IMPROVEMENTS IN THE CONSTRUCTION OF STRONG ROOMS AND SAFES
Year: 1884

page_text: I SAMUEL CHATWOOD of the Lancashire Safe and Lock Works Bolton in the
County of Lancaster Banker's Engineer do hereby declare the nature of my
Invention for IMPROVEMENTS IN THE CONSTRUCTION OF STRONG ROOMS AND
SAFES to be as follows:-
"
[E
This Invention has for its object improvements in the construction of strong
rooms and safes.
I form the walls of strong rooms and safes of plates with inwardly directed
flanges at their edges; these plates are arranged side by side and connected together
by bolts or rivets passing through the flanges.
To avoid a straight joint, into which a wedge might be driven with the object of
rending the plates asunder, I form these flanges at a short distance back from the
extreme edge of the plates, so that when the edges of the plates are butted together
a space is left between the flanges in the rear, and into this space I introduce a
filling piece. The bolts or rivets pass through the filling piece as well as through
the two flanges.
The filling piece may be of T form in section with the cross head directed
inwards. Cells are thus formed between the inner surface of the plate and T heads
I introduce into these cells compound steel plates, part of metal so hard that it
cannot be drilled and part of softer material, which will prevent the hard metal
from being broken in pieces by violence.
Usually the hard steel is enclosed between two surfaces of soft metal. Case
hardened plate may be similarly employed.
Sometimes I cause the filling pieces to pass through to the face of the plates
and there also to terminate in a T head. The plates are then confined between the
heads of these double T pieces. The flanges upon the plates in this case are
hardly necessary, as the plates are then securely held by the double T pieces.
The stem of the T piece may be of a tapering or dovetail forin to aid in retaining the
plates in place the edges of the plates fitting to the dove tail. The inner T heads
may in this case be dispensed with.
I prefer to recess the surface of the outer plates to receive the T head so that it
may be impossible to insert a wedge between the head and the plate.
In some cases I provide for the insertion of refractory material in the sides or
walls of the strong room or safe; this is simply done by giving an additional depth
sufficient for the purpose to the double T pieces.

page_text: The corner of the strong room or safe I construct, with an angle iron which
receives upon it the outer plates of the safe; these are fixed by screws or rivets.
The outer plates do not form the corner but this is formed by an enlargement on
the angle iron which covers the ends of the plates in such a manner as to prevent
the insertion of wedges, The enlargement where the plates abut against it is
formed with inclined or undercut surfaces and the edges of the plates are similarly
fashioned.
Within the corner of the strong room or safe I fix another angle piece made of
compound steel or case hardened metal and I attach it by screws to the main
corner piece. These screws do not pass to the exterior so that their ends are not
accessible. This angle piece covers the fastenings by which the outer plates are
attached to the corner iron and thus renders it impossible for these screws or rivets
to be driven inwards into the safe. The inner angle piece also serves to secure
compound or burgular proof plates against the plates which form the exterior of the
strong room or safe.
The door plate is rivetted to a frame formed of metal of L section which forms
the lock case.
The limb of the L iron or steel against which the door plate lies, is provided at
its end with a lip or thickening which when the door is closed is received into a
corresponding groove or recess in the door frame of the safe.
Another like enlargement upon the other side of the limb serves to cover the
outer edge of the door plate and to render it more secure than it otherwise
would be.
The bolts and locking parts of the safe I do not as heretofore mount upon the
door plate, but upon an inner plate securely fixed within the lock case. Between
the plate carrying the lock and the door plate I insert a slab of compound burgular
proof metal, which renders the parts of the lock altogether inaccessible, whereas
heretofore it has been possible to drill through the soft outer door plate down on
to the lock attachments assuming the position of these to be known.
I give motion to the bolts by means of a small cam in the manner now usual,
but I also provide upon the cam blocking pieces, which, when the bolts are shot
home pass in behind their ends and support them. Pressure applied to the bolts
to force them in is then resisted by the blocking pieces on the cam and not simply
as at present by the pin on the bolt which works in the groove on the small cam.
• Dated this 11th day of Santambon 1001

