WO2002000405A1

WO2002000405A1 - Linear cutting blade

Info

Publication number: WO2002000405A1
Application number: PCT/EP2001/006352
Authority: WO
Inventors: Jean-Claude Naudon
Original assignee: Ferriera Di Cittadella S.P.A.
Priority date: 2000-06-28
Filing date: 2001-06-05
Publication date: 2002-01-03
Also published as: ES2235587A1; JP2004501794A; AU6905101A; ES2235587B1; ITMI20000394U1; AR031246A4; BR0112190A; KR20030014713A; EG22793A; CN2476403Y; BR0112190B1; TW573605U; IT250009Y1; ITMI20000394V0

Abstract

A linear cutting blade (10), especially suitable for cutting blocks of natural stone, made from steel or other suitable materials, comprises a strip-like body (12) having a limited thickness, provided with through-holes (18) in proximity of the heads, optionally with grooves (16) having a vertical and/or oblique development on the opposite sides or faces, and with at least one grooved lowering (20), extending rectilinear and parallel to the lower edge (14) of said body (12), on at least one of the opposite sides or faces.

Description

"LINEAR CUTTING BLADE" BACKGROUND OF THE INVENTION Field of the invention

The present invention relates to a linear cutting blade.

More particularly, the present invention relates to a metal cutting blade particularly suitable for cutting blocks of natural stone, to obtain from them slabs having a prefixed and uniform thickness. Description of the prior art

As is known, stone blocks, for instance from granite and marble, are subjected to cutting operations and specific metal blades having a rectilinear development are used for these operations. Said blades, generally made from carbon steel, are mounted on frames associated to appropriate machines that handle them with a reciprocating motion along a horizontal plane, parallel to the one of the exposed upper face of the block to be cut. Each frame bears many blades, aligned with each other and suitably spaced according to the thickness of the slabs to be obtained.

The size of the blades, generally obtained by lamination, varies according to the frame and the extension of the stone block to be cut, especially as concerns the length. Thus, for example, when the length is comprised between 3,500 and 5,000 mm; the thickness of the blades is limited, such as by way of orientation, to 4- 5 mm, while their height is comprised between 50 and 150 mm. In correspondence of the opposite heads, the blades are provided with through- holes for the fastening to the handling frame, and usually have, on both faces, grooves suitable to cause and favour the descent of abrasive metal grains that progressively incise the stone block and facilitate the cutting. The known blades have a main drawback connected to the wear that occurs along the lower edge that strikes the block to be cut. Said edge, in fact, is progressively eroded and originates worn curved zones that alter the original linearity markedly. In correspondence of the ends of such curved zones, teeth or extensions are formed that have an irregular shape and which need to be removed in order to continue the use of the blade.

The removal of said teeth is conventionally obtained with handicraft- and manual methods, utilising lever-like tools that have at the bottom end a cavity suitable to house the deteriorated blade portion. Said portion, once it is inserted into the cavity, is broken with an upwards or downwards movement of the tool. The so obtained break is however generally inaccurate and can, sometimes, generate extended fracture lines, that cause the blade not to be usable afterwards. According to a less rudimentary manner, hydraulic apparatuses, called nibblers, also hand-activated, are also used. The use of these hydraulic apparatuses allows to circumscribe better the blade zone to be removed, substantially preventing the danger of irreparably deteriorating the blade.

Another known solution consists in providing the cutting blade with shaped or curvilinear impressions or scorings, having an arched trend and superposed to one another. These impressions or scorings, which are cold-obtained by presses, are realised in correspondence of the wear blade zone. This involves the necessity of critically prefixing the positioning and the development according to the length of the stone block to be cut. The so obtained curvilinear scorings facilitate the removal of the teeth of wear curves, as they form a pre-impression of the blade zone to be removed and prevent the danger of breaking said blade irregularly.

However, also this solution is not without drawbacks, the first of which ensues from the same presence of the scorings. In fact, these scorings are pre-formed along a given part of the blade, i.e. in correspondence of the wear curvilinear zones that form during the cutting.

The scorings obtained allow, therefore, utilising the blade only for determined blocks, in particular those that have a length shorter than the length of the curvilinear scorings. When the length of the block increases, it is therefore necessary to utilise blades having more extended scorings.

