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
A capsule filling machine
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.
BACKGROUND OF THE INVENTION
Dosage forms of pharmaceuticals like medicinal powders, pellets or microtablets are generally made by volumetric filling thereof in hard gelatin capsules. Various types of machines are used for volumetric filling of pharmaceuticals in hard gelatin capsules. British Patent 1089747 describes an apparatus and a method for metering and discharging measured quantity of dry particulate material. The apparatus comprises a metering device comprising an elongated metering member supported on a supporting member and provided with one or more generally cylindrical transversely extended metering chambers. The metering member is slidable on the supporting member. The metering chambers are movable to a filling position to receive the particulate material and to an ejection position to discharge the particulate material into hard gelatin capsules being formed. During the sliding movement of the metering member against the supporting member, the particulate material may get crushed and damaged between the metering member and supporting member. This may cause loss of the material and dust generation. This may also reduce dissolution properties of the coated pellets. Further it may cause weight variations in the capsules and reduce the reliability of the apparatus. The particulate material may also clog the clearance between the metering member and supporting member and obstruct the smooth sliding movement of the metering member.
US 6286567B1 relates to an apparatus for volumetric filling of a product such as medicinal powder or granules in hard gelatin capsules. The apparatus comprises a


metering disc that revolves around a vertical axis and has metering chambers embodied as through apertures provided in the metering disc in groups on a pitch circle. Curved pushers with apertures are coaxially secured to the underside of the metering disc between stop protrusions by bearing rings and are held spring tensioned. The pushers are displaced circumferentially of the metering disc on a circular arc to close the metering chambers in the filling position and to open the metering chambers in the evacuation position. As the pushers are secured to the metering disc, they are to be dismantled from the metering disc in order to clean or change the metering disc. This is cumbersome and inconvenient and labour oriented and time consuming.
WO 2007/012966 Al relates to a capsule filling machine for producing hard gelatin capsules containing pharmaceutical material particles, in particular microtablets. The machine comprises a rotary carousel having a plurality of slide units for holding and handling the capsules. The machine further comprises a series of hollow conduits uniformly distributed on a disc like element mounted on the carousel. The machine also comprises a hopper and a roller partly immersed in the pharmaceutical material mass contained in the hopper. The roller has a plurality of suction recesses for accommodating and retaining a predetermined number of the particles drawn from the hopper and then releasing the particles into the capsules via the hollow conduits mounted on the carousel. The pharmaceutical material gets transferred into the capsules through the hollow conduits and not directly from the suction recesses. As a result, there may be delay in the capsules getting filled with the pharmaceutical material and the productivity may reduce.


WO 2007/062980 Al relates to a device for filling hard gelatin capsules with pellets. The device comprises atleast one dosing chamber which receives the pellets and discharges the pellets into a hard gelatin capsule positioned below it. Means are provided to apply a mechanical force on the pellets and fill the dosing chamber with the pellets. A slide gate valve is provided to open the dosing chamber and discharge the pellets into the capsule and to close the dosing chamber. Closing and opening of the dosing chamber is carried out by dragging the gate valve horizontally. While being dragged, the pellets may get crushed and damaged between the dosing chamber and gate valve. This may not only result in material loss and dust generation but also may create weight variations in the capsules and reduce the reliability of the device. The pellets may also clog the clearance between the dosing chamber and gate valve and obstruct the smooth movement of the gate valve
US 2007/0144674 Al relates to a machine for metering microtablets into hard gelatin capsules and having a metering surface subjected to vibrations and to rotation about a vertical axis. The metering surface comprises a number of sloping surfaces along which the microtablets travel upwards and enter respective number of pockets provided for receiving the microtablets from the sloping surfaces. The machine also comprises an unloading device cooperating with the metering device and comprising a cam member. A supporting plate is located beneath the cam member to support the microtablets dropping out of the open pockets and guide the microtablets into capsule bodies. A catch bin is provided to collect microtablets sliding off the supporting plate and away from the capsules bodies. In this machine, there is a possibility of the microtablets missing the catch bin and causing material loss.


