FR2525530A1 - Multilayer boat hull esp. of aluminium profiles - embedded in duroplastics and faced with fibre reinforced laminates - Google Patents

Abstract

Mfr. of multilayer, self-supporting shell, esp. a boat hull, consists of using strips of profiles all of the same I-section, alternately arranged rotated through 90 deg. so that the axis of one is perpendicular to the axis of its neighbours, then embedding these profiles in duroplastics material and laminating both sides with fibre-reinforced duroplastics sheet. The entire hull is formed on a skeleton or frame. Pref. the I-section is composed of two V-forms with their apexes joined. Pref. materials for the members are metals, esp. aluminium.

Description

 The invention relates to a method of manufacturing self-supporting enveloping surfaces with several layers, in particular of a plywood hull plating, using a forming framework predetermining the desired three-dimensional shape of the enveloping surface and on which are fitted with profiles of the same section so that they overlap with each other, they are fixed by points to the forming framework and they are assembled together using a thermosetting filling material which partially penetrates between them, laminate of thermosetting synthetic material reinforced with fibers is applied to the surfaces thus formed and is assembled to these surfaces.

In a process of this kind, known by the
DE-OS 26 26 537, hollow profiles are joined together, respectively forming a section, for example using mounting clips which are plastically deformed, before the introduction of the hollow profiles into the mounting clips, in accordance with the outline desired in each case and preddtermind by the forming framework, then the profiles are placed on the corresponding section of the forming framework. The various hollow sections of this section are fixed at points to the forming framework, for example by means of screws. pbdr adhesive to seat the hollow sections between them, after which all the hollow sections of a section, or for example only one in two, are attached to the forming framework. Once the forming framework is completely covered with the hollow profiles, these are assembled together using the thermosetting filling material which penetrates each time at least partially between the upper and lower sides and finally, on the surfaces thus formed, we apply the laminate of thermosetting synthetic material reinforced with fibers and we assemble it to the surfaces. of air inside the hollow sections, greatly improves the desired 1 1 unsinkability of the boat hull. By this method, boat hull planks of the most different shapes and sizes can be manufactured in a simple manner, without using expensive negative molds.

 The forming framework used in this process is formed of structural elements used in any case in the boat hull, in addition to the planking, such as the transom, the transverse walls or partitions, the greenhouses which predetermine the plank edge, the keel as well as a bow. Given that in the hull planks of long boats, relatively large distances are also provided between the different partitions, or between the last partition and the transom, it is difficult to arrange the profiles hollow to be placed on the forming framework between the various partitions, or between the rear partition and the transom, taking into account the contours and contour transitions desired in each case, because without the use of mounting clips, the hollow profiles tend to connect each other by the shortest route each time. The hollow sections used in this known process have a uniform cross-sectional shape, the upper side of which ur has the shape of an obtuse V-shaped gutter open towards the outside while the lower side has a convex U-shaped curvature towards the outside. When the upper and lower sides of neighboring profiles respectively engage with each other, the longitudinal grooves are formed, each open towards the interior and exterior surfaces of the base plating and into which the filling material is introduced. to join the hollow sections together and form the practically smooth interior and exterior surfaces of the base planking. Precisely, when planking contours are required, requiring relatively large means, one must be deflected with respect to the further to a relatively large extent the adjacent hollow sections of a section, so that, while it is true that the longitudinal grooves of one of the inner and outer surfaces may become deeper or wider, the longitudinal grooves of the other respective surface will close approximately at the same time, or may even disappear completely. As a result, sufficient penetration of the filling material is no longer ensured, at at least one of the surfaces, which means that the strength of the assembly of neighboring hollow sections may suffer, in the case of strong bends within of a section of the hollow sections.

