Method for determining a machining profile of a stave and associated machining machine

Abstract

The present invention relates to a method for determining a machining profile (12a, 12b) of a stave from a wooden blade (1). To this end, computer means obtain a first data item representative of a wooden blade profile (10a, 10b) and determine a second data item representative of said machining profile (12a, 12b) as a function of said first data item, said machining profile (12a, 12b) being inscribed in said wooden blade profile (10a, 10b) and having a width evolving along said stave. Said machining profile (12a, 12b) has a non-rectilinear shaped average fiber (12c) over the width of said stave, so that said machining profile (12a, 12b) follows said wood blade profile (10a, 10b), maximizes the stave width and minimizes material losses between said wood blade (1) and said stave. Figure for abstract: Figure 2

Description

Title of the invention: Method for determining a machining profile of a stave and associated machining machine Technical field

[0001] The present invention relates to the machining of staves for the manufacture of staves, which are used for the manufacture of barrels or casks, as well as vats.

[0002] The present invention relates more particularly to a method for determining a machining profile of the lateral edges of a stave making it possible to minimize the losses of material associated with the machining, as well as a machining machine implementing such a method, in particular a machining machine equipped with associated machining means. The present invention also relates to a stave whose machining profile of its lateral edges makes it possible to minimize the losses of material associated with the machining, called a curved stave, as well as a method for manufacturing barrels from a curved stave.

[0003] The present invention will thus find numerous advantageous applications in the field of woodworking and cooperage. State of the art

[0004] The shell of a barrel or cask is made from staves, for example of the order of thirty staves, and metal hoops of different diameters. The staves are arranged next to each other in a joined manner inside an end metal hoop on a first side, which makes it possible to form a cone. Then one or two intermediate metal hoops of increasing diameters are inserted by force around the staves on this first side, which makes it possible to constitute a stable structure. After bending the flared part of the cone by adding water and heat, and obtaining the shape of the barrel or cask by means of a cable or jaws making it possible to make the staves joined also on the second side, metal hoops are also driven around the staves on this second side, which makes it possible to definitively constitute the shell of said barrel.Two bottoms then close the hull of the barrel at its two peripheral end edges.

[0005] In France, staves are made by machining pieces of wood called staves. Staves are boards obtained by splitting oak logs along the direction of the fibers and medullary rays, in order to ensure watertightness and mechanical resistance. This type of oak wood is of first quality and, therefore, of high cost.

[0006] The staves have a general shape that is substantially parallelepiped or even trapezoidal of known length, but of variable width because they are cut annually depending on the dimensions of the oak trunk quarters and the defects present in the wood. These staves may have curvatures and warping.

[0007] In the United States, stave machining is carried out from sawn timber. Oak logs are successively sawn into quarters, then into a plurality of wooden strips. In particular, this sawing does not follow the grain of the wood. When the wood dries before machining, the numerous cut grains result in a pronounced and frequent curvature of the wooden strips. Such drying also results in curvatures, although less pronounced, for staves manufactured according to French methods.

[0008] The wooden strips or staves (hereinafter referred to as "wooden strips") are then machined on their six faces in several stages in order to obtain staves. A first stage consists of cutting the wooden strip to length by double sawing at its two longitudinal extreme edges, which allows the wooden strip to have a defined length, while its width is variable. A second stage consists of a dolage operation according to which the wooden strip is machined rounded, with a convex shape, on its outer face used to constitute the outer wall of the shell of the barrel or cask. A third stage consists of a joining operation according to which the wooden strip is machined with an oblong profile in the direction of its length and with an inclined profile in the direction of its width, on its two lateral edges which will be in contact with the neighboring staves during the constitution of the shell.A fourth step consists of a hollowing operation in which the wooden blade is machined hollow over all or part of its length and with a concave shape, on its inner face constituting the inner wall of the shell of the barrel or cask.

[0009] For the manufacture of barrels or casks, the oblong shape obtained during the joining operation is characterized by three zones, namely: two "heads" corresponding to the two longitudinal end parts of the stave and a "bow" corresponding to the most swollen central part of the stave.

[0010] For the manufacture of tanks from staves, in particular truncated cone-shaped tanks, the oblong shape has a foot, having a maximum width, at a first longitudinal end, and a head, having a minimum width, at a second opposite longitudinal end. In addition, truncated cone-shaped tanks generally correspond to containers of large dimensions, for example having a capacity of 10 to 50 hectoliters. The manufacture of truncated cone-shaped tanks thus requires very long wooden blades, on which any curvature will have a very significant impact.

[0011] According to the state of the art, the joining operation can be obtained on different kinds of machines. Some machines are mechanical; the oblong profiles are obtained by controlling machining spindles by means of a cam. Other machines are digital; the oblong profiles are obtained by controlling machining spindles using a PLC or a computer.

[0012] The material yield requirements, due to the cost of the top quality oak used, oblige coopers to take particular care to minimize the quantity of wood consumed by machining each side edge of the wooden blade, so as to use the minimum number of staves for the manufacture of the barrel, cask or vat.

[0013] Document FR3023742B1 thus seeks to reduce the amount of material chipped as much as possible when machining the side edges by proposing a more precise measurement of the side edges of the stave. Such a solution thus makes it possible to avoid measurement errors and to better take into account variations in the width and geometry of the stave.

[0014] The Applicant submits, however, that this solution only makes it possible to obtain a better visualization of the shape of the stave, without any real improvement in the cutting itself.

