Year: 1898

page_text: I, WILLIAM BRETT, of 20, Moselle Street, Tottenham, in the County of Middle-
sex, Carpenter, do hereby declare the nature of this invention to be as follows:-
My invention relates to locks and comprises the novel construction hereinafter
described whereby greater security is afforded than with locks as heretofore
constructed.
In a lock constructed according to my invention the bolt instead of being operated
directly by the key in the usual manner is operated by a tumbler plate with which
the key engages, the said tumbler plate being pivoted and formed with one or
more holes or apertures with which pins or projections upon the key engage in such
a manner that when the key is in engagement with the tumbler plate the latter
can be turned to move the bolt.
The
The tumbler plate is locked against movement by spring pins which enter the
holes in the tumbler plate with which the key engages, the said pins being of such
size and shape that they fill the said holes in the tumbler plate and lie flush with
the surface thereof. It will thus be obvious that in order to move back the bolt it
will be necessary to have a key which will depress the said pins simultaneously
and that the position and number of these pins can be varied to a very large
extent so as to prevent keys of different locks from being interchangeable.
holes in the tumbler plate and the corresponding pins are arranged at some
distance from the key hole so that they are not accessible through the key hole.
In proximity to these holes is arranged a stop which when the proper key is
inserted will stop the same so that the pins thereof are immediately above the
holes in the tumbler plate, pressure upon the key then moves back the studs out
of the said holes and enables the bit of the key to clear the stop. This stop may,
if desired, have wards arranged in conjunction with it or be otherwise suitably
constructed so that even if a key having the pins properly arranged to release
the tumbler plate is used in the lock the said key cannot be turned to move the
bolt unless the slots in the key correspond with the wards of the stop. As a
further precaution I sometimes place behind or beneath the tumbler plate a bar
which if the pins of the key used to open the lock are longer than the thickness
of the tumbler plate they will strike against the said bar and so prevent the
key from turning.
A lock constructed as herein before described is practically unpickable as the
pins which lock the tumbler plate being flush with the surface of the said plate
will afford nothing to indicate when an instrument inserted into the lock is in
the proper position to depress the said spring pins.
A guard plate extends over, the bolt to prevent the introduction of an instrument
to directly engage with the bolt and furthermore a partition is advantageously
placed across the lock to protect the end of the bolt. The said guard plate may
be formed with a flange to enter a groove on the tumbler plate or vice-vered to
prevent an instrument from being inserted between the guard and tumbler plates.
ED
877

page_text: A catch is provided for holding back the bolt when.required, the said catch
being advantageously arranged between a flange on the end of the bolt and the
partition.
Dated the 5th day of Janua 1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements in Locks.
I, WILLIAM BRETT, of 20, Moselle Street, Tottenham, in the County of Middle-
sex, Carpenter, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-.
My invention relates to locks and comprises the novel construction hereinafter
described whereby greater security is afforded than with locks as heretofore
constructed.
In a lock constructed according to my invention the bolt instead of being operated
directly by the key in the usual manner is operated by a tumbler plate with which
the key engages, the said tumbler plate being pivoted and formed with one or
more holes or apertures with which pins or projections upon the key engage in such
a manner that when the key is in engagement with the tumbler plate the latter
can be turned to move the bolt.
The tumbler plate is locked against movement by spring pins which enter the
holes in the tumbler plate with which the key engages. In proximity to these
holes is arranged a stop.
A guard plate extends over the bolt to prevent the introduction of an instru-
ment to directly engage with the bolt and furthermore a partition is advantageously
placed across the lock to protect the end of the bolt.
A catch is provided for holding back the bolt when required, the said catch
being advantageously arranged between a flange on the end of the bolt and the
partition.
To enable my invention to be fully understood I will describe the same by
reference to the accompanying drawings, in which :-
Figure 1 is an elevation of a lock constructed according to my invention;
Figure 2 is a section on the line 2-2 Figure 1;
Figure 3 is a section on the line 3-3 Figures 1 and 2;
Figure 4 is a section on the line 4-4 Figures 1 and 2;
Figure 5 is a rear face view of the lock with the cover plate removed; and,
Figure 6 is a view similar to Figure 5 but shewing the guard plate removed:
Figure 7 is a section on the line 7-7 of Figure 6;
Figure 8 is a view of a portion of the rear side of the cover plate as herein-
after described.
Figure 9 is an elevation of a key suitable for the lock hereinbefore describeil.
a is the case of the lock (which in the drawing is represented as a rim lock)
and b is the cover plate of the said case, which cover plate is adapted to be secured
in the usual manner by screws c, c. d is the bolt of the lock which is arranged
to slide in suitable guides and e is the spring for normally retaining the said bolt
in its locking position.
f is the tumbler plate through the medium of which the bolt is operated from
the key, this tumbler plate (which as shewn is approximately of semicircular

