IMPROVEMENTS IN MIDDLINGS-PURIFIERS
Year: 1883

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine Lake
& Co, Patent Agents, Southampton Buildings London for an Invention of
"IMPROVEMENTS IN MIDDLINGS-PURIFIERS" communicated to him from abroad
by John Tilghman Walter of Easton, Pennsylvania, United States of America,
Manufacturer.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at
"
the Office of the Commissioners of Patents on the 18th December 1883.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN MIDDLINGS-PURIFIERS [a
communication to him from abroad by John Tilghman Walter of Easton,
Pennsylvania, United States of America, Manufacturer.]
This invention relates to middlings-purifiers, which comprise a housing or casing,
one or more inclined vibrating screens contained therein, and means for inducing
an air current through the screens.
Another
One object of this invention is to provide means in such a machine for separating
the coarser particles from the dust that is taken up by the air-blast.
object is to provide means in a machine having two or more oppositely inclined
screens arranged so that the tailings from one screen are delivered to the head of
the screen below, for removing the larger and lighter specks or impurities from the
tailings of each screen so as to prevent such impurities from passing to the
succeeding screen of the series. Other objects of the invention are to provide an
improved means for separating the material passing through the different portions
of a screen, to provide an improved device for operating the rotary beaters which
clear the bolting-cloth, and to improve the details of construction in the class of
machines referred to, in other particulars, and it consists in the combination and
arrangement of parts as hereinafter described.
In carrying the said invention into practice I provide a rectangular frame, upon
which the several operative parts are mounted, and also an inner frame or casing
in which the screens are supported. The inner casing is reciprocated by means
hereinafter described, for the purpose of giving the necessary shaking movement to
the said screens,

page_text: The said screens which are three in number are inclined in opposite directions
and so arranged that the material passing over the lower end of one screen is
received at the head of the one below it. The said screens are graduated in
fineness, the one allowing the passage of the finest particles being placed at the top
of the machine.
A self-regulating separating feeder is provided which is placed over the head of
the upper screen and is constructed to deliver material thereto in a thin stream the
full width of the screen.
The inner casing is composed of corner frame-pieces side walls, end walls, and a
closed top or roof and its interior is divided into three compartments by means of
inclined partitions placed intermediately of the screens and upon which the
material passing through the screens is received, such material being the purified
middlings. The said partitions are connected by vertical passages which conduct
the material from the lower end of the upper partition around the middle screen to
the lower partition, and similar passages extend from the lower end of the lower
partition to the space beneath the lower screen whereby the material from the
said upper portion partition is delivered to a spout placed beneath the said screen
by which it is discharged to the outside of the machine, as will hereinafter be
described. The tailings from the upper and middle screens pass to the head of the
screens below them, and around the ends of the partitions through passages, and
the tailings from the lower screen pass to a trough having its bottom inclined to a
central spout through which the said tailings are discharged from the machine.
Upon either side of the inner casing and occupying the space between the end
parts of the frame of the machine I have placed chambers which communicate with
the interior of the compartments in the said casing above each of the screens, by
means of air-trunks, and are connected by suitable passages with an exhaust-fan
placed upon the top of the machine. By means of the said exhaust-fan an upward
air-blast is maintained through the screens for separating the dust and finer
impurities from the middlings: the air enters the inner casing through openings
in the end wall of the said casing and below the screens, and passes outward
through the trunks and chambers to the exhaust-fan.
The said trunks are supported in the side walls of the inner casing and their
open ends project a short distance into the said chambers for a purpose hereinafter
set forth. The said trunks are provided with inlet openings, preferably placed in
.their top surfaces through which openings the air from the interior of said casing
is drawn. In order to regulate the air-current through the several screens, the
said openings are provided with valves the shafts of which valves extend outwardly
through the chambers to the exterior of the machine, and are provided with means
for holding the valves in any desired position, consisting of slotted segmental arms
and thumb-screws passing through the slots in the said arms for securing them to
the side walls of the machine.
The outer walls of the chambers are formed by a casing placed between the
vertical end posts of the frame, and the inner walls thereof by the side walls of the
inner casing, a close fitting sliding joint being formed between the frame-pieces at
each corner of the inner casing and the inwardly projecting pieces which form the
ends of the chambers so as to allow the reciprocation of the said casing, and at
the same time prevent the entrance of air to the said chambers. The bottoms of
the chambers consist of inclined pieces the lower and inner ends of which are in
contact with, and slide upon, longitudinal side pieces placed parallel with and
outside of the side walls at the lower margin thereof.
A close covering is placed over the top, and the end walls of the inner casing
extend upwardy to the said covering and form a close joint therewith, thus forming
a closed space over the inner casing, which space communicates at either side with
the chambers. The exhaust-fan is placed upon the covering and its inlet is
connected with the space by means of vertical passages.
