EP1335864B1 - Child-resistant safety closure - Google Patents

Abstract

Safety screw-closure device for a container provided with an outer screw thread opening, which is made up of two coaxial caps, nested one inside the other, one of them, an outer cap, being able to turn the other, an inner one, by axial pressure and turning: the outer cap comprising, on the inner surface of one of its walls, mutual-engagement means; the inner cap comprising a screw thread on the inner surface of its cylindrical side wall and mutual-engagement means on the outer surface of its wall, facing the wall of the inner cap comprising the mutual-engagement means; and an elastic means disengaging the mutual-engagement means of the walls of the two inner and outer caps, placed between the upper end walls of the two caps, and made of a material of different composition from the composition of the caps.

Description

Field of the invention

The invention relates to a closure device for safety by screwing a container whose mouth is equipped with an external screw thread, device to the test of a young child.

The invention relates more particularly to a device safety closing device for container, such bottle, comprising an internal cap to be screwed on said container and a coaxial outer cap covering completely the inner cap, the outer cap having ability to drive the inner cap by through a snap system when are on the outer cap, axial pressure and a rotation.

State of the art

Youth-proof safety devices children, for fastening screwed containers of a screw thread mouthpiece, have appeared since many years.

These devices consist of two caps / caps nested one inside the other, each formed of a wall cylindrical side and an upper end wall closing the cylindrical wall.

The inner cap has a screw thread on the inner surface of its cylindrical wall allowing it to screw off the container, and means on its cylindrical outer walls and / or end allowing it to be rotated by the external cap.
The external cap coaxial to the inner cap which completely covers the inner cap, comprises, on its inner walls, means for causing, in rotation, the inner cap in the direction of closure or opening of the container, by axial pressure. / rotation applied to the outer cap, this pressure to mechanically engage the drive means of the outer cap in the corresponding means of the inner cap, then transmit the rotational movement of said inner cap.

One or other of the two caps also has resilient means for mechanical disengagement means for driving the outer and inner plugs, these elastic means being made of the same material than injection-molded plugs.

Such safety closing devices to the test young children have been described in many patents some of which are referred to below as illustrative.

A first device that was the subject of the patent EP 0631943 concerns the safety closure ( the test of a child) of a container with a net screw, which consists of two interlocking plugs, one internal part for closing said container, the other externally intended to drive the inner plug for the opening or closing of the container, by an action combined pressure and / or rotation.

• le bouchon interne à visser comporte, sur la surface externe de sa paroi cylindrique, un cannelage constitué de nervures successives, en forme de lamelles, qui se prolonge sur la surface externe de sa paroi d'extrémité supérieure, sous la forme d'un cannelage radial dont les lamelles ont un côté long, orienté dans la direction de rotation pour l'ouverture, et un côté court situé de préférence dans le plan contenant l'axe longitudinal médian de la fermeture du récipient ;
• le bouchon externe comporte, sur la surface interne de sa paroi d'extrémité supérieure qui est volontairement convexe (fermant la paroi cylindrique), des saillies, qui s'engagent dans le cannelage du bouchon interne quand une déformation élastique de la paroi d'extrémité supérieure dudit bouchon externe est pratiquée par pression axiale sur ladite paroi.

In this device:

• the internal screw cap comprises, on the outer surface of its cylindrical wall, a groove constituted by successive ribs, in the form of lamellae, which extends on the outer surface of its upper end wall, in the form of a groove radial whose lamellae have a long side, oriented in the direction of rotation for the opening, and a short side preferably located in the plane containing the median longitudinal axis of the closure of the container;
• the outer cap has, on the inner surface of its upper end wall which is deliberately convex (closing the cylindrical wall), protrusions, which engage in the splitting of the inner plug when an elastic deformation of the end wall upper end of said outer cap is made by axial pressure on said wall.

Therefore, by axial pressure on the face inside the convex end wall of the cap external, then printed rotation to said stopper, a couple of rotation is transmitted to the radial groove of the plug internal, by the projections of the outer cap, such so that the inner cap is unscrewed from the container.

The device also includes, as already stated, the fluting in strips oriented on the outer wall cylindrical inner plug, whose function is to facilitate the rotation of the inner cap to be screwed into the outer cap, when the projections of the outer cap do not are not engaged in the oblique slats of the groove radial of the inner cap.

