Cutting tool and method of cutting a board, such as a mineral wool board

Abstract

A cutting tool (1) for cutting a board (1000) comprises a support body (2), a first cutting blade (3a) and a second cutting blade (3b). Each cutting blade (3a, 3b) comprises a first portion (4a, 4b), a second portion (5a, 5b), and a third portion (6a, 6b). The first portion (4a, 4b) of each cutting blade extends downwards from the support body (2). The second cutting blade (3b) is placed behind the first cutting blade (3a). The first portion (4a) of the first cutting blade can serve to produce a slit (1005) in a top surface of the board, such as in a facing (1002) thereof. The second (5a, 5b) and third (6a, 6b) portions of the cutting blades define a cut-out (1004A) that, after removal, leaves a groove (1004) in the board. Also disclosed is a method of cutting a groove (1004) in a board (1000).

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of cutting tools and methods of cutting boards so as to form grooves in the boards, such as in insulation material boards, such as in mineral wool boards.STATE OF THE ART

[0002] It is known in the art to use cutting tools to cut grooves in boards, such as in mineral wool boards. For example, in the context of insulating conduits, for example, for heating, ventilation and air conditioning installations (HVAC), it is known to form duct sections by folding a mineral wool board to form a duct section having a polygonal, typically a rectangular, cross section. These types of conduits are also referred to as self-bearing conduits. For this purpose, typically, three grooves are cut in a mineral wool board, and the board is then folded along these grooves, to form the duct section, with the grooves present in three of the corners of the duct section. For example, figure 1 schematically illustrates how a mineral wool board 1000, provided with three V-shaped grooves 1004, can be folded along these grooves to form a duct section having a substantially rectangular cross section.

[0003] Tools for producing this kind of grooves are known in the art. For example, US-4180908-A discloses a cutting tool for cutting groves in a board, such as an insulating board, featuring two blades with cutting edges that, in a front view of the cutting tool, extend downwards and convergently from a support body arranged to slide on top of the board. In the front view, the cutting edges of the two blades extend downwards in a converging manner, jointly featuring a U-shape or a V-shape, such as to provide a U-shaped or V-shaped groove. One of the blades is mounted after the other blade in the cutting direction.

[0004] Mineral wool boards frequently comprise a mineral wool core and a facing on at least one main surface of the core. Often, both main surfaces of the core are provided with a facing. When cutting a groove in the board using a tool as known from US-4180908-A, part of the facing is removed, namely, the part of the facing that covers the cut-out portion of the board. Thus, the facing that remains on the board will thus be interrupted at the edges of the groove.DEFINITIONS

[0005] In the present document, some terms and expression are to be understood in the manner discussed below: The terms "cut-out" or "board cut-out" are to be understood to refer to portions of a board that can be removed after having cut a board using a cutting tool as described herein. Generally, terms like "lowermost", "uppermost", "top", "bottom", "up", "down", horizontal", "vertical", "downwards", etc., are used herein considering the situation in which the board to be cut is arranged horizontally (that is, with the main surfaces arranged in respective horizontal planes) and the cutting tool is applied to slide on the upper main surface of the board, such as on an upper facing on the main upper surface of the board. The downwards direction is any direction that has a downward component parallel with the vertical z-axis; in specific embodiments the downward direction is vertical, parallel with the z-axis, for example, as shown in some of the figures illustrating embodiments of the invention. Generally, terms like "in front of", "forwards", etc., refer to the situation in which the tool is displaced in its cutting direction, such as when cutting a groove in a board. The tool is then moved "forwards", toward something placed "in front of" the tool. The forwards direction is, for example, as per the x-axis indicated in some of the figures. Generally, and accordance with the system of coordinates (x, y, z) represented in some of the figures, the "x-axis" extends parallel to the "cutting direction" (also referred to as "forwards direction", the "y-axis" extends horizontally and perpendicularly to the "x-axis", and the "z-axis" extends parallel to the "vertical direction" and perpendicularly to the "x-axis" and the "y-axis". Expressions like "straight" and "substantially straight" basically have the same meaning, namely, implying that the item referred to would be conceived to be "straight" by the person skilled in the art. The same applies to "vertical" and "substantially vertical", "horizontal" and "substantially horizontal", etc. When referring to a "front view", reference is made to a view in which the observer observes the cutting tool from a point where the cutting tool moves towards the observer when carrying out a cutting operation as intended, that is, in parallel with the x axis indicated in some of the figures illustrating embodiments of the invention. Thus, the front view is a projection onto the y-z plane, considering the axes indicated in some of the figures illustrating embodiments of the invention. When referring to a "board", reference is made to an object comprising two main, substantially planar, surfaces and having a thickness corresponding to the distance between the two main surfaces. In accordance with system of coordinates described above, both main surfaces extend in an "x-y-plane" while the thickness of the board extends in the "z-direction". The cutting tool can be used to cut one or more grooves in the board, for example, to allow folding of the board in correspondence with the groove. Examples of boards are mineral wool boards comprising a mineral wool core with a facing on at least one main surface thereof, such as on both main surfaces thereof. When reference is made to a "main portion of the board core", reference is made to the portion of the board core that is separated from a minor portion of the board core by the cuts performed by the second portions of the cutting blades described below, basically, from the minor portion of the board core that remains adhered to the portions of facing on both sides of the slit, after cutting. When reference is made to a support body, reference is made to an object having any possible shape and that can be used to support a blade arrangement as discussed below. The support body typically has a bottom surface, a top surface and a height corresponding to the distance, in the vertical direction, between the lowermost part of the bottom surface and the uppermost part of the top surface. The bottom surface is, in some embodiments, planar and / or comprises one or more planar portions. The bottom surface may comprise one or more portions adapted to slide on a top surface of the board during cutting. When reference is made to a "bend", reference is made to a change of orientation in the cutting blade, in particular, in the cutting edges of the cutting blades when observed in a front view. In the present application reference is made to first bends A, A', second ends B, B', as well as to end points C, C'. The first bend A, A' refers to the transition between the first portion and the second portion of the respective cutting blade. The second bend B, B' refers to the transition between the second portion and the third portion of the respective cutting blade. The ends C, C' of the respective third portion is the position where the downwards extension of the third portion ends, thereby defining the cut depth. When used in relation to a groove, the term "apex" is used herein to refer to the lowermost point of a groove, that is, to a point where the sloping sides of the groove meet, when there is such a point. When used in the context of the blade arrangement of the cutting tool the term "apex" denotes the point (shown as "D" in the drawings) towards which the third portions are generally directed. In many embodiments, the third portions of the cutting blades substantially meet at the apex D, which thus determines the lowermost portion of the cut-out. When used in relation to a groove, the term "apex" is used herein to refer to the lowermost point of a groove, that is, to a point where the sloping sides of the groove meet, when there is such a point. When used in the context of the blade arrangement of the cutting tool the term "apex" denotes the point towards which the third blade portions are oriented. In the present document, "α" is used to designate the angle between the third portion (the blade portion that extends downwards from the second bend "B") and the horizontal "y-axis" or the horizontal x-y plane, in the front view. In the present document, "β" is used to designate the angle under which the two third portions meet at the apex, in the front view. In the present document, "δ" is used to designate the angle between the second portion (the blade portion that extends downwards from the first bend "A") and the horizontal "y-axis" or the horizontal x-y plane, in the front view, in some embodiments of the invention. All ranges referred to throughout this text (for example, in terms of "in the range of x and y" or "between x and y") include the recited endpoints of the range, unless the contrary is explicitly indicated. In this text, the term "comprises" and its derivations (such as "comprising", etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc. DESCRIPTION OF THE INVENTION

