Patent Description:
From the current state of the art, trimming devices, stripping devices, removing devices etcetera are known with heads capable of removing a low emission layer and/or protective layer from the surface of a glass panel, using a standardized devices such as a grinding wheel.

It should be noted that, during the removing operation of the low emission layer and/or protective layer by following the trajectory of the future cut, the grinding wheel may become warm due to the friction of the grinding wheel against the glass panel when removing the low emission layer and/or the protective layer. Furthermore, the grinding wheel may become dirty due to the the residues that are originated when removing the low emission layer and/or the protective layer from the surface of the glass panel.

The low emission layer are usually delicate and may be easily damaged. Therefore, one or more protective layers can be arranged covering the low emission layer in order to protect it from damage. However, these protective layers difficult the stripping process.

Depending on the material, it may be necessary to remove both the protective layer and the low emission layer.

From <CIT> there is known a device for removing a low emission layer and/or a protective layer of a glass panel, comprising:- supporting means for supporting the glass panel, wherein, when the glass panel is positioned horizontally on the supporting means, an upper surface of the glass panel is provided with the low emission layer and/or the protective layer to be removed, a positioning bridge having a horizontally extending positioning portion arranged at a vertical distance from the upper surface of the glass panel and the supporting means, a stripping device configured to remove the low emission layer and/or the protective layer of the glass panel wherein the stripping device comprises a stripping member, wherein the stripping member comprises a grinding wheel being rotatable arranged around a wheel rotation axis, and wherein the stripping device comprises a blowing device comprising a support element and a blowing element wherein the blowing element is mounted on the support element and arranged to blow a gas and wherein the stripping device is arranged to move along the positioning portion in a horizontal direction, and over the upper surface of the glass panel, and the wheel rotation axis of the grinding wheel is parallel to the upper surface of the glass panel.

It is an object of the present invention to provide a device for removing a low emission layer and/or protective layer from a glass panel, which can overcome at least one of the above-mentioned drawbacks.

An embodiment of the invention is directed to a device as defined by claim <NUM>. Further embodiments are described by the dependent claims.

According to this, a stripping device for removing a low emission layer and/or a protective layer of a glass panel is provided, wherein the stripping device comprises a stripping member, wherein the stripping member comprises a grinding wheel being rotatable arranged around a wheel rotation axis, and wherein the stripping device comprises a blowing device comprising a support element and a blowing element wherein the blowing element is mounted on the support element and arranged to blow a fluid or a gas and wherein the support element is arranged to keep the blowing element at a set distance from the grinding wheel such that the blowing element can direct a stream of the fluid or the gas towards the grinding wheel.

This provides an advantage when removing the low emission layer and/or the protective layer from the surface of the glass panel because the blowing element allows to cool and/or clean the grinding wheel. As it has been explained, the grinding wheel may become warm due to the friction and/or dirty due to the the residues that are originated during the removing operation. The blowing element, by directing a stream of a fluid and/or a gas to the surface of the grinding wheel, allows to cool down and/or clean the surface of the grinding wheel. This device provides the possibility to have a continuous flow of glass panels mounted and ready for operation, because after performing the removing operation, the grinding wheel will be substantially cleaned and/or cooled down. This minimizes the amount of downtime between removing operations.

The blowing device may further comprise a conduct fluidly connected to the blowing element such that the fluid or the gas can pass through the conduct to the blowing element. This is an efficient way of proving the fluid or gas to the blowing element.

The conduct may be arranged through a grinding wheel orientation axis such that the grinding wheel can freely turn around the grinding wheel orientation axis such that the grinding wheel can orientate freely like a multi-turn axis. This allows for an efficient positioning of the grinding wheel as the blowing device does not interfere with the orientation movement of the grinding wheel.

The distance between the blowing element and the grinding wheel may be adjustable. This provides an advantageous blowing device because it allows to place the blowing element at a desired distance from the surface of the grinding wheel. Furthermore, it also allows to keep the desired distance constant even when the grinding wheel diameter reduces due to the grinding wheel surface wearing away when removing the low emission layer and/or the protective layer. As the diameter of the grinding wheel reduces, the distance between the blowing element and the grinding wheel increase. By adjusting the distance between the blowing element and the grinding wheel based on the change in diameter, it is possible to keep the distance substantially constant.

