Apparatus

The present application relates to a dispensing apparatus including overflow apparatus for selectively preventing the flow of a powder product from an outlet. In particular the invention relates to the selective prevention of powder flow from the outlet of a dispensing apparatus including an auger in a pharmaceutical powder encapsulation apparatus.

When encapsulating powder, particularly when the filled capsules are for use within the pharmaceutical industry , it is important that the fill level of the capsules is correct as the powder fill level determines the dose administered to a patient.

Augers can be used to transfer quantities of granulated powder material from a hopper to a bowl from which the powder passes into cavities and is filled into capsules. In order to maintain a predetermined level of powder fill within the bowl the auger is controlled by a proximity switch which selectively activates the auger when the level is determined to be low and deactivates the auger when the level is determined to be substantially correct. The level of powder within the granulation bowl has a direct effect upon the amount of powder within the cavities and therefore a direct effect on the powder fill of the capsules and it is therefore important to maintain the powder fill level in the bowl accurately.

Some powders such as free flowing or particularly fine powders may flow through the auger even when it is deactivated and thereby overfill the granulation bowl, particularly as vibrations caused by operation of the other apparatus may be transmitted to the auger thereby agitating the powder within the auger. It is known to include a plate or baffle adjacent the outlet of the auger to try to prevent such overflow, but this is not always successful and could cause clogging or binding at or within the auger outlet. The distance of the baffle from the auger outlet is fixed during operation, but can be varied depending upon the powder characteristics to allow free flow from the outlet and thus avoid binding or clogging of the outlet.

The invention provides a dispensing apparatus comprising a hopper, a granulation bowl and overflow apparatus, a conduit and a powder outlet, the conduit extending

between the hopper and powder outlet and the conduit arranged such that the conduit extends from the hopper to the powder outlet above the granulation bowl, the overflow apparatus being actuable to substantially prevent the flow of a powder substance through the powder outlet, the overflow apparatus comprising a stopper and an actuator, the actuator comprising a body and an arm, the overflow apparatus is connected to the conduit such that the position of the body of the actuator is substantially fixed relative to the conduit, the stopper is coupled to the arm of the actuator and the actuator is actuable to move the arm relative to the body such that the stopper moves relative to the body, the overflow apparatus being arranged such that actuation of the actuator moves the stopper between a first position in which is substantially blocks the powder outlet thereby substantially preventing powder flow therefrom and a second position in which the stopper is displaced from the powder outlet such that powder is permitted to flow from said powder outlet.

The invention also provides a dispensing apparatus comprising a hopper, an auger, a granulation bowl and overflow apparatus, the auger comprising an auger screw, a conduit and a powder outlet, the conduit extending between the hopper and powder outlet and the auger screw being arranged within the conduit such that, when active, the auger causes powder to move from the hopper to the powder outlet along the conduit and into the granulation bowl, the overflow apparatus being actuable to substantially prevent the flow of a powder substance through the powder outlet, the overflow apparatus comprising a stopper and an actuator, the actuator comprising a body and an arm, the overflow apparatus is connected to the powder conduit such that the position of the body of the actuator is substantially fixed relative to the conduit, the stopper is coupled to the arm of the actuator and the actuator is actuable to move the arm relative to the body such that the stopper moves relative to the body, the overflow apparatus being arranged such that actuation of the actuator moves the stopper between a first position in which it substantially blocks the outlet thereby substantially preventing powder flow therefrom and a second position in which the stopper is displaced from the outlet such that powder is permitted to flow from said powder outlet.

The hopper can be formed by any suitable container, for example a cylindrical, cubic, spherical or other shaped container. The hopper can be substantially conical in shape

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with the conduit extending from a hopper outlet located at the narrowest end of the cone.

The granulation bowl can be any suitable receptacle into which a controlled amount of powder is to be dispensed. Such apparatus is typically used during capsule filling of pharmaceutical capsules, for example in a Bosch H&K™-400 Capsule Filling Machine. The granulation bowl in such capsule filling machines is the bowl from which powder is drawn to fill capsules and the powder is typically drawn from the bowl under gravity into a cavity from which it is moved into a capsule. The fill level of the bowl therefore has a direct effect on the fill level of the cavity and hence the capsule.

