EP2759375A1 - Device and method for grinding at least one separating blade fixed on a blade drum and driven rotating separating blade - Google Patents

Abstract

The device has a grinding roll support portion (13) which is provided with a grinding roller (14) rotationally drivable about a grinding axis (II). The grinding roll support portion is designed movably in such a way in that the grinding roller performs sliding engagement with a cutting knife (12) transversely to the grinding axis. A straightening device (15) straightens the surface of the grinding roller which is moved transversely with a movable straightening portion (17) straightening portion moved in parallel on a cross beam (18) along the grinding axis. An independent claim is included for method for grinding/separating tobacco from tobacco cake fixed on blade drum.

Description

The invention relates to a device, designed and arranged for grinding at least one arranged on a cutterhead, which is rotatable about a drum axis I within a device for separating tobacco from a tobacco cake, separating knife, comprising a Schleifwalzenträger with a grinding roller, which around a grinding axis II is driven in rotation, as well as a device for dressing the surface of the grinding roller.

Furthermore, the invention relates to a method for grinding at least one separating knife arranged on a cutterhead, which is driven circumferentially about a drum axis I within a device for separating tobacco from a tobacco cake, comprising the steps of: grinding each cutting knife with one around the grinding axis II rotatably driven, in engagement with the grinding knife to be ground grinding wheel, and dressing the grinding roller with a device in engagement with the grinding roller to be dressed means for dressing the surface of the grinding roller.

Such devices and methods are used in the tobacco processing industry to grind severing blades of a tobacco cutter during the separation process. With the tobacco cutter or cutting blades of the tobacco cutter, a previously compacted, cut-resistant tobacco cake is cut into short tobacco fibers. For this purpose, a cutterhead has at least one cutting knife, but usually several cutting blades, which are distributed uniformly over the circumference of the cutterhead. By separating the tobacco fibers from the tobacco cake and possible foreign substances in the tobacco cake, the cutting blades are subject to wear.

In addition to wear, there is also a considerable contamination by tobacco dust, tobacco sauces and the like. In particular, the tobacco sauces settle on the cutting edges of the cutting knife. In order to maintain the quality of the cut, the separating blades are guided past the drum axis I on the device for grinding during each rotation. The cutting blades form or describe by the rotation about the drum axis I a cutting circle. This cutting circle must be brought into coincidence with a grinding roller or its grinding circle. In other words, the cutting circle and the grinding circle described by the grinding roller must touch each other. In other words, the grinding circle crosses the cutting circle, so that each cutting knife is reground cyclically, namely preferably once each drum revolution. By grinding the cutting blades shorten these. However, since the cutting circle should always have an identical radius, the separating knife to compensate for the reduction in length are readjusted, such that the cutting blades always protrude by a constant amount over the circumference U of the cutterhead.

For grinding the cutting blades, devices are known in which a grinding wheel or sanding roller grinds the cutting blades by the grinding wheel or sanding roller whose width is usually much smaller than the width of the cutting knife, known to be a factor of 10, from one side to the other side is moved back and forth. By traversing the grinding wheel / sanding roller over the entire width of the separating knife, individual points of the separating blade width are ground only sporadically. Furthermore, due to the wide traversing of the grinding wheel / sanding roller across the entire width, an uneven sanding pattern is produced, which has an adverse effect on the quality of the cut.

When separating the tobacco fibers from the tobacco cake not only the cutting blades but also the grinding wheel / sanding roller are exposed to considerable contamination by tobacco dust and in particular also tobacco sauces and the like. These contaminants settle on the grinding wheel / grinding roller, which is why the surface of the grinding wheel / grinding roller has to be reworked. The grinding rollers or their surfaces can be dressed using the example of ceramic bond grinding rollers. This means that a dressing body is the surface peel off, thereby loosening the stains and sharpening the surface. In known solutions, for example, the grinding wheel / sanding roller is guided past fixed diamonds. However, this requires a considerable amount of space, especially when the width of the grinding wheels / grinding rollers increases. In any case, the grinding process for dressing the grinding wheel / grinding roll must be interrupted for a longer period of time. This can also lead to interruptions of the separation process.

