IMPROVEMENTS IN LOCKS APPLICABLE ESPECIALLY TO SAFES AND STRONG ROOмs
Year: 1873

page_text: LETTERS PATENT to Samuel Chatwood, of the Lancashire Safe and
Lock Works, Bolton, in the County of Lancaster, for the Invention
Scaled the 20th February 1874, and dated the 31st October 1873.
PROVISIONAL SPECIFICATION left by the said Samuel Chatwood at
the Office of the Commissioners of Patents, with his Petition, on
the 31st October 1873.
I, SAMUEL CHATWOOD, of the Lancashire Safe and Lock Works,
Bolton, in the 'County of Lancaster, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN LOCKS APPLICABLE ESPECIALLY TO SAFES
AND STRONG ROOмs," to be as follows:-
This Invention has for its object improvements in locks applicable
especially to safes and strong rooms.
In order to obtain security in the use of locks it is necessary for
reasons which I need not here explain that the impediments, whatever
they may be to the withdrawal of the bolt or bolts, should be numerous

page_text: and distant the one from the other. To meet this requirement I adopt
the following construction :-To secure the door of a safe or strong
room I employ four or other number of bolts, which by turning a handle
arc by means of a cam or otherwise shot out radially from all the sides.
On the axis I mount a number of discs or instruments which perform
the functions of "levers." These discs or instruments are able to turn
on the axis, but a slight pressure on their peripheries prevents them
turning too freely.
The bolts carry stumps, as many as may be thought desirable, and the
discs or instruments are gated to receive the stumps when the bolts are
shot back. Before however this can be done the discs or instruments
must be suitably arranged, this is donc by inserting the key and turning
it partly round.
The keyhole may pass through the discs or instruments and the
key may act directly upon them or the discs or instruments may
be geared with levers upon which the key acts. I do not always fix the
stumps directly upon the bolts but upon safety levers which prevent
pressure applied in any way to the bolts to withdraw them from being
transmitted to the discs or instruments in such a way as to allow the
gatings to be felt. To prevent such pressure being applied by means of
the handle I form a square on the axis, and apply a strong forked bolt
which shoots over it; this bolt also carries a safety lever and stump, and
for this stump the discs or instruments are gated. The withdrawal of
this bolt is performed by the key after it has arranged the discs or
instruments for the stumps of the main bolts.
For safe and strong room doors nozzle locks are sometimes used, in the
nozzle are a number of sliding pins which have to be pressed in different
distances by means of a pin key in order to unfasten the lock, such locks
are now put on from the inside and the nozzle just fills a hole formed
for it in the door. This construction admits of the lock being forced off
by violence into the interior of the safe or strong room. To prevent this
I form the nozzle as a separate piece, I make it conical and insert it.
from the outside into a corresponding hole, securing it at the back by a
nut.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Chatwood in the Great Seal Patent Office
on the 30th April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL.
CHATWOOD, of the Lancashire Safe and Lock Works, Bolton, in the
County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of October, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Samuel Chatwood, Her special license.
that I, the said Samuel Chatwood, my executors, administrators, and
assigns, or such others as I, the said Samuel Chatwood, my executors,
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
LOCKS APPLICABLE ESPECIALLY TO SAFES AND STRONG ROOMS," upon the con-
dition (amongst others) that I, the said Samuel Chatwood, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and scals, 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 Samuel Chatwood, 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 :-
This Invention has for its object improvements in locks applicable.
especially to safes and strong rooms.
In order to obtain security in the use of locks it is necessary for
reasons which I need not here explain that the impediments, whatever
they may be, to the withdrawal of the bolt or bolts should be numerous

