EP1545849B1

EP1545849B1 - Manual tile-cutting machine

Info

Publication number: EP1545849B1
Application number: EP03757880A
Authority: EP
Inventors: Luigi Casartelli; Vincenzo Montoli
Original assignee: Brevetti Montolit SpA
Current assignee: Brevetti Montolit SpA
Priority date: 2002-10-01
Filing date: 2003-09-22
Publication date: 2009-04-29
Anticipated expiration: 2023-09-22
Also published as: DE60327444D1; AU2003273915A1; WO2004030883A1; ITMI20022075A1; ATE430009T1; EP1545849B9; EP1545849A1; ES2324777T3

Abstract

A manual tile-cutting machine, of the type comprising a base (1) having a header (3), a sliding rail (4) for a tool-supporting member (5) equipped with a cutting tool, and a graduated bar (8) for measuring and registration, is disclosed, a stiffening arc structure (12) being fixed to the bar (8), having at least one interruption and reconnection point.

Description

Technical field

The present invention relates to a tile-cutting machine according to the preamble of independent claim 1. Such a tile-cutting machine is known from EP608476 . Furthermore, the present invention relates to a manufacturing method of a measurement and registration graduated bar according to the preamble of independent claim 19 and to a tile-cutting machine comprising such a measurement and registration graduated bar. Such a method and tile-cutting machine are also known from EP608476 .

