HK1113110B - Device for ultrasonic welding - Google Patents

Description

The invention relates to a device for ultrasonic welding, for example, a device used to close film bags, where the top end of the bag must be closed after filling the bags, the top end is clamped between the ultrasonic hammer and the amber and then welded by applying ultrasonic sound emitted by the ultrasonic hammer.

For a good welding, it is advantageous for the elbow and ultrasonic hammer to have a good surface contact to ensure that the ultrasonic waves are connected to the film material.

In order to allow the welded material to be wedged between the ultrasonic hammer and the amber, these two parts must be mobilityally aligned against each other.

The present invention is intended to maintain this mobility in such a way as to maintain well-sealing welds and to reduce wear on the device.

This task is solved by a device described in claim 1.

The invention is based on a parallel lever, which has two levers that can be rotated around axes and are aligned parallel to each other. This storage ensures the parallelism of the surface of the amboss and the ultrasonic hammer at each position. This minimizes friction between amboss and ultrasonic hammer, since there is always a superficial contact at the different positions that amboss and ultrasonic hammer can occupy relative to each other.

Preferably, the amber is suspended from the parallel lever to provide a defined resting position.

The parallel lever is preferably fixed to a support, the support itself being rotatable on an axis, which, if approximately perpendicular to the axes around which the parallel lever is rotated, allows the anvil to adjust in two dimensions to the position and orientation of the ultrasonic hammer, so as to ensure an even contact pressure between the ultrasonic hammer and the anvil along the welding point.

The anvil is preferably further pre-tensioned with a pre-tensioning agent towards an ultrasonic hammer, which allows the ultrasonic hammer to press the material to be welded (e.g. foil bag) against the anvil and slightly push the anvil back, so that a pre-defined pressure between the anvil and the ultrasonic hammer is applied.

The aim is to ensure that, after the ultrasonic hammer and the amber are joined, the hammer and the amber are in permanent contact with the welding material between them as quickly as possible, so that any possible bumps can be largely suppressed.

The advantage of this is that the embodiment can be individually adjusted to the ultrasonic hammer or the material in between, ensuring uniform pressure across the welding site. The larger the embodiment, the more difficult it is to achieve a uniform pressure across the entire weld site. The lever is also preferably positioned in a separate parallel holder.

To simplify the design, several swivel supports are mounted on a common support.

An exemplary embodiment of the invention is shown in the figures. Figure 1a three-dimensional schematic representation of an anvil and its storage;Figure 2a schematic cross-sectional drawing of the device from Figure 1;Figure 3a three-dimensional schematic representation of several anvils side by side.

The parallel lever 2 has two levers 6, 7 which are pivotable and parallel to each other. At the bottom of the parallel lever there are two cross-sections 13 which connect the two lower ends of the parallel lever 6, 7. Here two pivotable axes 11 and 12 are provided. The ambush 1 is placed at the lower parts of the 13. The axes 8 and 9 are arranged in upper quadrants 10 which are in turn attached to a holder 3. The holder 3 extends from the parallel lever 2 in a substantially horizontal direction. The end of the holder 3 is charged with a pivotable holder 4 on a 5 carrier.

The amber 1 has 15 welding lips on its front side, which can be either a single or multiple, depending on the number of welds to be formed.

The element 14 or other spring element may have a piston that presses against the amphora 1, either by compressed air, by the force of a spring or an elastic element, or by some other force. The element 14 or other spring element may have a piston that presses against the amphora 1, either by compressed air, by the force of a spring or an elastic element, or by some other force.

The element 14 or an element placed next to it, which interacts with the ambulation 1 or a moving part of the parallel lever 2, can also act as a dampener on the movement of the ambulation 1 and the parallel lever 2 in order to dampen the movement of the ambulation 1.

Preferably, an element 14 is provided at each end of an anvil 1, preferably two elements 14 per anvil.

