WO2021130436A1

WO2021130436A1 - Block for cutting wooden logs and unit comprising such a block

Info

Publication number: WO2021130436A1
Application number: PCT/FR2020/052476
Authority: WO
Inventors: Eric BAJER; Manuel LAUWERS; Hervé MIZON
Original assignee: Home Clotures D'aquitaine
Priority date: 2019-12-23
Filing date: 2020-12-16
Publication date: 2021-07-01
Also published as: FR3105060A1; EP4081378A1; FR3105060B1

Abstract

The present invention relates to a block (100) for cutting wooden logs, comprising: - a support member (10) extending in a plane (P), referred to as the support plane, which is substantially perpendicular to a cutting axis (A) of the wooden log; and - a plurality of substantially planar blades (20) attached to the support member (10) and extending perpendicular to the plane of the support member (P), each of the blades (20) comprising a cutting edge (20a), wherein the blades (20) are arranged relative to each other in order to form, as a projection orthogonal to the plane of the support member (P), a star in which the cutting edges (20a) are aligned with respect to the cutting axis (A) so as to split the wooden log longitudinally into a plurality of stakes when the wooden log is inserted longitudinally into the cutting block (100) along the cutting axis (A).

Description

DESCRIPTION

Title: CUTTING BLOCK FOR WOOD RODS AND INSTALLATION

INCLUDING SUCH A BLOCK

Technical area

The present invention relates to the field of splitting wood, and more particularly to the field of splitting logs to obtain stakes.

One of the objects of the present invention is to provide ganivelle manufacturers with a cutting block capable of splitting logs of wood to obtain stakes.

The present invention will thus find numerous advantageous applications in the field of the manufacture of ganivelles, also called Girondine fences.

Prior art

The ganivelles are classically fences formed by an assembly of wooden slats. According to this assembly, the slats are held vertically together and are separated from each other by a space whose width determines the permeability of the barrier.

The slats are kept in position by turns of galvanized iron wires. Traditionally, these wooden slats are obtained from chestnut, and in particular chestnut poles with a diameter of about six to twelve centimeters.

Once peeled and split, the poles produce what are called stakes; such stakes have a naturally rounded side (this is the peeled outer part of the perch).

The use of chestnut is appreciated for making ganivelles.

The chestnut tree indeed offers a durable and rot-resistant wood essence due in particular to its richness in tannin. It is therefore a wood particularly suited to resist attack by fungi and insects.

The chestnut tree also has good properties for being split.

The Applicant submits that consumers do not want other woods, both for aesthetic reasons and for qualitative reasons (resistance over time in particular).

For the manufacture of a ganivelle, the chestnut poles are therefore split manually or mechanically to obtain the stakes, this technique ensures better durability than sawn slats. The Applicant has, however, observed that the supply of poles was very difficult and that, as a result, the demand for poles was very much greater than the supply.

Conventional techniques for cutting chestnut poles do not today meet the expectations of ganivelle manufacturers.

The current mechanical process used by the entire profession to obtain chestnut stakes consists of splitting the poles using a splitter equipped with a splitting die, a splitting guide and a jack. ensuring the thrust of the pole towards the die or the displacement of the die from upstream to downstream of the pole.

The die is designed with blades welded together, forming a central starting point and giving the die a convex shape.

The splitting guide is a mobile tool that allows the operator to follow the shape of the pole, which is not naturally straight, in order to split along the grain of the wood, and to form stakes.

Such a guide is suitable for chestnut poles.

However, as noted above, the supply of such poles is difficult and cannot meet demand. The Applicant observes here that the use of chestnut ridges would make it possible to satisfy the demand for stakes, the supply of chestnut logs being easier.

In contrast, chestnut ridges have a diameter of between twelve and twenty-five centimeters. The numerous tests carried out with conventional dies show that they are not suitable for splitting chestnut logs 4 to 8 cm in diameter, obtained by milling after division of the log.

