EP2024171A1

EP2024171A1 - Filling shoe for rotary tablet presses

Info

Publication number: EP2024171A1
Application number: EP08707567A
Authority: EP
Inventors: Hans Krämer
Original assignee: IMA Kilian GmbH and Co KG
Current assignee: KILIAN TABLETING GMBH
Priority date: 2007-02-21
Filing date: 2008-02-06
Publication date: 2009-02-18
Anticipated expiration: 2028-02-06
Also published as: US20100015264A1; EP2024171B1; CN101678628A; DE202007002707U1; JP2010519049A; CN101678628B; PL2024171T3; WO2008101598A1; US8167598B2; ES2540214T3

Abstract

The invention relates to a filling shoe for rotary tablet presses, comprising a filling shoe housing (12) with at least one discharge port (15) for a starting product that is to be compressed and a seal (20) for sealing the gap between the die disk (4) and the filling shoe housing (12), said seal (20) being interchangeably attached to a bottom wall (13) of the filling shoe housing. In order to shorten the downtimes when replacing the seals, the seal is attached to the bottom wall by means of magnetic force in the mounted state. If necessary, the seal can thus be changed even without using any additional aid by overcoming the magnetic retaining force and replacing the seal by a new seal. The invention also relates to a seal (20) for sealing the gap, said seal (20) being attached by means of magnetic elements (26, 27).

Description

Applicant: IMA KILIAN GmbH & Co. KG, Scarletallee 11, D-50735 Cologne Title: Filling shoe for rotary tablet presses

The invention relates to a filling shoe for rotary tablet presses, comprising a Füllschuhgehäuse positionable above a die plate of a rotor of the rotary tablet press with at least one discharge opening for a starting product to be pressed and with a replaceable at a discharge opening having bottom wall of the Füllschuhgehäuses fastened or fixed seal for sealing the gap between the rotatable die plate and the Füllschuhgehäuse. The invention also relates to the seal for sealing the gap.

In the rotary tablet presses used in the prior art, the product to be compressed, such as in particular a powder for the production of medicaments or a powder for the preparation of cleaning tablets or the like., The matrices interchangeably used in the die plate, in the die bores the supplied powder to a Tablet of the desired shape is pressed by means of oppositely moving punch, fed through suitable grooves or hoses, a funnel and called a filling shoe feeding. The funnel as well as the gutters can also be an integral part of the filling shoe. The filling shoe can in this case be mounted in a stationary manner relative to the die plate or else attached to a pivoting device which is pivoted into its operating position during operation, in which the filling shoe assumes a predetermined position relative to the dies in the die plate. In the interior of the filling shoe impellers or other movable distributing organs are often arranged, which are driven by a motor in order to achieve a better distribution of the product to be pressed or powder to be filled by means of the Füllschuhs Matrizenbohrungen. At the same time, the filling shoe should ensure that the product to be compacted, in particular powder, substantially only fills the die bore up to the desired filling level To avoid product losses and to achieve a favorable dosing accuracy of the product or powder to be pressed. For this purpose, a seal is attached to the underside of a bottom wall of the Füllschuhgehäuses comprehensive the discharge opening, which consists of a material which is optimally adapted to the product to be pressed. Usual materials for such seals may be, for example, bronze, stainless steel or plastic and depending on the used, to be pressed product, purpose, wear resistance of the seal, etc., the seal against a new, or when changing the product to be tableted against a seal of other material be replaced.

In the prior art, the replacement or replacement of the seals by loosening a plurality of screws, which pass through the bottom wall of the Füllschuhgehäuses and engage in associated threaded holes in the seal. It is also known to use gaskets e.g. made of bronze by means of a rib in suitable dovetail guides or the like. insert and anchor there form-fitting. The more abrasive the product to be compacted and the smaller the free gap between the seal and the surface of the die plate is set, the faster the seal wears and a change of seal on the filling shoe, which change requires longer downtime of the tablet press, must be done. As e.g. briquetting powder dust that adds threaded holes or undercut guides, even the change of the seal can cause problems and cause longer downtime.

The object of the invention is to provide an improved filling shoe that allows shorter downtime when changing the seals.

