EP0808277B1 - Extensible and compressible hollow element - Google Patents

Description

The subject of the present invention is an element compressible and expandable hollow.

It generally concerns bodies compressible and expandable troughs, whether containers such as cans or bottles, or elements tubular such as pipes.

These hollow elements are made up of several sections whose side walls form one or several bellows allowing their compression and their extension. Can be found in patent applications US Nos. 4,492,313 and US 4,773,458 examples such blow molded articles from plastics such as polyethylene or polychloride vinyl.

Each elementary bellows is generally formed of two opposite flared side wall portions in the direction of the central axis, connected by their small bases thus constituting a playing fold the role of an expandable circular internal hinge radially. The large bases are each connected to the large base of one of the flared parts of a bellows adjacent elementary thus forming circular hinges radially extendable external. The two parts flared constituting an elementary bellows can be the same width or different widths. In the second case, there is an eccentricity during the compression that could cause the bellows to lock.

So far, it has been considered that the generator flared parts should preferably have a constant length over the entire circumference, said generator being the line of intersection of the wall of a flared part with a plane parallel to the axis main and perpendicular to this wall, the length of the generator corresponding to the length of this intersection between the small base and the large base of a flared part. However, this known solution is not optimal in all cases, especially for hollow bodies not having a circular section at any point on the main axis.

The invention aims to remedy these drawbacks, by dispensing with the need for a constant dimension of the side walls of the bellows. On the contrary, the applicants have discovered that the variation in the length of the generators along the circumference of the flared parts forming the bellows could have very interesting advantages. In. This feature makes it possible to considerably increase the field of application of compressible and extensible hollow elements, in particular for hollow articles which do not have a circular cross section at all points along their length.
Patent N ° US 5 310 068 describes a squeezable bottle comprising a central portion (14) pleated "in accordion", as well as a system, main object of protection, making it possible to vary the internal pressure by means of flexible rods. 'extending along the periphery of the bottle from the neck to a snap device disposed at the bottom of the container. The description part of this document seems to indicate that the distance between the external folds and the internal folds is constant, radial folds being combined with the internal folds.

The present invention describes a hollow element compressible and expandable with a side wall extending around the main axis of the element and comprising at least one bellows type structure composed of two parts, the length of the periphery gradually increases from a small common base joining the two parties and constituting an internal peripheral hinge, up to the sections transverse end of the two parts forming the large bases, the length of the generators of these two sections being variable along the periphery of said side wall.

In certain hollow body applications according to the invention, the terminal cross sections of the two flared parts are separated from each other, that is to say that the peripheral lines defining the large bases do not meet at any point. of the hollow element.
Advantageously, the shape of the peripheral internal "hinge" (small base) joining the two parts of a bellows will be different from the shape of the terminal cross sections (large bases). Preferably, the small base will have an annular or rounded shape, while the two opposite large bases will have a substantially polygonal shape. This combination of annular and polygonal shapes allows easier and more efficient storage of the hollow bodies, each element occupying less space, however, because of the annular shape, preferably substantially circular of the small base, any interference of the polygonal parts of the bellows with neighboring parts, during compression or extension of said bellows.
The bellows will advantageously be of the eccentric type, the generator of one of the flared parts being smaller than the generator of the second flared part at each point of the periphery of the bellows.

For other applications, both parties flared can each consist of two portions, the first being arranged in the extension each other and having generators of a substantially constant length, the generators of second portions being curved and of different lengths so as to allow an eccentricity and a corresponding bellows lock, the curvature of the second portion being larger than that of first. A compressible hollow body is thus obtained and extendable provided with a locking zone and of which bending resistance is increased in one plane perpendicular to the main axis, due to the small angle formed by the first portion in this plane. This configuration is particularly interesting for large containers such as jerry cans.

