DEVICE FOR SHAPING TAMPONS

Abstract

The present invention relates to an apparatus for forming tampons, which comprises a plurality of processing drums 2, 4, 5.1, 5.2 for forming a tampon from band-form material. It also comprises at least one transfer station 7 for continuously transferring a preform from a first processing drum 2, 4, 5.1, 5.2 to a second processing drum 4, 5.1, 5.2. The invention also relates to a method for forming a tampon from band-form material, wherein transfer from a first processing drum to a second processing drum takes place by means of a continuously rotating transfer wheel.

Claims

1. An apparatus (1) for forming tampons, comprising a. a plurality of processing drums (2, 4, 5.1, 5.2) for forming a tampon from band-form material, and comprising b. at least one transfer station (7) for continuously transferring a preform from a first processing drum (2, 4, 5.1, 5.2) to a second processing drum (4, 5.1, 5.2).

2. The apparatus according to claim 1, wherein the transfer station (7) is a transfer wheel (7) for continuously transferring a preform from a first processing drum (2, 4, 5.1, 5.2) to a second processing drum (4, 5.1, 5.2), in particular a transfer wheel (7) that is mounted so as to be rotatable about an axis of rotation R2, wherein the axis of rotation R2 is parallel to an axis of rotation R1 of the processing drums (2, 4, 5.1, 5.2).

3. The apparatus (1) according to claim 1, wherein the plurality of processing drums (2, 4, 5.1, 5.2) comprises a first processing drum (2) for winding the band-form material to form a first preform.

4. The apparatus (1) according to claim 1, wherein the plurality of processing drums (2, 4, 5.1, 5.2) comprises a second processing drum (4) for pressing the first preform to form a second preform.

5. The apparatus (1) according to claim 1, wherein the plurality of processing drums (2, 4, 5.1, 5.2) comprises at least one third processing drum (5.1, 5.2) for forming and/or smoothing a tampon head on the second preform.

6. The apparatus (1) according to claim 2, wherein the transfer wheel (7) comprises a plurality of receiving grippers (12), which are designed such that they engage in a transfer region (18, 19) at a rotation radius (20, 23) of at least one of the processing drums (2, 4, 5.1, 5.2).

7. The apparatus (1) according to claim 6, wherein the transfer wheel (7) has at least one guide curve (10.1, 10.2) that guides the receiving gripper (12) in a radial movement such that, during a rotation of the transfer wheel (7) relative to a processing drum (2, 4, 5.1, 5.2), a transfer region (18, 19) is defined, in which, at least for a while, a receiving nest (11) of a receiving gripper (12) is substantially coaxial with a processing tool (39) of a processing drum.

8. The apparatus (1) according to claim 2, wherein the transfer wheel (7) has radially arranged receiving grippers (12) and these receiving grippers (12) comprise: a. a receiving nest (11) for receiving a tampon or a preform; b. a guide rod (13) on which the receiving nest (11) is arranged; and c. a guide bushing (14) by way of which the guide rod (13) is mounted so as to be displaceable along its longitudinal axis, and which is mounted on a rotatable hub (16), in particular is mounted by means of a radial bearing.

9. The apparatus according to claim 2, wherein the transfer wheel comprises two guide discs (45.1, 45.2), on each of which there is formed a guide curve (10.1, 10.2), by way of which the receiving grippers (12) are guided in a radial movement about the axis of rotation R2 of the transfer wheel such that an effective radius of the receiving gripper follows a rotation radius (21, 23) of a processing tool at least for a while and transfer takes place at a tangent to the rotation radius (21, 23) of the processing drum (2, 4, 5.1, 5.2).

10. The apparatus (1) according to claim 1, wherein the processing drums (2, 4, 5.1, 5.2) comprise an ejection drum (32, 34, 35.1, 35.2), which is arranged so as to be rotatable about the same axis as the associated processing drum (2, 4, 5.1, 5.2).

11. The apparatus (1) according to claim 10, wherein the ejection drum (32, 34, 35.1, 35.2) comprises a plurality of ejection push rods (37) that are arranged at a radius on the ejection drum (32, 34, 35.1, 35.2) such that they are arranged coaxially with the processing tools of the associated processing drum.

12. A method for forming a tampon from band-form material using the apparatus according to claim 1, comprising the steps of: a. providing a band-form material; and b. incrementally forming the band-form material via a plurality of rotating processing drums, in particular continuously rotating processing drums, wherein transfer from a first processing drum to a second processing drum takes place continuously by means of a transfer wheel.

