AN IMPROVED PORTABLE OVEN,
Year: 1870

page_text: LETTERS PATENT to James Wadsworth, of the City of Manchester,
Machinist, for the Invention of "AN IMPROVED PORTABLE OVEN, A
PROVISIONAL SPECIFICATION left by the said James Wadsworth at
the Office of the Commissioners of Patents, with his Petition, on
the 2nd April 1870.
I, JAMES WADSWORTH, of the City of Manchester, Machinist, do
hereby declare the nature of the said Invention for "AN IMPROVED PORT-
ABLE OVEN, A MODIFICATION OP WHICH MAY ALSO BE USED FOR HEATING APART-
MENTS," to be as follows:-
The object of this Invention is to provide a portable oven which can
be hung upon the bars of any ordinary fire grate in front of the fire,
O and thus be useful for cooking or baking purposes, and will still leave
the top of the fire at liberty for boiling purposes.
Now this Invention consists in constructing an oven of sheet metal
with a door at the front, and surrounding the same by an outer casing,

page_text: except at the frout where the door is situated, and at the back of such
outer casing at the bottom is formed an aperture, the mouth of which
opens into the fire-place between the fire-bars, and thus allows the
products of combustion and heat from the fire to enter and pass along
the bottom, between the oven and outer casing towards the front, and
then to ascend up the sides and over the top between the oven and outer
casing, where it escapes into the chimney by a pipe or nozzle which is
attached to the outer casing.
I also make a portable oven applicable to any common stove used for
heating apartments or for cooking on ship board, which consists of an
inner oven and outer casing constructed upon the same principle as the
one herein-before described, but the bottom of the outer casing is coupled
to the stove pipe in the same manner as stove piping is usually con-
nected together, so that the whole products of combustion pass between
the oven and outer casing and escape by the ordinary stove pipe which
is connected to the top of the outer casing.
The application of this oven forms a large additional heating surface
to the stove, and upon the same principle the outer casing of the oven
may constitute the entire heating surface and be used as a stove, the
fire-place in such case being surrounded by plumbago, fire-clay, or other
non-conducting material, to preserve the lower part of the outer casing
and thereby to cause all the heat to pass up between the oven and outer
casing, and in order to shew the state of the fire I arrange mirrors in
suitable positions beneath the fire-bars.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 25
filed by the said James Wadsworth in the Great Seal Patent Office
on the 1st October 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
WADSWORTH, of the City of Manchester, Machinist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 30
Letters Patent, bearing date the Second day of April, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said James Wadsworth, Her special license that I, the

page_text: said James Wadsworth, my executors, administrators, and assigns, or such
others as I, the said James Wadsworth, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "AN IMPROVED PORTABLE OVEN, A MODI-
FICATION OF WHICH MAY ALSO BE USED FOR HEATING APARTMENTS," upon the
condition (amongst others) that I, the said James Wadsworth, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Wadsworth, do hereby declare
the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by
the following statement:-
The object of this Invention is to provide a portable oven which can
be hung upon the bars of any ordinary fire-grate in front of the fire,.
and thus be useful for cooking or baking purposes and still leave the
top of the fire at liberty for boiling or other purposes.
Now this Invention consists in constructing an oven of sheet metal
with a door at the front, and surrounding the same by an outer casing,
except at the front where the door is situated, and at the back of such
outer casing at the bottom is formed an aperture, the mouth of which opens
into the fire-place between the fire-bars, and thus allows the products
of combustion and heat from the fire to enter and pass along the bottom
between the oven and outer casing towards the front, and then to ascend
up the sides and over the top between the oven and outer casing, where
it escapes into the chimney by a pipe or nozzle which is attached to the
outer casing.
I also make a portable oven applicable to any common stove used for
heating apartments or for cooking, which consists of an inner oven and
outer casing constructed upon the same principle as the one herein-before
described, but the bottom of the outer casing is coupled to the stove in
the same manner as stove piping is usually connected together, so that

page_text: the whole products of combustion pass between the oven and outer
casing and escape by the ordinary stove pipe which is connected to the
top or back of such outer casing.
In order that this my said Invention may be more readily seen and
understood I have hereunto annexed a Sheet of Drawings illustrating
several modifications of my Invention.
Fig. 1 is a front exterior view of a portable oven constructed according
to this Invention; Fig. 2 is a side view partly in section; Fig. 3 a
cross section, Fig. 4 a plan, and Fig. 5 a sectional plan of the oven
represented by Fig. 1; Fig. 6 is a side sectional view of a fire-place,
shewing my portable oven hanging upon the fire-bars; Fig. 7 is a side
view, Fig. 8 a front view, and Fig. 9 a plan of an adjustable stand
suitable for supporting my oven when in position before a fire-place;
Fig. 10 is a side sectional view of a fire-place, shewing how all the
products of combustion from any ordinary fire-place may be caused to
pass through one of my portable ovens; Fig. 11 represents an ordinary
stove having one of my portable ovens (shewn partly in section) con-
nected to the stove pipe; Fig. 12 is a side exterior view and Fig. 13 is a
front sectional view of a portable wash boiler constructed on the principle
of my Invention. Similar letters marked on the Drawings are used to
denote similar parts in all the views.
In Figs. 1, 2, 3, 4, and 5, A is the oven formed of sheet or cast iron
and fitted with ledges B for supporting the ordinary shelves, and with a
hinged door C for obtaining access to the oven. This oven A is
surrounded or enclosed, except at the back and front, with an outer
casing D, leaving a hollow space E between the oven and outer casing,
and an aperture or opening is formed into such hollow space at the back,
to which aperture or opening a cast-iron nozzle F is affixed, the mouth
of which is arranged to extend into the fire-place, as hereîn-after
described. G is a chimney connected to the top of the outer casing for
carrying off the products of combustion and for promoting a draught
through the hollow space between the oven and outer casing. This
chimney is made in two or moro lengths arranged to slide one over the
other, thus forming a telescopic joint and allowing the length of the
chimney to be regulated to the greatest nicety. II is a partition plate
(seen in Figs. 2 and 5) which extends about two-thirds across the lower
part of the hollow space, and thus prevents the products of combustion
rising direct to the chimney immediately upon passing the nozzle. In

