FR2840970A1 - Method for articulating and locking semi-rigid plates comprises articulation connecting plates by means of curved hinge lines and rectilinear hinge lines - Google Patents

Abstract

The method consists of an articulation (27) connecting semi-rigid plates (1,2,17) by means of curved hinge lines (3,22) and rectilinear hinge lines (21). The plates are plane when the articulation is folded and when it is unfolded the plates curve to form concave or convex cylindrical surfaces which are locked when the maximum opening is obtained.

Description

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The invention relates to a method for articulating and locking semi-rigid plates together and product obtained.

The plates qualified as semi-rigid in the context of the invention are thin flat plates which are liable to flex elastically under a load; semi-rigid plates can have different deformability characteristics when they are made from a compact sheet formed from a single material, such as for example compact cardboard or an extruded and or calendered polystyrene sheet which can be mono-oriented or bi-oriented; semi-rigid plates can be made up of several materials of the same or different nature assembled, such as for example corrugated cardboard with a kraft on one side or on two two sides or plywood; it can also be a single material whose section is cellular.

A semi-rigid plate of the type that we have just described has the characteristic of being able to deform elastically by forming a cylindrical surface sector in at least one direction of the generators so that the section taken perpendicular to the generators has a continuous curvature.

 There are semi-rigid plates which have the same characteristics of flexibility whatever the direction of the generators: When two parallel edges of a sheet of paper or of rectangular compact cardboard are substantially brought together in parallel with one another naturally forms a surface in the form of a cylinder sector; the

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 sheet of paper or compact cardboard is resting on a flat table, it resumes its initial flat shape without any creases appearing because the deformation has remained in the elastic range; same type of deformation is noted if for example opposite angles are brought closer except that the generatrices have a different direction.

The curvature, obtained by bending the semi-rigid plate under a determined force gives a very significant increase in the resistance to bending of the same plate in the direction parallel to the generatrices.

There are semi-rigid plates which have different flexibility characteristics depending on the directions of the generators considered: To illustrate this example it can be considered a sheet of corrugated cardboard one face formed from a sheet of corrugated kraft paper glued on a sheet flat kraft paper; this semi-rigid sheet of corrugated cardboard on one side is flexible when curved parallel to the fluting and relatively rigid when curved perpendicular to the fluting.

It may therefore be advantageous, depending on a desired result, to, for example, strengthen the rigidity in one direction and promote flexibility in the other.

Certain packages of compact cardboard or microchannel cardboard use a technique of folding a semi-rigid thin sheet, along a continuous curved fold line having a hollow side and a solid side and preferably having an axis of symmetry; the sheet is folded along its curved fold line it has, seen from the outside of the packaging, a first

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 concave cylindrical face on the hollow side and a second convex cylindrical face on the solid side; the angle formed at the level of the curved fold line by the generatrices of the first and second faces closes as the folding increases and the curvature of the faces increases; folding mode constitutes a joint. In the description which follows, the qualifier "curve" means that the curvature is qualified as positive, that it is constant or varies continuously upward or downward without changing sign and preferably has an axis of symmetry; to these criteria in particular an arc of a circle, more generally a conical arc having an axis of symmetry of the conic as an axis of symmetry; arrow, which is the maximum distance between the cord, which is a straight line joining the two ends of the curved fold line, and the curved fold line itself, is preferably between ten and twenty percent of the length of the rope. Such a folding corresponds in what follows to a "first type joint" but but what is called in what follows the "curved fold line" can be of a design different from a simple folding depending on the materials used for the production of semi-rigid plates which do not necessarily lend themselves to folding.

The object of the invention consists in proposing a method of assembly by articulation of at least two semi-rigid plates, between them, making it possible by their combination to obtain objects which can be unfolded along hinge lines, having improved mechanical strength by the curvature of the semi-rigid plates, which, when folded, have a minimum bulk in the form

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 a stack of flat semi-rigid plates.

The following description is illustrated by the following figures.

Figure.1A is a perspective view of a second type joint, according to the method, in the folded position.

Figure.1B is a perspective view of the second type joint when it is unfolded.

FIG. 2A is a perspective view of a joint of the third type, according to the method, in the folded position.

