IMPROVEMENTS IN SCREENS FOR DRESSING AND SEPARATING GRAIN AND OTHER SUBSTANCES
Year: 1885

page_text: HC Costances.
We, WILLIAM RAINFORTH, Senior, WILLIAM RAINFORTH, Junior, and HENRY
SLACK RAINFORTH, Manufacturers, of Britannia Iron Works, Lincoln, c/o, Day,
Davies and Hunt, Patent Agents, 321, High Holborn, in the County of Middlesex,
do hereby declare the nature of our Invention for "IMPROVEMENTS IN SCREENS FOR
DRESSING AND SEPARATING GRAIN AND OTHER SUBSTANCES "
to be as follows:-
This Invention relates to certain improvements in or applicable to the construction
of screens for dressing and separating grain and other substances.
The improvements constituting the present Invention have special reference to
rotary self cleaning screens, and consist essentially in combining with a rotary self-
cleaning screen having a fixed mesh and a fixed diameter, an adjustable stationary
segmental cradle also having a fixed mesh but being capable of adjustment as
regards its diameter in such a manner as that it can be distended equally at all
parts of its surface from a diameter equal to that of the screen to such a greater
diameter as may be required for the purposes hereinafter more fully set forth; the
parts being combined in such a manner as that the wires of the screen and of the
cradle alternate and so that when in their closed position the smallest mesh
between the adjacent wires will be existent, and so that the radial distension of
the cradle shall have the effect of increasing the mesh between the adjacent wires
of the screen and of the cradle to any required degree as hereinafter set forth, to
an equal degree at all parts of the screen, the wires of the screen and of the cradio
occupying parallel and concentric positions about the centre of rotation of the
screen irrespective of their several relative distances apart.
It is not necessary that the wires of the screen, or of the crade (now considering
the same separately,) should be equidistant apart throughout the length of the
screen, they may be so, or the spaces between them may be less at the entering end
and greater at the exit end, and there may be an equal difference between or
graduation of the adjacent spaces, or adjacent sections of the length of the screen
may have the spaces between their wires gradually increased, there then being
an equal difference between or graduation of the spaces of the adjacent sections,
and this difference may be obtained either by placing the centres of the wires
equidistant apart and using wires of different gauges to give the intervening spaces
as required, or by using wires of the same gauge, and placing them at the required

page_text: distances apart but it is essential (now considering both the screen and the
cradle) that the wires of the cradle should in the closed position thereof occupy a
position exactly inidway of the spaces between the wires of the screen, so that
whether the spaces between the wires of the latter be equidistant or vary through-
out the length of the screen, the mesh may be the same, or gradually and equally
increasing, throughout such length.
It is obvious that this result may be attained either by varying the wires of the
screen alone as described, or by correspondingly varying the wires of the cradle
alone, or by varying the wires of both the screen and the cradle, but the feature of
varying the mesh at different parts of the same screen at one and the same time is
not peculiar to the present Invention, and especial reference is drawn to it merely
in order that it may be fully understood that the present Invention may be applied
with equal advantage both to rotary screens in which the mesh is uniform through-
out the length of the screen at any one time, and to such screens in which the mesh
gradually increases cither as regards the successive spaces or the successive scries
of spaces from the entering to the exit end of the screen.
An especial object of the present Invention is to construct a rotary screen in
which the fullest range or alteration of mesh can be obtained practically instantly,
and with a minimum of movement and exertion, and which will allow of the mesh
being instantly set to any size required with the greatest degree of nicety. The
improved screen is also of a strong and durable construction, and not liable get
out of order in its usual operation, and it is moreover perfectly self-cleaning, and
dispenses with the need of brushes or other cleaning devices hitherto used.
A screen constructed in accordance with the present Invention is capable of having
its mesh altered from the very finest mesh required for say linseed or like seeds or
grain, to the coarsest mesh required for say beans, with an angular movement of a
handle or like means of actuation of say about 20 degrees, or even less, and any
intermediate mesh may of course be obtained with a correspondingly still less
movement.
A further especial advantage attendant upon the present improvements is that
the fullest length of the screen can be used for screening purposes at all times,
irrespective of the difference of mesh, which is a most important advantage.
The herein described improved screen possesses these advantages, which in
combination are peculiar to it, and are non-existent in previously existing screens,
and its improved construction and mode of actuation in altering the mesh is
altogether unique, and we therefore wish it to be distinctly understood that the
present Invention has more particular reference to the herein before described
peculiar feature of novelty characteristic of it, viz, the combination of a rotary
screen having a fixed mesh and a fixed diameter, with a stationary adjustable
segmental cradle also having a fixed mesh but being capable of radial adjustment
and distension of its diameter equally at all parts of its length and several radii,
when such parts are combined in such a manner as to vary the mesh of the screen
by more or less distending the cradle, than to any peculiar formation of such parts,
separately considered, as it is obvious that the principle of the Invention may be
carried into effect in various ways, and that both the screen and the cradle may
each be constructed in different ways, and the distension of the cradle may be
effected in various ways, and by the Application of various mechanical equivalents,
without affecting the improved principle of their co-operation as herein described
when in combination.
