Patent Description:
Transport systems are known which are used to move glass plates between two stations of a production plant, in which processing operations for the production of glass plates are carried out. These known glass plate transport systems present the problem of requiring optimal occupation of the available area, especially in the case of processes, such as tempering, which, in order to obtain a good quality of the process, require that plates of different sizes are spaced and arranged in a suitable manner.

In order to optimally arrange the plates, known glass plate transport systems comprise a feed table on which the glass plates to be moved are arranged, comprising first conveyor means for moving the glass plate in a longitudinal direction and second conveyor means for moving the glass plate in a transverse direction so as to arrange the glass plates on the feed table in appropriate positions for movement to the next processing station.

Known glass plate transport systems comprising a feeding table have problems of reliability, due to the complexity of implementation and management of the first and second conveyor means, which also cause high implementation and management costs, significant encumbrances and do not guarantee optimal occupation of the area available for arranging the glass plates.

A bench having conveyor means configured to distribute a plurality of plates over a bench area in an optimized manner is known from <CIT>. This known device is complex and expensive and requires the use of conveyor devices each having its own drive system. An optimization bench is also described in <CIT>, but involves an even more complex conveyor system with a matrix of pivoting conveying rollers. Document <CIT> shows a conveyor system for transporting industrial components, for example automotive body components, comprising a plurality of belt conveyors parallel to each other, each of which is adjustable in position both vertically and transversely, to adapt the group of belt conveyors to receive and support components having different configurations. Each belt conveyor has its own drive system. Such a conveyor system is not configured to optimise the distribution of a plurality of products in a given area.

A bench according to the preamble of claim <NUM> is known from <CIT>. Another solution is known from <CIT>.

The purpose of the present invention is to solve the above-mentioned problems of the prior art by providing an optimization bench for glass plates which is reliable, whci can be produced and operated at low cost, which is space-saving and able to achieve an optimal occupation of the area available for the glass plates.

The above and other purposes and advantages of the invention, as will result from the following description, are achieved with a glass plate optimization bench according to claim <NUM> and a method according to claim <NUM>. Preferred embodiments of the present invention form the subject matter of the dependent claims.

It is understood that the appended claims form an integral part of the present description.

It will be immediately obvious that innumerable variations and modifications (e.g., with respect to shape, dimensions, arrangements and parts with equivalent functionality) can be made to what is described without departing from the scope of protection of the invention as reflected in the appended claims.

The present invention will be best described by a preferred embodiment, provided by way of not-limiting example, with reference to the accompanying drawings, in which:.

Referring to the figures, the optimization bench <NUM> for glass plates according to the invention comprises a base <NUM> and conveyor means in the form of a plurality of belt conveyors <NUM>, parallel to each other and extending in a horizontal longitudinal direction X-X of the bench. The belt conveyors <NUM> are configured for supporting and positioning a plurality of glass plates over the area available on the bench, so as to achieve optimal occupation of this area.

The belt conveyors <NUM> constituting the conveyor means can be selectively driven, individually or in groups, by drive means <NUM>, <NUM> which will be described below, which in turn are controlled by an electronic controller E (<FIG>), comprising one or more electronic units, to control and coordinate the movement of the plates on the optimization bench <NUM> so as to arrange the plates in the most suitable positions to obtain an optimal occupation of the available area.

As will be apparent from the description below, the belt conveyors <NUM> are therefore operable selectively, according to any criteria, i.e. also independently of each other, or in groups independent of each other, with the possibility of varying as desired which and how many conveyors make up each group of conveyors that are operated simultaneously and in synchronism.

The drive means comprise motor means, which in a preferred example comprise a single electric motor <NUM> and a transmission system <NUM>. The belt conveyors <NUM> are driven by the electric motor <NUM> via respective electrically operated clutches <NUM>, forming part of the transmission system <NUM>, which are controlled by the electronic controller E, to make possible the aforementioned selective drive of the belt conveyors <NUM>. Naturally, it would be also possibile to provide more electric motors <NUM>, each of which controls a respective sub-group of belt conveyors <NUM>, by means of respective electrically operated clutches <NUM> controlled by the electronic controller E.

