AN IMPROVED CENTRIFUGAL FLOUR-DRESSING MACHINE
Year: 1877

page_text: LETTERS PATENT to Carl Pieper, of Dresden, Saxony, for the Invention of
"AN IMPROVED CENTRIFUGAL FLOUR-DRESSING MACHINE." A communication
from Moritz Martin, of Bitterfeld, Prussia.
Sealed the 12th April 1878, and dated the 15th October 1877.
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office
of the Commissioners of Patents on the 15th October 1877.
CARL PIEPER, of Dresden, Saxony. "AN IMPROVED CENTRIFUGAL FLOUR-
DRESSING MACHINE." A communication from Moritz Martin, of Bitterfeld
Prussia.
This Invention relates to a flour-dressing machine in which the meal is sifted by
being thrown against the gauze by a system of rotating blades or beaters, whilst
the cylinder slowly-revolves in the opposite direction.
The frame of the cylinder consists of two discs, connected together at the edges
by stays. Each disc is provided with a hollow trunnion, supported in a proper
bearing. The gauze or bolting cloth is fixed at one end to the periphery of a
circular rib on the face of one of the discs, which may be at the bottom of the
cylinder. At the other end it is fastened to a ring, sliding on a circular rib of the
other or top disc. This ring is inade adjustable by screws for stretching the gauze
taut lengthwise.
A solid shaft, passing through the said hollow trunnions, is provided inside the
cylinder with two or more sets of arms carrying perforated blades or beaters, by
preference of wood. The shaft is driven by a strap and pulleys, or otherwise, at a
speed high enough to cause the blades or beaters to scatter the meal by centrifugal
action over the whole surface of the gauze, so that the flour passes through the
same, whilst the bran and the incompletely reduced particles of the grain are

page_text: retained on the inside. The meal is introduced into the cylinder through the hollow
trunnion at the front end, and within this trunnion it is propelled forward by a
worm on the main shaft. The cylinder is placed slightly at an incline, and, more-
over, the blades or beaters are arranged somewhat obliquely, so that the meal slowly
moves towards the back end or bottoin of the cylinder. After the flour has been
sifted off, the bran and the like is taken up by ribs on the bottom disc. These ribs
lift the same and thereupon let it slide down behind a disc of about half the
diameter of the cylinder, whereupon it finds its exit through openings around the
trunnion.
If it is desired to have two sorts of gauze on the cylinder for flour of different
degrees of fineness, a ring of the proper diameter is fixed by sliding brackets to the
herein-described stays, and the sheets of gauze are fastened with one edge to this
ring, and with the other respectively to the bottom disc and to the adjustable ring
of the top disc.
For the purpose of fastening the gauze it is first attached at two corners by
clamping screws, the edges are then hooked on pins provided therefor and the ends
glued together. Straps of hoop iron being subsequently laid around the edges of
the gauze, the same is drawn tightly by them into shallow grooves of the rib and
the ring, and finally, the gauze is stretched lengthwise by the screws of the
adjustable ring.

