U.S. patent application number 09/757619 was filed with the patent office on 2001-11-01 for apparatus for metering and dispensing powder into hard gelatin capsules or the like.
This patent application is currently assigned to Robert Bosch GmbH. Invention is credited to Runft, Werner.
Application Number | 20010035431 09/757619 |
Document ID | / |
Family ID | 7627334 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010035431 |
Kind Code |
A1 |
Runft, Werner |
November 1, 2001 |
Apparatus for metering and dispensing powder into hard gelatin
capsules or the like
Abstract
An apparatus for metering and dispensing powder into hard
gelatin capsules or the like. The apparatus has a metering disk
that rotates in advancing steps, with bores disposed in its base.
The bores which cooperate with tamping plungers that move up and
down. The tamping plungers are disposed on a common tamping plunger
support and when inserted into the bores, compress the powder into
compressed pellets. In order to detect breakage of the springs and
in order to be able to make a statement as to the mass of the
compressed pellets, means are provided which detect the spring path
of the tamping plungers immediately preceding the ejection
plungers.
Inventors: |
Runft, Werner; (Winnenden,
DE) |
Correspondence
Address: |
Ronald E. Greigg
GREIGG & GREIGG P.L.L.C.
1423 Powhatan Street Unit One
Alexandria
VA
22314
US
|
Assignee: |
Robert Bosch GmbH
|
Family ID: |
7627334 |
Appl. No.: |
09/757619 |
Filed: |
January 11, 2001 |
Current U.S.
Class: |
222/168.5 ;
141/146; 141/238; 141/71; 141/81 |
Current CPC
Class: |
B65B 1/38 20130101; A61J
3/074 20130101; A61J 2200/74 20130101 |
Class at
Publication: |
222/168.5 ;
141/71; 141/81; 141/146; 141/238 |
International
Class: |
B65B 001/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 13, 2000 |
DE |
1 00 01 068.7 |
Claims
We claim:
1. An apparatus (10) for metering and dispensing powder into hard
gelatin capsules (1), comprising a filling material container (11)
for the powder, a metering disk (14) with bores (22), which is
disposed underneath the filling material container (11), the
metering disk rotates in steps, and during a stop phase, comes into
alignment with tamping plungers (30), the tamping plungers can be
moved into and out of the bores (22) and when the tamping plungers
are inserted into the bores (22), the tamping plungers dispense the
powder into the bores (22) and compresses the powder, the tamping
plungers (30) are disposed so that they are damped by spring means
(19) or by pneumatically acting means (38, 39, 42) so that when the
powder is compressed in the bores (22) the tamping plungers are
deflected by a particular distance, and ejection plungers (31)
following the tamping plungers (30), in which the ejection plungers
transfer the compressed pellets previously formed in the bores (22)
by the tamping plungers (30) into supplied capsule parts (3), at
least the tamping plungers (30) immediately preceding the ejection
plungers (31) have means (44; 50) for detecting the spring path of
the tamping plungers (30) and that the means (44; 50) are coupled
to a control device (40) which compares the detected spring paths
to a spring path stored in the control device (40).
2. The apparatus according to claim 1, in which the tamping
plungers (30) immediately preceding the ejection plungers (31) have
pneumatically acting means (38, 39, 42) and that the tamping
plungers (30) immediately preceding these tamping plungers (30) are
coupled to springs (19).
3. The apparatus according to claim 1, in which all of the tamping
plungers (30) are coupled to pneumatically acting means (38, 39,
42).
4. The apparatus according to claim 2, in which the means for
detecting the spring path of the tamping plungers (30) have
pressure sensors (44).
5. The apparatus according to claim 3, in which the means for
detecting the spring path of the tamping plungers (30) have
pressure sensors (44).
6. The apparatus according to claim 1, in which in regard to the
tamping plungers (30) cooperating with the pneumatically acting
means (38, 42), the ends of the tamping plungers (30) remote from
the bores (22) are embodied as pistons (35) that are guided in
sliding fashion in cylinder bores (34) and are acted on by a
compressed air source.
