EP0003839A1 - Strip of bags and method and device for the manufacture thereof - Google Patents

Abstract

A bag band is specified which has a carrier tape (20) to which individual bags (22) are attached via discrete suspension sections (24). Incisions (30) are provided in the suspension sections (24) at the end at the rear in the packaging conveying direction up to the edge of the suspension sections (24), which allow the bags (22) to be inflated against the filling opening of the bag, essentially in the bag plane facilitate directed air curtain. For the very first lifting of the front wall of the bag, additional openings (18) can be provided in the rear wall of the bag at the level of the end of the front wall of the bag, through which a jet standing vertically on the bag plane can be directed against the front wall of the bags. In order to enlarge the transverse area (W) within which the bags (22) can be separated from the carrier tape (20) by a cut running in the longitudinal direction of the web, the incisions (30) are provided with an essentially transverse section (30a) which runs transversely outwards from the inner end of the incisions (30).

Description

The invention relates to a bag band according to the preamble of claim 1 and a method and an apparatus for producing such a bag band.

Bag tapes are available commercially in rolls, in which successive individual bags hang on a carrying tape. The bags are folded flat on the roll, but can be opened and inflated to introduce objects into the bags by inflowing air. The air flow is essentially in the exit plane of the folded bags and is directed against the edge of the bag which later defines the filling opening. The incision provided at the top of the bag serves to allow the bag to be inflated to an oval or round shape from the starting level. The latter is defined by guides in the usual machines for packing objects using pouch tapes.

In practice it has been found that not all bags open properly when air flows into such a known bag band; often up to 20% of the bags remain closed.

The invention is therefore intended to create a bag band, the individual bags of which can be opened reliably by air flowing against them. A method for producing such a bag band and an apparatus for carrying out such a method are also to be specified.

For this purpose, the invention creates a bag band according to claim 1, a method according to claim 13 and according to claim 16 and an apparatus according to claim 18.

• Bei den bekannten Tütenbändern werden die den Einschnitten benachbarten Abschnitte der Tüten geschoben und werden durch Reibungskräfte, welche durch die die Tüten abstützende Maschinenführung hervorgerufen werden, gebremst. Dabei besteht die Gefahr, daß sich diese Abschnitte der Tüte umschlagen. Die Tüte wird dann gerade an dem Teil der Einfüllöffnung zusammengefaltet, wo das Sichöffnen durch den Luftstrom einsetzen soll. Bei dem erfindungsgemäßen Tütenband werden dagegen die den Einschnitten benachbarten Tütenabschnitte geschleppt. Durch Reibung an den entsprechenden Führungen der Abpackmaschine werden sie also in der gewünschten Weise nach außen gezogen; sogar ein anfänglich umgeklappter, dem Einschnitt benachbarter Tütenabschnitt wird wieder zurückgeklappt.

In practice, it has been shown that in a bag belt, in which the bags are provided with the incision at the rear edge according to the invention when they are being packaged, they are opened and inflated very safely by the flow of air. There are probably two reasons for this:

• In the known bag belts, the sections of the bags adjacent to the incisions are pushed and are braked by frictional forces which are caused by the machine guide supporting the bags. There is a risk that these sections of the bag will turn over. The bag is then just folded up at the part of the filling opening where the opening by the air flow is to begin. In the case of the bag belt according to the invention, however, the bag sections adjacent to the incisions are dragged. By friction on the corresponding guides of the packaging machine, they are thus pulled outwards in the desired manner; even an initially folded bag section adjacent to the incision is folded back again.

In the very first phase of inflation, part of the rear wall section of the bag adjacent to the incision is initially increasingly pressed against the machine guide located behind by the inflowing air. In the known bag belt, in which this section of the bag rear wall is pushed under friction, this leads to a force counteracting the opening movement. In the case of the bag band according to the invention, in which the corresponding wall section is drawn, such a force that prevents the bag from opening does not occur.

Advantageous developments of the invention are specified in further 'claims.

In the case of a bag band according to claim 2, the individual bags can be cut off within a tolerance range of the same material thickness. The dimensions of this tolerance range are specified in the development of the invention according to claim 3 by the dimensions of the gaps, in the development of the invention according to claim 4 by the dimensions of the further incision.

