EP0644961B1 - Method and device for feeding weft yarn - Google Patents

Abstract

The invention concerns a method for feeding weft yarn to a loom, each weft yarn being unwound overhead from a spool on a yarn-feed device, within a single stroke of the loom as a function of the operation of a yarn-retention element. The weft yarn is force-fed using the yarn-retention element which is driven to rotate and acts continuously upstream of the yarn take-off point. The yarn-retention element is accelerated and decelerated in accordance with a speed-time curve which determines the rate of feed of yarn to the loom. The invention also concerns a weft yarn feed device in which the yarn-retention element (R) is of lightweight design and is coupled to the rotary drive (A) in such a way that it cannot move radially with respect to the spool axis (11) and so that it continuously crosses the rotational trajectory (U) of the yarn take-off point upstream of the weft yarn (Y) in the direction of rotation (2') of the take-off point, the rotary drive (A) being connected to a control device (8) which produces a speed-time curve (I) which determines the rate of feed to the loom (W).

Description

The invention relates to a method according to the preamble of claim 1 and an apparatus for performing the method according to the preamble of claim 2.

In a method known from EP-B1-0 253 760, a radially adjustable retaining element which can be driven in the circumferential direction of the stationary storage drum is used to precisely measure the weft thread length and to brake the weft thread at the entry end. In the case of a weft, the retaining member which is at a predetermined circumferential position of the storage drum is disengaged, so that when the weft thread is drawn off, the take-off point rotates at a rapidly increasing speed. During the shot, the disengaged retaining element is accelerated in the direction of rotation to a speed which approximately corresponds to the speed of rotation of the trigger point. However, the trigger point first runs through under the disengaged retaining element. Then the retention element is engaged. The weft thread runs onto the retention element at the take-off point and is delayed to a new predetermined circumferential position until it comes to a standstill with the retention element engaged. The retaining element contained in an armature with an actuating magnet has a relatively large mass, which creates problems when accelerating and decelerating. Timely control of the actuating magnet during the rotational movement of the retaining element is difficult. Stopping the engaged retaining element is difficult because of the large masses to be decelerated, so that the braking process takes a relatively long time. This adversely affects the entry process in the weaving machine because the delay phase extends over a relatively long time.

In a method known from JP 85-077 054 (60-28 552), the radially adjustable retaining element is rotated in the circumferential direction of the storage drum as soon as the retaining element is disengaged in order to precisely measure the weft thread length. In the new position, the retaining element is re-engaged after the last permissible passage of the take-off point, so that the weft thread is reliably intercepted. During the weft, the retaining element does not influence the weft withdrawal movement. At the end of the weft, the weft is stopped abruptly. The storage drum is stationary.

In a method known from EP-A1-08 80 692, both the storage drum and the retaining element are driven in rotation. The retaining element can additionally be moved back and forth between an engagement position in which it blocks the orbit of the withdrawal point and a release position.

In a method known from EP-A1-02 26 930 for delivering a thread to a flat knitting machine, a switch is made between a compulsory delivery and a free delivery of the thread. A stationary storage drum is assigned a rotatable thread guide element which can be driven to rotate about the storage drum axis and is designed such that the withdrawal point of the thread can overtake the thread guide element under certain conditions (free delivery), while in the case of forced delivery the peripheral speed of the thread guide element is the one supplied Thread quantity determined per unit of time.

In a method known from EP-A-0 477 877, the weft thread, which is measured by a measuring supplier by means of a radially adjustable retaining element, is fed to the input device by an automatically driven positive delivery device arranged downstream of the storage drum. However, the compulsory delivery is interrupted during the entry, so that the entry device continues to convey the weft thread to a standstill.

The invention has for its object to provide a method and a device of the type mentioned, with which the entry process can be optimized on the one hand for the weaving machine and on the other hand as gentle as possible for the weft thread, the entry process even from one weft to the other should be modular. The weft length should be precisely measurable for jet looms. In the case of defenseless weaving machines, projectile or rapier weaving machines, the draw-off process should be able to be coordinated with an optimized entry.

The stated object is achieved with the characterizing features of claim 1 and with a device according to the characterizing features of the independent claim 2.

