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
Blister pack machine for blister packing products
APPLICANTS
Sci-tech Centre, 7 Prabhat Nagar, Jogeshwari West, Mumbai 400 102, Maharashtra, India, an Indian company
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed :

FIELD OF THE INVENTION
This invention relates to a blister pack machine for blister packing products.
BACKGROUND OF THE INVENTION
Blister pack machines are used to blister pack products in a very compact, convenient, economical and efficient manner, especially dosages of pharmaceutical or neutraceutical products in tablet or capsule form. A typical blister pack machine for blister packing dosages of pharmaceutical or neutraceutical products generally comprises a web foil loading and unwinding station, a cavity forming station, an inspection or vision station, a product recovery station, a sealing station and a strip cutting station and a PLC (Programmable Logic Control) for controlling the operation of the machine at the various stations thereof. A blister pack machine may be a single track or multi tracks type.
A web foil, usually made of aluminium or plastics such as polyvinyl chloride (PVC), is loaded and unwound at the loading and unwinding station and fed to the various other stations successively through web guides fixed to the machine frame. Depending on the type of the web foil, cavities are thermoformed or cold formed in the web foil at the cavity forming station in one track or row or in two or multiples of two tracks or rows based on whether the machine is single track or multiple tracks and according to the shape and size of the products. The cavities are filled with dosages of the products in tablet or capsule form at the feeding station, cavities

having defective products or no products or insufficient number of products, if any, are detected at the inspection station, defective products and products in sufficient numbers, if any, are recovered from the respective cavity(ies) at the product recovery station, the cavities are sealed from the top with a lid foil at the sealing station and the web foil with the lid foil sealed thereto is cut into blister strips at the cutting station. The defective strips are collected in a bin and the good blister strips with products are loaded onto a conveyor or taken for secondary packaging.
A typical product recovery unit disposed at the product recovery station of a two track blister pack machine comprises a product guide assembly consisting of a base block having a longitudinal slot at the top thereof defined by a bottom portion, an outer side with a side wall, an end wall at each end, a product passage through each of the end walls in communication with the longitudinal slot and opening to the cavities in the web foil and an open inner side. The base block also consists of a partition member at the center of the longitudinal slot at the top of the base block integral with the base block.
The product guide assembly also consists of a plurality of spaced apart product guide members on either side of the partition member at the open inner side outer face of the longitudinal slot. The product guide assembly further consists of a top closure plate mounted at the top of the base block and a side closure plate mounted at the inner side of the base block abutting the product guide members at the open inner side

outer face of the longitudinal slot. Gaps formed between the product guide members on either side of the partition member at the open inner side outer face of the longitudinal slot and the side closure plate form passageways for the products to travel down therethrough and depend upon the shape and size of the products to be blister packed.
The product recovery unit also comprises a venturi assembly consisting of a pair of Venturis, each having an axial opening and plurality of side openings and housed in a venturi box having a top opening and a bottom opening concentric with the axial opening of the respective venturi and further having an air injection port at the side thereof. The venturi boxes with the Venturis are spaced apart from each other and held between a top mounting plate and a bottom mounting plate. Each of the top and bottom mounting plates consists of a pair of end openings. The end openings in the top mounting plate are concentric with the top openings in the venturi boxes and the end openings in the bottom mounting plate are concentric with the bottom openings in the venturi boxes. The venturi boxes with the Venturis assembled between the top and bottom mounting plates are housed in a open bottom housing.
The venturi assembly is disposed below the produce guide assembly describing a clearance with the product guide assembly for the web foil to pass therethrough. Both the product guide assembly and venturi assembly are fixed to a pair of spacer blocks each at each side thereof. The spacer blocks are fixed to the machine frame. The

product passages in the base block open to the cavities in the web foil. The product
recovery unit also comprises a product collector tray detachably fitted to the housing
and having air vents.
During operation of the machine, air is forced through the air injection ports at the side of the venturi boxes of the product recovery unit at the product recovery station. The forced air enters the Venturis through the side openings in the Venturis and flows down through the axial openings in the venturies and flows out of the venturies via the end openings in the bottom mounting plate, open bottom housing and air vents in the product collector tray. The air velocity depends upon the air pressure. Depending upon the air velocity, a suction effect is created in the longitudinal slot at the top of the base block and in the product passages in the base block opening to the cavities in the web foil and defective or insufficient number of products in the cavities are sucked into the product passages and from there the products enter the longitudinal slot at the top of the base block.
The products in the longitudinal slot travel down to the product collector tray via the gaps or passageways between the product guide members at the open inner side outer face of the longitudinal slot and the side closure plate, end openings in the top mounting plate, venturies, end openings in the bottom mounting plate and open bottom housing. The product collector tray is periodically emptied to collect the

