Improvements in Safes and Strong Rooms and in Locks for the same.
Year: 1888

page_text: Improvements in Safes and Strong Rooms and in Locks for
the same.
We, SAMUEL CHATWOOD of 76 Newgate Street in the City of London, Bankers
Engineer, SAMUEL RAWSTHRONE CHATWOOD of 76 Newgate Street in the City of
London, Manager, and ARTHUR BRUNEL CHATWOOD of Bolton in the County of
Lancaster, Manager, do hereby declare the nature of this invention to be as
follows:-
Wo construct safes of cylindrical form or of rectangular form with circular doors
and door frames and these we sometimes place inside safes of the ordinary rectangular
construction.*
The bodies of cylindrical safes we construct in various ways for example by casting
them of steel or compressed steel or by making a cylindrical cage formed of castings
of Spiegeleisen covered on the outer surface with conical projections and casting
upon the inside and outside of this cage a layer of mild steel or ingot iron. The
Spiegeleisen cage may be heated before the mild steel is cast upon it. The door
with its lockcase may be cast in a similar manner.
We sometimes construct them of wrought iron or steel in which case we shrink a
tube of the requisite diameter upon suitable front and back frames and upon a circular
plate forming the back of the safe.
Grooves may be provided on the inner side of this tube corresponding with
projections on the front and back frames and the back for the purpose of more
securely attaching it to them. The lockcase formed of iron or steel of suitable
section may be shrunk on to the door plates which may be of any ordinary
construction.
The bodies of rectangular safes with circular doors and door frames we construct
in any ordinary manner or by casting them by the method above described which is
also applicable to safes of the usual form.
The doors we secure preferably by providing on their edge and upon the lockcase
a screw thread and we provide on the inside of the doorframe (which in the case.

page_text: of cast bodies may be a solid part of the body) a corresponding screw thread. We
secure the door by screwing it into the body by means of these screw threads and
throw bolts and lock them to prevent the door from being unscrewed.
In order to prevent the necessity of turning the door round a number of times
we remove sections of the screw thread on the door and door frame so that
the door may be pushed in and only require to be turned a portion of a
revolution.
We hang the door in such a manner that it can revolve about its centre and we
provide hinges of a suitable form to allow the door to be drawn out straight. Wo
throw and secure the bolts preferably by the self blocking cam described in the
specification of a patent granted to two of us dated the 19th day of October 1875,
No. 3626.
This cam or whatever other device we employ we secure by suitable locks preferably
by a key-lock controlled by an improved form of the combination lock described in
the Specification of a patent granted to two of us dated the 6th day of December 1886,
No. 15962.
The lock described in the patent referred to has two sets of geared discs mounted
in packs on two spindles and so arranged that one of the spindles can be moved away
from the other and thus the wheels unmeshed for the purpose of setting a new
combination.
Our improvement consists in arranging the pack of discs which we call the dial
discs loose on a solid spindle and having fixed to the spindle another disc which has
a slot or gating in its outer edge. We attach to the bolt preferably at the front
end a lever working on a pivot and carrying at its further end a projecting piece of
suitable form to drop into the gating of the disc just described.
We attach to the case of the lock a lever pivotted at one end and carrying at
the other end a knife or stump calculated to enter gatings in the gated discs when
brought into the right position for unlocking.
These two levers we link together in such a manner that one cannot approach the
discs without the other. Thus the knife or stump is kept from contact with the gated
discs by the projecting piece on the lever first described resting against the periphery
of the disc fixed to the spindle.
Some-
Sometimes instead of screw threads we use grooves and projections parallel to the
face of the door instead of inclined and similarly remove sections of these.
times we make the ends of the bolts to correspond to the portions of the grooved
lock-case removed so that when they are shot out the door may be freely revolved
but cannot be drawn out.
Sometimes instead of forming these grooves and projections whether screw threads
or not upon the solid door and lock case we form them on a separate ring which can
be revolved by means of a handle or we use this moveable ring in lieu of the fixed
thread on the door frame.
Sometimes we place a safe so that the door is at the top and we cause the door and
a cage beneath it to be raised by means of balance weights, springs working through
fusees, fluid or air under pressure or by other suitable means.
In order to prevent safes and strong rooms from being perforated or parts softened
or destroyed by means of the oxyhydrogen blowpipe or other instruments for
producing intense heat we cover the outsides or parts of the outsides with plates
having between them and the inner plates a layer of fulminate of mercury dynamite
or other suitable explosive or vessels of liquid and other liquids or solids capable of
forming explosive compounds.