Such a device, with regard to the quality of cut, the u.a. depends on the grinding quality, and the handling is disadvantageous, is known for example from German Utility Model G 83 25 419.6 from the house of the applicant.

The invention is therefore an object of the invention to provide a grinding device by means of a time and quality-optimized grinding of the cutting blade of a tobacco cutter is realized. The object continues to be to propose a corresponding method.

This object is achieved by a device having the features mentioned, characterized in that the grinding roller carrier is designed to be movable, such that the grinding roller can be brought transversely to the grinding axis II in looping engagement and out of engagement with the cutting blade to be ground, and that the means for dressing the Surface of the grinding roller has a relative to the grinding roller traversal movable dressing body which is movable on a cross-beam parallel to the grinding axis II back and forth. Due to the mobility of the grinding roller carrier and thus the grinding roller transversely to the grinding axis, the grinding roller can be moved quickly and precisely between the engagement with the or each cutting knife, so the grinding position, and the engagement of the grinding roller with the dressing body, so the dressing position, back and forth so that the grinding operation of the cutting knife for dressing the sanding roller must be interrupted only for a short period of time. The dressing itself is by the traversing body traversing in the direction of the arrow T ₃ , which is movable from one side of the grinding roller over the entire width to the other side and back, while the grinding roller rotates, easily and quickly realized. The term "cross-beam" is synonymous with any type of cross-connection, For example, transverse spindle, cross tube guide, transverse band guide, cross rail, etc., on which or on which the dressing body is guided parallel to the grinding axis II movable or movable.

Advantageously, the grinding roller carrier is arranged on a linearly movable guide carriage, whereby the mobility of the grinding roller between the grinding position and the dressing position is particularly fast and accurate executable.

According to the invention, the device is further developed in that the dressing body additionally designed to be linearly movable, such that it can be brought transversely to the grinding axis II in dressing engagement and out of engagement with the grinding roller to be dressed. In other words, the dressing body itself or in conjunction with the cross-beam in the direction of arrow T ₂ to the grinding roller to and away from the movable. This ensures an exact positioning of the dressing body to the grinding roller, so that an optimal dressing position is adjustable, which ensures as much removal as necessary and as little removal as possible. The dressing is because of the resulting tobacco dust and in particular the tobacco sauces and the like for the grinding result of particular importance, which means that the dressing means according to the invention contribute a special contribution to increasing the quality of the grinding result. The linear movement of the dressing body is superimposed on the linear movement of the guide carriage. This adjustment and / or positioning operations can be performed at least partially simultaneously.

Advantageously, the cross-beam is arranged on the guide carriage with the dressing body movable thereon. As a result, a compact and wobble-free embodiment is created, which leads to an increase in the grinding and dressing quality.

In a particularly preferred embodiment of the invention, the grinding roll carrier two grinding rollers are assigned, which are pivotable about a pivot axis III by means of a pivoting mechanism. As a result, the interruption of the loop process can be shortened even further, since no grinding is possible only in the pivoting phase. One of the sanding rollers is thereby in the grinding position while the other sanding roller is in the dressing position. While one sanding roller grinds the separating blade, the other sanding roller is pulled off across the full width by means of the dressing body. In other words, one of the grinding rollers - with the exception of the pivoting process - is brought into permanent sliding contact with the or each cutting knife to be ground, while the other grinding roll is in permanent contact with the dressing body and vice versa. As a result, grinding is particularly effective in terms of time and quality. By means of the movability of the grinding roller carrier, the grinding rollers, which are each located in the grinding position, can be brought out of engagement with each separating knife to initiate the pivoting process.

