IMPROVEMENTS IN THE VENTILATING APPARATUSES OF MILL- STONES
Year: 1878

page_text: LETTERS PATENT to Carl Pieper, of Dresden, Saxony, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE VENTILATING APPARATUSES OF MILL-
STONES." A communication by Moritz Martin, of Bitterfeld, Prussia.
Sealed the 24th December 1878, and dated the 9th July 1878.
-"
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office of
the Commissioners of Patents on the 9th July 1878.
CARL PIEPER, of Dresden, Saxony, Civil Engineer. IMPROVEMENTS IN THE
VENTILATING APPARATUSES OF MILLSTONES." A communication by Moritz Martin,
of Bitterfeld, Prussia.
This Invention relates to certain improvements in the ventilating apparatuses of
millstones, and the object of the same is to provide for simple and effective means
for separating from the air current the flour dust carried along by the same.
On the accompanying Drawing, A is a box into which the flour is discharged from
the case of the millstones by the spout b; B is a creeper which conveys the flour to
a channel c, provided with suitable arrangements for preventing the air from enter-
ing; E is a pipe connecting the box with an exhaust fan.
Within the box A a flour dust separator C is suspended, consisting of a frame-
work over which a sheet of cloth or felt is stretched, the edges of the cloth, &c., being
attached to the sides of the box, but so as to allow the separator to be moved up
and down. The air is thus forced to pass through the cloth of the separator, and
the flour dust is retained on its under side.
To one end of the separator frame C, a leg or rod R is attached, which is acted
upon by a cam disk K whenever the frame C is allowed to descend. For the greater
part of the time, however, the rod R is kept out of contact with cam disk K by the
cam N lifting rod R by its arm R¹, so that meanwhile the separator C is at rest.
At the same time the throttle valve F is open. After a certain period the shaft T
is turned to a certain amount, whereby the throttle valve F is closed, and cam N
brought into a position as to allow arm R¹ to descend, so that the cams K. can now act
on rod R. A shaking motion is thereby imparted to the separator C, in consequence
Price fidl

page_text: of which the flour adhering to the cloth is detached. After the shaking has con-
tinued a few seconds, shaft T is turned back to its original position, whereby rod R
is brought out of contact with K, and valve F re-opened.
The shaft T is turned backward and forward in the following manner :-S is a
worm keyed on the creeper shaft, and gearing into worm wheel H, provided with
pins and ; G and G¹ are two disks fixed to each other, and rotating on a bolt.
The toothed disk G is impelled forward by one tooth at every revolution of wheel H
by means of pin l.
The disk G has an arm z, on which the pin acts whenever the disk G has been
turned far enough by pin l, as to bring z within reach of . As soon as l comes in
contact with arm z, the two disks G & G are rotated at once by a greater angle
than otherwise, and at the same time a tooth on disk G¹ acts on the small cam
disk P keyed on shaft T. The disk P in thereby turned by an angle of about
60 degrees, the throttle valve is closed, and rod R allowed to drop by cam N. Very
soon after this the edge of a slot in disk G returns cam disk P into its original
position, whereby valve F is re-opened, and rod R lifted again by cam N.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Pieper in the Great Seal Patent Office on the 31st December
1878.
CARL PIEPER, of Dresden, Saxony, Civil Engineer. "IMPROVEMENTS IN THE
VENTILATING APPARATUSES OF MILLSTONES." (A communication by Moritz Martin,
of Bitterfeld, Prussia.)
This Invention relates to certain improvements in the ventilating apparatuses of
millstones; and the object of the same is to provide for simple and effective nieans
for separating from the air current the flour dust carried along by the same.
On the accompanying Sheet of Drawings one modification of the arrangement
which I have designed for this purpose is represented by Figs. 1 and 2 in a longi-
tudinal and transverse section respectively. The Figures 3 and 4 represent the chief
mechanism on a larger scale; and Figs: 5 to 8 show details.
A is a box into which the flour is discharged from the case of the millstones by
the spout b; B is a creeper which conveys the flour to a channel c communicating
with the elevator Q: Within the channel c a shaft revolves, provided with a number
of ribs or vanes, two or more of which constantly close the channel, so as to prevent
air from entering into the box while they deliver to the elevator the flour falling on
them. E is a pipe connecting the box with an exhaust fan.
