FR3119999A1 - Knife and circular blade disc for cutting vegetables - Google Patents

Abstract

Knife and circular blade disc for cutting vegetables with The knife is provided for a circular blade (2) comprising a disk (4) and knives (6) removably mounted in respective housings (8) each having the shape of a notch opening out via an opening (10) on a peripheral edge (9) of the disk (4). The knife comprises a mounting part (40) and a cutting part (42), the mounting part (40) being configured for its insertion in a housing (8) substantially parallel to a central axis (A) of the disc (4) , the knife being retained in the housing (8) perpendicular to the central axis (A) by form-fitting the mounting part (40) and the housing (8), the cutting part (42) projecting out of the housing ( 8) through the opening (10). Figure for abstract: Figure 5

Description

Knife and circular blade disc for cutting vegetables

The present invention relates to the field of pruning plants such as trees, and in particular the field of circular blades provided with cutting elements removably mounted on a disc.

A harvester is a cutting tool that has a large-diameter circular blade and is generally mounted on a motorized machine with an articulated arm allowing the harvester to be manipulated to fell trees by cutting their trunk.

The circular blade advantageously comprises a disc carrying on its periphery cutting elements (or “knives”) removably mounted on the disc, which makes it possible to replace the knives when they are broken or worn.

US5261306A discloses a circular blade that can be fitted to a harvester, the circular blade comprising knives which are removably fixed to the disk by means of fixing screws passing through the knives.

A disadvantage of such a circular blade is that the knives break from time to time during felling operations.

This can affect the quality of the slaughtering that is carried out and requires interrupting the slaughtering operations to replace the broken knife(s). Replacing a broken blade can be difficult, for example when a head of a fixing screw is itself broken, which requires extracting the threaded rod of the fixing screw in order to install a new one. screw.

These operations carried out on site are time-consuming and costly, and increase the time during which the forest domain on which the cutting operations are carried out is exposed to discharges and/or leaks of gases or harmful liquids (fuel, lubricating oil, exhaust…).

One of the aims of the invention is to propose a knife which can be removably mounted on a disc so as to produce a circular blade which is reliable and robust.

To this end, the invention proposes a knife for a circular blade comprising a disk and knives removably mounted in respective housings each having the shape of a notch opening out through an opening on a peripheral edge of the disk, the knife comprising a mounting part and a cutting part, the mounting part being configured for its insertion into a housing substantially parallel to a central axis of the disc, the knife being retained in the housing perpendicular to the central axis by form-fitting the part of mounting and the housing, the cutting part projecting out of the housing through the opening.

The mounting of the blade on the disc by form complementarity between the blade and the housing makes it possible to have a blade that can be removably mounted on the disc while being held in a reliable manner, limiting the risk of breakage.

In particular, the greatest stresses on the knife during cutting are directed perpendicularly to the central axis of the disc, in particular radially and tangentially with respect to the central axis of the disc, and the maintenance of the knife in a transverse plane by complementarity of form makes it possible to limit the stresses of a possible fixing screw ensuring the fixing of the knife on the disc, and thus the risk of breakage of such a fixing screw.

According to particular embodiments, the knife comprises one or more of the following optional characteristics, taken individually or according to all the technically possible combinations:

- the mounting part has a width greater than that of the opening of the housing so as to prevent the mounting part from coming out of the housing through the opening;

- the knife has a retaining projection configured to fit into an associated recess of the housing to prevent the mounting part from exiting the housing through the opening;

- the mounting part has a rear face intended to bear against a rear wall of the housing, the rear face being turned tangentially rearward and radially outward when the blade is mounted on the disc;

- the knife has a bottom face intended to bear against a bottom wall of the housing, the bottom face being turned tangentially rearward and, preferably, radially inward, when the knife is mounted on the disc;

- the rear face and the bottom face define between them an angle comprised between 115° and 125°.

- the mounting part comprises a support portion bearing the rear face and, if applicable, the bottom face, and a fixing portion having a fixing orifice for the passage of a fixing member such as a screw , the fixing orifice being provided through the fixing portion without passing through the support portion;

- the cutting part has a radial cutting tooth having a radial cutting edge;

- viewed along a tangential reference direction, the radial cutting edge makes an angle of between -3° and 3° with the central axis of the disc when the knife is mounted on the disc;

- the radial cutting edge is located in a radial plane containing the central axis of the disc when the knife is mounted on the disc;

- the cutting part further comprises an axial cutting tooth having an axial cutting edge arranged to be located in front of the radial cutting edge extending tangentially forwards and radially inwards from the radial cutting edge;

- the radial cutting edge and the axial cutting edge meet to form an "L" shaped edge, one branch of which is defined by the radial cutting edge and the other branch is defined by the axial section;

- when the knife is mounted on the disc, the attack angle of the radial cutting edge is between 42° and 47°, the cutting angle of the radial cutting edge is between 42° and 47 °, and/or the clearance angle of the radial cutting edge is between 5° and 10°.