But we will now describe a modification of construction, which among many
others we have practically tried, and which we have found to possess certain
important advantages as regards simplicity and strength of construction, ease of
operation and nicety of adjustment; and great durability without needing special
attention.
In accordance with this modification, the screen proper is made of a cylindrical
form and of an unalterable length, diameter, and mesh, and the shaft by which it
is rotated is formed with a series of equidistant bosses keyed on the shaft and

page_text: provided with radiating arms carrying external rims. The outer or end rims are
made of the full diameter of the outside of the screen, and the intermediate rims
are made of a less diameter than the inside of the screen, and all the rims are
connected by equidistant parallel rods or bars running in a direction parallel with
the axis of the shaft or in a more or less helical direction, and these bars are bolted
to or otherwise conveniently held in position by inwardly projecting lugs of the end
rims, and by outwardly projecting lugs of the intermediate rims, and they may be
of a curved formation or other suitable shape as regards their cross section, and are
preferably so arranged as to have the least tendency to lift the grain and carry it
round when the screen is rotated.
These bars are also provided with outwardly projecting studs which are rivetted,
screwed or otherwise secured into their outer peripheries, and are so placed as to
determine the distance apart or mesh of the adjacent wire of the screen, and the
studs are formed with small bosses the depth or height of which determines the
distance between the outer surface of the said bars and the inner surface of
the surrounding wires forming the screening surface, which are formed of separate
rings, of even diameter, of wire, which are pierced at distances apart equal to the
difference between the adjacent studded bars, and are lapped around the circular
series of studs on the said bars, the studs passing through the openings formed in
the wires, the ends of which are then brazed, soldered or otherwise suitably secured
together, and the outer ends of the studs are then hammered down or rivetted to
make all fast to retain the adjacent rings of wire truly parallel.
The screen,
when mounted horizontally, may be fitted with an inner Archimedian
screw in the usual manner, for keeping the grain in about equal bulk throughout
the length of the screen, and continuously advancing it over its surface, and when
mounted in convenient supports, and suitably driven, the screen as thus formed
may be rotated in the usual manner.
Externally of each end of the screen, there is loosely mounted upon its shaft, a
boss formed with radial arms and external rims, and these rims have a fixed
position in relation to the frame of the machine, and neither any movement of
rotation nor of alteration as regards their distance apart.
The inner opposite faces of these said fixed rims are formed with flanges on their
inner circumference, and with lugs on their outer circumference, and between these
rins and around the said flanges and between them and the said lugs the framing
of the cradle is situated and operated as hereinafter described.
The framing of the cradle consists of end segmental rims which are disposed
against the inner sides of the said fixed rims and around and between its flanges
and the said lugs, and these segmental rims are capable of being operated as here-
inafter described in such a manner as that they can be concentrically turned about
the centre of rotation of the screen, and more or less opened apart or closed at the
upper part of the screen where the screen is open and is not enclosed by the
segmental cradle, and at a bottom part opposite the centre of the said opening, and
at which bottom part they are actuated, or caused to receive such circular move-
ments as and at the times desired by means of a rod parallel with the shaft of the
screen and extending from one of the said fixed rims to the other, the rod being
supported by external bosses on the inner sides of such lugs and to which bosses
the ends of thrust rods are connected to the adjacent open ends of the said segmental
rims, the connection being such that a slight angular movement given to the said
rod by a handle or like means of actuation will cause a circular movement of the
said segmental rims between the flanges and lugs of the said fixed rims, and this
movement is caused to be effective in causing the diametrical extension or with-
drawal of the cradle as hereinafter appears.
The cradle is further composed of a series of outer parallel rods or bars, also
parallel with the shaft of, the screen, which are inserted between the opposite
segmental rims, equidistant, apart, and their ends are reduced in diameter and ara
inserted through both the said fixed rims and the segmental rims. At the several
intersections of the said rods and of the fixed and segmental rims, the rims are

page_text: formed with slots in opposite directions, that is the slots in the fixed rims incline
at an angle or angles to the axis of the shaft, in one direction, and those in the
segmental rims incline at an angle or angles to the said shaft, but in an opposite
direction, so that the slots of the adjacent fixed and segmental rims cross each
other, the effect of which, (in the modification now being described) is, that when
the innermost ends of the cross slots are coincident, the said rods are in their
innermost positions, and the cradle is closed, and the smallest mesh is caused, and
that when the outermost ends of the cross slots are coincident, the said rods are in
their outermost positions, and the cradle is fully distended, and the largest mesh is
caused, and any intermediate mesh is also determined by the positions in which
such slots are caused to intersect.