13. The method according to claim 12, wherein the incremental forming of the band-form material comprises a winding step, a pressing step and a forming and/or smoothing step, and wherein each of these steps takes place on a particular, continuously rotating processing drum.

14. The method according to claim 13, wherein the processing drums move the workpiece in a conveying direction in each incremental forming step.

15. The method according to claim 12, wherein, during the transfer from a first processing drum to a second processing drum, the transfer wheel executes the following steps of: a. engaging with a receiving gripper in a transfer region of a first processing drum, such that a receiving nest of the receiving gripper is located at least for a while in a coaxial arrangement with a tool, and b. ejecting a workpiece from the tool into the receiving nest, or from the receiving nest into the tool, in particular by displacing an ejection push rod in the longitudinal direction of the tool or receiving nest.

16. The method according to claim 12, wherein, in step b), the ejection push rod is arranged on an ejection drum, which rotates parallel to the corresponding processing drum, such that the ejection push rods are each assigned to a corresponding tool.

17. The method according to claim 12, wherein a receiving gripper of the transfer wheel is guided, during the rotation of the latter, over a guide curve, such that there is the same speed in a transfer region between the processing drum, in particular a tool of the processing drum, and receiving nest.

18. Use of a transfer station (7) having radially circumferentially arranged receiving grippers (12), in particular of a transfer wheel (7), for the continuous transfer of a preform from a first processing drum (2, 4, 5.1, 5.2) to a second processing drum (4, 5.1, 5.2) of an apparatus for producing tampons or preforms.

Description

DESCRIPTION OF THE FIGURES

[0066] In the following text, the present invention will now be explained in more detail with reference to specific exemplary embodiments and schematic drawings, but without being limited to these particular embodiments.

[0067] For the sake of simplicity, in the present figures, identical components are provided with the same reference signs.

[0068] In the figures, in each case schematically:

[0069] FIG. 1 shows an embodiment of the apparatus according to the invention with a total of four processing drums;

[0070] FIG. 2a shows a transfer wheel;

[0071] FIG. 2b shows a receiving gripper in a retracted state;

[0072] FIG. 2c shows a receiving gripper in an extended state;

[0073] FIG. 2d shows the receiving gripper from FIG. 2c in side view;

[0074] FIG. 3a shows a basic design of an apparatus according to the present invention with two processing drums and a transfer wheel arranged in between;

[0075] FIG. 3b schematically shows a transfer region;

[0076] FIG. 4 schematically shows the engagement of a transfer wheel in a cross section through the axis of rotation of a processing drum; and

[0077] FIG. 5 shows a detail of a radius of a transfer wheel according to the invention.

EMBODIMENT OF THE INVENTION

[0078] FIG. 1 schematically shows an apparatus 1 according to the invention with a total of four processing drums 2, 4, 5.1, 5.2. Although this example is illustrated with four drums 2, 4, 5.1, 5.2, the apparatus is already functional even with just two drums 2, 4. The processing drums 2, 4, 5.1, 5.2 are arranged in succession and each execute a processing step in the forming of tampons.

[0079] A first processing drum 2 serves as a winding station. The band-form material is introduced into the first processing drum 2 and is then wound by the first processing drum 2 to form coils and the first preform. In order to wind the band-form material, the first processing drum 2 can be equipped with a set of forks that take the band-form material and wind it into a coil by means of a rotary movement about their respective axes of rotation. The band-form material can, as outlined at the beginning, be a laminate made of a nonwoven and absorbent cotton. In this case, the absorbent cotton can originate from any cellulose fibre material, but is preferably made of viscose. Alternatively, cotton or hemp fibres are conceivable. The nonwoven comprises preferably a thermoplastic copolymer.

[0080] The apparatus 1 has a conveying direction. For the present example, the conveying direction is from left to right in FIG. 1. The workpieces travel in this conveying direction during operation.

[0081] Upstream processing stations that are not shown can produce the corresponding laminate and introduce the band-form material, already cut to the right size, into the first processing drum 2.

[0082] The first processing drum 2 is followed by a first transfer wheel 7. This transfer wheel takes the coil from the first processing drum 2 and transfers it to the second processing drum 4. In the present example, the first processing drum 2 is equipped such that it rotates in the clockwise direction about the horizontal axis of rotation. The tools, in particular winding forks, are arranged radially. The transfer wheel 7 is configured such that it rotates in the anticlockwise direction about a likewise horizontally extending axis of rotation.