The abovementioned embodiments can be optimized according to the invention in that each grinding roller has a (grinding) width that is slightly larger than the (cutting) width of the separating blades. This means that each grinding roller engaged with the separating knife protrudes laterally beyond the separating knife, so that almost permanent grinding of the cutting knife over the entire width takes place. This creates a uniform microsection to increase the quality of the cut. Another advantage of this embodiment is that it can be dispensed with a relative movement between the grinding roller and separating knife. As a result, all individual points (across the width) of the cutting blades are ground simultaneously and uniformly, which leads to a quality-optimized grinding. By the uniform grinding of the cutting blade, moreover, the life of the cutting blade can be increased, since the blade feed, so the Nachschieben the cutting blade can be chosen lower. The term "minor" - based on the width of the sanding roller or the supernatant against the cutting blades - means that the sanding roller has to survive only minimally on the cutting knife. Of course, a larger projection, so a clear survive, possible.

In a further embodiment of the invention, the drum axis 1 and the grinding axis II extend parallel and obliquely to one another. Due to the inclination or tilted position of the grinding roller to the cutterhead or vice versa, the deflection of the grinding roller or the curvature of the surface of the grinding roller be compensated. This also improves the microsection. As mentioned, the grinding roller can laterally protrude significantly beyond the cutting knife. This is particularly important for the inclination of the grinding roller to the cutterhead, because then, despite the inclination always a cut can be made over the entire width of the cutting blade.

The object is also achieved by a method with the above-mentioned steps in that the grinding roller between a grinding position in which the grinding roller for grinding the cutting blade is in engagement with the or each cutting knife, and a position in which the grinding roller out of engagement with the or each cutting knife is moved transversely to the grinding axis II of the grinding roller, and that the dressing of the grinding roller by a dressing body of the device for dressing the grinding roller in engagement with the grinding roller parallel to the grinding axis II is traversed back and forth while the Grinding roller rotates.

In a development according to the invention, the grinding roller is moved linearly back and forth by means of a guide carriage. This movability refers to the movement between the grinding position and the dressing position.

Preferably, the dressing body is moved transversely to the grinding axis II of the grinding roller linearly in dressing engagement and disengaged from the grinding roller to be dressed.

It is particularly advantageous if the linear movement of the dressing body transversely to the grinding axis II of the grinding roller and the linear movement of the guide carriage are performed overlapping each other.

The method is inventively further developed in that during grinding of the cutting knife with the grinding roller located in the grinding position, a second grinding roller in the dressing position is in engagement with the dressing body and is subtracted from this over the entire width S _B , and that the grinding rollers by means of a Pivoting mechanism can be pivoted about a pivot axis III to the just withdrawn grinding roller from the dressing position to the grinding position and the currently located in engagement with each cutting knife grinding roller of the Swiveling grinding position in the dressing position and vice versa, wherein the two grinding rollers are moved transversely to the grinding axis II of the grinding rollers to bring the respective located in the grinding position grinding roller for pivoting out of engagement and after pivoting again in grinding engagement with the cutting blades to be ground.

A preferred development is characterized in that each cutting blade is ground simultaneously by a grinding roller over the entire width M _B.

Advantageously, the drive speed of the grinding rollers is adapted to the drive speed of the cutterhead and / or to the diameter reduction of the grinding rollers.

Further advantages resulting from the individual method steps have already been explained in connection with the device, for which reason reference is made to the corresponding statements in order to avoid repetition.

The method according to the invention can be carried out particularly advantageously with the device according to the invention as claimed in any one of claims 1 to 6, as explained above.

Fig. 1

eine schematische Darstellung einer ersten Ausführungsform der erfindungsgemäßen Schleifvorrichtung in Seitenansicht,

Fig. 2

die Schleifvorrichtung gemäß Figur 1 in Draufsicht, wobei lediglich eine Hälfte der Schleifvorrichtung entlang der Symmetrieachse dargestellt ist,

Fig. 3

eine schematische Darstellung einer weiteren Ausführungsform der erfindungsgemäßen Schleifvorrichtung in Seitenansicht, und

Fig. 4

die Schleifvorrichtung gemäß Figur 3 in Draufsicht, wobei lediglich eine Hälfte der Schleifvorrichtung entlang der Symmetrieachse dargestellt ist.

