IMPROVE- MENTS IN THE CONSTRUCTION OF APPARATUS FOR PURIFYING MIDDLINGS,' OR FOR CLEANING GRAIN OR SEEDS
Year: 1877

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LETTERS PATENT to Abraham Crabtree, of Bacup, and Lewis Firth, of
Rochdale, in the County of Laucaster, for the Invention of IMPROVE-
MENTS IN THE CONSTRUCTION OF APPARATUS FOR PURIFYING MIDDLINGS,' OR
FOR CLEANING GRAIN OR SEEDS."
'
Sealed the 2nd November 1877, and dated the 25th July 1877.
PROVISIONAL SPECIFICATION left by the said Abraham Crabtree and Lewis
Firth at the Office of the Commissioners of Patents on the 25th July 1877.
ABRAHAM CRABTREE, of Bacup, and LEWIS FIRTH, of Rochdale, both in the
County of Lancaster. "IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS for
PURIFYING MIDDLINGS,' OR FOR CLEANING GRAIN OR SEEDS."
"
This Invention relates principally to apparatus intended to be applied to the
middlings purifier," for which Letters Patent, dated April 10th 1875, No. 1304, were
granted to the said Abraham Crabtree, but it can be used also in connection with
other purifiers, and can be placed either above or below the silk or other sieve (or
both above and below); or it can be used alone for purifying middlings" or
cleaning all kinds of grain or seed, either whole or more or less broken or crushed.
The Invention consists chiefly of a series of sloping boards placed one above the
other, and sloping alternately in opposite directions, so arranged that when the
middlings or grain falls from the hopper and feeding rollers above on to the upper
board it rolls down the sloping surface thereof, and falls from its lower edge on to
the higher edge of the board next below, which slopes in the opposite direction.
It then runs down this board and falls on to the next, aud so on in succession.
The apparatus is provided with an exhausting fan upon one side of the series of
sloping boards, and with a partition on the other side, having narrow slits or openings
opposite each space between the sloping boards, so that when the fan is put into
operation a current of air is drawn in through each of these narrow slits or openings
and between the sloping boards, and passing through the middlings or grain as it
Price dl

page_text: falls from one board on to the other, it carries away all the dust, fluff, and lighter
particles, and allows the heavier "middlings" or grain to fall on to the board
beneath. It is delivered from the lowest board, on to the silk or other sieve, and
after being sifted it may again fall on to another similar series of sloping boards
if required.
Between the sloping boards and fan there is also a partition, either
made like a Venetian blind or with narrow slits or openings opposite to the spaces
between the boards, for the purpose of arresting any comparatively heavy particles
which may have been drawn with the dust, fluff, and lighter particles by the current
of air. These particles fall on to a false bottom or sloping board beneath, which
delivers them on to the lowest of the series of sloping boards first named, where
they mix with the other heavy particles.
Arrangements are made for opening or closing, more or less, the spaces between
the sloping boards and the narrow slips or openings in the partitions, so as to
regulate the current of air to suit the nature of the material to be operated upon.
In some cases we propose to make the air duct leading to the fan wider as it
approaches the latter, so as to diminish the intensity of the current, and to allow
other still lighter particles to fall, and only to carry off the dust and the very lightest
particles with the air.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Abraham Crabtree and Lewis Firth in the Great Seal Patent Office
on the 23rd January 1878.
ABRAHAM CRABTREE, of Bacup, and LEWIS FIRTH, of Rochdale, in the County
of Lancaster. "IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUS FOR
PURIFYING 'MIDDLINGS, OR FOR CLEANING GRAIN OR SEEDS."
This Invention relates principally to apparatus intended to be applied to the
"middlings purifier," for which Letters Patent, dated April 5th* 1875, No. 1304,
were granted to the said Abraham Crabtree, but it can also be used in connection
with other purifiers, and can be placed either above or below the silk or other
sieve (or both above and below the same); or it can be used alone for purifying
or cleaning all kinds of grain or seed, either whole or more or less broken or
crushed.
The use of this Invention will keep the screen room perfectly free from dust, and
will thus prevent the accumulation of dust and grit on the bearings, which is a
frequent cause of their heating, and it will thus lessen the danger of fires in the
mill.
Such being the nature and object of our said Invention we will now proceed to
describe in detail the manner in which the same is to be or may be performed or
carried into practical effect, and in order that the same may be clearly understood
we have annexed hereunto a Sheet of Drawings illustrative thereof, and have
marked the same with figures and letters of reference, corresponding with those in
the following explanation thereof.
Fig. 1 in the annexed Drawing is a longitudinal section taken vertically through
about the centre of the annaratus

