Saw blade with suction channels and abrasive segments

Abstract

The invention relates to a saw blade (1) for sawing in materials which, during sawing, form debris hazardous to human health if inhaled and passed to lungs of a human. The saw blade (1) has suction channels (9) extending from inlets (12) of the suction channels (9) at an outer circumference of the saw blade (1) to outlets (10) of the suction channels (9) at a central part of the saw blade (1). A suction housing (15) is provided at the centre of the saw blade (1), establishing a vacuum at the outlet (10) of the suction channels (9). The invention also relates to an abrasive segment (13) for a saw blade (1), the abrasive segment (13) intended for extending along the outer circumference of the saw blade (1), having holes (31) with an inlet and an outlet, the outlet of the abrasive segment (13) intended for leading to an inlet (12) of a suction channel (9) of a saw blade (1).

Description

[0001] SAW BLADE WITH SUCTION CHANNELS AND ABRASIVE SEGMENTS

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a saw blade for sawing in materials which, during sawing, form debris hazardous to human health if the debris is inhaled and passed to the lungs of the human. The saw blade has suction channels for extracting air and debris formed during sawing. The invention also relates to an abrasive segment for a saw blade.

[0004] BACKGROUND OF THE INVENTION

[0005] Saw blades are commonly known and used for sawing in cementitious materials which, during sawing, form dust hazardous to human health if inhaled by humans.

[0006] Dust may be cementitious dust formed during sawing in concrete, when having to make openings in buildings or when having to break down buildings or when having to dig into or break up pavements or other structures made of a cementitious material. During sawing, abrasive segments of the saw blade advance into the material, leaving a gap the width of the saw blade in the building or pavement or other structure.

[0007] Debris formed may also be fibrous material formed during sawing in fibrous material such as fibreglass material when having to break down wind turbine wings or boat hulls for recycling or for deposit. Debris formed may also be fibrous material formed during sawing in fibrous material such as asbestos-filled material when having to break down roof cladding or ceiling materials for deposit of the asbestos-filled material.

[0008] During sawing, debris is formed. The debris is hazardous to the person performing sawing and possibly other persons in vicinity of a sawing site, and the debris must be removed. Often water is used during sawing to cool the abrasive segments, but possibly also for collecting the debris before being emitted into surroundings of the sawing site. Use of water necessitates access to water during sawing and special equipment for providing the water and for extracting the water from the sawing site and for extracting the combined water and debris formed during sawing.

[0009] WO 2013 / 093191 Al discloses a method for the removal of dust formed in the sawing of concrete, rock material, or other such like material, said method comprising sawing the material with a saw comprising a rotatable saw blade, the dust being sucked throughsuction channels provided inside the saw blade. The invention relates also to such a saw blade, as well as to a saw equipped with the saw blade.

[0010] The saw blade of WO 2013 / 093191 Al has suction channels for sucking dust from between abrasive segments of the saw blade. Each of the suction channels are configured as one channel, with one inlet and one cross-sectional area along the extension from the inlet between the abrasive segments to a central part where an outlet of each suction channel is provided. No features of the outlet are disclosed.

[0011] US 4,243,011 A discloses a pipe-cutting circular saw. A shroud is provided comprising upper and lower blade housings which are nested and guided so that the lower housing can be moved into and out of the upper housing. The lower periphery of the lower housing generally conforms to the shape of the pipe to be cut. An exhaust duct may be provided on the shroud so that if a source of vacuum is connected to said exhaust duct debris formed during cutting of the object may be extracted through the exhaust duct.

[0012] The saw of US 4,243,011 A has a shroud for collecting dust formed during cutting of the pipe. Dust expelled into the shroud may be extracted through the exhaust duct.

[0013] Furthermore, an interior dust collection means comprising a hollow extending conduit together with a first baffle and a second baffle may be mounted inside the pipe, both baffles having a shape conforming generally to an interior shape of the pipe. Dust expelled into the pipe may thereby also be extracted through the hollow conduit.

[0014] One object of the invention may be to provide a saw blade where the amount of debris formed during sawing is extracted from the sawing site in an efficient and safe manner.

[0015] Another object of the invention may also be to provide a saw blade assembly, where one and same suction housing is capable of being attached to saw blades with various diameters and / or various thicknesses and / or various debris collecting channels.

[0016] Still another object of the invention may be to provide a saw blade having better and safer debris extraction and having other improved properties to known saw blades.

[0017] Yet another object of the invention may be to provide a saw blade having better and a higher degree of structural properties by providing better cooling of the saw blade.

[0018] An even further object of the invention may be to provide an abrasive segment having debris extraction and having other improved properties to known abrasive segments.SUMMARY OF THE INVENTION

[0019] One or more objects of the invention may be obtained by a saw blade, where the suction channels extending from inlets of the suction channels at the outer circumference of the saw blade to outlets of the suction channels at the central part of the saw blade, and where a number of all inlets is higher than a number of one of the following: all suction channels or all outlets of all suction channels.

[0020] A number of inlets of all suction channels and / or all outlets being higher than the number of outlets of the suction channels result the number of inlets may be higher than the number of suction channels, which is an advantage if the saw blade only has either a limited number of suction channels, or a limited number of outlets, or a limited number of both suction channels and outlets.

[0021] According to one aspect of a saw blade according to the invention, the plurality of suction channels provided between along inner surfaces of the first plate and the second plate is provided by an intermediate plate of the saw blade, positioned between the first plate and the second plate, the intermediate plate having cut-outs forming the suction channels.

[0022] Providing an intermediate plate between the first plate and the second plate has the advantage of the intermediate plate being manufactured separately, and the first plate and the second plate, constituting outer lateral surfaces of the saw blade, maintains same properties along the entire extension of the first plate and the second plate.

[0023] According to another aspect of a saw blade according to the invention, the plurality of suction channels provided along inner surfaces of the first plate and the second plate is provided by groves along an inner surfaces of at least one of the first plate and the second plate, so that when inner surfaces of the first plate and the second plate is in abutment, the groves extend along an interface between the plates.

[0024] Providing groves either along an inner surface of the first plate or along an inner surface of the second plate or along the inner surfaces of both the first plate or the second plate, thereby providing suction channels in the inner surface of at least one of the first plate and second plate, has the advantage that the intermediate plate may be omitted.

[0025] In a preferred embodiment of a saw blade according to the invention, at least some of the suction channels, preferably each of the suction channels, have at least two inlets atthe outer circumference of the saw blade, and at least some of the suction channels, preferably each of the suction channels, have only one outlet at the central part of the saw blade.

[0026] Dividing the suction channels in two or more suction channels, at least towards the inlets of the suction channel, result in a number of inlets being multiplied compared to a number of outlets. Thereby, the number of inlets at an outer circumference of the saw blade may be increased, and the number of outlets at the central part of the saw blade, where space is limited, may be limited.

[0027] In a preferred embodiment of the saw blade according to the invention, the suction channels have at least two inlets with an extension between the inlets and the outlet being an extension from the at least two inlets along divided extensions of the suction channel to an intermediate position between the outer circumference of the saw blade and the central part of the saw blade, and an extension from the intermediate position along a non-divided extension of the suction channel to the central part of the saw blade.

[0028] Dividing each of the suction channels into two or more channels from the outer circumference of the saw blade and towards an intermediate position, and limiting the number of channels from the intermediate position towards the central secvtion of the saw blade, optimises the space available for increasing the number of inlets and limiting the number of outlets, with an intersection at the intermediate portion, for also maintaining a sufficient amount of material for a necessary rigidity of the saw blade.

[0029] In one possible embodiment of the saw blade according to the invention, and where the saw blade comprises suction channels for sucking air and debris formed during sawing, and provided between the first plate and the second plate, the suction channels extend from inlets of the suction channels between abrasive segments to outlets of the suction channels at the central part of the saw blade.