The invention also relates to a disc for a circular blade comprising a disc and knives removably mounted on the disc, the disc comprising a plurality of housings distributed along its peripheral edge, each housing having the shape of a notch opening through an opening on the peripheral edge and having a rear wall, a bottom wall and a front wall, each housing being configured to receive a knife as defined above.

The invention also relates to a circular blade comprising a disc as defined above and a plurality of knives as defined above mounted in a removable manner on the disc.

According to particular embodiments, the circular blade comprises one or more of the following optional characteristics, taken individually or according to all the technically possible combinations:

- the radial cutting edge of each knife comprises a first end and a second end, the knives including first knives whose radial cutting edge is inclined with respect to the central axis such that the first end is more remote from the central axis than the second end and from the second knives, the radial cutting edge of which is inclined with respect to the central axis such that the first end is closer to the central axis than the second end;

- the first knives and the second knives are arranged alternately at the periphery of the disc;

- the angle of inclination of the radial cutting edge of each knife with respect to the central axis is between -5° and +5°, in particular between -3° and +3°.

The invention also relates to a harvester comprising a circular blade as defined above.

The invention and its advantages will be better understood on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings, in which:

- there is a top view of a circular blade comprising a disc and knives removably mounted on the disc;

- there is a detail view of Zone II on the , illustrating a knife received in a corresponding seat of the disc;

- there is a view analogous to that of , the knife being shown out of its housing;

- there is a perspective view of the knife;

- there is a perspective view illustrating the insertion of the knife into its housing;

- there illustrate two knives provided with radial cutting edges have opposite inclinations;

- there is a perspective view of a harvester fitted with the circular blade of the .

The circular blade 2 shown in the is configured for cutting plants, for example for cutting wood, in particular for felling trees.

The circular blade 2 is configured to be mounted on a cutting tool, for example on a harvester, the cutting tool itself being able to be mounted at the end of an articulated arm of a machine.

The circular blade 2 has a central axis A. The circular blade 2 is configured to be driven in rotation around the central axis A in a direction of forward rotation for cutting plants. In Figure 1, the direction of forward rotation is clockwise, as shown by the arrow S.

The circular blade 2 has a disc 4 centered on the central axis A and a plurality of knives 6 removably mounted on the periphery of the disc 4. The disc 4 is configured to be mounted on a shaft (not shown) for its drive in rotation, and configured to support the knives 6.

During the rotation of the disc 4 in the direction of forward rotation S and the application of the disc 4 against a plant, each knife 6 moves tangentially and comes into contact with the plant to cut it.

In the rest of the description, the terms “front” and “rear” are understood to refer to the tangential displacement (or “orthoradial” displacement) of a knife 6 during the rotation of the disc 4 in the direction of forward rotation S .

The number of knives 6 is for example between eight and sixteen. In a particular embodiment, the number of knives 6 is equal to twelve.

Advantageously, as will be described in more detail below, the knives 6 are configured for a "skew" cut, the circular blade 2 preferably having an alternation of knives 6 for a cut on the bias to the left and a cut on the bias. right (considering the direction of orthoradial movement of the blades 6 during the rotation of the disc 4 in the forward direction of rotation S).

Disc 4 has a plurality of housings 8 at its periphery, each housing 8 being configured to receive a respective knife 6.

The knives 6 are similar to each other, and the housings 8 are similar to each other. A single blade 6 and its associated housing 8 will be described in detail below, with reference to Figures 2 to 5.

As visible in particular in Figures 3 and 5, the housing 8 has the shape of a notch made in a peripheral edge 9 of the disc 4 and opening onto the peripheral edge 9 of the disc 4 through an opening 10.

The housing 8 has a rear wall 12, a bottom wall 14 and a front wall 16. The rear wall 12 and the front wall 16 are located opposite each other. The bottom wall 14 is located opposite the opening 10.

The rear wall 12 extends from a rear edge 12A, located on the peripheral edge 9, towards the bottom of the housing 8. The front wall 16 extends from a front edge 16A, on the peripheral edge 9, towards the bottom of the housing 8. The rear edge 12A and the front edge 16A delimit between them the opening 10. The bottom wall 14 extends between the rear wall 12 and the front wall 16.

Preferably, the rear wall 12 is substantially planar and faces radially inward and tangentially forward. At each point of the rear wall 12, the normal to the rear wall 12 is directed radially inwards and tangentially forwards.

Preferably, in axial view (along the central axis A) from above, and as illustrated in the , the rear wall 12 defines, with a radial direction DR relative to the central axis A and passing through the rear edge 12A, an angle θ of between 40° and 50°. In a particular embodiment, the angle θ is equal to 45°.

Advantageously, the bottom wall 14 is substantially flat and turned tangentially forwards, and preferably radially outwards. At each point of the bottom wall 12, the normal to the bottom wall is directed tangentially rearward, and preferably radially outward.

The rear wall 12 and the bottom wall 14 are inclined relative to each other. The rear wall 12 and the bottom wall 14 define a non-zero angle between them.

Preferably, in axial view, as illustrated in the , the rear wall 12 and the bottom wall 14 define between them an angle φ of between 115° and 125°. In a particular embodiment, the angle φ is equal to 120°.