products. The recovered products are processed and reused or reused as such depending upon the condition thereof.
The base block of a product recovery unit of the above construction is required to be held at the product recovery station with the center of the longitudinal slot positioned at the center between the two tracks or row of cavities in the web foil to ensure that the suction effect is uniformly and evenly created in both the sides of the longitudinal slot defined by the partition member and to ensure that the products in the cavities in both the tracks are effectively sucked into the respective sides of the longitudinal slot. If the product recovery unit of the above construction is used in a single track machine with the center of the longitudinal slot in the base block thereof aligned with the center of the single track, the partition member which is fixed in position remains at the center of the longitudinal slot at the top of the base block and the single track. As a result, the suction effect will not be evenly and uniformly distributed in the longitudinal slot and defective products or insufficient number of products in cavities at the center of the track will not be effectively sucked into the longitudinal slot thereby reducing the performance efficiency of the machine and resulting in wastage of products and losses.
Therefore, a product recovery unit of the above construction can be used effectively only in a two track blister pack machine or in blister pack machines having multiples of two tracks and cannot be readily effectively used with a single track blister pack

machine because of the fixed partition member at the center of the longitudinal slot at the top of the base block. A single track blister pack machine normally requires a dedicated product recovery unit without the fixed partition member in the longitudinal slot in the base block.
Besides this, the product guide members at the open inner side outer face of the longitudinal slot in the base block are fixed in position and the shape and size of the product guide members and the gaps (passageways) formed between the product guide members on either side of the partition member at the open inner side outer face of the longitudinal slot and the inner side of the side closure plate are preset or fixed depending upon the shape and size of the products. Therefore, the product recovery unit cannot be used to recover products of shapes and sizes different from the predetermined shapes and sizes.
Furthermore, the open inner side outer face of the longitudinal slot leading to the gaps between the product guide members at the open inner side outer face of the longitudinal slot and the inner side of the side closure plate is practically straight and abrupt. Therefore, the products travelling down through the gaps between the product guide members at the open inner side outer face of the longitudinal slot and the side closure plate may tend to move up into the longitudinal slot, especially when there is any pressure drop or pressure variation of the air being injected through the air injection ports at the sides of the venturi boxes. This may choke up the product

passages and disrupt product recovery thereby reducing performance efficiency of the machine and resulting in wastage of products and losses.
Therefore, there is need for blister pack machines comprising product recovery units which obviate the above disadvantages.
DESCRIPTION OF THE INVENTION
According to the invention there is provided a blister pack machine for blister packing products, comprising a product recovery station having a product recovery unit comprising a product guide assembly consisting of a base block having a longitudinal slot at the top thereof defined by a bottom portion, an outer side with a side wall, an end wall at each end, a product passage extending through each of the end walls in communication with the longitudinal slot and opening to the cavities in the web foil and an open inner side, a partition member disposed at the center of the longitudinal slot, a top closure plate fitted at the top of the base block and a side closure plate fitted at the open inner side of the longitudinal slot describing a gap with the open inner side of the longitudinal slot, a venturi assembly consisting of a pair of Venturis, each having an axial opening and a plurality of side openings and housed in a venturi box having a top opening and a bottom opening concentric with the axial opening of the respective venturi and further having an air injection port at the side thereof, the venturi boxes with the Venturis being spaced apart from each other and held between a top mounting plate and a bottom mounting plate, each of the top and

bottom mounting plates having a pair of end openings registering with the respective top openings and bottom openings in the venturi boxes, the venturi boxes with the Venturis assembled between the top and bottom mounting plates being housed in a open bottom housing, the venturi assembly being disposed below the product guide assembly describing a clearance with the product guide assembly for a web foil to pass therethrough and a product collector tray detachably fitted to the housing and having air vents, wherein the web foil consists of a single track or two tracks of cavities formed therein, the partition member is detachably fitted to the base block and the product guide assembly consists of gap adjustment means to adjust the gap between the open inner side of the longitudinal slot and the side closure plate.
DESCRIPTION OF THE ACCOMPANYING SCHEMATIC DRAWINGS
Fig 1 is an isometric view of the product recovery unit of a blister pack machine for
blister packing products in capsule or tablet form according to an embodiment of the
invention;
Fig 2 is a side view of the product recovery unit of Fig 1;
Fig 3 is an enlarged scrap view at X in Fig 2;
Fig 4 is a cut section isometric view of the blister pack machine of Fig 1;