[0030] Inlets may be provided between the abrasive segments, provided that a space is present between neighbouring abrasive segments. Debris formed during sawing will collect in the spaces between the abrasive segments and will be sucked from the saw site as soon as the debris enters the space between the abrasive segments.

[0031] In another possible embodiment of the invention according to the invention, and where the saw blade comprises suction channels for sucking air and debris formed duringsawing, and provided between the first plate and the second plate, the suction channels extending from inlets of the suction channels in the abrasive segments to outlets of the suction channels at the central part of the saw blade.

[0032] Inlets may be provided at outer surfaces of the abrasive segments. Debris formed during sawing will be sucked from the saw site, onto the inlets of the abrasive segments, as soon as the debris forms, before debris enters a space between the abrasive segments, provided that a space is present between neighbouring abrasive segments.

[0033] In a preferred embodiment, inlets may be provided both in the abrasive segments and in spaces between the abrasive segments, so that debris preferably is sucked from the saw site, possibly before debris enters a space between the abrasive segments, but if debris enters the space between abrasive segments, that debris is also sucked from the saw site.

[0034] Both if inlets are provided between the abrasive segments and when inlets lead to holes in in the abrasive segments and when inlets are provided both between the abrasive segments and leading to holes in the abrasive segments, a combination of air and debris sucked into the inlets of the suctions channels and to the outlets of the suction channels results in cooling the saw blade from the inside by the flow of air being sucked through the inlet and the suction channels, additional to sucking air and debris through the inlets. In a preferred embodiment of the saw blade according to the invention, the saw blade has an outer circumference onto which a plurality of abrasive segments is attached and a central part, radially opposite to the outer circumference, the central part having a fastening mechanism for fastening the saw blade to a drive shaft of a sawing motor, and - the saw blade has a first plate between the circumference and the central part of the saw blade, facing outwards, and a second plate between the circumference and the central part of the saw blade, also facing outwards, the first plate facing opposite to the second plate, and

[0035] - the saw blade comprises suction channels for sucking air and debris formed during sawing, and provided between the first plate and the second plate, the suction channels extending from inlets of the suction channels in the abrasive segments to outlets of the suction channels at the central part of the saw blade,

[0036] - where the saw blade comprises a first plate and a second plate and an intermediate plate positioned between the first plate and the second plate, and

[0037] - where the first plate is provided with one or more holes, a position of which at least one hole overlaps at least part of the outlets of the suction channels.In a possible embodiment of the saw blade according to the invention, the saw blade assembly also comprises a suction outlet abutting the central part of the saw blade, where the suction outlets are positioned, and providing a gas tight connection at one of the first plate and the second plate of the saw blade where the central part openings are positioned, the suction outlet is intended for being connected to a vacuum source, and the suction housing covers at least part of the central part orifices of the saw blade, and the suction housing capable of providing a suction force only at a limited number of the outlets at the central part, the limited number being suction channels, which during sawing, have suction inlets facing the cementitious material.

[0038] In a possible embodiment of the saw blade according to the invention, and where the saw blade is provided with a plurality of abrasive segments along an outer circumference of the saw blade,

[0039] - each of the abrasive segments has a leading surface and a trailing surface in relation to an intended rotational direction of a saw blade, and

[0040] - each of the abrasive segments has opposite side surfaces extending substantially tangentially to the rotational direction of the saw blade, and the side surfaces extending substantially horizontally to a rotational axis of the saw blade,

[0041] - a space is provided between a trailing surface of a leading abrasive segment and a leading surface of a neighbouring trailing abrasive segment, the space leading from the outer circumference of the sap lade to an inlet of a suction channel of the saw blade, so that debris collected in the space is sucked away from the space, into the inlet and to the suction channel between a first plate and a second plate of the saw blade.

[0042] In a possible embodiment of a saw blade according to the invention with the saw blade being provided with a plurality of abrasive segments along an outer circumference of the saw blade,

[0043] - where at least some of the abrasive segments has an outer surface and an inner surface, opposite to the inner surface, the outer surface and the inner surface extending substantially tangentially in relation to an intended rotational direction of a saw blade, and the outer surface and the inner surface extending substantially parallel to a rotational axis of the saw blade of a saw blade,

[0044] - the abrasive segment having at least one hole extending between the outer surface and the inner surface, and an orifice of the at least one hole at the inner surface of the abrasive segment intended for being in communication with an inlet of a suction channel of the saw blade, so that debris collected at the outer circumference of the saw blade is sucked away at the outer circumference of the saw blade, into the inlet and to the suction channel between a first plate and a second plate of the saw blade.In a possible embodiment of the saw blade according to the invention with the saw blade being provided with a plurality of abrasive segments along an outer circumference of the saw blade,

[0045] - where each of the abrasive segments has a leading surface and a trailing surface in relation to an intended rotational direction of a saw blade, and

[0046] - where each of the abrasive segments has opposite side surfaces extending substantially tangentially to the rotational direction of the saw blade, and the side surfaces extending substantially horizontally to a rotational axis of the saw blade, - where one side surface of a leading abrasive segment extends along another plane than a corresponding side surface of a neighbouring trailing surface, seen in a tangential direction, so that at least part of a leading surface of a trailing abrasive segment extends laterally outside a trailing surface of the leading abrasive segment.

[0047] According to another invention, or according to a possible embodiment of the saw blade invention, objects of the invention is obtained by an abrasive segment for a saw blade, - the abrasive segment having a leading surface and a trailing surface in relation to an intended rotational direction of a saw blade which the abrasive segment is intended for being part of,

[0048] - the leading surface and trailing surface extending substantially parallel to a rotational axis of the saw blade of a saw blade which the abrasive segment is intended for being part of

[0049] - the abrasive segment having opposite side surfaces extending substantially tangentially to the rotation al direction of the saw blade and extending substantially parallel to a rotational axis of the saw blade of a saw blade which the abrasive segment is intended for being part of,

[0050] - the abrasive segment having an outer surface and an inner surface, opposite to the inner surface, the outer surface and the inner surface extending substantially tangentially in relation to an intended rotational direction of a saw blade which the abrasive segment is intended for being part of, and the outer surface and the inner surface extending substantially parallel to a rotational axis of the saw blade of a saw blade which the abrasive segment is intended for being part of,

[0051] - the outer surface of the abrasive segment intended for constituting a section of an outer circumference of the saw blade which the abrasive segment is intended for being part of, and the abrasive segment having at least one hole extending between the outer surface and the inner surface, and an orifice of the at least one hole at the inner surface of the abrasive segment intended for being in communication with an inlet of a suction channel of the saw blade which the abrasive segment is intended for being part of.Inlets may be provided at outer surfaces of the abrasive segments. Debris formed during sawing will be sucked from the saw site, onto the inlets of the abrasive segments, as soon as the debris forms, before debris enters a space between the abrasive segments, provided that a space is present between neighbouring abrasive segments.

[0052] According to a an embodiment of an abrasive segment according to the invention, the inner orifice has a cross-sectional area being larger than a cross-sectional area of the outer orifice, so that the at least one hole has a tapering extension between the inner surface and the outer surface of the abrasive segment, the at least one hole becoming gradually narrower from the inner surface towards the outer surface of the abrasive segment.

[0053] Holes through the abrasive segments having a tapering extension has the advantage, that debris entering the inlet at the outer surface of an abrasive segment and passing through the hole to the outlet at the inner surface of the abrasive segment, does not risk clogging in the hole, because the hole has an increasing cross-sectional area from the inlet towards the outlet. The inlet defines the smallest cross-sectional area of the hole.

[0054] According to the possible embodiment of an abrasive segment according to the invention, the inner orifice has a cross-sectional area being between 25% and 150% larger than the cross-sectional area of the outer orifice, possibly between 25% and 100% larger than the cross-sectional area of the outer orifice, preferably between 50% and 100% larger than the cross-sectional area of the outer orifice.

