IMPROVEMENTS IN OR
Year: 1883

page_text: LETTERS PATENT to William Phillips Thompson of the firm of W. P. Thompson
& Boult of 323 High Holborn in the county of Middlesex British and
International Patent Agents for an Invention of IMPROVEMENTS IN OR
"
" a
RELATING TO MIDDLINGS PURIFIERS AND OTHER SEPARATING MACHINES
communication to him from Frederick Andrew Price a resident of Barnawartha,
Victoria Australia
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 6th September 1883.
WILLIAM PHILLIPS THOMPSON of the firm of W. P. Thompson and Boult of
323, High Holborn in the county of Middlesex, British and International Patent
Agents. "IMPROVEMENTS IN OR RELATING TO MIDDLINGS PURIFIERS AND OTHER
SEPARATING MACHINES"-A communication to me from Frederick Andrew Price,
A resident of Barnawartha, Victoria-Australia.
This invention has more especially for its object a middlings purifier, but the
invention can be modified too, so as to be used for separating or grading other
pulverulent matters. The invention consists of a screen for agitating the middlings
or other pulverulent matter to be operated upon, a fan below the screen arranged
with special contrivance for distributing the air currents equally over the screen
bottom, and an arrangement of travelling brush to keep the sieve clean.
The fan is placed directly under the screen or sieve and has a portion of its
circumference removed and replaced by a grid or its equivalent, dividing the exit
into a number of streams directed against the under surface of the sieve, so
proportioned that the impulsive force shall be as nearly as possible equal all over
the sieve for most purposes, but for those uses, where a greater force is required at
the lower end of the sieve the passages or openings are regulated so as to give a
somewhat greater blast at that part. The grid is preferably composed of simple
flat bars placed in a radial direction parallel to the fan shaft and following the
periphery of the fan case.
The travelling brushes have their bristles inclined backward whichever direction
they are travelling, and are so hung that the shaking of the screen itself causes

page_text: them to travel forward, the material of the cloth or silk acting against the inclined
bristles more in one direction than in the other. The silk during the forward
motion of the sieves grips the bristles through their being inclined to meet it,
but during the return motion the silk slides past the inclined bristles, the
inclination being such that they cannot catch in it. Projecting pins, cams or
other objects on the brushes and on the framing of the machine, automatically
reverse the position of the brushes as they approach the ends of their travel, and
thus automatically change the direction of that travel.
The brushes can be appended in the following manner. At a convenient height
above the screen bars are placed with grooves in them to receive a small upright
roller attached to each brush, or combination of brushes. The roller travels in the
groove from end to end, to guide the brushes and at the ends forms a pivot for the
brushes to turn upon. A second roller is placed to run against the outside of said
bars. The brushes can either extend across the screen and reciprocate from end to
end, or can travel up one side of the screen and down the other being guided only
at the centre line, in such cases, I place two brushes joined in a V to assist in
turning the ends. There can be two or three such V's if desired.

page_text: Referring first to Figs. 1 and 2. In these A is a reciprocating sieve of ordinary
construction hung by any suitable supports, and operated by crank on shaft H,
Fig. 3. B are the travelling brushes.
The brushes B have their bristles b inclined in a direction contrary to that in
which they travel as plainly shown in Fig. 1. The shaking or vibratory motion
of the sieve causes the brushes to travel along it. As the sieve noves in tho
direction meeting the points of the bristles of the brush, the friction between the
brush and the sieve surface carries the brush forward, but when moving in the
opposite direction the friction is not sufficient to carry the brush back. The sieve
thus during its forward motion grips the bristles through their being inclined to
meet it, but during the return motion the sieve slides past the inclined bristles, the
inclination being such that the surface of the sieve does not catch them.
The sieve may be supported or suspended in any suitable manner to receive a
reciprocating motion. The brushes are carried in a fixed slide or frame C
suspended by rods or otherwise from above, preferably from the same support or
beam from which the sieve is hung. This slide or frame C is placed at any
convenient height above the sieve surface but preferably just sufficiently high to
allow of the brush passing freely under for the purposes of turning; attached to
the brush is a small pin D which works in the slide c of the frame C and moves
to and fro therein as the brushes are carried along. The pin D is preferably
provided with a friction roller d. The roller & travels in the groove or slide c from
end to end to guide the brushes, and at the ends forms a pivot for the brushes to
turn upon. A second pin E is placed in the framework of the brush and travels
against the outside of the frame C. The pin E keeps the brush in a straight
course otherwise it would be inclined to move in a circle instead of lengthwise of
the sieve. If this portion of the invention were applied to a circular sieve, the
brush would keep going round on the pivot in a fixed centre and without a slide.
Two brushes are shown in the drawing but one only or a greater number may
be used, but I prefer two rather than one as less space is then left in the corners
of the sieve unbrushed. While the brushes may be of any desired shape or
construction I prefer those of the V shape shown, as by this shape they are
prevented sticking in turning at the end of the slide. When travelling the length