Each belt conveyor <NUM> comprises an endless belt engaged on two pulleys <NUM>, <NUM> rotatably supported by the base <NUM>.

As indicated, in a preferred example there is provided a single electric motor <NUM> (<FIG>) which drives (through a <NUM> degree gearbox in the example of <FIG>) a drive shaft <NUM> arranged transversely to the longitudinal direction of the bench, which is rotatably supported by the base <NUM> by means of rolling bearings (see <FIG>).

Preferably, the glass plate optimization bench <NUM> of the invention comprises a plurality of transmission units <NUM> respectively associated with the belt conveyors <NUM> and configured to control the rotation of the traction pulley <NUM> of each belt conveyor <NUM>.

A plurality of pulleys <NUM> (two of which are visible in <FIG>) are rigidly connected to the transverse shaft <NUM> at axially spaced positions.

Each transmission unit <NUM> associated with each belt conveyor <NUM> comprises a respective pulley <NUM> (of said pulleys <NUM> which are mounted on the shaft <NUM>) and a respective drive pulley <NUM> pivotably supported on the base <NUM> and connected to the respective pulley <NUM> by a belt drive <NUM> (see <FIG> and <FIG>).

Referring to <FIG>, in the illustrated example, each traction pulley <NUM> of a respective belt conveyor <NUM> is rigidly rotationally mounted on a respective shaft <NUM> which is rotatably supported, for example by means of rolling bearings (in the manner which will be described in detail below) on the base <NUM>. Above each shaft <NUM> the respective drive pulley <NUM> of the respective drive unit <NUM> is also freely rotatably mounted, in the example by means of a rolling bearing.

Between the traction pulley <NUM> of each belt conveyor <NUM> and the respective drive pulley <NUM> there is axially interposed an electrically operated clutch <NUM> which, when activated, is capable of rotationally connecting the drive pulley <NUM> with the traction pulley <NUM>.

The electrically actuated clutch <NUM> associated with each belt conveyor <NUM> may be of any known type. In the illustrated example, each clutch <NUM> is an electromagnetically actuated disc clutch. In accordance with a conventional technique for clutches of this type, the clutch comprises discs <NUM> (<FIG>) that can be axially pushed into frictional contact with each other by the electromagnetic drive, such that a first portion of the clutch <NUM> that is rotationally connected with the respective shaft <NUM> (the portion on the righthand side of the discs <NUM> in <FIG>) is rotationally connected with a second portion of the clutch that is rotationally connected with the pulley <NUM>. Further constructional details of the clutch <NUM> are not described herein, as they may be of any known type and are not, taken alone, within the scope of the present invention.

Due to the arrangement described above, the electric motor <NUM>, when activated, drives the rotation of the transverse shaft <NUM>. The rotation of the shaft <NUM> is transmitted by the belt transmissions <NUM> to the pulleys <NUM>. The rotation of each pulley <NUM> may be transmitted to the pulley <NUM> of the respective belt conveyor through activation of the respective clutch <NUM> by the electronic controller E. The electronic controller E is therefore capable of independently activating each belt conveyor <NUM>.

As indicated above, the shaft <NUM> associated with each belt conveyor <NUM> is rotatably supported by the base <NUM>, via rolling bearings. In the preferred example illustrated herein, the bearings rotatably supporting each shaft <NUM> are carried by supports <NUM> which arev removably connected to the base <NUM>. Thus, the group of pulleys, indicated as a whole by reference <NUM> in <FIG>, which is associated with the traction pulley <NUM> of each belt conveyor <NUM>, the group comprising the shaft <NUM> with the traction pulley <NUM>, the pulley <NUM> and the clutch <NUM> interposed therebetween, constitutes a single unit removable as a whole from the base.

At the end of each belt conveyor <NUM> opposite to that illustrated in <FIG>, the belt of the conveyor <NUM> is engaged on a pulley <NUM> (see <FIG>) freely rotatably supported on the base. In the preferred example, the pulley <NUM> is also rigidly connected to a shaft mounted in a manner similar to the shaft <NUM> of <FIG>, i.e. supported in rotation by means of rolling bearings carried on supports similar to the supports <NUM> of <FIG>, which are removably connected (for example by screws) to the base <NUM>.

