FR3067378A1 - DEVICE COMPRISING A FLEXIBLE HINGE AND SIDE PORTIONS - Google Patents

Abstract

The invention relates to a device comprising a flexible film hinge, connecting two rigid plates (10, 12), so as to be displaceable between at least one deployed angular position and a folded angular position, and in which: - each rigid plate present at at least one main portion (4, 6) flexibly elastic with a rest form corresponding to a curvature in a constant direction of curvature so that the rigid plates are elastically biased towards their angular position closest to the resting form , characterized in that: - there is a larger circle inscribed within said curvature of constant direction, - each rigid plate has, from the hinge, at least one lateral portion (11, 13) extending on each side the main portion, each lateral portion having a shape at rest away from said largest inscribed circle.

Description

DEVICE COMPRISING A FLEXIBLE HINGE AND SIDE PORTIONS

The invention relates to a device comprising at least one hinge, in particular a flexible hinge (not articulated), integrated between two rigid plates, the two rigid plates being able to be moved by pivoting around the hinge between a deployed angular position and an angular position. folded.

In particular, each rigid plate has at least one elastic main portion in flexion with a shape at rest corresponding to a warping with a curvature of constant direction, so that the rigid plates are biased elastically towards their angular position closest to the form. at rest of their central portion.

Integrated non-articulated hinges, for example of the so-called film hinge type, have been known for a long time and are the subject of numerous applications, in particular in the field of packaging. They generally consist of a local reduction in thickness of an elastic material in bending making it possible to form a more flexible portion between two more rigid portions of this material.

Such known hinges do not have sufficient mechanical characteristics in certain applications, for example in the space field.

US 7,354,033 describes a device forming an elastic monolithic hinge not articulated between two portions of a flat or curved strip (tiled) of the “Carpentier joint” type forming a spring that can be formed from spring steel, copper alloy and beryllium or a composite or other material. In a first embodiment, the hinge is formed of a portion of a second material which is more flexible than that forming the spring band, for example a shape memory alloy, a steel, an alloy of copper and beryllium. In a second embodiment, the hinge is formed of a portion made of the same material as that of the strip forming a spring, but in a smaller thickness, in the manner of film hinges. The third embodiment is similar to the second and also has lateral reinforcements in shape memory alloy.

The first embodiment poses the problem of reliable manufacture of the junction between the hinge portion and the portions forming the strip. In particular, in the space and aeronautical field, such a foldable device must be reliable and have sufficient resistance to mechanical stresses, and in particular to mechanical stresses undergone by the device during any deployment and any folding. On the other hand, metallic and shape memory materials do not allow a very small radius of curvature to be obtained without degradation of their elastic property after several displacements corresponding to deployments and folds of the device.

However, it turns out that the mechanical stresses undergone by the device during any deployment and any folding, in particular when these are repeated many times, lead to a deterioration of the device and in particular of the flexible hinge thereof. .

The invention therefore aims in particular to provide a device for overcoming these drawbacks.

The invention also aims to provide such a device which can be folded or deployed reliably.

The invention also aims to propose such a device which can be the subject of numerous variant embodiments, and compatible with numerous applications, including in the space and aeronautical field.

The invention also aims to provide such a device which, moreover, can be produced so as to have an improved resistance in longitudinal compression in a deployed angular position.

To do this, the invention relates to a device comprising a flexible film hinge connecting two plates, called rigid plates, more rigid than the hinge, so that they can be moved by pivoting the rigid plates around the hinge between at least one angular position. deployed and a folded angular position, the rigid plates forming between them in the deployed angular position an angle greater than that formed in the folded angular position, and in which:

each rigid plate presents from the hinge at least one portion, called the main portion, elastic in bending with a shape at rest corresponding to warping according to a curvature of constant direction around an axis intersecting at the hinge, so that the rigid plates are resiliently returned to their angular position closest to the shape at rest of their main portion, characterized in that:

there is a larger circle inscribed within said constant curvature of each main portion of each rigid plate, each rigid plate has, from the hinge, at least one lateral portion extending on each side of the main portion (that is to say at least along a portion of each longitudinal edge of a rigid plate), each lateral portion having a shape at rest deviating from said larger inscribed circle and outside of it.

The inventors have found that the presence of such lateral portions along the rigid plates of the device makes it possible to improve the stability of the device as well as the resistance in transverse flexion (or to a shearing force) and / or in lateral shear and / or the resistance in longitudinal compression of the device in the deployed position. During a spontaneous deployment of the device for example, the presence of said lateral portions makes it possible to facilitate and guide its deployment, by avoiding any unwanted shift or displacement of a rigid plate, such as a superposition of rigid plates, liable to compromise the possibility of reaching the predetermined state of rest of the device according to the invention. This also makes it possible to avoid, or at least to significantly reduce, any deterioration or premature wear of the flexible hinge which is particularly stressed during any movement between a deployed angular position and a folded angular position (from an deployed angular position to a folded angular position or a folded angular position to a deployed angular position).

Another advantage linked to the presence of the lateral portions also consists in obtaining a more robust device, capable of accumulating more energy, in the manner of a spring, in an angular position distinct from the rest position which allows, when the device is released or released, a return to the rest position with strong guidance provided by the presence of said side portions. This is explained in particular by the fact that the material forming the hinge can be stressed in a distinct manner between the lateral portions and the main portion of the rigid plates, for example by being put in traction when the device is in an angular position sufficiently away from its rest position. The presence of said lateral portions therefore makes it possible to generate, from an angular position distinct from the rest position, a greater restoring force on either side of each rigid plate and to provide better guidance of the device during the return of the device to its rest position. In addition, this greater restoring force provided by a device according to the invention is produced for a set of positions distinct from the rest position, and in particular even for angular positions close to the rest position, for example for a angular displacement of less than 90 °, or even less than 50 ° or even 30 °, of a rigid plate relative to the other from the rest position of the device.

