Note: Descriptions are shown in the official language in which they were submitted.
~3~ 5~3
Dosing apparatus for granular or powder material
The present invention relates to a dosing apparatus
for granular or powder material, comprising a feeding-out
device which is rotatable about a normally substantially
vertical axis, and is adap-ted to be supplied with said ma-
terial in a central material-receiving area, whereby the
supplied material by rotation of the device is flung out from
the central area by the action of the cen~rifugal force, to be
fed out through a number of outfeed openings~
Such a dosing apparatus or centrifugal feeding-out
device which is supplied wi-th "flowable" material, such as
grain, seed, fertilizer or the like, from a receptacle so
that the feeding-out device is filled at the center, is
characteristic of several centrif~gal~eeding-out devices.
The previously known centrifugal feeding-out devices operate
with relatively high rotational speeds, and it is in practice
attended with difficulties to dose the material quantities
with varying speeds, such as it is e. g. done with conventional
outfeed rollers. The speeds become too high for the greatest
quantities, as it is the question of considerable quantity
variations, according to the machine type in question. Simi~
larly, also the openings from the outfeed means easily become
too small when the quantities are adjusted only by means of
larger and smaller openings or volumes.
The object of the invention is therefore to provide
a dosing apparatus which is based on the cen-trifugal outfeed
- 35 principle, but which is without the aforementioned drawbacks
and which enables a very stable feeding-out of very small as
well as of larger material quantities per unit of time, both
when it is the question of material consisting of relatively
large grains or particles and when it is the question of
~L~3~f~58
material consisting of very small particles, i. e. powder
material.
For the achievement of the above-mentioned object
there is provided a dosing apparatus of the type set forth
above which, according to the inven-tlon, is characterized
in that it comprises first and second, concentrically dis-
posed outfeed means which are arranged to rotate with mutually
different speeds, the outfeed means having cooperating parts
which, by relative speed difference between said parts, move
the thrown-out material out from suitable outfeed openings.
An advantageous embodiment of the invention is
characterized in that the first ou-tfeed means, containing said
central area, comprises a pair of peripheral1yextending, inner
respectively outer shielding walls having respective outfeed
openings mutually displaced along the circumference, and
defining an outfeed compartment together with a boundary wall
of the second outfeed means.
Eurther, it is advantageous that the outfeed openings
of the outer shielding wall are sufficiently peripherally dis-
placed in relation to the outfeed openings of the innershielding wall that the outer shielding wall prevents direct
discharge of material from the outfeed openings of the inner
shielding wall.
The dosing apparatus according to the invention,
which operates with mutually different speeds on its two out-
feed means, will not have any difficulties in that it has to
be driven with high, unrealistic speeds or has to work with
too small outfeed openings. When e. g. the shielding walls
with the outfeed openings have the same speed as outfeed ele-
ments on the second outfeed means, this works as if both out-
feed means stand still irrespective of what rotational speed
they might have. In practice this means that the outfeed
elemen-ts, for example, give larger discharged material
quantities the faster or the slower they move in relation to
3~ the outfeed openings. I-t is here essential that, with the
present apparatus, one may use the same large outfeed openings
also for small discharged or fed-out quantities. Even if
one might also vary the size of the outfeed openings, one has
found that pure speed regulation normally is preferable.
The invention willbe more closely described below in
connection with two exemplary embodiments with reference to
the accompanying drawings, wherein
Fig. 1 shows a longitudinal, central section through
6 a dosing apparatus according to the invention;
Fig. 2 shows a section along the line II - Il in
Fig. l;
Fig. 3 shows another embodiment of a dosing apparatus
according to the invention which is illustrated partly in
side view and ~artly in axial longitudinal section;
Fig. 4 shows an inner outfeed means in the apparatus
in Fig. 3, partly in side view and partly in axial longitudinal
section; and
Fig. 5 shows -the outfeed means in Fig. 4, partly in
top view and partly in cross-section along the line V - V in
Fig. 4.
The embodiment shown in Figs. l and 2 has a feeding-
out device comprising a first outfeed means l (hatched with
lines inclined upwards -to the right) and a second outfeed means
2 (hatched with lines inclined upwards -to the left), of which
the first outfeed means l is connected to or fixed in a suit-
able manner on a rotatable, central shaft 3 which in operational
position is substantially vertical as shown in Fig. 1, and of
which the second outfeed means 2 is rotatably mounted on the
shaft 3 and further is rotatably mounted in a stationary
supporting means 4 by a bearing means which in the illustrated
embodiment consists of a pair of ball bearings 5 and 6 re-
spectively. Such as appears from Fig. 1, the stationary
supporting means 4 is fixedly connected with and supported by
additional stationary members forming part of the illustrated
dosing apparatus and which are to be described more closely
below.
