DE2515053C3 - Additional device for folding a sheet material and forming edge covers - Google Patents

Description

The invention relates to an accessory device for folding and forming a sheet material of edge covers, which can be combined with a carrier bag machine, in which one longitudinal folded web of a heat sealable arcuate Material advances continuously to a leveling roller assembly and then intermittently for the execution of the work steps for the production of the carrier bags on longitudinally spaced Workstations is moved on at the same time during corresponding rest periods, with a Frame that supports at least one supply roll of the heat-sealed web material carries and a folding device for continuous longitudinal folding of the web material.

The manufacture of carrier bags from a heat-sealable sheet material is usually accomplished by longitudinally folding a substantially continuous supply of preprinted, heat-sealable web to create what will ultimately be referred to as the front and back panels, which at a bottom fold line in each manufactured carrying bags are connected. The folded continuous web manufacturing machine supporting bag is moved forward in a longitudinally in steps corresponding to the width of each manufactured support bag, namely past egg r number of processing stations at which certain operations for manufac ^ i_ of the finished support the bag be carried out, e.g. . B. the attachment of handles, the punching of handle openings, etc. Near the end of this stepped; With the folded web moving, the overlying layers of the longitudinally folded web are simultaneously heat sealed and transversely severed to form the side edges of each carrier bag and further sever each finished carrier bag from the continuous web.

Machines for making the tote bags in this way are known and typically instructive relatively heavy elongated bed or frame on which the Can carry machining components at the corresponding machining stations that are longitudinally in Are arranged at a distance from each other, which is the width of the widest carrier bag to be produced is equivalent to. The bed also carries various guide rollers for the longitudinal advancement Web, drive rollers and compensator roller assemblies and control systems through which printed Characters on the web can be set in relation to the operations at the processing stations.

In another known type of machine (CH-PS 4 49 502) is used to manufacture bags Adhesive to the packaging web, through a cooling or drying device up to pulleys and guided by these onto a mandrel, where the bag is formed and simultaneously with a material is filled, which is introduced through the hollow mandrel. After the filling material has been introduced the bag is heat-sealed, with the lower edge of the next bag at the same time is trained. The laterally protruding edges of the packaging material web, which are on the mandrel are connected by further sealing jaws arranged parallel to the mandrel. This well-known However, the machine is only suitable for the production of a very specific type of bag and is in any case not easily combined with additional devices for performing special operations, which also applies to the type of machine explained at the beginning, assuming that expensive Changes to the machine base parts should be avoided. In this connection, the Manufacture of carrier bags with additional layers of sheet material in the form of a Envelope or cover along opposite sides of the finished tote bag opening

ίο should be provided, problems on, in particular, if such carrier bags with other elements, e.g. B. carrying handles or handle punchings or the like. Provided should be. Although it is z. B. by the US-PS 22 59 886 basically known edge covers to be applied to a material web for the production of packaging and in doing so along the material web to lead a loop-shaped path. There is also a device for applying and welding become known of edge covers on a web of material (US-PS 36 99 633), but this is not Can easily be combined with conventional carrier bag manufacturing machines because here the number of Processing stations is limited by the fixed length of the machine bed. The attachment of a such an envelope or such a cover at the edges of the web of material required in conventional Carrying bag manufacturing machines z. B. a reciprocating heat sealer, which longitudinal Space in the machine takes up at least the entire width of the sealant Carrying bag corresponds and can be adjusted to any different width of the carrying bag to be produced got to. There are also two superimposed but separate longitudinal welds or seals must be carried out to the envelopes or covers on the now superimposed To secure the front and rear walls, some shielding device must be placed between the separated Layers of the heat sealable web in forming an envelope or cover of this type are provided. The length of the material track that is required to make a fold Manufacturing in the tote bag making machine also takes up at least the space of a full one Processing station.

So far, these problems have resulted in significant costs, either for specialized purchase Carrying bag manufacturing machines that focus on relatively narrow areas of different carrier bag designs customized, or for extensive modifications to the basic tote bag making machine or for the production of dual track tracks by the carrier bag making machine through or for combinations of these expensive and time consuming solutions.

The invention is based on the object of providing an additional device for carrier bag machines of the initially mentioned to create designated type, by means of which an edge cover is folded and on at least one side edge of the web material can be applied and which is both space-saving and easy to use Different carrier bag machines can be attached to the most diverse types of carrier bags to be able to manufacture.

