IMPROVEMENTS IN HYDRO-EXTRACTORS, OR CENTRIFUGAL MACHINES
Year: 1856

page_text: LETTERS PATENT to Richard Albert Tilghman, of Philadelphia, in the
United States of America, Chemist, for the Invention of "IMPROVEMENTS
IN HYDRO-EXTRACTORS, OR CENTRIFUGAL MACHINES."
Sealed the 16th January 1857, and dated the 1st August 1856.
PROVISIONAL SPECIFICATION left by the said Richard Albert Tilghman
at the Office of the Commissioners of Patents, with his Petition, on the
1st August 1856.
I, RICHARD ALBERT TILGHNAN, of Philadelphia, in the United States of
America, Chemist, do hereby declare the nature of the Invention for "Im-
PROVEMENTS IN HYDRO-EXTRACTORS OR CENTRIFUGAL MACHINES," to be as follows:-
In separating liquid from solid substances by means of the hydro-extractor
or centrifugal machine, the pores of the filtering fabric become gradually
choked or clogged with the solid matter, so that the passage of the liquid is
rendered very slow.
Various plans have been suggested for cleaning the filtering fabric while
the machine is in rotation by means of scrapers, brushes, &c., but their action
has been found imperfect, particularly when clammy substances are treated.
Now my Invention consists in effecting the removal of the solid matter and the
cleansing of the filtering fabric by reversing the surfaces of the said fabric, so
that its inner surface on which the solid matter collects is turned outwards at

page_text: pleasure, and thus allows the solid matter to be thrown off by the centrifugal
force. The way of effecting this reversal of surfaces may be varied. One
method is to arrange on the inside of the wire gauze drum of the machine a
belt of the filtering fabric, the upper edge of which belt is fastened to the
drum at about the middle of its height, and the lower edge of the belt is
fastened to a moveable ring, which can be raised at pleasure, and thereby
inverts or turns inside out the belt of filtering fabric.
Another method is to place round the periphery of the drum one or more
endless bands of the filtering fabric stretched upon rollers, which rollers being
caused to turn, carry with them the endless bands, and thus reverse their
surfaces. Or, the fabric may be stretched upon frames, which being made to
turn upon hinges, will cause a reversal of the surfaces. While the filter is in
its reversed position, and in the act of throwing off the solid matter, water
or other suitable fluid may be thrown on its inner surface, and being carried
through its substance by centrifugal force, will aid in clearing the pores of the
fabric, and in loosening the solid matter from its clogged outer surface.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Albert Tilghman in the Great Seal Patent Office
on the 31st January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ALBERT TILGHMAN, of Philadelphia, in the United States of America, Chemist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the First day of August, in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Richard Albert Tilghman, Her special licence that I, the said Richard
Albert Tilghman, my executors, administrators, and assigns, or such others
as I, the said Richard Albert Tilghman, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to- time and
at all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN HYDRO-EXTRACTORS, OR CENTRIFUGAL MACHINES," upon the
condition (amongst others) that I, the said Richard Albert Tilghman, my
executors or administrators, by an instrument in writing under my; or their, or

page_text: -
one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Richard Albert Tilghman, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
In separating liquid from solid substances by means of the hydro-extractor or
centrifugal machine, the pores of the filtering fabric become gradually choaked
or clogged with the solid matter, so that the passage of the liquid is rendered
very slow. Now my Invention consists in effecting the removal of the solid
matter, and the cleansing of the filtering fabric while the machine is in motion
by reversing the surfaces of said fabric, so that its inner surface on which the
solid matter collects is turned outwards at pleasure, and thus allows the solid
matter to be thrown off by the centrifugal force. The way of effecting this
reversal of surfaces may be varied. One mode is to arrange on the inside of
the wire gauze drum of the machine a belt of the filtering fabric, the upper
edge of which belt is fastened to the drum at about the middle of its height,
and the lower edge of the belt is fastened to a moveable ring, which can be
raised at pleasure, and thus inverts or turns inside out the belt of filtering
fabric.
. Another method is to place round the periphery of the drum one or more
endless bands of the filtering fabric stretched upon rollers, which rollers being
caused to turn, carry with them the endless bands, and thus reverse their
surfaces in a steady and continuous manner. Cr, the fabric may be stretched
upon frames, which being made to turn upon hinges, will cause a reversal of.
the surfaces.
The annexed Drawing represents one mode of carrying the Invention into
effect, the reversal of the filtering fabric being therein produced by means of a
sliding plate, which is the mode of arrangement I prefer, though I do not
confine myself thereto.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWING.
A, A, is the drum or basket of a centrifugal machine, covered with wire net

page_text: to which is secured one end of a belt of filtering fabric C, the other end of
which is secured to the edge of the circular plate D. This plate is fitted to the
shaft E by a feather and slot, and can be moved up and down upon it by
means of the forked lever F. The mode of working is as follows:-The
machine being in motion, the material to be dried or filtered is run in until
a layer of solid matter has collected on the cloth C, the further supply is then
stopped, and the handle of the lever F is pressed down, so as to raise the
plate D to the position shewn by the dotted lines. When the solid matter is
thrown off from the cloth C through the meshes of the wire net; the handle
of the lever F is then raised, so as to replace the filter cloth C in its original
position, and the operation repeated. The outer case of the machine is divided
into two parts G and H; the lower half I receives the filtered-liquid, and the
upper part G receives the solid matter, which is removed at intervals by lifting
the covers K. While the filter is in its reversed position, as shewn by the
dotted lines, and in the act of throwing off the solid matter, water or other
suitable fluid may be thrown on its inner surface through holes made in the
plate D, and being carried through the substance of the fabric by centrifugal
force, will aid in clearing its pores, and in loosening the solid matter from its
clogged surface.
What I claim as my Invention is the effecting the removal of the solid
matter from centrifugal machines, and the cleansing of their filtering fabric, by
reversing the surfaces of said fabric, so that the solid matter is thrown off by
the centrifugal force.
In witness whereof, I, the said Richard Albert Tilghman, have hereunto
set my hand and seal, this Thirtieth day of January, in the year of
our Lord One thousand eight hundred and fifty-seven.
Witness,
GEO. PITT.
R. A. TILGHMAN. (L.8.)