[0055] Holes through the abrasive segments having a tapering extension may be tapered differently depending on the kind of debris to be sucked through the hole, as example dust or fibres, and depending on the size of debris to be sucked through the holes, as example, dust probably being smaller-sized objects than fibres, and dust from concrete possibly being smaller-sized objects than dust from rocks.

[0056] In a possible embodiment of an abrasive segment according to the invention,

[0057] - the abrasive segment having a leading surface and a trailing surface in relation to an intended rotational direction of a saw blade which the abrasive segment is intended for being part of,

[0058] - the leading surface and trailing surface extending substantially parallel to a rotational axis of the saw blade of a saw blade which the abrasive segment is intended for being part of- the abrasive segment has opposite side surfaces extending substantially tangentially to the rotation al direction of the saw blade and extending substantially parallel to a rotational axis of the saw blade of a saw blade which the abrasive segment is intended for being part of,

[0059] - the abrasive segment having an outer surface and an inner surface, opposite to the inner surface, the outer surface and the inner surface extending substantially tangentially in relation to an intended rotational direction of a saw blade which the abrasive segment is intended for being part of, and the outer surface and the inner surface extending substantially parallel to a rotational axis of the saw blade of a saw blade which the abrasive segment is intended for being part of,

[0060] - the outer surface of the abrasive segment intended for constituting a section of an outer circumference of the saw blade which the abrasive segment is intended for being part of, and the abrasive segment having a trailing surface having a cavity with a recessed shape such as an arrow-like shape, a polygon shape or an oval shape.

[0061] Providing a recessed shape of the trailing edge of the abrasive segment result in a vacuum created when the abrasive segment is part of a saw blade and when the saw blade is rotating during sawing in a cementitious material. The vacuum created, apart from the suction force at the inlets of the suction channels, ensures that debris formed during sawing is collected in the space between neighbouring abrasive segments.

[0062] BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Fig. 1 is a drawing showing a first plate of an embodiment of a saw blade according to the invention,

[0064] Fig. 2 is a drawing showing an intermediate plate of the embodiment of the saw blade according to the invention,

[0065] Fig. 3 and Fig. 4 are drawings showing an embodiment of a first plate and a second plate, opposite to the first plate, of a saw blade according to the invention,

[0066] Fig. 5 is a drawing showing an embodiment of an intermediate part of a saw blade according to the invention, placed between the first plate and the second plate, Fig. 6 is a drawing showing a part of one embodiment of a saw blade with suction channels divided into three branches having inlets between abrasive segments of the saw blade,

[0067] Fig. 7 and Fig. 8 are drawings showing a part of another embodiment of a saw blade with suction channels divided into four branches having inlets leading to holes in abrasive segments of the saw blade,Fig. 9 and Fig. 10 are drawings showing a part of yet another embodiment of a saw blade with suction channels divided into four branches having inlets leading to holes in abrasive segments of the saw blade and having thermal conductive liners,

[0068] Fig. 11A and Fig. 11B are drawings with a perspective view and a plane side view of one embodiment of a suction housing for sucking air and debris from outlets of the suction channels of the saw blade,

[0069] Fig. 12A and Fig. 12B are drawings with a perspective view and a plane side view of another embodiment of a suction housing for sucking air and debris from outlets of the suction channels of the saw blade,

[0070] Fig. 13A and Fig. 13B are drawings with two plane front and rear side views of yet another embodiment of a suction housing for sucking air and debris from outlets of the suction channels of the saw blade,

[0071] Fig. 14A and Fig. 14B are drawings with a view and a side view of the yet other embodiment of a suction housing attached to a central part of a saw blade,

[0072] Fig. 15 is a sketch showing an alternative embodiment of abrasive segments, with an alternative configuration and positioning of the abrasive segments, and

[0073] Fig. 16 is a drawing showing a part of another embodiment of a saw blade with suction channels divided into four branches having inlets leading to holes in abrasive segments of the saw blade.

[0074] DETAILED DESRCIPTION OF EMBODIMENTS OF THE INVENTION

[0075] Fig. 1 shows one of a first plate 1 and of a saw blade. The first plate 1 constitute one of a first plate and a second plate of the saw blade. The first plate 1 shown in Fig. 1 has an inner centre hole 2, around which two circular ranges of holes are provided. A first circular range of holes shows six holes 3. The six holes 3 are for fastening means for fastening the saw blade to a drive shaft of a motor for rotating the saw blade. A second circular range of holes shows a plurality of holes 4. The plurality of holes 4 overlap and are in connection with outlets of suction channels (see Fig. 2 and Fig. 5), each suction channel intended for passing air and debris such as dust or fibres, formed during sawing, from an inlet of each of the suction channels, along an outer circumference 5, to the outlet of each of the suction channels. In the embodiment shown, the second range of holes count numerous holes. In alternative embodiments, the second range of holes may count lees holes, possibly only two oblong holes, each hole overlapping and being in connection with two or more outlets of two or more the suction channels.

[0076] Fig. 2 shows an intermediate plate 6 of the saw blade. The intermediate plate 6 is positioned between the first plate 1 and a second plate of the saw blade, when the firstplate, the intermediate plate and the second plate is assembled, and abrasive segments are fixed to the first platel, the second plate 11 and the intermediate plate 6 along the outer circumference 5, thereby constituting the saw blade.

[0077] Around an inner centre hole 7 one circular range of holes 8 is provided. The one circular range of holes shows six holes 8. The six holes 8 are for fastening means for fastening the saw blade to a drive shaft of a motor for rotating the saw blade. The intermediate plate 6 has a plurality of channels 9, each channel provided with three branches 9A,9B,9C at an outer circumference of the intermediate plate 6 and one outlet 10 at a central part of the intermediate plate 6. Each of the suction channels 9 has a fork-like shape, with an outer extension of each of the suction channels 9 being divided into three branches 9A,9B,9C, being a trifurcation of each of the suction channels 9, each branch 9A,9B,9C constituting an outer extension of a suction channel 9.

[0078] The intermediate plate 6 (see also Fig. 5), in the figure shown in light grey, is fixed to a second plate 11 of the saw blade (see also Fig. 4), in the figure shown in dark grey, and in the figure positioned underneath the intermediate plate 6. The extension 5 (see also Fig. 1 and Fig. 5) for the abrasive segments (see Fig. 6) of the saw blade to the intermediate part is shown along an outer circumference of the intermediate plate 6.

[0079] The number of inlets at the outer circumference of the intermediate plate is higher than the number of outlets at the central part of the intermediate plate. In the embodiment shown, the number of inlets is three times the number of outlets. The higher number of inlets is established by dividing each suction channel 9 into three branches, at an intermediate position of the intermediate plate, between the outlets and the inlets. The number of inlets may be less than three times, or more than three times, the number outlets.

[0080] The cross-sectional area of each of the inlets is either smaller or larger than a cross-sectional area of the suction channel, before the suction channels is divided into branches, which a given inlet communicates with. In the embodiment shown, the cross-sectional area of each of the inlets is smaller than a cross-sectional area of the suction channel. However, an added cross-sectional area of three inlets communicating with the one and same suction channel is larger than a cross-sectional area of the suction channel before being divided into branches.

[0081] Fig. 3 and Fig. 4 show the first plate 1 and the second plate 11 of a saw blade.The first outer plate 1 shown in Fig. 3, the same as shown in Fig. 1, has an outer circumference and an inner centre hole 2. Around the inner centre hole 2, the two circular ranges of holes are provided. The first circular range of holes 3 has six holes. The six holes 3 are for fastening means for fastening the saw blade to a drive shaft of a motor for rotating the saw blade. The second circular range of holes 4 has a plurality of holes. The plurality of holes 4 is intended for being in connection with the outlets of the suction channels (see Fig. 2 and Fig. 5) when the plates of the saw blade are assembled, each suction channels intended for passing air and debris such as dust or fibres, formed during sawing, from at least one inlet (see Fig. 2 and Fig. 5) of each of the suction channels to the outlet (see Fig. 2 and Fig. 5) of each of the suction channels. In the embodiment shown, the second range of holes count numerous holes. In alternative embodiments, the second range of holes may count lees holes, possibly only two oblong holes, each hole overlapping and being in connection with two or more outlets of two or more the suction channels.

