FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
Capsule filling machine for dosing capsules with dry powder
APPLICANTS
Sci-tech Centre, 7 Prabhat Nagar, Jogeshwari West, Mumbai 400 102, Maharashtra, India, an Indian company
INVENTORS
Singh Jasjit, a British subject and Deshmukh Prakash and D'Silva James, both Indian nationals and all of Sci-tech Centre, 7 Prabhat Nagar, Jogeshwari West, Mumbai 400 102, Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed :

FIELD OF THE INVENTION
This invention relates to a capsule filling machine for dosing capsules with dry
powder.
BACKGROUND OF THE INVENTION
There are capsule filling machines of various designs and configurations for volumetric filling or dosing of dry particulate material in hard capsules, especially pharmaceutical or neutraceutical products such as powders, pellets or microtablets and for making dosages thereof. Dosages of such pharmaceutical or neutraceutical products encapsulated in capsules are easy and convenient to handle and to take orally. Microdoses of dry medicinal powders which are highly active and very expensive such as those for inhalation in the treatment of asthma and other respiratory diseases consist of small quantities of the drug in the order of 2 - 30 milligrams. Capsule filling machine used for volumetric filling of capsules with very small quantities of the drug are to be very precise and accurate in the filling of the capsules with the drug. Consequences of weight variations in the case of dosages of pharmaceutical or medicinal powders, especially microdosages is very serious. Furthermore, in the case of microdoses of drugs for inhalation, the

powder should be well dispersed and loosely distributed in order to ensure that the entire dosage is available to the user effectively and easily.
Amongst the various designs of capsule filling machines that are known or reported, one typical capsule filling machine for filling capsules with dry powder, comprises a dosing chamber disposed for intermittent rotation about a vertical axis and around a filling cum tamping station, a plurality of tamping stations and an ejection station. The dosing chamber consists of a circular dosing disc at the bottom thereof and a circular sidewall projecting upwardly from the periphery of the dosing disc defining a space within the sidewall for containing the powder. The dosing chamber also consists of a cover plate at the top thereof. The dosing disc consists of groups of metering chambers extending transversely through the periphery thereof in a radially and equidistantly distributed manner corresponding to the stations.
A plurality of bottom plates corresponding to the number of groups of metering chambers in the dosing disc are disposed underneath the dosing disc concentric with the dosing disc and slidably engaged to the dosing disc. Each of the bottom plates consists of a group of discharge openings extending transversely

therethrough matching with a group of metering chambers. Each of the stations consists of a group of pistons disposed for guided up and down movement in the dosing chamber aligned with the groups of metering chambers in the dosing disc. The machine operates in a cyclic manner and its cyclic operation is controlled by a PLC (Programmable Logic Circuit). Normally the discharge openings in the bottom plates underneath the dosing disc remain misaligned with the metering chambers in the dosing disc so that the powder in the metering chambers is retained in the metering chambers against the bottom plates without allowing the powder to fall down from the metering chambers.
In each cycle of operation of the machine, the dosing chamber indexes or rotates around the various stations and dwells or stops at the stations for predetermined intervals of time. During the dwelling interval, the metering chambers in the dosing disc at the filling cum tamping station get filled with the powder and the powder is compacted by the respective group of pistons at the filling cum tamping station while describing the downward stroke. Powder in the metering chambers in the dosing disc at the tamping stations is also successively compacted into slugs of dosages by the respective groups of pistons at the tamping stations while describing the downward stroke. Powder in the metering chambers at the filling

cum tamping station and tamping stations is retained in the metering chambers by the bottom plates underneath the dosing disc.
In order to eject the slugs in the metering chambers at the ejection station, the bottom plate underneath the dosing disc at the ejection station is slid in to align the discharge openings in the bottom plate with the metering chambers in the dosing disc at the ejection station. While the pistons at the ejection station describe the downward stroke, dosages of slugs in the metering chambers in the dosing disc at the ejection station are pushed out from the metering chambers by the respective group of pistons at the ejection station into capsule bottoms with their open ends facing upwards positioned at the ejection station via the discharge openings in the bottom plate.
In the above capsule filling machine, the pistons at the various stations move up and down almost or near steadily. Due to the piston movements being almost steady and the compaction force exerted by the pistons being mild, there are chances for voids or air pockets in the slugs to remain in the slugs. Because of the voids or air pockets, weight variations of the dosages may occur. Excessive compaction force on the pistons to minimize or eliminate voids or air pockets in

the slugs will increase power consumption of the machine and will also develop excessive stresses and strains on the machine. Dosages of slugs may also get compressed excessively thereby hardening the slugs.
Excessive compression of the dosages may not be desirable and acceptable, especially in the case of microdosages for inhalation by asthma patients or patients suffering from other respiratory diseases. In the case of microdosages, especially those meant for inhalation, the powder is required to be well dispersed and distributed to facilitate easy and effortless inhalation. Excessive compaction and hardening of the dosages will make inhalation difficult. Because of the almost steady movement of the pistons there is also possibility that the powder may stick to the pistons, especially in the case of amorphous powder thereby further causing weight and dosage variations.
There is thus need for capsule filling machines for dosing or microdosing capsules with dry powder, especially pharmaceutical or neutraceutical powder which obviates the above problems or disadvantages.