The support element may be movable mounted on the stripping device such that, by moving the support element, the distance between the blowing element and the grinding wheel can be adjusted. This provides an efficient way of adjusting the distance between the blowing element and the grinding wheel.

The blowing element may be arranged to adjust a force of the stream of the fluid or the gas such that by increasing or decreasing the force the blowing element is move away or towards the grinding wheel thereby allowing to adjust the distance between the blowing element and the grinding wheel. This is a very efficient way of adjusting said distance. For instance, the stripping device may comprises a sensor to detect changes in the diameter of the grinding wheel or changes in the distance between the blowing element and the grinding wheel, and processor may regulate the stream of fluid or gas based on information received from the sensor such that, when the diameter of the grinding wheel reduces, the force of the stream decreases allowing that the force of gravity moves the blowing element towards the grinding wheel for compensating the reduction in the diameter of the grinding wheel and thereby keeping the distance constant. The distance between the grinding wheel and the blowing element may be adjusted in any other suitable way. For instance, instead of moving the blowing element for adjusting the distance, the grinding wheel may be arranged to move towards the blowing element. A combination of movement of the grinding wheel and the blowing element may be also use for adjusting the distance between grinding wheel and the blowing element.

The support element may be movable mounted on the stripping device via a hinge such that the support element can rotate over the hinge for adjusting the distance between the grinding wheel and the blowing element. As the blowing element is mounted on the support element, by pivoting the supporting element around the hinge, it is possible to move the blowing element away or towards the grinding wheel, thereby easily adjusting the distance between the grinding wheel and the blowing element.

The support element may further comprise a regulating element arranged to contact the grinding wheel such that the distance between the grinding wheel and the blowing element is kept constant even when a diameter of the grinding wheel is reduced. In this way, when the diameter of the grinding wheel reduces, the regulating element which is in contact with the grinding wheel pulls from the support element which pivots over the hinge thereby bringing the blowing element in towards the grinding wheel and compensating for the diameter change such that the blowing element and the grinding wheel are kept at substantially the same distance.

Instead of the regulating element, any other way of moving and keeping the support element in the desired position such that the distance is adjusted may be used. For instance, a mechanism may raise or lower the support element and a lock element may lock the support element in the desired position. The lock element may be any suitable element that is able to fix the support element at a certain position. For instance, the support element may comprise a pin that fits in openings located at different heights of the stripping device such that each opening corresponds to a different position of the support element.

The regulating element may further be a wheel. This allows the support member to easily move when the diameter of the grinding wheel reduces.

The regulating element being a wheel may further be arranged to provide a measurement of a change in the grinding wheel diameter. As the wheel is in contact with the grinding wheel, the wheel can provide a measurement of the reduction of the diameter of the grinding wheel. For instance by providing the regulating wheel with a movement sensor. The amount of movement measured by the sensor may be a measurement of the amount of reduction in the grinding wheel diameter due to use.

The blowing device comprises a cooling device. In this manner, the cooling of the grinding wheel will be improved as the fluid or gas to be streamed towards the gridding wheel has been previously cooled by the cooling device.

Further characteristics and advantages of the invention will become better apparent from the description of preferred embodiments of devices for removing a low emission layer and/or a protective layer of glass panels, illustrated by way of non-limiting example in the accompanying drawings, wherein:.

<FIG> shows a glass panel <NUM> that is to be processed by a stripping device <NUM> according to the present invention. The stripping device <NUM> is preferably specifically designed for removing a low emission layer and/or a protective layer provided on the glass panel <NUM> for use on a cutting table <NUM>. The stripping device <NUM>, which can be best seen in <FIG>, <FIG> & <FIG>, is mounted in a positioning bridge <NUM> and it is installed in the cutting table <NUM>. The cutting table <NUM> comprises a supporting means having a support surface <NUM> for supporting the glass panel <NUM> in a horizontal orientation as to be treated. The glass panel <NUM> comprises an upper surface <NUM> and a lower surface (not shown in <FIG>) wherein the lower surface of the glass panel <NUM> is in contact with the support surface <NUM>. The upper surface <NUM> of the glass panel <NUM> is positioned at a vertical distance from the positioning bridge <NUM> and the stripping device <NUM>.

