EP2933076B1

EP2933076B1 - Self-positioning knife to make joining profiles in wood and tool provided with one or more knives

Info

Publication number: EP2933076B1
Application number: EP15164006.7A
Authority: EP
Inventors: Remo Solari
Original assignee: Stark SpA
Current assignee: Stark SpA
Priority date: 2014-04-18
Filing date: 2015-04-17
Publication date: 2017-02-08
Anticipated expiration: 2035-04-17
Also published as: EP2933076A1; PL2933076T3

Description

FIELD OF THE INVENTION

The present invention concerns a knife configured to make joining profiles of the comb or finger type, in boards, layers or planks usable in the field of working wood, in particular in the field of the production of products in laminated wood, for example in the building sector, the furniture sector or the production of articles or gifts and fancy goods in general according to the preamble of claim 1. The present invention also concerns a support for one or more knifes according to the preamble of claim 8, a tool for making joining profiles according to the preamble of claim 9 and a method to assemble a tool according to the preamble of claim 13. Such a knife, support, tool and method are disclosed by document GB-A-742 603 .

BACKGROUND OF THE INVENTION

It is known to use laminated wood to make building structures, such as beams, walls or other support structures, or for furnishing objects, such as stairs, furniture, or other objects, or again artisan articles, gifts or fancy goods of various types. According to this known construction technique, the products are made by coupling together planks, boards, or layers of wood, suitably shaped and glued to each other.
Normally, on one or more perimeter faces of the boards, joining profiles are made, with a comb- or finger-shaped configuration; in the perimeter faces a series of alternate ridges and hollows are thus made, in a transverse direction with respect to the longitudinal development of the boards. The ridges and hollows are also configured to couple with respective hollows and ridges of boards to be joined, worked in a complementary manner.
In known solutions, as well as mechanically coupling the boards by inserting the projections of a first joining profile into hollows of a second joining profile and vice versa, it is also provided to use glues to glue together under pressure the parts in contact.
It is known to make joining profiles using milling tools where a cutting part, defined by a plurality of knives, is integrated with a rotary device, or head of the tool, generally by welding.
Milling tools are also known, provided with fixed knives removable from the head of the tool.
The knives are generally inserted each into a housing seating made radially in the head of the tool and attached to it using screws, normally inserted into the head of the tool in a front zone with respect to the knife.
Known solutions provide to screw the screws to two portions of the head of the tool opposite the housing seating, in order to move the opposite portions closer to each other and thus hold the knife due to interference.
Solutions are also known in which the screws are screwed into the head of the tool and put in contact with the front part of the knife to exert constantly thereon a thrust force that allows to keep it in abutment against the back portion of the housing seating.
Known tools normally have a plurality of knives both mounted circumferentially on the head, and also positioned adjacent parallel along the transverse direction cited above. To obtain this configuration, cutting tools are known, which have a plurality of rotating heads positioned adjacent in said transverse direction with respect to the longitudinal development of the boards.
One disadvantage of known tools having knives welded to the head is that they have a limited duration, mainly due to the fact that it is necessary to replace the whole tool when the knives are worn.
One disadvantage of known tools provided with removable knives is that they can suffer from blockages or damage of the attachment screws, or damage to the zone of the head of the tool where the holes are made, due to impacts, dirt or accumulation of working residues near the front part of the knives. The blockages or damage can render it difficult, if not impossible, to remove the knives once they are worn, and can thus reduce the overall working life of the tools; in any case, the maintenance operations of the tools are made longer and more complicated.
Another disadvantage of known knives is that they require a considerable number of operations and components in order to position them correctly; consequently, the procedures to produce, assemble, test and maintain the tools are made longer and more complicated.
Document GB-A-742.603 describes a rotating cutting head of a known type, in particular for machines for working wood, which provides circumferential recesses to position two or more cutting members.
There is therefore a need to perfect a self-positioning knife to make joining profiles in wood, and a tool provided with one or more knives that can overcome at least one of the disadvantages of the state of the art.
In particular, one purpose of the present invention is to obtain a knife to make joining profiles in wood that can be positioned easily and quickly on a rotating device, such as a head of a tool, and which allows a stable, secure and precise positioning with a minimum number of operations and with distributed and optimized attachment tensions.
Another purpose of the present invention is to obtain a knife to make joining profiles that allows to save working and maintenance time and costs compared with known knives.