[0015] In particular, and as stated above, the wooden slats have variable shapes and widths resulting from their manual cutting or sawing, as well as from drying before machining, and are in particular likely to have curvatures or warping. The production of the stave, in particular the jointing, consists solely of obtaining a stave shape that fits into the profile of the wooden slat. Thus, if the wooden slat has a shape that is very different from the desired oblong profile of the stave, the machining of the stave results in significant material losses. The Applicant thus estimates at 20% the quantity of material loss resulting from the manufacture of staves from wooden slats having an edge deflection (also called in English "crook"), that is to say a curvature making the lateral edges concave or convex.Furthermore, some wooden slats with too much curvature are considered completely unusable for the manufacture of staves.

[0016] It is also known to carry out an operation prior to machining the wooden blade, in which the latter is "straightened" in order to correct its curvature, in particular by compressing the wooden blade into a straight shape allowing ideal machining. Such an operation is however very energy-intensive and is not implemented in practice.

[0017] The Applicant therefore submits that there is currently no satisfactory alternative solution for obtaining staves from wooden slats while minimizing the quantity of raw wood to be removed. Summary of the invention

[0018] The present invention aims to improve the current situation described above.

[0019] The present invention aims more particularly to remedy the above drawbacks- above by proposing a stave machining solution from a wooden blade which determines, depending on the wooden blade, the stave profile requiring the least loss of material.

[0020] It is understood here, as stated above, that the wooden blade corresponds to a piece of wood intended to be machined for the manufacture of a barrel, a cask or a vat. The wooden blade is for example obtained by the methods of manufacturing staves or from quarter-sawn wood, as described in the prior art, or any other means known to those skilled in the art.

[0021] To this end, the subject of the present invention relates in a first aspect to a method for determining a machining profile of a stave from a wooden blade, the method being implemented by at least one processor, the method comprising the following steps: - obtaining initial data representative of a wooden blade profile; - determination of a second data item representative of the machining profile as a function of the first data item, the machining profile being part of the wooden blade profile and having a width varying along the stave.

[0022] It is understood here that the first data item is for example received from measuring means integrated into or in communication with the processor, or from computer means in communication with the processor, for example having determined the first data item after processing measurements carried out on the wooden blade.

[0023] It is considered here and throughout the following description that the notions of length, width and thickness of the wooden blade and the stave will be understood so that, taking as a reference a barrel assembled from staves, the length of the stave corresponds to its largest dimension and extends along the height of the barrel, the thickness of the stave corresponds to its smallest dimension and extends along the thickness of the barrel and the width of the stave corresponds to its intermediate dimension and extends along the circumference of the barrel. Thus, the length and width define the faces (also called "flat") of the stave, the length and thickness define the ends of the stave, and the width and thickness define the (lateral) edges of the stave. Such reasoning applies similarly when taking as a reference a truncated cone-shaped tank assembled from staves.

[0024] It is also understood that the machining profile corresponds to the profile used during the joining operation as described above, that is to say the machining of the lateral edges of the stave, in particular so as to define the contour of the face of the stave.

[0025] As described above and known in the prior art, the machining profile is determined, for a stave suitable for the manufacture of barrels, so that the stave has a "saddle" corresponding to a central part, in its longitudinal direction, and whose width is maximum, as well as two "heads" corresponding to the longitudinal ends of the stave, and whose width is minimum. The width of the heads is for example equal. The machining profile is also determined so that the width of the stave decreases between the saddle and the heads, for example with a faster decrease in width as one moves away from the saddle.

[0026] In a second case corresponding to a stave suitable for the manufacture of truncated cone-shaped tanks, the machining profile is determined so that the stave has a "foot" corresponding to a first longitudinal end of the stave, the width of which is maximum, and a "head" corresponding to a second longitudinal end of the stave, the width of which is minimum. The machining profile is also determined so that the width of the stave decreases between the foot and the head, for example with a more rapid decrease in width as one moves away from the foot.

[0027] The machining profile therefore corresponds to a machining profile of the lateral edges of the stave. Similarly, the first data is representative in particular of the lateral edges of the wooden blade profile.

[0028] Advantageously, the machining profile has a non-rectilinear shaped average fiber across the width of the stave, so that the machining profile follows the wood blade profile, maximizes the stave width and minimizes material losses between the wood blade and the stave.

[0029] By average fiber in the sense of the present invention, is meant here the intermediate fiber of the stave along its width, that is to say a line following the length of the stave and arranged equidistant from the lateral edges of the stave. In a stave of the prior art, called a “straight stave”, such an average fiber is rectilinear forming an axis of symmetry of the lateral edges, which have a simple oblong shape.

[0030] The machining profile is therefore no longer constrained by a rectilinear shape of average fiber, allowing it to be adapted more precisely to the profile of the wooden blade, in particular so as to follow the curvature of the wooden blade. The machining profile therefore becomes mainly constrained by the inscription, along the stave, of the width of the stave in the width of the wooden blade.

