MXPA00009959A - Machine for enrobing tablets with gelatin - Google Patents

Abstract

An apparatus for enrobing tablets in a gelatin layer includes a pair of die assemblies with each assembly including a rotatable, cylindrical die support and a series of die blocks mounted on this support for movement along a circular path. Each block has recesses formed in a top surface thereof and each recess of one assembly cooperates with a similar recess in the other assembly to form a cavity at a nip formed by the two assemblies. Each cavity is dimensioned to receive loosely therein one of the tablets. Two casting drums deliver gelatin strips to the die assemblies and each strip is pulled by one assembly into the nip. A time tablet dispensing mechanism is used to dispense tablets onto one of the strips at a feeding location. The preferred die blocks are made of hard plastics material. The tablet dispensing mechanism employs vacuum applying members operatively connected to a vacuum source and air cylinder transfer mechanisms for moving these members from a tablet pick-up position to the feeding location.

Description

MACHINE FOR COVERING TABLETS WITH GELATIN FIELD OF THE INVENTION This invention relates to an apparatus for coating tablets of medicines and other products that can be ingested, with a digestible film.

BACKGROUND OF THE INVENTION The pharmaceutical industry commonly provides drugs in the form of a capsule or tablet that can be easily swallowed by a person. The dosage form known as a tablet is solid and hard and has a predetermined fc shape. Its active ingredients are kept together with a suitable binder. The recent US Patent No. 5,146,730 issued September 15, 1992 to Banner Gelatin Products Corp., describes a method and apparatus for producing medicated tablets that are coated with a gelatin coating formed by the application of two layers of film, a the opposite sides of the tablet. The hard cores or preforms are provided in an automatically synchronized base, in simultaneous contact with the two films that are supported on rotating matrices of joint action that are put together to form a contact free space. The hard cores make contact with the films adjacent to this contact free space, in places that remain on cavities formed in the matrices. The elastic films deform around each core and are sealed by the matrices against each other. The matrices then cut the covered cores to remove them from the films. One of the difficulties of this known apparatus is that the rotating die members, which are believed to be made of metal, are quite expensive to manufacture. If one or both of the rotating dies will be damaged for some reason, it may be necessary to completely replace one or both rotating die members, at a substantial cost. In addition, should this occur and it would be necessary to stop a manufacturing operation until one or more rotating matrices, it is very likely that as a result of the stoppage of operations there will be an additional and substantial expense and loss. The recent North American Patent No. 5,682,733 issued November 4, 1997 to the present applicant, describes another device for coating 5 tablets, apparatus that employs a main guide crawling of matrix blocks where each block has a number of cavities formed in its upper surface. There is also a co-operating, rotating matrix device, which may be either another link rail or a cylindrical rotating die and this device also has a plurality of cavities, each of which cooperates with a cavity of similar size in the main crawler, to provide an enclosed cavity capable of storing one of the tablets. A strip of gelatin is supplied to the main link and moves along its upper path. A tablet dispenser drops tablets into depressions formed in this strip of gelatin. A second strip of gelatin is supplied to the apparatus and is placed on the first strip when the two strips reach a contact region. An object of the present invention is to provide an apparatus for coating tablets with a layer of gelatin, apparatus employing assemblies of rotating dies, each of which has a series of matrix-holding blocks 0 and the apparatus can be repaired if damaged, with a reasonable speed, and with less expense than that caused by rotating die members of the prior art. Another object of the present invention is to provide relatively inexpensive die-cast blocks for use in an apparatus for coating ingestible tablets, these blocks are made of a hard plastic material and each has a number of similar cavities formed in the upper part. A further object of the present invention is to provide an apparatus for coating tablets with a gelatin layer, which employs a novel, synchronized tablet dispensing mechanism, having one or more 0 members for vacuum application, which can be functionally connected to a source of vacuum and a transfer mechanism for moving one or more of these members from a position to pick up the tablets to a feeding site. 9 SUMMARY OF THE INVENTION 5 According to one aspect of the invention, an apparatus for coating tablets with a gelatin layer includes a pair of rotating, cylindrical die assemblies, wherein each die assembly includes a die support, rotating , substantially cylindrical, and a series of die-holder blocks mounted on the die support to rotate about a central axis of the support matrix. Each block has at least one cavity formed in an upper surface thereof and each cavity of each die assembly cooperates with a similar cavity that is located in the other die assembly, to form a cavity in a contact surface formed by the assemblies of matrices. Each cavity is dimensioned to receive loosely in it, one of the tablets. The device also includes an actuator system for rotating both arrays of matrices about their respective central axes, such that the two series move in synchronism with each other. The feeding apparatus supplies a strip of gelatin of selected thickness and composition to each of the die assemblies. During the use of the apparatus, each strip of gelatin is pulled by one of the respective matrix assemblies, towards the contact surface and remains on a section of the series of matrix blocks of the respective matrix assembly. A synchronized tablet dispensing mechanism dispenses whole, individual tablets onto one of the gelatin strips at a feeding site which is upstream of the contact surface. Each tablet dispensed is moves with the gelatin strip towards the contact surface and the portions of both gelatin strips are stretched around the tablet dispensed in one of the respective cavities, in such a way that the tablet is coated by the portions of both strips. In a preferred embodiment, each matrix holder block of each series, has a number of cavities arranged in one or more rows that are they extend transversely to their respective matrix assembly and are made of a hard, plastic material. According to another aspect of the invention, a block Matrix holder, for use in an apparatus for coating ingestible tablets, of selected size and shape, with a gelatin film, has an upper part, a bottom and sides extending between the top and the bottom. There is a number of similar cavities formed in the upper part where each cavity is sized to loosely receive therein at least one half of one of the tablets. A raised ridge extends around a perimeter of each cavity, to cut a gelatin film placed on top of the top of the _ block, during the use of the block, which is made of plastic material, hard ^ In a particularly preferred embodiment, the block is made of plastic material reinforced with carbon fiber. According to a further aspect of the invention, an apparatus for coating tablets in a gelatin layer, includes a pair of rotatable, cylindrical die assemblies, having jointly acting work surfaces, which are located in a contact surface of the assemblies. Each die assembly has a number of cavities formed in its work surface, along a circumferential line and each cavity cooperates with a similar cavity that is finds in the other die assembly, to form, on the contact surface of the assemblies, a cavity sized to loosely receive one of the tablets therein. The apparatus further includes an actuator system for rotating the die assemblies, such that these die assemblies move in synchronization with each other and with the feeding mechanisms for the delivery of two. gelatin strips to the matrix assemblies, whereby, during the use of the apparatus, the gelatin strips are pulled by the matrix assemblies, towards the contact surface. A synchronized tablet dispensing mechanism for dispensing individual tablets on one of the gelatin strips is provided at a feeding site located upstream of the contact surface between assemblies.