According to the invention, this object is achieved by those listed in the characterizing part of claim 1 Features solved. The invention advantageously enables the implementation of various types of edge cover

sound on the web of material before it is folded lengthways and feeding into the bag making machine because of the edge covering and folding operations in the first upward movement section or on one side of the frame can be carried out. The material web runs together with the cover over a Deflection roller on the top of the frame and then down through the second movement section in which the cover is melted. The folded cover is in this case during the movement of the material web before it passes through the heat sealers held firmly in place. Furthermore, through the additional device according to the invention, the machine length is not increased, since the movement sections of the loop-like Path run vertically.

Further refinements of the invention emerge from the subclaims.

The invention will then be explained in more detail with reference to the drawings of an exemplary embodiment. It shows

F i g. 1 is a side view of the attachment according to the invention;

F i g. FIG. 2 is a front view of the FIG. 1 additional device shown;

F i g. 3 is a rear view of the accessory device shown in connection with the insertion end of a usual carrying bag making machine;

4 is an enlarged partial cross-sectional view along line 4-4 of FIG. 2;

F i g. 5 is an enlarged partial cross-sectional view taken along line 5-5 of FIG. 2;

F i g. 6 is an enlarged perspective partial view of a cover strip folding mandrel in the ben according to the invention Additional device;

F i g. 7 is an enlarged partial cross-sectional view taken along line 7-7 of FIG. 4;

F i g. 8 is a partial cross-section taken along line 8-8 of FIG. 7 and

F i g. 9 to 12 perspective partial views of various Executions of carrier bag opening constructions, for the production of which the additional device suitable is.

The in the F i g. 1 to 3 of the drawing shown additional device according to the invention includes a . Frame structure, indicated generally by the reference number 10. This frame construction consists of a base or block 12 and two substantially vertical or perpendicular supports 14 and 16. The supports 14 and 16 are structurally connected to one another by transverse beam-like components connected, which are then identified and described in connection with the operational elements carried by these components.

Cantilevered forwardly vertically spaced sets of roll support arms 18, 20 and 22 extend from the supports 14 and 16, each such set of arms defining at least two storage points for rolls of thermoplastic sheet material used for the carrier bag manufacturing operations will. In the illustrated embodiment and as in FIGS. 1 and 2, the arm sets 18 and 20 each carry a web supply roll 24 and 26, respectively, the rolls being supported on central shafts 28 of similar design . It should be noted that two supply rolls of the strip material are usually used for the production of carrier bags of double thickness of plastic material, the web forming the outer layer, which is printed with corresponding characters or images, being supplied by the roll 26, whereas an inner layer or sliding one Position is created by the web which is supplied from the roll 24. In practice, the two webs are superposed and then guided as a single web in the working sections carried out for the device according to the present invention and in the carrier bag making machine. At this point it should be noted that the manufacture of a carrier bag without double thickness of plastic material or without a liner requires only one set of arms 18 or 20 to feed single thickness sheet material.

The roller support shafts 28 protrude axially from their respective rollers 24 and 26 on these shafts are supported, so that the opposite ends of each shaft 28 to two spaced Pairs of rollers 30 are movably supported, which in turn are mounted near the upper edge of the support arms. At the one end of each shaft 28 that protrudes beyond the arms carried by the support 16 is a spool-like ring 32 attached with two flanges, which engages with an axially adjustable positioning slide 34 can be brought, which is mounted on cylindrical guides 36 which are attached to the support 16 are. Each slide 34 is connected to a hydraulic piston 37 which, under the control of a electrically operated valve 38 is operated. The function of the carriage 34 and the associated Components is the individual rollers 24 and 26 with respect to a predetermined vertical reference plane between the supports 14 and 16 under the control of known edge position sensors or feelers (not shown) to position the downstream of the rolls 24 and 26 in sections of the web runway are positioned.

Arm set 22 similarly supports two cover strip supply rolls 40 and 42. In the event that two independent cover strip supply rolls are to be used, each roll is supported on an independent shaft 44 which is supported at its outer end by the arms 22 is rotatably held and at its inner end in each case by arms 22a, which in turn are carried by a carrier 46 which extends between the supports 14 and 16 (see FIG. 2!). The outboard end of shafts 44, like shafts 28 described above, carries axially fixed rings 48 with two flanges which engage slides 50 for axial movement, which are in the manner of a traveling nut on an adjusting spindle 52 function. It can now be seen that with this arrangement, the axial or transverse position of the ring 48 and thus the roller 40 is determined by a rotation of the spindle 52. The roller 42 is also equipped with similar devices which adjust its axial or transverse position with respect to a central vertical plane between the supports 14 and 16.