The chambers are for the purpose of accomplishing a separation of the coarser
particles contained in the dust drawn by the air-current from the interior of the

page_text: 2
inner casing the said chambers being of sufficient size to cause a reduced movement
of the air therein, and allow a settlement of the larger and heavier particles to
the bottom of said chambers. To ensure a more complete separation of the
larger particles from the dust, a vertical partition is placed in each of the chambers
parallel with the side walls thereof, the said partition being composed of bolting-
cloth, muslin, or other perforate material of suitable fineness to allow the fine dust
or fuzz"
to pass through it, and to retain the coarser particles. The said
partitions consist of end pieces and three transverse strips, the said strips being
provided with apertures corresponding in position with the ends of the trunks.
The ends of the said trunks, which extend beyond the side walls of the inner
casing, fit closely against the transverse strips and are constructed to slide thereon,
so as to permit the reciprocation of the said casing, to which they are rigidly
attached. By this construction, the dust drawn from the interior of the inner
casing passes through the partition to the outside thereof, and is then drawn back
through the said partition to the closed space, with which space the exhaust inlet
of the exhaust-fan communicates, the coarser particles in the said dust being
arrested by the said partition, while the finer dust or "fuzz" passes through it to
the exhaust-fan and is conveyed by the air-blast therefrom to a dust-room or
elsewhere.
The coarser particles separated from the dust in the chamber fall upon an
inclined board near the bottom of said chamber, over the lower edge of which
they fall into a longitudinal trough or conveyor having its bottom inclined from
each end of the machine to a central discharge spout. The said spout is provided
with an outwardly opening flap-valve for the purpose of preventing the entrance of
air to the chamber the said valve being constructed so as to open by the pressure
of the material which accumulates behind it, in order to allow the exit of such
material. The longitudinal trough is placed a short distance above the inclined
bottom of the chamber, and at the junction of the said bottom with the side-casing
is a narrow opening extending the full length of the chamber, through which
opening air is admitted to the space between the inclined board and the bottom,
which air is drawn upwards through the material as it falls from the lower end of
the longitudinal trough, and by lifting the lighter particles, performs an additional
separation of the fine dust from the said material. A movable slide is placed over
the narrow opening for adjusting the width of the said opening, whereby the
strength of the air-current passing through the material falling from the longitudinal
trough may be regulated as desired.
For the purpose of removing any large and light specks or impurities which
have not been separated from the middlings by the upward blast through the
screens, and which would otherwise pass with the tailings to the screen below,
I subject the said tailings, as they fall from the lower end of one screen, to the
head of the next, to an upward blast of air, by which the said specks are separated
from the tailings and carried out of the machine. To produce this air-blast I have
formed horizontal openings or slits in the outer walls of passages, a short distance
below the end of the upper and middle screens. By the action of the exhaust-fan
a current of air is drawn inwardly through the said slits and passes upwardly
through the tailings into the space above the screens and out through the trunks,
carrying with it the specks and impurities mentioned.
For the purpose of regulating the air-blast mentioned, the openings or slits are
provided with sliding valves which may be clamped in any desired position by
means of thumb-nuts placed on bolts which are secured to the walls of the casing
and pass through slots in the said valves.
At the lower end of the passages are placed downwardly-opening valves con-
sisting of depending strips of india rubber or other flexible substance, the said
valves being constructed to prevent the upward passage of air into the passage
and to yield by the weight of the material which accumulates above them, so as
to allow such material to pass to the screen below.

page_text: In order to economize space in the inner casing and to permit the use of screens of
greater length than otherwise could be placed in the said casing, the passages are
formed in projecting portions upon the ends of the said casing. The tops of the
said projecting portions consist of inclined hinged covers which open immediately
over the lower ends of the screens so that the said screens and the adjacent parts
may be inspected, and access readily had to them.
The frames of the several screens are of ordinary construction and the said
screens are supported in the inner casing, at either side thereof, by having their
edges placed in a groove formed by two strips attached to the side walls. The
beads of the several screens extend to the end walls of the inner casing and may
readily be removed for the purpose of repairs or renewal, by drawing them out
through the said end walls. A fastening device is placed at the head of the screens,
whereby they are held in place in the said grooves.
The self regulating feeder is placed upon the top covering of the machine and is
constructed to deliver the material to be operated upon into a receptacle placed in
the inner casing over the head of the upper screen. The said receptacle has a
narrow slit in its bottom through which the material is delivered to the screen, and
which is provided with a depending flexible strip arranged so as to allow the
downward passage of material through it, but to prevent the upward passage of
air. This construction in the receptacle however, relates to the operation of the
feeder, and has no operative relation to the middlings-purifier proper.
Beneath the lower screen are placed two transversely inclined surfaces which are
arranged to discharge the material passing through the said screen to a central
longitudinal trough having an inclined bottom which terminates at its lower end
in a discharge spout. The purified middlings passing from the partitions through
the passages are discharged at the lower end of the said trough and pass out of the
machine by the said spout.