Though the slots of the fixed rims, or of the said segmental rims (now considering.
them separately) all incline in the same direction, the adjacent slots do not neces-
Barily incline at the same angle to the said shaft ;-as the said bars of the cradle
are connected (excepting at the said upper opening) by the wires forming the 1
cradle, and which are secured to the bars by the use of inner projecting studs and
bosses in like manner as hereinbefore described with reference to the connection of
the wires composing the screen, the special object of this means of connection being
to leave the screening surface free from any obstruction, so that the whole surface
thereof shall be available for its intended use, and so as to provide every facility
for its efficient self cleaning; and this connection of the rods of the cradle by the
inextensible wires forming the cradle, prevents the radial distension of the rods,
and though they all have to nove outwards to an equal radial extent, they have,
nevertheless, to traverse different angular or oblique distances to do so, increasing
as they are more and more distant from the said rod as the centre of actuation;
and therefore the angles of the successive slots have to be determined to give the
gradually increasing movements required, so that, though the length of the wires
of the cradle cannot be increased, yet its diameter can, the cradle being segmental
and its opening accommodating the requirements.
It will now be seen that the parts are so arranged as that the inner screen can
be revolved and actuated quite independently of the cradle, and that the latter can
be adjusted quite independently of the screen, and that they are so constructed and
occupy such relative positions as that the adjustment of the cradle effects its radial
extension equally at all parts from the centre of the axis of the screen, and con-
sequently the adjustment of the mesh is similar throughout the extent of its acting
surface.
The adjustment of the mesh may be effected with equal facility for any degree
intermediate between the nearest distance of the adjacent wires of the screen and
of the cradle, when the latter is closed, and its wires are of the same cylindrical
diameter as the screen, and the greatest width between the adjacent wires of the
screen alone, when the cradle is most fully opened and is distended to its greatest
diameter, and when its wires are as far from the wires of the screen as the wires
of the latter are from each other, and this may be effected with a very slight
angular turning of the said rod; and any desired mesh can be at once given to the
screen and cradle as the said rod is continued outside the framing of the threshing
or other machine with which the screen may be used, and is provided with an index
finger or pointer and a graduated and marked dial so that the inesh required may
be given at once by simply turning the said rod the required angle. In former
adjustable rotary screens some considerable time was effected, and very many
complete turns required, in winding up and unwinding the same until the mesh
was adjusted as required, and we thus obtain an improved result, with the minimum
of movement, and of time occupied, with certainty of result, and without liability
of straining or injuring the screen.
As herein before mentioned, it is obvious that the same principle of action as
regards the distension of the cradle, may be carried into effect in a variety of ways,
aud by a variety of mechanical equivalents. As an example, we would further
mention that the said segmental rims may be arranged externally of the said fixed

page_text: rims, which alone may be angularly slotted, the said segmental rims to which the
rods of the cradle are connected being made of a spring formation, and being
radially thrust out by rods connected to a common boss loose on the shaft of the
screen, and the position of which may be regulated with relation to a fixed part of
the framing of the machine by means of a screw and suitable means of turning it.
It will be further obvious, as is herein before referred to, that the same mode of
operation and adjustment of the mesh may be effected when the cradle is so con-
structed as that its innermost diameter will give the largest mesh between its wires
and the alternating wires of the screen, and as that when fully distended to a
diameter equal to that of the screen it will give the smallest mesh.
In the operation of the screen, its self cleaning from any grain which may have
become lodged between its wires is effected as it passes over the open part of the
screen, which the cradle does not surround, after leaving the one edge of the cradle,
when such grain falls within the screen, or is knocked out as it again encounters
the other edge of the cradle.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C.,
Agents for the Applicants.

page_text: and other Substances..
We, WILLIAM RAINFORTH, Senior, WILLIAM RAINFORTH, Junior, and HENRY
SLACK RAINFORTH, Manufacturers, of Britannia Iron Works, Lincoln, c/o, Day,
Davies, & Hunt, Patent Agents, 321, High Holborn, in the County of Middlesex,
do hereby declare the nature of our Invention for "IMPROVEMENTS IN SCREENS FOR
DRESSING AND SEPARATING GRAIN AND OTHER SUBSTANCES," and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This Invention relates to cortain improvements in or applicable to the construction
of screens for dressing and separating grain and other substances.
