CLIAMS:We claim:
1. A feed mechanism for feeding tablets to blisters of a blister band, including a vibratory tablet feeder comprising a feed chamber disposed at an elevation for vibration about a vertical axis and having a feed sector at the bottom thereof with a plurality of tablet feed channels leading to a row of tablet feed openings, a row of rigid tablet feed tubes vertically disposed below the feed chamber and mounted in position with the upper ends of the tablet feed tubes registering with the row of tablet feed openings in the feed sector, a rotary drum disposed between the lower ends of the tablet feed tubes and a blister band moving on a linear conveyor and having a plurality of rows of blisters along the length thereof, the drum being disposed across the blister band and being rotatable about a horizontal axis, the drum having a plurality of rows of tablet cavities across the drum about its circumference, each row of tablet cavities registering with the lower ends of the tablet feed tubes and each row of blisters in the blister band and a curved tablet guide plate disposed over the drum in the direction of rotation of the drum and mounted in position with one end of the guide plate disposed close to the lower ends of the tablet feed tubes and the other end of the guide plate extending over a segment of the drum, wherein the lower end of each tablet feed tube has an uncut portion and a cut out portion diametrically opposite to each other and wherein the cutout portion is disposed in the direction of rotation of the drum and wherein the lower end of the uncut portion is at a distance of 1 to 2mm from the circumference of the drum and the cutout portion extends upto a distance of 3-4mm from the circumference of the drum.

2. The feed mechanism as claimed in claim 1, wherein the rigid tubes are made of stainless steel.

3. The feed mechanism as claimed in claim 1, wherein the rigid tubes are slitted tubes, each having a longitudinal slit along the length thereof extending through the uncut portion at the lower end thereof.

4. The feed mechanism as claimed in claim 3, wherein the longitudinal slit extends through the center of the uncut portion.

Dated this 8th day of July 2015

(Jose M A)
Agent for the Applicants
of Khaitan & Co
Reg No IN/PA-44
,TagSPECI:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
and
THE PATENTS RULES, 2003
As amended by the Patents (Amendment) Rules, 2014

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

TITLE OF THE INVENTION
Feed mechanism for feeding tablets to blisters of a blister band

APPLICANTS
Sci-tech Centre and ACG PamPac Machines Pvt Ltd, both having offices at 7 Prabhat Nagar, Jogeshwari West, Mumbai 400 102, Maharashtra, both Indian companies

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 feed mechanism for feeding tablets to blisters of a blister band.

BACKGROUND OF THE INVENTION
Blister packing of solid articles, especially dosages of pharmaceuticals, neutraceuticals or food supplements, such as tablets, pills or capsules is a very compact, efficient, effective, convenient and economical way of packing such articles and is very widely and commonly used in a large number of packaging industries. A blister packing machine for packing tablets includes a feed mechanism for feeding the tablets to blisters of a blister band moving on a linear conveyor. There are several designs (configurations, constructions or versions) of the feed mechanism.

In one design, the feed mechanism for feeding tablets to blisters of a blister band includes a vibratory tablet feeder comprising a tablet feed chamber disposed at an elevation for vibration about a vertical axis. The tablet feed chamber comprises a feed sector at the bottom thereof having a plurality of tablet feed channels leading to a row oftablet feed openings.A row of flexible feed tubes are vertically disposed below the tablet feed chamberwith the upper ends of the flexible feed tubes connected to the row of tablet feed openings in the feed sector of the feed chamberthrough a top feed manifold (deflection plate) having a row of tablet feed openings registering with the row oftablet feed openings in the feed sector. The lower ends of the flexible feed tubes are connected to a row of matching tablet feed openings in a bottom feed manifold disposed above a tablet feed drum and mounted to the machine frame. The tablet feed drum extends across a blister band moving on a linear conveyor and having rows of blisters along the length thereof.

The tablet feed drum is rotatable about a horizontal axis and has rows of tablet cavities extending across the drum about its circumference and registering with the tablet feed openings in the bottom manifold and the rows of blisters along the length of the blister band. The feed mechanism also includes a curved tablet guide platehaving its one end fixed to the bottom manifold and its other end extending over a segment of the drum.

The feed mechanism operates cyclically. During operation of the feed mechanism, the tablet feed chamber vibrates about its vertical axis and the tablet feed drum rotates about its horizontal axis. Tablets in the feed chamber enter the flexible feed tubes through the feed openings in the feed sector of the feed chamber and the feed openings in the top feed manifold, travel down through the flexible feed tubes into the feed openings in the bottom feed manifold and drop down into a row of tablet cavities on the drum through the tablet feed openings in the bottom feed manifold. During continued rotation of the drum, the tablets in the row of tablet cavities on the drum are retained in position and guided on the drum by the curved tablet guide plate. The tablets in the row of tablet cavities on the drum drop down into a row of blisters in the blister band aligned with the row of tablet cavities on the drum with the tablets after the row tablet cavities with the tablets on the drum have crossed over the other end of the curved tablet guide plate. Feeding of tablets into rows of the blister band continues and the blister band with the tablets move forward for further processing.