Another purpose of the present invention is to obtain a tool provided with one or more cutting knives that allows to achieve a stable, secure and precise attachment of the knives, and which is light, compact and stable in functioning.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
In accordance with the above purposes, a knife for making joining profiles in wood according to claim 1 is provided.
The four positioning surfaces comprise a first resting surface, parallel to the face and located in an intermediate position between the threaded through holes and the blades, an axial abutment surface transverse, for example perpendicular, to the face and to the bottom wall, a radial abutment surface, inclined with respect to the first resting surface, and transverse, for example orthogonal, to the axial abutment surface, and a second resting surface, inclined with respect to the first resting surface, transverse to the threaded through holes and converging from the bottom wall toward the radial abutment surface.
The possibility of making four surfaces in the knife is thus obtained, which allow a simple positioning and a quick and safe univocal support.
Indeed, due to the effect of the different lying planes and their location, the four surfaces allow to obtain precisely and rapidly the correct positioning of each knife in both an axial direction, a radial direction and a circumferential direction.
The threaded through holes allow to make this positioning secure, and keep the knives in their seating once they have been positioned.
According to one aspect of the present invention, a support for one or more knives to make joining profiles in wood according to claim 8 is provided.
The back portion comprises one or more through holes and the housing seating is provided with four positioning surfaces of the knife, including two resting surfaces and two abutment surfaces.
The four positioning surfaces comprise an axial abutment surface of the back delimitation wall, lying on a plane perpendicular to the axis and a first resting surface of the back delimitation wall, a second resting surface of the back delimitation wall and a radial abutment surface lying on planes parallel to the same axis. The first resting surface is perpendicular to the through holes, the second abutment surface is inclined toward the inside of the corresponding housing seating, and the radial abutment surface is inclined with respect to the first and second abutment surface and lies on a plane transverse, for example orthogonal, to the axial abutment surface.
The present invention also concerns a tool for making joining profiles in wood according to claim 9.
According to the present invention, each knife of the tool is provided with four positioning surfaces, comprising an axial abutment surface located in contact with a corresponding axial abutment surface present in the support, in the back delimitation wall of the corresponding housing seating. The axial abutment surface is perpendicular to the axis of support and is configured for the axial abutment of the knife on it.
The four positioning surfaces also comprise a radial abutment surface located in contact with a radial abutment surface of the housing seating, transverse, for example perpendicular, to the axial abutment surface of the same back delimitation wall and configured for the radial abutment of the knife on the support.
Finally, the positioning surfaces comprise a first resting surface and a second resting surface located in contact with respective first resting surface and second resting surface of the back delimitation wall of the support, reciprocally inclined and both lying on planes parallel to the axis of the support, wherein the second resting surface is inclined toward the inside of the housing seating.
The coupling between positioning surfaces of each knife and corresponding positioning surfaces of the support allows to advantageously obtain the axial, radial and circumferential abutment of each knife in the respective housing seating. The abutments define the correct self-positioning of the knife in the support.
In some forms of embodiment of the present invention, each back portion of the at least one support of the tool comprises one or more through holes, each front portion comprises a contact surface facing toward the inside of the respective housing seating, and each knife comprises one or more threaded through holes. Moreover, threaded worm screws are provided, each inserted in one of the through holes, screwed into one of the threaded through holes and located in contact with the contact surface.
These and other aspects, characteristics and advantages of the present disclosure will be better understood with reference to the following description, drawings and attached claims. The drawings, which are integrated and form part of the present description, show some forms of embodiment of the present invention, and together with the description, are intended to describe the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of some forms of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

fig. 1 is a three-dimensional view of a knife according to the present invention to make joining profiles in wood,
fig. 2 is a three-dimensional view of a tool provided with a plurality of knives as in fig. 1;
fig. 3 is a plan view, partly sectioned, of the tool in fig. 2;
figs. 4a and 4b show an enlarged detail of fig. 3 in subsequent assembly steps of the tool in fig. 2;
fig. 5 is a variant of fig. 2;
fig. 6 is a three-dimensional view of a coupling between two tools as in fig. 2;
figs. 7a and 7b show an enlarged detail of other forms of embodiment.

