IMPROVEMENTS IN LOCKS OR FASTENINGS
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
RESTELL, of the Strand, in the City of Westminster, Watchmaker, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing dato at
Westminster, the Eighth day of December, in the fifteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto nie, tlie said
Thomas Restell, Her especial licence, full power, sole privilege and authority,
that I, the said Thomas Restell, my exors, adññors, and assigns; and such
others as I, the said Thomas Restell, 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 mentioned, should and lawfully might
make, use, exercise, and vend, within England, Wales, the Town of Berwick-
upon-Tweed, and in all Her Majesty's Colonies and Plantations abroad, and
in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, my Inven-
tion of "IMPROVEMENTS IN LOCKS OR FASTENINGS;" in which said Letters Patent
is contained a proviso obliging me, the said Thomas Restell, by an instru-
ment in writing under my hand and seal, particularly to describe and ascertain
the nature of my said Invention, and in what manner the same is to be
perforined, and to cause the same to be inrolled in Her Majesty's High
Court of Chancery within six calendar iñonths next and immediately after
the date of the said in part recited Letters Patent, as in and by the saine,
reference being thereunto had, will inore fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Restell, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is particularly described
and ascertained in and by the following description thereof, reference being
had to the Drawings hereunto annexed, and to the letters and figures marked
thercon (that is to say):-
The object of my Invention of Improvements in Locks or Fastenings is, to
construct locks or fastenings for various purposes in such a manner as to afford
perfect security, combined with great simplicity of parts, and consequent mode-
rate cost. Hitherto, when perfect security from thieves or picklocks has been
the desideratum, this object has been sought to be obtained by a combination
of complicated parts, consisting of sliders, tumblers, or other moving parts, all
of which it would be requisite to bring into certain positions before the bolt of
the lock could be shot or forced back, and the door or drawer to which such
lock is secured could be opened. It has usually been considered that by
increasing the number of these sliders or tumblers they become susceptible
of such an infinite variety of changes that it is next to impossible for any
person from the outside to throw back the bolt without employing the right
key, or to make an instrument or instruments to suit the peculiar combination
of the sliders or tumblers, and consequently that (practically speaking) it would
be impossible to pick such a lock. It has, however, been demonstrated that
such is not the case, and that locks depending for their security entirely upon
a combination of tumblers or sliders are not impregnable, whatever may be the
complication of their parts. This insecurity, in my opinion, arises in a great
measure from the fact that more than one instrument can be introduced into
the keyhole at the same time, and consequently that while one instrument may
be made to hold and fix or retain in any required position certain of the
tumblers or other portions of the internal parts of the lock, another instru-
ment may also be introduced to act upon other parts. In most of the
combination locks hitherto constructed the position and operation of the tum-
blers may also be ascertained by forcing back the bolt a short distance and
bringing the "bit" or stud affixed thereto to bear against the face of the
notches of the tumblers, so as to hold some of the said tumblers or sliders
in a certain position while the situation and operation of others may be
examined by means of any instrument introduced into the keyhole. It is
evident, therefore, that in constructing a combination lock which is to be
deemed impregnable these points must not be overlooked, but care taken, first,
that not more than one instrument can be introduced into the keyhole at
a time; and, secondly, that the bolt cannot be forced back, and made to hold

page_text: any of the sliders or tumblers in any given position. The object, therefore, of
one part of my improvements is, to construct the keyhole in such a manner
that not more than one instrument can be introduced into the lock at one
time; and further, that if any instrument other than the proper key be intro-
duced, and turned partly round, it will meet with an obstruction as usual
in all combination locks, but cannot be withdrawn therefrom until all the
internal parts have been brought back into their natural position. This will
effectually prevent any person from feeling where all the obstructions lie, and
will consequently give him no opportunity of dealing with them. I effect this
object by surrounding the spindle of the keyhole with a cylindrical curtain or
guard, combined with a circular plate or shield, these parts being constructed
in such a manner in relation to the internal parts as to effectually prevent the
introduction of more than one instrument at a time. The circular plate or
shield is secured to the top of the cylindrical curtain, so that when the key
or other instrument is introduced, and turned round in the keyhole, the circular
plate or shield is carried round inside the lock, and covers up the hole, and
thereby prevents the introduction of a second instrument.
This part of my improvements is shewn in the accompanying Drawings at
Figures 1, 2, 3, and 4.
Fig. 1 is an elevation of the inside of a drawer or box lock, with my
improvements adapted thereto. Fig. 2 is a transverse section of the same.