These and other objects are inventively achieved in that the seal is fixed in the assembled state by means of magnetic force on the bottom wall. If a change of the seal is required in the filling shoe according to the invention, then, if necessary, even without any further aids, the seal can be achieved by overcoming the magnetic holding force and then against a new, at the same position Ie positioned seal to be replaced. Basically, this could be the seal made of magnetized material, in particular made of suitable material for high energy magnets (super magnets). For attachment of seals made of steel or stainless steel could also be the bottom wall made of magnetized material, in particular made of material for high-energy magnets (super magnets) or inserts or ^'the like. made of suitable magnetized material.

The use of magnetic force, in particular magnetic force of high energy magnets, as a holding force for the seal has the particular advantage that can be dispensed with the attachment of through holes or screw holes in the bottom wall of the Füllschuhgehäuses and in the seal. This not only eliminates debuffs or minimizations, e.g. the cross-section of the body of the seal, on which otherwise possibly even after a short time wear or fractures of the seal body may occur, but due to the fact that no cavities or holes in the bottom wall and the seal must be provided, the number of Cavities and the like., Which form undesirable dead spaces in which components of the product to be compressed, in particular dust, powder body od. Like. Accumulate, and must be cleaned consuming in a product change, minimized. Since holes for attaching the screws or slot-like guides for positive anchoring of the seals omitted, the risk is minimized at the same time that enforce appropriate cavities with the product to be pressed, whereby a loosening and changing the seal could be difficult.

In the particularly preferred embodiment, magnetic bodies are locked to apply the magnetic force to the seal and / or on the bottom wall, it being particularly advantageous if the magnetic bodies are locked in pairs on both the seal and on the bottom wall of the Füllschuhgehäuses to apply the magnetic force. By using magnetic body pairs particularly high holding forces can be achieved because then the tightening force or the magnetic field of both magnetic body for applying the magnetic holding force can be exploited. In particular, attached to the seals, trained or locked magnetic body may consist in particular of flat bodies such as flat slices, flat cylinders or cuboids and / or be designed as high energy magnets. High-energy magnets which have an energy product of at least 150 KJ / m ³ , in particular at least 200 KJ / m ³ , preferably at least about 250 KJ / m ³ , can be used as the magnetic body. The corresponding high-energy magnets or supermagnetic magnets may consist particularly advantageously of hard ferrites, neodymium-iron-boron (NdFeB), samarium-cobalt (SmCO) or other suitable materials, for example the rare earths. By using high-energy magnets made of, for example, NdFeB with an energy product of about 250 KJ / m ³ , few magnets or pairs of magnets suffice to securely apply the required holding forces.

It is furthermore particularly advantageous if at least two magnetic bodies, one pair of magnetic bodies or a plurality of magnetic body pairs form a centering means for the exact positioning of the seal relative to the dispensing opening. In the simplest embodiment, in this case at least two magnetic body can be locked projecting over the bottom wall of the Füllschuhgehäuses or over the top of the seal to effect by positive engagement in a recess on the contrary, ie on the seal respectively the bottom wall, a positional fixation of the seal. The possibly existing counter magnet of the pair can then be arranged set back to the surface. The locking of the magnetic body to the seal and / or in the bottom wall can ins-, especially by sticking the magnets or pressing the magnets done in appropriate recordings. Alternatively, the magnetic bodies or high-energy magnets can also be used by means of hardenable and / or plastic-bonded, magnetizable masses or the like. be formed. The centering could then possibly also of centering pins or the like. are taken, which are provided in addition to the holding force determining magnet. The optionally additionally provided centering pins or the magnets, which take over a centering function, can at the same time also absorb part of the thrust forces acting on the seal in the peripheral or rotational direction, which inevitably arise during operation in the case of a rotating die plate. The thrust forces can be intercepted, in addition to the magnetic holding forces, in particular by positive engagement between magnet or centering pin and bottom wall. Alternatively or additionally, in particular a transversely lying to the direction of rotation transition sheet or the like. abut the seal on a projection or rib on the bottom wall to provide over the protrusions or ribs an additional safeguard against loosening of the seal. Depending on the product used, the individual magnets can additionally be galvanized, coated, encapsulated in a food-safe manner or the like. be educated.

