IMPROVEMENTS IN COFFEE POTS
Year: 1876

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN COFFEE
POTS." A communication from abroad by George Watts Hubbard, of Windsor,
in the County of Windsor, and State of Vermont, United States of America.
Sealed the 14th October 1876, and dated the 16th May 1876.
PROVISIONAL SPECIFICATION left by the said William Clark at the Office
of the Commissioners of Patents on the 16th May 1876.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "IMPROVEMENTS IN COFFEE POTS."
The essential feature of the Invention consists of a curb surrounding the upper
part of funnel employed to force the hot water up through the pipe by which it
is conducted into the percolating cup, and also surrounding the lower end of the
percolating cup with a space between it and said lower end so that in descending
from the percolating cup the liquid takes an upward turn in passing under the cup
and over the curb, which tends to deposit all sediment escaping from the percolating
cup within said curb where it is separated from the liquor, so that it is cleaner and
purer.
Another feature of the Invention is an annular elevation of the outer margin of
the bottom of the pot under the annular space between the aforesaid curb and the
shell of the pot, through which the water descends to the space under the funnel
for being heated again to prevent counter currents by the forcing of water up in
said space which would be the case if that part of the bottom rested on the stove
the same as the rest.
The outer shell of the pot is of the ordinary construction excepting that its sides
are nearly or quite parallel and that the middle portion of its bottom is slightly
depressed. An inverted funnel of a diameter somewhat less than that of the interior
of the pot is supported by short legs a short distance above the bottom of the pot.
Attached to the middle of the funnel is a tube, the upper portion of which is per-
forated with small openings around, and attached to the base of the funnel is a curb,
and one or more small holes for drainage are made in the funnel near its base.
A filtering cup having a gauze or perforated bottom fits freely into the inside of
the pot, being supported at a proper height in the same either by resting upon the
upper edge or upon projections upon the interior of the shell. The bottom of the

page_text: cup projects inside of and below the upper edge of the curb, and is of such diameter
as to leave an annular passage between the two. In the middle of the bottom of
the cup an opening is made to allow its freely passing over the central perforated
tube.
The operation of the improved coffee pot is as follows:-The ground coffee is put
into the filtering cup lying upon its bottom; sufficient water, preferably boiling, is
then poured into the pot either through the tube or upon the coffee until the entire
interior is filled to any proper height; heat is then applied to the middle portion of
the bottom of the pot, which by incans of the depression may be readily done by
placing the pot upon a stove, the effect being to cause the water to boil over the
depressed surface in the latter, and by reason of the funnel and perforated tube to rise
slightly in the latter and to flow outward through the perforations in the tube into the
filtering cup and amongst the coffee, a portion of which will have floated to the
surface of the water in the pot. The accumulating water in the cup filters slowly
through the ground coffee and screen into the settling cup below, and by reason of
the curb extending above the bottom of the cup is compelled to flow upward in its
further passage toward the bottom of the pot, causing it to deposit whatever
sediment it may have carried through the screen upon the upper face of the funnel
at its junction with the curb. Continuing its course it passes over the upper edge
of the curb downward and under the funnel to be again neted upon by the heat
applied to the bottom and to repeat the above described circulation until the
strength of the ground coffee is sufficiently extracted. The action of the heat being
limited by the depression to the middle portion of the bottom of the pot an upward
current in the passage is prevented.
In this pot the screen and coffee are kept as low down as is practicable, generally
considerably below the water line, by which means a slight boiling under the
funnel is sufficient to compel the circulation of water above described.
In case of excessive ebullition the water overflows at the top of the perforated
tube, but I do not consider this necessary or particularly desirable.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Clark in the Great Seal Patent Office on the 7th November
1876.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "IMPROVEMENTS IN COFFEE POTS." A communication from abroad by
George Watts Hubbard, of Windsor, in the County, of Windsor, and State of
Vermont, United States of America.
The essential feature of this Invention consists of a curb surrounding the upper
part of the funnel employed to force the hot water up through the pipe by which
it is conducted into the percolating cup and also surrounding the lower end of the
percolating cup with a space between it and said lower end so that in descending
from the percolating cup the liquid takes an upward turn in passing under the cup
and over the curb which tends to deposit all sediment escaping from the percolating
cup within said curb where it is separated from the liquor, so that it is cleaner and
purer.
Another feature of the Invention is an annular elevation of the outer margin of
the bottom of the pot under the annular space between the aforesaid curb and the
shell of the pot, through which the water descends to the space under the funnel
for being heated again to prevent counter currents by the forcing of water up in
said space, which would be the case if that part of the bottom rested on the stove
the same as the rest.
The Drawing shows a sectional elevation of the improved coffee pot.
A represents the outer shell of the pot which is of the ordinary construction
excepting that its sides are nearly or quite parallel, and that the middle portion of