The improvements constituting the present Invention have special reference to
rotary self-cleaning screens, and consist, essentially, in the combination with a
rotary self-cleaning screen having a fixed mesh, and a fixed length and diameter, of
a stationary adjustable segmental cradle also having a fixed mesh and length, but
being capable of adjustment as regards its diameter in such a manner as that it
can be distended equally at all parts of its surface from a diameter less than or
equal to that of the screen, to a diameter equal thereto or to such a greater
diameter as may be required for the purposes hereinafter more fully set forth;
when such parts are combined in such a manner, 1) as that the wires of the screen
and of the cradle alternate, 2) as that the smallest mesh between the adjacent wires
is existent when the screen and cradle are in the position of equal diameter, and
their circumferences are coincident, 3.) as that the radial distension or the radial
collapse of the cradle to an equal extent at all parts of its surface has the effect of
increasing the mesh between the adjacent wires of the screen and of the cradle to
an equal degree at all parts of the screening surface, and to any extent or degree
required between its minimum or maximum mesh, this being dependent upon the
diametrical or radial extent of distension or collapse given to the cradle, and 4) as
that the wires of the screen and of the cradle occupy parallel and concentric
positions about the centre of rotation of the screen irrespective of their several
relative distances apart.
It is not necessary that the wires of the screen, or of the cradle, (now considering
the same separately,) should be equidistant apart throughout the length of the
screen, they may be so, or the spaces between them may be less at the entering end
and greater at the exit end, and there may be an equal difference between or
graduation of the adjacent spaces, or adjacent sections of the length of the screen
may have the spaces between such sections of wires gradually increased, there then
being an equal difference between the spaces of the successive sections, and this
difference may be obtained either by placing the centres of the wires equidistant
apart and using wires of different and diminishing gauges to give the intervening
spaces as required, or by using wires of the same gauge, and placing them at the
required increasing distances apart;-but it is essential to this Invention, (now
considering both the screen, and the cradle,) that the wires of the cradle, should, in

page_text: all positions thereof, occupy a position exactly bisecting or midway of the spaces
between the wires of the screen, so that whether the spaces between the wires of
the latter be equidistant or vary throughout the length of the screen, the mesh at
any one time, and at any one position of the cradle, may be the same, or gradually
and equally increasing throughout the length of the whole screening surface.
It is obvious that this result may be attained either by varying the wires of the
screen alone, as described; or by correspondingly. varying the wires of the cradle
alone, or by varying the wires of both the screen and the cradle, but the feature of
varying the mesh at different parts of the same screen at one and the same time
is not peculiar to the present Invention, and especial reference is drawn to it
merely in order that it may be fully understood that the present Invention may
be applied with equal advantage both to rotary screens in which the mesh is
uniform throughout the length of the screen at any one time, and to such screens
in which the inesh gradually increases either as regards the successive spaces or
the successive series of spaces from the entering to the exit end of the screen.
An especial object of the present Invention, is to construct a rotary screen in
which the fullest range or alteration of mesh can be obtained practically instantly,
and with a minimum of movement and exertion, and which will allow of the mesh
being almost instantly set to any size required with the greatest degree of nicety.
A screen constructed in accordance with the present Invention, is capable of
having its mesh altered from the very finest mesh required for (say) linseed, or likė
seeds or grain, to the coarsest mesh required. for (say) beans, with an angular
movement of a handle or like means of actuation of (say) about 20 degrees, or
even less, and any intermediate mesh, may be obtained with a correspondingly still
less movement.
A further especial advantage attendant upon the present improvements, is that
the fullest length of the screen can be used for screening purposes at all times,
irrespective of any alteration of mesh, which is a most important advantage.
The improved screen is also of a strong and durable construction, and not liable
to get out of order in its usual operation, and it is, moreover, perfectly self-cleaning,
and dispenses with the need of brushes or other cleaning devices hitherto used.
The herein described improved screen possesses these advantages, which, in
combination, are peculiar to it, and are non-existent in previously existing screens,
and its improved construction and modes of operation and actuation in altering the
mesh are altogether unique, and we therefore wish it to be distinctly understood
that the present Invention has more particular reference to the hereinbefore
described peculiar features of novelty characteristic of it, viz, the combination
with a rotary self-cleaning screen having a fixed mesh, length and diameter, of
a stationary adjustable segmental cradle also having a fixed mesh and length but
being capable of radial adjustment of distension or collapse of its diameter equally
at all parts of its length and several radii, when such parts are combined in
such a manner as to attain or comprise the five essential requirements herein before
enumerated, than to an peculiar formation of such parts, separately considered, as
it is obvious that the principle peculiar to this Invention both as regards the
combination of such parts within such specified limits, and their method of
co-operation and actuation when in combination as herein described, will permit
of both the screen and the cradle, or of either the screen or the cradle, being
constructed in different ways, and of the distension or collapse of the cradle being
effected in various ways and by the application of various mechanical equivalents,
without in any way affecting or departing from the improved principle of their
co-operation as herein described when in combination.
