ASSORTMENT OF SMALL AMOUNTS OF POWDER
DESCRIPTIVE MEMORY
The present invention relates to an apparatus and method for dispensing small amounts of powder. The present invention has special application in the gravimetric measurement of powder, namely medicament in the form of powder, which is gravimetrically dispensed in small receptacles such as capsules. Dusts, by the characteristics of their flow, tend to prevent the flow of dust through small holes, for example, a sieve that contains dust, under the action of gravity because the dust particles tend to agglomerate in larger particles. However, it is well known that shaking the hopper makes the powder flow. It has been found that applying discrete movements of a well-defined nature to the hopper can cause a quantity of reproducible powder to flow through the orifices. For example, WO-A-01/33176 discloses an apparatus and method for dispensing small amounts of particles, particularly small amounts of medicament, especially in powder form. The apparatus uses a funnel-shaped hopper with a plurality of holes in a membrane at the base of the hopper, which forms a sieve-like element, through which the powder present in the hopper can fall. A preferred method is to tap the hopper horizontally to produce said movement, thereby dispensing powder controllably through the membrane. The tapping is achieved by an electromechanical actuator that applies impact energy to the hopper, which, in turn, causes a small number of particles to fall through the sieve-like element and onto a weight-measuring scale. The actuator is a horizontally oriented solenoid that hits the side of the hopper by means of a rod that supports the hopper at one end and has the solenoid mounted at the other end. You can also perform a tapping action with a vertical component for the action of the actuator or the resulting movement of the hopper. The dispensed powder falls into a receptacle that is arranged on a weighing pan of a precision weighing scale so that the dispensed powder is weighed progressively in real time, controlling the feed back of the dispensing actuator so that the dispensing is finished once it has been dispensed. The desired powder weight has been dispensed. In order to dispense very small amounts of powder within a very narrow tolerance with respect to a total weight target dispensed, the powder particles that are dispensed through the sieve holes have a very small dimension which means that when the individual powder particles are compacted together into agglomerate particles before dispensing, the agglomerates are broken before passing through the holes. This means that the powder dispensed progressively into the receptacle has a low bulk density, and consequently a large volume. This can lead to overfilling problems of the capsules. This occurs specifically when a common capsule size containing different drugs of different densities, or different amounts of the same drug is required. There is a need for a dispensing system that can avoid the problem of overfilling the capsules. In addition, controlled dispensing of the powder is achieved by continuously measuring the weight of the powder dispensed, and using a computer program to control the knocking action of the actuator. In this way the weight of the powder dispensed by each tapping is calculated, based on the previous weight increases by the previous tapping, and it is predicted if another tapping is necessary in order to increase the total weight dispensed up to a predetermined target value. . The software also takes into account any delay between the moment when an added powder actually produces a certain weight of total powder, and the moment in which the weighing scale that weighs the weight of the powder in real time accurately indicates that weight, because it is necessary a period of time before each measurement so that the weighing pan reaches a stable situation in order to to make an exact measurement. However, this procedure leads to the problem of slowness in the dispensing of dust, especially when large amounts of dust are dispensed, which leads to prolonged measurement cycles. There is a need for an apparatus and a dispensing method that can maintain the measurement accuracy of this known system, but operate in faster time cycles. Said faster cycles of time would extend the use of this dispensing apparatus and method to the large-scale commercial production of pharmaceutical capsules containing individually heavy amounts of drug registered therein. There is a need for such an application. For the use in such large-scale commercial production of pharmaceutical capsules containing individually measured and heavy amounts of medicament there is also a need for an apparatus and method for automatically feeding empty receptacles to be filled in the weighing scale and removing the filled receptacles of the weighing scale so that a large number of receptacles can be filled quickly and accurately with the required powder weight. It is of great importance that the feeding and withdrawal systems do not interfere with the precision weighing of the powder, which is obviously important when the drugs are being measured gravimetrically in the capsules. In addition, the known system, although it allows a great precision in achieving a value of the target weight of the drug, however, could be improved allowing even lower tolerances in the target weight, but without increasing the dispensing cycle times. The present invention aims to overcome, at least partially, these problems of the known apparatus and method and meet said needs. Accordingly, the present invention proposes an apparatus for dispensing small amounts of powder into a receptacle, the apparatus comprising a hopper, the hopper in use containing the powder to be dispensed therefrom, a hopper support by means of which the hopper in use it can be maintained above a receptacle that is to receive the powder dispensed, at least one actuator for applying impact energy to the hopper to cause the powder to be dispensed therefrom and a powder compaction means to improve the compaction of at least some of the dust in the receptacle. The present invention also proposes a method of dispensing small amounts of powder into a receptacle, the method comprising the steps of: disposing in a hopper of a powder to be dispensed therefrom.; maintenance of the hopper over a receptacle that will receive the powder dispensed; application of impact energy to the hopper by means of at least one actuator to thereby cause the powder to be dispensed therefrom into the receptacle; and, at any stage of the process, compaction of at least some of the powder to thereby improve the compaction of the powder in the receptacle.