A known machine for filling hard gelatin capsules with pellets comprises a feeding chamber communicating with a hopper at the top thereof and provided with a feeding jaw mechanism at the bottom thereof. The jaw mechanism comprises a fixed jaw member and a pair of moving jaw members provided at opposite sides of the fixed jaw member. The moving jaw members are in mesh with the fixed jaw member in order to form open spaces or cavities between the teeth thereof. These open spaces or cavities form the metering chambers for the pellets. Capsule bodies are positioned below the metering chambers to receive the pellets. The metering chambers are opened and closed by closing and opening plates provided at the top and bottom of the fixed jaw member. The top and bottom plates are slid onto and away from the fixed jaw member to close and open the metering chambers. During sliding movement of the top and bottom plates, the pellets may get crushed and damaged between the fixed jaw member and top and bottom plates. This may cause material loss, dust formation and weight variations in the capsules and may also reduce the reliability of the machine. Besides, the pellets may clog the clearance between the fixed jaw member and the top and bottom plates and obstruct the smooth sliding movement of the top and bottom plates against the fixed jaw member.
A known machine for filling hard gelatin capsules with medicinal power comprises a metering turret and a capsule turret disposed adjacent to each other and rotatable about their respective vertical axes intermittently in the same direction. The metering turret comprises a plurality of stations provided angularly equidistantly around the periphery of a dosing disc rotatably held on the respective vertical axis at the bottom of a dosing chamber. Each of the stations comprises a plurality of groups of through vertical passages provided in the periphery of the dosing disc on a pitch circle and


respective number of plungers or pistons disposed above the dosing disc in the same lay out as the groups of vertical passages. The vertical passages form the metering chambers for the medicinal powder and the pistons at the tamping stations are disposed for progressively increasing the strokes and compacting the powder in the vertical passages to the required dosages. The capsule turret comprises a plurality of capsule handling stations provided angularly equidistantly around the periphery of a capsule carrier disc rotatably held on the respective vertical axis. Each of the capsule handling stations comprises a plurality of groups of capsule holding through vertical apertures provided in the periphery of the capsule carrier disc on a pitch circle in the same layout as the groups of vertical passages in the dosing disc. During the cyclic operation of the machine, medicinal powder flowing into the vertical passages in the dosing disc are progressively compacted into the required dosages by the respective pistons moving down into the vertical passages. A back plate with an interrupted portion (part annulus) is provided below the dosing disc so as to close the vertical passages in the dosing disc at the bottom thereof except the vertical passages in the dosing disc corresponding to the interrupted portion of the back plate at the ejection station. The intermittent rotational movement of the dosing disc and capsule carrier disc is synchronised such that the compacted powder in the vertical passages in the dosing disc coinciding with the interrupted portion of the back plate at the ejection station is pushed out of the vertical passages by the respective plungers moving down into the vertical passages and the powder expelled from the vertical passages enter the capsule bodies held in the corresponding vertical apertures in the capsule carrier disc positioned below the respective vertical passages at the ejection station. In order to facilitate rotation of the dosing disc over the back plate a clearance is required to be provided between the dosing disc and the back plate. The powder


invariably leaks into the clearance between the dosing disc and back plate and gets crushed between the dosing disc and back plate. As a result there will be loss of valuable material, weight variations and dust generation. The leaked powder may also obstruct smooth rotation of the dosing disc over the back plate. Further the powder needs to be progressively compacted in order to prevent it from freely falling down through the interrupted portion of the back plate when the dosing disc is indexing to the ejection station for dispensation into the capsule bodies. Tamping of the powder may damage the powder and reduce the dissolution properties of coated powder. So is the case with the powder getting crushed.
OBJECTS OF THE INVENTION
An object of the invention is to provide a capsule filling machine which dispenses the product directly into the capsules to improve productivity.
Another object of the invention is to provide a capsule filling machine which prevents leakage and damage to the product, weight variations and dust generation.
Another object of the invention is to provide a capsule filling machine which eliminates the plungers or pistons and tamping and compaction of the product to prevent the product from falling freely as the dosing disc is indexing to the ejection station where dispensation of the product takes place.


Another object of the invention is to provide a capsule filling machine which comprises a dosing disc which is easy to clean and change and maintain.
Another object of the invention is to provide a capsule filling machine which is compact, simple in construction, cost effective and easy and convenient to operate.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention there is provided a capsule filling machine comprising a dosing chamber having a dosing disc rotatably held at the underside thereof, the dosing disc being mounted on a vertical shaft adapted to describe an intermittent rotary motion, a plurality of stations provided angularly equidistantly around the periphery of the dosing disc, each of the stations comprising a group of through vertical passages provided at the periphery of the dosing disc on a pitch circle to form metering chambers and a plurality of radial slide means each corresponding to each station and disposed underside the dosing disc in abutment therewith and supported on a support disc mounted on the said vertical shaft, the radial slide means being adapted to slide against the underside of the dosing disc and close and open the corresponding groups of metering chambers.
The following is a detailed description of the invention with reference to the accompanying drawings, in which :
Fig 1 is a crosssectional view in part of the metering turret of a capsule filling machine according to an embodiment of the invention with a radial slide member