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 13th April 1878.
CARL PIEPER, of Dresden, Saxony. "AN IMPROVED CENTRIFUGAL FLOUR-
DRESSING MACHINE." A communication from Moritz Martin, of Bitterfeld,
Prussia.
This Invention relates to a flour-dressing machine in which the meal is sifted
by being thrown against the gauze by a system of rotating blades or beaters, whilst
the cylinder slowly revolves in the same, or, if preferred, in opposite direction.
On the annexed Sheet of Drawings this machine is represented in two views;
Fig. 1 being a vertical longitudinal section, and Fig. 2 a transverse section; Figure 3
shows details on a larger scale.
The cylinder frame consists of two disks b and 6', connected together near the
edges by the stays c, c. The disks are provided respectively with the hollow
trunnions a and a¹, supported in proper bearings. The gauze or bolting cloth is
fixed at one end to the periphery of the circular rib d', Fig. 1 & 3, on the face of
the disk 6', or, if preferred, the said rib may be on the disk b. At the other end
it is fastened to the ring e, sliding on the circular rib d of the opposite disk, i.e., the
disk b of the Drawing. This ring can be adjusted by the screws f for stretching
the gauze lengthwise.
A shaft, passing through the hollow trunnions a and a¹, and revolving in
separate bearings, is provided inside of the cylinder with two or more sets of arms
carrying the blades or beaters m, m, which are by preference made of wood. The
shaft is driven by a strap and pulleys, or otherwise, at a speed high enough to
cause the beaters m to scatter the meal by centrifugal action over the whole surface
of the gauze, so that the flour passes through the meshes of the same whilst the
bran and the incompletely reduced particles of the grain are retained on the inside.
The cylinder meanwhile also revolves, although but slowly, it receiving its motion
from the shaft by any suitable gearing. The beaters m are by preference per-
forated, for the purpose of causing them better to stir up the meal and to throw
but small quantities of the same against the gauze at once, whereby a speedy
deterioration of the latter is prevented. The blades, when perforated, may also be
driven at a higher speed, which makes the sifting process more intense. The meal
is introduced into the cylinder through the hollow trunnion a at the front end, and
within this trunnion it is propelled forward by a worm t on the main shaft l, and
thrown against a small disk n so as to spread it out. The cylinder must be placed
slightly at an incline or the blades or beaters m arranged somewhat obliquely, i.e.,
in a screw line of a long pitch, so that the meal slowly moves towards the back end
or bottom of the cylinder, or the inclination of the cylinder is combined with the
oblique position of the beaters, as may be preferred. After the flour has been sifted
off, the bran, &c., is taken up by radial ribs o on the bottom disk b¹. . These ribs lift
the same, and thereupon let it slide behind a conical or otherwise suitably shaped
disk P fixed to the said ribs or cast together with them. This disk conducts the
material towards the openings q, arranged around the trunnion a¹, so that it is
discharged into the channel r. The flour passing through the gauze falls into the
lower part of the casing which incloses the cylinder, and is there conveyed into one
or more channels 8 by means of a creeper or otherwise.
If the cylinder is to be provided with two sheets of gauze, whether of equal or of
different fineness; and if the latter should thereby become too long to be properly
stretched, a ring k is fixed by lugs k' to the stays c, as shown in detail by Fig. 3. Tho
parts of this ring, as well as of the ring e to which the gauze is to be fixed, should
be of equal diameter with the outside of the rib d'. The two sheets of gauze are
fastened with one edge to the ring k, and with the other respectively to the rib d',
and to the ring e. In a similar manner three or more sheets may be applied.
The mode of fastening the gauze is as follows:-A cord having been sewed to

page_text: the edges of the gauze, the latter is attached at two corners to the rings e and k,
respectively to the rib d', by the clamping screws x. Its edges are then hooked on
pins y provided therefor. The screws having been slackened, the end corners of
the gauze are pushed under them and the screws tightened again. The overlapping
gauze ends must be glued together. A strap h of iron or other suitable material,
is subsequently laid around each edge of the gauze and drawn tightly by the
screw z into the shallow groove of the rib respectively of the rings, thereby firmly
uniting these parts. The gauze is finally stretched lengthwise by the adjusting
screws f, until it has become perfectly smooth and taut.
The arrangement of the stays c may be modified, as shown by Fig. 4. They are
in this case placed inside of the gauze, and are, by preference, made square or flat
in section, to keep them as much as possible out of the way of the beaters m.
The ring k is permanently attached to the stays, the gauze not being fastened to
the same, and the ring e is made of a shape to suit the modified arrangement.
Having thus described the nature and object of this Invention, and the manner
in which it is to be performed or put into practice, I claim as new and essential
features of the said centrifugal flour-dressing machine,-
1. The cylinder, consisting of the two discs b and b¹, provided with the hollow
trunnions a and a¹ and the circular ribs d and d¹, moreover of the stays c and of
the ring e adjustable by screws f, substantially as and for the purpose described.
2. The method of fastening the gauze to the rib d of the disk b¹, or to the
rings e ork of the cylinder by means of a strap h, as and for the purpose specified.
3. The perforated blades or beaters m on the shaft in combination with the
dressing cylinder, substantially as described and for the purpose stated.
4. The hollow trunnion a of the disk b in combination with the worm t, as and
for the purpose specified.
5. The radial ribs o of the disc b¹ in combination with the disk p and the
openings g, as described and for the purpose stated.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand
and seal, this Twenty-fifth day of March, in the year of our Lord One
thousand eight hundred and seventy-eight.
Anr DIGDEn