page_text: COMPLETE SPECIFICATION.
I, SAMUEL CHATWOOD of the Lancashire Safe and Lock Works, Bolton in
the County of Lancaster, Bankers Engineer do hereby declare the nature of my
invention for "IMPROVEMENTS IN THE CONSTRUCTION OF STRONG ROOMS AND
SAFES" and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
This invention has for its object improvements in the construction of strong
rooms and safes.
I form the walls of strong rooms and safes of plates with inwardly directed
flanges at their edges; these plates are arranged side by side and connected
together by bolts or rivets passing through the flanges.
To avoid a straight joint into which a wedge might be driven with the object of
rending the plates asunder I form these flanges at a short distance back from the
extreme edge of the plates so that when the edges of the plates are butted together
a space is left between the flanges in the rear and into this space I introduce a
filling piece. The bolts or rivets pass through the filling piece as well as through
the two flanges.
The filling piece may be of T form in section with the cross head directed
inwards. Cells are thus formed between the inner surface of the plate and
Theads; I introduce into these cells compound steel plates, part of metal so hard
that it cannot be drilled and part of softer material which will prevent the hard
metal from being broken in pieces by violence.
Usually the hard steel is enclosed between two surfaces of soft metal. Case
hardened plate may be similarly employed.
Figure 1 is a sectional view illustrating this arrangement. a. a are the plates
forming the walls of a strong room or safe a¹ a' are the inwardly directed flanges
of the plates which are not at the extreme edge of the plate or the flanges are so
arranged that a space is left to receive a filling piece. b b. are the filling pieces,
preferably they have T heads b'. b¹. c. c are burglar proof plates introduced into
the cells between the inner surfaces of the plates a and the T heads b¹. The
plates c may be of a size to completely fill the cells but usually as the drawing
represents a space is left between the plates which I fill with fire-resisting
material.
Sometimes I cause the filling pieces to pass through to the face of the plates and
there also to terminate in a T head. The plates are then confined between the
heads of these double T pieces. The flanges upon the plates in this case are hardly
necessary, as the plates are then securely held by the double T pieces.
Figure 2 is a sectional view illustrating this arrangement.
plates b the filling pieces having heads 61 and 62 both at back and front and c
are the inner plates. The filling pieces in this arrangement become angle iron
frames.
a. a are the front
If the flanges on the plates a be retained as the drawing indicates the screws or
rivets which hold the structure together are quite inaccessible.

page_text: The stem of the T piece may be of a tapering or dovetail form to aid in retaining
the plates in place the edges of the plates fitting to the dovetail. The inner T heads
may in this case be dispensed with.
I prefer to recess the surface of the outer plates to receive the T head so that it
may be impossible to insert a wedge between the head and the plate.
Figure 3 is a sectional view illustrating this arrangement.
a. a. are the front plates 6 the dovetail filling pieces with T heads between them
and c. c. are the back burglar resisting plates which the inclined filling pieces serve
to keep in position. In this case as will be seen the plates a. a. are recessed on
the face to receive the flanges b' so that a wedge cannot be inserted beneath the
flange.
In some cases I provide for the insertion of refractory material in the sides or
walls of the strong room or safe; this is simply done by giving an additional depth
sufficient for the purpose to the double T pieces.
The corner of the strong room or safe I construct with an angle iron which
receives upon it the outer plates of the safe; theso are fixed by screws or rivets.
The outer plates do not form the corner but this is formed by an enlargement on
the angle iron which covers the ends of the plates in such a manner as to prevent
the insertion of wedges. The enlargement, where the plates abut against it, is
formed with inclined or undercut surfaces and the edges of the plates are similarly
fashioned.
Within the corner of the strong room or safe I fix another angle piece made of
compound steel or casehardened metal and I attach it by screws to the main
corner piece. These screws do not pass to the exterior so that their ends are not
accessible. This inner angle piece covers the fastenings by which the outer plates
are attached to the corner iron and thus renders it impossible for these screws or
rivets to be driven inwards into the safe. The inner angle piece also serves to
secure compound or burglar proof plates against the plates which form the exterior
of the strong room or safe.
Figure 4 is a sectional perspective view illustrating this arrangement.
d is the exterior corner iron and d¹ is the enlargement thereon which provides a
flush surface although the outer plates e. e do not extend to the angle. The
surfaces where the edges of the plates e. e. meet the enlargement d' are inclined in
order that the plates may be more securely held. f. f. are screws or fastenings
securing the plates to the angle iron d.-g. g. is the interior corner iron it is
attached by the screws or fastenings h. h. to the outer corner iron d and it covers
the ends of the fastenings f so that they cannot be driven inwards. The outer ends
of the fastenings are covered by the plates c. i. i. are burglar proof plates
confined between the plates e and the inner corner iron g.
Another part of my invention relates to the door and door frame of strong rooms
and safes.
The door plate is rivetted or suitably secured to a frame formed of metal of
L section which forms the lock case.
The limb of the L iron or steel against which the door plate lies is provided at
its end with a lip or thickening which when the door is closed is received into a
corresponding groove or recess in the door frame of the safe.
Another like enlargement upon the other side of the limb serves to cover the
outer edge of the door plate and to render it more secure than it otherwise
would be.
The bolts and locking parts of the safe I do not as heretofore mount upon the
door plate but upon an inner plate securely fixed within the lock case. Between
the plate carrying the lock and the door plate I insert a slab of compound burglar:
proof metal which renders the parts of the lock altogether inaccessible, whereas
heretofore it has been possible to drill through the soft outer door plate down ou-to
the lock attachments assuming the position of these to be known.

