DEVICE FOR TRIMMING THE EDGES OF TILES

Abstract

 A motorised device for trimming the edges of coating tiles is disclosed, comprising a hand-held support frame, on which a motor assembly (2) driving a shaft (2a) carrying an abrasive disc (3) is mounted, said frame comprising a support plate (1) with a lower planar side, and an upper side on which holding means (13) of said motor assembly (2) are provided, further comprising
a drive shaft (2a) which is rotatingly mounted according to a rotation axis X-X and crosses perpendicularly said support plate (1), the lower end of said shaft (2a) projecting from the lower side of said support plate (1) with an engaging head for an abrasive disc (3),
a rectilinear guiding bar (4), provided with an abutment edge on which said tile edge (M') to be trimmed is meant to slide, mounted, on the lower side of said support plate (1), adjustable in position with respect to said rotation axis X-X.

Description

Field of Invention

[0001] The present invention relates to a motorised device for bevelling of the edges of coating tiles, in particular ceramic tiles.

BACKGROUND ART

[0002] It is well known that, in the technique of coating of building surfaces, there is an extensive use of coating tiles, typically tiles with a ceramic surface. In the laying of this tiles, particularly along the connecting edges, there is the problem of trimming, or rather bevelling, the edges of the tiles in order to give continuity to the outer surface despite the non-negligible thickness of the tiles.

[0003] Typically, this bevelling operation allows to create an inclined bevel, typically at 45°, along the two opposite edges of two adjoining tiles. This bevel is also called "jolly" cut in the jargon. The bevel is realised on the lower side of the tile, i.e. reducing the thickness of the base (typically made of ceramic or stoneware) and leaving the surface finishing layer unaltered, defining the typical wedge-shaped section along the edge of the tile.

[0004] The bevelling operation is carried out not only with an inclined flat surface, such as the classic "jolly" cut to make two tiles abut on a 90° corner, but can also be employed to confer to said edge a half-circle or a quarter-circle section profile or other desirable profile. In general, however, there are specific issues concerning coating tiles, in which there is a noble side (i.e. the one that is exposed to view) whose integrity should be maintained and a bonding side (i.e. the one that is made to adhere to the slab, or to the wall), expendable during machining.

[0005] Devices allowing to obtain this trimming operation are known. They include, in general, a small hand-held frame, on which a drive motor of a spindle is mounted, a disc for cutting and properly shaping materials being fixed on the latter. Normally, the small frame is designed to mount directly a typically commercially available angle grinder, which represents the universal tool for operators in this sector.

[0006] The small frame is configured in such a way that the disc will be placed obliquely with respect to the plane of the tile, according to a desired inclination, which can be precisely 45° in the case of the above mentioned "jolly" cutting.

[0007] When a simple 45°-bevel is to be performed, it is sufficient to use a flat disc, the surface of which is progressively disposed obliquely at 45°. On the other hand, when a trimming with a more elaborate profile must be performed, it is necessary to place the drive spindle of the abrasive disc vertically and to exploit action of the edge surface of the abrasive disc or of a grinding wheel, suitably shaped so as to obtain the desired profile of the tile, having a matching shape.

[0008] Such a system is arranged to be put on the tile surface and then guided by hand to move along the edge of the tile, while the abrasive disc - which is located between the small frame and the tile - rotates in speed against the edge of the tiles, removing the desired part of this edge. This implies machining on the tile turned upside down, namely with its noble finished surface facing downwards, so that the abrasive disc works on the hidden and expendable side of the tile.

[0009] However, these known types of configurations are not entirely desirable, especially because it is difficult to determine the correct distance adjustment of the abrasive disc from the tile, with the risk of damaging or excessively weakening the outer surface of the tile, in particular in the case of a glazed or polished surface. Furthermore, since the support frame works in contact with the hidden surface of the tile, which is the one provided with reliefs and shapings to facilitate the grip of the laying adhesive, the sliding of the tool is disrupted and irregular, with consequences in terms of machining accuracy.

[0010] Similar abrasion devices exist in multiple sectors, such as for example US2984270.

[0011] Document US2006/0217044 illustrates a frame for a polishing machine; in this case, the frame can also slide on the upper surface of the tile because the polishing tool cannot impair its integrity.

Summary of the invention

[0012] The problem underlying the invention is therefore to supply a motorised device for trimming tiles that overcomes the drawbacks mentioned above, by a simpler and lighter, as well as more cost-effective, structure, and which allows to obtain an improved machining in terms of aesthetic effect and precision.

[0013] These objects are achieved through the features mentioned in claim 1. The dependent claims describe preferred features of the invention.