The first outfeed means l comprises a bottom portion
7 which is located around the shaft 3 and is connected to
an inner, cylindrical shielding wall 8 defining a central
area 9 to which material to be fed out is supplied from an
overlying, stationary feed hopper lO. Further, the outfeed
means l comprises an outer cylindrical shielding wall ll which
4 ~ .3~658
is coaxial with the inner shielding wall 8 and together with
the latter wall defines an annular compartment 12. The two
shielding walls are connected by way of an upper plate portion
13 which thus forms an upper limitation of the annular compart-
ment.
In the illustrated embodimen-t the inner shieldiny
wall 8 is provided with a pair of diametrically opposite out-
feed openings 14, and the outer shielding wall 11 is provided
with a pair of diametrically opposite outfeed openings 15,
the outer pair of openings being peripherally displaced in
relation to the inner pair. It will be understood that also
a largernu~ber of outfeed openings could be used, each shielding
wall having to have an ou-tfeed opening which is angularly
displaced in relation to the outfeed opening or openings in the
other shielding wall, so that the outer wall by rotation of
the outfeed means shields against direct feeding out of
material from the opening or openings in the inner wall.
To assist in smooth feeding-out from the apparatus, the out-
feed openings of the first outfeed means 1 have inclined side-
limiting walls as suggested in Fig. 1, and more specificallysuch that these walls are inclined upwards and rearwards in
relation to the movemen-t direction.
The second outfeed means 2 comprises a sleeve portion
16 for said mounting on the shaft 3 and a suppor-ting portion
outwards
17 projecting~at the upper end of the sleeve portion, which
supporting portion firstly supports an annular plate member 18
defining a lower bottom surface in the annular compartment 12,
and secondly supports an outer throwing dish or bowl 19
extending along the outside of the outer shielding wall 11.
. 30 The throwing bowl 19 is provided with a number of upstanding,
plate-shaped winnowing fans or throwing blades 20 for distri-
bution of fed-out or discharged material to the inlet openings
of a plurality of adjacent, stationary outfeed tubes 21
arranged around the outer circumference of the throwing bowl.
The second outfeed means 2 is further provided with
a plurality of outfeed elements 22 projecting upwards in the
annular compartment 12 from the bottom plate member 18 and
being arranged with suitable spacing in the longitudinal
direction of the annular compartment. In the illustrated
'
~3~
embodiment the outfeed elements consist of cylindrical posts
or pins having brush elements 23 projecting therefrom and
wiping along the inner surface of the outer shielding wall
11. The distance between the ,outfeed elements 22 and the
6 outer surface of the inner shielding wall 8 is sufficiently
large to allow passage and prevent damage by sqeezing or
crushing of the largest particles which the apparatus is in-
tended to feed out.
As shown in Fig. 1, the outfeed elements 22 also
support an additional, upper bottom plate'member 24, so that
in the upper portion of the annular compartmen-t there is
defined a smaller annular compartment 25 wherein outfeed ele-
ments 26 analogous to the outfeed elements 22 project upwards
from the bottom plate member 24. This upper annular compartment
25 is provided for feeding-out of material consisting of small
particles or being in powder form, and as shown the distance
between the outfeed elements 26 and the inside located portion
of the shielding wall 8 is substantially smaller than in the
lower portion of the annular compartment. In order to provide
for feeding out of material only to the upper annular compart-
ment portion, a bottom-surface-forming cover 27 is provided
in the central area 9 of the first outfeed means 1, which
cover may be lifted from the illustrated position and fixed
at a suitable height on the shaft 3 for feeding out material
to the bottom plate member 24.
The outfeed tubes 21, which e. g. in connection with
a seed drill constitute seed tubes connected to the drill
coulters of the sowing machine, are provided with bottom
openings 28 (Fig. 2) along the outer circumference of the
,, 30 throwing bowl 19 for supply of fed-out material to an under-
lying, stationary return bowl 29 forming connection between
the stationary supporting member 4 and the stationary member
comprising the outfeed tubes 21. The return bowl 29 is
provided in order to be able to effect rotation test of
the dosing apparatus, i. e. control of the function of -the
apparatus by rotation and feeding-out of material without
the material being passed out through the outfeed tubes. For
this purpose there are provided flap or gate means 30 for
closing of the outfeed tubes 21 outside the bottom openings
6 ~3~
28, so that the material is diverted to the return bowl 29
from which it flows downwards via a lower opening (not shown)
and is fed out via a return plate 31 which is connected to
the sleeve portion 16 of the second outfeed means 2.
