IMPROVEMENTS IN 'SELF- ACTING APPARATUS FOR VENTILATING THE CASES OF MILLSTONES
Year: 1877

page_text: LETTERS PATENT to Henry Bernoulli Barlow, of Manchester, in the County
of Lancaster, Patent Agent, for the Invention of "IMPROVEMENTS IN 'SELF-
ACTING APPARATUS FOR VENTILATING THE CASES OF MILLSTONES." A com-
munication from abroad by William Seck, of Bockenheim, near Frankfort-on-
the Main, Germany.
Scaled the 1st February 1878, and dated the 1st December 1877.
PROVISIONAL SPECIFICATION left by the said Henry Bernoulli Barlow at
the Office of the Commissioners of Patents on the 1st December 1877.
HENRY BERNOULLI BARLOW, of Manchester, in the County of Lancaster,
Patent Agent.
"IMPROVEMENTS IN SELF-ACTING APPARATUS FOR VENTILATING
THE CASES OF MILLSTONES." A communication from abroad by William Seck, of
Bockenheim, near Frankfort-on-the-Main, Germany.
This Invention consists of a peculiar construction of dust sieves placed in the case
of the millstones, between the cover of the case and the upper millstone or runner;
also in a chamber placed above the case of the millstone, and an exhausting
apparatus or fan, which is connected by pipes with the chamber.
The dust sieves are constructed as follows:-Concentric rings are fixed on the
bottom of the upper chamber; other concentric rings are suspended on iron bars
between the former. Flannel or other suitable cloth is carried over and under
these annular rings. This flannel is fixed at its outer diameter to a wooden ring on
the bottom of the upper chamber, and after passing under and over iron rings
the inner end is fastened on a ring which slides in an annular groove of another
ring fixed in the eye of the runner. A sheet-iron pipe is also fixed in this eye, and
rises up to the upper surface of the chamber. The central hole being greater than
the sheet-iron pipe an annular space is left between the pipe and the bottom and
cover of the upper chamber.
The upper annular space is covered by a ring of leather nailed on the wooden
cover and freely touching the round-shaped border of the sheet-iron pipe.

page_text: The upper chamber is connected by a pipe provided with a throttle valve, with
the fan that draws the air from the chamber.
The dust is shaken off the sieve cloth periodically by moving the under rings up
and down by a cross shaft and lovers. One of the levers is connected by a cord to
an agitator, consisting of a vibrating lever, the latter being actuated by the driving
shaft of a self-acting apparatus, which consists of worms and worm wheels, one of
the worms being fastened on the driving shaft of the apparatus.
At regular periods a lever is forced to make one oscillation and to withdraw
a clutch which is connected with the shaking apparatus.
The upper chamber is at all times in communication with the fan, excepting when
the shaking apparatus is at work
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Bernoulli Barlow in the Great Seal Patent Office on the
21st February 1878.
HENRY BERNOULLI BARLOW, of Manchester, in the County of Lancaster,
Patent Agent.
"IMPROVEMENTS IN SELF-ACTING APPARATUS FOR VENTILATING
THE CASES OF MILLSTONES." A communication from abroad by William Seck, of
Bockenheim, near Frankfort-on-the-Main, Germany.
This Invention consists of a peculiar construction of dust sieve placed in the case
of the millstones, between the cover of the case and the upper millstone or runner;
also of a chamber placed above the case of the millstone, and of an exhausting
apparatus or fan which is connected by pipes with the chamber.
The dust sieves are constructed as follows:-Concentric round iron rings are
fixed on the cover of the case, that is to say, on the bottom of the upper chamber.
Other concentric rings are suspended on iron bars between the former, but at a
Flannel or
certain distance from the same, near the upper surface of the runner.
other suitable cloth is carried over and under these annular rings. This flannel, in
the shape of the surface of a truncated cone, is fixed with its wide end on a wooden
ring on the bottom of the upper chamber, and after passing over the upper and
under the under iron rings the inner end is fastened to a ring which slides in an
I sometimes prefer
annular groove of another ring fixed in the eye of the runner.
to make this former ring so as to pass freely through the bore of a flat ring, which
is fastened concentrically on the stone. A sheet-iron pipe is also fixed on the
sliding ring, and rises up to the upper surface of the chamber, this latter having a
central hole in its bottom and its cover; the central hole being greater than the
sheet-iron pipe, an annular space is left between the pipe and the bottom and the
cover of the upper chamber.
The upper annular space between the edge of the hole in the cover and the edge
of the sheet-iron ring is covered by a ring of leather nailed on the wooden cover
and freely touching the round-shaped border of the sheet-iron pipe.
I sometimes prefer to employ a flexible pipe of leather or other suitable material,
and to nail this on the border of the hole in the cover of the case, this pipe hanging
down to the flat-iron ring upon the runner, whero it is provided with another ring