Figure.2B is a perspective sectional view of the third type joint when it is unfolded and locked.

Figure.2C is an elevational view of a section of the third type joint being unfolded.

Figure.3A is a perspective view of a fourth type joint, according to the method, in the folded position.

Figure.3B is a perspective view of the fourth type joint when it is unfolded.

Figure.4A is a perspective view of a fifth type joint, according to the method, in the folded position.

Figure 4B is a perspective view of the fifth type joint when it is unfolded.

Figure 5 is a perspective view in section of a seat using joints of the third and fifth type.

Figure 6 is a perspective view of another seat also using joints of the third and fifth type.

The method according to the invention consists in hinging together a first plate and a second semi-rigid plate 1 and 2 (FIG. 1A and FIG. 1B), of the same nature.

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 of different materials or nature, following all or part of a first curved hinge line 3; the two semi-rigid plates 1 and 2 (figure.lA) are flat and bear one on the other; the first semi-rigid plate 1 serves as a support for the articulation and projects beyond the hollow side 4 as the solid side 5 of the first curved hinge line 3, while the second semi-rigid plate 2 is articulated to the first semi-plate rigid 1 along this first curved hinge line 3 and has a free zone 6 situated on the hollow side 4 of the first curved hinge line 3; the joint thus obtained is hereinafter called a "second type joint" 8 whatever the type of hinge used.

The second type of articulation 8 is produced by a connecting means adapted to the nature of the semi-rigid plates 1 and 2 used; that the first curved hinge line 3 constitutes the end of the second semi-rigid plate 2 to which it is linked by a hinge of the first type (not shown in the drawing), namely that a fixing zone 7 of the second semi-plate -rigide 2 located on the solid side 5 of the first curved hinge line 3 is fixed on the first semi-rigid plate 1 at least along the first curved hinge line 3 along which the second semi-rigid plate 2 folds which constitutes a second type hinge 9; what follows the joints are drawn with hinges of the second type but each of them can always be replaced by a hinge of the first type if the material of the semi-rigid plate used is suitable for this.

A connecting means is a first type hinge which

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 is made, for example, by a flexible strip attached to the first curved hinge line 3 on either side of the latter and fixed, for example by gluing, on the one hand on the hollow side 4 of the first curved hinge line 3 on the second semi-rigid plate 2 and on the other hand full side 5 on the first semi-rigid plate 1.

Another connection means is a hinge of the second type 9 can be produced, for example, by gluing the attachment zone 7 of the second semi-rigid plate 2 located on the solid side 5 of the first curved hinge line 3 to the first plate. semi-rigid 1 and for example by creasing the second semi-rigid plate 2 along the first curved hinge line 3 so that the second semi-rigid plate 2 can bend along this first curved hinge line 3.

In a preferred version of the invention, the first and second semi-rigid plates 1 and 2 are substantially rectangular; they have parallel side edges 10 and 11 the distance of which constitutes the width 12 of the semi-rigid plates 1 and 2 and which are identical while the respective length 13 and 14 of the first and second semi-rigid plates 1 and 2 is substantially different ; first and second semi-rigid plates 1 and 2 are superimposed along their width 12; first curved hinge line 3 crosses the first and second semi-rigid plates 1 and 2 along their common width 12 and has an axis of symmetry 15 located parallel and equidistant from the lateral edges 10 and 11; general shape of the first curved hinge line 3 preferably corresponds to a conical arc (circle, ellipse, parabola or

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 hyperbola) having an axis of symmetry; arrow of the first curved hinge line 3 represents ten to twenty percent of the width 12. In what follows the description is based on the joint of the second type 8 according to the preferred version of the invention.

When the first semi-rigid plate and second plate 1 and 2 (FIG. 1B) are being separated from the hollow side 4 of the first curved hinge line 3, around which they are articulated, the first and second plates semi-rigid 1 and 2 are curved along two concave cylindrical sectors whose sections taken perpendicular to the respective generatrices are curved while remaining within the elastic limit of deformation of the first and second semi-rigid plates 1 and 2; the spacing of the semi-rigid plates 1 and 2 requires an effort corresponding to the effort necessary to bend them elastically and if the effort is relaxed the semi-rigid plates resume their initial shape and overlap again (Figure.1A) .

