DE2852258A1 - Thermoplastic foil bags made as continuous strip - on machine where rotating drum has heated ribs making continuous weld between foils - Google Patents

Abstract

Two strips of foil are fed from spools onto a conveyor belt travelling continuously underneath a continuously rotating welding drum, which makes a profiled weld between the two foils. The drum is fitted with U-shaped ribs with perforated arms welded to the periphery of the drum. Each leg of the ribs pref. has a longitudinal groove contg. electric insulation and then a strip-shaped heating element employed to make the weld. The insulation is pref. a glass with high m.pt.; and a glass with lower m.pt. is pref used to locate the heating element in the insulation. The drum is pref. fitted with electric contact rings sliding on fixed contacts in the machine frame to supply power to the heating elements. The invention provides a machine making continuous bag strip at 2-10 metres/sec.

Description

Device for the production of bags

ribbons Description The invention relates to a Device for the production of cone tapes according to the preamble of the claim 1.

So far, bag tapes have been made by having two sheets of film transversely offset against each other and moved intermittently into a welding station, which has a welding head that can be displaced perpendicular to the plane of the film webs.

This intermittent work is, however, for the production of Conveyor belts with a large number of items per unit of time are not suitable. Appropriate Devices also require complicated step conveyors and also work with them relatively high noise development, which indicates the frequent reversal of movement of Is due to machine parts.

The present invention is intended to provide a device according to the preamble of claim 1 are developed so that a continuous production of Conveyor belts is possible.

Based on what is considered in the preamble of claim 1 In the prior art, this object is achieved according to the invention with the characteristics shown in FIG of claim 1 specified features.

With the device according to the invention can belts in high Number of pieces with web speeds of 2 up to 10 m / s easily produced will. The same alignment problems arise. When moving intermittently Welding heads, however, must have a very precise step-by-step conveying de eolienbahnen be ensured so that the front of the welding lines to be generated and the back of the weld lines that have already been created butt cleanly against one another. the Set-up times and adjustment work are in accordance with the invention contraption considerably shortened compared to the known devices for the same reason. The manufacture of the welding drum is compared to the manufacture of a flat one Welding head only marginally expensive; when driving the welding head and when Conveying for the film webs is, however, in the device according to the invention achieved a considerable saving in terms of equipment.

Advantageous further developments of the invention are set out in the subclaims specified.

With the development of the invention according to claim 2 it is achieved that the welding ribs have a smooth, continuous outer back and nevertheless can easily be bent in such a way that they are inclined at any desired angle Follow the direction of the curvature of the drum body to a surface line.

Recesses, as specified in claim 3, can be particularly simply by drilling. They also have the advantage that the free ends of the arms lying between the recesses are relatively long, so that one a larger joint area between each of the arms and the drum body is obtained.

With the development of the invention # according to claim 4 is simple Way an electrical insulation between a current-heated resistance heating element and the drum body. The resistance heating element, which is used with the Foil webs cooperating active back of the welding ribs is generated the heat exactly where it is needed for welding.

With the development of the invention according to claim 5 it is achieved that when embedding the heating element no careful positioning must be made to ensure that the heating element does not touch the welding rib. The electrical insulation is already through the as first applied layer of glass material that melts at high temperatures ensured that by melting down the heating element using low-melting glass frit is no longer impaired.

While you have a weld line pattern, which is through a can produce a single meandering weld rib, even with a single one Heating element gets by, one can weld line patterns, which star-shaped branch points and having free ends of weld lines, with a device according to claim 6 generate.

With the development of the invention according to claim 8 it is achieved that the heat radiation through the large surface area of the drum body is small. So you can keep the required heating power small and get further Advantage that the drum body even under stationary running conditions up to heats up close to the temperature of the heating elements. You can therefore on the drum body attach even thermally conductive rod-shaped welding bodies, which also through the heat insulating layer are passed through and are used at predetermined Make spot welds on the film web.

In a device according to claim 9, the welding drum has a particularly good thermal insulation; Asbestos foam can also be used very precisely in situ apply the desired shape.