The stripping device <NUM> is mounted in the positioning bridge <NUM>. The positioning bridge <NUM> has a horizontally portion (i.e. extending in a direction perpendicular to the plane defined by the X- and Z-axes) arranged at a vertical distance from the support surface <NUM>, and also from the top surface <NUM> of the glass panel <NUM>, when the glass panel <NUM> is in a position for performing the removing operation of the low emission layer and/or the protective layer provided onto the upper surface <NUM> of the glass panel <NUM>. The stripping device <NUM> is moveable along the positioning bridge <NUM> in such a way that the stripping device <NUM> can be positioned at any position over the glass panel <NUM> and/or the support surface <NUM> of the cutting table <NUM>.

The skilled person will appreciate that the glass panel <NUM> is a low emission glass panel that comprises a low emission layer, which can be in the form of a coating(s). The low emission layer has been developed to minimize the amount of ultraviolet and infrared light that can pass through glass without compromising the amount of visible light that is transmitted. The low emission layer is subject to oxidation when touched by a bear hand or in contact with other material. Moreover, this layer or coating(s) can be subject to damage if not handle with care. The skilled person will also appreciate that the glass panel <NUM> may also comprise a temporary protective layer. The protective layer may be a film and/or a coating. The temporary protective layer may have a full-coverage of the upper and lower surfaces of the glass panel <NUM>. The temporary protective layer may be, for example, a plastic film ln the form of a low-adhesive recyclable film that protects the surface of the glass panel having the low emission film from mechanical and/or chemical damage often experience during handling operations. The temporary protective layer may be made of a suitable polymer material e.g. polyethylene, or may be made of any other suitable material. The glass panel may comprise any other number of layers for different purposes. An example of a glass panel comprising protective layers is, for instance, the glass panel Easy Pro © from Saint Gobain ©. An example of a glass panel comprising a protective film is, for instance, the glass panel Guardian Glass ©.

<FIG>, <FIG>, <FIG>, and <FIG> show further details of the stripping device <NUM> of <FIG>. As can be seen more clearly in <FIG>, <FIG>, <FIG> and <FIG>, the stripping device <NUM> comprises a grinding wheel <NUM> and a blowing device <NUM>. The blowing device <NUM> comprises a support element <NUM> and a blowing element <NUM>. The blowing element <NUM> is arranged to blow a fluid or a gas (for instance air). The blowing element <NUM> is mounted on the support element <NUM> such that can direct a stream of the fluid or the gas towards the grinding wheel. The blowing element <NUM> may be a fan, or any other device suitable for generating a pressurize streaming of gas or fluid or a combination thereof and direct it to a desired location. The support element <NUM> is arranged to keep the blowing element <NUM> at a set distance d from the grinding wheel <NUM>. The grinding wheel <NUM> is rotatable connected to a driving motor <NUM> shown in <FIG> and <FIG>. The driving motor <NUM> provides rotational movement to the grinding wheel <NUM> in a parallel axis with respect to a stripping plane. Moreover, the grinding wheel <NUM> is connected to a bearing element <NUM> for moving the grinding wheel <NUM> around a perpendicular axis with respect to the stripping plane. As it can be seen in <FIG>, <FIG>, <FIG>, <FIG> and <FIG>, the blowing element <NUM> is mounted on the support element <NUM> and orientated such that the blowing element <NUM> can direct a stream of gas or fluid to the outside surface of the grinding wheel <NUM>. The blowing element <NUM> comprises an output <NUM> which in normal use is facing the surface of the grinding wheel <NUM>. The blowing element <NUM> is arranged to blow a fluid or a gas through the output <NUM> such that a stream of fluid or gas can be directed to the grinding wheel <NUM>.