The auger can be a conventional auger comprising an auger screw located in a close fitting conduit such that as the screw turns it draws material into the conduit from the hopper and thereby forces material along the conduit and out of the powder outlet. The auger can be arranged at an angle of between 0 degrees and 45 degrees away from vertical with the hopper at the top and the powder outlet at the bottom. The auger can be arranged at an angle of between 0 degrees and 10 degrees away from vertical and can be substantially vertical. The powder conduit may be substantially linear and extend along a conduit axis. The auger screw may be omitted so that only a conduit is provided.

The dispensing apparatus can additionally comprise a sensor. The sensor can be any type of sensor that can generate a fill signal indicative of the fill level of the granulation bowl, for example the sensor could weigh the bowl and contents or could be a proximity sensor detecting when the upper surface of the powder in the bowl reached a predetermined distance from the sensor. The proximity sensor could be based on visible light , infra red or other electromagnetic waves or could be an acoustic sensor.

If the dispensing apparatus includes a sensor then the dispensing apparatus may include an auger controller that is capable of receiving the fill signal and activating or de-activating the auger depending upon the fill signal. The overflow apparatus can include an overflow controller that is able to actuate the overflow apparatus to move

the stopper between the first and second positions. The overflow sensor may receive the fill signal, or may receive an auger signal from the auger controller or other device, the auger signal being indicative of whether the auger is active or not.

The sensor generates a fill signal indicative of the fill level of the granulation bowl and the auger controller may be set to activate or de-activate the auger depending upon the signal There may be predetermined low threshold level indicating that the fill level is low. There may be a predetermined high threshold level indicating that the fill level is high. These thresholds may be substantially identical as this minimises significant cycling in the fill level in the granulation bowl.

The overflow controller may actuate the overflow apparatus to move the stopper to the first position after a time delay of at least 1 second from the de-activation of the auger. The time delay can be between 1 and 5 seconds. The time delay allows draining of powder from the auger before the outlet is substantially sealed. This prevents or reduces any build up of powder in the conduit which may clog the outlet as it is known for granulated powders to bind together when they settle. The time delay to reduce such powder settling combined with the movement of the stopper act to reduce the likelihood of such binding.

The actuator can be any suitable actuator and may be a linear actuator. The actuator may be pneumatic, hydraulic, electric or mechanical. The actuator may be a pneumatic actuator in which the arm is selectively movable along a first axis between a closed position and an open position. The first axis may be substantially parallel with the conduit axis.

The stopper may be any suitable size and shape, but must be able to substantially prevent powder from flowing through the powder outlet. The stopper may be substantially flat and have an area larger than the conduit such that in the first position the stopper makes contact with a powder outlet edge that defines the powder outlet thereby blocking the powder outlet.

The stopper may have a cross section substantially perpendicular with the conduit axis that is shaped to correspond with the shape of the powder outlet. The stopper can

extend substantially parallel with the conduit axis between a proximal end and a distal end and be tapered from the distal end to the proximal end such that the distal end has a circumference greater than the circumference of the powder outlet and the proximal end has a circumference less than the circumference of the powder outlet. The tapering means that in the first position the proximal end may be positioned substantially within the conduit. The stopper can therefore act as a plug. The tapering can be linear or curved.

A portion of the arm of the overflow apparatus may extend perpendicular to the first axis such that the stopper is offset from the actuator and moves substantially parallel with the first axis. This allows the body of the actuator to be located away from the powder outlet and it will therefore not interfere with the powder flow or need to be located within the conduit in some way.

The overflow may also include a sleeve sized to fit over and be secured to the conduit such that the overflow apparatus can be simply fitted to an existing dispensing apparatus. The sleeve may extend the conduit and the outlet from the sleeve then becomes the powder outlet. The overflow controller can also be adapted to receive a fill signal from a sensor already fitted to the dispensing apparatus as this enables the overflow system to be retrofitted to existing automatic apparatus.

The invention also provides overflow apparatus suitable for use in the dispensing apparatus above, the overflow apparatus comprising a stopper, a connector and an actuator comprising a body and an arm, the connector being for connecting the apparatus to the conduit such that the position of the body of the actuator is substantially fixed relative to the conduit, the stopper is coupled to the arm of the actuator and the actuator is actuable to move the arm relative to the body such that the stopper moves relative to the body.