In a bag band designed according to claim 5, the opening of the bag can be ensured even under very unfavorable conditions in that an air jet directed perpendicular to the exit plane reaches the front wall of the bag through the perforation of the bag and thus lifts it off the rear wall.

If the opening according to claim 6 is provided at the end of the incisions, it can be easily produced together with these and at the same time closes off the incisions so that they no longer tear under tensile forces, since at the end of the incisions there is no longer any notch effect .

A bag band according to claim 7 has a single-layer carrier tape. In the known bag tapes, the carrier tape consists of two layers welded together. However, welding these two layers means additional effort, and nevertheless they can still move against each other under unfavorable transport conditions, which leads to irregularities in the operation of the packaging machine.

A double bag band according to claim 8 can be wound particularly well into a roll, since it has the same thickness over the entire width and is continuous. At the place of use, the double bag band can easily be divided into two separate bag bands by mechanical forces. ,

With the development according to claim 9 it is achieved that a still slightly resilient bond between the two bag bands is obtained, but the two bag bands can also be easily separated from each other.

If the individual bags in the packaging machine are not cut off exactly at the level of the incisions running in the longitudinal direction of the web in the case of bag bands, it can happen, especially in the case of bags filled with heavy goods, that the bags are still connected to the carrier tape by a narrow strip of material towards the end of the cutting process , which is formed by the film section lying between the cutting line and the incision. Although this is not a nuisance for many applications, in particular when packing heavy goods and when working at high speed, there may be malfunctions in the guidance of the carrier tape and the bags.

A bag band according to claim 10 is developed so that even when the cutting line is not exactly aligned with the incisions, the bags are properly separated and the carrying tape is guided properly, even if the bag band is filled with heavier goods or is running at high speed .

The flawless separation of the bags is thus achieved without additional effort in the production of the bag band, since it makes no difference in terms of cost whether the incision made by a rotating knife or separating welds which one the inflation of the bags is promoted, and is additionally provided with an angled section which is essentially transverse to the longitudinal direction of the web.

In the bag band according to claim 10, regardless of the respective transverse position of the cutting line within a predetermined cutting area, all bags are cut off equally when the cutting line reaches the assigned transverse section of the incision favoring the inflation. When the orientation of their longitudinal axis, which is generally used during packaging, the bags then fall off under exactly reproducible conditions, in particular under a given orientation. This orientation is closer to the original orientation of the bags in the bag band than with a bag band without an angled section 30a.

With the development of the invention according to claim 11, a particularly wide cutting area is obtained, within which the transverse position of the knife used for cutting the bags can fluctuate, without this having an influence on the cutting of the bags.

With the development of the invention according to claim 12 it is achieved that in the packaging machine when cutting the individual bags in addition to the rewound to a roll of the carrier tape and the separated bags, there are also no additional film sections which would have to be removed separately.

With the method according to claim 13, bag tapes can be produced in which the individual bags follow one another at a short distance and are closed at the bottom.

If the incisions are made according to claim 14 using cutting knives, it is ensured that the filling opening of the bags opens reliably when air flows against them.

With the development of the invention according to claim 15 it is ensured that the incision goes through to the rear edge of a bag in any case. If a web remains at the rearmost point of an incision, the bag cannot bulge out of the starting level, just as if no incision were provided at all.

The method according to claim 16 is suitable for the simple production of a double bag band, the edge sections of the film webs projecting beyond the overlap area each forming support sections for a finished bag band.

The double-bag band obtained by the process according to claim 16 can either be put on the market as such or, according to claim 17, be broken at the separating welds and broken down into two simple bag bands.

A device as specified in claim 18 only requires a single control device for the cutting units which produce the incisions in the nested bag sets.

A device according to claim 19 is particularly well suited for the continuous production of a bag band.

With the development of the invention according to claim 20 it is achieved that the two simultaneously created bag bands by attacking perpendicular to the common starting plane Forces are separated without exerting any significant tensile loads on the bags themselves, which could distort the bags made of very thin film. Another advantage of the device according to claim 20 is that the two bag tapes are also spatially separated after the predetermined separation points have been broken open.

