Apparatus for compaction of containers

10836130 ยท 2020-11-17

    Inventors

    Cpc classification

    International classification

    Abstract

    Apparatus for compaction of containers, particularly beverage cans or tin cans from the foods sector, having two pressure rolls disposed at a parallel distance from one another, forming a gap, which rolls can rotate about their axis of rotation, in each instance, and rotate in opposite directions, wherein their mantle surface has multiple essentially strip-shaped elements, in each instance, which reach longitudinally from one face surface to the opposite face surface of the pressure rolls, wherein the strip-shaped elements of each pressure roll are strip-shaped active elements, which each diverge at a setting angle relative to a reference line that runs parallel to its axis of rotation in the mantle surface.

    Claims

    1. An apparatus for compaction of containers, comprising two pressure rolls, which rolls can rotate about their axis of rotation, in each instance, and rotate in opposite directions, wherein a plurality of grooves has been sunk longitudinally into their mantle surface, so that their mantle surface has the form of multiple essentially strip-shaped elements with planar pressure surfaces being in areas of the mantel surface without grooves, in each instance, which reach longitudinally from one face surface to the opposite face surface of the pressure rolls, wherein the two pressure rolls are disposed at a parallel distance from one another, forming a gap defining a minimum distance between the planar pressure surfaces of the mantle surfaces of the two pressure rolls along a direction from one axis of rotation to the other, wherein the strip-shaped elements of each pressure roll are strip-shaped active elements, which each diverge at a setting angle relative to a reference line that runs parallel to its axis of rotation in the mantle surface, wherein for one pressure roll the strip-shaped elements diverge with said setting angle of said strip-shaped element in rotation direction of the one pressure roll from the reference line while with the other pressure roll the strip-shaped elements diverge with said setting angle of said strip-shaped element against the rotation direction of the other pressure roll, so that the strip-shaped elements are crosswise to each other when adjacent to the gap, wherein each of the strip-shaped active elements lies between two of the grooves, in each instance, wherein each groove comprises a planar groove root and each strip-shaped element comprises a planar pressure surface, wherein a width of each planar pressure surface is smaller than a width of each planar groove root, wherein when the strip-shaped elements are adjacent to the gap, the planar pressure surfaces of the strip-shaped elements of the one pressure roll and the planar pressure surfaces of the other pressure roll face each other along a direction from one axis of rotation to the other, wherein when the strip-shaped elements are adjacent to the gap, the planar pressure surfaces of the striped-shaped elements of one pressure roll are spaced apart from the planar pressure surfaces of the striped-shaped elements of the other pressure roll along the direction from one axis of rotation to the other by the minimum distance, and wherein the strip-shaped elements of one of the pressure rolls comprise grooves separating each strip-shaped element into at least two segments.

    2. The apparatus according to claim 1, wherein the setting angle of each strip-shaped active element has the same size.

    3. The apparatus according to claim 1, wherein the strip-shaped active elements, seen in cross-section, possess a trapezoid shape, which is delimited, toward the outside, by a front side surface in a direction of rotation, an opposite side surface, and the planar pressure surface that connects the two side surfaces, wherein both side surfaces are disposed at a respective inclination angle relative to a respective radius line that runs through the edge formed by an intersection point of the respective side surface and the adjacent planar pressure surface that lies at the top, and wherein the inclination angles of the respective side surfaces are different from each other, so that the trapezoid shape of the strip-shaped active elements, seen in cross-section, is a non-symmetrical trapezoid shape.

    4. The apparatus according to claim 1, wherein the strip-shaped active elements, seen in cross-section, possess a trapezoid shape, which is delimited, toward the outside, by a front side surface in a direction of rotation, an opposite side surface, and the planar pressure surface that connects the two side surfaces, wherein both side surfaces are disposed at a respective inclination angle relative to a respective radius line that runs through the edge formed by an intersection point of the respective side surface and the adjacent planar pressure surface that lies at the top, and wherein the inclination angles of the respective side surfaces are identical to each other, so that the trapezoid shape of the strip-shaped active elements, seen in cross-section, is a symmetrical trapezoid shape.