The material passing through the lower screen may pass out of the machine by
the spout with the purified middlings from the upper and middle screens, or if it is
desired, may be delivered to a separate spout or exit and form another grade of
middlings called "seconds." In order to effect such separation of the middlings,
and at the same time to provide a means for sending the material passing through
any desired portion of the screen to the spout and the remainder to the exit, I
have provided a peculiar construction in the spout. Over the lower end of the
inclined bottom of the said spout is placed an oppositely inclined partition the
lower end of which terminates over a valved aperture in the said bottom, the said
aperture being placed immediately over the exit aperture. Below the upper end
of the inclined bottom, and parallel to it there is a second incline which terminates
at its lower end in the said exit aperture. In the upper portion of the first
mentioned incline is placed a series of valved openings and in the inclined partition
is a similar series of openings. By closing all the apertures mentioned, the
material passing into the trough is all conveyed to the spout, and by opening the
valved aperture all such material will pass out of the exit aperture. When one of
the valved openings is opened, all the material falling upon the inclined bottom
above the said opening will be intercepted and pass to the second incline and out
of the machine through the exit opening and in the same manner the valved aperture
being open when one of the series of openings is opened the material falling
upon said incline above said aperture will be delivered at the spout and below to
the exit.
For the purpose of keeping the bolting-cloths in the several screens clear, rotary
beaters are preferably used, which consist of rollers having small tags of leather
attached thereto, which tags are thrown outward by centrifugal force as the rollers
are moved across under the screens so as to strike the surface of the cloth thereon
and clean it without injury thereto. The said rollers rest upon tracks or ways at
their ends and receive their rotary motion by rolling on the said ways when
moved back and forth beneath the screens. Such rotary beaters have been
previously used, and form in themselves, no part of this invention.

page_text: The said tracks or ways are placed outside of the inner casing and are supported
upon cross pieces attached to the frame of the machine, and the ends of the rollers
are extended outside of the said casting through openings so as to rest on the said
ways. The opposite ends of the rollers are supported on a rod secured at its ends
in the frame. The said rod extends through the interior of the inner casing
beneath the lower cross-piece of the screen frame the apertures in the sides of the
casing through which it passes, being enlarged so as to allow for the vibrating
movement of the casing. One object in placing the ways as described is to prevent
the middlings passing through the screens from falling upon them and being
crushed into flour by the beater-rollers.
It has been found in practice that the rotary beaters described and arranged
to pass under the longitudinal ribs by which the bolting-cloth is supported
intermediately of its edges, are liable to cut or injure the cloth at its point of
attachment to the said ribs. In order to remedy this difficulty, one beater is
placed beneath each section of the screen and its movement is limited to the width
of such section. When one section of cloth alone is used, or more than two, &
corresponding number of beaters is provided.
For the purpose of moving the beaters laterally to accomplish the cleaning of
the bolting-cloths as described, a lever pivotted upon the cross-piece, one end of
which extends outwardly from the end of the machine, and the other inwardly
through the rollers. Such lever consists of two end pieces to which the ends of
the rollers are journalled, and two central longitudinal rods connecting the said
end pieces. Upon the longitudinal rods, near their centre, is attached a block
provided with a slot, through which the inner end of the lever passes. The said
block is clamped to the rods by means of a plate, between which plate and the
block the said rods are placed. The block and the plate are provided with
corresponding semicircular grooves in which the rods fit, and are secured together
by a bolt, or in any other convenient manner. By moving the block longitudinally
upon the rods the length of the inner arm of the lever may be changed and the
amount of lateral movement given to the rollers varied thereby, as desired. The
levers are connected, by means of rods, to arms upon vertical rock-shafts journalled
in brackets placed at the corners of the frame at one side of the machine. The
said rock-shafts are provided with arms placed at right angles to the first named
arms and are connected by means of rods with a double crank arm placed upon a
short shaft attached to the outer casing of the machine, and near the centre of the
side thereof. Upon the short shaft is also placed a sprocket-wheel which is
driven by a chain-belt from a sprocket-wheel having bearings on a shaft. A second
sprocket-wheel is placed on the said shaft and is driven by a second chain-belt
from a counter-shaft mounted upon the top of the frame of the machine. Upon the
hub of the first sprocket-wheel, and adjacent to the face of the second sprocket,
wheel, is a second lever, having two equal and oppositely arranged arms, the
ends of which arms extend slightly beyond the peripheries of the said
sprocket-wheels. The chain-belt has upon one of its links a laterally projecting
stop which is so placed that in its passage around the second sprocket-wheel it
will encounter one of the ends of the said lever so as to give a half-revolution
both to the said lever, and to the first sprocket-wheel to which the said lever is
attached. The latter wheel thus receives a half revolution at each passage of the
stop around the second sprocket-wheel, which movement is transmitted by means
of the first chain-belt to the chain wheel. The first chain belt is provided with a
stop which acts upon the ends of the lever so as to give to the said lever a half
revolution on its axis in the manner before described in connection with the
second lever. At each half revolution of the lever the rods are given a half stroke,
and such movement, by means of the devices before described, transmitted to the
beater rollers which thus receive a reciprocatory movement at regular periods, first
over one half of each section of the bolting cloth and then over the opposing half.
The frequency with which the lever is revolved and the beaters are moved, may be
increased by placing additional stops upon the belts.

page_text: The frequency of the said movements of the beaters may be decreased by
introducing one or more additional pairs of sprocket-wheels, or by placing the said
wheels so that the lengths of the connecting belts will be increased.
