DE29501527U1 - Device for producing inhalable active substance particles - Google Patents

Description

Device for generating inhalable active substance particles

The invention relates to a device for the mechanical production of inhalable active substance particles according to the preamble of claim 1.

Such a device has become known from the international patent application PCT/EP 93/01157. In the known device, both the active ingredient supply in the form of a ring-shaped tablet and a grinding wheel in the form of a face milling cutter, which carries three evenly spaced milling blades and can be driven in rotation by a rotary drive also housed in the housing, are arranged in a housing equipped with a mouthpiece. The rotary drive is designed as a spring motor that can be wound up by a tension wheel and started using a release button. This removes active ingredient particles and removes them by sucking in (breathing) air.

However, this device has a number of disadvantages. It is often observed that the grinding wheel or the cutter blades do not evenly break up the active ingredient particles by

Postbank: Karlsruhe 76979-754 BankkorUpJ.Deutsche'einkj\G j/illi'ng^n (BL£-£94jf0039) 146332 V.A.T.No.DE14280S261

They are not removed by the particles, but are moved along the front of the active ingredient reservoir in the form of a rattling or slipping movement. This leads to a high proportion of particles not reaching the prescribed size in the range of one to 10^m. This reduces the effect, as particles that are outside the specified range are not respirable, i.e. do not reach the lungs. In addition, there is a risk that sintering processes occur on the surface of the active ingredient reservoir, which make it difficult to remove active ingredient particles properly and/or change the chemical composition of the active ingredient.

Furthermore, it can be seen that the grinding wheel overshoots at the end of the intended grinding process, so that the prescribed discharge angle, which determines, among other things, the removal and thus the dosage, is not exactly maintained.

Since the milling blades of the grinding wheel come to a standstill in the same angular position after each cycle, radial grooves can form in the active ingredient supply during use, which further complicates the uniform course of the removal or grinding process.

There is also the danger that the spring of the rotary drive will be subjected to too much stress during the winding process, since the winding path is limited by the contact of the spring coils with the spring core. Since the spring has a strongly increasing characteristic curve in this area, it is hardly possible in practice to generate a specified torque with repeatability, which is required for a precisely dosed process. Therefore, the rotary drive is often wound up too much, resulting in excessive torque. The running speed of the grinding wheel becomes too high and the problems of rattling or

Slippages are becoming more common.

The invention was therefore based on the problem of improving a device of the type mentioned at the beginning in such a way that it no longer has the problems described. In particular, it should be able to remove a precisely specified amount of active ingredient particles in the prescribed particle size in an exactly reproducible manner during each grinding process. The removal should be ensured evenly without rattling or slippage.

This problem is solved with a device having the features of claim 1. Advantageous embodiments are specified by the features of the subclaims.

The invention is based on the idea of equipping the rotary drive with a control regulator that reduces the running speed of the rotary drive and thus the rotation speed of the grinding wheel. This ensures that the grinding wheel is operated at a lower speed and thus a consistent contact of the milling blades with the active ingredient supply is guaranteed. At the same time, active ingredient particles are released in the desired homogeneity, which results in an optimal active ingredient dosage.

The inhibiting regulator also ensures that the rotational energy of the grinding wheel or the entire drive rod is minimized. An overshoot of the drive at the end of the grinding process is thus reliably avoided.

Preferably, the escapement regulator is designed as a mechanical control mechanism or escapement with an armature as a vibration element, which is connected via a toothing to the grinding wheel or the rotary

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drive. Such mechanical control systems, which are known from the watchmaking industry, for example, offer the advantage that the rotational movement is slowed down considerably or comes to a standstill with each engagement cycle of the anchor. The rotational energy of the grinding wheel is thus reduced to zero, and overshooting when the intended run-off angle is reached is thus excluded.

Preferably, the anchor is designed as a bracket so that the escapement can be designed to save space.

The armature is particularly preferably designed as a closed ring, which has the advantage over the previously described bow shape that the annular space available within the housing can be used optimally in order to achieve the largest possible volume and the greatest possible distance between the armature's center of gravity and the axis of rotation for the vibration element. A large volume and the greatest possible distance between the center of gravity are required in order to set the desired inertia behavior of the armature. The ring shape makes it possible to realize the armature as an inexpensive and stable plastic injection molded part, since the large volume means that a sufficient mass can be achieved despite the low specific density.

