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

Abstract

A cutting tool (1) for cutting a board comprises a support body (2) and a blade arrangement (3a, 3b) extending downwards from a bottom surface (21) of the support body (2). The blade arrangement comprises a first cutting edge (4a, 4b), a second cutting edge (5a, 6a) and a third cutting edge (5b, 6b). The first cutting edge (4a) can serve to produce a slit (1005) in a top surface of the board (1000), such as in a facing (1002) thereof. The second (5a, 6a) and third (5a, 6b) cutting edges define the top and sides of 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.

[0006] 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.

[0007] 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.

[0008] 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".

[0009] 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.

[0010] 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.

[0011] When reference is made to a "bend" in the context of the front view, reference is made to a change of orientation in the cutting edges observed in the front view. Thus, for example, the reference to a "bend" in relation to the first cutting edge and the first sections of the second and third cutting edges in the front view imply that there a change of angle, that is, that the first sections extend at an angle to the first cutting edge. This does not mean that in the physical implementation of the invention, the first section has to be a physical continuation of the first cutting edge. For example, the first section of the second and / or third cutting edge may not even start at the end of the first cutting edge, but may start at an intermediate portion of the first cutting edge. However, when observed in the front view, the first sections will extend from the first cutting edge, at an angle to the first cutting edge, that is, branching off from the first cutting edge. However, the first cutting edge does not necessarily form part of the same physical blade element as the second cutting edge / the third cutting edge, although this may often be preferred.

[0012] 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 position where the respective first section (of the second and third cutting edge, respectively) begins, that is, where the respective first section can be observed extending away from the first cutting edge, when viewed in the front view.

[0013] The second bends B, B' are the position where the first sections end, corresponding to the cut width. Here, the transition to the respective second section typically takes place.

[0014] The ends C, C' of the respective second section is the position where the downwards extension of the second section ends, thereby defining the cut depth.

[0015] 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 lower portions of the second and third cutting edges (that is, the second sections of these cutting edges) are directed. In many embodiments, the second sections substantially meet at the apex D, which thus determines the lowermost portion of the cut-out.

[0016] 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 the "x-y-plane" while the thickness of the board extends in "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.

[0017] 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 sections 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.

[0018] 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.

[0019] In the present text, reference is sometimes made to "edge sections" and "edge portions". The term "edge section" is typically used to prefer to a section or segment of a cutting edge when viewed in a front view, that is, basically, when considering the projection of the edge on a plane perpendicular to the cutting direction. The term "edge portion" is typically used when referring to a portion of a physical blade, that is, the real 3D-item, that contains part of the edge of the blade.

[0020] In the present text, when reference is made to "first section", "first sections", "second section" or "second sections", this refers to the respective sections of the second and / or third cutting edges (for example: first section of the second cutting edge etc.).

[0021] In the present document, "α" is used to designate the angle between the second section (corresponding to 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.

[0022] In the present document, "β" is used to designate the angle under which the two second sections meet at the apex, in the front view.

[0023] In the present document, "δ" is used to designate the angle between the first section 5a (corresponding to 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.

[0024] 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.

[0025] 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

[0026] 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.

[0027] 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.

[0028] 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 -that is, with its main surfaces arranged in respective horizontal planes- and the cutting tool is applied to slide on the upper surface of the board, such as on an upper facing of the board.

[0029] The cutting tool comprises a support body and a blade arrangement attached to the support body, the support body comprising a bottom surface and a top surface. The top and the bottom surfaces are typically located opposite to each other and the distance between them defines the height of the support body. The support body can have any suitable shape, for example, a substantially parallelepipedal shape, with more or less planar or curved surfaces, etc. In some embodiments, the bottom surface is substantially planar or comprises a substantially planar surface portion, for example, intended to abut against the board -such as against a top surface of the board- during the cut-out operation. In some embodiments, the top surface of the support body may be curved, for example, featuring a shape similar to the one of a top surface of a computer mouse. In some embodiments, the support body comprises a handle or has a handle attached to it. In some embodiments, the support body has a shape adapted to fit into the hand of a human being, so as to allow an operator to grip the support body in a convenient manner, facilitating manual cutting operations. In some embodiments, the support body is adapted to be attached to a more complex device or machine, for carrying out cutting operations.

[0030] The blade arrangement extends downwards from the bottom surface of the support body. As indicated above, the terms "downwards" and "bottom" are to be understood as referring to a situation in which the cutting tool is oriented so as to carry out the cutting operation with the support body moving above the board, such as sliding on the top surface of the board, for example, with the blade arrangement interacting with a volume segment of the board, such as with a volume segment of the board comprising a top facing and a mineral wool core. The cutting operation involves slitting the top portion of the board, typically comprising a facing, and simultaneously cutting a groove in the mineral wool core while the upper layer of the board containing the top facing is maintained connected to the body of the board after the cutting operation.