page_text: and distant the one from the other. To meet this requirement I adopt
the following construction :-To secure the doors of a safe or strong.
room I employ four or other number of bolts, which by turning a
handle are by means of a cam or otherwise shot out radially from all
the sides. On the axis I mount a number of discs or instruments,
which perform the functions of "levers." These discs or instruments
are able to turn on the axis, but a slight pressure on their peripheries
prevents them turning too freely.
The bolts carry stumps, as many as may be thought desirable, and
the discs or instruments are gated to receive the stumps when the bolts
are shot back. Before however this can be done the discs or instru-
ments must be suitably arranged. This is done by inserting the key and
turning it partly round.
The keyhole may pass through the discs or instruments, and the key
may act directly upon them, or the discs or instruments may be geared
with levers upon which the key acts. I do not always fix the stumps
directly upon the bolts, but upon safety levers, which prevent pressure
applied in any way to the bolts to withdraw them from being trans-
mitted to the discs or instruments in such a way as to allow the gatings
to be felt. To prevent such pressure being applied by means of the
handle I form a square on the axis and apply a strong forked bolt,
which shoots over it. This bolt also carries a safety lever and stump,
and for this stump the discs or instruments are gated. The withdrawal
of this bolt is performed by the key after it has arranged the discs or
instruments for the stumps of the main bolts.
.
For safe and strong room doors nozzle locks are sometimes used;
in the nozzle are a number of sliding pins, which have to be pressed
in different distances by means of a pin key in order to unfasten the
lock; such locks are now put on from the inside, and the nozzle just
fills a hole formed for it in the door. This construction admits of the
lock being forced off by violence into the interior of the safe or strong
room. To prevent this I form the nozzle as a separate piece, I make it
conical and insert it from the outside into a corresponding hole, securing
it at the back by a nut.
In order that my said Invention may be most fully understood, and
readily carried into effect, I will proceed to describe the Drawings

page_text: Figure 1 is a transverse section of a safe or strong room lock
constructed according to my Invention; Figure 2 is an elevation of
the same, with some of the parts removed.
a, a, is the lock case, it is fixed to the door by the lugs a¹, a¹; bis
a snail cam, it has a central boss 6¹ which enters a corresponding hole
in the back of the lock case; c is a spindle, it passes through a square
hole in the boss of the cam and receives a nut c¹ beyond; the spindle
is also squared at c² in order that a forked bolt d may be shot over it;...
is the handle by which the spindle and cam may be turned; c¹ is
the portion of the spindle which passes through the massive door of
the safe or strong room, the spindle is made conical at this part in order
that it may not be driven inwards by force.
The door represented in the Drawing has an inner plate of wrought
iron and an outer plate, between which cast iron is inserted; e, e, e, e,
are four radial bolts, also shewn separately in front view and section
at Figures 3 and 4. On the under side of cach bolt are two
projections e¹, e¹, fitting between the convolutions of the thread of the
snail cam b, so that when the cam is turned the bolts are moved in or
out simultaneously..
Each bolt e carries upon a
firmly riveted into the safety-
safety levers e³ in position;
the "tumblers"
or "levers
The bolts are shewn in Figures 1 and 2 in the positions they occupy
when they, or rather when lengthening pieces attached to their ends,
which lengthening pieces are not shewn, are shot home into the bolt
holes in the frame. The bolts e are kept in their places by means of the
3 grooved cover plate f, which is fixed by screws to the back of the lock
case, this plate is also shewn at Figure 5.
pin e, a safety lever e³, and a stump e' is
lever; e, e are springs, which hold the
g; g, are a number of discs which serve as
of the lock; one of them is shewn separately at Figure 6. The discs g
are mounted so as to be able to turn on the spindle c which by means of
the cam 6 gives motion to the main bolts e, and light springs, not shewn
in the Drawings, press upon their peripheries to prevent them moving
too freely. When the bolts are shot the stumps e* stand beyond the
peripheries of the discs and the return of the bolts is thus prevented
b
"

