IMPROVEMENTS IN GAS COOKING AND HEATING STOVES
Year: 1881

page_text: LETTERS PATENT to George James Cox, of Lower Fant Road, Maidstone, in
the County of Kent, for an Invention of "IMPROVEMENTS IN GAS COOKING
AND HEATING STOVES."
PROVISIONAL SPECIFICATION left by the said George James Cox at the
Office of the Commissioners of Patents on the 16th June 1881.
GEORGE JAMES Cox, of Lower Fant Road, Maidstone, in the County of Kent.
"IMPROVEMENTS IN GAS COOKING AND HEATING STOVES."
The object of my Invention is to utilize more perfectly the heat given out by
the combustion of coal gas or any other combustible gas that can be applied to
and burnt in stoves, either for the purpose of warming and ventilating buildings or
apparatus, or for cooking food, or for heating, boiling, or melting solid or liquid
substances.
All gas cooking and heating stoves that have been constructed to my knowledge
have been made to receive their necessary supply of air for ventilating the stove
and supporting combustion of the gas in a cold state, or at the temperature of the
atmosphere surrounding, and stoves jacketted or cased with nonconducting material
to prevent radiation of heat do only absorb the heat (and thus prevent radiation),
but do not materially contribute to the effectual heat for cooking or heating
purposes at the time when it is most required.
I apply my improvements to the class of gas stoves known as "reflecting"
stoves, in which the burner is placed above the substance to be heated or cooked;
also to the class of gas stoves known as "closed" stoves, wherein the heated air
and products of combustion are made to ascend throughout the stove and flues
connected therewith; also to the class of gas stoves wherein the combustion of the
fuel goes on in one chamber, and the heat and products of combustion of the same
is made to circulate around and through the linings of or outside another chamber
or other chambers; also to the class of gas stoves fitted with boilers for heating
conservatories, baths, and tanks; also to stoves or burners specially constructed to
beat water quickly.

page_text: In my cooking or heating stoves, which may be made rectangular, cylindrical,
or any other shape, I entirely enclose the burner or burners and air bulb or mixing
chamber (if atmospheric burners are used) within the stove. I place tho burner or
burners near the bottom, or at any height or in any position I deem necessary,
according to the class of stove it is applied to, and I make the bottom of the stove
practically airtight, except to such currents of air to be hereinafter mentioned.
The necessary air required for supporting combustion of the gas, to ventilate the
stove, and to mix with the gas in the air bulb (if atmospheric burners are used) is
caused to enter in at the bottom of and to travel up within an outer casing
surrounding three sides of the stove (in the case of a rectangular cookor), and then
down within a second or inner casing fixed to the bottom plate. This inner casing
or lining has an outlet near its bottom into the stove, and all air entering the stove
must pass up between the outside lining first, then down through the inside lining
into the stove.
In travelling through these spaces the air becomes considerably heated, and by
this means carries into the stove and utilizes within the stove hoat which has been
radiated from the stove. At the same time this current of air being formed and
continuously travelling through the jacketting spaces form a good means of
preventing useless radiation from the stove taking place.
To assist this air current in preventing heat radiation taking place outwardly, I
propose to construct the outside jacket or casing in tinned sheet iron or any other
bright smoothed substance, metallic or non-metallic; it need only be bright and
smooth on its inner surface, or on that part or side next the stove interior. I also
propose to shape the plates or sheets or other material used in forming the outer
casing into a series of corrugations or ridges, but I may also construct them flat
and plane surfaced.
At the top part of the cooker or oven, and where tho heat is often deficient in
intensity, I propose to retain and utilize it by constructing the under side of the
oven top in tin plate, or some other bright reflecting substance, inctallic or non
metallic, such as porcelain, or a composite, such as enamelled sheet iron formed
into corrugations or ridges, or I may make it flat. To make the heat strike this
flat or irregular surface, and then to traverse two horizontal flues placed one over
the other immediately above the aforementioned heat diffuser plate, before escaping
to the chimney, the chimnoy pipe attached to tho stoves will be furnished with an
ordinary disc throttle valve in order to control the escaping gases and vapours to
any desired speed of exit.