There is currently no splitting die suitable for splitting chestnut logs. Object of the present invention

The present invention aims to improve the situation described above

The present invention aims in particular to remedy at least one of the various technical problems mentioned above by proposing a wood log cutting technique making it possible to split said log longitudinally into a plurality of stakes.

To this end, the object of the present invention relates according to a first aspect to a cutting block, also called a splitting die, for a wooden log comprising a support extending in a plane substantially perpendicular to a cutting axis of the log. wood. Advantageously, the cutting block according to the present invention comprises a plurality of blades which are preferably substantially flat.

Advantageously, the blades are fixed to the support and extend perpendicularly to the plane of the support, each of the blades preferably comprising a sharp edge.

It is therefore understood here that each blade and therefore each cutting edge extends in a plane which includes the cutting axis and which is perpendicular to the plane of the support.

According to the present invention, the blades are arranged relative to each other to form, in orthogonal projection on the plane of the support, a star in which the cutting edges are directed opposite the cutting axis.

The cutting edges are therefore directed towards the cutting axis and are not oriented frontally with respect to the wooden log; that is, facing the log as it engages the cutting block. Here by front configuration is meant cutting edges which are substantially perpendicular to the cutting axis. This is because in a frontal cutting edge configuration, splitting logs into stakes is inefficient and causes a lot of loss as well as machine damage.

Thus, the orientation of the edges directed opposite the cutting axis makes it possible to split the wooden log longitudinally into a plurality of stakes, this in particular when the wooden log is engaged longitudinally in the cutting block along the axis. cutting. Advantageously, the support according to the present invention comprises a passage opening sized for the passage of the wooden log when the latter is engaged longitudinally in the cutting block along the cutting axis.

Such a passage opening serves as a guide for the passage of the logs through the cutting block.

Preferably, the passage opening is circular.

Preferably, the passage opening is centered on the support.

Advantageously, the cutting edges extend through a cylindrical volume orthogonal to the plane of the support.

Preferably, the cross section of this cylindrical volume is defined by the passage opening. It is understood here that this is a fictitious cylinder through which the blades extend. Such a cylinder has a cross section whose dimensions are greater than or equal to those of the passage opening. In other words, the orthogonal projection of the slats on the plane of the support covers the passage opening.

In a variant, each of the cutting edges extends parallel to the cutting axis. In another preferred variant, each of the cutting edges is inclined so as to converge towards the same point of convergence situated on the cutting axis.

By tilting the edges of the blades, it is understood here that the edges of the blades tighten from upstream to downstream with respect to the cutting direction. The inclination of the cutting edges of the blades forms a funnel that guides the logs along the cutting axis for proper splitting of the logs.

The blades, by this funnel shape, constitute an inverted splitting initiator giving the die a concave shape facilitating the guiding of the logs in the cutting block.

Thus, it will be understood that the cutting edges of the blades each extend in a radial plane relative to the support plane, the edges extending obliquely relative to the cutting axis to converge towards a same point of convergence.

Preferably, this point of convergence coincides with the center of the passage opening. Advantageously, at least one of the cutting edges is bevelled.

Preferably, the bevel of at least one of the cutting edges forms an angle of between 5 and 25 °; such an angle allows the log to be split correctly.

Advantageously, the blades each have a flat portion.

Preferably, the blades are each fixed to the support via these flat portions. For example, provision can be made for fixing the blades to the support by welding, crimping or the like.

In an advantageous embodiment of the present invention, considered in orthogonal projection in a plane orthogonal to the cutting axis, the distances between the adjacent blades are substantially equal to each other so as to form identical cutting sections.

It is thus understood that the blades are arranged between them so that the orthogonal projection of said blades in a plane orthogonal to the cutting axis forms identical cutting sections; more exactly, it is understood here that the blades divide the fictitious cylinder mentioned above into cutting sections of identical dimensions, this to obtain stakes of identical dimensions at the output of the cutting block.

Advantageously, the cutting block according to the present invention comprises four blades arranged so that the blades adjacent to each other extend in respective orthogonal directions to form four cutting sections at right angles.