The cylindrical curtain a surrounds the spindle in the keyhole, and carries
the circular plate or shield b, which is moved round by the key with the
curtain a, and thereby effectually closes the keyhole, and prevents any other
instrument from being introduced until the several parts are brought back into
their original position, and the key or other instrument withdrawn. The cylin-
drical curtain passes through the top plate of the lock, and being flush with the
upper surface thereof is held in its proper position thereby without further
assistance. The bolt c of the lock is furnished as usual with a pin, stud,
or "bit" d, which moves in the slots or gates of the tumblers or sliders e,
the notches of which are purposely made much wider than usual, for reasons
hereafter explained. In order to prevent the key from being turned in the
wrong direction, a projecting stud or tooth f is formed on or attached to the
periphery of the circular plate or shield b, as shewn in the detached views
Figures 3 and 4, and when the plate b and curtain a are moved round either
way, either to lock or unlock the bolt, this tooth or stud f will be brought
against one side or the other of the "bit" d of the bolt, and the key will be
thereby prevented from going round any further. The tooth f serves also to
hold the curtain a and circular shield 6 in their proper position to receive the
key, either for opening or closing the lock. It will be evident that unless

page_text: some precaution of this kind were taken, the circular shield might accidentally
slip round and close the keyhole. Shields or plates to prevent the introduction
of instruments into the keyhole have heretofore been used; and in order to
prevent those shields from slipping round, and accidentally closing the keyhole,
it has been the custom to pinch or bear upon the shield or plate by the upper
plate of the lock, so as to cause such an amount of friction as will prevent tho
shield from moving except when acted upon by the key.
One of the methods I adopt for preventing the circular plate from slipping
round accidentally consists in causing the tooth f to take into a notch g made in
a block that is attached to the upper part of the uppermost tumbler e. It will
be seen upon inspecting Fig. 2 that whether the bolt is shot back or forward
the tooth will always take into the notch g, the only difference in the relative
position of the pieces being, that when the bolt is shot forward, as when the
drawer is locked, then the tooth f will be on the right side of the "bit" d, but
when the bolt is shot back, as when the drawer is unlocked, then the tooth will
be on the left side of the "bit" d. By this arrangement I am enabled
to relieve the shield from the friction to which it has hitherto been subjected.
I sometimes surround the cylindrical guard with a small spiral spring, as
shewn in Figures 5 and 6, which represent plan and edge views of a modifica-
tion of the above, shewing the curtain and shield just described adapted to a
drawer lock, with a different mode of holding them in their place. The lock is
shewn in elevation at Fig. 7 and in transverse section at Fig. 8. The principal
difference between this modification and that just described is, that instead of the
curtain a and circular shield being held in their proper place by means of the
tooth f, as in the former instance, the same object is effected by means of an
indentation h, in which rests a projecting point on the front edge of the upper
tumbler c. The key is prevented from being turned in the wrong direction by
means of the tooth f on the circular shield, as in the former instance; but,
instead of abutting against the "bit" or stud on the bolt, there is a moveable
stop piece i, which is secured to the plate of the lock by means of two screws,
but may be moved up or down by the tooth f whenever the bolt of the lock is
moved up or down by the key.
Fig. 9 is another modification, in which the curtain a and circular shield b
are held by a point on the edge tumbler, taking into a notch on the edge of
the circular shield, which in this instance is furnished with two teeth f, f*,
which, by abutting against one or other of the studs or pins d, d, on the bolt,
prevent the key from being turned in the wrong direction.
Fig. 10 represents the curtain and circular shield detached, and Fig. 11 is a
view of the key for either of these locks.
Figures 12 and 13 represent another mode of holding the circular shield or

page_text: plate. In this instance, instead of effecting the object by means of a project-
ing tooth or point on the edge of one of the tumblers, a spring j is employed,
which being aflixed to the inside of the upper plate of the lock, as shewn in
Fig. 13, bears against the edge of the plate or shield as it is moved round, and
when the latter is brought into the proper position for removing the key, either
when the lock is open or closed, the lower end of the spring ; takes into the
notch on the periphery of the circular shield, and holds it in its proper position.
In Fig. 12 I have also shown a simple means of so altering the combination of
the tumblers with the bolt that the original key, when the alteration is made,
will not open the lock. This object is obtained without altering the position
or combination of the tumblers in relation to one another, and is effected
simply by making the "bit" or stud d of the bolt moveable.
Fig. 14 is a view of the lock with the circular shield and tumblers
removed, in order that the construction of the bolt may be more clearly seen!
