Safety Casing for Gasoline Stoves.
Year: 1896

page_text: Date of Application, 8th Sept., 1896-Accepted, 17th Oct., 1.96
COMPLETE SPECIFICATION.
Safety Casing for Gasoline Stoves.
I, JOHN ANTON RUTH, of 622 Frederick Avenue, in the City of Baltimore,
and State of Maryland, and United States of America, Manufacturer, 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 :-
This invention relates to a safety casing for gasoline stoves and has for its object
to provide a casing having doors, which shall contain an oil stove while in use and
with a movable diaphragm within the casing, and suitable mechanism which may
be operated by the movable diaphragm, whereby, in the event the stove should
explode, the expansion within the casing of gases resulting from such explosion will
shift the movable diaphragm and thereby cause the doors to be automatically
closed, and by such closing to practically seal the casing and in this way smother
any fire that may result from the explosion and also prevent the said fire from
spreading.
In order to make the invention more clearly understood I have shown in the
accompanying drawing certain means for carrying the same into practical effect,
without, however, intending to limit my invention to the particular construction
which, for the sake of illustration, I have shown.
Figure 1. is a front view of the stove and the case, the latter with doors in open
condition.
Figure 2 is a view of one end of the case showing the mechanism for operating
the doors, part of the upper door being broken off.
Figures 3 and 4 are views in detail of the spring catch and rod which is moved
automatically.
'
Figures 5 and 6 are views of the movable diaphragm employed to effect the
automatic closing of the doors.
Figure 7 is a central vertical section of the case.
Figure 8 shows a modification in construction of the upper door; here the door
is in two sections joined together and shown folded.
Figure 9 is a view of the end of the case showing the automatic mechanism for
controlling the supply of oil.
Figures 10, 11 and 12 are views showing the construction of the mechanism
which connects between one of the doors and the valve which controls the supply
of oil.
Referring to the drawing, the letter, A, designates a gasoline stove of ordinary
construction having one or more burners, a, and supported on legs, b; a gasoline
stove with an elevated tank, G, is here shown for the purpose of illustrating the
invention, although the invention is applicable to other oil stoves. The casing, D,
in the present instance is shown as rectangular, and must be made of material
which is fireproof, such as sheet-metal which I deem preferable. The bottom, d,
of this case, below the stove is water-tight or oil-tight and the legs, b, of the stove
rest on said bottom. The case is supported on a frame or legs, b, and the front
part, b, of this frame projects far enough forward to serve as a rest for the lower
door, J, when the latter is open. The stove, including the burners, a, aud
horizontal part of the supply pipe, e, and cocks are wholly enclosed by the casing;
the gasoline storage tank, G, which is on the exterior has a pipe, f, connected with

page_text: the horizontal pipe, e. Shelves, h, are in the upper part of the casing and serve to
hold dishes or cooking utensils containing food to be kept warm.
The case, D, is open at the front so as to afford access to the shelves and to the
stove for cooking, and doors are provided to close the opening; in the present
instance two doors, J, J', are employed which are hinged horizontally at the top
and bottom of the case. The larger door, J, is the upper one and is mounted on a
shaft, K, at the top and is adapted to tilt down when closing, while the lower
door, J', is on a shaft, k', and tilts up when closing.
In order to close the doors and top opening, i, and in effect, hermetically seal the
casing, should the gas or oil stove explode, I have provided means to automatically
,close the two doors, J, J, and vent slide, . In addition to this I have hand-
operated mechanism to hold the doors open and to enable them to be closed when
using the apparatus in the ordinary way, when no explosion is involved. This
mechanism is on one end of the casing and connects the two doors, J, J', and vent
slide, so that said three parts may be opened and closed simultaneously. A
lever, M, has one end rigidly fixed to the upper shaft, K, on which the doors, J, is
mounted; a bell-crank lever, N, has one arm connected with the shaft, K, on
which the lower door, J', is mounted through the medium of a link, o, and short
arm, o, rigid on said lower shaft, 'K', the other arm of the bell-crank lever is
jointed to one end of a connecting rod, P, whose upper end is jointed to the
.lever, M. On top of the case is a pivoted lever, q, connected at one end with a
slide, and at the opposite end with a link, q, and said link is jointed to an
angle-arm, n, on the hand-lever, M. This hand-lever has at its lower end a handle
by which the lever may be moved by hand, if desired. A spring catch, R, is
employed, one end engages the hand-lever, M, and holds the doors in the open
position; the other end engages said lever and holds the doors closed.
The pipe of the gasoline tank has a valve, f, to cut off or let on the supply of
fluid; this valve is operated by hand. But should a fire or explosion occur it is
desirable to have a valve which will close and cut off the supply of oil automatically
by the closing of the doors. I bave, therefore, provided the supply. pipe with a
valve, f, which has a head-piece, x, attached to its stem; this head piece has
cog-teeth, by turning this head piece one way the valve opens and by turning
it the opposite way the valve closes. A rack-bar, y, has teeth formed by a series
of slots, y', which engage with the cog-teeth, a¹, on the valve; this rack bar slides
in bearings or guides, y², on the end of the case. This rack bar, y, is so connected
with the shaft, K', of the lower door that on turning the door up to close it, the
rack-bar will slide and close the valve, f. To this end a short arm, s, is fixed
rigidly on the door shaft, K', and a rod, 21, connects between said short arm and
the rack-bar, y. The operation will now be readily understood.
Special provision is made for adjusting the connection between the rod, ¹, and
the rack-bar, so as to ensure that when the lower door is in its closed position the
rack-bar shall have slid far enough to tightly close the valve, f2. This provision
.consists, see Figures 10, 11 and 12, of a slot, y³, in the end of the rack-bar and a
set-screw pivot, y, secured in said slot; this set-screw pivot may be adjusted
.anywhere in the slot.
The means which I have invented for effecting the automatic closing of the
doors, should an explosion occur, will now be described. It will be obvious that
doors having any well-known means for effecting self-closure may be employed.
As already stated I have selected horizontally hinged doors and arranged them so
that they will close by their own gravity. The front of the case is slightly
inclined, as shown at the left upright line, Figure 7, that is, the case is broader at
the bottom than the top, in order that when the doors are closed against the incline
they will not be in a perfectly vertical line, but will lie, as it were, against the said
incline.
A movable diaphragm, B, is hung on pivots; this diaphragm is a sheet
metal plate placed, across one side of the cooking chamber in the case in such
position as to be moved by the sudden expansion of air or gases which will occur