In an alternative embodiment of a hollow body according to the invention, the length of the generatrices of the two flared parts varies, along the periphery, from zero, at one point of the side wall, to a maximum value at the opposite point. Thanks to this configuration, a variable compressibility of the hollow element is obtained from one side to the opposite side, the result of which is a curvature of the hollow element in line with the bellows concerned. This embodiment will advantageously be used for pouring tubes of cans or jerry cans.
The external walls will preferably comprise at least two contiguous bellows-type structures, the "internal peripheral hinges" (small bases) of which are spaced apart from each other, and the directions of extension of which are opposite, which allows bending of the hollow body, as well as a substantially rectilinear extension and compression in the direction of the central axis. The bellows will advantageously be of the eccentric type, the generator of one of the flared parts being smaller than the generator of the second flared part at each point of the periphery of the bellows.

In all cases, at least part of the "peripheral hinge" constituting the small common base of the two flared parts will preferably be formed by a recess opening towards the outside and constituting a peripheral channel, for example in the form of a U or V.
In the case described above, where the length of the generatrices of the two flared parts varies from zero to a maximum value, it is very advantageous to also vary the dimensions of the peripheral channel from zero to a maximum value in parallel with the increase in the length of the generators, which in addition facilitates the blow molding of the hollow body.

la figure 1 est une vue isométrique d'une première variante de réalisation de l'élément creux en position étirée,

la figure 2 est une vue isométrique de l'élément creux de la figure 1 lorsqu'il est compressé,

la figure 3 représente, vu de côté en élévation, une seconde variante d'élément creux en état d'extension,

la figure 4 est une coupe transversale horizontale de l'élément creux de la figure 3,

la figure 5 est une vue partielle de l'élément creux de la figure 4 lorsqu'il est compressé,

la figure 6 est une vue schématique partielle en élévation, d'une troisième variante d'élément creux montrant, en état d'extension, le tuyau verseur d'un jerrican,

la figure 7 est une vue partielle schématique de l'élément creux de la figure 6, en état de compression

et la figure 8 représente, vu de côté en élévation, le jerrican équipé du tuyau verseur de la figure 6.

In the accompanying drawings, given by way of nonlimiting examples of preferred embodiments of the subject of the invention:

FIG. 1 is an isometric view of a first alternative embodiment of the hollow element in the stretched position,

FIG. 2 is an isometric view of the hollow element of FIG. 1 when it is compressed,

FIG. 3 represents, seen from the side in elevation, a second variant of hollow element in the extended state,

FIG. 4 is a horizontal cross section of the hollow element of FIG. 3,

FIG. 5 is a partial view of the hollow element of FIG. 4 when it is compressed,

FIG. 6 is a partial schematic view in elevation of a third variant of hollow element showing, in the extended state, the pouring pipe of a jerry can,

Figure 7 is a partial schematic view of the hollow member of Figure 6, in the compression state

and FIG. 8 represents, seen from the side in elevation, the jerry can equipped with the pouring pipe of FIG. 6.

In FIGS. 1 and 2 a container 1 blow molded from plastic material such as polyethylene or polyvinyl chloride comprises an upper part 2, a base 3 and a side wall 17 extending around a central axis A.
The upper part 2 and the base 3 have the shape of parallelepipeds defined respectively by an upper face 2 "square and sides 2 ', and a bottom 3" square and sides 3'. The upper face 2 "is open to facilitate access to the interior of the container 1 and can be closed by a suitable plug not shown here. The bottom 3" is closed.
The side walls 17 are composed of two bellows 17 'and 17 ", each of them comprising a flared upward part 9, 11, and a flared downward part 10 12, linked together by an inner circular hinge zone 7 , 8 U-shaped. This type of hinge zone is known in itself and has been the subject of an American patent application No. US 4,773,458.
The upwardly flared part 9 of the upper bellows 17 ′ is connected, at its end opposite to the circular hinge zone 7, to the lowest edge of the sides 2 ′ by an edge 6 forming a square and constituted by a peripheral fold of Wall. Likewise, the downwardly flared part 10 of the upper bellows 17 ′, and the upwardly flared part 11 of the lower bellows 17 "are connected together by their ends opposite respectively to the circular hinge zones 7, 8 by a peripheral edge 4 in the shape of a square. And finally, the flared part 12 at the bottom of the lower bellows 17 "is connected, at its end opposite to the circular hinge zone 8, to the upper edge of the sides 3 ′ by a square peripheral edge 5.
The angles of the edges 4, 5 and 6, of the base 3 and of the upper part 2 can be rounded.
As can be seen, each flared part 9, 10, 11, 12 has a square base and a circular apex. Corner edges 13, 14, 15, 16 form the connections between the adjacent faces of said flared parts and are less and less accentuated as one approaches the circular hinge zones 7 and 8.
In container 1, at each point of the circumference, the length of the walls of the downward flared parts 10 and 12, measured along their intersection with a plane passing through the central axis A, is greater than that of the walls upwardly flared portions 9 and 11, measured in the same manner.