page_text: its bottom at a, a, is slightly depressed. C is an inverted funnel of a diameter
somewhat less than that of the interior the pot, and which is supported as by
short legs Da short distance above the bottom of the pot. Attached to the middle
of the funnel C is the tube H, the upper portion of which is perforated with small
openings, as shown in the Drawing. Around and attached to the base of the
funnel C is a curb K, and one or more small holes c for drainage are made in the
funnel C near its base.
The filtering cup G having a gauze or perforated bottom g, g, fits freely into the
inside of the pot, being supported at a proper height in the same either by rosting
upon the upper edge or upon projections upon the interior of the shell A. The
bottom of the cup G projects inside of and below the upper edge of the curb K, and
is of such diameter as to leave an annular passage K between the two. In the
middle of the bottom of the cup G' an opening g', gl, is made to allow its freely
passing over the tube.
The operation of the improved coffee pot is as follows:-The ground coffee is put
into the filtering cup G lying upon its bottom, as shown at L, L, sufficient water,
preferably boiling, is then poured into the pot either through the tube or upon the
coffee L, L, until the entire interior is filled to any proper height, as M, M. Heat
is then applied to the middle portion of the bottom of the pot, which by means of
the depression a, a, may be readily done by placing the pot upon a stove, the effect
being to cause the water to boil over the depressed surface a, a, and by reason of
the funnel C and tube H to rise slightly in the latter above the line M, M, and to
flow outward through the perforations in the tube H into the cup G and amongst
the coffee L, L, a portion of which will have floated to the surface of the water in
the pot. The accumulating water in the cup G filters slowly through the ground
coffee L, L, and screen g, g, into the settling cup below, and by reason of the curb K
extending above the bottom of the cup G is compelled to flow upward in its further
passage toward the bottom of the pot, causing it to deposit whatever sediment it
may have carried through the screen g, g, upon the upper face of the funnel Cat
its junction P with the curb K. Continuing its course it passes over the upper edge
of the curb downward through the passage n, n, and under the funnel C to be again
acted upon by the heat applied to a, a, and to repeat the above described circula-
tion until the strength of the ground coffee is sufficiently extracted. The action of
the heat being limited by the depression a, a, to the middle portion of the bottom
of the pot an upward current in the passage n, n, is prevented.
In this pot the screen g, g, and coffee L, L, are kept as low down as is practicablo
generally considerably below the water line M, M, by which means a slight boiling
under the funnel C is sufficient to compel the circulating of water above described.
In case of excessive ebullition the water overflows at the top of the tube H, but I
do not consider this necessary or particularly desirable.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,-
1st The combination of curb K with the funnel C and percolating cup G substan-
tially in the manner shown and described.
2nd. In a coffee pot having the funnel C and pipe H for the upward flow of the
water, and the annular space n for the downward passage, the bottom having the
nargin under said passage n elevated above the portion a under the funnel, sub-
stantially as specified.
In witness whereof, I, the said William Clark, have hereunto set my hand
and seal, this Sixth day of November, in the year of our Lord One thousand
W. CLARK. (L.S.)