A further drawback of this known solution is that the operation of removing the teeth of the wear curve from the blade, which operation is carried out following the pre-formed curvilinear scoring, causes to obtain an edge not rectilinear, but corresponding to the trend of said scoring. Therefore, the so restored blade is markedly different from the same blade in its original form wherein the lower edge appeared unimpaired and extended rectilinearly; the consequence is that the cutting operation performed by the restored blade results more difficult than that performed by the original blade.

SUMMARY OF THE INVENTION

The object of the present invention is to obviate the above drawbacks.

More particularly, the object of the present invention is to provide a linear cutting blade, especially suitable for cutting stone blocks, and allowing to easily and exactly remove, from any zone of its lower edge, more or less extended parts in correspondence of the wear zones, as well as before and/or behind said curves.

A further object of the present invention is to provide a blade, as defined above, which allows not only to eliminate the teeth of the wear zones, but also to restore at the same time the original linearity of the lower edge.

Again a further object of the present invention is to provide a blade capable to distribute in an optimal manner the abrasive metal grains or the abrasive mixture along the cutting line of the stone block.

Another further object of the present invention is to provide a cutting blade suitable to ensure a high level of resistance and reliability in the use, and also such as to be easily and economically realised.

According to the present invention, these and still other objects are achieved by a linear cutting blade, especially suitable for cutting natural stone blocks, obtained from steel or other suitable materials and comprising a strip-like body having opposite sides or faces and a lower edge and optionally provided with grooves having a vertical and or oblique development on the opposite sides or faces, wherein at least one of said opposite sides or faces is provided with at least one grooved lowering, extending rectilinear and parallel to the lower edge.

Preferably, both the opposite sides or faces can be provided with rectilinear grooved lowerings placed by twos at the same height.

The number of grooved lowerings on each side or face is not critical and can vary such as, for example, two, three or more.

The profile or cross-section of each grooved lowering is not critical and can be varied; preferably, the profile is half-hexagonal or semicircular.

BRIEF DESCRIPRION OF THE DRAWINGS

The constructive and functional characteristics of the linear cutting blade of the present invention may be better understood from the following description, wherein reference is made to the figures of the attached drawings that represent a preferred and non-limiting example of embodiment, and wherein:

Figure 1 shows a schematic partial side view of the cutting blade of the present invention;

Figure 2 shows a schematic enlarged cross-section view of the cutting blade of figure 1;

Figure 3 shows a schematic partial side view of the cutting blade of the present invention according to a variant, and

Figure 4 shows a schematic enlarged cross-section view of the cutting blade of figure 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to said figures, the linear cutting blade of the present invention, indicated as a whole by 10 in Figure 1, consists in a strip-like body 12, having a limited thickness comprised, for example, between 3 and 6 mm, preferably obtained from carbon steel.

Said blade 10, in the preferred embodiments illustrated in the figures, has a rectilinear development with a rectangular profile defined by the opposite sides; and it is provided with a lower edge 14 which is intended for striking the stone block, to incise it progressively, by the reciprocating motion imposed to said blade by the frame of the machine to which it is applied.

The opposite sides or faces of the body 12 of the blade 10 are preferably provided with grooves 16, vertically oriented by way of example, extended for the whole height of the body 10 and equidistant from one another.

Said grooves 16, having a substantially rectangular profile and a limited depth, form as many channels to convey the grains of the metal or of the abrasive mixture towards the lower edge 14.

The channels 16, as is illustrated in Figures 1 and 3, are advantageously alternated with each other on the opposite sides of body 12. In proximity of each head, said body 12 is provided with a through-hole 18, as shown in Figure 3, for the tying and tensioning of the blade 10 to the mobile frame of the cutting machine (not shown).

According to the features of the present invention, along one side or both sides of the body 12 there is formed at least one grooved lowering 20 extending rectilinear and parallel to the lower edge 14 and involving the whole longitudinal development of said body 12.

Said grooved lowering 20 is obtained in proximity of the lower edge 14 and intersects orthogonally all the vertically developed grooves 16. The grooved lowering 20, running parallel to edge 14, is spaced from said edge 14 by a length comprised, for example, between 10 and 20 mm. It is preferably obtained by hot lamination with rollers during the forming of the blade 10. Figures 1 and 2 show a cutting blade 10 provided on both faces with two parallel and equidistant grooved lowerings 20 whose profile is substantially half- hexagonal. The number of said grooved lowerings 20 and the configuration of their profile may however vary, as illustrated in Figures 3 and 4. These figures show a body 12 of the blade 10 provided with three grooved lowerings 20, obtained on both faces of said body. The profile of said grooved lowerings 20, preferably arranged equidistant from one another, is substantially semicircular.