The inner casing is supported from the lower cross-pieces at either end of the
frame by means of flexible standards which are bolted at their lower ends to the
said cross-pieces and at their upper ends to the corner frame-pieces of the casing.
A suitable vibrating motion is given to the casing by means of excentrics which
are mounted on a shaft placed in suitable bearings upon one end of the main
frame, which excentrics bear against opposing rollers placed upon a cross-shaft
having bearings upon one end of the casing. Motion is given to the excentrics by
means of a driving belt upon a pulley placed upon one end of the said shaft. At
the opposite end of the machine are located springs which are placed between
brackets upon the vertical posts of the frame, and the frame of the inner casing so
as to keep the rollers in contact with the excentrics. In order to prevent the
slipping of the excentrics upon the rollers the bearing edges of the latter are
provided with a covering of india-rubber or similar elastic material, which also
acts as a cushion to lessen the jar on the adjoining parts as the casing is vibrated.
A horizontal spring brace may be attached at one end of the inner face of the
vertical end-post, with its opposite end secured near the opposite side of the
end-wall of the inner casing so as to prevent lateral movement or swaying of
the upper part of the said casing, and the consequent unequal pressure and friction
on the sliding joint between the sides of the casing and the end pieces of the outer
frame.
The screens, the receiving surfaces placed below said screens, and the several
carrying spouts and troughs mentioned, all being rigidly attached to the inner
casing the oscillating motion imparted to said casing not only causes the said
screens to effect the necessary separation of the material thereon, but serves to
facilitate the passage of the material over the several receiving surfaces and through
the several troughs and passages described.
By the construction in the machine described, whereby a separation of the
material carried from the middlings by the air-blast is effected in compartments
placed in the frame of the machine on either side of the screen-casing, I am enabled
to accomplish such separation without the use of a separate machine or apparatus,
and without materially increasing the size or cost of the middlings purifier proper.
The construction described also presents great advantages in point of simplicity
and economy, from the fact that by the location of the chambers adjacent to
the sides of the screen-casing the air can be drawn directly from the several
compartments over the screens in such casing and into said chambers, and the use
of a complicated system of air-passages for connecting said compartments with the
exhaust-fan is thereby avoided.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Patent Office on the 17th June 1884.
WILLIAM ROBERT LAKE of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN MIDDLINGS-PURIFIERS "―a
communication to me from abroad by John Tilghman Walter, of Easton,
Pennsylvania, United States of America, Manufacturer.
This invention relates to middlings-purifiers, which comprise a housing or casing,
one or more inclined vibrating screens contained therein, and means for inducing
an air-current through the screens.
One object of the said invention is to provide, in such a machine, means for
separating the coarser particles from the dust that is taken up by the air-blast.
Another object is to provide means, in a machine having two or more oppositely
inclined screens arranged so that the tailings from one screen are delivered to the
head of the screen below, for removing the larger and lighter specks or impurities
from the tailings of each screen so as to prevent such impurities from passing to the
succeeding screen of the series. The said invention also has for its objects to
provide improved means for separating the material passing through the different
portions of a screen, to provide an improved device for operating the rotary beaters
which clear the bolting-cloth, and to improve the details of construction in the class
of machines referred to, in other particulars, and to this end it consists in the
combination and arrangement of parts as hereinafter described.
In the accompanying drawings-
Figure 1 is a perspective view of a middlings-purifier embodying my invention.
Figure 2 is a horizontal section of the same on the line x, x Figure 3 drawn to an
eularged scale.
Figure 3 is a central vertical section of the same,
Figure 4 is a transverse vertical section on the line y,-
Figure 5 is an end elevation, and
Figure 6 is a side elevation of the same,
y Figure 3.
Figure 7 is a view of the muslin partition in the air-chamber and its frame
removed from the machine.
Figure 8 is a view of the lever for operating the rotary cloth-cleaners and its
means of attachment thereto.
Figure 9 is a separate view of the block for connecting the lever with the
cloth-cleaners.
A indicates the rectangular frame of the machine upon which the several
operative parts are mounted, and B an inner frame or casing in which the screens
are supported. The casing B is reciprocated by means hereinafter described, for
the purpose of giving the necessary shaking movement to the said screens.
C, C, and C, indicate three screens which are inclined in opposite directions
and so arranged that the material passing over the lower end of one screen is
received at the head of the one below it. The said screens are graduated in fineness,
the one allowing the passage of the finest particles being placed at the top of the
machine.
C³ indicates a self-regulating separating feeder which is placed over the head of
the screen C and is constructed to deliver material thereto in a thin stream the full
width of the screen.

page_text: The inner casing B is composed of corner frame-pieces B¹, side-walls b, end
walls 6, and a closed top or roof 62 and its interior is divided into three
compartments by means of inclined partitions D, D¹ placed between the screens,
and upon which the material passing through the screens is received, such material
being the purified middlings. The partitions D, D₁ are connected by vertical
passages d which conduct the material from the lower end of the partition D
around the screen C¹ to the partition D', and similar passages d' extend from the
lower end of the partition D¹ to the space beneath the lower screen C², whereby
the material from the said partition D¹ is delivered to a spout placed beneath the
said screen, by which it is discharged to the outside of the machine, as will herein-
after be described. The tailings from the screens C C¹ pass to the head of the
screens below them, and around the ends of the partitions D D¹, through passages E,
as shown, and the tailings from the lower screen C, pass to a trough E² having its
bottom inclined to a central spout Es through which the said tailings are
discharged from the machine.
