Improvements in Bolting Mills, Screens, and the like.
Year: 1898

page_text: Date of Application, 8th Dec., 1898-Accepted, 4th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in Bolting Mills, Screens, and the like.
I, HERMANN DIETZ, of 16, Funkenburghstrasse, Leipzig, Germany, Manufac-
turer, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement:-
This invention has reference to improvements in bolting mills, screens and the
like, and has for its object to construct a mill or screening apparatus, which will
distribute the flour or other material to be sifted, evenly over the entire surface
of the sieve or sieves, and which will do its work more thoroughly and with less
inotive power than the mills or screens now in use. In the vertically arranged
bolting mills, as used at present, the flour is thrown in at one end of the machine
and is conveyed by means of the helically arranged wings or sweeps across the
length of the sieve, the coarse particles being delivered at the other end of the
mill Now this arrangement is in no way satisfactory, as naturally at the front
end of the mill most of the flour is sifted, while comparatively only very little of
it is carried to the further end of the sieve. The amount of power used for
driving such a mill is relatively too high, as the flour is thrown in bulk into the
hopper, delivering it upon wings or sweeps, which not only have to sift the flour
but also to transport it to the further end of the mill. To do away with these and
similar disadvantages is the aim of the present invention and I attain the desired
end by the hereinafter described means, reference being had to the accompanying
drawings, Figure 1 of which shews a sectional elevation of one embodiment of my
invention. Figures 2 and 3 represent transverse sections of two modifications.
Figures 4 and 5 shew transverse sections of a curved and of a polygonal sieve
respectively. Figures 6 and 7 shew respectively a front and side elevation of a
distributing roller, partly in section. Figure 8 represents a sectional elevation of
a delivering roller with ventilation openings.
Figures 1 and 2 represent a bolting mill with a number of sieves, arranged one
below the other, The funnel-shaped hopper T is substantially of the same width
as are the fans F1, F2.
I prefer to employ a distributing device, as shewn
in Figures 6 and 7 for distributing the flour evenly across the width of the first
fan F. This distributing device consists of a roller V, revolubly arranged within
the outlet of the hopper and being provided with grooves or ribs A³, starting from
the middle of the roller and running spirally in opposite directions to the ends of
the roller. A blade or strike A prevents the flour from falling down in bulk.
Upon the distributing roller being rotated the flour falls upon the first fan Fi
provided with wings or sweeps f, which latter throw it against an obliquely
arranged sieve S¹. The coarse particles of the flour are retained by the meshes
of this sieve and roll down into the second fan F2, provided underneath the fan F¹,
as is clearly shewn in Figure 2. The flour, having passed through the sieve,
falls into and down the chute C. The fan F2 and the subsequent fans F3, F4
work in a manner similar to fan F1, each fan throwing the coarse or heavier par-
ticles, which have rolled down from the fan above, against a sieve. The fan does
no transporting, it simply throws the flour against the sieves, the motive power