In order to properly understand the construction and operation of the present invention , it should be noted that conventional operations for the production of carrier bags consistently pulling a web from a supply roll, for. B. in front of one or both supply rolls 24 and 26 over a longitudinal folding mandrel in the wire bag manufacturing machine, at which point the continuous

before longitudinal advancement of the longitudinally folded web is converted into an intermittent longitudinal advancement process. Referring to Figure 3 of the drawings, there is shown the infeed end of a conventional tote bag making machine 54 which includes an electric motor 56 or any other suitable rotary drive connected to a continuously rotatable drive roller 58 around which a loop or part of the longitudinal folded web W is wrapped around, which is thereby continuously moved forward in the longitudinal direction at speeds corresponding to the production speed of the carrier bag production machine. Down the web in the machine with respect to the web movement, one or more intermittently driven drive rollers (not shown) are arranged by which the web is advanced in steps to successive carrier bag manufacturing stations which are mounted on the machine. The conversion of the continuous feed by the drive roller 58 into an intermittent feed in the above manner is made possible by a set of compensating or compensating rollers 60 which are mounted on an arm 62 which is biased by a spring or a weight and around a bearing point 64 can swing around. As is known in the field in question, such compensating rolls serve to catch a longitudinal segment of the continuously conveyed web section during the rest periods in the intermittently conveyed web section downstream from the compensating rolls. Also in accordance with common practice, longitudinal folding of the web W is achieved by pulling a web down from a horizontally stored supply roll over a V-shaped folder or mandrel. As shown in Figs. 1 and 3 of the drawings, the longitudinal track folding horn is formed in the exemplary embodiment by two round rods 66 which are held between the rear of the bracket 12 and the supports 14 and 16. The rods 66 are arranged so that they lie in a plane which is inclined at about 45 ° with respect to the supports 14 and 16, and they converge at their lower ends in the vicinity of a guide roller 68 from which the now folded web is directed to drive roller 58. As the collapsed and longitudinally folded web W is withdrawn from the supply rolls 24 and 26, some tension is maintained in the web by drag strips 70 carried by rods 72 and laid over each roll of web material. The braking strips are made of any suitable textile material, e.g. B. od a cotton fabric. Like. And loaded by rods 74 at their hanging ends to ensure a correct braking value.

The path of movement through which the web material is drawn in the attachment according to the invention is essentially formed by a series of freely rotatable, parallel guide rollers which extend transversely between the supports 14 and 16. As shown in FIG. 1 of the drawings, the web material consequently runs from the lowermost supply roll 24 around a guide roll 76 upwards over a guide roll 78, around which the web from the supply roll 26 is also guided, and thus onto the web from the supply roll 24 The superimposed or double-ply web runs from roller 78 upwards past a guide roller 80 over a cover folding horn 82, which will then be described in detail later, and then to a guide roller 84 which is located near the upper end of the supports 14 and 16 is positioned. When the web runs from the guide roll 78 to the cover horn 82 over the guide roll 8 <, the web is slightly reversed, so that in the event that edge strips are used, di (from the supply rolls 40 and 42 come here, placed on the opposite edges of the double-layered stretcher and pressed against it, which comes from in front of the rollers 24 and 26. The composite te web W is then from the guide roller 84 we (guided over the top of the device to a guide roller 86 and then in a rectilinear movement section down to a guide roller 88. After the web has passed the guide roller 8t, it is after inside and below around two guide rollers 90 and 92 and then over the folding bars 66, as already described above. It can thus be seen that the web material roll during its run from the supply 24, 26, 40 and 42 to the folding bars 66 is inevitably brought into a vertically oriented loop-like shape, which has an upward or running and generally vertical section between the guide rollers 8 (and 84 and a horizontally spaced down vertical section between the rollers 86 and 88. It is further noted that due to the arrangement of the guide rollers, the web mat erial from each or both of the supply rolls 24 and 26 can be passed directly over the guide rollers 90 and 92 and then down over the folding bars 6t. This path of travel can be used in tote bag manufacturing operations that do not require a cover or envelope layer.

