Improvements in or connected with Bakers' and other Cooking Ovens.
Year: 1893

page_text: Date of Application, 17th Feb., 1893-Accepted, 22nd Apr., 1893
COMPLETE SPECIFICATION.
Improvements in or connected with Bakers' and other Cooking
Ovens.
We, WILLIAM BUTLER, and HENRY BUTLER, trading as Henry and William
Butler, of 14, Osmaston Street, Lenton, in the County of Nottingham, Builders,
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, reference being had to the accompanying drawings and to the letters
and figures marked thereon, that is to say:-
:
Our invention relates to improvements in ovens for baking bread, or other food,
whereby the oven is always ready for use, less fuel is consumed in heating it, than
heretofore, the whole can be heated uniformly, the fire place and all coke and dust
can be kept away from the bread, and the flues are less liable to burn and more
easily cleaned and repaired than in similar ovens hitherto constructed.
For the purpose of our invention, we construct the ovens for use in bakeries,
hotels, and for other purposes, with a double flue or returning flue below the hearth,
said flue being suitably constructed in fire brick with brick arches, and diminishing
in sectional area near the end where it enters the vertical flue. The hearth and
crown of the oven are constructed of quarries or tiles tongued and grooved, or
fitting into each other, and laid on light iron T bars or girders, and joined with
fire cement and made smoke-tight. The hearth is arranged at a sufficient height
above the brickwork and arches of the said double flue, to form a hot air chamber
about five or six inches high, and of the same length and breadth as the oven
hearth, without partitions of any kind, and provided with dampers so arranged
that the air chamber may constitute a Hue, or not, as desired. Above the crown
of the oven is a similar hot air chamber, also without partitions, and provided with
dampers. The furnace is preferably arranged at one side, or it may be at the back
of the oven, and can be separated from the bake-house proper by a wall or
partition, so that the firing may be performed, and the fuel kept, outside the bake-
house.
The arrangement of furnace, flues, and hot air chambers above described,
permits of soot doors being arranged in convenient positions at the front and side
of the oven, and renders the cleaning of said flues easy. The dampers employed
are preferably throttling dampers, with handles sunk in recesses in the brickwork ;
sliding dampers may however be used. The top of the oven is preferably covered
with sand and concrete to keep down the heat. Ovens can thus be constructed on
"decker" principles, that is to say one oven or chamber above another, and the
turnace being at the side or back, a high pressure boiler can conveniently be built
in at one side of the front of the oven, and heated from the same fire, if desired.
The manner of carrying our invention into effect will be more clearly understood
by reference to the annexed drawings, in which :
Fig. 1 is a sectional elevation of a two decker oven constructed according to our
invention, the section being taken on line C, D, Fig. 2.
Fig. 2 is a transverse section on line A, B, Fig. 1.
Fig. 3 is a sectional plan.
Fig. 4 is a perspective view of the tongued and grooved tiles or quarries.
Figs. 5 and 6 are modifications of the said tiles or quarries.
a, is the grate or furnace, and b, b, the double or returning flue, by means of
which the hent is retained below the ovens for a longer period than with a single
flue, the brick partition and arches becoming hot and retaining and equalizing the

page_text: heat from the furnace. c, c, are the hot air chambers under and over the ovens d, d,
the interior of the shell being divided into horizontal compartments or decks by
the floors e, e, constructed of quarries and T bars or girders, and forming the
hearths and crowns of the ovens. At each side of the front of the oven are vertical
flues g', g', connecting each hot air chamber e with the hot air chamber above it.
At the back of the oven are vertical flues f,f,f, also connecting the hot air
chambers. These vertical flues f, f', and are connected by horizontal flues 9, 9;
the said flues and also the flues g', g', being provided with dampers f³, f; and by
the manipulation of these one or more of the hot air chambers can be shut off,
and the heated air current directed to the chamber, or chambers, which remains, or
remain, in communication with the double flues b, b.
It frequently happens with ovens, as formerly constructed on decker principles,
that the bottom oven becomes thoroughly heated while the top one remains
insufficiently warm. Now, by our invention, this is avoided, for if the upper oven
is not hot enough, it is merely necessary to shut off the other air chambers by
means of their dampers, and fully open those affecting the top oven, when the heat
from the furnace will go directly thereto and heat said top oven to the same degree
as the bottom one; and should the baker require a sharp heat to either of the
ovens it can be got by our construction to suit any kind of bread, confectionery,
joints, etc. Dampers are arranged at each end of the air chambers so that the
current of hot air can be made to pass from front to back, or back to front, at will.
If it be desired to use only the bottom oven, the dampers of the upper hot air
chambers are closed.
In order to have the smallest possible quantity of iron within the oven, and to
produce hearths and crowns as nearly flat and even as practicable, the tiles or
quarries h, constituting the floors e, are formed with a groove i at each side into
which is fitted a tongue of iron to join the two quarries together, the joint being
afterwards completed with fire cement. Or the tiles or quarries may be made with
a ledge or flange k, at each end, and cemented together as shewn at Fig. 5, or be
otherwise suitably shaped to fit into each other, as for instance with one end 1,
grooved, and the other end m, wedge-shaped, as shewn at Fig. 6.
The tiles or quarries are preferably three or four inches longer from T bar to
Tbar, or girder to girder, than from groove to groove. A further advantage of
the arrangement above described is, that if a tile cracks it will not fall, but remain
in position until repaired.
The chimney flue from the oven can be connected to any ordinary flue or
chimney shaft, as the smoke is almost entirely consumed in the flues, or hot air
chambers, within the oven.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what
we claim is:
1. In bakers' and other cooking ovens, the double or returning flue in combination
with air chambers and vertical connecting flues so arranged, and provided with
dampers, that the current of hot air from the furnace may be caused to pass
through any one or mure of them in either direction as desired, substantially as
described..
2. In bakers' and other cooking ovens, the use of tongued and grooved or
similarly jointed tiles or quarries supported on T bars or girders, and constituting
the floors for separating the ovens proper from the hot air chambers, substantially
-as described and shewn with reference to Figures 4, 5, and 6 of the drawings.
3. The arrangement of furnace, ovens, double flues, and hot air chambers, in
combination with vertical flues at the back and vertical connecting flues at each
side of the front of the oven, thus constituting a two-decker oven, substantially as
described and shewn.
;

page_text: 4. Our improvements in or connected with bakers' and other cooking ovens,
substantially as described and shewn by the annexed drawings.
Dated this 17th day of February 1893.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 6, Victoria Street, Nottingham,
Agent for the Applicants.