In the method according to claim 1, the weft thread is never left to itself during the weft, but is constantly forcibly delivered. Due to the compulsory delivery, he must follow a speed profile that is carefully designed for him and is tailored to an optimal entry for the weaving machine. This avoids harmful tension changes in the weft. There is no sudden and critical acceleration and jerky deceleration. Since the speed profile is predetermined, the drive of the input device can be set precisely to the forced delivery, which saves drive energy, for example compressed air, because it is no longer necessary to work with excess drive energy as before. In jet looms, the weft thread length required is precisely measured by the monitored angular position of the retaining element. In the case of defenseless weaving machines, the speed profile is tailored precisely to the working behavior in the weaving machine, especially in the transfer phase, so that harmful tension variations in the weft thread are avoided. In any case, there is a favorable thread geometry in the draw-off area and in the shed (controlled thread balloon and optimized stretching).

In the method and for the device, it is essential that the retaining element and its rotary drive have as little mass as possible so that it can be accelerated and decelerated sufficiently quickly. The low-mass design of the retaining element is possible in that it constantly engages in the orbit and does not require any additional actuating device for radial adjustment. Monitoring the angular position of the retaining element in relation to the storage drum is important in order on the one hand to precisely control the desired speed profile and on the other hand - if this is necessary - to be able to precisely measure the weft thread length. The forced delivery is carried out cheaply without a mechanically loading conveyor roller gap, because there is contact with the retaining element only negligible effects.

In the embodiment according to claim 3, the storage drum is stationary; the retaining element moves relative to the storage drum. The rotary drive of the retaining element is responsible for the desired speed profile during the shot.

Alternatively, the embodiment according to claim 4 is advantageous, in which the storage drum is also driven in rotation and at the same time forms the winding device. This has the advantage of particularly favorable feed conditions for the weft thread to the weft thread supply on the storage drum, because a straight tangential feed that is gentle on the weft thread is possible and the operational disturbances on the feed side are reduced to a minimum. The draw-off conditions (balloon formation) are also improved in this embodiment because the rotating storage drum delivers the weft thread with less resistance since the weft thread supply rotates. The speed profile, which determines the course of the entry, is derived from the speed ratios between the rotational movement of the storage drum and the rotational movement of the retaining element, it being favorable that the retaining element no longer needs to be accelerated so much relative to the storage drum because the weft thread supply already has a certain one Has basic speed that can be used for the entry. In this embodiment, both the inflow and the take-off conditions for the weft thread are favorable with regard to small deflections, barely noticeable changes in thread tension and a stabilized thread take-off.

The embodiment according to claim is also expedient 5. In the case of a stationary storage drum, a unidirectional rotary drive is sufficient to achieve the desired speed profile, a drive motor with a high acceleration and deceleration capability being expedient, which can be operated sufficiently small due to the low-mass smoke element, yet can be operated efficiently and with little loss. In the case of a rotatable storage drum, the rotary drive can expediently be reversed in the direction of rotation in order to be able to precisely control the deceleration phase. If necessary, a rapidly decelerable or decelerable drive motor with a drive device is sufficient.

An expedient embodiment emerges from claim 6. The pointer is extremely low-mass for the forced delivery. It can be quickly accelerated and decelerated again. The weft cannot overtake the pointer. The speed of the weft is precisely controlled by the pointer.

A structurally simple, compact embodiment emerges from claim 7. This pointer drive principle can be used for both a stationary and a rotating storage drum.

Another advantageous embodiment is set out in claim 8. In this configuration, the weft thread drawn off runs through the hollow drive shaft of the arm. This design variant is particularly suitable for a stationary storage drum, to which the weft thread runs centrally through the drive shaft before it is brought into the thread supply by the winding device.

In the embodiment according to claim 9, the necessary Accelerations and decelerations achieved without any problems, the rotary angle decoder or the stepping motor permanently permitting the control device to determine the exact angular position of the retaining element in relation to the circumference of the storage drum and to take it into account in the control.

An important embodiment is also apparent from claim 10. The acceleration phase is of particular importance for the desired speed profile in order to accelerate the weft thread to the maximum insertion speed as quickly as possible. Despite the low-mass design of the retaining element and a quickly responding rotary drive, even modern electric motors can reach or exceed their performance limit, which could be problematic with the high shot frequencies realized today. The booster supports the rotary drive in the acceleration and / or the equally important deceleration phase. It is important that the control device does not lose control of the movement of the retaining element, but that the booster compensates or eliminates mechanical inertia effects.