Instead of an anchor designed as a bracket or ring with the associated anchor wheel, the escapement regulator can also be designed as a centrifugal governor or even in the form of an eddy current brake.

An advantageous embodiment of the invention provides that the rotary drive is provided with a first stop for fixing the

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end position, upon reaching which the drive torque of the rotary drive assumes the value zero, i.e. the rotary drive comes to a standstill upon reaching this stop.

At the same time, the slowing down of the drive speed of the rotary drive caused by the inhibiting regulator ensures that the grinding wheel, which is preferably rigidly coupled to the rotary drive, comes to a standstill immediately and does not continue to vibrate. This in turn is important for the correct production of active ingredient particles, as it ensures that the same particle size is always maintained and that larger or smaller chunks outside the desired size are not accidentally knocked out of the solidified active ingredient body as a result of uneven impact by the milling blades.

According to a further advantageous embodiment of the device according to the invention, a second stop is provided which serves to limit the maximum winding angle and interacts with the tension wheel of the rotary drive. This prevents the spring used in the rotary drive from being overtensioned and ensures a constant drive speed and a constant torque of the rotary drive with high repeatability. Since the spring is always only tensioned up to a defined load point, fatigue or damage to the drive spring is practically impossible.

It also proves to be advantageous that the design of the stops enables the selection of a specific characteristic range of the springs used in the rotary drive. If necessary, the device according to the invention can be adapted to different requirements by exchanging the spring.

different active ingredient preparations with correspondingly different removal rates can be set.

A further preferred embodiment of the device according to the invention provides that the stops are designed as drag stops, which change the location of the grinding wheel's standstill after each actuation. This advantageously results in the end point, and thus the position of the grinding wheel, constantly changing after each actuation of the rotary drive. The milling blades no longer dig in due to standing still at the same angular position.

The drag stop is preferably designed as a sliding block that is arranged in a groove provided on the circumference of a driver for the grinding wheel. The groove can be designed to be almost completely circumferential, with a web limiting the rotation angle of the sliding block. This means that run-off angles of more than 360°, i.e. up to almost two full revolutions, are possible. On the one hand, this means that the grinding wheel comes to rest at a different angular position with each operation, and on the other hand, this configuration allows a high removal rate, since the run-off angle can be almost doubled compared to the previously known solution.

In order to further improve the handling of the device according to the invention, it can also be provided with a trigger with an integrated locking pawl, with which the rotary drive can be locked at any angle of rotation. In this way, multiple, short actuations of the grinding wheel can be achieved without additional tensioning of the rotary drive.

The invention, as well as particular features thereof, are explained in greater detail with reference to an embodiment shown in the schematic drawing.

Advantages of the invention are explained and described in more detail. Ss show:

Figure 1 shows a longitudinal section through a device according to the invention,

Figure 2 shows a cross-section through the device according to Figure 1 along the section line A-A with a bow-shaped anchor,

Figure 3 shows a cross-section through the device according to Figure 1 along the section line A-A with a ring-shaped anchor,

Figure 4 shows a cross-section through the device according to Figure 1 along the section line B-B with the face milling machine in the initial position,

Figure 5 shows a cross-section through the device according to Figure 1 along the section line B-B with the face milling machine in the end position and

Figure δ shows a cross section through the device according to Figure 1 along the section line C-C.

Figure 1 shows a longitudinal section through a device 2 for mechanically producing inhalable active ingredient particles, which has a housing 42 in which a solidified active ingredient supply 14 is located. The front side of the housing 42 shown on the left in Figure 1 is provided with a mouthpiece 10 in which the active ingredient supply 14, which is acted upon by a compression spring 12, is housed. The active ingredient supply 14 is designed in the form of a ring-shaped tablet which is held in a hollow cylindrical tablet holder.

me 44 is arranged and is pressed against a grinding wheel 16, which is designed in the manner of a face milling machine, which in turn is set in rotation by a leg spring 24 of a rotary drive 4. In the area of the housing 42 in which the active ingredient supply 14 is in engagement with the grinding wheel, there is an air gap 18 let into the wall of the housing 42, which is only interrupted by 4 pillars or webs, through which the incoming air absorbs the particles removed from the active ingredient supply 14 during engagement with the grinding wheel 16 as an aerosol and supplies them to the user (not shown here) through the mouthpiece 10 or tablet holder 44.

