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
Apparatus for automatically weighing hard gelatin capsules in a continuous cycle
APPLICANTS
Scitech Centre, Plot No 7, Prabhat Nagar, Jogeshwari West, Mumbai 400 102, Maharashtra, India, an Indian Company
INVENTORS
Singh Jasjit, a British subject and Deshmukh Prakash and Barde Mahesh, both Indian national's and all of Scitech Centre, 7 Prabhat Nagar, Jogesnwari West, Mumbai 400 I02.t Maharashtra, India
PREAMBLE TC) 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 an apparatus for automatically weighing hard gelatin capsules in a
continuous cycle
BACKGROUND OF THE INVENTION
Hard gelatin capsules are generally used for making dosages of pharmaceuticals or nutraceuticals by filling the capsules with the required dosages of the pharmaceuticals or nutraceuticals and sealing the filled capsules. Being pharmaceuticals or nutraceuticals, it is extremely important that uniformity and consistency of the dosages is maintained. Quality check on uniformity and consistency of the dosages is carried out by continuously weighing the filled and sealed capsules in a weighing apparatus. A typical capsule weighing apparatus comprises a feed mechanism having a feed magazine disposed for up and down movement vertically and comprising a plurality of feed passages vertically spaced apart in a line. The feed magazine also comprises a feed hopper at its top end and a feed control gate at its bottom. The feed mechanism also comprises a guide block located below the feed control gate. The guide block comprises an oblong body having a plurality of guide passages in a line corresporiding to and aligned with the feed passages in the feed magazine. Each of the guide passages comprises a capsule receiving portion and an entry portion at one side of the capsule receiving portion in continuity therewith and an exit portion at the opposite side of the capsule receiving portion in continuity therewith. The feed mechanism also comprises a retainer slide gate disposed across the opposite sides of the capsule receiving portions. The retainer slide gate comprises a fiat member having a plurality of open slots corresponding to the guide passages in the guide block. The retainer slide gate is movable back and forth transversely across the guide passages in the guide block to align and misalign the open slots in the retainer slide gate with the guide passages in the guide

block. The feed mechanism also comprises a plurality of pusher rods corresponding to and aligned with the entry portions of the guide passages in the guide block and disposed for forward and reverse movements with respect to the entry portions. The weighing apparatus also comprises a rotary drum mounted for rotation about a horizontal axis in the proximity of the guide block along the length of the guide block facing the exit portions of the guide passages in the guide block. The rotary drum has a plurality of sets of capsule collector heads projecting out from the outer circumference of the rotary drum along the length thereof. Each of the sets of capsule collector heads comprises several capsule collector heads equally radially spaced apart on the outer circumference of the drum in a line and formed with capsule retaining sockets. The capsule retaining sockets are connected to suction passages in the drum. The number of sets of capsule collector heads correspond to the exit portions of the guide passages in the guide block and the sets of capsule collector heads are aligned with the exist portions of the guide passages in the guide block. A weighing machine comprising a plurality of weighing pans is mounted below the drum. The number of weighing pans corresponds to the sets of capsule collector heads and the weighing pans are aligned with the sets of capsule collector heads. A capsule collector jute having a diverter for separating correct weight capsules and reject capsules is mounted below the weighing pans in the proximity of the weighing machine. (EP0685714 Al).
In such a capsule weighing apparatus, the retainer slide gate is required to retain the capsules in position in the capsule receiving portions of the guide passages in the guide block until they are pushed out into the capsule collector heads on the rotary drum by the pusher rods. The capsule retainer slide gate and the drive for the capsule retainer slide gate add to the cost of the apparatus and also increase the maintenance cost of the apparatus. In the absence of the retainer slide gate, the capsules may tilt down into the exit portions of the