Sometimes we provide on the inner surface. of the outer plate, or upon the outer
surface of the inner plate or both suitable cavities for containing the explosive
material. The explosive material on being heated by the blow-pipe is caused to
explode with sufficient force to alarm the neighbourhood and the burglar is exposed
to great risk.
Any attempt to remove the explosive materials by cutting breaking or drilling the
outer plate causes the explosion in consequence of concussion or friction.

page_text: Sometimes we use an explosive which requires a very high temperature to explode
and we make the plates covering it drill proof.
This improvement can also be applied to existing safes.
To avoid the risk of an accidental explosion we sometimes cover the outside of
such plates with india rubber or other cushions. We sometimes arrange electrical
combinations in such a way that the application of heat will ring alarm bells suitably
placed or will give notice of the attack in any convenient manner.
These combinations may be formed for example by pieces of different metals in
contact or separated by a chemical substance such as nitre which on the application of
heat will set up an electrical current.
Sometimes in combination with one or other or both of the above improvements
or in lieu of them we arrange in the doors and sides of safes and strong rooms
suitable cavities which we fill with water or other suitable fluid for the purpose of
carrying away the heat by evaporation and we provide suitable safety valves or fusible
plugs to allow the vapour to escape.
Sometimes we line these cavities or chambers with copper or other metal of high
conductivity.
We secure together the parts of built up safes by welding by means of the
oxyhydrogen blowpipe or by electric current in lien of rivetting and screwing in the
ordinary manner.
The separate plates forming the sides of strong rooms and very large safes we
attach together in the following manner:
We provide at the junction a steel or iron bar of I (H) section. The grooves of
the Iwe sometimes make about equal to the total thickness of a mild steel plate and
a plate of compound steel which we propose to employ. The mild steel plate is placed
in the Inext to the inside and attached to it by screws or rivets or both. The
compound steel plate is placed in the I next to the outside and thus protects the
screws or rivets.
For strong rooms which are intended to be fireproof as well as thief proof we
use H section material of a width equal to the thickness of the fireproof chambers
which we require plus the thickness of the two plates.
We sometimes attach to the blade of the H channel or angle irons of such section
as will leave a groove at each side about equal to the width of the inside and outside
plates. When it is not desired to attach the plates to the girders the girders may be
attached to each other by tie rods imbedded in the refractory material with which we
fill the chambers between the plates.
Dated this 22nd day of March 1888

page_text: COMPLETE SPECIFICATION.
Improvements in Safes and Strong Rooms and in Locks for
the same.
We, SAMUEL CHATWOOD of 76 Newgate Street, in the City of London, Bankers
Engineer, SAMUEL RAWSTHRONE CHATWOOD, of 76 Newgate Street in the City of
London, Manager, and ARTHUR BRUNEL CHATWOOD of Bolton in the County of
Lancaster, Manager, 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:-
We construct safes of cylindrical form or of rectangular form with circular doors
and door frames and these we sometimes place inside safes of the ordinary rectangular
construction.
On sheets 1 and 2 of the drawings safes of this description are represented.
The bodies of cylindrical safes we construct in various ways for example by casting
them of steel or compressed steel or by making a cylindrical cage formed of castings
of Spiegeleisen covered on the outer surface with conical projections and casting upon
the inside and outside of this cage a layer of mild steel or ingot iron. The Spiegeleisen
cage may be heated before the mild steel is cast upon it. The door with its lockease
may be cast in a similar manner.
Figure 1 is a section of a safe the body of which is of steel cast upon a cage of
Spiegeleisen.
Figure 2 is a front elevation partly in section of the same.
In
a a is the cage, it is put together in parts and is roughened on the surface to prevent
drilling, bis the covering of mild steel cast upon the cage. The door c is similarly
made of steel cast upon bars of Spiegeleisen. This safe is rectangular in front and it
is adapted to fit into a rectangular outer casting or safe; the space between the two is
filled with fire resisting material. Figures 3, 4 and 5 show modifications.
Figure 3 the cage is made of Spiegeleisen bars a¹ a¹ arranged with intervals between
them and the steel runs into these spaces. In Figure 4 round rods a² a² of Spiegeleisen
are represented as forming the cage and in Figure 5 triangular bars a³ a³ are
indicated.