I shall also fit a bright radiating surface on the inside of stove door, formed into
lines of corrugations, either vertical or horizontal, or use any other common method
of making an irregular surface for the purpose of reflecting heat, or I may use a
flat reflector for that purpose. I shall also make the stove doors practically air-
tight by facing the door and frame surfaces plane, or by using a flexible packing
joint, as asbestos sheeting or other such like material; and I propose to case or
jacket the doors of stoves with a nouconducting material, as is commonly done.
I intend to construct my stoves generally of wrought iron, tinned sheet iron,
and cast iron, but I do not restrict myself to such inaterial, but may employ other
metals or materials of a refractory nature, such as firo clay tiles, porcelain, and
enamelled substances. I also provide my cooking stoves with tiers of shelves, or
grids, or bars, and with boiling, toasting, and grilling burners on the tops and at
the sides, as is commonly and usually done.
Though I havo described an inner and a outer space through which the air
required for combustion and ventilation shall travel, I do not confine myself to two
divisions, but may use only one, or three, or more divisions before allowing the
heated air to enter the oven or heating chamber; and I may reverse the order by
causing the outer lining to have its openings at the top, whereby the air first
descends, and then rises within the inner lining.
The top and upper sides not required for air spaces I intend either to pack them
with a nonconducting material enclosed or cased in, or simply laid on open where

page_text: required, so that it may be easily taken off to make the stove lighter and more
easily portable.
For all roasting and baking and heating purposes, where there is a solid or
dense substance to be heated through or cooked, my ordinary burner or burners
will suffice, but as there are occasional operations where light delicaces require a
quick, fierce oven to cook then promptly, I claim the use of an auxiliary burner or
burners placed in the oven or heating chamber, in the manner and position herein-
before described, for the burners, controlled by a seperate tap, and to be used for
the purpose of creating an extraordinary heat when required; such an arrange-
ment I also apply to my circulating hotwater boilers heated by gas, and any
other class of gas stove where a quick and concentrated heat is promptly
required.
By such an arrangement I restrict and adjust the size of the ordinary cooking
burner or burners in cooking stoves, to do away with the necessity of turning
down the gas when the operations of cooking or heating are partly over.
The novelty of my Invention consists,-
First. In entirely closing the bottom of my stoves against the outer air entering
direct to the burners.
Secondly. In enclosing the burners completely in the heat, and enveloping the
air ball or mixing chamber in an atmosphere of heated air.
Thirdly. In the means whereby air is supplied to the stove, and in the fact
that this necessary air is heated by waste heat from the stove before entering the
stove.
Fourthly. In the manner in which I prevent radiation from the stove, and by
the air current bring into use unavoidable radiation instead of its being absorbed
and bound up in a mass of nonconducting material.
Fifthly. In applying a corrugated or irregular surface, smooth and bright on the
inside next the heat, for my outer casing or jacket, top heat diffuser plate, and
door plate, and by which I present surfaces offering varying angles to the heat
rays, enabling them to be reflected back again on to the next inner casing (those
of the side casing), from whence they are radiating.
Sixth. In using a burner or series of burners of definite size just powerful
enough to do one, the principal class of work, using an auxiliary burner for special
work or on an emergency.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George James Cox in the Great Seal Patent Office on the
16th December 1881.
GEORGE JAMES Cox, of Lower Fant Road, Maidstone, in the County of Kent.
"IMPROVEMENTS IN GAS COOKING AND HEATING STOVES."
My Invention is for the purpose of utilizing more fully and more perfectly the
heat given out by the combustion of coal gas or any other combustible gas that
can be applied to and burnt in stoves or apparatus, either for the purpose of
warming and ventilating buildings, or apparatus, or for cooking or heating food, or
for heating, boiling; or melting solid or liquid substances.