Such being the essential nature, scope and object of the present Invention, we
will now proceed to describe more in detail a modification of construction in
which the cradle is distended from a diameter equal to to a diameter greater than
that of the screen in varying the mesh, and which (among many other modifications
of construction) we have practically tried, and which we have found to possess
certain important advantages as regards simplicity and strength of construction,
1

page_text: ease of operation, and nicety of adjustment; and great durability without needing
special attention, and in order that the Invention and such modification of
construction may be fully understood, we have annexed hereunto two sheets of
drawings illustrative thereof, and have marked the same with figures of reference
corresponding with those in the following explanation thereof.
Fig. 1 of the accompanying drawings represents in part a side or external view,
and in part a sectional or internal view, of a rotary screen and adjustable cradle
combined in accordance with the principle of the present Invention.
Fig. 2, represents an end view of the exit end of the screen, illustrating the
position of the parts, and of the actuating mechanism, wlien the cradle is in its
innermost position, (coincident with the diameter of the screen,) giving the smallest
mesh between its wires and the wires of the screen.
Fig. 3, represents a transverse section of the screen and cradle, when in the
position illustrated in Fig. 2.
Fig. 4, represents an end view corresponding to that of Fig. 2, but omitting the
connecting or supporting parts of the parts illustrated, to more clearly represent
the means of operating the cradle, and illustrating the position of the parts, and
of the actuating mechanism, when the cradle is in its most distended, position, (of a
diameter greater than, but of a circumference concentric with, the diameter and
circumference respectively of the screen), giving the largest mesh between its wires
and the wires of the screen.
Fig. 5, represents a transverse section of the screen and cradle when in the
position illustrated in Fig. 4.
Fig. 6, is a transverse section of the wires of the screen, and of the cradle,
when at their least distance apart, when the parts are in the respective positions
illustrated in Figs. 1, 2, and 3.
Fig. 7, represents a view corresponding to that of Fig. 6, when the said wires
are at their greatest distance apart, when the parts are in the respective positions
illustrated in Figs. 4, and, 5.
Figs. 8, represent detail sectional views illustrating methods (forming important
features of the present Invention) of mounting the wires of the screen and of the
cradle upon their several supporting bars or rods.
Fig. 9, represents an end view, and Fig. 10, a side view, of another modification
of the means of radially distending or collapsing the cradle.
Figs. 1, to, 5, and, 9, and, 10, are drawn to a scale of 4 inches to the foot, and the
remaining Figs. are full size.
In accordance with this modification, the screen proper is made of a cylindrical
form, and of an unalterable length, diameter, and mesh, and the shaft, 1, by which
it is rotated, is formed with a series of equidistant bosses, 2, keyed on the shaft,
and provided with radiating arms, 3, carrying external rims, 4. The outer or end
rims, 5, are made of the full diameter of the outside of the screen, and the inter-
mediate rims, 4, are made of a less diameter than the inside of the screen, and all
the rims, 4, 5, are connected by equidistant parallel rods or bars, 6, running in a
direction parallel with the axis of the shaft, or in a more or less helical direction,
and these bars are bolted to or otherwise conveniently held in position by inwardly
projecting lugs, 7, of the end rims, and by outwardly projecting lugs, 8, of the
intermediate rims and by external nuts, 33, or equivalent fastenings, and they may
be of a curved formation or other suitable shape as regards their cross section, and
are preferably so arranged as to have the least tendency to lift the grain or carry
it round when the screen is rotated.
The wires of the screen are made in the form of truly cylindrical rings, 9, of
equal diameter, and they are drilled with radial holes, 10, at equal distances apart,
and in number equal to that of the bars, 6. The outer edges of the bars, 6, are
also drilled with holes, 11, at equal distances apart, and in number equal to that of
the wire rings, 9.
The wire rings, 9, are made of a greater diameter than the distance between the
outer edges of the opposite bars, 6; and they are mounted thereupon at an equal

page_text: radial distance from all of them by means of studs or screw pins, 12, (vide Figs. 8,).
which are entered in the said holes, 10, of the rings, and, 11, of the bars, 6, and
which thus securely retain the adjacent rings, 9, at equal distance apart, or at the
required fixed mesh, throughout the whole surface of the screen, and which studs
or pins are formed with rounded bosses, 13, or are fitted or provided with rounded
collars or washers, 14, of a diameter not exceeding that of the wires, 9, in cross
section, and of the depth or height equal to the radial distance required to be kept
between the outer surface of the bars, 6, and the inner surface of the surrounding
wires, 9, forming the screening surface.
The screen, when mounted horizontally, may be fitted with an inner Archimedian
screw, 15, in the usual manner, for keeping the grain in about equal bulk throughout
the length of the screen, and continuously advancing it over its surface, and when
mounted in convenient supports, and suitably driven, the screen, as thus formed;
may be rotated in the usual manner.