This is achieved in a structurally simple manner in the embodiment according to claim 11. The booster engages directly on the retaining element or on its drive shaft and helps the rotary drive to provide the necessary acceleration and / or deceleration.

A structurally simple, reliable and low-mass embodiment is also apparent from claim 12. The turbine wheel is used for acceleration and / or deceleration of the retaining element from at least one compressed air nozzle. The turbine wheel can be uncoupled from the pointer via a freewheel if it only needs to work in one direction of rotation.

Also important is the embodiment according to claim 13, in which, despite the booster, the control device is constantly informed about the exact angular position of the holding element. The booster is only a tool that provides the drive motor with additional drive energy (for deceleration and / or acceleration), so to speak, without actively intervening in the control system. This has the advantage of a small-sized, low-mass and therefore quickly responsive drive motor, which would otherwise have to be much larger for the desired acceleration and / or deceleration behavior without a booster and thus be designed with more harmful mass.

Another useful embodiment is set out in claim 14. Especially when the storage drum is at a standstill, the signals to and from the drive motor and the supply voltage are transmitted without contact. However, this can also be advantageous for a rotatable storage drum.

The embodiment according to claim 15 is advantageous because with the programmable microprocessor the desired speed profile can be precisely controlled, varied, modulated and repeated. The control device can be supplied with information from the weaving machine and / or from the control device of the supplier in order to be able to match the individual parameters exactly to one another. The speed profile will changed from one entry to the other, if necessary, or just the thread length that was supplied.

In the embodiment according to claim 16, the pointer is arranged in a rotor which is driven from the outside. This simplifies the mechanical structure of the device, especially in the case of a stationary storage drum.

In the embodiment according to claim 17, the ring ensures the forced delivery of the weft. The point of contact between the ring and the storage drum circumference revolves in front of the withdrawal point. A small eccentricity is sufficient for the desired effect. The ring also has balloon-reducing properties. The mechanical construction of the rotary drive is simple and reliable.

Finally, the embodiment according to claim 18 is expedient, in which the ring takes on a balloon-limiting function and forms the retaining element during its tumbling movement.

Of fundamental importance to the invention, especially for air jet weaving machines, is the permanent forced delivery with simultaneous weft length measurement in the case of an overhead take-off.

Fig. 1

schematisch eine Vorrichtung zum Liefern von Schußfäden zu einer Webmaschine,

Fig. 2

eine Stirnansicht eines Teils der Vorrichtung von Fig. 1,

Fig. 3 + 4

Schaubilder von zweckmäßigen Geschwindigkeitsprofilen,

Fig. 5

einen schematischen Längsschnitt einer alternativen Ausführungsform einer solchen Vorrichtung,

Fig. 6

eine Stirnansicht zur Vorrichtung von Fig. 5,

Fig. 7

ein Schaubild einer Ausführungsform der Fig. 5 und 6,

Fig. 8 + 9

zwei Detailvarianten in einem Längsschnitt,

Fig. 10

eine Stirnansicht einer weiteren Detailvariante,

Fig. 11

einen Längsschnitt einer weiteren Detailvariante, und

Fig. 12

eine schematische Perspektivansicht einer weiteren Variante.

Embodiments of the subject matter of the invention are explained with the aid of the drawing. It shows:

Fig. 1

schematically a device for delivering weft threads to a weaving machine,

Fig. 2

2 shows an end view of part of the device from FIG. 1,

3 + 4

Diagrams of expedient speed profiles,

Fig. 5

2 shows a schematic longitudinal section of an alternative embodiment of such a device,

Fig. 6

5 shows an end view of the device from FIG. 5,

Fig. 7

5 shows a diagram of an embodiment of FIGS. 5 and 6,

Fig. 8 + 9

two detail variants in a longitudinal section,

Fig. 10

an end view of a further detail variant,

Fig. 11

a longitudinal section of a further detail variant, and

Fig. 12

is a schematic perspective view of another variant.

According to FIG. 1, a feeder F for supplying a weft Y is provided on one side of a weaving machine W. The feeder F draws the weft Y from a supply spool (not shown) and winds it with a winding device 2, which contains a winding element 10, tangentially in turns into a weft supply V on the circumference of a storage drum 1. An insertion device E of the weaving machine W pulls the weft overhead of the storage drum out of the weft supply V and brings it into the shed S. The insertion device E is either a main nozzle (air jet weaving machine), the Auxiliary nozzles, not shown, are assigned within the compartment, or for example a rapier of a rapier weaving machine.