[0006] It has been found that it can be desirable to avoid, minimize or at least reduce the removal of facing material when producing grooves in boards, such as insulation material boards, particularly in mineral wool boards.

[0007] A first aspect of the invention relates to a cutting tool for cutting a board, for example, an insulation board, especially a mineral wool board, for example, a mineral wool board comprising a mineral wool core having a facing on at least one major surface thereof. The facing may, for example, be a veil (such as a veil made of mineral wool, a veil made of a fabric, a reinforced veil, for example, reinforced with additional threads), a foil -such as an aluminium foil-, kraft paper, or similar). Typically, the facing is placed on one of the main surfaces of the insulation board and the facing is at least applied to that side of the board which will form the inside of a duct element after having folded the grooved board. For example, the cutting tool may be adapted for making a groove in the board by moving the cutting tool in a cutting direction with respect to the board (that is, moving it "forwards", for example, in parallel with an "x-axis"), so as to cut out and remove an elongate portion of the board, such as a portion having, for example, a substantially polygonal, such as triangular, cross-section, optionally with curved portions. The cut-outs have the negative shape of the grooves obtained in the board after cutting. Thereby, using the cutting tool, a groove can be established that allows the folding of the board with regard to an axis substantially corresponding to a lowermost point or apex of the groove. For example, a plurality of cuts can be carried out in parallel so as to allow the board to be folded around a plurality of such grooves, to adopt a configuration that is substantially polygonal, such as rectangular, in cross section, as known in, for example, the art of mineral wool duct elements, for example, for air conditioning conduit elements.

[0008] Generally, terms like "lowermost", "uppermost", "top", "bottom", "up", "down", horizontal", "vertical", "downwards", "upwards", etc., are used herein considering the situation in which the board is arranged horizontally and the cutting tool is applied to slide on the upper surface of the board, such as on an upper facing of the board.

[0009] The cutting tool comprises a support body, a first cutting blade and a second cutting blade, the cutting blades being attached to the support body, the cutting blades being arranged for cutting a board by moving the cutting tool in a cutting direction with the cutting blades interacting with the board. The term "support body" is not to be interpreted narrowly but encompasses any item suitable for supporting the blades, that is, any item to which the blades can be attached and supported so that by displacing the support body the blades are displaced with it, such as during a cutting operation.

[0010] Each cutting blade comprises a first portion, a second portion and a third portion.

[0011] The first portion of each cutting blade extends downwards from the support body. The second cutting blade is placed behind the first cutting blade in the cutting direction so that the first portion of the second cutting blade is arranged substantially behind the first portion of the first cutting blade along the cutting direction, so that the first portions are arranged in a common vertical plane parallel with the cutting direction. Optionally, the first portions extend completely vertically, that is, only in the z-direction. Thus, during a cutting operation, the first portion of the first cutting blade can serve to produce a slit in a top surface of the board, such as a slit in the facing and optionally in an uppermost portion of a core of the board, such as a mineral wool core of the board.

[0012] Each cutting blade comprises a first bend separating the second portion of the respective cutting blade from the first portion of the respective cutting blade, the second portions extending divergently from the respective first bend to a respective second bend. Typically, the second portions extend substantially horizontally. Thus, the extension of the second portions define a cut width, corresponding to the distance, when projected onto a vertical plane perpendicular to the cutting direction (that is, in a front view), between the two second bends. The second portions typically serve to define the upper portion of the cut-out, for example, by cutting the core of a board under the facing, preferably relatively close to the facing, such as at a distance of less than 3 mm under the facing, such as at a distance of less than 2, 1 or 0.5 mm under the facing.

[0013] The respective second bend separates the respective second portion from the respective third portion of the respective cutting blade, the third portions extending downwardly and convergently, preferably, towards an apex. Thus, the third portions serve to define a cut depth, for example, corresponding to the distance, in the vertical direction, between the first bend and lowermost ends of the third portions. Thus, the third portions define side-walls of the cut-out and of the corresponding groove.

[0014] Thus, the first portions serve to slit the facing, and the second and third portions jointly define the cross-section of the cut-out: the second portions determine the shape and width of the top portion of the cut-out, whereas the third portions define the shape, size and orientation of the side-walls of the cut-out, and thus the shape, size and orientation of the side walls of the groove that is formed by removal of the cut-out.

[0015] In some embodiments of the invention, the second portions, in a front view, extend substantially horizontally, so as to provide for a substantially planar top surface of the cut-out.

[0016] In some embodiments of the invention, the second portions, in a front view, are arranged at respective acute angles (δ) in relation to a horizontal line. That is, the second portions may be inclined versus the y-axis, that is, oriented somewhat upwards or downwards, at a certain angle in relation to the horizontal plane, whereby the size of the gap varies along the second portions, and whereby the top of the cut-out will feature two parts arranged at an angle to each other, as defined by the angle between the second portions. This can, for example, cause the cut-out portion to have a substantially deltoid cross-section, that is, a kite-shaped cross section. The second portions of the cutting blades can preferably be oriented downwards at an angle δ ranging between 0 and 15° with regard to the horizontal line, that, is, with regard to a line parallel with the y-axis. For example, when cutting under a facing, this kind of sloping first sections may contribute to provide more core material left under the facing towards the parts of the undercut facing that are more remote from the slit, thereby potentially reinforcing the support for the facing.