Correspondingly, the object of the present invention relates, according to a second aspect, to a cutting installation for a wooden log. Advantageously, such an installation comprises a cutting block as described above and a wooden log conveyor arranged upstream of said cutting block.

Preferably, such a conveyor comprises conveying means configured to convey each log of wood towards the cutting block and engage each log of wood longitudinally in the cutting block along the cutting axis so as to split each log longitudinally. of wood in a plurality of stakes

Advantageously, the delivery means are hydraulic and include pressurized hydraulic fluid.

Advantageously, the conveying means comprise a push arm, one end of which, called the distal end, is configured to push said wooden log towards said cutting block along the cutting axis. Preferably, said distal end of said pusher arm has shaped grooves complementary to the shape of the blades of said blade block so that the grooves and the blades fit into each other. Such grooves allow automation of the production line by allowing the logs to be engaged in said block without human intervention.

According to a third aspect, the object of the present invention relates to a method for manufacturing stakes from at least one wooden log, said method implementing a cutting installation as described above.

In such a method according to the present invention, at least one wooden log is provided on the conveyor and the at least one wooden log is engaged in the cutting block by actuating the conveyor so that the latter engages the cutting block. 'at least one log of wood longitudinally in the cutting block along the cutting axis so as to split the at least one log longitudinally into a plurality of stakes.

The object of the present invention relates according to a fourth aspect to at least one stakes obtained by the implementation of a manufacturing process as described above.

According to a fifth aspect, the object of the present invention relates to a use of a cutting installation for a wooden log as described above for the manufacture of ganivelle.

Thus, by virtue of its various technical, functional and structural characteristics described above, the Applicant makes a cutting block available to manufacturers of ganivelles. innovative allowing efficient splitting of a log to obtain a plurality of stakes.

Brief description of the attached figures

Other characteristics and advantages of the present invention will emerge from the description below, with reference to the appended figures which illustrate two exemplary embodiments thereof without any limiting nature and on which:

[Fig- 1]

Figure 1 shows a schematic profile view of a cutting block according to a first embodiment of the present invention.

[Fig.2]

Figure 2 shows a schematic front view of a cutting block according to the embodiment of Figure 1.

[Fig.3]

Figure 3 shows a schematic profile view of a cutting block according to a second embodiment of the present invention.

[Fig.4]

Figure 4 shows a schematic front view of a cutting block according to the embodiment of Figure 3.

detailed description

A cutting block according to two exemplary embodiments of the present invention will now be described in what follows with reference jointly to FIGS. 1 to 4.

As mentioned in the preamble, manufacturers of ganivelles today use chestnut poles with a diameter of approximately six to twelve centimeters to make their ganivelles.

However, current techniques and the equipment used are suitable for splitting chestnut poles; the supply capacity for poles is low and cannot meet the demand for poles.

More exactly and as explained in the preamble to the description, the Applicant submits that the manufacturing techniques used for splitting chestnut poles are not suitable for chestnut logs, in particular for the following reasons: - the large diameter of the chestnut logs does not allow the splitting operation to be carried out with current splitting dies which are specifically adapted to chestnut poles;

- the hardness, the density of the core of the log and / or the knots present in the log cause blocking of the wood in the splitting die;

- the timber positioned in the mechanical splitter not being sufficiently maintained and although the split is initiated with the tip of the die in the center of the timber, when the ram is pushed, the splitting follows the threads of the timber; which produces conical stakes and very often of variable length, and therefore not compliant for the manufacture of ganivelles.

The Applicant has therefore developed an innovative and alternative technique for the manufacture of stakes and therefore of ganivelles.

The concept behind the present invention is the use of chestnut logs, not poles.

By chestnut log, we mean here a piece of chestnut with a diameter of four to eight centimeters obtained after milling a quarter of ridge (obtained by dividing the latter).

It should be noted here that the supply of chestnut logs is easy (unlike the supply of chestnut poles).

It will be understood here that, in the following description, the wood logs are chestnut logs. The use of chestnut is particularly appreciated here for the manufacture of ganivelles. However, this is just one example of a possible wood.