Background art

As known, tile-cutting machines may be roughly divided into two types: manual and electric ones. In the present description we shall deal exclusively with manual tile-cutting machines, which represent an extremely specialised field, where few skilled manufacturers possess the knowledge necessary to identify the peculiar solutions needed to determine the success of a simple but functional product.
Among latest-generation machines, light, professional tile-cutting machines have generated a great deal of interest, said machines being built exploiting the lightness of special metallic materials (for instance aluminium alloys) - so as to make them particularly desirable for manual use in building sites - and with a strategic combination of peculiar features, making their use effective and practical to satisfy the requirements of professional users, too.
A typical example of these devices is represented by patent application EP 608.476 in the name of the same Applicant.
In this type of tile-cutting machine, the graduated bar for tile measuring and correct registration of the tile during cutting is pivoted at a point slightly offset with respect to the cut line. This produces some drawbacks, which are well-known to users who, when choosing, can also find on the market tile-cutting machines in which the pivot axis is located along the cut line.
However, the choice of an offset pivot described in EP 608.476 , as well as in all tile-cutting machines marketed so far by Brevetti Montolit S.p.A. under the trade name MASTER^™, was dictated by advisability considerations. As a matter of fact, on the one hand the manufacturing tradition of the products offered by the Applicant grew on this type of tools, to which their client base was used; on the other hand, the Applicant had always preferred to adopt this configuration, with good reason, meaning that tile registration was somewhat inconvenient only in very specific cases: however, this offered in return advantageous conditions in terms of bulk, quality and structural strength of the tile-cutting machine itself.
In effect, the location of the pivot axis along the cut line affects the structural strength of the machine frame in an already extremely vulnerable position, namely underneath a site where pressure is applied by the cutting tool, where the frame is further weakened due to outlet holes.
What's more, in so-called "push"-type tile-cutting machined, i.e. those in which the tool-supporting member is pushed away from the user during cutting, in the terminal area of the cut line (indeed near the position where the graduated bar is pivoting) the base must have a stubbing or step, which further weakens the frame structure, discontinuing a central, longitudinal ribbing (or spire), onto which the pressure applied onto the tile would otherwise discharge. In this type of machine such stubbing is essential in order to enable the cutting tool (usually a small wheel made of special steel) to descend below the top surface of the tile when a tile-breaking projection of the tool-supporting member must be pressed against the tile itself.
It is further to be noted that modern tiles are made of tough materials (glass, stoneware and others), which require application of a good deal of pressure onto the tool in order to be cut properly. In these conditions, the base of the tile-cutting machine tends to bend, making engraving difficult and affecting cutting precision. Consequently, this is a further reason why the frame structure should be suitably designed to withstand such strains, which has so far advised against - with rare exceptions - placing the pivoting axis along the cutting axis in long-lasting tile-cutting machines for professional use.
Progress made both in the choice of materials and in pressure die casting technology, as well as the experience acquired in frame design and configuration, have led to a situation in which positioning of the pivoting axis along the cut line - a concept, as already said, widely known per se in the field (see, for instance, EP no. 315,728 ) - does not represent a real problem and can even prove convenient, even for a device which must fully satisfy a professional buyer in terms of cutting quality, handiness, practicality and durability, essential features for the typical product famously offered by the Applicant.
However, other drawbacks do exist in prior art tile-cutting machines.
Firstly, the pivoting graduated bar for tile measuring and registration is still somewhat weak, due to its structural slenderness.
A further problem, also linked to graduated bar solidity, is apparent in the manufacturing process of the bar itself. In fact, if this measurement element is pressure die cast in aluminium alloy, it tends to bend during or after cooling due to its slenderness and section: therefore it must be straightened and rectified employing known processes. However, if on the one hand it is advantageous for the bar to be sufficiently capable of being deformed so that it can be easily straightened and rectified, on the other hand this implies a drawback, because it leads to deformation of the bar upon use. Therefore, the need exists to supply a graduated bar so construed that it is sufficiently capable of being deformed during assembling, but that at the same time is rigid during its subsequent use.
Furthermore, the choice of position of the graduated bar clamping member always brings about complications. As a matter of fact, said position must be defined in such a way as not to cause interference between the clamping member and the bar itself for a wide rotation arc, preferably wider than 90°, and allowing said member to exert a clamping force in such a direction as not to apply a load transverse to the graduated bar - which would be exposed to irreparable warping within a short space of time - or to the rotation pivot - which would end up seizing or with an excessive play in its housing.
Furthermore, there is a demand for a graduated bar that is easily readable in many conditions of use of the machine, without the need for tailoring or adjusting already at the manufacturing stage in order to satisfy such specific circumstances.
Finally, it is more and more necessary that a series of elements, having an important technical function per se, are laid out respecting an overall harmonic design to contribute to that added value that may be decisive for the user's decision to buy.
Thus, it is an object of the present invention to supply a tile-cutting machine of a manual and light type, as is broadly described above, embodying a series of clever solutions that overcome the drawbacks described above in a harmonious and pleasant whole, and make the graduated bar for measurement and registration particularly durable, advantageous, and practical to use compared to state of the art ones.
Such object is achieved by means of a tile-cutting machine according to independent claims 1 and 20 and by means of a manufacturing method according to independent claim 19.

Brief description of the drawings

Further details on the features and advantages of the machine according to the invention will become apparent from the following description of a preferred embodiment of the invention, given as an example and taken in conjunction with the following accompanying drawings, wherein:

fig. 1 is a perspective view of the whole machine according to the invention;
fig. 2 is a plan view of the head portion only and of the graduated bar according to the invention, the bar being depicted without stiffening arc and rotated at the stop;
fig. 3 is a plan top view of a similar machine to that depicted in fig. 2, with the complete graduated bar, shorter and set at 0°;
fig. 3A is a section view taken along the line III-III of fig. 3;
fig. 4 is a perspective view of the head portion only according to the invention;
fig. 5A is a perspective view of the graduated bar;
fig. 5B is a perspective view of the stiffening arc;
fig. 5C-5F are a plan view, an elevation front view and two section views along lines V-V and VI-VI of the graduated bar shown in fig. 5A respectively;
fig. 6 is an exploded perspective view of the two elements that make up an abutting portion for the graduated bar.