[0082] In the embodiment shown, an outer diameter of the first plate is approximately 800 mm, and the first plate is made from a steel plate with a thickness of approximately 1 mm. In the alternative, the outer diameter may be smaller, perhaps down to 500 mm, or larger, perhaps up to 2000 mm. The thickness of the plate may also be smaller or larger, depending on a need for material strength of the plate and depending on the material, possibly other than steel, which the plate is made of. The material may be a compound between possibly steel and another material having a larger thermal conductivity than steel in order for the saw blade being better suited for transferring heat from abrasive segments (see Fig. 9) at the outer circumference of the saw blade.

[0083] The second plate 11 shown in Fig. 4 has an outer circumference the same as the outer circumference of the one part 1 (see Fig. 1 and Fig. 3) and has an inner centre hole 7. Around the inner 2 hole 7 only one circular range of holes 8 is provided. The one circular range of holes 8 has six holes 8. The six holes 8 are for fastening means for fastening the saw blade to a drive shaft of a motor for rotating the saw blade. In an alternative embodiment, also the second plate 11 of the saw blade could have a second circular range of holes, as the ones shown for the first plate, and also being in communication with outlets of each of the suction channels, when the plates of the saw blase is assembled.

[0084] In the embodiment shown, an outer diameter of the first plate is approximately 800 mm, and the first plate is made from a steel plate with a thickness of approximately 1 mm. In the alternative, the outer diameter may be smaller, perhaps down to 500 mm, or larger,perhaps up to 2000 mm. The thickness of the plate may also be smaller or larger, depending on a need for material strength of the plate and depending on the material, possibly other than steel, which the plate is made of. The material may be a compound between possibly steel and another material having a larger thermal conductivity than steel in order for the saw blade being better suited for transferring heat from abrasive segments (see Fig. 9) at the outer circumference of the saw blade.

[0085] Fig. 5 shows an outline of the intermediate plate 6 of the saw blade, intended to be positioned between the first plate 1, see Fig. 1 and Fig. 3, and the second plate 11, see Fig. 2 and Fig. 4. Around the inner centre hole 7, the one circular range of holes 8 is shown. The one circular range of holes 8 has six holes 8. The six holes 8 are for fastening means for fastening the saw blade to a drive shaft of a motor for rotating the saw blade. In the embodiment shown, the intermediate plate has an outer diameter of approximately 800 mm. and a thickness of approximately 2 mm.

[0086] The intermediate plate 6 has the plurality of suction channels 9, each suction channel 9 provided with the three branches 9A,9B,9C at the outer circumference of the intermediate plate 6 and the one outlet 10 at a central part of the intermediate plate 6. Each of the n channels 9 has a fork-like shape, with an outer extension of each of the suction channels 9 being divided into three branches, an outer extension of each of the branched 9A,9B,9C having an inlet, and with an inner extension of each of the suction channels 9 not being forked, each inner extension having the outlet 10 at the central part of the intermediate plate 6. The outlet 10 of each of the suction channels 9 are intended for being aligned with the holes 4 in the first plate 1 of the saw blade, see Fig.

[0087] 1 and Fig 3.

[0088] The suction channels 9 constitute suction channels for sucking air and debris such as dust or fibres, formed during sawing, from the outer circumference of the saw blade, where abrasive segments are attached to the extensions 5 of the intermediate part 6, and to the outlets 10 of the intermediate plate 6 and the holes 4 (see Fig. 3) of the one part 1, when a vacuum source is applied to the saw blade.

[0089] Fig. 6 is a close-up of three branches 9A,9B,9C of a suction channel 9 of the intermediate plate 6 and along an outer circumference 5 of the intermediate plate 6. The branches 9A,9B,9C of each of the suction channels have inlets provided in spaces 12A,12B,12C, for sucking air and debris such as dust or fibres, formed during sawing, between abrasive segments 13, and to be sucked into each of the branches 9A,9B,9C.The intermediate plate 6 has an outermost circumference onto which abrasive segments 13 are attached to the extension 5 of the intermediate plate 6. An outer extension 14 of each of the abrasive segments 13 extends beyond the outer circumference of the intermediate plate 6. Thereby, during sawing, the outer extension of the segments will engage the cementitious material to be handled by the saw blade.

[0090] Fig. 7 shows a first embodiment of the intermediate plate 6 of the saw blade. In the following, the description related Fig. 7 is similar to the description related to Fig. 5.

[0091] The intermediate plate 6 is intended to be positioned between the first plate 1, see Fig. 1 and Fig. 3, and the second plate 11, see Fig. 3 and Fig. 4. Around the inner centre hole 7, the one circular range of holes 8 is shown. The one circular range of holes 8 has six holes 8. The six holes 8 are for fastening means for fastening the saw blade to a drive shaft of a motor for rotating the saw blade. In the embodiment shown, the intermediate plate has an outer diameter of approximately 800 mm. and a thickness of approximately 2 mm.

[0092] The intermediate plate 6 has the plurality of suction channels 9, each suction channel 9 provided with the four branches 9A,9B,9C,9D at the outer circumference of the intermediate plate 6 and the one outlet 10 at a central part of the intermediate plate 6, being a quadrifurcation of each of the suction channels 9, each branch 9A,9B,9C, 9D constituting an outer extension of a suction channel 9.

[0093] Each of the suction channels 9 has a fork-like shape, with an outer extension of each of the suction channels being 9 divided into four branches, each outer extension of each of the suction channels 9 having an inlet 9A,9B,9C,9D, and with an inner extension of each of the suction channels 9 only exhibiting one channel branch, each inner extension having the outlet 10 at the central part of the intermediate plate 6. The outlet 10 of each of the suction channels 9 are intended for being aligned with the holes 4 in the first plate 1 of the saw blade, see Fig. 1 and Fig 3.

[0094] The suction channels 9 constitute suction channels for sucking air and debris, formed during sawing, from the outer circumference of the saw blade, where abrasive segments are attached to the outer circumference of the first plate, the intermediate plate 6 and the second plate 11, and to the outlets 10 of the intermediate plate 6 and the holes 4 of the first plate 1, when a vacuum source is applied to the outlets of the suction channels 9.Fig. 8 is a close-up of the branches of some of the suction channels 9 of the intermediate plate 6. The intermediate plate 6 has an outermost circumference onto which abrasive segments 13 are attached. An outer extension of each of the abrasive segments 13 extends beyond the outer circumference of the intermediate plate 6.

[0095] Each of the abrasive segment have holes extending through the abrasive segments, the holes having orifices leading to inlets of the branches. During sawing, the outer extension of the abrasive segments 13 will engage the cementitious material to be handled by the saw blade. During sawing, debris formed during sawing, is sucked into the holes of the abrasive segments 13, through the holes and into branches.

[0096] Fig. 9 shows a second embodiment of the intermediate plate 6 of the saw blade, intended to be positioned between the first plate 1, see Fig. 1 and Fig. 3, and the second plate 11, see Fig. 3 and Fig. 4. Around the inner centre hole 7, the one circular range of holes 8 is shown. The one circular range of holes 8 has six holes 8. The six holes 8 are for fastening means for fastening the saw blade to a drive shaft of a motor for rotating the saw blade. In the embodiment shown, the intermediate plate has an outer diameter of approximately 800 mm. and a thickness of approximately 2 mm.