[0031] It is also understood that the method according to the invention does not aim to provide a stave of specific final shape, but on the contrary a stave whose profile of the lateral edges adapts more precisely to the profile of the lateral edges of the wooden blade. The machining profile shares for example a width with the profile of the wooden blade, corresponding to the longitudinal portion of the wooden blade for which it is not necessary to carry out cutting - sufficient surface planing - to obtain the desired width change along the stave. In other words terms, the ideal machining profile only reduces the width of the wooden strip along its profile, by being constrained in a longitudinal portion, for which no reduction in width is necessary. The person skilled in the art also understands that the machining of the side edges is determined so that the side edges are inclined according to the thickness of the stave, in other words that the profile of an "outer" face of the stave has a greater width than the "inner" face, thus reflecting the evolution of the perimeter of a barrel between its outer and inner faces. In practice, the machining of the side edges of the wooden strip is therefore carried out along its entire length.

[0032] Thanks to the present invention, material losses are limited by providing a machining profile whose lateral edges are closer to the profile of the lateral edges of the wooden strip. Obviously, the material losses associated with each wooden strip depend on its specific profile, and are not fixed from one wooden strip to another. Thus, if the present invention achieves results similar to the prior art with respect to wooden strips having little or no curvature, the Applicant submits that the present invention allows a material saving of between 5 and 10% compared to the prior art on the machining of curved wooden strips, and allows the machining into staves of previously unusable wooden strips via the techniques known from the prior art (theoretically corresponding to a material saving of 100% compared to a fully discarded wooden strip).

[0033] The Applicant further submits that a stave obtained by the method according to the invention, that is to say a curved stave as described below, can be used in a method for manufacturing barrels, casks or vats, without loss of material or additional expenditure of energy.

[0034] In particular, the bending operations described above with regard to the manufacture of barrels from staves, and also implemented during the manufacture of truncated cone-shaped tanks from staves, naturally result in a "straightening" of a curved stave when it is juxtaposed with other straight staves. On the contrary, when a set of curved staves are used for the manufacture of the same barrel, cask or tank, their curvature is maintained during the bending operation, resulting in a "twisted" barrel, without impacting the sealing or the mechanical resistance of the barrel, cask or tank obtained. Thus, the method according to the present invention makes it possible to obtain a curved stave directly usable in the processes for manufacturing barrels, casks or tanks, without necessary adaptation, and by minimizing material losses.

[0035] In an advantageous embodiment of the invention, obtaining comprises a step of receiving dimensional information associated with a plurality of points of the wooden blade profile.

[0036] The dimensional information is for example received from measuring means in communication with the processor. The measuring means correspond for example to a plurality of rollers arranged along the wooden blade, on each side thereof, for example three sets of rollers respectively associated with the shank and the heads of the wooden blade, or to any other section near the heads of the wooden blade. Obviously, it is also possible to design measuring means allowing the determination of a greater number of points of the wooden blade profile.For example, two rollers may be provided, arranged respectively on the lateral sides of the wooden blade and moving along its entire length to measure the width of the wooden blade, or two rollers arranged respectively on the lateral sides of the wooden blade and measuring the width of the wooden blade during the advancement of the wooden blade, placed between the two rollers, along its entire length. Any optical profilometry system, by probing or otherwise, known to those skilled in the art, may also be provided.

[0037] The dimensional information corresponds for example to a measurement of the width of the wooden strip at several points arranged along the length of the wooden strip. According to another example, the dimensional information corresponds to a measurement of the position of a set of points arranged along the lateral edges of the wooden strip. The profile of the wooden strip can be determined from such a set of points for example by interpolation.

[0038] It is further understood that the dimensional information is mainly associated with a measurement of the width, or at least of an arrangement of the points of the wooden strip along a transverse axis of the wooden strip. In particular, as described above, the length of the wooden strips is generally known in advance and does not require additional measurement.

[0039] Preferably, obtaining further comprises a step of modeling the wooden blade profile as a function of the dimensional information.

[0040] The modeling of the wood blade profile corresponds for example to an interpolation, in particular a circular interpolation or a polynomial interpolation, from the set of measured points of the wood blade.

[0041] In one embodiment, the wood blade profile and / or the machining profile are modeled by circular interpolation.

[0042] In an additional embodiment, the wood blade profile and / or the machining profile are modeled by using polynomial equations of degree greater than or equal to 2.

[0043] For example, both the wood blade profile and the machining profile are modeled in a similar manner to facilitate the determination of the machining profile. Polynomial equations and / or circular interpolation may be used to model the side edges of the wood blade, the machining profile, as well as model the average fiber.

[0044] Similarly, the average fiber can also be modeled by circular interpolation and / or according to a polynomial equation of degree greater than or equal to 2.

[0045] A person skilled in the art understands that circular interpolation is commonly used in interpolation machining techniques. Modeling the machining profile, in particular by circular interpolation, thus allows its direct use in the context of numerically controlled machining, for example by adjusting milling of the lateral edges of the wooden blade.

[0046] The Applicant further submits that the use of polynomial equations of degree equal to 2 corresponds, for solutions implementing a polynomial equation, to the simplest solution for modeling a profile of a wooden blade and / or machining having a curved shape, and therefore taking into account the curvature of the wooden blade, without presenting oscillations. The use of polynomial equations of higher degree is however also conceivable, depending on the quantity of information available for modeling, possibly allowing more precise modeling of the real shape of the wooden blade and consequently obtaining a more optimized stave profile resulting in reduced material loss.

[0047] It is further understood that the use of minimum second-degree polynomials is essential to achieve stave shapes exhibiting the desired width evolution.

[0048] In an additional embodiment, the method further comprises receiving a third datum representative of a stave shape objective, the second datum being further determined based on the third datum.