It should be understood that the "bit" or stud d'which traverses in the gates
or notches of the tumblers is usually a fixture on the bolt, as seen in Fig. 1.
In the present instance, however, it is secured to a small moveable plate k,
shewn detached at Fig. 15, and seen also in the back view, Fig. 16, and trans-
verse section, Fig. 17. It will be seen also, in Fig. 14, that two holes are
made in the bolt c, in either of which the "bit" d may be inserted, and made
to project through the tumblers, as shewn in the Figures. A recess is made
in the back plate of the lock, as seen in Fig. 16, to receive the moveable
plate k, and when the "bit" d, which is attached thereto, is inserted in its
place in one of the holes of the bolt, the plate is secured by means of a
sliding plate or shutter 1. When it is required to spoil the combination, and
render the original key useless, it will only be necessary to open the shutter
at the back, and remove the bit from one hole to the other.in the bolt. The
effect of this alteration in the position of the "bit" d, in reference to the
tumblers, will be, that in order to allow the bit to pass freely through the gates
of the tumblers, and thereby allow the bolt to be shot, the tumblers must be
raised to a different height to that which was before required, and consequently
a different key must be employed to produce this effect. Hitherto, in order to
spoil the combination of the several parts of a lock so as to prevent them from
being opened by the original key, it has usually been necessary to partially take
the lock to pieces, and change the arrangement of the tumblers, and also to
make a corresponding change in the bits of the key; and although it has been
proposed to alter the combination inside the lock by merely altering the com-
bination of the bits of the key, which will afterwards change the combination
in the lock to suit the alteration in the key, by merely locking and unlocking

page_text: the bolt with the changed key, yet it will be evident that such a plan is inap-
plicable to small locks, which must be produced at moderate cost, and in
which, therefore, a multiplicity of small pieces are inconvenient.
In constructing locks with my present improvement adapted thereto, I
propose to make three keys, two for the first combination, and one for the
second, so that if by accident one key belonging to the first combination should
be lost the lock may be opened with the fellow key, and then the combination
spoiled by raising the shutter 1, and moving the plate k and "bit" d from one
hole to the other, as before mentioned, when it will be found that the
third key only will open and close the lock, and therefore that the other
two keys will be useless. In order to prevent the bolt from moving
while the position of the "bit" is being changed, I have found it
convenient to attach to the lower part of the bolt a small pin 1, Figures 12
and 14. This pin is made to enter a notch made in the lowest tumbler, or
that nearest the bolt, and will prevent the bolt from shifting its position. The
method just described of changing the combination of a lock is so simple in
its arrangement that the most inexperienced person can make the alteration
with facility. The same effect, that is, spoiling the combination, may be
produced by mounting the pin m, Fig. 12, on which the tumblers turn, on a
inoveable plate. The "bit "d will, in this case, of course be fixed to the bolt
as usual. The pin m being attached to a moveable plate, such as that shewn
at k, Figures 15, 16, and 17, will be caused to project through a slot or hole
made in the back plate of the lock, precisely as in the former instance. It
will therefore be evident, that to alter the combination by changing the position
of the tumbler, it will only be necessary to shift the position of the moveable
plate which carries the pin on which the tumblers are mounted.
Figures 18, 19, and 20 represent various views of a method of altering the
combination in a Bramah's lock by means of a moveable plate. It is well
known that the security of a Bramah's lock depends upon a number of vertical
sliders which have notches cut on their faces, and which sliders must all be
pressed down to a certain point, so as to bring all the notches made therein
into the same plane and coincident with the edge of a fixed horizontal plate,
until which is done the horizontal plate will prevent the barrel containing the
vertical sliders from rotating, and consequently the bolt cannot be shot. In
applying my improvements to locks of this description I secure the horizontal
plate », seen in Figures 18 and 19, and detached in Figures 21, to a move-
able bridge piece or bracket o, also shewn detached in Figs. 21. The barrel
p, in which the vertical sliders work, is constructed in the ordinary way, with
the exception, that the annular groove which receives the horizontal circular

page_text: plate n is made wider than usual, to admit of the horizontal plate being moved
up or down when it is required to shift its position. At the centre part of
this bridge piece or bracket is made a female screw m, which works the
male screws, whereby the bracket may be raised or lowered, when required,
by simply turning the screw, which is furnished with a shoulder, whereby
it is held in its bearings in the back plate, but yet can be turned therein
with facility merely by applying a turnscrew or screwdriver in the ordinary
manner. The vertical sliders are supported by a coiled spring, as in the
ordinary construction of Bramah's lock; but the bolt c is furnished with a
toothed rack, as shewn in the sectional plan view, Fig. 20, and the bolt is
shot by means of a pinion 7, Figures 18 and 19, at the lower end of the
spindler, which is supported in the end of the screw s. Now, supposing all
the parts to be in the position shewn in Fig. 18, a key such as that shown in
Fig. 22 would open it; but supposing this key to be lost, or to have got into
other hands than those of the proprietor, it would be necessary to so alter the
internal arrangement or combination that this key would not open the lock.