• Fig. 1 eine Aufsicht auf einen Abschnitt eines ersten Tütenbandes, das geschlossene, eng aufeinander folgende Tüten aufweist;
• Fig. 2 eine Ansicht eines Abschnittes eines zweiten Tütenbandes mit in Abstand aufeinander folgenden, unten offenen Tüten zum Abpacken von Blumen;
• Fig. 3 einen ersten Herstellungsabschnitt des Tütenbandes nach Fig. 2;
• Fig. 4 einen zweiten Herstellungsabschnitt des Tütenbandes nach Fig. 2;
• Fig. 5 eine schematische Ansicht einer Maschine zum Herstellen des Tütenbandes nach Fig. 2;
• Fig. 6 eine Abwicklung der Mantelfläche einer Schweißtrommel der Maschine nach Fig. 5;
• Fig. 7 eine Abwicklung der Mantelf.läche einer Trenntrommel der Maschine nach Fig. 5;
• Fig. 8 eine erste Ausführungsform eines Tütenbandes ' aus Kunststoffolie, bei dem das Aufblasen der Tüten begünstigende Einschnitte zusätzlich mit einem transversalen Abschnitt versehen sind; und
• Fig. 9 ein ähnliches Tütenband wie in Fig. 8 dargestellt, wobei jedoch zusätzlich die in Abpackrichtung hinter den transversalen Einschnitten liegenden Folienteile entfernt sind.

The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawing. In this show:

• Figure 1 is a plan view of a portion of a first bag band, which has closed, closely consecutive bags.
• 2 shows a view of a section of a second bag belt with spaced successive, open bottom bags for packaging flowers;
• 3 shows a first manufacturing section of the bag band according to FIG. 2;
• FIG. 4 shows a second production section of the bag band according to FIG. 2;
• 5 shows a schematic view of a machine for producing the bag band according to FIG. 2;
• 6 shows a development of the lateral surface of a welding drum of the machine according to FIG. 5;
• 7 shows a development of the jacket surface of a separating drum of the machine according to FIG. 5;
• 8 shows a first embodiment of a bag band made of plastic film, in which incisions favoring the inflation of the bags are additionally provided with a transverse section; and
• FIG. 9 shows a bag band similar to that shown in FIG. 8, but additionally the film parts lying behind the transverse incisions in the packaging direction have been removed.

Fig. 1 shows an endless belt of bags consisting of a carrier tape 2 and successive bags 4, which are integrally formed with their rear wall on the single-layer carrier tape. The front wall 6 of the individual bags ends in an upper edge 8 which limits the later filling opening of the bag. The bags 4 are divided by separating welds 10, which end with a section 10a a predetermined distance above the upper edge 8 of the bags. In this way, a cut-off area 12 with the width W indicated in the drawing is obtained for each bag, within which the bags can be cut at any point by a cutting device (not shown) of the packaging machine. The cutting area, like the carrier tape itself, has one layer, so that when the individual bags are cut from the carrier tape, the cutting conditions are constant and good.

In the part of the cut-off areas 12 lying at the rear in the conveying direction when packing, incisions 14 are provided which extend horizontally over approximately a third of the bag width and are slightly extended beyond the subsequent separating weld 10. In this way it is achieved that the upper edge of the bags with an essentially in the flow from above can open air flow 16 lying through the bags predetermined starting level and can assume oval shape or the shape of a flattened circle, as indicated in the right part of FIG. 1.

For particularly unfavorable inflow conditions, e.g. B. long and narrow bags, or when using bag tapes made of such films that adhere well to each other, a hole 18 is additionally provided in the rear wall of the bags through which a not shown sharp air jet directed from the back of the bag to the front wall of the bags can be, whereby this is lifted somewhat and thus offers the air flow 16 lying in the bag plane a larger area of attack. In this way, the air flow 16 can more easily open the bag. The holes 18 are preferably arranged at the inner end of the incisions 14, that is to say at a central section of the upper edge 8.