The device also includes a second system of rotation of the inner cap by the outer cap in the screwing direction, independent of first training system, so that the outer cap causes the inner cap in the closing operation, by a simple rotation, without that it is necessary to apply an axial pressure on the outer convex end wall of the outer cap: this training system is constituted by means placed on the inner cylindrical wall of the stopper externally, as referred to as "front surfaces" and means placed on the outer cylindrical wall of the closure internal, as designated as protrusions.

This closing device, called security, for children, presents disadvantages that may arise during its exploitation.

For example, the outer cap (like the inner cap) is made of a single polymeric material having a property more or less elastic and the projections of the inner side of the upper end wall of the outer cap are made of the same material and are obtained by injection-molding superstructure of said inner face of said cap: like the top end wall of the cap external is convex and solicited on many occasions by the practice of torque axial-rotation pressure for the opening of the container, the elastic memory of the material constitutive weakens and the deformation of this wall upper end can become quasi-permanent by fatigue effect of the material, so that the protrusions can be engaged in a relatively permanent and that the internal plug can be driven in rotation in either direction screwing or unscrewing.

Thus, when the fatigue effect of the material occurs, the upper end wall of the outer cap does not deviates more sufficiently from the outer surface of the end wall of the inner cap: the device is more then of absolute security, because the snapping of two plugs can occur regardless of the necessary axial pressure-rotation.

• le bouchon externe comporte, sur la face interne de sa paroi d'extrémité supérieure, des barrettes oblongues d'encliquetage orientées radialement et un moyen élastique dans sa partie centrale, pour tenir écartée la paroi d'extrémité supérieure du bouchon externe de la paroi d'extrémité supérieure du bouchon interne ;
• le bouchon interne à visser comporte, sur la surface interne de sa paroi cylindrique, un filet de vis et sur sa paroi d'extrémité supérieure des barrettes d'encliquetage oblongues et radialement orientées. Ces barrettes ont des faces inclinées (dans le sens du vissage du bouchon interne) et butent sur les barrettes d'encliquetage du bouchon externe, quand ledit bouchon externe est soumis à rotation dans le sens vissage en entraínant le bouchon interne. Mais, quand ledit bouchon est soumis à rotation dans le sens du dévissage, sans l'application préalable d'une force axiale sur la paroi d'extrémité supérieure du bouchon externe, les barrettes de la face interne de la paroi d'extrémité supérieure du bouchon externe glissent sur les faces inclinées et le bouchon interne n'est pas entraíné.

Another device which has been the subject of the European patent EP0602925 relates to the closure, inviolable by a child, a container having a screw thread which also consists of two plugs fitted into one another, one internal for closing said container, the other external to cause the first for opening or closing the container by the action of axial pressure and / or rotation.
In this device:

• the outer plug has, on the inner face of its upper end wall, radially oriented oblong latching lugs and resilient means in its central part, to keep the upper end wall of the outer plug of the outer wall away. upper end of the inner cap;
• the internal screw cap comprises, on the inner surface of its cylindrical wall, a screw thread and on its upper end wall oblong and radially oriented latching bars. These bars have inclined faces (in the screwing direction of the inner cap) and abut on the latching lugs of the outer cap, when said outer cap is rotated in the screwing direction by causing the inner cap. But, when said plug is rotated in the unscrewing direction, without the prior application of an axial force on the upper end wall of the outer plug, the bars of the inner face of the upper end wall of the outer cap slide on the inclined faces and the inner cap is not driven.

Thus, it follows that the unscrewing of the internal plug is obtained by the successive application of a pressure axial on its upper end wall, which brings said wall closer to the upper end wall of the inner cap and causes the snap bars of the top end wall of the stopper external in the bars of the end wall top of the inner cap, the inner cap being then rotated by the outer cap.

Since the pressure applied to the wall upper end of the outer cap is released, the latching bars of the outer cap are disengage snap-in tabs from the stopper internal, thanks to the elastic system that causes the uncoupling of the two plugs.

However, this closure device, called security, for children with two stoppers, also presents disadvantages that are revealed only in use.