It follows that the angle α between the above intersection lines of the walls 9 and 11 with a plane perpendicular to the central axis A is greater than the angle β between the intersection lines of the walls 10 and 11 and the same plane perpendicular to the central axis A.
The angles α and β have an increasing value from an angle edge 13, 14, 15, 16 and an intermediate point between two of these angle edges. Similarly, the length of the generators gradually decreases from a value (g, h) measured at the corner edge to a value (e, f) corresponding to a point equidistant from two corner edges.
The bellows 17 ', 17 "are of eccentric type, which means that, during compression (FIG. 2), the external edges pass below the internal edges. The bellows are preferably self-locking so as not to return to their uncompressed state in the absence of an external force Compared to a container similar to container 1 also having a polygonal contour, but whose internal hinge zones are square instead of being circular, the internal and external parts of the bellows have less risk of interference during extension or compression.

The container 101 shown in Figures 3, 4 and 5 is formed of a base 104, a side wall 102 consisting of bellows extending around the central axis B, and an upper part 103 having an opening closable by a plug 105 and a handle 106. The side wall comprises three complete bellows 102 ', 102 "and 102"', as well as an upper half-bellows 107 'consisting of a part flared downwards. Each bellows 102 ', 102 "and 102"' is formed by a portion of wall flared up 108 and a portion of wall flared 107 connected to the previous one by an internal peripheral hinge zone 110 in the form of U. The bellows 102 ', 102 "and 102"' are connected to each other, as well as with the half-bellows 107 'and the base 104 by foldable zones forming peripheral edges 109.
The container 101 is made of blow molded polyethylene or polyvinyl chloride.
As can be seen in Figures 3 and 4 the flared parts 107 and 108 have a varying width along the periphery of the side wall. In the zones 111 and 112 situated at the front and at the rear of the flared parts 107 and 108 respectively, the width c of the flared part 107 is greater than the width d of the flared part 108 allowing blocking of the bellows in these zones, said width being equal to the local length of the generatrix of the wall of the flared part considered. In the zones 113 and 114 situated on the sides of the parts 107 and 108 respectively, the width a of the part 107 is equal to the width b of the part 108.
Between the zones 112 and 114, as well as 111 and 113, along the periphery, the width c gradually decreases towards the width a, while the width d increases towards the width b. Since in zones 113 and 114 the width a and b of the flared parts 107 and 108 are equal, there will be no eccentricity of the bellows at the location of these zones during the compression of the container, the zones 113 and 114 being simply applied one against the other and superimposed. On the other hand, the zones 111 and 112 will be off-center and blocked during the compression of the container 101. As a result, the latter can be kept in the compressed state as seen in FIG. 5, while the side wall will have a large resistance to deformation forces caused by the contents of the container.