Each lateral portion of a rigid plate may have a flat or curved external surface, for example an arc of a circle of radius greater than the radius of the largest circle inscribed within the curvature of constant direction of the main portion of the rigid plate. The width of the lateral portions of the rigid plates is not necessarily important compared to the width of a rigid plate of the device. Even a small side portion width compared to the width of the rigid plate may be sufficient to provide a significant stabilization and guiding effect. Advantageously and according to the invention, each lateral portion has a width at least equal to 1.5%, in particular at least equal to 3%, and in particular at least equal to 5%, of the width of the main portion of the plate. rigid (to which it is juxtaposed) when said rigid plate is flattened (that is to say made flat). In particular, advantageously and according to the invention, each lateral portion has a width of between 1.5% and 40%, in particular between 2% and 30%, and in particular between 5% and 25%, of the width of the portion main of the rigid plate (to which it is juxtaposed) when said rigid plate is flattened (that is to say made flat). The more the width of the lateral portions increases, the more the stabilizing, guiding and restoring effect provided by the device are also increased. The wider the side portions, the easier it will be for the device to deploy to its rest position easily, quickly and without the risk of overlapping the rigid plates between them, regardless of the starting angle formed between the rigid plates. in the folded angular position.

Said lateral portions of each rigid plate of the device can extend over all or part of the length of each rigid plate. In an advantageous embodiment, said lateral portions of each rigid plate of the device are arranged at least on a part of the lateral portion extending from the hinge. Said lateral portions of each rigid plate of the device may themselves have a thickness and a width which may or may not vary. In addition, each rigid plate of the device has at least one lateral portion on each of its two longitudinal edges. The device according to the invention therefore has in an advantageous embodiment of a device according to the invention an axial symmetry with respect to a longitudinal or transverse axis of symmetry.

Throughout the text, the term "longitudinal" and its derivatives refer, when the device has a straight line of deployment, to the right longitudinal direction in which it is deployed. When the device is more or less curved or has a more or less curved deployment line between its two longitudinal ends, they refer, in any cross section of the structure, to a direction tangent to the deployment line. The term "transverse" and its derivatives, and the term "lateral" and its derivatives, refer to directions orthogonal to the longitudinal direction. The terms “top” and “upper” and their derivatives refer to any zone of the device situated outside the curvature of constant direction of the main portion of a rigid plate of the device (convex side) as opposed to the terms “ bottom ”and“ lower ”and their derivatives referring to any zone of the device situated inside said curvature (concave side).

Each main portion of a rigid plate has, in the rest position, a general shape of a closed curve portion (said general shape corresponding to a cross section of said main portion). This closed curve portion can be a simple closed curve portion (which does not admit a double point), for example an arc of a circle, an arc of an ellipse, an arc of a parabola, a hyperbola arc or an arc of any other curve, mathematically remarkable or not.

In a particularly advantageous variant of a device according to the invention, the cross section of each rigid plate is such that each main portion has a shape at rest in an arc of a circle and in that each side portion has a shape at rest s 'deviating from said arc. There is therefore at least one discontinuity or an inflection point between a main portion and a lateral portion of the same rigid plate of a device according to the invention (said main portion and said lateral portion being juxtaposed, in contact l from one another and directly related to each other).

Advantageously and according to the invention, the cross section of each rigid plate has a general shape at rest distinct from an arc of a circle (that is to say in cross section). Thus, each rigid plate can have a general shape at rest comprising an arc of a circle (corresponding in particular to at least one main portion of a rigid plate), but not only an arc of a circle, this arc of circle being able to be juxtaposed with at least one other separate portion of said circular arc (corresponding in particular to at least one lateral portion of a rigid plate).

The cross section of the main portion of each rigid plate has a shape at rest corresponding to warping and said main portion is elastic in bending at least in the direction of the flattening of its cross section. It is therefore possible, under the application of a compressive stress having at least one component normal to the surface of the main portion, to remove said warpage by a punctual flattening of the rigid plate. If the compressive stress is removed, the main portion of the rigid plate regains its rest form corresponding to warping.

The shape at rest of each rigid plate corresponds in particular to a deployed angular position of the device according to the invention. In this case, to arrange the device according to the invention in a folded angular position, it is necessary to apply a stress in a direction substantially normal to the surface of the main portion of each rigid plate so as to flatten them and then make an effort to bring the two rigid plates together, then if this constraint is removed, the device deploys spontaneously again towards its deployed rest position. In such an alternative embodiment of a device according to the invention, the rigid plates are resiliently recalled in bending towards said at least one deployed angular position.

The invention therefore also relates to a foldable / deployable device with spontaneous deployment that can be placed:

in the deployed state in which it has at least two rigid plates connected by a film hinge, each rigid plate being elastic in bending with a shape at rest corresponding to a warping around an axis orthogonal to the hinge, in a folded state wherein the rigid plates form an angle between them less than that formed in the deployed state, each rigid plate being flattened elastically in bending so that the device is returned to the deployed state.