In the embodiment according to FIG. 1, the storage drum 1 of the supplier is at a standstill. The winding device 2 is driven by means of a drive 3 and by a control device 4 via a control device part 5 in such a way that a certain supply size is always available. On the trigger side, the weft Y is automatically delivered with each weft. For this purpose, a retaining element R in the form of a radial pointer 7 is provided, which is arranged on a drive shaft 6 which is coaxial with the storage drum axis 11 and (see FIG. 2) the orbit U of the take-off point of the weft thread Y continuously over the front edge of the storage drum 1 enforced. A separate rotary drive A (indicated by dashed lines in the interior of the storage drum 1) is provided for the retaining element R and controls a specific speed profile of the pointer 7 via a control device 8.

2, the winding device 2 winds up the weft thread in the direction of an arrow 2 'on the storage drum 1. When the trigger is drawn, the take-off point of the weft thread Y rotates in an orbit U in the direction of the arrow 2 '. The retaining element R is in the direction of rotation 2 'before the withdrawal point. When the shot is the restraining element R accelerates in the direction of an arrow 6 'from a first angular position from standstill and at the end of the shot decelerates to a second predetermined angular position to standstill.

Fig. 3 illustrates a speed profile I that determines the withdrawal process. The take-off speed v is on the vertical axis; time Z is plotted on the horizontal axis. The speed profile I is characterized by an acceleration section a, a high-speed section b and a subsequent deceleration section c. The retaining element R is driven in the direction of the arrow 6 'exactly according to the speed profile I according to FIG. 3, so that the weft thread Y is forcibly delivered and entered by the input device E. The speed profile I belongs, for example, to an air jet loom.

Fig. 3 illustrates the speed profile I of a rapier-less rapier weaving machine in which the weft thread is passed approximately in the middle of the compartment S. 4 is characterized by a first acceleration phase a1, a subsequent high-speed phase b1, a subsequent first deceleration phase c1, a second acceleration phase a2, a subsequent second high-speed phase b2 and a final deceleration phase c2.

In this case, the retaining element R is driven according to the speed profile I of FIG. 4, so that the weft thread is forcibly delivered during the entire weft.

The retaining element R as a pointer 7 is low in mass and therefore can be decelerated and accelerated with a small-sized, responsive electric motor. The electric motor is either provided with a rotation angle decoder, not shown, which transmits the respective angular position of the pointer 7 in relation to the circumference of the storage drum 1 of the control device 8, or is designed as a stepper motor, the respective angular position of which the control device knows anyway.

In the embodiment of FIGS. 5 and 6, the storage drum 1 of the feeder F can be driven to rotate about its axis 11. For example, a peripheral flange 13 is designed as a support for a drive belt 12, which is connected to the drive 3. The weft Y is fed tangentially without deflection and introduced into the supply V. The storage drum 1 is rotatably mounted on a holding tube 15 of a stationary holder 14. Inside the storage drum 1, the rotary drive A for the retaining element R (pointer 7) is arranged on the holding tube 15, such that the drive shaft 6 protrudes from the front end of the storage drum 1 and carries the pointer 7. The control device 8, which expediently contains a programmable microprocessor, is connected to the rotary drive A by the holding tube 15.

6, the storage drum 1 rotates in the direction of an arrow 1 '. Upon entry, the take-off point of the weft thread Y (counterclockwise) moves in the direction of arrow 2 'along the front edge of the storage drum 1. The storage drum 1 simultaneously forms the take-up device to supplement the supply V. Between the entry, the pointer 7 rotates synchronously with the storage drum 1. The pointer 7 is initially accelerated counterclockwise to a higher speed than the peripheral speed of the storage drum 1 in the direction of arrow 6 ', and is delayed or reversed at the end of the entry in the direction of arrow 6 "until after the entry rotates again at the same peripheral speed and in the same direction as the storage drum 1.

FIG. 7 illustrates the work of the feeder F according to FIG. 5 for an air jet loom. The speed profile I corresponds to the speed profile I of FIG. 3 and represents the speed of the weft thread when weft. There is again the acceleration phase a, the subsequent high-speed phase b and the final deceleration phase c. The horizontal line 1 represents a constant speed of the storage drum 1 assumed for the sake of simplicity. The retaining element R rotates at this speed until the start of the entry. At the beginning of the entry, the retaining element R is accelerated counter to the direction of rotation of the storage drum 1, runs at a relatively constant speed during the high-speed phase b and is then decelerated again relative to the storage drum 1 or reversed in the opposite direction until the speed of the storage drum 1 is reached again.

