PROCEDURE FOR THE TREATMENT OF CATHODE-RAY TUBES AND

RELATED SYSTEM.

The invention concerns the sector of disposal of electronic equipment waste.

More particularly, the present invention concerns the treatment and/or recycling of cathode-ray tubes.

Even more particularly, the present invention concerns a procedure for treating cathode-ray tubes and a corresponding system intended to recover the parts of the equipment to be recycled or subjected to safety treatments.

As is known, cathode-ray tubes (CRT) are devices for reproducing images typically employed in television sets or computer screens, as well as in other equipment like automatic ticket or money dispensers or clinical and industrial devices.

A CRT substantially comprises a glass casing, inside which vacuum is created, consisting of a front panel or screen rigidly connected to one part, called cone, that tapers and ends with a cylindrical neck at the rear end of which one or more electron guns are positioned.

Each electron gun sends out a beam of electrons destined to be properly conveyed and directed onto a layer comprising fluorescent phosphoric material that covers the inner surface of the screen. The elements of phosphoric material of the above mentioned layer that are hit by the beam are excited and generate the desired image.

As is also known, the screen is rigidly connected to the cone along its perimetral edge by welding and the glass that makes it up is characterised by a high content of barium oxide and strontium oxide. This welding is carried out using a mixture containing metal powders, glass and a significant quantity of lead that form a connection area.

In turn, the glass of which the cone and the neck are made contains a high quantity of lead to limit the diffusion of the radiations generated by the electron guns, as well as other heavy metals. Considering the high number of CRTs discarded every year and the substances they contain, which are potentially harmful to the environment and to man, various directives and regulations have been issued regarding their final disposal.

According to said directives and regulations, when said CRTs are decommissioned they must be subjected to certain specific procedures. In particular, the above mentioned procedures include the separation of the

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components of the CRT and the recovery of those materials that can be used again, like glass, which represents more than 80% of the weight of the equipment, the phosphoric material and the metal components, if present.

Considering the various types of glass that make up the CRT, in order to guarantee a correct reutilization of said material it is necessary to duly separate the glass with high lead content used for the connection area, the cone and the neck from the glass with negligible lead content or no lead at all used for the screen.

Once separated and properly treated, the two types of glass obtained can be recycled and used for different purposes.

Therefore, the cutting of the CRT near the area connecting the two different types of glass, that is, between the screen and the cone, is a primary problem.

Said cutting operation must be carried out with great precision, in order to prevent the glass to be recycled of the screen from being contaminated by the lead present in the connection area and in the cone.

At present said cutting operation is performed manually by operators with the aid of suitable tools.

Before cutting, the operators ventilate the CRT in order to create a balance between the internal and external pressure and extract the electron guns. After cutting the CRT, the operators themselves provide for recovering the powders of phosphoric material of the screen and the glass components of the

CRT.

A first drawback posed by the procedures for recovering CRTs of known type lies therefore in that they require the intervention of one or more operators. A further drawback lies in that during these procedures the operators carry out dangerous and potentially toxic operations, in fact they are exposed to the particles of phosphoric material, of lead and of other heavy metals dispersed in the air.

Another drawback is represented by the fact that the working conditions of the operators are difficult due to the presence of said powders, to the vibrations transmitted to them and to the sparks and glass fragments produced during the cutting operation.

A further drawback is represented by the fact that the operator who handles the

CRT must proceed with the due care and competence, since this piece of equipment comprises fragile and delicate parts that can break and injure him/her.

The CRT, furthermore, may contain residual electrostatic charges. Another drawback is represented by the fact that the operations mentioned above require the intervention of specialised and skilled operators and the use of special equipment. A further drawback is constituted by the fact that execution times and costs are considerable and sometimes difficult to quantify.