having a group of vertical passages (metering chambers) positioned at the ejection station prior to ejection of the product;
Fig 2 is a cut section isometric view in part of the metering turret of Fig 1;
Fig 3 is a crosssectional view in part of the metering turret of Fig 1 with the radial slide member positioned at the ejection station at the time of ejection of the product;
Fig 4 is an exploded view of the metering turret of Fig 1; and
Figs 5 and 6 are top isometric view and bottom isometric view of a radial slide member of the metering turret of Fig 1.
The metering turret 1 as illustrated in Figs 1 to 6 of the accompanying drawings comprises a dosing chamber 2 having a dosing disc 3 rotatably held at the underside thereof. The dosing disc is mounted on a vertical shaft 4 which is rotatably held in the turret frame 5 using bearings 6 and 7 and adapted to describe an intermittent rotary motion. The dosing disc is provided with groups of through vertical passages at the periphery thereof on a pitch circle to form metering chambers 8. The groups of metering chambers are distributed angularly equidistantly around the periphery of the dosing disc and constitute stations of the dosing disc. Each of the groups of metering chambers is associated with a T-shaped radial slide member 9 disposed underside the dosing disc in abutment therewith and supported on a support disc 10 mounted on the vertical shaft. The support disc is formed with seats 11 for the slide members. The radial slide members are formed with cross channels 12 underneath
9

the slide members across the perpendicular flanges thereof and the cross channels protrude down through slots 11a provided in the seats in the support disc. The slide members are also formed with vertical grooves 13 in the cross flanges thereof in the same layout and pattern as the groups of vertical passages or metering chambers in the dosing disc. The slide members each is held biased radially outwardly by compression spring 14 one end of which is located in a notch 15 formed in each of the slide members and the other end of which is located in a corresponding recess 16 formed in the support disc. The slide members are spring biased radially outwardly such that the vertical grooves therein are normally offset with the vertical passages or metering chambers at the periphery of the dosing disc. 17 is a vertically disposed swivel rod rotatably held in bearings 18 and 19. The swivel rod extends through passages 20 and 21 provided in the turret frame 5 and top plate 22 of the metering turret, respectively. The upper end of the swivel rod is located in the crosschannel formed underneath the slide member and is formed with a lateral extension 23 corresponding to the inward radial displacement of the slide member. 24 is pneumatic cylinder mounted to the top plate of the metering turret with bolt 24a. 25 is a U-shaped link fitted to the piston rod 26 of the pneumatic cylinder. 27 is a tapered link the narrow end of which is disposed in the U-shaped link and pivoted thereto by pivot pin 28. The lower end of the swivel rod is fitted to the wide end of the tapered link.
During operation of the capsule filling machine the product (not shown) to be metered to the required doses is fed into the dosing chamber and the product gets filled in the vertical passages or metering chambers 8 in the dosing disc during intermittent indexing or rotation of the dosing disc. The radial slide members


positioned and located below the metering chambers in the dosing disc are spring biased radially outwardly such that the vertical grooves in the radial slide members are normally offset with the metering chambers in the dosing disc. Therefore, during dosing and indexing of the dosing disc the metering chambers are fully closed at the bottom thereof by the radial slide members and no leakage of the product from the bottom of the metering chambers takes place. Also during indexing of the dosing disc the support disc alongwith the slide members rotate with the dosing disc as a single unit and there is no relative motion between the dosing disc and the slide members. As a result, tamping and compaction of the product to the required dosage to hold the product in the metering chambers during dosing and indexing are not required and the product in the metering chambers do not get crushed or damaged. During indexing of the dosing disc, the lateral extension at the upper end of the swivel rod is aligned with the crosschannels underneath the slide members. Therefore during rotation of the support disc along with the dosing disc, the sidewalls of the crosschannels underneath the slide members slide against the lateral extension at the upper end of the swivel rod and the lateral extension at the upper end of the swivel rod does not cause any obstruction to the rotational movement of the support disc along with the slide members. When the product in a group of metering chambers positioned at the ejection station (not shown) is to be expelled into the capsule bodies (not shown) held in a corresponding group of vertical apertures (not shown) in the capsule carrier disc (not shown) of the capsule handling turret (not shown) positioned below the above group of metering chambers, the pneumatic cylinder 24 is operated to allow the piston rod 26 to describe the forward stroke. As a result the tapered link 27 describes a rotary motion in the horizontal plane about the pivot pin 28 and the swivel rod 17 describes a corresponding rotary motion in the