Regarding, for example, the outer cap, its means constituted by the latching bars of the stopper external and its elastic means present on the surface internal of the upper end wall of said plug, are produced (by injection into a mold) by means of a single polymeric material having a certain natural elasticity. More specifically, the elastic means is formed by four vertical tabs secured by one of their ends of the inner surface of the end wall upper of said plug. These four tabs form a virtual cylindrical wall, coaxial with the cap external. When applying a pressure on the wall upper end of the outer cap, these four tongues tend to deviate from each other, in their lower end and then crash on the upper end wall of the inner cap, all along the application of the aforementioned pressure.

By releasing said pressure, the tongues must return to a vertical position. But in practice, the repetition of the axial forces (pressure axial-rotation), on the outer cap for unscrewing of the device, causes fatigue of the materials constituent polymers which manifests itself by a almost permanent deformation of the elastic means and possibly its break in all or part.

Thus, the upper end faces of the two plugs are no longer sufficiently separated from each other rest and their relative relative position tends to cause accidental clipping of teeth to drive the outer cap with the teeth drive of the inner cap. The device closing, said security, for children is no longer absolute security.

d'un bouchon interne muni d'une paroi latérale cylindrique et d'une paroi d'extrémité, destiné à être entraíné,

d'une enveloppe cylindrique externe d'entraínement ouverte de telle sorte que l'ouverture supérieure de cette enveloppe cylindrique a un diamètre légèrement supérieur au diamètre du fût du bouchon interne, ce qui permet au bouchon interne d'émerger au dessus de ladite enveloppe cylindrique externe.

Another device which is the subject of the European patent EP 0725012, proposes a closure considered inviolable by a child of a container having a screw thread which consists of:

an inner plug provided with a cylindrical side wall and an end wall, intended to be driven,

an outer cylindrical casing open so that the upper opening of this cylindrical casing has a diameter slightly greater than the diameter of the inner cap barrel, which allows the inner cap to emerge above said cylindrical casing external.

Once inserted into the outer cylindrical shell, the inner cap retains said cylindrical shell, lower part by a crown on which it comes in stop, and in the upper part by an outer ring on which abuts its upper perimeter area.

The outer cylindrical drive envelope comprises on its inner surface snap-fastening means which can also be cap guiding means internal.

As for the internal cap, its only means of snapping allowing it to be driven by the cylindrical envelope is present on the outer side wall of said plug. The mechanical drive of the internal plug by the outer cylindrical shell is, therefore, via the snap-fastening means of the envelope cylindrical and snapped means of said plug internal when applying a mechanical torque of pressure on the envelope to make it descend and snap, and rotation of the envelope to cause the plug internal.

The elastic means of uncoupling is formed by blades of the lower crown of the inner cap, these blades being of the same composition and solidary of said crown low by one of their end and finding housing in said crown when pressure is exerted from up and down on the outer cylindrical shell.

Thus, it appears that the means implemented in this device make the drive of the inner cap difficult because they require the application of force vertical on the outer cylindrical shell, demanding first the complete perimetric grip of the said envelope in an inconvenient movement, and then the application of vertical force on the perimeter of the envelope to cause the latching of said envelope and cap and finally the cap drive internal rotation of the outer cylindrical shell.

It also appears that the elastic means of uncoupling is placed on the lower crown of the cap internal and is made with the same material (composition) constituent of the plug and the cylindrical envelope external material that, when frequently requested, can lose some of its elastic capacity, and can to reach a state of fatigue such that it can crack and lose its elasticity, or even break.

Le bouchon interne dispose d'un filet de vis sur sa paroi interne qui s'engage sur le filet de vis du nez de la sortie d'eau.

Le bouchon externe est maintenu dans une position coaxiale avec le bouchon interne par l'intermédiaire d'un anneau périmétrique qui constitue le moyen de guidage, maintenant coaxialement les deux bouchons constituant le moyen élastique de désaccouplement des deux bouchons.

Un ressort est situé entre leurs faces supérieures en regard, prenant appui dans des rainures circulaires coaxiales appropriées.

Finally, another device which was the subject of patent GB 2,209,156, discloses a safety closure device for fire hydrants water supply. This device comprises an inner stopper made of technical polyamide and an outer stopper made of aluminum alloy.

The inner cap has a screw thread on its inner wall that engages the screw thread of the nose of the water outlet.