This gelatin strip is supported by the work surface of one of the assemblies of matrices, on the feeding site. The tablet dispensing mechanism includes at least one vacuum application member operatively connected to a vacuum source and a transfer mechanism for moving the at least one • Vacuum application member, from a position to pick up tablets, to the feeding site, wherein, during the use of the apparatus, at least one tablet is released by the vacuum application member, on the gelatin strip. The operation of the tablet dispensing mechanism is synchronized with the rotation of the die assemblies, such that each tablet is released onto one of the respective cavities of one of those die assemblies.

Preferably the tablet dispensing mechanism comprises a number of vacuum application members arranged in a row 9 which extends transversely in a die assembly and the transfer mechanism includes a sliding structure member on which the vacuum application members are mounted. Additional features and advantages will be apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS 20 Figure 1 is a front elevational view of an apparatus for coating tablets, constructed in accordance with the invention, wherein a front cover plate shown with dotted lines and the tablet feeding mechanism is shown. it is omitted for reasons of illustration; Figure 2a is a plan view, partially in section Cross section, showing front and back support plates, for the apparatus of figure 1, a bowl feeder, and hoppers feeding the tablets towards the array of dies; Figure 2b is a detailed view illustrating the coupling between each matrix block and its cylindrical support; 30 Figure 3 is an elevation view, in cross section, vertical, showing the two array assemblies of the apparatus and the contact surface formed by them; Figure 4 is an elevation view, partly in cross section, showing an actuator motor and a drive shaft for the apparatus; Figure 5 is a cross section taken along the line -5 of Figure 1, which shows details of array assemblies; Figure 6a is an elevational view, cross-sectional, taken along line 6a-6a of Figure 6b, showing a roll for scrap tape and a spring-driven, cooperative roll, mounted downstream of the assemblies of rotating dies; Figure 6b is an end view of the left side, of the rollers, of Figure 6a and the assembly thereof; Figure 7 is a plan view of one of the die-holder blocks, used on the two die assemblies shown in Figure 3; Figure 8 is an end view of the die block of FIG. 7; Figure 9 is a cross-sectional view of the die block, taken along the line IX-IX of Figure 7; Figure 10 is a side view of a metal support ring used to separate the matrix blocks, in the assembly, and the ring is shown on the side facing the matrix blocks; Figure 11 is a front elevational view, illustrating the front attachment plate covering the front of the rotating die assemblies; Fig. 12 is a side elevational view showing a synchronized tablet dispensing mechanism for use in the apparatus of Fig. 1; and Figure 13 is a front view of the tablet dispensing mechanism of Figure 12.