The front wall 16 is for example turned radially outward and tangentially rearward. Preferably, the front wall 16 is flat and substantially parallel to the rear wall 12.

In an exemplary embodiment, the disc 4 is provided, inside the housing 8, with a fixing hole 18 extending along a fixing axis F for fixing the blade 6 using a member fixing 20, such as a screw, having a threaded rod 22 extending along the fixing axis F.

Preferably, the fixing axis F is located in a transverse plane, i.e. a plane perpendicular to the central axis A.

Advantageously, the fixing axis F is oriented so that the fixing member 20 can be inserted into the fixing hole 18 and removed from the fixing hole 18 along the fixing axis F by passing through the opening 10 .

The fixing hole 18 does not open onto the rear wall 12, and, preferably, does not open onto the bottom wall 14.

Preferably, in axial top view, as illustrated in the , the fixing axis F defines with the radial direction DR passing through the rear outer edge 12A an angle η of between 42° and 47°. In a particular embodiment, the angle η is equal to 45°.

In a preferred embodiment, the angle θ and the angle η are substantially equal. Thus, the fixing axis F is advantageously substantially parallel to the rear wall 12 of the housing 8.

Advantageously, the fixing hole 18 and the fixing member 20 are configured in such a way that there is a functional clearance between the fixing hole 18 and the fixing member 20. In other words, the fixing 20 is received in the fixing hole with a radial clearance relative to the fixing axis F.

This prevents the fixing member 20 from taking up the forces undergone by the knife 6 during use.

In a particular embodiment, the fixing member 20 is an M14 type screw and the hole has an internal diameter of 18 mm, which defines a functional clearance, radially relative to the axis of the fixing hole 18, d about 1.1mm.

The fixing hole 18 is for example made in a fixing element 24 located inside the housing 8. The fixing hole 18 crosses for example the fixing element 24 right through.

The fixing element 24 is preferably arranged on the front wall 16 of the housing 8, and projects for example from the front wall 16 towards the rear wall 12.

In a particular exemplary embodiment, the fixing element 24 is attached and fixed rigidly to the front wall 16. It can be welded to the front wall 16.

The fixing element 24 is offset towards the inside of the housing 8 with respect to the opening 10. The fixing element 24 is located at a distance D ( ) of the opening 10. At least one free portion of the front wall 16 extends between the fixing element 24 and the opening 10.

Optionally, the housing 8 has, at the level of the opening 10, a protuberance projecting from the rear wall 12 or from the front wall 16 so that the opening 10 is less wide than the distance E between the rear wall 12 and the front wall 16 in a zone of the housing 8 adjacent to the opening 10. This makes it possible to prevent the knife 6 from being extracted from the housing 8 through the opening 10.

In the illustrated embodiment, as visible in the , the housing 8 has, at the level of the opening 10, a protrusion 26 projecting from the front wall 16 of the housing 8.

Optionally, housing 8 has a recess 28 intended to receive a retaining projection provided on knife 6 and configured to oppose extraction of knife 6 from housing 8 through opening 10 when this retaining projection is received in recess 28.

The recess 28 is for example provided close to the bottom wall 14 of the housing 8. In a particular embodiment, the recess 28 is delimited between the bottom wall 14 and the fixing element 24.

Optionally, the housing 8 has a clearance 30 configured to receive a fixing nut 32 ( ) intended to be screwed onto the threaded rod 22 of the fixing member 20.

The clearance 30 is for example provided to allow the insertion of the fixing nut 32 by preventing its rotation during the screwing of the fixing member 20. This avoids using a tool to block the fixing nut 32 by rotation during the screwing of the fixing member 20.

The distance from the rear edge 12A of the opening 10 of the housing 8 to the central axis A is strictly greater than the distance from the front edge 16A of the opening 10 of the housing 8 to the central axis A. The front edge 16A is set back radially relative to the rear edge 12A of the opening 10

Preferably, between two adjacent housings 8, the peripheral edge 9 of the disc 4 has a guide surface 34 whose distance from the central axis A gradually decreases when moving from the housing 8 located in front towards the adjacent housing 8 located behind.

This makes it possible to provide each housing 8 with a radially advanced rear edge 12A making it possible to define an extended rear wall 12 to limit the concentration of stresses, and a front edge 16A set back radially with respect to the rear edge 12A to allow the knife 6 received in housing 8 to penetrate the material to be cut.

The knife 6 is configured to be removably mounted on the disc 4 by being partially inserted into the housing 8, protruding from it through the opening 10 to ensure the cutting of the plants during the rotation of the disc 4.

More particularly, the knife 6 comprises a mounting part 40 configured to be removably inserted into the housing 8, and a cutting part 42 configured to protrude from the disc 4 through the opening 10 to ensure the cutting of the plants during the rotation of the disc 4.

The mounting part 40 is configured for its insertion into the housing 8 substantially parallel to the central axis A of the disk 4, the mounting part 40 inserted into the housing 8 being retained in the housing 8 perpendicular to the central axis A by complementarity of form between the mounting part 40 and the housing 8.

The cutting part 42 has a radial cutting tooth 44 having a radial cutting edge 46. The radial cutting edge 46 is defined at the junction between a leading face 48 and a relief face 50.