In the following description, the same reference numbers indicate identical parts of the knife and tool for working wood according to the present invention, also in different forms of embodiment.

DETAILED DESCRIPTION OF SOME FORMS OF EMBODIMENT

We shall now refer in detail to the various forms of embodiment of the present invention, of which one or more examples are shown in the attached drawing. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof.
Fig. 1 is used to describe forms of embodiment of a knife 10 usable in the field of production of laminated wood to make joining profiles in boards or layers of wood.
The joining profiles, made on one or more faces of the boards, are the comb or finger type and have alternate ridges and hollows.
With reference to its final use, the knife 10 has a front zone that, during use, is configured to contact and penetrate first into the material to be worked, and a back zone opposite the front zone.
The knife 10 can also include a support part 11, configured to define the attachment of the knife 10 to a tool, and a cutting part 12, configured to shape the joining profiles in the wooden boards.
The support part 11 has a shape defined by a front wall 13, a back wall 14, opposite each other and positioned respectively in the front zone and the back zone of the knife 10, by a bottom wall 15 and by two lateral walls 16a, 16b, all shaped to define a quick and secure positioning of the knife 10 in its position of use.
The support part 11 can have a tapered shape at least in a portion near the bottom wall 15. The tapered shape can be defined by the reciprocal inclination of the front wall 13 and back wall 14 in this portion.
In some forms of embodiment, the front wall 13 and back wall 14 can both be inclined convergent toward the center line of the support part 11, giving the latter a greater bulk in correspondence with the bottom wall 15 compared with that in correspondence with the center line.
The cutting part 12 is connected to the support part 11 in a position opposite the bottom wall 15, and includes a plurality of blades 17, adjacent to each other and projecting from the support part 11.
With reference to the attached drawings, merely by way of example and not excluding any other possible solution, the present description considers knives 10 provided with four blades 17.
In some forms of embodiment, the blades 17 are made in a piece with the support part 11, so that cutting part 12 and support part 11 identify two portions of a single physical entity that defines the knife 10.
The blades 17 are distanced from each other in a transverse direction of the knife 10 to define a plurality of concavities 18, in this case three.
Each blade 17 is provided at the front with a sharpened surface, or face 19, and a cutting profile 20.
The cutting profile 20 is configured to penetrate into the wood of the boards in which the joining profile is to be obtained, while the blades 17 are configured to complete the work so as to obtain, in the faces of the boards, ridges and hollows corresponding respectively to the shape of the concavities 18 and the blades 17.
According to possible forms of embodiment, at least the cutting part 12 of the knife 10 can be made of steel, for example a rapid or super-rapid steel or hard metal, or ceramic material with a greater hardness than said steels.
In possible solutions, the blades 17 can be made of steel and coated with a layer of hard material that promotes penetration and sliding inside the wood fibers, for example a ceramic material with great hardness.
The coating can be made using physical vapor deposition techniques, also indicated by the acronym PVD.
Each of the blades 17 also includes a back surface 21, positioned on the opposite side of the blade 17 with respect to the face 19.
In some forms of embodiment, the back surface 21 is parallel to the face 19. In this way, the advantage is obtained of promoting the sharpening of the cutting profiles 20 of the cutting part 12 once they are worn, since a univocal reference is obtained for positioning the knife 10 in a sharpening machine.
Furthermore, the cutting profile 20 of the blades 17 is configured to keep constant the penetration depth of the blades 17 in the wood of the boards, even when the cutting profile 20 is worn, compensating the radial position of the tool.
This not only allows to keep the functionality of the knife 10 practically unchanged as time passes, but is particularly useful for making joining profiles in big batches of boards, for which - for example in the production of beams for building structures - stringent and uniform tolerances are required.
In some forms of embodiment, described by way of example with reference to fig. 1, the knife 10 can include one or more, for example two, threaded through holes 22, made in the support part 11.
The threaded through holes 22 have parallel axes and pass through the support part 11 in a direction that joins the front wall 13 and the back wall 14.
In some forms of embodiment, the threaded through holes 22 of the knife 10 can have axes perpendicular to the face 19.
The threaded through holes 22 allow to attach the knife 10 to a support or body 28, for example a rotating head of a milling tool 100, as shown by way of example in fig. 2.
With reference to fig. 1, the back wall 14 of the support part 11 can include a first resting surface 23, parallel to the face 19 and in an intermediate position between the threaded through holes 22 and the back surface 21 of the blades 17.