page_text: shape) is pivoted upon the key pintle 9 and is at one end in engagement with the
lug h upon the bolt whilst the other end is formed with one; or more holes i, i
adapted to receive corresponding pins or projections j, j upon the key. k, kare
pins adapted to enter the said holes i, i and fixed to the free ends of spring
blades, secured to the case a in such a manner that when the bolt is in the
locking position the said pins k, k will lie in the holes i, i and so lock the tumbler
plate, the said pins being of such size and shape that they fill the holes i, i and lie
flush with the front surface of the said tumbler plate.
It will be obvious that in order to move back the bolt it will be necessary to
have a key which will depress the said pins simultaneously and that the position
and number of these pins can be varied to a very large extent so as to prevent
kevs of different locks from being interchangeable.
The said holes i, i and the corresponding pins are arranged at some distance
from the key hole (which is indicated by the letter m) so that they cannot be
tampered with by an improper instrument introduced into the key hole. The
position of the key hole relatively with the said holes i, i is illustrated in Figure 5.
although, as a matter of fact, the cover plate b in which the key hole is formed
is not represented in this figure.
m is the ston which is fixed to the back of the cover plate, as shewn in Figures 2,
3 and 8 and also in dotted lines in Figure 5, (although actually removed from this
latter figure) and o, o,are recesses formed in the key for allowing the latter to
pass the stop when the required conditions are complied with.
In drawing back the bolt of the lock herein before described by means of the
key the operation is as follows, that is to say, the key is inserted into the key
hole m the ends of the pins or projections j, j coming in contact with the surface
of the tumbler plate f. The key is now turned until its bit comes in contact
with the stop n the said pins or projections j. j.then being immediately in contact
with the pins i, i. When in this position the key is pushed inwards, the effect
of which is to press back the pins i, i out of engagement with the tumbler plate f
and to engage the pins j, j with the said tumbler plate and at the same time bring
the notches o, o in the bit into proper coincidence with the stop n to permit the
further turning of the key and the consequent movement of the bolt; the pins k, k
during this movement of the tumbler plate bearing against the flat rearside of the
latter. On the backward movement of the key to remove it from the lock the
spring blades 7,7 when the holes i, i are opposite to the pins k, k cause the said
pins to act against the pins on the key to disengage the latter from the
tumbler plate f and lock the said plate whilst a slight further turn of the key
enables the latter to be taken out of the lock. p is a stop for limiting the back-
ward movement of the tumbler plate.
As shewn in the drawing the stop n is in the form of three wards which are
adapted to coincide with the corresponding slots o, o, in the key, it is to be
understood, however, that any other desirable arrangement of wards may be made
use of.
It will be obvious that for a key to open my improved lock it will not only
be necessary that the pins j, j should coincide with the pins i, i but also necessary
that the notches o, o should coincide with the wards of the stop n.
As a further precaution against the use of an improper key I preferably place
behind or beneath the tumbler plate a bar q, Figures 6 and 7, which if the pins j, j
of the key used to open the lock have a greater length than the thickness of the
tumbler plate will come in contact with the said bar and so prevent the tumbler
plate from being turned.
It will be obvious that to pick my improved lock it will be necessary to depress
all the pins i, i simultaneously, and as normally the said pins are flush with the
surface of the tumbler plate it will be very difficult, if not impossible, to locate the
said pins so that my lock may be regarded as being practically unpickable.
r is the guard plate and is the partition which I use to prevent an instrument
introduced into the lock through the key hole from operating directly on the

page_text: bolt to move it back without operating the tumbler plate f; the said partition s
extends right across the casing, as shewn, and forms one of the guides in which
the bolt slides. The guard plater which extends from the top to the bottom of
the casing and from the outer edge of the lock to the partition s, as shewn in
Figures 2, and 5, has in it an opening t of segmental shape large enough to
permit of the movement of the key in the manner herein before described. In
order that the surface of this guard plate shall be flush with the surface of the
tumbler plate f the latter is rabbetted at u, as shewn clearly in Figures 3 and 6.
is the catch which is provided for holding back the bolt when desired; this
catch when not in use is above the level of the top of the bolt, as shewn in
Figure 4, and when in use is designed to engage with the flange w, Figure 2,
upon the rear end of the bolt which flange also serves for limiting the forward
movement of the bolt under the action of the spring e. x is a knob which can
be fixed to the bolt for enabling the latter to be operated from the inside of a
door.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. A lock wherein the movement of the key is transmitted to the bolt through
the medium of a tumbler plate with which the key engages and which has arranged
in conjunction with it means for preventing the movement of the same except
upon the insertion of the key, substantially as described.
2. In a lock the combination of a bolt, a tumbler plate engaging with the
said bolt, a key designed to engage with the said tumbler plate to move it and
locking pins designed to engage with the tumbler plate and to be moved out of
engagement therewith by means of the key, substantially as described.
3. In a lock the combination with the bolt and a tumbler plate designed to be
operated by a key for imparting movement to the said bolt, of a guard plate and
a partition within the lock case for preventing the fraudulent operation of the
bolt through the medium of an instrument inserted through the key hole of the
lock, substantially as described.
4. The manufacture and use of locks, substantially as hereinbefore described
and illustrated in the accompanying drawings.
Dated the 5th day of Ontahan 1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.