Note: Descriptions are shown in the official language in which they were submitted.
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
Dosing device and method for filling a cavity
Field of the invention
The present invention relates to a dosing device comprising a powder hopper
and a
plate with a surface, wherein said plate is provided with at least one cavity
adapted for
receiving a particulate material, and filling means being movable along said
surface for
moving particulate material into said at least one cavity. The present
invention also relates
to a method for filling a cavity provided in a plate of a dosing device with a
quantity of
particulate material.
Background of the invention
Today supply and distribution of medicament is accomplished in many different
ways.
Within health care more and more effort is focused on the possibility to dose
and distribute
medicaments in the form of powder directly to the lungs of a user by means of
a dispensing
is device, for example an inhalation device, to obtain an efficient and user
friendly
administration of the specific medicament. In most cases, some form of dosing
process is
used for preparing the dose to be inhaled. For instance, the doses of
medicament may be
provided in packs having several cavities for housing a dose of medicament.
The cavities
filled with a dose are subsequently sealed by a sealing sheet, for example a
foil of
aluminium. These packs are loaded into a dispensing device, in which the foil
above the
cavity is penetrated or and the dose of medicament is released for inhalation
by the user.
By this sealing, the medicament is well protected before inhalation.
There are also other cases where it is suitable to provide doses of medicament
in packs
having cavities for housing a dose of medicament, which cavities are sealed by
a foil. The
packs containing the doses of medicament can be in the form of blister packs
or injection
moulded discs provided with blisters and cavities, respectively, for housing
the powdered
medicament, the packs can have various shapes, and the cavities can be
distributed in
various patterns. The method for filling said cavities should provide an
accurate and
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
2
changeable dosing into the cavities, to provide packs containing accurate
doses of
medicament of different sizes.
It is often desired, in both of the above-mentioned situations, that the
cavities are not
completely filled with the medicament. Therefore, a dosing process may be used
in which
cavities of a dosing device are filled with desired dose of medicament, said
cavities of the
dosing device having a smaller volume than the cavities of the final packs,
and thereafter
the medicament is transferred to the final pack. By this it is possible to
distribute a
specified dose of powder having a smaller volume than the volume of the cavity
housing
the dose, with a satisfactory accuracy.
One method and device for filling cavities in a drug disc with a quantity of
particulate
material is disclosed in WO 06/118526. It discloses a filling element which is
provided
with a bottom surface comprising several chambers, the amount of which is the
same as the
amount of cavities in the drug disc. The filling element has scraper means in
the form of
four rotating scrapers for scrape filling the chambers. When using the filling
element,
is powdered medicament is dispensed on the surface of the filling element and
scraped into
the chambers by the scraper means. After the particulate material has been
filled in the
chambers of the filling element, the particulate material is transferred to
the drug disc.
However, the above-mentioned solution has the drawback that it is not suitable
for all
forms of particulate material. For example particulate material that has
limited free-flowing
characteristics may be adhered to lumps, which may cause uneven distribution
of the
material between different cavities, i.e. some of the cavities may not be
filled with the
desired amount of medicament.
An object of the present invention is therefore to provide a method and device
for
filling at least one cavity with a quantity of particulate material (such as
powder), which
thereafter can distribute an accurate dose of particulate material having a
smaller volume
than that of the cavity housing the dose, that can handle cohesive particulate
material, i.e.
particulate material that does not flow freely, and that gives an accurate
distribution of the
particulate material in each of the cavities.
Summary of the invention
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
3
The above-mentioned objects are achieved by a dosing device of the kind
defined in
claim 1. Said dosing device comprises a powder hopper and a plate with a
surface, wherein
said plate is provided with at least one cavity adapted for receiving a
particulate material,
and filling means being movable along said surface for moving particulate
material into
said at least one cavity, wherein said filling means is adapted to exert a
compressing force
on said particulate material in a direction towards said surface so that said
particulate
material is forced into said at least one cavity.
