IMPROVEMENTS IN MACHINERY POR CLEANING AND SEPARATING GRAIN AND FOR OTHER LIKE PURPOSES
Year: 1868

page_text: LETTERS PATENT to Thomas Corbett, of Shrewsbury, in the County
of Salop, Manufacturer, for the Invention of "IMPROVEMENTS IN
MACHINERY POR CLEANING AND SEPARATING GRAIN AND FOR OTHER LIKE
PURPOSES."
Bealed the 26th June 1868, and dated the 28th January 1868.
PROVISIONAL SPECIFICATION left by the said Thomas Corbett at
the Office of the Commissioners of Patents, with his Petition, on
the 28th January 1868.
I, THOMAS CORBETT, of Shrewsbury, in the County of Salop, Manu-
facturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MACHINERY FOR CLEANING AND SEPARATING GRAIN AND
FOR OTHER LIKE PURPOSES," to be as follows:-
In machines for cleaning and separating grain the meshes of the
screen often become clogged by the fixing of the grain therein, and
the object of my Invention is principally to prevent the said clogging
of the screen. This I effect by means of an endless band situated
underneath and parallel to the screen. This endless band travels over
rollers, to one of which a rotary motion is given by suitable gearing
connecting it with the principal shaft of the machine. To the outer

page_text: side of the said endless band a brush is fixed, the said brush
having a length equal to the width of the screen and being situated
transversely to the said screen. When the machine is in action
the said brush is carried slowly underneath the whole surface of the
screen, and by pressing on the under side of the said screen raises
out of its meshes any grains that may have become fixed therein; or
instead of a brush the endless band may carry a fixed or moveable
roller. When a fixed roller is employed it may be made elliptical in
cross section, and may be set so as to press more or less against the
under side of the screen. In place of the said rollers and endless
band a frame carrying a series of transverse rollers may be supported
underneath and parallel to the screen. A longitudinal oscillating
motion being given to the said frame the said rollers press the grains
out of the meshes of the screen.
In order to raise and lower the screen and the endless band or frame
described simultaneously I make use of the following arrangement:―
At each side and at the lower end of the screen is an upright in a
slot in which a cross piece works, the said cross piece being raised and
lowered by means of a screw worked by a winch. To cach end of the
cross piece a sling or connecting link is jointed, the lower ends of the
said links supporting the lower ends of the screen and rollers or frame
respectively. By turning the winch the lower end of the screen and
rollers or frame may be raised or lowered simultaneously. I give the
required oscillating motion to the screen by connecting it at the upper
end to a small crank instead of connecting it at its lower end as is 2
usual.
My improvements are especially applicable to corn screens and corn-
dressing machines, but may also be applied to machines in general
for cleaning or screening various articles.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of January, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Corbett, Her special licence
that I, the said Thomas Corbett, my executors, administrators, and.
assigus, or such others as I, the said Thomas Corbett, my executors,
adminstrators, and assigns, should at any time agree with, and no.
others, from time to time, and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise,.
and vend, within the United Kingdom of Great Britain and Ireland,.
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS.
IN MACHINERY FOR CLEANING AND SEPARATING GRAIN AND FOR OTHER LIKE
PURPOSES," upon the condition (amongst others) that I, the said Thomas
Corbett, my executors or administrators, by an instrument in writing.
under my, or their, or one of their hands and seals, should particularly,
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Corbett, do hereby
declare the nature of the said Invention, and in what manner the'
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
In machines for cleaning and separating grain the meshes of the
screen often become clogged by the fixing of the grain therein, and the
object of my Invention is principally to prevent the said clogging of
the screen. This I effect by means of endless bands situated underneath
and parallel to the screen. These endless bands travel over rollers, to
one of which a rotary motion is given by suitable gearing connecting
it with the principal shaft of the machine. To the outer side of the
said endless bands a brush is fixed, the said brush having a length
equal to the width of the screen and being situated transversely to the
said screen. When the machine is in action the said brush is carried
slowly underneath the whole surface of the screen, and by pressing on
the under side of the said screen raises out of its meshes any grains that
may have become fixed therein. Instead of a brush the endless bands
may carry a fixed or moveable roller or rollers or bars. In place of