Preferably, the radial cutting edge 46 is coplanar with the central axis A. The radial cutting edge 46 is located in a radial plane including the central axis A and a radius passing through the radial cutting edge 46 .

When the knife 6 is mounted on the disc 4, the radial cutting edge 46 defines, with the central axis A, an angle ω ( ) comprised between −5° and +5°, preferably an angle ω comprised between −3° and +3°.

Note that on the , the angle ω of each of the two blades 6 illustrated is represented with respect to a direction parallel to the central axis A.

As indicated in more detail later also, advantageously, the edge of each blade 6 forms a non-zero angle with the central axis A, in particular an angle less than −1° or greater than +1°.

When the radial cutting edge 46 is slightly inclined with respect to the central axis A, the radial cutting edge 46 is configured in a so-called “skew” cut.

The radial cutting edge 46 has a first end 46A and a second end 46B.

Preferably, when the knife 6 is mounted on the disc 4, the first end 46A is an upper end of the radial cutting edge 46 and the second end 46B is a lower end of the radial cutting edge 46.

When the knife 6 is mounted on the disc 4, there is a reference radial direction RR ( ) which is radial with respect to the central axis A of the disc 4 and which passes through the first end 46A of the radial cutting edge 46.

When the knife 6 is mounted on the disc 4, there is a reference tangential direction TR ( ) which is perpendicular to the radial reference direction RR and passes through the first end 46A of the radial cutting edge 46.

When the knife 6 is mounted on the disc 4, and as shown in the , the cutting height HC (the distance over which the knife 6 can penetrate the material to be cut) corresponds to the minimum distance between the tangential reference direction TR and the portion of the peripheral edge 9 located immediately in front of the housing 8 receiving the knife 4.

Advantageously, when the knife 6 is mounted on the disc 4, in axial view, the attack face 48 of the axial cutting tooth 44 forms with the radial direction of reference an angle of attack γ comprised between 42° and 47° . In an exemplary embodiment, the angle of attack γ is equal to 45°.

Advantageously, when the blade 6 is mounted on the disc 4, in axial view, the clearance face 50 of the axial cutting tooth 44 forms with the tangential direction of reference TR a clearance angle α of between 5° and 10°. In a particular embodiment, the draft angle α is equal to 6°.

Advantageously, the attack face 48 and the undercut face 50 of the axial cutting tooth 44 form between them a cutting angle β of between 42° and 47°. In an exemplary embodiment, the cutting angle β is equal to 45°.

Optionally, the cutting part 42 comprises an axial cutting tooth 54 having an axial cutting edge 56 extending, when the knife 6 is mounted on the disc 4, tangentially forwards and radially inwards with respect to the radial cutting edge 46.

The axial cutting edge 56 is located for example at the junction between a leading face 58 and a clearance face 60.

Preferably, when the knife 6 is mounted on the disc 4, the axial cutting edge 56 extends in a transverse plane, i.e. perpendicular to the central axis A.

The axial cutting edge 56 is located in front of the radial cutting edge 46 considering the displacement of the knife 6 during the rotation of the disk 4 in the direction of forward rotation S, and extends obliquely with respect to the reference tangential direction TR.

Axial cutting edge 56 has a first end 56A adjacent to radial cutting edge 46 and a second end 56B remote from radial cutting edge 46.

Preferably, when the knife 6 is mounted on the disc, the first end 56A is a rear end of the axial cutting edge 56 and the second end 56B is a front end of the axial cutting edge 56.

The second end 56B is located forward relative to the first end 56A considering the forward direction of rotation S of the disk 4 during the cutting operations.

Second end 56B is offset radially inward relative to first end 56A. The distance between the first end 56A and the central axis A is greater than the distance between the second end 56B and the central axis A.

Preferably, when the knife 6 is mounted on the disc 4, the axial cutting edge 56 forms with the tangential reference direction TR a non-zero angle σ comprised between 42° and 47°. In an exemplary embodiment, the angle σ is equal to 45° ( ).

Preferably, as illustrated in the , viewed in the direction of the radial cutting edge 46, the axial cutting edge 56 projects forward relative to the radial cutting edge 46 at an angle Ω of between 85° and 95° , in particular an angle Ω of 90° with the leading face 48 of the radial cutting tooth 44.

In an exemplary embodiment, the radial cutting edge 46 and the axial cutting edge 56 come together and form an "L" shaped cutting edge.

The mounting part 40 has a rear face 62 intended to bear against the rear wall 12 of the housing 8.

Preferably, the rear face 62 is substantially planar. The rear face 62 is for example configured for flat support against the rear wall 12 of the housing 8.

Advantageously, when knife 6 is mounted on disc 4, rear face 62 faces radially outwards and tangentially rearwards.

The rear face 62 is oblique with respect to the radial reference direction RR. It forms a non-zero angle with the radial reference direction R and a non-zero angle with the tangential reference direction TR.

Preferably, when knife 6 is mounted on disc 4, rear face 62 forms an angle of between 42° and 47° with radial reference direction RR. In a particular embodiment, this angle is equal to 45°.