In a device according to claim 10, the film webs are at of the welding drum by the continuous conveyor precisely at the desired peripheral speed fed to and removed from the welding drum, while at the same time represents is that the welded cone belt does not get stuck on the belt conveyor, but rather easily separates from this.

With the development of the invention according to claim 11 it is achieved that the foil strips when welding snugly against the welding ribs of the welding drum be pressed. The welding takes place under the influence of heat and pressure, what is very important especially for the creation of separating welds.

In a device according to claim 13, the film webs lift off the welding drum by swiveling the belt conveyor when the machine for changing the supply rolls or the take-up roll or for maintenance purposes is stopped. Since the welding drum has a greater heat capacity, can you cannot prevent by simply switching off the heating current in this case that the film webs are locally severely overheated. The lifting of the film webs from the welding drum by pivoting the belt conveyor, however, can be very short-term take place.

With the development of the invention according to claim 14 on the one hand a large lifting path of the belt conveyor obtained from the welding drum, on the other hand arise at the upstream end of the belt conveyor, where at the same time also the Drive drum is arranged with a high wrap angle, no noteworthy Changes in the leadership of the.

Foil web In a device according to claim 17 one obtains a Drive drum for conveying the film webs with a high wrap angle, including but only one additional leadership role is required.

With the development of the invention according to claim 18 is achieved, that the film webs as they run onto the belt conveyor are fed up against the conveyor belt be pressed. So there is no slippage and no wrinkling.

With a device according to claim 19, bag belts can easily be made produce, which have a double-layered fastener tape. Folding the edges of the film web takes place practically without additional equipment expenditure using an already existing one Pulley.

For a clean welding of the foil webs it is important to that these lie flat against each other and on the belt conveyor. One such concern would be affected by electrostatic charges on the film webs, like them can be generated by slipping and rubbing the film webs against one another.

In a device according to claim 20 and claim 21.

such electrostatic charges are generated before welding of the foil strips and dismantled before the finished strip of cones is wound up.

In a device according to claim 22, the welding drum particularly easy to remove from the device and wait or against another Replace the welding drum with a welding rib arrangement with a different geometry.

The fixing of the shaft stubs of the # welding drum in the bearings Stub shafts are particularly simple according to claim 23.

The synchronous conveying of the film webs in the device takes place particularly advantageous according to claims 24 to 27 and 29. With the specified there Measures is a precisely synchronous supply and removal of the film webs to and ensured by the welding drum.

With the developments of the invention according to claims 28 and 30 it is ensured that in the fed film webs and in the withdrawn bag tape a small tension is maintained.

In a device according to claim 31 it is ensured that also large diameter winding unwound in a precise transverse position are or are wound up without the end faces of the winding overlapping Flanges of the winding cores are required.

In a device according to claim 32 it is ensured that the Welding ribs and the drum body are essentially the same when the temperature changes Experienced dimensional changes, so that no thermal stresses in the welding drum appear.

The method specified in claim 33 is therefore particularly advantageous, because the welding ribs are exactly along the desired course on the jacket surface of the drum body can adapt to the corresponding contour of the drum body.

According to claim 34, this adaptation is preferably carried out successively Fasten and re-bend the arms of the welding fins.

The longitudinal groove for inserting the heating element is created according to claim 34, preferably as the very first processing step on the starting material strips of material used for the welding ribs. The strip of material then has still the greatest bending stiffness, so that the longitudinal groove is with great accuracy can be milled.

In the method according to claim 36 it is ensured that all walls the longitudinal groove equally with at high temperatures melting Glass coated.

With the development of the invention according to claim 37 it is ensured that the previously obtained glass insulation of the walls of the longitudinal groove can no longer be damaged when melting down the resistance heating elements.

With the development of the invention according to claim 38 it is enough that the active welding surfaces of the welding drum all on a common cylindrical Area, which in turn is exactly coaxial with the axis of rotation of the welding drum.