 By DE-OS 30 03 969, it has already been proposed to use to manufacture such a boat hull planking hollow profiles with two different section shapes, the first section shape being practically circular while the second shape section has, along the mutual contact surfaces, obtuse V-shaped obturators open to the outside and interconnected by parallel side walls. At the free ends of the gutters of the second section form, projections extending practically in the direction of their side walls are formed so as to form, with the hollow profile with circular section respectively adjacent, cavities roughly in dovetail to receive the filling material. On the other hand, these protrusions close these cavities almost completely on the side of the interior and exterior surfaces of the plating, so that the assembly between the laminate of synthetic material to be applied to the surfaces. interior and exterior and the filling material is not optimal.

 The method according to the invention as defined above allows a reliable assembly of neighboring profiles, by the filling material to be introduced between the profiles and the laminate of synthetic material connected to this material which fully matches the cavity between the neighboring profiles, is ensured even when, when forming enveloping surface contours which require significant resources, strong curves must be formed between neighboring profiles.

 By giving the sections a practically double T section, it is possible, despite the use of a single uniform kind of section which considerably simplifies the processing and keeping of stocks, to ensure grooves on the interior and exterior of the plating longitudinal of sufficient width and depth between the profiles, if the neighboring profiles are each oriented at 900 from each other.

 Thus, while a profile has a longitudinal median plane practically aligned vertically, the two profiles adjacent to the first have a longitudinal median plane practically aligned horizontally.

 Thanks to the double-T section of the profiles, the longitudinal grooves form in this arrangement dovetail cavities which have a large opening section open towards the interior and exterior surfaces of the plating and through which the filling material thermosetting can bond to laminate of synthetic material also thermosetting which can be applied on each of the interior and exterior surfaces. Such an intimate assembly, by a surface as large as possible, between the filling material penetrating in the longitudinal grooves and the laminates of synthetic material, is particularly important since the assembly of profiles formed of any material, but preferably of a thermoplastic synthetic material or of a metal such as aluminum, and of laminate of thermosetting synthetic material, can be critical. Preferably, also in the process according to the invention, the sections are in hollow form and then their cross section in double T is continued by a cross section in double V, that is to say that the hollow sections have a section with little close in the shape of a bone ". This section shape also allows, with very great freedom, even relatively strong torsion between neighboring profiles, making it possible to form in a simple manner even contours which require great resources. The edges of the profiles are rounded to exclude the effects of nicks between neighboring profiles, in particular also in case of possible kinking of certain profiles.

These rounded profile edges at the same time facilitate the manufacture of the profiles, which is preferably carried out by extrusion. But on the other hand, profiles having the shape of the indicated section can also be very well handled in the form of solid profiles, that is to say that they can even be twisted if, in the longitudinal direction of a enveloping surface such as a boat plating, successive sections must have different contours.

On the other hand, however, the hollow sections are preferred because, by virtue of the air inclusions, they lead to a very low average density of the
-3 hollow body, which is for example 0.3 to 0.4 g.cm referred to the overall section of the enveloping surface.This density is therefore only about half that of the wood and the filling material used in the process according to the invention, has a mass
-3 volume of about 0.6 g .cm. According to a preferred mode of execution, also in the method according to the invention, to generate the contours of the enveloping surface, mounting clamps in detail below and which allow a practically simple and precise implementation of the method according to the invention.

 These mounting clips are preferably arranged in a frame which surrounds their U-shaped profile and which carries the adjustment screws used to establish the outline. At the sides facing the profiles, the U-profile can be provided with button-shaped projections which facilitate the arrangement of the profiles in the mounting clips or fix their position in the mounting clips when the latter can at least partially open or move away so that they can be adapted to the profiles of a section, which must be curved to a determined contour. But on the other hand, the mounting clips can also be slid over the profiles of a section, the button-shaped projections then sliding beyond the profiles which project the most towards the interior and exterior surfaces respectively of the plating and then yielding elastically outwards. For this purpose, the button-shaped projections can also be subjected to an elastic preload in the direction of the cavities of the longitudinal grooves, for example using coil springs, or even be formed by adjustable screws.