• In eine Folienbahn, deren Breite gleich der des Tragbandes plus der doppelten Tiefe der Tüten ist, werden die Einschnitte 14 und die Löcher 18 mit exzenterbetätigten Stanzmessern eingeschnitten. Dann wird der untere Bahnabschnitt zur Bildung der Tütenvorderwand hochgeklappt und die Trennschweißungen 10 werden um die Strecke W bis über den oberen Rand der Vorderwand 6 hochgezogen, was z. B. mit einer Schweißtrommel mit entsprechend langen Schweißrippen erfolgen kann. Dann werden die äußeren Enden der Einschnitte 14, über die die Trennschweißungen hinweggeführt sind, sicherheitshalber noch einmal aufgebrochen, was durch Zusammenarbeiten der Rollen mit komplementärem, V-förmigem Profil erfolgen kann. Wo Löcher 18 nicht benötigt werden, erfolgt das Erzeugen der Einschnitte 14 einfach erst nach dem Erzeugen der Trennschweißungen, wodurch sichergestellt ist, daß die hinteren Enden der Abschnitte 14 völlig offen sind. Man kann auch zuerst nur die Löcher 18 einstanzen, dann die Trennschweißungen 10 durchführen und zuletzt die Einschnitte 14 anbringen.

The bag band shown in FIG. 1 can be produced as follows:

• The incisions 14 and the holes 18 are cut into a film web, the width of which is equal to that of the carrier tape plus twice the depth of the bags, with eccentrically operated punching knives. Then the lower web section is folded up to form the bag front wall and the separating welds 10 are pulled up by the distance W up to the upper edge of the front wall 6. B. can be done with a welding drum with appropriately long welding ribs. Then, for safety's sake, the outer ends of the incisions 14, over which the separating welds are guided, are broken open again, which is achieved by the roles of the rollers working together complementary, V-shaped profile can be made. Where holes 18 are not required, the cuts 14 are simply made only after the separating welds have been made, thereby ensuring that the rear ends of the sections 14 are fully open. You can also just punch holes 18 first, then carry out the separating welds 10 and finally make the cuts 14.

The bag band thus produced has bags closed at the bottom, which z. B. are suitable for filling bulk goods.

FIG. 2 shows a bag band suitable for packaging flowers with a carrying band 20 and successively spaced bags 22. The rear wall of the bag is molded onto the single-layer carrying band 20 via projecting, discrete hanging sections 24. The width of the latter perpendicular to the longitudinal axis of the strip is again designated W. In this way, the bags can again be cut off from the carrier tape within a tolerance range in the single-layer material. The front wall 26 in turn ends in an upper edge 28 which limits the filling opening of the bags. Incisions 30 are provided in the discrete suspension sections 24 at the rear end. Partition welds 32 are inclined to the longitudinal direction of the tape, so that the individual bags have a frustoconical shape after inflation. The bags are open at the bottom, with the lower edge 36 of the rear wall of the bag lying a distance W above the lower edge 38 of the front wall of the bag.

The manufacture of the bag band according to FIG. 2 will now be discussed with reference to FIGS. 3 and 4.

Two equal-width sheets of polyethylene or PVC with a thickness of about 2g (maximum thickness 50n) are brought together offset from one another by the width of the carrier tape. Thereafter, the separating welds 32 are carried out, some of which have sections 44 and 46 guided through single-layer material. For the sake of clarity and for a better correlation with FIG. 2, the opposite direction is shown as the conveying direction in the production of a bag tape supply roll as is the conveying direction during packaging. Of course, the direction of conveyance during production can also be selected to be the same as when packing, especially if you want to couple a machine for producing a bag band directly to a packaging machine, in which case the bag band is then not wound up into a roll.

In the production of a bag band roll shown in the drawing, the incisions 30, as seen in the production conveying direction, are produced in the front in the suspension sections 24. When the bag band is unwound again from the roll, they lie in the rear part of the suspension sections 24, as seen in the packaging conveying direction. The incisions 30 are in turn slightly extended beyond the adjacent separating weld.

The thus obtained, still coherent double bag band, in which the corresponding parts are provided with corresponding, but provided with a comma, can be put on the market as such, in order to be later broken up into two bag bands along the separation welds at the place of use and then to supply two packaging machines simultaneously. The double bag belt can also be pulled apart during manufacture and wound up into two separate supply rolls.

FIG. 4 schematically shows a machine for producing two separate bag tapes starting from two plastic films according to the method described above with reference to FIGS. 3 and 4.

The two film webs 40, 42 are drawn off from two supply rolls 48, 50, which are already offset with respect to one another by the width of the carrier tape. The two film webs then run together in the roller gap between a welding drum 52 and a counter drum 54 coated with heat-resistant rubber. The film webs welded to one another in a line then run through between a cutting drum 56 and a counter drum 58 associated therewith. The cutting drum 56 is provided with knives at the locations assigned to the incisions 30, its counter drum with corresponding counter knives.