The outer cap is held in a coaxial position with the inner cap by means of a perimetric ring which constitutes the guide means, now coaxially the two plugs constituting the elastic means of uncoupling the two plugs.

A spring is located between their facing upper faces, bearing in appropriate coaxial circular grooves.

trois dents placées sur la surface interne de l'extrémité supérieure du bouchon externe qui s'engagent, quand est effectuée une pression-rotation, dans trois cavités présentes sur la surface externe de l'extrémité supérieure du bouchon interne.

The drive means by pressure-rotation of the inner cap by the outer cap is constituted by:

three teeth placed on the inner surface of the upper end of the outer cap which engage, when is carried out a pressure-rotation, in three cavities present on the outer surface of the upper end of the inner cap.

il nécessite une manoeuvre mécanique relativement précise qui consiste en une pression axiale pour faire entrer exactement et simultanément les trois dents dans trois cavités de diamètre très légèrement supérieur à celui des dents, ce qui exige une bonne adresse manuelle et beaucoup d'efforts pour que l'entraínement en ouverture ou fermeture puisse se réaliser ;

le moyen élastique de désaccouplement qui est un ressort métallique est calibré pour une très longue durée de vie, mais peu de manipulations en raison de cette application très particulière, exigeant force humaine importante et adresse manuelle particulière lors de sa manipulation ;

cette fermeture de sécurité se révèle totalement inadaptée à la fermeture de conteneurs tels que des flacons.

However, it is obvious that such a device is difficult to exploit because:

it requires a relatively precise mechanical maneuver which consists of an axial pressure to enter exactly and simultaneously the three teeth in three cavities of diameter slightly greater than that of the teeth, which requires a good manual address and a lot of effort for the drive opening or closing can be achieved;

the resilient means of uncoupling which is a metal spring is calibrated for a very long life, but little manipulation because of this very particular application, requiring significant human strength and particular manual address when handling;

this security closure is totally unsuitable for closing containers such as flasks.

Objectives of the invention

Many objectives are therefore assigned to the device according to the invention, so that it can eliminate the above-mentioned disadvantages and brings improved and improved solutions to the various means used in the closing devices of security known.

A first object of the invention is to provide a security closure device of a container by screwing, to the test of a child on unscrewing, this device consisting of two polymer plugs thermoplastics interlocking into one another, operating by a snap-fastening means of the outer cap on the internal cap by the application of a pressure torque axial-rotation, on the upper end wall of the device.

Another object of the invention is to provide a security closure device of a container by screwing, to the test of a child on unscrewing, this device having a decoupling means immediately the external plug of drive of the internal plug resulting from the end of the pressure exerted on the upper end wall of the device.

Another object of the invention is to provide a security closure device of a container by screwing, to the test of a child in unscrewing, whose means for snapping and disengaging the external cap of drive with the internal cap coaches do not suffer, in part, fatigue, permanent deformation or breakage by repetition of the application of the axial pressure-rotation torque on the upper end wall of said device.

Another object of the invention is to provide a security closure device of a container by screwing, to the test of a child in unscrewing, whose means for snapping and disengaging the external cap of drive and internal cap result compensate the adjustment or wear games between external and internal plugs, and provide them with excellent cohesion when they are snapped and a independence, without play, when they are disengaged.

Summary of the invention

All the objectives stated above can be achieved by the closure device, the object of the invention.

• le bouchon externe comportant, sur sa surface interne des moyens d'encliquetage lui permettant d'entraíner en rotation le bouchon interne, par l'application d'un couple mécanique pression axiale-rotation ;
• le bouchon interne comportant un filet de vis sur la surface interne de sa paroi latérale cylindrique et des moyens d'encliquetage correspondant à ceux du bouchon externe sur sa surface externe, lui permettant d'être entraíné en rotation par le bouchon externe quand ce dernier est soumis à un couple mécanique de pression axiale-rotation ;
• un moyen élastique de désaccouplement des moyens d'encliquetage des bouchons interne et externe quand cesse l'application du couple mécanique pression axiale-rotation sur le bouchon externe ;
• des moyens de guidage des bouchons interne et externe assurant leur coaxialité,

qui se caractérise en ce que le moyen élastique de désaccouplement :

• est placé entre les parois d'extrémités supérieures des bouchons internes et externes,
• et est formé d'un matériau polymère thermoplastique à mémoire de forme de composition différente des compositions des matériaux constituant les bouchons eux-mêmes.