    5. The apparatus according to claim 1, wherein the strip-shaped active elements, seen in cross-section, possess a trapezoid shape, which is delimited, toward the outside, by a front side surface in a direction of rotation, an opposite side surface, and the planar pressure surface that connects the two side surfaces, wherein both side surfaces are disposed at a respective inclination angle relative to a respective radius line that runs through the edge formed by an intersection point of the respective side surface and the adjacent planar pressure surface that lies at the top, and wherein the side surfaces are disposed at different absolute inclination angles relative to a radius line that symmetrically divides the planar pressure surface, so that the trapezoid shape of the strip-shaped active elements, seen in cross-section, is a non-symmetrical trapezoid shape.

    6. The apparatus according to claim 1, wherein the strip-shaped active elements, seen in cross-section, possess a trapezoid shape, which is delimited, toward the outside, by a front side surface in a direction of rotation, an opposite side surface, and the planar pressure surface that connects the two side surfaces, wherein both side surfaces are disposed at a respective inclination angle relative to a respective radius line that runs through the edge formed by an intersection point of the respective side surface and the adjacent planar pressure surface that lies at the top, and wherein the side surfaces are disposed at an identical absolute inclination angle relative to a radius line that symmetrically divides the planar pressure surface, so that the trapezoid shape of the strip-shaped active elements, seen in cross-section, is a symmetrical trapezoid shape.

    7. The apparatus according to claim 1, wherein each strip-shaped active element, with reference to the groove, has a height between 2 to 6 mm.

    8. The apparatus according to claim 1, wherein each strip-shaped active element, with reference to the groove, has a height between 2 to 5 mm.

    9. The apparatus according to claim 3, wherein the inclination angle of the front side surface lies in a value range between 8 and 12.

    10. The apparatus according to claim 9, wherein an angle between the front side surface of one active element and of the opposite side surface of a next active element in the direction of rotation lies in a value range between 54 and 62.

    11. The apparatus according to claim 4, wherein the inclination angle of the front side surface lies in a value range between 25 and 40.

    12. The apparatus according to claim 11, wherein an angle between the front side surface of one active element and of the opposite side surface of a next active element in the direction of rotation lies in a value range between 82 and 95.

    13. The apparatus according to claim 1, wherein the strip-shaped active elements, seen in cross-section, possess a trapezoid shape, which is delimited, toward the outside, by a front side surface in a direction of rotation, an opposite side surface, and the planar pressure surface that connects the two side surfaces, wherein both side surfaces are disposed at a respective inclination angle relative to a respective radius line that runs through the edge formed by an intersection point of the respective side surface and the adjacent planar pressure surface that lies at the top, and wherein both side surfaces are disposed at a respective groove inclination angle relative to a respective radius line that runs through the edge formed by an intersection point of the respective side surface and the adjacent planar groove root.

    14. The apparatus according to claim 13, wherein the groove inclination angles of the respective side surfaces are different from each other.

    15. The apparatus according to claim 13, wherein the groove inclination angles of the respective side surfaces are identical to each other.

    16. An apparatus for compaction of containers, comprising two pressure rolls, disposed at a parallel distance from one another, forming a gap, which rolls can rotate about their axis of rotation, in each instance, and rotate in opposite directions, wherein their mantle surface has multiple essentially strip-shaped elements, in each instance, which reach longitudinally from one face surface to the opposite face surface of the pressure rolls, wherein the strip-shaped elements of each pressure roll are strip-shaped active elements, which each diverge at a setting angle relative to a reference line that runs parallel to its axis of rotation in the mantle surface, wherein for one pressure roll, the strip-shaped elements diverge with said setting angle of said strip-shaped element in a rotation direction of the one pressure roll from the reference line while with the other pressure roll, the strip-shaped elements diverge with said setting angle of said strip-shaped element against the rotation direction of the other pressure roll, so that the strip-shaped elements are crosswise to each other when adjacent to the gap, wherein longitudinal grooves are disposed in the mantle surface of each pressure roll, wherein a strip-shaped active element lies between two grooves, in each instance, wherein the strip-shaped elements of one of the pressure rolls comprise grooves separating each strip-shaped element into at least two segments; and wherein the strip-shaped elements of the other one of the pressure rolls does not comprise grooves separating each strip-shaped element into at least two segments.