For the sake of simplicity, the speed of the storage drum 1 is shown constant. However, it is also possible to vary the speed of the storage drum 1. The control device 4, which is responsible for the rotation of the storage drum 1 and the retaining element R, then controls the desired speed profile I from the two relative speeds.

In the embodiment according to FIG. 8, the retaining element R is a radially inwardly projecting pointer 7 on an oblique arm 16, which is seated on a hollow drive shaft 17, which is spaced from the front end of the storage drum 1 e.g. is mounted in the rotary drive A and forms a withdrawal eye for the weft Y.

In the embodiment according to FIG. 9, the retaining element is fastened as a radially inwardly projecting pointer to an annular rotor 18 which engages around the front end of the storage drum 1 and is seated in a drive bearing 19 of the rotary drive A. The rotary drive A is arranged externally of the storage drum 1.

In the embodiment according to FIG. 10, the retaining element R is a ring 19 which is arranged perpendicular to the storage drum axis 11 at the front end of the storage drum 1 and has an inner diameter 20 which is larger than the outer diameter of the storage drum 1. The center 22 of the ring 19 is arranged eccentrically to the storage drum axis 11 and rotatably mounted on a crank rotary drive A, 24 indicated by a broken line. The crank drive 24 rotates about the storage drum axis 11, a point of contact between the inner circumference 20 and the storage drum 1 rotating in the circumferential direction of the take-off point of the weft yarn Y in front of the take-off point. Optionally, the inner circumference 20 is equipped with a circumferential toothing 21 which cooperates with corresponding recesses on the storage drum 1.

In the embodiment according to FIG. 11, the retaining element R is a ring 25, the inside diameter of which is larger than the outside diameter of the storage drum 1. The ring 25 is inclined with an adjusting axis 27 which intersects the storage drum axis 11 and is fastened to a hollow drive shaft 26 on which the rotary drive A attacks. When the drive shaft 26 rotates, the ring 25 executes a wobbling movement with a rotating contact point with the front edge of the storage drum 1.

FIG. 12 shows an embodiment of the rotary drive A for the retaining element R designed as a pointer 7. The electric motor M drives the drive shaft 6. The drive shaft 6 is assigned a booster B, which is preferably temporarily activated for the acceleration and / or deceleration phases a, c, a1, a2, c1, c2 in order to support the electric motor M. In the embodiment shown, the booster B has a turbine wheel 28 on the drive shaft 6. The turbine wheel 28 carries turbine blades 29, to which compressed air nozzles 30, 31 are aligned. Furthermore, on the drive shaft 6, in the case that it is not a stepping motor M, a disk 32 is fastened, which carries rotary encoder 33, are aligned with the rotary angle sensors 34, which transmit the signals to the control device 8, so that the Control device 8 is constantly informed about the angular position of the pointer 7.

The booster could also be driven mechanically via a flywheel, electromagnetically or by eddy current. It is important that the control device controls the rotational position of the pointer 7 despite the intervention of the booster when accelerating or decelerating cannot lose, even if the booster creates an acceleration or deceleration characteristic for the drive shaft that the electric motor M itself cannot control.

Claims (18)