In operation of the dosing appara-tus the fed-ou-t
material is normally thrown over the bo-t-tom openings 28 of
the outfeed tubcs 21 and fed out directly through the out-
feed tubes. However, for the return to the outfeed tubes of
possible mate~ial which during normal operation falls down
into the return bowl 29 and further down therefrom, there is
provided a return -throwing screen 32 which by way of an
ejection channel 33 forms connection from the return plate
31 to the outfeed tubes 21. The return throwing screen 32
is carried by a supporting plate 34 which is fixedly connected
to the second outfeed means, and it is height-adjustably
arranged on the supporting plate 34 by means of telescopically
adjustable tube connections 35 with associated set screws 36
for fixing of the return throwing screen 32 in the position
of interest. Thus, in the illustrated, lower position the
return throwing screen provides for return of material from
the return bowl 29 to the outfeed tubes 21, whereas in an
upper position it allows direct outlet of material flowing
down from the return bowl.
The aforementioned gate means 30 are also provided
to allow selective closing of the outfeed tubes, to enable
feeding-out e. g. only through desired drill coulters on a
sowing machine, in order to thereby adjust the row spacing.
In order in this case to ~Void feeding-out to the closed out-
feed tubes by way of the ejection channel 33, the gate means
30 are also provided with a closing plate 37 providing for
closing of the opening between the ejection channel 33 and
the outfeed tube 21 in question when the inlet opening to
the outfeed tube is closed.
Such as schematically shown in Figs. 1 and 2, the
stationary member with the outfeed tubes 21 is rigidly
connected to the feed hopper 10 by means of screw bolt
connections 38 passing through bores in respective connection
members 39.
The driving means for operation of the two outfeed
7 ~.~.3~i658
means 1 and 2 with mutually adjustable speeds may be designed
in different ways. In the illustrated embodiment the drive
means comprises first and second drive shafts 40 and 41,
respectively, which are disposed a-t right angles to the
6 shaft 3 of the first outfeed means 1 and are mounted in a
schema-tically shown casing 42 wherein there is also provided
an additional bearing 43 for supplementary mounting of the
sleeve portion 16 of the second outfeed means. The first
shaft 40 is coupled through a bevel gear means 44 to the
shaft 3 of the first ou-tfeed means, whereas the second
shaft 41 is coupled through a bevel gear means 45 to the
sleeve portion 16 of the second outfeed means. Of the two
shafts e.g. the second shaft 41 may be arranged to be driven
directly from a running wheel on the machine wherein the
apparatus is to be used, e. g. on a seed drill, or the shaft
may be driven from a suitable mo-tor. For driving of the
firs-t shaft, i. e. the shaft 40, this may be coupled to the
second shaft by way of a variator (not shown) which may e. g.
allow the second shaft 41 to rotate 0 - 20 % faster than
the first one, something which is sufficient to achieve an
outfeed quantity which varies from zero to the largest
quantity which normally will be of interest.
The described apparatus is constructed and designed
so that it is suitable for manufacturing from parts which
26 essentially consist of suitable plastics materials. This
enablesrational and economic manufacture and also that the
entire apparatus becomes light of weight.
The operation of the apparatus is supposed to be
clear from the preceding description, so that only a short
review of the principal main features will he given here.