The invention is based on a Ausführungsbei game explained in more detail with reference to the accompanying drawing. In this show: 1: a longitudinal section through a machine for the continuous production of Bag tapes; Fig. 2: a perspective view of the welding drum in Fig. 1 shown machine; 3: a schematic representation shown in development of the band-shaped resistance heating elements of the welding drum according to FIG. 1, wherein the series connection of the heating elements and their connection with contact rings of the welding drum are shown in more detail; 4: a transverse section through a welding rib.

the welding drum; Fig. 5: a transverse section through a Section of a frame plate of the machine in which a stub shaft is mounted is the end of the sweat drum carries; and Fig. 6: a Section of the finished belt of cones as produced by the machine according to FIG. 1 will.

Fig. 1 shows a machine for the continuous production of cone tapes with two frame plates 10, which over a plurality of solid transverse rods 12 are firmly connected to each other. These rods are arranged so that of both At the ends of the machine there is free access to supply rolls 14a and 14b and to one Take-up roll 16 consists.

The supply rolls 14a and 14b each consist of a winding core 18a or 18b and a thermoplastic roll 20a or 20b located on the latter Plastic film.

The supply rolls 14 each rest on one seen in the conveying direction upstream support roller 22a or 22b and a downstream support roller 24a or 24b. The support rollers 22 and 24 are each axially adjustable fixed with pairs Collars 26a and 26b, respectively, through which the end faces of the supply rolls 14 are positioned. The collars 26a are axially offset with respect to the collar 26b, so that the film webs 28a and 28b withdrawn from the supply rolls 14a and 14b, which both run over a first pulley 30 of the machine, each other in one overlap the middle area, which will later be the front wall and the rear wall of the Forms bags, while the edge areas remain a single layer.

The pulley 30 fixed to the frame is arranged so that the Point of departure of the film webs 28a and 28b from the supply rolls 14a and 14b for full Supply rolls in front of the contact point between the supply rolls and the downstream ones Support rollers 24 is and this point of contact when unwinding the film webs approaching.

From the deflection roller 30 the laterally offset one above the other run Foil webs 28a and 28b down to a further deflection roller 32. This carries axially arranged at an adjustable spacing collar 34. By the latter the lateral single-layer sections of the film webs 28a and 28b partly by 90a pushed out of the plane of the film webs and out of this with respect to the elastic Energy unstable position fold the bent film web sections 36 with reduction of the elastic energy by a further 900 μm, so that one at the lateral edges of the Foil webs also receive a double layer, but which is made of the material one only one of the film webs 28a and 28b.

These double layers later each form a support tape (see FIG. 6) 37, on which successive bags 38 of the conveyor belt hang. Behind the pulley 32, the film webs 28a and 28b run between two UV radiators 40 and 42, which each consist of a light stick and a curved reflector. on in this way, electrostatic charges are removed from the film webs, which when pulling from the supply rolls by slip between the conveyed under train Foil webs have been produced.

The film webs run behind the UV radiators 40 and 42 over a further pulley 44 on a drive drum. 46, which it over a large Wrap around corners. The film webs are behind the drive drum 46 taken over by a total of 48 designated belt conveyor. This one has one upstream, the drive drum 46 adjacent guide drum 50 and a downstream Deflection drum 52, which are mounted in a frame 54. This in turn is over the axis of the deflecting drum 50 is mounted pivotably on the frame plates 10. A conveyor belt 56 runs over the pulleys 50 and 52 from a welding pad suitable fabric, on which the material of the film webs also in plasticized state does not adhere well.

The film webs 28a and 28b run carried by the conveyor belt 56 under a welding drum designated overall by 58. At this point are the film webs and the upper run of the conveyor belt 56 by a pressure roller 60, which is also supported in the frame 54. The pressure roller 60 has a thick pad 64 made of silicone rubber.

The welding drum 58 is shown only schematically in FIG Welding ribs 62 made of stainless steel, which are also made of stainless steel Drum body 66 are firmly welded. The one between the welding ribs 62 The surface of the drum body 66 is covered by a layer 68 of asbestos foam. Details of the welding drum 58 will be given later with reference to FIG described in more detail.