[0031] The blade arrangement comprises a first cutting edge, a second cutting edge and a third cutting edge. In some embodiments, the second cutting edge is implemented by an edge portion of a first blade element and the third cutting edge is implemented by an edge portion of a second blade element. In some of these embodiments, the first cutting edge is implemented by an edge portion, such as a substantially vertical edge portion, of one of these blade elements only, whereas in other embodiments the first cutting edge is implemented by edge portions, such as substantially vertical edge portions, of both blade elements, whereby these edge portions may be placed next to each other, side by side (in the direction of the "y-axis"), so as to jointly serve to produce a single slit in the board, such as a slit in the facing of a mineral wool board.

[0032] Each one of the second cutting edge and the third cutting edge comprises a first section and a second section.

[0033] In a front view of the cutting tool, the first cutting edge extends downwards (such as, for example, vertically in accordance with a z-axis, although also other orientations are possible, preferably within an angle between + / - 45 degrees with regard to the z-axis) from the bottom surface of the support body. The term "in a front view" refers to an orthogonal projection of the cutting tool onto a projection plane (which can be referred to as a "y-z plane" herein), the projection plane being perpendicular to the cutting direction (which is then in parallel with an "x-axis", considering for example the axes illustrated in some of the figures illustrating embodiments of the invention). The projection plane is "in front of' the cutting tool in the cutting direction, thus facing the cutting edges. In other words, the front view is taken from a person (= the observer) who is positioned in front of the cutting tool while the cutting tool is moved towards the observer in the cutting direction.

[0034] In some embodiments, and particularly in those embodiments wherein the bottom surface of the support body is not flat, the first cutting edge extends in the z-direction below the lowermost portion of the bottom surface. This enables that the cutting depth generated by the first cutting edge extends below the bottom surface of the support body, for example, slitting a top portion of a board, wherein the top portion of the board might comprise a facing. In a preferred embodiment, the bottom surface of the support body is substantially flat. In some embodiments, the first cutting edge extends vertically (parallel to "z-axis"). In some embodiments, the bottom surface is substantially flat and the first cutting edge extends vertically.

[0035] In the front view, each of the first sections extends substantially sideways from a respective first bend at the first cutting edge (that is, in the front view, each first section can be observed extending at an angle δ, such as at an angle of between + / - 15 degrees, preferentially 0°, with regard to the horizontal plane -that is, the "x-y plane"-, that is, with regard to the y-axis) and until a respective second bend, so that the first sections extend from the first cutting edge, away from the first cutting edge in substantially opposite directions or sideways, that is, the first sections extend away from each other and from the first cutting edge in substantially opposite directions. Thereby, the first sections diverge. In other words, the first sections branch-off from the first cutting edge, either at the endpoint of the first cutting edge or at any point between the starting point of the first cutting edge and the end point thereof. Both first sections may or may not branch-off at the same vertical position of the first cutting edge when viewing the blade arrangement from the front view. The first sections may extend horizontally, that is, in parallel with a horizontal axis ("y-axis"), or in an inclined manner versus the horizontal axis or plane, such as inclined downwards, such as at an angle δ ranging from 0 to 15 degrees with regard to the horizontal plane or the horizontal y-axis. The first sections extend away from the first cutting edge in a manner that provides for a gap between the bottom surface of the support body and each of the first sections, the first sections defining a cut width between the second bends.

[0036] The gap is a space that enables that a portion of a board - i.e. the top layer of the board - passes through the cutting tool without being removed from the bulk body of the board by the cutting tool. For example, in the case of cutting a mineral wool board comprising a mineral wool core having a facing on top of it, when cutting the board using a cutting tool as described, the first cutting edge can cut a slit in the top facing of the board, and the first sections of the second and third cutting edges can cut the mineral wool core just under the facing, that is, near the facing, so as to separate the facing from most of the mineral wool while maintaining, after cutting, the separated top layer of the board connected with the bulk body of the board; the facing will thus be present in the gap during the cutting operation.

[0037] The second bend correspond to the position where there is a change in the trajectory of the second and third cutting edge, respectively, from the generally diverging first section to the generally converging second section.

[0038] In the front view, each of the second sections extends downwardly and convergently from the respective second bend to a respective end of the respective second section, , so that the second sections converge towards an apex, whereby the second sections define a cut depth. The second sections may extend at an angle α in relation to the horizontal plane, preferably at an angle α of between 45 and 55 degrees, which has been found appropriate when the grooves are intended to facilitate the folding of the board at a right (90 degree) angle β in correspondence with the groove, for example, to form a duct section having a rectangular cross section. In a preferred embodiment, the angle α is 45 degrees, whereby the two second sections may, in some embodiments, meet at an approximately right angle β (90 degrees) at the apex.