Another drawback lies in that the manual cutting of the CRT near the connection area between the screen and the cone is difficult to carry out in a precise and accurate manner while at the same time avoiding undesired breakages. The object of the present invention is to overcome all the drawbacks described. In particular, it is one object of the present invention to implement a procedure and a corresponding system that considerably reduce the need for the intervention of operators during the treatment and/or recycling of a CRT. It is another object of the invention to implement a procedure and a corresponding system that reduce the time necessary for treating and/or recycling the discarded CRTs compared to the procedures and systems of known type. It is a further object of the invention to implement a procedure and a system intended to recover those parts of a CRT that can be recycled or subjected to safety treatments, reducing to a minimum and if possible eliminating the need for specialised labour.

It is another object of the invention to implement a procedure and a corresponding system that reduce to a minimum the costs for treating and/or recycling discarded CRTs. It is another object of the invention to implement a procedure and a corresponding system capable of separating the screen of a CRT from the cone of the same in a precise and accurate manner while at the same time avoiding undesired breakages.

It is another object of the invention to implement a procedure and a corresponding system that automatically remove the fluorescent phosphoric material that covers the screen of a CRT.

It is another object of the invention to implement a procedure and a corresponding system that ensure that the operators work in absolutely safe conditions, without being exposed to powders, vapours and other agents. It is another object of the invention to carry out a system that is protected from external contamination.

It is a further object of the invention to implement a procedure and a system that are simple to operate, efficient and economic, and that can be employed in continuous cycle lines for the treatment and/or recycling of CRTs.

The objects mentioned above are achieved by a procedure for the treatment of cathode-ray tubes and by a corresponding system as described and characterised in the respective independent claims.

Advantageous embodiments of the invention are described in the dependent claims.

One of the proposed solutions advantageously makes it possible to implement a procedure and a corresponding system that reduce to a minimum the need for the intervention of operators.

Still advantageously, one of the proposed solutions makes it possible to implement a procedure and a corresponding system including several operations that can be performed even on a continuous cycle line. Still advantageously, one of the proposed solutions makes it possible to carry out the treatment of a CRT in total safety, protecting the health of the operators.

Still advantageously, one of the proposed solutions makes it possible to cut a

CRT in an optimal manner and more rapidly than allowed by the procedures and systems of known type. Still advantageously, a proposed solution makes it possible to remove the phosphoric material of the screen of a CRT more rapidly and precisely than allowed by the procedures and systems of known type.

Still advantageously, a proposed solution makes it possible to implement a procedure and a system capable of reaching optimal efficiency, which means a higher number of treated pieces per unit of time compared to the procedures and systems of known type.

Still advantageously, a proposed solution makes it possible to carry out a system that ensures reduced noise levels and does not pollute the environment in which it is installed, and that will certainly obtain approval according to environmental protection regulations.

Still advantageously, a proposed solution makes it possible to carry out a system suitable for being monitored also by a remote control station.

The aims and advantages described above will be highlighted in greater detail in the description of some preferred embodiments of the invention, provided indicatively as examples without limitation, with reference to the enclosed

drawings, wherein:

- Figure 1 shows a schematic view of one operation of the procedure that is the subject of the invention;

- Figures from 2 to 6 show each a schematic view of the same number of operations included in some variants of the procedure that is the subject of the invention;

- Figure 7 shows a schematic side view of a system carried out according to the present invention;

- Figure 8 shows a schematic plan view of the system of Figure 7; - Figure 9 shows a schematic front view of the system of Figure 7;

- Figures from 10 to 14 show some schematic views of some parts of the system of Figure 7 in a corresponding number of operating positions;

- Figures 15 and 16 respectively show a schematic side view and a plan view of another example of a system carried out according to the present invention; - Figure 17 shows a schematic side view of another construction variant of a system carried out according to the invention;

- Figures from 18 to 20 show each a schematic front view of an operating position of the system of Figure 17;

- Figures 21 and 22 respectively show a side view and a plan view of another example of a system carried out according to the invention;

- Figure 23 shows a front view of a first operating phase of the system shown in Figure 21;

- Figures from 24 to 26 show each a schematic side view of the system of Figure 21 in a corresponding number of operating positions; - Figure 27 shows a schematic plan view of the system of Figure 21 in a successive operating position;

- Figures from 28 to 31 show each a schematic side view of the same number of successive operating phases of the system of Figure 21;

- Figure 32 shows some parts of a further embodiment of the system that is the subject of the invention;

- Figure 33 shows a schematic side view of a part of another example of the system that is the subject of the invention.