The construction of the components in the cover horn 82 is best seen in Figures 4-6 of the drawings. As shown therein, the cover mandrel is supported by a transverse plate-like support or guide 94 that is attached to the front of the posts 14 and 16. Two overlapping or telescopic plate-like carriages 100 and 102 are supported on the guide 94 via two pairs of sliding pieces 96 and 98. The front edges of the plate-shaped carriages 100 and 102 are aligned one above the other and are suitably rounded or otherwise shaped so that no noticeable braking force is exerted by them on the web material running over it when it traverses the path of movement between the guide rollers 80 and 84, as most clearly from Fig. 4 of the drawings. Both plate-shaped carriages 100 and 102 are provided with a welded-on plate 104 , each of which has a threaded opening for receiving hand spindles 106 in the manner of running nuts, which are secured against axial displacement with respect to the supports 14 and 16. An adjustment or rotation of the hand spindles 108 brings about a transverse adjustment of one or both plate-shaped carriages 100 and 102

In the vicinity of the lateral end of each plate-shaped slide 100 and 102 , a slot 108 is provided for the folding of the cover. The folding slots ! 08 open into the rounded front

808621/361

Edge of the corresponding plate-shaped carriage 100 and 102 and extend under a pointed Angle with respect to the rounded front edge in the plate in order to capture the web can. Further on the plate-shaped carriages 100 and 102 are next to the slots 108 inwards relocated folding mandrels or shoes 110 attached to the under run diagonally upwards, which corresponds approximately to the inclination of the path movement section, which runs between the cover shift mandrel and the guide roller 84. Two retractable Pressure rollers 112 and 114 are also arranged on the plate-shaped carriage above the slots, to hold the web material against the folding mandrels or shoes 110 with a slight pressure. As a result of this construction, with particular reference to Figs. 4 and 5 of the drawings it can be determined that the envelope or cover strips coming from the supply rolls 40 and 42, after placing them on the edge of the double-ply sheet material that is being fed from rolls 24 and 26 comes from, need only thread into the slots 108 so that each cover or envelope layer is continuous and is folded seamlessly around the corresponding edge of the web. By adjusting the Adjusting screws 52 for adjusting the position of the rollers 40 and 42 and by adjusting the hand spindles 106 for positioning the plate-shaped carriages 100 and 102, the process for folding of the cover or envelope with respect to the web regardless of its width or lateral position between the supports 14 and 16.

As shown in Figs. 1, 3 through 5. 7 and 8 of the drawings, two pairs of elongate welders 116 and 118 are provided for use near the opposite edges of the web W in its moving portion which extends between the guide rollers 86 and 88. The weld body pairs 116 and 118 are constructed in the same way and arranged or attached in a manner similar to that in which the plate-shaped carriages 100 and 102 described above are arranged. In detail, each welding body pair 116 and 118 is held by a C-shaped bracket 120 which is attached to a slide 122 which in turn is slidably mounted on a transverse plate-like guide or carrier 124 which extends transversely between the supports 14 and 16 extends and is attached to the rear sides. The carriages 122 are connected to axially fixed hand spindles 126, in the manner of running nuts, as is most clearly shown in FIGS. 4 and 5 of the drawings.

The construction of the weld body pairs 116 and 118 is best illustrated in FIG. 5 of the drawing. Accordingly, two identically designed plate arrangements 128 are provided in each pair, which are connected to two vertically arranged, rotatable shafts 130 and are rotatable with them. The shafts 130 are coupled for simultaneous rotation in opposite directions by two meshing pinions 132 , at least one of which can be rotated or reciprocated by a hydraulic cylinder 134. As a result of this construction, it is possible for the plate assemblies 128 in each welded body pair 116 and 118 to be between an operative position, shown in solid lines in Figure 5, in which the plate assemblies 128 overlap the edge portion of the web JV in a substantially parallel arrangement , and an inoperative position, shown in phantom in Figure 5, in which both plate assemblies 128 are pivoted simultaneously outwardly from the track.

The facing sides of the plate assemblies 128 are elongated vertical Groove 136 is provided in which a chromium-nickel heating wire 138 is positioned such that it does not interfere with any surface of the

ίο Plate arrangements are in contact. Vertical Running cooling channels 140 are in assemblies 128 on opposite sides of wire 138 provided, and through these channels 140 a suitable cooling medium, for. B. Water over corresponding

■ 5 de flexible lines 142 (compare Fig. 7!) be circulated.

