DE1151921B - Press with dielectric heating for pressing a pattern into a thermoplastic film - Google Patents

Description

Press with dielectric heating to press a pattern into a thermoplastic film The invention relates to a press with dielectric Heating for pressing a pattern into a thermoplastic film, which is a pair having relatively movable welding jaws, of which at least one Jaw has protruding cutting edges.

There is already a process of cutting out and welding one on Trimming on a thermoplastic film on a base of the same Material using radio frequency has been proposed. in which the document is on a Electrode of a press with dielectric heating is placed, the other electrode carries a punch with a rib in the shape of the desired cutting line, and a frame is placed against the base, the interior space of which is larger than the stamp, but preferably has the same shape as the stamp, and in which the material for the fitting to be cut is clamped and in one Distance from the substrate is maintained by the movement of the stamp that im Frame clamped material is brought to bear on the base. So that the Materials between the electrodes are pressed together, with the voltage of the material for the trimming between the ribs and the tenter frame increased while at the same time applying a high frequency alternating voltage to the electrodes is placed so that the material for the trimming softens and along the edge of the rib is separated, and in which the pressure of the electrodes and the AC voltage are maintained until the cut-out trim piece is welded onto the base of the materials lying on top of one another.

The aim of the present invention is to create the possibility to apply decorative strips made of flexible, thermoplastic material to a base film. without any significant waste occurring.

This object is achieved according to the invention by a device for pulling on decorative strips made of flexible, thermoplastic material a base sheet, the apparatus comprising a carriage interposed between the opened Welding jaws can be moved on the machine bed and the one clamping device (Lip and jaw) for holding the strip ends, and by fixed Clamps used to hold the other ends of the strips.

An embodiment of a device according to the invention is described and illustrated in detail with reference to the drawing.

Figures 1 to 3 are schematic representations of the press; Fig. 4 illustrates a film with a decorative strip attached thereon; Fig. 5 is a plan view on the press; Figures 6 and 7 are partial views of a clamp head on a carriage on an enlarged scale; Figure 8 is a side view of the clamp head cart on an enlarged scale along section line 8-8 in FIG. 5; Fig. 9 is a View in the direction of arrows 9-9 in Fig. 8; Fig. 10 is a view in the direction of the arrows 10-10 in Fig. 9; Figure 11 is a view in the direction of arrows 11-11 in Fig. 8; Figure 12 is a partial perspective view of the lower welding jaw the press; 13 and 14 are partial sections showing the interaction of the lower and the upper welding jaws, and FIG. 15 is a partial section through the embossing cut the lower welding jaw on an enlarged scale.

1 to 3 of the drawing is a schematic representation Given the apparatus, which includes a dielectric press 10, the lower one Welding jaw 12 and an upper welding jaw 14 has. One of these jaws is to close the press movable with respect to the other jaw.

To illustrate, it is assumed that the upper jaw 14 with reference is movable up and down on the lower jaw 12.

At 16, a high-frequency generator is indicated which an alternating current allows flow between the welding jaws when dielectric heating is desired will.

On both sides of the lower or fixed welding jaw 12 are guides 20 provided on which a carriage 22 runs. Clamp heads belong to the carriage 22, which are indicated at 24 and which are the ends of the thermoplastic trim strips 26 detect which are rolled up on spools 28 which are rotatable on bearing blocks 30 are mounted. When the clamping heads 24 on the carriage have gripped the decorative strip 26, the car is driven to the left in the guide 20, and in this way the strips are fed and into the alignment or guide grooves 32 of the lower jaw 12 inserted. After the carriage has moved so far that the trim strips 26 over lie the entire length of the grooves 32, the clamping or tensioning arms 34 and 36 capture, which are pivotably mounted on the machine bed 42 at 38 and 40, the decorative strips and cut them from the two rollers 28 and from the clamping head 24 at the same time away. Then, as best seen in FIGS. 13-15, a thermoplastic Foil 44 placed over the strips and the upper sealing jaw 14 on the lower sealing jaw 12 moved to pressurize the panel. Then the high frequency generator switched on, which connects the strips dielectrically with the film.

A pair of rubber pads are placed between the film 44 and the welding jaw 14 46, which prevent arcing during dielectric heating. After the dielectric embossing, the cladding part is removed from the tool and the car moved back to its original position.

The items of the device according to the invention are now in described in more detail below.

The Car In FIGS. 6 to 9, the car is shown in detail. A couple of cross members 50 are provided at their ends with rollers or wheels 52, the run in the guides 20. The cross beams 50 are braced by beams 51 and 53.