The invention further provides a method of operating a dispensing apparatus to fill a granulation bowl, the dispensing apparatus comprising a hopper for containing powder, an auger, a granulation bowl and overflow apparatus, the auger comprising an auger screw, a conduit and a powder outlet, the conduit extending between the hopper and powder outlet and the auger screw being arranged within the conduit, the

- D - overflow apparatus being actuable to substantially prevent the flow of a powder substance through the powder outlet, the overflow apparatus comprising a stopper and an actuator, the actuator comprising a body and an arm, the overflow apparatus is connected to the powder conduit such that the position of the body of the actuator is substantially fixed relative to the conduit, the stopper is coupled to the arm of the actuator and the actuator is actuable to move the arm relative to the body such that the stopper moves relative to the body, the overflow apparatus being arranged such that actuation of the actuator moves the stopper between a first position in which it substantially blocks the outlet thereby substantially preventing powder flow therefrom and a second position in which the stopper is displaced from the outlet such that powder is permitted to flow from said powder outlet, the method comprising the steps of: monitoring the fill level of the granulation bowl; when the fill level is below a predetermined low threshold actuating the overflow apparatus to move the stopper to the second position and activating the auger such that powder from the hopper is moved along the conduit and through the powder outlet into the granulation bowl; and when the fill level is at or above a predetermined high threshold de-activating the auger and subsequently actuating the overflow apparatus to move the stopper to the first position.

If the dispensing apparatus further comprises a sensor then the fill sensor can be used to monitor the fill level of the granulation bowl and to generate a fill signal indicative of the fill level of the granulation bowl. An auger controller could receive the fill signal and automatically activate or de-activate the auger as required. An overflow controller could automatically actuate the overflow apparatus to automatically move the stopper between the first and second positions as required by receiving the fill signal or another signal indicative of whether the auger is active or not.

The auger controller may also only move the stopper to the first position after a time delay of at least one second and possibly a delay of between 1 and 5 seconds.

The apparatus and process above are intended for use in a capsule filling operation for creating pharmaceutical capsules.

It should be understood that throughout this specification and in the claims that follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", implies the inclusion of the stated integer or step, or group of integers or steps.

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The invention will now be described, by way of example only, with reference to the following drawings in which;

Figure 1 shows dispensing apparatus;

Figure 2 shows dispensing apparatus, a granulation bowl and sensor together with overflow apparatus;

Figure 3 shows a flowchart of a method for controlling dispensing apparatus.

Figure 1 shows a dispensing apparatus 1 including a granulation bowl 2 and sensor 4. The dispensing apparatus comprises a hopper 6, an auger 8 including an auger screw 10, a conduit 12 and a powder outlet 14.

The conduit 12 extends between the hopper 6 and powder outlet 14 and the auger screw 10 is arranged within the conduit 12 such that, when active, the auger 8 causes powder to move from the hopper 6 to the powder outlet 14 along the conduit 12 and into the granulation bowl 2. The conduit extends along a conduit axis 16 which is arranged substantially vertically. The rotation force for the auger screw 10 is provided by the auger drive 18 which is coupled to the auger screw 10 above the hopper 6. In this case the auger drive 18 is an electric motor, but could be a hydraulic or pneumatic motor or other suitable drive means.

The auger screw 10 includes scrapers 20 for causing powder within the hopper to fall towards the hopper outlet 22 from which location the auger screw can draw the powder from the hopper 6 and through the conduit 12. The hopper includes a substantially cylindrical top section 24 and a substantially conical lower section 26.

The granulation bowl is located below the powder outlet 14 such that powder leaving the powder outlet 14 falls into the granulation bowl 2. The sensor 4 is a proximity sensor and monitors the fill level of powder within the granulation bowl 2. The sensor 4 generates a fill signal indicative of the fill level of the granulation bowl 2.

An auger controller 28 receives the fill signal from the sensor 4. If the fill signal is indicative that the fill level is below a predetermined low threshold the auger controller 28 activates the auger drive 18 such that powder from the hopper 6 is moved along the conduit 12 and through the powder outlet 14 into the granulation bowl 2. If the fill signal is indicative that the fill level is at or above a predetermined high threshold the auger controller 28 de-activates the auger drive 18. In this case the high threshold and low threshold are substantially identical and form a fill threshold 30.