Thanks to the aforementioned features, the entire assembly comprising each individual belt conveyor can be easily and quickly removed from the bench <NUM>, in order to carry out maintenance operations or a replacement. In particular, it is possible to disengage the belt of the belt transmission <NUM> associated with an individual belt conveyor <NUM>. After that, at each end of the belt conveyor it is possible to remove the connection between the base <NUM> and the supports <NUM> carrying the unit of traction pulley <NUM> and the unit of non-driving pulley <NUM>. Having done so, the entire belt conveyor assembly can be removed by a sliding movement thereof in the direction X-X until it is removed from the bench.

Naturally, it would also be possible to provide more than one electric drive motor, each motor being able to control the selective activation of a group of belt conveyors <NUM> by activation of the respective clutches <NUM>.

With reference to <FIG>, a conveyor system comprising the optimization bench <NUM> for glass plates of the invention includes a plate loading system <NUM>, which may be operated manually by an operator or in an automized manner, and a plate unloading system <NUM>, for example comprising a roller conveyor, for forwarding the plates, which have been positioned in an optimized manner on the optimization bench <NUM>, to a subsequent station, for example a tempering furnace.

In the operation of the optimization bench <NUM> for glass plates according to the invention, the glass plates are loaded onto the optimization bench <NUM> using the plate loading system <NUM>, operated manually or automatically. In a subsequent step, the optimization of the space occupied by the plates on the bench <NUM> is carried out by activating the electric motor <NUM> and activating the belt conveyors <NUM> on which the plate, or plates, to be moved are positioned, through activation of the corresponding clutches <NUM>. The clutches are selected by the electronic controller to perform the optimal positioning of the glass plates on the optimization bench <NUM>, through a movement of the plates in the X-X longitudinal direction.

<FIG> are schematic plan views of the optimization bench <NUM>, showing examples of distribution of a plurality of glass plates on the bench.

In the example illustrated in <FIG>, the glass plates are arranged on the bench in parallel "rows" of plates, extending in the direction of the longitudinal dimension X of the bench <NUM>. The plates in each row all have the same transverse dimension, i.e. the dimension parallel to the transverse dimension Y of the bench <NUM>.

In the specific example of <FIG>, in the condition that the bench is totally occupied by plates, there is provided a first row of plates L1 all having the same transverse dimension Y1. A second row comprises a plate L2 having transverse dimension Y2 and three plates L4 arranged side by side, having widths Y4 less than Y2, so that the plates L4 occupy the space of one plate L2. A third row is occupied by plates L3 all having the same transverse dimension Y3.

The condition illustrated in <FIG> is achieved by placing the plates one at a time on the bench <NUM> by means of the plate loading system <NUM> or by means of any other loading system, for example by means of a manipulator robot. Once positioned on the bench <NUM>, each plate is advanced on the table by activating only the belt conveyors on which it is supported. Thus, in the case of <FIG>, the plates L1 progressively reach the position illustrated by activating only the belt conveyors on which the plates L1 are supported, and the same applies to the plates L2, L3 and L4.

In an embodiment, a plate magazine of any known type is arranged upstream of the optimization bench <NUM>, in which the plates are stored by dividing them into groups according to their transverse dimension (with reference to the condition in which the plate will be supported on the bench). Means of any known type are associated with the magazine to detect the presence and type of plates in the magazine and to send an information to the electronic controller which is saved in a memory associated with the electronic controller E, to form a database of the available plates.

The electronic controller E is thus able to control the plate loading system in such a way as to position the plates in different positions with respect to the transverse direction Y of the bench <NUM>, as a function of the transverse dimension of each plate, after which the electronic controller advances each plate placed on the table by operating only the belt conveyors on which the plate is supported (by activating the corresponding clutches <NUM>), until the plates are arranged on the bench in parallel longitudinal rows, in which the plates forming each row all have the same predetermined transverse dimension (or a transverse dimension smaller than said predetermined transverse dimension).