Fig 5 is an isometric view of the product recovery unit of Fig 1 with a web foil passing therethrough;
Fig 6 is an isometric view of the product guide assembly of the product recovery unit of Fig 1;
Fig 7 is a cut section isometric view of the product guide assembly of Fig 6;
Fig 8 is an enlarged scrap sectional view at Y in Fig 7;
Fig 9 is an exploded view of the product guide assembly of Fig 6;
Fig 10 is a cut section isometric view of the base block of the product guide assembly of Fig 6;
Fig 11 is a bottom isometric view of the gap adjuster plate of the product guide assembly of Fig 6;
Fig 12 is a sectional view of the gap adjuster plate of the product guide assembly of Fig 6;

Fig 13 is an enlarged view of a L-shaped support block of the product guide assembly of Fig 6;
Fig 14 is an exploded view of the venturi assembly of the product recovery unit of Figl;
Fig 15 is an isometric view of a venturi of the venturi assembly of Fig 14; and
Fig 16 is an isometric view of the product collector tray of the product recovery unit of Fig 1.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION As illustrated in Figs 1 to 16 of the accompanying drawings, the product recovery unit 1 disposed at the product recovery station (not shown) of a two track blister pack machine (not shown) consists of a product guide assembly 2 consisting of a base block 3 having a longitudinal slot 4 at the top thereof defined by a bottom portion 5, an outer side with a side wall 6, an end wall 7 at each end and a product passage 8 extending through each of the end walls in communication with the longitudinal slot (Figs 1, 2, 4, 5, 6, 7, 9 and 10). The longitudinal slot is further defined by an open inner side 9. A top closure plate 10 is fitted at the top of the base block and a side closure plate 11 is fitted at the inner side of the base block describing a gap 12 with

the open inner side outer face of the longitudinal slot and the side closure plate (Figs 4, 7 and 8).
The product recovery unit also comprises a venturi assembly 13 consisting of a pair of venturies 14 each having an axial opening 15 and a plurality of side openings 16 and housed in a venturi box 17 having a top opening 18 and a bottom opening (Figs 1, 2, 4, 5, 14 and 15). The bottom opening in the venturi box is not seen in the drawings but can be visualised in Fig 14. Both the top and bottom openings in the venturi box are concentric with the axial opening of the respective venturi. The venturi box also consist of an air injunction port 19 at the side thereof. The venturi boxes with the venturies are spaced apart from each other and held between a top mounting plate 20 and a bottom mounting plate 21. The top mounting plate consists of a pair of end openings 22, 22 registering with the top openings in the venturi box. The bottom mounting plate consists of a pair of end openings 23, 23 registering with the bottom openings in the venturi boxes.
The venturi boxes with the venturies assembled between the top and bottom mounting plates are located within a housing 23 with open bottom 24 and mounting flanges 25, 25 at the sides thereof. A pair of oblong guide members 26, 26 are fixed to the mounting flanges at the both sides of the housing. Each of the oblong guide members consists of an oblong guide groove 27 along the length thereof. A product collector tray 28 provided with a holding knob 29, air vents 30 and a pair of lateral

projections 31 at the sides thereof, is detachably slide fitted to the guide members by engaging the lateral projections 31 thereof in the oblong grooves 27, 27 in the guide -members (Figs 1, 2, 3, 4, 5, 14 and 16).
The venturi assembly 13 is disposed below the product guide assembly describing a clearance 60 with the product guide assembly for a web foil A travelling through the product recovery station to pass therethrough (Figs 1 and 5). Al and A2 are the two tracks or rows of cavities B in the foil. Product passages 8 in the base block 3 open to the cavities in the web foil. The product guide assembly and venturi assembly are held together with a pair of spacer blocks 61, one at each side thereof (Figs 1 and 5). The spacer blocks are mounted to the machine frame (not shown). The web foil is guided in web guides (not shown) fixed to the machine frame.
The longitudinal slot 4 consists of a tapered extension 32 slopping down from the open inner side thereof (Figs 8 and 10). 33, 33 are pair of L-shaped support blocks each consisting of a vertical portion 34 formed with an oblong vertical slot 35 along the length thereof and a horizontal portion 36 formed with an oblong horizontal slot 37 across the width thereof (Figs 1, 2, 4, 5, 6, 7 and 13). L-shaped support blocks are fitted at the inner side of the end walls 7 of the longitudinal slot 4 at the top of the base block 3 with first screws 38 passing through the oblong slots in the vertical portions of the L-shaped support blocks and fixed in position in the holes 39 at the inner side of the end walls of the longitudinal slot (Figs 9 and 13).

