EP2133185B1

EP2133185B1 - Electric cutting machine for tiles and stone material

Info

Publication number: EP2133185B1
Application number: EP20090155050
Authority: EP
Inventors: Vincenzo Montoli; Stefano Montoli
Original assignee: Brevetti Montolit SpA
Current assignee: Brevetti Montolit SpA
Priority date: 2008-06-13
Filing date: 2009-03-12
Publication date: 2015-02-25
Anticipated expiration: 2029-03-12
Also published as: EP2133185A1; ITMI20080191U1; ES2535402T3

Description

Field of the Invention

The present invention concerns an electric cutter as per the preamble of claim 1. Such a cutter is known from DE 74 41748 U .

Background Art

As known, electric cutters for tiles and stone material consist of a raised base, whereon the tile or stone slab is placed, which base supports a circular blade - of extremely hard material - driven into rotation by a respective electric motor. Tile cutting can be accomplished in two ways: if the circular blade is stationary, tile advancement with respect to the blade is caused, or if it is provided to keep the tile stationary on the base, an advancement of the circular blade with respect to the base is caused. The present invention deals with this second type of machine.
In the electric cutters considered here, the tile or stone slab is typically placed on the base plane abutting against a reference square, which ensures the desired alignment with respect to the presumed cutting line of the circular blade. In other words, the reference square allows to keep an edge of the tile with a desired alignment with respect to the cutting line.
The circular cutting blade is mounted slidable, together with the electric motor thereof, along a horizontal guide aligned along the longitudinal axis of the machine. The displacement of the motor and of the circular blade normally occurs due to the operator's manual intervention, the operator moving the cutting tool (the circular blade) while pushing it into contact with the material to be cut.
In order to perform the cut effectively, the circular blade is designed to drop, at least partly, even below the tile support plane. For such purpose, the central area of the machine base has a longitudinal, recessed channel within which the circular blade can translate during the cut without interfering with the base. Consistently, also the reference square is designed to lie all on one side of the channel or is divided into two aligned bars which lie on both sides of the channel.
In order to be able to perform oblique cuts with respect to one of the tile sides, the reference square further has a reference appendix pivotable about an axis perpendicular to the base. In particular, the appendix is shaped as a short length of rectilinear rod hinged to the main bar of the reference square, normally at a significant distance from the cutting line.
This solution, however, implies some drawbacks. Since the appendix has a rotation axis which does not lie on the cutting axis, the actual detection of the inclination angle with respect to the cutting line is difficult and furthermore no univocal reading of the distances - reported on the bar by means of a graduated scale - of the cutting line with respect to the tile edge can be obtained.
Of course these problems would not arise if a reference square pivotable about an axis falling in correspondence of the cutting line was available. However, this was not feasible so far, because the circular blade needs - due to its own dimensions - to largely exceed the reference abutment of the tile against the square, to be able to accomplish the cut, and it would hence end up cutting also the reference square itself.
In order to partly overcome this drawback, in Italian patent no. 1 278 283 it was suggested to arrange an entire rotary square pivoted in a point detached from the cutting line. By this solution the problems mentioned above have been partly solved - except for measurement and alignment errors which are often negligible - but the offset between the rotation pivot with respect to the cutting line - in any case necessary to leave the passage of the circular blade free - does not allow to achieve fully satisfactory results yet.
The object of the present invention is hence that of providing an electric cutting machine wherein a reference square pivoting about a pin arranged centrally on the cutting line is provided.
A further object of the present invention is that of providing an electric machine equipped with a square pivoting about an axis which intercepts the cutting line, which is particularly effective also in performing so-called "all-rounder" cuts, i.e. cuts with bevel.

Summary of the Invention

Such objects are achieved through a device as disclosed in its essential features in the enclosed main claim 1.
In particular, according to a main aspect of the invention, an electric cutter for tiles and stone slabs is provided, comprising a base above which a circular blade is longitudinally slidable, driven into rotation by a respective electric motor, the base providing a sliding channel, in correspondence of a cutting line, apt to allow the cutting edge of the circular blade to drop as low as a cutting plane arranged at a level below the support plane of said base, a reference square mounted pivoting on the base being further provided, said square consisting of a support body, integral with pivoting means, provided with lateral plates having a seagull-wing configuration lying on a same rotation plane, and of a pair of reference bars arranged aligned on said lateral plates on both sides of said pivoting means, the centre of rotation of said square being on the cutting line of said blade, said pivoting means being below said cutting plane and the rotation plane of said lateral plates being above said support plane of the base.
Preferred embodiments of the machine are described in the dependent claims.

