IMPROVED APPARATUS FOR OBTAINING EXTRACTS FROM TEA, COFFEE, AND OTHER VEGETABLE SUBSTANCES
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Edward Loysel at the Office of
the Commissioners of Patents, with his Petition, on the 6th June
1864.
I, EDWARD LOYSEL, of Manor House, Old Town, Clapham, in the County
of Surrey, Civil Engineer, do hereby declare the nature of the said Invention
for "IMPROVED APPARATUS FOR OBTAINING EXTRACTS FROM TEA, COFFEE, AND
OTHER VEGETABLE SUBSTANCES," to be as follows:-
My Invention of improved apparatus for obtaining extracts from tea,
coffee, and other vegetable substances, relates to a novel construction of
apparatus in which the infusion or extract of the vegetable substance is forced
by the pressure of air through a filtering medium into a vessel or receptacle
conveniently placed to receive the clear liquid extract. To this end the
apparatus is divided into two principal parts, consisting of two distinct.
vessels, which by preference should be made separate, but so that they may
be connected together with an air-tight joint. The upper vessel receives the
vegetable substance to be operated upon, and which must be ground up or
reduced to a coarse powder as usual with coffee. This upper vessel is pro-
vided at its lower end with a perforated false bottom on which the ground
coffee, tea, or other vegetable substance is placed, and the vessel is then filled
with boiling water. Beneath the false bottom is a chamber provided with a
double-action stop-cock, and from this chamber rises a vertical pipe, the
lower end of which communicates with one of the passages of the stop-cock,
while the other end is open, so that a clear passage is made from the lower
vessel through the upper one to the external air. The other opening of the

page_text: stop-cock forms a communication between the chamber beneath the false
bottom of the upper vessel and the capacity of the lower vessel, which is the
recipient for the vegetable extract when it passes through the filtering
medium. If the two vessels are made separate the upper one must be
provided with a packing joint whereby it may be fitted air-tight into the neck
or other convenient part of the lower one, so as to convert the latter into a
close chamber. Beneath this lower vessel a spirit lamp or other flame for
heating the same is placed, and in using the improved apparatus a small
quantity of water must be introduced into the lower vessel in order to be
converted into steam by the heat from the lamp or flame below. While this
is taking place the stop-cock should be so turned that a free communication
from the lower vessel up the vertical pipe in the upper vessel is kept up with
the external atmosphere. While this is going on the infusion of the tea or
coffee is proceeding, and an extract is being produced. By the generation of
steam in the lower vessel the air will be expelled therefrom, and upon
removing the flame from below and closing the stop-cock the generation of
steam will be stopped and condensation will commence, thereby creating a
partial vacuum in the lower vessel. The pressure of the air on the surface
of the infusion or extract in the upper vessel will force the liquid through the
filtering medium into the chamber below the false bottom, and from thence
through the second aperture in the stop-cock into the lower vessel. When
all the liquid extract has passed into the lower vessel the upper vessel may be
removed, and the lower vessel being provided with a suitable lid and spout
the clear liquid may be poured therefrom as may be required. For some
purposes it may be found convenient to connect the upper and lower vessels
permanently together, I therefore reserve to myself the right to do so in all
cases where it may be desired. The principle of my Invention may be
applied to obtaining extracts from various other vegetable substances besides
tea and coffee, and may be not only carried out on a small scale for domestic
purposes, but also on a large scale for obtaining infusions, decoctions, or
extracts from drugs, malt, hops, and other vegetable substances.