7. The apparatus according to claim 2, in which in regard to the
tamping plungers (30) cooperating with the pneumatically acting
means (38, 42), the ends of the tamping plungers (30) remote from
the bores (22) are embodied as pistons (35) that are guided in
sliding fashion in cylinder bores (34) and are acted on by a
compressed air source.
8. The apparatus according to claim 3, in which in regard to the
tamping plungers (30) cooperating with the pneumatically acting
means (38, 42), the ends of the tamping plungers (30) remote from
the bores (22) are embodied as pistons (35) that are guided in
sliding fashion in cylinder bores (34) and are acted on by a
compressed air source.
9. The apparatus according to claim 4, in which in regard to the
tamping plungers (30) cooperating with the pneumatically acting
means (38, 42), the ends of the tamping plungers (30) remote from
the bores (22) are embodied as pistons (35) that are guided in
sliding fashion in cylinder bores (34) and are acted on by a
compressed air source.
10. The apparatus according to claim 6, in which the cylinder bores
(34) are connected by means of a common compressed air connection
(37) coupled to the compressed air source (39).
11. The apparatus according to claim 7, in which the cylinder bores
(34) are connected by means of a common compressed air connection
(37) coupled to the compressed air source (39).
12. The apparatus according to claim 8, in which the cylinder bores
(34) are connected by means of a common compressed air connection
(37) coupled to the compressed air source (39).
13. The apparatus according to claim 9, in which the cylinder bores
(34) are connected by means of a common compressed air connection
(37) coupled to the compressed air source (39).
14. The apparatus according to claim 1, in which all of the tamping
plungers (30) are coupled to spring means (19) and that the means
for detecting the spring path of the tamping plungers (30) have
path sensors (50).
Description
PRIOR ART
[0001] The invention relates to an apparatus for metering and
dispensing powder into hard gelatin capsules or the like as has
been disclosed by DE 197 20 362 A1. In the known apparatus, the
springs, which were previously coupled to the tamping plungers for
the metering and compression of the powder in the bores of the
metering disk, are replaced with pneumatically acting means. It is
therefore possible to eliminate the danger of spring breakage and
at the same time to minimize the conversion work required in a
format change of the apparatus. Mention is also made of the fact
that by means of pressure sensors for the pneumatic means, which
are coupled to the control device of the apparatus, make it
possible for there to be a monitoring/control of the tamping
plungers.
[0002] However, a quantitative statement as to the powder
quantities metered into the bores of the metering disk by the
tamping plungers has not been possible up to this point with either
the known apparatus with pneumatic means instead of the springs or
with an apparatus that has springs for the tamping plungers.
ADVANTAGES OF THE INVENTION
[0003] The apparatus according to the invention for metering and
dispensing powder into hard gelatin capsules or the like has the
advantage over the prior art that it is possible to make a
quantitative statement as to the weight of the compressed pellets
formed in the bores of the metering disk. In a simple way, this
permits a 100% weight control of the compressed pellets, which
previously took place outside the apparatus by means of a weighing
device, for example the closed hard gelatin capsules were weighed.
With a 100% weight control of the hard gelatin capsules by means of
the weighing device, the performance of the apparatus was limited
or a number of weighing devices were required.
[0004] Other advantageous improvements of the apparatus according
to the invention are disclosed herein. An embodiment set forth
makes it possible, for example, to convert existing conventional
tamping plungers that cooperate with mechanically acting springs.
This embodiment permits both a weight control of each individual
compressed pellet and also optionally permits a statement to be
made as to the presence of possibly broken springs. A particularly
simple format adaptation and adjustability of the apparatus are
permitted. With this embodiment, the pneumatically acting means of
the individual tamping plunger groups can be adjusted in order to
permit a format or weight adaptation of the compressed pellets.
Another embodiment permits a conversion of existing apparatuses
with springs without having to insert pneumatic means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] An exemplary embodiment of the invention is shown in the
drawings and will be explained in detail in the subsequent
description.