Externally of each end of the screen, there is loosely mounted upon its shaft,
a boss, 16, formed with radial arms, 17, and an external rim, 18, and both of these
rims have a fixed position in relation to the frame of the machine, and neither any
movement of rotation nor of alteration as regards their distance apart, being
prevented from endway movement by the bosses, 46, fast on the shaft, 1, and
being rigidly held by rods, 19, or by other convenient means.
The inner opposite faces of the fixed rims, 18, are formed with flanges, 20, on
their inner circumference, and with lugs, 21, on their outer circumference, and
between these opposite ritns, 18, and around the flanges, 20, and between them
and the lugs, 21, the framing of the cradle is situated and operated as hereinafter
described.
Against the inner side of each fixed rim, 18, and around and between its
flange, 20, and lugs, 21, there is arranged a pair of segmental rims, 22, which are
capable of being operated as hereinafter described in such a manner as that they
can be concentrically turned about the centre of rotation of the screen in a circle
always of the same diameter, and more or less opened apart or separated or closed
together endways both at the upper part, 23, of the screen, where the screen is
open and is not enclosed by the segmental cradle, and at a bottom part, 24, opposite
the centre of the opening, 23, and at which bottom part such segmental rims aro
actuated, or caused to receive such circular movements, as and at the times and to
the extent desired, by means of a rod, 25, parallel with the shaft of the screen, and
extending from one of the fixed rims, 18, to the other, the rod being supported by
extensions, 26, depending from the rims, 18, and being fitted at each end with a
disc, 27, securely keyed thereon, and to which the inner ends 28, of the thrust
rods, 29, are connected, the outer ends, 30, of which thrust rods are connected to
the adjacent ends of the said pairs of segmental rims, 22, as shown most clearly in
Figs. 2, to, 5, the connection being such that a slight angular movement (indicated
by the altered position of the pin, 31, in Figs. 2 and 4) given to the rod, 25, in the
direction of the arrows Figs. 2 and 5 by a handle or like means of actuation, will
cause a circular movement of both pairs of opposite segmental rims, 22, between
the flanges, 20, and lugs, 21, of the fixed rims, 18, from the position indicated in
Figs. 2, and, 3, to that indicated in Figs. 4, and, 5, and this movement is caused to
be effective in causing the radial or diametrical distension of the cradle as herein-
after appears, and the opposite of return movement is similarly effective in causing
'the like collapse of the cradle.
The cradle proper is composed of a series of outer parallel rods or bars, 32, also
parallel with the shaft of the screen, which are situated, equidistant apart, between
the opposite segmental rims, 22; and their ends are reduced in diameter or other-
'wise formed or provided so as to be capable of being inserted through both the
adjacent fixed rims, 18, and segmental rims, 22, and of being secured by external
nuts, 34. At the several intersections of the said bars, 32, and of the fixed and
segmental rims, 18, 22, these rims, are respectively formed with slots, 35, 36, in

page_text: opposite directions, that is, the slots, 35, in the fixed rims, 18, incline at an angle
or angles to the axis of the shaft, in one direction, and those, 36, in the segmental
rims, 22, incline at an angle or angles to the said shaft, but in an opposite direction,
as clearly shown in Figs. 2, to, 5, so that the slots 35, 36, of the adjacent fixed and
segmental rims, 18, 22, cross each other, the effect of which, (in the modification
now being described,) is that when the innermost ends of the cross slots, 35, 36,
are coincident, as represented in Fig. 2, the said bars 32, are in their innermost
positions, vide Fig. 2, and the cradle is closed vide Figs. 1, and, 3, and the smallest
mesh of the wires of the screen and cradle is caused, as shown in Fig. 6; and that
when the outermost ends of the cross slots, 35, 36, are coincident, as represented in
Fig. 4, the said bars, 32, are in their outermost positions, and the cradle is fully
distended, vide Fig. 5, and the largest mesh of the wires of the screen and cradle is
caused, as represented in Fig. 7, and any intermediate mesh is also determined by
the positions in which such slots, 35, 36, are caused to intersect.
Though the slots, 35, of the fixed rims, 18, or those, 36, of the segmental
rims, 22, (now considering them separately,) all incline in the same direction, the
adjacent slots in each rim do not necessarily incline at the same angle to the said
shaft as the said bars, 32, of the cradle are connected (excepting at the said upper
opening, 23, thereof,) by the wires, 37, forming the cradle, and which are secured
to and at a distance from the bars, 32, by being pierced with holes, 38, and by the
use of inner projecting studs, 39, and shoulders or bosses, 40, or collars, 41, in like
manner as herein before described with reference to the mounting of the wires, 9,
composing the screen, vide Figs. 8..