As it can be seen in <FIG> and <FIG>, the support element <NUM> is movable mounted on the stripping device <NUM> via a hinge <NUM> such that the support element <NUM> can rotate over the hinge <NUM>. The support element <NUM> further comprises a regulating element <NUM> having the shape of a wheel. The regulating element <NUM> is arranged to stay in contact with the grinding wheel <NUM>. <FIG> provide further views of the support element <NUM> comprising the blowing element <NUM>, the hinge <NUM> and the regulating element <NUM>. <FIG> show the support element <NUM> without the blowing element <NUM>, the hinge <NUM> and the regulating element <NUM>. As it can be seen in <FIG>, the support element <NUM> comprises an opening <NUM> through which a bolt <NUM> (shown in <FIG>, <FIG> and <FIG>) is introduced such that the support element <NUM> is attached to the stripping device <NUM> and is able to pivot around the bolt <NUM>. As the blowing element <NUM> is mounted on the support element <NUM>, by pivoting the supporting element <NUM> around the hinge <NUM>, it is possible to move the blowing element <NUM> away or towards the grinding wheel <NUM>, thereby easily adjusting the distance between the grinding wheel and the blowing element. As the support element <NUM> further comprises the regulating element <NUM> which is arranged to contact the grinding wheel, the distance between the grinding wheel <NUM> and the blowing element <NUM> is kept substantially constant even when a diameter of the grinding wheel <NUM> is reduced due to use of the grinding wheel. When the diameter of the grinding wheel reduces, the regulating element <NUM> descends towards the grinding wheel <NUM> and pulls from the support element <NUM> which pivots around the hinge <NUM> thereby bringing the blowing element <NUM> towards the grinding wheel <NUM> and compensating for the diameter change such that the blowing element <NUM> and the grinding wheel <NUM> are kept at substantially the same distance d. This can be seen in <FIG>, which shows the stripping device of <FIG> wherein the grinding wheel <NUM> has a reduced diameter compared to <FIG> because the grinding wheel <NUM> surface has been wasted away after being used for a certain time. <FIG> also shows how the support element <NUM> has pivot around the hinge <NUM> from a first position shown in <FIG> to a second position shown in <FIG> such that the distance between the blowing element <NUM> and the grinding wheel <NUM> is kept substantially the same in both <FIG> and <FIG>. Although the regulating element <NUM> is shown as a wheel, it may have any other suitable shape or configuration that allows the support member <NUM> to move for compensating a diameter reduction of the grinding wheel. The desired distance d may depend on the blowing speed of the blowing element <NUM> or any other system parameter.

The regulating element <NUM> may be further arranged to provide a measurement of a change in the grinding wheel diameter. As the wheel is in contact with the grinding wheel <NUM>, the regulating element <NUM> can provide a measurement of the reduction of the diameter of the grinding wheel <NUM>. The regulating element <NUM> may comprise a movement sensor which can indicate the reduction in the grinding wheel diameter.

As shown in <FIG>, <FIG>, <FIG>, <FIG>, the blowing device <NUM> comprises a conduct <NUM> fluidly connected to the blowing element <NUM> such that a fluid or a gas or any combination thereby can pass through the conduct <NUM> to the blowing element <NUM> for providing a stream of the fluid or gas to the grinding wheel <NUM>. The conduct <NUM> may be fluidly connected to the blowing element <NUM> at input <NUM>. Part of the conduct <NUM> may partially surround the outside of the stripping device <NUM> before entering the inside of the stripping device <NUM> at a connection input <NUM>. The conduct <NUM> may be arranged in any other suitable way. After entering the device <NUM> at the connection input <NUM>, the conduct <NUM> may be further arranged extending along a grinding wheel orientation axis <NUM> (shown in <FIG>, <FIG>, <FIG>, <FIG> and <FIG>) of the stripping device such that the grinding wheel <NUM> can turn for positioning around the wheel orientation axis <NUM> without interference of the conduct <NUM>.