First of all it is important to point out that corresponding components in different examples of embodiment are indicated by the same reference numbers. In the case of a change in the position of the parts that make up the invention, the

position indications given in the individual executive examples must be transferred, according to logic, to the new position.

While the following description, made with reference to the above mentioned figures, illustrates some particular embodiments of the present invention, it is clear that the invention is not limited to said particular embodiments, rather, the individual embodiments described here below clarify different aspects of the present invention, the scope and purpose of which are defined in the claims.

A procedure for the treatment of cathode-ray tubes (CRT), which is the subject of the present invention, is schematically illustrated in Figure 1. The CRT, indicated as a whole by the letter T, comprises a screen S, a cone C and an area G that connects the screen S to the cone C.

The above mentioned procedure substantially comprises an operation for cutting the CRT T carried out along a cutting plane 50 by arranging the CRT T with the screen S facing upwards. More particularly, according to the procedure, the screen S is preferably arranged on a substantially horizontal plane.

The cutting operation is suited to divide the CRT T into at least a first part A and at least a second part B.

During said cutting operation the second part B is arranged below the part A with respect to the cutting plane 50.

It should be noted that the cutting plane 50 preferably intersects the connection area G or part of the screen S but does not involve the cone C.

More particularly, the cutting plane 50 preferably involves a part of the screen S near the connection area G. This in order to advantageously allow the CRT T to be divided into a first part A preferably including the glass that makes up the screen S, said glass having a negligible lead content or no lead at all, and a second part B preferably including the glass that makes up the connection area G and the cone C, said glass having a high lead content. The procedure that is the subject of the invention also comprises an operation for separating the second part B from the first part A wherein the second part B preferably falls by gravity, as illustrated in Figure 2.

This procedure therefore advantageously makes it possibile to recover the two different types of glass mentioned above that are present in a CRT T in order to subject them to successive recycling or safety treatments.

The procedure proposed may also comprise an operation intended to hit/shake the CRT T near the cut performed on the CRT T itself. This operation is suited to facilitate the separation of the second part B from the first part A, as shown in Figure 3, and is carried out by means of hitting members 60. Said members 60 are suited to hit the CRT T substantially in the area affected by the cutting plane 50 after said cutting operation has been performed.

This last operation advantageously makes it possible to obtain the separation of the two parts A and B also in the cases in which there are uncut portions of glass that maintain the two parts A and B still joined together. These areas mainly affect the vertexes of the CRT and more precisely of the screen S.

The procedure that is the subject of the invention may also comprise an operation for removing the phosphoric material that covers a surface S 1 of the screen S of the CRT T and in particular the surface Sl facing the cutting plane 50. This operation is preferably performed by brushing the surface Sl with rotary brushes 51, as schematically shown in Figures 4, 5, and/or by washing the surface Sl, as schematically shown in Figure 6.

The washing operation is carried out with at least one liquid jet 52, preferably comprising water. More particularly, it is carried out by spraying a liquid that is successively and preferably collected into a tank 53 in order to be subjected to specific treatments for the recovery of the phosphoric material M contained therein or, alternatively, to be disposed of and/or treated.

Obviously, the procedure may also comprise a phase for the suction of the phosphors present on the surface Sl, for example during the brushing phase. A preferred and non-limiting example of embodiment of a system that is also the subject of the present invention and is suited to implement the procedure described above is schematically represented in Figures 7, 8 and 9, where it is indicated as a whole by 1.

Said system 1 is particularly suited to be used in continuous cycle lines for the treatment and/or recycling of CRTs. It is intended to cut a CRT T along a cutting plane 50 preferably near the connection area G in order to divide it into a first part A and a second part B and to separate the second part B from the first part A as described above. More particularly, the first part A preferably comprises glass of the screen S and the second part B preferably comprises glass of the connection area G and of the cone C as already explained above.