Further expedient and / or advantageous features and development of the invention will become apparent from the dependent claims and the description. Particularly preferred embodiments of the invention will be explained in more detail with reference to the accompanying drawings. In the drawing shows:

Fig. 1

a schematic representation of a first embodiment of the grinding device according to the invention in side view,

Fig. 2

the grinding device according to FIG. 1 in plan view, wherein only one half of the grinding device is shown along the axis of symmetry,

Fig. 3

a schematic representation of another embodiment of the grinding device according to the invention in side view, and

Fig. 4

the grinding device according to FIG. 3 in plan view, wherein only one half of the grinding device is shown along the axis of symmetry.

The invention will be described with reference to a device for grinding cutting knives of a tobacco cutter. Of course, the invention extends to all devices for grinding rotary driven knives. The invention can be directed both to a separate grinding device as a stand-alone device and to a cutting device having such a grinding device.

The device 10 shown in the drawing is designed and arranged for grinding at least one separating knife 12 arranged on a knife drum 11, which can be driven in rotation around a drum axis I within a device for separating tobacco from a tobacco cake. The apparatus 10 comprises a grinding roll carrier 13 with a grinding roller 14 which can be driven to rotate about a grinding axis II, and a device 15 for dressing the surface O of the grinding roller 14. The cutterhead 11 can be equipped with a separating knife 12. Preferably, however, several, for example, eight cutting blades 12 are evenly distributed over the circumference. The separating blades 12 protrude beyond the peripheral surface U of the cutterhead 11. The knife drum 11 can be driven in rotation about the drum axis I by drive means, not shown. As a result, all cutting blades 12 describe a cutting circle S _K , which always and independently of the wear of the cutting blade 12 has the same diameter. To ensure this, the cutting blades 12 are adjustable. Optionally, the separating knife advance is clocked or - preferably - formed continuously.

The grinding roller 14 is - in contrast to a grinding wheel - a Schleilkörper with a width S _B , wherein the width S _B corresponds to at least half the width M _{B of} the cutting knife 12 to be ground. The grinding roller 14 is rotatably driven by the drive means, not shown, about the grinding axis II. This describes the Peripheral surface or the surface O of the grinding roller 14 a grinding circle. In the invention, the abrasive roller 14 at least in the surface coating of a material which can be dressed by the means 15 for dressing the surface O of the grinding roller 14. An example is a material called ceramic bond.

This device 10 is inventively characterized in that the grinding roll carrier 13 is designed to be movable, such that the grinding roller 14 transverse to the grinding axis II in grinding engagement and out of engagement with the cutting blade 12 to be ground can be brought, and that the means 15 for dressing the surface O of the grinding roller 14 has a relative to the grinding roller 14 traversally movable dressing body 17 which is movable on a cross-beam 18 parallel to the grinding axis II back and forth. According to the invention, the grinding roller 14 is movable transversely to the grinding axis II, and the dressing body 17 is movable in the direction of arrow T ₃ , wherein the two movements are superimposed on each other. The cross-beam 18 is in the embodiment shown a simple or double cross-brace, on which the dressing body 17 is guided guided. Instead of the crossbeam 18 but also other transverse guides, rails or the like can be used. Each grinding roller 14 is reduced in diameter by dressing, which also changes the diameter of the grinding circle. This geometric change of the grinding roller 14 can be compensated by the linear movability of the guide carriage 16.

The features and developments described below represent individually or in combination with each other preferred embodiments. It is expressly understood that features that are summarized in the claims and / or the description or described in a common embodiment, also functionally independent the can further develop device 10 described above.

The grinding roll carrier 13 is preferably arranged on a linearly movable guide carriage 16. In the embodiment according to the Figures 1 and 2 the individual grinding roller 14 is disengaged from the cutting blade 12 in the Dressing position in which the dressing body 17 rests on the surface O of the grinding roller 14. For grinding the cutting knife 12, the guide carriage 16 with the grinding roller 14 in the direction T ₁ to the cutterhead 11 to be moved until the grinding circle (formed by the circumference O of the rotating grinding roller 14) and the cutting circle S _{K of} the cutting blade 12 touch or to cut. In this grinding position, the dressing body 17 is out of engagement with the grinding roller 14. The dressing body 17 is a diamond in the embodiment shown with punctiform contact with the grinding roller 14. However, there are also other dressing 17, such as a diamond strip with linear contact with the grinding roller 14th , as well as dressing of other dressings whose hardness is higher than that of the grinding roller 14, can be used. There are also several dressings 17 on a crossbeam 18 or on a plurality of crossbeams 18 can be used.

