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(11) | EP 1 316 390 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Guiding device for machines for working marble-like articles |
| (57) A guiding device (1) to be installed on a machine (2) for polishing the edges (3a)
of workpieces (3) made of marble-like material. The device (1) comprises a runner
(14) extending in the feeding direction of the workpieces (3), over the whole extension
of the machine itself. Operatively in engagement with the runner is a locking means
(23) set to keep the workpieces (3), during the machine (2) working operations, to
a steady position relative to the feeding direction ("X") of the workpieces (3) themselves.
The device is further equipped with a disabling member (31) which is designed to directly
act on the locking means (23) bringing said locking means (23) to a rest position. |
[0001] The present invention relates to a guiding device applicable to machines for working marble-like articles. It should be pointed out that, to the aims of the present invention, also included in the term "marble-like material" is granite and similar materials of natural or artificial origin.
[0002] The invention also relates to a machine for working marble-like articles comprising the features set out in claim 14.
[0003] The present invention applies to any machine for polishing edges of marble-like articles, such as slabs commonly used both in the building field for finishing of interiors and/or rooms, and in the furniture field for making components and/or equipment elements, such as flat surfaces for kitchens, bathrooms, benches and so on.
[0004] It is known that such machines usually called "edge-polishing machines" generally have a work top on which the edges of one or more articles of marble-like material are submitted to a polishing operation by a plurality of grinding wheels or similar abrasive tools consecutively distributed along one side of the work top itself. For carrying out the polishing operation, a contact is required between the abrasive tools and the workpiece, so that the workpiece is disposed on the work top with the edge to be polished turned towards the abrasive tools and in slight contact with the same.
[0005] Such machines are also provided with a feeding system bringing the articles close to each abrasive tool in a rectilinear feeding direction so that each tool can directly act on the edge being polished over the whole extension thereof.
[0006] Close to the side of the work top on which the tools are disposed, a plurality of thrust rollers is also provided which are oriented obliquely of the feeding direction and act on the upper surface of the workpiece to transmit the same a force component transverse to the feeding direction. This transverse component tends to push the workpiece towards the tool to ensure contact of said tools against the edge to be polished.
[0007] Vertically-oriented sliding rollers are also interposed between one tool and the other along the corresponding side of the work top, so as give the workpieces a series of support points for the edge being polished, counteracting the transverse component provided by the thrust rollers.
[0008] The foregoing being stated, the Applicant has found that while known edge-polishing machines enable polishing of the edges of workpieces of great sizes, they are not however free from some problems and can be improved under different points of view, mainly in connection with working of edges of limited sizes as well as in terms of efficiency and rapidity in carrying out the working operations.
[0009] In more detail, known edge-polishing machines are set to operate exclusively on workpieces in which the length of the edges to be polished is greater that twice the distance intervening between a sliding roller and the other. In fact, only a simultaneous resting of the edge on at least two sliding rollers ensures maintenance of the workpiece position during the action of the abrasive tools.
[0010] Should the edge to be polished have a smaller length than the above stated size, conditions of unsteadiness would be created in which the workpiece edge bears against a single sliding roller, because the rear end of the edge is no longer in engagement with the preceding sliding roller whereas the front end has not yet engaged the subsequent roller. Under this circumstance, the action of the thrust rollers against the abrasive tools would give rise, at best, to unacceptable discontinuities in the edge working and, at worst, to breaking of the workpiece and the tools.
[0011] As a result, presently polishing of edges of reduced sizes must be necessarily carried out manually, which is very time-consuming and therefore causes an increase in the production costs.
[0012] It is an object of the present invention to solve the problems found in the known art by proposing a guiding device applicable to machines for working articles of marble-like material, so as to enable an automated polishing of the edges even of reduced sizes.
[0013] The foregoing and further objects that will become more apparent in the course of the following description are substantially achieved by a guiding device applicable to machines for working articles of marble-like material, comprising the features set out in the characterizing portion of claim 1, as well as by a machine for working articles of marble-like material comprising the features set out in the characterizing portion of claim 14.