Particulate material that has limited free-flowing abilities has a tendency to
adhere
to each other, causing small lumps of the material. When shovelling material
into cavities,
as described above for the prior art device, such a lump may be shovelled into
a cavity and
block e.g. the entry opening of the cavity so that it does not become filled
with the desired
amount of particulate material. The dosing device according to the present
invention will
instead press the particulate material into the cavities of the dosing device.
This has the
advantage that e.g. small lumps formed in the particulate material will be
split up by the
is force exerted onto them. By this, the filling of the cavities will be more
reliable, thus
ensuring an accurate dose of medicaments in each cavity. However, the device
according
to the present invention is not only beneficial for packing particulate
material when small
lumps have been formed in the material. It also gives accurate packing of
material that has
limited free-flowing characteristics also when no lumps have been formed in
it.
Furthermore, the device according to the present invention is also suitable
for packing free-
flowing particulate material. Experiments have shown that doses of
approximately 5 mg of
particulate material can be packed with a device according to the present
invention with a
relative standard deviation of only 3 %.
The cavities in the dosing device according to the present invention can be
arranged
in any desirable shape, and, suitably, so that they correspond to the pattern
of a drug
dispenser.
Suitably, the cavities of the dosing device have a smaller volume than that of
the
cavity housing the dose in the final pack. Since the particulate material is
pressed down
into the cavity of the dosing device, a very accurate dosing is achieved.
Hence, when the
particulate material later is transferred to the cavity in the final pack, it
will provide a very
accurate dosing even if the cavity in the final housing has a larger volume.
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
4
Furthermore, the device provides an uncomplicated filling of particulate
material in
cavities at a low cost. Advantageously, the cavity of the dosing device is
exchangeable to
adapt to the size of the dose to be dosed in said cavity.
Materials that can be filled include powder of organic materials with particle
sizes
in the range of 0.5-1000 m. For example, powders of lactose monohydrate with
particle
sizes ranging from 1-50 m have been successfully filled with the method
according to the
invention. With particle size is here by meant the mass median diameter, MMD,
for
example measured by a laser diffraction method.
According to at least one example embodiment, the dosing device further
comprises scraper means, wherein said scraper means is movable along said
surface of the
plate.
When the filling means are moved along the surface of the plate in the dosing
device, and exerts a force on the particulate material in the direction
towards the plate,
some of the particulate material may be compressed on the plate surface
located between
is neighbouring cavities. It is therefore advantageous to have scraper means
that is movable
along the surface and that can loosen up the compressed material. Suitably,
the scraper
means has a geometry that is designed to efficiently turn up the particulate
material
retained on the surface of the plate. The loosened up particulate material may
thereafter be
moved and pressed into a cavity by the filling means, or be transferred and
reused in
another dosing device. Alternatively, the loosened up particulate material may
be removed
and later reused in the same dosing device. The scraper means may also loosen
up material
that is compressed over the cavities, i.e. on top of the material that has
been pressed into
the cavities. However, by providing the scraper means movable along the
surface, the
scraper means is prevented from loosen up or removing material that has been
pressed into
a cavity. Hence, the scraper means does not negatively affect the accuracy of
the dosing.
It is advantageous if said filling means may also move in a direction that is
perpendicular to the surface of the plate. The reason for this is that the
filling means may
then be moved a short distance away from the surface when they come into
contact with
more compressed particulate material, e.g. small lumps, and thereafter be
moved towards
the surface, and hence, exert a force on the particulate material in that
direction. By that, it
acts to split up the lump and compress the particulate material into a cavity.
According to at least one example embodiment, said filling means is biased
towards said surface. In order for the filling means to exert a force on the
particulate
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
material in the direction towards the plate, it is preferred that said filling
means is biased
towards the plate. This may e.g. be achieved by the filling means being spring-
loaded
towards the plate. By this arrangement, the filling means may be movable a
short distance
away from the surface, in order to "climb" over e.g. lumps as described above,
but at the
5 same time strive to return in a direction towards the plate and compress the
particulate
material.