This invention relates, in particular, to a gravimetric measurement system, mainly for the dispensing of drugs in the form of powder into small receptacles such as capsules. Preferably, the apparatus includes a transfer mechanism which can feed a plurality of receptacles successively on the weighing pan plate in such a way that they can be filled with a medicament in powder form while they are on the weighing pan of a balance and, Then, they are removed successively from the saucer once the filling is completed. The transfer mechanism used to put the receptacles on the pan uses a lateral movement to bring the receptacles to the center of the pan and then a vertical movement to support the receptacles on the pan so that the pan and the receptacle on it do not have any contact with the transfer mechanism. An especially preferred arrangement uses a rotary transfer mechanism that employs a rotary movement to carry the receptacles successively one after the other on the pan and then a vertical movement of either the pan or the receptacle, depending on the type of balance used, to deposit the receptacle on the pan. , or remove the receptacle from the weighing pan. Accordingly, the apparatus allows the receptacle to be filled to be fed onto, and removed from, the pan of a precision balance, automatically. A dispensing system gradually fills the receptacle on the weighing pan with the powder, stopping when the desired powder weight has been placed in the receptacle. Next, the filled receptacle is removed from the pan and replaced by another vacuum for the next fill cycle. In order for the measurement to be done as quickly as possible it is important that the loading and unloading operations are as fast as possible, while minimizing any disturbance of the weighing system. This requires the soft positioning of the capsule on the saucer; gentle removal of the dish capsule; the displacement of the capsule in a manner that prevents the spillage of dust; and the rapid movement of the capsule without generating air movements or heating. The transfer mechanism that has been developed to perform the transfer on and off the cymbal requires the movement both in the plane of the cymbal to bring the receptacle to the desired position on the cymbal, as normal (or orthogonal) to the plane of the cymbal to descend the receptacle on the saucer and raise it again. The transfer mechanism of the preferred embodiments performs the required movements in a smooth, silent, cleanable manner and generates a minimum of spilled powder. Since the mechanism is typically made of stainless steel to meet the standards or conventional requirements of pharmaceutical process equipment, any simplification of the mechanism provides benefits by reducing the cost of equipment, and by simplifying the operation and cleanliness of the mechanism in use. Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is a view of a schematic section, from one side, through a hopper of an apparatus for dispensing powder for use in the method and apparatus of the present invention for dispensing powder into a receptacle; Figure 2 is a view of a schematic section, from one side, through a hopper and a knocking device of a powder dispensing apparatus for use in the method and apparatus of the present invention of powder dispensing within a receptacle; Figure 3 is a schematic view, from one side, of a real embodiment of a mechanism for transferring the loading and unloading of receptacles on and from a weighing dish pan under a filling apparatus according to the present invention; Figure 4 is a schematic plan view of a second embodiment of a rotary transfer mechanism for loading and unloading receptacles on and from the pan of a weighing scale under a filling apparatus according to the present invention;
Figure 5 is a schematic view, from one side, of the rotary transfer mechanism of Figure 4; Fig. 6 is a schematic enlarged plan view of part of the transfer mechanism of Fig. 4 showing the interrelation between the rotary carousel and a carrier of a receptacle; Figure 7 is a view of a schematic side section on the line A-A of part of the carousel and of the carrier of Figure 6; Figure 8 is a schematic view, from one side, of a compaction apparatus for use in the method and apparatus of the invention for dispensing powder into a receptacle; Fig. 9 is a graph showing the relationship between the measured weight and the time when the apparatus of Fig. 8 is used; Fig. 10 is a schematic view, from one side, of another embodiment of a compaction apparatus for use in the method and apparatus of the present invention for dispensing powder into a receptacle; Figure 11 is a graph showing the relationship between the measured weight and the time when the compaction apparatus of Figure 10 is used; Figure 12 is a schematic view, from one side, of another embodiment of a compaction apparatus for use in the method and apparatus of the present invention for dispensing powder into a receptacle;
Figures 13a, 13b, 13c, 13d and 13e are schematic views, from one side, showing the sequential steps of a powder receptacle filling procedure scheme according to another embodiment of the present invention; Figures 14a, 14b, 14c and 14d are schematic plan views showing the sequential steps of a powder dispensing process within a receptacle according to another embodiment of the present invention; Figure 15 is a graph showing the relationship between the measured weight and the time in the method of Figures 14a-14d; and Figures 16a, 16b, 16c and 16d are schematic plan views showing the sequential steps of a powder dispensing process within a receptacle according to another embodiment of the present invention. Figure 1 schematically shows the dispensing head of a precision powder measuring system for use in the method and apparatus of the invention. Said dispensing head is known from WO-A-01/33176. Referring to Figure 1, the device consists of a hopper 1 for a powder, for example, a medicament used for administration to the lungs of a patient by means of a powder inhaler. The hopper 1 is generally frusto-conical in shape with the larger end 2 open and higher. The smaller end 3 is closed by a plate 4 in which a plurality of holes 5 are formed, thus forming a screen. When a powder 7 is placed in the hopper 1, some of the powder 7 can initially fall through the holes 5 but then, in general, the powder flow stops as the powder 7 becomes clogged in the holes 5. The flow of powder 7 through the holes 5 can be controlled and reproduced by choosing the appropriate dimensions of the holes to match the properties of the powder. Typically, the size of the holes is between 100 microns and 2000 microns. In order to use the apparatus for precision dispensing, a receptacle 8 for the powder 7 is placed under the plate 4 and the hopper 1 is tapped on its side wall 9 at a site 6. The tapping may be so as to be the result of the impact of a mass moving at a controllable speed. The resulting movement of the hopper 1 and the powder 7 causes the powder 7 to flow through the holes 5 of the plate 4 for a small period of time after impact, after which the powder flow is stopped. In this way a quantity of discrete powder 7 is controllably dispensed into the receptacle 8 as a result of each tapping. In order to accurately dispense a desired total amount of the powder 7, a plurality of taps is used to fill each receptacle 8 and the total weight of the powder 7 dispensed in the receptacle 8 is measured in real time so that as soon as it is has dispensed the required amount, stops the tapping.