[0014] Further features and advantages will be best understood from the detailed description of a preferred but not exclusive embodiment of a guiding device applicable to machines for working articles of marble-like material and a machine provided with such a device, in accordance with the present invention. This description will be stated hereinafter with reference to the accompanying drawings given by way of non-limiting example, in which:
- Fig. 1 is an elevation view of a machine for working articles of marble-like material equipped with a device in accordance with the present invention;
- Fig. 2 is a fragmentary perspective view of the machine shown in Fig. 1;
- Fig. 3 shows a detail of the machine shown in Fig. 2, to an enlarged scale.
[0015] With reference to the drawings, a guiding device applicable to machines for working articles of marble-like material in accordance with the present invention has been generally identified by reference numeral 1.
[0016] As shown in the drawings, the guiding device 1 is applied to a machine 2 for polishing edges 3a of articles 3 of marble-like materials.
[0017] The machine 2, commonly referred to as edge-polishing machine 2, comprises a support structure 4 designed to support a substantially horizontal work top 5 at which, by a plurality of abrasive tools 6 distributed one after the other along an operating side 5a of the work top itself, polishing of the edges 3a is carried out.
[0018] The workpieces 3 are conducted on the work top 5 along a feeding direction "X" which is substantially parallel to the operating side 5a, so that each abrasive tool 6, usually consisting of a grinding wheel the rotation axis of which substantially normal to the feeding direction "X", can act on the whole extension of the edge 3b being polished. Displacement of the workpieces 3 along the feeding direction "X" is carried out by appropriate feeding means 7 operatively associated with the work top 5.
[0019] As shown in the accompanying figures, the feeding means 7 is preferably made up of a conveyor belt 8 which consists of a continuously moving mat 8a defining the work top 5 on which the workpieces move forward. The continuous mat 8a is wrapped over a plurality of feed rollers 8b disposed horizontally close to each other in the workpiece-feeding direction and each oriented in a direction substantially perpendicular to the feeding direction "X". Appropriate powering means (not shown as known) operating on one or more feed rollers 8b for example, causes running of the continuous mat 8a and, consequently, moving forward of the workpieces 3.
[0020] At the operating side 5a of the work top 5, the machine 2 is further equipped with a plurality of slide rollers 9 that are at least partly alternated with the abrasive tools 6. The slide rollers 9 are oriented substantially in a vertical direction to supply the workpieces 3 moving forward on the work top 5 with a series of side support points so as to ensure a constant alignment of the edges 3a being worked with respect to the tools 6, counteracting a transverse-thrust component tending to move the workpiece 3 towards the tools themselves. This transverse-thrust component is given by other thrust rollers, not shown as known, distributed over the work top 5 along the operating side 5a and acting on the upper surface of each workpiece 3.
[0021] As viewed from the accompanying drawings, the machine 2 is further provided with a loading platform 10 for preparation of the workpieces 3 to be polished and a collecting platform 11 for removal of the worked workpieces 3 that are disposed in the extension of the work top 5, upstream and downstream of the latter respectively, with reference to the feeding direction "X".
[0022] The loading platform 10 which is substantially in the same plane as the work top 5, is supported by a bearing structure 10a and is defined by a plurality of sliding plates 10b made of a material having a low friction coefficient. The sliding plates 10b are disposed in parallel side by side relationship with each other along the feeding direction "X" and each have a substantially rectangular shape the major sides of which are oriented substantially perpendicular to the feeding direction "X".
[0023] Advantageously, the loading platform 10 further has a vertical abutment surface 10c substantially parallel to the feeding direction "X" and in alignment with the operating side 5a of the work top 5. In this way, each workpiece 3 can be quickly set to the correct work position by merely making the edge to be polished 3a rest against the abutment surface 10c of the loading platform 10.
[0024] In the same manner as the loading platform 10, the collecting platform 11 too has a bearing structure 11a and is disposed in the same plane as the work top 5. The collecting platform 11 is preferably defined by a plurality of rolling elements 11b constituting the running bed for the worked workpieces 3.
