EP1157795A1 - Method and apparatus for shaping articles from solid wood - Google Patents

Abstract

The forming procedure comprises subjecting the wood part to be processed to a humid atmosphere at a high temperature in order to make it malleable. The respective positions of stops (14) along respective rails (12) on which the stops are sliding mounted are adjusted. Each stop comprises a support face, the curve connecting the stop support faces corresponding to the bending profile to be given to the wood. The wood part is then placed across the rails compared with the support faces. This is followed by an application of transverse forces on the part simultaneously against each stop support face. Finally the part is held until it retrieves its original rigidity at ambient temperature. An Independent claim is also included for a forming device.

Description

The present invention relates to a method and a device for shaping solid wood parts.

It applies in particular, but not exclusively, to the conformation of planks or planks covering the frame of a ship's hull.

Traditionally, the operation of shaping a planking is carried out by machining of an appropriately shaped barrel. It is then necessary to find a tree with a trunk having the desired shape, which can be extremely long and therefore very expensive.

More recently, for relatively small parts, this operation is carried out from a rectilinear board, by submitting the part to the humid heat from an oven to make it malleable, then applying and fixing the non-conforming board, still at high and humid temperature, directly on the hull frame, fixing the plating on each frame member ensuring its conformation to the shape of the shell.

According to this technique, the plating must be fixed in a very short time. short, about fifteen minutes before the wood regains its original rigidity. This is done manually and requires labor important to carry and force the board to conform to the shape of the hull. As, the parts leaving the oven are at high temperature, of the order from 100 ° C, this operation is delicate and presents significant risks of burns for people handling the shell.

It turns out that this technique can only be applied to the manufacture of hulls relatively small. Indeed, from a certain size, the planks become too heavy to handle and set up on frames, and the forces necessary to bend and twist the planking during its poses on the frames become out of reach of human force or very difficult to implement in such a short time.

The present invention aims to eliminate these drawbacks. To this end, it proposes a method of shaping a piece of wood to be treated, with a view to it give a curved shape, this process comprising a step of submitting the part to be treated in a humid atmosphere and at high temperature, to make it malleable.

• une étape préalable de positionnement et de réglage des positions respectives d'une pluralité de butées comprenant chacune une face d'appui, montées coulissantes sur des rails parallèles respectifs, la courbe reliant les faces d'appui des butées correspondant au profil de cintrage à donner à la pièce de bois à traiter,
• lorsque la pièce à traiter est devenue suffisamment malléable, une étape de disposition de la pièce de bois en travers des rails, en regard des faces d'appui des butées,
• une étape d'application de forces transversales sur la pièce à traiter pour appliquer celle-ci simultanément contre la face d'appui de chaque butée, et
• une étape de maintien de la pièce à traiter ainsi conformée jusqu'à ce qu'elle retrouve sa rigidité d'origine, à température ambiante.

According to the invention, this process is characterized in that it comprises:

• a prior step of positioning and adjusting the respective positions of a plurality of stops each comprising a bearing face, slidingly mounted on respective parallel rails, the curve connecting the bearing faces of the stops corresponding to the bending profile to be given the piece of wood to be treated,
• when the part to be treated has become sufficiently malleable, a step of placing the piece of wood across the rails, facing the bearing faces of the stops,
• a step of applying transverse forces to the part to be treated in order to apply it simultaneously against the bearing face of each stop, and
• a step of maintaining the part to be treated thus conformed until it regains its original rigidity, at room temperature.

Advantageously, the method according to the invention also makes it possible to twist the part to be treated. It includes for this purpose a preliminary step of fixing on the face to support the respective stops and thrust members against the stops, shims having the twist angle that we want to obtain at the stop corresponding.

If the piece of wood to be treated has a rectangular section, the forces of bending are applied to the part, in the direction of its thickness (perpendicular to one of its two lateral faces), the twisting of the part being obtained by means of shims having a bearing face inclined relative to the width of the workpiece.

The invention thus makes it possible to treat large pieces of wood, by example 11.5 m long, 36 cm wide and 16 cm thick, without requiring direct manual intervention on the part. Depending on the properties of the types of wood used, the conformation according to the invention of a part having these dimensions allows to reach a boom of 1; 6 m and a twist of 10 cm between the two ends of the room.

The invention also relates to a device for shaping a workpiece. elongated wood, by applying stress constraints perpendicular to its longitudinal axis.