Brief description of the drawings

[0014] Further features and advantages of the invention will anyhow be more evident from the following detailed description of a preferred embodiment, given by mere way of nonlimiting example and illustrated in the accompanying drawings, wherein:

Fig. 1 is a top perspective view of the trimming device according to the present invention;

Fig. 2 is a perspective view from below of the device machining a tile;

Fig. 3 is an exploded view of the device of Fig. 1, Fig. 4 is a perspective view from below of the device of the invention; and

Fig. 5 is a cross-sectional view of a part of the device of the invention on which an abrasive disc is mounted.

Detailed description of preferred embodiments

[0015] As shown in the drawings, and in particular in Figures 1 and 3, the device for trimming tiles according to the invention is constituted by a structure comprising a support and guiding plate 1 and a control group of an abrasive disc.

[0016] The latter comprises a drive shaft 2a which is mounted on the plate 1 by means of a bearing (not shown) and protrudes with an upper end, to which an actual motor 2 can be engaged, and a lower end, to which an abrasive disc 3 is rotationally fixed.

[0017] The motor 2 is preferably a standard commercial apparatus, such as an angle grinder (as clearly shown in Fig. 3), which is engaged on the drive shaft 2a and held in position by a suitably shaped support or bracket 13.

[0018] The drive shaft 2a is mounted free in rotation, integral with the plate 1 and with the axis X-X perpendicular to it.

[0019] Preferably, for better operating ergonomics, the plate 1 is of a generically isosceles triangle shape, with the drive shaft 2a arranged close to the vertex.

[0020] On the plate 1 gripping members are also fixed in order to operate the device by hand. Such members are for example in the form of a pair of manoeuvring handles 5, 6, attached to the top of the plate 1 - that is, the one where the motor 2 is also arranged - by means of studs (not shown), which engage in threaded holes 11 and 12 of the plate 1.

[0021] Preferably, the motor assembly 2 is fixed with the support 13 in such a way that the centre of gravity falls as much as possible between the two handles 5 and 6, in order to achieve an advantageous balance of the device.

[0022] Finally, the plate 1 can also be associated to a conveying duct 14, forming a fastening attachment of the flexible tube of a vacuum cleaner for processing scrap (not shown).

[0023] According to an essential feature of the invention, a guiding bar 4 is mounted on the lower portion of the plate 1, the distance of said bar being adjustable with respect to the rotation axis X-X of the drive shaft 2a. In particular, preferably, the guiding bar 4 is constrained at one end by a vertical pin 4a inserted in a respective seat 7 (see Fig. 3), which allows its rotation according to an axis perpendicular to the plate 1; at its opposite end, the bar 4 has a threaded hole 4b, in which a threaded pin 8 is engaged, which is long enough to pass through an elongated aperture 10 made in the plate 1, engaging on its free end a tightening knob or wheel handle 9, by which the locking of the threaded pin 8 in the desired position is determined.

[0024] Due to this configuration, it is possible to adjust the position of the bar 4 by rotation around the pin 4a, preferably according to a maximum arch delimited by two abutment lines 1a and 1b provided on the lower side of the plate 1.

[0025] Once the desired position of the bar 4 is defined, for the purpose better described in the following, this position is locked by tightening the knob 9.

[0026] Furthermore, according to one essential feature of the invention, the bar 4 has, for most of its length, a continuous section structure, for example a quadrilateral section, but has a central area 4c recessed according to a large flaring. As it may be seen in the bottom view of Fig. 4, but also in the sectional view of Fig. 5, this recessed area 4c is defined in correspondence to the rotation area of the abrasive disc, because it is intended to leave room for a peripheral part of the abrasive disc 3. In this way, at least a peripheral area of the disc 3 can move into contact with the edge M' of a tile intended to remain in abutment against the bar 4.

[0027] Note that this configuration is particularly advantageous so that the abrasive disc 3 can work "from below", that is to say below the tile against which the plate 1 rests. Thus the abrasive disc is configured and mounted on the drive shaft 2a so as to remove material between the disc itself and the motor 2.

[0028] The abrasive disc is not comparable to a classic thin cutting disc, which should be operated in a significantly different way, but is rather in the form of a grinding wheel of a certain thickness, so that its peripheral edge has a suitable shape to work on the edge of the tile. A suitable abrasive grinding disc is, for example, a cut-out disc of the type available from the Applicant under the trade name Mondrillo^™.

[0029] The abrasive disc or grinding wheel 3 is arranged on a plane parallel to that of the tile and operate with its bevelled circumferential part (for example at 45° to perform "jolly" cutting).

