IMPROVEMENTS IN APPARATUS FOR COLLECTING AND REMOVING DUST FROM AIR WHICH HAS PASSED THROUGH MIDDLINGS PURIFIERS OR SIMILAR MACHINES
Year: 1883

page_text: LETTERS PATENT to William Robert Lake of the firm of Haseltine, Lake,
and Co, Patent Agents, Southampton Buildings London for an Invention of
"IMPROVEMENTS IN APPARATUS FOR COLLECTING AND REMOVING DUST FROM
AIR WHICH HAS PASSED THROUGH MIDDLINGS PURIFIERS OR SIMILAR MACHINES
"
Communicated to him from abroad by Faustin Prinz, of Milwaukee, Wisconsin,
United States of America, Millwright.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 8th February 1883.
.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co Patent Agents,
Southampton Buildings, London "IMPROVEMENTS IN APPARATUS FOR COLLECTING
AND REMOVING DUST FROM AIR WHICH HAS PASSED THROUGH MIDDLINGS
PURIFIERS OR SIMILAR MACHINES" Communicated to me from abroad by Faustin
Prinz of Milwaukee, Wisconsin, United States of America Millwright,
This invention relates to apparatus for collecting and removing the dust or other
foreign matter from air after it has passed through middlings purifiers, crushing
rolls, smut mills, mill stones or other machinery used in flour and similar mills,
and the said invention consists essentially in the construction and arrangement of
parts as hereinafter described
In the accompanying drawing
Figure
is a transverse vertical section of a machine constructed according to
this invention
Figure 2 is an view of a portion of the cloth covered balloon or cage illustrating
the manner of revolving it, and knocking the dust from the cloth
Figure 3 is a longitudinal sectional view
Figure 4 is a side view of the knocker, and case revolving mechanism

page_text: Figure 6 is a side view of the base plate of the knocker, and balloon revolving
mechanism detached
Figure 7 is a side view, and
Figure 8 is a plan view, of the combined ratchet and knocker actuating wheel,
illustrating the manner of operating the knocker mechanism.
5
Figures 9 and 10, are detail views drawn to an enlarged scale of the adjustable
crank upon the end of the conveyor, which operates the knocker and balloon
revolving mechanism.
Figure 11 is a side view, and
Figure 12 is an underside view, of the back draft tube detached.
1
Figure 13 is a detail view drawn to an enlarged scale of a portion of the
balloon illustrating its construction.
Figure 14 is a view of one of the dust collectors and a fan illustrating one
manner of connecting them
Figure 15 is a perspective view of one of the cloth bags or sections, and its 1
holding plate detached.
Figure 16 is a sectional view of portions of the heads of the balloon and one of
the cloth sections, illustrating the manner of connecting them.
Like letters indicate corresponding parts in the several figures.
A¹, is the casing or frame constructed in any desired manner, upon-either end of 1
which square or other suitable shaped hoods or boxes A, A are placed as shown.
Through the ends of the casing A³, in the centres of the hoods A, A, circular
openings are formed in which metal or wooden rings B, B fit. The outer ends
of the said rings are level with the outer surface of the casing A', and their inner
edges project inside the said casing far enough to receive two circular wooden
heads C, C which are secured thereto by screws or by other means, while the
outer edges of the rings are free to revolve in the openings through the casing.
Attached to the inside of the beads C¹, C are two other heads C, C somewhat
larger than the heads C³, C and connected to each other at their outer peripheries
by wooden bars al arranged at equal distances apart and parallel with each other
The centres of these inner heads C, C are cut out, so that they shall be even
with the rings B1 B2, and the edges of these cut out portions are connected to each
other by small wooden bars a, equal in number to the bars a', as shown, and
arranged parallel to each other, and with equal spaces between them.