[0025] At all events, it is to be considered that use of loading and collecting platforms 10 and 11 made following known solutions different from the described ones may be provided.
[0026] As shown in the accompanying drawings, the machine 2 is also provided with at least one auxiliary support bar 12 to be used on the opposite side with respect to the edge 3a under working, for support of workpieces 3 the sizes of which perpendicularly of the feeding direction "X" overcome the transverse sizes of the work top 5 also to a great extent. In detail, the support bar 12 is operatively associated with a guide side 5b of the work top 5 opposite to the operating side 5a and is shiftable between a first position at which it is close to the guide side 5b and a second position at which it is spaced apart from the work top 5.
[0027] For facilitating moving forward of workpieces 3, the support bar 12 can have a plurality of slide wheels 12b at the upper part thereof which are aligned one after the other in a direction parallel to the feeding direction "X".
[0028] As shown in Fig. 1, the machine 2 further has a control and command unit 13 by which the course of the working operations carried out during the production process can be managed and checked.
[0029] In accordance with the present invention, the guiding device 1 advantageously comprises at least one runner 14 to be installed on the machine 2 close to the guide side 5b of the work top 5 and extending substantially parallel to the feeding direction "X". Preferably, as shown in the drawings, runner 14 also extends along the loading platform 10 and the collecting platform 11 of machine 2.
[0030] In the embodiment shown in the drawings, runner 14 preferably consists of a first and a second guide bars 15, 16 integrally in engagement with a first and a second attachment elements 17, 18 respectively, which are preferably integral with each other and can be fastened to the machine 2 by threaded elements 19. In more detail, the attachment elements 17, 18 have a flattened conformation enabling application of same against a vertical engagement surface 20, 21, 22 of the work top 5, and of the loading and collecting platforms 10 and 11, respectively.
[0031] Still with reference to Fig. 2, each guide bar 15, 16 extends horizontally in cantilevered fashion from the respective attachment element 17, 18 and has an outline with a substantially circular extension seen in cross-section.
[0032] The guiding device 1 further comprises locking means 23 slidably connected to runner 14. The locking means 23 is movable between a start position, at which it is positioned, with reference to the feeding direction "X", upstream of tools 6, and an end position, at which it is positioned downstream of said tools 6. Advantageously, the locking means 23 is designed to engage one or more workpieces 3 moving forward on the work top 5 to ensure maintenance by each workpiece 3, during the whole polishing operation, of a predetermined orientation, preferably with a longitudinal axis "Y" thereof oriented perpendicular to, or at a predetermined different angle with respect to the feeding direction "X".
[0033] In more detail, the locking means 23 comprises a first and a second abutment elements 24, 25 moving close to each other for rigidly engaging the workpiece or workpieces interposed therebetween. Each abutment element 24, 25 has a substantially flat active surface 24a, 25a which is substantially perpendicular to the feeding direction "X" and the work top 5. The active surfaces 24a, 25a face each other and are set to engage the workpieces 3 on respectively opposite sides.
[0034] The locking means 23 is further provided with at least one locking member 26 adapted to be operatively connected to the abutment elements 24, 25 to keep the same in thrust relationship against the workpieces 3 interposed therebetween, so as to carry out clamp-like tightening of the latter.
[0035] As shown in Fig. 2, the locking member 26 may for example consist of a screw 27 insertable through openings or slots formed in the abutment elements 24, 25 and cooperating with at least one stop nut 28 to tighten the abutment elements 24, 25 clamp-like against the workpieces 3. It should be noted however that the locking member 26 herein represented can be possibly replaced by any other known locking system ensuring engagement between the abutment elements 24, 25 and workpieces 3.
[0036] As shown in the figures, the first and second abutment elements 24, 25 are rigidly fastened, by respective vertically-extending support structures 29c, 30c for example, to a first and a second slider 29, 30, each of them being longitudinally movable along the runner 14. Each slider 29, 30 has a first and a second sliding seat 29a, 29b, 30a, 30b conforming in shape to the respective guide bars 15, 16 and susceptible of engagement therealong.