For moving the frame 54 between the working position shown in FIG and a rest position in which the belt conveyor 48 and the pressure roller 60 and thus also the film webs 28a and 28b lifted down from the welding drum 58 Are, a fixed to the frame plate 10 electromagnet 70 is provided which works on the frame 54 via a rod 72 hinged to it and to the frame 54.

A tension spring 74 for biasing the frame 54 into the working position acts as a shoulder 76 of the rod 74 and a pin 78 fixed to the frame shown.

In order to improve the entrainment of the film webs by the belt conveyor 48 and the formation of creases when the film webs run onto the belt conveyor 48 Avoid is in the one formed by the pulley 44 and the pulley 50 Nip a massive roller 80 arranged freely movable, which under their weight without sliding on the surfaces of the pulley 44 and the pulley 50 or rolls on the film web sections carried by these.

Behind the welding drum 58 they run to a double bag belt welded film webs 28a and 28b over a further deflection roller 82, the outer surface of which with the belt conveyor 48 lowered into the rest position with the upper run of the conveyor belt 56 aligns. The belt of bags runs from the deflection roller 82 between two UV lamps 84 and 86, each consisting of a light stick and a curved Consist of reflector. The ribbon of bags is then wound onto the take-up roll 16. The latter rolls again on support rollers 88 and 90 with the axial position of the origin Wrap defining collar 92.

There is one behind the frame plate to drive the entire machine 10 seated common electric motor with flanged reduction gear provided, which works directly on the drive drum 46 and via an additional reduction gear, whose reduction factor is the diameter ratio of the drive drum 46 and Welding drum 58 corresponds to the welding drum 58 drives. The drive drum 46 carries a gear that meshes directly with an identical gear, which of the return drum 50 of the belt conveyor 48 is carried. The tail pulley 50 has the same diameter as the drive drum 46. The drive drum gear 46 additionally meshes with a gearwheel which is connected to the deflection roller 44. The latter has a diameter that corresponds to the diameter of the drive drum 46 and the Deflection drum 50 is different (as in the embodiment shown here, whereby the angle of wrap of the drive drum 46 is increased), so it has Your connected gear has such a number of teeth that the same peripheral speed is obtained as with the drive drum 46.

The pulleys 30, 34 and 82 each have the same diameter like the pulley 40 and are driven by this by a common toothed belt drive driven, as are the support rollers 22 and 24 as well as 88 and 90. The support rollers 22 and 24 but have a slightly smaller diameter than the deflection roller 44, whereby the film webs withdrawn from the supply rolls 14a and 14b under tension being held. The support rollers 88 and 90 have slightly larger diameters as the deflection roller 44, whereby in the finished cone belt downstream of the welding drum 58 a low tension is maintained and a clean, wrinkle-free Winding up of the cone belt is ensured.

As can be seen from FIG. 2, they have on the drum body 66 welded welding ribs 62 facing the outer surface of the drum body 66 and arms 94 welded there, between which circular recesses 96 lie. The welding ribs can be attached to the webs 98 remaining above the recesses 96 62 relatively easily around an axis that is perpendicular to its broad side as well as about axes lying in their plane. The first option the bend is required to adapt to curved surfaces, e.g. for bending to an annular segment 100 perpendicular to the welding drum axis or to die to a helical segment 102. Of the second possibility the bend is used on the kink line between segments of the weld ribs made, e.g. at the kink line 104.

Axially outside of the segments 100 extending in the circumferential direction carries the drum body 66 has two contact rings 106 and 108, over which the current becomes band-shaped Resistance heating elements 110 are supplied, which are embedded in the welding ribs 62 are. A heating element 110 extends over a segment 100 and a segment 102 a welding rib 62 and is with wires at both ends 112 or 114 e.g.

connected by brazing.

As can best be seen from FIG. 3, they are geometrically equivalent Heating elements 110 'and 110 "are electrically connected in series via wires 112 and The beginning and end of each series circuit are connected via wires 114 one of the contact rings 106 and 108 connected. In this way it is possible not only to produce meander-shaped welding lines, but also those with free end sections 116 or generally weld line patterns with star-shaped branch points. the free-ended end sections 116 are used in the bag belts when in the packaging conveying direction to produce an incision 118, seen at the rear end of the rear wall of the bag, which facilitates the inflation of the bags 38 for filling goods such as flowers.

