Apparatus for braking glass panes scored at only one side.

(42) Date of commencement of the patent: 15. 6.1990 (45) Date of issue: 10.12.1990 (51) Int.Cl.⁵ : CO3B 33/02 (56) Documentation:

(73)

Patentee:

DE-Al-2925981 DE-Al-3428863 US-PS3372847 US-PS 3693852

LISEC PETER

A-3363 AMSTETTEN-HAUSMENING, LOWER AUSTRIA (AT).

(54) DEVICE FOR BREAKING SINGLE-SIDED GLASS PANELS (57) In a device for breaking unilaterally scribed glass sheets (2), in particular one-sidedly coated with metal, are a crushing bar (7) or a rotationally driven crushing roller (28) from below against the Giastafel (2) can be raised, and two on the Giastafel (2) arranged abutment (9 and 10) provided. The abutments (9 and 10) are not physically at break on the top of the glass sheet (2), but hold them by a between their sloping and arched undersides (13) and the top of the glass sheet (2) generated by the air cushion Nozzles (14) are formed from the flow of compressed air. In this way, friction movements, which could damage the coating (3) of the glass sheet (2) during the breaking process, excluded.

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CQ

AT 391 858

WR C07881S

No. 391 858

The invention relates to a device for breaking unilaterally grazed glass panels, with a trained example as a table support surface for the scored glass panel, with a pair of above against the glass sheet acting abutment, which are aligned substantially parallel to each other, and with a bottom between the Abutment against the glass panel applied lever bar or roller.

Such devices, which are also called Brecht tables (DE-Al-2,925,981, DE-Al-3,428,863, US-PS 3,570,734, US-PS 3,668,955 and US-PS 3,253,756), are connected provided on glass cutting tables, in order to break the glass panels unilaterally cut in glass cutting tables along the scribe lines to the desired formats. The breaking process on the Brechtischen takes place in that from the support surface from below a bar or a roll is raised, while rest on both sides of the bar or roller abutment from above against the glass sheet. During the breaking process arises between the top of the glass sheet and this pressing down abutments a relative movement, which can scratch the surface of the glass sheets and in particular there can destroy any existing coatings. Increases the risk of scratching glass panes or damaging coatings on the glass sheets by producing very fine pieces of glass during the crushing process which, when passing between the abutments and the glass sheets, will scratch the glass sheet during the crushing operation.

US Pat. No. 3,693,852 discloses an apparatus for breaking a continuously moving glass ribbon (float glass) along scribe lines extending transversely to the longitudinal extent of the glass ribbon. The apparatus of US Pat. No. 3,693,852 has a feed conveyor formed by rotationally driven rollers through which the glass ribbon is conveyed to a rotary driven roll higher than the transport rolls and a split glass discharge conveyor also formed by rotary driven transport rolls. Although the position of the roller between the supply and the discharge conveyor is adjustable in the frame of the device by means of adjusting screws, during the breaking process, the position of the roller is not changed, d. H. she is not raised. Above the conveyor above the roller a hollow box is mounted, which is connected to a compressed gas source. In the bottom of the box there are two rows of gas outlet nozzles aligned parallel to the roller. By emerging from the gas outlet nozzle gas which moves over the roller glass ribbon is bent so that it breaks along the scribe lines previously generated in it. The device known from US Pat. No. 3,693,852 is suitable only for the division of float glass (still referred to as sheet glass in US Pat. No. 3,693,852), which has scribing lines oriented exclusively transversely to its longitudinal extension. Namely, the glass ribbon is bent in the apparatus of U.S. Patent No. 3,693,852 so that it would also break along scribe lines aligned in its longitudinal extent, if any. However, this bending of the glass ribbon under the action of the gas cushion formed between the box and the glass ribbon is essential for breaking the glass ribbon in the apparatus of US Pat. No. 3,693,852 because the glass ribbon from the roll is separated from the areas located on both sides thereof of the conveyor and the conveyor is lifted. A disadvantage of the device according to US-PS 3,693,852 is still that the glass sheet separated from the glass sheet is not supported by the roller (see. FIG. 3 US Pat. No. 3,693,852), so that after the breaking operation, the rear edge of the separated glass sheet is moved along the front edge of the glass sheet. As a result, both edges are damaged, they break shell-shaped.