DESCRIPTION OF INVENTION
According to the invention there is provided a capsule filling machine for dosing capsules with dry powder, comprising a dosing chamber disposed for intermittent rotation about a vertical axis and around a filling cum tamping station, a plurality of tamping stations and an ejection station and having a circular dosing disc at the bottom thereof and a circular sidewall projecting upwardly from the periphery of the dosing disc defining a space within the sidewall for containing the powder, and a cover plate at the top thereof, the dosing disc having groups of metering chambers extending transversely through the periphery thereof in a radially and equidistantly distributed manner corresponding to the stations and a plurality of bottom plates corresponding to the number of groups of metering chambers disposed underneath the dosing disc concentric with and radially slidably engaged to the dosing disc, each of the bottom plates having a group of discharge openings extending transversely therethrough matching with a group of metering chambers, each of the stations having a group of height adjustable pistons disposed for guided up and down movement in the dosing chamber aligned with the groups of metering chambers in the dosing disc, wherein the machine further comprises an ultrasonic vibrator consisting of a high frequency, low amplitude ultrasonic generator powered by an AC supply and

connected to the group of pistons at the ejection station and the group of pistons at atleast one tamping station immediately preceding the ejection station through corresponding number of groups of transducers.
According to an embodiment of the invention, the high frequency, low amplitude ultrasonic generator is capable of generating ultrasonic waves in the frequency range of 20 to 50 kHz and in the amplitude range of 20 to 60 μ and is powered by AC supply of 50 or 60 Hz frequency.
According to an embodiment of the invention, each group of height adjustable pistons is mounted to a mounting block and is guided in a common guide plate which is disposed below the mounting blocks and mounted on upright guide rods, each mounting block is height adjustably mounted on the common guide plate and guided on guide pins which are supported on the common guide plate and the groups of transducers are mounted on the respective mounting blocks.

DESCRIPTION OF ACCOMPANYING SCHEMATIC DRAWINGS Fig 1 of the accompanying drawings is a plan view of a dosing chamber of a caspule filling machine for dosing or filling capsules with dry powder according to an embodiment of the invention;
Fig 2 is a sectional view at A-A in Fig 1 without the ultrasonic vibrator;
Fig 3 is a sectional view at B-B in Fig 1 including the ultrasonic vibrator;
Fig 4 is an enlarged partial sectional view at B-B in Fig 1 without the ultrasonic vibrator;
Fig 5 is a sectional view at C-C in Fig 1;
Fig 6 is a sectional view at D-D in Fig 1 without the ultrasonic vibrator;
Fig 7 is a sectional view at E-E in Fig 1 including the ultrasonic vibrator; and

Fig 8 is a partial enlarged sectional view at E-E in Fig 1 without the ultrasonic vibrator.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION As illustrated in Figs 1 to 8 of the accompanying drawings, the dosing chamber 1 of a capsule filling machine (not shown) for dosing capsules (not shown) with dry powder 2 is disposed for intermittent rotation about a vertical axis 3 and around a filling cum tamping station A, a plurality of tamping stations B, C, D and E and an ejection station F. The dosing chamber consists of a circular dosing disc 4 at the bottom thereof and a circular sidewall 5 projecting upwardly from the periphery of the dosing disc defining a space 6 within the sidewall for containing the powder. 7 is a cover plate at the top of the dosing chamber. The dosing disc consists of groups of metering chambers 8 extending transversely through the periphery thereof in a radially and equidistantly distributed manner corresponding to the stations. A plurality of bottom plates 9 corresponding to the number of groups of metering chambers are disposed underneath the dosing disc concentric with and radially slidably engaged to the dosing disc. Each of the bottom plates consists of a group of discharge openings 10 extending transversely therethrough matching with a group of metering chambers.

Each of the stations consists of a group of pistons 11 mounted to a mounting block 12 and up and down movably disposed in the dosing chamber aligned with the groups of metering chambers in the dosing disc. The up and down movements of the pistons are guided in guide grooves 13 in a common guiding plate 14 which is disposed below the mounting blocks and mounted on upright guide rods 15. Each mounting block is height adjustably mounted on the common guide plate with a screw 16 (screw head marked 17) which is in thread engagement with the mounting block and the common guide plate. By turning the screw in opposite directions, the mounting block can be moved up and moved down with respect to the common guide plate to adjust the height of the mounting block and the respective group of pistons. During the up and down movement of the guide block, the guide block is guided on guide pins 18 which are supported on the common guide plate.
19 is an ultrasonic vibrator consisting of a high frequency, low amplitude ultrasonic generator 20 capable of generating ultrasonic waves, preferably, in the frequency range of 20 to 50 kHz and amplitude range of 20 to 60 μ and powered by a AC supply 21 (50 or 60 Hz frequency). The ultrasonic generator is