• un élément de blocage de la butée sur son rail respectif, de manière à bloquer la butée en une position respective le long de son rail respectif, l'ensemble des positions des butées définissant le profil de cintrage à donner à la pièce à traiter, et
• un organe de poussée respectif conçu pour exercer une poussée suivant l'axe de coulissement de la butée en direction de celle-ci, pour appliquer la pièce à traiter contre la butée.

According to the invention, this device is characterized in that it comprises a plurality of stops mounted to slide on respective parallel rails, each stop being associated with:

• a stop blocking element on its respective rail, so as to block the stop in a respective position along its respective rail, the set of stop positions defining the bending profile to be given to the part to be treated, and
• a respective thrust member designed to exert a thrust along the sliding axis of the stop in the direction of the latter, to apply the part to be treated against the stop.

Advantageously, the part to be treated has a cross section rectangular, each stop and each pushing member comprising means fixing intended to receive a wedge having a shaped support face suitable for twisting the workpiece, when forcibly applied against this one.

La figure 1 représente schématiquement le dispositif selon l'invention ;

La figure 2 montre d'une manière plus détaillée le dispositif de conformation représenté sur la figure 1 ;

La figure 3 montre en coupe transversale une butée montrée en vue arrière, montée sur son rail ;

La figure 4 montre une butée en vue de profil ;

La figure 5 montre en vue de profil un organe de poussée.

An embodiment of the shaping device according to the invention will be described below, by way of nonlimiting example, with reference to the accompanying drawings in which

Figure 1 schematically shows the device according to the invention;

Figure 2 shows in more detail the shaping device shown in Figure 1;

Figure 3 shows in cross section a stopper shown in rear view, mounted on its rail;

Figure 4 shows a stop in profile view;

Figure 5 shows a side view of a thrust member.

Figure 1 shows a device for shaping pieces of wood comprising an oven 1 having an elongated shape corresponding to that of pieces of wood to be treated, and comprising a raceway intended to facilitate the passage of the pieces of wood in the oven, and at its two ends, an opening inlet 2 and an outlet opening 3 opening on the longitudinal axis of a conforming device 10, these openings being able to be closed by doors.

As can be seen in Figure 1, the raceway inside the oven 1 comprises rollers 4, 5 arranged respectively at the inlet and at the outlet of the oven, intended to facilitate the sliding of the piece of wood to be treated, during its introduction and its extraction in and out of the oven.

The oven is designed to keep a piece of wood to be treated in an atmosphere humid at about 100 ° C, so as to make it malleable.

In FIG. 2, the shaping device 10 comprises a rigid frame of form rectangular, comprising two parallel longitudinal members 11 forming the edges longitudinal of the device 10, on which are fixed rails 12 arranged perpendicular to the side members and distributed at equal distances along these last. On each rail are slidably mounted a stop 14 and a member thrust 15 comprising for example a hydraulic cylinder.

The rigidity of the frame can be reinforced by a set of slashes 17 which are each fixed to the two longitudinal members 11.

The position of each stop 14 on its rail is manually adjustable.
According to a feature of the invention, the stroke of the jacks 15 is less than the length of the rails 12. The position or fulcrum of each jack 15 on its rail, and therefore its starting position, is also manually adjustable.

The mobile part of each jack 15 on its rail 12 pushes a mobile carriage on the rail towards the stop plate 14 fixed on the same rail, the front of the mobile trolley also comprising a plate.

The position of the stops 14 on their respective rail 12 makes it possible to define the profile longitudinal bending that we want to give to the piece of wood to be treated, each cylinder 15 forcing the piece of wood to be treated, arranged according to the longitudinal axis of the shaping device 10, to be applied against the stop corresponding, so as to bend the piece of wood.

All of the jacks 15 are connected via a hydraulic circuit (not shown) to a single source of hydraulic pressure 6 and to consoles 7.

Advantageously, each cylinder is controlled individually and can be blocked in pressure, four cylinders can be controlled simultaneously.

The device described also makes it possible to twist the part to be treated. using shims, for example wooden, which are fixed on the plates of the stops 14 and movable carriages, for example by means of screws and nuts. These wedges each have a support face parallel or inclined with respect to a transverse axis of the part to be treated, depending on the twist angle that is wishes to apply to the part to be treated at the level of the corresponding rail 12.