Suitably, said scraper means is biased towards said surface. The purpose of
the
scraper means is that it is movable along the surface and that it can loosen
up the
compressed material. It is therefore advantageous if it is biased towards said
surface so that
it during movement along the surface remains in close relationship with the
surface.
Suitably, said filling means is biased towards said surface with a lower force
than
the force biasing said scraper means towards said surface. This is
advantageous since the
scraper means should follow in close relationship with the surface and the
filling means
should be able to move a short distance away from said surface, in a direction
substantially
is perpendicular to said surface. However, when moved away from the surface,
the filling
means should strive to move back into close relationship with the surface.
According to at least one example embodiment, said surface has a circular
shape
and is provided with several cavities, said cavities being arranged in a
circular pattern
around said surface. Suitably, said filling means and said scraper means are
provided at a
common boss. Suitably, said common boss is arranged in the centre of said
circular pattern
of cavities.
A circular plate being provided with several cavities and having a centrally
arranged boss, on which said filling means and scraper means are arranged has
proven to
be a beneficial design for a dosing device. The circular boss, and hence the
filling and
scraper means, may be arranged for rotation both clockwise and counter-
clockwise. Even
though the filling means compresses the particulate material towards the
surface, and the
scraper means loosens up the particulate material, they also move the
particulate material
along the surface. By providing a circulate plate, the particulate material
may be
transferred around the surface of the plate without ending up at an end
thereof.
Furthermore, it is also possible to alternatingly rotate the boss clockwise
and counter
clockwise in order to transfer the particulate material along the surface in
both directions.
By this, it is possible to provide and maintain an even distribution of the
particulate
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
6
material on the surface. This is beneficial in terms of obtaining an even
distribution of the
particulate material in each cavity.
Other alternative designs, such as a rectangular plate, are however also
conceivable.
According to at least one example embodiment, said filling means is
constituted of
at least one wheel, said wheel being able to rotate on said surface. By that,
an efficient
manner in compressing the particulate material into the cavities is achieved.
The wheel
may be adapted to rotate on said surface of the plate and compress the
particulate material
into the cavities. With this design the wheel does not have to enter the
cavity in order to
compress the material and hence, the portion of the wheel compressing
particulate material
into a specific cavity may have larger dimensions than the cavity. This is
advantageous in
terms of production tolerances since no exact match of the filling means and
the cavity is
necessary. Furthermore, a wheel of one size may be used for filling cavities
of different
sizes.
According to at least one example embodiment, the dosing device comprises a
is filling arrangement comprising two wheels and two scrapers being arranged
at a common
boss. The wheels and scrapers are alternatingly arranged around the common
boss so after
each wheel a scraper is provided. This is advantageous since if a first wheel
compresses the
particulate material, a scraper will loosen it up before the second wheel
reaches that
portion of the particulate material.
Furthermore, in accordance with the invention it is presented a method for
filling a
cavity provided in a plate of a dosing device with a quantity of particulate
material,
comprising the steps of providing particulate material to a powder hopper,
moving filling
means along a surface of said plate so that said filling means, at the same
time as it is being
moved along said surface, exerts a compressive force on said particulate
material in the
direction towards said plate.
As stated above, particulate material that has limited free-flowing abilities
has a
tendency to adhere to each other, causing lumps in the powdered medicament.
With the
method described above the particulate material will be pressed into the
cavities of the
dosing device. This has the advantage that e.g. lumps formed in the
particulate material
will be split up by a force exerted onto them. By this, the filling of the
cavities will be
more reliable, thus ensuring an accurate dose of medicaments in each cavity.