DETAILED DESCRIPTION OF THE PREFERRED MODE Figures 1 to 3 illustrate a preferred apparatus 10 for completely cover ingestible tablets of medicine or similar products, in a layer of gelatin, and one of these finished tablets is shown in 12 in the ^ figures 12 and 13. Not shown in figure 1 but shown in figure 2 is found ^ a bowl feeder 14 which per se is of known structure. Also, not shown in Figures 1 to 3 is a synchronized tablet dispensing mechanism 16, a preferred form of which is presented in Figures 12 and 13. This synchronized tablet dispensing mechanism is assembled rigidly on a vertically extending front support plate 18 and which is rigidly attached to a rigid base structure 20 adequate. The structure 20 supports the apparatus 10 on a floor or other surface A suitable horizontal and only part of the structure is shown. Extending parallel to the plate 18 is a back support plate 22. These plates 18, 22 as well as the other components and metal parts of the apparatus are generally made of aluminum or stainless steel, due to the requirements sanitary and cleaning for a machine of this type. The tablets produced by the apparatus 10 are completely enclosed and sealed and comprise preforms supplied from the bowl feeder 14 and a gelatin coating produced from two continuous belts or gelatin films indicated in 24 and 28. The individual preforms are dispensed on the gelatin strip 24 at a feeding site indicated at 30 That, in a particularly preferred embodiment, it is approximately . 24 cm (6 inches) from a contact surface 32 formed by two die assemblies, rotating, cylindrical, indicated in general at 34 and 36. The two gelatin strips 24, 28 are joined on the contact surface 32 The assemblies of matrices each include a rotating, substantially cylindrical die support, 38, and a series of portamatnces blocks 40 mounted on the die support, for rotation about a central axis of the die support 38. One of these die-holder blocks 40 is illustrated in figures from 7 to 9 and it will be understood that all of the matrix-holder blocks 40 in the two mounts of matrices can be of identical structure. For ease of manufacture and costs reduced, the matrix-holder blocks 40 are preferably made of a hard, strong and durable plastic material, and can be manufactured by an injection molding process. A preferred form of plastic material is a ™ plastic material reinforced with carbon fiber. In a preferred embodiment of apparatus 10, the blocks are made of thermally stabilized polyphthalamide (PPA), reinforced with carbon fiber. This preferred plastic material has a tensile strength of 3,269.3 kg / cm2 (46,500 psi) (ASTM method D638) and a flexural strength of 4535 kg / cm2 (64,500 psi) (ASTM method D790). Each matrix block 40 has at least one cavity 42 formed on an upper surface 44 thereof. It will be understood that each cavity ^ of each rotating assembly 34, 36 cooperates with a similar cavity 42 which is located in the other rotating assembly, to form a substantially enclosed cavity, in the contact surface 32 formed by the rotating assemblies. This cavity is dimensioned to receive loosely in it one of the tablets 12. The illustrated matrix block 40, preferred, has a number of cavities 42 arranged in a single row that extends longitudinally in the matrix block and transversely to the guide 38 of respective matrixes of the block. Although the illustrated matrix block is presented with only one row of cavities, it is of course possible to construct a matrix block with two or more rows of cavities, if desired. The illustrated cavities are of fc, substantially oval form in order to accommodate tablets of this general form, but it will be understood that other shapes such as for example round, depending on the shape of the tablets for which the apparatus is designed are also possible. Slots or holes 46 can be provided in the bottom of the cavities to allow the escape of air from the cavities during the encapsulation process of the tablets. Each matrix block 40 has two or more rows of teeth 48 formed on a bottom 50 thereof. In one embodiment of the block having eight cavities on top, there are nine rows of three teeth per row, each of which extends transversely in the elongated block. 30 Using this number of rows of teeth, it is ensured that no undue stress or load on the individual teeth, when the blocks rotate with the matrix support. The preferred matrix building blocks have cavities formed 9 52 of the bottom, the number and shape of which may correspond to the number and 5 shape of the cavities 42. Two rows of the teeth 48 are located on each side of each cavity 52. Each matrix block has molded connecting members that are laterally projecting 54, 56. In the illustrated embodiment, each of these connecting members comprises three, generally cylindrical protuberances 57, 58 and 59 and these are connected by integral structures 60. These connecting members 54, 56 extend respectively into a hole or holes 62 having a similar cross-sectional shape in a metal ring support 64, one of which is shown in figure 10. There are two of these rings 64 mounted on each assembly to rotate the matrix, one on each side of the series of matrix blocks. These rings, which may be manufactured from bronze, act to connect each series of matrix blocks, so that they are evenly separated, some relative to each other, around their respective matrix support. The rings are connected, so that they can be disengaged, to the die-holder blocks, since the connecting members 54, 56 simply slide into their holes 62. The preferred die-holder block 40 also includes limbs 66 of i locating the dies, projecting upwardly from the opposite ends of the upper part of the die-holder block and help to align the die-holder block with another cooperating die-holder block of the apparatus, during the use thereof. In block 40, as illustrated in Figure 7, there is a member 66 of location of the matrix, central, at the far left, and two members 66 at the far right. There are also cavities 68 locating the dies, formed at opposite ends of the upper part of the matrix block 40. It is the combination of the members 66 and the cavities 68 that helps to align the matrix block 40 with another cooperating matrix-bearing block It will be understood that the cavities 68 have such a size to receive the members 66 of the block die carrier, cooperating, which will be arranged in such a way that its end sections are the opposite of the end sections of the first matrix block. • An elevated flange 70 extends around the perimeter of each cavity 42 for cutting the continuous ribbon or gelatin strip 24, 28 after it is above the upper part of the block and is pulled inward from the contact surface 32. The upper edge 72 of the flange should be slightly curved from one end of the cavity, to the opposite end, to coincide with the curvature of the circumference of the matrix support. In this way, the opposite ridges on the opposite matrix-bearing blocks, as they pass to _ through the contact surface 32, they will cut uniformly and completely the ^ Continuous gelatin tapes to encapsulate the tablet. Preferably, the ridges 70 formed on the upper part of the matrix-bearing blocks 40 have a width of one to two times the thickness of the remaining gelatin ribbon. above the cavity. For example, for a tablet or capsule of small size, the width of the flange may be approximately 0.10 cm (0.04 inches). The height of the flange 70 should be greater than the thickness of the continuous ribbon of gelatin. Returning to figure 1, there are shown in the same, means of feed to supply a strip of gelatin 24, 28 of selected thickness and composition fc, to each of the assemblies 34, 36 to rotate the die. The continuous films or tapes 24, 28 are molded separately, by rotating molding drums which per se are of known structure. These drums 74, 76 can be made of stainless steel. It will be understood that gelatin in a state Liquid is supplied to each drum through a heated hose (not shown). Before use, gelatin is stored in a jacketed tank that holds liquid gelatin at a temperature of at least 60 ° C (140 degrees F).