A gap adjuster plate 40 is disposed on the horizontal portions of the L-shaped support members and mounted on the horizontal portions with second screws 41 passing through holes 42 at the ends of the gap adjuster plate and the oblong slots in the horizontal portions and fixed in position at the bottom of the horizontal portions (Figs 9, 11 and 13). The inner side of the gap adjuster plate protrudes into the gap 12 between the open inner side of the longitudinal slot 4 and the side closure plate 11 and is tapered marked 43 matching with the tapered extension at the open inner side of the longitudinal slot 4 (Figs 8 and 12).
The height of the gap adjuster plate 40 is adjusted vertically to align the gap adjuster plate with the tapered extension 32 at the open inner side 9 of the longitudinal slot by loosening the first screws 38 and moving the L-shaped support blocks up or down as required and refixing them with the first screws. The gap between the tapered inner side of the gap adjuster plate and the tapered extension at the open inner side of the longitudinal slot and hence the gap 12 between the open inner side of the longitudinal slot and the side closure plate is adjusted by loosening the second screws 41 and moving the gap adjuster plate horizontally back and forth on the horizontal portions 36 of the L-shaped support blocks 33 as required and refixing it in position with the second screws. The horizontal portions of the L-shaped support blocks are provided with scales or calibrations 44 (Fig 13) to adjust the position of the second screws in the oblong slots in the horizontal portions and thereby to adjust the position of the

gap adjuster plate and the gap between the tapered inner side of the gap adjuster plate and tapered extension at the open inner side of the longitudinal slot.
45 is a partition member disposed at the center of the longitudinal slot 4 at the top of the base block (Figs 9 and 10). The partition member is T-shaped and consists of a cross flange 46 and a pendicular flange 47. The cross flange has a tapered notch 48 at the outer side center thereof and the sidewall 6 at the outer side of the longitudinal slot at the top of the base block consists of a tapered projection 49 at the center of the inner side thereof. The T-shaped partition member is detachably press fitted to the tapered projection by engaging the tapered notch at the center of the cross flange over the tapered projection.
During operation of the machine, defective or insufficient member of products in the cavities in the web foil are sucked into the product recovery unit and recovered as described earlier in the background description. However, according to the invention, the partition member 45 is detachable and can be easily removed to use the product recovery unit in a single track blister pack machine also easily and conveniently besides in a two track blister pack machine or in a blister pack machine with multiples of two tracks. While disposed at the product recovery station of a single track blister pack machine with the center of the longitudinal slot in the base block and center of the track aligned, the longitudinal slot at the top of the base block is no longer blocked by the partition member which has been removed. Therefore, suction

effect will be uniform throughout the longitudinal slot and defective products or insufficient number of products in the cavities at the center of the track also will be effectively sucked into the longitudinal slot via the product passages thereby maintaining the performance efficiency of the product recovery unit and avoiding wastage of products and losses even in a single track blister pack machine.
Besides this, the product guide members have been eliminated and the gap between the open inner side of the longitudinal slot in the base block and the inner side of the gap adjuster plate and hence the gap between the open inner side of the longitudinal slot and the side closure plate can be adjusted with the gap adjuster plate 40 to accommodate and allow products of different shapes and sizes to travel down through the gap into the product collector tray via the end openings in the top mounting plate, Venturis, end openings in the bottom mounting plate and open bottom housing. Therefore, the blister pack machine with the product recovery unit can be used to recover products of different sizes and shapes.
Furthermore, the slopping effect of the confronting slopping surface of the tapered extension at the open inner side of the longitudinal slot at the top of the base block and the slopping surface at the tapered inner side of the gap adjuster plate will facilitate the products to slide down smoothly over the slopping surfaces into the product collector tray via the gap between the open inner side of the longitudinal slot and inner side of the gap adjuster plate and end openings in the top mounting plate,