page_text: accordingly being relatively low. The bolted flour is removed out of the bottom
opening A, whilst the coarse particles are taken out at opening A'.
The sieves and the fans may be arranged vertically one below another, or they
may vary and be arranged at an inclination to the vertical.
A modification of the arrangement is shewn in Fig. 3. The hopper T in the
drawing is shewn without the distributing roller V, but it is obvious that such a
distributing roller may be used with advantage. The uppermost fan F1 throws
the flour upon the sieve S¹, the coarse particles falling down upon the conveyer T.
which conveys them sideways out of the mill. The sifted flour falls into the
chute G, leading it to the second fan F2, which throws it through the second
sieve S2 and so on, to the lowermost fan F, which has no conveyer, the coarse
particles falling straight down and out of the opening A¹. The sifted Hour is
removed out of the opening A².
I may also provide arrangements whereby the flour of each compartment or
chute may be taken out separately and may in this case provide different widths
of meshes for the various sieves, beginning with the widest meshes at the upper
sieve and giving the finest meshes to the lowest sieve.
The sieves may be straight or may have a curved or polygonal shape, as is shewn
by the Figures 4 and 5. In the former the sieve is shown to be displaceable
laterally; screws D serve to secure it in the desired position.
In Figure 5 the sieve is shewn pivotally fastened at one end, the opposite
end being displaceable towards or away from the fan.
Figures 6 and 7 illustrate a delivering roller with a distributing device arranged
in the form of a helix. The delivering roller V is furnished with spiral grooves
or ribs which run from the middle to each side in an opposite direction, (the one
left-hand, the other right). The distributing grooves or ribs may be uniform
Instead
throughout or otherwise, and continuous or interrupted in their course.
of the ribs, a thread, flange or other piece of any desired cross-section, wound
spirally, can be attached to the roller V. The distributing roller may be single
or otherwise, according to the number of hopper extensions. (In Figure 6 a single
delivering roller is shewn with two inlets or chutes from the hopper). Even
when the material being screened or sifted accumulates before the regulating
blade, slide or strike A, the spiral-fitted distributing device will separate it at the
bottom and uniformly distribute it.
The sifting or bolting process can also be assisted by introducing air through
one or more sides or ends of the machine to the fan mechanism, in proximity to
its shaft. In Figure 8, a part of the apparatus is shewn separately, in which
the ends or sides are furnished with openings 0, which can be more or less closed
by means of any suitable slide or slides, so that it is possible to regulate the current
of air which enters, One or more such openings is or are placed in direct proximity
to the shaft of the fan mechanism F, in order that when the latter is rotated, a
current of air may be introduced in the direction of the arrow by the suction action
of the same.
By the use of such a current of air, it is also possible to more or less dry damp
flour, meal and other cereals or materials treated.
i
In addition to bolting flour, this apparatus can also be easily adapted to sift or
screen small coal, charcoal, cements, colors and other pulverized or powdered
materials, and although I have described the apparatus chiefly with regard to the
treatment of flour, it is apparent that other more or less pulverized materials can
be treated in place thereof.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is: ;--
(1). In a sifting or bolting mill or the like, means for distributing the flour or
material to be bolted, evenly over the entire width of the mill, consisting of a
hopper having a comparatively narrow outlet and extending across the entire

page_text: width of a fan, the wings or sweeps of which throw the flour against a sieve,
arranged in front of the fan, a chute behind the sieve for carrying off the bolted
flour or material and an outlet for the retained coarse particles, as and for the
purposes specified.
(2). In a bolting mill or the like, the combination of a hopper extending over
the entire width of the mill, a distributing roller arranged at the outlet of the
hopper and having grooves or ribs provided upon its circumference, said grooves
or ribs to start at the middle of the roller and running spirally in opposite direc-
tions towards the ends of the roller, a strike extending across the said distributing
roller, a fan arranged below and parallel to the said distributing roller, a sieve
arranged in front of the fan, and chutes to separately carry off the bolted flour
or other material and the coarse particles thereof, as set forth.
(3). In a bolting mill or the like, the combination of a number of fans, arranged
one below the other, the upper one receiving the flour or other material to be
bolted, either directly or from a distributing roller arranged at the outlet of the
hopper, sieves arranged obliquely in front of each fan, a chute or outlet for the
sifted flour or other material and an outlet for the coarse particles thereof, as and
For the purpose stated.
(4). In a bolting mill or the like, the combination of a number of fans, arranged
one below the other, the upper one receiving the flour or material to be bolted,
sieves arranged obliquely in front of each fan, chutes behind each sieve leading
the bolted flour upon the next lower fan, a conveyer at the bottom end of each sieve
for conveying the coarse particles out of the mill and an outlet for the finished
product, as set forth.
(5). In a bolting mill or the like, in combination a number of fans, arranged
one below the other, the upper one receiving the flour or material to be bolted,
curved sieves arranged in front of each fan and adapted to be displaced towards or
away from the fans and means for securing the said sieves in the desired position,
as set forth.
(6). In a bolting mill or the like, the combination of a number of fans, arranged
one below another, the upper one receiving the flour or material to be bolted,
polygonal sieves pivotally secured with one end in front of each fan, so as to allow
of the other end being displaced toward or away from the sieve, as above described.
(7). In a bolting mill or the like, the combination of a number of fans arranged
one below another, the upper one receiving the flour or material to be bolted from
a distributing roller having grooves or ribs arranged upon its circumference,
said grooves or ribs starting at the middle of the roller and running spirally in
opposite directions towards the ends of the roller, a strike extending across the said
distributing roller, sieves arranged obliquely in front of each fan, a chute and
outlet for the bolted flour or other material and an outlet for the coarse particles,
the parts being constructed, arranged and working substantially as set forth.
(8). In a bolting mill or the like, means for admitting air to the rotating fan
at one or more ends or sides of the said mechanism, said means being controllable
so that air may be supplied or such supply be cut off, for the purpose of assisting
the bolting action of the fan or drying damp cereals or other material, substan-
tially as above described.
Dotad this Eighth day of December 1898.