In the Specification of former Letters, Patent, No 10,102, dated, 12, July, 1884,.
granted to us, we have described the Application of like means of mounting the.
wires of an expansible flat screen at a distance from and when used in combination
with a series of connecting links, for the special purpose therein mentioned;-but
the method herein described of mounting the wires of rotary inexpansible cylin-
drical screens, and of an expansible segmental cradle, when used in combination,
at a distance from their respective supports, is novel and materially different from
that formerly described by us, in so far as that such studs or like means of ensuring
a sufficient radial distance between the said wires of the screen and of the cradle
and their respective supports, are combined, in accordance with the present improve-
ments, with rigid supports of the respective wires, and so far as this difference is
existent, it constitutes a material feature of the present Invention to mount the
wires of such screens and cradles at a distance from their respective supports by
the use of the means berein described or analogous thereto.
We are aware from long continued experiments in combined screens and cradles
of the kind herein described, that serious disadvantages result, if the wires of the
screen and the cradle are mounted directly upon their respective supports, or at a
distance therefrom and upon projections thereof if such supporting projections are
simply the projections left after slotting out the said supports, as the grain is then
very liable to be crushed or broken in the operation of the machine; and it has
been for the express purposes of avoiding this most serious disadvantage, and of
leaving the whole screening surface free from any obstruction and available for its
intended use, and of providing every facility for its efficient self-cleaning, that we
have adapted this improved system of mounting the wires of the screen and of the
cradle upon supporting studs or like means, which are rounded as regards their
cross section, and are of a diameter not exceeding that of the wires they support,
and are combined with rigid supports.
This connection of the bars, 32, of the cradle by the inextensible wires, 37,
forming the screening surface thereof, prevents the radial distension of the rods 32,
and though they all have to move outwards, to an equal radial extent, they have,
nevertheless, to traverse different angular or oblique distances to do so, increasing
as they are more and more distant from the said rod, 25, as the centre of actuation;
and therefore the angles of the successive slots, of each series, 35, 36, have to be
determined to give the gradually increasing movements required; so that, though

page_text: the length of the wires of the cradle cannot be increased, yet its diameter can, the
cradle being segmental, and its opening, 23, accommodating the requirements.
It will now be seen that the parts are so arranged as that the inner screen can
be revolved and actuated quite independently of the cradle, and as that the latter
can be adjusted quite independently of the screen, and that they are so constructed
and occupy such relative positions as that the adjustment of the cradle effects its
radial distension or collapse equally at all parts from the axis of the screen, and
consequently the adjustment of the mesh is similar throughout the extent of its
acting surface.
The adjustment of the mesh may be effected with equal facility for any degree
intermediate between the nearest distance of the adjacent wires of the screen and
of the cradle, when the latter is closed, and its wires are of the same cylindrical
diameter as the screen, as shown in Figs. 3 and 6 and the greatest width between
the adjacent wires of the screen alone, when the cradle is most fully opened, and
is distended to its greatest diameter, (or, in other modifications, collapsed to its
least diameter,) and when its wires are as far from the wires of the screen, as the
wires of the latter are from each other, as shown in Figs. 5 and 7 as the rod, 25,
is continued outside the framing of the threshing or other machine to which the
screen may be applied, and is provided with any suitable index finger or pointer,
working against a fixed and suitably graduated and marked segmental dial, so
than any mesh required can be at once given to the screen and cradle by simply
turning the rod, 25, the required and relatively corresponding angular distance.
In former adjustable rotary screens some considerable time was effected, and
very many complete turns were required, in winding up and unwinding the same
until the mesh was adjusted approximately to what was required, and this when
effected hastily by a careless attendant was very liable to and frequently did strain
or injure the screen; but by the present improvements we obtain an improved
result, with the minimum of movement, and of time occupied, with certainty of
obtaining the exact mesh required, and without any liability of straining or
injuring the screen.
As herein before mentioned, it is obvions that the same principle of action as
regards the radial distension or collapse of the cradle, may be carried into effect in
a variety of ways, and by a variety of mechanical equivalents. As an example,
we will now refer to the modification illustrated in Figs. 9, and, 10, wherein one
segmental rim, 22, is arranged externally of each fixed rim, 18, and wherein the
rims, 18, alone are angularly slotted at, 35, the seginental rims, 22, (to which the
rods, 32, of the cradle are connected,) being made of a spring or slightly yielding
formation, and being radially distended by rods, 42, connected to a common
boss, 43, loose on the shaft, 1, of the screen, and the position of which boss may be
regulated with relation to any convenient fixed part, 44, of the framing of the
machine by means of a screw, 45, and suitable means of turning it.
It will be further obvious, as is herein before referred to, that the same mode
and means of operation and adjustment of the mesh may be effected and used
when the cradle is so constructed as that its innermost diameter will give the
largest mesh between its wires and the alternating wires of the screen, and as that
when fully distended to a diameter equal to that of the screen it will give the
smallest mesh.