Venturis, end openings in the bottom mounting plate and the open bottom housing and will prevent the products from sliding up and reentering the longitudinal slot in the base block and choking the product passages and disrupting product recovery even if there is any pressure drop or pressure variation of the air being injected through the air injection ports at the sides of the venturi boxes. As a result, performance efficiency of the machine is maintained and wastage and losses are prevented.
It is to be understood that there are several variations possible in the embodiment of the invention as illustrated in the drawings without deviating from the scope thereof. The gap adjustment means for adjusting the gap between the open inner side of the longitudinal slot and the inner side of the gap adjuster plate and hence the side closure plate can be of different construction or configuration. The partition member can be of a different construction or configuration and can be detachably mounted in the longitudinal slot at the top of the base block in a different manner. 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. The scope of the invention is defined by the accompanying claims.

We claim:
1. A blister pack machine for blister packing products, comprising a product recovery station having a product recovery unit comprising a product guide assembly consisting of a base block having a longitudinal slot at the top thereof defined by a bottom portion, an outer side with a side wall, an end wall at each end, a product passage extending through each of the end walls in communication with the longitudinal slot and opening to the cavities in the web foil and an open inner side, a partition member disposed at the center of the longitudinal slot, a top closure plate fitted at the top of the base block and a side closure plate fitted at the open inner side of the longitudinal slot describing a gap with the open inner side of the longitudinal slot, a venturi assembly consisting of a pair of Venturis, each having an axial opening and a plurality of side openings and housed in a venturi box having a top opening and a bottom opening concentric with the axial opening of the respective venturi and further having an air injection port at the side thereof, the venturi boxes with the Venturis being spaced apart from each other and held between a top mounting plate and a bottom mounting plate, each of the top and bottom mounting plates having a pair of end openings registering with the respective top openings and bottom openings in the venturi boxes, the venturi boxes with the Venturis assembled between the top and bottom mounting plates being housed in a open bottom housing, the venturi assembly being disposed below the product guide assembly describing a clearance with the product guide assembly for a web foil to pass therethrough and a product collector tray detachably fitted to the housing and having air vents, wherein

the web foil consists of a single track or two tracks of cavities formed therein, the partition member is detachably fitted to the base block and the product guide assembly consists of gap adjustment means to adjust the gap between the open inner side of the longitudinal slot and the side closure plate.
2. The blister pack machine as claimed in claim 1, wherein gap adjustment means consists of a gap adjuster plate disposed below the side closure plate with the inner side of the gap adjuster plate aligned and describing a gap with the open inner side of the longitudinal slot, the gap adjuster plate being adjustable with adjuster means to adjust the gap between the open inner side of the longitudinal slot and the inner side of the gap adjuster plate.
3. The blister pack machine as claimed in claim 2, wherein the open inner side of the longitudinal slot consists of a tapered extension slopping down from the open inner side of the longitudinal slot and the inner side of the gap adjuster plate is tapered matching with the tapered extension at the open inner side of the longitudinal slot.
4. The blister pack machine as claimed in claim 2, wherein the adjuster means consists of a pair of L-shaped support blocks each having a vertical portion formed with an oblong vertical slot along the length thereof and a horizontal portion formed with an oblong horizontal slot across the width thereof, each of the L-shaped support

blocks being vertically adjustably mounted at the inner side of each of the end walls of the longitudinal slot with a pair of first screws each passing through the oblong vertical slot in each of the vertical portions and fixed in position, the gap adjuster plate being horizontally adjustably mounted on the horizontal portions with a pair of second screws each passing through each end of the gap adjuster plate and each of the oblong horizontal slots in the horizontal portions and fixed in position.
5. The blister pack machine as claimed in claim 4, wherein each of the horizontal portions of the L-shaped support blocks consists of calibrations aligned with the second screws to adjust the adjuster plate position horizontally.
6. The blister pack machine as claimed in claim 1, wherein the partition member is T-shaped and consists of a cross flange and a perpendicular flange, the cross flange having a tapered notch at the outer side center thereof and the outer sidewall of the longitudinal slot at the top of the base block consists of a tapered projection at the center of the inner side thereof, the T-shaped partition member being detachably press fitted to the tapered projection by engaging the tapered notch at the center of the cross flange over the tapered projection.