[0037] The guiding device 1 is also preferably equipped with a disabling member 31 for the locking means 23. The disabling member 31 is substantially defined by at least one prolonging portion 32 extending from runner 14. The prolonging portion 32 is made in the same manner as runner 14, i.e. it has a pair of guide bars 32a that are substantially identical, in terms of outline and transverse sizes, with the guide bars 15, 16 of runner 14. The prolonging portion 32 also has respective attachment elements 32b ensuring fastening against a support portion 33 oscillatably linked to the loading platform 10. The prolonging portion is therefore movable between an operating condition at which, as shown in chain line in Fig. 2, it is aligned with runner 14 in the extension of an end 14a of the latter, and a rest position at which the auxiliary guide portion 32 is oriented vertically or in another angled direction with respect to the runner itself.
[0038] A stop element 34 carried by the bearing structure 10a of the loading platform 10 and susceptible of being removably engaged in a respective fitting seat (not shown in the drawings) formed through the support portion 33, enables the prolonging portion 32 to be stopped to the operating position.
[0039] In the embodiment described, the disabling member 31 is operatively positioned at the loading platform 10. However, the disabling member 31 could also be associated with runner 14 at the collecting platform 11, or several disabling members 31 could also be provided.
[0040] Operation of the concerned device and the machine with which it is associated, which are described above mainly as regards structure, is as follows.
[0041] The workpieces of marble-like material 3 are first prepared on the loading platform 10 of the machine 2 with the edge 3a to be polished against the abutment surface 10c, to be then brought to the work top 5. At the work top 5, the workpieces 3 are transported by the continuous mat 8a, for being submitted to the action of the abrasive tools 6 and ultimately they reach the collecting platform 11 from which they will be gradually removed.
[0042] When the workpiece edge 3a to be polished has a sufficiently great extension, just as an indication at least as high as twice the distance between the runners' centres, the edge-polishing machine 2 can be used following known and conventional modalities briefly described above.
[0043] Under this circumstance, the locking means 23 can be easily brought close to the prolonging portion 32 set to the operating position, to be subsequently disabled by mere displacement of the prolonging portion 32 to the rest position. Advantageously, the locking means 23 thus takes such a position that bulkiness of same is reduced thereby making the operators' work easier.
[0044] The locking means 23 at all events lends itself to be readily utilized, by bringing the prolonging portion 32 to the operating position when polishing of edges 3a of a reduced extension is to be carried out, just as an indication an extension that is less than twice the distance between the rollers' centres.
[0045] To this aim, the locking means 23 is positioned at the loading platform 10 with the abutment elements 24, 25 spaced apart from each other a sufficient distance to enable interposition of the workpieces 3 to be polished, which are disposed in parallel side by side relationship and the number of which is sufficient to cause the sum of the lengths of edges 3a to overcome double the distance between the runners' centres. Subsequently the abutment elements 24, 25 are brought to the engagement position, i.e. directly in contact with the workpieces 3, to be clamped against the same by means of the bolt 27 and stop nut 28. In this way a single block is defined which is made up of the abutment elements 24, 25 and workpieces 3. The workpieces are therefore each clamped with their longitudinal axis "Y" disposed according to an orientation perpendicular to the feeding direction "X". Once the workpieces 3 have been clamped together with the locking means 23, they are manually or automatically brought close to the work top 5 to be engaged by the continuous mat 8a.
[0046] When the workpieces 3 are on the continuous mat 8a, they are transported by the latter along the feeding direction "X" from the start position to the end position. During their moving forward, the workpieces 3 are sequentially engaged by the above described thrust rollers ensuring contact of edges 3a against the slide rollers 9 and abrasive tools 6 polishing the workpiece surface. Once polishing of the workpiece edges 3a is over, said workpieces 3 are brought to a collecting platform 11 at which unlocking and moving apart of the abutment elements 24, 25 can be carried out, in order to be able to remove the worked workpieces 3.
[0047] The present invention solves the problems found in the known art and achieves the intended purposes.