In some gaskets, a web extending through the dispensing opening can be present, which at the same time advantageously forms a disassembly aid for better gripping the gasket to be loosened. In particular, in embodiments of seals that lie flush against the underside of the bottom wall of the Füllschuhgehäuses, may be advantageous if the seal or the bottom wall is provided with at least one partial slope for applying a disassembly aid.

An inventive sealing element for a filling shoe for rotary tablet presses solves the above-mentioned object, in particular by the fact that the seal of magnetized material, in particular material for high energy magnets, consists, or that are fixed to the seal magnetic body, in particular magnetic body made of material for high energy magnets. Also, in the case of the sealing elements or seals, advantageously at least one magnet body locked on the seal can be fastened projecting in order to be able to center or position the seal relative to the dispensing opening at the same time with this magnet body.

Further embodiments of a filling shoe according to the invention with a seal according to the invention will become apparent from the following description of an embodiment schematically shown in the drawing, in which:

Figure 1 is a perspective view of a portion of a rotor and a filling shoe, partially broken away. Fig. 2 is a view of the underside of the Füllschuhgehäuses of FIG. 1 with attached seal, - and

Fig. 3 shows schematically in a vertical section through Matrizenscheibe and Füllschuh the attachment of a seal by means of a plurality of magnetic body.

In Fig. 1, reference numeral 1 denotes the rotor of a rotary tablet press, not further shown. The rotor 1 has in known manner a Oberstempelführungsring 2, in which a plurality of upper dies 3 are guided vertically movable in suitable guides. The rotor further comprises a die plate 4 with a number of dies corresponding number of matrices 5, in which by means of the punch a product to be pressed as particular powder is pressed into a tablet, as well as an indicated only Unterstempelführungsring 6, in which for each upper punch. 3 a shown in Fig. 3 shown associated lower punch 7 is guided adjustable in height. The number of punches 3, 7 per punch guide ring 2, 6 and the number of matrices 5, depending on the size of the tablet to be pressed and size of the rotary tablet press, usually vary between about 15 and up to 100 and with appropriate rotary tablet presses tablets from a to pressing product or from several products to be pressed, such as multi-phase pharmaceutical tablets or cleaning tablets. For pressing tablets from a supplied powder, the rotor 1 is rotated in the direction of rotation R and the punches are moved up and down by means of suitable link or cam tracks, depending on the position of the dies and punches 3, 6, the dies 5 with the product to be pressed to fill, to squeeze the tablet or to eject the pressed tablet.

In order to fill the dies during operation, a rotary tablet press has at least one filling shoe 10 which is fixedly assigned to the rotor 1 and to which the product to be compressed, in particular powder via a funnel, not shown, and suitable accessories. Guides and feed tubes 11 is fed to a Füllschuhgehäuse 12. Here, the filling shoe housing 12 has a solid plate as the bottom wall 13, which is centrally provided with an approximately achtförmigen Verteilaus- recess 14, which opens into a continuous or possibly multi-divided discharge opening 15 on the bottom 16 of the bottom wall 13. Within the Verteilausnehmung 14 here two impellers 17 are rotatably arranged as distributing members, which are driven by drive shafts 18 which lead inside or outside the Füllschuhgehäuses 12 to a motor drive, so that the impellers 17 rotated during operation for moving and distributing the product to be pressed can be.

The filling shoe 10 may either be fixedly mounted within the rotary tablet press or it may or the like on a pivoting arm. be pivoted to pivot the filling shoe 10 for the operation of the rotary tablet press in a working position so that the discharge openings 15 are located on a portion of the rotary tablet press directly over a plurality of matrices 5 to be filled. The matrices 5 in the die plate 4 are moved past the discharge openings 15 in the filling shoe 10 for a time dependent on the rotational speed of the rotor 1 and must be optimally and completely filled with the product to be compacted in this usually extremely short period of time. In the embodiment shown, the underside 16 of the bottom wall 13 of the Füllschuhgehäu- ses 12 is provided with a step 19 whose radius of curvature substantially corresponds to the outer diameter of the die plate 4, so that the filling shoe 10 can be positioned with the least possible radial and axial distance to the die plate 4.