page_text: the brush or roller or bar and endless bands a frame carrying a series
of rollers, brushes, or bars may be supported underneath and parallel
to the screen, the said frame having a longitudinal oscillating motion
given to it. Instead of endless bands endless chains may be used.
In order to raise and lower the screen and the endless bands or chains
described simultaneously I make use of the following arrangement:-
At each side and at the lower end of the screen is an upright, in a slot
in which a cross piece works, the said cross piece carrying a toothed
plate and the upright being provided with a rack. To the cross piece
slings or connecting links are jointed, the lower ends of the said links
supporting the lower ends of the screen and rollers respectively. By
means of the links described and the toothed plate and rack the lower
end of the screen and rollers may be raised or lowered simultaneously.
I give the required oscillating motion to the screen by connecting it
at the upper end to a small crank instead of connecting it at its lower
end as is usual.
My improvements are especially applicable to corn screens and corn-
dressing machines, but may also be applied to machines in general for
cleaning or screening various articles.
Having explained the nature of my Invention I will proceed to
describe, with reference to the accompanying Drawing, the manner -in
which the same is to be performed.
Figure 1 represents in side elevation, Figure 2 in end elevation,
and Figure 3 in plan, a machine for screening grain and seeds constructed
according to my Invention; Figures 4, 5, 6, 7, and 8 are parts of the
same on a larger scale as herein-after described; the same letters of
reference are employed to indicate the same parts in each Figure of
the Drawing, a, a, is the framing of the machine supported by the
uprights b, b; c is the screen to which an oscillating motion is given,
the said screen being suspended in the manner herein-after described; d
is the hopper containing the grain or seeds to be screened; and e
is the slide for regulating the feed to the screen. The oscillating
motion of the screen c is effected in the following manner :-f is
a shaft provided with a crank g and fly wheel f. The said crank g
is connected by the connecting rod h to the upper end of the
soreen c. A separate view of the connecting rod h and part of the
screen c on a larger scale is shown in Figure 4. Rotatory motion is

page_text: communicated to the crank shaft through the toothed wheel i on the
axis gearing with a pinion k on one end of the said crank shaft f.
The toothed wheel is driven by the winch or handle 1. m, m, are
endless bands situated underneath and parallel to the screen c; the
said endless bands m travel over a pair of rollers or pulleys n, p, one at
each end of the screen. Rotatory motion is given to the said rollers n, p.
by means of a driving band q passing over a pulley on the axis of the
front pair of rollers n, n, the said band q taking motion from a pulley
on the axis of the toothed wheel i. To the outer side of the said
endless bands ma brush is fixed, the said brush
having a length
nearly equal to the width of the screen c and being situated transversely
to the said screen, as best seen in Figure 2. The manner in which the
brush is fixed to the endless bands m, m, is also seen in Figure 2. By
the motion communicated to the front pair of rollers n, n, by the driving
band q the endless bands m are made to travel over the rollers n, p, and
the brush is carried slowly underneath the whole surface of the screen
c, and by pressing on the under side of the said screen raises out of the
meshes any grains that may have become fixed therein. The screen c
is thereby effectually prevented from becoming clogged during use.
The oscillating screen c is suspended, the two pair of rollers n, p, are
supported, and the back pair of rollers p, p, and screen c are raised
or lowered simultaneously by the following arrangements of parts:-
At the front and at each side of the frame of the machine is an
upright to the upper end of which is jointed a link or arm t, the
lower end of each arm being jointed to the front end of the screen c
in the manner best seen in Figure 2. At the back and at each side
of the framing is also an upright u in a vertical slot, in which a cross
piece or axis works. On the inner end of each of the cross pieces
v, v, a sling or connecting link w turns, the lower ends of the said
slings or connecting links being connected to and supporting the
lower end of the screen c. One of the uprights u and parts connected
with it are represented separately in front elevation and side elevation
(partly in section) on a larger scale in Figure 5. The front pair of
rollers n, n, of the endless bands m are supported in fixed bearing
plates secured to the framing of the machine, while the back pair
of rollers p, p, are supported in moveable metallic straps or plates y
passing on either side the framing, the said straps y being connected
to the fixed plates or bearings x, x, in the manner herein-after explained.
The outer ends of the metal straps y are connected to the lower ends

page_text: of the slings or connecting links, the upper ends of which links
turn on the cross picces v. A side elevation and cross section of the
endless band m, rollers n, p, fixed bearing x, and metal strap y are
represented on a larger scale in Figure 6, and an end elevation of the
said bearing and roller n is represented in Figure 7. On the outer
end of each of the cross pieces is a toothed plate 2, the teeth of which
are engaged with the teeth of the rack 3 on the outer side of the
uprights u. By unscrewing the nut 4 the toothed plate 2 may be
disengaged from the rack 3, when the cross piece may be raised or
lowered in the upright u, and afterwards fixed in its adjusted position
by re-engaging the said plate 2 with the rack 3 and securing it by the
screw nut 4. By this means the lower end of the screen and the
rollers p, p, and endless bands m are raised or lowered simultaneously
When the brush is worn it may be brought nearer to the screen c
by raising the end rollers p, p, on the slings or connecting links,,
by means of the adjusting nuts 5, which fix the metal straps y, y, of
the rollers to the lower ends of the said slings or connecting links =,=.
The endless bands m, mi, carrying the brush may be tightened upon
the rollers n, p, in the manner which will be best understood by
reference to Figures 6 and 7. The metal straps y are capable of being
brought nearer to or placed further from the fixed bearing plates x.
This is effected by connecting the straps y to the bearing plates by
means of a pin at 6 working through a slot 7 in the said hearing
plates x. On the said pin 6 is a screw 8 passing through a flange 10
fixed to the framing of the machine. By means of the nuts 11, 11,
and screw 8 the straps y may be adjusted the required distance from
In
the fixed bearing plates a so as to tighten the endless bands m.
order to prevent the yielding of the endless bands m during the action
of the brush against the under side of the screen the said endless
bands mare supported by means of wooden or metallic supports y
fixed by screwing to the metal straps y. The manner in which I
construct the screen c is represented in plan and longitudinal section
in Figure 8. 12 is the outer frame of the screen, and 13 is the inner
frame, to which inner frame and on its under side the wire meshes 144
are secured, a plate of iron 15 being fastened at the front end of the
screen. The inner frame 13 is placed in the outer frame 12, so that
the bevilled inner end of the said inner frame engages under the
bevilled end 16 of the outer frame in the manner represented in the
section, Figure 8. The other end of the screen frame 13 is then fixed