Figure 2 shows a specific hopper and tapping device of a powder dispensing apparatus for use in the present invention for dispensing powder into a receptacle. In this embodiment, a frustoconical hopper 20 has a screen 21 at its lower infeed end 22 and a larger upper end 23 for receiving bulk powder 24, such as a medicament, to be dispensed through the screen 21. The hopper 20 is supported by a cantilevered arm 25, which is attached to, or supported against, a side wall 26 of the hopper 20. Within the cantilevered arm 25 there is a cavity 27 longitudinally oriented, and an electromechanical actuator is arranged in the cavity 27. The electromechanical actuator may have the structure and operation of the actuator disclosed in WO-A-01/33176, the disclosures of which are incorporated herein by reference. Specifically, the actuator may comprise a solenoid that is energizable to move in a single direction, against the biasing force of a spring, to apply a striking force to the cantilevered arm. However, in the present illustrated embodiment, by way of example, the actuator is a double acting solenoid, energizable to be successively movable in two opposite directions against the predisposition force of one of two respective springs. Accordingly, in this embodiment, a pair of first and second longitudinally oriented solenoid coils 28, 29 of a solenoid 30, comprising the electromechanical actuator, are arranged in a mutually spaced longitudinally spaced configuration. The coils 28, 29 are rigidly connected to the cantilever arm 25. An armature 31 of the solenoid 30 comprises a longitudinally extended body having a central bushing 32 and two opposite portions 33, 34, ppmera and second, each of the projecting portions 33, 34 extending within one of the respective coils 28, 29 , and with the bushing 32 arranged centrally between the two coils 28, 29. If desired, a pair of helical compression springs (not shown) can be installed opposite each spring located between the bushing 32 and the respective coil 28, 29, whereby the armature 34 is urged toward a central position in the absence of any actuation force on the armature 31. The first and second projecting portions 33, 34 have respective first and second terminal walls 35, 36 that are each spaced apart. of a respective first and second terminal faces 37, 38 of the cavity 27 when the armature 31 is in the central position. When a first pulse of current passes through the ppmera coil 28, the armature 31 accelerates towards the second terminal face 38 of the cavity 27 and the terminal wall 36 impacts against it. The moment of impact is transferred by cantilever arm 25 to hopper 20 and to bulk powder 24 therein and causes a discrete amount of powder 24 to fall into receptacle 39 located, in use, below screen 21 of the hopper 20. Subsequently, when a second pulse of current passes through the coil 28, the armature 31 will accelerate towards the first terminal face 37 of the cavity 27 and the terminal wall 35 will impact against it. Again, the moment of impact will be transferred by cantilever arm 25 to hopper 20 and bulk powder 24 from its interior and will cause a discrete amount of dust 24 to fall into receptacle 39. As a result, the alternating energization of the two coils 28, 29 cause the armature 31 to move in opposite directions alternately. With this arrangement it is possible to tap the hopper 20 in any direction along the cantilever arm 25. Consequently, powder dispensing can be performed either by alternating the knocking direction in successive knocking steps corresponding to successive powder dispensing actions or alternatively by always using a pair of taps severely spaced in time in a single tapping step to perform a single action of powder dispensing. The use of a solenoid 30 to generate the impact on the hopper 20 and the bulk powder 24 inside allows the magnitude of the impact to be controlled by controlling the excitation voltage of the first and second coils 28, 29 of the solenoid 30. In this way, even when the mechanical arrangement produces some difference between the magnitude or effect of the forward and backward taps associated with the energization of the two coils 28, 29, the total cumulative effect can be balanced using different excitation voltages forwards and backwards. The same effect can be achieved by changing the pulse width, i.e., the period of time during which each coil 28, 29 is connected.