[0039] That is, the depth of the cut-out and the groove - which extends in z-direction - will basically be determined by the difference of two positions, namely the starting points of the first section(s) (i.e. the position where the section(s) branch(s)-off from the first cutting edge(s) on the one hand, and the position of the lowermost end points of the second sections on the other hand. For instance, the lowermost end points of those second sections might coincide with the apex where the second sections of the corresponding second and third cutting edges meet. In this document, the term "apex" generally refers to a point towards which the second sections are directed to. In some embodiments, the apex is coincident with the lowermost ends of the second sections. In some embodiments, the second sections do not reach the apex (however, a complete cut for removal of a portion of the core of the board can still be ensured by, for example, a bridge in the form of an additional cutting edge that joins the ends of the second sections, for example, a horizontal bridge that corresponds to one side of a trapezoidal cut-out cross section). In some embodiments, the second sections extend beyond the apex, such as further down than the apex, for example, to ensure a complete circumferential cut for removal of a piece of the board core even in the case in which the second and third cutting edges are implemented at different positions along the cutting direction, such as on two different blade elements positioned one after the other in the cutting direction ("x-axis"). In some embodiments, the apex corresponds to the lowermost point of the groove to be cut, for example, to the lowermost point of a substantially triangular cut-out.

[0040] By extending downwardly and convergently, the lowermost parts of the cuts performed by the second sections -that is, the portions that are furthest away from the top surface of a board that is being cut by moving the tool along the top surface of the board in the cutting direction- are relatively close to each other compared with the parts of the cuts performed with the ends of the first sections. This enables weakening and preferably removing the connection between the lowermost part of the cut portion of the board with the rest of the board, so as to facilitate the removal of the cut-out from the rest of the board. In some embodiments, the second sections extend to the apex or beyond the apex. Thereby, the cutting edges form a closed shape in the front view referred to above, such as a closed polygonal or substantially polygonal shape, substantially defining the cross section of a portion of material to be removed when cutting a board with the cutting tool, such as when removing an elongate portion of a mineral wool board to form an elongate groove in the mineral wool core.

[0041] In some embodiments, the lowermost parts of the second sections of the second and third cutting edges are joined by a bridge section so as to create a closed shape.

[0042] Thus, basically, the lengths of the first sections of the second and third cutting edges define the width of the cut, such as the maximum width of the portion of material to be removed from the core of the board, such as from the mineral wool core. The fact that the first sections extend from the first cutting edge spaced from the bottom surface of the support body leaving the gap as explained above, allows the cutting to be performed without removing the top layer of the board. The top main surface of the board might contain a facing, such that during the cutting operation with the cutting tool, the first cutting edge(s) will just apply a slit to the facing or to the facing and the core material located immediately below the facing. In other words, the cutting depth of the slit generated by the first cutting edge(s) extends only to the top portion of the board. Typically, the cutting depth of the slit is smaller than 5 mm, preferentially smaller than 3 mm. Thereby, the facing or top layer stays connected with the grooved board, so that the facing will remain over the groove so that it can cover at least part of the side surfaces of the groove - i.e the shoulders of the groove - once the cut-out core material has been removed after cutting.

[0043] Thus, with this kind of cutting tool and when applied for cutting a mineral wool board comprising a mineral wool core with a facing on the top surface thereof, an advantage may reside in the capacity of the cutting tool to remove an elongate portion of the wool core to produce a groove (for example, for allowing the folding of the board in correspondence with the groove), without removing the part of the facing that covered the removed (cut-out) portion of the mineral wool core. This may be advantageous in that it may facilitate waste separation (the cut-out pieces may simply consist of the mineral wool and not include parts of the facing) and thus contribute to circular economy. Also, the portions of facing that remain over the groove can cover, at least in part, the walls of the groove, and thus extend into the corner that is formed when the board is folded in correspondence with the groove. This can serve, for example, to improve the appearance of the interior of a duct section formed by folding a board (for example, along three parallel grooves so as to form the four walls of a rectangular duct section) and also to facilitate the cleaning of the duct section, as the cleaning equipment will be in contact with the inner facing of the duct section, rather than with mineral wool material, in the corners of the duct section. Also, when used in air ducts, the presence of the facing may serve to minimize interaction between the mineral wool core material and the air stream, thereby reducing the risk of removal of mineral wool material and, for example, of mineral wool material being drawn into the air conditioning machinery.

[0044] The orientation and configuration of the second and third cutting edges in the front view of the cutting tool as explained above thus define the size and shape of the cross-section of the cut-out from the board, such as from the mineral wool core of a mineral wool board. The second and third cutting edges determine the width and depth (or height) of the cut-out, and also the orientation and shapes of the top and side portions of the cut-out, and thus the shape of the walls and bottom of the groove.

[0045] As indicated above, each of the first sections extends substantially sideways from a respective first bend or pivot point, for example, when considered in the front view discussed above, present at the position of the lower end of the first cutting edge, and until a respective second bend or pivot point. Each of the second sections extends from the respective second bend or pivot point to a respective end of the respective second section. The reference to "bend" or "pivot point" denotes a significant change of direction of the cutting edges. The first bend is a bend from the downwards, such as generally vertical, direction of the first cutting edge to the (more) horizontal direction of the first sections, which diverge outwardly to establish a cut relatively close to the top surface of the board, such as relatively close under the facing of the board, until substantially reaching the respective second bend, typically defining the width of the cut and the groove it corresponds to. At the respective second bend, the first sections end and the second sections begin, and, as explained, the second sections are directed downwardly and convergently towards an apex. In some embodiments, the apex is coincident with the ends of the second sections. In some embodiments, the second sections do not reach the apex, and in some embodiments the second sections extend beyond the apex, as discussed above. The ends of the second sections typically define the lowermost portion of the cut and, thus, the cut depth which corresponds to the height of the groove in the board. In this sense, the slit depth generated by the first cutting edge is not included in the cut depth generated by the combined work of the respective first and second sections of the second and third cutting edges. With other words: in the present text the term "cut depth" refers to the depth of the cut carried out by the second and third cutting edges, that is, basically, to the height of the cut-out to be removed.