We sometimes construct these safes of wrought iron or steel in which case we shrink
a tube of the requisite diameter upon suitable front and back frames and upon a
circular plate forming the back of the safe.
Figure 6 shows a section of a safe the body d of which is a wrought tube; it is
shrunk upon a back plate d¹ and the door frame e; the front is strengthened by a
hoop shrunk upon the body.
Figure 7 shows a modification; here the body is shrunk upon front and back frames
and the latter is previously shrunk on to a back plate.
Figure 8 shows another modification in which a cast door frame is shrunk on to the
body.
Figure 9 shows another modification in which the back frame is a flanged plate
which is shrunk on to the body and a flanged ring is shrunk on in front over the joint

page_text: between the body and the door frame. In Figure 10 the body is shown to be shrunk
upon the door frame.
Figure 11 is a section and Figure 12 is a front view showing another modification
in which the door frame is cast on to the body. Where the body tube is shrunk on to
the front and back frames grooves may be provided on the inner side of this tube
corresponding with projections on the front and back frames and the back for the
purpose of more securely attaching it to them. Tho lockcase formed of iron or steel
of suitable section may be shrunk on to the door plates which may be of any ordinary
construction.
The bodies of rectangular safes with circular doors and door frames we construct in
any ordinary manner or by casting them by the method above described which is also
applicable to safes of the usual form.
The doors we secure preferably by providing on their edge and upon the lockcase a
screw thread and we provide on the inside of the door frame (which in the case of cast
bodies may be a solid part of the body) a corresponding screw thread. We secure the
door by screwing it into the body by means of these screw threads and throw bolts
and lock them to prevent the door from being unscrewed.
In order to prevent the necessity of turning the door round a number of times we
remove sections of the screw thread on the door and door frame so that the door may
be pushed in and only require to be turned a portion of a revolution.
We hang the door in such a manner that it can revolve about its centre and we
provide hinges of a suitable form to allow the door to be drawn out straight. We
throw and secure the bolts preferably by the self blocking cam described in the
Specification of a patent granted to two of us dated the 19th day of October 1875,
No. 3626.
This cam or whatever other device we employ we secure by suitable locks preferably
by a key-lock controlled by an improved form of the combination lock described in
the Specification of a patent granted to two of us dated the 6th day of December 1886,
No. 15,962.
Sometimes instead of screw threads we use grooves and projections parallel to the
face of the door instead of inclined and similarly remove sections of these. Sometimes
we make the ends of the bolts to correspond to the portions of the grooved lock-case
removed so that when they are shot out the door may be freely revolved but cannot be
drawn out.
The safes shown by the preceding figures on Sheet 1 are represented with circular
doors secured by divided threads-the arrangement is shown more in detail by figures
on Sheets 3 and 4. Figure 13 is a section and Figure 14 is a front view. Figure 15
is a section of the door only and the lock which it carries is shown in its place.
Figure 16 shows the parts of the lock. The thread g is by preference made parallel
both in the door frame and upon the door and it is, divided into sections as is shown
by the Figures 6, 11 and 12. The door is held in a ring in which it can be turned.
Steel balls are inserted between the ring and the neck or flange upon the door
which it embraces so that the door may be turned with facility. The ring is pivoted
to the frame i and this in turn is connected by a double hinge joint with the body of
the safe. The bolts are shot out radially from the door into recesses in the door
frame by the cam which is turned by means of a handle applied to a central spindle.
are blocks upon the cam which block the bolts when they are shot. m is the key
lock which secures the cain and m¹ is the key hole.
Sometimes we groove the ends of the bolts so that when shot they may engage with
the parallel threads in the door case.
Figure 16 shows a perspective view of a door in which the bolts are so arranged.
As will be seen when the bolts are shot the threads are continuous around the
door.
Sometimes instead of forming these grooves and projections whether screw threads
or not upon the solid door and lock case we form them on a separate ring which can
be revolved by means of a handle or we use this moveable ring in lieu of the fixed
thread on the door frame.

page_text: upon it engaging with a pinion n¹.
Figure 18 is a front view.
Figure 19 shows a modification; here the moveable ring is held in a recess in the
door frame.
Figure 20 shows a modification in which screw or parallel threads are not employed
but a locking ring with projections upon it engages with lugs upon the door.
Figure 21 is a front view.
Figure 22 shows a modification in which the moveable locking ring is carried upon
the door.