Upon either side of the casing B, and occupying the space between the end parts
of the frame of the machine, I have placed chambers G which communicate with
the interior of the compartments in the casing B above each of the screens, by
means of air-trunks F and are connected by suitable passages with an exhaust-fan H,
placed upon the top of the machine. By means of the said exhaust-fan an upward
air-blast is maintained through the screens for separating the dust and finer
impurities from the middlings. The air enters the casing B through openings b³
in the end wall 61 of the said casing, and below the screens, and passes outward
through the trunks F and chambers G to the exhaust-fan.
The trunks F are supported in the side walls 6 of the casing B, and their open
ends project a short distance into the chambers G for a purpose hereinafter set
forth. The said trunks are provided with inlet openings preferably placed in
their top surfaces, through which openings the air from the interior of said casing
is drawn. In order to regulate the air-current through the several screens, the
openings are provided with valves f¹ the shafts f¹ of which valves extend
outwardly through the chambers G to the exterior of the machine, and are provided
with means for holding the valves in any desired position, consisting, as shown, of
slotted segmental arms f³ and thumb-screws f* passing through the slots in the said
arms for securing them to the side walls of the machine.
The outer walls of the chambers G are formed by a casing a placed between the
vertical end posts of the frame, and the inner walls thereof by the side walls b of
the casing B, a close fitting sliding joint being formed between the frame-pieces B¹
at each corner of the casing B, and the inwardly projecting pieces a³ which form
the ends of the chambers G, so as to allow the reciprocation of the said casing B
and at the same time prevent the entrance of air to the said chambers. The
bottoms of the chambers G consist of inclined pieces a³, the lower and inner ends
of which are in contact with and slide upon longitudinal side pieces b* placed
parallel with and outside of the side walls b at the lower margin thereof.
A close covering a¹ is placed over the top of the frame A, and the end walls b¹ of
the casing B extend upwardly to the said covering and form a close joint therewith,
as shown in Figure 3, thus forming a closed space Glover the casing B, which
space communicates at either side with the chambers G. The exhaust-fan H is
placed upon the covering a¹ and its inlet is connected with the space G¹ by
means of vertical passages.
The chambers G are for the purpose of accomplishing a separation of the coarser
particles contained in the dust drawn by the air-current from the interior of the
casing B, the said chambers being of sufficient size to cause a reduced movement of
the air therein, and allow a settlement of the larger and heavier particles to the
bottom of the said chambers. To ensure a more complete separation of the larger
particles from the dust, a vertical partition I is placed in each of the chambers G
parallel with the side walls thereof, the said partition being composed of bolting-

page_text: cloth, muslin, or other perforate material of suitable fineness to allow the fine dust
or fuzz to pass through it, and to retain the coarser particles. The said partitions I,
one of which is shown separately in Figure 7, consist of end pieces i and three
transverse strips i, the said strips being provided with apertures i³, corresponding
in position with the ends of the trunks F. The ends of the said trunks, which
extend beyond the side walls of the casing B, fit closely against the strips i¹, and
are constructed to slide thereon, so as to permit the reciprocation of the said casing,
to which they are rigidly attached. By this construction as is shown more clearly
in Figure 4, the dust drawn from the interior of the casing B passes through the
partition I to the outside thereof, and is then drawn back through the said
partition to the space G', with which space the exhaust-inlet of the exhaust-fan
communicates, the coarser particles in the said dust being arrested by the said
partition, while the finer dust or fuzz passes through it to the exhaust-fan and is
conveyed by the air-blast therefrom to a dust-room or elsewhere.
The coarser particles separated from the dust in the chamber G fall upon an
inclined board J near the bottom of the said chamber, over the lower edge
of which they fall into a longitudinal trough or conveyer j having its bottom
inclined from each end of the machine to a central discharge spout j¹. The said
spout is provided with an outwardly opening flap-valve j², for the purpose of
preventing the entrance of air to the chamber G through the said spout, said valve
being constructed so as to open by the pressure of the material which accumulates
behind it, in order to allow the exit of such material. The board J is placed a
short distance above the iuclined bottom a³ of the chamber G, and at the junction
of the said bottom with the side-casing a is a narrow opening a extending the full
length of the chamber G, through which opening air is admitted to the space
between the inclined board and the bottom a³, which air is drawn upwards through
the material as it falls from the lower end of the board J, and by lifting the
lighter particles, performs an additional separation of the fine dust from the said
material. A movable slide a³ is placed over the aperture a' for adjusting the width
of the said opening, whereby the strength of the air-current passing through the
material falling from the board J may be regulated as desired.