In possible solutions, the first resting surface 23 and the back surface 21 can be contiguous; in substance they can be reciprocally continuous.
The back wall 14 of the support part 11 can include a positioning seating 24 made transverse in the support part 11 and developing in a direction that joins the lateral walls 16a, 16b.
In some forms of embodiment, the positioning seating 24 develops from a first lateral wall 16a, in correspondence with which it is open toward the outside of the support part 11, and has an extension less than the transverse bulk of the latter, and is therefore blind.
The positioning seating 24 includes an axial abutment surface 25, that constitutes the axial abutment of the knife 10 on the body 28, transverse, for example perpendicular, to the face 19 and transverse to the bottom wall 15 of the support part 11, for example orthogonal thereto.
The axial abutment surface 25 is positioned near a second lateral wall 16b, opposite the first lateral wall 16a, and defines a surface that delimits the positioning seating 24 in a transverse direction.
In some forms of embodiment, the axial abutment surface 25 is parallel to the second lateral wall 16b.
In possible implementations, the axial abutment surface 25 is perpendicular to the first resting surface 23.
It can be provided, in possible forms of embodiment, shown for example in fig. 1, that the axial abutment surface 25 has a substantially triangular shape, but this does not exclude different shapes of the axial abutment surface 25, for example trapezoid or parallelogram, or quadrangular in general, or other shapes again, deriving from specific technical design strategies.
The positioning seating 24 also includes a radial abutment surface 26, transverse to the axial abutment surface 25.
It can be provided that the radial abutment surface 26 is inclined with respect to the first resting surface 23, recessed in the support part 11 of the knife 10 and transverse to the threaded through holes 22.
In possible implementations, it is provided that the radial abutment surface 26 is perpendicular to the axial abutment surface 25.
In other implementations, which can be combined with all the forms of embodiment described here, the radial abutment surface 26 can be perpendicular to the first resting surface 23 and the face 19.
Fig. 1 is used to describe forms of embodiment in which the radial abutment surface 26 is divided into several segments due to the presence of the threaded through holes 22.
According to some forms of embodiment, the positioning seating 24 can also include a second resting surface 27, inclined with respect to the first resting surface 23 toward the center of the support part 11 of the knife 10, transverse to the threaded through holes 22 and converging from the bottom wall 15 toward the radial abutment surface 26.
In possible solutions, the radial abutment surface 26 is interposed between the first resting surface 23 and the second resting surface 27.
It can also be provided that the second resting surface 27 lies on a plane orthogonal to the lying plane of the axial abutment surface 25.
In some forms of embodiment, the axial abutment surface 25 can be shaped like a right triangle, in which one cathetus and the hypotenuse are defined by the intersection with the lying plane of the axial abutment surface 25 respectively of the radial abutment surface 26 and the second resting surface 27.
The abutment surfaces 25 and 26 and the resting surfaces 23 and 27 are configured to allow the self-positioning or self-centering of the knife 10, as will be clear hereafter in the description.
Fig. 2 is used to describe forms of embodiment of a tool 100 to make joining profiles in wood, provided with a plurality of knives 10, in this case four.
The tool 100 includes a support or body 28, provided with a plurality of housing seatings 30, or hollows, made in the radial periphery of the body 28 and in each of which a knife 10 is housed.
The body 28 can have a shape developing around a central axis X and can include an axial hole 29 configured to house a rotary shaft, not shown in the drawings.
The coupling of the body 28 and rotary shaft can allow the tool 100 to rotate around the axis X.
In some forms of embodiment, each housing seating 30 can be axially through with respect to the body 28.
In some forms of embodiment, each housing seating 30 can be interposed between a front portion 30a and a back portion 30b of the body 28, respectively provided with a front delimitation wall 130a and a back delimitation wall 130b that delimit the housing seating 30 circumferentially.
According to some forms of embodiment, the front delimitation wall 130a and the back delimitation wall 130b are reciprocally inclined to define a tapered shape of the housing seating 30.
The tapered shape, together with the shape of the support part 11 of the knife 10, also tapered, allows to keep the knife 10 in the housing seating 30 even in the presence of the centrifugal force due to the rotation of the tool 100 around axis X during use.
One or more through holes 31 are made in the back portion 30b, in this case by way of example two, adjacent to each other and having reciprocally parallel axes.
Each knife 10 is inserted into the corresponding housing seating 30 axially, that is, it is inserted with a movement parallel to axis X.