Figure 23 is a section, Figure 24 is an elevation and Figure 25 is a local section
showing another modification. The door carries studs oo which pass through holes
in the door frame and in a moveable ring p beneath. The ring is turned by means of
a follower upon the door and then engages with the heads of the studs.
Figure 26, Sheet 1, shews a modification in which the door closes with a bayonet
joint.
Sometimes we place a safe so that the door is at the top and we cause the door and
a cage beneath it to be raised by means of balance weights, springs working through
fusees, fluid or air under pressure or by other suitable means.
Figure 27 shews in section a safe of this sort in which the door and cage for con-
taining the valuables are counterbalanced by weights.
Figures 28 and 29 are sections taken at right angles the one to the other of a safe
in which the counterbalancing is effected by a spring. The spring is contained in a
fusee spring box upon which the chain suspending the moveable parts is wound.
Figure 30 shews a section through the lock of this safe.
In order to prevent safes and strong rooms from being perforated or parts softened
or destroyed by means of the oxyhydrogen blowpipe or other instruments for
producing intense heat we cover the outsides or parts of the outsides with plates
having between them and the inner plates a layer of fulminate of mercury dynamite
or other suitable explosive or vessels of liquid and other liquids or solids capable of
forming explosive compounds.
Sometimes we provide on the inner surface of the outer plate or upon the outer
surface of the inner plate or both suitable cavities for containing the explosive material.
The explosive material on being heated by the blow-pipe is caused to explode with
sufficient force to alarm the neighbourhood and the burglar is exposed to great risk.
Any attempt to remove the explosive materials by cutting breaking or drilling the
outer plate causes the explosion in consequence of concussion or friction.
Sometimes we use an explosive which requires a very high temperature to explode
and we make the plates covering it drill proof.
This improvement can also be applied to existing safes.
To avoid the risk of an accidental explosion we sometimes cover the outside of such
plates with india rubber or other cushions.
Figure 31 is a section of a portion of a safe which is protected by explosive as
above described s is the outer and t is the inner plate and between the two at u is a
material or compound which explodes when subjected to heat or to friction. v is a
jacket of india rubber effectually protecting the safe from concussions which otherwise
might cause accident.
Figure 32 shows a modification; here a liquid is enclosed in thin glass vessels
packed between the plates s and t amongst a material which explodes when the liquid
reaches it on one of these glass vessels being broken.
.
Figure 33 shews the application of an explosive plate to protect the lock of an
existing safe. The plate is in two parts or thicknesses with the explosive between as
already described.
Studs with heads are screwed into the safe door and these enter long key hole like
apertures in the inner plate. The inner plate also has a groove in it to receive a stud
upon the door and this stud is provided with a locking pawl w as is shown in

page_text: Figure 33. This pawl allows of the explosive plate being slidden along the face of
the door in the direction required to fasten the plate in position but if it be attempted
to remove the plate by a movement in the opposite direction the pawl digs down
amidst the explosive and causes it to detonate.
We sometimes arrange electrical combinations in such a way that the application of
heat will ring alarm bells suitably placed or will give notice of the attack in any
convenient manner.
These combinations may be formed for example by pieces of different metals in
contact or separated by a chemical substance such as nitre which on the application of
heat will set up an electrical current.
Sometimes in combination with one or other or both of the above improvements or
in lieu of them we arrange in the doors and sides of safes and strong rooms suitable
cavities which we fill with water or other suitable fluid for the purpose of carrying
away the heat by evaporation and we provide suitable safety valves or fusible plugs to
allow the vapour to escape.
Sometimes we line these cavities or chambers with copper or other metal of high
conductivity.
We secure together the parts of built up safes by welding by means of the
oxyhydrogen blow pipe or by electric current in lieu of rivetting and screwing in the
'ordinary manner.
The separate plates forming the sides of strong rooms and very large safes we attach
together in the following manner.
We provide at the junction a steel or iron bar of I (H) section. The grooves of
the Iwe sometimes make about equal to the total thickness of a mild steel plate and
a plate of compound steel which we propose to employ. The mild steel plate is placed
in the next to the inside and attached to it by screws or rivets or both. The
compound steel plate is placed in the I next to the outside and thus protects the
screws or rivets.
This method of construction is illustrated by Figure 34. A. is the junction bar.
B B are mild steel plates fixed to it by screws CC. from the inner side and DD are
compound undrillable steel plates forming the exterior of the safe.