By this means a circular balloon or cage is formed with annular ends C', C³,
C, C connected by two rows of slats or bars a¹, a³, leaving an open circular
central space running entirely through the said cage and connecting the hoods
A, A³ with each other, the balloon being suspended by the rings B1, B2 in the
frame A', and adapted to be revolved upon the said rings as journals
These slots a¹, a form the supports for the dust collecting fabric, which is
usually of heavy flannel or cotton cloth, arranged thereon in the following manner
that is to say. A section of cloth, of the proper quality, a little wider than the
distance between the heads C, C and long enough to reach from the outer side of
one of the outer bars a' to the outer surface of one of the inner bars a³, and thence
back to the next bar a', is taken and doubled over upon itself with the fold across
the centre of the length of the cloth. The edges at right angles to the fold are
then sewed together forming a bag or pocket closed at one side by the fold in the
cloth and at the ends by the edges being sewed together, while the remaining side
is left open. This is more clearly shewn in Figure 15 which shows one of these
pockets detached, in this figure D represents the main part of the cloth b¹ the
folded part 6 the sewed up ends, and 6 the open front. As many of these pockets
are provided as there are inner slats a', the folded edge b¹ of each pocket being
attached to the outer sides of one of the bars a³ by tacking, or otherwise, through
a cord, wooden strip, or other suitable binding b*, from the inside of the said pocket.
This cord, or strip b, lies along the inside of the folded part 6', and serves to
prevent the cloth from tearing loose when stretched.
The bags are attached to the slats a before the slats are set in place on the

page_text: heads C³, C, or the ends served up. The slats a² are then placed in position, and
the outer edges 63 of the attached bags D are drawn through the space, between
the slats a¹, which comes opposite to the inner slat to which the folded sides are
respectively attached, and then tacked and glued to the outwardly slanting sides of
the ribs a¹, as shown in Figure 6.
The wood of the bars a¹ is cut away on the inside next the cloth thereby
increasing the cloth surface without materially decreasing the strength of the
bars a'. This arrangement brings the sewed edges b' against the inner surface of
the heads C, C (as shown in Figure 16, which represents a section of one of these
bags and a portion of one set of the heads C, C) to secure these ends to the said
beads, wedge-shaped blocks E are inserted into the bags D, and nailed or other-
wise secured to the heads C, C from inside the bags, thus firmly securing the
ends of the bags between them. Screws may be substituted for nails if desired.
A dust-collecting balloon having a "zig-zag" conformation of the cloth is thus
produced, whereby a large cloth surface is gained in a very small space
To strengthen the bars a² a series of hoops d' are placed around their inner sides,
to which each bar is secured by screws or nails, the length of the machine
determining the number of the hoops, a long machine requiring a larger number of
the boops than a short machine.
"
For supporting the outer bars a¹ hoops d' are used, encircling the outer bars at
suitable distances apart, to which each bar is secured by nails or screws.
In very
long machines, each outer bar a' provided with a "truss wire or rod e' and
bridge blocks e, the said wires being secured at the ends of the bars a' or through
the heads C³, Chy nuts, so that they may be drawn up to to tighten the rods. The
bridge blocks e fit between the bars a', and the rods e¹, to cause the rods to assume
the bracing form shown. By this means the bars in long machines may be kept
from sagging by the strain of the cloth or their own weight. Light bars can
thus be used, and bridge blocks as heavy bars. In the drawings I have
shown both the rings d³ the rods e¹, and the bridge blocks e² arranged on
one machine, but in practice the rings will be used only on short machines,
and the trusses used only on long machines. In some forms of the apparatus
the balloon or cage is increased in diameter and reduced in length, in which
case all the outer rings d' the trusses e¹, e* and all but one of the inner
rings d, will be dispensed with.. The inner ribs a' are necessarily very small,
hence one of the supporting rings d will always be required to support them, but
the outer ribs a¹ being larger than the inner ribs a', in short machines, none of the
strengthening rings d, or truss wires e¹, will be required.
In the lower part of the casing A' a screw conveyor F is arranged, to carry off
the dust that falls from the surface of the balloon or cage. The shaft of the .
conveyor runs through both ends of the casing, and one end of it outside the
casing is provided with the belt pulley or gear wheel F, by means of which the said
conveyor is revolved, while the other end outside the casing is provided with a
crank arm T, the object of which will be hereinafter explained. G, is a shaft
passing through the casing A', parallel with the conveyor F¹, but at a greater
elevation and upon one side as shown. The said shaft is journalled at one end in
the casing at g while the outer end passes through the said casing and is provided
outside thereof with two bell-cranks H, I the crank H, being tight upon the
shaft G, and the crank I loose upon the same shaft. Attached to the shaft G
inside the casing A¹, at intervals, are knockers K, adapted to strike the rib a', which
for the time being happen to be in a line directly beneath the centre of the balloon,
a series of blows, as hereinafter shown
L, is a third short shaft passing through the casing A, parallel with the shaft G,
and conveyor F, and provided on the end inside the casing with a cam or arm M,
and on the outside with a ratchet wheel N.