However, the
method according to the present invention is not only beneficial for packing
particulate
material when small lumps have been formed in the material. It also gives
accurate packing
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
7
of material that has limited free-flowing characteristics also when no lumps
have been
formed in it. Furthermore, the method according to the present invention is
also suitable for
packing free-flowing particulate material.
Suitably, the cavities of the dosing device have a smaller volume than that of
the
cavity housing the dose in the final pack. Since the particulate material is
pressed down
into the cavity of the dosing device, a very accurate dosing is achieved.
Hence, when the
particulate material later is transferred to the cavity in the final pack, it
still has a very
accurate dosing even if the cavity in the final housing has a larger volume.
Experiments
have shown that doses of approximately 5 mg of particulate material can be
packed with a
method according to the present invention with a relative standard deviation
of only 3 %.
Furthermore, the method provides an uncomplicated filling of particulate
material in
cavities at a low cost. Advantageously, the cavity of the dosing device is
exchangeable to
adapt to the size of the dose to be dosed in said cavity. The particulate
material handled by
the method according to the invention may, for instance, be a powdered
medicament in
is pure form or admixed with a suitable excipient in powder form.
For example, mixtures of micronised medicaments used for asthma treatment,
e.g.
budesonide and beclomethasone dipropionate (BDP) and lactose monohydrate
excipient
have been successfully filled with the method according to the invention.
According to at least one example embodiment, the method further comprises the
step of loosen up compressed particulate material on said surface by means of
scraper
means.
According to at least one example embodiment, said particulate material
comprises
pharmaceutical powder for use in dry powder inhalers.
It should be understood that the above described inventive method encompasses
and may be implemented with any embodiments or any features described in
connection
with the previously discussed inventive dosing device, as long as those
embodiments or
features are compatible with the method.
Brief description of the drawings
The present invention will now be described, for exemplary purposes, in more
detail
by way of embodiments and with reference to the enclosed drawings, in which:
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
8
Fig 1 is a schematic perspective view of an embodiment of a dosing device, and
an
embodiment of the filling and scraper means according to the present
invention,
Fig 2 is a schematic cross sectional view of an embodiment of the dosing
device,
and an embodiment of the filling and scraper means according to the present
invention,
Figs 3a - 3c are partial schematic cross sectional side views disclosing a
hole
structure illustrating the main steps of a dosing and pouring method,
Fig 4 is a schematic perspective view of an alternative cavity structure.
Detailed description of the drawings
Figs 1 and 2 show a dosing device 1 provided with a powder hopper 2 for
housing
particulate material, such as powdered medicament (not shown). The powder
hopper has a
is funnel shaped interior and the sloping surfaces 12 thereof are intended to
guide the
powdered medicament (not shown) towards a plate 11 having a surface 3, which
can be
seen as forming the bottom of the powder hopper 2. The surface 3 is formed as
a hole
structure 4 with cavities 5 extending into the plate 11. In this embodiment,
the cavities are
distributed in a circular pattern around the plate 11. In the middle of the
circular pattern of
cavities 5 a filling arrangement 13 is rotatably arranged.
The filling arrangement 13 comprises two filling means, which in this
exemplifying
embodiment are two wheels 6, and two scrapers 14. The wheels 6 and scrapers 14
are
provided at a common boss 15. A driving axis 16 is connected to the boss 15 so
that the
boss 15, and hence the wheels 6 and scrapers 14, can be rotated. As can be
seen in e.g. fig
1, the wheels 6 and scrapers 14 are evenly distributed, i.e. at approximately
90 intervals,
around the boss, with each wheel 6 being followed by a scraper 14. The
geometry of the
scrapers 14 is designed to turn up compressed particulate material on the
surface 3. For
instance, regarded in the travelling direction of the scrapers 14, the
forwardly facing or
leading surface of the scrapers may have its most forwardly located portion
substantially in
contact with the plate surface 3. Herein, the scrapers 14 are illustrated as
having inclined
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
9
surfaces and having e.g. a triangular cross section. This enables turn up of
compressed
particulate material for both clockwise and counter clockwise travel.
