be.
withdrawn) by a small pin on the excentric coming in contact with a bent
arm fixed to the inside of the front plate C. In the other arrangements of
locks before described, the small pin and bent arm could not be used, as the
excentric is compelled to make one complete revolution, both in locking and
unlocking, in order that the right key may be withdrawn; but when the
detaining apparatus is combined with a Bramah lock, the excentric is only
required to perform part of a revolution to bring the key opposite the keyhole
of the Bramah barrel, and when the key has moved the barrel through part of
a revolution in either direction (accompanied by the excentric), so as to shoot
or draw back the bolt, it is withdrawn from the keyhole of the barrel, and
then the excentric moves back (the hooked piece K. being raised by the means
before described in order to permit it to do so) until its keyhole coincides with
the keyhole in the front plate.
Another part of this Invention consists in the application to locks of various
kinds of a spring catch sliding bolt, or other similar contrivance, in combina-
tion with the detaining apparatus (arranged according to any of the methods
before described), in such manner that in the event of the right key being lost
the owner can so adjust the internal parts of the lock that if the right key be
introduced by the person who has found or fraudulently obtained the same,
the key will not open the lock, but will be caught by the detaining apparatus,
and can only be released by the owner.
Figures 23 and 24 represent the interior of a tumbler lock, similar to that
shewn at Figure 2 in Sheet I. of the accompanying Drawings, but furnished
in the present case with a spring catch; it being exhibited at Figure 28 in
a locked state and at Figure 24 in an unlocked state. Figure 25 shews the
proper key for opening and securing the lock; Figure 26 is the key used for
setting the spring catch, and Figure 27 is the key for throwing it out of action
when the right key, Figure 25, is lost. The owner raises the first tumbler E
by means of the key, Figure 26 (which has its step or tappit 2 made of a
suitable length for this purpose), to such a height that the hooked extremity of
the catch X will enter into the notch 3 of that tumbler, and retain it' in-its

page_text: elevated position; then he withdraws the key, Figure 26, which he is enabled
to do by acting on the detaining apparatus according to any of the methods
before described. Now, if the right key be introduced, it will raise the second
and third tumblers to the proper height for allowing the bolt to be drawn back,
but its step 2 will not be able to act on the elevated tumbler, and, therefore,
it will not be able to draw back the bolt, nor can the key be withdrawn
from the lock until the owner acts on the detaining apparatus in the proper
manner for releasing the key. The elevated tumbler is restored to its proper
position by the use of the key, Figure 27, the step 2 of which acting on the
projecting portion 4 of the spring catch, causes the extremity of the catch to
leave the notch of the tumbler, and allow the latter to descend.
Figure 28 shews the application of a small sliding bolt Y to a lock of the
same kind as the one represented at Figure 18 in Sheet I. of the accom-
panying Drawings. This bolt works between guides 5, 5; and when the right
key is lost the owner causes the upper end of the bolt Y to enter a notch in
the bolt D of the lock (as shewn at Figure 28), by means of a key with a
long and narrow "bit," which acts on the projection 6 of the bolt Y. If the
right key should now be introduced into the lock, it will not be able to draw
back the bolt D (which is prevented from moving by the small bolt Y, nor
can the key be withdrawn until the owner acts on the detaining apparatus, as
before mentioned. The small bolt is caused to descend by means of the same
key that was employed for raising it, the "bit" of which key is so narrow that
it can move freely between the side of the bolt D and the plate that carries
the detaining apparatus, being, of course, accompanied in its movements by
the excentric.
Although only two modes of carrying out this part of the Invention are
shewn, yet various other methods of effecting the same may be adopted. It
should be mentioned that the application of this part of the Invention will
render it necessary to form the keyhole of the lock longer than usual, in order
to admit the keys with "bits" of increased length.
Having now described the nature of the said Invention, and in what
manner the same is to be performed, I wish it to be understood that I do not
claim as of the said Invention, or the exclusive use of the several parts of the
tumbler and Bramah locks herein-before described and referred to, except
when the same are employed in combination with the several parts or
apparatus herein-after particularly enumerated; but what I claim as the
Invention whereof the exclusive use is intended to be secured by the said
Letters Patent is,―
Firstly, the application to locks of apparatus constructed and arranged as

page_text: above described for retaining and releasing a false key inserted into the
lock.
Secondly, the application of an additional ward or tumbler, as above
described, to locks, for the purpose of greater security.
Thirdly, the application of the spring catch and sliding bolt, as above
described.
And, lastly, the improvement in the Bramah locks by constructing them
with the boss or central barrel projecting at the back instead of at the front,
as above described.
In witness whereof, I, the said Charles Minors Collett, have hereunto
set my hand and seal, this Fifteenth day of October, One thousand
eight hundred and forty-seven.