[0097] The intermediate plate 6 has the plurality of suction channels 9, each suction channel 9 provided with the four branches 9A,9B,9C,9D at the outer circumference of the intermediate plate 6 and the one outlet 10 at a central part of the intermediate plate 6, being a quadrifurcation of each of the suction channels 9, each branch 9A,9B,9C.9D constituting an outer extension of a suction channel 9.

[0098] Each of the suction channels 9 has a fork-like shape, with an outer extension of each of the suction channels being divided into four branches, each outer extension of each of the suction channels having an inlet 9A,9B,9C, and with an inner extension of each of the suction channels 9 only exhibiting one channel branch, each inner extension having the outlet 10 at the central part of the intermediate plate 6. The outlet 10 of each of the suction channels 9 are intended for being aligned with the holes 4 in the first plate 1 of the saw blade, see Fig. 1 and Fig 3.

[0099] The suction channels 9 constitute suction channels for sucking air and debris formed during sawing, from the outer circumference of the saw blade, where abrasive segments 13 are attached along the outer circumference of the plates 1,6,11 of the saw blade, and to the outlets 10 of suction channels 9 in the intermediate plate 6 and to the holes 4 of the first plate 1, when a vacuum, during sawing, is applied to at least some of the holes4 along the range of the holes at the central part of the saw blade (see Fig. 1 and Fig.

[0100] 3).

[0101] Fig. 10 is a close-up of branches 9A-9D of some of the suction channels 9.

[0102] The intermediate plate 6 has an outermost circumference onto which abrasive segments 13 are attached to the extension 5 of the intermediate plate 6. An outer extension 14 of each of the abrasive segments 13 extends beyond the outer circumference of the intermediate plate 6. Thereby, during sawing, the outer extension of the abrasive segments 13 will engage the cementitious material to be handled by the saw blade.

[0103] The intermediate plate shown in Fig. 9 and Fig. 10 comprises thermal conducting liners 38,39, shown with hatched lines, positioned radially at selected positions. The thermal conducting liners 38,39 are made from a material having a higher thermal conductivity than the material which the first plate 1 and the second plate 11 and possibly also the intermediate plate 6 is made from. The plates 1,11,6 will conduct some heat from the abrasive segments 13, however, limited by the material which the plates 1,11,6 are made from, and limited by the contact area between the plates 1,11,6 and each of the abrasive segments 13 attached to the outer circumference of the plates.

[0104] In the embodiment shown, the thermal conductive liners 38,39 are positioned at two various selected positions. In other embodiments, the thermal conductive liners may be positioned in only the one position or only in the other position.

[0105] One position of placing thermal conductive liners 38 is within the branches, along a radial direction, so that heat generated during sawing is conducted from as close to a centre of the abrasive segments 13, where the abrasive segments are attached to plates 1,11,6, however, still allowing air and debris conducted through inlets of the abrasive segment (see Fig. 15) to enter the suction channels 9, not obstructing flow of air and debris from the holes in the abrasive segments and into the suction channels 9.

[0106] Another position of placing thermal conductive liners 39 is between suction channels 9, along a radial direction, so that heat generated during sawing is conducted from as close to lateral surfaces of the abrasive segments, where the abrasive segments are attached to the plates 1,11,6. Thermal conductive liners 39 between the suction channels preferably extend all the way to a central part of the saw blade, where air are sucked from the suction cannels.At the enter of the intermediate plate, cooling by water may be provided, resulting in increased thermal conduction of the plate 1,11,6, and an end of the thermal conductive liners 39, opposite to an end at the abrasive segments, may be in connection with the water for cooling, resulting in increased thermal conduction also by the thermal conductive liners 39.

[0107] Thermal conductive liners are made from selected materials having a higher thermal conductivity than the material which the plates 1,6,11 is made from. A preferred material is copper or a copper alloy, which is possible to solder to, as example, a steel plate, which the plates 1,6,11 preferably is made from. Other materials which the thermal conductive liners may be made from is aluminium, brass or other metals and alloys.

[0108] Fig. 11A and Fig. 11B show a first embodiment of a suction housing 15 to be in connection with the first plate 1 of the saw blade during sawing. The suction housing 15 has a cover 16 to be positioned so that the cover 16 covers the holes of the second range of holes 4 of the first plate 1, the holes 4 of the second range of holes of the first plate 1 being in connection with the outlets 10 of the suction channels 9 of the intermediate plate 6 of the saw blade. The cover 16 has a centre hole 17 allowing a drive shaft of a motor for driving the saw blade to interact with the holes along the first range of holes (see Fig. 1 and Fig. 3) of the first plate 1.

[0109] A suction pipe 18 extends from the cover 16 to an outlet flange 19 to be connected with a hose or pipe (not shown) of a vacuum source. The suction pipe 18 is elongated so that the outlet flange 19 is positioned outside an outer circumference of the saw blade, when the suction housing 15 is attached to and connected with the saw blade.

[0110] When the saw blade is sawing in cementitious material and a vacuum source is connected to the suction flange 19, and suction is provided, dust is sucked from the abrasive segments, through the inlets of the suction channels of the saw blade, through the suction channels and through the outlets of the suction channels, through the holes along the second range of holes in the one plate of the saw blade, through the cover 16, through the suction pipe 18 to the suction flange 19 and to the vacuum source.

[0111] The suction housing 15 is not rotating during sawing. Therefore, a gas tight sealing is preferably provided between an outer circumference of the cover 16 of the suction housing 15 and an outer surface of the first plate 1 of the saw blade. Such gas tight sealing may be a sealing ring, possibly made from an abrasive resistant material such aspolyoxymethylene (POM), provided as a circular ring in a corresponding groove in the outer circumference of the cover 16 of the suction housing 15.

[0112] Fig. 12A and Fig. 12B show a second embodiment of a suction housing 20 to be in connection with an outer surface of the first plate 1 of the saw blade during sawing. The suction housing 20 has a cover 21 to be positioned so that the cover 21 covers the holes 4 of the second range of holes of the first plate 1 of the saw blade (see Fig. 1 and Fig.

[0113] 3), the holes 4 of the second range of holes of the first plate 1 being in connection with the outlets 10 of the suction channels 9 of the intermediate plate 6 of the saw blade. The cover 21 has a centre hole 22 allowing a drive shaft of a motor for driving the saw blade to interact with the holes along the first range of holes (see Fig. 1 and Fig. 3) of the first plate 1.

[0114] A suction pipe 23 extends from the cover 16 to an outlet flange 24 to be connected with a hose or pipe (not shown) of a vacuum source. The suction pipe 23 is elongated so that the outlet flange 24 is positioned outside an outer circumference of the saw blade, when the suction housing 20 is attached to and connected with the saw blade.

[0115] When the saw blade is sawing in cementitious material and a vacuum source is connected to the suction flange 24, and suction is provided, dust is sucked from the abrasive segments, through the inlets of the suction channels of the saw blade, through the suction channels and through the outlets of the suction channels, through the holes along the second range of holes in the one plate of the saw blade, through the cover 16, through the suction pipe 23 to the suction flange 19 and to the vacuum source.

[0116] The suction housing 20 is not rotating during sawing. Therefore, a gas tight sealing is preferably provided between an outer circumference of the cover 21 of the suction housing 20 and an outer surface of the first plate 1 of the saw blade. Such gas tight sealing may be a sealing ring, possibly made from an abrasive resistant material such as polyoxymethylene (POM), provided as a circular ring in a corresponding groove in the outer circumference of the cover 21 of the suction housing 20.

[0117] In the embodiment shown, a section of a cover ring 25 is attached along part of an inner circumference of the cover 21. The cover ring 25 covers 180 degrees of the internal circumference of the cover 21. The cover ring is attached to the cover 21 by fastening elements 26, so that the cover ring 25 may be replaced or may be exchanged with another cover ring possibly covering another circumference than 180 degrees.The 180 degrees are positioned so that a middle of the angular extension is facing the suction pipe, however, not covering the suction pipe. The cover ring 25 has a radial extension between and outer circumference of the cover ring 25 and an inner circumference of the cover ring 25 corresponding to the position where the outlet holes in the one part of the saw blade, see Fig. 3, are situated.

