An Improved. Device for Retaining Heat in Foods or other Matters.
Year: 1894

page_text: COMPLETE SPECIFICATION.
An Improved. Device for Retaining Heat in Foods or other Matters.
I STEFAN MARIA BOGUMIL VON SZCZAWINSKI of Untergrünewalder-strasse 30
Elberfeld in the Empire of Germany, Gentleman, 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 :-
The apparatus described hereinafter is intended to meet a generally felt
requirement namely to keep hot foods or beverages for a long time in a warm or
hot condition, so that they may be consumed for instance in the open air or away
from the place where they were prepared, or to keep milk and other nourishment
ready for use during night-time without the necessity of warming them by means
of a burner or lamp which is inconvenient and not unconnected with danger.
The principle of this improved apparatus remains in all cases the same, only the
method of constructing the apparatus may vary to adapt it to the respective
circumstances.
The annexed drawing illustrates a form of the device adapted for instance where
milk for an infant is to be kept warm during the night time and shows the apparatus
adapted to receive a milk bottle of cylindrical shape.
Fig. 1 is an elevation of the device with its cover open and Fig. 2 a vertical
section thereof with its cover closed.
Fig. 3 shows in front elevation the device adapted to receive for instance two
bottles.
The hollow space A open at the top is at the bottom and round about bounded
and constituted by the double walled vessel B, which again is surrounded by a
larger double walled vessel C.
By means of the likewise double walled cover D, the inner space A can be
secluded from the outer air, cover D and vessel C are connected by hinges.
The walls of the vessel B are filled with a substance (for instance a salt, such as
acetate of soda) which possesses as high a temperature and latent heat of fusion as
possible; however preferably the fusing point should not be above 100° C. in order
that boiling water may be used for melting the said material. Otherwise, that is to
say for substances of a higher fusing point, furnace heat would be requisite.
The vessel B filled with such substance can be taken out of the outer vessel C
by means of its bail or handle (shown in Fig. 1) after first the cover has been
opened; if then the vessel B is dipped into boiling water, the substance with which
its walls are filled becomes liquid and takes up a large amount of latent heat. In
this state the vessel B is again inserted into the outer vessel C and then, the object
(milk bottle) to be kept warm during the night or otherwise is placed into the
hollow space A and the cover D is closed.
The hollow spaces within the walls of the vessel C and cover D are filled with a.
bad heat conducting material such as silk refuse, cork, silicious sinter etc. and thus
the liquified substance in the vessel B is prevented from radiating its heat outwards,
so that the heat stored up can be used almost completely for keeping warm the
milk bottle or other receptacle containing food, while the latent heat only becomes
free very slowly according to the kind of heating substance chosen for filling the
walls of vessel B.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
An improved device for keeping warm food or other matter wherein the latent

page_text: or other heat of a salt or other suitable body placed in a suitable hollow vessel B
and liquified by boiling water or other previous application of heat is prevented
from being lost by outward radiation by means of a non conducting surrounding C
so that the heat is reserved for the hollow space A adapted to receive a vessel
-containing the food or matter to be kept warm, substantially as set forth.
Dated thin 10th day of Lu 1901
R. HADDAN,
Of the Firm of Herbert Haddan & Co.,
18, Buckingham Street, Strand, London, W.C., Agent for Applicant.