connected to the group of pistons at the ejection station F and the groups of pistons at the tamping stations D and E immediately preceding the ejection station through groups of transducers 22. Each group of transducers is mounted on the mounting block of each of the stations D, E and F. The transducers are preferably piezoelectric transducers as they are cost effective and efficient. However, other transducers including piezomagnetic transducers also can be used according to the invention.
During the up and down movements of the pistons at the tamping stations D and E and at the ejection station F to perform the respective tamping and ejection operations of the slugs 23 of dosages in the respective metering chambers in the dosing disc in the usual manner, the ultrasonic generator operates and transmits ultrasonic waves at very high frequency and at very low amplitude, preferably in the frequency range of 20 kHz to 50 kHz and in the amplitude range of 20 to 60 μ. As a result, the transducers expand and contract alternatively at the very high frequency of the order of 20 kHz to 50 kHz and at the very low amplitudes of the order of 20 micron to 60 micron. This causes the mounting blocks and the pistons at the tamping stations D and E and ejection station F to vibrate at the very

high frequency of the order of 20 kHz to 50 kHz and at the very low amplitudes of the order of 20 micron to 60 micron.
The very high frequency and very low amplitude vibrations of the pistons at the tamping stations D and E and ejection station F are very mild. Due to the very mild vibrations of the pistons performing the tamping at the tamping stations D and E, and ejection at the ejection station F, the slugs are also very mildly vibrated and shaken besides being compacted at the tamping stations D and E and while being pushed out from the metering chambers at the ejection station F. As a result, chances for formation of voids and air gaps in the slugs at the tamping stations D and E and ejection station F is practically eliminated or minimized. Because of the vibration of the pistons at the tamping stations D and E and at the ejection station F, chances for the powder, even for amorphous powder to stick to the pistons are also practically eliminated or minimized. As a result of all this, weight variations of the dosages are practically eliminated or minimized. Due to vibration of the pistons, the powder also remains well dispersed and distributed in the slugs. This is particularly advantages in the case of microdosages of drugs, especially for treatment of asthma and respiratory disorders.

In Fig 6, 24 is machine frame. 25 is a powder leveler at the ejection station (Figs 6 and 7). Slugs of dosages being ejected at the ejection station fall down into capsule bodies 26 positioned below the ejection station with their open ends facing upwards. Capsule handling unit of the machine holding the capsule bodies has not been illustrated in the accompanying drawings as such is not necessary for understanding the invention.
The above embodiment of the invention is only illustrative of the invention and not limitative of the scope thereof. There can be more number of filling cum tamping stations and more or less number of tamping stations. The number of groups of metering chambers and the number of bottom plates will very accordingly. The number of pistons in a group of pistons can vary and the number of metering chambers in the dosing disc and the number of discharge openings in the bottom plates will vary accordingly. The tamping station(s) immediately preceding the ejection station that can be provided with the transducers may vary and can be one or more than two. The number of transducers in respect of a group of pistons can vary. Such variations of the invention are obvious to a person skilled in the art and are to be construed and

understood to be within the scope of the invention which is defined by the accompanying claims.

We claim:
1. A capsule filling machine for dosing capsules with dry powder, comprising a dosing chamber disposed for intermittent rotation about a vertical axis and around a filling cum tamping station, a plurality of tamping stations and an ejection station and having a circular dosing disc at the bottom thereof and a circular sidewall projecting upwardly from the periphery of the dosing disc defining a space within the sidewall for containing the powder, and a cover plate at the top thereof, the dosing disc having groups of metering chambers extending transversely through the periphery thereof in a radially and equidistantly distributed manner corresponding to the stations and a plurality of bottom plates corresponding to the number of groups of metering chambers disposed underneath the dosing disc concentric with and radially slidably engaged to the dosing disc, each of the bottom plates having a group of discharge openings extending transversely therethrough matching with a group of metering chambers, each of the stations having a group of height adjustable pistons disposed for guided up and down movement in the dosing chamber aligned with the groups of metering chambers in the dosing disc, wherein the machine further comprises an ultrasonic vibrator

consisting of a high frequency, low amplitude ultrasonic generator powered by an AC supply and connected to the group of pistons at the ejection station and the group of pistons at atleast one tamping station immediately preceding the ejection station through corresponding number of groups of transducers.
2. The capsule filling machine as claimed in claim 1, wherein the high frequency, low amplitude ultrasonic generator is capable of generating ultrasonic waves in the frequency range of 20 to 50 kHz and in the amplitude range of 20 to 60 μ and is powered by AC supply of 50 or 60 Hz frequency.
3. The capsule filling machine as claimed in claim 1, wherein each group of height adjustable pistons is mounted to a mounting block and is guided in a common guide plate which is disposed below the mounting blocks and mounted on upright guide rods, each mounting block is height adjustably mounted on the common guide plate and guided on guide pins which are supported on the common guide plate and wherein the groups of transducers are mounted on the respective mounting blocks.

4. The capsule filling machine as claimed in claim 1 or 3, wherein the transducers are piezoelectric transducers.