The Applicant has therefore developed, within the framework of the present invention, specific cutting equipment making it possible to split chestnut logs in order to obtain stakes, necessary for the manufacture of ganivelle.

In Figures 1 to 4, there is schematically shown a cutting block 100 according to two examples for a cutting installation (not shown here) of chestnut logs. Such an installation comprises a hydraulic conveyor (not shown here) in which circulates a hydraulic fluid causing the movement of the chestnut logs along a cutting axis A.

The installation according to the present invention further comprises a cutting block 100.

Such a cutting block 100 is characteristic of the present invention.

The latter will be described in more detail below.

In the two examples described here, the cutting block 100 is located downstream of the conveyor. It is therefore understood that the flow of hydraulic fluid constitutes conveying means for conveying the chestnut log (s) on the conveyor towards the cutting block 100. The hydraulic fluid flow thus has the function of guiding and bringing the logs. to chestnut along the cutting axis A through the cutting block 100 so that the logs are split longitudinally to form stakes; such stakes will then be used in the manufacture of ganivelles.

The cutting axis A corresponds in other words to a so-called feed axis corresponding to the axis in which the chestnut logs are brought to the cutting block 100. Here, it is understood that the elongated axis of the log is confused with the cutting axis since the chestnut log is engaged in the block along its entire length.

With the aid of Figures 1 to 4, two exemplary embodiments of a cutting block 100 in accordance with the present invention will now be described in more detail.

It will be noted first of all that such a cutting block 100 according to the present invention is made of an abrasion-resistant steel-type material such as, for example, "Hardox". The use of such a material is appreciated for its mechanical properties which make it a robust part capable of withstanding the various mechanical stresses (shear forces and others) exerted during the splitting of chestnut logs.

In each of the two examples described here, the cutting block 100 includes a support 10 and a plurality of blades 20.

A passage opening 11, through which the chestnut logs enter the cutting block 100, is provided on the support 10. The passage opening 11 is therefore dimensioned for the passage of the chestnut logs and allow the guidance of these. here through the support 10.

In the two examples described here, provision is also made for the passage opening 11 to be circular and centered on the support 10.

As can be seen in the figures, the support 10 extends in a plane P called the support plane which is perpendicular to the cutting axis A of the chestnut logs.

In the embodiment of Figures 1 and 2, the support 10 is a metal plate 12 having the passage opening 11.

In the embodiment of Figures 3 and 4, the support 10 is in the form of a frame 13 and a cylindrical part 14 open at the ends so as to form a splitting guide or ring.

Such a cylindrical part 14 comes in orthogonal projection on the plane P to be superimposed with the passage opening 11. Such a part 14 does not extend in the plane P. It is understood here that the plane P corresponds to the plane of the frame 13 and that the plane P 'is the plane in which the cylindrical part 14 extends, the plane P' being parallel to said plane P of the frame 13. More exactly, this cylindrical part 14 extends in the plane P 'which is located upstream of the plane P with respect to the direction of splitting. According to the invention, the cutting block 10 described in these two examples further comprises a plurality of blades 20.

The arrangement of these blades 20 has been the subject of numerous research tests to suit the splitting of chestnut logs.

Such blades 20 are characteristic of the present invention.

In the examples described here, provision is made for the use of substantially planar blades 20 having a thickness of about five millimeters.

These blades 20 each have a cutting edge 20a which is preferably bevelled and the bevel of which forms an angle of between 5 and 25 °. Such a bevel makes it possible to split the logs. In these two examples, the blades 20 are fixed to the support 10 while extending perpendicular to the support plane P. More exactly, the blades 20 are fixed to said support 10 by G intermediate their respective flat portions 20b. Fixing can be provided by welding or crimping, for example.

It will be noted that, in these two examples, the blades 20 are all identical and of the same dimensions.

In each of the examples described here and as illustrated in Figures 2 and 4, the blades 20 are arranged relative to each other to form, in orthogonal projection on the plane of the support P, a star in which the cutting edges 20a are directed in sight of the cutting axis A.