[0046] In some embodiments, the second cutting edge is spaced from the third cutting edge in a cutting direction. For example, the first cutting edge and the second cutting edge can be implemented at an edge of a first blade element, whereas the third cutting edge can be implemented at an edge of a second blade element different from the first blade element, the blade elements being mounted at different positions of the support body in the cutting direction, such as at different positions along an x-axis. This can help to facilitate manufacture of the cutting tool and, in particular, of the blade arrangement. Also, it can sometimes be preferred, in order to facilitate cutting, that not all of the cutting edges enter into contact with the board to be cut at the same time.

[0047] In some embodiments, the first cutting edge and the second cutting edge are implemented on a first blade element, whereas the third cutting edge is implemented on a second blade element distinct from the first blade element, the second blade element being situated behind the first blade element in the cutting direction. That is, when viewed from the front, the second blade element, with the third cutting edge, can be placed behind the first blade element, in the cutting direction.

[0048] In some embodiments, the first cutting edge extends in a vertical direction and the third cutting edge is attached to the support body via a vertical edge or section of the second blade element, this vertical edge being positioned behind the first cutting edge in the cutting direction, so that the first cutting edge and the vertical edge are arranged in the same vertical plane (the x-z plane) parallel with the cutting direction. This vertical edge of the second blade element may be embodied as a cutting edge in the sense that it may be sharp and suitable for cutting, but as it is placed behind the first cutting edge (implemented on the first blade element), it will not participate actively in the cutting. In particular, when cutting a board with a facing as discussed above, the first edge of the second blade element will not produce an additional slit in the facing, in addition to the slit produced by the first cutting edge of the first blade element during the cutting operation.

[0049] When implementing the cutting edges on blade elements, the bends or pivot points discussed above can be implemented as simple bends in the blade. Thus, in some embodiments, each blade may comprise two bends: a first bend, separating a first part of the blade, for example, a part that extends downwards from the support body and that may incorporate the first cutting edge (or part thereof) from a part that incorporates the first section of the second (or third) cutting edge; and a second bend, that separates the first section of the second (or third) cutting edge from the second section of the second (or third) cutting edge.

[0050] In some embodiments, the second blade element comprises a first edge extending downwards from the bottom surface of the support body. This edge may be at least partly hidden behind the first cutting edge when the cutting tool is viewed from the front, that is, in the front view of the cutting tool. In such embodiments, this edge of the second blade element will not take an active part in the cutting operation, as it will simply follow the first cutting edge, implemented in the first blade element.

[0051] In some embodiments, the second cutting edge is implemented on a first blade element, whereas the third cutting edge is implemented on a second blade element distinct from the first blade element, the first blade element and the second blade element being situated one beside the other (i.e. in y-direction), that is, so that both blade elements can be traversed by a common plane (the "y-z-plane") perpendicular to the cutting direction. Preferably, the first cutting edge is implemented partly by a substantially vertical section of the first blade element and partly by a substantially vertical section of the second blade element, that is, in the front view discussed above, both the substantially vertical section of the first blade element and the substantially vertical section of the second blade element will be visible and they jointly constitute the cutting edge. These substantially vertical sections preferably are placed one next to the other, that is, one immediately adjacent one to the other, so as to jointly produce one single slit in a board when cutting the board, such as one single slit in the facing of the board.

[0052] In some embodiments of the invention the first sections extend substantially horizontally in said front view. The fact that the first sections extend substantially horizontally implies that the cut-out may have a substantially flat top portion. In this document, the reference to the first sections extending substantially horizontally does not rule out that the first sections may end, towards their end points, in a curved or angled manner, at their transition to the respective second sections, thereby providing for curved or angled transitions between the top and the lateral sides of the cut-out. In preferred embodiments, the bottom surface of the support body is flat. In further preferred embodiments, additionally the first sections extend substantially horizontally, such that the two surfaces defining the gap between the bottom surface of the support body and the first sections extend substantially in parallel. In other words, in such embodiments the height of the gap is substantially constant over the whole width of the gap.

[0053] In some embodiments, the second sections are substantially straight in said front view. Substantially straight second sections can provide a substantially V-shaped cut, and provide for a cut-out having, for example, a substantially triangular cross section (when the first sections are horizontal) or a substantially deltoid or kite-shaped cross section (when the first sections are inclined, as further described below).