In FIGS. 6, 7 and 8 we can see a container 201 of the jerrycan type, with a handle 206 and a pouring pipe 203 comprising a neck 204 provided with a threaded opening 205 intended to receive a stopper (not shown), and a tubular part consisting of a wall 202 extending around a central axis C and formed of a series of bellows 202 ′ to 202 ^v between the upper part 212 of the container and the shoulder 211 of the neck 204. The pouring pipe may be made for example of polyethylene or polyvinyl chloride blow molded.
Each bellows 202 ′ at 202 ^v comprises a wall part flared upwards 207 and a wall part flared downwards 208 connected together by hinge zones 209 in a U shape. The bellows are connected to one another as well as 'to parts 211 and 212 by external edges 210 formed by peripheral folds of the side wall.
This exemplary embodiment has a remarkable particularity. Indeed, the flared parts 207 and 208 are tapered between two opposite sides of the wall 202 of the pouring pipe. As can be seen in Figures 6 to 8, the heights of the flared parts 207, 208 have values i, j on one side, values k, l at a point between the two sides and are practically zero on the side opposite. The direction of this transverse tapering is reversed by a bellows to the adjacent bellows and so on. As a result, two contiguous bellows are located between two parallel external edges 210.

In FIGS. 6, 7 and 8, the height of the flared part 208 has a maximum value greater than the width of the flared part 207, which allows eccentricity of the bellows during the compression of the pipe 203. The compression of the pouring pipe 203 can be performed step by step, the inclination of the opening of the pouring pipe being modified with each step, which gives the user many possible positions of the opening of the pouring pipe.
In Figure 6 we can notice that the dimension of the hinge areas 209 U-shaped whose size decreases gradually to be zero at the crossing of two adjacent external edges 210, to the point where the heights two flared parts 207 and 208 are also zero. Consequently, the depth / width ratio of the U-shaped hinge zone varies along the periphery, which has, among other things, the advantage of facilitating molding.
The positioning of the various constituent elements gives the object of the invention a maximum of useful effects which had not, to date, been obtained by similar devices.

Claims (7)

1. Extensible and compressible hollow element (1, 101, 202), that can be used to make various bendable hollow bodies such as cans, bottles or other containers (1, 201), or tubular elements (202), having a sidewall of one or more bellows type structures made up of two parts (9 to 12, 107 and 108, 207 and 208) that increase progressively in size from a small common base forming an inner peripheral hinge (7, 8, 110, 209), the large bases of these progressively larger parts consisting of peripheral edges (4 to 6, 109, 210) formed of foldable zones of the sidewall,
      characterized in that, on the one hand, the lengths of the generators of the progressively larger parts vary gradually along the periphery, the said generators being formed by the intersection of the wall of the said progressively larger parts with a plane parallel to the main axis (A, B, C) and perpendicular to this wall and in that, on the other hand, at least one part of the inner peripheral hinge (7, 8, 110, 209) is formed of an outward opening section and constituting a peripheral channel, with U or V shape for instance.
2. Hollow element according to claim 1, characterised in that length (i, j, k, l) of the generators of parts (207, 208) varies along the periphery, from nil at one point on the sidewall, to a maximum value at the opposite point, so that parts (207, 208) become thinner transversally between two opposite sides.
3. Hollow element according to the claim 2, characterised in that it includes at least two bellows type structures and that the direction of transversal thinning of parts (207, 208) is reversed from one bellows to the adjoining bellows, so that two adjoining bellows are placed between two parallel outer peripheral edges (210).
4. Hollow element according to any one of claims 2 and 3, characterised in that the size of the main channel comprising the inner peripheral hinge (7, 8, 110, 209) gradually decreases to nil at the crossing of two adjacent outer edges (210), at the point where the heights of the two progressively larger parts (207, 208) are also nil.
5. Hollow element according to the claim 1, characterised in that the inner peripheral hinge (7, 8) joining the two progressively larger parts of a bellows has an annular or rounded shape, whereas the peripheral edges (4, 5, 6) comprising the large base of the said progressively larger parts have a roughly polygonal shape.
6. Hollow element according to any one of the aforesaid claims, characterised in that the generator of one of parts (10, 12, 107, 207) is smaller than the generator of second part (9, 11, 108, 208) of a bellows at each point of its periphery.
7. Hollow element according to claim 1, characterised in that the two progressively larger parts comprising a bellows each comprises two portions, the first ones forming the extension of the other and having generators of roughly constant length, the generators of the second portions being curves with different lengths so as to allow excentration and locking of the corresponding bellows, the curvature of the second portion being larger than the first.

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