The rigid plates and the flexible hinge can be formed from the same material (the flexible hinge being for example formed by a thinning of the material between the two rigid plates), said material being able to be chosen from the group of metallic materials, polymers (in particular thermoplastics or thermosets) and composite materials (in particular with a polymer matrix). The rigid plates and the flexible hinge can also be formed from separate materials, the rigid plates being for example formed from a first material and the flexible hinge being formed from a second material distinct from said first material.

Advantageously and according to the invention, each rigid plate comprises at least one reinforcing structure of a rigid composite material which composes it, capable of imparting resistance at least in longitudinal tension and compression to this rigid composite material, and a matrix at within which the reinforcing structure extends.

Throughout the text, the term “composite material” denotes any heterogeneous synthetic solid material comprising at least one reinforcing structure, formed from at least one first material, and adapted to confer mainly mechanical resistance properties on said composite material, this structure reinforcement being associated with at least one other part, called a matrix, formed from at least one second polymeric material having mechanical properties different from those of the reinforcement structure. In particular, this expression covers composite materials traditionally made up of a reinforcing structure formed from sheets, strips or fabrics of fibers (having the function of transmitting the stresses at least in longitudinal traction (in the direction of the fibers), and in general also the constraints in longitudinal compression), this reinforcement structure being embedded in a matrix of polymer material (having the function of imparting the general shape and dimensions of the material, of supporting the reinforcement structure and of resisting in transverse compression ( orthogonally to the fibers of the reinforcing structure)). But it also designates in particular multilayer materials (such as those traditionally qualified as complexes or laminates), for example comprising a central core (formed of one or more layers, for example metallic (s) and / or made of rigid synthetic material in traction) acting as a reinforcement structure capable of transmitting stresses at least in longitudinal traction (in any direction parallel to the plane of each layer constituting this core) interposed between two thicknesses (each formed of one or more layers) of polymeric materials, these two thicknesses acting as a matrix.

Advantageously and according to the invention, said hinge is formed of at least one connecting layer of a reinforcing structure extending in continuity and in common between said rigid plates. The rigid plates are more rigid than the flexible film hinge.

Advantageously and according to the invention, said hinge comprises at least one matrix within which extends said connecting layer of a reinforcing structure, the matrix of said hinge itself being formed from a material which is more flexible in bending than that constituting a matrix of rigid composite material of each rigid wafer.

The main portion may have a different curvature in the different angular positions. In particular, advantageously and according to the invention, each main portion of each rigid plate has different curvatures in the deployed angular position and in the folded angular position.

In particular, advantageously and according to the invention, each main portion of each rigid plate has at least one end extending along the hinge whose curvature is zero in a folded angular position. Each main portion of a rigid plate may have a flat portion in a folded angular position of the device according to the invention.

Advantageously and according to the invention, each rigid plate has at least one end stop in contact with at least one end stop of a separate rigid plate, by presenting facing edges, in the angular deployed position, said stops. not being in contact in the folded angular position.

Advantageously and according to the invention, said facing edges are arranged to be able to act as a compression stop in a direction normal to the edges while allowing folding of the hinge at least in one direction from the deployed angular position.

The invention also relates to a device according to the invention comprising a plurality of main portions within the same rigid plate, said main portions being juxtaposed one with respect to the other laterally and connected together by said lateral portions, so as to forming a structure having a general shape of the “corrugated sheet” type (said corrugations thus formed being regular or irregular with respect to each other). Advantageously and according to the invention, each rigid plate comprises at least two main portions interconnected by at least one lateral portion. Advantageously and according to the invention, the number of main portions of each of the two rigid plates is identical and the number of lateral portions of each of the two rigid plates is identical, at least one lateral portion being disposed between two main portions of the same rigid plate. The lateral portions disposed between two main portions which they connect together can have any generally planar shape (in particular by having several planar portions intersecting between them) or curved (with constant or variable curvature). Such a device according to the invention comprising a plurality of main portions can therefore be symmetrical with respect to the hinge or not.

In addition, in a particularly advantageous variant of a device according to the invention, each lateral portion has a shape at rest corresponding to warping according to a curvature, around an axis intersecting at the hinge, having an opposite direction to the curvature of the main portion to the side of which it extends. Such a device comprising several main portions and several lateral portions juxtaposed laterally alternately with each other contributes to forming successive corrugations in the manner of a corrugated sheet.

A device according to the invention, in particular a device comprising several main portions, also has the advantage of being able to have a greater length than that of other separate devices.

The invention also relates to a device characterized in combination by all or some of the characteristics mentioned above or below.

Other objects, characteristics and advantages of the invention appear on reading the following description of one of its preferred embodiments given by way of nonlimiting example, and which refers to the appended figures in which:

- Figure 1 is a schematic perspective view showing a device according to the invention according to a first embodiment of the invention in a deployed angular position,

FIG. 2 is a schematic perspective view of the device according to the first embodiment of the invention in a deployed angular position,

- Figure 3 is a schematic perspective view of the device according to the first embodiment of the invention in an angular position folded at 90 °,

- Figure 4 is a schematic perspective view of the device according to the first embodiment of the invention in an angular position folded at 180 °,

FIG. 5 is a schematic view of the device according to the first embodiment of the invention in an angular position folded 180 °, on the side of the folded hinge,

FIG. 6 is a schematic view in longitudinal section of the device according to the first embodiment of the invention in a deployed angular position,

FIG. 7 is a schematic view in longitudinal section of the device according to the first embodiment of the invention in an angular position folded back to 180 °,

FIG. 8 is a schematic cross-sectional view of the device according to the first embodiment of the invention in an angular position folded back by 180 °,

- Figure 9 is a schematic cross-sectional view of the device according to the first embodiment of the invention in an angular position folded 180 °,

