IMPROVEMENTS IN ROTATORY SCREENS
Year: 1859

page_text: LETTERS PATENT to Henry
Henry Brinsmead and Jeremiah Lawrence,
Ipswich, for the Invention of "IMPROVEMENTS IN ROTATORY SCREENS."
Sealed the 4th January 1860, and dated the 8th July 1859.
PROVISIONAL SPECIFICATION left by the said Henry Brinsmead and
Jeremiah Lawrence at the Office of the Commissioners of Patents,
with their Petition, on the 8th July 1859.
We, HENRY BRINSMEAD and JEBEMIAH LAWRENCE, of Ipswich, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN ROTATORY SCREENS,"
to be as follows:-
This Invention has for its object improvements in rotatory screens. Here-
tofore the parallel wires, bars, or rods of which a rotatory screen has been
composed have been fixed, and the spaces between them constant. Now our
Invention consists in so combining the parallel wires, bars, or rods, of which
a rotatory screen is composed, that the wires, bars, or rods may be moveable,
and so that the sizes of the spaces between them may be varied; also in
combining the wires, rods, aud bars of rotatory screens in such manner that
rotatory screens may be self-cleansing, and also in applying apparatus to
rotatory screens to cleanse the spaces between the wires, rods, or bars. The

page_text: construction and arrangement of the parts of a rotatory screen may be greatly
varied. In some cases we construct a rotatory screen consisting of a com-
bination of two screens, (by preference of a circular section) one being some-
what of a less diameter than the other; the lesser one is placed within the larger
one, and they are caused to rotate together and act as one rotating screen, and
according as the inner screen is placed more or less excentric to the other, so will
the wires, rods, or bars thereof on one side of the axis be caused to come into
and divide the spaces between the wires, rods, or bars of the other screen, whilst
the wires, rods, or bars of the inner screen on the other side of the axis will
be caused at the same time to be moved away from the wires, rods, or bars of
the other screen and the parts of the two screens which, as they revolve, come
nearest together, and consequently cause the spaces between the wires, rods,
or bars thereof to be smallest may be at the lower part or bottom of the
screens or in any other position by varying the relative positions of the axes
on which the two parts of the screen rotate. In addition to the advantages
obtained from the capability of varying the sizes of the spaces of a screen so
constructed, there is another important advantage in combining two screens
as above described, viz., that the same become self-cleaning. It is preferred
to employ cylindrical wire in constructing these screens, tho' wire of other
sections, or bars or rods of other forms may be used, and it is also preferred
that the wire should be wound round the frames, so that where they come
together and interspace each other, they may represent a two-threaded screw,
but this may be varied.
Another arrangement or construction of rotatory screens consists in forming
a rotatory screen by combining around the axis of motion, and parallel or at
an angle to such axis a series of frames or panels, each being wires, rods, or
bars parallel to each other, the wires, rods, or bars of each frame or panel by
preference inclined to the sides of the frame, and the wires, rods, or bars, or
some of them of each frame or panel are arranged to move in such manner as
to enlarge or contract the spaces between them, and this may be done in any
convenient manner, but by preference in like manner to what has been done
in regard to flat screens, that is, by one half of the wires having a movement to
and from the other half, or by one half being made of an oblong section, and
Pro-
capable of being rotated on their axes, or by other convenient means.
vision is made for moving the wires, rods, or bars, or some of them more or
less in respect to each other in order to obtain for the time being the desired
sized spaces required. In some cases the whole length of a screen is not
arranged to have the spaces varied, but the upper or feed end is made with
all fixed wires at an inclination with the sides of the frames or panels corres