The dressing body 17 is in addition to the transverse movement in the direction of arrow T ₃ also linearly movable (in the direction of arrow T ₂ ), such that the dressing body 17 can be brought transversely to the grinding axis II in dressing engagement and out of engagement with the grinding roller 14 to be dressed. The two linear movements of the dressing body 17 are superimposed on each other. The linear movement of the dressing body 17 on the grinding roller 14 to and from this can be achieved in different ways. In the embodiment shown, the cross-beam 18 is arranged with the dressing body 17 on the guide carriage 16 and movable relative thereto. In this case, the feed ratio of the device 15 for dressing the abrasive roller 14 or, more precisely, the diamond to the guide carriage 16 is preferably 2: 1. It can also be provided separate feeds for the diamond on the one hand and the guide carriage 16 on the other. The device 15 for dressing the sanding roller 14 may also be formed completely separate from the guide carriage 16. The guide carriage 16 is as shown on a support structure, such as a housing wall 20, attached and / or guided. The device 15 for dressing the sanding roller 14, if it is not arranged on the guide carriage 16, attached to the housing wall 20 or the like and / or be guided. When the grinding roller 14 is in engagement with the or each cutting knife 12, by means of the linear movement of the dressing body 17 in the direction T ₂ on the grinding roller 14 are dressed to this at the same time for grinding the cutting blade 12.

The grinding axis II and the drum axis I can lie in a common horizontal plane. However, an axial offset is preferred. In the embodiment of the drawing, the grinding axis II lies in a plane by the amount a above the drum axis I. However, this amount a may vary in size. Due to the axial offset, the wedge angle of the separating knife 12 can be influenced at least to a small extent.

The grinding roller 14 has a width S _B , which corresponds to at least half the width M _{B of} the cutting blade 12. However, as long as the width S _B is smaller than the width M _B , the grinding roller 14 is movable relative to the cutterhead 11 in order to grind the cutting blades 12 over its entire width M _B. The relative movement between the grinding roller 14 and the separating knife 12 can be generated by an axial movement of the grinding roller 14 and / or the cutterhead 11 and / or the cutting knife 12 parallel to the drum axis I or the grinding axis 11 in the longitudinal direction thereof. Particularly preferably, the width S _{B of} the grinding roller 14 is slightly larger than the width M _{B of} the separating blade 12. In other words, the grinding roller 14 is on both sides beyond the cutting blade 12 out.

The width M _{B of} the cutting blade 12 may for example be between 400mm and 600mm. Correspondingly, the sanding rollers 14 have a width S _B of at least 200 mm to 300 mm and preferably also 400 mm to 600 mm, and more preferably plus a minimum projection on both sides of a few mm up to a larger projection on both sides of several mm.

The drum axis I and the grinding axis II can be parallel and rectilinear (that is lying in parallel planes), as in the embodiments of FIGS. 1 to 4 shown. The drum axis I and the grinding axis II can also be parallel and oblique to each other. In the latter example, the grinding roller 14 and the cutterhead 11 are tilted to each other, so that the two axes I and II are indeed parallel, but in different, intersecting planes.

In a further embodiment of the invention according to the FIGS. 3 and 4 are assigned to the grinding roll carrier 13, two grinding rollers 14, 14A. Basically, the structure and design of the latter embodiment with two sanding rolls 14, 14A corresponds to that embodiment with a single sanding roll 14, so that all the features and developments described above apply equally to the embodiment with two sanding rolls 14, 14A. In addition, in the embodiment with two sanding rolls 14, 14A, the device 10 comprises a pivoting mechanism 19 for pivoting the two sanding rolls 14, 14A from a grinding position to a dressing position and vice versa. For this purpose, the grinding rollers 14, 14A by means of the pivoting mechanism preferably about 180 ° about a pivot axis III pivotally (see arrow T ₄ ).