The system 1 comprises means for cutting the CRT T, indicated as a whole by number 10, holding means suited to hold the CRT T during the cutting phase and indicated as a whole by 20, and moving means suited to mutually move the CRT T with respect to the cutting means 10 and indicated as a whole by 30. According to the preferred embodiment of the invention illustrated herein, said holding means 20 are suited to hold the CRT T so that it is arranged with the screen S substantially facing upwards during the cutting operation. In other words, the second part B is arranged below the first part A with respect to the cutting plane 50, as will be described in greater detail below. This advantageously allows the second part B to fall by gravity after the cutting operation.

Said holding means 20, represented in greater detail in Figure 10, preferably comprise one or more devices 21 suited to be bound to the screen S of the CRT T. More particularly, said devices operate through suction and/or the creation of vacuum.

More precisely, in the preferred non-limiting embodiment represented herein, said devices 21 comprise suckers that are suited to come into contact with the surface S2 of the screen S and cooperate with means suited to create vacuum between each sucker and the screen S. It is clear that, alternatively, said holding means 20 may comprise other types of devices 21 like for example pliers or handling mechanisms. As regards the cutting means 10, in the preferred and non-limiting embodiment of the invention represented herein they comprise at least one cutting station indicated as a whole by 11 in Figures 8, 9 and 10. Said cutting station 11 comprises one or more cutting devices, each one indicated as a whole by 12. Each of them defines a cutting plane that is substantially coplanar to the cutting plane 50.

In the particular example of embodiment illustrated in the figure, said cutting devices 12 are two and they move along at least one axis, indicated by 2 in Figures 8, 9 and 10, that is substantially parallel to the cutting plane 50 and transversal and more particularly orthogonal to the mutual direction of movement of the means 10 and the CRT. This makes it possibile to adapt their mutual position to the size of the CRT T to be treated, as will be described more clearly below, in order to allow CRTs T of various sizes to be cut. According to the invention, the cutting devices 12 are preferably carried by

carriages, not represented, suited to slide along at least one rail.

In the non-limiting example of embodiment represented herein, each one of the cutting devices 12 comprises at least one circular blade 13, rotating around a respective axis 3 that is substantially orthogonal to the cutting plane 50. Said circular blade 13 is preferably of the diamond type.

Tests have shown that this material has mechanical and physical properties that make it particularly suitable for cutting CRTs T rapidly and with great precision and accuracy.

Nonetheless, it is clear that other types of blades 13, even if not circular in shape and made of materials having characteristics similar to those of the material specified above can be used, provided that they are suitable for achieving the objects of the invention.

Alternatively, in further embodiments of the invention, each cutting device 12 may comprise at least one laser cutting device or a water jet cutting device. It should be observed that in these further construction variants the cutting station

11 may advantageously comprise only one cutting device 12.

As regards the moving means 30 represented in Figures from 8 to 13, in the preferred embodiment of the invention illustrated herein they cooperate with the holding means 20. More particularly, said moving means 30 are suited to move the cathode-ray tube

T and in particular the holding means 20 at least along one axis 4, shown in

Figures 7 and 8, substantially parallel to the cutting plane 50, in order to make the CRT engage with the cutting means 10.

In the non-limiting example of embodiment illustrated herein, they comprise guide means, not represented, comprising two parallel rails on which corresponding moving carriages slide.

In the particular embodiment of the invention represented herein, each carriage is moved by a timing belt that is not represented, either, cooperating with a pinion, not represented, operated by a preferably electric driving means. Alternatively, rack systems may be used.

It is clear that these movements can be alternatively performed by means of hydraulic or pneumatic devices.

It is clear that in other embodiments of the invention the mentioned mechanical members can consist of other systems having equivalent functions. The moving means 30, furthermore, a suited to move the holding means 20 along

an axis 9 substantially orthogonal to the cutting plane 50 to move the CRT T from at least a first collection position, represented in Figures from 7 to 11, to at least a second raised position, shown in Figure 12.

More particularly, when the holding means are in the raised position the CRT T is arranged so that the cutting plane 50 intersects the CRT in the desired area as described above.

