Apparatus for cutting laminated glass

The invention relates to a device for dividing laminated glass with the features of the introductory part of claim 1.

Devices for dividing laminated glass are known, for example, from AT 403 689 ES, DE A 32 30 554 or US A 5,704,959.

In the known devices for dividing laminated glass, this is scored on both sides along the intended division line and then bent (arched) or kinked first to one side and then to the other in order to open the break along the score lines. This bending or kinking takes place in known devices by pressure bars or pressure rollers or by pivoting one of the bearing surfaces on which the laminated glass to be divided rests relative to the other bearing surface about an axis aligned parallel to the scoring line.

Since the bearing surfaces must be so large that laminated glass is supported over the entire surface, the devices for pivoting one part of the bearing surfaces represent a considerable mechanical effort.

The invention is based on the object of specifying a device of the type mentioned at the beginning with which laminated glass scored on both sides can be broken with less effort.

This object is achieved according to the invention by the features mentioned in claim 1.

Preferred and advantageous embodiments of the device according to the invention are the subject of the subclaims.

In the device according to the invention, it is no longer necessary to pivot one of the two bearing surfaces with respect to the other bearing surface in order to open the break in the panes of the laminated glass (by bending the same), but only the two bars are pivoted in such a way that the laminated glass pane is curved convexly in one direction and then in the other, so that the fracture on the convex side of the laminated glass opens along the previously generated score line. The bearing surfaces and the areas of the laminated glass lying on them remain stationary, ie the bars move independently of the bearing surfaces.

In a preferred embodiment of the device according to the invention, the bars are designed as suction bars, so that the laminated glass is held on the bars by negative pressure. Thus, the clamping bars required in the known devices, which are pressed with great force from above against the laminated glass, can be dispensed with.

In principle, it is sufficient for the device according to the invention if it is equipped with the two pivotable bars when laminated glass that has already been scored is conveyed onto the device. But it is also possible to equip the device according to the invention with devices for scratching the two panes of the laminated glass.

In the same way, the device according to the invention can have a device with which the plastic film, which is held between the two panes of the laminated glass, can be severed along the dividing line after breaking. Such devices can be designed as in the prior art. It is particularly preferred within the scope of the invention if the plastic film is melted off by the action of heat (thermal radiation) after the break has been opened. In the context of the invention, the separation of the film can also take place with the aid of a blade which moves along the then opened break and cuts through the film.

It is particularly preferred to use thermal radiation with a wavelength that is absorbed to a greater extent only by the plastic film, but not by the two glass panes, so that only the plastic film but not the two glass panes heat up when the plastic film is melted.

Further details, features and advantages of the device according to the invention emerge from the following description of the exemplary embodiment shown largely schematically in the drawings. 1 shows a side view of a device according to the invention (partially) and FIGS. 2 and 3 pivot positions of the bars when one and the other glass pane of the laminated glass is broken.

A device shown in FIG. 1 has support plates 1 and 2 mounted in a machine frame, on which a laminated glass pane 3 rests. In a between the support plates 1, 2

AT 408 652 B located gap 4, two bars 5 are provided which can be pivoted about axes 6 running perpendicular to the plane of the drawing. For this purpose, the bars 5 are connected to levers 7 on which pressure medium motors 8 act.

Devices for scoring the two glass panes 9, 10 of the laminated glass pane 3 can be provided between the two bars 5. These facilities are not shown in the drawing. Furthermore, in the area 4 between the bars 5, a device for cutting through the plastic film in the area of ​​a break made in the laminated glass, eg a blade movable between the bars 5 or a device 11 for emitting thermal radiation 12 may be provided, this device 11 emitting thermal radiation 12 with a wavelength that is not or little from the glass 9, 10 of the laminated glass pane 3 and from the plastic film 15 between the two Glass panes 9, 10 of the laminated glass pane 3 is strongly absorbed.

The bars 5 are provided on their upper side with supports 20 made of elastic material, in which openings are provided which are open to the support surface 21 of the bars 5 and which can be subjected to negative pressure. For this purpose, lines 22 for connection to a vacuum source are provided on the bar 5.