vertical plane. Consequently the lateral extension 23 at the upper end of the swivel rod pushes the corresponding radial slide member inwardly so as to align the metering chambers in the dosing disc with the vertical grooves in the radial slide member and the product in the metering chambers is expelled or discharged into the capsule bodies via the vertical grooves. On completion of ejection of the product in the metering chambers into the capsule bodies, the pneumatic cylinder is operated to allow the piston rod to describe the reverse stroke. The piston rod moves back to its original position and the tapered link describes a rotary motion in the reverse direction about the pivot pin. The swivel rod rotates back to its original position and the metering turret and the capsule handling turret are now ready for the next cycle of operation. The cross channels underneath the slide members abut against the respective opposite sidewalls of the slots in the seats of the support disc and restrict the radial movements of the slide members.
According to the invention metered doses of the product at the ejection station of the dosing disc are directly emptied into the capsule bodies. Tamping and compaction of the product in the metering chambers is not required as the metering chambers remain closed at the bottom thereof by the slide members except when the product is intended to be emptied into the capsule bodies. The dosing disc and slide members rotate in unison and there is no relative movement therebetween. As a result of all this, productivity is increased, leakage and damage to the product and weight variation and dust generation are prevented and the reliability of the capsule filling machine is improved. The radial slide members are supported on the support disc independently of the dosing disc but rotatably with the dosing disc in unison. Therefore, it is not necessary to disassemble the radial slide members to clean or


replace the dosing disc and maintenance of the dosing disc is easy and convenient. As the invention eliminates the tamping plungers or pistons and tamping, the metering turret is compact, simple in construction, cost effective and easy and convenient to operate.
The other parts of the metering turret and the capsule handling turret have not been illustrated and described as such are not necessary for understanding the invention. The radial slide member geometry can be different; and displacement means for displacing the slide members can be different. Instead of displacing the radial slide members inwardly they can be displaced radially outwardly to align the vertical grooves in the radial slide members with the metering chambers in the dosing disc. Drive means for the displacement means of the swivel rod can be different. Each slide member may be held biased by more than one spring. Cam system or servo drive system can be used to displace the slide members radially Such variations of the invention are obvious to those skilled in the art and are to be construed and understood to be within the scope of the invention.


We claim :
1. A capsule filling machine comprising a dosing chamber having a dosing disc rotatably held at the underside thereof, the dosing disc being mounted on a vertical shaft adapted to describe an intermittent rotary motion, a plurality of stations provided angularly equidistantly around the periphery of the dosing disc, each of the stations comprising a group of through vertical passages provided at the periphery of the dosing disc on a pitch circle to form metering chambers and a plurality of radial slide means each corresponding to each station and disposed underside the dosing disc in abutment therewith and supported on a support disc mounted on the said vertical shaft, the radial slide means being adapted to slide against the underside of the dosing disc and close and open the corresponding groups of metering chambers.
2. The capsule filling machine as claimed in claim 1, wherein the radial slide means comprises a radial slide member radially slidably located in a seat in the support disc and formed with a group of through vertical grooves corresponding to the group of metering chambers, the slide member being spring biased radially outwardly such that the groups of vertical grooves are offset with the groups of metering chambers and displacement means for displacing the slide member radially inwardly to coincide the corresponding vertical grooves with the corresponding group of metering chambers.
3. The capsule filling machine as claimed in claim 2, wherein the slide member is T-shaped and the vertical grooves are formed in the cross-flange thereof.


4. The capsule filling machine as claimed in claim 2 or 3, wherein the displacement means comprises a vertically rotatably held swivel rod, the upper end of which is located in a cross channel formed underneath the perpendicular flange of the slide member and protruding down through a slot in the seat in the support disc, the swivel rod being formed with a lateral extension at the upper end thereof corresponding to the inward radial displacement of the radial slide member and drive means for vertically angularly displacing the swivel rod, the crosschannel underneath the slide member restricting the radial movement of the slide member with the crosschannel abutting against the respective opposite side walls of the slot.
5. The capsule filling machine as claimed in claim 4, wherein the drive means comprises a pneumatic cylinder connected to the lower end of the swivel rod through a linkage.
6. The capsule filling machine as claimed in claim 5, wherein the linkage comprises a U-shaped link fitted to the piston rod of the pneumatic cylinder and a tapered link the narrow end of which is disposed in the U-shaped link and pivoted thereto, the lower end of the swivel rod being fitted to the wide end of the tapered link.



ABSTRACT
A capsule filling machine comprising a metering turret (1) comprising a dosing chamber (2) having a dosing disc (3) rotatably held at the underside thereof. The dosing disc is mounted on a vertical shaft (4) adapted to describe an intermittent rotary motion. A plurality of stations are provided angularly equidistantly around the periphery of the dosing disc. Each of the stations comprises a group of through vertical passages (8) provided at the periphery of the dosing disc on a pitch circle to form metering chambers and a plurality of radial slide means (9). Each of the radial slide means corresponds to each station and is disposed underside the dosing disc in abutment therewith and supported on a support disc (10) mounted on the said vertical shaft. The radial slide means is adapted to slide against the underside of the dosing disc and close and open the corresponding groups of metering chambers (Fig 1).