For the purpose of removing any large and light specks or impurities which
have not been separated from the middlings by the upward blast through the screens,
and which would otherwise pass with the tailings to the screen below, I subject
the said tailings as they fall from the lower end of one screen to the head of the next,
to an upward blast of air, by which the said specks are separated from the tailings
and carried out of the machine. To produce this air-blast, I have formed horizontal
openings or slits El in the outer walls of the passages E, a short distance below the
end of the screens C and C¹, as shown. By the action of the exhaust-fan, a current
of air is drawn inwardly through the said slits and passes upwardly through the
tailings into the space above the screens and out through the trunks F, carrying
with it the specks and impurities mentioned.
For the purpose of regulating the air-blast mentioned, the openings El are
provided with sliding-valves e, which may be clamped in any desired position by
means of thumb-nuts e¹ placed on bolts which are secured to the walls of the casing
and pass through slots in the said valves.
At the lower end of the passages E are placed downwardly opening-valves e
consisting of depending strips of india-rubber or other flexible substance, the said
valves being constructed to prevent the upward passage of air into the passage E,
and to yield by the weight of the material which accumulates above them, so as to
allow such material to pass to the screen below.
In order to economise space in the casing B, and to permit the use of screens of
greater length than otherwise could be placed in the said casing, the passages E are
formed in projecting portions B³ upon the ends of the said casing (as shown in
Figure 3.) The tops of the said projecting portions consist of inclined hinged
covers 6** which open immediately over the lower ends of the screens so that the

page_text: said screens and the adjacent parts may be inspected, and access readily had to
them.
The frames of the several screens are of ordinary construction and the said
screens are supported in the casing B at either side thereof by having their edges
placed in grooves formed by strips c c¹ attached to the side walls b, as shown in
Figure 4. The heads of the several screens extend to the end walls b¹ of the
casing B and the screens may readily be removed for the purpose of repairs or
renewal by drawing them out through the said end walls. A fastening device c
is placed at the head of each screen, whereby it is held in place in the said
grooves.
The feeder C³ is placed upon the top covering a¹ of the machine, and is
constructed to deliver the material to be operated upon into a receptacle c³, placed
in the casing B over the head of the screen C. The receptacle c³, as shown, has a
narrow slit c in its bottom through which the material is delivered to the screen,
and which is provided with a depending flexible strip arranged as shown, so as
to allow the downward passage of material through it, but to prevent the upward
passage of air. This construction in the receptacle c³, however, relates to the
operation of the feeder shown, and has no operative relation to the middlings-
purifier proper.
Beneath the lower screen C³ are placed two transversely inclined surfaces D²,
which are arranged to discharge the material passing through the said screen to a
central longitudinal trough D³, having an inclined bottom d³ which terminates at
its lower end in a discharge spout d. The purified middlings passing from the
partitions D and D' through the passages d and d¹, are discharged at the lower end
of the said trough and pass out of the machine by the said spout d*.
The material passing through the screen C³ may pass out of the machine by the
spout d with the purified middlings from the screens C and C', or if it is desired,
may be delivered to a separate spout or exit d³ and form another grade of
middlings called "seconds." In order to effect such separation of the middlings,
and at the same time to provide a means for sending the material passing through
any desired portion of the screen to the spout d' and the remainder to the exit d³,
I have provided a peculiar construction in the trough D³, as is shown more clearly
in Figure 3. Over the lower end of the inclined bottom d³ of the said spout is
placed an oppositely inclined partition d³, the lower end of which terminates over
a valved aperture d in the said bottom, the said aperture being placed immediately
over the exit aperture d³. Below the upper end of the bottom d³ and parallel to it,
there is a second incline d³, which terminates at its lower end in the exit
aperture d³. In the upper portion of the incline d³ is placed a series of valved
openings do, and in the partition d is a similar series of openings do. By closing
all the apertures mentioned, the material passing into the trough D³ is conveyed to
the spout d', as will be readily seen by the drawing, and by opening the
aperture d', all such material will pass out of the exit-opening d³. When one of
the apertures do is opened, all the material falling upon the incline d³ above
said aperture will be intercepted and pass to the incline ds and out of the machine
through the exit d³, and in the same manner, the aperture d being open, when
one of the apertures do is opened, the material falling upon the said incline above
the said aperture will be delivered at the spout d* and that below to the exit d³.
For the purpose of keeping the bolting-cloths in the several screens clear, rotary
beaters are preferably used, which consist of rollers K (shown more clearly in
Figure 8), having small tags of leather attached thereto, which tags are thrown
outward by centrifugal force as the rollers are moved across under the screens, so
as to strike the surface of the cloth thereon and clean it without injury thereto.
The said rollers rest upon tracks or ways L, L³ at their ends, and receive their
rotary motion by rolling on the said ways when moved back and forth beneath the
screens. Such rotary beaters have been previously used and form, in themselves,
no part of this invention.

page_text: The ways L' are placed outside of the casing B, and are supported upon cross
pieces L attached to the frame of the machine, and the ends of the rollers K are
extended outside of the said casing through the openings 63 so as to rest on the
said ways. The opposite ends of the rollers are supported on a rod L³ secured at
its ends in the frame A, as shown in Figure 3. The said rod extends through the
interior of the casing B beneath the lower cross piece of the screen-frame, the
apertures in the sides of the casing through which it passes, being enlarged so as
to allow for the vibrating movement of the casing. One object in placing the
ways L¹ and L³ as described is to prevent the middlings passing through the
screens from falling upon them and being crushed into flour by the beater rollers.