Naturally, the electronic controller E can activate different groups of belt conveyors <NUM> simultaneously, to form differnt rows of glass plates simultaneously.

Again with reference to <FIG>, in an actual implementation, the bench <NUM> has a longitudinal dimension X of <NUM> and a transverse dimension Y of <NUM>. In the example shown, plates L1, L2, L3 and L4 had transverse dimensions Y1, Y2, Y3 and Y4 of <NUM>, <NUM>, <NUM> and <NUM> respectively. In the case of this example, bench <NUM> was configured to operate with plates having any transverse dimension starting from <NUM> and any longitudinal dimension starting from <NUM>.

The electronic controller E is programmed to read the database of plates in the magazine and to define, based on the transverse dimension of the plates, the arrangement of the "rows" of plates in order to optimise the area of the optimization table.

Once the optimization has been defined, the plate loading system starts to transfer the plates that are to make up each "row" to the bench <NUM> and the electronic controller E activates the belt conveyors <NUM> required to advance each glass plate on the bench to the desired position.

Due to the fact that the optimization bench has independent belts, it is possible to exploit a second optimization criterion, which makes it possible to optimally distribute glass plates with different transverse dimensions Y on the same "row" of the bench <NUM>.

By way of example, <FIG> shows a distribution identical to that in <FIG>, except that on the row of glass plates L3 there are arranged plates L5 with a transverse dimension Y5 smaller than Y3 (in an actual example Y5 was <NUM>).

To achieve this condition, first the plates L5 are positioned, as illustrated in <FIG>, for example by activating only three belt conveyors <NUM> on which the L5 plates are supported. Subsequently, the plate L3 is transferred as in <FIG>, for example by activating a fourth belt conveyor <NUM>, on which the plate L3 also rests, in addition to the three belt conveyors already activated to transport the plates L5. The final positioning of the plates L5 and L3 is thus obtained by driving the aforementioned four belt conveyors at the same speed.

A third optimization criterion allows the positioning of shaped plates on the bench, enabling them to be kept adjacent to each other along the direction of the longitudinal dimension X of the table. By way of example, <FIG> shows a row of identical plates L6 with a parallelogram shape and oblique transverse sides. As illustrated, in this case the plates L6 may be arranged adjacent to each other, the distance between each plate L6 and the other being less than the space occupied in the X direction by each oblique side of the plates.

Claim 1:
A bench (<NUM>) for glass plates, comprising:
- a base (<NUM>)
- conveyor means (<NUM>) carried by the base and configured to support a plurality of glass plates (L1-L6) and to move the plates in a longitudinal direction (X-X) of the bench, and
- drive means (<NUM>, <NUM>), controlled by an electronic controller (E), for driving said conveyor means (<NUM>),
wherein:
- said conveyor means comprise a plurality of belt conveyors (<NUM>) parallel to each other, extending in the longitudinal direction (X-X) of the bench (<NUM>) and each comprising a belt and two end pulleys (<NUM>, <NUM>) engaged by the belt and rotatably supported by the base (<NUM>), said belt conveyors (<NUM>) being configured to support and transport the glass plates in the longitudinal direction (X-X) of the bench,
- said drive means comprise common motor means (<NUM>) for said belt conveyors and a transmission system (<NUM>) operatively interposed between said motor means (<NUM>) and said belt conveyors (<NUM>),
said bench being characterized in that:
- said transmission system (<NUM>) includes a plurality of electrically operated clutches (<NUM>) respectively associated with the belt conveyors (<NUM>) and selectively operable by said electronic controller (E) to control the movement of the respective belt conveyors (<NUM>), such that each belt conveyor (<NUM>) can be activated by said common motor means (<NUM>) independently of the other belt conveyors (<NUM>), by activation of the respective clutch (<NUM>),
- wherein said bench is an optimization bench, in which said electronic controller is configured to transport each plate by activating selectively only the belt conveyors (<NUM>) on which each plate is supported, coordinating the movements of the plates on the bench (<NUM>), in such a way as to distribute the plates in positions suitable to obtain an optimal occupation of the area available on the bench.