WO2009092394A1

WO2009092394A1 - Vibrating screen apparatus for conglomerates

Info

Publication number: WO2009092394A1
Application number: PCT/EP2008/000526
Authority: WO
Inventors: Nereo Portello; Fabio Bagnaresi; Andrea Pirazzini
Original assignee: Marini S.P.A.
Priority date: 2008-01-24
Filing date: 2008-01-24
Publication date: 2009-07-30
Also published as: EP2257391B1; EP2257391A1; ES2409742T3

Abstract

Vibrating screen apparatus (1) embodying at least one screen element (7) transversely insertable and/or extractable by means of movement substantially on the riddling plane, said screen element (7) including at the internal end hooking means (8) to hook to a supporting structure (6) characterised in that said supporting structure (6) includes: first deviation means to deviate the insertion path of said screen element (7) from an insertion plane to an hooking plane in retraction; second deviation mean to deviate the path of said screen element (7) from an off-hook plane, to an extraction plane, during the movement of said first screen element first towards the inside as releasing action and then towards the exterior as extraction action.

Description

DESCRIPTION VIBRATING SCREEN APPARATUS FOR CONGLOMERATES

Technical Field

The present invention relates to a vibrating screen apparatus for conglomerates according to the characteristics of the pre-characterizing part of claim 1. Field of the Invention

This invention preferentially is applied even if not exclusively to the sector of machines and installations for the road flooring. Background Art In the treatment of inert materials an important role is paid by the size classification of themselves. Such operation intervenes in numerous processes for which is necessary that the material has well precise granulometric characteristics.

To carry out such classification or division on the basis of the material size one resorts to sifts, grids, etc, by means of such each element is classified on the basis of the sizes of openings of the used devices. Such method is said "riddling". The vibrating screen apparatus consists of a carpentry inside of which are accommodated one or more screen elements placed on one or more riddling levels. Each screen element is equipped with calibrated openings, with sizes progressively decreasing from a surface to the other, through which pass the constituting progressively smaller of the material to be classified. The biggest size material is stopped by the upper screen elements and the smaller size material falls on the lower screen elements until comes to rest on the screen element with openings of sizes lower than its size. The material that crosses the screen element is defined throughs, the one that remains over not passing refuse, that can be in turn crashed to be later reintroduced in the vibrating screen apparatus.

In function of the size of the material to riddle the screen elements can be in the form of grids, perforated metal-sheets, nets or plies. Problems of the Prior Art Following the prolonged use of the vibrating screen apparatus, screen elements must periodically be removed or for replacement due to damages and wearing or for cleaning due to clogging of the element itself because of the shape of the conglomerates, both in the case of virgin inert materials (such as, for instance, gravels with clays that with the humidity are kneaded inglobing the inert materials themselves) either in the case of recycle materials enclosing sticky components (such as, for instance, bitumen enclosing bituminous conglomerates that with the heat are kneaded with the other materials). It's necessary, thus, the periodic operation of removing the screen elements for control, cleaning or replacement. For this reason the screen elements are equipped with hooks able to facilitate the operations of removal and assembly of themselves inside the vibrating screen apparatus that is equipped with corresponding supporting structures to fix them and tie-rods to allow the tensioning in order to improve the efficiency of the riddling. The supporting structures of the screen elements of the vibrating screen apparatus of the prior art provide that the hooking of screen elements is central to the vibrating screen apparatus and the hooking occurs with the fixing of the hook present on them to the inside of the corresponding supporting structure. In case of screen elements with calibrated openings of lower sizes, the structure of the element itself could undergo deformations that do not allow the easy fixing since it has been removed and clean with consequent waste of time for the operator.

Moreover, the supporting structures of the screen elements of the vibrating screen apparatus of the prior art are subjected to the progressive material deposit on their inside. Such material, at the moment of the removing of the screen element for control, cleaning or replacement, completely or partially invades the seat of the structure so preventing the following reinsertion of the screen element. Screen elements more subjects to clogging and wearing and that therefore require more often a maintenance operation are those with calibrated openings of lower sizes, which are downwardly placed inside of the vibrating screen apparatus. If the material deposit inside of the corresponding supporting structure does not allow the assembly of the screen element, the only solution is to dismount also the upper screen elements that would have required no intervention. This involves: - considerable waste of time with prolonged unpredictable and unforeseen stop of the vibrating screen apparatus and complete break-off of the activity