It is assumed that the clamping heads 24 depending on the desired lateral position of the strips on the film can be moved across the carriage can, even if the necessary resources are not shown. The clamping heads 24 each have a bearing block 54 which is mounted in a suitable manner on the cross member 50 is. A rake-like part 56 is held at the bottom of the bearing block 54 and extends forward towards the feed rollers 28 for the trim strips. Of the Part 56 has at one end a stepped down part 58, which is in prongs 60 ends. A similar part 62 is on block 54 above part 56 on a bolt 64 rotatably mounted. The block 54 has a recess at 66 which allows the part 62 to to pivot its pivot point. The part 62 also has a downward one Part 68, which is in a horizontal lip 70 ends. From the horizontal lip 70 are aligned with the prongs 60 of the part 56, an equal number of jaws 72 down. These jaws 72 are made of hardened steel and are on the lip 70 mounted on rubber blocks 73.

A U-shaped spring 74 is arranged in the recess 66 of the block 54, which pushes the pivotable part 62 off the fixed part 56. In the block 54 is a lever 76 rotatably mounted on a bolt 78 above the pivotable part 62, when rotated clockwise into its vertical position (Fig. 8) with a cam acts on the part 62 so that the jaws 72 are on the prongs 60 of part 56 lay.

The strip brake The decorative strips 26 are from the individual Rolls 28 are fed by a strip pay-off brake, which is indicated at 80. The drain brake 80 consists of a block 82 with openings 84, the number with the grooves 32 coincides and are aligned with them. They are vertically adjustable Bolts 86 are provided with punches 88 which fit into each of the openings 84 for the strips protrude. A chuck is attached to the lower end of the bolts 86 which, not injuring the strip 26 and gently rubbing it, placed on the strip can be and thus opposes a variable resistance to the expiration of the strip. The purpose of the device 80 is to ensure that the trim remains tensioned while the carriage 22 pulls it over the welding jaw 12, and when the clamp or tie rods 34 and 36 hold the strip onto the tool. The degree of tension on the strips can be varied by adjusting the bolts 86.

At the block 82 of the strip run-off brake is to rest for the Ends of the trim strips an L-shaped lip 90 clamped, creating the trim the clamping head 24 of the carriage 22 are presented in an approximately horizontal position.

The process of gripping the decorative strip is as follows: The clamping head operating lever 76 is shown in FIG. 8 in dotted lines indicated position, whereby the spring 74 the parts 56 and 62 can "open". The carriage 22 is then moved in the direction of the rollers 28, and finally the front wheels of the carriage into the downwardly sloping portions 92 of the guide 20 fall (Fig. 8). This allows the fixed part 56 of the clamping device under the Grip the lip 90 carrying the strip. The movement of the car is controlled by stops 94, which are made of a suitable hard material, for example hard rubber are manufactured, limited. In this position of the carriage, the parts 72 and are the prongs 60 on both sides of the lip in alignment with one another. Now the lever will 76 folded over into its vertical position, whereby the resilient parts 72 open place the strip held on lip 90. The carriage 22 then turns to the left driven, whereby the strips 26 between the prongs 60 and the resilient parts 72 can be pinched. By moving the car further to the left, the corresponding a lot of strip material is introduced into the grooves 32 machined in the welding jaw 12. The carriage 22 continues to run in the guides 20 left until its rear wheels abut the stops 96, which are at suitable longitudinal intervals of the lower welding jaw 12 are attached so that the grooves 32 completely with the trim strips 26 are designed.

The movement of the lever 76 as well as the movement of the carriage 22 can of course be done either manually or automatically. To the representation too simplify. is in the embodiment of the invention, the device with manual operation illustrated.

The clamping and cutting device When the carriage is in the up is now explained position, the strips 26 have the clamping and cutting devices, which are indicated at 98 and 100, go through. The clamping and cutting devices are at both ends of the lower welding jaws 12 on the bed 42 for the tool mounted and protrude beyond the jaw 12. Since the devices are the same, will only one of the two devices described. The device 100 has a solid one Part 102, which is mounted directly on the bed, and an arm 36 which can be rotated on a bracket 104 is mounted. When strip material is fed into the tool, the arms 36, as shown in FIGS. 1 and 2, in an upright position tilted so that the carriage can drive away over the tool. Is the car in the extreme left position, however, the arms 34 and 36 are against the fixed Part 102 folded down and clamp the strip between you and the fixed one Part 102 a. In order to achieve a firm clamping between the parts 36 and 102, are the parts, as shown for example in Fig. 10, with beveled cross-sections Mistake.

A cutting edge 106 is attached to the pivotable arm 36 so that, when the arm has clamped the trim on the fixed part 102, the cutting edge towards the end of the movement of the arm, the decorative strip between the clamping head 24 and the drain brake 80 disconnects. A similar cutter and cutting action is achieved by arm 34.