The boss 15 is axially spring loaded towards the plate 11 and the scrapers 14,
being
fixedly arranged to the boss 15, are hence also spring loaded towards the
plate 11. In the
illustrated embodiment, a spring 9 is provided in relation to the driving axis
16 and may be
connected to an outer casing (not shown) in order to bias the boss towards the
surface 3.
The spring load decides the force between the two scrapers 14 and the surface
3 of the
plate 11. It is beneficial that the scrapers 14 are arranged in close
proximity to the surface
3, the reason for this is described in more detail below.
Each wheel 6 is independently moveable in an axial relation, i.e. towards and
away
from the surface 3 of the plate 11, in relation to the boss 15. Each wheel is
also
independently spring-loaded towards the surface 3, but with a spring load that
is lower than
the spring load on the boss 15 towards the surface 3. The reason for this is
that the wheels
6 shall be able to move a short distance away from the surface 3 when they
encounter e.g. a
is portion of adhered and/or compressed particulate material, such as a small
lump. The
wheels 6 may then climb on the lump of compressed material and, due to the
spring
loading, exert a force on the lump in the direction towards the plate 11 and
thus break up
the lump. The spring or other means biasing each of the wheels towards the
surface may
e.g. be provided in the connection between the boss 15 and each of the wheels
6. In fig 3a
there is shown a shaft 10, which the wheels 6 is rotatable around. The shaft
10 is arranged
to bias the wheels 6 towards the surface 3, at the same time as it allows a
certain movement
of the wheels 6 in a direction that is substantially perpendicular in relation
to the surface 3,
as is illustrated by the arrow D in fig 3a.
The spring load on the boss 15 and the wheels 6 can be adjusted so that an
accurate
dosing of the particulate material in each cavity is achieved.
The wheels 6 are for example made of, or have a surface of, silicone. The
reason for
this is to avoid that the particulate material adheres to the wheels. However,
other materials
than silicone may also be used as long as the particulate material does not
adhere to it.
The dosing device will now be explained in use. First, particulate material is
provided to
the hopper 2. Suitably, the particulate material is provided in such an amount
that it
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
extends from the surface 3 to approximately the centre of the wheels 6,
thereby covering
the scrapers 14. The filling arrangement 13, i.e. the boss 15, the wheels 6
and the scrapers
14, are thereafter rotated by the driving axis 16, bringing the wheels 6 to
rotate on the
surface 3. Due to the spring-load biasing the boss 15 towards the surface 3,
the scrapers 14
5 follow in close relation with the surface 3. The wheels 6 and scrapers 14
each pass the
cavities 5 one by one during rotation of the filling arrangement 13. When the
wheels 6
rotate, they exert a compressing force on the particulate material and when
they pass a
cavity 5 they press the particulate material into the cavity. This is
illustrated in fig 3a in
which the arrow A indicates the movement of the wheel 6 in relation to the
surface 3, the
10 arrow B indicates the rotational direction of the wheel 6 and the arrow C
illustrates how
particulate material 21 is being introduced into a cavity 5 of a hole
structure 4. Due to the
rotation of the wheel 6 different portions of the wheel will press the
particulate material
into the cavity 5.
A layer of compressed particulate material retains on the surface 3 between
each
is cavity 5 after the wheel has passed. When the scrapers 14 passes the
compressed retained
particulate material it turns it up so that the lifted particulate material
can be reused.
In order for the cavities 5 to be filled with the desired amount of
particulate material,
the filling arrangement 13 is rotated one or several turns. The driving axis
16 may also be
so arranged that the filling arrangement 13 may rotate both clockwise and
counter-
clockwise. By this, the filling arrangement may be rotated alternatingly
between these two
directions in order to fill the cavities with an even amount of particulate
material. When all
cavities 5 are filled with the desired quantity, the excessive particulate
material can be
moved to another dosing device for use in that system or be returned to a
storage system.