Best mode of carrying out the invention

As shown in fig. 1, a tile-cutting machine consists of, in a manner known per se, a base 1, pressure die cast for example in an aluminium alloy - from which a first post 1a projects and on which two floating supporting pads 2a and 2b are mounted - and a header 3, from which a second post 3a projects. Between the two posts 1a and 3a a sliding rail 4 lies longitudinally along the base, onto which a tool-supporting member 5 is slideably guided. Such tool-supporting member is equipped with a cutting tool, such as a small wheel made of special steel (not shown in fig. 1). The coupling between tool-supporting member 5 and the sliding rail 4 thereof further determines positioning of the cut line, commonly placed exactly along the longitudinal axis of the rail 4, shown in fig. 2 in the axis a-a'. Along axis a-a', close to the front post 3a, the head of frame 3 further carries a seat (fig. 4) in which a pivot 7 of a graduated bar 8 is engaged allowing it to rotate.
The arrangement of the tool-supporting member determines its operation, i.e. whether it is of a "push" or "pull" type, according to the jargon used in this field. However, such arrangement does not affect the inventive teaching offered here - since the machine can be equipped without distinction with the one or the other tool-supporting member - and consequently will not be further described in detail.
According to a preferred embodiment of the invention, the pivot 7 and the seat 6 thereof are of a frusto-conical shape. This eases precise coupling of the two pieces, without requiring costly machining and even when a certain degree of wear becomes apparent. -
Since a possible embodiment of the graduated bar, as explained below, does not require dismounting from the base for transport, the pivot 7 preferably has at its end retaining means such as a bolt to prevent it from falling out of its seat 6. This advantageous solution allows to maintain machine alignment and measurement precision. In the opposite case, when bending moments are applied to the bar, the tapered pivot would tend to come out of its seat in an asymmetrical way, and then to be irregularly blocked by a clamping member, determining misalignment of the bar.
Furthermore, according to the invention, the graduated bar 8 (fig. 5A) has a semicircular cup 81, whose symmetrical centre coincides with the revolution axis of the pivot 7 and from which two co-axial, rectilinear portions of the bar depart: a first shorter portion 82 and a longer portion 83. The whole body of the graduated bar is preferably obtained using a thin-walled pressure die casting of an aluminium alloy (as shown in fig. 5C also).
Cup 81 consists of a semicircular sector plane 81a from whose periphery a perimeter rim 81b projects perpendicularly that links with the ends of the two bar portions 82 and 83, strengthening the assembly. The cup 81 ends at the front with a straight edge 81c. Only in a limited central area, around the revolution axis of the pivot 7, does the bottom plane 81a have a recess 81a', which advantageously allows the cutting tool to descend below the tile top plane in the final phase of the operation, i.e. when the tile-breaking element of the tool-supporting member must be pressed vigorously onto the tile to open the engraving.
Since material thickness of the recess 81a' would become excessively small, only in this limited area material is kept sufficiently thick by creating a step or shimming 81a" on the lower side of the cup 81.
To allow regular rotation of the graduated bar 8 without interference from the floating pads 2a and 2b, these have a slight and limited stubbing 2a" and 2b'' at the shimming 81a'', the stubbing not causing any disadvantage in terms of strength or operation, due to its limited size.
Moreover, due to the limited size of these stubbings, the pads can adequately support the tile up to a distance very close to the area where the breaking element shall act.
The base frame before the front edge of the pad also has slits F at a right angle to the engraving axis (fig. 4). These slits advantageously allow discharge of debris below the base, so that they do not end up underneath the working surface of the floating pads affecting their regular functioning.
The two bar portions 82 and 83 consist of a thin side panel, 82a and 83a respectively, substantially perpendicular to the tile supporting pad, and of a slanting upper panel, 82b and 83b respectively, oriented so as to be easily read by the operator during use and slightly recessed in relation to the bar profile.
The vertical side panels 82a and 83a are provided with first measurement notches. These notches are engraved in the side panel at an increasing depth towards the slanting side. The peculiar shape of the notches allows an easy extraction of the pressure die cast piece from its mould.