While the tablets move down in the flexible feed tubes, they are not identically aligned and do not move down smoothly because of the flexible nature of the feed tubes. The flexible tubes are like tubular springs and twist and turn under the vibrations of the vibratory tablet feeder getting transmitted to the flexible tubes. Due to the twisting and turning of the flexible tubes, the tablets often tilt and turn in the flexible feed tubes and abut and lock to each other.

In case of tablet locking, the feed mechanism has to be stopped to unlock the tablets in the flexible feed tubes manually by introducing a thin rod or the like into the concerned flexible feed tubes through the feed openings in the bottom feed manifold. As a result, productivity is reduced. Because of the twisting and turning of the flexible feed tubes, the feed mechanism has to be operated at low speeds to prevent locking of the tablets in the flexible feed tubes under twisting and turning of the feed tubes. Productivity is reduced because of the low speed operation of the feed mechanism also.

Movement of the tablets in the flexible feed tubes is not visible to the operator as the flexible tubes are fully enclosed at the sides thereof ie the sidewalls of the tubes are fully closed. Therefore, the operator will come to know about the tablet locking only when the operator does not see tablets moving down through the bottom feed manifold. Productivity is lost because of the time delay in observing the locking of the tablets in the flexible feed tubes and in rectifying the locking of the tablets in the flexible feed tubes.

The feed mechanism comprises a large number of component parts thereby increasing the cost. The flexible feed tubes are complex and complicated in construction thereby increasing cost and reducing reliability. Because of the spring characteristics of the flexible tubes, mounting and setting of the flexible feed tubes in the feed mechanism is cumbersome and difficult and also time consuming. Productivity is reduced because of the time required for setting of the flexible feed tubes in the feed mechanism.

In another design, the feed mechanism comprises a row of slitted rigid feed tubes disposed vertically below the row of tablet feed openings in the feed sector of the vibratory tablet feeder and mounted to the machine frame. A shuttle mechanism is disposed between the lower ends of the rigid feed tubes and a blister band moving on a linear conveyor. The shuttle mechanism is reciprocable in the horizontal plane and has a row of tablet feed openings registering with the lower ends of the feed tubes and the rows of blisters on the blister band. The shuttle mechanism includes an electro pneumatic drive and is configured to move forward and position itself below the lower ends of the feed tubes with the lower ends of the feed tubes aligned with the feed openings in the shuttle mechanism to allow the tablets in the feed tubes to drop down into a row of blisters in the blister band through the feed openings in the shuttle mechanism and then move back from the lower ends of the feed tubes to the original position thereof.

The above feed mechanism also has to be operated at low speeds because of the time required for reciprocal movement of the shuttle mechanism. Furthermore, the shuttle mechanism is complicated in construction and operation. The shuttle mechanism also requires periodic maintenance and is also not reliable. Operation of the feed mechanism is also noisy because of the shuttle mechanism.

Esposti et al teach a system for stepless feeding of articles such as tablets, pills, capsules and the like to blisters of a blister band moving on a linear conveyor. The system comprises a rotary cylindrical mantle disposed between feed magazines and a blister band. The mantle is rotatable about a horizontal axis and comprises depressions on the outer surface thereof for the articles. The mantle also comprises a low air pressure chamber and a high air pressure chamber connected to the depressions on the mantle through holes. The system employs vacuum or negative air pressure to suck in articles being fed from the magazines into the depressions on the mantle and hold the articles on the mantle during rotation of the mantle. It also employs positive air pressure to push out the articles in the depressions on the mantle into the blisters of the blister band (US 5802804).

The above system is complicated and complex in construction and operation because of the use of negative and positive air pressures and the difficulty in controlling vacuum and positive air pressure precisely. There are chances for more than one article being sucked out at a time from the magazines unless the vacuum is very critically controlled. Unless the rotational movement of the mantle and application of vacuum are not precisely controlled and synchronised, the articles may not be properly sucked into the depressions on the mantle and properly seated in the depressions. As a result, the articles may fall down from the rotating mantle resulting in wastage and losses.The system is also not reliable for the above reasons.

There is thus need for feed mechanisms for feeding tablets to blisters of a blister band, which increase productivity and which are simple in construction, economical and reliable and which are less noisy in operation.