Usually a pair of clamping and clamping heads are used for each of the clamping heads Cutting devices provided. In the illustrated embodiment are therefore a pair of clamping and cutting devices 98 'and 100' are provided which are associated with the clamping head 24 'work together. Since, as can be seen from Fig. 5, the devices 98-98 'and 100-100 'aligned with each other, it is possible to use a single tensioning and locking device 108-110 at each end of the lower welding jaw 12 to be used. As shown in Fig. 9, the locking member 108 has an arm 112 which is rotatable on the bolt 116 is mounted.

The arm 112 is urged in the clamping direction by a spring 114. Around To release the clamp, the arm 112 of the clamp device 100-100 'is rotated.

The trim strip is now separated from the carriage 22 and the rollers 28 and held under tension in the grooves 32, ready for welding and embossing with the appropriate thermoplastic film 44.

The Construction of the Welding Jaws As illustrated in Figures 12 to 15, the lower welding jaw 12 is composed of a number of elements. So are aligned and in Cross-spaced embossing cutting edges 116 on the support plate 42 attached. The embossing tools are of L-shaped cross-section in order to be firm To have edition. The embossing ends 120 of the cutting edges 116 are fluted in an arc shape, in order to produce a suitable embossing contour on the decorative strips 26 on the film 44. So that the decorative strips lie correctly over the die cutting when the car the decorative strips that feed the lower welding jaw are embossed on both sides Guide plates 122 are provided. At least part of the guide plates protrudes the embossing cutting edges sufficiently far up to allow the cutting edges 116 to die To form grooves 32 in the tool into which the trim strips are inserted by the carriage will.

However, while the guide plates for proper alignment of the trim strips with the die cutting required, it is also necessary that these plates be lowered or pushed down so that they emboss and dielectric Do not hinder the welding process (see Figs. 14 to 15). For this purpose are channel-shaped Guide plate carrier 124 is provided next to the die cutting 116 and by bolts 118 mounted on the bed 42. So that the guide plates, however, during the embossing process can be pushed down, they are on resilient pillows or strips 126 mounted, which od from rubber. The like. Are made.

The lips of the guide plates are kept at approximately the same height which have the embossing ends 120 of the cutting edges. As can be seen from FIG. understands below the height of the guide plates, the height of the ribs or lips 128 that finish with the embossing edge c 1YO when the plates are pressed down during embossing are. This creates the dielectric field between the top welding jaw 14 and the embossing cutting edge 116 distributed more evenly and the field strength at the edges the decorative stripe is greatly reduced, which results in a better embossing. This can be proven good imprinting is attributed, at least in part, to the fact that the field line spread is collected by the lips 128 of the guide plates rather than the edges of the Embossing cutting.

The electrical voltage of the embossing cutting edges is applied to all guide plates 122 through a copper contact strip 130. This contact strip 130 is at one end to the channel-shaped support 124 by a screw 118 attached. The other end of the contact strip is with a screw 132 with the Guide plate 122 connected.

In this way, the tension of the embossing cutting edge is reduced by the short Leg 134 of the channel-shaped carrier 124 transferred on the horizontal Leg 136 of the embossing cutting edge rests.

Claims (7)

PATENT CLAIMS: 1. Press with dielectric heating for pressing of a pattern in a thermoplastic film, a pair of which are movable relative to one another Has welding jaws, of which at least one jaw has protruding cutting edges, characterized by a device for pulling decorative strips made of flexible, thermoplastic material on a base film, the device being a trolley (22) comprises, which between the open welding jaws (12, 14) on the machine bed (42) can be moved and the one clamping device (lip 70 and Having clamping jaw 72) for holding the strip ends, and by fixed clamping devices (98, g00) that hold the other ends of the strips in place. 2. Press according to claim 1, characterized in that the cutting edges (116) are separated from each other by guide plates (122) above the edges (120) of the cutting (116) lie before the press is closed, and that the Guide plates (122) against elastic support elements (126) when the press goes down to be depressed. 3. Press according to claim 2, characterized by guide grooves for the strips passing through the edges (128) of the guide plates (122) and through the Edges (120) of the cutting edges (116) are formed. 4. Press according to claim 3, characterized in that the edges (128) of the guide plates (122) are formed in the shape of upwardly bent lips are. 5. Press according to claim 3 or 4, characterized in that the Edges (120) of the cutting edges (116) are fluted in cross section. 6. Press according to one of the preceding claims, characterized in that that the clamping devices (98, 100) cutting devices (106) for separating the Have stripes. 7. Press according to one of the preceding claims, characterized by an adjustable tensioning device (80) that holds the strips from multiple spools (28) bends.