[0049] Preferably, the third data item comprises information representative of a ratio between two widths of the stave, the second data item being further determined as a function of the ratio.

[0050] In accordance with the above description, the ratio corresponds, according to a first example, to a ratio between a width of the stave and a width at the ends of the stave. According to a second example, the ratio corresponds to a ratio between a foot width and a head width of the stave.

[0051] It is understood here that, if each stave necessarily has a width of the bilge greater than the width of the heads, or a width of the foot greater than the width of the head, the ratio between these widths can be more or less important, impacting the final curvature of the barrel or the tank. This ratio is, likewise, also impacted by the length of the stave. Thus, like the length of the stave, the ratio corresponds to a parameter allowing the determination of the stave profile, which is likely to change according to subsequent objectives on the shape of the barrel or the tank, that is to say that the stave profile depends on the desired shape of the barrel, of the barrel or vat. Each barrel, barrel or vat is, for example, associated with a specific ratio, corresponding to its own curvature.

[0052] In other words, each barrel, cask or vat has physical characteristics, the third data item comprising information representative of physical characteristics necessary for the stave to be used in the manufacture of a given barrel, cask or vat. The third data item also comprises, for example, information representative of the shape of the stave, making it possible to determine whether the stave profile corresponds to that of a barrel stave, having a shank and two heads, or to that of a truncated cone-shaped vat stave, having a foot and a head.

[0053] In yet another embodiment, the method further comprises a step of transmitting the second data item to machining means.

[0054] It is understood here that the method is designed so as to generate an electronic signal capable of controlling machining means, or capable of being interpreted by means for controlling the machining means.

[0055] In another embodiment, the method further comprises a step of machining the wooden blade for the manufacture of the stave according to the second data, via machining means.

[0056] It is understood here that the method according to the invention corresponds to a broader method of manufacturing staves, which comprises steps of determining the profile of the lateral edges of the stave before its machining. The method comprises, for example, other operations of machining the wooden blade, in particular so as to reproduce all of the steps known to those skilled in the art and described with regard to the prior art, in which the joining operation is carried out as a function of the second data.

[0057] According to a second aspect, the present invention relates to a computer program comprising instructions for implementing the method according to the first aspect of the present invention, when these instructions are executed by a processor.

[0058] According to a third aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the method according to the first aspect of the invention.

[0059] On the one hand, the recording medium may be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM memory, a CD-ROM or a microelectronic circuit type ROM memory, or even a magnetic recording means or a hard disk.

[0060] Furthermore, this recording medium may also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or hertzian radio or by self-directed laser beam or by other means. The computer program according to the present invention may in particular be downloaded from an Internet-type network.

[0061] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to perform or to be used in performing the method in question.

[0062] According to a fourth aspect, the present invention relates to a machine for machining a wooden blade for the manufacture of a stave. Furthermore, the machine comprises computer means configured for implementing the method according to the first aspect of the present invention, as well as machining means controlled by the computer means.

[0063] It is understood here that the computer means are configured to communicate with or control the machining means, and that the machine is configured to machine a wooden blade for the manufacture of a stave according to the second data via the machining means.

[0064] The computing means comprise for example a beacon unit configured to obtain a first data item representative of a wooden blade profile, and a processing unit configured to determine a second data item representative of the machining profile as a function of the first data item.

[0065] Obviously, the machining machine can comprise a plurality of other elements known to those skilled in the art for the manufacture of staves, making it possible to carry out a plurality, or even all, of the steps of machining wooden slats for the manufacture of staves.

[0066] According to a fifth aspect, the present invention relates to a stave for manufacturing barrels, the stave having a stave profile defining a non-rectilinear shaped average fiber in the width direction of the stave.

[0067] It is understood here that the stave has a stave profile which is preferably determined by the method according to the first aspect of the present invention. The stave is for example obtained by carrying out the method according to the first aspect of the present invention and / or by the machining machine according to the fourth aspect of the present invention.

[0068] According to a sixth aspect, the present invention relates to a method of manufacturing a barrel or vat from a plurality of staves, in which the plurality of staves comprises at least one stave having a stave profile defining a mean fiber of non-rectilinear shape in the direction of the width of the stave, called a curved stave.

[0069] It is understood here that the method of manufacturing a barrel or vat corresponds to a method known to those skilled in the art, for example the method as described with regard to the prior art or any other method known from the state of the art, the method of manufacturing a barrel or vat being implemented from a set of staves including at least one curved stave. As stated above, depending on the number of curved staves and straight staves used for the manufacture of the barrel or vat, the bending operation results alternately in a straightening of the curved stave(s), causing them to adopt the shape of a straight stave and resulting in a barrel or vat with an appearance indistinguishable from those of the prior art, or in the adoption of a more or less pronounced curve on all the staves, resulting in a barrel or vat with a "twisted" appearance but having the same physical properties as those of the prior art.