On the slanting sides 82b and 83b - or at least on the longer one 83b - a main graduated scale can advantageously be obtained, for example engraved during pressure die casting also, coinciding with the first notches mentioned above. At the same time, however, due to the slanted sides being recessed, they can accommodate a thin adhesive strip onto which another measuring scale is reproduced, preferably a different one (for instance employing another unit of measure) or with a different orientation to the one represented by the notches on sides 82a and 83a. This solution - comprising two graduated scales having different angles and orientations, which can also be chosen as desired (applying or not applying the adhesive strip) - improves readability of the tile measure in all conditions.
Advantageously, the main printed scale is intended to be employed in machines with a "pull" tool-supporting member (which typically represents a cheaper option), whereas the scale applied with an adhesive strip is intended to be employed in machines with a "push" tool-supporting member (which, typically representing a more expensive option, can absorb the extra cost of the adhesive strip).
The scale represented by the notches on the side panels 82a and 83a further continues on the front edge 81c of the cup 81 (fig. 5D and 5E). Intuitively, the "zero" (0) position of the graduated scale is always found at the revolution axis, since the revolution axis is always located along the cut line a-a'.
The shorter portion 82 features a length of the same order as the radius of the header 3 to the rotation centre 6: this prevents the portion 82 from protruding excessively from the perimeter of the header 3, in the position of lower stop of the bar 8 (fig. 2), which benefits machine transportability and eliminates the need to remove the graduated bar from the base.
The longer bar portion 83 further features a horizontal side 83c, onto which an additional graduated scale can be applied, for example one with reference notches slanting 45°, which is in any case useful to engrave the tile when measurements are taken between the tile edge and the side to be cut.
At the ends of the longer portion of the bar 83 two small brackets 9a and 9b project. A guiding rail 10 is secured to two small brackets 9a and 9b. On this rail 10 a reference element 11 is sliding, which will be described later. Preferably, the rail 10 is in the shape of a cylindrical rod, mounted freely rotating on the brackets 9a and 9b: this allows to rotate the reference element or prong 11, axially and torsionally integral with the rod 10, to temporarily exclude the element so that it does not obstruct the working surface without losing the measurement registration already set.
Furthermore, according to a preferred embodiment of the invention, the connecting means 84 and 85 are provided, respectively integral with the shorter portion 82 and the longer portion 83 of the graduated bar 8, to which the ends of an arc-shaped stiffening and guiding structure 12 are fixed.
The arc structure is preferably in the shape of a thin-walled, upside-down U profile (as is clearly shown in fig. 5E). Such shape is particularly advantageous in terms of lightness and resistance to bending and torsion stresses.
Furthermore, it involves a remarkable advantage in terms of friction in its guiding function. As a matter of fact, at least the arc portion defined by angle α is sufficiently high to rest, with its lower part, on a corresponding track 31 obtained on the header 3. Due to the fact that the arc structure 12 has a thin U-section, the impression on the track 31 is limited to two thin arched and parallel lines: hence the support is well-balanced and at the same time the effort required to rotate the device overcoming friction is consequently reduced to a minimum.
Preferably, in order to better guide, laterally too, the arc structure 12, the track 31 features shoulders or lateral containment edges, at least in some areas (see, for instance, the side steps 31a shown in fig. 4).
The coupling of the arc structure 12 with the bar 8 allows to obtain an assembly which is altogether light but sufficiently rigid to guarantee the necessary durability, and measurement and registration precision; the fact that the arc structure 12 can be joined with the connecting means 84 and 85 after manufacturing of such parts, totally overcomes the bending and shrinkage problems that would otherwise be apparent if the assembly was obtained as a single piece by pressure die casting.
Preferably, the connecting means 84 and 85 comprise a slot hole, so that mounting of the arc using locking means (for example bolts, nails or rivets) may occur with a certain room for adjustment, allowing to absorb moulding and assembling tolerances.