FIG. 10 is a schematic perspective view showing a device according to the invention according to a second embodiment of the invention in a deployed angular position,

FIG. 11 is a schematic view in longitudinal section of the device according to the second embodiment of the invention in a deployed angular position,

FIG. 12 is a schematic view in longitudinal section of the device according to the second embodiment of the invention in an angular position folded back by 180 °,

FIG. 13 is a diagram representing a portion of a larger circle which can be inscribed within a rigid plate of a device according to the invention,

FIGS. 14 to 16 are schematic cross-section views showing different embodiments of a device according to the invention with a larger circle inscribed within a rigid plate of said device,

FIG. 17 is a schematic perspective view showing a device according to the invention according to a third embodiment of the invention in a deployed angular position,

FIG. 18 is a schematic view in longitudinal section of the device according to the third embodiment of the invention in a deployed angular position,

FIG. 19 is a schematic perspective view showing a device according to the invention according to a fourth embodiment of the invention in a deployed angular position,

FIG. 20 is a schematic perspective view of the device according to the fourth embodiment of the invention in an angular position folded at 90 °,

FIG. 21 is a schematic perspective view of the device according to the fourth embodiment of the invention in an angular position folded back by 180 °,

- Figures 22 to 25 are schematic cross-sectional views showing different embodiments of a device according to the invention with a larger circle inscribed within a rigid plate of said device.

In the first embodiment shown in FIGS. 1 to 9, the device according to the invention comprises two rigid plates 10 and 12 formed from rigid material, more rigid than the material forming a hinge 20 connecting the two rigid plates 10, 12. The rigid plates 10, 12 are adapted so that they can be moved by pivoting around the hinge 20 between a deployed angular position and at least one folded angular position, the rigid plates 10, 12 forming an angle between them, in the deployed angular position greater than that formed in the folded angular position.

The rigid plates can be made of polymeric synthetic material or rigid composite material, the film hinge being formed by a thinning of the material between the two sections (FIGS. 17 and 18), or by a common reinforcement structure with a more flexible (Figures 1 to 12).

The material forming each rigid wafer can for example be chosen from thermoplastic polymers: polyethylenes, polypropylenes, polyethylene terephthalates (PET), polystyrenes, polycarbonates, polyethers, polyether ketones; or thermosetting: polyester resins, epoxy resins, phenolic resins, polyimide resins, cyanate ester resins and melamine resins. The material forming each rigid wafer can for example be chosen from composite materials, in particular composite materials with a polymer matrix (thermoplastic or thermosetting) within which extends at least one reinforcement such as particles (mineral, ceramic or even metallic). ), synthetic fiber fabrics (carbon fibers, glass fibers, aramid fibers, boron fibers ...), synthetic fiber threads (polyamide fibers, polyester fibers, polyethylene fibers, chlorofibers, acrylic fibers, polypropylene fibers, polyurethane fibers ...), metallic fibers, beryllium fibers, ceramic fibers, cellulose fibers and their mixtures.

The hinge may for example be formed from at least one strip 15 made from at least one material chosen from the group formed from flexible polymeric materials (in particular natural rubbers, silicone elastomers, polyurethane elastomers, polychloroprene elastomers, polyethylenes, polystyrenes ...), flexible composite materials, flexible metallic materials, fabrics of synthetic fibers (carbon fibers, glass fibers, aramid fibers (aromatic polyamides), boron fibers ...), yarns synthetic fibers (polyamide fibers, polyester fibers, polyethylene fibers, polyvinyl chloride (PVC) fibers (chlorofibres), acrylic fibers, polypropylene fibers, polyurethane fibers ...), metallic fibers, fiber beryllium, ceramic fibers, cellulosic fibers and their mixtures.

Each rigid plate 10, 12 has:

a main portion 4, 6 which is elastic in bending with a shape at rest corresponding to warping according to a curvature of constant direction around a secant axis at the hinge 20, and

- lateral portions 11, 13 extending on each side of the main portions 4, 6, each lateral portion 11, 13 having a shape at rest deviating from the largest circle inscribed within the curvature of each main portion.

Each main portion 4, 6 is elastic in bending with a shape at rest corresponding to a warping according to a curvature of constant direction around an axis intersecting at the hinge, so that the rigid plates 10, 12 are resiliently returned to their position angular closest to the shape at rest of their main portion.

Figures 1 and 2 show the device in the rest position which corresponds to a deployed state thereof in which the rigid plates are in the extension of one another and extend longitudinally substantially in the same plane. The hinge 20 connects the rigid plates together. On the upper side of the device, the rigid plates are extended towards each other, above the hinge, over part of the thickness of the device.

On this part of the thickness, the rigid plates 10, 12 are extended so as to form end edges 30 extending transversely and coming into contact with one another in the angular position deployed so as to make office of stop in longitudinal compression. The edges 30 extend over the entire width of the rigid plates 10, 12 and also make it possible to block the device according to the invention in the deployed angular position by preventing the folding of the hinge in one direction, while allowing the folding of the hinge only the other way around.