DESCRIPTION OF THE INVENTION
According to the invention there is provided a feed mechanism for feeding tablets to blisters of a blister band, including a vibratory tablet feeder comprising a feed chamber disposed at an elevation for vibration about a vertical axis and having a feed sector at the bottom thereof with a plurality of tablet feed channels leading to a row of tablet feed openings, a row of rigid tablet feed tubes vertically disposed below the feed chamber and mounted in position with the upper ends of the tablet feed tubes registering with the row of tablet feed openings in the feed sector, a rotary drum disposed between the lower ends of the tablet feed tubes and a blister band moving on a linear conveyor and having a plurality of rows of blisters along the length thereof, the drum being disposed across the blister band and being rotatable about a horizontal axis, the drum having a plurality of rows of tablet cavities across the drum about its circumference, each row of tablet cavities registering with the lower ends of the tablet feed tubes and each row of blisters in the blister band and a curved tablet guide plate disposed over the drum in the direction of rotation of the drum and mounted in position with one end of the guide plate disposed close to the lower ends of the tablet feed tubes and the other end of the guide plate extending over a segment of the drum, wherein the lower end of each tablet feed tube has an uncut portion and a cut out portion diametrically opposite to each other and wherein the cut out portion is disposed in the direction of rotation of the drum and wherein the lower end of the uncut portion is at a distance of 1 to 2mm from the circumference of the drum and the cutout portion extends upto a distance of 3-4mm from the circumference of the drum.

DESCRIPTION OF THE ACCOMPANYING SCHEMATIC DRAWINGS
Figs 1 and 2 are isometric views of a feed mechanism for feeding tablets to blisters of a blister band from opposite sides of the feed mechanism according to an embodiment of the invention disposed above a blister band;

Fig 3 is a top isometric view of the feed mechanism of Figs 1 and 2 disposed above a blister band;

Fig 4is a front view of the feed mechanism of Figs 1 to 3 disposed above a blister band.

Fig 5 is an isometric view of the upper ends of the tablet feed tubes of the feed mechanism of Figs 1 to 3 from below the tablet feed chamber;

Fig 6 is an isometric view of the lower ends of the tablet feed tubes of the feed mechanism of Figs 1 to 3 disposed above the rotary drum;

Fig 7 is a scrap front isometric view of a tablet feed tube and drum of the feed mechanism of Figs 1 to 3; and

Fig 8 is an isometric view of a tablet feed tube of the feed mechanism of Figs 1 to 3.

DESCIRPTION OF EMBODIMENTS OF THE INVENTION
The feed mechanism 1 for feeding tablets (not shown) to blisters 2 of a blister band 3 moving on a linear conveyor 4 and having a plurality of rows of blisters along the length thereof, includes a vibratory tablet feeder 5 comprising a feed chamber 5adisposed at an elevation for vibration about a vertical axis6. The feed chamber comprises a feed sector 7 at the bottom thereof having a plurality of tablet feed channels 8 leading toa row of tablet feed openings 9.

A row of rigid tablet feed tubes 10 are vertically disposed below the feed chamber with the upper ends of the tablet feed tubes registering with the row of tablet feed openings in the feed sector. 11 is a bracket for holding the tablet feed tubes together at the upper ends thereof (Fig 5).The tablet feed tubes are mounted in position to a bracket 12 which is turn is mounted to the blister packing machine frame 13. A rotary drum 14 is disposed between the lower ends of the tablet feed tubes and the blister band. The drum is disposed across the blister band and is rotatable about a horizontal axis15 and consists of a plurality of rows of tablet cavities16 extending across the drum about its circumference. Each row of tablet cavities register with the lower ends of the tablet feed tubes and each row of blisters in the blister band. A curved tablet guide plate 17 is disposed over the drum in the direction of rotation of the drum and mounted to the bracket 12. One end of the guide plate is disposed close to the lower ends of the tablet feed tubes and the other end of the guide plate extends over a segment of the drum.

Each of the tablet feed tubes 10 is slitted and has a longitudinal slit 18 along the length thereof (Figs 5, 6, 8). The lower end of each tablet feed tube has an uncut portion 19 and a cut out portion 20 diametrically opposite to each other. The cut out portion is disposed in the direction of rotation of the drum (Figs 4, 6, 7, 8). The lower end of the uncut portion is at a distance of 1 to 2mm from the circumference of the drum and the cut out portion extends upto a distance of 3-4mm from the circumference of the drum. The longitudinal slit 18 extends through the uncut portion at the lower end of the tablet feed tube, preferably through the center of the uncut portion.

During cyclic operation of the feed mechanism 1, the tablet feed chamber5 vibrates about its vertical axis 6 and the tablets in the tablet feed chamber enter the rigid tablet feed tubes10through the tablet feed openings9 in the tablet feed sector7of the tablet feed chamber and travel down through the tablet feed tubes. Bottom most tablets in the tablet feed tubes drop down into a row of tablet cavities 16on the drum 14under gravity. During rotation of the drum about its horizontal axis, the tablets in the row of cavities on the drum are retained in position and guided on the drum by the curved tablet guide plate 17. The tablets in the row of cavities on the drum drop down into a row of blisters 2 in the blister band3 aligned with the row of tablet cavities with tablets when the row of tablet cavities with tablets have crossed over the other end of the curved guide plate. The tablet feeding into the blisters in the blister band continues and the blister band with the tablets move forward for further processing.