[0030] Apart from a slight clearance that the grinding wheel 3 must have with respect to the lower surface of the plate 1, the bar 4 also has the function of a spacer to determine the height of the tile that is not affected by the wear action of the grinding wheel 3. In fact, the bar 4, properly adjusted, defines an abutment line of the tile which prevents a mutual approach of the grinding wheel to the edge of the tile over a certain extent and also the minimum tile thickness which is not affected by wear of the grinding wheel, as clearly shown in Fig. 5. To this end, the recessed thickness 4c of the bar 4 in the flaring area defines the desired spacing between the working surface of the grinding wheel 3 and the noble surface of the tile on which plate 1 is moved.

[0031] The operation of the device according to the invention involves, first of all, the adjustment of the correct distance between the bar 4 and the rotation axis X-X of the abrasive disc, so as to define the desired bevelling depth to be realised on the edge of the tile. Then, the operator grasps the handles 5 and 6 of the device with hands, in the manner shown in Fig. 1, and lies it with the plate 1 on the upper, noble surface of a tile M, with the corresponding bar 4 close to the edge M' of the same tile.

[0032] In these conditions the operator, always keeping the support plate 1 with pressure on the surface of the tile M, in the top-to-bottom direction, starts the rotation of the abrasive disc and moves the disc towards the tile M, as long as the bar 4 does not abut against the edge M'. At this point, the bevel can be completed by sliding the device along the edge M' of the tile, with the bar 4 always in abutment. In doing so, the disc 3 can trim this edge, so as to shape it as desired.

[0033] Figures 2 and 5 show an abrasive disc 3, whose periphery has an abrasive edge 3a which is bevelled at 45° with respect to the vertical axis X-X of the rotary motor shaft. This profile of the edge 3a of the disc is intended to bevel the edge of the tiles for "jolly" cutting, as mentioned in the introductory part.

[0034] Finally, since each trimming operation with an abrasive disc produces a significant amount of dust, it is preferable that the operator, before starting the motor assembly, installs the hose of a vacuum cleaner on fitting 14. In this way, dust generated by the abrasive disc is sucked and does not pollute the environment.

[0035] As will be understood, the trimming device according to the present invention perfectly achieves the aim of allowing, with an extremely simple and lightweight structure, easy to be hand-driven, and also cost-effective, the trimming on the lower side of the edge of the tile, without working on the upside-down tile. This condition improves machining precision and avoids damage to the outer noble surface of the tile.

[0036] It is understood, however, that the invention is not to be considered as limited by the particular arrangement illustrated above, which represents only an exemplary implementation of the same, but different variants are possible, all within the reach of a person skilled in the art, included within the scope of the invention itself, as defined by the following claims.

Claims

1. Motorised device for trimming the edges of coating tiles, comprising a hand-held support frame, on which a motor assembly (2) driving a shaft (2a) carrying an abrasive disc (3) is mounted, said frame comprising a support plate (1) with a lower planar side, and an upper side on which holding means (13) of said motor assembly (2) are provided, characterised in that it comprises
a drive shaft (2a) which is rotatingly mounted according to a rotation axis X-X and crosses perpendicularly said support plate (1), the lower end of said shaft (2a) projecting from the lower side of said support plate (1) with an engaging head for an abrasive disc (3),
a rectilinear guiding bar (4), provided with an abutment edge on which said tile edge (M') to be trimmed is meant to slide, said bar being mounted, on the lower side of said support plate (1), adjustable in position with respect to said rotation axis X-X.

2. Trimming device as in 1, wherein said bar (4) has a constant section except in a central recessed area (4c) with a flared out shape obtained in a portion close to said rotation axis X-X.

3. Trimming device as in 1 or 2, wherein said bar (4) is mounted pivoting about an axis perpendicular to the lower planar side of said support plate (1).

4. Trimming device as in 3, wherein said bar (4) is constrained in the lower part of the plate (1) with a fixed pin (4a), associated at one end thereof, and with a threaded pin (8) projecting from the opposite end (4b) and slidable in an elongated aperture (10) of the plate (1).

5. Trimming device as in 4, wherein said threaded pin (8) is provided, in the upper part of the plate (1), with a tightening hand-actuated knob (9).

6. Trimming device as in any one of the preceding claims, wherein a pair of manoeuvring handles (5, 6) projecting perpendicularly from the upper side of said plate (1) is provided.

7. Trimming device as in any one of the preceding claims, wherein said support plate (1) is of a generically isosceles triangle shape, wherein said rotation axis X-X is arranged in the proximity of the vertex angle thereof.

8. Trimming device as in any one of the preceding claims, wherein said holding means (13) are in the shape of a saddle for the housing of a standard motor assembly (2), in the shape of an angle grinder, arranged so as to have its centre of gravity close to the centre of gravity of said plate (1).

Drawing