In this first embodiment, the device is formed of a strip 15 of aramid (aromatic polyamide) fiber fabric disposed between upper lamellae 16, 17 and lower lamellae 18, 19, the lower lamellae 18, 19 n ' not being in contact with one another (in particular in the deployed state) but are sufficiently spaced to allow the device to be folded while the upper lamellae 16, 17 are juxtaposed one in the extension of the other of so as to present edges 30 in contact in the deployed angular position. The upper and lower lamellae can be formed from any polymer or composite material with a polymer matrix as defined above with regard to the rigid plates. The strip 15 of fabric is linked (by gluing or by copolymerization or prior melting of the strips 16, 17, 18, 19) to the upper strips 16, 17 and to the lower strips 18, 19, the strip 15 is not linked to the strips upper 16, 17 in the region of the band 15 forming a hinge. The strip 15 of fabric is linked to the upper strips 16, 17 only opposite the lower strips 18, 19. The rigid plate 10 therefore comprises a part of the strip 15 of fabric between an upper strip 16 and a lower strip 18 The rigid plate 12 therefore comprises a part of the strip 15 of fabric between an upper strip 17 and a lower strip 19.

In Figure 1, we can not see the hinge, the latter being covered by rigid plates extended towards one another. The hinge 20 is visible in FIG. 2 showing a perspective view of the device and making it possible to view the underside of the device (inside the curvature of the main portions of the rigid plates).

FIG. 3 represents the device in a partially folded angular position, the two rigid plates forming between them an angle of the order of 90 ° (or one of the two rigid plates having undergone a rotation of the order of 90 ° from the deployed angular position). In this angular position, along the hinge the main portions of the rigid plates have zero or less curvature than in the deployed angular position. The spacing of the ends of the rigid plates at the hinge reveals the hinge 20. In the position shown in Figure 3, the lateral portions 11, 13 of each of the rigid plates 10, 12 are in contact with each other at during deployment of the device and make it possible to avoid any overlapping or any superposition of one rigid plate by the other rigid plate of the device.

FIG. 4 represents a perspective view and from the side opposite the hinge of the device in a fully folded angular position, one of the two rigid plates having undergone a rotation of the order of 180 ° from the deployed angular position.

FIG. 5 represents a front and side view of the hinge of the device in an entirely folded angular position, one of the two rigid plates having undergone a rotation of the order of 180 ° from the deployed angular position. It can be seen in FIG. 5 that the strip 15 of fabric is more stretched at the ends of the lateral portions 11, 13, the strip 15 of fabric being in tension. The strip 15 of fabric is in tension in zones 3 of the lateral portions and in a zone 2 corresponding to the width of the main portion of the rigid plates, the rigid plates being compressed towards one another by the exercise of pressure on each of their main portions. In the hinge zone of the device thus folded back, zones 2 and 3 of the strip 15 of fabric at the level of the lateral portions and of the main portion, which deviate in the folded angular position, are in traction, which generates a return force. of each rigid plate providing better guiding of the device when it returns to the rest position (angular position deployed). Consequently, this also makes it possible to prevent any untimely overlapping of the rigid plates between them. Another advantage linked to the presence of the lateral portions also consists in making it possible to obtain a more robust device, capable of accumulating more energy (in the manner of a spring) in folded angular position which allows, when the device is released or released, a return to the rest position with strong guidance provided by the presence of the side portions. In other words, the restoring force linked to the pulling of the strip 15 of tissue improves the deployment force of the device for its spontaneous return to the rest position. This "motorization" (by spontaneous deployment) is linked to the increase in the energy accumulated by the device moved out of the rest position. In addition, during folding (displacement of the rigid plates towards a folded angular position), the contact surface of the rigid plates is increased at the level of the lateral portions, which has the effect of reducing the contact pressure and therefore improving the resistance of rigid pads as well as preventing delamination.

A spontaneous deployment of the device can take place from any angular position distinct from an angular position corresponding to the rest position (Figure 1), in particular from a folded position as shown in Figures 3 and 4 but could also take place spontaneously from an intermediate position between the position shown in Figure 1 and the position shown in Figure 3. In other words, it is not absolutely necessary to fold as much as possible (as shown in Figure 4) the device to be able to generate a sufficient restoring force to allow spontaneous deployment.

Figures 6 and 7 are views in longitudinal section of the device showing the rigid plates 10 and 12 and the hinge 20 in a deployed state (Figure 6) and a fully folded state (Figure 7).

Figures 8 and 9 show cross-sectional views of the device in a fully folded angular position, one of the two rigid plates having undergone a rotation of the order of 180 ° from the deployed angular position. In FIG. 8, the main portions 4, 6 of the rigid plates 10, 12 are flattened (so as to be flat, at least in the place of the section shown), the lateral portions appearing raised towards the outside. The diagram in FIG. 8 corresponds to an embodiment such as the first embodiment shown, in which the lateral portions deviate from said largest circle inscribed within the curvature of each main portion and deviate in particular from the tangent to said largest circle at a point corresponding to the junction between the main portion and the lateral portion of the rigid plate. In FIG. 9, the main portions 4, 6 of the rigid plates 10, 12 are flattened, each rigid plate therefore appearing to be flat (at least at the location of the section shown) under the application of a compressive stress on the main portions of the rigid plates 10, 12. The diagram in FIG. 9 corresponds to an embodiment in which the lateral portions deviate from said largest circle inscribed within the curvature of each main portion by being parallel to the tangent to said largest circle at a point corresponding to the junction between the main portion and the lateral portion of the rigid plate.

The lateral portions of the rigid plates and of the hinge make it possible to improve the stability of the device, and in particular to increase the resistance in transverse bending (that is to say the resistance to a shearing force) in the deployed state. as in an at least partially folded state. Consequently, the lateral portions of the rigid plates and of the hinge make it possible to improve the stability of the device during its deployment or its folding by providing a guiding effect. In the case of the first embodiment of FIGS. 1 to 9, this makes it possible in particular to avoid any overlap of the rigid plates at the level of the hinge when the device is deployed to the rest position shown in the figure. 1.