The blowing device <NUM> may further comprise a cooling device (not shown in the figures). The conduct <NUM> may pass through the cooling device thereby cooling the fluid or gas inside of the conduct <NUM>.

<FIG> shows also a transmission system <NUM>, which is connected to the computer system, actuates the bearing element <NUM> that rotates the gridding wheel <NUM>. The gridding wheel <NUM> may be made of an abrasive material having a fine or ultra-fine grain size of at least <NUM> in grain diameter. Upon usage of the gridding wheel <NUM>, the material may be subject to some wear and tear, meaning this that the outer diameter of the gridding wheel <NUM> is progressively decreasing. Initially, the gridding wheel <NUM> may have an outer diameter of at least <NUM>. Due to the continuous decrease of the outer diameter of the gridding wheel <NUM>, calibration of the height positioning of the gridding wheel <NUM> is necessary. This calibration is done by lowering the gridding wheel <NUM> up to a level wherein its outer periphery is in contact with the surface of the glass panel. Also due to this decrease of the outer diameter, the position of the blowing element <NUM> with respect to the grinding wheel <NUM> may need adjustment in order to keep a desired distance between the blowing element <NUM> and the grinding wheel <NUM>.

The stripping device <NUM> further comprises a calibration system <NUM> for the stripping member <NUM> which can be best seen in <FIG> and <FIG>. The stripping device <NUM> also comprises a main supporting element <NUM> wherein the different parts and/or elements forming the device <NUM> are mounted.

As shown, a height adjustment system <NUM> for the grinding wheel <NUM> is mounted on a supporting plate <NUM>. The supporting plate provides a fix and steady supporting point to the calibration and adjustment systems <NUM>, <NUM>, <NUM>. In this manner, a support structure for the calibration systems is provided, which can be accessed for maintenance and/or reparations of any of parts of the calibration systems <NUM>, <NUM>, <NUM> in an easy manner.

The operation of calibration of the gridding wheel <NUM> is done by firstly moving the stripping device <NUM> to a calibration area. The calibration area can be any position on top of the support surface of the cutting table. Once the stripping device <NUM> is at the position within the calibration area, the calibration system <NUM> for the gridding wheel <NUM> will move the gridding wheel <NUM> along the vertical axis Y until the lower point of the gridding wheel <NUM> is in contact with the support surface of the cutting table in a first contact position. This first contact position is stored in a memory, such that when a glass panel <NUM> is positioned in a substantially horizontal position on the support surface, the user can enter the thickness of the glass panel <NUM>, previously known by the user, such that the height adjustment system <NUM> can move the gridding wheel <NUM> to a lower level where the lower point of the gridding wheel <NUM> contacts the surface of the glass panel <NUM>.

The operation of the device according to the present invention will be explained here. During the operation of the system, and after the calibration of the gridding wheel <NUM>, the removing operation of the low emission layer and/or the protective layer on glass panel <NUM> can be safely and efficiently done. Firstly, the glass panel <NUM> is positioned in the support surface <NUM> of the cutting table <NUM>. The glass panel <NUM> has been previously measured and this data has been stored in a memory of the computer system controlling the stripping device <NUM>. The user will enter data concerning the number of intersections and predetermined linear stripping lines to be performed on the surface of the glass panel <NUM>, in order to perform the stripping operation on the glass panel <NUM>.

The skilled person will appreciate that, this detail explanation on the operation of the stripping device <NUM>, is meant for a glass panels having a number of perpendicular intersections between predetermined linear stripping lines, otherwise indicated.

Following, the positioning bridge <NUM> moves over the glass panel <NUM> along the axis X and Z. During this movement, the grinding wheel <NUM> is at a minimum vertical distance from the surface of the glass panel <NUM>. In this manner, a substantial height adjustment prior to start the removing operation is avoided at a later stage of the stripping operation. Said distance is always at this stage a non-touching distance. Once the stripping device <NUM> is positioned at a predetermined starting point, the grinding wheel <NUM> is lowered up to a level wherein its lower point is in contact with the surface of the glass panel <NUM>. In order to have a proper control of this movement and of the positioning of the grinding wheel <NUM>, an analogue sensor (not illustrated) for accurate movement of the grinding wheel <NUM> is installed in the height adjustment system <NUM>. The blowing device <NUM> may be blowing a fluid or a gas towards the grinding wheel <NUM> since the beginning of the stripping operation or may start upon detection that the grinding wheel is heated above a certain threshold. This might be detected by using a temperature sensor located at or near the grinding wheel. Furthermore, the blowing device may be activated or deactivated at any convenient moment.