In connection with the welding body pairs 116 and 118 it should be noted that the length; the Plate assemblies 128 and, in a corresponding manner, the heating wires 138 in practice usually approximately Can be 457 mm (18 inches). It is also noted that the welding body pairs in their working position put little or no pressure on the web. The result of this construction is that extremely uniform heating over a relatively low temperature the length of the chromium-nickel wires 138 is achieved and consequently a uniform fusion all the layers of thermoplastic material between the two chromium-nickel wires of each Couple runs through. As a result of the length of the sheet material, the heating by the chromium-nickel wires is subject and the correspondingly low required melting temperatures is the control Ie Relieved considerably by the melting temperatures, up to a degree at which one complicated things thermostatic control circuits no longer required. In other words, the temperature of the chromium-nickel wires only needs to be adjusted to match the combined thickness of the layers that are to be fused are, and the linear speed of the web is taken into account, which is between the guide rollers 86 and 88 passes through.

It is important, however, that any suspension of orbit movement should be instantaneous Movement of the weld body pairs 116 and 118 into an inoperative position. this will achieved according to the invention by a controller which is shown in FIG. 3 of the drawings is shown schematically. in the

individual is at the introductory end of a conventional carrier bag manufacturing machine 54, the drive for the drive roller 58 is automatically switched off after the intermittent advance of the web IV down the web in the bag making machine has stopped when

the length of the material in the compensating or compensating rollers 60 becomes so great that the arm 62 can pivot into its lowest position, as in FIG. 3 z. B. indicated by dashed lines. At this point the arm 62 opens a switch 144 which breaks the circuit to the drive motor 56 for the drive roller 58. A control unit 146 is provided for carrying out the present invention and is also connected in series with the switch 144 , so that when the switch is opened to block the rotation of the drive roller 58, a signal is simultaneously sent via conventional devices to the hydraulic piston 134 of each welding body pair 116 and 118 is sent so that the disk assemblies 128 and

the heating wires 138 are moved to their inoperative positions. Similarly, when operation commences, the closure of switch 144 will reverse this operation. It is also noted that the control unit 146 is drivingly connected to each one of the valves 38 which actuate the hydraulic cylinders 36 to control the lateral positioning or alignment of the rollers 26. This circuit is designed so that the switch 144, when it is opened on reaching the end of the web, actuates the valves 38 so that the carriages 34 remain in a neutral position. Otherwise the edge sensors (not shown) would actuate the hydraulic pistons, which would unnecessarily move the carriages 34 into an extreme edge position.

To clarify the various types of support bulges that can be handled by the additional device according to the invention, reference is made to FIGS. 9 to 12 of the drawing. For example, as shown in FIG. 9, the carrier bag top 150 is provided with edge envelopes 152 which are formed merely by turning over a single web of material which can be fed from one of the rollers 24 or 25. In the manufacture of this carrier bag, the rollers 40 and 42 are omitted and only the opposite edges of the web are threaded or inserted into the folding slots 108. The folded or folded edges of the web material are welded along a weld line 154 , which is determined by the position of the heating wires 138 .

In Fig. 10, a carrier bag 156 is shown in which a separate cover strip 158 is folded over the opposite edges of the initial web in the manner as is immediately apparent from the above description of the additional device selected as an exemplary embodiment. Punched handle openings 160 are, of course, usually machined in the carrier bag manufacturing machine 54 during the intermittent advance of the web material. In Fig. 11 there is shown a carrier bag construction 162 which is similar to that of Fig. 10 except that the sheet material for making this carrier bag is folded offset from its longitudinal centerline so that the edge flaps or covers 164 and 166 of the front and rear walls of the carrier bag are offset accordingly. In this carrying bag design, a closure is achieved that the covered strip or the

ίο folds covered flap 166 over the recessed cover 164 of the other flap.

FIG. 12 shows a carrier bag construction 168 in which a cover is folded over on one side of the carrier bag and is welded in this position

5, whereas an unfolded strip 172 is provided on the other wall or front wall of the carrier bag, which is used to attach a single handle 174 . In the finally completed tote bag, the unfolded flap 172 is intended to be inserted into the

ίο folded cover 170 to be plugged into the other wall of the carrier bag so that the handle protrudes through a slot 176 in this. Although the attachment of the handle 174 and other discontinuous operations are carried out by conventional devices in the carrier bag manufacturing machine 54, the fusing of the cover or envelope strips with the carrier bag material is carried out very easily according to the invention Cover strip 170, which is used to form the folded edge of the carrier bag, is inserted through the folding slot 108 , whereas the cover strip 172 on the other side of the carrier bag is merely placed on the opposite edge of the web without a fold.