page_text: until the discs have been arranged by the action of the key, so that
notches g¹ in the discs are all brought opposite to the stumps e¹ and then
by turning the handle c³ the bolts may be drawn back; is the pin to
receive the key, it is fixed in the cover plate f. The key passes througli
the thickness of the door and also through all the discs. 9. holes being
formed in the discs. for the purpose, as is shewn at 92, in Figure 6, and
the bits of the key act on the sides of these holes, and so as the key is
turned each disc is moved round a distance more or less according to the
length of the bit of the key which acts upon it, and the corresponding
form which is given to the hole in the disc. This action of the key
brings the notches in all the discs to range with each other and with the
stumps.
9
=
66
"
The bolt d, by which the spindle c is prevented turning until the
discs have first been ranged by the key, is shown in Figure 5, and also
in Figure 1. It works in a groove in the cover plate f on the side of
the plate opposite to the grooves in which the bolts e, e, work. The last
bit of the key enters a recess d¹ in this bolt, which is of such a form
that when the discs g have been ranged the key proceeds to act on the
bolt d to withdraw its forked end from the spindle. d² is a safety lever
on the bolt & turning on a pin d* fixed in the bolt and carrying a
stump d. All the discs g are perforated and gated to receive this stump,
as is shewn at g³ in Figure 6, the position of the gating being of course
different in the different discs. f* is the fixed stop for the safety lever d²
to act against; it is fixed in the cover plate f. The safety lever is a
well-known device to prevent the positions of the notches or gatings
in the levers or equivalent instruments being ascertained by pressing
back the bolt so as to cause the stump to bear against them, and then
moving the "levers" in succession until the stump drops into all tho
notches. If this be attempted where safety levers are used, as in the
present lock, the lever tips on its centre and its end comes against a
fixed stop, which takes the pressure in place of the "levers." f**,f**, arc
the fixed stops for the levers e³; they are riveted into the cover plate f.
I do not however always use the safety levers e³ at any rate upon all the
bolts, as in some cases safety levers are liable to be deficient in strength.
In this construction I am able to obtain very great strength by providing
that the head of the bolt itself shall serve the purpose of a stump, and
when the bolt is withdrawn shall recede into notches of the full width
of the bolt in the edges of the discs g.

page_text: Figures 7 shew in front view and section a bolt of this construction,
and Figure 7* a portion of a disc g with notches to suit the bolt shewn
at Figure 7.
Figure 8 is an elevation partly in section, and Figure 9 is a transverse
section of a lock of simpler construction, in which the spindle c is
capable of being secured by a bolt d, as in the lock already described,
and this bolt is controlled by "levers" turning concentrically with the
spindle, and corresponding with the discs g of the first arrangement.
The main bolts in this case however are connected with arms b, b, which
take the place of the cam, and they are not controlled by instruments in
the nature of levers, so that the lock depends for its security wholly upon
the bolt & which secures the spindle.
Figure 10 is a longitudinal section of a part of a nozzle lock with its
key; Figure 11 is a section of a part of the nozzle and of the door with
all the moving parts of the lock removed. a, a, is the conical nozzle
which is inserted from the outside of the door, and is secured by a nut b,
which in turn is made fast by a screw; c, c, are a number of rods
pressed forward in the guide tubes, which contain them by the coiled
springs d, d.. The key e has pegs upon it of different lengths, and when
pressed into the keyhole it pushes back the rods c until the notches c¹, c¹,
in their sides range the one with the other, and when this is the case the
bolt can be withdrawn. The exact arrangement of this part of the
mechanism it is unnecessary to describe, as it is well known, and forms
no part of my Invention.
Having thus described the nature of my said Invention, I would have
it understood that I do not confine myself to the exact details described,
but what I claim is, the construction of locks with radial bolts operated
by a cam (or its equivalent), and controlled by discs or instruments
which perform the functions of "levers," and having a motion concentric
with that of the cam, substantially as described.
I also claim the construction of locks in which the main bolts aro
actuated by turning a spindle by means of a handle, and in which such
spindle is capable of being secured by a locking bolt controlled by
instruments moving concentrically with the spindle and performing the
functions of "levers," substantially as described.
I also claim the combination of radial bolts with discs or instruments
which perform the functions of "levers," such discs or instruments

page_text: having notches in them which receive the back part of the head of the
bolts, substantially as described in respect to Figures 7 and 7*.
I also claim the method of constructing nozzle locks so as to render it
impossible to force the nozzle inwards, substantially as described.
In witness whereof, I, the said Samuel Chatwood, have hereunto set 5
my hand and seal, this Thirtieth day of April, in the year of our
Lord One thousand eight hundred and seventy-four.