The moving means 30 are furthermore suited to rotate the holding means 20 by at least 90° with respect to the axis 9.

In other words, in the particular non-limiting example of embodiment described herein, the moving means 30 comprise members suited to translate the holding means 20 along the two axes 4 and 9, as well as to rotate said holding means 20 with respect to the axis 9, as shown in particular in Figure 13 and as will be better described below.

These members are preferably operated by hydraulic and/or pneumatic driving means.

Always according to the invention, the system 1 also comprises measuring means, indicated as a whole by 40 in Figures 9 and 10.

Said means 40 are suited to measure the size of the CRT T and cooperate with the cutting devices 11 in order to allow them to move away from/approach each other by moving along the directions indicated by 2 in Figures 8, 9 and 10, in such a way as to be able to come into contact with the CRT T and cut it.

In the preferred and non-limiting embodiment of the invention represented herein, said measuring means 40, two of which are visible in Figures 9 and 10, comprise two pairs of proximity sensors indicated by 41, a first pair arranged upstream of the cutting means 11 and a second pair arranged downstream of the cutting means 11, as shown in particular in Figure 14.

Each one of said proximity sensors 41 comprises two feeler elements suited to come into contact with the CRT T.

This advantageously allows the cutting devices 11 to be positioned a first time so as to be able to come into contact with two opposite sides of the CRT T and to carry out the first cutting operation, and then to be positioned a second time so as to be able to come into contact with the other two sides of the CRT and to carry out the second cutting operation, as will be described more clearly below.

It is clear that in other embodiments of the invention different types of sensors having equivalent functions may be used, like for example photosensors, laser

sensors, position sensors or photocells.

Another preferred example of embodiment of a system suited to implement the procedure that is the subject of the invention is represented in Figures 15 and 16, where it is indicated as a whole by 100. It differs from the previous one due to the fact that the cutting means 10 comprise at least two cutting stations.

More particularly, the cutting means 10 comprise a first cutting station 11a and a second cutting station l ib arranged along axis 4 and defining substantially coincident cutting planes 50. The first cutting station 1 Ia is suited to perform a first cut of two opposite sides of the CRT T and the second cutting station 1 Ib is suited to cut the other two sides.

It is clear that in further embodiments of the system that is the subject of the invention the cutting stations 11 may also be more than two. Another preferred embodiment of a system suited to implement the procedure that is the subject of the invention is represented in Figures from 17 to 20, where it is indicated as a whole by 200.

It differs from the previous embodiment described in that it comprises hitting/shaking means 70 arranged downstream of the second cutting station 1 Ib. Said means 70 comprise hitting members 71 moved by kinematic mechanisms and are suited to hit the CRT T, as shown in Figures from 18 to 20, near the cutting area in order to facilitate the separation of the two parts by breaking any connection area that may have not been cut.

This advantageously makes it possible to separate the two parts even if the part B is particularly resistant and difficult to be detached from the part A and/or if there are areas where the cut has not been performed completely.

Another preferred embodiment of a system suited to implement the procedure that is the subject of the invention is represented in Figures 21 and 22, where it is indicated as a whole by 300. It differs from the previous embodiment in that it also comprises means 80 suited to remove the phosphoric material that covers the surface Sl of the screen S of the CRT T.

More particularly, said means 80 comprise one or more powered rotary brushes

81 suited to remove the above mentioned material M and devices for sucking the powders released by the brushes 81 , not represented.

As an alternative or in addition to the brushes 81 and the suction devices, the means 80 may comprise washing devices suited to release liquid jets, preferably water jets, onto the layer of phosphoric material of the surface Sl of the screen S.

The liquid containing said phosphoric material may then be properly collected into a tank 84 located under the washing devices and subjected to successive treatments for the recovery of said material or, alternatively, it may be disposed of.

It should be observed that, to advantage, in this embodiment of the invention the dispersion of phosphoric powders in the air is eliminated or at least reduced to a minimum.

The system may also advantageously be provided with side walls suited to define a tunnel inside which all of the operations described above are performed.