As the first and second semi-rigid plates 1 and 2 move apart, keeping the first curved hinge line 3 in common, the sections of the cylindrical sectors bend until the semi-rigid plates 1 and 2 having exceeded their elastic limit fold back on themselves along the axis of symmetry 15 of the first curved hinge line 3.

It is therefore necessary to limit the possibility of opening the joint of the second type 8 described before having reached the elastic limit of the semi-rigid plates 1 and 2 by a locking means; these conditions it is also

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 necessary to have a means of locking the joint of the second type 8 when it is in a maximum admitted opening position to prevent it from closing by itself as soon as the opening force stops.

A blocking and locking means is constituted by a first locking device 16 (figure.1A, figure.1B, figure.1C), ensuring the limitation of the opening of the second type 8 joint as well as its locking in open position (Figure.2B), is constituted by a third semi-rigid plate 17 comprising a first type articulation; third semi-rigid plate 17 is substantially rectangular with a width substantially identical to the first and second semi-rigid plates 1 and 2 previously described; is superimposed fixed on the first semi-rigid plate 1 along its lateral edges 19, on the solid side 5 (FIG. 1A) of the first curved hinge line 3 to the immediate vicinity of the ends 20 (FIG. 1A, FIG. 2A and figure.2B) of the first curved hinge line 3; third semi-rigid plate 17 (FIG. 2A) is superimposed on the second semi-rigid plate 2 at the level of the first curved hinge line 3 with the first semi-rigid plate 1; it is articulated on the second semi-rigid plate 2 along the cord joining the ends of the first curved hinge line and constituting a second straight hinge line 21; the third semi-rigid plate 17 comprises a curved fold line constituting a third line of curved hinge 22, making it possible to constitute the joint of the first type, which, for example, is superimposed on the first line of curved hinge 3; third semi-rigid plate 17 has a

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 first locking zone 23 comprised between the second straight hinge line 21 and the hollow side 18 of the third curved hinge line 22 and a second locking zone 24 situated on the solid side 25 of the third curved hinge line 22: Under these conditions when the first and second semi-rigid plates 1 and 2 (FIG. 2C) are separated as previously described the second rectilinear hinge line 21 bends and forces the first locking zone to take substantially the form of a concave cylindrical sector whose generatrices are parallel in the foreground formed by the lateral edges 10 and 11 of the first and second semi-rigid plates 1 and 2 located on the same side; the first locking zone 23 pushes back the third curved hinge line 22, progressively moving away from the second semi-rigid plate 2, which forces the second locking zone 24 to move away in a direction 28 and to take a convex cylindrical shape of symmetrical section with the concave cylindrical shape of the first plate 1, with respect to a second plane passing through the contact line 26 of the lateral edges 10 and 19 of the first and third semi-rigid plates 1 and 17, while the first and third curved hinge lines 3 and 22 remain symmetrical; of the second type of articulation continues until the second semi-rigid plate 2 (FIG. 2B) comes to bear on the third curved hinge line 22 at the end of the second locking zone 24 and that the first zone of locking 23 comes to bear on the convex face opposite to the concave face of the second semi-rigid plate 2 thus the

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 third curved hinge line 22 which becomes fixed relative to the second semi-rigid plate 2; these conditions the limitation of opening is obtained by the fact that if the second semi-rigid plate 2 continues to undergo a force tending to increase the opening angle between the first and the second semi-rigid plate 1 and 2, the curvature of the second locking zone 24 tends to increase which is prevented by the fixed position of the third line of curved hinge 22; first and third curved hinge line 3 and 22 being identical and initially superimposed, the locking is obtained by the fact that during the opening the shape of the first locking zone 23 induced by the deformation of the second semi plate rigid 2 are not coherent and induce tensions at the level of the first locking zone 23 which relax at the end of opening of the joint; so that the joint remains in the open position until sufficient closing force has been exerted in the opposite direction, which constitutes a form of locking. The combination described above concerning a second type hinge 8 which can be locked by a first type hinge when it is in the maximum permitted opening constitutes a third type hinge 27.