[0054] In some embodiments, the second sections, in said front view, extend substantially until the apex or beyond the apex, for example, so as to provide for a groove having a cross section in the form of an isosceles triangle or an equilateral triangle. This kind of symmetrical triangular 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.

[0055] In some embodiments, the first sections are substantially straight in said front view.

[0056] In some embodiments, the first sections have the same length, and / or the second sections have the same length. This can serve to enhance symmetry. In some of these embodiments, the first sections and the second sections, in said front view, 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.

[0057] In some embodiments, the first sections, in said front view, are arranged at respective acute angles (δ) in relation to a horizontal line. That is, the first sections 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 first sections, 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 first sections. This can, for example, cause the cut-out portion to have a substantially deltoid cross-section, that is, a kite-shaped cross section. The first sections are preferably oriented downwards at an angle ranging between 0 and 15° with regard to a horizontal line, that is, with regard to a line parallel with the y-axis.

[0058] 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.

[0059] In some embodiments, the second sections, in said 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.

[0060] In some embodiments, the first sections may, in said front view, be curved or have curved portions. In some embodiments, the first and / or the second sections may, in said front view, have a wavy shape, a zig-zag shape, or any other suitable geometric shape.

[0061] Thus, depending on the specific size, orientation and shape of the first and second sections, a desired cross-section of the cut-out of the board can be obtained.

[0062] In some embodiments, in the front view, the second sections reach the apex and are curved adjacent to the apex, such as to provide for a groove having a rounded bottom.

[0063] In some embodiments, the second sections, in the front view, do not reach the apex, and lowermost ends of the second sections are joined by an additional cutting edge. The cutting tool is optionally configured to cut a groove having a substantially trapezoidal cross section.

[0064] In some embodiments, the first cutting edge extends vertically downwards from the bottom surface of the support body. A vertically oriented first cutting edge may be especially appropriate for providing a slit in, for example, a top facing of a mineral wool board.

[0065] In some embodiments, the gap has a height of between 1 mm and 3 mm, such as 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 first section of the respective second / third cutting edge (= first bend or pivot point, shown as A, A' in some of the figures illustrating preferred embodiments) and the bottom surface of the support body of the tool, in the front view discussed above. 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 first section 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 first section, such as right in the middle between two bends of a blade element that delimit the first section. It has been found that such a height is adequate for allowing the first sections 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.

[0066] In some embodiments, the cutting tool is a hand-held tool, optionally including a handle to be gripped by a user.

[0067] Another 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 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.

[0068] 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.

[0069] 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 may, for example, comprise and / or consist of one or more rods, slides, etc., and 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.

[0070] A further aspect of the invention relates to a cutting machine comprising the cutting device as described above, and further comprising 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.

[0071] 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 (1002) on at least one major surface thereof. The method comprises: A- producing 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, 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).

[0072] Steps A and B 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).

[0073] The method further comprises: C- producing two converging cuts in the mineral wool core that determine the depth of the groove.

[0074] Steps A, B and C are carried out substantially simultaneously by moving a cutting tool (for example, in a single stroke) along the mineral wool board.

[0075] In some embodiments, the method further comprises removing a cut-out portion of the mineral wool core having a top surface determined by step B and two converging side walls determined by step C.

[0076] In some embodiments, the groove comprises two side walls, and wherein, after removing the cut-out portion, the two portions of facing 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.

[0077] In some embodiments, the top surface of the cut-out portion is not covered by a portion of the facing.

[0078] In some embodiments of the method, the cutting tool is a cutting tool as described above.

[0079] 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. The method comprises: producing at least three parallel grooves in such 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.

[0080] A further aspect of the invention relates to the 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

[0081] 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 11 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. Figure 5 is a schematic front view ("y-z") of the cutting tool in accordance with another 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. Figures 11A and 11B 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 DESCRIPTION OF WAYS OF CARRYING OUT THE INVENTION

[0082] 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 is, in the illustrated embodiment, oriented horizontally, with its main surfaces extending in the x-y plane and its thickness extending in z-direction.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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. A blade arrangement (not shown in figure 3A) is attached to the support body and extends downwards from the support body. A cutting action has been performed moving the cutting tool 1 over the top surface of the board 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, 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 slit 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 1004A will 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 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.

[0087] 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, generating a thicker top layer being connected to the main portion of the core 1001 of the board, by leaving more core material between the top facing 1002 and the cut-out 1004A. Thus, more core material will remain adhered to the facing 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 may also serve to reduce the risk of damage to the facing during the cutting operation.

[0088] 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. A blade arrangement 3a,3b is attached to the support body and extends 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, the blade arrangement comprises two blade elements, namely, a first blade element 3a and a second blade element 3b, both attached to the support body. The second blade element 3b is situated behind the first blade element 3a when the tool is observed from a position in front of the tool, as in figure 4B.

[0089] Each blade element comprises a front edge that is shaped for cutting and which comprises three different portions, separated by bends, as explained below. Basically, each blade element is a bent blade element, comprising a first substantially vertical portion 4a, 4b, extending downwards from the bottom surface 21 of the support body 2 of the cutting tool 1.