guide passages in the guide block. In case tilting of the capsules takes place in the capsule receiving portions, the capsules will not be properly pushed out from the exit portions of the guide passages in their vertical position and the capsules will not be properly seated in the capsule retaining sockets of the capsule collector heads on the rotary drum. As a result, the suction effect on the capsules may not be uniform and the capsules may fall down from the capsule collector heads while the rotary drum is rotating with capsules in the capsule retaining sockets from near the guide block towards the weighing pans. Further there is a gap between the outer ends of the capsule collector heads and the outer ends of the respective exit portions of the guide passages in the guide block. Because of this gap, the capsules may tilt while being pushed out into the capsule collector heads and may not sit in position in the capsule collector heads. Therefore, the suction effect on the capsules in the capsule collector heads may not be uniform and the capsules may fall down from the capsule collector heads while the rotary drum is rotating with capsules in the capsule retaining sockets from near the guide block towards the weighing pans. Because of the clearance between the capsule collector heads and the guide block, there are also chances for the capsules to misalign and get stuck between the capsule collector heads and the guide block and jam the rotary drum while the capsules are being pushed out into the capsule collector heads. There are also possibility for the capsules in the capsule collector heads to fall down while the capsule collector heads travel between the guide block and the weighing pans. All this can result in wastage of valuable material, down time and loss of productivity.

OBJECTS OF THE INVENTION
An object of the invention is to provide an apparatus for automatically weighing hard gelatin capsules in a continuous cycle, which apparatus eliminates the retainer slide gate and the drive therefor and simplifies the construction of the apparatus so as to reduce the cost and maintenance cost of the apparatus.
Another object of the invention is to provide an apparatus for automatically weighing hard gelatin capsules in a continuous cycle, which apparatus ensures safe delivery of capsules from the exit portions of the guide passages in the guide block to the capsule retainer sockets on the rotary drum and to the weighing pans of the weighing machine so as to prevent wastage of material and reduce down time and improve productivity.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention there is provided an apparatus for automatically weighing hard gelatin capsules in a continuous cycle, the apparatus comprising a capsule feed mechanism having a feed magazine disposed for up and down movement vertically, the feed magazine comprising a plurality of feed passages vertically spaced apart in a line, a feed hopper at the top thereof and a feed control gate at the bottom thereof, the feed mechanism further comprising a guide block located below the feed control gate and comprising an oblong body having a plurality of guide passages corresponding to and aligned with the feed passages in the feed magazine, each of the guide passages having a capsule receiving portion and an entry portion at one side of the capsule receiving portion in continuity with the capsule receiving portion and an exit portion at the opposite side of the capsule receiving potion, the exit portion describing an interference portion at the opposite side of

the capsule receiving portion providing a constriction in continuity with the opposite side of the capsule receiving portion and a following wide portion, the feed mechanism further comprising a plurality of pusher rods corresponding to and aligned with the entry portions in the guide block and disposed for forward and reverse movements with respect to the entry portions in the guide block, a rotary drum mounted for rotation about a horizontal axis in the proximity of the guide block along the length thereof facing the exit portions of the guide passages in the guide block, the rotary drum comprising a plurality of rows of capsule retaining sockets along the length thereof in a spaced apart relationship corresponding to and aligned with the exit portions of the guide passages in the guide block, each of the rows of capsule retaining sockets comprising a plurality of capsule retaining sockets equally radially spaced apart on the outer circumference of the drum in a line and connected to suction passages in the drum and having a capsule landing at the lead end bottom thereof projecting out therefrom, a weighing machine located below the rotary drum and having a plurality of weighing pans corresponding to and disposed below the rows of capsule retaining sockets aligned therewith, a capsule guide sector plate located below the rotary drum between the guide block and the weighing pans and extending along the length of the rotary drum, the guide sector plate having a plurality of guide grooves along the upper surface thereof corresponding to the rows of capsule retaining sockets and a capsule collector chute located below the weighing pans in the proximity of the weighing machine along the length of the weighing machine.
The following is a detailed description of the invention with reference to the accompanying drawings, in which:
Fig 1 is a partial elevation partly in crossection of the apparatus for automatically weighing hard gelatin capsule in a continuous cycle;