As already stated, the outer surface of the drum body 66 is from a layer 68 of asbestos foam, in which the welding ribs 62 with Except for their outermost back. Layer 68 extends in the axial direction up to the contact rings 106 and 108. It is in the upper Part of Fig. 2 broken away in order to better show the shape of the welding ribs.

Shaft stubs 120 are provided on the end faces of the drum body 66 a square-prismatic end section 122 is placed. The latter is with one axial threaded hole 124 provided.

The storage of the welding drum 58 in the side frame plates 10 is done using stub shafts 126 and bearings 128, as shown in Fig. 5 is shown in more detail. The stub shafts 126 have an enlarged coupling head 130 with a radial groove 132, the width of which is the width of the square End section 122 of the stub shaft 120 corresponds. Through an axial bore 134 the stub shaft 126 is a not shown fixing bolt insertable with his Thread in the threaded bore 124 of a stub shaft 120 fits. In this way a welding drum 58 can be removed with the groove 132 pointing vertically upwards Remove the fixing bolt slightly upwards out of the machine and vice versa use again like this.

4 shows a transverse section through a welding rib 62. One recognizes the circular recess 96, the web 98 and remaining above it the heating element 110 having a rectangular cross section. The latter is in a longitudinal direction the welding rib 62 running groove 136 embedded in an insulated manner. For this purpose, the groove 136 provided with a coating 138 made of high temperature melting glass, and in the insulating channel thus obtained, the heating element 110 is used one that melts at relatively low temperatures and is electrically non-conductive Glass mass 140 embedded.

The heating elements 110 are made of constantan and typically have a cross section of 6 to 8 by 0.6 to 0.8 mm.

They are operated with low voltages, e.g. 10 V, e.g.

using a control transformer. Receives under these conditions one current strengths of about 40 A. The welding drum 58 thus has a relatively small power consumption, which is due to the fact that the heat radiation is kept small by the drum body 66 by the layer 68 of asbestos foam. Thus, the drum body 66 comes to a relatively high temperature during operation, whereby the heat flow through conduction away from the heating elements ~ 110 is kept small will.

That the drum body 66 heats up relatively strongly, can one can also take advantage of small spot welds through heat-conducting ones carried by it Carry out welding bodies that do not have their own heating. Such Welding bodies are e.g. in Fig. 2 in the right front half of the welding drum 58 shown at 142. The welding bodies 142 are located in the axial direction between the Segments 100 of the welding ribs 62 and the contact rings 106 and 108. Their radial Dimension corresponds to that of the welding ribs 62. They form at the ends of the Welding drum 58 each have a radial ring and are used for the double layers in the edge area of the carrier tape, which can be removed by folding down the film web sections 36 were obtained to staple together, so that a load-bearing tape is obtained whose positions cannot slip against each other.

Fig. 6 shows schematically the sequence of the production of a double-bag tape with the machine described above. The transversely offset can be seen on the left Merging of the film webs 28a and 28b, which takes place on the deflection roller 30. Folding over the film web sections 36 is shown further to the right, again further on the right are the separating welding lines produced with the welding drum 58 and tack weld points are drawn in, each with the one used for creating Welding tool belonging, additionally provided with an asterisk reference numerals Marked are. ~ The finished double-cone belt has an upper one (in the drawing) Carrying tape 37 and a lower carrying tape 37, on each of which a set of bags 38 hangs. The two bag belts, which each consist of one of the fastener tapes 37 and the associated set of bags 38 from each other separate.

The welding drum 58 can be manufactured as follows: A strip of material made of stainless steel with rectangular cross cut from the side provided with the longitudinal groove 136 by milling. Then will the recesses 96 are drilled and the webs opposite the groove 136, which the webs 98 correspond to be milled off.

Now, starting from one end, the material strips are each with an arm 94 is welded to the drum body 66.