The pivot mechanism 19 also includes a drive means (not explicitly shown) for pivoting the sanding rollers 14, 14A. These are optionally arranged on a common carrier 21, which is pivotable about the pivot axis III or rotatable circumferentially. The two grinding rollers 14, 14A can be driven by individual drives or by a common synchronous drive. The position of the grinding rollers 14, 14A on the carrier 21 may be stationary and provided at a fixed distance from each other. Optionally, however, the grinding rollers 14, 14A can also be designed to be adjustable relative to the carrier 21

The devices 10 described above are available as a single component, e.g. as retrofit kit or spare part, can be used. Optionally, however, these devices 10 are part of a cutting device 22, in particular a tobacco cutter, which in addition to the device 10 further comprises a rotary driven knife drum 11 with at least one cutting knife 12.

• Jedes Trennmesser 12, das an einer um die Trommelachse I rotierend angetriebenen Messertrommel 11 angeordnet ist, wird durch eine Schleifwalze 14 geschliffen, die um die Schleifachse II rotierend angetrieben ist und sich mit dem zu schleifenden Trennmesser 12 in Eingriff befindet. Das Schleifen erfolgt, wenn sich der Schleifkreis der Schleifwalze 14 und der Schneidkreis S_K der Trennmesser 12 berühren bzw. schneiden. Um die Schneidergebisse konstant zu halten, werden die Schleifwalzen 14 abgerichtet. Dazu wird die Oberfläche O der Schleifwalze 14 mittels einer Einrichtung 15 zum Abrichten der Oberfläche O der Schleifwalze 14 abgezogen.

The process according to the invention is described in more detail below:

• Each cutting knife 12, which is arranged on a drum drum 11 driven to rotate about the drum axis I, is ground by a grinding roller 14, which is driven in rotation about the grinding axis II and is engaged with the cutting knife 12 to be ground. The grinding takes place when the grinding circle the grinding roller 14 and the cutting circle S _{K of} the cutting blade 12 touch or cut. In order to keep the cutting teeth constant, the grinding rollers 14 are dressed. For this purpose, the surface O of the grinding roller 14 is removed by means of a device 15 for dressing the surface O of the grinding roller 14.

This method is inventively characterized in that the grinding roller 14 between a grinding position in which the grinding roller 14 for grinding the cutting blade 12 is in engagement with the or each cutting knife 12, and a position in which the grinding roller 14 out of engagement with the or each severing knife 12 is moved transversely to the grinding axis II of the grinding roller 14, and that the dressing of the grinding roller 14 in a dressing position by a dressing body 17 of the device 15 for dressing the grinding roller 14 in engagement with the grinding roller 14 parallel to the grinding axis II traversal is moved back and forth while the grinding roller 14 rotates. In other words, each grinding roller 14 is moved between the grinding position and the dressing position transversely to the grinding axis II, wherein the grinding roller 14 is predominantly in the grinding position and only sporadically in the dressing position for a period of, for example, 10 to 15 seconds to the grinding roller 14 with the Dressing dressings 17 over the entire width S _B.

In the event that the width S _{B of} the grinding roller 14 is less than the separating blade width M _B , a relative movement between the grinding roller 14 and the cutting blade 12 to be ground is generated. For this purpose, the grinding roller 14 over the entire width M _{B of} the cutting blade 12 are moved back and forth. Alternatively, the knife drum 11 and / or the separating knife 12 itself can be moved longitudinally along the drum axis I. Because of the said width S _{B of} the grinding roller 14, which corresponds to at least half of the width M _{B of} the cutting blade 12, only small transverse movements are necessary. Incidentally, the fact that always at least half of the width M _{B of} the cutting blade 12 is ground simultaneously, achieved a fast grinding with a uniform grinding pattern. In the event that the width S _{B of} the grinding roller 14 is equal to or greater than the width M _{B of} the separating blade 12, each cutting blade 12 is ground simultaneously by a grinding roller 14, 14A over the entire width M _B. As a result, it is possible to dispense with the relative movement between the grinding roller 14 and the separating knife 12. This will be one more produces a more uniform microsection, since all individual points of the separating blade width M _B are ground simultaneously and continuously.