An alternative embodiment of the invention, not shown, features an arc structure consisting of two converging, curved arms integral with the graduated bar. In the point of convergence, where the resulting arc is hence interrupted, the two arms are joined by locking means inserted into slots similar to the ones described above.
In a particularly preferable embodiment of the invention, as shown in fig. 3A, the arc structure has its centre in the pivoting axis 6 and such a radius as to pass externally just beyond the front post 3a. This layout, amongst other things, provides the tile-cutting machine with a pleasantness and overall harmony which allows to contribute to the added value mentioned earlier.
Furthermore, on the header 3, in particular next to the front post 3a, in a radially external position, a clamping member 13 is provided, for example a small, screw-in, adjustable clamping handle, known per se in the field. Such clamping member is screwed into a seat 32 and, by adjustable rotation, rises or descends towards the base pushing a suitable pressure pad 13a against the arc structure 12; the arc structure is thus tightened against the track 31, establishing in this way a fixed working condition of the graduated bar integral with it.
Advantageously, to avoid excessive and repetitive pressure by the clamping member 13 permanently bending the arc 12, at pressure pad 13a a small abutting column 33 is provided, that rises vertically from the track 31. The top end 33a of the column 33 is located in close contact (distance d shown in fig. 3A) with the lower inner surface 12a (fig. 5F) of the arc 12 so as to directly contrast the downward load by the pressure pad 13a, without an excessive load discharging onto the sides of the arc structure 12.
With this arrangement it is hence possible to lock the graduated bar in a fixed position within an angle range of about +70° to -50° (including angle 0° equivalent to a perpendicular position between the graduated bar and the cut line a-a') without having to remove any element (as is instead the case for certain prior art tile-cutting machines).
A catch 12b projects over the arc and is capable of abutting a shoulder element (not shown), mounted integral with the base or with the post 3a, which allows accurate positioning at 0° of the graduated bar in a repeatable way (fig. 3).
Fig. 6 depicts instead the reference element against which the edge of a tile-is placed to establish the desired measure or adjustment of the cut.
Said reference element consists of a lower half portion 110 and of an upper half portion 111, that can be coupled with each other by means of a threaded knob 112 turning idle in a bush 111a and screwed into a threaded seat 110a.
Two clamping jaw portions, 110b and 111b respectively, are capable of clamping or releasing the guide 10 when the knob 112 is screwed on or off respectively.
While the upper half portion 111 has a mere locking function on the guide 10, the lower half portion 110 also features a reference bracket 113 which, during use, lies substantially horizontal resting over the working surface (fig. 1).
The bracket 113 has a peculiar shape, which can be well gleaned from fig. 6. From the main slanting body 110c a first triangular plate 113a departs, about 7,5 mm tall, ending with a slanting side edge 113b at whose end a small reference column 113c is provided.
The column 113c, with a substantially triangular section, features a side facing the cut line a-a' which is perpendicular to the graduated bar 8.
From the edge 113b a second plate 113d projects, which is thinner (about 3 mm, which is the minimum thickness commonly found in commercially available tiles) than the first plate 113a, of length L equal to about 48 mm, with a general parallelogram plan shape.
The longer base 113d' is perpendicular to the measuring bar 8. At the free end of the longer base 113d' a second column 113e is provided, with similar characteristics as the first one 113c.
Furthermore, the prong 11 has a short side 110 parallel to the graduated scale provided on the horizontal side 83c of the graduated bar: this enables the user to read easily the position of the prong along the bar even using this slanting scale (typically for 45° engravings).
As can be gathered from the information above, the invention offers some original solutions that allow the tile-cutting machine manufactured according to the teachings described above to fully achieve the objects cited in the preamble, so as to obtain excellent results in terms of strength, lightness and quality of the cut.
It is understood, however, that the invention is not limited to the specific embodiments illustrated above, which represent only a non-limiting example of the scope of the invention, but that a number of changes may be made, all within the reach of a skilled person in the field, without departing from the scope of the claims

