DEVICE FOR REMOVING A COATING FROM A GLASS PANE

The present finding regards an edge trimming group for glass panes according to the overview part of claim 1.

Included among the various machining operations to which glass panes are subjected is the so-called "edge trimming" operation, by means of which a portion of the film which covers the low thermal emission glasses is removed.

Such glasses are used to manufacture the so-called "double glazing", made up of a coupling between two glass panes not kept reciprocally distanced by a perimeter framework which delimits and encloses the intermediate chamber.

Specifically, the edge trimming operation consists in removing from the glass pane covered by a low emission film, a few microns thick, a strip of equivalent width with respect to the height of framework profile against which the abovementioned pane lies, to make a double glazing pane.

The edge-trimming operation is combined with the cutting operation, through which the single glass panes are cut to the required size, obtaining them from a larger pane, placed on the workbench.

Usually the edge trimming group is fixed on the nozzle, sliding along a moveable bar.

According to current technique, the edge-trimming operation of glass panes provided with the low emission film occurs by employing an abrasive spring, made is up of a rotating diamond slitting wheel, whose thickness is equivalent to the width of the film strip intended to be removed, which comes into contact with the abovementioned pane . From a practical point of view, such operation system reveals numerous drawbacks both in terms of construction and operation .

Construction drawbacks are due to the fact that, in order to ensure an accurate removal of the film, the diamond slitting wheel must rotate at a high velocity and remain pressed against the surface, thus requiring construction of a rather complex support structure.

A first operation drawback is due to the quick wear of the disc, hence requiring continuous adjustment to recover abrasion and to maintain the contact with the pane, until the disc itself is replaced; this inevitably requires stopping machine.

A second operation drawback is due to dust particles which form during the abrasion and which, due to their composition, are harmful to the operator.

Lastly, the diamond slitting wheel, coming into contact with the film made of plastic material, loses its abrasion properties after operating for a given period of time, and thus it must be replaced, hence leading to stopping the machine temporarily.

The objective of the present finding is that of manufacturing an edge trimming group for glass panes covered by a low emission film, free of the drawbacks revealed by similar groups of the known type.

Specifically, the objective of the present finding is that of manufacturing an edge trimming group which is easy to construct, does not require frequent replacement of the of the abrasive tool and capable of ensuring ideal work conditions for the operator.

Such objectives are attained by an edge-trimming group using a "paintbrush-shaped" brush as an abrasive tool, with steel bristles and rotating around its longitudinal axis.

Said objectives are further obtained by providing for the rotating brush to be directly fixed onto a motor,

integrally joined with the pane cutting group.

Still such objectives are obtained by proving for the brush to be provided with a device which holds the bristles, to ensure an accurate width of the portion removed by means of abrasion, as well as a device preventing the dust particles from being dispersed into the environment, by means of complete suction of the same.

The finding shall be defined better through the description of one of its possible embodiments, strictly provided for exemplifying and non-limiting purposes, with the help of the drawing tables attached, wherein:

Fig 1 represents a perspective view of a nozzle provided with the edge trimming group according to the finding; - Fig. 2 represents an elevation and section view of said nozzle following lines II-II of fig. 1;

Fig. 3 represents an exploded view of the edge trimming group according to fig. 2 ;

Figures 4 and 5 represent two detailed views of the edge trimming group respectively in the idle and operating steps;

Fig. 6 represents a particular shape of the abrasive tool according top the finding.

As observable in fig. 1, in order to remove the portion 1 of the low emission film 2, covering the glass pane 3 placed on the work surface 4, employed is an edge trimming group, indicated in its entirety by number 10, fixed onto the cutting group, indicated in its entirety with reference

5, integrally joined with a plate 6, sliding along a bar 7, the overall structure according to methods already known.

As visible in fig. 2, the edge-trimming group 10

comprises an abrasive tool made up of a paintbrush-shaped brush 11, directly fixed onto an electric motor 12, in turn fixed onto a cutting group 5 by means of screws 8.

The entire brush 11 is held inside a chuck 13, integrally joined to the motor 12 and which is provided, at the lower part, with a rolling bearing 14, which keeps firmly constrained the most external bristles of said brush.

Fitted in the lower part of the chuck 13 is a ring 15, moveable vertically, which serves to prevent dispersion of the abrasive dust particles into the environment.

As a matter of fact, as evident upon observation of figures 4 and 5, the moveable ring 15, during the idle step, is withheld by the projecting pin 16, which is engaged into the slit 17, while during the operating abrasion step said ring lies on the surface of the glass pane, thus defining a vacuum chamber 18, which withholds the abrasion dust particles which are evacuated through a pipe 19, extending from the chuck 13 and connected, by means of a flexible external pipe 20, to a suction device, preferably of the so- called "Venturi pipe" type.

Lastly, as observable in fig. 6, the abrasive tool 11 is ha the body 21 of the bristles provided with a cavity 22 which reduces the contact surface between the bristles and the film 3, thus ensuring longer durability of the tool itself.

Obviously there are various embodiment of the device according to the finding, depending on the type and shape of the abrasive tool, without, for this reason, departing from the scope of the following claims.