In a preferred embodiment, rear face 62 is substantially parallel with leading face 48 of radial cutting tooth 44.

Thus, preferably, the angle defines between the rear face 62 and the radial direction of reference RR and equal to the angle of attack γ.

Advantageously, the mounting part 40 has a bottom face 64 configured to bear against the bottom wall 14 of the housing 8.

Preferably, bottom face 64 is substantially planar. The bottom face 64 is for example configured to bear flat against the bottom wall 14 when the blade 6 is mounted on the disc 4.

The rear face 62 and the bottom face 64 define between them an angle δ which is preferably between 115° and 125°. In a particular embodiment, the angle δ is equal to 120°.

The angle δ between the rear face 62 and the bottom face 64 is equal to the angle φ between the rear wall 12 and the bottom wall 14 against which respectively bear the rear face 62 and the bottom face 64 of the knife 6.

Advantageously, when knife 6 is mounted on disc 4, bottom face 64 is turned tangentially rearward, and preferably radially inward.

Advantageously, the mounting part 40 has a front face 66 intended to come opposite the front wall 16 of the housing 8. Preferably, the front face 66 is flat and configured to come into flat contact with the front wall 16.

When the housing 8 is provided with a fixing hole 18, the mounting part 40 has a fixing hole 68 for the passage of the fixing member 20. The fixing hole 68 is arranged so as to be aligned with the fixing hole 18 along the fixing axis F when the mounting part 40 is inserted into the housing 8.

The fixing hole 68 is arranged on the mounting part 40 in such a way that the fixing hole 68 does not open onto the rear face 62, nor, where applicable, onto the bottom face 64. This makes it possible to retain a rear face 62 and a bottom face 64 of great extent and to limit the stress concentrations on the rear face 62 and the bottom face 64.

The assembly part 40 comprises for example a support portion 70 bearing the rear face 62 and the bottom face 64, and a fixing portion 72 in which the fixing orifice 68 is provided.

The rear face 62 is located on a rear side of the attachment portion 72 and the support portion 70 is arranged on a front side of the attachment portion 72, opposite the rear face 62. The attachment portion 72 carries the front face 66 of the mounting part 40.

The fixing hole 68 extends into the fixing portion 72 without extending into the support portion 70. In particular, the fixing hole 68 passes through the fixing portion 72. The fixing hole 68 does not does not lead to the rear face 62, nor, where applicable, to the bottom face 64.

The fixing portion 72 has an external face 74 which is turned towards the opening 10 when the knife 6 is received in the housing 8, and an internal face 76 which is turned towards the bottom of the housing 8 when the knife 6 is received in the housing 8. The fixing hole 68 extends between the outer face 74 and the inner face 76 of the fixing portion 72.

The bearing portion 70 is longer than the fixing portion 72. The bearing portion 70 has an internal zone 78 which extends beyond the internal face of the fixing portion 72. The internal zone 78 bears the bottom face 64

The blade 6 defines a cavity 80 for receiving the fixing element 24. The cavity 80 is delimited by the support portion 70 and the fixing portion 72. In particular, is delimited by the inner face 76 of the attachment 72 and the bottom zone 78 of the support portion 70.

The mounting part 40 has a width taken between the rear face 62 and the front face 66, which is equal to the width E of the zone of the housing 8 adjacent to the opening 10 and greater than the width of the opening 10. Once the mounting part 40 is inserted into the housing 8 along the central axis A, this prevents the exit of the mounting part 40 from the housing 8 through the opening 10.

The mounting part 40 has a retaining projection 82 intended to fit into the recess 28 of the housing 8 so as to oppose the extraction of the knife 6 from the housing through the opening 10.

The retaining projection 82 is located, for example, at one end of the mounting part 40 adjacent to the bottom face 64. The retaining projection 82 is provided to pass behind the fastening element 24 and hook behind the latter. to oppose extraction of the mounting part 40 through the opening 10.

Advantageously, the mounting part 40 has an abutment facet 84 configured to bear against the protrusion 26 to oppose the exit of the mounting portion 40 from the housing 8 through the opening 10. The abutment facet 84 is for example provided on the fixing portion 72 of the mounting part 40, between the outer face 74 of the fixing portion 72 and the front face 66.

Advantageously, the housing 8 and the assembly part 40 are configured in such a way that a force exerted on the knife 6 pushing the knife 6 towards the bottom of the housing 8, in particular a force directed in a transverse plane and substantially parallel to the rear face 62, generates a bearing force of the rear face 62 against the rear wall 12, and preferably a bearing force of the bottom face 64 against the bottom wall 64. Such a force exerted inwards of the housing 8 results for example from a reaction force undergone by the cutting part 42 of the knife 6 during a cutting operation and/or due to the tightening of the fixing member 20.

In particular, the assembly part 40 is provided with a support facet 86 inclined with respect to the rear face 62 and configured to come into plane support on a support zone 88 located in the housing 8, here on the fixing element 24, so as to convert a force exerted on the knife 6 pushing the knife 6 towards the bottom of the housing 8, into a force for pressing the rear face 62 against the rear wall 12, and preferably a force support of the bottom face 64 against the bottom wall 14.