In other embodiments of the invention, it may be convenient in some cases to use a different actuator arrangement to stimulate the powder flow and thus the averaging means of the excitation direction would be modified to optimize performance with that arrangement. Alternatively, the actuator may have only a single coil so that the armature impacts on the hopper only in one direction. Although the actuator comprising the impact mechanism on the hopper is described in the illustrated embodiment as a solenoid, this is only a possible actuator. Other alternative actuators may comprise an electric motor and cams; a piezoelectric actuator; or a linear actuator with loudspeaker voice coil. Other alternative arrangements may include a vertically oriented connection or solenoid such that the horizontal action of the solenoid causes the hopper to have a vertical as well as a horizontal response to the tapping action. In accordance with this invention, the receptacles to be filled with powder from the hopper are arranged on the weighing pan of a balance while filling. Figure 3 shows a mechanism for transferring loading and unloading of the receptacles on and from the pan of a balance under the hopper and the actuator system as described above. The receptacles 42, which typically comprise a lower half of a capsule for containing a spray medication are each mounted on respective carriers 41 having an annular flange 51 arranged so that the carriers 41 can be lifted vertically by a transfer arm 44. The empty receptacles 42 in their carriers 41 are brought to the gravimetric dispensing head, which comprises the hopper and the actuator, on a transport system such as a conveyor belt 55. The transfer arm 44 for transferring the carriers 41 is moved to a pick-up position 43, inserted under the flange 51 and raised to remove the receptacle 42 from the carrier 41, supported by the arm 44 of the tape 45. Next, the arm 44 of transfer moves laterally until it is on the center of pan 48 of the balance. Next, the arm 44 is lowered until the carrier 41 rests on the upper surface 46 of the pan 48. The arm 44 moves a little further downwards so that the arm 44 does not have any contact with the pan 48 or with the carrier 41. At this point the receptacle 42 is available to be filled by a filling system 47 (comprising the hopper and the actuator system described above) while its weight is measured by the weighing scale 52. Upon completion of the filling the transfer arm 44 is raised to remove the carrier 41 and the receptacle 42 therein from the weighing pan 48, and then the transfer arm 44 is moved horizontally to a seating position 49 where the carrier 41 is placed on a second conveyor belt 50. At this point the carrier 41 is lowered, releasing the carrier 41 from contact with the transfer arm 44, such that the carrier 41 rests on a second conveyor belt 50. Next, the transfer arm 44 is free to return to the collection position 43 and repeat the filling / weighing process in a subsequent receptacle filling cycle. Figures 4 and 5 show an alternative rotary transfer mechanism for loading and unloading. receptacles on and from the balance pan under a hopper and actuator system as described above, which uses a carousel (or rotating disc) to maintain a plurality of carriers / receptacles in respective angular positions around the carousel, better than an arm of transfer to maintain one carrier / receptacle each time, in association with a pair of conveyor belts as used in the embodiment of Figure 3. Figures 4 and 5 show the main components of the mechanism. The incoming receptacle to be filled that has previously been mounted on the carrier 61, it is placed together with the carrier 61 in a hole selected from a plurality of holes 63 located circumferentially around the rotary transfer mechanism 60 in the form of a carousel. The hole 63 maintains the carrier 61 at a specific angular location of the outer circumference, and with a specific orientation as the rotary transfer mechanism 60 moves. The preferred structure of the hole 63 and associated carrier 61 are shown in greater detail in Figure 6.
Figure 6 shows in an enlarged view only a part of the rotary transfer mechanism 60 in which only two carrier locations are shown, constituted by the holes 63, while the rotary transfer mechanism 60 can have as many holes 63 for the carriers 61 as necessary. Figure 7 shows in greater detail the structures of the holes 63 and of the carrier 61. The holes 63 of the rotary transfer mechanism 60 each have a slot 62 that communicates with the outer circumference 70 of the carousel 60 through which it can pass. a central portion 64 of the carrier 61 to allow the longitudinal axis of the carrier 61 to center on a central circular portion 69 of the hole 63. The central circular portion 69 and the slot 62 of each hole 63 resemble a structure similar to an eye of lock. The upper edges 80 of the circular portions 69 of the holes 63 are tapered to match the corresponding taper angle of the edge 66 of the upper flange 67 of the carrier 61. In this way, the unsupported carrier 61 can be seated in the part 69 orifice central 63, maintained in position by gravity and centered in the hole 63 by the tapered tapered shape of the contact surfaces of the edge 80 of the carousel 60 and the edge 66 of the upper flange 67 of the carrier 61. The flat base 65 of the carrier 61 is made with a diameter greater than that of the central region 64 so that, when the base of the carrier 61 is pushed upward or supported by a flat surface, such as the upper surface 46 of the plate 48, in that case the carrier 61 will rest stably on that flat surface. Therefore, if the carrier 61 is raised relative to the transfer mechanism 60 so that the tapered edge 66 of the flange 67 ceases to be in contact with the upper edge 80 of the circular portion 69 of the hole 63, in that case the carrier 61 will no longer be in contact with the transfer mechanism, and will only rest stably and securely on the flat support surface beneath the carrier 61. The upper portion 68 of the carrier 61 is shaped to accept the receptacle to be filled. In the illustrated case this is in the form of a half 81 of a capsule for containing medication. In this manner, the incoming capsules to be filled can be loaded in a loading station 59 within the transfer mechanism 60 either by being placed in carriers 61 already in position in the transfer mechanism 60 or being placed in carriers 61 by a separate mechanism ( not shown) before the carriers 61 are loaded into the holes 63 of the transfer mechanism 60. Once the receptacle is in position on the respective carrier 61 the transfer mechanism 60 that is free to rotate around the vertical axis 84 can be angled to move an empty receptacle to its filling position 83 on a weighing pan 48 of the balance of heavy. Thereafter, the entire transfer mechanism 60 can be lowered a sufficient distance so that the base 65 of the carrier 61 contacts the upper surface 46 of the weighing plate 48 of the weighing scale. Other capsules and carriers 61 remain in position on the transfer mechanism 60 as