When the two outfeed means of the apparatus rotate
with suitable speed in the direction of the arrow A shown
in Fig. 2, and granular material (or powder material) is
supplied to the central area 9 of the first outfeed means,
36 this material will, under the action of the centrifugal
force, be flung out through the openings 14 of the inner
shielding wall 8 and against the inner surface of the outer
shielding wall 11, the material in the annular compartment
~13~658
12resting on the bottom plate 18 (possibly on the bottom plate
24 by feeding-out through the upper annular compar-tment por-
tion). If the outfeed means rotate with the same speed, no
material will be fed out from the apparatus as the outer
shielding wall blocks or obstructs the material in the annu-
lar compartment and this material lies still in relation to
the shieldin~ walls. On the o-ther hand, as soon as the two
outfeed means are driven with different speeds, a movement
of the material takes place in the direction towards the
outfeed openings 15 in the outer shielding wall 11. In the
illustrated embodiment it is presupposed that the second out-
feed means 2 is driven with higher speed than the firs-t out-
feed means 1, and when the speedsthusare di-fferent, the
material is advanced by means of the outfeed elements 22,
respectively 26, to the outfeed openings 15 of the outer
shielding wall 11 in a quantity per unit of time which is
directly dependent on the relative speed difference between
the outfeed means. It will be seen that the material
quantity which is fed out to each outfeed -tube 21 through a
respective outfeed opening 15 in the short time during which
the opening passes the outfeed tube in question, may be varied
from zero and upwards to a maximum outfeed capacity for -the
opening in that the relative speed difference is increased
- correspondingly from zero and upwards. Executed tests have
shown that, with varying particle size of the fed-out material
and with varying feeding-out speed, one achieves a feeding-
out having a very high degree of stability compared with the
devices according to the prior art.
The embodiment of the dosing apparatus according to
the invention which is shown in Fig. 3, is that which at
present is considered as the preferred embodiment as it has
a particularly simple construction and may be manufactured
correspondingly rationally and e conomically by means of
suitable plastics materials.
The apparatus comprises a first outfeed means 51
and a second outfeed means 52 (which are both hatched in a
manner corresponding to that of the embodiment in Fig. 1).
The firs-t outfeed means 51 comprises an upper l-oundary
1~3~6S8
wall portion 53 and a downwards projecting, cylindrical
sleeve portion 54 which, by means of a pair of ball bearings
55 and 56, is rotatably mounted on a shaft 57 which in this
embodiment is stationary and is rigidly connected to other
stationary members of the apparatus, such as more closely
described below. The second outfeed means 52 also comprises
an uppcr b~ln~ry wall portion 58 and a downwards projecting
sleeve portion 59 which is rotatably moun-ted on the sleeve
portion 54 of the first outfeed means by means of a pair of
ball bearings 60 and 61. On the lower end of the sleeve
portion 54 of the first outfeed means there is fixed a V-
belt pulley 62, and on the lower end of the sleeve portion
59 of the second outfeed means there is fixed a V-belt
pulley 63. q~he V-belt pulleys are driven by means of driving
means which may be arranged in a manner corresponding to
that of the embodiment according to Figs. 1 - 2, and such
that the second or outer outfeed means 52 is preferably driven
with the highest speed.
In Figs. 4 - 5 the design of the first outfeed means
- 20 51 is shown in more detail. Even if the outfeed means may
be manufactured in one piece, it consists in the illustrated
embodiment of two parts fixed to each other by means Of three
screws 64. The bo~ndary ~ wall portion 53 of the outfeed
means comprises an upwards extending, inner shielding wall
26 65, an outer shielding wall 66 projecting outwards and in
the illustrated embodiment also somewhat upwards from an
upper portion of the outside of the inner shielding wall 65,
and further a lower bottom wall flange 67. The central area
to which material to be fed out is supplied, is designated
30 68 and is defined by the bottom surface of the boundary wall
portion and the cylindrical inner surface of the inner
shielding wall 65. The inner shielding wall is provided with
three equally spaced outfeed openings 69, and the outer
shielding wall 66 is similarly provided with three equally
- 35 spaced outfeed openings 70 which, as viewed in -the rotational
direction of the outfeed means (the arrow B in Fig. 5), Y~
placed behind the first-mentioned outfeed openings 69, i. e.
they are sufficiently peripherally displaced in relation to
lo ~32~5~
these in order that the outer shielding wall 66 by rotation
of the outfeed means 51, 52 prevents direct material discharge
from the outfeed openings of the inner shielding wall.
Such as appears from Fig. 3, the boundary wall
6 portion 58 of the second outfeed means 52 has an upwards
diverging boundary wall which extends substantially
parallel with the outer side of the inner shielding wall and,
together with the shielding walls 65, 66 and the bottom wall
- flange 67 on the first outfeed means 51, define an annular
outfeed compartmen-t 71, and which further passes into a conical
outfeed hopper 72. The outfeed hopper is shown as a separate
member which is fixed to the second outfeed means 52, e. g.
by means of rivets (not shown), but it may also be formed
integrally therewith.
It will be seen that the outfeed hopper 72 corresponds
to the throwing bowl 19 in the embodiment according to Figs.