Exemplary embodiments of the invention are given below with reference to the accompanying drawings in which
FIG. 1 schematically shows the constitution, using profiles, of a boat hull planking here forming the enveloping surfaces,
FIG. 2, diagrammatically, the possible arrangement of the profiles used in the method according to the invention,
FIG. 3 a possible form of section of these sections,
FIG. 4, diagrammatically, a mounting clamp used to form the contours of a section of the profiles,
FIG. 5, a detail of such a mounting clip, provided with button-shaped projections, and,
- Figure 6, schematically, the application of plastic laminate on the profiles.

 As shown diagrammatically in FIG. 1, a boat hull planking 1 is made, using a forming frame 2, starting from multiple sections 3, 3 '. The forming framework 2 includes a transom 2a, couples 2b or transverse walls 2c or partitions 2d, greenhouses 2e predetermining the edge of the planking, a keel 2f connecting these structural elements to their lower side and a bow 2g constituting the bow part. On this forming framework, the elongated sections are applied, formed of any suitable material and these, by virtue of their cross-sectional shape, engage each other respectively by their upper sides and inferior.

 As shown in Figures 2 and 3, only one kind of profiles is used which preferably has the shape of section indicated in Figure 3 and constitutes a hollow profile with rounded edges.

In the manner shown in FIG. 2, the profiles having an approximately “bone-shaped” section are arranged, so that a profile 3 'each has a practically horizontal longitudinal median plane while the neighboring profile 3 has respectively a practically vertical longitudinal median plane.

As shown in the lower part of FIG. 2, the sections thus arranged are inclined or twisted suitably relative to each other so as to be able to form the contour whenever desired of the plating.

The roughly dovetail cavities formed each time between two neighboring ileus practically arranged horizontally 3 ′ and a profile 3, practically vertically arranged between these profiles 3 ′, are filled with thermosetting filling material. determined contour, one still obtains sufficiently large opening sections of these cavities towards the outside, allowing an excellent bond between the thermosetting filling material and the laminates of synthetic material also thermosetting 4 which are applied to each of the interior surfaces and exterior of the plating.

 The rounded edges of the profiles prevent a notching action between neighboring profiles even in the event of a relatively strong deviation from one profile to another, when it is a question of forming plank contours requiring great resources.

 Although this is not shown in Figure 2, when constructing such contours, it is also possible, in extreme cases, to rotate outward or inward out of the overall section of the planking the sections practically vertically aligned and then the parts of the sections which project relative to the overall section of the planking are ground before applying the laminates of synthetic material to the interior and exterior surfaces of the plating. The open cavities possibly formed by such grinding are also filled with thermosetting filling material so that neither the tightness of the plating nor its bearing strength suffers.

 Although we have shown in FIG. 1 as enveloping surfaces those of a boat hull plating, which we manufacture. According to the method indicated, it is of course possible to manufacture, according to the method, enveloping surfaces of any shape, preferably three-dimensional, which are formed of several layers and are self-supporting. The profiles can be made of any suitable material, that is to say as light as possible. Preferably, the profiles are formed from a thermoplastic synthetic material or a light metal, for example aluminum.

Other areas of possible application of enveloping surfaces are in the construction technique, for example in the construction of hipped roofs, tanks, aircraft, etc.

 To improve the connection between the profiles 3 and 3 'and the thermosetting filling material introduced into the cavities, in particular when the profiles are formed for example of aluminum, it is possible, as shown diagrammatically in FIG. 6, to apply to the substantially horizontally aligned 3 'sections of the fiber-reinforced plastic laminate 4', such that these cover the head surfaces of each of the sections 3 'and at least parts of the side surfaces of the substantially vertical sections 3. After the application of these laminates of synthetic material 4 ′, the filling material is introduced into the cavities practically in dovetail, then, again, as also shown in FIG. 2, the laminates of synthetic material 4 are applied to form the exterior and interior coating. As a result, the connection between the filling material and the profiles can be improved even when the profiles are material of a different nature from the replenishment material. But on the other hand, even without these additional laminates of synthetic material 4 ', a self-supporting constitution sufficiently resistant of the enveloping surfaces is obtained, by the only fact that by virtue of the particular alternating arrangement of the profiles, cavities are obtained practically in the tail dovetail into which the filling material is then introduced to form in each cavity corners of filling material which, with the outer layers, maintain the assembly of the self-supporting enveloping surface.