This insertion provides to position the front zone of the knife 10, in particular the front wall 13 of the support part 11, facing toward the front delimitation wall 130a of the housing seating 30 and the back zone of the knife 10, in particular the back wall 14 of the support part 11, facing toward the back delimitation wall 130b of the housing seating 30.
Furthermore, the insertion of the knife 10 into the housing seating 30 provides that the threaded through holes 22 are positioned aligned with the through holes 31 of the back portion 30b.
Fig. 2 is used to describe forms of embodiment in which the tool 100 includes threaded worm screws 32 to attach the knives 10 to the body 28. They are attached by inserting the threaded worm screws 32 into the through holes 31 and by screwing them into the threaded through holes 22 of the knife 10.
Screwing in the threaded worm screws 32 determines a progressive entrance into the housing seating 30, until contact with the front delimitation wall 130a, which acts as a thrust surface. Subsequently, due to the effect of the relative motion of the threads of the threaded worm screws 32 and the threaded through holes 22, and of the constraint exerted on the former by the front delimitation wall 130a, the further screwing in of the threaded worm screws 32 determines a displacement of the knife 10 inside the housing seating 30 until it is taken into contact with the back delimitation wall 130b.
In this way the correct positioning is obtained, simply and quickly, of the knife 10 in the respective housing seating 30.
The fact that the threaded worm screws 32 are inserted from the back portion 30b of the body 28 allows to keep the front portion 30a clean, where the body 28 is without interstices and has a substantially planar development, since the through holes 31 are not present here, which could cause an accumulation of work residues.
Furthermore, the coupling of the threaded worm screws 32 and threaded through holes 22 has the advantage of subjecting a limited zone of the body 28 to mechanical stresses due to the attachment of the knife 10, which zone is in practice limited to the close proximity of the housing seating 30.
Most of the attachment force is in fact discharged on the threads, none of which is made on the body 28.
Figs. 3 to 4b are used to describe forms of embodiment, which can be combined with all the forms of embodiment described here, in which each front portion 30a of the body 28 includes one or more blind holes 35 made in the front delimitation wall 130a, each aligned coaxial with a through hole 31 of the back portion 30b opposite the corresponding housing seating 30.
Each blind hole 35 is also delimited terminally by a bottom surface 135 that performs the function of a thrust surface of the threaded worm screws 32 on the body 28.
As shown by way of example in figs. 3 and 4b, each threaded worm screw 32 is inserted into a through hole 31, after which it is screwed into a threaded through hole 22, enters into contact with the bottom surface 135 and, as screwing continues, determines contact of the back zone of the knife 10 with the back delimitation wall 130b of the body 28.
Figs. 3 and 4a are used to describe forms of embodiment of the body 28 in which the back delimitation wall 130b includes an axial abutment surface 125, lying on a plane perpendicular to axis X.
In some forms of embodiment, different housing seatings 30 can have axial abutment surfaces 125 lying on parallel and different planes, to ensure the axial abutment of the knives 10 at different heights in a direction parallel to axis X.
The through holes 31 and blind holes 35 are made in the respective portions back 30b and front 30a of the body 28 depending on the position of the axial abutment surfaces 125 of the body 28.
Each axial abutment surface 125 is configured to enter into contact with the corresponding axial abutment surface 25 of the knife 10, with the function of axial positioning element of the knife 10.
It is therefore possible to position each knife 10 in the desired axial position only by the insertion operation into the corresponding housing seating 30, by translating the knife 10 in an axial direction along axis X (figs. 4a and 4b) and to the desired radial position by tightening the threaded worm screws 32 (fig. 4b) during a subsequent assembly step of the tool 100.
Furthermore, fig. 4a shows how, by inserting the knife 10 and bringing the axial abutment surfaces 25 and 125 into contact, the threaded through holes 22 of the knife 10 are automatically aligned in an axial direction with the through holes 31 and possibly with the blind holes 35 of the body 28.
The back delimitation wall 130b also includes a first resting surface 123 and a second resting surface 127, inclined with respect to each other and connected by a radial abutment surface 126 interposed between them.
The surfaces 123, 126 and 127 lie on planes parallel to axis X and define a broken line development of the profile of the back delimitation wall 130b.
The first resting surface 123 also lies on a plane which, as well as parallel to axis X, is also perpendicular to the axis of the through holes 31.
The second resting surface 127 lies on a plane parallel to axis X and is inclined toward the inside of the housing seating 30, defining the taper of the latter in the part radially innermost to the body 28.