Attachment portion 72 of mounting portion 40 is configured to fit between attachment member 24 and aperture 10, with attachment hole 68 aligned with attachment hole 18.

For mounting the blade 6 in the housing 8, the mounting part 40 is inserted into the housing 8 along the central axis A of the disc 4 ( ). Mounting portion 40 is configured to snugly fit into housing 8. Preferably, the fit is snug and mounting portion 40 is press-fit into housing 8.

The mounting part 40 and the housing 8 have complementary shapes, such that once the mounting part 40 is inserted into the housing 8, the mounting part 40 and the housing 8 cooperate to prevent any movement of the knife 6 by relative to disk 6 perpendicular to central axis A, and any pivoting of knife 6.

Due to the shape complementarity between the mounting part 40 and the housing 8, the blade 6 is blocked in translation and in rotation inside the housing 8, except in translation parallel to the central axis A to allow mounting and the dismantling of the knife 6 on the disc 4.

In particular, the knife 6 is prevented from moving perpendicularly to the central axis A in the housing 8 with respect to the disc 4 and is prevented from pivoting in the housing 8 with respect to the disc 4.

During cutting operations, the disc 4 is driven in rotation in the direction of forward rotation S and is pushed radially to sink into the material to be cut.

The cutting part 42 of the knife 6 comes into contact with the material to be cut by moving tangentially due to the rotation of the disc 4 around the central axis A and radially due to the movement of the disc 4 to push it into the material. to cut.

The knife 6 undergoes a reaction force having a tangential component FT and a radial component FR.

Due to the tangential component CT, the assembly part 40 of the blade 6 is applied by its rear face 62 against the rear wall 12 of the housing 8.

The extended rear face 62 distributes the effort and avoids concentrations of stress. The orientation of the rear face 62 and of the rear wall 12 makes it possible to maintain the assembly part 40 in the housing 8 by biasing the blade 6 towards the inside of the housing 8 and taking up the stresses tending to cause the blade 6 to come out of his accommodation 8.

The bottom face 64 makes it possible to absorb part of the forces generated on the blade 6 by the radial component FR and by the tangential component FT.

The provision of the rear face 62 and the bottom face 64 inclined with respect to each other and each facing forwards makes it possible to stabilize the knife 6 by taking up the majority of the forces applied to the knife 6 via the rear face 62 and bottom face 64.

If necessary, the protuberance 26 and/or the retaining projection 68 block(s) the knife 6 by taking up part of the forces tending to cause the knife 6 to come out of its housing 8.

The fixing member 20 is little stressed by the forces undergone by the knife 6 due to the cutting operations. The fixing member 20 is arranged through a fixing portion 72 located on the mounting part 40 on the side opposite the rear face 62, and a fixing element 24 located on the front wall 16 of the housing 8 opposite the wall rear 12. The fixing member 20 is therefore located on the side opposite that where its taken up the stresses due to the reaction force undergone by the knife 6 during the cutting operations.

The function of the fixing member 20 is therefore mainly to retain the knife 6 in the housing 8, in particular along the direction of insertion of the knife 6 in the housing 8 along the central axis A. This limits the risk of breakage of the fixing member 20.

Furthermore, the radial cutting edge 46 and the axial cutting edge 56 make it possible to ensure a clean and efficient cut of the material to be cut, in particular a tree trunk.

The radial cutting edge 46 is substantially parallel to the central axis A and to the fibers of the wood during the cut. It allows the knives 6 to remove the wood fibers in successive layers as the disc 4 advances through the wood.

The oblique axial cutting edge 56 located in front of the radial cutting edge 46 makes it possible, during cutting operations, to cut cleanly the wood fibers which extend substantially parallel to the central axis A.

In an advantageous exemplary embodiment, and as illustrated in the , the circular blade 2 comprises first knives 6 each configured so that its radial cutting edge 46 is inclined with respect to the central axis A in a first direction when the first knife 6 is mounted on the disc 4 and second knives 6 each configured so that its radial cutting edge 46 is inclined in a second direction with respect to the central axis A, opposite to the first direction, when the first knife 6 is mounted on the disc 4.

The radial cutting edge 46 of each of the first knives 6 and of the second knives 6 forms a non-zero angle with the central axis A.

Preferably, the radial cutting edge 46 of each of the first knives 6 and of the second knives 6 forms an angle less than −1° or greater than +1° with the central axis A. By observing each knife 6 in the direction tangential reference TR and from back to front, the radial cutting edge 46 of each first knife 6 is inclined to the left (at the top on the ), and the radial cutting edge 46 of each second knife 6 is inclined to the right (bottom in Figure 6).

On the radial cutting edge 4 of each first knife 6 (top in Figure 6), the first end 46A is farther from the central axis A than the second end 46A. On the radial cutting edge 4 of each second knife 6 (bottom on the ), the first end 46A is closer to the central axis A than the lower end 46B.

By observing each first knife 6 in the tangential direction of reference TR and from the rear to the front, its radial cutting edge 46 makes with the central axis A an angle ω less than -1° and/or greater than - 5°, in particular above -3°.