The lateral portions of the rigid plates and of the hinge of a device according to the invention also make it possible to avoid overlapping of the plates.

In the embodiment shown, the rigid plates 10, 12 have facing edges 30 which are plane faces parallel to each other, said edges 30 being in contact with each other in the deployed position ( rest position).

In the second embodiment shown in Figures 10 to 12, the device according to the invention comprises two rigid plates 10 and 12 formed of rigid material more rigid than a hinge 20 connecting the two rigid plates 10, 12. Each rigid plate 10, 12 has a main portion 4, 6 and lateral portions 11, 13.

FIGS. 11 and 12 are views in longitudinal section of the device according to this second embodiment representing the rigid plates 10 and 12 and the hinge 20 in a rectilinear deployed state (FIG. 11) and in a fully folded state (after a rotation of 180 ° from one of the two rigid plates around the hinge) (Figure 12).

The device according to this second embodiment differs from the device according to the first embodiment in that it does not have said lower strips 18, 19. The device is therefore formed from a strip 15 of aramid fiber fabric (polyamide aromatic) arranged under the upper lamellae 16, 17, the upper lamellae 16, 17 being juxtaposed one in the extension of the other so as to present edges 30 in contact in the deployed angular position. The upper lamellae can be formed from any polymer or composite material with a polymer matrix as defined above with regard to the rigid plates. The strip 15 of fabric is bonded (by gluing or by copolymerization or prior melting of the strips 16, 17, 18, 19) to the upper strips 16, 17, except in a central zone corresponding to the hinge, the strip 15 not being linked to the upper strips 16, 17 in an area of the strip 15 forming a hinge. The rigid plate 10 therefore comprises an upper strip 16 disposed on a part of the strip 15 of fabric. The rigid plate 12 therefore comprises an upper strip 17 disposed on the other part of the strip 15 of fabric. In the embodiments shown, the thickness of the rigid plates and the thickness of the hinge are substantially identical, the thickness of the device being substantially constant in the deployed state.

In the first and second embodiments shown, the strip 15 of fabric extends along the entire width and the entire length of the device, but the strip 15 of fabric could also completely stop before without spanning the entire length. width and / or length of the device, from the moment it connects the two rigid plates by forming a hinge 20.

FIG. 13 represents a portion 60 of a circle likely to be the largest circle that can be inscribed within the curvature of the main portion of a rigid plate of a device according to the invention. The right-hand portions represented in the area 62 located between a straight line intersecting the portion of a circle 60 illustrate all of the accessible positions (portions of straight lines represented by dotted lines in the area 62) that the lateral portions of a plate can take. rigid in its rest position (in cross section). Within the domain 62 represented in FIG. 13, the lateral portions can also take other forms than straight portions.

Figures 14, 15 and 16 show a portion 60 of the largest circle inscribed within the curvature of the main portion 65 of a rigid plate 1 of a device according to the invention.

In the embodiment illustrated in FIG. 14, the lateral portions 64 of the rigid plate 1 are straight portions deviating from said largest inscribed circle and extending in a direction extending between said largest inscribed circle and the straight line 61 intersects this circle.

In the embodiment illustrated in FIG. 15, the lateral portions 66 of the rigid plate 1 are straight portions deviating from said largest inscribed circle and parallel to the straight line 61 intersecting this circle.

In the embodiment illustrated in FIG. 16, the lateral portions 66 of the rigid plate 1 are arcs of a circle moving away from said largest inscribed circle and extending between said largest inscribed circle and the straight line intersecting this circle. In addition, the lateral portions 68 of the rigid plate 1 have a curvature in the opposite direction to the curvature of the circle portion 60 of the main portion of the rigid plate, the radius of the arcs of circle of the lateral portions 68 being greater than the radius. of the arc of a circle 60.

In a third embodiment shown in FIGS. 17 and 18, the device according to the invention comprises two rigid plates 40 and 41 formed from rigid material more rigid than a hinge 50 connecting the two rigid plates 40, 41, the rigid plates and the hinge 50 being formed of the same material, the thickness of which is smaller with regard to the hinge 50, so as to allow the device to be folded back by pivoting the rigid plates 40, 41 around the hinge 50. In the embodiment shown in Figures 17 and 18, Γthinning is achieved in the form of a transverse groove formed in the hinge 50 on the upper side of the device, the underside of the hinge 50 being planar. However, it could also for example be a thinning having any other shape and which can also be provided in the hinge 50 on the lower side of the device.

The device can be formed from a material chosen from the group formed from polymer materials (thermoplastics: polypropylenes, polyethylenes, polystyrenes, polyether ketones, polyvinyl chlorides ...; or thermosets: polyester resins, epoxy resins, phenolic resins, polyimide resins , cyanate ester resins, melamine resins ...), and composite materials, in particular composite materials with a polymer matrix (thermoplastic or thermosetting) within which extends at least one reinforcement such as particles (mineral, ceramic or still metallic), synthetic fiber fabrics (carbon fibers, glass fibers, aramid fibers, boron fibers ...), synthetic fiber threads (polyamide fibers, polyester fibers, polyethylene fibers, polychloride fibers vinyl (PVC) (chlorofibres), acrylic fibers, polypropylene fibers, polyurethane fibers ...), metallic fibers, fi beryllium berries, ceramic fibers, cellulosic fibers.