The welded and incised film webs then run through a pair of separating drums 60, 62 which pull the two bag bands apart using a force directed perpendicular to the film web. This is done in such a way that the bag band lying at the top in FIG. 4 is pressed down. This bag band is then deflected further downward and wound up in an essentially unchanged orientation to the bag band roll 64. The bags are supported by a support plate 66.

The band of bags lying at the bottom in FIG. 4 is pulled off upwards, the bags initially being supported by a helical support plate. The bags slide overall upwards on it, but the bag ends are increasingly lowered with respect to the assigned carrying band section. There, where the bags of the upward torn tape no longer come into contact with the lower one _T bag band can occur, the support plate 68 ends, and by a further helical support plate 70, the bags are raised in the same direction of rotation as in the previous lowering, the support band itself being correspondingly limited. At the end of the support plate 70, the bags of the bag strip pulled upwards are aligned exactly like those of the bag strips pulled downward, only they are offset laterally from above, essentially by the width of the bag belt. The upwardly withdrawn bag band is wound up into a bag band roll 72 which is offset laterally to the lower bag band roll 64.

Fig. 6 shows a development of the outer surface of the welding drum 52. One recognizes welding ribs 74 placed on the outer surface. B. inserted into the drum body, provided with welded rods, which are electrically heated.

FIG. 7 shows the development of the outer surface of one of the separating drums, projecting outer surface sections 76 being shown in stippled form, while recessed outer surface sections 78 are not particularly marked. The other separating drum has a precisely complementary shape and meshes with the first separating drum like a gear. In this way, the double bag band is so heavily stressed as it passes through the separating drums on the separating welds perpendicular to the plane of the web that the separating welds break through. The two bag bands obtained thus run out of the pair of separating drums at different heights.

As is symbolically represented in the drawing by dashed lines, the welding drum, the cutting drum and the separation drum as well as the ones assigned to them Counter drums synchronously driven by a common drive. The preset phase difference in the angular position of the various drums corresponds to their center distance, viewed in the direction of production, divided by the drum radius.

Figures 8 and 9 show modified bag tapes, in which the incisions 30 are additionally provided with a transverse section. In these exemplary embodiments, parts which already correspond to the parts described above with reference to FIGS. 2 to 4 are provided with the same reference symbols.

FIG. 8 shows a bag band suitable for packaging flowers with a carrier tape 20 and bags 22 which follow one another at intervals. The rear wall of the bag is in each case molded onto the single-layer carrier tape 20 via transversely projecting discrete suspension sections 24. Between these suspension sections 24 there are reduced width supporting tape sections 24a, the lower edge of which is designated 24b in the drawing.

A front wall 26 of the bags 22 ends in an upper edge 28, which limits the filling opening of the bags. In the drawing, the direction in which the bag band is moved during packing is indicated by an arrow 29. In the ends of the discrete suspension sections 24 which are at the rear with respect to the packaging conveying direction, incisions 30 are provided which facilitate the inflation of the bags when they flow against them with an air flow which runs transversely to the longitudinal direction of the web and which in the drawing is directed from top to bottom. Lateral edges of the bags formed by separating welds 32 are inclined to the longitudinal direction of the tape, so that the individual bags have a frustoconical shape after inflation. The bags are open at the bottom, the lower edge 36 of the bag rear wall being a distance above the lower edge 38 of the bag front wall which is equal to the distance of the upper edge 28 of the front wall 26 from the edges 24b.

The incisions 30 have at the end adjacent to the middle of the bags a subsequent, in the transverse direction to the free edge of the carrier tape 20, i. H. in the drawing, section 30a which extends slightly above a straight line connecting the edges 24b.

In the drawing, the transverse distance between the edges 24b of the reduced-width supporting tape sections 24a and the incisions 30 is designated by W. The knife used to cut the bags can be in any transverse position within the cutting range thus predefined, without this having any influence on the time at which the bags were cut off or on the orientation with which the bags are released from the carrier tape. The bag band therefore does not need to be precisely adjusted with respect to the knife. In the case of a bag band, as is usually used for packaging flowers, the bags have a height of approximately 40 cm, the distance W is approximately 20 mm and the width of the narrow carrier tape sections 24a is likewise approximately 20 mm.

