FR2809341A1 - PROCESS AND DEVICE FOR CONFORMING SOLID WOOD PIECES - Google Patents

Abstract

This shaping process comprises a step of subjecting the part to be treated to a humid atmosphere and at high temperature, to make it malleable; 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 bending to be given to the piece of wood to be treated; when the piece to be treated has become sufficiently malleable, a step of placing the piece of wood across the rails (12), opposite the bearing faces of the stops (14), a step of applying transverse forces to the workpiece to be applied simultaneously against the bearing face of each stop (14); and a step of maintaining the part to be treated thus shaped until it regains its original rigidity, at room temperature.

Description

- 1 -

  METHOD AND DEVICE FOR CONFORMING PARTS INTO

SOLID WOOD.

  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 a barrel of suitable shape. 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 pieces, this operation is carried out from a straight board, by subjecting the piece to the humid heat of an oven to make it malleable, then by applying and fixing the non-conformed board. , still at high and humid temperature, directly on the frame of the hull, the fixing of the plating on each frame of the frame ensuring the conformation of the latter to the shape of the hull. 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 a high temperature, of the order of 1 00 ° 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 relatively small shells. Indeed, from a certain size, the planking becomes too heavy to handle and put in place on the frames, and the forces necessary for bending and twisting the plating when it is placed on the frames become out of reach of human strength or very

  difficult to implement in such a short time.

  -2- The present invention aims to eliminate these drawbacks. To this end, it proposes a process for shaping a piece of wood to be treated, with a view to giving it a curved shape, this process comprising a step of subjecting the piece to be treated to a humid atmosphere and at high temperature, for make it malleable. According to the invention, this method 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, mounted sliding on respective parallel rails, the curve connecting the bearing faces of the stops corresponding to the bending profile to be given to the piece of wood to be treated, - when the piece to be treated has become sufficiently malleable, a step of placing the piece of wood across the rails, opposite the bearing faces of the stops, - a step of applying transverse forces on the part to be treated to apply it simultaneously against the bearing face of each stop, and - a step of holding the part to treat well consistent 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 prior step of fixing on the bearing face of the stops and respective thrust members against the stops, shims having the twist angle which it is desired to obtain at the corresponding stop. If the piece of wood to be treated has a rectangular section, the bending forces are applied to the piece, in the direction of its thickness (perpendicular to one of its two lateral faces), the twisting of the piece being obtained at with wedges having a bearing face inclined relative to the

width of the workpiece.

  The invention thus makes it possible to treat large pieces of wood, for example 11.5 m in length, 36 cm in width and 16 cm in thickness, without requiring direct manual intervention on the piece. According to the properties of the types of wood used, the conformation according to the invention of a part having these dimensions makes it possible to reach an arrow 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 piece of wood of elongated shape, by applying force constraints.

  perpendicular to its longitudinal axis.

  According to the invention, this device is characterized in that it comprises a plurality of stops slidingly mounted on respective parallel rails, each stop being associated with: - a blocking element of the stop on its respective rail, so as to block the stop in a respective position along its respective rail, all the positions of the stops 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 axis of sliding of the stopper towards it, to apply the part to

treat against the stopper.

  Advantageously, the part to be treated has a rectangular cross section, each stop and each thrust member comprising fixing means intended to receive a wedge having a bearing face of suitable shape for twisting the part to be treated, when it is applied. in force against it. An embodiment of the shaping device according to the invention will be described below, by way of nonlimiting example, with reference to the appended drawings in which FIG. 1 schematically represents the device according to the invention; Figure 2 shows in more detail the shaping device shown in Figure 1 -4- 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.

  FIG. 1 represents a device for shaping pieces of wood comprising an oven 1 having an elongated shape corresponding to that of the 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 inlet opening 2 and an outlet opening 3 opening onto the longitudinal axis of a shaping device 10, these openings can be closed by doors. As can be seen in Figure 1, the raceway inside the oven 1 comprises rollers 4, 5 disposed respectively at the inlet and at the outlet of the oven, intended to facilitate the sliding of the piece of wood to be treated, when

  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 around 1 00 C, so as to make it malleable.

  In Figure 2, the shaping device 10 comprises a rigid frame of rectangular shape, comprising two parallel rails 1 1 forming the longitudinal edges of the device 10, on which are fixed rails 12 arranged perpendicular to the beams and distributed at equal distances along of these. 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 cylinders 15 is less than the length of the rails 12. The position or fulcrum of each cylinder 15 on its

  rail, and therefore its starting position, is also manually adjustable.

  - The mobile part of each cylinder 15 on its rail 12 pushes a mobile carriage on the rail in the direction of the plate of the stop 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 longitudinal bending profile which it is desired to give to the piece of wood to be treated, each jack 15 making it possible to force the piece of wood to be treated, arranged along the axis longitudinal of the shaping device 10, to be applied against the stop

  corresponding, so as to bend the piece of wood.