P, is a triangular metal plate attached to the outside of the casing A¹, through
the corners of which the two shafts G and L, and the shaft of the conveyor F', are
ournalled, the plate thus forming a hanger or base frame for the said shafts and

page_text: conveyor, and preventing them, from wearing the wood of the casing A'. Hubs h
will be formed upon the inside of the plate P around the shafts, to project through
the casing A¹ and thus prevent the shafts from coming in contact with the wood,
and also to form longer bearings for the shafts.
is a small slotted plate attached to the casing A by a thumb screw m, and
with one end turned up at right angles and facing toward the lower arm x¹ of
the bell crank H. Between this turned up portion and the arm x¹, a coiled
spring n is arranged being held in position by small studs upon the part i³ and the
arm a¹ which project into the spring at its ends. The spring n may be arranged
to be extended by the movement of the arm a¹, if preferred, instead of compressed 1
as shown. The upper arm x³, of the bell crank H projects in a nearly horizontal
line toward, and a short distance beyond, the rim of the ratchet wheel N.
Projecting from the inner rim of the ratchet wheel N, are a series of pins t
adapted to strike the end of the arm a³, force it down, and compress the spring n
and then when the pins pass beyond the end of the arm, the spring will throw the 1
arm up again ready for the next pin. This action oscillates the shaft G and
causes the knockers K to be moved downward by the pins t forcing the arm ³
down, to be suddenly thrown up against the rib a' by the reaction of the spring n,
thus delivering as many blows to the ribs a¹ as there are pins in the ratchet
wheel N. The ribs at, will be protected by a sheathing of band iron where the
-knockers strike them, to prevent wear. The outer end of the arm a³ is provided
with a small adjustable plate, which may be set farther away from or nearer to
the shaft G to lengthen or shorten the arm a³, for regulating the distance which
the pins t shall move the arm downward, the shorter the arms the shorter the
stroke of the knockers, and the longer the arms the longer the stroke. By this
means heavy or light blows may be struck as desired, and by adjusting the slotted
plate to and fro by the thumb nut m, the strength of the spring may be
adjusted
The bell crank arm I is also provided with the two arms v', v² similar to the
arms a¹³ of the bell crank H, except that the short arm v' projects upward instead
of downward. Pivotted to the upper end of the arm v³ is a dog v³ adapted to catch
over the teeth of the ratchet wheel N above the centre while another dog vis
pivoted to the arm v², and adapted to engage with the teeth of the ratchet wheel
below the centre as shewn. The dog remains in contact with the teeth of the
ratchet wheel by its own weight, but a counter weight or a spring, will be
necessary to hold the dog v' in contact with the teeth. The pivotted points of the
dogs, are at equal distances from the centre of the shaft G. R is a small rod
connecting the outer end of the arm with the small crank T, before mentioned.
By this arrangement the constant revolution of the conveyor F' causes the crank T
to revolve and move the arm up and down, and the arm to and fro. This
action causes the dog to catch over the teeth of the ratchet wheel N when moved
away from it and revolve it a short distance toward the shaft G, and then to slip
back with the return stroke and catch again on the next tooth, while at the same
time the dog is slipping over the teeth at the up stroke of the arm catching
upon them at the down stroke, and revolving the wheel while the dog is making
its return stroke. By this means the dogs act alternately, and keep the
ratchet wheel steadily revolving there being no perceptible pauses between the
changes of the dogs.