 However, the additional thermosetting synthetic laminates reinforced with fibers 4 ′, can themselves serve as filler, since after their assembly with the synthetic laminates 4 forming the outer layers and the hardening of the resin which connects to the profiles as well as to each other, they have sufficient strength to form an anchoring body in the dovetail cavity. From this point of view, it should be emphasized that the filling material does not need '' be exclusively a mass to be introduced into the dovetail cavities, but on the contrary it can also for example be formed of laminates of synthetic material which serve to form a body applying against the marginal surfaces of the hollow body in dovetail or connected to these surfaces and having sufficient strength to keep the self-supporting enveloping surface assembled, together with the forma plastic laminates nt the outer layers. Thus, in this case, in the dovetail cavities, additional "artificial" hollow profiles are formed which, with the plastic laminates forming the outer layers and with the profiles, form the enveloping surface.

 FIG. 4 schematically represents a mounting clip used to form contours on sections of the profiles. This mounting clamp is formed of a practically U-shaped frame 13, which has wings 113, 113 'and a connecting core 113 ". As indicated diagrammatically at 15, the wings 113, 113' can be articulated to the core 113 "so as to be able to pivot so as to move the U-shaped profile apart from the mounting clamp itself 11, provided with wings 111 and 111 ′, which greatly facilitates the application of the mounting clamp on a section formed of profiles. After applying the mounting pliers, the articulated connections 15 between the wings 113, 113 'and the core 113 "are blocked and each is fixed to the part already covered with plating or to the greenhouses. In the wings 113 and 113 'of the frame 13 are provided with multiple adjustment screws 114 provided with finned heads 115. By adjusting the various adjustment screws, it is possible to resiliently establish the actual U-shaped profile 11 of the mounting clamp, as desired in each case, so that the contour desired can be communicated each time to the profiles 3, 3 ′ inserted in this U-shaped profile. After the constitution of this desired contour in the present case, the profiles 3 are fixed, 3 'in the usual manner on parts of the forming framework and also between them, for example by spot welding, and then, after having removed the mounting clamps, the filling material is introduced and the application of plastic laminates.

 The mounting clamp shown in Figure 4 is suitable for the formation of a contour which ensures a concave shape of plating, open to the right of the drawing. If it is a question of forming a curved contour in the opposite direction, or even more difficult contours, it is necessary to give the frames 13 of these mounting clamps a corresponding structure, several mounting clamps of different structures being available to form different contours in different sections and which can also, of course, be arranged simultaneously on sections of the sections which, for example, succeed one another in the longitudinal direction of the plating and can be adjusted differently.

 To facilitate the arrangement of the various profiles and their alignment with one another and in the mounting clamp, button-shaped projections 14, 14 ′ can be provided, their distance from the inside of the wings 111, 1111 of the U-shaped profile 11 being chosen so that they penetrate into the respective cavities of the longitudinal grooves to be formed.

As indicated diagrammatically in FIG. 5, the projections 14 ′ can also be arranged so as to be able to slide elastically towards the outside, which can be obtained for example by means of coil springs 15 which apply an elastic preload to a projection in the shape of a rivet head, in the direction of the cavity of the longitudinal grooves.

 However, the protrusions can also be formed by adjustable screws towards the inside of the cavities, although this is not shown. If you do not bend the mounting clip over the profiles of a section by spreading or opening the U-profile 11, as shown in Figure 4, you can also adapt the mounting clamp by friction profiles of a section and then the button-shaped projections yield elastically outward and to the side when they are slipped over the profiles 3 'practically aligned horizontally.

 Another advantage of the self-supporting enveloping surfaces produced according to the process indicated is that when profiles made of a suitable material are used, it is possible, by hot welding and deformation of the profiles, to insert additional elements into the enveloping surface or to form perforations therein, before applying or introducing the thermosetting filler and then applying the laminates of synthetic material on the interior and exterior surfaces.