A variant of the joint of the third type 27 consists of a fourth and a fifth semi-rigid plate 28 and 29 superimposed; fourth and fifth semi-rigid plate 28 and 29 are substantially rectangular; they have parallel side edges 30 and 31 the distance of which constitutes the width 32 of the

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 fourth and fifth semi-rigid plates 28 and 29 and which are identical while the respective length 33 and 34 of the fourth and fifth semi-rigid plates 28 and 29 is substantially different; the fourth and fifth semi-rigid plates 28 and 29 are superimposed along their width 32; a fourth curved hinge line 35 crosses the fourth and fifth semi-rigid plates 28 and 29 along their common width 32; general shape of the fourth curved hinge line 35 preferably corresponds to a conical arc (circle, ellipse, parabola or hyperbola) having an axis of symmetry; fourth semi-rigid plate 28 serves to support the articulation and projects beyond the solid side 36 as well as the hollow side 37 of the fourth curved hinge line 35, while the fifth semi-rigid plate 29 is articulated to the fourth semi-rigid plate 28 along this fourth curved hinge line 35 and has a free area 38 located on the solid side 36 of the fourth curved hinge line 35; that the fourth curved hinge line 35 constitutes the end of the fifth semi-rigid plate 29 to which it is linked by a hinge of the first type, namely that the fixing zone 39 of the fifth semi-rigid plate 29 situated on the hollow side 37 from the fourth curved hinge line 35 is fixed to the fourth semi-rigid plate 28 at least along the fourth curved hinge line 35 along which the fifth semi-rigid plate 29 folds; which constitutes, what is called hereinafter a "fourth type joint" 40.

When the fourth and fifth semi-rigid plate 28 and 29 (FIG. 3B) are separated from the solid side 36 of the

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 fourth curved hinge line 35 the fourth and fifth semi-rigid plates 28 and 29 are curved along two convex cylindrical sectors.

A blocking and locking means is constituted by a second locking device 59, ensuring the limitation of the opening of the fourth type joint 40 (FIG. 3B) as well as its locking in the open position, consists of a sixth semi-rigid plate 41 (FIG. 4A and FIG. 4B) comprising a first type articulation 42; sixth semi-rigid plate 41 is substantially rectangular with a width 57 substantially identical to the fourth and fifth semi-rigid plates 28 and 29 previously described; it is superimposed fixed on the fifth semi-rigid plate 29 along its lateral edges 31, on the solid side 36 (FIG. 3A) of the fourth curved hinge line 35 to the immediate vicinity of the ends 43 of the fourth curved hinge line 35; this sixth semi-rigid plate 41 (FIG. 4A) is superimposed on the fifth semi-rigid plate 29 at its fourth type articulation 40 (FIG. 3A) with the fourth plate 29; is articulated on the fourth semi-rigid plate 29 along the cord joining the ends 43 of the fourth curved hinge line 35 and constituting a fifth straight hinge line 44 (FIG. 4A); the sixth semi-rigid plate 41 has a curved fold line constituting a sixth line of curved hinge 45, making it possible to constitute the first type joint 42, which, for example, is superimposed on the fourth line of curved hinge 35 (FIG. 3A); the sixth semi-rigid plate 41 has a third zone of

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 locking 46 included between the fifth rectilinear hinge line 44 and the hollow of the sixth curved hinge line 45 and a fourth locking zone 47 situated on the solid side 48 of the sixth curved hinge line 45.

The combination described above relating to a hinge of the fourth type lockable 40 (FIG. 3A) by a hinge of the first type 42 (FIG. 4A) when it is in maximum permissible opening constitutes an articulation of fifth type 49 (FIG. 4A and figure.4B).

One way of making a semi-rigid plate consists, for example, of placing wooden slats in parallel close to one another and of connecting them to one another at regular intervals by steel strips; the deformation of the semi-rigid plates these wooden slats constitute the generatrices of the cylindrical sectors; in the case of a joint of the third type 27 (FIG. 2C) the first line of curved hinge 3 is formed by the end of the second semi-rigid plate 2 having the shape of the first line of curved hinge 3 and fixed to the first semi-rigid plate 1 by a simple articulation located in the middle of the first line of curved hinge 3; the first locking zone 23 is constituted by a simple connecting rod which connects the middle of the second straight hinge line 21 with the middle of the third curved hinge line 22 while the upper limit of the second locking zone is formed by the third curved hinge line 22 on which the second semi-rigid plate 2 conforms.