Upon the outer side of the head C² between the outer rims of the heads C and C³
are small projecting pins w one for each slat a¹ against which the cam or arm M
strikes when the shaft L is revolved by the action of the dogs va, v* thereby
revolving the balloon or cage the distance between two of the bars a', and then
remaining stationary until the cam comes around again. The pins t on the
ratchet N, are arranged to occupy about three-fourths of the circumference of the
wheel N leaving an open space t¹ for the purpose of causing the knockers K to
remain inactive while the balloon is been revolved, the open space t' being formed at
the proper point to bring the arm ³, inside of it, while the cam M is in contact

page_text: with one of the pins w on the balloon By this arrangement, the revolution of the
conveyor F' imparts the revolving motion to the ratchet wheel N and its shaft L,
and causes the cam M, to catch one of the pins w on the balloon and revolve it
until the cam passes beyond the pin, when the said cam will leave the balloon
stationary until it comes around again and catches upon the next pin. While
the cam M is in contact with the pins w, the open space t¹ will be opposite the
arma, and not affect the knockers; but as soon as the said cam leaves the
pin w, and the balloon again becomes stationary, the pins t again begin to act and
operate the knockers K. In the drawings eight of the pins t are shown but a
greater or less number may be used as desired, the open space t' being long enough
BO, that the knockers will not operate while the balloon is in motion, as, if they
operated unintermittently, part of the blows would be struck between the ribs a¹
thus each rib a' will be struck eight light rapid blows at each pause of the balloon
and the knockers remain stationary when the balloon is in motion.
V₁ is a flat plate, usually of wood, lying through the interior of the balloon, wide
enough to cover four or more of the ribs a' and having its ends extending through
the covers of the hoods A2 A3, and armed with a felt or other suitable packing y
where it comes in contact with the said ribs a² so as to make an air tight joint
between them. This packing is formed of a thin sheet of india-rubber, felt, or other
suitable material, stretched over the wooden plate V¹, with a layer of cotton, wool,
or other soft material between them. By this means the soft surface presses into
all irregularities of the ribs a², and forms a perfectly air-tight joint at all times.
V³, is a bollow sheet metal covering to the plate V₁, attached to its sides, these
two parts vis: the plate V¹, and covering plate V form a tube having a convex
bottom fitting the concave form of the interior of the balloon and opening at either
end through the hoods A³, A³. Through the bottom of the plate V' a slot z is cut
nearly as wide as the width of one of the spaces between the ribs a², and the length
of the space inside the heads C³, C, communication is thus opened between the
cloth bags D, and the tube V₁ V', one after the other, as the balloon is revolved, to
afford a back draught to assist in cleaning the cloth, as hereinafter shown. Small
bolts may be set down through the outer ends of the plate V₁, and surrounded
by india-rubber or other spring collars so that by screwing the nuts of the
bolts up, the plate V₁ may be drawn down upon the ribs a² to increase the
pressure in event of wear and prevent leakage, the spring collars x allowing the
plate to give a little, to permit it to adapt itself to any irregularities of the surface
of the ribs. By this means the tubular plates V', V' may be kept pressed upon the
ribs with sufficient force at all times.
Any other suitable means may be employed for securing the tube, as I do not
wish to confine myself to this particular method of fastening.
The holes in the covers of the hoods A² A³ through which the ends of the tubular
plates V, V pass, are larger than the tubes themselves in order to permit the
requisite adjustment by the bolts ¹, and to prevent leakage at these points
collars V3, V are arranged around the tube to cover these open spaces, as shown
in Figure 3
Y¹, Y are two frames covered with cloth Y³, Y* and hinged or otherwise
attached to the hoods A2, A³ as shewn in Figure 1, to form screens to remove the
dust from the air which enters the tube V1, V³, as hereinafter shewn. These
frames Y', Y' are made removable, for cleaning their cloth coverings, or for other
purposes. Leading from the sides of the hoods A², A³ are spouts A5, A7, which are
connected with a suction fan A³, (see Figure 14) by which the dust laden air from
the purifiers or other machines, is drawn through the machine, entering at the sides,
bottom or top of the casing A¹, as desired but preferably from the bottom, as
shown at A⁹.