When the cavities of the dosing device 1 has been filled with the desired
quantity of
particulate material, the particulate material is transferred to a drug disc
to be used in a
dispensing device such as an inhalation device. Several different methods and
devices may
be used for transferring the particulate material from the dosing device 1 to
the drug disc.
One such method and device that may be used in conjunction with the present
invention are ejector means. The cavities 5 may then be formed with a
retractable bottom.
When the cavities are filled with the desired amount of particulate material,
the bottom of
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
11
each of the cavities is removed and the ejector means may be inserted into the
cavity and
push the material out of the cavity and into a final pack of a drug dispenser.
Another such method and device that may be used in conjunction with the
present
invention is disclosed in the pending patent application WO 2006/118526 in the
name of
s ASTRA ZENECA AB. In this method the plate 11 of the dosing device 1 is
positioned on
top of the drug disc, with the cavities 5 positioned opposite corresponding
cavities in the
drug disc so that the particulate material can be transferred from the
cavities 5 of the plate
11 to the cavities of the drug disc. The dosing device may be provided with
vibrating
means or ultrasonic elements for enabling controlled emptying of the cavities
into a
corresponding cavity of a drug disc.
Yet another method and device for transferring the quantity of particulate
material
from the dosing device 1 to a drug disc is disclosed in the pending U.S.
Provisional Patent
Application No. 60/957822 in the name of ASTRA ZENECA AB. In this application,
a
plate having holes with moveable wall portions is disclosed. This method and
device may
is suitable be used in combination with the present invention and will be
further described
with reference to figs. 3a - 3c. In fig. 3a a section of one cavity 5, of a
hole structure 4, is
outlined schematically. The wall structure of said cavities 5 comprises a
plurality of
movable wall portions 22, which may be moved in relation to one another. The
cavities 5
of the dosing device 1 are in this embodiment formed of holes, which may be
closed by a
closing arrangement 8. The closing arrangement 8 is conveniently formed as a
plate which,
in a first position, is positionable so that it will block the holes 5 entry
into or out from the
hole from that side. The closing arrangement 8 is thus adapted to form a
bottom of the
holes 5 when in the first position.
The blocking of a hole 5 is in effect during filling of the hole 5 as
disclosed in fig. 3a.
When a sufficient amount of powder 21 has been introduced into the hole 5 it
may be
closed. For this purpose the dosing system 3 comprises a lid arrangement 7.
The lid
arrangement 7 has openings, which, in a first position, is positionable in
register with the
holes 5 of the hole structure 4. The first position of the lid arrangement
openings is
disclosed in fig. 3a illustrating an initial step in the powder providing
sequence. During this
step the powder is introducible into the hole 5, in the manner described
above.
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
12
Now, continuing to fig. 3b an intermediate condition of the dosing operation
is
disclosed. In said intermediate condition the lid arrangement 7 is provided in
a closing
state and the closing arrangement 8 as well. The movable wall portions of
plates piled upon
each other define a closed volume together with the lid and closing
arrangement 7, 8. As
will be readily appreciated from the cross section of fig. 3b the hole 5 will
be completely
filled with particulate material 21 in this intermediate operation condition.
Referring further to fig. 3c, in which the emptying operation of the hole 5 is
illustrated.
Sideways of the hole closing arrangement part, which is adapted to form the
bottom of
anyone of said holes 5, there exist openings with generally the same
dimensions as the
hole 5 openings. In a second position the openings of the hole closing
arrangement 8 are
positioned in register with the holes 5 as seen from the side. When an opening
of the hole
closing arrangement 8 is in a corresponding position to that of a hole 5 the
powder may be
discharged from said hole 5. Suitably the lid arrangement 7, when emptying of
the powder
from any one of the holes 5 is due, is positionable in an offset position so
as to block the
is opening of the holes 5. This is performed in order to prevent additional
powder from
entering the hole 5 once a metered dose has been accomplished and thus it is
assured that a
correct dose of powder is delivered further to the system. In order to further
improve
correct delivery of powder quantity the wall portions 22 of the hole/holes in
questions are
moved in relation to one another. The relative movement of the wall portions
22 has
proven to enable a reliable emptying effect and an accurate further dosing of
powder with
low retention of powder.