By the force of gravity the liquid gelatine passes through the hoses to a rolling box 75 located in the upper part of each molding drum. The rolling box itself can be heated with two heating cartridges to keep liquid gelatin at a temperature of approximately 60 ° C (140 degrees F). The liquid gelatine is sprayed onto the molding drum which rotates and gives the gelatin the shape of a ribbon or strip. A fan blower 78 is provided on each molding drum and acts to cool the gelatin, such that it changes to a solid strip that can be detached from the molding drum, on a small, adjustable roller 80. Preferably a lid metal 79 extends over the strip formed on the drum. The thickness of the gelatin strip can vary from 0.0254 to 0.0762 cm (10 to 30 thousandths of an inch). Each strip of gelatin passes through a lubricating roller with oil, rotating 82 which applies a thin layer of oil on the outer surface of the strip. The oil helps to ensure the release of the gelatin strip from its assembly for the rotation of the matrix,? respective, after the strip passes through the contact surface 32. The gelatin web 24 then extends to a lower die assembly 36 where it is placed on the die-holder blocks 40 located in the top of the assembly. The gelatin ribbon 28 extends to the upper die assembly 34 where it is placed on top of the rotating die blocks, which extend through the upper part of the die assembly 34 and below one side thereof, up to the contact surface 32. After the two continuous tapes 24, 28 pass through the contact surface 32, these adhere to each other and, in this state, are pulled downward through a roll 84 for waste tape, which is presented with details in Figures 6a and 6b. > The used gelatin web can then be deposited in a suitable container (not shown) for subsequent disposal. An actuator system is provided to rotate both arrays of matrices 34, 36 about their respective central axes, in such a way that the two series of blocks move in synchronization with each other. The start of the preferred actuator system is shown in Figure 4 and starts with an electric motor 86. The illustrated motor is mounted on a horizontal support plate 88 but it is also possible to mount the drive motor on the floor. One uses bracket 90 extending vertically, to secure the plate 88 to the plate main back 22 which can be an aluminum or stainless steel plate of 2.54 cm (one inch). Four connection pins 92 extend between the bracket 90 and the back plate 22. An output shaft 94 of the motor, is connected to a main motor shaft 96 which is rotatably mounted on the back plate 22 by the ball bearings 98. These bearings are held in place by a support cover plate 100 and the bolts 102. A standard shaft coupling 104 secures the motor shaft 94 to the shaft 96. It will be understood that if the motor 86 is mounted on the floor, suitable pulleys and a drive belt 97 can connect the output shaft 94 of the motor to the shaft. 96. An actuator of this type is presented in part in FIG. 5. Referring now to FIG. 5, the front section of the main drive shaft 96 is shown extending through the main drive gear 108. The front section of the shaft is mounted so that it can rotate, in the faceplate 18, which can also be a 2.54 cm (one inch) plate, and in the front support plate 160. The ball bearings 110, 112 rotatably support the shaft. The drive gear 108 rotates a smaller pinion or drive gear 114 mounted on the horizontal shaft 116. The shaft 116 is supported on the ball bearings at 118 and 120. The bearings 118 are secured to the front plate 18 by the plate support cover 122 and connecting bolts 124. The shaft 116 which is made of stainless steel supports an actuator gear 126 mounted to the rear of the rear plate 22. The gear 126 is coupled to a similar gear 127 mounted on the shaft rotary 131. The gear 127 is functionally coupled to another similar gear 132 of equal size and mounted on the stainless steel drive shaft 134. The shaft 134 extends through the front and rear plates and through a conduit formed along the central axis of the upper die assembly 34. The shaft 134 is supported, so as to be able to rotate, by three ball bearings at 136 , 137 and 138. The two series of matrix blocks 40 and their cylindrical supports are rotated at the same speed. The central shaft 134 is used to properly position the die assembly 34 relative to the lower mount 36.