    17. The apparatus according to claim 16, wherein each groove comprises a planar groove root and each strip-shaped element comprises a planar pressure surface, wherein a width of each planar pressure surface is smaller than a width of each planar groove root, wherein the strip-shaped active elements, seen in cross-section, possess a trapezoid shape, which is delimited, toward the outside, by a front side surface in a direction of rotation, an opposite side surface, and the planar pressure surface that connects the two side surfaces, and wherein both side surfaces are disposed at a respective inclination angle relative to a respective radius line that runs through the edge formed by an intersection point of the respective side surface and the adjacent planar pressure surface that lies at the top.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    (1) The invention will be explained further and in greater detail using exemplary embodiments shown in drawings, which embodiments do not, however, restrict the invention. The drawings show:

    (2) FIG. 1 a schematic side view of an apparatus according to the invention with a view into the working space of this apparatus;

    (3) FIG. 2 the pressure rolls of the apparatus according to FIG. 1, which rolls are assigned to one another;

    (4) FIG. 2a, 2b, 2c details of the pressure rolls according to FIG. 2;

    (5) FIG. 3 the pressure rolls according to FIG. 2 with a first embodiment of strip-shaped active elements;

    (6) FIG. 3a details regarding FIG. 3;

    (7) FIG. 4 the pressure rolls according to FIG. 2, with a second embodiment of strip-shaped active elements;

    (8) FIG. 4a details regarding FIG. 4;

    (9) FIG. 5 a perspective view of pressure rolls of the apparatus according to the invention, with strip-shaped active elements of a second embodiment;

    (10) FIG. 6 in a sectional representation, mounting of the pressure rolls of the new apparatus having a new type of seal;

    DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

    (11) In the following description of the exemplary embodiments, terms such as at the top, at the bottom, on the left, and on the right relate only to the figures in question and can therefore deviate from reality. Also, the proportions can be different, in reality, from the figures. Furthermore, the figures are not precise technical drawings, but rather are merely supposed to show the nature of the invention. With regard to the reference symbols, it is noted that the same numbers in the different figures always refer to the same components. Reference symbols not mentioned in the description are evident from the reference symbol list or from being mentioned in another figure of this disclosure. The reference numbers used in the figures have the same meaning, in each instance, even if they are not explicitly mentioned with regard to every figure in the description of the embodiments.

    (12) A schematic side view of an apparatus having a pressure roll 5 according to the invention and a pressure roll 6 according to the invention is shown in FIG. 1. Here, one of the lateral housing walls has been removed, so that the view is open into the working space of the apparatus.

    (13) In a housing 2, a filling opening 3 is provided on one side, in an upper region, for throwing in the said containers/hollow bodies 15 that are to be recycled. In the upper inner region, there is a feed chamber 3a; in the lower region of this housing 2, following the feed chamber 3a, the first pressure roll 5 is disposed, and, lying opposite to it, parallel, and at a distance from it, the pressure roll 6, which is the same as the pressure roll 5 according to the invention, in terms of type and embodiment. It, the pressure roll 6, is merely rotated by 180, so that the left face side of the pressure roll 5 is then the right face side of the pressure roll 6.

    (14) The pressure roll 5 and the pressure roll 6 form a gap 9 between them. This gap is an intake gap, working gap, and ejection gap at the same time. The containers 15, 16, etc. to be compacted are introduced into the feed space 3a by way of the fill-in opening 3, one after the other, and slip down to the gap 9 by way of the chute 10. An entrainment unit 7 is disposed in the feed space 3a and supports the feed of the containers 15 or 16 that are thrown in, to the gap 9, with one of its vanes 71, 72 or 73, in each instance, which move according to arrow 11; this gap is the intake gap, wherein these vanes push the container in the direction of the gap and, at the same time, press it against this intake gap, as long as they have contact with the container.

    (15) The containers that are thrown in are reliably drawn in and compacted by means of the pressure rolls 5 and 6 that rotate in opposite directions, i.e. by their strip-shaped active elements 59 and 69, which act crosswise in the intake gap and working gap, according to the invention. The sections of the wall of the containers that are pressed against one another, which wall then has a double layer in the working gap, is accordingly reliably compacted in accordance with the explanations already provided above. Any deposit markings that might be present are effectively voided. The double-layer body, in the compacted state, contains an embossed-like shaping at least in certain sections, which shaping is such, because of the rotation and the strip-shaped active elements disposed in a new manner, that hooking of the said sections into one another more or less takes place. According to the invention, the strip-shaped active elements, here, in the exemplary embodiment shown, the strip-shaped active elements 59 and 69 of the pressure roll 5 and 6, respectively, are disposed in such a manner that they possess the same setting angle W1. During the installation/assembly of these pressure rolls in the apparatus, attention must be paid to ensure that this setting angle W1 is approximately the same on both pressure rolls, i.e. for the respective strip-shaped active elements.