[0006] FIG. 1 is a longitudinal section through an apparatus for
metering and dispensing powder into hard gelatin capsules or the
like,
[0007] FIG. 2 is a simplified top view of a metering disk,
[0008] FIG. 3 is a schematic depiction for indicating the pneumatic
triggering of a tamping plunger group,
[0009] FIG. 4 is a section through a metering disk in the vicinity
of a tamping plunger loaded by a spring, and
[0010] FIG. 5 is a section through a metering disk in the vicinity
of a tamping plunger in a modified exemplary embodiment.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0011] The apparatus 10 for metering and dispensing powder into
hard gelatin capsules 1 or the like shown in FIG. 1 has a filling
material container 11. The filling material container 11 is
constituted by a casing 12, a cover 13, and a metering disk 14. At
the same level as the metering disk 14, the filling material
container 11 is encompassed by a ring 15, which is used to hold
capsule tops 2. Underneath the ring 15, segments 17 are provided,
which are correspondingly embodied to hold capsule bottoms 3. The
segments 17 are supported so that they can each pivot around a
bolt, not shown, fastened in the ring 15 and during the rotation
through a fixed curve 20 via a curve roller 21, are moved inward as
needed, i.e. under the bores 22 of the metering disk 14, or
outward, i.e. beyond the circumference of the ring 15. The metering
disk 14 is fastened to a shaft 23 which is coupled to the drive
mechanism of the apparatus 10 and rotates the metering disk 14 in
advancing steps, by a respective angular amount each time. As can
be seen from FIG. 2, the metering disk 14 has a total of four
groups 18a to 18d offset from one another by 90 degrees, with five
bores 22 each.
[0012] For the fastening of the curve 20, a second ring 24 is
provided, which is in turn fastened to the table top 25 of the
apparatus 10. Between the curve 20 and the metering disk 14, an
intermediary ring 26 is provided, which can be pressed against the
underside of the metering disk 14 in an intrinsically known manner
by adjusting means not shown. This intermediary ring 26 is used to
seal the bores 22 of the metering disk 14 in the vicinity of the
powder metering.
[0013] As FIG. 1 also shows, a support 28, which can be moved up
and down by means of columns 27 and is disposed above the filling
material container 11, respectively executes a particular stroke. A
number of tamping plunger supports 29, three tamping plunger
supports 29 in the exemplary embodiment, are disposed on a
graduated circle of the support 28 at uniform angular intervals,
each of which has five tamping plungers 30 guided in it, which pass
through the cover 13 of the filling material container 11 in
corresponding bores. In addition, ejection plungers 31 are disposed
on the support 28, which are connected to a retainer 32 disposed on
the support 28 in such a way that they can move vertically. The
ejection plungers 31 are encompassed inside the filling material
container 11 by a powder deflecting body 33 that is intrinsically
known and is not essential to the invention.
[0014] What is essential to the invention is the disposition,
embodiment, and function of the tamping plungers 30. In particular
according to the first exemplary embodiment of the invention, at
least the tamping plungers 30 immediately preceding the ejection
plungers 31 when the metering disk 14 is rotated clockwise (FIG. 2)
(i.e. in the position of the metering disk 14 shown, the tamping
plungers 30 which are disposed above the group 18d of bores 22) are
equipped with pneumatic means instead of the conventional springs
19 (FIG. 4). To that end, a bore 34 for each of the tamping
plungers 30 is embodied in the tamping plunger support 29
associated with the tamping plungers 30. The upper ends of the
tamping plungers 30, which are embodied as pistons 35, are guided
in a sealed fashion in the bores 34 so that they can slide for a
particular distance. A stop 36 limits the maximal stroke of the
pistons 35 in the direction of the metering disk 14. The bores 34
of the tamping plunger support 29 have a common compressed air
connection 37 (FIG. 3), which is connected to a compressed air
source with the interposition of a pressure regulating circuit 38.