Now the preferred structure of each assembly 34, 36 which rotates the die will be explained, with reference to Figs. 3 and particularly Fig. 5. Reference will be made to the assembly 36 which rotates the die, shown in detail in FIG. 9 figure 5 and it will be understood that the assembly 34 is constructed in a similar manner. The main component of the die guide is a solid aluminum cylindrical block 146 through the center of which is a duct 148 that houses the front end section of the main drive shaft. A series of small teeth 150 that extend transversely, is formed around the circumference of this block, for the coupling with the rows of teeth formed on the bottom of the blocks 40 (see Figure 2b). In a preferred embodiment, the diameter of this block is 28 cm (eleven inches). The teeth 150 ^ they extend across the width of block 146 preferably. Connected to the opposite sides of the block are two circular, stainless steel side plates 152, 154 which may have a thickness of 1.9 cm (3/4 inch). These plates are rigidly connected to the block by connecting screws 156. An annular rim is formed around each plate 152, 154, at 158, in order to hold each brass ring 64 in place. The end of the bottom of the fixing plate 160 can be connected, so that it can be disconnected, to the front plate 18 by means of the connection plate 168 and screws suitable for this purpose can be used. A similar connection plate 169 can connect the upper part of the fixing plate 160 to the front plate. The assembly 34 that rotates the upper die is adjustably mounted to the front plate 18 and the front attachment plate 160. The adjustable assembly 25 for the shaft 142 is substantially the same on each of the plates 18, 22 and 160 and therefore, herein, reference will be made only to the adjustable support on the front fastening plate 160. As shown in Figure 11, two parallel, straight, guide plates 168, 170 are joined by screws 172. to the outer surface of the plate 160. The guide plates have an inner edge 174 projecting 30 over a rectangular opening 183. These plates 168, 170 hold in a form sliding a rectangular support plate 176 having a central hole 178. This plate 176 can be moved up or down in the opening 183 formed in the plate 160. The bearing 138 is mounted in the plate 176. Leaning on the upper edge of each plate 176 is a pressure bolt 186 extending downward from the end of a threaded bolt or screw member 188 that is part of a pressure gauge 190 of the die plate. Preferred calibrators 190 have a graduated disk (not shown) at its upper end 192 which provides a reading of the pressure, and this pressure can be read in psi. In a preferred embodiment, by rotating each pressure gauge in the direction of clockwise movement, additional pressure is exerted on the upper part of the plate or slide 176. This plate and the attached die assembly move against the pressure of two or more coil springs 194, the upper ends of which can be accommodated in cylindrical cavities 195 formed in the bottom of the plate 182. The bottom end of each spring presses against the support surface 196 in the fixing plate 160 As shown in Figure 5, three pressure gauges of similar structure are preferably used, in order to provide a precise adjustment of the position of the upper die assembly 34 and its axis 134. The preferred gear arrangement for rotating the two molding drums 74, 76 at the same speed and at the same time, by means of the individual main drive shaft, 96, will now be described with particular reference to the Figures 1 and 2. The shaft 96 rotates the main drive gear 108 shown in Figure 5 and drawn with dotted lines in Figure 1. This drive gear turns five free secondary gears, identical, from 200 to 204 arranged in a horizontal row, each of which are mounted on its own rotating shaft 206. These shafts are mounted by ball bearings, on the rear support plate 22 and on the front plate 18 such as shown in figure 2. Mounted on the last shaft 206 is a smaller gear 208 that rotates with the free secondary gear 204 and drives a larger gear 210. This gear is mounted on the rotating shaft 212 that supports, of Way that can rotate, the molding drum 74. It will be understood that the sizes of the gears are arranged to drive the molding drum at the required rotational speed, with the rotation of the main drive shaft 96. In order to drive the molding drum 76 , the drive gear main 108 rotates a free, smaller secondary gear 220, which then rotates three free, identical and in-line secondary gears 222 through 224. Gear 224 has been omitted from Figure 2 for illustration purposes. The free secondary gears 222 to 224 are supported on their respective shafts 226 that are supported, so that they can rotate, on the plate front 18 and on the back plate 22. Mounted on the outermost shaft 226 is a second smaller gear 228 shown with dashes in the figure ^ 1. The gear 228 in turn drives a larger gear 236 which is mounted on a relatively large shaft 238 on which the molding drum 76 is mounted. In this way the rotation of the main drive shaft 96 makes also rotate the molding drum 76 and at the same speed as the drum 74. Now focusing on the means for dispensing tablets on the gelatin strip 24, the aforementioned bowl feeder 14 is capable of supplying appropriately oriented pills to a number of hoppers 240 for tablets, which extend downwards and along a slope, from the exit of the bowl feeder located at 242. If there are eight cavities 42 formed in each matrix block, there are then eight separate hoppers 240, which form eight inclined lines of tablets. The hoppers are sized, each, to receive the preforms or tablets arranged in a single line and oriented properly, and are arranged side by side across the width of the assembly 36 that spins the matrices. Preferably the hoppers are made of a non-abrasive, slippery material, in such a way that the preforms slide easily along. The inclination of the hoppers should be large enough so that the preforms slide easily under the force of gravity, but not so large enough to exert an undue weight on the preforms in the background of the hoppers. The hoppers extend down to a site near the feed site 30 at the top of the assembly 36 that rotates the die. The tablet dispensing mechanism includes a tablet transfer device, generally indicated at 250 in Figures 12 and 13. The illustrated device is capable of moving eight tablets 12 from a bottom section 252 of the hoppers, to the strip gelatin 24 which, at this time, is supported by the die-holder blocks 40. The preferred transfer device includes vacuum application members 254 used to collect tablets 12 from their respective hoppers, and a vacuum source 256 indicated only schematically in FIG. Figure 12. The vacuum source is functionally connected to the vacuum application members, by a vacuum line or hose 258 on which a suitable vacuum control valve 259 is mounted. The end of line 258 can be connected to a tubular support member 260 which extends horizontally and which can extend substantially across the length of the adjacent matrix holder blocks, as shown in Figure 13. The application members vacuum, preferred, illustrated, include a suction cup 262 of rubber or rubber-like material, with such a size to fit over the top of the tablet 12 and a tubular metal cup connector 264 that is firmly connected to the bottom of the support member 260. A plenum chamber 266 within the support member 260 is enclosed and evacuated by the vacuum line 258. Each vacuum application member 254 is functionally connected to this plenum chamber and consequently vacuum is provided to each of the members 254 when it is required to pick up a tablet. It will be appreciated that the valve 259 is provided to control the vacuum in the plenum chamber and in the limbs 254 and the air can be supplied quickly to the plenum and the limbs 254., when required, to release the tablets that are on the gelatin strip. The tablets 12 are each collected by a respective vacuum application member 254, in a position for picking up tablets, indicated at 270 in Figure 12. This position is at the end of the hopper 240 for tablets The ends of the hoppers are closed by an end wall 272 that extends vertically, but the upper part of the end section of each hopper is open to allow the lifting of individual tablets at the bottom end of the hoppers. It will be understood that the tablet transfer device 5 causes the vacuum application member 254 to move into the next operating sequence. Members 254 with their flexible vacuum cups are placed directly above the bottom tablets and then lowered to make contact with the end tablets. Preferably the vacuum cup 262 is applied to the front portion of the upper part of the tablet 12. This is done to ensure that, in the event that the bottom tablet is broken or split, the vacuum cup will always pick up the less the portion of the tablet that is in the most extreme portion of the hopper, in other words, the portion adjacent to the end wall 272. In this way the unwanted accumulation of pieces of tablets at the end is largely prevented. background of the hoppers. After the vacuum cup has been lowered to the top of the pill, vacuum is generated in the plenum chamber 266 thus allowing the vacuum cup to hold the end tablet securely. The members 254 are then raised together with the support member 260 and the end tablets are raised enough to clear the end wall 262. 0 Subsequently the transfer device 250 causes the tablets, with the support member 260, to be moved. about 2.54 to 3.81 cm (one to one and a half inches), horizontally, and then the tablets and the member 260 are lowered so that the bottom of each tablet is just above the surface of the continuous ribbon of jelly. At the same time that the tablet 5 reaches this position above the continuous ribbon of gelatin, the vacuum in the plenum 260 is eliminated, thereby releasing the tablets 12. It will be understood that the operation of the tablet dispensing mechanism is synchronized with the rotation of the matrix blocks, particularly the blocks on the assembly 36, such that each tablet 12 is released above each of the respective cavities of the blocks.