The embodiment of a bag band shown in FIG. ₉ is almost completely the same as that shown in FIG. 8. Only the edges 24b are drawn through to the upper end of the sections 30a of the incisions 30. In this way, when the bags 22 are cut off, there are no small film sections, as is the case with the exemplary embodiment according to FIG. 8, if at the same time a part of the section through the incision 30 and the section adjoining it is made by the knife 30a limited film tab is separated.

In practice, with the bag tapes shown in FIGS. 1 and 2 with the dimensions given above at a speed of 12 m / min. to be worked well. From the construction of the bag belt, speeds of 30 to 40 m / min. achievable, however, such high packing speeds are generally not required when the bags are filled manually with a product.

Claims (20)

1. bag belt with at least one continuous carrier tape and on this hanging successive bags, which are provided at the top edge of the bag with a substantially in the longitudinal direction of the incision, characterized in that the incisions (14; 30) seen in the conveying direction of the bag band when packing at rear edge of the bags (4 '; 22) are provided. 2. Bag band according to claim 1, characterized in that the incisions (14; 30) are each formed in a lower, an extension of the rear bag wall, projecting from the actual continuous carrier tape, discrete hanging section (12; 24). 3. Bag band according to claim 2, characterized in that between adjacent suspension sections (24) there are spaces (44). 4. Bag band according to claim 2, characterized in that adjacent suspension sections (12) are separated from one another by a further incision (10a). 5. Bag band according to one of claims 1 to 4, characterized by at least one opening (18) formed in the rear walls of the bags (4). 6. Bag band according to claim 5, characterized in that the openings (18) are at the end of the incisions (14). 7. Bag band according to one of claims 1 to 6, characterized in that the carrier tape (2) represents a single-layer extension of the rear bag wall. 8. bag band according to one of claims 1 to 7, .d characterized in that it has two transversely opposite carrier tapes (20; 20 ') carrying comb-like interlocking bags (22; 22') and that the carrier tapes and Bags of the two sets are held together to form a web via predetermined separation points (32). 9. bag band according to claim 8, characterized in that it consists of weldable plastic material and the predetermined separation points are separating welds (32). 10. Bag band according to one of claims 1 to 9, characterized in that the incisions (30) have a section (30a) extending in a substantially transverse direction to the free edge of the carrier tape (20). 11. Bag band according to claim 10, wherein the carrier tape has sections of reduced width lying between the bags, characterized in that the ends of the transverse sections (30a) of the incisions (30) essentially with the edges (24a) delimiting the narrower carrier tape sections (24a) ) are aligned or slightly extended beyond them. 12. Bag band according to claim 11, characterized in that the edges (24b) delimiting the narrower support band sections (24a) are carried out up to the transverse sections (30a) of the incisions (30). 13. A method for producing a bag band according to one of claims 1 to 12, characterized in that a film web of plastic material is folded in the longitudinal direction of the web so that the longitudinal edge of one axial web section lies at a distance from the longitudinal edge of the other axial web section, which the Width of the carrier tape corresponds to the fact that separating welds are carried out essentially transversely to the longitudinal direction of the folded web, which are led beyond the longitudinal edge of the first axial web section, and that in the transverse region between the ends of the transverse separating welds and the first longitudinal edge, the incisions in the Direction of conveyance during the manufacture of the front and in the conveying direction during the packaging of the rear section of the bags. 14. The method according to claim 13, characterized in that the incisions are produced by cutting. 15. The method according to claim 13 or 14, characterized in that the incisions are made slightly beyond the next adjacent separating weld. 16. A method for the simultaneous production of two bag tapes according to one of claims 1 to 12, characterized in that two film webs of plastic material are merged transversely offset from one another by the width of the carrier tape and that separating welds with a transverse component are guided beyond the overlap area of the film webs. 17. The method according to claim 16, characterized in that the double bag band is broken up to form two individual bag bands on the separating welds. 18. Device for performing the method according to claim 16 or 17, characterized by a cutting device for producing the incisions on the two bag sets, which has offset in the conveying direction by half a periodicity interval, at the same time periodically operable cutting units. 19. The apparatus according to claim 18, characterized in that the cutting units have circumferential cutting knives (56, 58). 20. The apparatus of claim 18 or 19, characterized by a pair of separating drums with the bag tapes respectively assigned raised or recessed lateral surface sections (76, 78).

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