[0017] In some embodiments of the invention, the support body has a bottom surface, and there is a gap between the second portions of the cutting blades and the bottom surface of the support body. Thus, this gap can serve to accommodate the facing, so that during the cutting operation, the second portions can cut the board under the facing, thereby providing a cut-out without removing any substantial part of the facing, so as to provide for a substantially planar top surface of the cut-out without any substantial portion of the facing remaining adhered to it. In some embodiments, the bottom surface of the support body may be planar or partly planar, and the second portions may be substantially horizontal (in a front view), whereby the gap may feature a substantially constant height in the vertical direction at least during part of, such as most of, the extension of the second portions between the respective first and second bends.

[0018] In some embodiments of the invention, the gap has a height of between 1 mm and 3 mm, such as of between 1.5 mm and 2.5 mm. For example, in some embodiments, a 1 mm gap may be preferred. The height of the gap refers to the shortest distance in the z-direction between the second portion of the respective cutting blade (extending between the first bend A, A' and the second bend B, B' in some of the figures illustrating preferred embodiments) and the bottom surface of the support body of the tool, in a front view. If the height of the gap varies along the gap in a direction perpendicular to the cutting direction, for example, due to a sloping / inclined second portion as discussed above, the height refers to the height in the middle of the gap, that is, right in the middle between the starting point and the end point of the second portion, such as right in the middle between the two bends that delimit the second portion. It has been found that such a height is adequate for allowing the second portions to undercut the typical facings of many typical mineral wool boards, allowing the facings and optionally a minor portion of the mineral wool core to be present in the gap during the cutting process.

[0019] In some embodiments of the invention, the second portions of the cutting blades, in a front view, are substantially straight between the respective first bend and the respective second bend. The fact that the first portions are substantially straight may serve to reduce variations in the height of the gap, especially if the second portions also extend substantially horizontally.

[0020] In some embodiments of the invention, the third portions of the cutting blades, in a front view, are substantially straight. Substantially straight third portions can provide a substantially V-shaped cut, and provide for a cut-out having, for example, a substantially triangular cross section (when the second portions are horizontal) or a substantially deltoid or kite-shaped cross section (when the second portions sections are inclined, as further described above).

[0021] In some embodiments of the invention, the third portions of the cutting blades, in a front view, are curved or include curved portions. This will cause the sides and / or bottom of the groove to deviate from the typical V-shape and feature, for example, a U-like shape, a partially curved cross-section with one or more curved walls, etc. This can sometimes be useful to reduce material so as, for example, to facilitate folding of the board with regard to the bottom of the groove.

[0022] In some embodiments, the second portions of the cutting blades may, in a front view, be curved or have curved portions. In some embodiments, the second and / or the third portions may, in said front view, have a wavy shape, a zig-zag shape, or any other suitable geometric shape.

[0023] Thus, depending on the specific size, orientation and shape of the second and third sections of the cutting blades, a desired cross-section of the cut-out of the board can be obtained.

[0024] In some embodiments, the second portions of the cutting blades have the same length between the respective first bend and the respective second bend, and / or the third portions have the same length between the respective second bend and an end of the respective third portion. This can serve to enhance symmetry. For example, the second portions and the third portions, in a front view, may jointly have the shape of an isosceles triangle or an equilateral triangle, optionally with one or more rounded corners. This can provide for a symmetric and attractive shape of the cut-outs and for the space allowing a board to be folded as described above, for example, to form a duct section having a polygonal cross-section.

[0025] In some embodiments, the third portions of the cutting blades, in a front view, extend substantially until an apex or beyond an apex, such as to provide for a V-shaped groove, the bottom of the groove corresponding to the apex. This kind of groove has proven to be useful in the art of insulating duct elements, for allowing folding of mineral wool boards to form duct sections with rectangular cross sections.

[0026] In some embodiments, the third portions of the cutting blades comprise a curved end portion or a horizontally oriented end portion, so as to provide for a groove having a cross section with a curved or flat apex region, respectively.

[0027] In some embodiments, the cutting tool is a hand-held tool, optionally including a handle to be gripped by a user.

[0028] A further aspect of the invention relates to a cutting device comprising: a support for supporting a mineral wool board (the term "support" is to be interpreted broadly, and encompasses any kind of arrangement appropriate for ensuring that a mineral wool board be positioned correctly in relation to the cutting device; that is, it does not necessarily imply that the board be "supported from below", just to give an example); a cutting tool as described above; and a first guide system, the first guide system being arranged for supporting the cutting tool and for guided displacement of the cutting tool, in parallel with a first axis (such as an x-axis), in relation to the support for supporting a mineral wool board, so as to cut an elongate groove in a mineral wool board in parallel with the first axis.

[0029] The guide system can, for example, comprise or consist of one or more rods extending in parallel with the first axis, which in some embodiments may be a horizontal axis, and a carriage or similar supporting the cutting tool for movement in parallel with the rod or rods, guided by the rod or rods. The displacement of the cutting device can, in some embodiments, be performed manually. The term "rod" is to be interpreted broadly and encompasses any elongate element suitable for guiding a cutting tool in parallel with an axis for carrying out a straight cut in parallel with that axis.

[0030] In some embodiments, the cutting device further comprises a second guide system for positioning the cutting tool according to a second axis (such as a y-axis), perpendicular to the first axis. The second guide system -which may comprise or consist of, for example, one or more rods, one or more slides, etc.- may, for example, serve to displace the cutting tool, for example, by displacing the first guide system supporting the cutting tool, perpendicularly to the first axis -the one in parallel with the grooves to be formed in a mineral wool board, which can be referred to as an "x axis"-, so as to subsequently position the cutting tool in relation to different "y axis" positions, which may correspond to the positions of different grooves. Thus, the device can be operable to use the second guide system to position the cutting tool in an "y axis" position corresponding to the position where a groove is to be executed -for example, a certain position in relation to one of the sides of the board, such as a transversal or "shorter" side of the board, and then to use the first guide system to guide the cutting tool in parallel with the x axis, to cut a straight groove in the board, for example, in parallel with a longitudinal or "longer" side of the board. Also, the second guide system may be manually operated, or otherwise.