page_text: ponding with the other wires, rods, or bars, and it is preferred that the wires,
rods, or bars should be arranged similar to a screw of several threads, say
from eight to twelve threads. In order to cleanse such a construction of screen,
a number of fixed blades on a bar are used, which are caused to pass into the
spaces between the wires, bars, or rods at the upper part of the screen, and
the bar when necessary, is moved endwise by a cam movement or otherwise
to follow the inclination of the wires, rods, or bars.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Brinsmead and Jeremiah Lawrence in the Great
Seal Patent Office on the 7th January 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
BRINSMEAD and JEREMIAH LAWRENCE, of Ipswich, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of July, in the year of our Lord One
thousand eight hundred and fifty-nine, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
Henry Brinsmead and Jeremiah Lawrence Her special licence that we,
the said Henry Brinsmead and Jeremiah Lawrence, our executors, adminis-
trators, and assigns, or such others as we, the said Henry Brinsmead
and Jeremiah Lawrence, our executors, administrators, 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 "IMPROVE-
MENTS IN ROTATORY SCREENS," upon the condition (amongst others) that we,
the said Henry Brinsmead and Jeremiah Lawrence, our executors or adminis-
trators, by an instrument in writing under our or their hands and seals, or
under the hand and seal of one of us or them, 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 we, the said Henry Brinsmead and Jeremiah
Lawrence, do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, that is to say :-

page_text: This Invention has for its object improvements in rotatory screens. Here-
tofore the parallel wires, bars, or rods of which a rotatory screen has been
composed have been fixed, and the spaces between them constant.
Now, our
Invention consists in so combining the parallel wires, bars, or rods of which a
rotatory screen is composed that the wires, bars, or rods may be moveable, and
so that the sizes of the spaces between them may be varied; also in com-
bining the wires, rods, and bars of rotatory screens in such manner that
rotatory screens may be self-cleansing; and also in applying apparatus to
rotatory screens to cleanse the spaces between the wires, rods, or bars. The
construction and arrangement of the parts of a rotatory screen may be greatly
varied. In some cases we construct a rotatory screen consisting of a combi-
nation of two screens (by preference of a circular section) one being somewhat
of a less diameter than the other, the lesser one is placed within the larger
one, and they are caused to rotate together and act as one rotating screen,
and according as the inner screen is placed more or less excentric to the other,
so will the wires, rods, or bars thereof on one side of the axis be caused to come
into and divide the spaces between the wires, rods, or bars of the other screen,
whilst the wires, rods, or bars of the inner screen on the other side of the
axis will be caused at the same time to be moved away from the wires, rods,
or bars of the other screen, and the parts of the two screens which as they
revolve come nearest together, and consequently cause the spaces between the
wires, rods, or bars thereof to be smallest may be at the lower part or bottom
of the screens, or in any other position, by varying the relative positions of the
axes on which the two parts of the screen rotate. In addition to the advan-
tages obtained from the capability of varying the sizes of the spaces of a
screen so constructed, there is another important advantage in combining two
screens as above described, viz., that the same become self-cleaning. It is
preferred to employ cylindrical wire in constructing these screens, though wire
of other sections, or bars or rods of other forms may be used; and it is also
preferred that the wires should be wound round the frames, so that where they
come together and interspace each other they may represent a two-threaded
screw, but this may be varied.
Another arrangement or construction of rotatory screens consists in forming
a rotatory screen by combining around the axis of motion and parallel, or at an
angle to such axis, a series of frames or panels, each having wires, rods, or
bars parallel to each other; the wires, rods, or bars of each frame or panel by
preference incline to the sides of the frame, and the wires, rods, or bars, or
some of them of each frame or panel are arranged to move in such manner as
to enlarge or contract the spaces between them, and this may be done in any

