IMPROVEMENTS IN STEAM FIRE- PROOF SAFES
Year: 1868

page_text: LETTERS PATENT to William Snell, of 22, Parliament Street,
Westminster, for the Invention of "IMPROVEMENTS IN STEAM FIRE-
PROOF SAFES."-A communication from abroad by Ebenezer D. Draper,
Russell A. Balton, Edward W. Glover, Edwin Austen Eaton,
and William Carlton Ireland, forming an Association for the
Manufacture of Sanborn's Patent Steam Fire-proof Safes at Boston,
Massachusetts. United States of America..
COMPLETE SPECIFICATION filed by the said William Snell at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 29th January 1868, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
SNELL, of 22, Parliament Street, Westminster, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
STEAM FIRE-PROOF SAPES," and have petitioned Her Majesty to grant
unto me, my executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that the

page_text: same is communicated to me from abroad by Ebenezer D. Draper, Russell
A. Balton, Edward W. Glover, Edwin Austen Eaton, and William
Carlton Ireland, forming an Association for the Manufacture of
Sanborn's Patent Steam Fire-proof Safes at Boston, Massachusetts,
United States of America.
NOW KNOW YE, that I, the said William Snell, do hereby declare
that the following Complete Specification, under my hand and seal,
fully describes and ascertains the nature of the said Invention, and in
what manner the same is to be performed, in and by the following
statement-
The nature of the said Invention or improvements are described in
the following Specification with the accompanying Drawing, in which
Fig. 1 represents a perspective view of a safe having our improve-
ments, a portion of the outer wall being shewn in section; Fig. 2 is a
view in detail of the exterior of the door of the safe shewing the devices
for forcing it into close contact with the jambs; Fig. 3, a perspective
view on a larger scale of one of the water vessels shewing the return
tubes; Fig. 4, a sectional view in detail illustrating the mode of closing
the internal openings of the return tubes; Fig. 5, a similar perspective
view of the cap covering the external openings of the return tubes;
Fig. 6, a detail view in perspective of a portion of the safe door showing
the device for obstructing the passage of heat through the door.
Our improvements relate to the steam fire-proof safe heretofore
patented by William Snell, as a communication to him from abroad by
Rufus- Sanborn, No. 229, and dated January 29, 1867, in which water
vessels are introduced between the external walls and the internal
chamber for the purpose of supplying steam to that chamber when the
safe is exposed to a heat sufficient to raise the water in the vessels to
the boiling point, but some of our improvements are applicable to
safes of the ordinary character.
Our first improvement consists in embedding in the filling of a safe
a stratum of wood for the purpose of increasing the non-conducting power
of the safe walls. The arrangement is shown in Fig. 1, where the safe
wall A is shown in horizontal section; B, marking the ordinary filling
of the safe; and C, the stratum of wood embedded in the filling, and
forming, in fact, an additional wall to the safe. When the safe
whose walls are thus constructed are exposed to a high heat the wood

page_text: is at first only charred, and in that condition is still a good non-
conductor.
Our second improvement consists in rendering one or more of the
interior chambers of a safe steam-tight by the employment of steam
packing on the door jambs and around the edges of the door or doors,
the object being to protect from the action of steam such articles as
would be injuriously affected by it. In Fig. 1 F marks the packing
around the edges to the outer door E of the safe chamber and its jambs,
and fmarks the same packing around the door and jambs of the inner
compartment G.
Our third improvement consists in the device for forcing. the safe
door into close contact with the jambs so as to secure the efficient action
of the packing; this device, which is shewn in Fig. 2, consists in an
excentric rod I suspended to the door by a swinging collar J in which
the rod I is free to rotate. The ends of the rod I when the door is
closed are engaged by the hooks h, h, on the door frame. The rod I
being then rotated by pressing down the hand lever K a great pressure
is exerted on the door to force it towards its jambs by reason of the
eccentricity of the rod I in relation to its end pivots. The steam
packing is thus compressed and the door rendered steam tight.
Our fourth improvement, which is shown in Fig. 3, consists in an
arrangement of tubes t, t, in connection with the water vessel L of a
safe by which the vessel may be nearly filled with water and yet none
be allowed to escape in any position of the vessel or safe, while a ready
escape is provided for the steam in any position of the vessel or safe.
In Fig. 37 marks the top and the bottom of such a water vessel,
and t, t, the steam tubes. The tubes are inserted in the upper and
lower heads of the vessel and run diagonally from one corner of the
upper to the opposite corner of the lower head, as shown. We prefer
to make the tubes conical in form, the larger end being fixed to one of
the heads of the vessel and the smaller end being free and open, and
reaching nearly to the head at the other end of the vessel. The conical
form is given to secure stiffness and to give a larger surface for
attachment, but a cylindrical tube can be used if preferred, and the outer
ends of the tube may be closed by a spring valve, by a fusible plug, or
by a metallic cap soldered over the end with an alloy so compounded
as to melt at or about 212° Fahrenheit.

page_text: This last method of covering the orifice of the steam tube constitutes
our fifth improvement. We use a concavo-convex cap c of larger size
than the orifice to be covered in order to give a larger surface for the
steam to act upon in forcing off the cap c; Figs. 4 and 5 illustrate
this improvement.
Our sixth and last improvement is illustrated in Fig. 6. The object
is to prevent or obstruct the ingress of heat through the door and
jambs which we have observed to be the readiest avenue for the passage
of heat to the interior of the safe. For this purpose we insert in the
door and in its jambs a stratum of mica or other equivalent non-
conducting substance, and also a sheet of fusible metal. In this
Figure E and P indicate the outer and inner surfaces of the door,
and N the stratum of mica and fusible metal. These strata are
laid in contact with each other. The alloy should be so compounded
as to melt at or about 212° Fahrenheit. When the safe is exposed to
that degree of heat the metallic stratum melts and runs out below,
leaving a stratum of air, a still better obstruction to the passage of
heat. The mica may be used without the fusible metal, but we prefer
to use the latter as additional security and on account of making a
better finish with it. We use the same means of insulation in other
portions of the safe when preferred.
Having thus fully described our improvements, what we claim is as
follows:-
1st. Embedding in the filling of the safe walls a stratum of wood for
the purpose of increasing their non-conducting power.
2nd. The employment of steam packing on the door frame and door
of a safe or of any compartment of a safe, for the purpose of rendering
such door steam tight, as described.
3rd. The eccentric rod I, in combination with the hooks h, h, arranged
and operating as and for the purpose specified.
:
4th. The combination of the tubes t, t', constructed and arranged
as described, with the water vessel of a safe, in the manner and for
the purpose set forth.
5th. The concavo-convex cap c soldered over the orifice of the
steam escape tube of the water vessel of a safe by a metallic alloy so
compounded as to melt at about 212° Fahrenheit.

page_text: 6th. Inserting in the door jambs and walls of a safe a stratum of
mica with or without a stratum of fusible metal to obstruct the passage
of heat, as set forth.
In witness whereof, I, the said William Snell, have hereunto set
my hand and seal, this Twenty-ninth day of January, in the
year of our Lord One thousand eight hundred and sixty-eight.