[0031] The cutting device may be part of a cutting machine that further comprises drive means for displacing the cutting tool in parallel with at least one axis, such as, for example, in parallel with the first axis, guided by the first guide system, and / or for displacing the cutting tool in parallel with the second axis, for example, before initiating cutting of a groove. Any suitable kind of drive means can be used, for example, pneumatic, hydraulic or electric drive means.

[0032] A further aspect of the invention relates to a method of cutting a groove in a board, such as an insulation material board, such as a mineral wool board comprising a board core, such as an insulation material core, such as a mineral wool core, having a facing on at least one major surface thereof, wherein the method comprises using a cutting tool as described above, for: A- producing, with the first portion of the first cutting blade, a slit in the facing, substantially without removal of material of the facing (in particular, there is no intentional removal of material; the facing is simply slit); B- cutting the board core, such as the insulation material core, such as the mineral wool core, with the second portions of the cutting blades, substantially adjacent to the facing over a distance that determines the width of the groove (that is, the width of the portion to be cut-out of the mineral wool core) (steps A and B optionally cause two portions of the facing, that is, one portion on each side of the slit and extending along the slit, to become separated from a main portion of the board core, such as the insulation material core, such as the mineral wool core; depending on the exact position -in the vertical direction- of the cut carried out in step B, some mineral wool may still adhere to these portions of the facing, but preferably this is just a reduced amount that does not prevent these portions from flexing, for example, to fold over the sides of the grooves produced in step C, described below); C- producing, with the third portions of the cutting blades, two converging cuts in the board core that determine the depth of the groove; wherein steps A, B and C are carried out substantially simultaneously by moving the cutting tool, for example, in a single stroke, along the board.

[0033] In some embodiments, the method further comprises removing a cut-out of the board core having a top surface determined by step B and two converging side walls determined by step C. The groove may comprise two side walls. After removing the cut-out, the two portions of facing may at least partly cover the two side walls. As explained above, this can contribute to an improved image of the product, for example, of a mineral wool duct formed by folding a mineral wool board in relation to three parallel groves, each one being produced as described above, and it can also facilitate maintenance, for example, cleaning of such a mineral wool duct. Preferable, the top surface of the cut-out portion is not covered by a portion of the facing.

[0034] A further aspect of the invention relates to a method for forming a mineral wool duct section out of a mineral wool board comprising a mineral wool core having a facing on at least one major surface thereof, comprising: producing at least three parallel grooves in a major surface of the mineral wool board, each groove being produced by a method as described above; and folding the mineral wool board along said grooves so as to form a mineral wool duct section having a polygonal cross section.

[0035] A further aspect of the invention relates to a use of the cutting tool as described above, for producing at least one groove (such as three or more parallel grooves) in a board, such as an insulation material board, such as a mineral wool board, especially a mineral wool board, comprising an insulation material core, especially mineral wool core having a facing on at least one major surface thereof. The tool can be used to slit the facing and to remove a portion of the mineral wool core under the facing, without removing a corresponding portion of the facing, which can thus be used to at least partly cover the side surfaces of the groove, thus enhancing appearance and quality of the product, for example, at a corner formed by folding the board in correspondence with the groove.BRIEF DESCRIPTION OF THE DRAWINGS

[0036] To complete the description and in order to provide for a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate embodiments of the invention, which should not be interpreted as restricting the scope of the invention, but just as examples of how the invention can be carried out. The drawings comprise the following figures: Figure 1 schematically illustrates how a grooved mineral wool board can be folded to form a duct section having a rectangular cross section. Figure 1 shows an example of a mineral wool board comprising grooves which have been prepared with cutting tools according to the state-of-the-art. Figures 2 to 10 show specific embodiments of the invention. The invention is obviously not limited to the specific embodiment(s) shown in those figures. Figure 2A schematically illustrates three steps of a process for producing a groove in a mineral wool board, in accordance with an embodiment of the invention. Figure 2B schematically illustrates how, when using a method as shown in figure 2A, portions of facing will cover the side walls of the groove in the corner of the duct section obtained by folding the grooved board. Figure 3A is a schematic cross-sectional view, in a vertical plane ("y-z") perpendicular to the cutting direction ("x"), of a mineral wool board being cut by a cutting tool, in accordance with an embodiment of the invention. Figure 3B is a schematic perspective view ("x-y-z") of a mineral wool board being cut by a cutting tool in accordance with an embodiment of the invention. Figure 4A is a schematic perspective view ("x-y-z") showing the bottom side of a cutting tool in accordance with an embodiment of the invention. Figure 4B is a schematic front view ("y-z") of the cutting tool of figure 4A, as it would be observed by an observer looking at the tool with the tool arranged to move towards the observer in the cutting direction ("x"), that is, in parallel with the x-axis. Figures 5A and 5B are a cross sectional side view and a rear cross sectional view, respectively, of a cutting device in accordance with an embodiment of the invention. Figures 6A-6H are schematic front views showing the cutting edges of a blade element, and the cross-section of the resulting cut-out (in the case the other blade element has a corresponding, mirror-inverted, shape; not shown). The respective cross-section of the grooves obtained in the board after cutting (not shown) have the negative shape of the cross-section of the corresponding cut-outs. In all examples, the respective top-layer (e.g. facing) remains attached to the board after cutting. Figure 7 is a schematic perspective view of a cutting device or cutting machine according to an embodiment of the invention. Figures 8A and 8B are a side cross sectional view and a rear cross sectional view, respectively, of a cutting tool in accordance with an embodiment of the invention. Figures 9A and 9B are a side cross sectional view and a rear cross sectional view of a cutting tool according to an embodiment of the invention. Figures 9C-9E are a side cross sectional view, a rear cross sectional view and a bottom view, respectively, of a carriage incorporating a cutting tool. Figure 10 is a perspective view of a cutting device operating on a mineral wool board, in accordance with an embodiment of the invention. DESCRIPTION OF WAYS OF CARRYING OUT THE INVENTION

[0037] Figure 2A schematically illustrates three steps of a process for producing a groove in an insulation material board, such as a mineral wool board, in accordance with an embodiment of the invention. In a first step, a mineral wool board 1000 is provided, comprising a mineral wool core 1001 having a top facing 1002 on a top surface thereof, and a bottom facing 1003 on a bottom surface thereof. The top facing 1002 and the bottom facing 1003 may be of identical materials or of different materials. The mineral wool board 1000 is, in the illustrated embodiment, oriented horizontally, with its main surfaces extending in the x-y plane and its thickness extending in z-direction.