- damage risk of the upper screen elements during the not required operations of dismounting and reinstalling

- exposure of the operator that must carry out the intervention to a dirty and potentially injurious for health environment because of the dusty residues present inside of the vibrating screen apparatus. Aim of the Invention

The aim of this invention is to supply a vibrating screen apparatus for conglomerates able to ensure the correct insertion of the screen element also if it is partially deformed and that at the same time precludes the progressive material deposit to constitute an obstacle to the fixing of the screen element itself. Concept of the Invention

The aim is reached with the characteristics of the main claim. The sub-claims represent advantageous solutions. Advantageous Effects of the Invention

The proposed solution according to the present invention presents both the advantages from the point of view of the operative practicalness because simplifies the hooking operation of the screen elements partially deformed, reducing the time of maintenance. Moreover precludes, given to the shape, the progressive material accumulation inside the vibrating screen apparatus to constitute an obstacle to the reinsertion of screen elements in the corresponding hooking seat of the supporting structure, reducing the time of maintenance, preventing the need to dismount upper screen elements in case of occlusion and reducing in this way the exposure of the operator to dusty and potentially injurious for health environments. Moreover allows to perform all the operations necessary for the removal and the fixing of the screen elements acting only outside to the vibrating screen apparatus itself. Description of the Drawings Hereunder is described a realizable solution with reference to the accompanying drawings to be considered as non-limiting example of this invention in which: Figure 1 is an isometric 3-dimensional view of a vibrating screen apparatus (1) according to the prior art in which it is possible to identify the carpentry (2), the vibratory group (3), the supports (4) and the tie-rods (5). Figure 2 is a front view of the vibrating screen apparatus of figure 1 where it is possible to find the previously described components.

Figure 3 is a sectional view of the prior art vibrating screen apparatus according to the section line indicated with A-A in figure 2, where in addiction to the previously described components it is possible to find also the central supporting structures (6) of screen elements.

Figure 4 represents an enlarged view of the portion indicated with E in figure 3, where in addiction to the previously described components it is possible to find also the screen element (7) and the supporting structure (6) according to the prior art. Figure 5 represents an enlarged view of the portion indicated with F in figure 4 and represents more in details one of the tie-rods (5), where in addiction to the previously described components it is possible to find also the tie-rod screw (36) and screw cover (9) with the corresponding head (10) acting on hook (8) anchoring clamp (13) of the of the screen element (7), the spring (12) and the bolt (11) of the tie-rod (10). Figure 6 represents an enlarged view of the portion indicated with G in figure 4 and represents more in details one of the supporting structures (6) of the screen element according to the prior art, where it is possible to find some of the previously described components. Figure 7 schematically represents a screen element (7) composed by the riddling mesh or net (14) and by the fixing hooks (8).

Figure 8 is an isometric 3-dimensional view of a vibrating screen apparatus (1 ) according to the invention in which it is possible identify some of the previously described components. Figure 9 is a front view of the vibrating screen apparatus of figure 8 where it is possible to find some of the previously described components.

Figure 10 is a sectional view of the vibrating screen apparatus in accordance with the invention, according to the section line indicated with B-B in figure 9, where in addiction to the previously described components it is possible to find also the supporting structures (6).

Figure 11 represents an enlarged view of the portion indicated with H in figure 10, where it is possible to find some of previously described components.

Figure 12 represents an enlarged view of the portion indicated with M in figure 11 and represents more in details one of the tie-rods (5), where it is possible to find the tie-rod screw (36) with the corresponding clamp (13), the hook (8) of the screen element (7), the spring (12) and the tie-rod bolt (11).

Figure 13 represents an enlarged view of the portion indicated with N in figure 11 and represents more in details one of the supporting structures (6) of the screen element, wherein, in addiction to the previously described components it is possible to find also the attachment (18) endowed with hooking profiles (15) and with hole (16) for the insertion of the guiding pin and the movable tool (17) used to dismount the screen element.

Figure 14 represents a front view of the movable tool (17).

Figure 15 is an isometric 3-dimensional view of the movable tool (17) of figure 14 where it is possible identify the head (23), the nonrotating slip block (25) and the threaded end (24) of said movable tool.