By observing each second knife 6 in the tangential direction of reference TR and from the rear to the front, its radial cutting edge 46 makes with the central axis A an angle ω greater than 1° and/or less than 5° , in particular less than 3°. Preferably, the first knives 6 and the second knives 6 are alternated along the peripheral edge 9 of the disc 4. This makes it possible to ensure a homogeneous cut with evacuation of the wood chips.

The circular blade 2 preferably comprises an even number of knives 6, and has as many first knives 6 as two second knives 6.

Preferably, each knife 6 is configured in such a way that the radial cutting edge 46 and/or, where applicable, the axial cutting edge 56 can be resharpened in situ , ie when the knife 6 is mounted on disc 4, without removing knife 6 from disc 4.

Preferably, the knife 6 is configured for resharpening each resharpenable cutting edge in situ up to 5 mm.

Preferably, again, when the knife 6 has a radial cutting edge 46 and also an axial cutting edge 56, the resharpening is carried out in a combined manner, i.e. simultaneously on the radial edge 46 and the axial edge 56.

To allow resharpening in situ of a radial cutting tooth 44, when the knife 6 is mounted on the disc 4, the relief face 48 of the radial cutting tooth 44 is for example located in a plane which does not cut through the disk 4. Thus, it is possible to resharpen the radial cutting tooth 46 without interference with disk 4.

Advantageously, to allow resharpening in situ of an axial cutting tooth 54, when the knife 6 is mounted on the disc 4, the relief face 58 of the axial cutting tooth 54 is located in a plane perpendicular to the axis central A and offset axially with respect to the disc4 so that this plane does not intersect the disc. The plane of the relief face 58 is for example located under the disc 4. Thus, it is possible to resharpen the axial cutting tooth 54 in interference with the disc 4.

As illustrated on the , the circular blade 2 is configured to be mounted on a cutting tool 90, for example on a harvester comprising for example a support 92 on which the disc 4 is rotatably mounted around its central axis A, and a clamping system 94 for clamp the harvester against a tree trunk or branch.

The clamping system comprising articulated arms 96 mounted on the support 92 so as to be able to embrace a trunk or a branch to clamp the support 92 against the trunk or the branch and thus apply the disc 4 driven in rotation against the trunk or the branch to cut it or cut it.

In operation, the circular blade 2 is driven in rotation, for example a speed of rotation between 1500 rpm (revolutions per minute) and 2500 rpm. A plant to be cut is for example enclosed with the articulated arms 96 in such a way as to apply the circular blade 2 against the plant.

Due to the rotation of the circular blade 2, the knives 6 carried by the disk 4 come to cut the plant material. When the plant material is the trunk of a tree, the fibers extend in the trunk substantially parallel to the central axis A of the disc 4. Each knife 6 has its radial cutting tooth 44 which removes a layer of plant fibers and its axial cutting tooth 54 which cuts the plant fibres. This allows a clean and reliable cut.

Due to the mounting of each blade 6 on the disc 4 by form complementarity, the forces are taken up by the rear faces and/or the bottom faces of the blades 6 resting on the rear walls and/or the bottom walls of the housings 8 are solicitation of a fixing element 20 which ensures reliability.

The knives 6 provided for a cut at an angle to the right and to the left, preferably alternately, allow a satisfactory cut.

The knives 6 can be easily resharpened in situ, which avoids dismantling to resharpen them, and makes it possible to limit the loss of time and to use the knives 6 as much as possible before replacing them.

The invention is not limited to the exemplary embodiments and to the variants described above, other exemplary embodiments and other variants being possible.

Furthermore, the circular blade 2 comprising knives 6 for cutting at an angle to the right and knives for cutting at an angle to the left, in particular arranged alternately along the periphery of the disc 4, is advantageous independently of the mounting of the knives 6 on disk 4.

Thus, in general, the invention relates to a circular blade for cutting plants, for example wood, comprising a disc 4 at the periphery of which are arranged knives 6, each knife 6 having a radial cutting edge 46 having a first end 46A and a second end 46B, the knives 6 including first knives 6 whose radial cutting edge 46 is inclined with respect to the central axis A such that the first end 46A is further from the axis center A than the second end 46B) and second knives 46B whose radial cutting edge 46 is inclined with respect to the central axis A such that the first end 46A is closer to the central axis A than the second end 46B.

Preferably, the radial cutting edge 46 of each knife 6 defines a non-zero angle comprised between -5° and +5° with the central axis A of the disc 4, in particular an angle comprised between -5° and -1 ° or between 1° and 5°, the knives 6 including first knives 6 whose radial cutting edge 46 is inclined in a first direction (angle of inclination with respect to the positive central axis A) and second knives 6 whose radial cutting edge 46 is inclined in a second direction opposite to the first direction (angle of inclination with respect to the negative central axis A).

The invention also relates to a set of knives 6 intended to be mounted on a disk of a circular blade for cutting plants, for example wood, including first knives 6 and second knives 6 configured for the production of a circular blade as defined above.