It is clear that in further embodiments of the invention the cutting station 11 may even be just one. Further embodiments of the system that is the subject of the invention, not represented herein, differ from the previous ones in that the moving means are suited to move the cutting means 10 with respect to the CRT T in such a way as to cut the CRT T along the plane 50.

According to an example of these different embodiments, the cutting devices 12 may move along at least two axes substantially parallel to said cutting plane 50 and/or move along at least one axis substantially orthogonal to said cutting plane

50 and/or may move angularly around at least one axis substantially orthogonal to said cutting plane 50.

Said movements respectively allow the cutting devices 12 to come into contact with the CRT T and cut it, to be positioned at the height of the cutting plane 50 and to move around the profile of the CRT T in line with the cutting plane 50 to cut the CRT itself.

It is also clear that in further embodiments of the system that is the subject of the invention the mutual movement between the CRT T and the cutting means 10 may take place through mixed systems, that is, systems that include the movement of both the CRT T and the cutting means 10.

The operation of the system of the invention will successively be described making reference to the embodiment illustrated in particular in Figures 21 and 22, the latter being the most complete among the described embodiments. The other embodiments of the system described herein, in fact, do not include

some of the operations or stations present in the system illustrated in Figure 21. The CRT to be treated is initially arranged in the collection position with the screen S facing upwards, as shown in particular in Figure 23, in order to allow the measuring means to measure one side of the CRT T and thus position the cutting devices 12 at the mutual distance that is useful to cut the CRT T.

Successively, the moving means 30 move the holding means 20 along the axis 9 until bringing the suckers 21 into contact with the surface S2 of the screen S. At this point vacuum is created and the CRT is anchored to the holding means 20 that, through the moving means 30, move it to the raised position shown in Figure 24, in which the cutting plane 50 intersects the CRT T in the desired cutting area.

Successively the moving means 30 move the CRT T along the longitudinal axis 4 of the system in such a way as to position the CRT T first in contact with the blades 13 and then downstream of the first cutting station 11a, thus cutting two sides of the CRT T, as shown in Figures 25 and 26. In this regard it should be noted that the opposing position of the cutting blades 13 is such that each of them exerts on the CRT T a force directed crosswise to its advance direction, but in opposite directions. As a consequence of the above, the two forces nullify each other and thus the CRT can be held more easily. Successively the moving means 30 rotate the CRT T by 90° around the axis 9, as shown in Figure 27.

The second pair of feelers 42 thus starts operating to determine the dimensions of the second side of the CRT T and thus position the second pair of blades 13 for the cutting operation, as shown in detail in Figure 28. Successively, the CRT T is further advanced until it is positioned downstream of the second pair of blades 13, as shown in Figure 29.

The CRT is then stopped and, if the lower part B has not yet detached from the upper part A, the hitting means 70 intervene and, as shown in Figure 30, shake the CRT T, thus ensuring the separation of the two parts. The second part B is collected in a first container not represented in the drawings. It should be noted that the screen S remains anchored to the holding means 20 that bring it to the successive washing station 80, where the water jets and the brushes eliminate the phosphors present on the surface S2. The waste is then collected in the tank 84 and sent to the treatment phase. The screen S, instead, is moved further forward until it is in line with a conveyor

belt 90 where it is released, as shown in Figure 32, and from where it is successively sent to a second container.

The operation of the other systems differs from the operation of the system described above in that the cutting is performed by means of a single blade that moves along the perimeter of the cutting area of the CRT T or alternatively by holding the cutting blade still and moving the CRT T in such a way as to cut it as shown for example in Figure 33.

It is clear that, alternatively, both the blade and the CRT T can move at the same time to carry out the above mentioned cutting operation, The above description clearly shows that the proposed solution allows the set objects to be achieved.

Even though the invention has been described making reference to the attached drawings, upon implementation changes can be made that shall all be considered protected by the present patent, provided that they fall within the scope of the inventive concept expressed in the following claims.

It is also important to remember that when the details mentioned in the claims below are followed by references, these must be understood as meant to improve the comprehensibility of the claim in question and not as a limit to the interpretation of the same.