I apply my Invention to the classes and kinds of gas stoves known as reflecting
stoves, in which the burner or burners are placed above the substances to be heated
or cooked, and in which the gas acts partly by radiation, reflection, and deflection
of the heat rays, the ascended licated air and products of combustion being further
utilized by circulating through flues surrounding another chamber for the purpose
of heating same, or is otherwise utilized directly under another utensil. I also
apply my improvements to the kinds known as closed stoves, cooking or otherwise,
wherein the heated air and products of combustion of the gas is made to ascend,
and in cooking stoves to have contact with the substance to be heated or cooked,
passing throughout the stove and flues thereof. My improvements are equally
applicable to closed cooking stoves, wherein the gas is burnt in jets from a burner
tube running round or partly round the stove, or to those closed stoves wherein
the gas is burnt in a small chamber, and the heat therein generated together with
the products of combustion passed up through the stove, as in Southbey's or
Hartley's system. I also apply my improvements to any of the classes of stoves
wherein gas is burnt, partly for the purpose of giving out radiated heat, and partly
for the purpose of inducing and setting up currents of air through warming
channels in such stoves, by which the air of an apartment or building is warmed
without being vitiated; also to boilers constructed to be heated by gas for the
purpose of warming conservatories, buildings, baths, tanks, and the like, by means
of a circulation of hot water or for generating steam under pressure, supplying
quantities of hot water, and such like useful purposes; also to ovens heated by gas
and specially constructed to bake bread or pastry; also to the classes of gas apparatus
specially constructed to heat liquids quickly, and known as instantaneous water
heaters; also to stoves for general domestic purposes, and gas furnaces to hent
tailors' or hatters' irons, plumbers' and tinmen's tools, or to melt metallic
substances.
These improvements which form my Invention consists generally in supplying
the burner with heated air, heated by waste heat from the stoves, retarding velocity
of heat current through some of the stoves, and providing a special arrangement of
gas nipple, to definitely adjust varying supplies of gas to apparatus. In any of the
aforementioned apparatus, which may be made cylindrical, rectangular, or any
other convenient shape, I entirely enclose the burner or burners and air ball (if
atmospheric burners are used) within the stove or apparatus. I place the burner
or burners near the bottom, or at any convenient height, or in any position I decm
necessary according to the class of stove or apparatus it is applied to, and I make
the bottoms of any stoves practically airtight except to such currents of air to be
hereinafter mentioned. To shew the novelty of my Invention and the utility
thereof, I will more particularly describe one mode of applying same to a rectangular
gas cooking stove of the closed kind, and as shewn in the Figures 1, 2, 3, and 4 on
the Drawings accompanying this Specification, and hereinafter called the Drawings.

page_text: In these Drawings the same reference letters are used for each piece of the
structure, having the same functions to perform in the respective apparatus.
The necessary air required for supporting combustion of the gas, to ventilate the
stovo, or to mix with the gas when atmospheric burners are used, instead of
rushing in cold or at the temperature of the surrounding atmosphere, is caused (in
the case of a rectangular cooker) to enter an outer casing A, Figs. 2, 3, 4, through
apertures E cut either in casing A, as shewn, or in the outer edge of bottom frame
casting, to travel up inside of A and return down within a second casing B, and
thus brought in close contact with the sheet or plate C forming the oven proper,
C soon getting hot through the gas burning within, communicates some of this
heat by radiation to the passing current of nir. Just below the burner there are
apertures G cut in C, and through these the air is drawn into the stove as required
in a heated state. The heat which is thus obtained and utilized through the
medium of the air current would otherwise have been wasted by uscless radiation
or bound up, and for a great part uselessly, within a mass of nonconducting
substances. The air current through these spaces act as a nonconductor and
assists in preventing useless outward radiation of heat from gas cooking stoves
taking place. To further assist in checking outward radiation of heat from gas
cooking stoves and others where necessary, I propose to construct the outsido
casing A in tinned sheet iron, galvanized iron, or any other bright or smooth
surfaced substance, metallic or non metallic; it need only be bright or smooth on
its inner surface; I also propose to shape the sheets, or plates, or other material
forming this outer casing in a series of corrugations or ridges, but I may also
construct them flat.