The suspension element (e.g. element 14) which protrudes the amboss 1 in the direction of the ultrasonic hammer 16 may be so designed that it only protrudes the amboss to a certain maximum deflection in the direction of the ultrasonic hammer 16 but cannot extend the amboss further. In this case it is useful to provide for another element which slightly protrudes the parallel lever 2 or the amboss 1 against the suspension element (e.g. element 14) in this position in order to give the amboss 1 such a defined position. The force which then protrudes the amboss 1 in the direction of the suspension element should be less than the force provided by the suspension element.

The ultrasonic hammer 16 in Figure 2 can be moved away from the amboss 1 to pin the top end of the welding material 17 (a foil bag) between amboss 1 and the ultrasonic hammer 16.

In this position, with the pressure controlled between ultrasonic hammer 16 and anvil 1, welding of material 17 can be carried out well.

However, the carrier 5 can also be designed to move the anvil away from the ultrasonic hammer, creating space for the insertion of the film bags between the ultrasonic hammer and the anvil.

Figure 3 shows an embodiment in which several beams 1a to 1d are arranged side by side on several parallel levers 2a to 2d. With such a device it is possible to perform several welding operations of several materials side by side. For example, this makes it possible to weld several foil bags side by side. This can significantly increase throughput rates. The individual beams are stored here independently of each other, so that each beam can individually orient itself by the parallel lever and the bending ability of the respective holder 3a to 3d.

Preferably, a separate ultrasonic hammer is assigned to each pole, but it is also possible to assign exactly one ultrasonic hammer to several poles or to all poles.

The bags or other articles to be welded may be fed to the studs in one direction along the row of studs or side by side in one direction perpendicular to them.

As shown in Figures 1 to 3, a two-piece welding lip 15 is provided, resulting in two welding seams which are placed side by side to ensure the sealing of, for example, film bags in a particularly safe manner.

Since the pressure on the two welding lips is always approximately equal, neither of these two welding lips wears more strongly than the other due to friction when moving between the amphora 1 and the ultrasonic hammer 16, so that the stand times are very good here.

Claims (11)

1. Device for ultrasonic welding with at least one ultrasonic hammer (16) and at least one anvil, characterised by mounting of the anvil (1) on a parallel lever (2) comprising two levers (6, 7) which are mounted for swivelling about axles (8, 9) and are aligned parallel to one another, such that parallelism of a surface of the anvil and the ultrasonic hammer is ensured in any position.
2. Device according to Claim 1, characterised in that the anvil (1) is mounted suspended on the parallel lever (2).
3. Device according to Claim 1 or 2, characterised in that the parallel lever (2) is fastened to a holder (3) which can be swivelled about an axle (4).
4. Device according to Claim 3, characterised in that the axle (4), about which the holder (3) can be swivelled, is located approximately perpendicular to the axles (8, 9), about which the parallel lever (2) swivels.
5. Device according to one of the Claims 1 to 4, characterised in that the anvil (1) is pretensioned with pretensioning means (14), such as springs, elastic elements, such as rubber elements or compressed air springs, in a direction of an ultrasonic hammer (16).
6. Device according to one of the Claims 1 to 5, characterised in that the anvil (1) is linked to a damping means (14) which damps the movement of the anvil (1).
7. Device according to one of the Claims 1 to 6, characterised in that a number of anvils (1a, 1b, 1c, 1d) are provided, wherein they are arranged adjacent to one another.
8. Device according to one of the Claims 1 to 7, characterised in that a number of anvils (1a, 1b, 1c, 1d) are provided and each is mounted on a dedicated parallel lever (2).
9. Device according to Claim 8, characterised in that each parallel lever (2a, 2b, 2c, 2d) is arranged on a swivelling holder, wherein the various holders (3a, 3b, 3c, 3d) are preferably mounted on a common carrier (5).
10. Device according to one of the Claims 1 to 9, characterised in that the device is provided for the ultrasonic welding of film, in particular of compound film.
11. Device according to one of the Claims 1 to 10, characterised in that the device is provided for the welding of filled plastic bags (17), in particular in combination with a filling station for plastic bags (17).