[0083] The following second processing drum 4 is a drum for compressing the coils and preforms to form second preforms.

[0084] The second processing drum comprises a plurality of pressing tools. The pressing tools can be radially arranged pressing jaws. Overall, however, the number of pressing tools is lower than the number of winding tools of the first processing drum. The transfer wheel is capable of compensating for different speeds between two processing drums 2, 4, 5.1, 5.2. This can be ensured for example in that the transfer wheel comprises a corresponding guide, as shown in detail below.

[0085] The second processing drum 4 is followed by a third and a fourth processing drum 5.1, 5.2. The apparatus 1 according to the invention has two head forming/smoothing drums 5.1, 5.2. These drums are also each connected by a transfer wheel 7 to the preceding processing drum 4, which feeds the corresponding processing drum 5.1. Likewise, the transfer from the head forming drum 5.1 to the smoothing drum 5.2 takes place via a transfer wheel 7.

[0086] The transfer wheels 7 are configured such that they are rotatable continuously about their central axes of rotation. In the present example, the axes of rotation are oriented horizontally and indicated by the dashed crosses in FIG. 1. In the present exemplary embodiment, during operation, the transfer wheels rotate anticlockwise, while the processing drums 2, 4, 5.1, 5.2 rotate clockwise. Of course, the opposite structure is possible.

[0087] The entire arrangement can be mounted on a machine frame (not shown). Alternatively, workbenches, or mounting in a workroom are also conceivable. Also conceivable is integration into a fully automated production line with upstream and downstream processing.

[0088] FIG. 2a schematically shows a transfer wheel 7 according to the invention in a detail view. The transfer wheel 7 is illustrated by way of example between two processing drums. The transfer wheel 7 is mounted so as to be rotatable about a central axis of rotation R2, which is oriented horizontally. In this case, a hub 16 rotates about the central axis of rotation R2. Connected to the hub 16 are the receiving grippers 12, which have radially displaceable guide rods 13, which are mounted in guide bushings. The guide rods 15 end in receiving nests 11, which are designed to receive a workpiece, in the present case a preform or a coil.

[0089] As is apparent in the figure, the processing drums are arranged in an offset manner with respect to one another along their axes of rotation, such that the transfer wheel 7 can act between the two processing drums 2, 4.

[0090] In order to compensate for the different speeds of the processing drums at the radii of the transfer wheels, a first guide curve 10.1, which is arranged rigidly with respect to the hub 16, is apparent in FIG. 2a.

[0091] The receiving grippers 12 are configured such that they are operatively connected to the first guide curve 10.1 and, during the rotation of the transfer wheel 7, follow the curve profile such that the guide rods 13, in addition to the radial rotation about the axis of rotation of the transfer wheel, can carry out a lateral pivoting movement and cranial displacement defined by the guide curve (with regard to the receiving nest as the head end). The receiving grippers 12 are guided by this first guide curve 10.1, as by a guide member.

[0092] In order to further explain the manner of operation of the receiving grippers 12 in the example according to the invention, one such receiving gripper 12 is also schematically illustrated on its own in FIGS. 2b, 2c and 2d.

[0093] The receiving gripper 12 comprises guided guide rods 13, which are mounted so as to be displaceable along their longitudinal axis by means of a guide bushing 14 having a linear bearing.

[0094] A first cam 15 is formed on the guide rod 13, in order to engage in a guide slot of the guide curve according to FIG. 2a. In the illustration in FIGS. 2b and 2c, this first cam 15 would extend in the plane of the paper facing away from the observer.

[0095] In the present example, the receiving gripper 12 is mounted so as to be rotatable about an axis of rotation R3 on the hub 16. This can be brought about by means of a radial bearing. In the present example, the radial bearing is formed by the hub and operatively connected to the guide bushing by a peg at the axis of rotation R3.

[0096] At the head side, the guide rod 13 ends with a receiving nest 11, which describes a lumen that serves to receive the workpiece. A lateral cutout serves, during positioning, to not touch the retrieval thread, projecting horizontally into a transfer region, during the transfer.

[0097] FIG. 2c shows a displacement of the mounted guide rod 13 along the longitudinal axis of the receiving gripper 12, as is allowed by a linear bearing of the guide bushing 14.