page_text: in the open end of the frame 12 by means of the pins and nuts at 17.
Instead of the pins and nuts at 17 springs or dowel pins may be employed
to retain the inner screen frame in its place.
Figure 9 represents in side elevation a winnowing machine to the
screen of which my Invention is applied. c is the oscillating screen
supported by the links at one end and by the links w at the other
end. The endless bands carrying the brush and the rollers of the
said bands are indicated in dotted lines. y is the metal straps to
which links are connected for supporting the end rollers p, p.
Instead of placing the links w, z, on the inner side of the upright
as already described I place the link w in this arrangement outside
the case of the machine and the link inside the said case, the parts
for adjusting and fixing the height of the two links, and the parts
to which they are connected being secured on the case of the
winnowing machine as represented.
Figure 10 represents in front elevation and side elevation the
rack 3, toothed plate 2, and parts connected therewith on a larger
scale, by an examination of which Figure 10 the manner in which
the links 10, z, are connected to the adjusting mechanism will be
readily understood. The screen c of the winnowing machine is
worked by a crank connected to its upper end as seen in the Drawing.
Corresponding parts of the winnowing machine are marked with the
same letters and figures of reference as the screening machine first
described.
My Invention may be carried into effect in the following ways:-
Instead of endless bands endless chains may be used to carry the
brush r, and instead of fixing the said brush to the endless bands
or endless chains a wooden roller or rollers covered with vulcanized
india-rubber or other soft material may be carried by the said bands
or chains. When a screen having longitudinal openings in it is
employed the following arrangement may be used, that is to say, I
connect a transverse bar to the endless bands or chains, to which
bar a series of projections is fixed, which projections on the motion
of the endless bands or chains work in the longitudinal openings
of the screen and lift therefrom any grains that may have become
fixed therein. A brush may be used in place of the bar and
projections described to lift the grains from screens having longitudinal
openings.

page_text: In carrying my Invention into effect by the use of a frame
carrying a scries of transverse rollers I support the said frame
underneath and parallel to the screen c in the position of the
endless bands m, m, and rollers n, n, and p, p, represented in the
Drawing. A longitudinal oscillating motion is given to the said
frame, and the said rollers are made to press the grains out of the
meshes of the screen C. In place of rollers in the oscillating
frame a transverse bar or bars may be used, or stationary or rotating
brushes may be carried by the said frame. When the screen has
longitudinal openings in it instead of the ordinary meshes I make
on the upper side of the said bar or bars projections which work in
the said openings. The longitudinal oscillating motion is given to
the said frame by means of a crank driven from the main shaft.
Although I prefer to give motion to the said frame by the machine
itself yet it may not be actuated by the machine but be worked by
hand, as occasion may require. My improvements are applicable
to all kinds of machines used for cleaning and separating grain and
for other like purposes.
Having now described the nature of my Invention, and the manner
in which the same is to be performed, I wish it to be understood
that I do not limit myself to the precise details herein described
and illustrated, as the same may be varied without departing from
the nature of my Invention; but I claim as my Invention of
improvements in machinery for cleaning and separating grain and
for other like purposes,
Firstly. The construction and arrangement of parts herein-before
described and illustrated in the accompanying Drawing for preventing
the clogging of the screens of the said machinery, that is to say,
preventing the said clogging by means of an endless band or bands
or endless chain or chains to which one or more brushes, rollers, or
bars are fixed, which said brushes, rollers, or bars are carried underneath
the surface of the screen so as to raise out of its meshes any grains
or other matter that may have become fixed therein, substantially as
described and illustrated.
Secondly. The construction and arrangement of parts herein-before
described for preventing the clogging of the screens of the said
machinery, that is to say, preventing the said clogging by means of
a frame situated underneath and parallel to the screen, the said

page_text: frame carrying transverse rollers, brushes, or bars, and being worked
either by the machine itself or by hand.
Thirdly. The construction and arrangement of parts herein described
and illustrated in the accompanying Drawing for raising and lowering
the screen and endless band or bands or endless chain or chains
simultaneously, also the arrangements of parts for adjusting and
fixing the height of the said screen and endless band or bands or
chain or chains, and for tightening the said endless band or bands
or chain or chains.
In witness whereof, I, the said Thomas Corbett, have hereunto
set my hand and seal, this Twentieth day of July, in the
year of our Lord One thousand eight hundred and sixty-
eight.
15 Witness,
EDWIN BETTON DEAKIN,
Shrewsbury.
THOMAS CORBETT. (L.s.)