Within the box A a flour dust separator C is suspended, consisting of a light
framework, by preference made of iron, over which a sheet of cloth, or felt, or other
suitable material is stretched in à zig-zag line, as may be seen to advantage from
Fig. 2. The edges of the cloth or felt are attached to ledges fixed to the sides of
the box A, but the attachment is effected in such a manner as to allow the said
separator to be moved up and down within narrow limits. The air which has served
for cooling the millstones, and which enters into the box A by spout b, is thereby
forced to pass through the meshes or pores of the cloth on the separator before it
can leave the box through tube E, the flour dust being retained on the under side of
the cloth. By this flour dust, however, the pores of the cloth are gradually filled
up, so as finally to prevent the air from passing freely. The separator has therefore
either to be made very large, or the cloth of the same must be cleaned repeatedly,
for keeping up the efficiency of the apparatus.
The special object of my Invention is now the construction of a mechanism by
which the flour dust is shaken off automatically from the separator after certain
intervals of time.
To one end of the frame of the separator C a leg or rod R is attached, which is of
such a length that it is acted upon by a cam disk K fixed on the shaft of creeper B
(or on any other suitable rotating shaft) whenever the separator C is allowed to
descend sufficiently by other parts of the mechanism. For the greater part of the
time, however, the rod R is kept out of contact with cam disk K by means of the
cam N keyed on shaft T, and acting on the rod R by its arm R', so that meanwhile
the separator C is at rest. During this state of the mechanism the throttle valve F
fixed on the same shaft T as cam N is open, so that the exhaust fan may freely
aspire air through the apparatus. After a certain period the shaft T is turned to a
certain amount, whereby throttle valve F is closed for the purpose of stopping the
air current, and cam N brought into a position (shown by Fig. 8) as to allow arm R²
to descend, so that the cams K can now act on rod R. A shaking motion, which is
yet made more effective by the spring P, is thereby imparted to the separator C.
In consequence, the flour adhering to the cloth, but which, on account of the stoppage
of the air current, is not any more sucked into the pores of the cloth, is detached.
After the shaking has continued for a few seconds the shaft T is turned back into its
original position, whereby rod R is lifted out of contact with cam disk K and throttle
valve F re-opened, so that the ventilation, and at the same time the separation of
flour dust from the air may go on again.
The mechanism for causing the shaft T to be turned backward and forward at the

page_text: desired intervals is specially represented by Figs. 3 to 8. S is a worm keyed on the
creeper shaft and gearing into worm wheel H, provided on its two faces with the
pins and The wheel H may however be driven by any other suitable
mechanism. G and G' are two disks fixed to each other, and freely rotating on a
bolt. The disk G is provided with ratchet teeth on which the pin / acts, so as to
cause the former to be turned by one tooth at every revolution of the wheel H.
The dsk G¹ (which in Fig. 3 is behind G), has an arm z on which the pin acts
during its rotation whenever the disk G has been turned far enough by pin as to
bring within reach of U.
While disk G is being slowly moved onward by pin no alteration of position of
shaft T takes place, but when pin l' comes into contact with arm z, the two disks G
and Gare rotated by a greater angle than otherwise, and at the same time the
tooth of disk G¹ (see Fig. 5, which is a top view of G and G¹), acts on the small
cam disk P keyed on the end of shaft T.
Fig. 5 represents the position in which begins to act, the throttle valve being
yet open.
Fig. 6 (in which Figure, as also in Fig. 7, the acting circles of the disks G and G'
appear developed into a plane) shows the cam disk P turned by an angle of about
60 degrees, and throttle valve F closed. When this position is attained the cam
disk N is in the position of Figure 8, so that the rod R is under the influence of cam
disk K. Very soon after this the edge x¹ of a slot in disk G (see Figure 6) returns
cam disk P into its original position (Figure 7), so that the throttle valve T is re-
opened and rod R lifed again by cam N (Figure 3).
It will be perceived that the period during which the throttle valve is closed and
the shaking mechanism in operation is but short in comparison to the time allowed
for the free passage of the air current.
While in the arrangement described the flour dust separator is placed in a box
below the millstone flour, Figure 9 represents a modified design, in which the sepa-
rator C is contained within the stone case.
The Figures 10 to 13 show the mechanism to a larger scale, analogous parts being
marked by the same letters of reference as in the different Figures of Sheet.