page_text: Figure 5 is a sectional perspective view of part of the door and door frame of a
strong room or safe. is the door plate and is a frame approximately of ↳ form
in section to which the door plate is fixed by screws or rivets.
is a lip on the frame which is received into a corresponding groove or
recess m in the door frame m. This lip and groove serve to prevent the door and
door frame from being wedged apart-it also adds greatly to the strength of the
parts to resist accidental violence such as a fall from an elevated story.
n is an angle iron fixed to the frame it carries the inner plate o on which
I mount the parts of the lock in place of upon the door plate k as at present.
I protect the lock by means of a burglar proof plate placed immediately within the
plate k. p indicates a hole in the wall of the lock chamber through the frame
for a bolt to pass.
Sometimes as is represented in Figure 6 I insert a filling piece q between the
door plate k and the frame l. in this figure is the plate for protecting the lock.
In some cases I provide for the plate being slidden into its place endwise the
parts being formed as indicated in Figure 7. Or again I sometimes insert a filling
piece between the plate and the lip 2 as is indicated in Figure 8.
In order more effectually to resist attempts to force back the bolts of the lock
I give motion to the bolts by means of a small cam in the manner now usual but
I also provide upon the cam blocking pieces which when the bolts are shot home
pass in behind their ends and support them. Pressure applied to the bolts to force
them in is then resisted by the blocking pieces on the cam and not simply as at
present by the pin on the bolt which works in the groove of the snail cam.
arrangement is illustrated by Figure 9.
This
is the snail cam, it is arranged as usual to be turned by an external handle,
the grooves in it receive pins upon the bolts 8. The usual grooves r¹, rl, of the
cam have concentric prolongations ²² which admit of the cam continuing to
turn after the bolts are fully shot and this further movement brings up blocks 3
into the interval between the ends of the bolts 8. s. Any pressure applied to force
back either of the bolts is resisted by these blocks and the bolts cannot be with-
drawn until the blocks have first been removed out of the way. t is a lock
shooting a small bolt into a recess in the cam and so securing it.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. Forming the walls of strong rooms and safes of plates with inwardly directed
flanges and with filling pieces between the flanges substantially as described in
respect to Figure 1.
2. Forming the walls of strong rooms and safes of plates with inwardly directed
flanges and other filling pieces between the flanges having heads serving to retain
in place other inner plates substantially as described in respect to Figure 1.
3. Forming the walls of strong rooms and safes with front and back plates
confined between flanges on double flanged following pieces or frames substantially
as described in respect to Figure 2.
4. Forming the walls of strong rooms and safes with front and back plates held
together by dovetail filling pieces having flanged heads substantially as described
in respect to Figure 3.
5. Forming the walls of strong rooms and safes with recessed plates and filling
pieces with flanges received into the recesses in the plates substantially as described
in respect to Figure 3.
6. Forming the corner of a strong room or safe with outer and inner corner
irons substantially as described in respect to Figure 4.
7. Forming the door of a strong room or safe with an L frame with enlarge-
ments upon it substantially as described in respect to Figures 5. 6. 7 and 8.
8. Mounting the lock of a strong room or safe upon an inner plate and protecting
the lock so mounted as herein described in respect to Figures 5 and 6.

page_text: 9. In the locks of strong rooms and safes the concentric prolongations of the
slots in the cam and the blocking pieces on the cam supporting the bolts substan-
tially as described in respect to Figure 9.
2