Improvements in or connected with Filter Press Cloths.
Year: 1891

page_text: Date of Application, 30th Sept., 1891-Accepted, 31st Oct., 1891
COMPLETE SPECIFICATION.
Improvements in or connected with Filter Press Cloths.
I, OTTO DANIEL DROOP, of Calle Teniente Rei 4, Havannah, in the Island
of Cuba, Importer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
Filtering cloths made of jute, hemp, or cotton for mechanical filtering presses, as
at present used in sugar factories, consist of a single piece of cloth, which is made
of the width of the filtering plates, and of length equal to the double length of the
plates. These filtering cloths are sewn at the edges in an overlapping manner and
hang on the vertical or horizontal plates covering each side with one half of the
cloth. By this mode of hanging, it frequently happens that the cloths are not
hung parallel with the frames, and that they project more on one side of the
filtering plates than on the other, so that one side of the filtering plate is not
thoroughly covered by the cloth. It may also easily happen by this mode of
hanging that a fold is formed. In consequence of these inequalities an imperfect
filtration results, a portion of the juice passing unfiltered through the press.
To avoid this objection is the object of the present invention, which consists in
the introduction and employment of a cross seam on the cloth, that has been folded
double, below the edge, and the placing of the cloth on this seam over the upper
edge of the filtering plate, in such a way that one half of the cloth hangs over each
side of the filter plate.
A filtering cloth formed in accordance with this invention is represented in the
annexed drawing, in which
Figure 1 is a side view; and
Figure 2 a front view.
Figure 3 represents a filter-press, which is supplied with filter-cloths in accordance
with this invention.
The filter-cloth a is cut to such a length that it is about 5 c. m. longer than the
double length of the filter-plate; and the cloth is bent over at b in such a manner
that both parts have an equal length. About 2 c. m. below the edge 6 a seam c
is sewn from one edge to the other so that both halves of the cloth are joined. By
doing this, a strip or ledge is produced over the seam c.
If the cloth is to be hung
up the ledge d is taken hold of, and the two cloth halves are brought over the two
surfaces of the filter-plate e, so that the seam c rests on the upper edge of the filter-
plate e. Care must be taken to keep the ledge d parallel with the upper edge of
5 the filter-plate. The ledge & supplies a handle for each cloth, which hangs itself
automatically evenly on both sides of the filter-plate in equal lengths.
When the cloths are hung and the press is ready for work, the ledges & must run
at equal distances over the upper edge of the filter plates and parallel to each
other, so that the operator will see at a glance, before beginning the work, that all the
cloths have been properly hung. After the operation of filtering has terminated,
the cloths can be easily removed, since the ledge d offers a convenient handle to
catch hold of the cloths, and shake off adhering particles of the pressed matter.
With filter-cloths hitherto in use it was necessary to sew the under edges to lap
over; a seam was in all cases to be avoided, as in the case of a defective hanging
5 it might interfere with the filter presses, which would cause a breaking of the plates
when screwed together. With the arrangement, as set forth in the present
invention, the filtering cloth can be made with a double, or trebly folded seam f,
which can be stitched by a sewing machine, as then the cloths can be hung on very
accurately; and there is then no danger of the seam getting into the press. The
O production of such a seam also is cheaper than a hand-made overlapping seam,

page_text: since it can be made with a sewing machine. Then again the seam does not get
undone or tear, as is the case with the hand stitched cloths. The new cloths are
therefore more durable.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The herein described filter-press cloths, consisting of a double cloth having a
ledge or projecting part or parts (d) provided on said cloths; for the purposes
set forth.
L
2. The filter-press cloths constructed as herein set forth with reference to and as 1
1
wings.
29th day of September 1891.
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicant's Patent Agents.
CHEESBROUGH & ROYSTON, Fels. Chart. Inst. P.A.,
15, Water Street, Liverpool, Applicant's Patent Agents.