it is arranged so that there are no surfaces under them, with which, otherwise, they would contact when the transfer mechanism 60 is lowered. After filling, the transfer mechanism 60 is raised, thereby resetting the carrier 61 in the respective hole 63 of the transfer mechanism 60. In this way, when the next empty capsule is transferred onto the plate 48, the previously filled capsule is transferred to the discharge station 82 where it is removed. Both loading and unloading mechanisms can use conventional capsule handling systems such as those found in capsule filling lines. In some cases it may be preferred to incorporate the application of a capsule cap to the filling body while the filling body is still in the transfer mechanism to ensure that no powder is lost during transport. In this case the design of the carrier should be made compatible with this requirement. The orientationThe lifting and lowering of the transfer mechanism can be done by actuators of servomotor or linear actuators so that a smooth and precise movement can be achieved. According to one aspect of the present invention, the powder, for example, of medicament, which has been dispensed into the receptacle, for example, a half of a gelatin capsule, is subjected to a compaction step while the powder is in the receptacle. The compaction is carried out by applying a force to the powder particles, either directly or indirectly, to increase the degree of compaction of the powder particles in the receptacle. The compaction can be carried out intermittently, or continuously. When the compaction is carried out intermittently, the compaction may be carried out between successive dispensing steps to dispense additional powder into the receptacle. When the compaction is carried out continuously, it can be carried out during the dispensing of the powder into the receptacle. The compacting of the powder in the receptacle can be done directly by physically contacting the powder in the receptacle to press and compact it more closely, thereby increasing the bulk density of the powder in the receptacle, and reducing its apparent volume. For example, a reciprocal plunger can be used vertically to compress the powder in the receptacle, and compact it in this way. When compaction is performed indirectly, the receptacle itself or a receptacle carrier may be tapped once or periodically in one or a plurality of directions or alternatively the receptacle powder may be subjected to vibration, for example, ultrasonic vibration. This causes the powder already dispensed inside the receptacle to settle under its own weight by the action of gravity to increase its narrow compaction, thereby increasing its apparent density and reducing its apparent volume. With reference to figures 8 and 9 an embodiment of the compaction apparatus and method according to the invention is shown. In this embodiment, the receptacle 100 into which a powder 102, such as a powdered medicament, is to be dispensed, typically comprises a lower half of a gelatin capsule for containing a powdered medicament. The receptacle 100 is mounted on a carrier 104, which may have the construction described above. In the dispensing and weighing stages, the carrier 104 rests on the upper surface 106 of the pan 108 of a weighing scale. In this type of configuration, the receptacle 100 is available for filling from a gravimetric dispensing head, such as the hopper and the actuator system described hereinabove, while its weight is being measured by the weighing scale during the step of dispensing until a target weight has been reached and measured and recorded. In this embodiment, the receptacle 100 and / or the carrier 104 is or are additionally tapped either intermittently or continuously by one or more knocking elements 110, 112 acting on them. The or each tapping element 110, 112 may act on the receptacle 100 and / or the carrier 104 in any suitable direction, for example, horizontally (as shown in Figure 8 by arrow A), or vertically downward (as it is shown in figure 8 by arrow B), or with any inclination between said directions, or in a plurality of directions. The or each tapping element 110, 112 can be moved by a dedicated actuator (not shown), or by a common actuator (not shown), or by the actuator (such as the actuator 30 of FIG. 2) which is configured to tap the hopper 1 14. Alternatively, as also shown in Figure 8, the hopper 114 may be constructed and positioned such that a portion of the hopper 114 (such as a tube 115 hanging downward), or an additional tapping element connected thereto, engages the receptacle 100 and / or the carrier 104 so that when the hopper 114 is moved by the actuator 30 to dispense powder 102 through the screen 116 into the receptacle 100, the hopper 114 also applies a knocking force on the receptacle 100 and / or the carrier 104, in order to make the already dispensed powder settle in the receptacle 100. Figure 9 shows the relationship between the measured weight of the dust
102 dispensed and time. In this particular embodiment there may be an initial dispensing phase (Dispensation # 1) in which the hopper 114 is tapped repeatedly by the actuator 30 to progressively dispense only a predetermined part substantially of the total target amount of the powder 102 within of the receptacle 100. Subsequently, the first dispensing phase is stopped and, in a first compaction phase (No. 1 patter), the powder 102 already dispensed is compacted, for example, by tapping on the receptacle 100 and / or the carrier 104. During this compaction phase, the pounding on the receptacle 100 and / or the carrier 104 causes fluctuations in the measured weight of the receptacle 100 and its contents. A second dispensing phase is then carried out (Dispensation No. 2) in which another part of the total desired weight of the powder 102 is dispensed into the receptacle 100 and, after this phase, a second compaction step is carried out (Knocking n 2) in which the already dispensed powder 103 is again compacted by tapping the receptacle 100 and / or the carrier 104. This sequence may be repeated several times. At the end of the weighing procedure, there is a final dispensing phase (Final dispensing), in which the final amount of the powder 102 inside the receptacle 100 is dispensed, and a final weighing phase (Final weighing), in which the total weight of the powder dispensed is weighed by the weighing scale. In the arrangement in which the movement of the hopper 1 14 by the actuator 30 produces a knocking movement on the receptacle 100 and / or the carrier 104, subsequently, during the compaction phase (s) it is possible to dispense more powder within the receptacle 100 as a consequence of said movement of the hopper 114. According to a second embodiment of the invention, as shown in figures 10 to 11, when the carrier 104 holding the receptacle 100 is disposed on the pan 108 of the weighing scale, the powder 102 dispensed from the receptacle 100 is subjected to external vibration, for example, from the vibration element 116 generally represented by a loudspeaker element in FIG. 10, which produces a non-contact