[0070] Thus, by the various functional and structural technical characteristics above, the Applicant proposes a method for determining a stave machining profile and a machining machine allowing increased efficiency by adapting the machining to the shape of the wooden blade used, resulting in a curved stave, which can be used without difficulty in conventional barrel manufacturing processes. Brief description of the figures

[0071] Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting exemplary embodiments of the present invention below, with reference to the appended figures 1 to 10 and in which:

[0072] [Fig.l]

[0073] [Fig.l] schematically illustrates a machining profile of a straight stave from a first wooden blade, according to the prior art;

[0074] [Fig.2]

[0075] [Fig.2] schematically illustrates a machining profile of a curved stave from a first wooden blade conforming to [Fig.l], according to an exemplary embodiment;

[0076] [Fig.3]

[0077] [Fig.3] illustrates a modeling of a machining profile of a straight stave from a second wooden blade, according to the prior art;

[0078] [Fig.4]

[0079] [Fig.4] illustrates a modeling of a machining profile of a curved stave from a second wooden blade conforming to [Fig.3], according to an exemplary embodiment;

[0080] [Fig.5]

[0081] [Fig.5] illustrates a modeling of a machining profile of a straight stave from a third wooden blade, according to the prior art;

[0082] [Fig.6]

[0083] [Fig.6] illustrates a modeling of a machining profile of a curved stave from a third wooden blade conforming to [Fig.5], according to an exemplary embodiment;

[0084] [Fig.7]

[0085] [Fig.7] illustrates a modeling of a machining profile of a straight stave from a fourth wooden blade, according to the prior art;

[0086] [Fig. 8]

[0087] [Fig.8] illustrates a modeling of a machining profile of a curved stave from a fourth wooden blade conforming to [Fig.7], according to an exemplary embodiment;

[0088] [Fig.9]

[0089] [Fig.9] schematically illustrates a device configured to determine a machining profile of a stave from a wooden blade, according to a particular and non-limiting exemplary embodiment of the present invention;

[0090] [Fig. 10]

[0091] [Fig. 10] illustrates a flowchart of the different steps of a method for determining a machining profile of a stave from a wooden blade, according to a particular and non-limiting exemplary embodiment of the present invention. Detailed description

[0092] A method for determining a machining profile of the lateral edges of a stave, a machine for machining wooden slats for obtaining staves, and a method for manufacturing a barrel will now be described in what follows with joint reference to Figures 1 to 10. The same elements are identified with the same reference signs throughout the description which follows.

[0093] As indicated in the preamble to the description, current solutions for manufacturing staves from wooden slats result in significant material losses, particularly when the wooden slat has curves.

[0094] One of the objectives of the present invention is to propose a new machining profile for the side edges of a stave, suitable for the manufacture of barrels, casks, vats or other, and the manufacture of which limits material losses. In the remainder of the description, when not specified, the term profile refers to the shape of the side edges, whether for the wooden blade or for the stave.

[0095] This is made possible in the examples described below, which consider the machining of the side edges of a stave from a plurality of blade shapes. of wood, during the jointing operation corresponding to the machining of the side edges of the wooden blade.

[0096] It will be understood that these examples are not limiting and that the method according to the invention can be adapted to any form of wooden blade. The method according to the invention can also be integrated within a broader method for manufacturing staves, incorporating other steps known to those skilled in the art, in particular sawing, smoothing and hollowing out steps.

[0097] According to the example of Figures 1, 3, 5 and 7, the operation of joining a wooden blade 1, 1', 1”, 1'” having a wooden blade profile 10a, 10b comprises the machining of an oblong profile 11a, 11b falling within the wooden blade profile 10a, 10b, that is to say the machining of the lateral edges of the wooden blade so as to form two curved symmetrical edges, the width of which decreases between the jamb and the heads, the symmetry of the oblong profiles 11a, 11b being defined with respect to a rectilinear average fiber 11e. This joining operation results in the formation of so-called straight staves, which have a rectilinear average fiber 11e.

[0098] This machining of the side edges naturally results in a loss of material, which is all the more pronounced when the wooden strip 1, 1', 1”, 1”' has a shape that is notably different from a straight stave. In particular, the wooden strip 1, 1', 1”, 1”' may have a more or less pronounced curvature, resulting from its manual cutting, and the inclusion of a straight stave in a curved profile involves significant losses of material.

[0099] Thus, according to the example of [Fig.l] associated with a stave for the manufacture of barrels, the wooden blade 1 is aligned along the longitudinal axis X forming an axis of symmetry of the stave to be machined, and the oblong profile 11a, 11b is defined with respect to the longitudinal axis X with a first lateral edge 11a having a lateral distance to the jamb Al and a lateral distance to the heads al, as well as a second lateral edge 11b having a lateral distance to the jamb B1 and a lateral distance to the heads bl, so that al = bl, Al = Bl, al < Al, bl < Bl and al+bl < Al+Bl. It is further understood that, in the context of a stave for the manufacture of truncated cone-shaped vats, the same set of constraints is obtained between the lateral distances at the foot (replacing the lateral distances to the jamb) and the lateral distances at the head.

[0100] In order to propose a solution to this problem, a method is provided for determining a machining profile of a stave, for example method 3 of [Fig.10]. Method 3 is for example implemented by a machine for machining a wooden blade for the manufacture of staves, the machining machine comprising computer means configured for the implementation of method 3.

[0101] As illustrated in [Fig.9], such computing means are for example advantageously grouped in an electronic device 2, for example a cal culator (hereinafter referred to as "computer"). The computer 2 is for example configured to transmit and receive data within a communication network. The elements of the computer 2, individually or in combination, can be integrated in a single integrated circuit, in several integrated circuits, and / or in discrete components. The computer 2 can be implemented in the form of electronic circuits and software modules.

[0102] The computer 2 comprises one (or more) processor(s) configured to execute instructions for carrying out the steps of the method and / or for executing the instructions of the software(s) embedded in the computer 2. The processor may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. The computer 2 further comprises at least one memory 20 corresponding for example to a volatile and / or non-volatile memory and / or comprises a memory storage device which may comprise volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SREAM, flash, magnetic or optical disk.