The adjacent next section of the strip of material is then bent in the desired manner and the next arm 94 is attached to the drum body 66 welded on, etc. The individual welding bodies 142 are now welded on. Thereon the walls of the groove 136 are then covered with a glass frit compound which is used for Example of a binder that decomposes when exposed to heat and finely ground, consists of glass that melts at high temperature. The applied mass is with The welding torch is heated to the melting point of the glass, so that you get a coherent Receives glass coating. The open end of the groove 136 is directed all the way down or pointing diagonally downwards, so that by the action of gravity on the melted frit compensates for the otherwise caused by surface tension The accumulation of material caused by the melt at the edges at the bottom the groove 136 is obtained.

Then the heating elements 110 are inserted and the space between them between them and the coated groove 136 is filled with a glass frit material, the low-melting, but lead-free and therefore electrically well insulating glass contains. This material is made to flow with a Bunsen burner.

Finally, the heating elements, which were initially used excessively 110 and the weld bodies 142, initially welded on with oversize, ground, wherein the welding drum 58 is rotated about its stub shaft 120. So lie then the surfaces of the active welding elements on a cylindrical thresh Area that is exactly coaxial with the axis of rotation of the welding drum 58. When sanding over burrs obtained are usually obtained using an oil stone or the like removed.

Claims (38)