[0098] The guide bushing 14 has a second cam 9 on the plane of the paper facing the observer. This second cam 9 can be operatively connected to a second guide curve (this not being shown in FIG. 2a). This second guide curve serves as a guide member for guiding the guide bushing 14 along a curve. As a result, the receiving nest 11 can move in two degrees of freedom during a rotation of the transfer wheel 7, namely a longitudinal displacement in the longitudinal direction and a rotation about the axis of rotation R3. Since the two cams 9, 15 are arranged in an offset manner with respect to one another, the guidance by the two guide curves supports the radial movement of the receiving grippers on their curves.

[0099] FIG. 2d shows the receiving gripper 12 from FIG. 2c again, rotated through 90 degrees, in side view. The guide rod 13 has in this case been displaced slightly in a radial direction (with regard to the axis of rotation R2 of the transfer wheel; not shown in FIG. 2d). The guide bushing has the cam 9. The guide rod has the cam 15. At the receiving nest 11, in plan view, the lateral cutout is discernible.

[0100] FIG. 3a shows an arrangement for better illustrating the transfer wheel 7 with two processing drums. A first processing drum describes, with the processing tools, a first radius 20, while a second processing drum 4 describes, with its tools, a second radius 23. In this case, these radii relate to the corresponding location of the workpiece in the tool. The second processing drum 4 is a processing drum 4 having a plurality of tampon presses 25, 30, which are arranged radially about the axis of rotation of the processing drum 4.

[0101] The axes of rotation of the processing drums 2, 4 are illustrated schematically by a central cross. Along these axes, a rotary shaft can be connected with rotary bearings to a rotary drive (this not being shown), wherein a direct drive of the individual processing drums, or an individual drive can drive both drums via a belt system.

[0102] The pressing tools 25, 30 are equipped with a plurality of radially arranged pressing tools, in particular with pressing jaws, which compress a preform located at their centre. Formed in the present example are six pressing tools 25, 30, which are arranged in a rotationally symmetric manner about the axis of rotation, in order to avoid imbalances.

[0103] In the present example, the pressing tools 25, 30 are configured such that they carry out a compression step from the time of receiving the workpiece until they transfer it to a next processing drum or to a removal unit. As a result, the compression step can be carried out over a period while the workpiece, i.e. the preform, is being moved in the conveying direction. At the same time, another pressing tool is prepared for receiving a following first preform.

[0104] The process can proceed continuously without there being a loss of processing time during the compression for the individual preform, thereby achieving good processing quality.

[0105] The transfer wheel 7 is likewise mounted so as to be rotatable about a horizontal axis of rotation, and is located between the two processing drums. The transfer wheel 7 has a total of twelve receiving grippers 12, which are arranged radially and likewise define an effective radius 21 with their receiving nests 11. During operation, a transfer region 18 is formed between the effective radius 21 of the transfer wheel 7 and the effective radius 20 of the first processing drum. At a tangent to the radius 20 of the processing drum within this transfer region 18, the transfer of the workpiece from the first processing drum to the transfer wheel 7 takes place.

[0106] In a manner corresponding to the lower number of tools at the second processing drum 4, the transfer region 19 between the transfer wheel 7 and the second processing drum 4 is designed differently.

[0107] By way of a corresponding curve guide (not shown in FIG. 3), the receiving gripper can optimally cover the corresponding transfer regions 18, 19 during its radial movement of the transfer wheel.

[0108] Thus, it is possible for example with the aid of the guide curves to ensure an identical turning speed between the receiving gripper 12 and processing tool during a particular time window in which the transfer can take place.

[0109] This concept is illustrated once more schematically as an example in FIG. 3b. A first rotation radius about the axis of rotation R1 of a processing drum is illustrated on the left. This radius overlaps a second rotation radius about the axis of rotation R2 of a transfer wheel. As a result, the transfer region 18 arises, in which the tools of the processing drum continue to follow their rotation radius, but the rotation radius of the transfer wheel follows a curve 43 that deviates from the rotation curve 44.

[0110] This is allowed by the degrees of freedom of the receiving grippers and the guidance along the guide curves, as explained above. Thus, a first curve radius 41.1 of a receiving gripper is adapted dynamically to the rotation radius of the processing drum, and the workpiece is transferred at a second curve radius 41.2 at a tangent to the rotation radius of the processing drum.

[0111] FIG. 4 shows the transfer in more detail using the example of any desired processing drum 2, 4, 5.1, 5.2 that has an associated ejection drum 32, 34, 35.1, 35.2, which is mounted so as to be rotatable about the same axis of rotation R1.