Figs 2 and 3 are scrap plan views of the drum and the guide block and the pusher rods of the apparatus of Fig 1 with the pusher rods in the extreme reverse position and extreme forward position, respectively;
Fig 4 is a scrap crossectional view of the feed magazine of the apparatus of Fig 1;
Fig 5 is an enlarged scrap view of the rotary drum and the guide block and a pusher rod of the apparatus of Fig 1 in the extreme forward position of the pusher rod;
Figs 6 and 7 are enlarged scrap views of the rotary drum and the guide block and the pusher rods of the apparatus of Fig 1 with the pusher rods in the extreme reverse position and extreme forward position, respectively;
Fig 8 is a scrap isometric view of the guide block of the apparatus of Fig 1;
Fig 9 is a scrap plan view of the drum and a landing of the apparatus of Fig 1; and
Fig 10 is an isometric view of the capsule guide sector plate of the apparatus of Fig 1,
The apparatus 1 for automatically weighing hard gelatin capsules in a continuous cycle as illustrated in Figs 1 to 10 of the accompanying drawings comprises a capsule feeding mechanism 2 having a feed magazine 3 disposed for up and down movement vertically. The feed magazine comprises a plurality of feed passages 4 vertically spaced apart in a line, a feed hopper 5 at the top thereof and a feed control gate 6 at the bottom thereof. The feed

mechanism also comprises a guide block 7 located below the feed control gate and supported on the bed 7a of the apparatus. The guide block comprises an oblong body 8 having a plurality of guide passages 9 corresponding to and aligned with the feed passages in the feed magazine. Each of the guide passages in the guide block has a capsule receiving portion 9a and an entry portion 9b at one side of the capsule receiving portion in continuity with the capsule receiving portion and an exit portion 9c at the opposite side of the capsule receiving portion describing an interference portion which comprises a pair of narrow protrusions 10a, 10b each at each opposite side of the exit portion of the guide passage at opposite side of the capsule receiving portion to provide a constriction 10c in continuity with the capsule receiving portion, The exit portion also describes a wide portion lOd following the constriction. A plurality of pusher rods 11 corresponding to and aligned with the entry portions of the guide passages in the guide block are disposed for forward and reverse movements with respect to the entry portions in the guide block. 12 is a rotary drum mounted for rotation about a horizontal axis 13 in the proximity of the guide block along the length thereof facing the exit portions of the guide passages in the guide block. The rotary drum comprises a plurality of rows of capsule retaining sockets 14 along the length thereof in a spaced apart relationship corresponding to and aligned with the exit portions of the guide passages in the guide block. Each of the rows of capsule retaining sockets comprises a plurality of capsule retaining sockets equally radially spaced apart on the outer circumference of the drum in a line and connected to suction passages 15 in the drum. Each of the capsule retaining sockets has a landing comprising a disc 16 projecting out from the bottom of the leading end thereof with the planar surfaces of the disc perpendicular to the drum. 17 is a weighing machine disposed below the rotary drum and mounted on the bed 7a. The weighing machine has a plurality of weighing pans 18 corresponding to and disposed below the sets of capsule retaining sockets aligned therewith.

19 is a capsule guide sector plate located below the rotary drum between the guide block and the weighing pans and fixed to support 19a. The guide sector plate has a plurality of guide grooves 20 along the upper surface thereof matching with the rows of capsule retaining sockets on the rotary drum. 21 is a capsule collector chute disposed below the weighing pans in the proximity of the weighing machine and mounted to the bed 7a. The capsule collector chute is disposed along the length of the weighing machine and has a diverter (not shown) for separating correct weight capsules and reject capsules.
The drive mechanism for the feed mechanism, feed control gate, pusher rods and rotary drum have not been illustrated and described as such are not necessary for understanding the invention. The intervals between the up and down movements of the feed magazine, closing and opening of the feed control gate and the forward and reverse movements or strokes of the pusher rods and the intermittent rotational movement of the rotary drum are all controlled by the central processing and control mechanism of the apparatus which is not also illustrated and described as such are also not necessary for understanding the invention. During operation of the apparatus, the up and down movements of the feed magazine, closing and opening of the feed control gate and forward and reverse movements of the pusher rods are synchronized with the intermittent rotational movement of the rotary drum. Filled and sealed capsules to be weighed are fed into or dropped into the feed hopper at the top of the feed magazine. Due to the up and down movements of the feed magazine, the capsules in the hopper move in the hopper and orient themselves and enter the feed passages in the feed magazine one by one and move down in the feed passages in a line under gravity. During intermittent rotational movement of the rotary drum in the clockwise direction, the capsule retaining sockets of the various rows or sets of capsule retaining sockets in a line along the axis of rotation of the drum align with the exit portions of the