The rotary drive 4 driving the grinding wheel 16 has, in addition to the already mentioned leg spring 24, a driver 40 for the leg spring 24 and a driver 36 for the grinding wheel 16. The driver 40 for the leg spring 24 works together with a stop 20, which is preferably designed as a drag stop and serves, on the one hand, to define a certain characteristic range of the leg spring 24 for the rotary drive 4 and, on the other hand, to ensure that the grinding wheel 16 does not come to a stop at the same point, but always reaches a different end point.

In order to allow the rotary movement of the rotary drive 4 to run in a controlled manner and to slow it down, an inhibiting regulator is integrated. For this purpose, an armature 38 serves as the oscillating element of the inhibiting regulator, which is supported in an armature bearing 22 and is coupled to the driver 36 for the grinding wheel 16 via a toothing 52.

A tensioning wheel 30 arranged on the end face of the housing 42 opposite the mouthpiece 10 serves to tension the leg spring 24, which is connected via a freewheel 32 to a

Flange 34 is mounted. The freewheel 32 enables the winding movement for the rotary drive 4 on the one hand, and prevents the tension wheel 30 from returning on the other.

The flange 34 also accommodates a trigger 26 with a pawl 27, which is held in the rest position by a compression spring 28. The trigger 26 serves to hold the driver 36 for the grinding wheel 16, which is acted upon by the tensioned leg spring 24. For this purpose, the driver has a locking toothing 54 in the engagement area of the pawl 27 (Figure 6). By pressing the trigger 26 against the restoring force of the compression spring 28, the driver 36 is released, so that the grinding wheel 16 is set in rotation.

Figure 2 shows a cross section through the device according to Figure 1 along the section line A-A, i.e. through the armature 38, which here is bow-shaped with a slight curvature and has an eccentric pivot point in the form of the armature bearing 22, around which the armature 38 swings when the trigger 26 is actuated and thus slows down the movement of the driver 36 for the grinding wheel 16 that is in engagement with it.

Figure 3 shows the same representation as Figure 2, with the difference that the armature 38 is designed as a ring armature. This design allows the armature 38 to be manufactured cost-effectively as a plastic injection-molded part, since the ring shape means that the moving mass of the armature 38 can be made sufficiently large so that it has the required inertia and the resulting slowing down of the rotary movement is ensured.

Figures 4 and 5 show another cross section

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by the device 2 according to Figure 1 along the section line B-B, where Figure 4 shows the initial position of the rotary drive 4 and Figure 5 its final position.

In the initial position shown in Figure 4, the rotary drive 4 is fully wound up. A sliding block 20 serves as a stop for the winding movement and is slidably mounted in a groove 46 on the circumference of the driver 40. The groove 46 is designed to be almost completely circumferential, forming a web 48, so that the sliding block 20 can basically be moved between the initial position shown in Figure 4 and the end position indicated in Figure 5. Depending on the width of the web 48, a displacement path can be realized that, in the limiting case, corresponds to almost a full rotation. In the exemplary embodiment shown, the web 48 is designed so that the sliding block 20 can cover an angular sector of approximately 340°.

Furthermore, a driver nose 50 is formed on the driver 40 for the leg spring 24, which interacts with the slot nut 20. In the position shown in Figure 4, the driver nose is brought into contact with the slot nut 20, which in turn rests against the web 48. The position shown thus represents the (second) stop, which limits the winding movement of the rotary drive 4.

Starting from this position, the grinding process is now started after the trigger 26 is actuated. The driver 36 for the grinding wheel 16 describes a clockwise rotational movement as shown in Figure 4, whereby the driver lug 50 initially detaches from the sliding block 20 and, after a rotational movement of approximately 320°, comes to rest on the sliding block 20 opposite. In the course of the further rotational movement, the sliding block 20 is released from the driver lug 50.