page_text: convenient manner, but by preference in like manner to what has been done
in regard to flat screens, that is, by one half of the wires having a movement
to and from the other half, or by one half being made of an oblong section,
and capable of being rotated on their axes, or by other convenient means.
Provision is made for moving the wires, rods, or bars, or some of them, more
or less in respect to each other, in order to obtain for the time being the
desired sized spaces required. In some cases the whole length of a screen is
not arranged to have the spaces varied, but the upper or feed end is made with
all fixed wires at an inclination with the sides of the frames or panels corre-
sponding with the other wires, rods, or bars, and it is preferred that the wires,
rods, or bars should be arranged similar to a screw of several threads, say from
eight to twelve threads. In order to cleanse such a construction of screen, a
number of fixed blades on a bar are used, which are caused to pass into the
spaces between the wires, bars, or rods at the upper part of the screen, and the
bar, when necessary, is moved endwise by a cam movement, or otherwise, to
follow the inclination of the wires, rods, or bars.
Having thus stated the nature of our said Invention, we will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWINGS.
The Drawings, Figures 1, 2, 3, 4, 5, 6, 7 and 8, Sheet 1, represent a
rotatory screen, consisting of two screens of a circular section, combined as
above described. Figures 1 and 2 are drawn to a scale of 1 inches to the
foot; Figures 3 and 4 are drawn to a scale of 6 inches to the foot; Figures 5,
6, 7 and 8 are drawn to a scale of 3 inches to the foot; Figure 1 is a side
elevation of the screen complete as arranged for ordinary purposes, with
wheels and handles, so as to be readily removed from place to place; Figure 2
is an end elevation as seen from the feeding end of the machine; Figure 8 is
an end elevation of the excentric adjustment collar, lever, and bearing block of
the lower end of the screen; Figure 4 is a horizontal section of the excentric
adjustment collar, lever, and bearing block; Figure 5 is an end view of the
lower end of the screening cylinder; Figure 6 is a vertical section of part of
the screening cylinder, showing position of wires, connections of the two
cylinders, &c.; Figures 7 and 8, represent the two extreme relative positions
of the wires of the screen in a direction nearly at right angles to the axis of
the cylinders. a, a, Figures 1 and 2, show the frame upon which the cylinder,
hopper, &c., is carried; this frame, consisting of two cast end pieces con-
nected together by three collar bolts b, b, b, and two diagonal stays c, c. The
higher end of this frame is supported by two small wheels d, d, running upon

page_text: an axle e, which is bolted to the frame.
The front or lower end of this frame.
terminates in one foot, so that only three points of bearing, viz., this foot and
the two wheels form the resting points for the frame upon the ground or floor,
thus ensuring a certain firm footing for the machine. There are two pro-
jecting cast-iron handles screwed upon the prolonged ends of the upper collar
bolts in front of the nuts and frame at f. Figure 1, for the convenience of
lifting this end of the machine, and thus moving it from place to place. The
casting g, Figures 1 and 2, is bolted to the end of the back frame a. This
casting forms a spout conveying the grain or other material to be screened from
the hopper h, into the head of the screening cylinder, the supply being regu-
lated at pleasure by means of a suitable sliding plate or regulator at the
bottom of the hopper. The compound screening cylinder consists of two
separate cylinders of wire of slightly different diameters, moving nearly, but not
exactly, upon the same imaginary centres. The two outer heads of the larger
cylinder k, k, are carried by their hollow bosses which turn in bearing blocks 1, 2,
attached directly to the end castings of the frame a, a. The upper head has
a rim of bevil wheel teeth cast upon it, and into these teeth a bevil pinion m
works, the axis of this pinion receives motion either through a hand fly wheel
(as shown) or by suitable pulley or gearing, so as to give the proper motion to
the screening cylinder, which should be driven at about 18 revolutions per
minute, and with an inclination of about 1 in 6 to the horizontal. The wire
connected with the two outer heads, and forming the larger cylinder, is firmly
soldered into notches cut into the six wrought-iron longitudinal ribs n, ni, n,
Figures 1 and 6. These ribs are firmly bolted to the two heads or ends k, k.
The wire composing each cylinder is best made in one long and entire
length, as then a very accurate cylinder can be made, first winding the wire
in a spiral direction upon a suitable cylinder having two threads cut upon
it corresponding to the pitch of the wires. The smaller and inner wire
cylinder is constructed in a similar way to that just described, o, o, being the
two cast heads, which are also connected to each other by six longitudinal
ribs p, p, p, which are firmly bolted to each head. The wire compassing this
cylinder is also firmly soldered into notches cut in the six alternate longitudinal
ribs, which connect the heads of the cylinder together. The longitudinal ribs
of both the cylinders have deep parallel notches cut in the spaces between
their respective wires to allow of the free motion of the wire in these notches,
this motion being necessary for the action of the screen not only in its regular
rotation, but as will also be seen hereafter, because of the adjustment of which
the screen admits. This heads of the smaller cylinder rotate upon a spindle q,
which runs through the compound wire cylinder, passing freely through the