[0118] Therefore, when suction is applied to the suction outlet 24, the suction pipe 23 and the cover 21, and when the saw blade is rotating, a plurality of outlet holes in the first plate 1 of the saw blade, see Fig. 3, covered by the cover ring 25 will be cut off from the suction. Only the remaining plurality of outlet holes in the first plate 1 of the saw blade not covered by the cover ring 25 will exposed to suction.

[0119] When the saw blade is attached to the drive shaft of the motor, and when the suction housing is applied to the outer surface of the one plate of the saw blade, when sawing, and if sawing in a direction from left to right in Fig.5, only half the suction channels will be exposed to suction, and it will only be the half of suction channels possibly having inlets at abrasive segments having entered the cementitious material.

[0120] The other half of the suction channels, not having inlets at abrasive segments having entered the cementitious material, will be cut off from a suction force. Therefore, all suction force is directed to the half of suction channels possibly having inlets at abrasive segments having entered the cementitious material, thereby not wasting suction force at not having inlets at abrasive segments having entered the cementitious material.

[0121] In the embodiment shown, the cover ring covers an angular extension of 180 degrees of the inner circumference of the cover. In alternative embodiments, a larger angular extension than 180 degrees of the inner circumference of the cover may be covered by the cover ring, or a smaller angular extension than 180 degrees of the inner circumference of the cover may be covered by the cover ring.

[0122] The larger angular extension of the inner circumference that the cover ring covers, the larger the suction force will be through the suction channels not being cut off from the suction force, and vice versa, the smaller angular extension of the inner circumference that the cover ring covers, the smaller the suction force will be through the suction channels not being cut off from the suction force.

[0123] Fig. 13A and Fig. 13B show a third embodiment of a suction housing 20 to be in connection with an outer surface of the first plate 1 of the saw blade during sawing. Thesuction housing 20 has a cover 21 to be positioned so that the cover 21 covers the holes 4 of the second range of holes of the first plate 1 of the saw blade (see Fig. 1 and Fig.

[0124] 3), the holes 4 of the second range of holes of the first plate 1 being in connection with the outlets 10 of the suction channels 9 of the intermediate plate 6 of the saw blade. The cover 21 has a centre hole 22 allowing a drive shaft of a motor for driving the saw blade to interact with the holes along the first range of holes (see Fig. 1 and Fig. 3) of the first plate 1.

[0125] A suction pipe 23 extends from the cover 16 to an outlet flange 24 to be connected with a hose or pipe (not shown) of a vacuum source. The suction pipe 23 is elongated so that the outlet flange 24 is positioned outside an outer circumference of the saw blade, when the suction housing 20 is attached to and connected with the saw blade.

[0126] When the saw blade is sawing in cementitious material and a vacuum source is connected to the suction flange 24, and suction is provided, dust is sucked from the abrasive segments, through the inlets of the suction channels of the saw blade, through the suction channels and through the outlets of the suction channels, through the holes along the second range of holes in the one plate of the saw blade, through the cover 16, through the suction pipe 23 to the suction flange 19 and to the vacuum source.

[0127] The suction housing 20 is not rotating during sawing. Therefore, a gas tight sealing is preferably provided between an outer circumference of the cover 21 of the suction housing 20 and an outer surface of the first plate 1 of the saw blade. Such gas tight sealing may be a sealing ring, possibly made from an abrasive resistant material such as polyoxymethylene (POM), provided as a circular ring in a corresponding groove in the outer circumference of the cover 21 of the suction housing 20.

[0128] In the embodiment shown, a section of a cover 25 extending along part of an inner circumference of the cover 21. The cover 25 covers 180 degrees of the internal circumference of the cover 21. The cover may be attached to the cover 21 by fastening elements, so that the cover ring 25 may be replaced or may be exchanged with another cover ring possibly covering another circumference than 180 degrees. Alternatively, the cover 25 may constitute an integral part of the suction housing 20.

[0129] The 180 degrees are positioned so that a middle of the angular extension is facing the suction pipe, however, not covering the suction pipe. The cover ring 25 has a radial extension between and outer circumference of the cover ring 25 and an innercircumference of the cover ring 25 corresponding to the position where the outlet holes in the one part of the saw blade, see Fig. 3, are situated.

[0130] Therefore, when suction is applied to the suction outlet 24, the suction pipe 23 and the cover 21, and when the saw blade is rotating, a plurality of outlet holes in the first plate 1 of the saw blade, see Fig. 3, covered by the cover ring 25 will be cut off from the suction. Only the remaining plurality of outlet holes in the first plate 1 of the saw blade not covered by the cover ring 25 will exposed to suction.

[0131] When the saw blade is attached to the drive shaft of the motor, and when the suction housing is applied to the outer surface of the one plate of the saw blade, when sawing, and if sawing in a direction from left to right in Fig.5, only half the suction channels will be exposed to suction, and it will only be the half of suction channels possibly having inlets at abrasive segments having entered the cementitious material.

[0132] The other half of the suction channels, not having inlets at abrasive segments having entered the cementitious material, will be cut off from a suction force. Therefore, all suction force is directed to the half of suction channels possibly having inlets at abrasive segments having entered the cementitious material, thereby not wasting suction force at not having inlets at abrasive segments having entered the cementitious material.

[0133] In the embodiment shown, the cover ring covers an angular extension of 180 degrees of the inner circumference of the cover. In alternative embodiments, a larger angular extension than 180 degrees of the inner circumference of the cover may be covered by the cover ring, or a smaller angular extension than 180 degrees of the inner circumference of the cover may be covered by the cover ring.

[0134] The larger angular extension of the inner circumference that the cover ring covers, the larger the suction force will be through the suction channels not being cut off from the suction force, and vice versa, the smaller angular extension of the inner circumference that the cover ring covers, the smaller the suction force will be through the suction channels not being cut off from the suction force.

[0135] Fig. 14A and Fig. 14B show the third embodiment of a suction housing 10 (see Fig. 13A and Fig. 13B) attached to a saw blade. The side of the suction housing shown in Fig. 13B is facing the saw blade. The cover 25 (not visible in Fig. 14A and Fig. 14B) is positioned along the upper half of the central part of the saw blade. When the saw blade is rotating during sawing, the number of holes along an upper half of the range of holes 4 (see Fig.1) at the central part of the saw blade, and which holes communicate with the outlets of the suction channels, is covered by the cover 25, and no suction from the suction housing is applied to the number of holes along the upper half of the range of holes 4.

[0136] The effect is that all vacuum applied to the suction housing is applied only to the number of holes along the lower half of the range of holes along the central part of the saw blade. This results in that the vacuum applied to the number of holes along the lower half of the range of holes may be at least the double compared to if the cover 25 was not provided.

[0137] If the cover 25 was not provided, all holes along the range of holes would be applied the vacuum through the suction housing. However, because at least the number of holes along the upper half of the range of holes not being subjected to cementitious material during sawing, no debris and / or fibres will be sucked to these holes during sawing, and during sawing there is no need to apply a vacuum through the suction housing to the holes along the upper half of the range of holes along central part of the saw blade.

[0138] Fig. 15 shows a second embodiment of possible abrasive segments 30 of a saw blade. Reference is made to Fig 2, Fig. 5 and Fig. 6 for description of a possible manner of attaching abrasive segments to extensions of an intermediate plate (not shown).

[0139] However, the embodiment of abrasive segments shown in Fig. 9 is not limited to the manner of attachment described previously. Other manners of attachment are possible.