[0103] The computer code of the embedded software(s) comprising the instructions to be loaded and executed by the processor is for example stored in the memory 20 of the computer 2.

[0104] According to an alternative embodiment, the calculator 2 is configured for the implementation of a method for determining a machining profile of a stave from a wooden blade forming part of a broader method.

[0105] The method according to the invention is part of, for example, a method of communication with means for machining the stave. The method is for example implemented by an electronic device separate from a machining machine and configured to communicate with the machining machine. According to another example, the method according to the invention is part of a method for machining a stave from a wooden blade, in which the data determined during the method according to the invention, in particular the second data item described below, are used as input data for machining the stave.

[0106] In a first operation 31, the calculator 2 obtains a first data item representative of a profile of a wooden blade 10a, 10b. In other words, the first data item makes it possible to characterize the lateral edges of the wooden blade 1, 1', 1”, 1'”.

[0107] The first operation 31 comprises for example a reception of dimensional information associated with a plurality of points of the wooden blade profile 10a, 10b, that is to say a parameter, for example a position along a lateral axis, associated with a plurality of measurement points. This plurality of points of the wooden blade profile 10a, 10b will for example be calculated by means of a measuring device described in patent FR3023742B1.

[0108] According to the example of figures 1 and 2, the wooden blade 1 is arranged opposite a machining machine via a cleat 14 and aligned so as to extend along a longitudinal axis X. The longitudinal extreme edges 13 of the wooden blade 1 are commonly already sawn so that the wooden blade 1 extends along a predefined length, in particular when it is cut to length by double sawing as known from the prior art.

[0109] The dimensional information is then received from measuring means MGO, MDO, MG1, MD1, MG2, MD2, MG3, MD3, MG4, MD4 (or MG, MD as a whole), associated with the lateral edges of the wooden strip and arranged in a plurality of longitudinal positions X0, XI, X2, X3, X4. The measuring means here form five sets arranged in five longitudinal positions. Due to the difficulty of measurement at the extreme longitudinal positions X0 and X4, a variant is also provided comprising three sets MG1, MD1, MG2, MD2, MG3, MD3, comprising for example rollers in contact with the wooden strip 1 associated with means for measuring the position of the rollers. Obviously, it is understood that it is possible to design a plurality of measuring means.It remains advantageous to have a first set of measuring means MG2, MD2 at the level of the X2 shank of the wooden blade, that is to say commonly at mid-length of the wooden blade, and a second set of measuring means MG1, MD1, MG3, MD3 near the heads of the wooden blade 1, that is to say as close as possible to the extreme longitudinal positions X0, X4 of the wooden blade 1.

[0110] According to the example of [Fig.9], the dimensional information is received by a beacon unit 21 of the computer 2, for example a beacon unit 21 in communication with the measuring means MG, MD. The computer 2 is for example in wired or wireless communication with the measuring means MG, MD.

[0111] After receiving the dimensional information, the computer 2 thus determines the profile of the wooden blade 10a, 10b. The profile of the wooden blade 10a, 10b is for example determined by a processing unit 22 integrated into the computer 2, the processing unit 22 corresponding for example to an integrated processor.

[0112] Optionally, the computer 2, for example the processing unit 22, performs a modeling of the wood strip profile 10a, 10b as a function of the dimensional information. In particular, the wood strip profile 10a, 10b is advantageously modeled by the use of polynomial equations, that is to say that each lateral edge of the wood strip profile 10a, 10b is represented by a polynomial equation. According to another example, the wood strip profile 10a, 10b is modeled by circular interpolation, that is to say that each lateral edge of the wood strip profile 10a, 10b is modeled as the curvature of a circle with a given center and radius. Figures 3 to 8 thus illustrate a plurality of wood strips 1', 1”, 1”' whose curvature is modeled via a pair of polynomial equations or by circular interpolation. The calculator 2 performs for example a polynomial or circular interpolation from the plurality of points characterized above. It is understood here that, to adequately represent the curvature of the wooden blade 1, 1', 1”, 1”', it is necessary to measure the position of at least three points of each lateral edge, so as to obtain polynomials of degree greater than or equal to 2.

[0113] According to another variant, the beacon unit 21 directly receives the first data item comprising information representative of a profile of a wooden blade 10a, 10b, for example by communication with measuring means integrating calculation means configured to determine the profile of the wooden blade 10a, 10b.

[0114] It would be possible to provide another variant providing for a relative movement between a set of two rollers each arranged on a lateral edge of the wooden strip and said wooden strip, so that the set of rollers moves relatively over the length of the wooden strip, thus making it possible to calculate the exact coordinates of the positions of the lateral edges of the wooden strip over its entire length, said coordinates being transmitted to the computer 2 which thus directly has the wooden strip profile 10a, 10b, constituting the first data item.

[0115] In a second operation 32, the computer 2, for example the processing unit 22, determines a second data item representative of a machining profile 12a, 12b as a function of the first data item.