For optimum operation of a rotary tablet press, the most exact possible filling of the die holes 5A of the matrices 5 is to be achieved, and at the same time ensured that in the direction of rotation R behind the filling shoe 10 as possible no product to be pressed over the top edge of the matrices 5 in the die plate 4 projects or . is transported out of the discharge opening 15. This is achieved in a manner known per se by means of a sealing segment which is open on one side in the direction of rotation as a seal 20, which extends with two segment legs 21 in a circular arc around the dispensing opening 15 and with a transitional arc 22, the two segment leg 21 connects such that no later than the transition sheet 22 the product to be pressed is stripped relative to the top of the die plate 4 by means of the transition sheet 22. At the opposite end of the transition bow 22, the seal 20 between the two segment legs 21 is open. The seal 20 is releasably secured to the bottom 16 of the bottom wall 13, so that it must be replaced depending on the product to be pressed in longer or shorter intervals against a new seal 20. A regular replacement of the seal 20 is required even if it consists for example of VA steel or bronze, since at least when abrasive powder as the product to be pressed relatively quickly at the output opening 15 facing inner edge in the region of the transition arc 22 wear occurs, the the Abstreiffunktion the seal 20 narrows or reverses.

The operating position of the seal 20 according to the invention forming, here rigid sealing segment relative to the die plate 4 shows particularly clearly the Fig. 3, to which reference is now made. Between the bottom 16 of the bottom wall 13 and the disc surface of the die plate 4, there is a relatively large gap which is substantially completely bridged by means of the seal 20 fastened to the bottom 16. In order to keep the wear of the seal 20 reasonably low and at the same time to use relatively stable materials for the seal 20, however, usually remains a gap distance in the range of about 1/10 mm between the lower surface of the seal 20 and the facing this disc surface of the die plate 4th

In contrast to the prior art, in the filling shoe 10 according to the invention, the seal 20 is preferably fastened exclusively to the underside 16 of the bottom wall 13 by means of magnetic force. The magnetic holding force between the seal 20 and the bottom wall 13 is applied in the illustrated and particularly preferred embodiment in each case with pairs of magnetic bodies 26 and 28, wherein the magnetic body 26 at the top of the sealing segment 20 and the magnetic body 28 are arranged and locked on the underside 16 of the bottom wall 13. The locking of the magnetic body 26, 28 can be done in particular by gluing or pressing and the magnetic body 26, 28 are preferably made of flat and relatively wide high energy magnets such as so-called super magnets of hard ferrite or neodymium-iron-boron (NdFeB). By distributing a plurality of pairs of magnetic bodies 26, 28 along the segment leg 21 of the seal 20 and possibly also the transition arc 22 and corresponding to the opposite surface on the bottom 16 of the bottom wall 13 can be achieved that by means of the magnetic body 26, 28 applied holding forces certainly sufficient to prevent disengagement of the seal 20 in spite of the frictional forces occurring during operation by the swept at the transition arc 22 powder. The powder to be pressed and distributed by means of the filling shoe on the matrices is indicated in Fig. 3 within the distribution chamber 14 and the discharge opening 15 and the die bore 5A. In order to ensure at the same time in the assembly of a new seal 20 that it is fixed exactly in the desired position and location on the bottom 16 of the bottom wall 13, with one or more pairs of magnetic bodies at the same centering can be effected, as for the magnetic body 27 and 29 in the left half of Fig. 3 is indicated. In the illustrated embodiment, the centering takes place such that the locked at the top of the seal 20 magnetic body 27 projects over the top and at the same time the locked in the bottom wall 13 magnetic body 29 is set back relative to the bottom 16, so that the magnetic body 27 positively in a recess 25 at the bottom 16 dips and thereby causes the centering of the seal 20. Advantageously, a plurality of magnetic body pairs at the same time form a centering or positioning means. The centering or positioning means could also be designed or arranged such that by means of them also shear forces in the direction of rotation of the rotor can be intercepted.