[0038] In a second step, a longitudinal cut has been performed in parallel with a horizontal x-axis. The cut comprises a first slit 1005 that traverses the top facing 1002, and a second slit that has a substantially isosceles-triangular shape (see for example slit 1006 in figure 3A), and that extends under two portions 1002a, 1002b of the top facing 1002, and down (that is, in the z-axis direction) into the core 1001. Thus, with this cut, a cut-out of the core has been established that features a substantially triangular cross section, and that has been removed at the illustrated stage of the process, leaving the groove 1004. As can be observed, the two facing portions 1002a and 1002b have not been removed with the cut-out, but remain attached to the rest of the facing.

[0039] In the third step, it is schematically illustrated how the two portions 1002a and 1002b have been flexed into the groove 1004, covering the sides thereof. In the illustrated figure they extend until the apex (the lowermost point) of the groove, but in practice they will typically end before reaching the apex. However, they will cover a substantial part of the sides of the groove 1004.

[0040] Figure 2B schematically illustrates how, when using a method as shown in figure 2A, portions 1002a, 1002b of facing will cover the side walls of the groove in the corner of the duct section obtained by folding the grooved board. As explained above, this can serve to enhance the appearance of the interior of the duct, as the core will not appear visible in the corners of the interior of the duct. Also, cleaning may be facilitated, and it becomes less likely that an air stream through the duct will interact with the core material, as the facing portions 1002a and 1002b contribute to shield the core from the air stream at the corners. This is advantageous compared to traditional methods in which the facing above the groove is removed as part of the cut-out when establishing the grooves.

[0041] Figure 3A is a cross-sectional view, in the vertical y-z-plane (perpendicular to the x-axis, that is, to the cutting direction) of a mineral wool board being cut in accordance with an embodiment of the invention, using a cutting tool 1 having a support body 2 with a handle 10. Two cutting blades (not shown in figure 3A) are attached to the support body 2 and extend downwards from the support body 2. A cutting action has been performed moving the cutting tool 1 over the top surface of the board 1000 in a cutting direction (parallel with the x axis), with a bottom surface of the support body 2 in contact with the top facing 1002 of the board 1000, thereby carrying out a slit 1005, 1006 in the board. More specifically, the tool has made a vertical slit 1005 in the top facing 1002, and a substantially triangular cut 1006 in the core 1001. This cut comprises a substantially horizontal part 1006A that extends sideways under the top facing 1002 on both sides of the slit 1005, and that defines the width of the cut. The cut additionally comprises a substantially V-shaped part 1006B, that extends from the ends of the horizontal part 1006A and down to an apex, which is positioned close to the bottom facing 1003 of the board. The triangular cut delimits a piece of the core, that is, an elongated piece or cut-out 1004A having a substantially triangular cross-section, which is to be removed after the cutting operation, as schematically shown by the curved arrow in figure 3A, thereby leaving a groove in the board. As readily understood from figure 3A, the cut-out 1004Awill be removed without removal of the top facing 1002, which will remain intact, except for the slit 1005. As schematically illustrated in figure 3A, the slit 1006 has a width w (the maximum width of the cut, corresponding to the distance between the ends of the horizontal part 1006A of the cut) and a cut depth d (with reference to the upper end of the cut-out). That is, the width w basically corresponds to the (upper) base of the isosceles triangle formed by the slit 1006, whereas the depth d corresponds to the height of the triangle. Preferably, the angle between the two side walls of the triangle formed by the V-shaped part 1006B is about 90 degrees or somewhat smaller, such as between 70 and 90 degrees, to facilitate the folding of the board to form a right-angled corner, for example, when the board is to form a duct section having a rectangular cross-section.

[0042] Figure 3B shows a similar arrangement, in a perspective view ("x-y-z"). Compared to the embodiment of figure 3A, in the case of figure 3B the horizontal part 1006A of the cut 1006 in the core 1001 is placed somewhat further down in the core 1001, generating a thicker top layer being connected to the main portion of the core 1001 of the board 1000, by leaving more core material between the top facing 1002 and the cut-out 1004A. Thus, more core material will remain adhered to the top facing 1002 after removal (as suggested by the arrow in figure 3B) of the cut-out 1004A, which may be desired in certain applications, for example, to provide more insulating material at the corner of the duct section after folding the board. A thicker top layer also helps to establish a more solid bond between undercut facing 1002 and the main portion of the core 1001, to reduce the risk of unintended tearing of the undercut facing 1002. Also, the greater distance between the horizontal part 1006A of the cut and the facing 1002 may also serve to reduce the risk of damage to the facing 1002 during the cutting operation.

[0043] Figures 4A and 4B illustrate a cutting tool 1 according to an embodiment of the invention, which can be used to cut a board substantially as shown in figures 3A and 3B. The cutting tool 1 comprises a schematically illustrated handle 10 (see figure 4B), and a support body 2 having a top surface 22 and a bottom surface 21. Two cutting blades 3a,3b are attached to the support body 2 and extend downwards from the support body. The tool is configured for cutting a groove in a board by moving the tool in parallel with an x-axis (when the board is arranged horizontally, for example, as shown in figure 3A). As schematically illustrated and as best shown in figure 4A, a first cutting blade 3a and a second cutting blade 3b are both attached to the support body 2. The second cutting blade 3b is situated behind the first cutting blade 3a when the cutting tool 1 is observed from a position in front of the tool, as in figure 4B.

[0044] Each cutting blade 3a, 3b comprises a front edge that is shaped for cutting. Each cutting blade 3a, 3b basically comprises three different portions, separated by bends, as explained below.

[0045] Basically, each cutting blade 3a, 3b is a bent blade element, comprising a first portion 4a, 4b, extending vertically downwards from the bottom surface 21 of the support body 2 of the cutting tool 1.