The first knives 6 and the second knives 6 can have all the characteristics considered above.

Furthermore, the geometric characteristics of a knife 6 as described previously are advantageous independently of the mounting of the knife 6 on the disc of the circular blade 2, in particular, the provision of an axial cutting edge 56 projecting towards the front with respect to the radial cutting edge 46, preferably by defining, in view along the direction of the radial cutting edge 46 of the knife 6, an angle comprised between 85° and 95°, in particular an angle of 90 ° of an attack face 48 of the radial cutting tooth 44.

Claims (19)

Knife for a circular blade (2) comprising a disk (4) and knives (6) removably mounted in respective housings (8) each having the shape of a notch opening out via an opening (10) on a peripheral edge (9) of the disc (4), the knife comprising a mounting part (40) and a cutting part (42), the mounting part (40) being configured for its insertion in a housing (8) substantially parallel to an axis (A) of the disc (4), the knife being retained in the housing (8) perpendicular to the central axis (A) by form complementarity the mounting part (40) and the housing (8), the cutting part (42) projecting out of the housing (8) through the opening (10). Knife according to claim 1, wherein the mounting part (40) has a width greater than that of the opening (10) of the housing (8) so as to prevent the mounting part (40) from coming out of the housing (8 ) through the opening (10). A knife as claimed in claim 1 or claim 2, wherein the knife has a retaining projection (82) configured to fit into an associated recess (28) of the housing (8) to prevent the mounting portion (40) from coming out of the housing (8) through the opening (10). Knife according to any one of the preceding claims, in which the mounting part (40) has a rear face (62) intended to bear against a rear wall (12) of the housing (8), the rear face (62) being turned tangentially rearward and radially outward when the knife is mounted on the disc (4). Knife according to any one of the preceding claims, in which the knife has a bottom face (64) intended to bear against a bottom wall (14) of the housing (8), the bottom face (64) being turned tangentially rearward and preferably radially inward when the knife is mounted on the disc (4). Knife according to Claims 4 and 5, in which the rear face (62) and the bottom face (64) define between them an angle (δ) comprised between 115° and 125°. Knife according to any one of the preceding claims 4 to 6, in which the mounting part (40) comprises a bearing portion (70) carrying the rear face (62) and, where appropriate, the bottom face (64 ), and a fixing portion (72) having a fixing orifice (68) for the passage of a fixing member (20) such as a screw, the fixing orifice being provided through the fixing portion ( 72) without crossing the support portion (70). A knife according to any preceding claim, wherein the cutting part (42) has a radial cutting tooth (44) having a radial cutting edge (46). Knife according to Claim 8, in which, when viewed along a tangential reference direction, the radial cutting edge (46) makes an angle (ω) comprised between -3° and 3° with the central axis (A) of the disc when the knife is mounted on the disc (4). Knife according to Claim 8 or 9, in which the radial cutting edge (46) lies in a radial plane containing the central axis (A) of the disc (4) when the knife is mounted on the disc (4). A knife as claimed in any one of claims 8 to 10, wherein the cutting part (42) further comprises an axial cutting tooth (54) having an axial cutting edge (56) arranged to be located in front of the cutting edge radial cutting edge (46) extending tangentially forward and radially inward from the radial cutting edge (46). A knife according to claim 11, wherein the radial cutting edge and the axial cutting edge meet to form an "L" shaped edge one leg of which is defined by the radial cutting edge (46) and the the other branch is defined by the axial cutting edge (56). Knife according to any one of the preceding claims, in which, when the knife is mounted on the disc, the angle of attack (γ) of the radial cutting edge (46) is between 42° and 47°, the cutting angle (β) of the radial cutting edge (46) is between 42° and 47°, and/or the clearance angle (α) of the radial cutting edge (46) is between 5° and 10°. Disc for a circular blade comprising a disc (4) and knives (6) removably mounted on the disc (4), the disc comprising a plurality of housings (8) distributed along its peripheral edge (9), each housing (8) having the shape of a notch opening out via an opening (10) on the peripheral edge (9) and having a rear wall (12), a bottom wall (14) and a front wall (16), each housing (8) being configured to receive a knife (6) according to any preceding claim. Circular blade comprising a disc (4) according to claim 14 and a plurality of knives (6) according to any one of claims 1 to 13 removably mounted on the disc (4). A circular blade according to claim 15, wherein the radial cutting edge (46) of each cutter (6) includes a first end (46A) and a second end (46B), the cutters (6) including first cutters (6 ) whose radial cutting edge (46) is inclined relative to the central axis (A) such that the first end (46A) is farther from the central axis (A) than the second end (46B ) and second knives (46B) whose radial cutting edge (46) is inclined relative to the central axis (A) so that the first end (46A) is closer to the central axis (A ) than the second end (46B). Circular blade according to Claim 16, in which the first knives (46) and the second knives (46) are arranged alternately at the periphery of the disc (4). Circular blade according to Claim 16 or 17, in which the angle of inclination of the radial cutting edge (46) of each knife (6) with respect to the central axis (A) is between -5° and +5°. A harvester comprising a circular blade according to any one of claims 15 to 18.