page_text: Fig. 2 is a front view of the feeding arrangement (drawn to a larger scale), and
Fig. 3 is a transverse section of the same.
The Invention consists principally of a series of sloping boards or metal
shelves a, a, placed one above the other, and sloping alternately in opposite directions,
so arranged that when the middlings or grain falls from a hopper b, b, and feeding
roller or rollers c, c, on to the upper board or shelf at a', a', it rolls down the sloping
surface thereof, and falls from its lower edge on to the sloping board or shelf a², a²,
next below, which slopes in the opposite direction. It then runs down this board or
shelf and falls on to the next, and so on in succession.
In the arrangement shown in the Drawing at Fig. 1, there is one series of sloping
boards or shelves a, a, between the hopper b, b, and the silks or sieves d, d, and
other series of sloping boards or shelves placed beneath the latter, but this arrange-
ment may be varied at discretion.
The apparatus is provided with an exhausting fan e, e, upon one side of the
sloping board, and the other side may either be left open, as shown at f, f, in the
Drawing, or it may be provided with a partition having narrow slits or openings
opposite each space between the sloping boards, so that when the fan e, e, is put into
operation a current of air is drawn in between the sloping boards, and passing
through the middlings or grain, as it falls from one board on to the other, it carries
away all the dust and lighter particles, and allows the heavier middlings or grain to
fall on to the board beneath. It is delivered from the lowest board on to the silk or
sieve d, d, and after being sifted it may again fall on to another similar series of
sloping boards a, a, if required. This second set of sloping boards is similar to the
first set, and is provided with a second exhausting fan e', e, the trunk or passage g, g,
leading from which is so arranged as to draw the air first from the compartment
furthest from the fan where the heaviest particles are. Between the sloping
boards a, a, and the fan in each instance there is a partition h, h, made with narrow
slits or openings opposite the spaces between the sloping boards or shelves a, a, and
which can be closed, more or less, as may be required, by means of regulating
valves i, i, for the purpose of regulating the strength of the current of air to the
material under operation. Any heavy particles passing through these openings fall
on to a false bottom or sloping board k, k, beneath, which delivers them on to the
lowest of the series of sloping boards a, a, where they mix with the other heavy
particles and fall on to the sieve.
Arrangements are made for opening or closing, more or less, the spaces between
the sloping boards and the narrow slits or openings in the partition, so as to regulate
the current of air to suit the nature of the material to be operated upon.
In some cases we propose also to make the air duct leading to the fan wider as it
approaches the latter, so as to diminish the intensity of the current and to allow
other still lighter particles to fall, and only to carry off the dust and the very lightest
particles with the air.
The arrangement for regulating the amount of "middlings" or grain passed
through the apparatus is shown on a larger scale at Figs. 2 and 3. To the
hopper b, b, is attached a bracket 1, 1, carrying a spindle m, m, having a right-hand
and a left-hand screw cut or formed upon its opposite ends. These screws work in
two nuts n, n, each of which is attached to (or forms part of) a slide o, o, working
in slightly inclined grooves or guides attached to the board or shuttle p, p, which
closes the opening. It will be evident that upon turning this screwed spindle in
one direction or the other (by means of the pulley q, q, and spur gearing 2, 7, the
slides o, o, will be caused to approach to or recede from each other, and consequently
the board or shutter p, p, will be raised or lowered so as to regulate the size of
feeding aperture between the shutter p, p, and the roller c, c. 8, 8, is a sliding door
for admitting or shutting-off the feed entirely, and can be opened and closed as
required without interfering with the setting of the board or shutter p, p, which
regulates the size of the feeding aperture.
Having now described the nature and object of our said Invention, together with

page_text: the manner in which the same is to be or may be performed or carried into practical
effect, we wish it to be understood that we claim as our Invention,—
Firstly. The arrangement of alternately sloping boards or metal shelves in com-
bination with transverse currents of air produced by a fan or otherwise, substan-
tially in the manner herein-before particularly described, and illustrated by the
Drawings annexed.
Secondly. We claim the use of partitions with openings and valves for regulating
the said currents of air.
And, Thirdly. We claim the apparatus, shown and described, for regulating the
size of the feeding aperture, such apparatus being capable of adjustment, once
for all, and not requiring re-adjustment each time that the feed is admitted or
shut off.
In witness whereof, I, the said Abraham Crabtree (on behalf of myself and the
said Lewis Firth), have hereunto set my hand and seal, this Nineteenth day
January, in the year of our Lord One thousand eight hundred and seventy-
eight.
ABRAHAM CRABTREE. (LS.)