This can be effected by simply turning round the screw s at the back of the
lock by means of a common screwdriver, and by this means the moveable
bridge piece or bracket o and the horizontal plate n is raised into another
plane, as shewn in Fig. 19. It will, therefore be evident that the first key,
shewn in Fig. 22, would push down the sliders too far, and consequently the
notches therein would be pushed beyond the edge of the horizontal plate n,
and therefore the barrel would be prevented by the horizontal plate from
turning round and shooting the bolt. The third key, or that shewn in Fig. 23,
must therefore be used, and the other keys will then be useless.
In reference to tumbler locks it has been already stated that one of the
difficulties which I wish to put in the way of any person attempting to tamper
with the lock is, not only that he shall not be able to introduce more than one
instrument at one time, but, further, that he shall be prevented from feeling
the position of the tumblers by pressing the bolt against them, as has usually
been the case. Hitherto the bolt has been held in its place by the tumblers,
as the "bit" of the bolt was made to nearly fit the notches made in the
tumbler; and therefore, by forcing the bolt back, and causing the bit to press
against the face of the notches in the tumblers, the latter might be held in
any given position, and the obstruction they would offer to opening the lock
might then be felt and possibly removed. I, however, construct the lock in
such a manner that the bit of the bolt cannot be brought to bear against the
tumblers so as to retain them in any given position. As, therefore, it will
not be necessary that the "bit" should fit the notches of the tumblers, I am

page_text: enabled to cut the notches much larger than usual, leaving a considerable.
space between the bit and the face of the notch; and, in order to prevent the
bolt from shifting its position except when acted on by the key, I place a
tooth or pin on the lower edge of the bolt, and cause it to bear against the
periphery of the cylindrical guard, and thereby prevent the bolt from being
moved either way until the guard is turned round by the key, and a notch
which is made therein is brought round so as to admit. the tooth. on the bolt,
and allow it to pass by. This improvement will be best. understood by
referring to Figures 12 and 14, which latter Figure represents. the bolt c with
all the tumblers removed. a is the cylindrical guard to the keyhole shewn in
most of the previous Figures, and detached in Fig. 24. u is the tooth at the.
bottom of the bolt, as seen in Fig. 14. It will be seen that the bolt cannot
be moved so as to bring the "bit" against the tumblers until a notch 2, in
the cylindrical guard,. is, by means of the key, brought round to admit the
tooth. Fig. 25 is a modification of the above. c is the bolt, and wis a
circular plate at the lower end of the cylindrical guard a.
This plate w
which is shewn detached at Figs. 26, is made to fit into curved. recesses cut
in the lower edge of the bolt, which is thereby prevented from moving until:
the notch 2 comes round, and allows the points.u, u, which are equivalent to
the tooth u in Fig. 14; to enter the notch. The key enters the notch made
in the bolt, and, provided the. tumblers (not shewn in the Drawings) are
brought into the proper position, the bolt can then be shot...
In Figures 27 and 28 I have shewn another mode of effecting a similar
object. In this case I make an additional notch in the face of the tumblers,
and one tumbler (say the lowermost one) is made a little longer than the
others. A small pin is fixed in the side of the bolt, and when the proper
key is used to open the lock the tumblers will be raised in such a manner
as to admit this pin through the front gate of the tumblers; but if a false
key or other instrument is introduced, and the bolt pressed back thereby,
the pin will be brought against the end of the lowermost or longest tumbler,
which will be retained thereby. Upon discovering the obstruction, and finding
all the other tumblers free, any person attempting to pick the lock will neces-
sarily be obliged to move the obstruction out of the way by raising that
tumbler; and immediately this is done, and the pressure being still on the
bolt, the pin will pass into the notches 3. of the other tumblers, and thereby
prevent them from being raised until all of them are set free again.
is a
Fig. 29 represents a common door lock with three tumblers, in which the
bolt can never be shot until the guard plate or shield is moved.
protector tumbler which securely holds the bolt, and is kept elevated by a pin

page_text: or stud v in the guard plate or shield. Before the bolt can be moved the
tumbler e* must be allowed to descend, and this cannot take place until the
pin vis brought round by the rotation of the shield plate b, which thereby
closes the keyhole.