Figure 16 is a top view of the guiding device (26) where it is possible identify the pin

(27). Figure 17 is an isometric 3-dimensional view of the guiding device (26) where it is possible identify the plate (28) on which ends are present the fixing hole (29) and the pin (27).

Figure 18 is a back-sight of the attachment (18) where it is possible find the rear hooking profile (15), the fixing flanges (35) and the guiding elements (37) of the screen element.

Figure 19 is a sectional view of the attachment (18) according to the section line indicated with C-C in figure 18, where it is possible to find the front and rear hooking profiles (15), the guiding elements (37) the protection (22), the hole (16) for the insertion of the guiding pin, the guiding slot (21) for the movable tool, the chute (19) and the backing plate (20).

Figure 20 is an isometric 3-dimensional view of the attachment (18) of figure 18 where it is possible to find some of previously described components. Figure 21a represents an enlarged view of the portion indicated with G in figure 8 and represents more in details the previously described devices, seen from the outside of the carpentry (2) of the vibrating screen apparatus.

Figures 21 b-21c represent an enlarged view of the portion indicated with P in figure 21a that illustrates the movement phase of the movable tool (17) within the guiding slot (31) present on the carpentry and the phase of fixing the movable tool itself in position by means of the fixing bolt (30).

Figures 21d-21e represent an enlarged view of the portion indicated with P in figure 21 a that illustrates the insertion phase of the guiding device (26) with the corresponding pin (27) that engages the hole (32) present on the carpentry and the fixing phase of the guiding device itself by means of the screw (33) which in turn engages the hole (29) present on said guiding device.

Figures 22a-22d represent the removal sequence of the screen element (7) of a vibrating screen apparatus of the prior art in which the accumulated material (34) occupies the space of the supporting structure (6) destined to the insertion of the hook (8) of the screen element itself.

Figures 23a-23i represent the removal sequence of the screen element (7) from a vibrating screen apparatus in accordance with the present invention, where it is possible to find some of previously described components. Figures 24a-24i represent the insertion and fixing sequence of the screen element (7) within a vibrating screen apparatus in accordance with the present invention, where it is possible to find some of previously described components. Description of the Invention Referring to the figures 1 , 2, 8, 9, the vibrating screen apparatus (1) consists of a carpentry (2) inside of which are accommodated one or more screen elements placed on one or more riddling levels.

In order for the riddling operation to be effective it is necessary that a relative movement between the screen element and the material to be classified is present and that the vibrating screen apparatus evacuates continuously both the refuse remaining on the surface and the throughs. Such fundamental conditions are reached keeping inclined the screen element in order to allow the material to scroll on it and/or moving the screen element and/or making it vibrate by means of electromagnetic or mechanical vibratory. In case of the represented vibrating screen apparatus in the aforementioned figures, the vibration is induced by means of the vibratory group (3) situated on the upper part to said carpentry, but said representation must not be considered as limitative of this invention, being admitted also other vibrating systems well-known in the state of the art, as will be evident to those skilled in the art, eventually directly coupled to the screen elements. For the purpose of this invention the screen elements can be indifferently grids, perforated metal-sheets, nets or plies. While in the figures reference will be made to the case of riddling nets, the invention must not be intended as limited to them, being applicable also to the other screen elements well-known to those skilled in the art. Vibrating screen apparatus can be fixed for assembly on riddling installation, transportable and movable on wheels or tracks in order to carry them in the working area or also for moving the inside of the working area itself. Moreover they can be equipped with means able to vary their inclination in order to adjust the speed and the riddling efficiency as well as with suitable means for the transportation of the material to the entrance of the vibrating screen apparatus and means for the transport of the classified material out coming from the vibrating screen apparatus itself such as, for instance, telescopic and fixed conveyor belts. While in the text reference will be made predominantly to the fixed vibrating screen apparatus case for assembly on a riddling installation, the invention must not be intended as limited with it, being applicable also to the other typology of riddling apparatus as will be evident to the ones skilled in the art.