Because the distance between the lower ends of the uncut portions 19 of the tablet feed tubes 10 from the circumference of the drum 14 is small of the order of 1-2mm, the gravitational force acts on the tablets at the lower ends of the tablet feed tubes effectively and the tablets at the lower ends of the tablet feed tubes slide down against the uncut portions and fall down into a row of tablet cavities 16 on the drum 14 under gravity. Due to the depth of the cutouts 20 at the lower ends of the tablets feed tubes 10 being 3-4mm from the circumference of the drum, there is sufficient clearance between the cut out portions 20 of the lower ends of the tablet feed tubes and the tablets in the row of tablet cavities on the drum. Therefore, during continued rotation of the drum with the tablets in the row of tablet cavities on the drum, the lower ends of the feed tubes do not obstruct the tablets in the tablet cavities and instead allow the drum to rotate with the tablets smoothly and continuously without damaging the tablets. The tablets in the tablet cavities on the drum drop down in to a row of blisters 2 in the blister band 3 as they cross over the other end of the tablet guide plate 17.

Because the tablet feed tubes 10 are rigid, the tablets move down in the feed tubes at a fast rate and there are no chances for the tablets to get locked in the feed tubes as the rigid tablet feed tubes are not to twisting and turning as in the case of the flexible feed tubes. Due to the faster movements of the tablets in the tablet feed tubes, the feed rate and productivity are substantially increased in the feed mechanism of the invention.

Because of the longitudinal slits 18 in the feed tubes 10, the movements of the tablets in the feed tubes can be continuously seen and monitored by the operator of the blister packing machine. In case of any tablet locking in the feed tubes such is instantly noticed by the operator and rectified. Productivity is increased because of this also. The feed mechanism of the invention comprises few component parts and is simple in construction, reliable and cost effective. The rigid feed tubes of the feed mechanism can be manufactured with materials such as stainless steel and are also simple in construction and cost effective as compared to the flexible feed tubes.

The feed mechanism of the invention eliminates the shuttle mechanism and is comparatively less noisy in operation. It does not employ suction and positive air pressure to suck in the tablets into the tablet cavities on the drum and to push out the tablets in the tablet cavities on the drum. The tablets fall down into the tablet cavities on the drum under gravity and also drop down from the tablet cavities on the drum under gravity. It is understood that the feed mechanism of the invention can be used for feeding any other solid articles such as pills, capsules and the like and that the applicability of the feed mechanism of the invention is not confined to tablets only.

We claim:
1. A feed mechanism for feeding tablets to blisters of a blister band, including a vibratory tablet feeder comprising a feed chamber disposed at an elevation for vibration about a vertical axis and having a feed sector at the bottom thereof with a plurality of tablet feed channels leading to a row of tablet feed openings, a row of rigid tablet feed tubes vertically disposed below the feed chamber and mounted in position with the upper ends of the tablet feed tubes registering with the row of tablet feed openings in the feed sector, a rotary drum disposed between the lower ends of the tablet feed tubes and a blister band moving on a linear conveyor and having a plurality of rows of blisters along the length thereof, the drum being disposed across the blister band and being rotatable about a horizontal axis, the drum having a plurality of rows of tablet cavities across the drum about its circumference, each row of tablet cavities registering with the lower ends of the tablet feed tubes and each row of blisters in the blister band and a curved tablet guide plate disposed over the drum in the direction of rotation of the drum and mounted in position with one end of the guide plate disposed close to the lower ends of the tablet feed tubes and the other end of the guide plate extending over a segment of the drum, wherein the lower end of each tablet feed tube has an uncut portion and a cut out portion diametrically opposite to each other and wherein the cutout portion is disposed in the direction of rotation of the drum and wherein the lower end of the uncut portion is at a distance of 1 to 2mm from the circumference of the drum and the cutout portion extends upto a distance of 3-4mm from the circumference of the drum.

2. The feed mechanism as claimed in claim 1, wherein the rigid tubes are made of stainless steel.

3. The feed mechanism as claimed in claim 1, wherein the rigid tubes are slitted tubes, each having a longitudinal slit along the length thereof extending through the uncut portion at the lower end thereof.

4. The feed mechanism as claimed in claim 3, wherein the longitudinal slit extends through the center of the uncut portion.

Dated this 8th day of July 2015

(Jose M A)
Agent for the Applicants
of Khaitan & Co
Reg No IN/PA-44