1 - 2, and in a manner corresponding -to tha-t of the first
embodiment a plurality of adjacent, stationary outfeed tubes
73 are arranged around the outfeed hopper at its upper end.
For a corresponding purpose as stated in connection with the
first embodimen-t, each of the outfeed tubes 73 are provided
with a gate or flap 7~ for possible closing of the outfeed
tube. In a manner corresponding to -that of the throwing bowl
~ 19 the outfeed hopper 72 may be provided with throwing blades
(not shown) in order ensure uniform distribution of fed-out
material to the outfeed tubes 73, also when the dosing
apparatus is used in an inclined position (e. g. during
operation in inclined country).
Under the outfeed hopper 72 there is provided a
stationary hopper 75 for return of fed-out material falling
back from the outfeed tubes 73, e. g. when these are closed.
For returning the return material to the outfeed compartment
71 the bo~ndary wall 58 of the second ou-tfeed means 52 is
in its lower region provided with a plurality of return
- ~5 openings 76 distributed along the circumference thereof. When
the return material fills the bottom region between the return
hopper 75 and the boundary wall 58 so that the material
because of its weight is carried through the return openings
76, it is flung upwards towards the outfeed compartment 71
11 ~13~i65~
as a result of the action of the centrifugal force during
operation of the apparatus, and for passage of this material
to the outfeed compartment the bottom wall flange 67 is
provided with three transfer openings 77 which are equally
spaced along the circumference of the flange, such as appears
from Fig. 5. Such as further appears from Fig. 5, these
transfer openings 77 are peripherally displaced in relation to,
and more specifically located behind, the outfeed openinys
69 of the inner shielding wall, as viewed in the rotational
direction B of the outfeed means, in such a way that the flo~J
of return material is not prevented by tlle outfeed flows from
the outfeed openings 69 of the inner shielding wall 65. Further,
as shown, the transfer openings 77 are also displaced in
relation to the outfeed openings 70 of the outer shielding
wall, so that return material is not allowed to be fed out
directly from the transfer openings 77 via the outfeed openings
70, as this would result in varying outfeed quantity with
and without return ma-terial. Thus, it is ensured that the
return material, in a corresponding manner to that of the
o-ther material, is fed out in a controlled manner in that it
is advanced to the outfeed openings 70 by means of the second
outfeed means 52 as a result of the relative speed difference
between the outfeed means.
In order to ensure uniform advance to the outfeed
openings 70 of the material which is present in the outfeed
compartment 71, the second outfeed means is provided with a
plurality of upstanding feeding-out elements 78 which are
arranged with suitable spacing along the circum~erence.
In the embodiment of Fig. 3 the stationary return
hopper 75 is supported by an annular holder 79 which is in
turn rigidly connected to a base member 80 by means of three
screw bolts 81 which are distributed around the stationary
l / shaft 57 and is passed through respective distance tubes 82.
~he lower end of the stationary shaft 57 is fixed in a
36 central hole in the base member 80, and to the upper end
portion of the shaft there is fixed three radially extending
brackets 83 (only one is shown) carrying a feed cylinder 84
for supply of material to the apparatus. In -the lower end
, .
3~6~8
portion of the feed cylinder 84 there is arranged a cylindrical
slide gate 85 which in Fig. 3 is fixed in an upper position
by means of at least one screw 86. An axial slot 87 in the
feed cylinder allows that the screw and therewith the slide
6 gate may be moved downwards in order to reduce the size of
the outfeed openings 69 or to close these if desired.
In order to be able to adjust the size and partly the
location of the outfced openings 70 of the outer shielding
wall 66, an additional slide gate means 88 with openings
corresponding to the outfeed openings 70 ls mounted on the
shielding wall portion 53. The gate means may be displaced
peripherally on the shielding wall portion 53 and may be
fixed in a suitable posi-tion by means~at least one screw 89
which is passed through a suitable peripheral slot in the
gate means and threaded into a hole 90 in the shielding
wall portion 53.
- It will be seen that the outer shielding wall 66
does not have to be a fixed part of the shielding wall portion
53, but may be displaceable along the periphery thereof in
a manner corresponding to that of -the slide gate means 88.
One may -then adjust the location of the outfeed openings 70
in relation to the position of the inner outfeed openings 69
and the transfer openings 77 (which may possibly also have
adjustable location), in order to optimize the function of
the apparatus under varying operational conditions.
36
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