page_text: which freely slides in the bore of the flat ring. By these means, the upper chamber
being in connection by a pipe provided with a suitable throttle valve with the fan,
the air in the chamber is withdrawn and forced to enter the sheet iron or flexible
pipe, to pass between the two stones, and to escape through the annular space on
the outer side of the pipe into the chamber. The air passing in this way through
the sieves of flannel leaves the dust on the inside of the cloth or flannel. This dust
is shaken off periodically, as the under iron rings are capable of being agitated by a
cross shaft and levers placed in the upper chamber and oscillating on a fulcrum. One
of the levers is connected by a cord to an agitator, consisting of a lever with a
shaking motion, the lever being actuated by the driving shaft of n self-acting
apparatus. This apparatus works a shaking nechanism at regular periods, closing
at the same time the suction pipe of the fan.
The dust on the inside of the sieves or cloths falls down on the runner, and is
driven into the outlet pipe for the flour
The self-acting apparatus consists of worms and worm wheels, one of the worms
being fastened on the driving shaft of the apparatus.
At regular periods a lever is caused to make one oscillation, and by this means to
engage the clutches of two coupling boxes, one of which is connected with the
shaking apparatus.
The upper chamber is at all times in connection with the fan, excepting during
the time for the shaking of the sieves; the case of the millstones is therefore venti-
lated, and owing to the absence of any condensed moisture on the grinding surfaces
a greatly increased yield is obtained, while the grinding surfaces are at the same
time kept cool.
Having thus explained the nature of this Invention, I will proceed to describe it
more fully by means of the annexed Sheet of Drawings.
The apparatus for ventilating millstones hitherto in use have several disadvantages;
either there are losses of flour caused by their use, or they are too complicated, and
are therefore not practically beneficial.
Losses of flour take place when the deposit of the dust is not effected, in the case
of the millstones itself, but in a place separated by the former. The flour deposited
in these apparatus is always of an inferior quality.
The arrangements by which the separation of the dust is effected in the cases of
the stones must be provided with an apparatus for shaking the dust sieves at certain
periods. This shaking when done by hand is not regular enough, and is often
forgotten, causing therefore the obstruction of the sieves and the stopping of the
ventilation. The shaking by an apparatus is often complicated, or it does not take
place at regular periods.
Another defect of many arrangements is to be found in the exhaustion of only
only one side of the case, namely, the side where the exhausting pipe is placed, on
this side the ventilation being better effected than on the other sides.
The good ventilation of the millstones can only be done in the manner of a regular
shaking of the sieves periodically, and by stopping in these periods of shaking the
ventilation for separating freely the dust from the sieves, and to facilitate its being
driven into the flour pipe by the centrifugal force of the stones.
This improved apparatus is constructed on the latter principle. It consists of
three parts, the dust sieves, the shaking apparatus, and self-acting apparatus for
working the shaking apparatus at certain fixed periods.
Fig. 1 of the accompanying Drawing represents the whole arrangement of the
apparatus.
Fig. 2 is a plan of the dust sieves.
Figs. 3 and 4 shew the self-acting apparatus for shaking, in vertical section;
and Fig. 5 is a front view of the self-acting apparatus and of the shaking
mechanism
The case a of the millstones is provided with a partition d and an exhaust pipe D
leading to the exhauster F. The partition & communicates with the case of the
stones by the hole in its centre. The upper cover S, S³, of the said partition & has