From US Pat. No. 3,372,847 a Glasbrechtisch is known in which glass is divided along scribe lines by the action of high frequency vibrations. For this purpose, for example, ultrasound sources are provided on both sides of the glass sheet. In addition to the upper ultrasonic source, which is provided above the glass sheet, in one embodiment of the apparatus according to US Pat. No. 3,372,847, spray pipes are provided from which a liquid is sprayed onto the glass sheet, thus effectively controlling the vibrations of the sound generator located above the glass sheet the glass panel are transferred.

The invention has for its object to provide a device of the type mentioned, especially with one side coated with a glass sheets can be broken without risk of damaging the glass panels or a possibly provided coating.

This is achieved according to the invention in that the abutments are hollow, have at their glass panel facing bottom outlet openings for the gaseous medium, and at least one source of pressurized gaseous medium, in particular air, are connected, that the support surface or the glass sheet facing the bottom of the abutment is formed obliquely, wherein the lower edge of the lever bar or roller adjacent lower edges of the abutment are arranged higher than the other lower edges of the same.

When Brechtisch invention the abutment are not on the top of the glass sheet, which is to be broken, but press them down by an air cushion formed between them and the glass sheet. In this way, the surface of the glass sheet can not be scratched or a possibly provided coating can not be destroyed because there is no physical contact between the abutments and the glass sheet.

Another advantage of the device according to the invention is that the abutments do not have to be set exactly to the thickness of the glass sheet to be crushed in contrast to abutting on the glass panel abutments. This is because the holding force exerted on the glass sheet via the air cushions under the abutments according to the invention is greater with thicker glass panels (smaller spacing) and smaller with thinner glass panels (larger spacing). Thus, without adjustment of the abutment in the vertical direction automatically the

-2Nr. 391 858 sufficient, smaller hold-down force applied for breaking thin sheets of glass This hold-down force increases with thicker glass sheets without adjustment of the abutments, so that then the greater hold-down force is required as it is required for the breaking of thicker glass sheets. For example, glass panels with a thickness between 2 and 10 mm can be broken without vertical adjustment of the abutment.

The fact that in the inventive device, the support surface or the glass sheet facing underside of the abutment is formed obliquely, the abutment can be placed just above the glass sheet without the glass sheet during the crushing process under the action of the lifting ledge or roller to each other facing lower edges of the abutment strikes

The openings in the abutments can be designed as round nozzles or as slot nozzles. In both cases, a plurality of rows of nozzles extending in the longitudinal direction of the abutments may be arranged. In this way, a particularly strong air cushion between the abutments and the glass panel is formed

Preferred in the context of the invention is when the support surface or the glass sheet facing bottom of the abutment is formed transversely to the longitudinal extent convexly curved. As a result, the shape of the bottom of the abutment is well adapted to the curvature of the glass sheet during the breaking process and the abutment can be arranged even closer to the glass sheet.

Further details and features of the invention will become apparent from the following description of embodiments, reference being made to the accompanying drawings. 1 shows, in section, a device for breaking glass sheets which have been cut on one side, and FIG. 2 shows a breaker table arranged following a glass cutting table, not shown, with a place for static and a place for dynamic breaking of glass sheets.

A device shown only in its essential parts for breaking unilaterally grazed glass panels has a support surface (1), which is designed for example as a table. On the support surface (1) is a glass sheet (2), on its upper side a coating, for. B. a vapor-deposited metal layer (3), carries in the direction of the arrow (4) promotes. The glass sheet (2) is moved in the direction of the arrow (4) until a scribe (5) provided on its upper side is arranged exactly above a lifting strip (7) arranged in a slot (6) of the bearing surface (1). The lifting bar (7) can be raised and lowered in the direction of the double arrow (8).