It has been found in practice that the rotary beaters described arranged to pass
under the longitudinal ribs by which the bolting cloth is supported intermediately
of its edges, are liable to cut or injure the cloth at its point of attachment to the
said ribs. In order to remedy this difficulty one beater is placed beneath each
section of the screen and its movement is limited to the width of such section. In
the drawing, the screens are shown as divided into two sections and two beaters
are used; but when one section of cloth alone is used, or more than two, a
corresponding number of beaters is provided.
For the purpose of moving the beaters laterally to accomplish the cleaning of
the bolting-cloths as described, a lever L is pivoted upon the cross piece L³ one end
of which extends outwardly from the end of the machine, and the other inwardly
through the rollers K. Such lever consists of two end pieces k, to which the ends
of the rollers are journalled, and two central longitudinal rods k¹ connecting the
said end pieces, as shown. Upon the rods k¹ near their centre is attached a
block provided with a slot k³, through which the inner end of the lever L passes.
The block k is clamped to the rods k¹ by means of a plate k, between which
plate and the block ka the said rods are placed. The block k and the plate / are
provided with corresponding semicircular grooves in which the rods k¹ fit, and are
secured together by a bolt as shown or in any other convenient manner. By
moving the block longitudinally upon the rods k¹ the length of the inner arm
of the lever L may be changed and the amount of lateral movement given to the
rollers varied thereby, as desired. The levers L are connected by means of rods
to arms m upon vertical rock-shafts M journalled in brackets M¹ placed at the
corners of the frame A at one side of the machine. The said rock-shafts are
provided with arms m¹ placed at right angles to the arms m and are connected by
means of rods m² with a double crank-arm N placed upon a short shaft n attached
to the outer casing a of the machine, and near the centre of the side thereof.
Upon the shaft n is also placed a sproket-wheel N¹ which is driven by a chain
belt N from a sprocket-wheel O having bearings on the shaft o. A second
sprocket wheel O¹ is placed on the shaft o which is driven from a chain belt O* from
a counter-shaft P mounted upon the top of the frame of the machine. Upon the
bub of the sprocket-wheel O and adjacent to the face of the wheel O¹, is a lever O³
having two equal and oppositely arranged arms, the ends of which arms extend
slightly beyond the peripheries of the wheels O and O¹.
The chain-belt O2 has upon one of its links a laterally projecting stop o' which
is so placed that in its passage around the wheel O¹ it will encounter one of the
ends of the lever 03 so as to give a half-revolution both to the said lever, and to
the wheel O to which the said lever is attached. The wheel O thus receives a half
revolution at each passage of the stop o¹ around the wheel O¹, which movement is
transmitted by means of the chain-belt N2 to the wheel N¹. The belt N is
provided with a stop n' which acts upon the ends of the lever N so as to give to
the said lever a half-revolution on its axis in the manner before described in
connection with the lever 0%. At each half-revolution of the lever N, the rods m²
are given a half-stroke, and such movement, by means of the devices before
described is transmitted to the beater-rollers K, which thus receive a reciprocatory
movement at regular periods, first over one half of each section of the bolting

page_text: cloth and then over the opposing half. The frequency with which the lever N is
revolved and the beaters K are moved, may be increased by placing additional
stops upon the belts O2 and N2 in an obvious manner.
The frequency of the said movements of the beaters may be decreased by
introducing one or more additional pairs of wheels sinuilar to the wheels O and ¹
between the driving-shaft and the wheel N¹, or by placing the said wheels so that
the lengths of the connecting belts will be increased, in a manner which will be
rendered obvious by an inspection of Figure 6.
Motion is
The casing B is supported from the lower cross-pieces at either end of the
frame A by means of flexible standards Q, which are bolted at their lower ends to
the said cross pieces and at their upper ends to the corner frame pieces B¹ of the
casing B.
A suitable vibrating motion is given to the casing B by means of
eccentrics R, which are mounted on a shaft R¹ placed in suitable bearings upon
one end of the main frame, which eccentrics bear against opposing rollers S placed
upon a cross-shaft S₁ having bearings upon one end of the casing B.
given to the eccentrics R by means of a driving-belt upon a pulley R² placed upon
one end of the shaft R¹. At the opposite end of the machine are located springs T
which are placed between brackets T¹ upon the vertical posts of the frame A, and
the frame B of the casing B, so as to keep the rollers S in contact with the
eccentrics R. In order to prevent the slipping of the eccentrics R upon the
rollers S, the bearing edges of the latter are provided with a coverings of india-
rubber or similar elastic material, which also acts as a cushion to lessen the jar on
the adjoining parts as the casing is vibrated.
A horizontal spring-brace U (shown in Figure 5) may be attached at one end of
the inner face of the vertical end post A' with its opposite end secured near the
opposite side of the end wall 61 of the casing B, so as to prevent any lateral
movement or swaying of the upper part of the said casing and the consequent
unequal pressure and friction on the sliding joint between the sides of the casing
and the end pieces of the outer frame.