guide passages in the guide block in succession. When the feed magazine moves up, the feed passages in the magazine are closed by the feed control gate at the bottom thereof. When the feed magazine moves down the feed passages in the magazine are opened at the bottom thereof by the feed control gate. At the bottom most position of the feed magazine the bottom most capsules in the feed passages enter the respective capsule receiving portions of the guide passages in the guide block. The pusher rods move forward in the guide passages and push the capsules in the capsule receiving portions into the capsule retaining sockets on the drum aligned with the exit portions of the guide passages via the constrictions and the remaining wide portions of the exit portions. Due to suction effect in the capsule retaining sockets on the drum, the capsules are sucked into and held in position in the capsule retaining sockets. When the drum rotates or indexes further in the clockwise direction, the capsule retaining sockets having capsules held therein under vacuum effect align themselves with the weighing pans of the weighing machine. In the meantime or in the intervening period, the pusher rods describe the reverse stroke and move back to their original position. The feed control gate closes the bottom of the feed passages and the feed magazine moves up. When the capsule retaining sockets of the drum with capsules held therein under vacuum effect have aligned with the weighing pans, the suction effect in the capsule retaining sockets is cut off and capsules in the capsule retaining sockets fall down into the weighing pans to be weighed in the weighing pans. While the capsule retaining sockets with capsules therein are moving towards the weighing pans, the landings at the leading ends thereof push or swipe down the capsules already weighed and remaining on the weighing pans into the capsule collector chute. The diverter in the collector chute diverts correct weight capsules and reject capsules into the respective collector bins (not shown). When the capsule retaining sockets with capsules therein are aligned with the weighing pans, the following line of capsule retaining sockets of the various sets of capsule

retaining sockets on the drum, align with the exit portions of the guide passages in the guide block. The feed magazine moves down to its bottom most position and the feed control gate opens to allow the bottom most capsules in the feed passages to drop down into the respective capsule receiving portions of the guide passages in the guide block. The pusher rods are moved forward to describe the forward strokes thereof and push out the capsules in the capsule receiving portions into the capsule retaining sockets on the drum facing the exit portions of the guide passages. The drum rotates further in the clockwise direction and the cycle is repeated in a continuous manner to weigh the capsules automatically continuously.
According to the invention, the capsules in the capsule receiving portions of the guide passages in the guide block are retained in the vertical position by the respective interference portions. The dimensions of the interference portions are judiciously and precisely selected and controlled such that the interference portions hold the capsules in the capsule receiving portions in a vertical position without allowing them to tilt down. At the same time, the constrictions provided by the interference portions are just sufficient for the capsules to be pushed out from the capsule receiving portions without getting damaged. The wide portions of the exit portions of the guide passages provide smooth exit passages for the capsules being pushed out. Because of the landings at the bottom of the leading ends of the capsule retaining sockets, the capsules getting transferred from the exit portions of the guide passages in the guide block into the capsule retaining sockets do not misalign or get stuck in the gap between the outer surface of the guide block and the outer circumference of the drum. The capsules being transferred from the exit portions into the capsule retaining sockets remain vertically aligned and are properly sucked into the capsule retaining sockets and seated in the capsule retaining sockets. Therefore, the vacuum effect on the capsules in the capsule retaining sockets is uniform and the capsules in the capsule