Above the bearing surface (1) abutment (9 and 10) are provided on both sides of the lifting bar (7) whose distance from each other in the direction of the double arrows (11) is variable, the abutment (9 and 10) even with a change in their distance remain symmetrically aligned with each other from the lever bar (7).

For possible adaptation to different thicknesses of the glass sheets (2) and possibly also to support the crushing process, the abutments (9 and 10) in the direction of the double arrow (12) relative to the support surface (1) can be raised and lowered.

As shown in Fig. 1, the abutments (9 and 10) are hollow and have on their, the glass sheet (2) facing side (wall (13)) a plurality of air outlet openings (14).

The air outlet openings (14) are formed in the embodiment shown as round nozzles, wherein three rows of round nozzles (14) are provided which extend in the longitudinal direction of the abutment (9 or 10).

At the ends of the abutments (9 and 10) are connected lines for supplying pressurized gas, in particular air, wherein the supplied compressed air then flows out via the nozzles (14) from the abutments (9 and 10), so that the glass sheet ( 2) is pressed against the support surface (1). When lifting the lifting bar (7) (if necessary in combination with a lowering of the abutments (9 and 10)), the glass sheet (2) along the scribe line (5) is broken, without that the abutments (9 and 10) physically with the glass sheet (2) or the applied coating (3) come into contact.

As shown in Fig. 1, the wall (13) of the abutments (9 and 10) is formed so that it extends obliquely to the support surface (1), wherein the abutment (10) adjacent edge (15) of the support surface ( 1) has a greater distance than the other edge (16) of the abutment (9 and 10). In addition, the underside of the wall (13) in the longitudinal direction of the abutment (9 and 10) is convex.

The abutments (9 and 10), for example, have a width of 10 cm and are depending on the size of the glass cutting table up to 3 m long.

In Fig. 2 a break table (20) is shown, in which a breaking point (21) for static breaking and a breaking point (22) for dynamic breaking of glass sheets (2) with scratches (5) is provided. The breaking point (21) for static breaking is, as shown in FIG. 1 shown executed. The resulting by breaking along the scratches (5) glass strips that still have scratches (23) are lowered by in the support surface (1) transport belts (24) in the direction of the arrow (25) and subsequently by conveyor belts (26) Promotes direction of the arrow (27) to the dynamic breaking point (22). The dynamic crushing point (22) corresponds, with the exception that instead of the breaking strip (7) a liftable crushing roller (28) is provided which is rotationally driven in the direction of the arrows (29), the static breaking point (21) with the in Fig. 1 shown construction. In the dynamic breaking point (22), the glass strips coming from the static breaking point (21) can be broken in a continuous process along the scratches (23).

In principle, it should be noted that static refraction of glass sheets (2) provided with scribes (5) is suitable primarily for thicker disks and smaller spacings of the scratches (5), whereas

-3Nr. 391 858 a dynamic refraction primarily for the transverse rupture (cf. FIG. 2 and the associated description) is suitable, preferably thinner glass sheets or Glass panes, which have larger distances of the scratches from each other, are broken in the dynamic breaking process. The crushing roller (28) serves not only to bend the glass sheets for breaking in cooperation with the abutments (9 and 10), but also for the transport of the glass sheets (2) by the dynamic breaking station (22).

On the side facing the abutment of the abutment (9) of the crushing point (22) additional nozzles (30) may be arranged (Fig. 3), from which gas, in particular air, flows downwards. By this measure it is prevented that the front edge of the glass panel lifts too far from the support surface (1) and

u. U. abuts the abutment (9). The nozzles (30) are preferably arranged higher than the nozzles (14) of the abutment (9). 5

It should also be noted that the Brecht table shown in Fig. 2 does not necessarily have to be angled, it may also be straight.