The preferred transfer device 250 shown in Figures 12 and 13 is firmly mounted to the faceplate 18 by screws 280. The preferred transfer device 250 comprises a first and a second ™ actuator devices, of air cylinders, wherein the first actuator device 282 provides substantially horizontal movement and the second actuator device 284 provides a substantially vertical movement. Each of these actuator devices can be of standard construction for that type of devices and therefore, a detailed description thereof is considered unnecessary here. Briefly, the first device actuator 282 extending horizontally, includes a rigid sliding table 286 containing an air cylinder or air chamber, indicated with lines ™ discontinuous at 288. Mounted in a sliding manner on this table is a rectangular support block 290. A guide rail 292 extends longitudinally along the center of the sliding table 286 and extends along a length of slit or groove having a similar cross-sectional shape in block 290. Movement of a piston member (not shown) that is in air cylinder 288 causes block 290 to move horizontally backward or forward. as required. The movable piston is connected to the block 290. The second, vertical actuator device, 284, is constructed in a similar manner and includes a vertically extending sliding table 294, which is rigidly mounted to the block 290 by bolts or connecting screws 295. A rectangular support block 296 is supported, so that it can slide, on the sliding table and moves as far as possible. along a central, longitudinal rail 298. Again, an air cylinder 300 is provided on the table 294 and a member of piston 302 slidable in this cylinder, is connected to support block 296. It will be understood that both actuator devices 282 and 284 are connected to pressurized air hoses (not shown) that provide pressurized air to these actuator devices in order to operate the same. The support block 296 is firmly and rigidly connected to the tubular support member 260 and in this way is able to move the member 260 upwards or downwards, when it's requested. Now focusing on the structure of the waste ribbon extractor 84, illustrated in Figures 6a and 6b, this device is driven by a train of 9 gears illustrated in Figure 1, from the main drive shaft 96. In particular, the main drive gear 108 drives a small free secondary gear 309 which in turn drives two free, larger, similar, secondary gears, 310, 311. The free secondary gear 311 drives a small gear 316 which in turn drives a larger free secondary gear 314, the purpose of which is to which is described later in the present. The gear 316 drives a roller 324 for waste tape, shown in Figure 6a. It will be appreciated that this gear train is supported, so that it can rotate, by axes W which extend through the faceplate 18 and which are mounted thereto. Shown in Figure 6a is the faceplate 18 through which the drive shaft 320 extends over which the gear 316 is mounted.

A pair of ball bearings at 322 supports the shaft on plate 18. Roller 324 for waste tape is mounted on shaft 320 for rotation therewith and this roller has a number of circumferential grooves 326 evenly spaced apart. These slots are provided to allow any tablets remaining on the waste ribbon to pass through the surface of the waste. contact formed by the roller and the adjacent spring tension roller 328 (shown in cross section). Small clamping teeth can be formed »On the flanges 330 in order to allow the roller to grip over and remove the waste tape better. A nut 332 and suitable washers hold the roller in place on the shaft 320. An annular spacer 334 helps maintain the roller in its position. The upper roller with spring tension, has grooves that are aligned with the grooves 326 and the ridges that form the grooves also have clamping teeth. The roller 328 is supported by a horizontal support bracket 336 connected to the faceplate 18 and to four extending posts 338. down, around which coil springs 340 extend used to spring-tension the roller. The posts are screwed into the bracket 336 from below. Two bearing clips 342, 344 are mounted on the posts. The roller bearings are mounted on the supports to support the roller 328 so that it can rotate. It will be appreciated that the upper roller 328 acts to press down the waste ribbon, so that the waste ribbon is held firmly between this roller and the roller 324. These two rollers can be made of aluminum. The encapsulated tablets normally fall from the matrix-bearing blocks 40 after they pass through the contact surface. The tablets that remain in the cavities found in the matrix-bearing blocks are removed from the cavities by means of the ejection brushes 350 and 352 that sweep through their series of matrix-holding blocks, respectively. The position of these brushes is indicated in Figure 1. Separate gear trains can be provided to rotate each of the brushes 350 and 352, wherein the gear train for the upper brush 350 is driven by the free secondary gear 202 and the gear train for the lower brush 352 is driven by the gear 316. The gear 202 drives a series of three small gears, 400 to 402, where the last gear 402 is mounted on the same axis as the brush 350. The first gear 400 can also be used, if desired, to rotate the roller 82 lubrication with oil. The gear 316 drives a series of four gears 314 and 404 to 406, where the gear 314 is substantially larger than the other gears. The small gear 406 is mounted on the same axis as the brush 352. It will be understood that the rotary axes for both of these gear trains are mounted on the front plate 18. To ensure that the two gelatin strips 24 and 28 are heated to At a suitable temperature for the encapsulation step, a thermal lamp 354 can be placed above the gelatin strip 24 at the site indicated in Figure 1. In a preferred embodiment, this location is removed approximately 30.48 cm (twelve inches) from the contact surface in where the two gelatin strips are located. The thermal lamp can be rigidly mounted on the front plate 18. It will be appreciated that the thermal lamp heats the gelatin strip 24 sufficiently to become sticky and flexible, 9 so that when the tablets are dropped on the strip, they adhere to the strip itself and remain in place as they pass through the contact surface. A separate thermal lamp may be provided to heat the strip 28 if only the lamp 354 is not sufficient for this purpose. Mounted in a position adjacent to the perimeter of the assembly 36 for rotating the lower die, there is an electronic sensor 356 which can be per se of standard construction. This sensor accurately detects the rotational position of the matrix blocks 40, which are located on the assembly 36.