Claims

manual tile-cutting machine, of the type comprising a base (1) provided with a header (3), a sliding rail (4) for a tool-supporting member (5) having a cutting tool and a graduated bar (8), for measurement and registration, pivoting on said base (1), characterised in that a stiffening arc structure (12) is fixed to said bar (8), at least one interruption and reconnection point (84, 85) being provided in said arc structure (12) or between the bar (8) and said arc structure (12).
Machine as claimed in claim 1), in which said arc structure (12) is obtained separately and made integral with the bar (8) through locking means engage with joints provided at the arc ends.
Machine as claimed in claim 1), in which said arc structure (12) consists of two arms integral with said bar (8) and convergent towards a common joint.
Machine as claimed in claim 2) or 3), in which said joints comprise at least one slot allowing adjustment during assembling.
Machine as claimed in any of the preceding claims, in which said arc structure (12) is shaped like an upside-down U-profile.
Machine as claimed in claim 5), in which at least one portion of said arc structure (12) is of such a height that the lower edges of the upside-down U-profile rest on a respective base track (31), acting as sliding shoes.
Machine as claimed in claim 6), in which said base track (31) has, at least in some portions, raised side edges (31a) acting as a side guide for said arc structure (12).
Machine as claimed in any of claims 5-7, in which a clamping member (13), suitable for locking in a fixed position said arc structure (12), clamping it between a pressure pad (13a) and said base (1), is also included, a small abutting column (33) being provided integral with the base (1) at said pressure pid (13a), and having one end in close proximity to the lower surface of the base side of said upside-down U-profile.
Machin as claimed in claim 8), in which said clamping member (13) is located in a fixed position, basically halfway the angle development of said arc structure (12) when it is at its "zero" position, i.e. with the graduated bar (8) perpendicular to the cut line.
Machine as claimed in any of the preceding claims, in which said arc structure (12) embraces externally a base post (3a) onto which an end of said sliding rail (4) is fixed.
Machine as claimed in any of the preceding claims, in which said graduated bar (8) is pivoting in a position along the tool cut line and also has a semicircular cup (8) centred on the pivot axis.
Machine s claimed in claim 11), in which said semicircular cup (8) has, in a limited area around the pivot axis, a recess (81a') below which a shimming step (81a") is provided.
Machine as claimed in claim 12), also provided with supporting pads (2a, 2b) which further extend to the area close to the pivot axis, characterised in that said pads (2a, 2b) feature a slight and limited stubbing (2a", 2b") at least in correspondence of said shimming step (81a") of the semicircular cup (81).
Machine as claimed in any of the preceding claims, in which said graduated bar (8) has a frusto-conical rotation pivot (7) to be accommodated in a respective, equally frusto-conical seat (6) on said base (1) and in which the end of said pivot (7) is provided with a locking element which prevents it from falling out of said seat (6).
Machine as claimed in any of the preceding claims, in which said graduated bar (8) has a first side (82a, 83a) perpendicular to the tile-supporting pad plane, having a first measurement scale and a second side (82b, 83b), slanted with respect to the former one and recessed, suitable to house an adhesive strip carrying a second measurement scale.
Machine as claimed in claim 15), in which even said second side (82b, 83b) carries a third permanent scale which can be covered by the adhesive strip with said second scale.
Machine as claimed in claim 16), in which said third scale is designed for a machine with a "pull" tool-supporting member, whereas said second scale on the adhesive strip is designed for a machine with a "push" tool-supporting member.
Machine as claimed in claim 15) or 16), in which said first scale is in the form of a plurality of notches on the graduated bar (8), each notch having an increasing depth in the direction of extraction of the bar (8) from the mould with which it is pressure die cast.
Manufacturing method of a measurement and registration graduated bar (8) for a manual tile-cutting machine, which includes the following steps:
- manufacturing of a linear graduated bar (8) integral with a circular sector and with a rotation pivot (7);
characterised in that the following steps are also carried out:

- manufacturing of a stiffening arc structure (12);

- providing means (84, 85) for connecting said linear bar (8) to the stiffening arc structure (12),

- joining of the ends of said arc structure (12) to said connecting means (84, 85).
Tile-cutting machine comprising a graduated bar (8) obtained by the method of claim 19).