According to the invention, the safety closing device by screwing a container provided with an opening with an external screw thread, consists of two coaxial plugs made of thermoplastic polymer materials fitted into each other, the an outer, the other internal, each formed of a cylindrical side wall and an upper end wall closing the cylindrical side wall,

• the outer cap having on its inner surface latching means allowing it to rotate the inner cap, by applying a mechanical torque axial pressure-rotation;
• the inner cap having a screw thread on the inner surface of its cylindrical side wall and latching means corresponding to those of the outer cap on its outer surface, allowing it to be rotated by the outer cap when the latter is subjected to a mechanical torque of axial pressure-rotation;
• an elastic means of uncoupling the latching means of the inner and outer plugs when the application of the mechanical torque axial pressure-rotation on the outer plug ceases;
• means for guiding inner and outer plugs ensuring their coaxiality,

which is characterized in that the elastic means of uncoupling:

• is placed between the upper end walls of the inner and outer plugs,
• and is formed of a thermoplastic polymeric memory material having a composition different from the compositions of the materials constituting the plugs themselves.

• le bouchon externe comporte, sur la surface interne de sa paroi d'extrémité supérieure, des moyens d'encliquetage lui permettant d'entraíner en rotation le bouchon interne, par l'application d'un couple mécanique pression axiale-rotation ;
• le bouchon interne comporte un filet de vis sur la surface interne de sa paroi latérale cylindrique et des moyens d'encliquetage correspondant à ceux du bouchon externe, sur la surface externe de sa paroi d'extrémité supérieure, lui permettant d'être entraíné en rotation par le bouchon externe quand ce dernier est soumis à un couple mécanique de pression axiale-rotation ;
• des moyens de guidage des bouchons interne et externe assurant leur coaxialité et
• un moyen élastique de désaccouplement des moyens d'encliquetage des parois d'extrémités supérieures des bouchons interne et externe quand cesse l'application du couple mécanique pression axiale-rotation sur le bouchon externe, ce moyen élastique de désaccouplement :
  • étant placé entre les parois d'extrémités supérieures des bouchons interne et externe,
  • et étant formé d'un matériau polymère thermoplastique à mémoire de forme de composition différente des compositions des matériaux constituant les bouchons eux-mêmes.

More specifically, and according to a first variant, the safety closing device by screwing a container provided with an opening with an external screw thread, which consists of two coaxial plugs made of thermoplastic polymer materials, fitted one into the other. another, one external, the other internal, each formed of a cylindrical side wall and an upper end wall closing the cylindrical side wall, is that:

• the outer cap comprises, on the inner surface of its upper end wall, latching means allowing it to rotate the inner cap, by the application of a mechanical torque axial pressure-rotation;
• the inner cap comprises a screw thread on the inner surface of its cylindrical side wall and latching means corresponding to those of the outer cap, on the outer surface of its upper end wall, allowing it to be rotated by the outer plug when the latter is subjected to a mechanical torque of axial pressure-rotation;
• means for guiding the inner and outer plugs ensuring their coaxiality and
• an elastic means of uncoupling the latching means of the upper end walls of the inner and outer plugs when the application of the mechanical torque axial pressure-rotation on the outer plug ceases, this elastic means of uncoupling:
  • being placed between the upper end walls of the inner and outer plugs,
  • and being formed of a thermoplastic polymeric memory material having a composition different from the compositions of the materials constituting the plugs themselves.

• le bouchon externe comporte, sur la surface interne de sa paroi latérale cylindrique des moyens d'encliquetage lui permettant d'entraíner en rotation le bouchon interne, par l'application d'un couple mécanique pression axiale-rotation ;
• le bouchon interne comporte un filet de vis sur la surface interne de sa paroi latérale cylindrique et des moyens d'encliquetage correspondant à ceux du bouchon externe, sur la surface externe de sa paroi latérale cylindrique, lui permettant d'être entraíné en rotation par le bouchon externe, quand ce dernier est soumis à un couple mécanique de pression axiale-rotation ;
• des moyens de guidage des bouchons interne et externe assurant leur coaxialité et
• un moyen élastique de désaccouplement des moyens d'encliquetage des parois latérales cylindriques des bouchons interne et externe quand cesse l'application du couple mécanique pression axiale-rotation sur le bouchon externe, ce moyen élastique de désaccouplement :
  • étant placé entre les parois d'extrémités supérieures des bouchons interne et externe,
  • et étant formé d'un matériau polymère thermoplastique à mémoire de forme de composition différente des compositions des matériaux constituant les bouchons eux-mêmes.