Suitably, the relative movement of wall portions in the exemplified embodiment
is
accomplished by movement of the plates constituting the hole structure 4. The
structure
surrounding the hole 5 walls 22 consequently constituting the wall structure
for the holes 5.
The plates forming said hole structure may be slidable back and forth in a
direction
substantially perpendicular relative to the main propagation direction of the
hole in
question, which main propagation direction substantially coincides with
intended path for
the powder. The movement of each plate 22 is conveniently, but not
exclusively, in the
range between 2 % to 50 % of the diameter of the hole 5 with reference from
the
aligned start and stop position. Suitably, the plate movement is between 5 %
to 25 % of
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
13
the diameter of the hole, for instance, between 7 % to 15 % of the diameter
of the hole 5.
When referring to the diameter of the hole 5 it is submitted that a hole 5 may
be formed
differently. Hence, the diameter in accordance with the present application
should be
interpreted in a broad meaning as representing the longest distance across the
hole in
question, whether it is squared or has another shape that may have different
distances
between sides thereof.
The dosing device 1 has been described in relation to an exemplified
embodiment.
However, several modifications and adaptations are possible within the scope
of the
present invention as defined in the appended claims.
For example, the plate 11 does not need to be circular. Fig 4 shows an
embodiment
with a rectangular plate 11' having the cavities 5 arranged along a straight
line of the
plate 11'. In this embodiment, the wheels 6 and scrapers 14 may be provided at
a linearly
moving means instead of a rotating boss. The wheels and scrapers may
thereafter be
moved back and forth over the surface 3' in order to fill the cavities 5 with
particulate
is material in the same manner as described above for the circular plate. In
this rectangular
embodiment it may be suitable that the scraper means 14 may be moved away a
short
distance from the surface 3' of the plate 11'. The reason for this is that the
filling means
and the scrapers during use may move the particulate material along the
surface of the
plate. Some of the material will therefore during the filling process become
positioned at
the end of the plate. It is therefore beneficial to be able to lift the
scraper means from the
plate, over the particulate material provided thereon, and position the
scraper means at the
outer end of the plate. The particulate material that has been positioned at
an outer end of
the plate may thereafter be moved towards the other end of the plate, and be
filled in
cavities.
Another possible modification is that the wheels and scrapers do not need to
be
provided at a common boss or hub. Instead, the movement of the scrapers and
wheels may
be provided by different means, which are controlled to move the wheels and
scrapers in a
desired mutual relationship.
Furthermore, the filling means has in the exemplified embodiment been
described as
wheels rotating on the surface 3, which compresses the particulate material
into the cavities
CA 02732166 2011-01-26
WO 2010/019102 PCT/SE2009/050933
14
by this rotating movement. However, it is for example also possible to provide
the filling
means as a substantially planar surface, such as a mat or similar non-rotating
means. This
non-rotating means may be spring-loaded towards the surface 3 of the plate 11
in order to
exert a compressive force on the particulate material when the non-rotating
means are
5 moved along the surface 3. As for the wheels, the means with a planar
surface may be
made of, or have a surface of, silicone in order to prevent particulate
material from
adhering to it. Filling means having a substantially planar surface may be
used both for a
circular plate 11 or a plate of any other shape, such as the rectangular plate
11'.
Furthermore, the filling arrangement 13 has in the exemplified embodiment been
described
as comprising two filling means, in the described embodiment wheels 6, and two
scrapers
14. However, other numbers of filling means and scrapers, e.g. one filling
means and one
scraper, is also conceivable.