It should be noted that the arrangement to determine the right order of performing the removing operation on a glass panel, depends on firstly performing the removing operation of the low emission layer and/or the protective layer along one of the predetermined linear stripping line, and subsequently, the device searches on a saved and stored matrix, in the computer system, which is composed of a number of predetermined linear stripping lines, where there is the closest intersection point between two predetermined linear stripping lines, in order to start the removing operation again along a new predetermined linear stripping line. Preferably, the closest intersection should be the intersection of the last predetermined linear stripping line wherein the stripping operation has been lastly performed.

The removing operation is performed in a similar manner, when the form to be striped is a non-rectangular form e.g. a triangle, the intersections between predetermined stripping lines are considered to be non-tangential between them. The starting point to perform the removing operation may be any point of the predetermined linear stripping lines.

The stripping device <NUM> may further comprise a cover element defining a stripping volume such that the grinding wheel <NUM> is arranged inside the stripping volume. The stripping device <NUM> may further comprise an aspiration device for creating a vacuum effect within the stripping volume and for collecting particles stripped off the low emission layer and/or the protective layer by the stripping action of the grinding wheel <NUM>. The aspiration device may be provided with an aspiration tube being fluidly connected to the stripping volume for discharging the particles stripped off the low emission layer and/or the protective layer. The stripping device <NUM> may further comprise a collector member with a storage part for collecting parts of the low emission layer and/or the protective layer, and an air exhaust part for exhausting air.

<CIT> shows embodiments in which this invention can be applied. The stripping device <NUM> may comprise further a cover element as the one described and explained in <CIT>, wherein the stripping member is arranged inside a stripping volume defined by the cover element, and wherein the stripping device <NUM> further comprises an aspiration device for creating a vacuum effect within said stripping volume and for collecting particles stripped off the low emission layer and/or the protective layer by the stripping action of the stripping member. The aspiration device <NUM> is provided with an aspiration tube being fluidly connected to the stripping volume for discharging the particles stripped off the low emission layer and/or the protective layer, a storage part for collecting parts of the low emission layer and/or the protective layer, and an air exhaust part for exhausting air.

Claim 1:
A device for removing a low emission layer and/or a protective layer of a glass panel, comprising:
- supporting means for supporting the glass panel, wherein, when the glass panel is positioned horizontally on the supporting means, an upper surface of the glass panel is provided with the low emission layer and/or the protective layer to be removed,
- a positioning bridge having a horizontally extending positioning portion arranged at a vertical distance from the upper surface of the glass panel and the supporting means,
- a stripping device configured to remove the low emission layer and/or the protective layer of the glass panel wherein the stripping device (<NUM>) comprises a stripping member, wherein the stripping member comprises a grinding wheel (<NUM>) being rotatable arranged around a wheel rotation axis, and wherein the stripping device comprises a blowing device (<NUM>) comprising a support element (<NUM>) and a blowing element (<NUM>) wherein the blowing element (<NUM>) is mounted on the support element (<NUM>) and arranged to blow a fluid or a gas and wherein the support element (<NUM>) is arranged to keep the blowing element (<NUM>) at a distance from the grinding wheel (<NUM>) such that the blowing element (<NUM>) can direct a stream of the fluid or the gas towards the grinding wheel (<NUM>), wherein the blowing device (<NUM>) further comprises a cooling device arranged to cool the fluid or gas before is streamed towards the grinding wheel, and wherein the stripping device is arranged to move along the positioning portion in a horizontal direction, and over the upper surface of the glass panel, and the wheel rotation axis of the grinding wheel is parallel to the upper surface of the glass panel.