In some cases, depending on the material usually classified, the vibrating screen apparatus can also incorporate washing systems like brushes or douches for the screen elements cleaning as well as heating systems to reduce the humidity of the material. Said systems are considered as well-known and will not be hereafter commented, intending that the vibrating screen apparatus in accordance with the invention can incorporated said devices depending of the application to which is designated. Also with reference to the aforementioned figures, on the carpentry (2) are present the supports (4) suitable for mounting the vibrating screen apparatus on a frame via means suitable for the damping (like, by the way of example springs, rubber buffers, etc.) of the vibrations needed for the riddling operation in order to prevent that said vibrations are transmitted to the support frame and to the base structures below, being them stationary as in case of riddling installations or transportable or movable. Referring to figure 3 and figure 4, that constitutes an enlargement of the portion indicated with E in figure 3, it is possible to identify the subsequent riddling levels composed by the screen elements (7) superimposed the ones to the others and with riddling meshes progressively more strict as proceeding downwards from the top. Said screen elements are centrally fixed to the vibrating screen apparatus by means of the supporting structures (6) and frontally to the vibrating screen apparatus by means of the tie-rods (5).

Referring to the figure 5, that constitutes an enlargement of the portion indicated with F in figure 4, the tie-rod of one of the screen elements (7) is represented. Said tie-rod is composed by a screw (36) protected by a screw cover (9) that is held in the preset position with the bolt (11) by means of the spring (12). Said spring, in fact, acts on the screw head (10) by means of the bolt (11) and of a washer (represented but not indicated with an identification number) on one side and on the carpentry on the other side, applying a force suitable to maintain the screw tense towards the exterior of the vibrating screen apparatus. Acting on the bolt (11), the length of the screw portion that internally protrudes to the vibrating screen apparatus is adjusted. By means of the clamp (13) the head of said screw acts on the hook (8) of the screen element (7). In this way acting on the bolt (11) it is possible to: - reduce the length of the screw portion that internally protrudes to the vibrating screen apparatus, pulling as a consequence the hook (8) of the screen element (7) towards the frame and tensioning said screen element.

- increase the length of the screw portion that internally protrudes to the vibrating screen apparatus, progressively releasing, as a consequence, the hook (8) of the screen element (7) and reducing the tension of said screen element.

A lock nut (represented but not indicated by means of an identification number) precludes the slackness of the bolt (11) in order to fix the preset position. Referring to figure 6, that constitutes an enlargement of the portion indicated with G in figure 4, one of the supporting structures (6) according to the prior art is shown. Said supporting structure (6) is a section bar with two side fixing flanges orthogonal to the transverse development of said section bar, said section bar being placed transversely to the vibrating screen apparatus at full width, internally to the vibrating screen apparatus itself at a distance from the ends of the vibrating screen apparatus corresponding to the length of the screen elements (7) to be fixed, as pointed out in figure 4. Said section bar is shaped as a "U" channel with both upper ends refolded 90° towards the inside of the channel thus realizing two opposite "C" shaped channels each of them suitable to fix the hook (8) of the corresponding screen element (7). Said screen element (7) is schematically illustrated in figure 7 and is composed by a riddling mesh (14) on which ends the fixing and tensioning hooks (8) are present. The characteristics of the riddling mesh as material, meshes dimension, etc. are selected on the basis of the characteristics of the material to be classified and are available in different lengths. Now, with reference to figure 10 that represents a section, along the line indicated with B-B in figure 9, and with reference to figure 11 , that constitutes an enlargement of the portion indicated with H in figure 10, the vibrating screen apparatus carried out in accordance with the present invention is represented. It is possible to identify the subsequent riddling levels composed by the screen elements (7) superimposed the ones to the others and with riddling meshes progressively more strict as proceeding downwards from the top. Said screen elements are centrally fixed to the vibrating screen apparatus by means of the supporting structures (6) and frontally to the vibrating screen apparatus by means of the tie-rods (5). Referring to figure 12, that constitutes an enlargement of the portion indicated with M in figure 11 , is represented the tie-rod of one of the screen elements (7). Said tie-rod is composed by a screw (36) that is held in the preset position with the bolt (11) by means of the spring (12). Said spring, in fact, acts on the screw by means of the bolt (11) and of a washer (represented but not indicated with an identification number) on one side and on the carpentry on the other side, applying a force suitable to maintain the screw tense towards the exterior of the vibrating screen apparatus. Acting on the bolt (11), the length of the screw portion that internally protrudes to the vibrating screen apparatus is adjusted. The head of said screw is shaped like clamp (13) and acts on the hook (8) of the screen element (7). In this way acting on the bolt (11) it is possible to:

- reduce the length of the screw portion that internally protrudes to the vibrating screen apparatus, pulling as a consequence the hook (8) of the screen element (7) towards the frame and tensioning said screen element. - increase the length of the screw portion that internally protrudes to the vibrating screen apparatus, progressively releasing, as a consequence, the hook (8) of the screen element (7) and reducing the tension of said screen element. A lock nut (represented but not indicated by means of an identification number) precludes the slackness of the bolt (11) in order to fix the preset position. Referring to figure 13, that constitutes an enlargement of the portion indicated with N in figure 11 , the supporting structure (6) of the vibrating screen apparatus in accordance with the present invention is represented. Said supporting structure (6) is composed by the attachment (18) and by the movable tool (17). The attachment (18) is represented more in detail in the figures 18, 19 and 20, of which figure 18 is a rear view, figure 19 is a sectional view according to the section line indicated with C-C in figure 18 and figure 20 is an isometric 3-dimensional view. Said attachment (18) is a section bar with two side fixing flanges (35) orthogonal to the transverse development of said section bar, said section bar being placed transversely to the vibrating screen apparatus (1) at full width, in an approximately central position in respect to the longitudinal development of the vibrating screen apparatus itself and at a distance from the ends of the vibrating screen apparatus that corresponding to the length of the screen elements (7) to be fixed, as pointed out in figure 10. With reference to figures 19 and 20, said section presents two hooking profiles (15), one located in front and one rearward, said hooking profiles being placed height staggered one in comparison with the other, with the upper hooking profile directed rearwardly and the lower hooking profile directed frontally with relative to the attachment (18) on the whole. On the upper side to the lower hooking profile (15) a protection (22) is present that transversely develops at full width of the attachment (18) suitable to prevent the material to classify that can fall down from the upper screen element to accumulate in correspondence to said lower hooking profile. Downwardly to the lower hooking profile (15) a hole (16) is present, whose function will be explained more in detail in the sequel of the present description. On the rear side of the Behind the attachment the guiding elements (37) are present, able to guide the screen element in the insertion phase of the screen element itself. On the underside of the attachment a chute (19) is present able to drive the screen element in the insertion phase of the screen element itself and a backing plate (20) able to form the ledge for said screen element in the insertion phase of the screen element itself as will be evident by the sequel of the present description.

Near the lower hooking profile (15), finally, a guiding slot (21) is present, suitable to drive the movable tool in its excursion as explained more in detail in the sequel of the present description. The supporting structure forms in this way a plurality of profiles with side fixing flanges, plurality of profiles that downwardly results opened in order to allow the fall of the classified material preventing its accumulation on the supporting structure itself. As will be evident to the ones skilled in the art, said attachment can comprise the lower hooking profile (15) only, the upper hooking profile being made separately. The movable tool (17) is schematically represented in figure 14 with a front view and in figure 15 with an isometric 3-dimensional view. Said movable tool consists of a threaded end (24) ending with an head (23) and including a nonrotating slip block (25) shaped in form of a parallelepiped and able to engage with the guiding slot (21 ) previously described with reference to the figures 19 and 20 of the attachment (18). The head of said movable tool is represented as shaped like triangle, but said shape must consider as an example not limitative for this invention.

Referring to figure 13, said nonrotating slip block of the movable tool (17) engages with the aforementioned guiding slot, said engaging allowing the sliding of the movable tool in approach toward the lower hooking profile (15) and receding apart from it. In figures 16 and 17 the guiding device (26) is schematically represented, respectively in a top view and in an isometric 3-dimensional view. Said guiding device, whose function will be explained more in detail in the sequel of the present description, is composed by a plate (28) on which ends are present the fixing hole (29) and the pin (27) stretching out orthogonally to the surface of said plate.

