ARTIFICIAL FREEZER.
To all whom it may concern:
Be it known that I, NANCY
M. JOHNSON of the city of Philadelphia and
State of Pennsylvania, have invented a new and useful improvement in
the Art of Producing Artificial Ices, and that the following is a full
and exact description of the machinery for carrying into effect the
said improvement.
Instead of causing the freezer or vessel A (see the accompanying
drawing) which contains the substance to be frozen to revolve as
heretofore has been practiced, within the ice and salt mixture, by the
hands of the operator, I place within it a vertical shaft or axis B,
reaching to the bottom and coming up a short distance above the cover
of the freezer, through which it passes in a tube C, traversing
centrally, the lid and its handle, which tube thus becomes the upper
support of the said shaft or axis—the top of this shaft or axis is
terminated by a square shank D, on which after the lid is placed over
it a crank E having a wooden or other nonconducting handle can be
placed to give motion to the shaft.
On the shaft below the lid of the freezer are two or more wings F, F,
extending to the bottom and reaching horizontally nearly to the sides
of the same, these wings are generally perforated with a number of
holes about half an inch or more in diameter: when but two wings are
used they form together a curved figure by their horizontal cross
section resembling the letter S reversed, thus , so that when the
revolutions are made by carrying the hand from right to left between
the axis and the operator, the vertical edges of the beater tend
constantly to carry the liquid or semi-fluid mass from the center to
the circumference of the containing cylinder or freezer and that on
the contrary when he turns the crank from left to right between himself
and the shaft, it will tend to cut off any frozen matter from the inner
surface of the freezer and to gather it toward the central parts, thus
constantly allowing fresh portions of the cream or other substances to
be frozen to come in contact with the refrigerating surface.
To confine the freezer itself and prevent its revolving with the beater
when the materials within it become stiff, the handle on the lid G is
embraced in a groove or cavity H formed in the under side of the cover
which is placed over the wooden tub or box I, within which the freezing
is conducted. This cover is itself prevented from turning by notches a,
a which take hold of the two ears, b, b, of the tub, the tub being thus
covered, the salt and ice as well as the freezer and its contents are
defended from the heat of the air and of the person of the operator.
The lower end of the shaft of the beater is generally formed into a
rounded pivot resting in a corresponding cavity in the bottom of the
freezer.
I do not confine myself to any particular material in the construction
of the freezer or beater for lemon, orange and other juices containing
acid which might react slightly upon tinned iron, I prefer glass
cylinders for freezers and hard wood or ivory for the wings of my
beater, for cream and other substances which are not acid in their
properties, the thickest of tinned iron is the most suitable material
of which to form the beater.
When the substance to be frozen is placed in a freezer formed of two
concentric cylinders and having ice and salt in a central cylinder
the beaters may be attached to horizontal arms on the main vertical
axis and go down on opposite sides of the central refrigerating
cylinder.
In seasons and at places where the economy of ice and salt is
important, I make use of a tub or box whose diameter exceeds that of
the freezer only by three or four inches and by closely wrapping this
in several folds of thick woolen blanket or blanket padded with wool,
fur or some similar material having a low conducting power for heat, I
am enabled so to defend the contents of the same from the action of
external heat as greatly to diminish the quantity of these materials
necessary to produce and maintain the low temperature required for
congelation.
When the economy of salt is particularly important, I effect it by
evaporating the salt water derived from the salt and ice, thus making a
very limited quantity of salt serve for an indefinite number of
operations.
What I claim as new in this my invention and for which I desire to
obtain Letters Patent is—
The above described revolving curved beater with its vertical axis, in
combination with a freezing apparatus described and adapted to the
purpose herein set forth.
In the presence of—
JOHN THOMPSON,
SAMUEL DAY.
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