retaining sockets are properly held in the capsule retaining sockets and there is no possibility for the capsules in the capsule retaining sockets to fall down under gravity when the drum is rotating with capsules in the capsule retaining sockets from near the guide block towards the weighing pans. The landings also perform the dual function of pushing down the capsules sitting on the weighing pans into the chute. The clearance between the outer ends of the landings and the outer end of the guide block is just sufficient to facilitate rotation of the drum, The invention also eliminates capsule collector heads of the drum and simplifies the construction of the drum resulting in saving of material cost and manufacturing cost. The guide grooves in the capsule guide sector plate also support, guide and prevent the capsules in the capsule retaining sockets from falling down when the drum is rotating from near the guide block towards the weighing pans. As a result of all this, the retainer slide gate and associated drive have been eliminated and the overall cost and the maintenance cost of the apparatus are reduced. As the capsules emerging from the exit portions of the guide passages in the guide block are well supported on the landings, misalignment of the capsules is prevented and the capsules are properly transferred into and seated in the capsule retaining sockets. Therefore, the suction effect is uniformly applied on the capsules and the capsules are properly held in the capsule retaining sockets. The guide grooves in the capsule guide sector plate also support and guide the capsules while the drum is moving from near the guide block to the weighing pans. As a result, there are no chances for the capsules to fall down while travelling from the guide block to the weighing pans. There is also no possibility for the capsules to get stuck between the drum and guide block and jam the drum. Downtime is reduced, wastage of material is reduced and productivity is increased.

It is understood that the weighing apparatus of the invention can be used for weighing unfilled capsules or other small articles like tablets. The capsules also can be used for filling any material other than pharmaceuticals or neutraceuticals. The construction / configuration of the interference portions can be different. 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. An apparatus for automatically weighing hard gelatin capsules in a continuous cycle, the apparatus comprising a capsule feed mechanism having a feed magazine disposed for up and down movement vertically, the feed magazine comprising a plurality of feed passages vertically spaced apart in a line, a feed hopper at the top thereof and a feed control gate at the bottom thereof, the feed mechanism further comprising a guide block located below the feed control gate and comprising an oblong body having a plurality of guide passages corresponding to and aligned with the feed passages in the feed magazine, each of the guide passages having a capsule receiving portion and an entry portion at one side of the capsule receiving portion in continuity with the capsule receiving portion and an exit portion at the opposite side of the capsule receiving potion, the exit portion describing an interference portion at the opposite side of the capsule receiving portion providing a constriction in continuity with the opposite side of the capsule receiving portion and a following wide portion, the feed mechanism further comprising a plurality of pusher rods corresponding to and aligned with the entry portions in the guide block and disposed for forward and reverse movements with respect to the entry portions in the guide block, a rotary drum mounted for rotation about a horizontal axis in the proximity of the guide block along the length thereof facing the exit portions of the guide passages in the guide block, the rotary drum comprising a plurality of rows of capsule retaining sockets along the length thereof in a spaced apart relationship corresponding to and aligned with the exit portions of the guide passages in the guide block, each of the rows of capsule retaining sockets comprising a plurality of capsule retaining sockets equally radially spaced apart on the outer circumference of the drum in a line and connected to suction passages in the drum and having a capsule landing at the lead end bottom thereof projecting out therefrom, a

weighing machine located below the rotary drum and having a plurality of weighing pans corresponding to and disposed below the rows of capsule retaining sockets aligned therewith, a capsule guide sector plate located below the rotary drum between the guide block and the weighing pans and extending along the length of the rotary drum, the guide sector plate having a plurality of guide grooves along the upper surface thereof corresponding to the rows of capsule retaining sockets and a capsule collector chute located below the weighing pans in the proximity of the weighing machine along the length of the weighing machine.
2. The apparatus as claimed in claim 1, wherein the interference portion comprises a
pair of narrow protrusions each at each opposite side of the exit passage at the opposite side
of the capsule receiving portion to provide a constriction in continuity with the capsule
receiving portion.
3. The apparatus as claimed in claim 1 or 2, wherein the landings each comprises a disc
projecting out from the bottom of the leading end of each of the capsule retaining sockets
with the planar surfaces thereof perpendicular to the drum.