    (16) In the representation shown in FIG. 1 (an instantaneous image of the working apparatus) it is the vane 73 that presses the container/hollow body 16 against the pressure rolls 5 and 6 and into the intake section of the gap 9. The next container 15 fed in is shown in two positions. Once while being thrown in and in a later position P, in terms of time; here, the container 15, introduced in the longitudinal direction, is drawn with a broken line for differentiation. It now lies crosswise, in other words parallel to the pressure rolls 5 and 6 and the intake gap formed between them, in terms of its longitudinal orientation, and waits, in this position P, for transfer to the intake gap of the gap 9 by means of advancing gravity feed along the chute 10 and/or the rear side of the vane 73. The subsequent vane 72 will then likewise press the container 15 up to the intake gap 9 and into it as the entrainment unit 7 continues to rotate about its axis of rotation 70, as is shown in this figure with regard to the container 16.

    (17) Preferably, the entrainment unit 7 is a separator according to EP 2 292 333 A2 or U.S. Pat. No. 7,540,235 B2. Not shown here are known modules and components that belong to an apparatus of this type, such as, for example, a gear mechanism and a motor, as well as a control unit, which are required for operation of the apparatus and are also provided here.

    (18) In FIG. 2, in a schematic view, the pressure rolls 5 and 6 of the new apparatus from FIG. 1, assigned to one another, are shown in a top view. The first pressure roll 5 is situated at the top. It possesses an axis of rotation 51, bearing journals 56 and 57 at the side, as well as a roll body having a mantle surface 53, between the left face surface 54 and the right face surface 55. Further details are shown in FIG. 2a, with regard to detail A. A plurality of grooves 58 has been sunk longitudinally into the mantle surface 53. These grooves 58 are uniformly distributed on the circumference of the first pressure roll 5. A strip-shaped active element 59 is formed between two grooves, in each instance, which element also reaches longitudinally from the left face surface 54 all the way to the right face surface 55.

    (19) In this FIG. 2, the second pressure roll 6 is disposed underneath the first pressure roll 5, at a parallel distance from the aforementioned first pressure roll 5. The distance between the two pressure rolls 5 and 6 is the gap 9 (see also FIG. 1).

    (20) The second pressure roll 6 possesses an axis of rotation 61, bearing journals 66 and 67 at the side, as well as a roll body having a mantle surface 63 between the left face surface 64 and the right face surface 65.

    (21) Further details are shown in FIG. 2b with regard to detail B. A plurality of grooves 68 has been sunk longitudinally into the mantle surface 63. These grooves 68 are uniformly distributed on the circumference of the second pressure roll 6. A strip-shaped active element 69 is formed between two grooves, in each instance, which element also reaches longitudinally from the left face surface 64 all the way to the right face surface 65.

    (22) In FIG. 2chere with reference to detail Bfurther details of the pressure rolls are shown. The strip-shaped active elements of the pressure rollshere shown using the example of the pressure roll 6diverge at a setting angle W1 relative to a reference line that runs parallel to its axis of rotation 61 in the mantle surface 63. The strip-shaped active elementshere the elements 69are disposed oriented to reach in a straight line from the left face surface 64 all the way to the right face surface 65.

    (23) In FIGS. 3 and 3a, the pressure rolls 5 and 6 are equipped with strip-shaped active elements 59 or 69 according to a first embodiment type. The respective direction of rotation is indicated with the reference symbol 52 and 62.

    (24) The strip-shaped active element 59 disposed between two grooves 58, in each instance, possesses a front-side side surface 12, which will also be called front surface hereinafter, and a side surface 14 that lies opposite, which will also be called rear surface hereinafter. Outward from the body, the two side surfaces are connected with one another by means of the section of the mantle surface 53 that still remains. This section of the mantle surface 53 is the pressure surface 13.

