Improvements in Sifting and Dressing Machinery, such as Middlings Purifiers.
Year: 1895

page_text: Date of Application, 13th June, 1895
Complete Specification Left, 22nd Feb., 1896-Accepted, 2nd May, 1896
PROVISIONAL SPECIFICATION.
[Communicated from abroad by WILHELM OSWALT, of Park Strasse, Nanheim,
in the Empire of Germany.]
Improvements in Sifting and Dressing Machinery, such as
Middlings Purifiers.
I, GEORGE HENRY HADDEN, of 36 Bromar Road, Denmark Park, in the County
of London, Shorthand Writer, do hereby déclare the nature of this invention to be
as follows:-
This invention relates to improvements in sifting & dressing machinery such as
middlings purifiers by which the lighter impurities are separated by ascending air
currents from the material as it travels along an oscillating sieve. The chief
object of the invention is to provide for the more efficient elimination of the heavier
impurities by removing them successively at several points in the travel of the
material to be purified down the sieve instead of eliminating them by a specially
strong wiud action at the tail end of the machine as it is at present mostly
the case.
In order to provide for this, I divide the space above the sieve, as usual, into
several compartments, each of which communicates with the exhaust of the fan by
a passage governed by a valve. In each compartment, above the sieve, I provide
suitable baffles which may be of any known kind, such for instance as transverse or
longitudinal channels, or plates with passages through them, or deflectors of other
forms, but I so arrange these baffles that there is a free passage between their ends
Each of those
and the partitions which separate the compartments above.
passages is provided with a valve by which it can be more or less closed, and thus
the force of the air current at the entering end of each section of the sieve may, by
closing or nearly closing the valve at that end, be moderated, while the force of
the current at the tail end of the section, where greater lifting power is required,
may be considerably greater, the valve at that end being open or nearly so.
As the valve at the entering end has usually to be closed, it may in some cases
be dispensed with, no passage being provided past the baffle at that end of the
sieve.
A convenient arrangement of baffle is the following.
. On each side of the sieve is fixed a plate inclined upwards towards the middle
line of the sieve and projecting inwards so as partly to overlap the sieve at each
side; above these plates, which may be adjusted in their inclination or in position
so as to project more or less over the sieve, there are supported, adjustably in
height, two similarly inclined plates, which meet in the middle, forming, as it were,
a roof projecting at each side partly over the inclined plates below.
. The air current passes on each hand out between the upper and lower plates
carrying with it the impurities some of which may be caught on conveying channels
at each side, some of which are deposited on the roof, whence they can slide into
the channels, and some are deposited in suitable chambers in the compartments
above the sieve.
By dividing the sieve into sections as above described, and providing for stronger
air currents at the tails of the several sections, the heavier impurities are raised in

page_text: portions in several places, instead of having to be all raised at or near the tail of
the sieve as is usually the case.
Dated this 10th day of June 1805
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Sifting and Dressing Machinery, such as
Middlings Purifiers.
I, GEORGE HENRY HADDEN, of 36 Bromar Road, Denmark Park, in the
County of London, Shorthand Writer, 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:-
This invention relates to improvements in sifting and dressing machinery such as
middlings purifiers by which the lighter impurities are separated by ascending air
currents from the material as it travels along an oscillating sieve.
The chief object of the invention is to provide against the inequalities of the
purifying action at different parts of the sieve, which inequalities are such that it
would require a considerably greater force of the air current near the tail end of
the sieve, to raise the particles that have to be removed there, than it requires near
the feed end of the sieve. In order to provide for this, I divide the space above the
sieve, as usual, into several compartments, each of which communicates with the
exhaust of the fan by a passage governed by a valve. In each compartment above
the sieve, I provide suitable baffles which may be of any known kind, such for
instance as transverse or longitudinal channels or plates with passages through
them, or deflectors of other forms, but I so arrange these baffles that there is a free
passage between their ends and the partitions which separate the compartments
above. Each of those passages is provided with a valve by which it can be more
or less closed, and thus the force of the air current at the entering end of each
section of the sieve may, by closing or nearly closing the valve at that end, be
moderated, while the force of the current at the tail end of the section, where
greater lifting power is required, may be considerably greater, the valve at that
end being open or nearly so. As the valve at the entering end has usually to be
closed, it may in some cases be dispensed with, no passage being provided past the
baffle at that end of the sieve.
A convenient arrangement of baffle and valve is shewn in the accompanying
drawings.
Fig. 1 is a transverse section of the sieve and baffle.
Fig. 2 is a longitudinal section and Fig. 3 is a plan of one of the compartments
above the sieve.
On each side of the sieve S is fixed a plate P inclined upwards towards the
middle line of the sievė and projecting inwards so as partly to overlap the sieve
at each side; above these plates P which may be made to project more or less
over the sieve, there are supported, adjustably in height, two similarly inclined
plates Qwhich meet in the middle, forming as it were, a roof projecting at each
side partly over the inclined plates below. The air current passes on each hand 4
out between the upper and lower plates (as indicated by the arrows in Fig. 1)
carrying with it the impurities some of which may be caught on conveying
channels C at each side, some of which are deposited on the upper sides of the
plates whence they can slide into the channels C and some are deposited in
suitable chambers in the compartments above the sieve.
The roof shaped space under the plates Q is closed at each end by a plate R at
some distance from the partition B that separates the compartment from the next,

page_text: and the passage upwards between R and B is provided with valve V which can be.
closed, as shewn at the left end of the compartment, or more or less opened, as
shewn at the right end.
Stepped springs D may be used to hold the valves in various positions.
By dividing the sieve into sections as above described, and providing for stronger
air currents at the tails of the several sections the heavier impurities are raised in
portions in several places, instead of having to be all raised at or near the tail of
the sieve as is usually the case.
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. In a middlings purifier, in each of the compartments above the sieve a baffle
of such length as to leave passages for air upwards between its ends and the
partitions which separate the compartments, substantially as and for the purposes.
set forth.
2. The construction of the baffle above referred to in form of a roof overlapping
adjustable plates sloping upwards and inwards from the sides of the sieve, substan-
tially as described.
3. In combination with the baffle referred to in Claim 1 adjustable valves.
arranged in the passages at its ends, substantially as and for the purpose set.
forth.
D
1
1 1
2 TL
1000
ABEL & IMRAY,
Agents for the Applicant.