™ This sensor is connected to a programmable logic controller (not shown) which can also be a controller of a standard type suitable for controlling the operation of the tablet transfer device 250, described above and of the vacuum application members 254. This logic controller controls the operation of the first and second air cylinder actuating devices, 282 and 284, and the application of vacuum to the members 254, such that these devices will know when to pick up the tablets from the bottom end of the hopper, transfer them to the moving gelatin strip 24 and release them later. After the rotating die assemblies form the > encapsulated tablets, the tablets will normally fall under the force of gravity towards a container 360 provided below the downward movement section of the waste ribbon, as shown in Figure 1. The tablets which remain adhered on the waste ribbon will be able to pass through the roll 84 for waste tape, due to the grooves formed therein. In addition to the thermal lamp (s) 354 for heating the gelatin strips, other conditioning means may be provided for the gelatin strips, so that they have a deformation capacity and a adhesiveness, predetermined, with the tablets and with each other. For example, the device Complete 10 is best located in an air-conditioned room, so that temperature and humidity can be controlled to maintain the desired condition of the films. Those skilled in the art will appreciate that various modifications and changes can be made to the disclosed tablet coating apparatus and to the described matrix-bearing blocks, without departing from the spirit and scope of this invention. For example, instead of employing a tablet dispensing mechanism such as that illustrated in FIGS. 12 and 13, known tablet dispensing mechanisms such as the one illustrated in FIG. 26 of FIG.

US Patent No. 5,459,983, the specification and drawings of which are incorporated herein by reference. In this known dispenser, the preforms pass through hoppers and an eccentric cam mounted on a motor shaft extends into each tubular hopper through a side opening and makes contact with a tablet that is in the hopper. The contour of the cam is defined in combination with the rotation speed of this axis, to be coupled to a tablet that is in the hopper, each time a row of cavities in the matrix-holding blocks 40 reaches a desired position and drives the tablets in each hopper, a desired distance along the hoppers, where this distance is sufficient to allow the end tablet in each hopper to fall out of the hopper and on the continuous belt that passes. A flexible element, ie a flexible leaf spring, is mounted on the bottom end of each hopper, to hold the tablet lower down, in the hopper, until the cam operation mentioned above forces it beyond the element. flexible. As indicated, many variations of this invention are will occur to those experienced in this technique. Accordingly, all such modifications and changes that fall within the scope of the appended claims are considered part of this invention.

Claims (25)

