An Improved Portable "Campaigning" Baking Oven.
Year: 1897

page_text: Date of Application, 15th Apr., 1897-Accepted, 19th June, 1897
COMPLETE SPECIFICATION.
An Improved Portable "Campaigning" Baking Oven.
I, MANFRED WEISS, of No. 4 Deákgasse, Budapest, in the Kingdom of
Hungary, 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 portable baking oven, arrangel for continuous
operation in the field or camp; the distinguishing feature of such baking oven
from all existing apparatus of the same class being, that the first stage of the
baking process takes place within a pipe or conduit constructed of firebricks (or
tiles), whereas the final stage is completed, partially, by the gases escaping from
the furnace, but mainly, by the action of air which has been heated by such gases;
such air being for the purpose admitted into the chamber in which the final baking
operation takes place, and sweeping past the materials which are being baked, in
contact with all sides thereof.
An oven constructed in accordance with this invention is represented in the
accompanying drawing, in which
Fig. 1 is partly a front elevation and partly a cross section, while
Fig. 2 is a vertical longitudinal section of the oven;
Fig. 4 is a section on line x-x, Fig. 2, through the smoke chamber; and
Fig. 3 a section on line y-y, Fig. 2.
The baking oven mainly consists of an outer sheet iron case or chamber b
Within such case
erected upon the carriage or other portable frame or support a.
or chamber, towards the rear thereof, a vertical partition c serves to separate it
from the smoke chamber e, carrying the hinged or collapsible funnel d. Between
this transverse partition c and the front wall of the outer casing b, an inner
chamber g, exactly conforming to the external chamber in shape, is arranged; an
air jacket being provided in order to insulate it from the said external casing b.
It is within this inner chamber g that the furnace and the baking compartment
are formed.
The furnace or fire box i consists of a trough shaped recess made in the bottom
of the chamber g, the front part of which is fitted with a grate j. Above such
furnace i, supported by stout iron plates k, is arranged the brick or tile conduit l,
of semi-cylindrical shape, wherein the initial stage of the baking process is to be
performed; such conduit being provided with a door n in its front wall f,-giving
The brick
access to its interior, while it is completely closed in the rear.
conduit is secured against falling to pieces, should it become cracked, by a wire
gauze sheath or envelope s, as well as by transverse hoops n and, if necessary, by
longitudinal rods or bars, such as o, embedded in the brickwork. Over such fire-
brick chamber 1, the compartment in which the final stage of the baking takes
place is erected upon a horizontal floor p and divided by intermediate plates or
diaphragms q into two storeys or tiers r, r, the various compartments of which
chamber are made accessible by means of small doors t fitted in the front
wall f.
The spaces or chambers thus formed on either side of the firebrick conduit or
chamber are each divided by a hollow sheet metal piece u extending from the
partition c in the rear to a short distance from the front wall f, into two flues
and w, arranged one above the other and communicating with each other in front;
y

page_text: the upper flue v, Fig. 3, communicating with the upper half of the smoke
chamber e, while the lower flue w is similarly connected with the lower half of the
said smoke chamber; for inasmuch as the last mentioned flue is divided into two
halves, insulated from each other by means of a horizontal partition or diaphragm, a',
and opens into the lower part of the smoke chamber e, it also consequently serves
to establish the connection with the furnace i; so that the course of the gases, as
they arrive from the furnace, is as follows: From the fireplace i they flow in the
rearward direction down into the lower half of the smoke chamber e; thence
through the flues w to the front; next, through the flue v back again into the
upper half of the smoke chamber e; and thence into the chimney or funnel d. In
taking this course, the products of combustion, on one side, heat the brick or
earthenware conduit 1, and on the other side, both the air jacket h and the hollow
pieces u, the interiors of which communicate with the said air jacket through
apertures, whilst the air space / communicates with the final baking chambers r
and through apertures c', so that the heated air is thus enabled, as it flows past,
to come in contact with all sides of the materials introduced into the final baking
chambers upon tins such as d', and thereby to thoroughly finish the baking of the
same. The outer casing b of the oven has double walls, between which there is
embedded a layer of asbestos e¹ to insure effective insulation from the heat. And
similarly, the bottom t and intermediate plates 9 of the initial baking chamber are
lined with asbestos plates f¹, so as to prevent the goods which are being baked
from burning.
The arrangement herein described enables the oven, by continuous operation, to
accomplish an uncommonly large amount of work in a given time, the bread or the
like to be baked being first placed upon the tin d¹ and inserted into the initial
baking chamber 7 where it is baked for about twenty minutes. The tin d' is then
withdrawn from 7 and introduced into one of the final baking chambers r, r. In
the meantime a fresh tin, or batch of goods, may be placed in the initial chamber 1,
bearing in mind however that the initial baking stage takes less time to complete
than the final. But then the goods on the tin d', the initial baking of which is
completed before the final baking of the preceding batch is concluded, may be
placed in another final baking chamber, so that the continuous operation is carried
on without any interruption, the daily output of baked goods being proportionately
increased.
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. A portable campaigning baking oven comprising a firebrick or earthenware
initial baking conduit and a final baking chamber separated from such conduit, and
consisting of an outer insulating casing & and an oven proper, or inner chamber,
corresponding to the said outer casing in shape and containing the fire box or
furnace and the baking chambers; such inner chamber being insulated from the
outer casing 6 by an air jacket h heated by flues; the air of which jacket is adapted
to heat the final baking chamber arranged in the upper half of the inner oven
chamber 9, while the initial baking conduit is heated direct by the gases escaping
from the fire box only.
2. In the campaigning baking oven referred to in the first claim the brickwork
or earthenware initial baking conduit l arranged over the trough shaped fireplace i
of semi-cylindrical shape, closed in the rear, and secured from breakage by a wire
gauze sheets transverse hoops n or by longitudinal iron bars o embedded in
the brickwork.
3. In campaigning baking ovens such as referred to in the first claim, conducting
the gases arising from the fireplace i, first rearwards, so that they may heat the
firebrick conduit from below; then into the lower half of the horizontally
partitioned smoke chamber c; then reversing the same so, that they may flow
through the side flues w arranged one above the other and heat the firebrick

page_text: tube on the side and top; and lastly allowing them to pass through the upper
half of the smoke chamber c into the chimney or funnel, after having heated the
bottom of the final baking chamber in passing through the flues v.
4. In campaigning baking ovens of the class above referred to, dividing the
final baking chamber into tiers or storeys r r¹.
Dated this 15th day of Anril 1897
ALLISON BROS.,
Agents for the Applicant.