[0046] In the case of the first cutting blade 3a, the first portion 4a extends vertically downwards until a first bend A. From the first bend A, which is about 90 degrees in the illustrated embodiment, a second portion 5a of the first cutting blade 3a is oriented substantially horizontally until reaching a second bend B, at the left of the first bend A when the cutting tool 1 is viewed from the front as in figure 4B. That is, between the two bends A and B, the first cutting blade 3a comprises a basically horizontal second portion 5a. From the second bend B, a third portion 6a of the first cutting blade 3a is oriented substantially downwards and back towards the right (when viewed from the front). In the embodiment of figures 4A and 4B, between the second end B and the lowermost end C of the first cutting blade 3a, the third portion 6a is substantially straight. This third portion 6a is, in this embodiment, oriented at an angle α (see figure 4B) of approximately 30-40 degrees with regard to the horizontal x-y plane. However, in many embodiments, a larger angle is preferred, such as an angle of between 45 and 55 degrees.

[0047] The second cutting blade 3b is basically a mirror-inverted version of the first cutting blade 3a. That is, in the case of the second cutting blade 3b, the vertical first portion 4b extends downwards until a first bend A'. From the first bend A', which is about 90 degrees, a second portion 5b of the second cutting blade 3b is oriented substantially horizontally until reaching a second bend B', at the right of the first bend A' when the cutting tool 1 is viewed from the front as in figure 4B. That is, between the two bends A' and B', the second cutting blade 3b comprises a basically horizontal second portion 5b. From the second bend B', a third portion 6b of the second cutting blade 3b is oriented substantially downwards and back towards the left (when viewed from the front). In the embodiment of figures 4A and 4B, between the second bend B' and the lowermost end C' of the third portion 6b, the third portion 6b is substantially straight. This third portion 6b is, in this embodiment, oriented at an angle α of approximately 30-40 degrees with regard to the horizontal x-y plane. However, in many embodiments, a larger angle is preferred, such as an angle of between 45 and 55 degrees.

[0048] Thus, from an operative perspective, in the front view as shown in figure 4B, each cutting blade 3a, 3b of the tool comprises a vertical first portion 4a, 4b. The vertical first portion 4b of the second cutting blade 3b is situated behind the vertical first portion 4a of the first cutting blade, and situated in the same vertical plane containing the cutting direction, that is, the same x-z-plane. Thus, the vertical first portion 4b of the second cutting blade 3b is "hidden" behind the vertical first portion 4a of the first cutting blade 3a, and does not act as an active cutting edge when the tool is used as intended. The first portion 4a of the first cutting blade 3a serves to slit the top facing 1002 of the board when used in a method as shown in, for example, figure 2A, or in figures 3A and 3B.

[0049] As best shown in figure 4B, the first and second cutting blades 3a, 3b diverge at the lower end of their vertical first portions 4a, 4b, as from the first bends A, A' and until the second bends B, B', so that the second portions 5a, 5b establish a substantially horizontal edge portion. From the second bend B, B', the cutting blades converge, that is, their third portions 6a, 6b extend downwards and convergently towards an apex D, until their ends C, C', forming an angle α with the horizontal (x-y) plane (in figure 4B the angle α is illustrated with regard to the second portions 5a, 5b, but this is only because these second portions 5a, 5b, in the illustrated embodiment, happen to extend in the horizontal (x-y) plane).

[0050] In the illustrated embodiment, the ends C, C' of the third portions 6a, 6b substantially meet at the apex D, corresponding to the apex (the bottom part) of the groove being formed when the cutting tool 1 is used as intended.

[0051] Thus, with this arrangement, the vertical first portion 4a of the first cutting blade 3a serves to perform a substantially vertical cut in the board, including slitting the facing, when the cutting tool 1 is used in a method as described above. On the other hand, the second 5a, 5b and third 6a, 6b portions cut the core such as to delimit the cut-out: the second portions 5a, 5b cut the core under the upper facing, establishing a cut having a width w corresponding to the distance between the second bends B, B', and the third portions 6a, 6b cut oblique cuts that determine the side walls and depth of the groove to be established. The sizes and orientations of the second portions 5a, 5b and the third portions 6a, 6b determine the cross-section of the cut-out in the y-z plane.

[0052] As best shown in figure 4B, as the second portions 5a, 5b are positioned at a distance from the bottom surface 21 of the support body 2, there is a gap G between these second portions 5a, 5b of the first and second cutting blades 3a, 3b and the bottom surface 21 of the support body 2. This gap G may serve to accommodate a facing, such as a top facing, of a board during a cutting operation, and optionally also part of the core material closest to the facing (such as shown in the embodiment of figure 3B). This gap G may, in some embodiments, have a size of between 1 and 3 mm, which has been found suitable for accommodating facing materials of many existing mineral wool boards. In the kind of cutting tool 1 shown in figures 4A and 4B, the size of the gap G is determined by the position of the first bend A, A' in relation to the bottom surface 21 of the support body 2 of the cutting tool 1.

[0053] In the illustrated embodiment, the second portions 5a, 5b have the same length and the third portions 6a, 6b have the same length, the second portions 5a, 5b and the third portions 6a, 6b are substantially straight, and the second portions 5a, 5b are oriented horizontally. Thus, the second portions 5a, 5b and the third portions 6a, 6b jointly form a cutting edge portion having a shape in the form of an isosceles triangle. However, any other suitable shape can be used.

[0054] The angle α between the third portions 6a, 6b and the horizontal plane is preferably in the order of 45 degrees, such as between 45 and 55 degrees. For example, when the two third portions 6a, 6b of figure 4B are arranged with an inclination α=45 degrees with regard to the horizontal plane, the two third portions 6a, 6b meet at a right angle β at the apex D. This can be appropriate for the production of grooves intended to allow the board to be folded at a right angle, for example, for forming a duct element having a rectangular cross section.

[0055] In the embodiment shown in figures 4A and 4B, the cutting blades 3a, 3b are attached to the bottom surface 21 of the support body 2 of the cutting tool 1.

[0056] Figures 5A and 5B are a cross sectional side view and a rear cross sectional view, respectively, of a cutting tool 1 in accordance with another embodiment of the invention, wherein the support body 2 comprises a through hole 11 with substantially square cross section, for accommodating a guide rod of a guide system (for example, as shown in figure 7). In this embodiment, and differently from what is the case with the embodiment shown in figures 4A and 4B, the cutting blades 3a, 3b are attached to a side of the support body 2, by screws 16.