Figure 21a represents an enlarged view of the portion indicated with G in figure 8. Figures 21 b-21 c represent an enlarged view of the portion indicated with P in figure 21a. As schematically shown, on the carpentry (2) of the said vibrating screen apparatus (1) a guiding slot (31) is obtained, which engages with the aforementioned guiding slot (21) present on the attachment (18) and shown in the figures 19 and 20, so that the threaded end (24) of the said movable tool (17) results to be accessible from the exterior of the carpentry (2). A bolt (30) screwed on said threaded end of the movable tool (17) allows to fix the position of said movable tool once it has been slide along the guiding slot (31) present on the frame and along the guiding slot (21) and present on the attachment (18) and shown in figures 19 and 20. Figure 21c represents the sliding of the movable tool (17) in the direction indicated by the arrow. Figures 21d-21e represent an enlarged view of the portion indicated with P in figure 21 a. As schematically shown, on the carpentry (2) of the said vibrating screen apparatus a hole (32) is obtained that joins with the aforementioned hole (16) present on the attachment (18) and represented in figures 19 and 20, so that the pin (27) present on the previously described guiding device (26)can freely be inserted inside to the vibrating screen apparatus, as schematically represented in figure 21 e. The hole (29) present on the guiding device (26) in turn engages with the screw (33) present on the carpentry to allow the fixing. Figures 22a-22d represent the removing sequence of the screen element (7) from a supporting structure (6) of the prior art. As schematically represented in the figures 22a and 22b, said screen element (7) is pushed in the direction indicated by the arrow and lifted to release the hook (8) of the screen element itself from the supporting structure. Later the screen element is removed, as can be seen in figure 22c, pulling it in the direction indicated by the arrow. As schematically shown in the figure 22d, the accumulated material around the supporting structure invades the inside of the supporting structure itself, constituting an obstacle that precludes the following hooking of the screen element that again is inserted inside the vibrating screen apparatus.

Figures 23a-23i represent the removal sequence of the screen element (7) from the supporting structure (6) of the vibrating screen apparatus in accordance with the present invention. More in detail, figure 23a represents the initial condition in which the screen element (7) results hooked on the supporting structure (6). The first operation to perform said screen element removing, as in the case of the prior art, consists in pushing said screen element in the direction indicated by the arrow in figure 23b to allow the release of the hook (8) from the hooking profile (15) of the previously described supporting structure (6). Such pushing operation continues until said hook (8) comes into abutment with the backing plate (20) present on the attachment (6) itself.

The following operation consists in the displacement of the movable tool (17) carried out by the operator, approaching said movable tool to the hooking profile (15), acting from the exterior of the vibrating screen apparatus as previously explained with reference to the figures 21a, 21b and 21c. As represented in figure 23d, the position reached by the movable tool (17) prevents the hook (8) of the screen element (7) to engage with the hooking profile (15) when said screen element is drawn in the direction indicated by the arrow in order to be completely removed. As shown in the figures 23e-23i, during the phase of complete removal in the direction indicated by the arrow, said screen element (7) does not meet any other obstacle in the supporting structure whose section bars, rather, form a guide for the corresponding movement of the hook (8) of said screen element, preventing in this way that it could hook on other components. Moreover the supporting structure (6) design that is downwardly open, allows the fall of the classified material preventing its accumulation in correspondence of the supporting structure itself. The material that eventually could tend to accumulate, thanks to the action of the vibrations induced by the previously described vibratory group, will fall along the chute (19) leaving completely free said supporting structure (6) for the insertion of a new screen element or of the previously removed screen element drawn off for cleaning or inspection.

Figures 24a-24i represent the insertion and fixing sequence of the screen element (7) on the supporting structure (6) in the vibrating screen apparatus in accordance with the present invention. More in detail, as schematically represented in figure 24a, the operator moves back the movable tool (17) to its initial position, receding apart from the hooking profile (15) in the direction indicated by the arrow, acting from the exterior of the vibrating screen apparatus as previously explained with reference to figures 21a, 21 b and 21c. The following operation consists in the insertion of the screen element (7) pushing it inside the vibrating screen apparatus in the direction indicated by the arrow in figures 24b and 24c and, as in case of the previously described extraction phase, the section bars of the supporting structure (6) operate as a guide for the corresponding movement of the hook (8) of said screen element, preventing it from going in directions different from the expected one, so avoiding the risk that said screen element could block so that it would be necessary to remove the upper screen elements in order to free it. The insertion movement of the screen element continues in the direction of arrow as represented in figures 24d and 24e until the hook (8) of said screen element gets in contact with the chute (19) present on the supporting structure, which chute guides said hook until it reaches the ledge position on the backing plate (20) surface. In this position the profile of the screen element results to be above the hole (16), not constituting in this way any obstacle to the operator for the guiding device (26) insertion, in the corresponding hole present outside the carpentry as previously described with reference to figures 21a, 21 d, 21 e. As schematically shown in figure 24f, the pin (27) of said guiding device enters through the hole (16) and is placed downwardly to the screen element (7). In the following phases, shown in figures 24g-24h, when the screen element (7) is drawn in the direction indicated by the arrow, said pin (27) acts as support and guide for the screen element, addressing in this way the hook (8) present on the screen element itself toward the hooking profile (15) of the supporting structure (6), until the hooking.