page_text: of the sieve both sets of bristles b come into play to propel the brush along, but
when turning the set of bristles attached to the arm of the brush b¹ are inoperative
when the brush is in position shown at F the bristles on the other arm bu serving
to carry the brush on until those at b¹ are acted upon on the return journey.
These then carry the brush on until both are again acted upon. It is not necessary
that the brush should work on the top of the sieve, as it may equally well be
worked against the bottom of the sieve with the addition of a hoop on which the
brush would rest and be kept up against the sieve. The brush will work in any
position provided it is kept against the cloth.
Although I prefer the means hereinbefore described for adjusting and actuating
the brush, this part of the invention is not confined to these exact details, as
brushes with bristles set obliquely may be fixed in different ways but at the same
time be carried backwards and forwards by the motion of the sieve. Thus for
instance a single brush stretching across the sieve and working on a ring attached
to each end of the brush by a short chain and each ring sliding upon a wire or
rod stretched above the sieve, the brush having two upright pins which upon
contact with a suspended stationary bar reverse the motion.
The second part of my invention is best described by reference to Figs. 3, 4, 5
and 6.
In these, A is the screen as before, operated by cranks from shaft H and
I I are
supported on four springs at or near the corners or in other usual manner.
two blast fans placed beneath the sieve and are open to the sieve above, except for
the grids J J formed of radial boards which are adjusted in position so as to cause
the draught to impinge equally over the under surface of the sieve or with
gradually increasing force toward the lower end as desired. Other forms of grid
can be used, the main point being to so regulate the effluent air as to cause it to bear
with required pressure on the various parts of the sieve and not with too much
force immediately over the fans and too little force elsewhere. Where the fan case
is of metal the radial bars can also be of metal and attached to the fan case by
screws passing through slots and having heads or nuts upon them. By loosening
the screws and moving the bars or adding to or subtracting from their number,
the adjustment of the draught can be accurately effected. If of wood the bars
can be wedged, nailed, screwed or otherwise fixed in place. K is the upper
(exhaust) fan having side boxes L. and a long pipe below (M) having adjustable
or adjusted openings so as to draw from all parts of the surface of the screen evenly
or with gradually increasing force from the lower end as required. These openings
if intended for one class of material can be adjusted once for all or can be
adjustable. P is the board for attaching the tin feeding plates to so as to feed
evenly over the surface of the sieve. Other forms of feeding mechanism can be
used and as the method of feeding such machines is well known and feeding
is no part of the invention protected by my application, I need not enlarge
upon this further than to say that any feed that will feed the material
evenly all along the breadth of the sieve will do. As to the exit from the sieve
and other parts, they are all similar to other well known existing mechanisms and
are not my invention so it is needless to enlarge further thereon.
Having now described my invention, I would state that I do not claim as new
the regulating of the exhaust only by taking it out through numerous regulated
openings, nor do I on the other hand confine myself to the use of one sieve or any
form of sieve or sieves, but what I do claim as new and to be protected by the
Letters Patent is :-
1st. The process of brushing the sieve or sieves of separating machines, which
consists in causing a guided brush to bear upon the sieve with its bristles all
pointing substantially in one direction oblique to the surface of the sieve, but in a
plane substantially perpendicular to the surface of the sieve and parallel to the
direction in which the sieve reciprocates.
2nd. The brushing apparatus for cleaning the sieves of separating machines,
consisting of a travelling brush having its bristles pointing obliquely to the sieve,

page_text: and worked along over; the surface of the sieve in being actuated by the
reciprocating motion of the latter, combined with the greater resistance the
brush has to meet in the direction in which its bristles point than in the opposite
direction.
3rd. The manufacture and use of brushing apparatus, substantially as and for
the purposes set forth in the specification.
4th. The combination with a separating machine, of a fan or fans blowing air
through the sieve or sieves and having an opening provided with a grating or
series of adjustable openings or guides around that portion of its periphery at
which it is required to deliver air, and so arranged as to regulate the blast to the
various portions of the sieve as required.
5th. The combination of a blowing fan on one side of the sieve, arranged with
grating or its equivalent as described to deliver the air in regulated force and
direction over that surface of the sieve, and an exhaust fan receiving the air on the
other side through a series of orifices adjusted so as to receive the air equitably
or in the requisite regulated amount from all parts of the upper surface of the
sieve.
In witness whereof I the said William Phillips Thompson have hereunto set
my hand and seal this fourth day of Marchţin the year of our Lord one thousand
eight hundred and eighty four.