Preferably, it will be noted here that the conveyor comprises a push-arm (not shown here). Such a push arm has a distal end in contact with the wooden log. It is this arm which, by the hydraulic means, will engage said log in the cutting block. The distal end of such a push arm has a groove of a shape complementary to the shape of the blades of the block so as to allow the log to be engaged in said block along its entire length.

Such a star configuration with the cutting edges 20a converging towards the cutting axis A makes it possible to split the wood log longitudinally into a plurality of stakes when the wood log is engaged longitudinally in the cutting block 100 along the axis. cutting A.

In the examples described here, four blades 20 are provided, forming a four-pointed star. It is understood here that the branches of this star each extend in directions d1, d2, d3 and d4; more exactly, the adjacent blades extend respectively in directions d1, d2, d3 and d4 orthogonal to each other two by two and thus form four cutting sections at right angles.

Other configurations will be possible for those skilled in the art.

Considered in orthogonal projection in a plane orthogonal (for example the plane P of said support) to the cutting axis A, the distance between a first pair of adjacent blades is equal to the distance between a second pair of adjacent blades; this is true for each of the adjacent slats.

By adjacent blades is meant here immediately adjacent blades fixed to the support.

It is thus noted that, according to this particular arrangement of blades, the orthogonal projection of this arrangement of blades forms a cutting grid whose spacing between two adjacent blades is constant regardless of the two adjacent blades.

This arrangement thus makes it possible to properly split the chestnut logs by distributing the forces exerted evenly on the cutting surface and to obtain evenly shaped stakes.

It can also be seen that the orthogonal projection of the blades 20 on the support plane P covers the passage opening 11. In other words, it can also be considered that the blades 20 extend through a cylindrical volume. orthogonal to the support plane P, the cross section of which is greater than or equal to the passage opening 20.

The projection of the blades 20 in the plane of the support thus covers the passage opening 11 so as to define a cutting area corresponding to the effective cutting area of the cutting block 100.

In the example of FIGS. 1 and 2, each of the cutting edges 20a is inclined so as to converge towards the same point of convergence PC located on the cutting axis A, and more exactly in this example at the center of the opening of passage 11.

This configuration with cutting edges 20b which tighten from upstream to downstream forms a funnel favoring the initiation of splitting as the log engages the block.

In the examples of Figures 3 and 4, another configuration is provided in which each of the cutting edges 20a extends parallel to the cutting axis A.

Such a configuration is very resistant.

The cutting block 100 for chestnut logs developed within the framework of the present invention has thus made it possible to design cutting installations incorporating such a block and implementing a manufacturing process to produce stakes from chestnut logs.

Such a manufacturing process includes the following steps in particular: splitting and milling.

The first splitting step allows the chestnut logs to be split into several quarters using a power and pneumatic tool. Each quarter is thus composed of a rounded side (which corresponds to the outside of the block) and two split flat sides.

In the milling step, each quarter is then fed into a milling machine to obtain a round timber of constant diameter from the triangular quarters - called a log.

The logs thus obtained are then grooved on all four sides by means of circular saws in order to constitute a guide for splitting.

Depending on the quality of the raw material (logs and logs obtained during milling), this step is not mandatory and can be omitted.

Finally, the method provides for a second step of splitting the logs using the cutting block 100 as described above.

The present invention thus makes it possible:

- to cut the threads of the wood and the knots (unlike the previous process which follows the threads of the wood and blocks on the knots);

- prevent the log from escaping from one side or the other of a knife (unlike the previous process which follows the strands of the wood and therefore allows the log to shift); and therefore to obtain stakes.

The stakes thus obtained are more or less identical in appearance and shape, in particular with a rounded face (result of milling) and two flat faces (result of splitting).

Thanks to the present invention, it becomes possible to obtain stakes from chestnut logs and thus manufacture ganivelles by assembling said stakes together, which will make it possible to meet current consumer demand.