    (25) The front surface 12 is disposed at an inclination angle W2 relative to the radius line, which runs through the edge formed by the intersection point of the front surface 12 and the adjacent pressure surface 13 that lies at the top. In this embodiment, this inclination angle W2 preferably amounts to approximately 10. The front surface 12 and the rear surface 14 of the leading strip-shaped active element are preferably disposed at a distance/angle W3 of preferably approximately 58 relative to one another.

    (26) The second pressure roll 6 also shown in FIG. 3, which is disposed more or less as a mirror image to the pressure roll 5 in the apparatus, has the same shape/shaping, as has already been said. There, the strip-shaped active elements 69 have a side surface/front surface 20, a side surface/rear surface 22, and a pressure surface 21. The inclination angle W2 of the front surface 20 and the distance/angle W3 are of the same type and embodiment as in the first pressure roll 5.

    (27) In FIGS. 4 and 4a, the pressure rolls, here the pressure rolls 30 and 40, are equipped with strip-shaped active elements 35 and 45 according to a second embodiment type. The respective direction of rotation is indicated with the reference symbol 32 and 42.

    (28) The strip-shaped active element 35 disposed between two grooves 34, in each instance, possesses a front-side side surface 39, which will also be called front surface hereinafter, and a side surface 37 that lies opposite, which will also be called rear surface hereinafter. Outward from the body, the two side surfaces are connected with one another by means of the section of the mantle surface 33 that still remains. This section of the mantle surface 33 is the pressure surface 38.

    (29) The front surface 39 is disposed at an inclination angle W4 relative to the radius line, which symmetrically divides the strip-shaped active element 35. In this embodiment, this inclination angle W4 preferably amounts to approximately 35. The front surface 39 and the rear surface 37 of the leading strip-shaped active element 35 are preferably disposed at a distance/angle W5 of preferably approximately 89 relative to one another.

    (30) The second pressure roll 40 of the second embodiment, also shown in FIG. 4, which is disposed more or less as a mirror image of the first pressure roll 30 of the second embodiment in the apparatus, has the same shape/shaping, as was already said above. There, the strip-shaped active elements 45 have a similarly shaped front surface, rear surface, and pressure surface, which are not specifically labeled in this figure; the reference symbols 37, 38, and 39 of the first pressure roll 30 of the second type have the same meaning on this second pressure roll 40.

    (31) The inclination angle W4 of the front surface 39 and the distance/angle W5 are of the same type and embodiment as in the first pressure roll 30 of the second type.

    (32) The roll pair shown in FIG. 4, with the pressure rolls 30 and 40 according to the invention, is shown in a perspective view in FIG. 5. The view is at the left face surface with the bearing journals 36 and 46. In this view, it can be clearly seen that the longitudinal strip-shaped active elementshere with the reference symbols 35 and 45do possess a setting angle W1 directed in the same direction (not drawn in here), but then intersect in the gap 9 (in the intake region, in the working region, and in the ejection region).

    (33) As the result of the similar structure of the pressure rolls 30 and 40, their mirror-image installation in the apparatus, as well as their opposite direction of rotation, this crossing of the strip-shaped active elements, which is advantageous in terms of effect, is implemented in simple manner and furthermore cost-advantageously. This advantage also occurs with the roll pair that is formed by the pressure rolls 5 and 6, which pair is shown in FIG. 2.

    (34) The crossing of the strip-shaped active elements in the gap 9 formed between the pressure rolls 5 and 6 or 30 and 40, as well as the further details of the form of the strip-shaped active elements and their placement on or in the mantle surface of the pressure rolls and the position at a setting angle W1 relative to the line parallel to the axis in the mantle surface of the pressure roll, with reference to its axis of rotation, have a particularly positive effect on problem-free drawing of the containers in between the pressure rolls and on reliable hooking of the wall sections of the containers, which are pressed against one another. The containers that are flattened as the result of compaction between the pressure rolls remain in this state that has been produced. As compared with the known apparatuses, significantly greater shape stability of the flattened containers is achieved with the apparatus according to the invention; furthermore, the number of bent edges having a small radius, in the body wall of the compacted containers, is reduced by a multiple, so that the formation of stress whitening spots, in particular, in the body wall and/or splitting off or projection of small, some more or less cut wall sections, which reduce the value of the containers, is avoided.