The radial abutment surface 126 is inclined with respect to the first 123 and second 127 resting surface and lies on a plane orthogonal to the axial abutment surface 125.
In possible solutions, the radial abutment surface 126 can be perpendicular with respect to the first resting surface 123.
The radial abutment surface 126 is configured to contact the radial abutment surface 26 of the knife 10, to define the radial self-positioning thereof with respect to axis X when the worm screws 32 are tightened.
In fact, by inserting the knife 10 into the housing seating 30 and making it rest with its radial abutment surface 26 on the radial abutment surface 126 of the body 28, the self-positioning of the knife 10 is completed.
In some forms of embodiment, the radial abutment surface 126 can lie on a plane parallel both to the axis X and also to the axis of the through holes 31 and the blind holes 35.
The first resting surface 123 can lie on a plane perpendicular both to the axial abutment surface 125, which constitutes its axial abutment, and also to the radial abutment surface 126.
The first resting surface 123, the second resting surface 127 and the radial abutment surface 126 of the body 28 have a complementary development with respect to that of the positioning seating 24 defined by the resting surfaces 23 and 27 and by the radial abutment surface 26 of the knife 10.
The first resting surface 123 and the second resting surface 127 of the back delimitation wall 130b are configured to contact respectively the first resting surface 23 and the second resting surface 27 of the knife 10 when the latter is thrust toward the back delimitation wall 130b by screwing the worm screws 32.
The resting surfaces 123 and 127 thus function as circumferential positioning elements of the knife 10.
In this way a univocal, precise and stable positioning of the knife 10 is obtained inside the respective housing seating 30, thanks to the reciprocally complementary configuration of the knife 10 and housing seating 30, which provides four reciprocal contact surfaces for the radial, axial and circumferential positioning of the knife 10.
Fig. 5 is used to describe forms of embodiment, which can be combined with all the forms of embodiment described here, in which the body 28 includes a plurality of reinforcement fins 36, positioned in the back portion 30b in correspondence with the blades 17 of the knife 10.
This allows to supply a support to the blades 17 when the tool 100 is functioning, at least partly compensating the thrust forces to which they are subjected due to contact with the material to be worked.
Fig. 6 is used to describe forms of embodiment of a tool 200 for milling wooden boards able to make therein comb-like joining profiles, wherein the tool 200 includes more than one body 28, in this case two, aligned along axis X and each provided with a plurality of knives 10.
The knives 10 of one body 28, if they protrude axially from it, are each housed in a corresponding lightening milling 34 of the adjacent body 28.
Bodies 28 can be provided in which, instead of the lightening millings 34, guide seatings are made, configured to house and contact the knives 10 protruding from adjacent bodies 28 and to determine in this way the coupling and rotational drawing of the bodies 28.
Figs. 7a and 7b are used to describe other forms of embodiment, in which the radial abutment surface 26 is not provided in the positioning seating 24 but on the bottom wall 15. It is understood that, in this form of embodiment too, the radial abutment surface 26, although provided on the bottom wall 15, is inclined with respect to the first resting surface 23, and transverse to the axial abutment surface 25.
Similarly, the correlated radial abutment surface 126 is not provided to connect the first resting surface 123 and the second resting surface 127 and is not part of the back delimitation wall 130b, but is provided inside the housing seating 30, being defined by an upper surface of a protruding element 126a that projects from the bottom of the housing seating 30. In other words, the radial abutment surface 126 is provided on the bottom of the housing seating 30. It is understood that, in this form of embodiment too, the radial abutment surface 126 is inclined with respect to the first resting surface 123 and the second resting surface 127 and lies on a plane transverse to the axial abutment surface 125.
In any case, in these forms of embodiment too, described using figs. 7a and 7b, the radial abutment surface 26 and the radial abutment surface 126 are configured to cooperate for the correct radial positioning of the knife 10, in particular to define the radial self-positioning thereof with respect to axis X when the worm screws 32 are tightened.
It is clear that modifications and/or additions of parts may be made to the self-positioning knife for making joining profiles in wood, and the tool provided with one or more knives as described heretofore, without departing from the field and scope of the present invention.
It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of self-positioning knife for making joining profiles in wood, and the tool provided with one or more knives, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.
Although the above refers to forms of embodiment of the invention, other forms of embodiment can be provided without departing from the main field of protection, which is defined by the following claims.