  The set of jacks 15 is 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 carry out a twisting of the part to be treated by using wedges, for example made of wood, which are fixed on the plates of stops 14 and movable carriages, for example by means of screws and nuts. These wedges each have a parallel or inclined bearing face with respect to a transverse axis of the part to be treated, depending on the twist angle which 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, actuated manually and preferably electrically, disposed in the axis of the device 10, opposite the opening of outlet 3 of the oven 1, other rollers 21 to 25 being provided on the axis of the shaping device between the rails to facilitate the positioning 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 6 - shims fixed on the plates of the stops and pushing carriages are defined in

function of the twist to be carried out.

  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 the parts to be treated must be placed. In this case, the longitudinal position of the piece of wood on the frame must also be adjusted so that the parts of the piece on which the wedges 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 shims of the pushing carriages, the jacks 15 are actuated one after the other, for example in groups of four, so as to apply the part against each of the shims of the stops. The respective forces exerted by the jacks 15 make it possible both to bend and to twist the part to be treated. When the part to be treated is applied against all the stop blocks 14 by the jacks, the pressure in the jacks is maintained for a few minutes, of the order of 15 minutes, while the piece cools and dries. Then, the pressure in the jacks can be released, so as to retract the push carriages 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 frames of the frame, this operation normally not requiring

  extra effort in shaping.

  For example, the frame of the shaping device 10 has a length of 11.5 m and a width of 4.5 m and includes 18 rails on each of which are slidably mounted an adjustable stop 14 and a jack 15 having a stroke 1.2 m, the respective positions of the cylinder support point and 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 bending deflection of 1.6 m 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 maintenance in position of this plate being reinforced by a square

  33 fixed on the slide 31 and the plate 32 perpendicular thereto.

  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, this

  which provides a rough adjustment of each stop.

  The interval between two adjacent fixing holes, formed in the rails 12

can be 10 cm.

  To allow a finer adjustment, it can be provided that each stop 14 comprises two parts connected together by a threaded rod, namely a stop body fixed to the rail 12 by pins and a part fixed to the plate 32, each part comprising a section of slide 31 mounted sliding on the rail. The distance between the body of the stopper and the plate 32 is adjusted by the threaded rod which passes through tapped 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 intended to receive a wedge 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 wedge 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 pushing member 15 comprises a hydraulic cylinder 40 -8- consisting of a fixed part 41 forming a cylindrical cavity closed by a piston secured to 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 that it can be slidably mounted on a rail 12. Holes 39' are provided in the slide to receive locking pins from the fixed part 41 on the rail 12 The free end of the piston rod 42 comprises fixing means 43 for coming to be fixed on a pushing carriage 18 having a shape substantially similar to that of a stop 15. Thus, the pushing carriage comprises a slide 31 "of identical profile to the slides 31 and 31 'to be able to slide on a rail 12, and a plate 32' designed to receive a wedge 34 and fixed on the slide 31" by means of 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, for example comprising 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, in

function of the ratings entered.

  The respective inclinations of the bearing faces of the thrust members can also be adjusted by actuating members, for example hydraulic, controlled by the digital control system, from the

  characteristics of the part to be produced.

-9-

Claims (12)

  1. A method of shaping a piece of wood to be treated, with a view to giving it a curved shape, this method 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 bending profile to be given to the piece of wood to be treated, - when the piece to be treated has become sufficiently malleable, a step of placing the piece of wood across the rails (12) , opposite the bearing faces of the stops (14), - a step of applying transverse forces on the workpiece to apply it simultaneously against the bearing face of each stop (14), and - a maintenance step d e the part to be treated thus conformed until it   regains its original rigidity at room temperature.   2. 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, 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.   3. Method according to claim 1, characterized in that it comprises a prior step of adjusting the inclination of the bearing face of the stops (14) and of respective pushing members (15) against the stops.   4. Method according to one of claims 1 to 3,   characterized in that it further comprises a prior step of adjusting the respective support points of a plurality of mounted thrust members (15) sliding on the rails (12).   5. Method according to one of claims 1 to 4,   characterized in that it includes a coarse adjustment and a fine adjustment of the - 10- position of each stop (14).   6. 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, starting from the dimensions of the part (13) to be treated.   7. 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: - an element for blocking the stop on its respective rail, so as to block the abutment in a respective position along its respective rail, all of the positions of the abutments defining the bending profile to be given to the part to be treated, and - a respective thrust member (15) designed to exert a thrust according to the sliding axis of the stop (14) in the direction of the latter, for applying   the part to be treated (13) against the stop.   8. 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 face of appropriately shaped support for twisting the workpiece when it is   applied in force against it.   9. Conformation device according to claim 78, 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 to be applied to the part to be treat.   10. Conformation device according to claim 7 or 9, characterized in that each stop (14) comprises a plate (32) for fixing a wedge (34), whose position relative to the stop along the axis of   sliding of it is adjustable.   11. Conformation device according to one of claims 7 to 10,   characterized in that each thrust member (15) comprises a jack (40) which   - 11 - activates a pushing carriage (18).   12. Conformation 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 pushing member.