Once completed the tensioning of the screen element (7) by means of the previously described tie-rods, the operator can remove the guiding device, extracting the pin (27). Figure 24i represents the final condition of the insertion and hooking phase of the screen element (7) to the supporting structure (6). Used Nomenclature

With reference to the identification numbers reported in the enclosed figures, it has been used the following nomenclature:

I . vibrating screen apparatus 2. carpentry

3. vibratory group

4. support

5. tie-rod

6. supporting structure 7. screen element

8. hook

9. tie-rod screw cover

10. screw head

I 1. tie-rod bolt 12. tie-rod spring

13. tie-rod clamp

14. riddling mesh

15. hooking profile 16. attachment pin hole

17. movable tool

18. attachment

19. chute 20. backing plate

21. attachment guiding slot

22. protection

23. movable tool head

24. movable tool threaded end 25. slip block

26. guiding device

27. pin

28. plate

29. fixing hole 30. movable tool fixing bolt

31. carpentry guiding slot

32. carpentry pin hole

33. guiding device fixing screw

34. accumulated material 35. fixing flanges

36. tie-rod screw

37. guiding elements of the screen element

Claims

1. Vibrating screen apparatus (1 ) embodying at least one screen element (7) transversely insertable and/or extractable by means of movement substantially on a riddling plane, said screen element (7) including at the internal end hooking means with head-hook (8) to hook to a supporting structure (6) characterised in that said supporting structure (6) includes:

- first deviation means to deviate the insertion path of said screen element (7) from an insertion plane to an hooking plane in retraction;

- second deviation means to deviate the path of said screen element (7) from an off- hook plane, to an extraction plane, during the movement of said first screen element first towards the inside as releasing action and then towards the exterior as extraction action.

2. Vibrating screen apparatus (1) according to the previous claim characterised in that said first deviation means to deviate the insertion path comprises a first downwards head-hook deviation sliding-guide (15), associated to a second upwards head-hook deviation sliding-counter-guide (19) and a third locking element (26-27).

3. Vibrating screen apparatus (1) according to the previous claim characterised in that said first deviation sliding-guide (15) is conceived to deviate downwards the insertion path of the screen element (7), and said second deviation sliding-guide (19) is structured to deviate upwards the insertion path of said screen element (7), and said third locking element (26-27) is structured to maintain deviated upwards the hooking path during the retraction of said screen element.

4. Vibrating screen apparatus (1 ) according to any one of the previous claims characterised in that said second deviation means to deviate the path of said screen element (7) from an off-hook plane, to an extraction plane comprises a first movable means (17) and said second deviation sliding-guide (15).

5. Vibrating screen apparatus (1) according to the previous claim characterised in that said first movable means (17) is structured to deviate downwards the path of the screen element (7) and said second deviation sliding-guide (15) is structured to maintain deviated downwards the path of said screen element.

6. Vibrating screen apparatus (1 ) according to any of the previous claims characterised in that said supporting structure (6) includes: - attachment (18) consisting of an hooking profile (15) transversely developing at the full width of the vibrating screen apparatus (1) with fixing flanges (35) at the ends, said attachment constituting in its complex an assembly resulting downwardly opened, said flanges being orthogonal to the transverse development of said profile and being equipped with means (19) able to deviate and to guide the end of the screen element (7) in the extraction and insertion phases of the screen element itself, said flanges incorporating the guiding slot (21) that engages with the corresponding guiding slot (31) on the carpentry (2) of said vibrating screen apparatus (1 ), said flanges incorporating the hole (16) that engages with the corresponding hole (32) on the carpentry (2) of said vibrating screen apparatus (1), said hooking profile (15) being directed in the direction opposite to the insertion direction of the screen element (7) in the vibrating screen apparatus.

- movable tool (17) able to slide along the guiding slot (21) present on the attachment (18) and along the guiding slot (31) present on the carpentry (2) entailing the approach or the receding apart of said movable tool towards or from the hooking profile (15) of the said attachment (18) until it comes into abutment with the hooking profile itself.

- guiding device (26) able to deviate and to guide the end of the screen element (7) in the hooking phase to said hooking profile (15) of the said attachment (18).

