IMPROVEMENTS .IN MACHINERY EMPLOYED IN THE MANUFACTURE OF FLOUR FOR THE PURIFICATION OF MIDDLINGS AND SIMILAR PURPOSES.”
Year: 1881

page_text: "
LETTERS PATENT to Abraham Crabtree and John Jackson, of Bolton, in the
County of Lancaster, Corn Millers, for an Invention of IMPROVEMENTS
.IN MACHINERY EMPLOYED IN THE MANUFACTURE OF FLOUR FOR THE
PURIFICATION OF MIDDLINGS AND SIMILAR PURPOSES.”
:
PROVISIONAL SPECIFICATION left by the said Abraham Crabtree and
John Jackson at the Office of the Commissioners of Patents on the 5th
April 1881.
ABRAHAM CRABTREE and JOHN JACKSON, of Bolton, in. the County of Lancaster,
Corn Millers. "IMPROVEMENTS IN MACHINERY EMPLOYED IN THE MANUFACTURE
OF FLOUR FOR THE PURIFICATION OF MIDDLINGS AND SIMILAR PURPOSES."
This Invention has reference to midling purifiers in which reciprocating sieves
are employed for sifting the midlings, and a fan for the purpose of carrying away
the dust and refuse.
Our improvements consists,-
Firstly. In constructing an air passage on each side of the fan, which extends across.
the machine. Instead of air being admitted directly to the centre of the fan, we form
a trough or hollow chamber around the shaft on the under side, the upper edges
of this trough reaching to about the centre of the shaft, but being capable of
adjustment according to requirement. The air has consequently to rise above the
edges of the trough before it can enter the fan, and by this arrangement any light
granules or middlings which may have been carried to the fan along with the
refuse become separated from the current and fall into the trough, and thence a.
revolving worm which conveys them to a suitable receptacle. Secondly. Our
improvements consists in securing the sections of sieve to the vibrating frame by
means of thumb screws or bolts which pass through the edges of the sieve into nuts
formed in the cross bars of the frame; strips of linen are then pasted over the
adjacent edges of the sieves so as to make the joint air tight. Thirdly. Our improve-
ments consist in the employment of a brush placed underneath each sieve and
caused to reciprocate in contact therewith by means of a double threaded screw.
Fourthly. We employ slotted brackets for securing the vibrating arms to the
sieve frame, and so arrange the same, that instead of vibrating an equal distance
on each side of the vertical arm the whole of the vibration shall take place between
the vertical arm and the delivery end of the machine, so that the vibrations shall
have a tendancy to propel the material towards that end.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Abraham Crabtree and John Jackson in the Great Seal Patent Office
on the 5th October 1881.
ABRAHAM CRABTREE and JOHN JACKSON, of Bolton, in the County of Lancaster,
Corn Millers. " IMPROVEMENTS IN MACHINERY EMPLOYED IN THE MANUFACTURE
OF FLOUR FOR THE PURIFICATION OF MIDDLINGS AND SIMILAR PURPOSES.”
-
This Invention has reference to middlings purifiers in which reciprocating sieves
are employed for sifting the middlings, and a fan for the purpose of carrying away-
the dust and refuse.
In order that our Invention may be more fully understood we have hereto
annexed three Sheets of Drawings illustrative thereof.
Fig. 1 represents a longitudinal elevation, partly in section, of one end of the
machine; Fig. 2 being a similar section of the other end.
Fig. 3 is a vertical cross section.
Our improvements consist,―
Firstly. In constructing an air passage on each side of the fan, such air passages
to extend entirely across the machine. The machine is divided into separate
compartments by means of partitions A, and each compartment is provided with a
fan B revolving within a casing C, which extends across the machine, as shewn in
Fig. 3, so as to draw the dust equally from the surface of the vibrating tray D.
Around the shaft of the fan, at each end, we form a trough or hollow receptacle E,
which reaches up to about the centre of the shaft, but may be adjusted according
to requirement. The air has consequently to rise above the edges of this trough
before it can enter the fan, and by this arrangement any light granules or middlings
which may have been carried to the fan along with the refuse have an opportunity
of becoming separated from the current and falling into the trough, and thence
through the pipe F into a revolving worm G, which conveys them to a suitable
receptacle.
Secondly. Our improvements consists in securing the sections of sieve to the
vibrating frame by means of thumb screws or bolts which pass through the edges
of the sieve into nuts formed in the cross bars of the frame. The adjacent edges of
the sieve are placed in contact with each other, and one half of each bolt hole is
formed in each sieve, so that one bolt secures two edges. Strips of linen are then
pasted over the adjacent edges to make them perfectly air tight. In Figs. 4 and 5
we have shewn detail of this method of fastening the sieves; d being the frame-
work of the sieves, 6 the cross bar to which they are secured, and c the bolt or
thumb screw.
Thirdly. Our improvements consists in the employment of a brush placed under-
neath each sieve, and caused to reciprocate in contact therewith by means of a
double-threaded screw. These brushes H are attached to two longitudinal bars J,
which ride on pullies K fixed to cross bars L. The reciprocating motion is given
by means of the cross threaded screw M passing through a nut or collar N attached
to the sieve, a pin or float within the said collar entering the screw thread, and
causing the brushes to travel to and fro as the screw revolves always in the same
direction.
Having thus described the nature of our Invention, and shewn by Drawings how
the same is to be or may be performed or carried into practice, we would have it
understood that we claim,-
Firstly. The improved construction of air passage described in the first part of
our Specification and herein fully illustrated.

page_text: Secondly. The improved method of securing the sieves as herein shown and
described.
Thirdly. The employment of a cross threaded screw for reciprocating the brushes,
substantially as herein shewn and described.
In witness whereof, we, the said Abraham Crabtree and John Jackson, have
hereunto set our hands and seals, this Fourth day of October, in the year
of our Lord One thousand eight hundred and eighty one.
ABRAHAM CRABTREE, (L.S.)
JOHN JACKSON.
(L.S.)