Each rigid plate 40, 41 has:

a main portion 44, 45 which is elastic in bending with a shape at rest corresponding to warping according to a curvature of constant direction around an axis intersecting at the hinge, and

- lateral portions 47, 48 extending on each side of the main portions 44, 45 each lateral portion 47, 48 having a shape at rest deviating from the largest circle inscribed within the curvature of each main portion 44, 45 .

Each main portion 44, 45 is elastic in flexion with a shape at rest corresponding to a warping according to a curvature of constant direction around an axis intersecting at the hinge, so that the rigid plates 40, 41 are resiliently biased towards their position. angular closest to the shape at rest of their main portion.

Figure 18 is a longitudinal sectional view of the device according to this third embodiment showing the rigid plates 40 and 41 and the hinge 50 in a deployed state.

In a fourth embodiment shown in FIGS. 19 to 21, the device differs from a device according to the first embodiment in that the lateral portions extend transversely in a form distinct from a plane but having several portions of curved surfaces, like a corrugated sheet. This makes it possible to provide a greater restoring force on either side of each rigid plate and to provide better guidance of the device when the device returns to its rest position than in a device according to the first embodiment, and therefore to obtain a device having a greater motorization, that is to say a restoring force towards the greater rest position. For a device having the same width and the same length, the invention therefore offers the possibility of providing a device having a reduced bulk, compared to the bulk of a device according to the first embodiment, according to the thickness of the device (the dimensions being similar to the peak-to-peak amplitude of the device). The device according to the invention according to the fourth embodiment comprises two rigid plates 70 and 72 formed of rigid material more rigid than a hinge 80 connecting the two rigid plates 70, 72. The rigid plates 70, 72 are adapted to be able to be displaced by pivoting around the hinge 80 between a deployed angular position and at least one folded angular position, the rigid plates 70, 72 forming between them, in the deployed angular position, an angle greater than that formed in the folded angular position.

In the four previous embodiments, the angle formed by the rigid plates between them refers to a projecting angle formed by the two plates (at least in the folded position of the device). However, it is also possible to provide that the folded position of the device corresponds to a position in which the angle formed between the two plates is greater than 180 °.

Figures 22 to 25 show a portion 60 of the largest circle inscribed within the curvature of the main portion 65 of a rigid plate of a device according to the invention.

In the embodiment illustrated in FIG. 22, the lateral portions 69 of the rigid plate are arcs of a circle deviating from said largest inscribed and intersecting circle to the right 61 intersecting at the largest inscribed circle. The lateral portions 69 of the rigid plate have a curvature in the opposite direction to the curvature of the circle portion 60 of the main portion of the rigid plate and the radius of the arcs of circle of the lateral portions 69 is less than the radius of the arc of circle 60.

In the embodiment illustrated in FIG. 23, the lateral portions of the rigid plate are formed by circular arcs 91 and 93 deviating from said largest inscribed circle, the circular arcs 90 and 92 forming main portions (the radius of the largest circle inscribed within the curvature of the portion 90 being greater than the radius of the largest circle inscribed within the curvature of the portions 92). The circular arcs 91 of the rigid plate have a curvature in the opposite direction to the curvature of the circle portion 60 of the main portion of the rigid plate. The circular arcs 92 of the rigid plate have a curvature in the opposite direction to the curvature of the circular arcs 91 and the circular arcs 93 of the rigid plate have a curvature in the opposite direction to the curvature of the circular arcs 92.

In the embodiment illustrated in FIG. 24, the lateral portions of the rigid plate are arcs of a circle 96, 97 deviating from said largest inscribed circle. The size of the device having a section as shown in Figure 24 is less than that of the device whose section is shown in Figure 22. The arcs of circle 96 of the rigid plate have a curvature in opposite direction to the curvature of the circle portion 60 of the main portion of the rigid wafer. The circular arcs 96 are themselves extended laterally by circular arcs 97 of the rigid plate having a curvature in the opposite direction to the curvature of the circular arcs 96.

In the embodiment illustrated in FIG. 25, the lateral portions of the rigid plate are arcs of a circle 101, 99, 102, 104 and 105 deviating respectively from the largest inscribed circles 106, 60 and 107 if we consider the circular arcs 100, 98 and 103 as main portions of the rigid plate. The cross section of a device as shown in Figure 25 has the shape of a portion of damped sinusoid. Between the arc of a circle 101 and the arc of a circle 105 (from left to right in FIG. 25), it can be seen that the arcs of circles adjoined one by one have decreasing radii, each arc of a circle having a curvature of direction inverse to the curvature of the previous arc and a radius smaller than the radius of the previous arc. Such a device may in particular be of interest in cases where it is useful to control the deployment of the device from a folded angular position so as to avoid, for example, a collision with another object placed nearby in the context of the simultaneous deployment of several instruments. . In fact, taking into account the decrease in the radii of the main portions and the width of the lateral portions, the area comprising the circular arc 100 will tend to deploy more rapidly than the zone of the rigid plate comprising the circular arc 103.

FIGS. 23 and 25 illustrate devices according to the invention comprising several main portions within the same rigid plate, said main portions being juxtaposed one with respect to the other laterally and connected to one another by lateral portions moving further away large circle inscribed within the curvature of each of the main portions.

The extension of the lateral portions of the rigid plates in forms as illustrated in the fourth embodiment (FIGS. 19 to 21) and in FIGS. 22 to 25 makes it possible to increase the restoring torque towards the rest position of a device and / or to reduce its size. To better understand, we can for example consider the example of a device having a single main portion on each rigid plate, the deflection of the main portion being for example 30 mm, this device being equivalent in terms of return force to a device comprising three main portions per rigid plate, the deflection of each main portion then being 10 mm (for the same dimensions elsewhere).

