IMPROVEMENTS IN COOKING APPARATUS
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Otto Fahnehjelm at the Office
of the Commissioners of Patents, with his Petition, on the 30th
October 1869.-A communication from abroad by Carl Daniel
Ekman, of Stockholm.
I, OTTO FAHNEHJELM, Civil Engineer, of Stockholm, but at present
of No. 2, Chiswell Street, Finsbury Square, in the County of Middlesex,
do hereby declaro the nature of the said Invention for "IMPROVEMENTS
IN COOKING APPARATUS," to be as follows:-
This Invention refers more particularly to cooking apparatus heated
by gas, petroleum, or other combustible fluids, but it may also with
advantage be used with other fuel. The heating apparatus therefor
consists of a shell with sides parallel or as a reversed trunkated cone or
a parallel sided vessel resting on a reversed cone consisting of metal,
china, or other suitable material. It may be cylindrical or elliptic or
rectangular in horizontal section, and with single or double walls, in the
latter case having the space between by preference filled with non-con-
ducting material. The burner or burners are placed at the bottom
open
of the shell and may be of any suitable construction. The vessel or
vessels to bo heated are placed in the upper part of the shell with bottom
and part of the sides exposed to the ascending products of combustion,

page_text: which escape thro' one or more holes in the upper part of the shell
thro' the spaces between the cooking vessels and the shell or thro'
a chimney. A suitable burner may be made of one or more rectilinear
or curvilinear wick tubes having a plate with a hole corresponding to
each tube placed above the same, with small holes around each slit and
attached to the wick tubes, oil reservoir, or shell.
The Invention as applied to steam cooking consists in a small steam
pan or boiler, above which or on the side of which is placed a vessel
containing the food to be cooked, the steam passing from one into the
other. The boiler may have a fixed or removeable lid with a tube
leading the steam into another tube fitting loosely in it and attached to
the bottom of a metal or earthenware vessel placed above it, which by
preference has double walls or is felted or otherwise protected against
radiation. The cooking vessel is placed inside; if more than one they
are placed one on the top of the other with a loose or close fit. The
heat retaining vessel or shell has a lid with a pipe for waste stcam or
air. The boiler may be without special lid, the same being formed by
the heat retainer or cooking vessel bottom. Or the sides of the boiler
may be made high enough to cover the cooking vessel and have a lid
with a waste pipe, or quite low with a close fitting cap with fixed or
removeable top covering the cooking vessels. The steam in the last case
ascends between cap and cooking vessels and escapes thro' a waste
pipe. The cap may also be made with a fixed perforated bottom ou
which the cooking vessels stand and with a removeable lid. The cap
should be protected from radiation as above similarly mentioned, or it
may be surmounted by a single or double outer cap with or without a
lid fitting closely to the heating apparatus and covering the holes thro'
which the products of combustion otherwise escape, which latter thus
are caused to pass into the space between the two caps and escape thro'
a flue or a hole at the top. In the last-named apparatus the boiler is
filled with water and the cooking vesssel with food with or without
water placed into it. The cooking vessels are then covered by the caps.
If the boiler is left without water the air contained in it and in the inner
cap is heated and the meat roasted if not immersed in water. For the
purpose of roasting and boiling at the same time the food to be roasted
is put into a vessel covered by a lid, and then put in the empty boiler or
rather in an iron pan of the same size. The cooking vessels containing
food and water are then placed on the cover of the roasting vessel and
the caps of the apparatus put on, the inner one may be dispensed with;

page_text: the cooking vessels should then be filled with water, fit closely one on
the top of the other, and the top one have a lid. The hot gases and the
steam conjointly then envelop the cooking vessels. The boiler may
also
be exchanged for a case made of two flat sheets of iron joined some
distance from cach other and on which the cooking vessels are placed.
Another part of the Invention consists in a steam pressure cooking
apparatus. The steam vessel for the same is of usual digestor con-
struction, with a lid, having a safety valve secured to it by a screw and
clamp. Some distance from the bottom inside projecting brackets or a
flange (which may be to detach) are provided for standing the cooking
vessels on. Water is poured into the steam vessel, which is then placed
on the fire; it may be covered with non-conducting material or with a
cap, the hot gases passing between the two before escaping.
A modification of the apparatus is arranged for cooking and roasting
at the same time, and consists in a casing with two or more compart-
ments; it is by preference made with double walls filled in with non-con-
ducting material. Onc compartment is either an entirely covered sheet iron
oven with a door on one side, or this oven may have a dividing perforated
shelf on which is placed the well closed pan containing the meat. The
products of combustion strike the shelf, pass thro' it, round the baking
pan, down over a vertical partition and then thro' an aperture into
the adjoining compartment. The apparatus containing a complete oven
may also have a cooking vessel or receiver placed above the oven for
keeping dishes warm, while roasting and boiling may be performed in
the other compartment. To cook in both at the same time the bottom
plate has an aperture (which is closed by the roasting pan when
roasting), which admits the hot gases and causes them to strike the
pan placed directly above.