Claims

Knife for making joining profiles in wood, comprising a support part (11) provided with a bottom wall (15), a front wall (13) and a back wall (14), and a cutting part (12) provided with a plurality of blades (17) projecting from said support part (11) and each having a face (19) at the front, said knife comprising one or more threaded through holes (22) made in said support part (11) in a direction uniting the front wall (13) and the back wall (14) and characterized in that said knife is provided with four positioning surfaces comprising:
- a first resting surface (23), parallel to said face (19) and located in an intermediate position between said threaded through holes (22) and said blades (17),

- an axial abutment surface (25) transverse to the face (19) and to said bottom wall (15),

- a radial abutment surface (26), inclined with respect to said first resting surface (23) and transverse to said axial abutment surface (25),

- a second resting surface (27), inclined with respect to said first resting surface (23), transverse to said threaded through holes (22) and converging from said bottom wall (15) toward said radial abutment surface (26).
Knife as in claim 1, characterized in that said first resting surface (23), said axial abutment surface (25) and said second resting surface (27) are provided on said back wall (14).
Knife as in claim 1 or 2, characterized in that said radial abutment surface (26) is provided on said back wall (14).
Knife as in claim 3, characterized in that said radial abutment surface (26) is recessed toward said support part (11).
Knife as in any claim from 1 to 4, characterized in that said radial abutment surface (26) is interposed between said first resting surface (23) and said second resting surface (27), and in that said first resting surface (23), said radial abutment surface (26) and said second resting surface (27) are adjacent and consecutive and define a transverse positioning seating (24).
Knife as in claim 5, characterized in that said axial abutment surface (25) defines a surface delimiting said positioning seating (24) in a transverse direction to said support part (11).
Knife as in claim 1 or 2, characterized in that said radial abutment surface (26) is provided on said bottom wall (15).
Support for one or more knives (10) to make joining profiles in wood, having a shape developing around an axis (X) and comprising, in its radial periphery, one or more housing seatings (30) for said knives (10), each comprised between a front portion (30a) and a back portion (30b) and delimited circumferentially by a front delimitation wall (130a) and by a back delimitation wall (130b) respectively of said front portion (30a) and said back portion (30b), said back portion (30b) comprising one or more through holes (31), and characterized in that said housing seating (30) is provided with four positioning surfaces of the knife (10) comprising an axial abutment surface (125) of said back delimitation wall (130b), lying on a plane perpendicular to said axis (X) and defining an axial abutment for a knife (10), a first resting surface (123) of said back delimitation wall (130b), a second resting surface (127) of said back delimitation wall (130b) and a radial abutment surface (126), lying on planes parallel to said axis (X), wherein said first resting surface (123) is perpendicular to said through holes (31), said second resting surface (127) is inclined toward the inside of the corresponding housing seating (30), and said radial abutment surface (126) is inclined with respect to the first resting surface (123) and the second resting surface (127) and lies on a plane transverse to said axial abutment surface (125).