The operation of the machine is as follows that is to say The fan or fans A³, being
set in motion, the dust laden air is drawn from the spouts A' through all the
sections of the cloth D, except those covered by the plate V₁ from the outside
toward the inside, the cloth catching and retaining all the dust, and similar

page_text: impurities, and permitting the purified air only to pass through. At the same
time, by reason of the ends of the tubes V, V opening out into the mill, a
strong current of air is drawn into the said tube and thence down through the
slot z, and out through the sections of cloth on either side of the space into which
the slot opens in the reverse direction to the air passing through the remainder 5
of the cloth, as indicated by the arrows in Figures 1, 3 and 13. At the same time
as before described, the rib a' that for the time being is directly downward, is
struck a series of blows by the knockers K, to shake the adhering dust loose from
the cloth, these two agents viz the back draught of air and the knockers
effectually removing all the dust from the cloth. By the means described each I
section of the cloth as it becomes coated with dust is brought beneath the slot s
and there held stationary while the rib a' is struck a series of blows and a strong
current of air is passed through the section of cloth in a direction opposite to that
taken by the current which deposited the dust. The adhering dust is thus
effectually removed and the operation is continued or repeated as often as is found 1
necessary. The dust will usually fall from the section being cleaned in a mass or
thick stream into the conveyor F¹, so that the main current of air will not affect it,
but to more effectually prevent any interference by the air currents, one side F³ of
the trough of the conveyor F' is extended up to the ribs a¹ of the balloon or cage
and provided with a soft felt or india rubber packing strip to form a tight joint 2
between the ribs a³, and the side of the trough, so that no-passage of the air to and
fro beneath the bottom is permitted hence the falling dust is undisturbed
It frequently happens that the air in the mill surrounding the casing A¹ is
impregnated with dust in such case the draught would draw any such loose dust
into the tube and drive it into the cloth from the inside, but I effectually prevent 2
this by drawing the supply of air for the back draught through the cloth Y³, Yʻ,
thus removing any dust and furnishing pure dustless air only for the back
draught.
By making the casings Y¹ Y² removable they can be easily cleaned when clogged
by dust.
The crank T consists of a main arm or shank set through a hole in the end of
the shaft of the conveyor F¹, as shown detached and enlarged in Figures 9 and 10
and is held at any point by a set screw, the crank pin for the lower end of the
rod R being secured in the outer end of this shank as shown. By adjusting the
crank pin nearer to or farther from the conveyor shaft the throw of the dogs v³,
may be increased or decreased, and the number of the teeth of the ratchet caught
by them at each stroke likewise increased or decreased, to regulate the speed of the
revolution of the balloon.
It will be understood that instead of drawing the air through the balloon and
slotted tube by suction, it may be forced through by separate blowers, one blower
impelling it through the balloon and the other through the tube, in which case the
current through the tube could be weaker than that through the balloon. Such
change is obvious and either method may be used. Two small separate fans may
also be used one upon each side of the balloon, instead of one fan only arranged as
shown in Figure 14
In Figure 3 a small detached section of the conveyor F¹ and the casing A' is
shown to illustrate a slight modification in the construction of the exit tube, to
prevent a back draught of air being drawn up through the exit tube into the
machine again.
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 in a machine for collecting and removing dust from air after it has
passed through middlings purifiers or similar machines.
First. A dust collecting medium or fabric formed, with separate compartments,
in combination with a device for isolating a portion of the said compartments from
the others and permitting air to pass into the said isolated portions through the

page_text: end next to the said device, and means for inducing an air current through the said
isolated and other compartments substantially as set forth.
Second. A dust collecting medium formed with separate compartments, in com-
bination with a device for isolating a portion of the said compartments from the
others and means for inducing an air current through the isolated portion from one
end and through the other portion from the opposite end, substantially as, and for
the purpose, set forth
Third. A dust collecting medium formed with separate compartments, in com-
bination with means for inducing an air current through a portion of the said
compartments from one end and then through another portion from the opposite
end, substantially as set forth.
Fourth. A dust collecting medium formed with separate compartments, in
combination with a device for isolating a portion of the said compartments from
the others, means for admitting an air current into the said isolated portion, and
means for purifying the air before its admission into the said isolated portion,
substantially as specified.
Fifth. The combination of a dust collecting medium formed with separate com-
partments, a device for isolating a portion of the said compartments from. the
others, means for admitting a current of air to such isolated portion, means for
purifying the air before its admission into the said isolated portion, and mechaniam
for jarring the isolated portion, substantially as specified
Sixth. A dust collecting medium formed with separate compartments in
combination with a tube connecting a portion of the said compartments with the
outside air, substantially as specified.
Seventh. A dust collecting medium formed with separate compartments, in
combination with a tube connecting a portion of the said compartments with the
outside air, and a screen for purifying the air before its admission into the said
tube, substantially as specified.
Eighth. A dust collecting balloon or cage having separate compartments composed
of dust collecting material, in combination with the casing A' the hoods A3, A3 and
the tube V, Vs having the slot z substantially as set forth.
Ninth. The combination of a dust collecting medium formed with separate
compartments, a device for isolating a portion of the said compartments from the
others, and means for automatically adjusting the said device, substantially as
specified.