[0112] The processing drum 2, 4, 5.1, 5.2 is shown in cross section, wherein two tools 39 are illustrated in each case schematically at radially opposite encircling radii. These tools 39 serve to receive the workpiece or preform. The tools 39 can also be responsible for a particular processing step. Thus, a tool of a processing station can be configured for example as a winding tool, as a pressing tool or as a head forming/smoothing tool.

[0113] With regard to the ejection drum 32, 34, 35.1, 35.2, the processing drum 2, 4, 5.1, 5.2 defines a gap through which a receiving gripper of a transfer wheel can engage in a transfer region that is located between the processing drum and the ejection drum, specifically coaxially between an ejection push rod 37 and the tool 39. The processing drums 2, 4, 5.1, 5.2 are shown by way of example with associated ejection drums 32, 34, 35.1, 35.2 in FIG. 4. In practice and in a specific configuration of an apparatus according to the invention, a processing drum 2, 4, 5.1, 5.2 can have permanently associated ejection drums 32, 34, 35.1, 35.2 which are adapted to the structural and functional properties of the processing drum 2, 4, 5.1, 5.2, for example with regard to the number of tools, the rotational speed, the geometry. Thus, it is possible for example for a second processing drum 4 that is provided for compressing the preforms and has a total of six tools, i.e. pressing tools, to have a correspondingly designed ejection drum 34 having six ejection push rods 37 and a corresponding guide element for guiding these ejection push rods.

[0114] During transfer, a receiving nest 11 is arranged in this intermediate space such that a receiving chamber defined by the receiving nest 11 is coaxial with the ejection push rod 37. This ejection push rod 37 can be guided three-dimensionally on the ejection drum 32, 34, 35.1, 35.2 such that it projects into the transfer region, synchronously in the transfer region with the coaxial arrangement of the receiving nest 11, such that it transports the workpiece from the receiving nest into the tool 39 in the arrow direction.

[0115] In order to equalize the speed between the transfer wheel and the processing drum or ejection drum at the time of the transfer, the transfer wheel is provided with cams 9, 15, which each act in a corresponding slot in a guide curve 10.1, 10.2 and by way of which the displaceably mounted guide rods 13 follow the movement profile of the curve. In this case, the guide rods 13 are mounted so as to be rotatable about an axis of rotation R2 via a hub 16. The guide curves 10.1, 10.2 are formed in the present example as slots on two guide discs 45.1, 45.2 that are arranged opposite and parallel to one another. The guide discs 45.1, 45.2 are fixed with respect to the hub 16. The guide curves 10.1, 10.2 thus form guide elements, which control the curve movement of the receiving grippers. The receiving grippers are additionally mounted in a rotatable manner on the hub 16, such that they can execute a pivoting movement perpendicular to the plane of the paper.

[0116] FIG. 5 schematically illustrates the structure of a transfer wheel with mounted receiving grippers in a detail view. Two guide discs 45.1, 45.2 are arranged in parallel, such that they have a front side facing one another. On the respective front sides, the guide curves 10.1, 10.2 are configured as slots. Engagement means 9, 15 of the receiving grippers engage in each case in the slots of the guide curves 10.1, 10.2, wherein the receiving grippers are illustrated without receiving nests in the present illustration, in order not to impede the view into the intermediate space between the guide discs 45.1, 45.2.

[0117] The guide bushing 14 is operatively connected to the remote second guide curve 10.2 via a second cam 9 as engagement means, such that it is guided on the guide bushing 14 during the rotary movement about the axis of rotation R2 of the transfer wheel as with a guide element. The guide bushing 14 is furthermore mounted in a pivotable manner via a radial bearing with the hub 16. The hub 16 is configured in the present case as a transport wheel, which has radially arranged bearings for operatively connecting to the guide bushings 14.

[0118] Via the guide bushing 14, the guide rod 13 is mounted in a linear manner. The guide rod 13 has a cam 15, which extends in an analogous manner into the first guide curve 10.1 configured as a slot, and enters into a guided operative connection therewith.

[0119] Rotors can be attached to the cams 9, 15 in order to minimize the friction with the slots of the guide curves 10.1, 10.2.

[0120] The present invention provides an apparatus which allows continuous and scalable tampon forming, which has a number of advantages compared with known systems. Further advantageous embodiments, which can be supplemented with further features from the general description, will become apparent to a person skilled in the art from these specific exemplary embodiments.