page_text: hollow central bosses of the heads k, k, of the larger wire cylinder. This
spindle has an excentric wrought-iron collar attached to each end of it by
steel pins, and the lower collar has a projecting piece forged upon it, seen
clearly in Figures 3, 4, and 5, which forms a lever handle, and by this the
spindle q is made to move in a delicate and slight degree vertically, and owing
to the excentric collar at each end of this spindle it rises and falls precisely
parallel to its axis, and by this means the two wire cylinders are adjusted so
as to admit of the centres of the cylinders composing the compound screening
cylinder being brought nearly concentric to each other when set at the greatest
degree of coarseness required as shown by Diagram Figure 8; Figure 7, and
also Figure 6, representing the cylinders at their greatest degree of excentricity,
which brings the lower surfaces of the wire cylinders to their finest screening
state possible. The central adjusting spindle of the screen is maintained in
its proper vertical motion by suitable slots (seen clearly in Figures 3 and 4),
cut in the outer blank ends of the bearing blocks 1, 7, which carry the heads of
the larger wire cylinder. This spindle is supported entirely by the two excentric
collars, which are retained in their respective positions by upper and lower pro-
jections from the bearing blocks 1, 1, as seen clearly in Figures 3, 4, 5, and 6,
and it will now be clearly understood that by moving the lever handle of the
lower excentric collar that any degree of fineness can be given to the screening
surface, and the lever maintained in any desired position of adjustment by
means of the arc and pin holes with pin as shown in Figures 3 and 5.
It is now only necessary to describe the action of the screen when in use
to clearly demonstrate its self-cleaning properties. It is, however, first desirable
to show that by rotating the larger cylinder upon its axis, the smaller
cylinder must rotate with it upon its separate axis, and this is ensured by
making one of the six longitudinal ribs of the larger cylinder pass through a
slot in the projecting lugs 8, s, cast upon each head of the smaller cylinder as
shown in Figures 1 and 6, which act as drivers to this cylinder.
The grain or substance to be screened, passing from the hopper h through
the spout g, into the head of the screen, gets carried by the motion of the
cylinders partially upwards, occupying as it were the space represented by
the dotted lines x, x, in Figures 7 and 8, the cylinder moving in the direction
of the arrows there shown, and any grains that may stick between the wires
and get carried above the horizontal centre of the cylinder become liberated
by the greater space formed between the wires at this elevation, (and fall
down by their own gravity perpendicularly within the cylinder), owing to the
difference in the diameters of the two wire cylinders combined with their
relative eccentric motions, and thus the screen never becomes choked, being

page_text: perfectly self-cleaning. The small corn falls through the lower side of the
cylinder, and the good or screened corn passing out at the lower end of the
cylinder is directed down the sheet iron shoot there shown.
We will now describe a rotatory screen constructed in accordance with the
second arrangement above described. .
Figures 9 and 10 (Sheet 2) represent side and end elevations of a rotatory
screen having portions of its screening surface adjustable and fitted with
cleaning apparatus, but if preferred the whole surface of the screening surface
may be made adjustable. These Figures are drawn to a scale of 1½ inches
to the foot. Figures 11, 12, 13, 14, 15, 16, and 17 represent parts of this
screen drawn to a scale of 3 inches to the foot to enable the arrangement to
be more clearly described and understood. The polygonal screening barrel is
here represented placed upon four flanged friction wheels a, a, a, a, Figures
9 and 10; these wheels are carried by two separate spindles moving in suitablo
bearings which are attached to the main framing of the machine b, b, shown
also in Figures 9 and 10. Rotatory motion is communicated to the screen
by turning one of the spindles carrying two of the friction wheels a, a, either
by hand or power, by means of a crank wheel or pulley placed as at e. It
will thus be understood that the mere frictional contact of the edges of the
heads of the screen resting upon these friction wheels is sufficient to give the
necessary motion to the screening barrel, but if desirable toothed gear could
readily be applied. The spout for conducting the grain into the screen from
any suitable hopper is shown at f, Figure 10, and the screened corn passes out
at the other end of the wired barrel of the screen, the thin grain passing through
the wire screening surface falls immediately under the screen. The screen as
here represented (and which we believe to be the best arrangement for this
kind of construction) consists of two cast-iron heads 9, 9, connected together
by means of seven ribs of hard wood h, h, h, as seen in Figures 9, 10, 11, 12,
and 13 fastened to the heads by means of dovetails and screws. The screening
surfaces are composed of straight pieces of wire or other suitable material.
For about one-third of the length of this screen from the feeding end, every
wire is firmly fixed at each end to the wooden ribs, and for the remaining
two-thirds of the length every other wire only is attached directly to these
ribs. This attachment is formed and the wires preserved in their relative
positions by means of a quantity of hot lead being poured into the dovetailed
longitudinal groove formed in the inside of the ribs, and clearly shown at
Figure 11. The last two-thirds of the length of the screen is so arranged
that every alternate wire is capable of being moved to or from the adjoining
wires so as to decrease or increase the width of the spaces between them, and