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taken along and dragged along in the groove 46 until it comes to rest on the web 48 opposite and reaches the end position shown in Figure 5. Further rotation is no longer possible and the grinding process is completed. The driver 36, and thus the grinding wheel 16, has completed almost two full revolutions, with the grinding wheel 16 coming to rest in an angular position that differs from that shown in Figure 4.

A new winding movement is now made possible by actuating the tension wheel 30, whereby the driver 40 for the leg spring 24 is rotated further together with the sliding block 20 until it rests on the driver 36 for the grinding wheel 16, which is now locked relative to the housing 42, or its driver nose 50. As the driver 40 continues to rotate, the groove 46 slides under the sliding block 20 held on the driver nose 50 until the web 48 comes to rest on the sliding block 20, thus preventing further winding movement. Compared to the initial position shown in Figure 4, the position now reached is offset by approximately 90° counterclockwise, so that the grinding wheel 16 is angularly offset in relation to the active substance supply 14. Pressing the release button 2 6 again causes the grinding process to run as described above. Different rest positions are gradually reached, since each grinding process involves slightly less than two full revolutions, for example a 640° rotation angle.

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FIGURE LEGEND

2 Device

4 Rotary drive

10 Mouthpiece

12 compression spring

14 Active ingredient supply (tablet)

16 Grinding wheel

18 Air inlet

20 T-slot nut 22 Anchor bearing 24 Leg spring 26 trigger 27 pawl 28 Compression spring 30 Tension wheel 32 Freewheel 34 flange 36 Driver for grinding wheel

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38 anchors

40 Driver for leg spring

42 Housing

44 Tablet intake

4 6 Groove

48 Bridge

50 Driving nose

52 Gearing

54 locking teeth

156/146/176

Claims (12)

PROTECTION CLAIMS 1. Device for the mechanical production of inhalable active ingredient particles from a solidified active ingredient supply (14) which is ring-shaped and accommodated in a housing (42), with a grinding wheel (16) in the form of a face milling machine arranged in the housing (42) and which can be driven in rotation by a rotary drive (4) designed in particular as a spring motor and which acts on the active ingredient supply (14), characterized in that the rotary drive (4) has an inhibiting regulator (38) which reduces the running speed of the rotary drive (4) or the rotation speed of the grinding wheel (16). 2. Device according to claim 1, characterized in that the escapement regulator is designed as a mechanical control mechanism (escapement mechanism) with an armature (38) as an oscillating element, which is coupled via a toothing (52) to the rotary drive (4) or the grinding wheel (16). 3. Device according to claim 2, characterized in that the anchor (38) is designed as a bracket. 4. Device according to claim 2, characterized in that the armature (38) is designed as a closed ring. Postbank: Karlsruhe 76979-754 Bank account: *Deutsche*&anlTAG Wfirigon (BLZ*99470039) 146332 VAT NO.DE142989261 5. Device according to one of claims 2 to 4, characterized in that the anchor (38) is designed as a plastic injection-molded part. 6. Device according to claim 1, characterized in that the brake regulator is designed as a centrifugal force regulator or eddy current brake. 7. Device according to one of the preceding claims, characterized in that the rotary drive (4) is provided with a first stop (20, 46, 50) which serves to limit the maximum run-off angle and, when reached, the drive torque of the rotary drive (4) assumes at least approximately the value zero. 8. Device according to claim 7, characterized in that the stop is designed as a drag stop (20, 46, 50), so that the location (angular position) of the standstill of the grinding wheel (16) is changed after each actuation. 9. Device according to one of the preceding claims, characterized in that a second stop (20, 46, 50) is provided, which serves to limit the maximum winding angle and prevents overtensioning of a spring (24) used in the rotary drive (4). 10. Device according to claim 8 or 9, characterized in that the drag stop is designed as a sliding block (20) which is guided in a groove (46) provided on the circumference of a driver (40) for the grinding wheel (16) and interacts with a driver nose (50) of a driver (36) for the rotary drive (4) or the spring (24) . 11. Device according to claim 10, characterized in that the groove (46) is designed to be almost completely circumferential, forming a web (48). 12. Device according to one of the preceding claims, characterized in that a trigger (26) is provided, which is in engagement with the rotary drive (4) in such a way that it can be locked at any desired angle of travel before the end position is reached.