In the operation of the screen, its self-cleaning is effected as its parts successively
traverse the space, 23, unenclosed by the cradle, during which any grain between
its wires falls into within the screen, or is knocked thereinto upon encountering
the edge of the cradle.
Having now particularly described and ascertained the nature and objects
of our said Invention, and in what manner the same is to be performed, we
declare that what we claim is
1. The combination with a rotary self-cleaning screen having a fixed mesh,
and a fixed length and diameter, of a stationary adjustable segmental cradle also

page_text: -
having a fixed mesh and length, but being capable of adjustment as regards its
diameter in such a manner as that it can be distended from a diameter less than
or equal to, to a diameter equal to or greater than that of the screen, when such
screen and cradle are constructed, arranged and combined in such a manner as to
co-operate in the manner hereinbefore described, and attain or comprise the several
essential requirements herein before set forth.
2. The hereinbefore described improved means and method of varying, altering,
adjusting or setting the mesh of the acting screening surface of a rotary cylindrical
screen of the kind hereinbefore described; such improved means and method
consisting in combining with such a screen, a segmental cradle of similar length
and mesh but capable of diametrical distension or collapse equally at all parts of
its acting screening surface, in such a manner as that the wires of the screen and
of the cradle alternate, and are in all positions exactly intermediate, parallel, and
concentric, and are of coincident diameter in the position of smallest mesh; and in
setting the mesh of the adjacent wires as desired by radially distending or
collapsing the cradle to the required degree substantially as herein before described.
3. The herein before described improved method and means of mounting a rotary
cylindrical screen of the kind hereinbefore described, and an adjustable stationary
segmental cradle co-operating therewith as hereinbefore described, in such a
manner as that the screen and cradle shall be capable of independent actuation,
and shall be otherwise quite independent of each other excepting as regards the
variation of their relative positions for adjusting the mesh as required, and as that
they shall be always retained concentric with each other; such means consisting
in the use in combination of the external rims, 18, having a fixed position in
relation to the framing of the machine and supporting the shaft of the screen, and
of the segmental rims, 22, capable of endwise movement away from or towards
each other in a circle always of the same diameter, such fixed and segmental rims
being formed with cross slots or equivalent means with which the supporting bars
of the cradle engage.
4. The means herein before described, or means analogous thereto, of radially
distending or collapsing an adjustable stationary segmental cradle, when combined
with a rotary cylindrical screen of fixed diameter; such means consisting in the
combination of the said fixed and segmental rims, 18, 22, slotted and co-operating
as herein before described, with the actuating rod, 25, and thrust rods, 29, or other
substantially similar means capable of actuating the segmental rims and imparting
endway movements thereto, and thus causing alteration of the positions of the
cross slots of the said rims, 18, 22, and corresponding distension or collapse of the
cradle.
5. The modification hereinbefore described for attaining the same object, such
modification consisting in the combination of the fixed rims, 18, and of segmental
rims, 22, of spring formation, with the thrust rods, 42, boss, 43, screen, 45, and
fixed part 44, or other substantially similar means of operating the spring
segmental rims.
6. The novel construction of rotary cylindrical screen hereinbefore described;
the same consisting in mounting a series of truly cylindrical rings of wire, radially
drilled at, preferably, equidistant intervals, parallel, externally of or around, and at
any desired radial distance from, a series of transverse, parallel, rigid, and,
preferably, equidistant, bars or supports, retained in position by end and inter-
mediate rims, and externally drilled at the required intervals apart to give the
fixed mesh desired, by means of pins or studs entering the opposite drilled holes of
both the said rings and bars, and formed, fitted or provided with fixed or loose
shoulders, bosses, collars or washers of a rounded form in cross section, of a
diameter not exceeding that of the wire in cross section, and of a depth in
accordance with the radial distance required between the said wires and rigid
supports thereof.
7. The novel construction of adjustable stationary segmental cradle hereinbefore
described; the same consisting in mounting a series of segmental wires drilled at,

page_text: preferably, equidistant intervals, parallel, internally of, and at any desired radial·
distance from, a series of transverse, parallel; and, preferably, equidistant, rigid
bars, drilled on their inner faces at the required intervals apart to give the fixed
mesh required, by means of pins or studs entering the opposite drilled holes of
both the said wires and bars, and formed, fitted or provided in the manner herein-
before described and referred to in the next preceding claim; the parts being
combined in such a manner as that the said bars, in the actuation of the cradle by
the means herein described, or by means analogous thereto, shall be capable of
oblique movement in relation to their centre of actuation, and of radial distension
or collapse in relation to the centre of the screen substantially in the manner
hereinbefore described.