Brief Description of the Drawings

Further features and advantages of the device according to the invention will be in any case more evident from the following detailed description, given by way of example and shown in the accompanying drawings, wherein:

fig. 1 is a top plan view of the machine according to the invention, with obliquely-arranged square, of which fig. 1A is a detail enlargement;
fig. 2 is a front elevation view of the machine of fig. 1, of which fig. 2A is a detail enlargement;
figs. 3 and 3A are views similar to those of figs. 1 and 1A with the square arranged at 90°;
figs. 4 and 4A are views similar to those of figs. 2 and 2A with the square arranged at 90°;
figs. 5 and 5A are views similar to those of figs. 4 and 4A with the cutting head inclined by 45°;
figs. 6A-6C are top and bottom perspective views of the goniometer support body according to the invention; and
fig. 7 is a perspective view of the full square according to the invention.

Detailed Description of a Preferred Embodiment of the Invention

As clearly shown in figs. 1 and 2, an electric cutter for tiles and stone slabs consists of a support frame 1 whereon a base 2 is mounted. The material to be cut is intended to be placed level on base 2. In the upper part of the machine a sliding bridge 3 is provided, whereon a cutting head 4 is slidable. Said head comprises suitable sliding guides (not shown) wherefrom an electric motor (simply schematised in the drawings) is suspended, which drives into rotation a circular cutting blade L.
In the standard working condition (shown in figs. 1-4), cutting blade L lies on a plane perpendicular to the plane of base 2.
In order to allow blade L to drop below the support plane of base 2 and hence to perform the cut correctly, a translation channel 2a is provided along the cutting line. The free passage of blade L is ensured by the fact that, along channel 2a, no surface or device is provided at or above the level where the lower cutting edge of blade L passes.
The electric machine further has a reference square 5 which comprises at least a rectilinear bar intended to act as an abutment to arrange a tile in the desired position.
The reference square is mounted pivoting on an axis orthogonal to the support plane of base 2.
According to the invention, the reference square has a pivoting element which is mounted pivoting precisely in correspondence of the cutting line, in the proximity of an end part of frame 1. In order not to interfere with cutting blade L the reference square consists of two main portions, a support or skeleton body 10 and a pair of extruded bars 21 and 22 which are couplable with body 10.
In particular, as visible in figs. 6A-6C, support body 10 has a central cap 11 - within which a hole is provided for coupling with a rotary pin (not shown) - from which two radial ribs depart which support a pair of lateral plates shaped as seagull wings. The two plates hence have respective raised posts 13a and 13b and respective elongated portions 12a and 12b which extend aligned on a same axis (a-a' axis) on a same plane.
Thereby a sort of well W is defined above rotation cap 11. The bottom of well W is made up by the upper part of cap 11, the side flanks thereof are instead defined by the inner walls of posts 13a and 13b of the two seagull- winged plates 12a and 12b.
Preferably, for the reason illustrated further on, the inner walls of the two raised posts 13a and 13b are not mutually parallel, but converging towards the rotation axis R of cap 11. The angle that such walls form with respect to the alignment axis a-a' of the two plates 12a and 12b is not necessarily symmetrical. That is, the two walls of posts 13a and 13b are not mirror-like with respect to an axis orthogonal to axis a-a' and passing through the centre of rotation of cap 11. This is due to the fact that the rotation of the reference square must not necessarily be symmetrical on the two sides of the cutting line; therefore, one of the two walls of posts 13a and 13b, in particular the one of post 13a, preferably diverges from the centre of rotation by a wider angle than the one of the opposite wall of well W. For example, post 13a diverges by an angle equal to or greater than 45° with respect to the axis perpendicular to the a-a' axis, while post 13b diverges only by a few degrees.
In order to strengthen the structure of the two seagull- winged plates 12a and 12b, two arch structures 14 and 15 are further provided, which connect the two plates 12a and 12b and which determine a goniometer shape. On the innermost arch structure 15 there is provided a graduated scale S, from 0° to 45°, intended to indicate the angle of rotation of the square with respect to the longitudinal axis of the cutting line passing through the centre of rotation R of cap 11.
Both arch structures 14 and 15 have an arched slot 14a and 15a, within which a pin of a blocking knob 30 is intended to be slidably inserted, said knob being able to be screwed and blocked in a threaded hole integral with frame 1. Therefore slots 14a and 15a extend across an arch of a circle equal to the angle of rotation allowed to the square once mounted on the cutter.