[0090] In the case of the first blade element 3a, the vertical portion 4a extends downwards until a first bend A. From the first bend A, which is about 90 degrees in the illustrated embodiment, the first blade element 3a is oriented substantially horizontally until reaching a second bend B, at the left of the first bend A when the tool is viewed from the front as in figure 4B. That is, between the two bends A and B, the blade element comprises a basically horizontal portion. From the second bend B, the blade element 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 blade element, the first blade element 3a comprises a substantially straight final portion. This portion 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.

[0091] The second blade element 3b is basically a mirror-inverted version of the first blade element 3a. That is, in the case of the second blade element 3b, the vertical portion 4b extends downwards until a first bend A'. From the first bend A', which is about 90 degrees, the second blade element 3b is oriented substantially horizontally until reaching a second bend B', at the right of the first bend A' when the tool is viewed from the front as in figure 4B. That is, between the two bends A' and B', the second blade element 3b comprises a basically horizontal portion. From the second bend B', the blade element 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 second blade element, the second blade element 3b comprises a substantially straight final portion. This portion 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.

[0092] Thus, from an operative perspective, in the front view as shown in figure 4B, the tool comprises a first cutting edge 4a, in this case embodied by the front edge of the vertical portion of the first blade element 3a. The vertical portion 4b of the second blade element 3b is situated behind the vertical portion of the first blade element, and situated in the same vertical plane containing the cutting direction, that is, the same x-z-plane. Thus, the vertical portion 4b of the second blade element 3b is "hidden" behind the vertical portion 4a of the first blade element 3a and does not act as an active cutting edge when the tool is used as intended. The first cutting edge 4a of the first blade element 3a serves to slit the top facing of the board when used in a method as shown in, for example, figure 2A, or in figures 3A and 3B.

[0093] The first blade element 3a further comprises a second cutting edge 5a, 6a, made up of a first section 5a and a second section 6a. Similarly, the second blade element 3b comprises a third cutting edge 5b, 6b, made up of a first section 5a and a second section 6a. In the illustrated embodiment, the second cutting edge 5a, 6a is the continuation of the first cutting edge 4a, that is the first cutting edge and the second cutting edge are parts of a continuous edge of the first blade element 3a. Similarly, the third cutting edge 5b, 6b is a continuation of the front edge of the vertical part 4b of the second blade element 3b.

[0094] As best shown in figure 4B, the first 3a and second 3b blade elements diverge at the lower end of their vertical portions. That is, the second cutting edge first extends to the left from the end of the first cutting edge, from the first bend A and until the second bend B, establishing the substantially horizontal first section 5a of the second cutting edge 5a, 6a. From the second bend B, the second cutting edge extends downwards and convergently towards an apex D, until its end C, establishing a substantially straight and inclined second section 6a, forming an angle α with the horizontal (x-y) plane (in figure 4B the angle α is illustrated with regard to the first section 5a, but this is only because the first section 5a, in the illustrated embodiment, happens to extend in the horizontal (x-y) plane).

[0095] On the other hand, the third cutting edge 5b, 6b first extends to the right from the first bend A' (at the lower end of the vertical portion 4b of the second cutting blade 3b) and until the corresponding second bend B', establishing the substantially horizontal first section 5b of the third cutting edge 5b, 6b. From the second bend B', the third cutting edge extends downwards and convergently towards the apex D, until its end C', establishing a substantially straight and inclined second section 6b.

[0096] In the illustrated embodiment, the ends C, C' of the second sections 6a, 6b substantially meet at the apex D of the blade arrangement, corresponding to the apex (the bottom part) of the groove being formed when the cutting tool 1 is used as intended.

[0097] Thus, with this arrangement, the vertical part of the first blade element 3a constitutes a first cutting edge 4a that 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, 6a and third 5b, 6b cutting edges cut the core such as to delimit the cut-out: the first sections 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 second sections 6a, 6b cut oblique cuts that determine the side walls and depth of the groove to be established. The sizes and orientations of the first sections 5a, 5b and second sections 6a, 6b determine the cross-section of the cut-out in the y-z plane.

[0098] As best shown in figure 4B, as the first sections 5a, 5b are positioned at a distance from the bottom surface 21 of the support body, there is a gap G between these sections of the second and third cutting edges (and the corresponding portions of the blade elements) and the bottom surface 21 of the support body. 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.

[0099] In the illustrated embodiment, the first sections 5a, 5b have the same length and the second sections 6a, 6b have the same length, the first sections 5a, 5b and the second sections 6a, 6b are substantially straight, and the first sections 5a, 5b are oriented horizontally. Thus, the first and second sections jointly form a cutting edge having a shape in the form of an isosceles triangle. However, any other suitable shape can be used.

[0100] The angle α between the second sections and the horizontal plane is preferably in the order of 45 degrees, such as between 45 and 55 degrees. For example, when the two second sections 6a, 6b of figure 4B are arranged with an inclination α=45 degrees with regard to the horizontal plane, the two second sections 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.