The movement of the grinding roller carrier 13 or the grinding roller 14 between the grinding position and the position in which the grinding roller 14 is disengaged from the separating knife 12, preferably the dressing position, may be e.g. be performed by means of a guide carriage 16 which is linearly reciprocated. Optionally, the dressing body 17 is moved transversely to the grinding axis II of the grinding roller 14 linearly in dressing engagement and disengaged from the grinding roller 14 to be dressed. This adjusting movement is advantageous, for example, when applying and / or when depositing the dressing body 17 on or from the grinding roller 14. The linear movement of the dressing body 17 transversely to the grinding axis II can be superimposed on the linear movement of the guide carriage 16 transversely to the grinding axis II.

In a grinding and dressing method with a device 10 having two grinding rolls 14, 14A, one of the grinding rolls 14 for grinding each cutting knife 12 in the grinding position engages each cutting knife 12 to be ground. The other grinding roll 14A engages the dressing body in the dressing position 17. Dressing and grinding can be done at the same time. Only for pivoting the two grinding rollers 14, 14A, the grinding and / or dressing process is interrupted, whereby the grinding and / or dressing-free time is further reduced. If a (rotation) change of the two grinding rollers 14, 14A is to be carried out, according to the invention, the pivoting mechanism 19 can pivot about the pivot axis III, preferably about 180 °, around the one grinding roller 14 from the grinding position to the dressing position and at the same time the other To pivot grinding roller 14A from the dressing position to the grinding position and vice versa.

The pivoting can be done directly from the grinding and / or dressing process out. However, the pivoting is preferably prepared by a linear movement of the guide carriage 16 and / or the dressing body 17 transversely to the grinding axis II. Before the pivoting operation is carried out, the grinding roller 14 located in the grinding position can be moved out of engagement with the separating knife 12 by moving the guide carriage 16. The dressing body 17 can are also moved from the dressing position out of engagement with the located in Abrichtposition sanding roller 14A. When the grinding rollers 14, 14A are both free to the cutting blade 12 and free to the dressing body 17, the pivoting about the pivot axis III can be performed. Once the pivoting is completed, on the one hand, the guide carriage 16 can be moved toward the cutterhead 12 until the (then dressed) grinding roller 14A is in engagement with each cutting knife 12. Simultaneously or successively, the dressing body 17 can be moved towards the (then worn and / or soiled) grinding roller 14 until the dressing body 17 is in engagement with the grinding roller 14.

As already mentioned, the grinding of the cutting blades 12 and the grinding rollers 14, 14A are changed by the grinding and dressing. The shortening of the cutting blade 12 by the grinding is preferably compensated continuously by the Nachschieben the cutting blade 12 to always have the cutting blade 12 describe a cutting circle S _K with the same diameter. Reducing the diameter of the sanding rolls 14, 14A results in a change in dressing and sanding conditions, as not only do the diameters of the sanding rolls 14, 14A reduce, but other peripheral speeds of the sanding rolls 14, 14A also result. Since the relative speed between the grinding roller 14, 14A and the cutterhead 11 or the separating blade 12 revolving therewith is preferably to be kept constant, it is therefore possible to adjust the driving speed of the grinding rollers 14, 14A to the drive speed of the cutterhead 11 and / or to adapt to the diameter reduction of the grinding rollers 14, 14A. For this purpose, suitable measuring and control means of the device 10 and the cutting device 22 are connected to a corresponding evaluation and control unit.