The extraction of the piece of wood from the oven 1 can be carried out by means of a winch 16, operated manually and preferably electrically, arranged in the axis of the device 10, opposite the outlet opening 3 of the oven 1, others rollers 21 to 25 being provided on the axis of the shaping device between the rails to facilitate the installation of the piece of wood on the device conformation 10.

The pieces of wood to be treated are very elongated, with a cross section of rectangular shape. They are introduced into the oven 1 flat, resting on their width. At the outlet of the oven 1, they are gradually raised to rest by their edges on the shaping device 10, by means of turning devices 19 arranged between the rails 12. Beforehand, the respective positions of the stops 14 on their respective rails are adjusted so as to define the bending profile to be produced, and the respective shapes of the shims fixed on the plates of the stops and pushing carriages are defined as a function of the twist to be produced.
Similarly, the respective positions are adjusted along the rails 12 of the support points of the thrust members as a function of the position of the stops and of the maximum stroke of the jacks 15.

In the case of the construction of a ship's hull, the spacing of the rails 12 advantageously corresponds to the spacing of the frames of the frame on which must be placed the parts to be treated. In this case, the position longitudinal of the piece of wood on the frame must also be adjusted by so that the parts of the part on which the shims will be applied are those which are intended to come into contact with the frames of the frame.

As soon as the part to be treated is in place on the frame between the shims of the stops 14 and the holds of the pushing carriages, the jacks 15 are actuated one after the others, for example in groups of four, so as to apply the piece against each of the shims of the stops. The respective forces exerted by the cylinders 15 allow both bending and twisting the workpiece. When the room to treat is applied against all the shims 14 by the cylinders, the pressure in the cylinders is maintained for a few minutes, of the order of 15 minutes, while the part cools and dries. Then the pressure in the cylinders can be released, so as to retract the push carts along their respective rails, the piece of wood thus treated retaining the bending and twisting thus applied.

It then suffices to set up and fix the piece thus shaped on the frame members, this operation does not normally require extra effort in shaping.

For example, the frame of the shaping device 10 has a length 11.5 m and 4.5 m wide and includes 18 rails on each of which are sliding mounted an adjustable stop 14 and a cylinder 15 having a stroke of 1.2 m, the respective positions of the support point of the jack and of the stop being adjustable over the entire length of the rail. Such a device makes it possible to treat pieces of oak wood 11.5 m long, 36 cm wide and 16 cm thick to give them a 1.6 m bend arrow and a distance of 10 cm twist.

It should be noted that thanks to the invention, the processing of a part of this size only requires the intervention of two operators.

In FIGS. 3 and 4, the rails 12 consist of two profiled elements 12a, 12b with an I-shaped cross section fixed on the side members 11 parallel to one another.
Each stop comprises a slide 31 of C-shaped cross section engaged by sliding on the upper part of the I-shaped elements, so as to wrap the outer upper lateral wings of the I-shaped. A plate 32 is fixed on this slide 31, perpendicular to the longitudinal axis thereof, the holding in position of this plate being reinforced by a bracket 33 fixed on the slide 31 and the plate 32 perpendicular to them.

Each stop 14 can be locked on its rail, for example by means of pins introduced simultaneously into holes 39 made in the slide 31 of the stop and into blocking holes formed in the inner upper lateral wings of the rail 12. For this purpose , each rail 12 comprises a plurality of locking bores uniformly distributed over its length, which makes it possible to obtain a rough adjustment of each stop.
The interval between two adjacent fixing holes, formed in the rails 12 can be 10 cm.

To allow finer adjustment, it can be provided that each stop 14 comprises two parts interconnected by a threaded rod, namely a body of stop fixed to the rail 12 by pins and a part fixed to the plate 32, each part comprising a section of slide 31 mounted to slide on the rail. The distance between the body of the stop and the plate 32 is adjusted by the threaded rod which crosses threaded holes provided in the part fixed to the plate or in the body of the stop.

The plate 32 includes lateral edges, so as to form a cavity designed to receive a shim 34 which can be fixed on the plate 32 by means of screws engaged in holes 36 formed in the lateral edges of the plate. The shim 34 may include a lower rim 36 and an upper rim 35 between which engages the part 13 to be treated so as to maintain it vertically during the tightening of the thrust members against the stops.