Figure 30 is a transverse section of Fig. 25, and represents an arrangement
for a mortice lock, and in which the key may be inserted from either side.
Figures 26 represent the double circular shield whereby the keyholes on
both sides may be simultaneously closed.
The arrangement and operation of the tumblers, and the construction of
other parts of the lock, may be according to any of the plans already described.
In order to facilitate the delivery of the key from the keyhole, I introduce
between the two circular plates or shields w, b, a coiled spring y (as shewn in
Fig. 30), which is compressed by the key when the latter is introduced into
the lock; and therefore, when the key, after having performed its duty in
opening or closing the lock, is brought opposite the keyhole again, the force of
the coiled spring, will force it out.
Figure 31 represents a side view and Fig. 32 a transverse section of a
latch with some of my improvements, already described, adapted thereto: c is
the spring latch bolt; a, the cylindrical guard; and b, the circular shield, to
which is adapted a stop pin or stud f, which abuts against a fixed pin g. The
circular shield may be held in its proper position by any of the means already
described, such as by the tumbler, as shewn in Figures 1, 7, and 9, or by a
spring, as shewn in Figures 12 and 13.
Having now described my various improvements in locks or fastenings,
and the best method with which I am at present acquainted for carrying the
same into effect, I would observe, in conclusion, that although, in order that
my several improvements may be properly understood, I have found it desirable
to shew and describe various parts of locks which have been before known and
in use, yet I do not mean or intend to claim such parts, except when con-
structed, combined, and arranged in the novel and improved manner herein
shewn and described; nor do I intend to confine myself rigidly to the precise
arrangement or construction of parts herein shewn and described, as they may
doubtless be varied without departing from the nature and object of my
present Invention. But that which I consider to be new in the above-
described improvements, and therefore wish to claim as the Invention secured
to me by the herein-before in part recited Letters Patent, is,-
First, the combination of the cylindrical curtain or guard a with the circular
shield b, and mode of applying the same, as herein shewn and described.
I

page_text: claim particularly the employment of a pin, tooth, notch, spring, or other
analogous contrivance adapted to the circular shield 6, together with the other
necessary parts connected therewith, whereby the curtain or guard and
circular shield may be held in their proper positions, and prevented from
slipping round accidentally when the key is withdrawn from the lock.
Second, I claim the employment of pins, studs, or projecting points adapted
either to the circular shield or other part of the lock, whereby the key may be
prevented from being turned in the wrong direction.
Third, I claim the use of the moveable plate k and "bit" or pin d, or any
mere modification thereof, whereby the position of the "bit" d in relation to
the notches in the tumblers e, or the position of the tumblers e in relation to
the "bit" d, may be altered when required, and the combination of the
several parts of the lock may be so changed as to render the original key
useless for opening the lock.
Fourth, I claim constructing the bolt with a tooth, pin, or projecting point
at its lower edge (as shown in Figures 14 and 25), which, by bearing against
the sides of the cylindrical shield, circular plate, or other suitable part, will
prevent the bolt from being shot until a suitable notch, cavity, or opening
made for the purpose in the said cylindrical shield, circular plate, or other part,
is brought round so that the tooth, pin, or projecting point on the bolt may
enter therein, and allow the bolt to be moved.
Fifth, I claim the use of the moveable plate n, and its moveable bridge
piece or bracket o, as applied to a Bramah's lock, for the purpose of changing
the relative position of certain parts of the lock, as shewn in Figures 18, 19,
20, and 21. I also claim the method shewn in the said Figures of actuating
the bolt of the lock.
Sixth, I claim constructing the tumblers, as shewn in Figures 27 and 28,
with an additional notch at the end, into which a pin, secured to the bolt, will
enter, upon applying force or pressure thereto, and by thus holding all the
tumblers will prevent any of them from being raised until the bolt is thrown
back again.
Seventh, I claim the use of a protector tumbler, as shewn in Fig. 29, which
tumbler is, by means of a pin connected to the circular shield, kept raised too
high to allow the bolt to be shot, and cannot be allowed to descend until the
circular plate is moved round and the keyhole closed.
Eighth, I claim the method shewn in Fig. 30 of constructing a mortice
tumbler lock, which can be opened by the key from either side, the keyhole
being protected with double shields.