[0140] In the embodiment shown, the abrasive segments are provided with holes 31A,31B,31C extending through the abrasive segments 30. Each abrasive segment 30 has three oblong holes 31A,31B,31C. Each of the holes 31A,31B,31C has an inlet at an outer surface of the abrasive segments 30, and each of the holes 31A,31B,31C has an outlet at an inner surface of the abrasive segment 30, where the abrasive segments 30 are attached to the intermediate plate, the outlet leading to inlets of the branches 9A,9B,9C. The inlet of each hole 31A,31B,31C is for intake of air and debris such as dust or fibres formed during sawing, and the outlet (not shown) of each hole is for passing the air and the debris to the inlets of the branches 9A,9B,9C of the intermediate plate 6 of the saw blade, subsequent to the debris having passed through the holes 31A,31B,31C in the abrasive segment 30.

[0141] In the alternative embodiment shown, a part of a suction channel 9 in the intermediate plate 6 of the saw blade is shown, see also Fig. 2, Fig. 5 and Fig. 6. Four branches9A,9B,9C,9D are shown. Three of the branches 9A,9B,9C lead to the outlets of the abrasive segment 30, positioned in extension of the branches.

[0142] A fourth channel branch 9D leads to a space 32 between the one abrasive segment and a neighbouring abrasive segment. Debris formed during sawing, and not passing through the holes 31A,31B,31C in an abrasive segment 30, may collect in the space 32 between abrasive segments. The branch 9D leading to the space 32 between the abrasive segments ensure that debris not passed through the holes 31A,31B,31C, but collected in the space 32 between the abrasive segments, are sucked from the sawing site.

[0143] In the alternative embodiment shown, each of the abrasive segments have a leading surface 33 with a substantially plane cross-section, seen along a radius of the saw blade, and a trailing surface 34 with an arrow-shaped cross-section, seen along a radius of the saw blade.

[0144] The leading surface 33 is directed forwards to an intended rotational direction of the saw blade as shown by an arrow A. The trailing surface 34 is directed rearwards to the intended rotational direction A of the saw blade. The trailing surface 34 with a cavity provides a better collection of debris in the space 32 between the abrasive segments.

[0145] In the embodiment shown, the trailing surface 34 has an arrow-shaped surface. In alternative embodiments, the trailing surface may have a shape being part of a polygon, part of a circle or part of an oval. The main purpose is to provide increased space for debris to collect between two neighbouring abrasive segments being part of the saw blade.

[0146] In the alternative embodiment shown, the abrasive segments are positioned along the circumference of the saw blade so that side surfaces 35,36 of the abrasive segments are displaced sideways in relation to neighbouring abrasive segments. The side surfaces 35,36 extend along planes along an intended rotational direction of the saw blade.

[0147] Fig. 16 shows a section of a saw blade. The section shows the suction channel 9 having inlets leading to four branches 9A,9B,9C,9D of the suction channel 9. The suction channel 9 has an outlet 10, opposite to the inlets of the branches, at a non-branch of the suction channel 9. Along an outer circumference 37 onto which the abrasive segments are attached, the inlets of each of the branches 9A,9B,9C,9D of the suction channel 9 communicate with holes 31A,31B in the abrasive segments.During sawing, the saw blade rotates and the saw blade is advanced through the material into which the saw blade is introduced. During sawing, the abrasive segments saw through the material into which the saw blade is introduced. Dust and / or fibres formed during sawing is sucked into the holes 31A,31B in the abrasive segments, into the branches 9A-9D of the suction channel 9, along the suction channel 9 and to the outlet 10 of the suction channel 9. From there the dust and / or fibres are sucked into and out of a suction housing (see Fig. 11A-11B, Fig. 12A-12B and Fig. 13A,13B).

[0148] In the various embodiments of a saw blade shown in the figures, each of the suction channels have either three or four branches towards the outer circumference of the intermediate plate. In other embodiments each or some of the suctions channels does not have branches towards the outer circumference of the intermediate plate. In even other embodiments each or some of the suction channels have more than three or four branches towards the outer circumference of the intermediate plate.

[0149] In the various embodiments of abrasive segments shown in the figures, each of the abrasive segments have either two or three holes leading to inlets of the branches of the suction channel. In other embodiments each or some of the abrasive segments have only one hole or have more than two or three holes leading to inlets of the branches of the suction channel. In even other embodiments, possible a few of the abrasive segments do not have holes and do not communicate with a suction channel.

Claims

CLAIMS1. Saw blade for sawing in materials which, during sawing, form debris hazardous to human health if inhaled and passed to lungs of a human, the saw blade being circular, - the saw blade having an outer circumference onto which a plurality of abrasive segments is attached and a central part, radially opposite to the outer circumference, the central part having a fastening mechanism for fastening the saw blade to a drive shaft of a sawing machine,- the saw blade having a first plate between the circumference and the central part of the saw blade, and facing outwards, and having a second plate between the circumference and the central part of the saw blade, also facing outwards, the first plate facing outwards oppositely to the second plate,- the saw blade comprising a plurality of suction channels for sucking air and debris, formed during sawing, the plurality of suction channels provided along inner surfaces of the first plate and the second plate,- the suction channels extending from inlets of the suction channels at the outer circumference of the saw blade to outlets of the suction channels at the central part of the saw blade, and where a number of all inlets is higher than a number of one of the following: all the suction channels or all outlets of the suction channels.

2. Saw blade according to claim 1, where at least some of the suction channels, preferably each of the suction channels, have at least two inlets at the outer circumference of the saw blade, and at least some of the suction channels, preferably each of the suction channels, have only one outlet at the central part of the saw blade.

3. Saw blade according to any of the preceding claims, where at least some of the suction channels have at least two inlets and have an initial extension from the at least two inlets to an intermediate position between the inlets and the outlet of the suction channel, the initial extension constituting a branched extension of the suction channel, and where the suction channels have a number of subsequent extensions from the intermediate position to the outlet of the suction channel, the number of subsequent extensions of the suction channel being lower than a number of initial extensions of the suction channel.

4. Saw blade according to any of the preceding claims, the saw blade comprising a plurality of suction channels for sucking air and debris formed during sawing, the suction channels extending from inlets positioned between abrasive segments to outlets at the central part of the saw blade.

5. Saw blade according to any of the preceding claims, where the plurality of suction channels provided between along inner surfaces of the first plate and the second plate is provided by an intermediate plate of the saw blade, positioned between the first plate and the second plate, the intermediate plate having cut-outs forming the suction channels.

6. Saw blade according to any of claims 1-4, where the plurality of suction channels provided along inner surfaces of the first plate and the second plate is provided by groves along an inner surfaces of at least one of the first plate and the second plate, so that when inner surfaces of the first plate and the second plate is in abutment, the groves extend along an interface between the plates.

7. Saw blade according to any of the preceding claims, the saw blade comprising a plurality of suction channels for sucking air and debris formed during sawing, the suction channels extending from inlets provided in the abrasive segments to outlets at the central part of the saw blade.

8. Abrasive segment for a saw blade,- the abrasive segment having a leading surface and a trailing surface transverse to a tangent along an intended rotational direction of a saw blade which the abrasive segment is intended for being part of,- the abrasive segment having opposite side surfaces extending parallel to a tangent along the intended rotational direction of the saw blade which the abrasive segment is intended for being part of,- the abrasive segment having an outer surface and an opposite inner surface, the outer surface of the abrasive segment intended for constituting part of an outer circumference of the saw blade which the abrasive segment is intended for being part of, and- the abrasive segment having at least one hole extending from an outer orifice at the outer surface of the abrasive segment and to an inner orifice at the inner surface of the abrasive segment, the inner orifice intended leading to an inlet of a suction channel of the saw blade which the abrasive segment is intended for being part of.

9. Abrasive segment according to claim 7, where the inner orifice has a cross-sectional area being larger than a cross-sectional area of the outer orifice, so that the at least one hole has a tapering extension between the inner surface and the outer surface of the abrasive segment, the at least one hole becoming gradually narrower from the inner surface towards the outer surface of the abrasive segment.