vibration of the powder 102 of the receptacle 100. The vibratory force applied to the powder 102 causes the particles to settle into a more closely packed morphology, thereby increasing the apparent density of the particles. l dust. The vibration has a frequency selected so that it does not affect the operation of the weighing scale, for example, ultrasonic vibration with a frequency of 20,000 Hz or greater. Optionally, the ultrasonic vibration can be focused, for example, by a lens element 118 as depicted schematically in Figure 10, on the receptacle 100. The vibration can be applied to the powder 102 of the receptacle 100 either periodically or, as shown in Figure 11, continuously during the dispensing of the powder 102 into the receptacle 100. Referring to Figure 11, this shows the relationship between the measured weight and the time during the dispensing and weighing of the powder 102 in the receptacle 100. The powder 102 is continuously dispensed into the receptacle 100 and the dispensed weight is continuously measured by the weighing scale. During the dispensing phase the powder that has been dispensed is continuously subjected to vibration, thus producing its continuous settling and the consequent increase in the apparent density of the powder that has already been dispensed into the receptacle. Dispensing is stopped when the weighing scale, with its associated software and processor, has calculated that the required powder weight 102 has been dispensed, after which, a sufficient period of time has elapsed to allow the measurement of the weight of the balance set a final stable reading, a final stable weight of powder 102 is measured. Ultrasonic vibration is terminated before final stable weight measurement, thus ensuring that the final stable weight is determined accurately. In another embodiment, as shown in Figure 12, the powder 102 that has been dispensed into the receptacle 100 is subject to physical compaction. After the powder 102 has been dispensed from the hopper 114 into the receptacle 100 that is carried on the carrier 104 which, in turn, is disposed on the pan 108 of the weighing scale, an element is inserted into the receptacle 100. 120 of compaction, for example, a plunger as shown in Figures 14a-14d, to physically press and compact the powder 102 in the receptacle 100. The physical compaction step can be performed once or several times in the dispensing cycle and heavy. Although physical compaction may be performed at the end of the dispensing cycle, before the final stable weight has been measured, this is not preferred because there is a possibility that the compaction element 120 may inadvertently reduce the actual weight with respect to the target value. inadvertently removing some of the powder 102 from the receptacle 100. Typically, the sequence of the dispensing and compaction steps is the same as that shown in Figure 9. According to another aspect of the invention, the powder is compacted in the receptacle by depositing within the receptacle a precompacted powder body for partially filling the receptacle with a predetermined part substantially of the target weight of the powder, and then completing the filling of the receptacle to the desired final target weight by dispensing the rest of the powder from the gravimetric dispensing head of the hopper . According to this aspect, and assuming that the benefit of a greater bulk density of the total powder in the receptacle is achieved, this aspect offers, in addition, the surprising combination of benefits of not only being able to increase the filling speed of a receptacle, but also be able to improve the accuracy in achieving the target weight required. Figures 13a, 13b, 13c, 13d and 13e consequently show the sequential steps of a powder receptacle filling procedure scheme according to another embodiment of the present invention. Referring to Figure 13a, initially, the receptacle 100, comprising the lower half of a gelatin capsule for containing a powdered medicament, is disposed on the carrier 104 which, in turn, is supported on the pan 108 of a balance of heavy. The tare of the empty receptacle 100 and its associated potador is measured with the weighing scale 104. However, this step is optional and, specifically, can be omitted, for example, when it is known that any manufacturing tolerance in the weight of the receptacle 100 is small, and specifically, it is within the target tolerances of the final capsule weight of the container. the capsule full. In the second stage, the receptacle 100 is partially filled with a powder body. This powder body has been precompacted, in the sense of having a bulk density that is greater than that obtainable by dispensing the powder from the hopper 114, which is used in the final dispensing and in the gravimetric weighing step. The body of the precompacted powder has preferably been measured volumetrically to have a controlled volume. Alternatively, the body has been measured gravimetrically to have a controlled weight. In any case, the volume or approximate weight of the body has been selected to constitute a proportion, for example, between 80 and 95% by weight of the total objective weight of the powder to be dispensed into the receptacle 100. When the powder body has been measured volumetrically, preferably the body is in the form of a powder pad that has been formed and dispensed into the receptacle 100 using a powder dispensing apparatus known in the art as a "dosator", which is conventionally used in the filling art. of gelatin capsules with powdered medicine. With reference to figures 13b and 13c, the dosator 122 comprises a tube 124, typically a cylindrical tube, which has a longitudinally reciprocating piston member 120 disposed therein. Prior to filling the tube 124 with a controlled volume of powder, the piston member 126 is retracted and the tube 124 oriented vertically so that the lower open end 128 of the tube 124 defines the lower part of a volume 129 of the tube 124 for receive a dust pad of controlled volume. In this configuration, the dosator 122 is pushed down into a bed 130 of powder containing the powder 132. In the bed 130, the powder 132 is homogeneously dispersed and, as is well known in the art, the bed is carefully controlled. properties of the powder 132, such as density, flow properties, temperature, etc., so that when the dosator 122 is pushed down to the powder bed 130 to a predefined depth, a repeatable determined volume 134 of the powder is introduced. inside and retained in the lower volume 129 of the tube 124 as a dust pad. The downward movement of the dosator 122 towards the powder bed 130 produces a degree of compaction of the powder to form the plug 134 of powder in the tube. Typically, the volume of the plug 134 is not defined by the position of the piston, but rather by the properties of the powder 132, the dimensions of the tube 124 and the speed, force and depth of the push of the 124 tube of the dosator in the bed 130 of dust. When the tube 124 of the dosator has been filled in this manner with a dust plug 134, the tube 124 of the dosator rises from