1. Method of delivering weft threads to a power loom, wherein a weft thread supply is wound onto a storage drum of a thread regulating wheel and each weft thread within a working cycle of the power loom in dependence upon the actuation of a controlled retention element is unwound over head with a take-off point rotating in a peripheral direction of the storage drum, characterized in that the weft thread upon each pick is permanently positively delivered by means of the retention element, which continuously engages in front of the take-off point and is driven so as to rotate, and that in the process the retention element is accelerated and decelerated in accordance with a speed profile which determines the weft characteristic in the power loom.
2. Device for delivering weft threads into a power loom (W) which has a picking device (E), having a thread regulating wheel (F) which comprises a storage drum (1) for holding a weft thread supply in readiness, a take-up device (2) for supplementing the weft thread supply (V) and a controlled retention element (R), which in a peripheral direction of the storage drum (1) is drivable by a rotary drive (A) so as to execute a rotational movement and at least intermittently penetrates the circular path (U) of the take-off point of the weft thread (Y) which may be unwound over head of the storage drum (1) by the picking device (E), characterized in that the retention element (R) continuously penetrates the circular path (U) in direction of rotation (2') of the take-off point in front of the weft thread and is of a low mass, and that the rotary drive (A) of the retention element (R) is connected to a control device (8), which may be used, with simultaneous monitoring of the angular position of the retention element (R), to control a rotational speed profile (I) of the retention element (R) which determines the weft sequence of the power loom (W).
3. Device according to claim 2, characterized in that the storage drum (1) is disposed in a stationary manner, and that the take-up device (2) comprises a winding element (10) which is drivable relative to the storage drum (1).
4. Device according to claim 2, characterized in that the storage drum (1) is drivable so as to rotate about the storage drum axis (11) and simultaneously forms the take-up device (2).
5. Device according to claims 2 to 4, characterized in that the rotary drive (A) for the retention element (R) is designed so as to be unidirectional or reversible in terms of its direction of rotation.
6. Device according to claims 2 to 5, characterized in that the retention element (R) takes the form of a substantially radial pointer (7) which is rotatable coaxially relative to the storage drum axis (11).
7. Device according to claim 6, characterized in that the pointer (7) is disposed on a drive shaft (6) which is coaxial relative to the storage drum axis (11), that the drive shaft (6) of the pointer (7) projects from the take-off end of the storage drum (1), and that the rotary drive (A) is disposed inside the storage drum (1).
8. Device according to claim 6, characterized in that the pointer (7) is disposed so as to be directed radially inwards from an arm (16) projecting obliquely outwards and towards the storage drum (1) from a hollow drive shaft (17) disposed coaxially relative to the storage drum axis (11), and that the arm (16), together with the hollow drive shaft (16) provided for passage of the weft thread (Y) and preferably with the rotary drive (A), is disposed at a distance in front of the end face of the storage drum (1).
9. Device according to claims 2 to 8, characterized in that the rotary drive (A) comprises a low-mass electric motor (M) with an angle-of-rotation decoder or a stepping motor (M).
10. Device according to claims 2 to 9, characterized in that an acceleration- and/or deceleration booster (B) is incorporated into the rotary drive (A).
11. Device according to claim 10, characterized in that the booster (B) drives the drive shaft (6) of the retention element (R).
12. Device according to claims 10 and 11, characterized in that the booster (B) comprises a turbine wheel (28) on the drive shaft (6), and that at least one compressed-air nozzle (30, 31) is aligned with the turbine wheel (28).
13. Device according to claims 2 to 12, characterized in that disposed on the drive shaft (6) of the retention element (R), preferably on a disk (32) on the drive shaft, are angular resolvers (33) with which is aligned at least one decoder sensor (34), which is connected to the control device (8).
14. Device according to claims 2 to 13, characterized in that a non-contact signal and working voltage transmission link is provided between an electric motor (M) provided in the rotary drive (A) and the control device (8).
15. Device according to claims 2 to 14, characterized in that the control device (8) comprises at least one programmable microprocessor.
16. Device according to claims 2 to 6, characterized in that the pointer (7) projects substantially radially inwards from a rotor (18) which coaxially externally encompasses the storage drum (1), and that the rotor (18) is supported in a rotary drive (A) disposed radially outside of the storage drum (1).
17. Device according to claims 2 to 5, characterized in that the retention element (R) is formed by a ring (19) which is preferably constructed with a toothed inner circumference (21), embraces the storage drum (1) at right angles to the storage drum axis (11) and of which the diameter of the inner circumference is greater than the diameter of the outer circumference of the storage drum, and that the ring (19) is supported with its centre (22) eccentric relative to the storage drum axis (11) rotatably on a rotary crank drive (24) disposed coaxially relative to the storage drum axis (11) and with its inner circumference (20) at least touches the storage drum circumference at one circumferential point.
18. Device according to claims 2 to 5, characterized in that the retention element (R) is formed by the inner circumference of a ring (25), which touches the storage drum circumference at one point, of which the diameter of the inner circumference is greater than the diameter of the outer circumference of the storage drum (1) and which with an actuating spindle (27) obliquely cutting the storage drum axis (11) is drivable about the storage drum axis (11) so as to execute a wobbling motion.

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