7. Vibrating screen apparatus (1 ) according to any of the previous claims characterised in that said movable tool consists of a head (23), of a nonrotating slip block (25) able to engage with the guiding slot (21) present on the attachment (18) and with the guiding slot (31) present on the carpentry (2) and consisting of an end (24) coming out externally to the carpentry (2) of the vibrating screen apparatus (1), said end incorporating means able to block said moving tool in at least two positions along the sliding path defined by the aforementioned guide slots (21) and (31).

8. Vibrating screen apparatus (1 ) according to any of the previous claims characterised in that said guiding device (26) includes suitable means for the fixing of the guiding device itself to the carpentry.

9. Vibrating screen apparatus (1 ) according to any of the previous claims characterised in that said guiding device (26) is a pin able to be inserted by the external side of the carpentry (2) of said vibrating screen apparatus (1) through the hole (32) on the carpentry itself and the hole (16) on the aforementioned flanges (35) of the attachment (18) until it enters internally to said vibrating screen apparatus (1).

10. Vibrating screen apparatus (1) according to the previous claim characterised in that said pin incorporates a rear plate (28) orthogonal to said pin, said plate including the fixing hole (29) able to fix said guiding device.

11. Vibrating screen apparatus (1 ) according to any of the previous claims characterised in that has an additional hooking profile transversely developing at the full width of the vibrating screen apparatus (1), said hooking profile (15) being placed on the upper part with respect to previous hooking profile which in this way becomes the lower hooking profile, said upper and lower hooking profiles being directed in opposite directions one compared to the other and each direction being opposite to the insertion direction of the screen element (7) that must be fixed on it.

12. Vibrating screen apparatus (1) according to the previous claim characterised in that also the upper hooking profile incorporates a movable tool able to come into abutment with said hooking profile.

13. Vibrating screen apparatus (1) according to the previous claim characterised in that also the upper hooking profile incorporates a guiding device constituting means able to deviate and guide the end of the screen element in the hooking phase to the said upper hooking profile.

14. Vibrating screen apparatus (1) according to any of the previous claims characterised in that said lower hooking profile on the upper part is covered by the protection (22) transversely developing at the full width of the attachment (18).

15. Vibrating screen apparatus (1 ) according to any of the previous claims characterised in that said hooking profiles (15) are interrupted constituting a plurality of hooking teeth.

16. Vibrating screen apparatus (1) manufactured according to any of the previous claims incorporating suitable means to clean the screen elements (7).

17. Vibrating screen apparatus (1 ) manufactured according to any of the previous claims incorporating a vibratory group (3).

18. Vibrating screen apparatus (1) manufactured according to any of the claims 1-16 incorporating one or more separate vibratory for each screen element (7).

19. Vibrating screen apparatus (1 ) manufactured according to any of the previous claims incorporating suitable means to heat the screen elements.

20. Vibrating screen apparatus (1) assembly manufactured according to any of the previous claims including a support frame and incorporating suitable means for the damping of vibrations between said vibrating screen apparatus (1) and said support frame.

21. Vibrating screen apparatus (1) manufactured according to any of the previous claims characterised in that it includes means able to vary its inclination.

22. Vibrating screen apparatus (1) manufactured according to any of the claims 1-21 characterised in that it includes means able to vary the inclination of the screen elements (7).

23. Riddling installation including vibrating screen apparatus (1) according to any of the previous claims.

24. Riddling installation manufactured according to the previous claim comprising suitable means for the transportation of the material to the inlet of said vibrating screen apparatus (1).

25. Riddling installation manufactured according to any of the claims 23-24 comprising suitable means for the transportation of the classified material coming out from said vibrating screen apparatus (1).

26. Vibrating screen apparatus (1) manufactured according to any of the claims 1-22 comprising suitable means for its transportation and suitable means for the positioning of the vibrating screen apparatus itself in the operative seat.

27. Vibrating screen apparatus (1) manufactured according to any of the claims 1-22 characterised in that it includes suitable means to move said vibrating screen apparatus.

28. Vibrating screen apparatus (1) manufactured according to any of the claims 26-27 comprising suitable means for the transportation of the material to the inlet of said riddling apparatus.

29. Vibrating screen apparatus (1) manufactured according to any of the claims 26-28 comprising means to transport the classified material issuing from said vibrating screen apparatus.