Those skilled in the art will recognize from the foregoing description numerous modifications which are intended to be within the scope of the appended claims. The attachment of gaskets by means of mag- netkraft, in particular by means of the magnetic force of high energy magnets, can be done substantially in any configuration of seal or sealing segments and the seals could also form, for example, closed rings, made of several parts or provided with other formats. In the case of multi-part seals, in particular the transition arc can be designed as a sub-segment, which can be replaced separately from other sub-segments of the seal, since the wear on the transition arc is normally the highest. The seals are preferably made of copper, stainless steel or bronze; However, it would also be possible to lock appropriate high-energy magnets to seals made of plastic or other materials. Furthermore, it would also be possible, for example, to form the entire sealing segment from a magnetized material, in particular from a material for high-energy magnets, so that consequently the sealing segment 20 is attached to the underside of the bottom wall 13 in a self-adhesive manner. Here, too, partial increase could be achieved in order to increase the adhesive force or circulating at least one other high-energy magnet or the like. be attached to the bottom wall of the filling shoe. The magnetic body or high-energy magnets can also be directly in recesses or the like. the sealing segment and / or the bottom wall of the Füllschuhgehäuses be pressed and / or for example, from plastic-bonded magnetic materials based on NdFeB, hard ferrite, sintered Hartfer- rites, or other sintered or plastic-bonded materials, rare earth materials or the like. exist with high energy magnetic properties. The die plate may, unlike the illustrated embodiment, be constructed differently and, for example, consist of sections with integral die holes or recesses for inserts comprising a plurality of die holes have.

Claims

Patent claim:

A filling shoe for rotary tablet presses, comprising a filling shoe housing (12) which can be positioned above a die plate of a rotor of the rotary tablet press with at least one delivery opening (15) for a starting product to be compressed and with a bottom wall (13) of the filling shoe housing interchangeable with the delivery opening (15) (12) fastened or fixed seal (20) for sealing the gap between the die plate and the Füllschuhgehäuse (12), characterized in that the seal (20) in the assembled state by means of magnetic force on the bottom wall (13) is attached.

2. filling shoe according to claim 1, characterized in that the

Seal made of magnetized material, in particular of a material for high-energy magnets consists.

3. filling shoe according to claim 1 or 2, characterized in that the bottom wall consists at least partially of magnetized material, in particular material for high energy magnets.

4. filling shoe according to one of claims 1 to 3, characterized in that for applying the magnetic force magnetic body are locked to the seal or on the bottom wall.

5. filling shoe according to one of claims 1 to 3, characterized in that for applying the magnetic force magnetic body (26, 28) in pairs on the seal (20) and on the bottom wall (13) of the Füllschuhgehäuses (12) are locked.

6. filling shoe according to claim 4 or 5, characterized in that the magnetic body (26, 27, 28, 29) consist of high energy magnets.

7. filling shoe according to one of claims 1 to 6, characterized in that the magnetic body or the magnetized material have an energy product of at least 150 KJ / m ³ or at least 200 KJ / m ³ , in particular at least 250 KJ / m ³ .

8. filling shoe according to one of claims 1 to 7, characterized in that the magnetic body or the magnetized material of neodymium-iron-boron (NdFeB), hard ferrite or samarium-cobalt (SmCO) exist.

9. filling shoe according to one of claims 1 to 8, characterized in that at least two magnetic body (27, 29) or magnetic body pairs form a centering means for the exact positioning of the seal (20) relative to the dispensing opening (15).

10. filling shoe according to claim 9, characterized in that at least two magnetic body (27) over the bottom wall of the Füllschuhgehäuses or over the top of the seal (20) are locked projecting.

11. filling shoe according to one of claims 1 to 10, characterized in that on the outer circumference of the seal at least one disassembly aid, in particular at least one wedge slope is formed.

12. seal for a filling shoe for rotary tablet presses, which is fastened to the underside of a bottom wall of a Füllschuhgehäuses, characterized in that the seal made of magnetized material, in particular material for high energy magnets, or that on the seal (20) magnetic body

(26, 27), in particular magnetic body made of material for high-energy magnets, are arranged, formed or locked.