    (35) In FIG. 6, in a schematic sectional representation, a further embodiment of the apparatus according to the invention is shown, by means of which the maintenance effort and expenditure, in particular, and the maintenance interval are positively influenced, because suspended solids and liquids from the work space of the apparatus are kept away from the bearings for the bearing journals of the pressure rolls, significantly better than in the case of known solutions. Specifically, it is provided, according to this solution, that on the inside of the passage opening 86 for a bearing journalhere the bearing journal 67 of the second pressure roll 60 according to FIG. 2an axially acting seal 85 is disposed on the inner side 82 of the bearing plate 80, and a radially acting seal 84 is disposed in the region of the outer side 81 of the bearing plate 80, on the bearing journal 67 that is passed through the passage opening 86.

    (36) This second, radially acting seal 84, does not lie directly against the outer side 81 of the bearing plate. In this way, the result is achieved that possibly, suspended solids and liquids that do pass by the axially acting seal 85 are drained away downward in the region of the passage opening 86, which possesses an additional longitudinal groove at the lower pointin the installed positionwhich groove is furthermore preferably inclined relative to the horizontal. The longitudinal groove not shown in the figure acts to support this.

    (37) The invention is not restricted to the exemplary embodiment that has been shown and described, but rather particularly also comprises variants that can be formed by means of a combination of characteristics and elements described in connection with the present invention. Furthermore, individual characteristics or methods of functioning described in connection with the figures can represent an independent invention, in and of themselves. The applicant therefore reserves the right to claim characteristics that are of essential significance for the invention, which have only been disclosed in the description until now, particularly in connection with the figures. The claims submitted with this application are therefore only proposed formulations, without prejudice to achieving further patent protection.

    REFERENCE NUMBER LIST

    (38) 1 apparatus 2 housing 3 fill-in opening 3a feed space 4 exit opening 5 first pressure rolls 51 axis of rotation 52 direction of rotation 53 mantle surface 54 left face surface 55 right face surface 56 bearing journal 57 bearing journal 58 grooves (longitudinal in item 53) 59 strip-shaped active elements 6 second pressure roll 61 axis of rotation 62 direction of rotation 63 mantle surface 64 left face surface 65 right face surface 66 bearing journal 67 bearing journal 68 grooves (longitudinal in item 63) 69 strip-shaped active elements 7 entrainment unit 70 axis of rotation of item 7 71, 72, 73 vanes of item 7 8 guide plate 9 gap (intake gap, perforation gap, working gap and ejection gap) 10 chute 11 arrow 12 side surface (front surface of item 59) 13 pressure surface (on item 59) 14 side surface (rear surface of item 59) 15, 16 container (container fed in, e.g. beverage cans, tin cans from the foods sector) 17 compacted container 20 side surface (front surface of item 69) 21 pressure surface (on item 69) 22 side surface (rear surface of item 69) 30 first pressure roll of second type 31 axis of rotation 32 direction of rotation 33 mantle surface 34 grooves (longitudinal in item 33) 35 strip-shaped active elements 36 bearing journal 37 side surface (rear surface of item 35) 38 pressure surface (on item 35) 39 side surface (front surface of item 35) 40 second pressure roll of second type 41 axis of rotation 42 direction of rotation 43 mantle surface 44 grooves (longitudinal in item 43) 45 strip-shaped active elements 46 bearing journal 80 bearing plate 81 outside 82 inside 83 bearing 84 radially acting seal 85 axially acting seal 86 passage opening (in item 80) H1 height (of item 59 with reference to groove root) H2 height (of item 35 with reference to groove root) W1 setting angle between the strip-shaped active element (59, 69, 35 or 45) and the line, parallel to the axis, in the mantle surface of the pressure roll W2 angle of inclination between the front surface 12 or 20 of the strip-shaped active element 59 or 69 and the radius line that runs through the edge formed by the intersection point of the front surface and the adjacent pressure surface 13 or 21 W3 distance/angle between the front surface 12 or 20 and the rear surface 14 or 22 of the next strip-shaped active element 59 or 69 that leads in the direction of rotation W4 angle of inclination between the front surface 39 of the strip-shaped active element 35 and the radius line that symmetrically divides the strip-shaped active element 35 W5 distance/angle between the front surface 39 and the rear surface 37 of the next strip-shaped active element 59 or 69 that leads in the direction of rotation