The screens, the receiving surfaces placed below said screens, and the several
carrying spouts and troughs mentioned, all being rigidly attached to the casing B,
the oscillating motion imparted to the said casing not only causes the said screens
to effect the necessary separation of the material thereon, but serves to facilitate
the passage of the material over the several receiving surfaces and through the
several troughs and passages described.
By the construction in the machine described, whereby a separation of the
material carried from the middlings by the air-blast is effected in compartments
placed in the frame of the machine on either side of the screen-casing, I am
enabled to accomplish such separation without the use of a separate machine or
apparatus and without materially increasing the size or cost of the middlings-
purifer proper. The construction described also presents great advantages in point
of simplicity and economy, from the fact that by the location of the chambers G
adjacent to the sides of the screen-casing the air can be drawn directly from the
several compartments over the screens in such casing and into the said chambers,
and the use of a complicated system of air-passages for connecting the said
compartments with the exhaust-fan is thereby avoided.
Having thus fully described the said invention as communicated to me by my
foreign Correspondent and the manner of performing the same I wish it understood
that I claim.
First The combination with the frame of a middlings purifier, an exhaust-fan,
a vibrating screen-casing B supported in the said frame and a separating screen
located within the said screen-casing, of settling chambers G located at the sides
of the frame adjacent to the screen-casing and having their inner walls formed by
the sides of the said screen-casing, and passages connecting the said settling chambers
with the interior of the screen casing and with the exhaust-fan, substantially as
described.

page_text: Second-The combination with the frame of a middlings-purifier, an exhaust,
fan, a vibrating screen-casing B supported in the said frame, and a separating-
screen located within the said casing, of settling-chambers G located at the sides
of the frame adjacent to the casing B and having their inner walls formed
by the sides of the said casing, vertical partitions I of perforate material
located within the said chambers, and passages connecting the said chambers with
the interior of the screen-casing-and with the exhaust-fan, the said passages being
arranged to communicate with the settling-chambers at opposite sides of the said
partition, substantially as described.
Third The combination with the machine-frame, of a vibrating screen-casing B
supported in the said frame, one or more screens located within the said casing,
settling-chambers G located at the sides of the said screen casing and provided
with vertical perforate partitions I, an exhaust-fan connected by suitable passages
with the space between the partitions I and the exterior of the screen-casing, and
an air trunk F communicating at its ends with the space between the said
partitions and the outside walls of the settling-chambers and provided within
the screen casing with a longitudinal opening f and a regulating-valve f¹ constructed
to control the said opening substantially as described.
Fourth-The combination with the frame of a middlings purifier, an exhaust-fan,
a vibrating-screen casing B, and a separating screen located within the said casing,
of a settling-chamber G connected with the said screen-casing and exhaust-fan,
and provided with an opening a near its bottom, an inclined board J located
within the said chamber above the said opening, a vertical perforate partition I
located in the upper portion of the said chamber, and passages connecting the
said chamber at opposite sides of the screen with the screen-casing and with
the exhaust-fan, substantially as, and for the purpose, set forth.
Fifth-The combination, with the vibrating casing B, screens C, air-chamber G
and air-trunks F, of the stationary partition I having sections i of perforate
material, and intermediate slats the latter being provided with apertures i³
arranged opposite the trunks F, substantially as, and for the purpose, set forth.
Sixth The combination with two or more oppositely inclined screens, a
casing B surrounding each of the said screens, and an exhaust-fan communicating
with the interior of the casing above the screens, of passages E extending from the
lower end of one screen to the head of the next one below it, and provided with
valved openings E' in their outer walls and downwardly-opening valves e² at their
lower ends, substantially as, and for the purpose, set forth.
Seventh-The combination with an inclined screen C², of a trough D³ constructed
to receive the material passing through the said screen the said trough having
an inclined bottom d³ provided with apertures d' and d³, an oppositely-inclined
partition d having valved apertures d¹º, and a secondary bottom d³ provided with
an exit opening d³, substantially as described.
Eighth The combination with the machine-frame and with a vibratory
screen-casing B, of the settling-chambers G having their walls formed partially
by the said casing B, and partially by stationary casings attached to the said
frame, the said movable casing B and stationary casings having substantially air
tight joints at their line of juncture, substantially as described.
Ninth-The combination with the machine-frame, a vibratory screen-casing B,
and a settling chamber G provided with a vertical perforate partition I, of a
longitudinal spout attached to and movable with the casing B, and constructed
to receive material falling upon the bottom of the said chamber, and provided with
an outwardly opening valve, substantially as, and for the purpose, set forth.
Tenth The combination with the machine-frame, the vibrating casing B, and
a screen located within the said casing, of tracks or ways L' L³ located upon the
said frame outside of the casing, rotating beaters K supported upon the said tracks,
a carriage k, for supporting the said beaters, having longitudinal rods k¹, a block k³
longitudinally adjustable upon the said rods, a lever L pivoted to the machine

page_text: frame and constructed to engage the said block, and means for actuating said lever,
substantially as described.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Fourteenth day of June in the year of Our Lord One thousand
eight hundred and eighty four.