page_text: in the cooking chamber when an explosion takes place; when the diaphragm is
thus moved, the doors will close and practically seal the case and thus smother any
fire that may result from said explosion.
In the present instance the diaphragm, B, extends horizontally across the cooking
chamber in the case above the burners, a, or stove; as here shown it comprises two
sections or plates which are jointed together at, C, in the middle of the case. The
sections may have perforations, e', to..allow hot air to ascend.;..each section has
pivot, E, by which it is suspended or balanced on ears, 9, attached to the lower
shelf, h, and by this construction of joint the two sections sag or tilt down at the
center, as shown in Figures 1 and 5. The two pivoted sections of the diaphragm
are nearly counterpoised or balanced on their pivots by means of weights, m, so
that by a slight puff of air on the lower surface will lift the sag part at the center.
This lifting or up-movement of the diaphragın, in this instance, has the effect to
cause the doors to close, by releasing the catch, R. A vertical rod, F, is movable
up and down in a guide, F; the end of this rod is jointed at, F, to one end of the
movable diaphragm. The rod has a hole, I, and the spring catch, R, has an
attached pin, I, which passes freely through a hole in the wall of the case, D, and
normally the end of the pin inside of the case will impinge or press against the side
of the said rod, F, as shown in Figure 3, or said pin will enter the hole, I, in the
rod when the diaphragm is raised at its center. It will be seen that when the
self-closing doors are open one end of the catch, R, engages the hand-lever, M,
and thereby holds said doors open, and the impinging pin, I', keeps the spring
catch pressed outward away from the wall of the case; at the same time the center
sag of the diaphragm, B, keeps the vertical rod, F, lifted and its hole, I, is thereby
above the end of the pin, 1', see Figure 3. Now if an explosion should occur, the
expansion of air in the cooking chamber will raise the center sagged part of the
diaphragm and lower the rod, F, until the hole, I, therein comes coincident with
the pin, 1', whereupon the end of the pin will enter said hole and the spring
catch, R, will thus be relieved of its pressure and will disengage itself from the
hand-lever, M, and then both doors will automatically close, the heavier weight
of the upper door, J, in lowering will cause the lighter weight lower door, J, to
tilt upward. The doors without reference to other parts are self-closing.
The front edge of the lower shelf to which the diaphragm is hung, see Figure 7,
has a down-flange, , to hide the diaphragm from view.
It is obvious the position and location of the movable diaphragm may be varied
from that shown.
From the foregoing description the operation of the parts will be understood.
The upper door may be made in two sections jointed together, as in Figure 8,
and if so made a suitable spring catch may be employed to temporarily retain the
free section in the folded position when the door is down.
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. In a safety case for enclosing oil stoves, the combination of a case having
self-closing doors; a catch to hold the doors open; a movable diaphragm in the
case and adapted to be moved by the expansion which ensues when an explosion
occurs; and connections between the movable diaphragm and said catch, whereby
when an explosion occurs the catch will be released from the doors and the latter
will be closed automatically.
2. In a safety case for enclosing oil stoves, the combination of a case having
doors provided with means for closing them; means for holding the doors open; a
diaphragm hung in the case on pivots and nearly counterpoised; and connections
leading from the said diaphragm to the said means which hold the doors open,
whereby when an explosion occurs the diaphragm will be shifted thereby causing
the doors to be closed automatically.

page_text: 3. The combination of a casing; an oil stove enclosed in the said casing; a door
or doors for the casing; and means including a movable diaphragm for closing said
-door or doors when an explosion occurs within the casing, as set forth.
Signed this 18th day of August 1896.
JOHN ANTON RUTH.