10. Abrasive segment according to claim 7 or 8, where the inner orifice has a cross-sectional area being between 25% and 150% larger than the cross-sectional area of the outer orifice, possibly between 25% and 100% larger than the cross-sectional area of the outer orifice, preferably between 50% and 100% larger than the cross-sectional area of the outer orifice.

11. Abrasive segment for a saw blade,- the abrasive segment having an intended leading surface and an intended trailing surface in relation to an intended rotational direction of a saw blade which the abrasive segment is intended for being part of,- the intended leading surface and the intended trailing surface extending traverse to the intended rotational axis of the saw blade which the abrasive segment is intended for being part of- the abrasive segment having opposite side surfaces- the abrasive segment having an outer surface and an inner surface, opposite to the inner surface,- the intended outer surface intended for constituting part of an outer circumference of the saw blade which the abrasive segment is intended for being part of,- the intended inner surface intended for being attached to at least one of the following: a first plate, a second plate, an intermediate plate of the saw blade, and- the abrasive segment having a trailing surface having a cavity with a recessed shape such as an arrow-like shape, a polygon shape or an oval shape.

12. Saw blade according to any of claims 1-7, the saw blade comprising a plurality of thermal conducting liners, the thermal conducting liners extending from an outer circumference of at least one of the first plate and the second plate and along an inner surface of at least one of the first plate and the second plate, the thermal conducting liners being made from a material having a higher thermal conductivity than a thermal conductivity of a material which the first plate and the second plate are made of.

13. Saw blade according to claim 12, where the thermal conductive liners extend from a position along the circumference of at least one of the first plate and the second plate, where inner surfaces of abrasive elements are attached to the outer circumference of the at least one of the first plate and the second plate, and the position being at a part of the inner surfaces of he abrasive elements between orifices of holes extending radially trough the abrasive elements.

14. Saw blade according to claim 12, where the thermal conductive liners extend from a position along the circumference of at least one of the first plate and the second plate, where inner surfaces of abrasive elements are attached to the outer circumference of the at least one of the first plate and the second plate, and the position being where at a part of the inner surfaces of he abrasive elements on lateral sides of at least one hole extending radially trough the abrasive elements.

15. Saw blade according to any of claims 12-14, where the thermal conductive liners extend from the outer circumference of at least one of the first plate and the second plate into at least two of a section of the suction channel, radially towards the central part of the saw blade, and to a position between the outer circumference of the at least one first plate and second plate and a non-section of the suction channel.

16. Saw blade according to any of claims 12-15, where the thermal conductive liners extend from the outer circumference of at least one of the first plate and the second plate into a part of the saw blade extending between suction channels, radially towards the central part of the saw blade, to a position along a circular circumference corresponding to a circular circumference of outlets of the suction channels at the central part of the saw blade.

17. Saw blade for sawing in materials which, during sawing, form debris hazardous to human health if inhaled and passed to lungs of a human, the saw blade being circular, - the saw blade having an outer circumference onto which a plurality of abrasive segments is attached and a central part, radially opposite to the outer circumference, the central part having a fastening mechanism for fastening the saw blade to a drive shaft of a motor of a sawing machine,- the saw blade having a first plate between the circumference and the central part of the saw blade, facing outwards, and a second plate between the circumference and the central part of the saw blade, also facing outwards, the first plate facing axially opposite to the second plate,- the saw blade comprising suction channels for sucking air and debris formed during sawing, and provided between the first plate and the second plate, the suction channels extending from inlets of the suction channels in the abrasive segments to outlets of the suction channels at the central part of the saw blade,- where the first plate is provided with a plurality of holes, a position of each of the plurality of holes provided at an outlet of the suction channels so that debris from the suction channels is extracted through the outlet of each of the suction channels and out through each of the holes in the first plate.

18. Saw blade according to any of claims 1-7 or 12-17, the saw blade having a plurality of abrasive segments along an outer circumference of the saw blade,- where each of the abrasive segments has a leading surface and an opposite a trailing surface extending traverse to a tangent along an intended rotational direction of a saw blade, and- where each of the abrasive segments has a first side surface and a second side surface extending parallel to a tangent along the intended rotational direction of the saw blade, - where a space is provided between a trailing surface of a precedent abrasive segment and a leading surface of a neighbouring succedent abrasive segment, the precedent abrasive segment and the succedent abrasive segment as viewed along a tangent along the intended rotational direction of the saw blade,- the space extending from the outer circumference of the saw blade to an inlet of a suction channel of the saw blade, so that debris collected in the space is extracted from the space, into the inlet of a suction channel, into the suction channel between the first plate and the second plate and to an outlet of the suction channel.

19. Saw blade according to any of claims 1-7 or 12-18, the saw blade having a plurality of abrasive segments along an outer circumference of the saw blade,- where each of the abrasive segments has an outer surface and an opposite inner surface, the outer surface and the inner surface extending along an intended rotational direction of the saw blade,- the outer surface of the plurality of abrasive elements constituting the outer circumference of the saw blade and the inner surface of each of the abrasive elements attached to an outer circumference of the first plate and the second plate,- the plurality of abrasive segments having at least one hole extending between the outer surface and the inner surface of the abrasive segment, and- where an orifice of the at least one hole, at the inner surface of the abrasive segment, is in communication with an inlet of a suction channel of the saw blade,- so that debris collected at the outer circumference of the saw blade is extracted from the outer circumference of the saw blade, into the holes in the plurality of abrasive segments, into the inlet of the suction channels, along the suction channels and to outlets of the suction channels.

20. Saw blade according to any of claims 1-7 or 12-19, the saw blade being provided with a plurality of abrasive segments along an outer circumference of the saw blade, - where each of the abrasive segments has a leading surface and a trailing surface extending traverse to an intended rotational direction of a saw blade, and- where each of the abrasive segments has opposite side surfaces extending along the rotational direction of the saw blade,- where one side surface of a leading abrasive segment extends along one plane along the intended rotational direction of the saw blade, and- where one side surface of a trailing abrasive segment extends along another plane along the intended rotational direction of the saw blade- so that at least part of a trailing surface of a leading abrasive segment, seen sideways, traverse to the intended rotational direction of the saw blade, extends outside a leading surface of the trailing abrasive segment.

21. Saw blade assembly with a saw blade according to any of claims 1-7 or 12-20, - the saw blade assembly comprising a suction housing at the central part of the saw blade, the suction housing providing a gas tight connection to an outer surface of at least one of the first plate and the second plate of the saw blade where the central part openings of at least one of the first plate and the second plate are positioned, the suction housing intended for being connected to a vacuum source,- the suction housing covering at least part of the central part outlet orifices of the saw blade, and the suction housing capable of providing a suction force at a limited number of the outlet orifices at the central part, the limited number of outlet orifices being outlet orifices of a limited number of suction channels, which, during sawing, have suction inlets facing the material which the saw blade is sawing into and along.

22. Saw blade for sawing in materials which, during sawing, form debris hazardous to human health if inhaled and passed to lungs of a human, the saw blade being circular, and with a plurality of abrasive segments according to any of claim 8-11, the plurality of abrasive segments provided along an outer circumference of the saw blade.

23. Saw blade according to any of claims 1-7 or 12-20, the saw blade having suctions channels extending form an outer circumference to a central part of the saw blade, the saw blade having a plurality of abrasive segments according to any of claim 8-11, the plurality of abrasive segments provided along the outer circumference of the saw blade.

24. Use of a saw blade according to any of claims 1-7 or 12-23 for sawing in a cementitious material such as concrete, cement, rock or stone which, during sawing, form dust hazardous to human health if inhaled and passed into lungs of a human.

25. Use of a saw blade according to any of claims 1-7 or 12-23 for sawing in a fibrous material such as glass-fibre materials or asbestos-fibre materials, which, during sawing, form fibres hazardous to human health if inhaled and passed into lungs of a human.

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