Notably, the Applicant observes that the present invention by implementing the steps of the above method and the use of the cutting block according to the invention makes it possible to obtain stakes from chestnut logs; it therefore becomes possible to obtain such stakes from sections of wood other than heartwoods. This had never been possible to obtain until now and finally makes it possible to satisfy the demand for posts for the manufacture of ganivelles. It should be noted that this detailed description relates to several particular exemplary embodiments of the present invention, but that in no case does this description have any character limiting the subject of the invention; on the contrary, its objective is to remove any possible imprecision or any misinterpretation of the following claims.

Claims

1. Cutting block (100) for wooden logs comprising:

- a support (10) extending in a plane (P), called the support plane, substantially perpendicular to a cutting axis (A) of said wooden log; and

- a plurality of substantially flat blades (20) fixed to the support (10) and extending perpendicular to the plane of said support (P), each of said blades (20) comprising a cutting edge (20a), said cutting block (100) being characterized in that the blades (20) are arranged relative to each other to form, in orthogonal projection on the plane of said support (P), a star in which the cutting edges (20a) are directed opposite said axis of cutting (A) so as to longitudinally split said wooden log into a plurality of stakes when said wooden log is engaged longitudinally in said cutting block (100) according to the cutting rate (A).

2. Cutting block (100) according to claim 1, wherein said support (10) comprises a passage opening (11) dimensioned for the passage of said log of wood when the latter is engaged longitudinally in said cutting block (100). ) according to Cutting tax (A).

3. Cutting block (100) according to claim 2, wherein the passage opening (11) is circular.

4. Cutting block (100) according to claim 2 or 3, wherein the passage opening (11) is centered on the support (10).

5. Cutting block (100) according to any one of claims 2 to 4, wherein the cutting edges (20a) extend through a cylindrical volume orthogonal to the plane of said support (P) whose cross section is defined by the passage opening (11).

6. Cutting block (100) according to any one of claims 2 to 5, wherein each of the cutting edges (20a) extends parallel to said cutting axis (A).

7. Cutting block (100) according to any one of claims 2 to 5, wherein each of the cutting edges (20a) is inclined so as to converge towards a same point of convergence (PC) located on said cutting axis (A). .

8. Cutting block (100) according to claim 7, wherein said point of convergence (PC) coincides with the center of the passage opening (11).

9. Cutting block (100) according to any one of the preceding claims, wherein at least one of the cutting edges (20a) is bevelled, preferably the bevel of at least one of the cutting edges (20a) forms an angle. between 5 and 25 °.

10. Cutting block (100) according to any one of the preceding claims, wherein said blades (20) each have a planar portion (20b), said blades (20) each being fixed to said support (10) via of said flat portions (20b).

11. Cutting block (100) according to any one of the preceding claims, in which, considered in orthogonal projection in a plane orthogonal to the cutting axis (A), the distances between the adjacent blades (20) are substantially equal. between them so as to form identical cutting sections.

12. A cutting block (100) according to claim 11, which comprises four blades (20) arranged so that the blades adjacent to each other extend in respective orthogonal directions (d1, d2, d3, d4) to form four right angle cutting sections.

13. A wood log cutting installation comprising: - a cutting block (100) according to any one of the preceding claims; and

- a log conveyor arranged upstream of said cutting block (100) and comprising conveying means configured to convey said wooden log in the direction of said cutting block (100) and engage said wooden log longitudinally in said block cutting (100) along the cutting axis (A) so as to longitudinally split said wooden log into a plurality of stakes.

14. Installation according to claim 13, wherein the conveying means are hydraulic and comprise a pressurized hydraulic fluid.

15. A method of manufacturing stakes from at least one log of wood, said method implementing a cutting installation according to claim 13 or 14, wherein at least one log of wood is provided on said conveyor and it is engages said at least one wooden log in the cutting block (100) by actuating said conveyor so that the latter engages said at least one wooden log longitudinally in said cutting block (100) along the cutting axis (A) so as to longitudinally split said at least one wooden log into a plurality of stakes.