The entire body consisting of cap 11, of plates 12a and 12b and of arch structures 14 and 15 is obtained integrally, for example by aluminium alloy pressure die casting. The outermost arch structure 14 is designed to be able to be fully removed, by machining, should its bulk be excessive on small-sized machines (in which cases the square too is normally laterally shorter and hence less stressed). Viceversa, in larger machines, arch 14 guarantees a greater strength of the assembly.
The seagull-wing configuration of plates 12a and 12b is such that, once cap 11 has been fitted onto the rotary pin integral with the frame 1 of the machine, the bottom of the well lies at a level below the lower plane p-p' where the cutting edge of blade L passes, while the lower surface of co-planar plates 12a and 12b and of arch structures 14 and 15 lies level with the support plane of base 2.
Each of the two plates 12a and 12b has a peculiar, ribbed section and a pair of holes F, to be able to insert and fit respective extruded bars 21 and 22. Bars 21 and 22 make up the effective element against which a tile to be cut is intended to be arranged. In particular, plates 12a and 12b, as visible in fig. 6C, have respective aligned ribbings 12a' and 12b' on the upper surface, intended to be inserted in and couple with respective longitudinal grooves 21a and 22a of the reference bars. Thereby it is possible to guarantee a first general, raw alignment of bars 21 and 22 by coupling them with plates 12a and 12b. The desired alignment precision and rectilinearity is later achievable by mounting the assembled square in a template and by tightening suitable tightening screws, inserted from the lower side of the square into the holes F of plates 12a and 12b, so as to consolidate bars 21 and 22 with goniometer body 10.
Extruded bars 21 and 22 are preferably of a prismatic shape with generically rectangular section.
For them to perform correctly their task of aligning and abutting against a tile to be cut, bars 21 and 22 are mounted on support body 10, so that their inner abutment side falls flush with the axis of rotation, shown by letter R in fig. 8.
Both bars 21 and 22 have the end surface 21c and 22c facing towards well W which is cut with the same diverging angle of the underlying post wall, as can be seen in fig. 8.
On at least one of the two bars 21 or 22 a prong N is slidably arranged, which serves to establish a lateral abutment for the tile. For such purpose, also grooves 21b and 22b are preferably provided on the outer side of the bars (i.e. the one opposite the side against which the tile is intended to abut) within which a pin N₁ for locking prong N is slidable. On the upper surface of bars 21 or 22 a graduated scale is further provided, which provides an indication of the distance from the axis of rotation R of cap 11: this scale may be used also to arrange the abutment prong N along bar 22 at the desired distance.
At the end of at least one of the two bars 21 or 22 there may be coupled an extension 22', having an identical extruded profile, which extends the available abutment surface of the reference square. For such purpose, a joining plug Z is provided, which may be tightly fitted, on one side, into lower groove 21a or 22a of one of the bars and, on the other, into the similar groove of the extension piece 22'. On plug Z there are arranged two blocking screws which tighten the profile once extension 22' has been correctly moved closer, to the end of bar 22.
Once bars 21 and 22 have been assembled with support body 10, one has a complete reference square available that can be engaged with a rotation pin arranged on the cutting line below base 2 and integral with the same or with frame 1. For such purpose, in the cutter head area, base 2 has an open area which provides easy access to the underlying rotation pin to mount and disassemble the abutment square. As already mentioned, with cap 11 fitted on the rotation pin, the lower surface of plates 12a and 12b ends up in contact with the support plane of base 2: hence the goniometer body 10 together with bars 21 and 22 are free to rotate by the desired angle.
Since bridge 3 is arranged on one side of the cutting line, the square will be free to rotate by an angle greater than 90° only on the opposite side, since the respective bar 21 does not face obstacles.
As already mentioned, on the base a threaded hole is further provided wherein tightening knob 30 may be engaged, intended to cooperate with one of two slots 14a or 15a.
According to a particularly effective preferred embodiment, bridge 3 and cutting head 4 are mounted pivoting on frame 1. In particular, as visible in figs. 2 and 5, the bridge can rotate about a longitudinal axis, so as to be able to be laterally inclined and perform bevelled cuts according to the set angle of inclination.
This inclined cut serves to perform so-called bevelled cuts, which allow to bring close and flush two tiles arranged on two non-parallel planes, typically on mutually orthogonal surfaces (such as along the edges of orthogonal walls).
For such purpose, it is provided that the end 21c of bar 21 on the side towards which circular blade L inclines (the one on the left-hand side in figs. 4A and 5) ends up being cut with an inclination equal to or greater than 45° with respect to the plane perpendicular to the a-a' axis. As can be guessed, this allows to tilt cutting blade L by an angle up to 45° without interfering with bar 21 itself.