More precisely also and according to a second variant, the safety closing device by screwing a container provided with an external screw thread opening, which consists of two coaxial plugs made of thermoplastic polymer materials, fitted one into the other. another, one external, the other internal, each formed of a cylindrical side wall and an upper end wall closing the cylindrical side wall, is that:

• the outer plug comprises, on the inner surface of its cylindrical side wall, latching means allowing it to rotate the inner plug, by applying a mechanical torque axial pressure-rotation;
• the inner cap comprises a screw thread on the inner surface of its cylindrical side wall and latching means corresponding to those of the outer cap, on the outer surface of its cylindrical side wall, allowing it to be rotated by the outer cap, when the latter is subjected to a mechanical torque of axial pressure-rotation;
• means for guiding the inner and outer plugs ensuring their coaxiality and
• an elastic means of uncoupling of the latching means of the cylindrical side walls of the inner and outer plugs when the application of the mechanical torque axial pressure-rotation on the outer plug ceases, this elastic means of uncoupling:
  • being placed between the upper end walls of the inner and outer plugs,
  • and being formed of a thermoplastic polymeric memory material having a composition different from the compositions of the materials constituting the plugs themselves.

Detailed description of the invention

The device according to the invention consists of two plugs, interlocked one inside the other, each of these plugs being provided with superstructure means such as the outer cap, when it is subjected to pressure axial, then a rotation, moves vertically through a downward movement, snap into the cork internally and leads to a movement of opening or closing on demand.

As soon as the axial pressure ceases on the plug external, the device, to be really safe, must ensure the upward reverse movement of the plug external, causing the uncoupling of the plugs external and internal: as soon as the outer cap is in position, and that it is subject to a only one rotation action, it can no longer cause the internal cap in a unscrewing motion.

Such a device is of great security with regard to young children whose coordination of gestures, to create simultaneously the axial pressure-rotation torque necessary to open the device, is not yet acquired.

The external and internal plugs of the device according to the invention are made by the methods of the adapted to their realization, by means of materials which are thermoplastic polymers, such for example, polyethylenes, polypropylenes, copolymers of ethylene / propylene and their mixtures, the polyamides, polystyrenes (PS), copolymers of acrylonitrile-butadiene-styrene (ABS), copolymers styrene-acrylonitrile (SAN), polyvinylchlorides (PVC), polycarbonates (PC), polymethacrylate methyl (PMMA), polyethylene terephthalates (PET).

According to the invention, and to the great difference of the state of the technique, the elastic means with memory of form allowing the disengagement of the external plugs and internally, as soon as the application of pressure axially on the outer cap followed by a rotation, is made of an elastic thermoplastic polymeric material shape memory, of different composition compositions of materials used for manufacturing external and internal plugs.

The elastic means with shape memory can be realized by the use of at least one elastomer thermoplastic of natural or synthetic origin. The OR the elastomers used can be chosen preferentially in the group consisting of rubber-like elastomers, rubber synthetic material, in particular mono-olefin rubbers, such as, for example, polymers isobutylene / isoprene, ethylene-vinyl acetate (EVA), ethylene-propylene (EPR), ethylene-propylene-diene (EPDM), ethylene-acrylic esters (EMA-EEA), polymers fluorinated diolefins, such as for example, polybutadienes, butadiene-styrene copolymers (SBR), rubbers made from condensation such as, for example, rubbers thermoplastic polyesters and polyurethanes, the silicones, styrene-butadiene-styrene styrene rubbers (SBS) and styrene-isoprene-styrene (SIS) and others, used alone or in mixture.

The elastic means with shape memory can also be realized by means of a thermoplastic polymer foam.