[0048] First of all, the present invention enables an excellent polishing of edges 3a of reduced sizes to be obtained, even of a length smaller than the distance existing between two consecutive slide rollers 9. In fact, these workpieces can be locked in an optimal work position and be maintained at such a position during the whole polishing process, thereby obtaining a high finishing degree for the edges.
1. A guiding device to be applied to machines for working articles of marble-like material,
characterized in that it comprises:
- locking means (23) for engagement with at least one article to be treated or workpiece (3) movable along a feeding direction ("X") on a work top (5) of a machine (2), to keep said workpiece (3) in a work position at which a longitudinal axis ("Y") of the workpiece is oriented transversely at a predetermined angle, preferably perpendicular to the feeding direction ("X"), at least when said workpiece (3) is in contact relationship with at least one tool (6) of said machine (2) disposed close to one side (5a) of the work top (5).
2. A device as claimed in claim 1, further comprising at least one runner (14) associable
with said work top (5) in a direction parallel to the feeding direction ("X") of the
workpiece (3) and slidably engaging the locking means (23), said locking means (23)
being movable between a start position at which it is located, with reference to the
feeding direction ("X"), upstream of said at least one tool (6) and an end position
at which it is located downstream of said at least one tool (6).
3. A device as claimed in claim 2, wherein said locking means (23) comprises at least
one first and one second abutment elements (24, 25) movable close to each other to
rigidly engage said at least one workpiece (3) interposed therebetween.
4. A device as claimed in claim 3, wherein each abutment element (24, 25) has a substantially
flat active surface (24a, 25a) which is substantially perpendicular to the feeding
direction ("X"), said active surfaces (24a, 25a) facing each other and being set to
engage said workpiece (3) from respectively opposite sides.
5. A device as claimed in claim 4, wherein said locking means (23) further comprises
at least one locking member (26) operatively in engagement with said abutment elements
(24, 25) to keep the latter in thrust relationship against the workpiece (3) interposed
therebetween.
6. A device as claimed in claim 3, wherein said first and second abutment elements (24,
25) are respectively disposed on a first and second slider (29, 30), each of them
being longitudinally movable along the runner (14).
7. A device as claimed in claim 2, wherein said runner (14) has:
- at least one attachment element (17, 18) to be fastened to said machine (2);
- at least one guide bar (15, 16) integrally in engagement with said attachment element (17, 18) and extending in cantilevered fashion therefrom.
8. A device as claimed in claims 6 and 7, wherein each slider (29, 30) has at least one
sliding seat (29a, 29b, 30a, 30b) to slidably engage said guide bar (15, 16).
9. A device as claimed in claim 2, wherein said runner (14) also extends parallel to
the feeding direction ("X") along at least one loading platform (10) and one collecting
platform (11) of said machine (2), which platforms are disposed in the extension of
the work top (5), upstream and downstream of the work top itself respectively, with
reference to the feeding direction ("X").
10. A device as claimed in claim 2, further comprising at least one disabling member (31)
for the locking means (23).
11. A device as claimed in claim 10, wherein said disabling member (31) comprises at least
one prolonging portion (32) for said runner (14), said portion being movable between
an operating position at which it is in alignment with the runner (14), and a rest
position at which it is oriented in an angled direction relative to the runner (14),
said auxiliary guide portion (32) by its displacement from the operating position
to the rest position, disabling said locking means (23) when said means is located
close to said auxiliary guide itself.
12. A device as claimed in claim 11, wherein said prolonging guide portion (32) is disposed
upstream of the work top (5) with reference to the feeding direction ("X").
13. A device as claimed in claim 11, further comprising at least one stop element (34)
operatively in engagement with said prolonging portion (32) to keep the latter to
the operating position.
14. A machine for working articles or workpieces of marble-like material, comprising:
- at least one work top (5) to feed at least one workpiece (3) in a preestablished feeding direction ("X");
- at least one tool (6) operatively disposed close to one side (5a) of said work top (5) and set to act on said workpiece (3) moving forward,
characterized in that it further comprises a guiding device (1) as claimed in one or more of claims 1 to 13.