The combination of the articulations of the first to the fifth type 42,8, 27,40, 49, makes it possible to conceive objects like

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 for example foldable seats; first foldable seat 50 (FIG. 5) can for example consist of a backrest 51 extended by a rear support 52, constituting a group of semi-rigid plates, and of a seat 53 comprising a front support 54, constituting a group semi-rigid plates, constituted by a third type assembly 27 (figure.2B) and a fifth type assembly 49 (figure.4B); the backrest 51 constituting the first semi-rigid plate 1 (FIG. 2B), the seat by the second semi-rigid plate 2, the rear support 52 constituting the first locking device 16; front support of the seat being constituted by a fifth type assembly 49 (FIG. 4B) in which the seat 53 (FIG. 5) is the fourth semi-rigid plate 28 (FIG. 4B), the front support 54 ( figure.5) being constituted by a second locking device 8 obtained by assembling the fifth 29 (figure.4B) and the sixth semi-rigid plate 41.

The base of the front and rear supports 55 and 56 (FIG. 6), constituting two groups of semi-rigid plates, of the foldable seat 57 can be reinforced by means of a semi-rigid plate 58 connecting the bases of the two front and rear supports 55 and 56 by joints of the fifth type 49 (FIG. 4B).

Claims (12)

 Claims 1-Device for assembly by the articulation (8) (27) (40) (49) between them, by means of connection, at least two semi-rigid plates (1) (2 ) (17) (28) (29) (41) (51) (53) (52) (54) (55) (56) planes along at least one curved hinge line (3) (35) (45) (22 ), of continuous curvature with an arrow, of a length of ten to twenty percent of the length of the rope joining its ends (20) (43), comprising a hollow side (4) (18) (37) and a solid side (5) (36) (25), so that when the joint (8) (27) (40) (49) is folded, the semi-rigid slaps (1) (2) (17) ( 28) (29) (41) are substantially flat and applied one against the other while when the joint (8) (27) (40) (49) is unfolded, the semi-rigid plates (1) (2 ) (17) (28) (29) (41) are elastically deformed in the form of a cylinder sector, the amplitude of unfolding and the locking of the joints (8) (40) being ensured by locking means e t locking (16) (59), the combination of plates (51) (53) or groups of semi-rigid plates (52) (54) (55) (56) allowing the design of objects (50) (57 ) unfoldable along curved hinge lines (3) (35), having improved mechanical resistance by the curvature of the semi-rigid plates or groups of plates (51) (53) or (52) (54) (55) (56) , which, when folded, have a minimum bulk in the form of a stack of semi-rigid flat plates. 2-assembly device according to claim 1, characterized in that a second type of articulation (8) consists in hinging between them a first plate and a second semi-rigid plate (1) and (2) of the same kind of <Desc / Clms Page number 16>  materials or of a different nature, substantially the same width (12), along all or part of a first curved hinge line (3) having a hollow side (4), a solid side (5) and ends (20), the first semi-rigid plate (1), having lateral edges (10), serving as support for the joint and projecting from the hollow side (4) as from the solid side (5) of the first curved hinge line (3), while that the second semi-rigid plate (2) has a free area (6) located on the hollow side (4) of the first curved hinge line (3). 3-assembly device, \ according to claims 1 and 2, characterized in that a blocking and locking means consists of a first locking device (16), forming in combination with the second type joint (8 ) a joint of the third type (27), which is constituted by a third semi-rigid plate (17) fixed on the lateral edges (10) of the first semi-rigid plate (1) along its own lateral edges (19) of the solid side (5) of the first curved hinge line (3) and articulated on the second semi-rigid plate (2) along the cord joining the ends (20) of the first curved hinge line (3) and constituting a second hinge line rectilinear (21), the third semi-rigid plate (17) comprising a third curved hinge line (22), comprising a hollow side (18) and a solid side (25) separating a first locking zone (23) between the second straight hinge line (21) and the hollow side (18) and a second locking zone (24) located on the solid side (25). 4-assembly device according to claim 1, <Desc / Clms Page number 17>  characterized in that a fourth type articulation (40) consists of a fourth and a fifth semi-rigid plate (28) and (29), articulated along a fourth curved hinge line (35), comprising one side solid (36) and a hollow side (37) and ends (43), the fourth semi-rigid plate (28) serving to support the articulation and projecting from the solid side (36) as from the hollow side (37), while the fifth semi-rigid plate (29) is articulated to the fourth semi-rigid plate (28) along this fourth curved hinge line (35) and has a free zone (38) located on the solid side (36). 