The upper sides of both support plates 1, 2 are, as is known in the prior art, equipped with a felt pad 25 and can be exposed to compressed gas (preferably compressed air), which came through openings in the support surface of the plates 1, 2 facing the laminated glass pane 3, so that the support plates 1, 2 act as air-cushion tables for the transport and alignment of a laminated glass pane 3 for dividing (breaking) the same. In order to support the fixing of the laminated glass pane 3 during breaking, the openings provided in the upper side of the support plates 1, 2 , from which compressed gas escapes when they act as air cushion tables, can be subjected to negative pressure so that the laminated glass pane 3 adheres to the plates 1, 2 is sucked in.

Due to the fact that the bars 5 are designed as suction bars, for which ribs crossing each other and in each of the mutually crossing ribs an opening for the negative pressure to take effect are formed in the upper end surfaces 21 of the supports 20, hold-down bars are formed which the laminated glass pane 3 press against the bars 5 and act from above on the laminated glass pane 3 in the area of ​​the bars 5, can be dispensed with.

For dividing laminated glass along scoring lines 13, 14 previously generated in it (in the same device or in an upstream scoring device) the bars 5 are pivoted once as shown in FIG. 2 and then as shown in FIG. 3. (It goes without saying that the bars 5 can also be pivoted first as shown in FIG. 3 and then as shown in FIG. 2). By pivoting the bars 5, the laminated glass pane 3 arches in the area between the bars 5, so that the break opens in the score line 13, 14 located on the convex side of the laminated glass pane.

It should be noted that the pivoting of the two bars in FIGS. 2 and 3 is shown exaggerated. As a rule, a slight pivoting movement of the bars 5 about their axes 6 is sufficient to cause the breakage. This is easily possible since the supports 20 of the beams 5 and the felt supports 25 of the support plates 1, 2 are elastically deformable, so that the arching of the laminated glass pane 3 to one side and to the other is readily possible to the extent that the break opens along the score line 13 or the score line 14.

If a laminated glass pane is to be broken which has thicker glass panes and requires increased arching in order to open the cracks, provision can additionally be made for the bars 5 to be adjusted up or down, as indicated in FIG. 1 by the double arrows 30. This adjustment is preferably carried out to such an extent that the upper surfaces 21 of the supports 20 of the bars 5 assume a position during pivoting and during the pivoting process which is shown in FIGS. 2 and 3 is indicated by dash-dotted lines. The lifting or lowering of the bars 5 is preferably carried out simultaneously with their pivoting movement, so that an imaginary extension of the bearing surfaces 21 goes through the upper edges 31 of the plates 1, 2 facing the bars 5.

This raising or lowering of the bars 5 is only necessary with thicker laminated glass 3, since laminated glass 3 with the usual thickness of the two glass panes 9, 10 can already be successfully broken in the device according to the invention if the axes 6

AT 408 652 B facing away edges 24 of the bars 5 compared to their rest position shown in Fig. 1 by a few tenths of a millimeter to about 1 mm up (Fig. 2) or down (Fig. 3) by pivoting the bars 5 .

After the breaks in both glass panes 9, 10 have been opened as described, the device 11 for emitting heat rays 12 is activated for the purpose of melting the plastic film 15 between the panes 9, 10 of the laminated glass 3 and the film 15 is melted in the area of ​​the break, see above that the dividing process has ended. In order to support this melting, the two support plates 1, 2 can be moved apart or only one of them can be moved away from the other, so that the plastic film 15 is tensioned in the area of ​​the break. This moving apart can also be done so that the support plates 1, 2 are pivoted about an axis perpendicular to their surfaces, which are arranged in the area of ​​an edge of the support plates 1, 2 perpendicular to the dividing line, so that the laminated glass pane 3 at one end the dividing line is pulled apart more than on the other (this is known in principle from US-A 5,704,959).

In summary, a preferred embodiment of the invention can be described as follows:

A device for dividing laminated glass 3 has two supports for double-sided scored 13, 14 laminated glass 3 and in a gap 4 between these two bars 5 designed as suction bars in such a way that the laminated glass 3 is curved once upwards and then downwards. By pivoting the bars 5 and the associated arching of the laminated glass pane 3, the breaks in the two glass panes 9, 10 are opened along the previously generated score lines 13, 14, with the score line 13 or 14 opening on the convex side of the domed laminated glass pane 3 lies. To separate the plastic film 15 between the glass panes 9, 10 of the laminated glass 3, a heat radiation source 11 is used, which preferably extends over the entire width of the device and which emits a heat radiation 12 that is preferably absorbed by the plastic film 15, but not by the Glass panes 9, 10, so that the latter are not significantly heated when the plastic film 15 is melted.