At the top part of ordinary gas cooking stoves the heat current escapes direct,
and unless the ventilator valve is nearly closed, which must be done at the cost of
destroying the ventilation, the working heat at this part is generally deficient in
intensity. I utilise the ascended heat more fully within my ovens or heating
chambers, and yet secure a perfect ventilation by constructing the underside of oven
top in tin plate or some other bright reflecting substance, metallic or non-metallic,
formed into ridges, or corrugations, or simply a flat reflector. I mako the ascending
heat current strike this flat or irregular surface, and then to traverse two horizontal
flues placed one over the other above this heat diffusor plate before escaping to
chimney. The object of these flues are to retard the velocity of exit heat current to
make same more effectual within the stove or apparatus. The chimney pipe attached
to my stoves will be provided whero required with a valve to further control the
exit current when required. I also provide a similar reflector, either corrugated,
or irregular surfaced, or plain, to my cooking stove doors to freely reflect back the
radiant heat rays to within the stove. I also intend to jacket or pack with non-
conducting material the doors and any portion of my cooking stoves casings not
required for air spaces, and do the same to any portion of other apparatus herein
described where I consider it advantageous so to do. I also provide my cooking
stoves with the usual bars, or grids, or shelves, and fix on stoves where required
boiling, grilling, toasting, and other burners, as is usually and commonly done.
The reference letters to the other Figures in the Drawings will shew the manner
in which I apply my improvements to the various apparatus therein illustrated.
Figs. 1, 2, 3, 4, being respectively front elevation, side elevation, and back
elevation, both partly in section, and a plan of a rectangular cooker, as herein
described. Fig. 5, 6, and 7 is a front clevation, side elevation, both partly in
section, and a back view of a reflecting cooker. In each of these stoves the double
horizontal exit flue is shewn, and the course of the exit current through same to
flue pipe H is shown by arrows. Figs. S, 9, 10, shew the application of my
improvements to another stove of the reflecting class, and known as a grilling stove.
Figs. 11, 12, 13, shew how I apply same to burners to be used for ordinary domestic
boiling or other purposes, such an arrangement being specially applicable to heating
or melting stoves, for trade, or other purposes. Figures 14, 15, and 16, shew my
improvements applied to an air warming stove. Fig. 17, 18, and 19; shew samo

page_text: applied to a gas boiler arranged to supply pipes or coils with a circulation of hot
water. Fig. 20 and 21 shew same applied to an instantaneous water heater. I
also apply my improvements to those kinds of stoves wherein the gas is burnt for
the combined purpose of lighting and heating apartments or buildings.
In the various kinds of apparatus, as herein described, and any others in which
gas is burnt for various useful purposes, one way in which I obtain the improve-
inents I claim is by surrounding the burner with preferably three casings, as shewn,
apertures being made round the bottoms of the outer and inner casings only; this
arrangement causes all air drawn into the stove to travel down on the outside of
the heated inner lining before entering to supply burner and support combustion.
This inner casing or lining is made in a thinner material than other casings in order
to transmit heat freely through, but the outer casings may be constructed in a
nonconducting material or otherwise.
Though I have described an inner and a outer space, through which the air
required for combustion of gas in the various apparatus do travel, I do not confino
myself to two divisions, but may use one or three or more divisions before allowing
the heated air to enter the oven or heating chamber. I may also cause the required
air to descend an annular space formed by a single casing, and enter stove through
orifices in bottom, as in Hill's Patent for solid fuel stoves, or I may also make a
single casing having the annular space open at bottom, but closed in and joined to
body of stove above orifices communicating with interior of stove; by this arrange-
ment the heated and rarified air ascends annular space and enters stove direct.
The orifices through which the air enters the stove or channels of same to be heated,
and those through which it leaves the channels and enters the oven or heating
chamber, may be made any convenient shape, and be placed in any the most
suitable position or height according to the shape and functions of the apparatus.