Claims (14)

Apparatus (10) adapted and arranged for grinding at least one knife (12) disposed on a cutterhead (11) circumferentially around a drum axis I within a device (22) for separating tobacco from a tobacco cake, comprising a grinding roll carrier (13) with a grinding roller (14) which is drivable to rotate about a grinding axis II, and a device (15) for dressing the surface O of the grinding roller (14), characterized in that the grinding roll carrier (13) is designed to be movable in that the grinding roller (14) can be brought into grinding engagement and disengagement with the grinding knife (12) to be ground transverse to the grinding axis II, and in that the means (15) for dressing the surface O of the grinding roll (14) with respect to the grinding roll (14 ) has traversal movable dressing body (17) which is movable on a cross-beam (18) parallel to the grinding axis II back and forth. Apparatus according to claim 1, characterized in that the grinding roll carrier (13) on a linearly movable guide carriage (16) is arranged. Apparatus according to claim 1 or 2, characterized in that the dressing body (17) is additionally formed linearly movable, such that it can be brought transversely to the grinding axis II in dressing engagement and out of engagement with the abraded grinding roller (14). Device according to one of claims 1 to 3, characterized in that the crosspiece (18) with the dressing body (17) movable thereon is arranged on the guide carriage (16). Device according to one of claims 1 to 4, characterized in that the grinding roll carrier (13) has two grinding rollers (14, 14A) are associated, which are pivotable about a pivot axis III by means of a pivot mechanism (19). Device according to one of claims 1 to 5, characterized in that each grinding roller (14, 14A) has a (grinding) width S _B , which is slightly larger than the (cut) width M _{B of} the separating knife (12). Device according to one of claims 1 to 6, characterized in that the drum axis I and the grinding axis II parallel and oblique to each other. Method for grinding at least one separating knife (12) arranged on a knife drum (11), which is driven around a drum axis I within a device (22) for separating tobacco from a tobacco cake, comprising the steps: - Grinding of each cutting knife (12) with a rotating about the grinding axis II driven, in engagement with the cutting knife to be ground (12) located grinding roller (14), and - dressing the grinding roller (14) with a device (15) for dressing the surface O of the grinding roller (14) in engagement with the dressing roller (14) to be dressed, characterized in that the grinding roller (14) is disposed between a grinding position in which the grinding roller (14) for grinding the separating blades (12) is engaged with the or each cutting blade (12), and a position in which the grinding roller (14) out of engagement with the or each cutting knife (12) is transverse to the grinding axis II of the grinding roller (14) is moved, and that the dressing of the grinding roller (14) in a dressing position by a dressing body (17) of the device (15) for Truing the grinding roller (14) in engagement with the grinding roller (14) parallel to the grinding axis II is reciprocally moved while the grinding roller (14) rotates. A method according to claim 8, characterized in that the grinding roller (14) by means of a guide carriage (16) is moved linearly back and forth. A method according to claim 8 or 9, characterized in that the dressing body (17) transversely to the grinding axis II of the grinding roller (14) linearly in Truing engagement and out of engagement with the dressing roller (14) to be dressed. A method according to claim 10, characterized in that the linear movement of the dressing body (17) transverse to the grinding axis II of the grinding roller (14) and the linear movement of the guide carriage (16) are performed overlapping each other. Method according to one of claims 8 to 11, characterized in that during grinding of the cutting knife (12) with the grinding roller (14) located in the grinding position, a second grinding roller (14A) in the dressing position is in engagement with the dressing body (17) and is subtracted from this over the entire width S _B , and that the grinding rollers (14, 14A) by means of a pivoting mechanism (19) are pivoted about a pivot axis III to the just withdrawn grinding roller (14A) from the dressing position to the grinding position and the straight to pivot the grinding roller (14) in engagement with each cutting knife (12) from the grinding position to the dressing position and vice versa, wherein the two grinding rollers (14, 14A) are moved transversely to the grinding axis II of the grinding rollers (14, 14A) to move each one In grinding position located grinding roller (14 or 14A) for pivoting disengaged and after pivoting again in grinding engagement with the tren to be ground to bring the knife (12). Method according to one of claims 8 to 12, characterized in that each cutting knife (12) by a grinding roller (14, 14A) over the entire width M _B is ground simultaneously. Method according to one of claims 8 to 13, characterized in that the drive speed of the grinding rollers (14, 14A) to the drive speed of the cutterhead (11) and / or to the diameter reduction of the grinding rollers (14, 14A) is adjusted.

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