The pivoting axis of bridge 3 lies precisely on the cutting line at a height matching the tile support plane, identified in the figures by line p-p'. Such arrangement of the pivoting axis causes blade L to be able to perform a bevelled cut in a repetitive way always along the same cutting line (i.e. corresponding to the line of 0 on a measurement scale reported on the reference square) regardless of the set inclination angle.
This feature is synergistically advantageous with the provision of a square pivoted on the cutting line, because it allows to have position and measurement references always constant for any orientation taken up by blade L and by square 5.
With reference to the various enclosed figures, one can also understand the operation of the cutter according to the invention. In figs. 1, 1A, 2 and 2A the obliquely set square is shown, i.e. rotated by 45° with respect to the cutting line, with circular blade L arranged perfectly vertical, i.e. orthogonal to base 2. The interference between the bar and blade L is excluded due to the fact that the head surface 21c of bar 21 has a divergence exceeding 45° with respect to the rotation axis. A partial divergence also of the end surface 22c of the other bar would allow to rotate the square also to the opposite side, beyond the angle of 0°. In actual fact, from a practical point of view, it has been acknowledged that this is not essential and it is hence sufficient to guarantee a minimum of divergence for the surface 22c just to avoid chafing of blade L on bar 22.
In figs. 3, 3A, 4 and 4A the bar set orthogonally to the cutting line is shown, i.e. in the typical standard position of 0°, with circular blade L arranged vertically. In this orientation, cuts perpendicular to one side of the tile can be performed, i.e. to the side abutting against bars 21 and 22 of square 5.
Finally, fig. 5 shows again the square set at 0° but with circular blade L inclined by 45°, to perform a so-called bevelled cut. As can be clearly detected, despite the inclination of head 4, even in the proximity of the centre of rotation of square 5 no interference of blade L with bar 21 takes place, due to the bevelled end surface, itself with an angle greater than 45°.
As can be clearly understood from the above description, the electric cutter provided with the square according to the invention allows to perfectly achieve the objects set forth in the premises.
As a matter of fact, due to the special configuration of support body 10 with a rotation cap, wherefrom two seagull-winged plates depart, it is possible to define a well - sunk with respect to the support plane of the tiles - wherein the cutting blade can freely move without any interference arising. This allows to arrange the centre of rotation of the reference square precisely on the cutting line, with evident advantages in terms of alignment and measurement for oblique cuts.
The strengthening arch structure surrounds the well area at a distance nevertheless sufficient (for example, for the inner arch, with a radius of at least 70 mm from the centre of rotation R) to allow blade L to progress until it cuts completely the tile abutted against the reference square.
Moreover, the presence of arch structures and the coupling of the support body (obtained in a single piece) with the two extruded bars allows to obtain a simple, strong square but with a good rectilinearity tolerance.
The support body can be manufactured in a single size and then, depending on it being intended for a large or small-sized machine, one can simply remove or not the outermost arch structure and define accordingly the length of the two extruded bars 21 and 22.
The peculiar inclination of the end surfaces of the two extruded reference bars removes any possibility of contact of the square with the cutting blade in any operation position.
Again, the original arrangement of the pivoting axis of bridge 3 ensures a synergistic effect with the position of the pivoting axis of the square accomplishing a system which maintains unchanged the measurement and angulation references for any orientation taken up by the square and by the bridge.
However, it is understood that the invention is not limited to the particular configurations illustrated above, which represent only non-limiting examples of the invention, but that a number of variants are possible, all within the reach of a person skilled in the field, without departing from the scope of the claims.
For example cap 11, intended to be coupled with a rotation pin integral with the machine frame, can similarly be replaced by a pin which is inserted into a seat of the machine, representing in actual fact alternative pivoting means wherefrom the seagull-winged plates depart.
Moreover, although the well area W of the square has been shown with an open configuration both in the front and in the rear part, an opening on the entry side of blade L would be sufficient per se; the opposite side, i.e. the one facing the arch structures, could also be closed at a certain distance from rotation centre R, for example in correspondence of the innermost arch structure 15.