[0101] Figure 5 shows an embodiment with similar components as those of the embodiment of figures 4A and 4B. The blade elements 3a, 3b may be configured just as those of the embodiment of figures 4A and 4B, but in the embodiment of figure 5, the blade elements are positioned side by side (that is, in the direction of the y-axis), rather than one after the other in the cutting direction. Thus, in this case, the vertical portion 4b of the second blade element is not hidden behind the vertical portion of the first blade element; instead, the vertical portions of both blade elements, extending downwards from the bottom surface 21 of the support body 2, jointly form the first cutting edge 4a, 4b, as can readily be understood from figure 5.

[0102] Thus, the blade elements in the embodiment of figure 5 can be identical to those of the embodiment of figures 4A and 4B, each blade element 3a, 3b comprising a front edge including two bends A, B / A', B', the difference between the embodiment residing in the positioning of the blade elements in relation to each other, that is, whether one behind the other (that is in the direction of the x-axis) as in the embodiment of figures 4A and 4B, or side by side (that is in the direction of the y-axis) as in figure 5. In the embodiment of figure 5, the vertical portion 4b of the second blade element becomes part of the first cutting edge 4a, 4b, that is, part of the cutting edge intended for cutting the top facing of the board (that is, forming the slit) when the cutting tool 1 is used as described herein.

[0103] Figure 6A schematically illustrates a blade element design in which the first cutting edge 4a is vertical, the first section 5a of the second cutting edge is horizontal, and the second section 6a of the second cutting edge is 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 first and second sections of the blade elements, will be shaped as an isosceles triangle, as schematically illustrated in figure 6A.

[0104] Figure 6B illustrates an alternative embodiment, which differs from the one of figure 6A only in that the second section 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.

[0105] Figure 6C illustrates an alternative embodiment, in which the second section 6a ends before reaching the apex D towards which it is directed. Instead, at the end of the second section there is a horizontal cutting edge portion (that is in the direction of the y-axis) which, together with a horizontal final portion of the other blade element (not shown), forms an additional horizontal cutting edge which 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.

[0106] Figure 6D illustrates an alternative embodiment in which the final portion of the first section 5a is bent downwards, thereby creating a bevel-shaped transition to the second section 6a. This provides for a cut-out 1004A having chamfered upper edges, as schematically illustrated in figure 6D.

[0107] Figure 6E illustrates an alternative embodiment in which the second section 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 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.

[0108] Figure 6F illustrates an alternative embodiment in which the second section 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 will thus adopt a concave configuration.

[0109] Figure 6G illustrates an alternative embodiment in which the second section 6a has an undulating shape, thereby providing for a cut-out 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.

[0110] Finally, figure 6H illustrates an alternative embodiment in which the first section 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 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 first section 5a with regard to the horizontal line / plane) and α (the inclination of the second section 6a with regard to the horizontal line / plane) are schematically indicated.

[0111] These are just some examples of the shapes that the blade elements may adopt and of the corresponding cross-sectional shape of the resulting cut-out (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.

[0112] 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, in parallel with the x-axis, in relation to the support 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.

[0113] In some embodiments, the cutting device 100 can be hand-driven, that is, the operator can displace the cutting tool and the slides 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 1 in parallel with the x-axis, and / or the slides 104, 106 along their respective axes.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] Figures 11A and 11B are a cross sectional side view and a rear cross sectional view, respectively, of a cutting tool 1 in accordance with an embodiment of the invention, wherein the support body 2 comprises a through hole 11 with substantially rectangular or square cross section, for accommodating a guide rod of a guide system (for example, as shown in figure 7). In this embodiment, the blade arrangement 3a, 3b is attached to a side of the support body 2, by screws 16.

[0119] 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) and a blade arrangement (3a, 3b) attached to the support body (2), the support body (2) comprising a bottom surface (21) and a top surface (22), the blade arrangement (3a, 3b) extending downwards from the bottom surface (21) of the support body (2), the blade arrangement (3a, 3b) comprising a first cutting edge (4a, 4b), a second cutting edge (5a, 6a) and a third cutting edge (5b, 6b), each one of said second cutting edge and third cutting edge comprising a first section (5a, 5b) and a second section (6a, 6b); wherein, in a front view of the cutting tool (1): the first cutting edge (4a, 4b) extends downwards from the bottom surface (21) of the support body (2); each of the first sections (5a, 5b) extends substantially sideways from a respective first bend (A, A') at the first cutting edge (4a, 4b) and until a respective second bend (B, B'), so that the first sections (5a, 5b) extend from the first cutting edge (4a, 4b), away from the first cutting edge (4a, 4b) in substantially opposite directions, in a manner that provides for a gap (G) between the bottom surface (21) of the support body (2) and each of the first sections (5a, 5b), the first sections (5a, 5b) defining a cut width (w) between the second bends (B, B'); each of the second sections (6a, 6b) extends downwardly and convergently from the respective second bend (B, B') to a respective end (C, C') of the respective second section (6a, 6b), so that the second sections (6a, 6b) converge towards an apex (D), whereby the second sections define a cut depth (d).