The pressure regulating circuit 38 can be triggered by the control
device 40 of the apparatus via a line 41. In particular, the
control device 40 supplies a pressure reference value P(ref) as a
preset to the pressure regulating circuit 38 via the line 41.
Furthermore, the pressure chambers 42 of the bores 34 embodied
above the pistons 35 are connected via lines 43 to pressure sensors
44, which supply the measured pressure values P(actual) to the
control device 40 as input values. The control unit 40 is also
coupled to a weighing device 45 which supplies the weighing result
M(capsule) of a hard gelatin capsule 1 to the control device 40 as
an input value via another line 46. Finally, an ejection device 48
can be triggered by means of a line 47 in order to be able to
discharge individual hard gelatin capsules 1 from the apparatus
10.
[0015] In the above-described first exemplary embodiment of the
invention, only the tamping plungers 30 immediately preceding the
ejection plungers 31 (in the vicinity of the bore group 18d) are
provided with the above-described pressure sensors 44. However,
according to FIG. 4, the other two groups of tamping plungers 30
are equipped with conventional springs 19, which act via the
tamping plunger support 29, for example on the top ends of the
tamping plungers 30.
[0016] The above-described apparatus 10 functions as follows: In
order to form the compressed pellets in the bores 22 from the
powder disposed in the filling material container 11, the metering
disk 14 is rotated in advancing clockwise steps under the tamping
plungers 30 of a tamping plunger support 29. Then with a downward
motion of the support 28, the tamping plungers 30 are inserted into
the bores 22 of the metering disk 14, wherein the powder disposed
in the bore 22 is compressed. During the compression or pressing of
the powder, the intermediary ring 26 constitutes a counter support
for the tamping plungers 30 and the powder. Then, the tamping
plungers 30 are moved back out of the bores 22 of the metering disk
14, whereupon the metering disk 14 is rotated into the vicinity of
the next tamping plunger support 29. After the last pressing
action, the compressed pellets thus produced travel into the
vicinity of the ejection plungers 31 where they are slid into the
capsule bottoms 3 supplied by the segments 17. Then the capsule
bottoms 3 are brought back together with the capsule tops 2.
[0017] The weight or mass of the compressed pellets formed in the
bores 22 by the tamping plungers 30 and consequently the mass
M(capsule) of the hard gelatin capsules 1 is determined on the one
hand by the stroke of the tamping plungers 30 (produced by the
stroke of the support 28), and is determined on the other hand by
the spring ratio of the springs 19 cooperating with the tamping
plungers 30 as well as the level of the pressure reference value
P(ref). The greater the spring ratio of the springs 19 and the
higher the pressure reference value P(ref), the less the tamping
plungers 30 of the last tamping plunger group are deflected into
the bores 22, i.e. the greater the density of the powder in the
bores 22 and consequently the greater the mass of the compressed
pellets as well.
[0018] It is now essential that by means of the pressure values
P(actual) measured by the pressure sensors, which values correspond
to the corresponding spring paths of the tamping plungers 30, for
one thing, a statement can be made as to whether for example one of
the springs 19 cooperating with the tamping plungers 30 is broken
and for another, whether the mass of the compressed pellets in the
bores 22 is within preset tolerances. This can be explained in that
with correctly functioning springs 19 and a correct preset pressure
reference value P(ref), the pressure value P(actual) and the spring
path when a tamping plunger 30 is inserted into a bore 22 is
increased by a particular amount or has a particular characteristic
course. The level or course of the pressure value P(actual)
consequently corresponds to the level or course of the spring path
of a tamping plunger 30. When a spring 19 breaks, however, the
powder disposed in a bore 22 is compressed much less or not at all
by the corresponding tamping plunger 30 so that the last tamping
plunger 30 coupled to the pressure sensor 44 is inserted more
forcefully into the corresponding bore 22 since the powder has been
compressed less beforehand. As a result, however, with its
insertion, the measured pressure value P(actual) increases by only
a slight amount and has a different characteristic curve. The
breaking of a spring 19 can consequently be detected by virtue of
the fact that the pressure value P(actual) is compared to a
pressure value stored in the control device 40.