[0116] The determination of the second data therefore corresponds to the establishment of a machining profile 12a, 12b falling within the wooden blade profile 10a, 10b, the machining profile 12a, 12b making it possible to obtain a stave. In the example of Figures 1 to 8, the machining of a stave is provided for the manufacture of barrels. In such an example, the machining profile 12a, 12b requires having a decreasing width between the shank X2 and the longitudinal ends X0, X4, so as to allow the subsequent bending of the stave resulting in a barrel that is wider at mid-height than at the ends. According to another example of machining a stave for the manufacture of truncated cone-shaped tanks, the machining profile 12a, 12b requires having a decreasing width between a first longitudinal end X0 (corresponding to the “foot”) and a second longitudinal end X4 (corresponding to the “head”).

[0117] Obviously, other parameters known to those skilled in the art can also influence the determination of the machining profile. Optionally, the computer 2, for example the beacon unit 21, receives a third data item representative of a shape objective of the stave, the second data item being further determined as a function of the third data item. The third data item comprises, for example, information representative of the type of stave to be machined, for example a stave for the manufacture of barrels according to figures 1 to 8 or a stave for the fa brication of truncated conical tanks. The third data also includes, for example, a ratio between two widths of the stave, for example between a width of the bilge and a width at the ends of the stave, or any other parameter allowing to specify to what extent the width of the stave must evolve along its longitudinal axis. In the context of a stave for the manufacture of truncated conical tanks, this ratio corresponds for example to a ratio between a width of the foot and a width of the head of the stave, that is to say a ratio between the width of the stave according to its two ends.

[0118] In accordance with the previous variant, the determination of the machining profile 12a, 12b comprises for example a modeling of the lateral edges of the stave via polynomial equations, or even by circular interpolation, in particular so as to facilitate the comparison between the wooden blade profile 10a, 10b and the machining profile 12a, 12b, via similar representations.

[0119] The person skilled in the art understands here that circular interpolation corresponds to describing a lateral edge as an arc of a circle of radius R and whose center is given by a pair of coordinates (xO, yO), the lateral edge being represented by a function f(x)=y so that:

[0120] [Math.l]

[0121] In accordance with the underlying concept of the invention and as illustrated in Figures 4, 6 and 8, the machining profile 12a, 12b is determined with a non-rectilinear mean fiber 12c in the direction of the width of the stave, that is to say without constraint on obtaining a final oblong shape. The mean fiber 12c is for example also modeled via a polynomial equation, by circular interpolation, or via any other means making it possible to determine a curvature in the direction of the width of the stave. In other words, and as illustrated in [Fig.2] also associated with a stave for the manufacture of barrels, the longitudinal axis X no longer forms an axis of symmetry of the stave to be machined, and the machining profile 12a, 12b is defined with respect to the longitudinal axis X with a third lateral edge 12a having a lateral distance to the jamb A2 and a lateral distance to the heads a2, as well as a fourth lateral edge 12b having a lateral distance to the jamb B2 and a lateral distance to the heads b2, so that A2+B2 > a2+b2 but without direct constraint between a2 and A2, b2 and B2, a2 ​​and b2 or A2 and B2. It is also possible, according to yet another variant, to define a machining profile 12a, 12b so that the lateral distances to the heads are not identical, provided that the total width respects the other constraints. It is further understood that, in the context of a stave for the manufacture of truncated cone-shaped tanks, the same constraint is obtained between the lateral distances at the foot (replacing the . lateral distances at the shank) and lateral distances at the head, the other constraints also being freed.

[0122] Obviously, whatever the constraints, the determination of the machining profile 12a, 12b aims to minimize material losses, that is to say to produce the widest possible stave. The non-rectilinear medium fiber design 12c according to the invention thus makes it possible to reduce the number of constraints on the machining profile 12a, 12b and to achieve wider staves than in the prior art from a given wooden blade.

[0123] Figures 1 to 8 thus illustrate the comparative results, for four shapes of wooden blades 1, 1', 1", 1"', between an oblong profile 11a, 11b as known from the prior art and a machining profile 12a, 12b obtained according to the invention. In particular, the first wooden blade 1 illustrates an almost perfect coincidence between the wooden blade profile 10a, 10b and the machining profile 12a, 12b, resulting in almost zero material losses despite the curvature of the first wooden blade 1.

[0124] For the second wooden blade 1' (figures 3 and 4), the machining profile 12a, 12b has a width at the level of the shank 4mm greater than the oblong profile 11a, 11b.

[0125] For the third wooden blade 1” (figures 5 and 6), the machining profile 12a, 12b has a width at the level of the shank substantially equal to that of the oblong profile 11a, 11b, the third wooden blade 1'' having a slight curvature resulting in a non-rectilinear average fiber 12c very close to the rectilinear average fiber 11e.

[0126] For the fourth wooden blade 1'” (figures 7 and 8), the machining profile 12a, 12b has a width at the level of the shank 4.7 mm greater than the oblong profile 11a, 11b.

[0127] This design thus makes it possible to greatly improve the wood yield of the jointing operation with respect to curved wooden slats while retaining the same performance in the absence of curvature of the wooden slat.

[0128] As stated above, the method according to the invention is optionally part of another broader method.

[0129] According to a first variant, the computer 2, for example the beacon unit 21, transmits the second data in a third operation 33 to machining means 24, that is to say to any means of the machining machine associated with and / or allowing the machining of the wooden blade according to the machining profile 12a, 12b. Such machining means 24 correspond for example to machining spindles. The computer 2 corresponds for example to a device remote from the machining machine and configured to communicate with the machining machine, in particular with an automaton or computer of the machining machine.