The set of devices according to the invention makes it possible to increase the life of devices comprising at least one hinge by reducing the residual stresses undergone by the devices and makes it possible to considerably reduce the risks of degradation at the edge, in particular of delamination, between the materials forming said device.

In addition, the devices according to the invention comprising several main portions (and therefore more than three separate lateral portions per rigid plate) have a restoring force towards a rest position of the device which is all the greater, thus making it possible to provide excellent deployment guidance and to prevent any untimely overlapping of the rigid plates of the same device with one another. The devices according to the invention comprising several main portions also make it possible to design and manufacture structures of larger dimensions, and in particular having greater lengths, taking into account their self-stiffening character in the manner of "omega" stiffeners. ".

The invention can also be the subject of very many different applications for producing a flexible flexible hinge and in particular spontaneous deployment. In particular, a device according to the invention advantageously applies to produce a deployable (deployable) or foldable (retractable) structure on a space system, for example a deployable mast after launch.

A device according to the invention can for example also be used for the deployment and / or the support of mechanical organs and / or of sensors, for space applications: solar photovoltaic panels of space systems, braking veil of a satellite allowing '' adjust the orbit, telescope baffle, space mast ...; or for terrestrial applications in which the same problems may arise: camera height support, detector, transmitter, receiver, various sensors, display panels, for the construction of temporary shelters, tents, marquees, etc. Such a foldable device can also more generally serve as a linear actuator, and in particular be integrated within a mechanism.

On the other hand, it is possible to provide that the device does not extend in the same plane in the deployed state but that the deployed state corresponds to a conformation in which the rigid plates form an angle between them less than 180 ° or that the deployed device has a curved shape (longitudinally).

Claims (14)

1 / - Device comprising a flexible film hinge (20) connecting two plates, called rigid plates (10, 12), more rigid than said hinge (20) so that they can be moved by pivoting the rigid plates (10, 12) around of the hinge (20) between at least one deployed angular position and one folded angular position, the rigid plates (10, 12) forming between them in the deployed angular position an angle greater than that formed in the folded angular position, and in which : each rigid plate presents from the hinge at least one portion, called the main portion (4, 6), elastic in bending with a shape at rest corresponding to warping according to a curvature of constant direction around an axis intersecting the hinge , so that the rigid plates (10, 12) are returned elastically to their angular position closest to the shape at rest of their main portion, characterized in that: there is a larger circle inscribed within said curvature of constant direction of each main portion (4, 6) of each rigid plate (10, 12), each rigid plate (10, 12) has, from the hinge, at least one lateral portion (11, 13) extending on each side of the main portion (4, 6), each lateral portion (11, 13) having a shape at rest deviating from said largest inscribed circle and at the outside of it. 2 / - Device according to claim 1, characterized in that the cross section of each rigid plate is such that each main portion (4, 6) has a shape at rest in an arc of a circle and in that each lateral portion (11 , 13) has a shape at rest deviating from said arc. 3 / - Device according to any one of claims 1 or 2, characterized in that the cross section of each rigid plate (10, 12) has a general shape at rest distinct from an arc of a circle. 4 / - Device according to any one of claims 1 to 3, characterized in that the rigid plates (10, 12) are biased elastically in bending towards said at least one deployed angular position. 5 / - Device according to any one of claims 1 to 4, characterized in that each rigid plate (10, 12) comprises at least one reinforcement structure of a rigid composite material which composes it, capable of imparting resistance at least in longitudinal tension and compression to this rigid composite material, and a matrix within which the reinforcing structure extends. 6 / - Device according to any one of claims 1 to 5, characterized in that said hinge (20) is formed of at least one connecting layer of a reinforcing structure extending in continuity and in common between said rigid plates. 7 / - Device according to claim 6, characterized in that said hinge (20) comprises at least one matrix within which extends said connecting layer of a reinforcing structure, the matrix of said hinge being itself formed of a material more flexible in bending than that constituting a matrix of rigid composite material of each rigid plate. 8 / - Device according to any one of claims 1 to 7, characterized in that each main portion (4, 6) of each rigid plate (10, 12) has different curvatures in the deployed angular position and in the folded angular position. 9 / - Device according to any one of claims 1 to 8, characterized in that each main portion (4, 6) of each rigid plate (10, 12) has at least one end extending along the hinge whose curvature is zero in a folded angular position. 10 / - Device according to any one of claims 1 to 9, characterized in that each rigid plate (10, 12) has at least one end stop in contact with at least one end stop of a separate rigid plate, having edges (30) opposite, in the angular position deployed, said stops not being in contact in the folded angular position. 11 / - Device according to claim 10, characterized in that said edges (30) facing are arranged to be able to act as a compression stop in a direction normal to the edges while allowing folding of the hinge (20) at least in meaning from position 5 angular deployed. 12 / - Device according to any one of claims 1 to 11, characterized in that each rigid plate (70, 72) comprises at least two main portions interconnected by at least one lateral portion. 13 / - Device according to any one of claims 1 to 10 12, characterized in that the number of main portions of each of the two rigid plates (70, 72) is identical and the number of side portions of each of the two rigid plates (70, 72) is identical, at least one lateral portion being disposed between two main portions of the same rigid plate. 14 / - Device according to any one of claims 1 to 15 13, characterized in that each lateral portion has a shape at rest corresponding to a warping according to a curvature, around an axis intersecting at the hinge, having an opposite direction the curvature of the main portion to the side of which it extends.