5-assembly device, according to claims 1,3 and 4 characterized in that a blocking and locking means consists of a second locking device (59), forming with the joint of the fourth type (40) a articulation of the fifth type (49), which consists of a sixth semi-rigid plate (41), articulated on the fourth semi-rigid plate (29) along the rope joining the ends (43) of the fourth curved hinge line (35 ) and constituting a fifth rectilinear hinge line (44), the sixth semi-rigid plate (41) comprising a curved fold line constituting a sixth curved hinge line (45), separating a third locking zone (46) between the fifth straight hinge line (44) and the hollow of the sixth curved hinge line (45) and a fourth locking zone (47) located on the solid side (48) of the sixth curved hinge line (45). 6-assembly device according to claims 1 to 5, characterized in that a first foldable seat (50) is <Desc / Clms Page number 18>  consisting of a backrest (51) extended by a rear support (52), constituting a group of semi-rigid plates, and a seat (53) comprising a front support (54), constituting a group of semi-rigid plates , and which is the combination of a third type assembly (27) in which the backrest (51) constitutes the first semi-rigid plate (1), the seat (53) by the second semi-rigid plate (2) , the rear support (52) constituting the first locking device (16), and an assembly of the fifth type (49) constituting the front support (54) of the seat (53) in which the seat (53) is the fourth semi-rigid plate (28), the front support (54) is constituted by the second locking device (59). 7-An assembly device according to claims 1 to 6 characterized in that the base of the front and rear supports (55) and (56) constituting two groups of semi-rigid plates, the foldable seat (57) are reinforced by a plate semi-rigid (58) connecting the bases of the two front and rear supports (55) and (56) by joints of the fifth type (49). 8-assembly device according to claims 1 to 3, characterized in that a way of producing a semi-rigid plate consists of placing wooden slats parallel to each other and connecting them to each other at intervals regular by steel strips, these wooden slats constituting the generatrices of the cylindrical sectors. 9-An assembly device according to claims 1 to 3 and 8 characterized in that in the case of a joint of the third type (27) the second plate (2) is fixed to the <Desc / Clms Page number 19>  first semi-rigid plate (1) by a simple articulation located in the middle of the first line of curved hinge (3) and the first locking zone (23) is constituted by a simple connecting rod which connects the middle of the second line of hinge rectilinear (21) with the middle of the third line of curved hinge (22) which serves as a conformator to the second semi-rigid plate (2). 10-A method of implementing the device according to any one of the preceding claims, characterized in that when the first plate and the second semi-rigid plate (1) and (2) are in the process of spacing the hollow side (4) of the first curved hinge line (3), the first and second semi-rigid plates (1) and (2) bend in two concave cylindrical sectors while remaining within the elastic limit of deformation, the spacing of the plates semi-rigid (1) and (2) requiring an effort, corresponding to the effort required to bend them elastically, which when released allows them to return to their original shape and overlap again. 11-Method of implementation according to claim 10, characterized in that when the first and second semi-rigid plates (1) and (2) are spaced apart the second rectilinear hinge line (21) curves and forces the first area locking (23) to take substantially the shape of a concave cylindrical sector and to push back the third line of curved hinge (22) which forces the second locking zone (24) to take a convex cylindrical shape of section symmetrical to the concave cylindrical shape from the first plate (1), until <Desc / Clms Page number 20>  that the second semi-rigid plate (2) comes to bear on the third curved hinge line (22) and that the first locking zone (23) comes to bear on the convex face opposite the concave face of the second semi-plate rigid (2). 12-A method according to claim 11, characterized in that when the fourth and fifth semi-rigid plate (28) and (29) are spaced from the solid side (36) of the fourth curved hinge line (35) the fourth and fifth semi-rigid plates (28) and (29) bend in two convex cylindrical sectors.