In FIG. 5, each thrust member 15 comprises a hydraulic cylinder 40 consisting of a fixed part 41 forming a cylindrical cavity closed by a piston integral with a piston rod 42. The cylindrical cavity is fixed on a slide 31 'having the same section as the slides 31 of the stops 14, so as to can be slidably mounted on a rail 12. Holes 39 'are provided in the slide to receive locking pins of the fixed part 41 on the rail 12.

The free end of the piston rod 42 includes fixing means 43 to be fixed on a push carriage 18 having a shape substantially similar to that of a stop 15. Thus, the pushing carriage comprises a 31 "slide identical profile to the 31 and 31 'slides to be able to slide on a rail 12, and a plate 32 'designed to receive a shim 34 and fixed on the slide 31 "via a bracket 33 '. The fixing means 43 of the piston rod are fixed on the slide 31 "and possibly on the bracket 33 '.

According to a variant of the invention, each stop is also mounted on a respective pushing member, comprising for example a jack.
Advantageously, all of the thrust members on either side of the part to be treated is controlled by a digital control system into which the dimensions of the part to be produced are introduced, this system determining the respective positions of the jacks to be reached to conform the part to be treated, according to the dimensions entered.

The respective inclinations of the bearing faces of the thrust members can also be regulated by actuators, for example hydraulic, controlled by the digital control system, from characteristics of the part to be produced.

Claims (12)

Process for shaping a solid wood piece, with a view to giving it a curved shape, this process comprising a step of subjecting the piece (13) to be treated to a humid atmosphere and at high temperature, to make it malleable,
characterized in that it comprises: a step of adjusting the respective positions of stops (14) along respective rails (12) on which the stops are slidably mounted, each stop comprising a bearing face, the curve connecting the bearing faces of the stops corresponding to the profile of bending to give to the piece of wood to be treated, when the part to be treated has become sufficiently malleable, a step of placing the piece of wood across the rails (12), facing the bearing faces of the stops (14), a step of applying transverse forces to the part to be treated in order to apply it simultaneously against the bearing face of each stop (14), and a step of maintaining the part to be treated thus conformed until it regains its original rigidity, at room temperature. Method according to claim 1,
characterized in that it further comprises a prior step of fixing on the bearing face of the stops (14) and of respective pushing members (15) against the stops, of shims (34) having an inclination corresponding to the 'twist angle that it is desired to obtain at the level of the corresponding stop on the part to be treated. Method according to claim 1,
characterized in that it comprises a preliminary step of adjusting the inclination of the bearing face of the stops (14) and of respective pushing members (15) against the stops. Method according to one of claims 1 to 3,
characterized in that it further comprises a preliminary step of adjusting the respective support points of a plurality of thrust members (15) slidably mounted on the rails (12). Method according to one of claims 1 to 4,
characterized in that it comprises a coarse adjustment and a fine adjustment of the position of each stop (14). Method according to one of claims 1 to 4,
characterized in that the steps for adjusting the positions of the stops (14) and applying transverse forces are carried out simultaneously, from the dimensions of the part (13) to be treated. Conformation device for implementing the method according to one of the preceding claims,
characterized in that it comprises a plurality of stops (14) slidingly mounted on respective parallel rails (12), each stop being associated with: a stop blocking element on its respective rail, so as to block the stop in a respective position along its respective rail, the set of stop positions defining the bending profile to be given to the part to be treated, and a respective thrust member (15) designed to exert a thrust along the sliding axis of the stop (14) in the direction of the latter, to apply the part to be treated (13) against the stop. Conformation device according to claim 7,
characterized in that each stop (14) and each thrust member (15) comprises fixing means (32, 36) intended to receive a wedge (34) having a bearing face of a suitable shape for twisting the part to be treated when applied in force against it. Conformation device according to claim 7,
characterized in that each stop (14) and pushing member (15) comprises a member for controlling and adjusting the inclination of their bearing face against the part to be treated, so as to adjust the twist angle at apply to the part to be treated. Conformation device according to claim 7 to 9,
characterized in that each stop (14) comprises a plate (32) for fixing a wedge (34), the position of which relative to the stop along the sliding axis thereof is adjustable. Conformation device according to one of claims 7 to 10,
characterized in that each pushing member (15) comprises a jack (40) which actuates a pushing carriage (18). Shaping device according to one of Claims 7 to 11,
characterized in that each stop (14) is driven in translation on its rail (12) by a thrust member.

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