page_text: a central hole, smaller in diameter than the under cover. On the edge of this hole
is fastened by means of an angle-iron ring. a flexible pipe of leather or other
suitable material m, hanging down to the runner. On the under end of this flexible
pipe a turned cast-iron ring O is sewn on, this ring sliding in a groove of the ring
9, 9, which is fastened by bolts on the runner; or the ring Ō passes through the bore
of the ring q, q. This latter revolving (around the axis of the runner) turns around
the ring o; by this means the outer air can only communicato with the exhauster
in the way marked by the arrows, see Fig. 1. In this manner a perfectly concentric
exhaustion of the case of the stone is obtained. The air passing through the
flexible pipe enters the space between the stones, cooling the grist, and leaving the
stones at their circumference. The air now ascends, and after passing the sieve
cloths enters the partition & through the annular space around the flexible pipe m.
From the partition & it is drawn off by the exhauster F.
The dust sieves are constructed as follows:-Three rings of round iron f. f. f, are
fixed concentrically on the bottom of the partition d, and three other similar rings
c, e, e, hang concentrically between the former on 6 bars i, i, i, at a little distance
from the runner, see Figs 1 and 2. Flannel or other suitable cloth is tied over
these rings, the one end of which is fastened on the ring o, the cloth being tied
over the first upper ring f, then under the first under ring e, then over the second
upper ring, and the second under one, and so on, until its outer circumference is
nailed on a wooden ring on the cover of the case, that is to say, on the bottom of
the partition d. This cloth or flannel forms a series of truncated cones. The
rings e and fare sewn on the cloth. The three under rings e, e, e, are in connection
with the two bars h, k, by means of 6 iron bars i, i, i, the latter passing through
holes in the bottom of d. Another bar Z, parallel to the two bars k, k, is connected
with these by two bars 1, 1; the bar having axle arms turns on fulcrum studs as
soon as the cord t is drawn. By these means the rings e, e, e, are moved up and
down together, and the cloth or flannel is shaken.
The self-acting shaking is effected by the following mechanism, which acts on
the cord t in such a manner that it draws the cord suddenly and then lets it fall,
and this is repeated several times. The shaking apparatus is represented in Fig. 1,
and on a larger scale in Fig. 5. Au axle or driving shaft provided with levers or
lifters is caused to revolve by a clutch ', which is keyed on the driving shaft of
the self-acting apparatus P. At each revolution of this shaft the little cams or
levers lift the ends of the levers it, the fulcrum of which is upon the shaft 25.
The cords t by means of pulleys lead from the levers to the bar of the several
cases of millstones, as there are as many levers as pairs of millstones. The bar l¹
by these means at each revolution of the shaft lifts the rings e, and then allows
them to fall to the bottom of the case, thus causing a shock which shakes off the
dust from the sieves. This dust falls upon the runner; and as the aspiration or
ventilating is stopped when the shaking works it is driven out by centrifugal force
into the flour pipe. In this pipe is a valve, which prevents the entering of the air
into the case, but which opens by the weight of the flour contained in the pipe.
Unless the ventilation were stopped at the time of shaking, the dust would not
fall off from the cloth as the pressure of the air would hold it fast on the flannel.
To effect this stopping the self-acting apparatus, when it engages the clutch 2³ for
working the shaking apparatus, closes the suction pipe of the exhauster F by means
of a valve G. After the requisite shaking the self-acting apparatus disengages the
clutch and re-opens the valve G. This opening and closing of the valve is simply
done by a cord, the end of which connects with a lever U of the self-acting
apparatus, and is carried over guide pulleys to the lever of the valve, see Figs.
and 4.
The lever U makes one oscillation every twenty minutes, or more or less, then it
rests a short time in its position, during which time the clutch is engaged, and the
valve G closed, and then it returns to its first position. This movement of this lever
U is effected by a continually rotating driving shaft L of the self-acting apparatus
as follows: In the case k, l, see Figs. 3 and 4, are two axles L and M, on each of

page_text: which is keyed a worm wheel O and T; these wheels are driven by worms x and y.
Supposing each of the worm wheels to have 34 teeth, and the worm upon the
axle L to be driven by a pulley k³ at a speed of 60 revolutions per minute, the
wheel O will make of revolutions in the same time, and the wheel T 34 x 34
revolutions per minute = 0519 of a revolution, that is, one revolution in 19
minutes.
60
Upon the wheel Ta disc P is fastened concentrically. A lever V rests upon the
circumference of this disc, having its fulcrum upon the axle 4, which also serves as
fulcrum for the levers W and U. At about each twenty minutes a recess w meets
the end of the lever V, which falls into the recess, and rests in it as long as the cam
Qupon the wheel O does not lift the lever W, and consequently lifts also the lever
V out of recess w. The wheel O makes #f=176 revolutions per minute, that is
to say, one revolution in 34 seconds. As long as the lever V rests upon the cir-
cumference of the disc P, the cam Q cannot meet the lever W, and does not move
the lover V But as soon as V falls in the recess w, the lever W comes within reach of
the cam Q. The whole duration of one revolution of the cam is 34 seconds, but only
during a part of this the effect of Q upon W is admitted. This duration is reduced
in proportion to the acting surface of the cam, that is to say, that part of its surface.
which is concentric. This acting surface can be made longer or shorter by turning the
cam Q upon a projecting plan of the wheel; this plan having the same radius, as
the cam serves to enlarge the acting surface. If the cam covers completely the
projecting plan, the acting surface is 1% of the circle, and the duration of the rest of
the lever V in the recess of P in that case is about 8 seconds. As long as it rests
in it, the clutches of the coupling boxes are engaged, and therefore the lifters ³, 1,
are brought into action. The length of the oscillation of U is greater than that of
W, as it is necessary to engage and disengage the coupling boxes; consequently the
bar U has some play which can be regulated or limited by a nut screw u¹.
Having thus described the nature of the Invention and in what manner it is to
be performed, I would have it understood that I claim,—
First. The shape and mode of constructing annular dust sieves of flannel or other
suitable cloth, as shewn and described.
Secondly. The arrangement of levers over the case of the millstones, on which
lovers the stud sieves are suspended by bars, as shewn and described.
Thirdly. Conducting the exhausting air stream in the direction from the eye of the
stone through the grinding surfaces, and rising on the circumference of the runner is
conveyed back through the sieves to an annular space, from which it passes into the
partition d, and thence to the exhauster, as described; this mode of conducting the
air stream is obtained either by a flexible pipe or by a sheet-iron pipe covered with
an annular leather, as above described.
Fourthly. The shaking apparatus, as above described.
And, lastly. The self-acting apparatus, as described, for the purpose of obtaining
a periodical shaking, and at the same time stopping the exhaust.
In witness whereof, I, the said Henry Bernoulli Barlow, have hereunto set
my hand and seal, this Twentieth day of February, One thousand eight
hundred and seventy-eight.