the powder bed 130 and moves laterally to a location above the receptacle 100 as shown in Figure 13d . Next, the piston 126 is urged downward, thereby pushing the plug 134 of precompacted powder out of the tube 124 so that it falls by gravity into the receptacle 100 as a preformed plug 134. Preferably, in this step, the receptacle 100, and the associated carrier 104 are not transported on a pan 108 of a weighing scale. However, the receptacle and the associated carrier can still be transported by the weighing scale that was used to measure the empty weight of the empty receptacle 100. Subsequently, as shown in FIG. 13e, the receptacle 100 carrying the powder pre-compacted plug 134 and its associated carrier 104 are transferred (for example, by the transfer apparatus described hereinabove) to weighing pan 136. of a second weighing scale where the remainder of the powder 102 is dispensed from the hopper 114 into the receptacle 100 and the total amount of the powder 102 is weighted to achieve the final desired target weight as described hereinabove. This embodiment offers the advantage of being able to incorporate a larger amount of a given powder 102 into the receptacle 100, such as a gelatin capsule, as compared to the filling of the receptacle 100 using only the dispensing patter head and the gravimetric weighing system, since the initial dust plug 134 is pre-compacted with respect to the powder that is finally dispensed into the receptacle 100 in order to obtain an accurate measurement of the final gravimetric weight of the total powder of the receptacle 100. This is achieved without compromising the weighing accuracy of the container. final weight or the precision of the final objective weight achieved. Also, the dispensing speed is generally increased, because the time spent to dispense the plug 134 of preformed powder into the receptacle 100 using the dosator 122 may be less compared to the dispensing of a corresponding amount of powder from within the receptacle 100 using only the dispensing tapping head and the gravimetric weighing system, without compromising the accuracy of the weighing. Referring to Figures 14a-14d and 15, another embodiment of the present invention is illustrated. In this embodiment, which is a modification of the previous embodiment of Figures 13a-13e, two weighing scales are used, one to weigh the final stable weight of the initial volume volumetrically measured from precompacted powder of the head of the dosator and another to subsequently measure the weight stable end of the total amount of powder dispensed into the receptacle, including the rest measured gravimetrically from the hopper of the dispensing patter head. The two weighing scales are operated in synchronism with a receptacle transfer mechanism, as described hereinabove, which is sequentially configured to transfer receptacles first to the first weighing balance, and then to the second weighing balance, thanks to which, when an initial receptacle is being weighed on the second weighing scale, a subsequent receptacle immediately upstream of the first is being weighed on the first weighing scale. Referring to Figures 14a, 14b, 14c and 14d, these schematically show the sequential steps of a method according to this embodiment of the present invention. Referring first to Figure 14a, two weighing scales are shown schematically. The first weighing scale 140 is associated with a dosator 122 which is arranged (as described above) to deposit a plug 134 of precompacted powder into the receptacle 100 which is carried on the carrier 104 which, in turn, is disposed in the first weighing scale 140. The second weighing scale 142 is adapted to operate in conjunction with a gravimetric tapping dispenser including a hopper 114 for dispensing powder 102 into the receptacle 100 that has already received the dust plug 134 with the second weighing scale 142 being arranged for weighing the final total weight of the powder 102 cumulatively deposited within the receptacle 100. As schematically shown in Figures Ma14d, a plurality of receptacles 100 are transferred, using a transfer apparatus (not shown) as described hereinabove, sequentially first to the first weighing scale 140, and then to the second weighing scale 142. In Figures 14a-14d three receptacles 160 are shown for purposes of illustration and it will be immediately apparent to one skilled in the art that continuous series of receptacles 100 can be transferred to the first and second weighing scales 140, 142 for sequential filling of the receptacles 100. Referring to the accompanying drawings, initially a first receptacle 100a is transferred by the transfer system to the first weighing scale 140. As described in connection with the previous embodiment, the empty weight of the receptacle is then measured
100a by the first weighing scale 140. The dosator 122 then deposits a plug 134 of precompacted powder into the receptacle 100a to, for example, fill the receptacle with between 80 and 95%, more typically about 90%, by weight of the total amount of powder a charge inside the receptacle 100a. Next, the first weighing scale 140 is used to measure the final stable weight of the partially filled receptacle 100a. Subsequently, the partially filled receptacle 100a is transferred, in a transfer step, from the first weighing scale 140 to the second weighing balance 142 and, simultaneously, the transfer mechanism transfers the next next empty receptacle 100b, in a step of corresponding transfer, on the first weighing scale. The next and only empty receptacle 100c is also transferred by the transfer mechanism to the position immediately upstream of the first weighing scale 140. Next, in a second filling step, the final remaining amount of the powder is filled, using the hopper 114, into the partially filled receptacle 100a to achieve the desired target weight of the filled receptacle 100a, and the second weighing scale 142 is used to Measure the final stable weight of the receptacle 100a full. The second scale 142 receives not only the partially filled receptacle, but also information of the first weighing scale 140 relative to the final stable weight of the partially filled receptacle 100a. At the same time, the next next receptacle 100b disposed on the first weighing scale 140 is partially filled by the dosator 122, and the final stable weight of the partially filled receptacle 100b is weighed. In a subsequent transfer stage, the first receptacle 100a fully filled, and now the final weight having been measured, is transferred from the second weighing scale 142 and the receptacle 100a is closed, for example, by closing the upper half of the gelatin capsule on the lower half of the gelatin capsule. Synchronously, the next partially filled receptacle 100b is transferred to the second weighing scale 142, and the next and only empty receptacle 100c is transferred to the first weighing balance 140. The sequence is then repeated until all the receptacles 100 are full. Figure 15 shows the relationship between the weight measured by the first and second weighing scales 140, 142, and time. The solid line