It can thus be seen that the present invention provides a high performance accessory device for tote bag making machines, by which the above objects are fully achieved will.

In addition 5 sheets of drawings

Claims (9)

Patent claims: 1. An additional device for folding a web-shaped material and forming edge covers, which can be combined with a carrier bag machine, in which a longitudinally folded web of a heat-sealable sheet-like material is continuously advanced to a leveling roller arrangement and then intermittently for the execution of the production steps the carrier bag is moved further at longitudinally spaced work stations simultaneously during corresponding idle periods, with a frame which carries a support for at least one supply roll of the heat-sealable web material and a folding device for the continuous longitudinal folding of the web material, characterized by a number of parallel guide rollers (80, 84, 86, 88, 90), which are stored in the frame (iO) and arranged in front of the folding device (66) so that between the supply roll (24) and the folding device (66) a vertical loop-like path for the unfolded sheet material is formed with the loop-like path including first and second moving portions of the sheet material, an edge cover device (82) disposed on the frame (10) along the first moving portion of the sheet material for at least one additional layer of a heat sealable arcuate To apply material (40) continuously to at least one lateral edge of the web material by heat sealing devices (116, 118) pivotably mounted on the frame (10) along the second movement section of the web material, which heat sealing devices (116, 118) the additional layer of the sheet material with the web material during the continuous movement of the web material and the additional layer merge in the second movement section of the loop-like path, by automatic drive devices (134, 146) for the heat sealing devices (116, 118) in order to pivot them away from the web material when the movement of the web material e is interrupted along the loop-like path, and by a guide device (68) which is connected downstream of the folding device (66) and which directs the folded web (W) provided with edge covers to the carrier bag machine (54). 2. Apparatus according to claim 1, characterized in that the frame (10) has a bracket (12) and has two vertical supports (14,16), the distance between the supports in the transverse direction is greater than the width of the heat-sealable sheet material before it is longitudinally folded, 5s that the guide rollers (80,84,86,88,90) in these Supports are mounted so that they the web material from the supply roll (24) up and then away down to the longitudinal folder (66), the first and second moving portions of the sheet material along the loop-like path in substantially vertical positions be positioned on opposite sides of the supports (14, 16), and that the edge-covering device (82) has a cover folding mandrel on the supports (14, 16) between two Guide rollers (80, 84) is attached, which limit the first portion of movement of the web material. 3. Device according to claims 1 or 2, characterized in that the edge-covering device a support arm (44) containing a cover strip supply roll (40) in the working position opposite the cover mandrel (82) and the edge of the sheet material 4. Device according to one or more of claims 1 to 3, characterized in that the Edge covering device (82) has two plate-like carriages (100, 102) which are positioned between the Supports (14, 16) are mounted and mutually telescopic and with respect to the supports are independently adjustable in the transverse direction that the plate-like carriages together form a guide edge for the web material when it is between the two guide rollers (80, 84) that limit the first section of movement of the loop-shaped path, and that the plate-like carriages each have a folding slot (108) which tapers away from the common guide edge at an acute angle extend this backwards and inwards. 5. Device according to one or more of claims 1 to 4, characterized in that the second movement portion of the web material is linear, and that the heat sealing devices (116, 118) have at least one pair of elongate parallel heating wires (136, 138) connected to opposite sides of the sheet material near an edge of the sheet material are pivoted. 6. Apparatus according to claim 5, characterized in that the heat sealing devices (116, 118) have plate assemblies containing facing surfaces along which the Heating wires (136, 138) are held that the plate assemblies between a working position, in which the mutually facing surfaces are essentially parallel on opposite sides of the web material and are pivotable to an inoperative position in which the surfaces like scissors at a distance from the web material. 7. Apparatus according to claim 5 or 6, characterized in that the plate assemblies (116, 118) on opposite sides of the heating wires (136, 138) have channels (40) in which a Cooling medium circulates. 8. Device according to one of claims 5 to 7, characterized in that the heat sealing devices have two pairs of plate assemblies and independently adjustable carriages (122), each supporting a pair of the plate assemblies whereby the heat sealers onto the respective width and position of a web material between the supports are adjustable. 9. Device according to one of claims 5 to 8, characterized in that drive devices (134) are provided for the plate arrangements with the heating wires, these between their working position «! and ineffective positions, and that the automatic Drive devices include switching means (146) responsive to the termination of web travel u ^ d switch the drive devices (134).