2. The cutting tool of claim 1, wherein the second cutting edge (5a, 6a) is spaced from the third cutting edge (5b, 6b) in a cutting direction.

3. The cutting tool of claim 2, wherein the first cutting edge (4a) and the second cutting edge (5a, 6a) are implemented on a first blade element (3a), whereas the third cutting edge (5b, 6b) is implemented on a second blade element (3b) distinct from the first blade element (3a), the second blade element (3b) being situated behind the first blade element (3a) in the cutting direction.

4. The cutting tool of claim 3, wherein the first cutting edge (4a) extends in a vertical direction and the third cutting edge (5b, 6b) is attached to the support body (2) via a first cutting edge (4b) of the second blade element (3b), this first cutting edge (4b) being positioned behind the first cutting edge (4a) in the cutting direction, so that the first cutting edge (4a) and the first cutting edge (4b) are arranged in the same vertical plane parallel with the cutting direction.

5. The cutting tool of claim 1, wherein the second cutting edge (5a, 6a) is implemented on a first blade element (3a), whereas the third cutting edge (5b, 6b) is implemented on a second blade element (3b) distinct from the first blade element (3a), the first blade element (3a) and the second blade element (3b) being situated one beside the other, and wherein, preferably, the first cutting edge (4a, 4b) is implemented partly by a substantially vertical section of the first blade element (3a) and partly by a substantially vertical section of the second blade element (3b), these substantially vertical sections preferably being placed one next to the other.

6. The cutting tool according to any one of the preceding claims, wherein, in said front view, the first sections (5a, 5b) extend substantially horizontally.

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

8. The cutting tool according to any one of the preceding claims, wherein the second sections (6a, 6b), in said front view, extend substantially until the apex (D) or beyond the apex (D).

9. The cutting tool according to any one of the preceding claims, wherein the first sections (5a, 5b), in said front view, are substantially straight.

10. The cutting tool according to any one of the preceding claims, wherein the first sections (5a, 5b) have the same length, and / or wherein the second sections (6a, 6b) have the same length.

11. The cutting tool according to claim 10, wherein the first sections (5a, 5b) and the second sections (6a, 6b), in said front view, jointly have the shape of an isosceles triangle or an equilateral triangle.

12. The cutting tool according to any one of claims 1-5, wherein the first sections (5a, 5b), in said front view, are arranged at respective acute angles (δ) in relation to a horizontal line, preferably oriented downwards at an angle ranging between 0 and 15° with regard to a horizontal line.

13. The cutting tool according to any one of claims 1-6 or 12, wherein the second sections (6a, 6b), in said front view, are curved or include curved portions.

14. The cutting tool according to claim 13, wherein, in the front view, the second sections (6a, 6b) reach the apex (D) and are curved adjacent to the apex (D).

15. The cutting tool according to any one of claims 1-7, wherein the second sections (6a, 6b), in the front view, do not reach the apex (D), and wherein the respective ends (C, C') of the second sections are joined by an additional cutting edge.

16. The cutting tool according to any one of the preceding claims, wherein the first cutting edge (4a, 4b) extends vertically downwards from the bottom surface (21) of the support body (2).

17. The cutting tool according to any one of the preceding claims, wherein the gap (G) has a height of between 1 mm and 3 mm.

18. 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.

19. 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 1-18; - 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 (x), in relation to the support (101) for supporting a mineral wool board (1000), so as to cut an elongate groove in a mineral wool board in parallel with the first axis (x).

20. The cutting device of claim 19, wherein the cutting device (100) further comprises a second guide system for positioning the cutting tool (1) according to a second axis (y), perpendicular to the first axis (x).

21. A cutting machine (100) comprising the cutting device (100) of claim 19 or 20, and further comprising drive means (107) for displacing the cutting tool (1) in parallel with at least one axis.

22. 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, A- producing 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) substantially adjacent to the facing (1002) over a distance that determines the width (w) of the groove (1004); whereby steps A and B 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 two converging cuts in the board core (1001) that determine the depth (d) of the groove; wherein steps A, B and C are carried out substantially simultaneously by moving a cutting tool (1) along the board (1000).

23. The method of claim 22, 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.

24. The method of claim 23, wherein the groove (1004) comprises two side walls, and wherein, after removing the cut-out (1004A), the two portions (1002a, 1002b) of the facing (1002) at least partly cover the two side walls.

25. The method of any one of claims 23 and 24, wherein the top surface of the cut-out (1004A) is not covered by a portion of the facing.

26. The method of any one of claims 22-25, wherein the cutting tool (1) is a cutting tool (1) according to any one of claims 1-19.

27. 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 such major surface of the mineral wool board (1000), each groove (1004) being produced by a method according to any one of claims 22-26; - folding the mineral wool board (1000) along said grooves (1004) so as to form a mineral wool duct section having a polygonal cross section.

28. Use of the cutting tool (1) according to any one of clams 1-18, for producing at least one groove (1004) in a board (1000), especially a mineral wool board (1000), comprising a insulation material core (1001), especially mineral wool core (1001) having a facing (1002) on at least one major surface thereof.

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