page_text: order to clean out the hollow space between the oven and outer casing
I form openings into the top of the outer casing near the edges, as seen
in Fig. 4, and I cover such openings with sliding plates I. This portable
oven may be hung upon the bars of any ordinary firc-place by means of
the adjustable hooks K, which swivel upon the screws L, the back
extremity of such hooks being serrated to correspond with serrations
formed in the washers M (as seen in Fig. 4) and having slots N formed
through them so as to allow of their length being adjusted to suit any
fire-bars, the serrations preventing such hooks slipping backwards when
the wing nuts O are loosened to allow the front part of the hooks to be
raised when the oven is being placed in position before the fire.
In Fig. 6 the oven is represented as hanging by means of the hooks
K upon the fire-bars P, the nozzle F being introduced between two of
the lower bars of the firc-grate, and the mouth of the telescopic
chimney G being extended so as to convey the products of combustion
direct to the chimney. The action of this oven may be thus described.
Being fixed in position as scen in Fig. 6 with the nozzle F between the
lower fire-bars, a portion of the products of combustion and heat from
the fire are caused to enter the nozzle F and to pass along the bottom
between the oven and outer casing towards the front, and then to
ascend up the sides and over the top between the oven and outer
casing when it escapes by means of chimney G into the flue, having
imparted a large proportion of its heat to the oven in its passage. A
circulation of the products of combustion and heat from the fire is then
established through the hollow space E, which is continued as long as
the oven is before the fire. Instead of the hooks K being employed
for hanging the oven upon the fire-bars, the oven may be placed upon
a stand before the fire or the adjustable stand represented by Figs.
7, 8 and 9 may be used, which is hung upon the fire-bars and is
adjustable in length by the upright leg Q being jointed to the sliding
plate R, which slides through the strap S, and such stand is adjustable
in height by the leg Q being formed in two parts (as illustrated) held
together by a lock nut and screw passing through a slot T or in any
other convenient manner.
In Fig. 10 is represented another method of supporting the oven in
position before the fire-place by mounting it upon four legs U, the two
front ones being provided with wheels at their lower extremities, and
handles Y being affixed for wheeling such oven about from place to

page_text: place. This Figure also represents the entire products of combustion
passing through the hollow space formed between the oven and outer
casing by covering over the top of the fire with a cast-iron plate W,
and the front of the fire-place above the fire-bars being closed by a
sheet metal plate X having an opening formed through it to insert
the mouth of the chimney as illustrated. This modification is useful
where it becomes necessary to heat a large oven constructed on this
principle by any ordinary fire-place. Although I prefer to construct
my portable ovens of a rectangular form as illustrated, it will be readily
understood that they may be made of a cylindrical or any other suitable
shape.
In Fig. 11, a is any ordinary stove having the smoke pipe b con-
nected to the bottom part of the casing surrounding the oven c, which
only differs from the one herein-before described in the casing being
continued across the back as well as up the sides, the upper or top part
of the casing opening in to the ordinary stove pipe 6¹. By this arrange-
ment the whole products of combustion from the stove are caused to
pass through the hollow space between the oven and outer casing thus
effectually heating the oven in its passage to the chimney.
In Figs. 12 and 13, c is an outer casing or frame open at the back a
and top, so that the rectangular wash boiler d may be inserted, thus
leaving a space at the bottom and up one side, and presenting the back
side of such wash boiler to the direct action of the heat radiated from
the fire-place. The outer casing or frame c is also provided with a
nozzle e to project between the fire-bars (as described in connection 2
with the oven) and a portion of the wash boiler may be also extended
forwards as seen at f, to project between one of the upper fire-bars, so
as to receive the full benefit of a closer contact with the fire. The
chimney g of this arrangement is connected at the side as illustrated,
and the products of combustion are caused to pass along the bottom 3
between the wash boiler and outer casing, and then to ascend up the
side to the chimney, or a wash boiler may be constructed with an outer
casing surrounding it except at the top and back and be supported
upon legs and wheels the same as the large oven herein-before dc-
scribed, and the whole products of combustion from the fire be caused a
to pass along the bottom and up the sides and front between such outer
casing and wash boiler and thus be effectual for heating a much larger
boiler.

page_text: I claim constructing a portable oven applicable to any ordinary
fire-place or stove as described and illustrated on the accompanying
Drawing.
In witness whereof, I, the said James Wadsworth, have hereunto
signed my hand and affixed my seal, this Twenty-seventh day
of September, in the year of our Lord One thousand eight
hundred and seventy.
Witness,
JOHN G. WILSON,
Patent Agent,
71, Market Street,
Manchester.
JAMES (L.s.) WADSWORTH.