1. CLAIMS 1.
2. An apparatus for coating tablets in a gelatin layer, the apparatus comprises: an apparatus (36) of cylindrical rotating dies, having a series of cavities (42) formed around its circumference; a rotating die assembly (34) including a rotating die holder, and a first series of die holder blocks (40) extending around the rotating die holder for rotation therewith, each block (40) has at least one cavity formed in an upper surface thereof and each cavity of the matrix assembly (34) cooperates with a similar cavity (42) of the array apparatus (36), to form a cavity in a contact surface formed by the apparatus (36) of dies and matrix assembly (34), each cavity is dimensioned to loosely receive in it one of the tablets; an actuator system (86, 96) for rotating both the array apparatus 36 and the array assembly (34), in synchronism with one another; feeding means (74, 76) for supplying a gelatin strip (24, 28) of selected thickness and composition, respectively, to both the die apparatus and the die assembly; and a synchronized tablet dispensing mechanism (16) for dispensing whole, individual tablets onto one of the gelatin strips (24) at a feed site (30), ie upstream of the contact surface (32), each dispensed tablet is moved with that gelatin strip (24) within the contact surface, during the use of the coating apparatus; the coating apparatus is characterized in that the apparatus (36) of rotating dies includes a matrix holder, rotating, (38), substantially cylindrical, and a second series of matrix holder blocks (40) mounted on the matrix holder for rotation about of a central axis, both the first and the second series of matrix blocks (40) are made of hard plastic material, each block of the second series has at least one of the cavities (42) of the matrix apparatus, formed on a surface upper thereof, the rotating die support (38) of the die assembly (34) is a single matrix support, substantially cylindrical, and the feeding site (30) is on the rotating, cylindrical die apparatus (36). ). • An apparatus according to claim 1, characterized in that each matrix block (40) of each series, has a number of cavities (42) arranged in one or more rows that extend transversely in the assembly (34) of matrix, respectively, or in the array apparatus (36).
3. 3. An apparatus according to claim 1 or 2, characterized in that each matrix holder block (40), of each series, has formed two 10 or more rows of teeth (48) on a bottom thereof and each matrix support (38), includes a series of teeth (150) extending around the > circumference of the matrix support and which are adapted to be coupled to the rows of teeth (48) that are on the blocks, in order to move the series of blocks with their respective matrix support.
4. 4. An apparatus according to any of claims 1 to 3, characterized in that the tablet dispensing mechanism (16) includes a bowl feeder (14) and a number of inclined hoppers (240) for tablets, in which, during operation, the bowl feeder feeds whole tablets properly oriented.
5. 5. An apparatus according to claim 4, characterized in that the tablet dispensing mechanism (16) includes a tablet transfer device for moving at least one tablet from a bottom section of each hopper (240) to a strip gelatin located at the feeding site (30), the transfer device includes application members from 25 vacuum (254) to collect the tablets from their respective hoppers and a vacuum source (256) functionally connected to the vacuum application members.
6. 6. An apparatus according to any of claims 1 to 5, characterized in that it has means for connecting together each series of matrix blocks (40), the connection means 30 comprises two metal rings (64) coupled, so that they can be separated, with two opposite sides of the series of matrix blocks (40) and mounted on the respective matrix support (38) for rotation therewith.
7. 7. An apparatus according to claim 6, characterized in that each matrix block (40) has molded limb members. 5 connections projecting laterally (54, 56) over the opposite ends thereof and each connecting member extends towards a hole formed in one of the adjacent rings (64).
8. 8. An apparatus according to any of claims 1 to 7, characterized in that the drive system includes a The main rotating motor shaft (96) connected to the apparatus (36) of rotating dies, for rotating it, a first gear (108) fixedly mounted on the shaft ^ main motor, a motor shaft (134) on which the rotating die assembly (34) is mounted, and a gear train that functionally connects the first gear (108) to the motor shaft (134) in order to rotate the last, with the rotation 15 of the main motor shaft.
9. 9. An apparatus according to any of claims 1 to 8, characterized in that each die block (40) is made of plastic material reinforced with carbon fiber.
10. An apparatus according to any of the claims 1 to 8, characterized in that each matrix block (40) t is made of thermally stabilized polyphthalamide, reinforced with carbon fiber.
11. 11. A matrix block for use in an apparatus for coating ingestible tablets, of selected size and shapes, with a gelatin film, The blocks (40) have an upper part (44), a bottom (50) and sides that extend between the upper part and the bottom, a number of similar cavities (42) formed in the upper part, wherein each cavity it is sized to loosely receive therein at least one half of one of the tablets, and a raised ridge (70) extending around the perimeter of each cavity for cutting 30 a gelatin film that remains on the upper part (44) of the block, during the -j4 * ' use of the block, the block is characterized in that said block (40) is made of hard plastic material and includes connecting members projecting ^ laterally (54, 56) formed on the opposite ends of the matrix holder block ^ (40) and adapted to connect the die block to two ring members that 5 connect the matrix holder block to other matrix holder blocks.
12. 12. A die block according to claim 11, characterized in that the block (40) is made of plastic material reinforced with carbon fiber.
13. A die block according to claim 11 or 12, characterized in that each cavity has an opening (46) in a bottom thereof, to allow air to escape from the cavity (42) after the Gelatin film is placed on top of the block and at least one half of a tablet is inserted into the respective cavity (42).
14. 14. A die block according to any of the claims from 11 to 13, characterized in that two or more rows of teeth (48) are formed on the bottom of the block, for coupling with at least one row of teeth, circumferential, formed on a matrix support, rotating, (38), substantially cylindrical.
15. 15. A die block according to any of the claims from 11 to 14, characterized in that the laterally projecting connection members f (54, 56) are molded on the matrix holder block, and the two ring members are made of metal.
16. 16. A die block according to claim 11, characterized in that the die block (40) consists essentially of material 25 plastic reinforced with carbon.
17. 17. A matrix block according to any of claims 11 to 15, characterized in that the block is made of thermally stabilized polyphthalamide, reinforced with carbon, very hard.
18. 18. A die-holder block according to any of the claims from 11 to 15 and 17, characterized in that the members of location (66) of the matrix, project upwards, from the opposite ends of the upper part of the matrix block (40).
19. 19. A block matrix according to any of the 9 claims from 11 to 15 and 17, characterized by location members 5 (66) of the matrix and location cavities (68) of the array, formed at opposite ends of the upper part of the matrix holder block.
20. 20. An apparatus for coating tablets, the apparatus comprises: a pair of rotating, cylindrical matrix assemblies (34, 36) having jointly acting work surfaces, which are located on a surface 10 of contact (32) of the assembly, each die assembly includes a series of cavities _ (42) formed along at least one circumferential line, each cavity cooperating with a similar cavity found in the other die assembly , to form, on the contact surface of the assembly, a cavity sized to loosely receive one of the tablets therein; 15 an actuator system (86, 94, 96, 108) for rotating the die assemblies in such a way that the die assemblies rotate in synchronism with each other, feeding means for supplying two coating strips to the array assemblies, for which, during the use of the device, the strips of 20 coating are pulled by the die assemblies, towards the contact surface; and a synchronized tablet dispensing mechanism (16) for dispensing individual tablets at a feeding site (30), the apparatus being characterized in that each die assembly includes a matrix holder, rotating 25 (38) and a series of matrix blocks (40) mounted on the matrix support, for rotation about a central axis of the matrix support and forming the working surface of the respective matrix assembly, each of the blocks die holder (40) is in accordance with claim 11, the coating strips are gelatin strips, the feeding site (30) is on 30 one of the gelatin strips located upstream of the contact surface of the assembly, the gelatin strip (24) is supported by the work surface of one of the die assemblies at the feeding site, the tablet dispensing mechanism includes at least one vacuum application member (254) that can be • connecting functionally to a vacuum source (256) and a transfer mechanism (250) to move at least one vacuum application member, from a position to pick up tablets, to the feeding site.
21. 21. An apparatus according to claim 20, characterized in that the tablet dispensing mechanism (16) comprises a number of vacuum application members (254) arranged in a row that is 10 extends transversely to the die assembly and the transfer mechanism _ includes a horizontally extending structure member, on which ^ the vacuum application members, and first and second air cylinder actuating devices (282, 284) are mounted, to move the structure member both horizontally and vertically, the structure member is 15 rigidly connected to a sliding member of the second of the drive devices
22. 22. An apparatus according to claim 20 or 21, characterized in that each matrix support (38) is substantially cylindrical.
23. 23. An apparatus according to any of the claims 20 to 22, characterized in that each matrix holder block (40) has a number of cavities (42) arranged in at least one row extending transversely to its support. respective matrix.
24. 24. An apparatus according to any of claims 20 to 23, characterized in that each assembly (34, 36) of The matrix has a central rotation axis and one of the arrays (36) of arrays is located at a lower level than the other matrix assembly, the two central axes of the assemblies that rotate the matrix, are horizontally traversed one from the other, and the feeding site (30) is on top of the die assembly that is at a lower level.
25. 25. An apparatus according to claim 20, characterized in that the tablet dispensing mechanism (16) includes a movable structure member and a number of vacuum application members (254) arranged in a row extending transversely to one of the mounts • matrix and which are mounted on the structure member, and the transfer mechanism (250) comprises a first actuator device (282), of air cylinder, capable of providing a substantially horizontal movement, and a second actuator (284) ), of air cylinder, mounted rigidly on a sliding support member, of the first actuator, of air cylinder, and capable of providing a substantially vertical movement, the first The actuator device (282), of air cylinder, is fixedly mounted on an adjacent support surface of the apparatus and the mobile structure member ™ is rigidly mounted on a sliding support member of the second air cylinder actuating device (284). fifteen twenty 25 0