Improvements in Cooking Apparatus.
Year: 1890

page_text: Date of Application, 22nd Jan., 1890-Accepted, 22nd Feb., 1890
[Communicated from abroad by EDWARD ATKINSON, of Boston, Massachusetts,
United States of America, Gentleman.]
Improvements in Cooking Apparatus.
I LOUIS STERNE of 2 Victoria Mansions, Westminster in the County of Middlesex
Civil Engineer 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 has for its object to provide a novel apparatus in which food may
be cooked in the most wholesome and nutritious manner at a minimum expense.
In order that food may be cooked in the most wholesome and nutritious way, it is
necessary that the heat required in the process of cooking should be under ready control
and should be so applied that it may be maintained uniformly, not so hot as to burn
the food, not so hot as to vaporise the more volatile portions of the fats or juices of
meats, yet hot enough to thoroughly cook the food.
In practice I find that bread and meat may be most thoroughly and nutritiously
cooked at degrees of heat ranging from 180 F. to 300 F., a longer time at a
comparatively low temperature more than compensating for the intensity of heat
which is customarily applied in what is called a "quick oven."
It is also desirable, when the heat is solely employed for cooking the food rather
than for heating the room in which the oven is placed, that the said heat should be
concentrated upon the vessels containing the food with the least possible waste and in
the most uniform manner at the top, bottom and sides of the said vessel; radiation
from the fuel when being applied to cooking, or from the outside of the oven in which
the vessels containing the food to be cooked are placed, working a waste of heat so
far as its application to the cooking is concerned.
In order that the heat may be concentrated upon the vessels containing the food,
and also that there may be no communication between the heat generator and the
oven in which the food is placed, lest the products of combustion should injure the
food, my improved cooking apparatus is composed of an inner oven in which the food
is placed and an outer oven within which the inner oven is located, the said ovens.
being constructed as will be hereinafter specifically described.
My invention therefore consists essentially in a combination with an outer oven
provided with a heat inlet and outlet, and composed of non-metallic material capable
of withstanding heat, of an inner oven located in the outer oven and separated
therefrom to form a space or passage for the products of combustion, substantially as
will be described.
Fig. 1 is a vertical section of a cooking apparatus embodying my invention, the
base of the lamp or heat generator being omitted to save space in the drawing; and
Fig. 2 is a horizontal section of the oven shown in Fig. 1 on line x, x.
The outer oven or casing a is made of non-metallic material sufficiently non heat
conducting to prevent the escape of heat from within through its walls, and sufficiently
incombustible to resist the degree of heat necessary for cooking.
The walls of the outer oven a may be made of wood or other pulp alone, preferably
indurated fibre, or combined with a non-combustible substance such as asbestos,
carbonate of magnesia, &c. ; or if desired the said walls may be made of slabs of wood
treated with a solution of zinc, or in any other manner to prevent combustion at the
degree of heat required for cooking.
The use of metal for the outer oven is carefully avoided especially on the outer side
except when the walls are made of slabs, in which case the said slabs may be bound or
securely fastened together at their corners by metal strips a¹

page_text: The bottom of the outer oven is provided with a hole, a² through which is conveyed
the heat from a lamp, gas burner or other generator.
The outer oven contains within it the inner oven b, which may and preferably will
be of sheet metal, the said inner oven being of such size, and being supported upon
suitable legs b¹ to leave a space 62 for the circulation of heat around it.
The outer and inner ovens will be provided with suitable doors b³, 64.
To prevent injury or burning out of the bottom of the inner oven and also to deflect
or diffuse the heat entering through the hole a², a slab ³, preferably of soapstone is
interposed between the inner and outer ovens, above the hole, the said slab protecting
the bottom of the inner oven and preventing food immediately over the hole from
being burnt or scorched.
The top of the outer oven is provided with a hole or opening c for the escape of the
waste heat, the inner oven being preferably provided with a chimney or ventilator c¹,
extended up through the said opening.
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
-
First: In a cooking apparatus, the combination with an outer oven provided with
a heat inlet and outlet, and composed of non-metallic material capable of withstanding
heat, of an inner oven located in the outer oven and separated therefrom to form a
space or passage for the products of combustion, and a heat generator, the outer
surface of the outer oven being substantially free from metal whereby outward
radiation of heat is prevented substantially as and for the purposes hereinbefore
described.
Secondly In a cooking apparatus, the combination with an outer oven provided
with a heat inlet and outlet, and composed of non-metallic material capable of
withstanding heat, of an inner oven located in the outer oven and separated therefrom
to form a space or passage for the products of combustion, a heat generator and a
deflector interposed between the inner and outer oven, substantially as and for the
purposes herein before described.
Dated this 21st day of January 1890