[0130] According to a second variant, the calculator 2, for example a control circuit 23 integrated, directly controls the machining of the wooden blade 1, 1', 1”, 1”' in a fourth operation 34, for the manufacture of the stave. In other words, the control circuit 23 is configured to directly control the machining means 24. The computer 2 corresponds for example to a device integrated in the machining machine, for example in an automaton or computer of the machining machine.

[0131] Such a machining machine could be comparable to that described in patent FR3023742B1, for example.

[0132] The method according to the invention thus makes it possible to obtain, with a minimum of material losses, a stave for the manufacture of barrels, which has a stave profile 12a, 12b defining a middle fiber 12c of non-rectilinear shape. Such a stave can be considered as a curved stave, as opposed to the straight staves known to those skilled in the art and commonly used for the assembly of barrels, casks or the like.

[0133] It then appears that this curved stave can be directly used in a process for manufacturing barrels, casks or vats. Such a process comprises, as stated with regard to the prior art, a bending operation during which the staves are compressed so as to adopt the shape of the barrel, in particular so as to have an arched shape, or arrow face, that is to say that the two faces of the staves become respectively concave and convex. However, this bending step also contributes to deforming the staves along their edges.Depending on the arrangement and distribution between the straight and curved staves before bending, i.e. depending on the number of straight staves relative to the number of curved staves, bending results alternately in a straightening of the curved staves, resulting in a barrel identical to the prior art, or in the adoption of a curvature on all the staves, resulting in a "twisted" barrel (or tub) whose staves are curved, the barrel (or tub) however having the same sealing and mechanical resistance properties as the barrels of the prior art.

[0134] Thus, it is possible to design a method for manufacturing a barrel or vat from a plurality of staves, the plurality of staves comprising one or more curved staves. Such a method for manufacturing a barrel or vat notably comprises a bending step as described above.

[0135] Thus, it will be understood that the present invention provides a method for determining a machining profile of a stave from a wooden blade, as well as a machining machine cutting a stave from such a machining profile, which makes it possible to obtain a curved stave allowing improved efficiency compared to the straight staves of the prior art. Such a curved stave can subsequently be used for the manufacture of barrels, in particular following a machining operation. compression allowing a straight profile to be applied to it.

[0136] It should be noted that this detailed description relates to a particular embodiment of the present invention, but that in no case does this description have any limiting character with respect to the subject of the invention; on the contrary, its objective is to remove any possible imprecision or misinterpretation of the claims which follow.

[0137] It should also be noted that the reference signs placed in parentheses in the following claims are in no way limiting; these signs have the sole purpose of improving the intelligibility and understanding of the following claims as well as the scope of the protection sought.

Claims

Claims

1. Method for determining a machining profile (12a, 12b) of a stave from a wooden blade (1, 1', 1”, 1”'), said method being implemented by at least one processor, said method comprising the following steps: - obtaining (31) a first data item representative of a wooden blade profile (10a, 10b); - determination (32) of a second data item representative of said machining profile (12a, 12b) as a function of said first data item, said machining profile (12a, 12b) being inscribed in said wooden blade profile (10a, 10b) and having a width evolving along said stave, characterized in that said machining profile (12a, 12b) has a mean fiber (12c) of non-rectilinear shape over the width of said stave, so that said machining profile (12a, 12b) follows said wooden blade profile (10a, 10b), maximizes the stave width and minimizes material losses between said wooden blade (1, 1', 1”, l”') and said stave.

2. A method according to claim 1, wherein said obtaining (31) comprises a step of receiving dimensional information associated with a plurality of points of said wood blade profile (10a, 10b).

3. A method according to claim 2, wherein said obtaining (31) further comprises a step of modeling said wood blade profile (10a, 10b) as a function of said dimensional information.

4. Method according to one of claims 1 to 3, wherein said wood blade profile (10a, 10b) and / or said machining profile (12a, 12b) are modeled by circular interpolation.

5. Method according to one of claims 1 to 3, wherein said wood blade profile (10a, 10b) and / or said machining profile (12a, 12b) are modeled by the use of polynomial equations of degree greater than or equal to 2.

6. Method according to one of claims 1 to 5, which further comprises receiving a third data item representative of a shape objective of said stave, said second data item being further determined as a function of said third data item.

7. Method according to claim 6, in which the third data item comprises information representative of a ratio between two widths of said stave, said second data item being further determined as a function of said ratio.

8. Method according to one of claims 1 to 7, which further comprises a step of transmitting (33) said second data to machining means (24).

9. Method according to one of claims 1 to 7, which further comprises a step of machining (34) said wooden blade (1, 1', 1”, 1'”) for the manufacture of said stave according to said second data, via machining means.

10. Computer program comprising instructions for implementing the method according to any one of the preceding claims, when these instructions are executed by a processor.

11. A computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the method according to one of claims 1 to 9.

12. Machine for machining a wooden blade (1, 1', 1”, 1'”) for the manufacture of a stave, said machine comprising computer means configured for implementing the method according to any one of claims 1 to 9, as well as machining means controlled by said computer means.

13. Stave for manufacturing barrels, characterized in that said stave has a stave profile (12a, 12b) defining a middle fiber (12c) of non-rectilinear shape over the width of said stave.

14. A method of manufacturing a barrel or vat from a plurality of staves, wherein said plurality of staves comprises at least one stave having a stave profile (12a, 12b) defining a middle fiber (12c) of non-rectilinear shape across the width of said stave, called a curved stave.

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