represents the weight of the first receptacle 100a and the dashed line represents the weight of the next receptacle 100b. In the initial transfer stage, the first receptacle 100a in the head is transferred to the first weighing scale 140. Once the balance has stabilized, the empty weight (tare) of the receptacle is recorded. Next, the dosator 122 dispenses the body 134 of precompacted powder into the receptacle 100a, the weight measured by the weighing scale 140 is allowed to stabilize, and then the same scale 140 measures the final stable weight. This step requires a first period of time to allow the empty capsule to stabilize and a second period of time to (a) dispense the powder plug 134 from the dosator 122, (b) let the measured weight stabilize again, and (c) recording the final stable weight of the receptacle 100a partially filled. In a next step, the first partially filled receptacle 100a is transferred from the first weighing scale 140 to the second weighing balance 142 and, simultaneously, the empty receptacle 100b immediately upstream is transferred to the first weighing balance 140 using the mechanism transfer. In a subsequent dispensing and weighing step, the partially filled upstream receptacle 100a is filled to the required amount gravimetrically calculated by the hopper 114, the weight is progressively weighed and the final weight is allowed to stabilize on the weighing and weighing scale 142., then, a measurement of the final weight is made by the second weighing scale 142. Simultaneously, the receptacle 100b immediately downstream thereof is partially filled by the dosator 122 and the first balance 140 determines the final stable weight of the partially filled receptacle 100b. These two stages of filling the two receptacles 100a and 100b operate synchronously and the total time required is determined by the most durable of the two stages, so that the transfer stages can also operate synchronously thereafter. This sequence of steps is repeated with the successive receptacles 100 to be filled. Using the sequence of steps of this embodiment, it can be seen that, although each receptacle 100 can substantially reverse the same filling time with the desired amount of final powder, as in the previous embodiment, synchronizing the operation of the dosator 122 with a first balance 140 of weighing and the gravimetric tapping head including the hopper 114 with the second weighing scale 142 and the transfer therebetween, a full container 100 is transferred from the second final weighing scale 142 at a speed approximately double that in the previous accomplishment. Accordingly, the production speed of full and heavy receptacles 100 is approximately double. Surprisingly, however, the accuracy, with respect to the value of the target weight, of the actual weight of the powder 100 of the receptacle also increases even though the speed has increased. This is because the ratio of the total weight of the powder in the ultimately filled receptacle 100 that has been dispensed by the gravimetric knocking head is typically between 5 and 20% of the total weight of the powder of the receptacle 100, since dosator 122 has dispensed between 80 and 95% by weight of the total amount of powder to be filled into any receptacle 100. Accordingly, the amount of powder dispensed by hopper 114 and gravimetrically weighed at any stage of dispensing and heavy gravimetric it is reduced compared to the use of only a gravimetric tapping dispenser to dispense all the powder. Consequently, the gravimetric weight of the powder required to be dispensed by tapping by the gravimetric tapping dispenser (specifically the hopper 114 containing the screen 16) can be reduced, which is achieved, for example, by configuring the hopper and its associated screen for dispense a smaller amount of dust by tapping on the hopper 114. More specifically, the sieve mesh size can be reduced, the sieve area can be reduced and / or the knocking force on the hopper 114. can be reduced. , in turn, it results that, since the weight is reduced by knocking, the total weight of the powder dispensed within the receptacle 100 can be controlled much more accurately. For example, if the weight per knocking is reduced by 2x micrograms At microgram, the total weight of receptacle 100 powder can be dispensed within a tolerance of x micrograms instead of 2x micrograms. In this embodiment, instead of the use of a dosator 122, a second gravimetric knocking head may be employed, although configured to dispense a significantly greater dust weight by knocking than that of the gravimetric knocking head associated with the second balance 142 of heavy. Another embodiment of the present invention is illustrated with respect to Figures 16a, 16b, 16c and 16d showing the sequential steps of the powder dispensing process. In this embodiment a single weighing scale is used in conjunction with a dosator and a gravimetric tapping dispenser, which move laterally selectively above the weighing balance when dispensing the powder, and move away from the weighing balance when It is not dispensed. As shown in Figure 16a, in the first stage of the procedure of this embodiment, a receptacle 100 to be filled, together with its associated carrier 104, is arranged on the saucer 150 of the weighing balance 152 using a transfer apparatus such as that described hereinabove. The weighing scale 152 measures the empty weight of the receptacle 100 and its carrier 104. In this step, the dosator 122 and the gravimetric tapping dispenser including the hopper 114 are both remote from the weighing balance 152. In a second step, as shown in Figure 16b, the dosator 122 is laterally displaced above the receptacle 100 carried on the weighing balance 152, and the precompacted powder plug 134 measured volumetrically is deposited within the receptacle 100 by the dosator 122. In a third step, as shown in Fig. 16c, the dosator 122 is removed from the receptacle 100 and synchronized therewith, the hopper 114 of the gravimetric tapping dispenser is displaced up over the receptacle 100, after which the Receptacle 100 is filled with the required powder weight. Subsequently, in the final stage, as shown in Figure 16d, the hopper 114 moves away from the weighing scale 152, the weighing pan 150 is allowed to stabilize and the final stable weighing of the receptacle 100 is made. full. Next, the transfer apparatus (not shown) removes the filled receptacle 100 from the pan of the weighing scale and a subsequent vacuum receptacle 100 is deposited to fill on the saucer of the weighing balance for filling in a subsequent cycle. Again, this embodiment has the advantage that the total amount of powder has a higher bulk density, and therefore is more compacted, compared to the prior art. In addition, since the gravimetric tapping dispenser including the hopper 114 is only used to partially fill the receptacle 100, this results in the dispensing of the hopper 114 a reduced weight by knocking of the powder, which, in turn, results in a more accurate final weight being achieved, relative to a desired target weight of the filled receptacle 100.