Tool for making joining profiles in wood, comprising at least a support (28) developing around an axis (X) and provided with one or more housing seatings (30) made in its radial periphery, each interposed between a front portion (30a) and a back portion (30b) respectively comprising a front delimitation wall (130a) and a back delimitation wall (130b) of a housing seating (30), said tool also comprising a plurality of knives (10) each housed in a housing seating (30), characterized in that each knife (10) has four positioning surfaces comprising:
- an axial abutment surface (25) located in contact with a corresponding axial abutment surface (125) present, in said support (28), in the back delimitation wall (130b) of the corresponding housing seating (30), perpendicular to said axis (X) and configured for the axial abutment of the knife (10) on the support (28),

- a radial abutment surface (26) located in contact with a radial abutment surface (126) of said housing seating (30) transverse to said axial abutment surface (125) of said back delimitation wall (130b) and configured for the radial abutment of the knife (10) on the support (28),

- a first resting surface (23) and a second resting surface (27) located in contact with respective first resting surface (123) and second resting surface (127) of said back delimitation wall (130b) of the support (28), reciprocally inclined and both lying on planes parallel to said axis (X), said second resting surface (127) being inclined toward the inside of said housing seating (30).
Tool as in claim 9, characterized in that each back portion (30b) comprises one or more through holes (31), each front portion (30a) comprises a thrust surface (130a, 135) facing toward the inside of the respective housing seating (30), each knife (10) comprises one or more threaded through holes (22), and in that threaded worm screws (32) are provided, each inserted in one of said through holes (31), screwed into one of said threaded through holes (22) and contacting said thrust surface (130a, 135).
Tool as in claim 10, characterized in that said thrust surface is said front delimitation wall (130a).
Tool as in claim 10, characterized in that each front portion (30a) comprises one or more blind holes (35) aligned with said through holes (31) of said back portion (30b) and in that said thrust surface is a bottom surface (135) of one of said blind holes (35).
Method to assemble a tool (100, 200) to make joining profiles in wood, comprising a step of positioning a plurality of knives (10) in corresponding housing seatings (30) made in the radial periphery of at least a support (28) developing around an axis (X), characterized in that, for each knife (10), it comprises the following operations:
- inserting the knife (10) in the corresponding housing seating (30) by translating said knife (10) in an axial direction along said axis (X) until it brings an axial abutment surface (25) of said knife (10) into contact with an axial abutment surface (125) of said housing seating (30), said insertion providing to place a radial abutment surface (26) of said knife (10) in contact with a radial abutment surface (126) of said housing seating (30), in order to align in said axial direction each threaded through hole (22) of said knife (10) with a through hole (31) made in a back portion (30b) of said support (28),

- inserting a threaded worm screw (32) in each through hole (31) and screwing said threaded worm screw (32) in said threaded through hole (22) until said threaded worm screw (32) is brought into contact with a thrust surface (130a, 135) of a front portion (30a) of said support (28), opposite said back portion (30b),

- further screwing said threaded worm screw (32), moving said knife (10) toward said back portion (30b) until a first resting surface (23) and a second resting surface (27) of said knife (10) are put respectively into contact with a first resting surface (123) and a second resting surface (127) of said back portion (30b).