IMPROVEMENTS IN FILTERS AND FILTERING APPARATUS
Year: 1869

page_text: LETTERS PATENT to Charles Anthony Ofverberg, of Finsbury, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN FILTERS
AND FILTERING APPARATUS."-A communication from abroad by
PROVISIONAL SPECIFICATION left by the said Charles Anthony
Öfverberg at the Office of the Commissioners of Patents, with his
Petition, on the 23rd October 1869.
I, CHARLES ANTHONY ŌFVERBERG, of Finsbury, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN FILTERS AND FILTERING APPARATUS," to be as follows:-
The first part of my Invention consists in the manufacture and
employment of a new filtering agent or filtering medium. This agent
or medium is wool or woollen stuff, ground, cleaned, made into a pulp,
and then submitted to pressure, which transforms it into a felt-like
substance; in this form it is kept until required for use. When required
for use it has mixed with it water or other liquid, by preference some of

page_text: the liquid or solution to be filtered, and the mixture is worked up into a
pasty or semi-liquid state free from lumps. This mixture is then placed
in the filtering apparatus.
The second part of my Invention relates to the filtering apparatus. I
construct apparatus as follows:-I take a vessel of cylindrical or other
form and place therein first a perforated plate of metal, china, or other
suitable material, then upon this plate I place a filtering cloth or strainer;
upon this strainer I place some of the mixture herein-before described so
that the mixture nearly fills the vessel; above the mixture I place another
cloth or strainer, and then another perforated plate; I next put upon
the vessel a cover provided with a screw passing through the same into
the vessel. By turning this screw the upper perforated plate is forced
downwards so as to express the greater part of the liquid from the
mixture, which is now packed closely together and fills up the entire
space between the strainers. The liquid to be filtered may then be
forced under pressure into the vessel below the lower perforated plate,
and it passes through the plates, strainers, and filtering medium, and
finally issues by an outlet at the upper part of the vessel.
For filtering when pressure is not used the liquid to be filtered is
supplied at the upper part of the vessel, and filters down through the
apparatus. The screw or pressing apparatus may in this case be
dispensed with, the necessary pressure being exerted by hand.
The shape and dimensions of the vessel, the material of which the
Vessel and the perforated plates are made, and the number of perforated
plates and strainers will depend upon the nature of the liquid to be
filtered.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Anthony Ofverberg in the Great Seal
Patent Office on the 23rd April 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES 3
ANTHONY OFVERBERG, of Finsbury, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of October, in the
year of our Lord One thousand eight hundred and sixty-nine, in the 3

page_text: thirty-third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles Anthony Öfverberg, Her special
licence, that I, the said Charles Anthony Öfverberg, my executors,
administrators, and assigns, or such others as I, the said Charles Anthony
Ofverberg, 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,
usc, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN FILTERS AND FILTERING APPARATUS," (communicated to
me from abroad by lampus Oldenburg, of Stockholm, Sweden,) upon
the condition (amongst others) that I, the said Charles Anthony
Ofverberg, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and scals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, 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 Charles Anthony Ofverberg, 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, reference being had to the
accompanying Drawings, that is to say:-
The first part of the Invention consists in the manufacture and
employment of a new filtering agent or filtering medium. This agent
or medium is wool or woollen stuff ground, cleaned, made into a pulp,
and then submitted to pressure, which transforms it into a felt-like
substance; in this form it is kept until required for use. When required
for use it has mixed with it water or other liquid, by preference some of
the liquid or solution to be filtered, and the mixture is worked up into a
pasty or semi-liquid state free from lumps; in this state it is placed in
the filtering apparatus. In many instances it is sufficient to mix cold
water with the material in order to make it into a pulp; but for beer or
wine free from alcohol the material should be dissolved in boiling water,
and if several liquids are to be filtered consecutively the material may
be cleaned without being disturbed by pouring hot water through the
apparatus until it comes out free of tasto. For oils the material should
be soaked in some of the oil for 10 or 12 hours, and then rubbed by the

page_text: hands into a pulp. In some cases in making my new filtering medium
I mix a small proportion of ground flax or ground raw silk with
the ground wool.
The second part of the Invention relates to the construction of
filtering apparatus adapted for using my new filtering medium. I
construct apparatus as follows:-I take a vessel of cylindrical or other
form, for instance a cylindrical vessel, like that represented at a in
Figures 1 and 2, which respectively represent a vertical section and
a plan of one of my apparatus. I place in this vessel first a perforated
plate 6 of metal, china, wood, or other suitable material; this plate may
rest upon a circular rib c fixed to the inside of the vessel; upon the
plate I place a filtering cloth or strainer d, and upon this strainer I
place some of my filtering material (marked e) made into a pulpy state
as before explained, the material being made to fill, say, about one-half
of the vessel; above the material I place another cloth or strainer f, and
then another perforated plate g. It is now necessary to express the
greater part of the liquid from the material e so as to pack the material
closely together, and make it fill up the entire space between the strainers.
For this purpose I prefer to employ a screw worked by a handle i;
this screw passes through a piece k which rests upon the top of the
vessel a, and which is held in place by the two half covers 1, 2, of the
vessel, and by pins m; the lower end of the screw bears upon a piece n
resting on two rods or rollers o on the upper perforated plate g. By
rotating the screw the plate g is forced downwards, and the material e
is thereby compressed into about the capacity seen in Figure 1. The
liquid to be filtered may then be forced under pressure into the vessel;
it enters by the inlet p, and passing up through the plate b, strainer d,
filtering material e, strainer f, and plate 9 it issues by the outlet 2. In
Figure 2 one of the half covers is shown removed.
For filtering when pressure of the liquid to be filtered is not used the
liquid is supplied at the upper part of the vessel and filters down through
the apparatus. The screw or pressing contrivance may in this case be
dispensed with.
Figure 3 shows in vertical section an apparatus suitable for filtering
without the liquid being subjected to pressure. The vessel a has placed
in it a perforated plate b, and two filtering cloths d and f; the filtering
materiale is between the cloths as before, and is pressed down firmly
with the hands before the upper cloth is inserted; the upper cloth is

page_text: kept in place by means of a rod r with a cork or pads at each end made
to fit tightly across the vessel. The liquid to be filtered is poured into
the vessel, and after having passed through the strainers, filtering
material, and perforated plate it issues by the outlet q. t is an air
pipe. Figure 4 represents a vertical section of an apparatus of funnel
form.
The shape and dimensions of the vessel, the material of which the
vessel and the perforated plates are made, the number of perforated plates
and strainers, and the amount of filtering material employed will depend
upon the nature of the liquid to be filtered.
And having now described the nature of the said Invention, and in
what manner the same is to be performed, I declare that I claim,—
First. The manufacture and employment of the new filtering agent or
filtering medium herein-before described.
And, secondly. Constructing filtering apparatus, substantially as hercin-
before described and represented in the accompanying Drawings.
In witness whereof, I, the said Charles Anthony Öfverberg, havo
hereunto set my hand and seal, this Twenty-third day of April
One thousand eight hundred and seventy.
Witness,
J. C. MEWBURN,
Patent Agent,
172, Fleet Street,
London.
C. A. OFVERBERG. (L.s.)