Claims

Electric cutter for tiles and stone slabs, comprising a base (2) above which a circular blade (L) is longitudinally slidable, driven into rotation by a respective electric motor, the base (2) providing a sliding channel (2a), in correspondence of a cutting line, apt to allow the cutting edge of the circular blade (L) to drop as low as a cutting plane arranged at a level below the support plane (p-p') of said base, a reference square (5) being further provided, mounted pivotable on the base (2), characterised in that said square consists of a support body (10), integral with pivoting means (11), provided with lateral plates (12a, 12b) having a seagull-winged configuration, lying on a same rotation plane, and of a pair of reference bars (21, 22) arranged aligned on said lateral plates (12a, 12b) on both sides of said pivoting means (11), in that the centre of rotation (R) of said square is on the cutting line of said blade (L), in that said pivoting means (11) are below said cutting plane and in that the plane of rotation of said lateral plates (12a, 12b) is above said support plane of the base (2).
Electric cutter as claimed in claim 1), wherein on said support body (10) a sunk well (W) is defined between said pivoting means (11) and the post walls (13a, 13b) of said seagull-winged plates (12a, 12b).
Electric cutter as claimed in claim 2), wherein said post walls (13a, 13b) are diverging from the centre of rotation (R) of said pivoting means (11).
Electric cutter as claimed in claim 3), wherein at least one of said post walls (13a) diverges by an angle equal to or greater than 45° with respect to an axis passing through said centre of rotation (R) and perpendicular to the axis of alignment (a-a') between said reference bars (12a, 12b).
Electric cutter as claimed in any one of claims 2) to 4), wherein said bars (21, 22) have inner ends (21c, 22c) ending in correspondence of said post walls (13a, 13b).
Electric cutter as claimed in claim 5), wherein at least one of said bars (21) has a terminal end (21c) bevelled with an angle greater than 45° with respect to the plane passing through the centre of rotation (R) and perpendicular to said lateral plates (12a, 12b).
Electric cutter as claimed in any one of the preceding claims, wherein said reference bars (21, 22) are shaped as extruded profiles and are engaged with said lateral plates (12a, 12b) and blocked there by fastening means.
Electric cutter as claimed in claim 7), wherein said extruded bars (21, 22) have a lower longitudinal groove (21a, 22a) intended to couple with corresponding ribbings (12a', 12b') of said lateral plates (12a, 12b).
Electric cutter as claimed in claim 8), wherein said lower longitudinal groove (21a, 22a) is designed to receive a joining pin (Z) apt to couple an extension bar (22') with the respective reference bar (22).
Electric cutter as claimed in any one of the preceding claims, wherein said support body (10) has at least one strengthening arch structure which connects said lateral plates (12a, 12b) to each other passing at a distance from said pivoting means (11).
Electric cutter as claimed in claim 10), wherein two concentric-arch structures (14, 15) are provided, the outermost (14) of the two being apt to be removed.
Electric cutter as claimed in any one of the preceding claims, wherein said pivoting means (11) are shaped as a hollow cap apt to be coupled with a rotation pin integral with the cutter frame (1).
Electric cutter as claimed in any one of the preceding claims, wherein said circular blade (L) and the relative motor are slidable on a bridge (3) which is mounted pivoting with respect to the base (2), the pivoting axis being arranged on the cutting line at a height corresponding to said support plane (p-P').