Claims (14)

REVNDILATIONS  1. Method of manufacturing self-supporting enveloping surfaces with several layers! in particular a multi-layer boat hull planking, using a forming framework predetermining the desired three-dimensional shape of the enveloping surface and on which profiles of the same section are placed so that they nested between them, they are fixed by points to the forming framework and they are assembled together using a thermosetting filler which partially penetrates them, we apply to the surfaces thus formed laminate of reinforced thermosetting synthetic material - of fibers and it is assembled to these surfaces, a process characterized in that one chooses in such a way for the sections a practically double section T and that the profiles are arranged in such a way that the neighboring profile sections are each turned practically 900 from one another.  2. Method according to claim 1, characterized in that, as profiles, hollow profiles are used having a practically double V section and that the wings of the two Vs each time limiting a large side of the hollow profile form a curved side wall concave on the outside and the edges are rounded each time  3. Method according to any one of claims 1 and 2, characterized in that around the head surface of each of the sections practically aligned horizontally, a laminate of thermosetting synthetic material reinforced with fibers is laid, which extends up to the lateral surfaces of the profiles practically vertically aligned and itself forms the filling material, or which is applied before the introduction of the filling material.  4. Method according to any one of claims 1 to 3, characterized in that lton uses profiles formed of synthetic material or metal, for example aluminum.  5. Method according to any one of claims 1 to 4, characterized in that several profiles are joined using drau at least one mounting clamp practically in U, to form each time a section, only by curvature of the mounting clamp, this section is adapted to the contour of the forming frame section which is each time to be covered and which is then fixed to the forming frame, after which the clamp (s) are removed. mounting.  6. Method according to claim 5, characterized in that one curves and that is individually fixed to different contours several mounting clamps (11) used for a section.  7. U-profile mounting clip with wings of elastic material, for use in the method according to any one of claims 1 to 6, characterized in that the U-profile (11) is fixed to a frame rigid (13) practically in a U which surrounds it in the same direction and which has wings (113, 113 ') adjoining the respective wings (111, 111') of the U profile and spaced therefrom, which bear adjusting screws (114, 115) with which the distance between each wing (111, 111 ') of the U-shaped profile (11) and the corresponding wing (113, 113') of the frame (13) can be adjusted.  8. Clamp according to claim 7, characterized in that the frame (13) has on each of its wings (113, 113 ') several adjusting screws (114, 115) spaced in the direction of its longitudinal axis and can be adjusted differently, so that one can establish, between the wings (113, 113 ') of the frame (13) and the respective wings (111, 111') of the U-shaped profile (11), distances which vary in the longitudinal direction of the wings.  9. Pliers according to any one of claims 7 and 8, characterized by the fact that the adjustment screws 1114, 115) are threaded bolts (114) screwed into threaded holes in the wings (113, 113 ') of the frame (13) and provided with finned heads (115) at their ends opposite the wings (111, 111 ') of the U-shaped profile (11).  10. Clamp according to any one of claims 7 to 9, characterized in that the U-shaped profile (11) is for spring steel.  11. Clamp according to any one of claims 7 to 10, characterized in that the wings (113, 113 ') of the frame (13) are articulated to their connecting core (113 ") so as to be able to pivot but at be able to be locked in their mounting position.  12. Pliers according to any one of claims 7 to 11, characterized in that the wings (111, 111 ') have, on their sides facing the profiles (3, 3') of button-shaped projections (14 , 14 ') whose mutual spacing is chosen so. as they commit. in the respective cavities formed each time by a profile (3) practically aligned vertically and neighboring profiles (3 ') practically aligned horizontally.  13. Pliers according to claim 12, characterized in that the button-shaped projections (14 ') are elastic in the direction of the cavities so that they touch, so as to align the profiles (3) practically vertically aligned.  14. Pliers according to claim 13, characterized in that the button-shaped projections (14 ') are formed by adjustable screws in the direction of the cavities and which touch, so as to align them, the profiles (3) practically aligned vertically.