:
Figure 35 shows the way in which the corner is formed.
Figure 36 shows a modification in which single plates are used.
Figures 37 and 38 show a like arrangement but with undrillable plates.
Figure 39 shows a modification in which the corner junction bar is built up in
parts. The intermediate connections may be made as is shown at Figure 40.
Figure 41 shows a built corner bar used without inner plating, the junction bars
being otherwise connected.
Figure 42 shews the intermediate junction.
Figure 43 shows another way in which the intermediate junction bar may be formed.
The plating here is in three thicknesses.
Figure 44 shows a corresponding corner.
Figures 45 and 46 show similar junction bars but built up in parts.
Figures 47 and 48 show a modification according to which the inner plating meets
at the junctions over the junction bars.
Figures 49 and 50 show a modification in which both the inner and the outer
plates meet at the junctions and the junction bars are enclosed between them.
For strong rooms which are intended to be fire proof as well as thief proof we
use H section material of a width equal to the thickness of the fireproof chambers
which we require plus the thickness of the two plates.
We sometimes attach to the blade of the H, channel, or angle irons of such section
as will leave a groove at each side about equal to the width of the inside and outside
plates. When it is not desired to attach the plates to the girders the girders may
be attached to each other by tie rods imbedded in the refractory material with which
we fill the chambers between the plates.
Figure 51 is a section of the wall of a strong room constructed in this manner,
E is the junction bar F, F channel irons bolted to it. H and I are the inner and

page_text: outer plates of undrillable metal held in grooves between the bars E and F. GG are
tye bars connecting the bars or girders E and K is fire proof material with which the
interval between the plates is filled.
Figures 52, 53, 54 and 55 show modifications.
The specification of the patent hereinbefore referred to No. 15962 in the year
1886 describes a lock which has two sets of geared discs mounted in packs on two
spindles and so arranged that one of the spindles can be moved away from the other
and thus the wheels unmeshed for the purpose of setting a new combination.
Our improvement consists in arranging the pack of discs which we call the dial
discs loose on a solid spindle and having fixed to the spindle another disc which
has a slot or gating in its outer edge. We attach to the bolt preferably at the
front end a lever working on a pivot and carrying at its further end a projecting
piece of suitable forin to drop into the gating of the disc just described.
We attach to the case of the lock a lever pivotted at one end and carrying at the
other end a knife or stump calculated to enter gatings in the gated discs when
brought into the right position for unlocking.
These two levers we link together in such a manner that one cannot approach
the discs without the other. Thus the knife or stump is kept from contact with the
gated discs by the projecting piece on the lever first described resting against the
periphery of the disc fixed to the spindle.
Figure 56 represents the lock with the cover removed. Figure 57 is an end
elevation and 58 is a transverse section. H is the spindle which is turned to and
fro as described in the former specification to arrange the gated discs. II are the
dial discs upon the spindle H. K is another disc fixed on the spindle it has in it
a recess or gating at K. L is the bolt. M is the lever jointed to the bolt; the
end M of this lever enters the gating K¹ to allow the bolt to be drawn back.
N are the gated discs in gear with the discs 1 when the door is locked. O is a
lever pivotted to the case at O' and at the other end carrying the stump 02. The
lever is also provided with a stud 03 which enters a slot M in the lever M. The
pin 03 sustains the lever M until the stump 02 can enter the gating of the discs N
but it then allows the end M¹ of the lever M to drop into the recess K. When the
lever M falls, it together with the bolt L can pass back without coming against an
abutment which prevents the bolt receding whilst the lever M is raised.
This improvement opposes great difficulty in the way of attempts to open tlic lock
by feeling for the gatings of the gated discs.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is :-
1. Cylindrical safes with circular doors substantially as described.
2. Safes with circular doors secured by means of divided screw or parallel threads
substantially as described.
3. Safes with circular doors substantially as described in respect to the Figures 17 to 26.
4. Safes with circular doors and cages counterbalanced and rising out of the safe
substantially as described.
5. The combination with safes substantially as described, of explosives so applied
that they become ignited when attempts are made to open the safe by heat or
cutting tools.
6. The construction of large safes or strong rooms substantially as described in
respect to Figures 35 to 55.
7. The improvement in locks applicable to safes and strong rooms substantially
as described in respect to the Figures 56 to 58.
n
32
1 1
T
1000
CARPMAEL & CO.,
Agents.