I wish it to be clearly understood I do not deem it necessary to provide a channel
all round or at any particular part of my stoves for the air current to flow through,
and that I may either do as hercinbefore described, that is, I may allow air to enter
at all or any points without regarding the size of air inlets, providing it takes the
intended course whereby it takes up radiated heat, or I may limit the air inlets so
that only air enough safely in excess of probable requirements of the burner
or burners can enter the stove or apparatus. I can also produce this same result
by regulating the exit apertures of stoves so that only just enough vitiated air is
allowed to leave the stove as will induce and make way for sufficient fresh air to
properly support combustion to enter the stove. The burners I prefer to use in all
my stoves and apparatus are of the kind known as atmospheric, but I may also use
jets of ordinary illuminating gas. Figs. 22, 23, 24, and 25, show one modification
of my arrangement for supplying varying quantities of gas into one and the samo
burner from two distinct supplies. It will be seon to consist of a solid piece of
metal having two holes of equal size at its upper end which receive gas supply
pipes; the lower end of this receiver is smaller than upper portion, and has two
small holes partly through and communicating with the two inlet supplies;
through these smaller holes horizontal discharging orifices are drilled so as to
form four orifices, the holes drilled through one of the vertical tubuleres is
about twice the area of the others, so that a large and a small discharging
orifice run side by side and face each way. This supply nipple being screwed
into burner tube F, in the manner and position shewn in Figs. 2 and 3, I
am enabled to discharge gas in contrary directions to supply both sides of burner,
either from the large or principal supply or from what I call the auxiliary supply,
or through both together, thus forming means to obtain three distinct and definite
quantities of gas into one and the same burner. This arrangement materially
differs from the bye-pass arrangement now adopted in soine stoves, inasmuch as in
my improvement both principal and secondary gas supply have their own regulated
discharging orifices into burner tube, while in the ordinary bye-pass, whether the
primary or secondary supply or both bo in use, the gas is all discharged through
one regulated orifice into burner tube, which while it enables the consumption of

page_text: gas to be readily reduced cannot give an auxiliary supply. In my stoves I intend
this auxiliary supply to form an important part in the economy of working, as the
principal supply will be regulated to furnish only enough gas to be capable
of doing ordinary operations at a steady heat, using the auxiliary supply in
combination when more than an ordinary heat is required. I apply another
modification of this compound supply nipple to hot water boilers, and any other
apparatus in the which a quick heat may be required at intervals or in cases of
emergency.
I intend to construct my stoves and apparatus generally in sheet iron, tinned,
galvanized, or otherwise, cast iron, copper, or any other suitable substance, metallic
or non-metallic, as fire-clay, tiles, slates, porcelain, asbestos, enamelled substances,
and such like material. I do not confine myself to the precise details as herein
described, as I may construct other modifications of such arrangements without
departing from the principles of my Invention.
Having now described the nature of my Invention, and the means whereby I
carry the same into operation, I herein declare that I claim as my Invention as
herein described and shewn,-
First. The construction of gas cooking and heating stoves, boilers, and other
apparatus, as herein described, with closed bottoms whereby I prevent air from
entering direct into the stove or apparatus, and wherein I provide channels,
divisions, or beating spaces through which all air necessary for the perfect working
of the stoves or apparatus must travel into same, either in vertical directions at
sides or in horizontal directions under bottoms, in which apparatus the burner or
burners are also closed within and enveloped in heated air.
Second. The construction of gas cooking stoves with two flues for exit current to
traverse, with corrugated reflectors for oven tops and interior of doors, and with a
corrugated bright outer casing to prevent outward radiation.
Third. The construction of a compound gas supply nipple for the purpose of more
readily adjusting gas supply to various requirements, as described and shown in
Drawings.
In witness whereof, I, the said George James Cox, have herein set my hand
and seal, this Eighth day of December, in the year of our Lord One
GEORGE JAMES COX. (L.S.)