The frame of the separator C consists of an outer and an inner ring connected
together by radial rods, to which the separating cloth is attached in any suitable
manner, and by preference in radiating zig-zag folds, so as to present the largest
surface possible within the given space. The frame is supported at one end by a
rod V passing into a socket U, containing a spring O, which pushes the frame towards
the shaking mechanism.
The edges of the cloth are attached all around to a wooden framework fixed to
the stone case, so that the air aspired by the exhaust fan through tube E is forced
to pass through the pores of the cloth. The meal spout 6 is kept closed against an-
entrance of air by the rotating vanes M in a similar manner as has been described
with regard to Figures 1 and 2.
The mechanism used for simultaneously closing the throttle valve F and for
putting the shaking gear into action is, in principle, the same as in the first
arrangement. The worm S, which is keyed on a shaft W driven from the mill-
stone spindle by a strap, gears into a worm wheel H, having on its front face the
two pins and . The short pin at every revolution of wheel H pushes the disk G
forward by one of its teeth, but without causing any operation of the mechanism.
As soon, however, as the arm 2 on the bottom side of G has come into the reach of
the long pin, the latter causes the disks G and G' to turn by a greater angle,
whereby, as in the first case, the cam disk P (shown in full lines in Figures 12 and
13), is turned forward and backward within a short space of time, so as to bring the
shaking apparatus into action for a few seconds.
The cam disk P, cam N, and throttle valve F not being plainly visible in Figure
10, have been represented in two different positions in Figures 12 and 13, without
the parts of the gear lying in front of them."
Figure 12 shows the position of non-activity of shaking gear. As soon as disk P

page_text: is turned into position Figure 13, in the same manner as described above, the valve
F is closed, and the cam N (which differs in shape from the analogous cam of the first
arrangement) lifts the arm R' of rod R. The end of R is in consequence exposed
to the action of the conical cams K fixed on shaft W, so that a to-and-fro jumping
motion is imparted to rod R, and also to the separator C, with which R is connected.
After the flour has been shaken off from the cloth, the disk P, and with it cam N,
valve F, and rod R are returned to the position of Figure 12, so that the action of
the shaking gear is stopped again, and the passage for the air re-opened.
A third modification of this apparatus is represented by the Figures 14 to 17 on
Sheet. The worm S, worm wheel H, disks G and G', and cam disk P require no explana-
tion, as they are similar to the analogous parts of the foregoing mechanism, though
somewhat simpler in detail. The separator consists of a cage C, to which the separ-
ating cloth is attached, this cage being suspended in a closed box A communicating
with the stone case. The interior of the cage communicates by pipe E with the ex-
haust fan. For the purpose of bringing the leg R of the cage under the action of the
cam K, the cage is connected by a chain to the throttle valve F, so that when the
latter is closed the cage is pulled forward, whereby its leg R is brought over the
higher parts of the cams K, which thereupon shake off the flour adhering to the
cloth.
By the application of the described shaking mechanism in combination with the
separating cloth and its frame or cage, the great advantage is attained, that the
surface of the said cloth may be made very small in comparison with other arrange-
ments of the kind, and that consequently the size of the flour separating apparatus,
as well as its cost, is considerably reduced, while its efficiency always remains the
same.
The arrangements of Figures 1 to 4, and 14 to 17, yet present the special advantage
that the flour dust is more speedily extracted from the stone case, so that no
inflammation of the same can take place by sparks accidentally thrown out by the
stones.
Having thus described the object and nature of my Invention, and the manner in
which the same is or may be put into practice, I declare that I claim as new and
important features of the same,—-
i. In combination with the flour dust separator C (Figures 1 to 13) the rotating
cams K, the rod R having the arm R¹, the wheel H, provided with pins or studs
and, the disks G and G, the arms, the cam disk P, cam N, and throttle valve P,
or any equivalents of these parts, substantially as and for the purpose described.
2. In combination with the flour dust separator C (Figures 14 to 17), the rotating
cams K, the leg or rod R, the rotating disks G and G₁, cam disk P, throttle valve F,
and chain or rod L, or any equivalents of these parts, substantially as and for the
purpose specified.
In witness whereof, I, the said Carl Pieper, have to this my Specification set
my hand and seal, this Thirtieth day of December, One thousand eight
hundred and seventy-eight
CARL PIEPER. (L.S.)