page_text: thus form an adjustable screening surface. This adjustment is accomplished
by means of a double T-ended rod n, placed upon the back of each wooden
rib, and made capable of end motion by means of a nut, having motion only
in a rotary direction clearly shown in Figures 12 and 13; so that when these
nuts are turned by means of a spanner, the screws upon the middle of the
T-ended rods cause then to move endways, the cross T-ends moving in the
slots formed in the four short plates j, j, j, Figure 13, fixed to the wooden
ribs h. Two longer plates 1, 1. slide radially upon the sides of the wooden ribs
guided by screws m, m, Figures 11 and 12, motion being given to these plates
by means of the cross end of the double T-ended rods n, n, Figures 12 and 13,
moving in the inclined slots of these plates, and as the alternate wires of this
portion of the screen are attached to these plates, it will be seen that the width
of the spaces between the wires can be adjusted as desired, by raising or
lowering every alternate wire. For the purpose of cleaning the spaces between
the wires, a bar of wood is used, p, p, Figures 9, 10, 14, and 15, carrying a
series of iron teeth which are fastened to it by being driven into saw cuts
inade in the bar. This bar is accurately adjusted and suspended from the
upper part of the main frame, and passes from end to end through the screen.
As the barrel revolves, this clearing bar receives an end motion, which preserves
the path of the teeth between the parallel wires of the screening surface, this
motion being communicated and regulated by the inclined faces cast upon the
lower head g of the screen, shewn clearly in Figures 10, 16, and 17. A small
friction roller q upon the clearing bar p works against these inclined faces, and
the weight of the inclined clearing bar keeps the roller in contact with the
cam faces of the lower head g of the barrel, or a spring can easily be applied
if necessary. It will be readily understood that the teeth of the clearing bar
always pass quite freely under the inner surfaces of the wooden ribs h, h, h,
because of the polygonal section of the screen, so that the clearing teeth
gradually enter between the spaces of the wired sides of the polygon, and are
as gradually withdrawn, so that no impediment to its action can take place,
all grains sticking between the wires being effectually removed by means of
this clearing bar and its teeth.
Having thus described the nature of our improvements and the manner of
performing the same, we would have it understood that we do not claim any
of the mechanical parts separately, nor do we confine ourselves to the details
herein described so long as the wires or rods and other parts of rotary screens
are combined as herein described, and are made adjustable, so as from time
to time to admit of the distances apart of such wires or rods or portions of
them being varied to suit different sizes of grain, seed, or other substances

page_text: requiring to be screened or separated, and the spaces between the wires or
rods are kept cleaned as explained.
In witness whereof, we, the said Henry Brinsmead and Jeremiah
Lawrence, have hereunto set our hands and seals, this Fifth day of
January, in the year of our Lord One thousand eight hundred and
sixty.
Witness,
ARTHUR THOMAS COLE,
(L.S.)
HENRY BRINSMEAD.
JEREMIAH LAWRENCE. (L.S.)
of Ipswich, Accountant.