The auger 8 and hopper 6 are supported by a housing 32 and support 34.

Figure 2 shows dispensing apparatus 101. The apparatus is similar to that shown in Figure 1, but with the inclusion of overflow apparatus 40. The overflow apparatus comprises a stopper 42 and an actuator 44. In this case the actuator is a Clippard Mini Matic™ air actuated spring return Model FSR- 12 actuator. The actuator 44 includes a body 46 and an arm 48. The overflow apparatus 40 is connected to the conduit 12 such that the position of the body 46 of the actuator 44 is substantially fixed relative to the conduit 12. In this case the body 46 is connected to a sleeve 50, a part of which is arranged over the powder outlet 14 of the conduit 12 and is secured to the outside of the conduit 12. In this case the sleeve 50 acts to extend the conduit 12 beyond the original outlet so that the powder outlet 114 from the conduit 12 is at the end of the sleeve 50.

The stopper 42 is coupled to the arm 48 of the actuator and the actuator is actuable to move the arm 48 relative to the body 46 such that the stopper 42 moves relative to the body 46. The overflow apparatus 40 are arranged such that actuation of the actuator 44 moves the stopper 42 between a first position in which is substantially blocks the powder outlet 14 thereby substantially preventing powder flow therefrom and a second position (as shown in Figure 2) in which the stopper 42 is displaced from the powder outlet 14 such that powder is permitted to flow through said powder outlet 114.

The dispensing apparatus 101 includes an overflow controller 52 and this works together with the auger controller 28 to control the dispensing apparatus 101.

The actuator 44 is arranged so that the body 46 is substantially fixed relative to the conduit 12, and the actuator is actuable to cause the arm 48 to move parallel with the conduit axis 16 along a first axis 56. The arm 48 from the body 46 moves substantially along the first axis 56 for a first arm portion 58. The arm 48 then extends substantially perpendicular to the first axis 56 for a second arm portion 60. The stopper 42 is attached to the second arm portion 60.

The auger controller 28 and overflow controller 52 receive the fill signal from the sensor 4. If the fill signal is indicative that the fill level is below a predetermined low threshold the overflow controller 52 actuates the actuator 44 and the auger controller 28 activates the auger drive 18 such that the stopper 42 is moved to the second position thereby unblocking the powder outlet 14 and powder from the hopper 6 is moved along the conduit 12 and through the powder outlet 14 into the granulation bowl 2. If the fill signal is indicative that the fill level is at or above a predetermined high threshold the auger controller 28 de-activates the auger drive 18 and the overflow controller 52 actuates the actuator 44 after a predetermined time delay of between 1 and 5 seconds to move the stopper 42 into the first position in which is substantially blocks the powder outlet 14.

The air supply to the actuator is regulated by a valve 55 in this case an ASCO™ electronic control valve which is controlled by the overflow controller which includes a time delay unit 54, in this case a time delay relay so that when the fill signal indicates that the overflow device should be moved to the first position the valve is not moved until after the predetermined time delay has elapsed.

Figure 3 shows a flow chart 70 showing steps in a control method for the dispensing apparatus of Figure 2. The method is started in step 72 and the fill signal from the sensor is monitored in step 74.

The fill signal is checked to see if it is indicative that the fill level is below a low threshold in step 76. If it is determined to be low then the overflow device is opened 78 and the auger is activated 80. If the signal is not indicative that the fill level is low then the fill signal is checked to see if it is indicative that the fill level is above a high

threshold in step 82. If it is above a high threshold then the auger 8 is de-activated 84 and the time delay unit 54 activated in step 86. Once the predetermined time delay has elapsed the overflow device 40 is closed by moving the stopper 42 to the first position.

In the method it should be understood that the steps of activating and of deactivating the auger and the actuating of the actuator to move the stopper to the first or second position should be read to mean that the state of the auger or actuator is maintained if the current state matches the desired state.

If the level is neither high or low or the actions following the decision that he level is high or low have been taken the method returns to the monitoring step 74.

The invention has been described above by way of example only and modifications in detail can be made within the scope of the invention as defined by the claims.