Claims 1. Device for the production of cone tapes superimposed thermoplastic film webs with a conveyor for the film webs and with a welding device for welding together and Welding through the film webs, characterized in that the welding device a continuously rotating welding drum (58) with a drum body (66) and having welding ribs (62) projecting therefrom and the conveyor device has a continuous conveyor (48). 2. Apparatus according to claim 1, characterized in that the welding ribs (62) have arms (94) separated by recesses (96) through which they are attached to the Drum body (66) of the welding drum (58) are attached. 3. Apparatus according to claim 2, characterized in that the recesses (96) are circular. 4. Device according to one of claims 1 to 3, characterized in that that the welding ribs (62) have an outwardly open longitudinal groove (136) which is provided with an electrically non-conductive coating (138) and in which a band-shaped heating element (110) is inserted. 5. Apparatus according to claim 4, characterized in that the coating (138) of the longitudinal groove (136) consists of glass material which melts at high temperatures and that the heating elements (110) of the welding fins (62) using an opposite low-melting, electrically insulating glass material in the coated groove (136) are embedded. 6. Apparatus according to claim 5, wherein some of the welding fins their ends butt against a central point of other welding ribs, thereby characterized in that the heating elements (110 ', 110 ") of the various welding fins (62) are combined in sets in series. 7. Device according to one of claims 1 to 6, characterized in that that the drum body (66) of the welding drum (58) electrically insulates contact rings from it (106, 108) which work together with sliding contacts fixed to the frame. 8. Device according to one of claims 1 to 7, characterized in that that the welding ribs (62) through one of the surface of the drum body (66) worn heat insulating layer (68) are passed to the outside. 9. Apparatus according to claim 8, characterized in that the heat insulating Layer (68) is asbestos foam applied in situ. 10. Device according to one of claims 1 to 9, characterized in that that the continuous conveyor has a belt conveyor (48) whose conveyor belt (56) consists of a welding textile material. 11. The device according to claim 10, characterized in that the Conveyor belt (56) between the welding drum (58) and - an elastic pressure drum (60) runs through, which is mounted in the frame of the belt conveyor (48). 12. The apparatus according to claim 11, characterized in that the Pressure roller (60) carries a thick pad (62) made of silicone rubber. 13. Device according to one of claims 10-12, characterized in that that the belt conveyor (48) is upstream of the welding drum as viewed in the conveying direction (58) lying axis is pivotable. 14. The apparatus according to claim 13, characterized in that the Pivot axis of the belt conveyor (48) with the axis of rotation of its upstream pulley (50) coincides. 15. Apparatus according to claim 13 or 14, characterized in that that the frame (54) of the belt conveyor (48) by a spring (74) in a working position is biased, in which the pressure drum (60) is resilient to the welding drum (58) is applied. 16. Device according to one of claims 13-15, characterized in that that the frame (54) of the belt conveyor (48) by an electromagnet (70) in a The rest position is movable in which the pressure drum (60) from the welding drum (58) is lifted. 17. Device according to one of claims 10 to 16, characterized in that that the upstream deflecting drum (50) of the belt conveyor (48) at the same time as the downstream Guide role for the film web in a working with a high angle of wrap Drive drum (46) is used, whose upstream # guide roller (44) is in the neighborhood the upstream pulley (50) of the belt conveyor (48). 18. The device according to claim 17, characterized by a massive Pressure roller (80), which under its own weight in the by the guide roller (44) and the upstream deflection drum (50) formed nip rolls. 19. Device according to one of claims 1 to 18, characterized in that that a device for turning over the edges of the film web carries a collar (34) Has deflection roller (34) which is arranged upstream of the welding drum (58). 20. Device according to one of claims 1 to 19, characterized by an upstream of the welding drum (58) arranged UV lamp arrangement (40, 42). 21. Device according to one of claims 1 to 20, characterized by a UV radiator arrangement (84) arranged downstream of the welding drum (58) 86). 22. Device according to one of claims 1 to 21, characterized in that that the welding drum (58) shaft stub (120) with prismatic end sections (122) which each form-fit into a radial slot (132) of a Stub shaft (126) can be used. 23. The device according to claim 22, characterized in that the Stub shaft (120) with a threaded hole (124) and the stub shafts (126) with a passage (134) are provided for a fixing bolt. 24. Device according to one of claims 1 to 23, characterized in that that the welding drum (58) and the continuous conveyor (48) run at the same speed. 25. The device according to claim 24, characterized in that the welding drum (58) and continuous conveyor (48) are coupled by a gear. 26 .. Device according to one of claims 17 to 24 in conjunction with claim 25, characterized in that the Drive drum (46) and the upstream pulley (50) of the belt conveyor (48) are the same Have diameter and are coupled via a pair of gears. 27. Device according to one of claims 1 to 26, wherein the supply rolls for the film webs on two parallel, spaced-apart support rollers rest, characterized in that in each case at least the downstream side of the support rollers (24, 26) is driven essentially synchronously with the welding drum (58). 28. The device according to claim 27, characterized in that the Peripheral speed of the support rollers (24, 26) is slightly smaller than that of the Welding drum (58). 29. Device according to one of claims 1 to 28, wherein the take-up roll for the welded cone belt on two parallel, spaced-apart support rollers rests, characterized in that at least the downstream of the support rollers (88, 90) is driven essentially synchronously with the welding drum (58). 30. The device according to claim 29, characterized in that the Circumferential speed of the support rollers (88, 90) for the take-up roller (16) slightly is larger than that of the welding drum (58). 31. Device according to one of claims 27 to 30, characterized in that that the support rollers (24, 26; 88, 90) the axial position of the roll rolling on them wear predetermined collar (26; 92). 32. Device according to one of claims 1 to 31, characterized in that that the drum body (66) and the welding ribs (62) consist of the same material. 33. Method for producing a welding drum according to one of the claims 1 to 32, characterized in that a rectangular cross-section in the broad side having through holes are attached so that remain between the holes and the edges of the strip of material webs that one of the webs running in the longitudinal direction by removing material by cutting is removed and that so obtained, outwardly open circular recesses having strips of material are bent and with the between the recesses remaining arms are attached to the drum body. 34. The method according to claim 32, characterized in that each one arm is attached to the drum body, then the next section of the strip of material is bent towards the surface of the drum body and then also on the drum body attached, etc. 35. The method according to claim 33 or 34, characterized in that Before making the holes in the narrow sides of the material strips, longitudinal grooves be milled. 36. The method according to claim 35, characterized in that the grooves after welding the welding ribs on the drum body by melting at high Temperature melting glass frit using a welding torch with a insulating coating are provided, wQ-with the groove with its open end is aligned downwards. 37. The method according to claim 36, characterized in that the melting a heating element in the longitudinal groove by melting low-melting glass frit he follows. 38. The method according to claim 37, characterized in that the melted heating elements are ground with a cylindrical grinding machine, whereby the welding drum is rotated about its axis.