Although it is considered advantageous the embodiment comprising grooved lowerings 20 on both faces of body 12, located by twos at the same height, the possibility of limiting the presence of said grooved lowerings 20 to only one front or face of the body 12 of the blade 10 is not excluded. According to the number of the grooved lowerings 20, the holes 18 for the assembly of the blade may be located at different heights. Preferably, said holes 18 are distant from grooved lowering 20, arranged in the upper part, of a distance at least equal to 5 mm.

The grooved lowerings 20 form as many horizontally developed, superposed pre-impression lines that allow to easily restoring, and by the conventional tools used in the sector, the rectilinearity of the lower edge 14 of the blade 10. When the wear has caused on said edge the creation of a worn curve with end teeth, the worn zone is removed before the curve reaches the grooved lowering 20 arranged at the lower level. The grooved lowering 20, that constitutes the pre- impression, allows to exactly break, one after the other, the various parts or sectors, indicated by 22 in Figure 1, of the blade 10, by restoring in this way the linearity along the lower edge 14.

Particularly advantageous is also the possibility of re-using the cutting blade 10, entirely restored, also for stone blocks having a length greater than that of the stone blocks previously worked, as it is possible to remove all the sectors 22 or at least some still intact ones located before and behind the worn curve that has formed. In substance, the removal of said sectors 22 may be modular, depending on the length of the rectilinear cutting edge one wishes to obtain.

From the foregoing, the advantages achieved by the present invention are evident.

The cutting blade of the present invention, thanks to the presence of the grooved lowerings 20, allows to restore easily and exactly the linearity of the lower edge

14, ensuring, therefore, a constant cutting precision. The restoring can be carried out repeatedly, depending on the number of grooved lowerings 20 provided on the body 12 of the blade 10, with marked economic advantages for users.

The presence of grooved lowerings 20, besides permitting the restoring of the linearity of the worn edge, causes the optimal linear distribution of the abrasive mixture along the stone block being worked, as the same grooved lowerings act as conveying channels connected to the vertical groovings 16.

Although the invention has been described in conjunctions with specific embodiments, it is evident that many alternatives and variations will be apparent to those skilled in the art in light of the foregoing description.

Accordingly, the invention is intended to embrace all of the alternatives and variations that fall within the spirit and scope of the appended claims.

Claims

1. A linear cutting blade (10), especially suitable for cutting blocks of natural stone, made from steel or other suitable materials, comprising a strip-like body (12) having opposite sides or faces and a lower edge (14) and optionally provided with grooves (16) having a vertical and/or oblique development on the opposite sides or faces, characterised in that at least one of said opposite sides or faces is provided with at least one grooved lowering (20) extending rectilinear and parallel to the lower edge (14).

2. The cutting blade according to claim 1, characterised in that at least one of said opposite sides or faces is provided with two or three grooved lowerings (20).

3. The cutting blade according to claim 2, characterised in that the grooved lowerings (20) are equidistant, parallel to each other and to the lower edge (14), and spaced at a length comprised between 10 and 20 mm.

4. The cutting blade according to anyone of the preceding claims, characterised in that both the opposite sides or faces are provided with at least one grooved lowering (20).

5. The cutting blade according to anyone of the preceding claims, characterised in that the grooved lowerings (20) are provided on both the opposite sides or faces and are located by twos at the same height.

6. The cutting blade according to anyone of the preceding claims, characterised in that the grooved lowering(s) (20) have a half-hexagonal or semicircular profile.

7. The cutting blade according to anyone of the preceding claims, characterised in that the grooved lowering(s) (20) intersects orthogonally the vertical grooves (16).

8. The cutting blade according to anyone of the preceding claims, characterised in that the grooved lowering(s) (20) is spaced from the lower edge (14) of a length comprised between 10 and 20 urn

9. The cutting blade according to anyone of the preceding claims, characterised in that the strip-like body (12) is provided with through-holes (18) in proximity of the heads; said through-holes (18) being spaced of a length equal to at least 5 mm from the grooved lowering (20) obtained on body (12) in a higher position with respect to edge (14). lO.The cutting blade according to anyone of the preceding claims, characterised in that the grooved lowerings (20) are obtained by hot lamination with rollers.