[0057] Figure 6A schematically illustrates a cutting blade design in which the first portion 4a is vertical, the second portion 5a horizontal, and the third portion 6a straight and inclined, reaching the apex D. Combined with another blade element having a complementary (mirror-inverted) shape, the cross-section of the cut-out 1004A, as determined by the second and third portions of the cutting blades, will be shaped as an isosceles triangle, as schematically illustrated in figure 6A.

[0058] Figure 6B illustrates an alternative embodiment, which differs from the one of figure 6A only in that the third portion 6a is curved inwards at its lowermost end, whereby the cut-out 1004A will feature a rounded bottom section converging to the apex D; the corresponding groove will thus feature a rounded bottom portion.

[0059] Figure 6C illustrates an alternative embodiment, in which the third portion 6a ends before reaching the apex D towards which it is directed. Instead, at the end of the third portion 6a there is a horizontal final portion (that is, oriented in the direction of the y-axis) which, together with a horizontal final portion of the other cutting blade (not shown), provides for a flat bottom portion of the cut-out 1004A. Thus, this configuration of the cutting blades provides for a trapezoidal cross-section of the cut-out 1004A, and a flat bottom of the groove formed by removal of the cut-out 1004A.

[0060] Figure 6D illustrates an alternative embodiment in which the final portion of the second portion 5a is bent downwards, thereby creating a bevel-shaped transition to the third portion 6a. This provides for a cut-out 1004A having chamfered upper edges, as schematically illustrated in figure 6D.

[0061] Figure 6E illustrates an alternative embodiment in which the third portion 6a is curved, providing for a cut-out 1004A having a curved lower surface, and for a groove featuring a corresponding, somewhat U-shaped, configuration. Basically, the sides of the groove will adopt a concave configuration, and the cut-out 1004A will feature a convex configuration. This can sometimes be advantageous, for example, for creating extra space for housing the undercut facing portions when the board is folded in correspondence with the groove.

[0062] Figure 6F illustrates an alternative embodiment in which the third portion 6a is likewise curved, but here inwardly, thereby providing for a groove the sides of which adopt a convex configuration (rather than a concave one, as in figure 6E); the cut-out 1004A will thus adopt a concave configuration.

[0063] Figure 6G illustrates an alternative embodiment in which the third portion 6a has an undulating shape, thereby providing for a cut-out 1004A having sides that are undulating when viewed in cross section, as schematically illustrated in figure 6G. Thus, also the corresponding groove will feature sides with this kind of undulating layout.

[0064] Finally, figure 6H illustrates an alternative embodiment in which the second portion 5a is inclined in the front view, sloping downwards at an angle δ of approximately 5-15 degrees with regard to the horizontal plane. This provides for a cut-out 1004A having a deltoid (kite-shaped) cross section, as schematically illustrated in figure 6H. In figure 6H, two dotted lines extend horizontally, and the angles δ (the inclination of the second portion 5a with regard to the horizontal line / plane) and α (the inclination of the third portion 6a with regard to the horizontal line / plane) are schematically indicated.

[0065] These are just some examples of the shapes that the cutting blades 3a, 3b may adopt and of the corresponding cross-sectional shape of the resulting cut-out 1004A (and the groove). Obviously, many other specific blade shapes can be used without departing from the concept of the invention, as explained above and as claimed.

[0066] Figure 7 schematically illustrates a cutting device 100 or cutting machine 100 according to an embodiment of the invention. The cutting device 100 comprises a support 101 for supporting a board 1000, and first guide system, comprising a horizontally arranged first guide rod 102, for supporting a cutting tool 1 and for guided displacement of the cutting tool 1, in parallel with the x-axis, in relation to the support 101 so as to cut an elongate groove in the board 1000 in parallel with the x-axis. The device further comprises a second guide system, comprising two parallel second guide rods 103 and corresponding slides 104, for positioning the cutting tool 1 according to the y-axis. In addition, the device comprises a third guide system, comprising two vertical posts 105 and corresponding slides 106, for displacing the first guide rod 102 and the cutting tool 1 vertically, in parallel with the z-axis.

[0067] In some embodiments, the cutting device 100 can be hand-driven, that is, the operator can displace the cutting tool 1 and the slides 104, 106 in accordance with the different axes. In some embodiments, the cutting device 100 may form part of a cutting machine 100 including drive means, such as drive means 107 (schematically illustrated by discontinuous lines) for displacing the cutting tool 101 in parallel with the x-axis, and / or the slides 104, 106 along their respective axes.

[0068] In figures 8A and 8B, a cutting tool 1 according to an embodiment of the invention can be observed, wherein the support body 2 is provided with a handle 10 and a through hole 11 having a substantially square cross section, intended to receive a rod having a complementary shape, so that the rod can act as a guide rod, guiding the cutting tool in its movement in the cutting direction, that is, in parallel with the x-axis, for example, as shown in figure 7.

[0069] Figures 9A and 9B are a side cross sectional view and a rear cross sectional view, in line with those of figures 8A and 8B, of a cutting tool 1 according to an alternative embodiment, in which the cutting tool 1 as such is not provided with a handle, but with screw bores 12 or similar to allow the cutting tool to be attached to a carriage of a cutting device 100 or a cutting machine 100.

[0070] Figures 9C-9E are a side cross sectional view, a rear cross sectional view and a bottom view, respectively, of a carriage 15 incorporating a cutting tool 1 as per figures 9A and 9B in a bottom recess in the body of the carriage 15. In figures 9C and 9D it is schematically illustrated how the cutting tool 1 is attached to the carriage by screws 13. The carriage 15 includes a through hole 11 to accommodate a guide rod, for guiding the carriage in parallel with the x-axis, for example, in line with what is shown in figure 7.

[0071] Figure 10 schematically illustrates how a cutting device 100 including a linear guide rod 102 can be used to cut a mineral wool board 1000, a cutting tool 1 according to an embodiment of the invention sliding along the guide rod 102 driven by the hand of an operator (or by any other means, including electrical, pneumatic or hydraulic means). The cutting tool 1 thus produces a slit 1005 in the upper facing 1002 of the board, and a cut having a substantially triangular cross section in the core 1001 of the board, to produce a cut-out which, after removal, leaves a groove having a substantially V-shaped cross section, and without removing any part of the facing.