Tenth. A dust collecting balloon or cage having separate compartments composed
of dust collecting material, in combination with the hoods A2, A3, back draught
tube V, V the flexible packing y and means for regulating the tension of the said
tube, substantially as set forth.
Eleventh. The dust collecting balloon or cage frame consisting of the heads C¹, C",
C, C the supporting rings B¹, B³ the outer ribs a¹ and the inner ribs a² in
combination with the supporting hoops d', d substantially as specified.
Twelfth. The combination of the pockets D, the supporting ribs therefor, a
strip 6 for strengthening the material of the pocket, and means for securing the
said strip to the supporting rib, substantially as, and for the purpose, set forth.
Thirteenth. The dust collecting medium D, in combination with the inner
supporting ribs a³ and the ribs a¹ bevelled on its inner and outer edges, the
medium being secured to the outer bevelled edge, substantially as, and for the
purposes, specified.
Fourteenth. The combination of the pocket D, the heads C³, C and the blocks E,
the ends of the said pocket being turned and secured to the heads by the blocks
for the purposes set forth.
Fifteenth. The combination of the pocket D the strip b' in its fold, the ribs a', a³,
and the blocks E, the ends of the pocket D, being turned and secured to the heads
by the blocks for the purposes set forth.
Sixteenth. The combination of the heads C, C³, the ribs a¹ a³ the cloth sections D

page_text: having their ends fastened together, clamping and strengthening strips b* and the
securing blocks E, substantially as, and for the purposes, set forth.
Seventeenth. The combination of the conveyor F1 having the adjustable crank
arm T, the shaft G, having the knockers K, and bell crank H fast thereon, the
spring n, the bell crank I having the dogs v³, the shaft L having the arm M
and the ratchet whee! N, provided with the pins t the connecting rod R and the
plate P, and a dust collecting balloon or cage provided with pins w substantially
as, and for the purpose, set forth.
Eighteenth. The dust collecting balloon or cage consisting of the heads C¹, C,
C, the ribs a¹ a³ the cloth sections D and the supporting rings B¹ B³ in com-
bination with the casing A¹, and the division plate F³, whereby air currents are
prevented from passing to and fro beneath the balloon, as and for the purpose set
forth.
Nineteenth. A dust collecting medium formed with separate compartments, in
combination with means for inducing a current of dust laden air against one side
of the said collecting medium, and means for admitting an induced current of air
against the opposite sides of the same section of the medium, whereby the dust
collected on the medium from the first air current is detached therefrom by the
second current, substantially as, and for the purposes, set forth.
Twentieth. The combination with a revolving balloon-and a case enclosing the
same, of a ring or bearing interposed between the said casing and the heads of the
balloon, substantially as, and for the purpose set forth.
Twenty-first. The combination of a balloon or cage with-means for revolving
the same and imparting a series of blows to the balloon while at rest, between
each partial revolution thereof, substantially as, and for the purpose, set forth.
Twenty-second. The combination of a dust collecting medium, a shut-off or valve
for isolating one portion of the medium from the other portion, and means for
admitting an air current to the isolated portion to form a back-draught to aid in
clearing the said isolated portion from dust, substantially as set forth.
Twenty-third. The combination of a dust collecting medium, a shut off or valve
for isolating one portion of the medium from the other portion, means for jarring
the isolated portion, and means for admitting an air current to the said isolated
and jarred portion to form a back draught to aid in clearing the isolated portion
from dust, substantially as set forth.
Twenty-fourth. The combination with a dust collecting balloon having a series 1
of compartments of a shut off or valve for shutting off a portion of the balloon from
the other portion, and means for imparting a series of blows to the shut off portion
while isolated substantially as and for the purpose, specified.
Twenty-fifth. The dust collecting balloon consisting of the heads C3, C4, the
ribs a¹, as, and the cloth D, and provided with the bearing rings B', B' in combination
with the casing A¹, and means for inducing a current of air to pass through the
said balloon, substantially as set forth.
Twenty-sixth. The combination with a dust collecting balloon having a series of
compartments, of a shut-off or valve for isolating a portion of the balloon from the
other portions, and means for agitating the isolated portions while shut off in a
direction parallel with the tension of the dust collecting medium, substantially as
set forth.
In witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Eighth day of February in the year of Our Lord one
LL
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