[0019] In addition, by means of the weighing device 45, the mass
M(capsule) of a hard gelatin capsule 1 can be determined, which is
associated with a particular progression of pressure values
P(actual) detected in succession during the insertion of a tamping
plunger 30 into a bore 22. If, for example, the determined mass
M(capsule) is too high, then a lower pressure reference value
P(ref) will be preset by the control device 40 so that the
corresponding last tamping plunger 30 is inserted somewhat less
into the bore 22 and consequently also introduces somewhat less
powder. Consequently, it is possible to make a statement as to the
mass of the compressed pellets by means of the pressure values
P(actual) measured.
[0020] If the measured pressure value P(actual) of a compressed
pellet and consequently the mass of the hard gelatin capsule 1
filled with the compressed pellet is outside predetermined
tolerances, then the corresponding hard gelatin capsule 1 can be
separated out by means of the ejection device 48.
[0021] With the above-described first exemplary embodiment, it is
also possible in a format change to change the mass of the
compressed pellets within certain limits by changing the pressure
reference values P(actual), without having to replace the springs
19, which reduces the conversion times of the apparatus 10.
[0022] In a second exemplary embodiment of the invention, all of
the tamping plungers 30 are equipped with pneumatic means, i.e. the
tamping plungers 30 do not have any springs 19 according to FIG. 4.
In accordance with the first exemplary embodiment, at least the
tamping plungers 30 immediately preceding the ejection plungers 31
have pressure sensors 44 for detecting pressure values
P(actual).
[0023] In order, in the second exemplary embodiment with a
predetermined stroke of the support 28, to be able to produce
different pressing powers of the tamping plungers 30 on the powder
and consequently different densities and volumes of the compressed
pellets, different pressure reference values P(ref) are provided.
Depending on the pressure reference value P(ref) that is set, a
corresponding air pressure acts on the tops of the pistons 35 so
that a corresponding damping degree of the tamping plungers 30 is
produced. This means that with a relatively high air pressure, the
tamping plungers 30 are damped relatively little so that with a
downward motion of the tamping plungers 30 into the bores 22, the
powder is compressed relatively forcefully. This produces a
relatively high density and mass of the compressed pellets. With a
relatively low air pressure, the air disposed above the pistons 35
in the bores 34 can be compressed relatively forcefully with the
compression by means of the compressed pellets. This means that a
relatively low density and mass of the compressed pellets is
produced.
[0024] In the third exemplary embodiment of the invention, however,
all of the tamping plungers 30 have springs 19 according to FIG. 4.
However, the tamping plungers 30 immediately preceding the ejection
plungers 31 are respectively equipped according to FIG. 5 with a
path sensor 50 for each tamping plunger 30. This path sensor 50
coupled to the control device 40 of the apparatus 10 can, for
example, be used as a strain gauge (DMS) or as an inductive sensor.
It is only essential that the path sensor 50 detect the spring
deflection characteristic curve of the tamping plungers 30 to a
sufficiently precise degree when the tamping plungers 30 are
inserted into the bores 22. This path characteristic curve
consequently corresponds to the characteristic curve of the
pressure values P(actual). With the third exemplary embodiment,
both breakage of the springs 19 and incorrect meterings can be
detected.
[0025] It should also be mentioned that the wiring example shown in
FIG. 2 can be modified in numerous ways in order to permit,
depending on the particular application, a more sensitive
regulation of the set air pressure, for example, or a greater
adjustment range.
[0026] In a modification of the first two exemplary embodiments, it
is also conceivable to couple the tops of each of the tamping
plungers to a membrane disposed in the tamping plunger support 29.
On one side, this membrane is acted on by a particular air pressure
so that the tamping plungers 30 are damped by the membranes in
accordance with the air pressure.
[0027] The foregoing relates to preferred exemplary embodiments of
the invention, it being understood that other variants and
embodiments thereof are possible within the spirit and scope of the
invention, the latter being defined by the appended claims.
* * * * *