[0072] The invention is obviously not limited to the specific embodiment(s) described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the invention as defined in the claims.

Claims

1. A cutting tool (1) for cutting a board, the cutting tool (1) comprising a support body (2), a first cutting blade (3a) and a second cutting blade (3b), the cutting blades (3a, 3b) being attached to the support body (2), the cutting blades (3a, 3b) being arranged for cutting a board by moving the cutting tool (1) in a cutting direction with the cutting blades (3a, 3b) interacting with the board, each cutting blade (3a, 3b) comprising a first portion (4a, 4b), a second portion (5a, 5b), and a third portion (6a, 6b), wherein: the first portion (4a, 4b) of each cutting blade (3a, 3b) extends downwards from the support body (2), wherein the second cutting blade (3b) is placed behind the first cutting blade (3a) in the cutting direction so that the first portion (4b) of the second cutting blade (3b) is arranged substantially behind the first portion (4a) of the first cutting blade (3a) along the cutting direction, so that the first portions (4a, 4b) are arranged in a common vertical plane parallel with the cutting direction; each cutting blade (3a, 3b) comprises a first bend (A, A') separating the second portion (5a, 5b) of the respective cutting blade (3a, 3b) from the first portion (4a, 4b) of the respective cutting blade (3a, 3b), the second portions (5a, 5b) extending divergently from the respective first bend (A, A') to a respective second bend (B, B'); the respective second bend (B, B') separating the respective second portion (5a, 5b) from the respective third portion (6a, 6b) of the respective cutting blade (3a, 3b), the third portions (6a, 6b) extending downwardly and convergently.

2. The cutting tool according to claim 1, wherein the second portions (5a, 5b), in a front view, extend substantially horizontally.

3. The cutting tool according to claim 1, wherein the second portions (5a, 5b), in a front view, are arranged at respective acute angles (δ) in relation to a horizontal line, preferably oriented downwards at an angle ranging from 0 to 15° with regard to the horizontal line.

4. The cutting tool according to any one of the preceding claims, wherein the support body (2) has a bottom surface (21), and wherein there is a gap (G) between the second portions (5a, 5b) of the cutting blades (3a, 3b) and the bottom surface (21) of the support body (2).

5. The cutting tool according to claim 4, wherein the gap (G) has a height of between 1 mm and 3 mm.

6. The cutting tool according to any one of the preceding claims, wherein the second portions (5a, 5b), in a front view, are substantially straight between the respective first bend (A, A') and the respective second bend (B, B').

7. The cutting tool according to any one of the preceding claims, wherein the third portions (6a, 6b), in a front view, are substantially straight.

8. The cutting tool according to any one of the preceding claims, wherein the second portions (5a, 5b) have the same length between the respective first bend (A, A') and the respective second bend (B, B'), and / or wherein the third portions (6a, 6b) have the same length between the respective second bend (B, B') and an end (C, C') of the respective third portion, and wherein, optionally, the second portions (5a, 5b) and the third portions (6a, 6b), in a front view, jointly have the shape of an isosceles triangle or an equilateral triangle.

9. The cutting tool according to any one of the preceding claims, wherein the third portions (6a, 6b), in a front view, extend substantially until an apex (D) or beyond an apex (D), and / or wherein the third portions (6a, 6b) comprise a curved end portion or a horizontally oriented end portion, so as to provide for a groove having a cross section with a curved or flat apex region, respectively.

10. The cutting tool according to any one of the preceding claims, wherein the cutting tool (1) is a hand-held tool, optionally including a handle (10) to be gripped by a user.

11. A cutting device (100) comprising: - a support (101) for supporting a mineral wool board (1000); - a cutting tool (1) as defined in any one of claims 1-9; - and a first guide system, the first guide system being arranged for supporting the cutting tool (1) and for guided displacement of the cutting tool (1), in parallel with a first axis, in relation to the support (101) for supporting a mineral wool board (1000), so as to cut an elongate groove (1004) in a mineral wool board (1000) in parallel with the first axis.

12. The cutting device of claim 11, wherein the cutting device (100) further comprises a second guide system for positioning the cutting tool (1) according to a second axis, perpendicular to the first axis.

13. A method of cutting a groove (1004) in a board (1000), such as an insulation material board (1000), such as a mineral wool board (1000) comprising a board core (1001), such as an insulation material core (1001), such as a mineral wool core (1001), having a facing (1002) on at least one major surface thereof, wherein the method comprises using a cutting tool (1) as per any one of claims 1-10, for: A- producing, with the first portion (4a) of the first cutting blade (3a), a slit (1005) in the facing (1002), substantially without removal of material of the facing (1002); B- cutting the board core (1001), such as the insulation material core (1001), such as the mineral wool core (1001), with the second portions (5a, 5b) of the cutting blades (3a, 3b), substantially adjacent to the facing (1002) over a distance that determines the width (w) of the groove (1004), - whereby steps A and B optionally cause two portions (1002a, 1002b) of the facing (1002) to become separated from a main portion of the board core (1001), such as the insulation material core (1001), such as the mineral wool core (1001); C- producing, with the third portions (6a, 6b) of the cutting blades (3a, 3b), two converging cuts in the board core (1001) that determine the depth (d) of the groove (1004); wherein steps A, B and C are carried out substantially simultaneously by moving the cutting tool (1) along the board (1000).

14. The method of claim 13, further comprising removing a cut-out (1004A) of the board core (1001) having a top surface determined by step B and two converging side walls determined by step C, wherein, optionally, the groove (1004) comprises two side walls, and wherein, after removing the cut-out (1004A), the two portions (1002a, 1002b) of facing at least partly cover the two side walls.

15. A method for forming a mineral wool duct section out of a mineral wool board (1000) comprising a mineral wool core (1001) having a facing (1002) on at least one major surface thereof, comprising: - producing at least three parallel grooves (1004) in a major surface of the mineral wool board (1000), each groove (1004) being produced by a method according to any one of claims 13 and 14; - folding the mineral wool board (1000) along said grooves (1004) so as to form a mineral wool duct section having a polygonal cross section.

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