The elastic memory means according to the invention can be in the form of a volume, preferably of substantially cylindrical, frustoconical, cylindro-frustoconical type, cylindrical-hemispherical - or hemispherical - whose diameter is adapted to that of the device and whose the height is at least equal to the minimum distance necessary for the locking means of the plugs external and internal are not in engaged position.

As already said, the elastic means with shape memory according to the invention may be a different volume. This volume can be full and, in this case, be illustrated by a disc, a truncated cone, a dome, or even can be hollow, and in this case, to be illustrated by a capsule, a truncated cone, a cap, this volume can be openwork to limit the effects of suction cup when is practiced, then release the axial pressure (followed by a rotation) on the outer cap.

The elastic means according to the invention is placed between the upper end walls of both plugs: it can to be inserted freely between these two walls, or to be indifferently adherent to the inner surface of the wall upper end of the outer cap or on the surface outer wall of the upper end wall of the cap internal, by gluing on the surface of the cap or by overmoulding on said plug.

The elastic memory means according to the invention, made of thermoplastic polymer materials, can be obtained by one of the means specific to the plastics making it possible to manufacture said means.

The latching means are generally known, but must be adapted in their form according to their zone because of the presence of the medium uncoupling elasticity of said detent means according to the invention, placed between the end walls upper internal and external plugs.

• de lames à section carrée, rectangulaire, triangulaire ou autre, présentes sur au moins une partie de la hauteur de ladite paroi latérale et implantées selon les génératrices,
• de couronnes crantées présentes en périmétrie sur lesdites surfaces concernées.

In the case where the implantation of the latching means is on the inner surface of the cylindrical side wall of the outer cap and on the outer surface of the cylindrical side wall of the inner cap, the latching means are generally of known type. and undergo no transformation: they are, for example, formed:

• blades of square, rectangular, triangular or other section, present on at least a portion of the height of said side wall and implanted according to the generatrices,
• notched crowns present in perimetry on said surfaces concerned.

In the case where the implantation of the latching means is done simultaneously on the surfaces facing the walls cylindrical sides and on the end surfaces of said plugs, the latching means are often of known types, such as for example blades. Such blades, which are described in the patent EP 0631943, form a groove consisting of successive ribs in the form of lamellae extending at least on one of the appropriate surfaces of the walls top end, in the form of a spline the radial length of each blade must be limited to create a reserve area, coaxial to plugs, necessary for the implantation of the elastic means according to the invention.

This radial length is at most equal to the radius of the face of the upper end wall of the plugs external and internal, less the radius of the base area the geometrical volume of the elastic means according to the invention.

In the case where the implantation of the latching means is made on the inner surface of the end wall upper outer cap and on the outer surface of the upper end wall of the inner cap, these means are formed, for example, of crown teeth, blades with square, rectangular, triangular or other, in a radial position, the radial dimension of which is limited to create a coaxial reserve surface at plugs, necessary for the implantation of the elastic means according to the invention.

This radial dimension is preferably at most equal to the radius of the face of the end wall upper outer and inner plugs, less radius of the base area of the geometric volume of the medium elastic according to the invention.

• la même morphologie telle que par exemple des dents montées en couronne, ou des lames radiales sur chacune des surfaces des parois d'extrémités supérieures des bouchons, ou des couronnes périmétriques crantées sur les surfaces en regard des parois latérales cylindriques des bouchons ;
• des morphologies différentes, telles que par exemple des dents montées en couronne sur la surface interne de la paroi d'extrémité supérieure du bouchon externe et des lames radiales sur la surface externe de la paroi d'extrémité supérieure du bouchon interne.

According to the invention, it is possible to implement locking means on the facing surfaces to be provided with, which have:

• the same morphology such as for example teeth mounted in a ring, or radial blades on each of the surfaces of the upper end walls of the plugs, or perimetric crowns notched on the facing surfaces of the cylindrical side walls of the plugs;
• different morphologies, such as for example crown-mounted teeth on the inner surface of the upper end wall of the outer plug and radial blades on the outer surface of the upper end wall of the inner plug.

According to a particular variant of the invention, the means snap-fasteners placed opposite on the inner surface of the upper end wall of the outer cap and on the outer surface of the upper end wall of the inner cap are formed on each of these surfaces, by a crown of teeth, whose apparent diameter is less than that of corks, is preferentially the same for both crowns.

The teeth forming one and the other of the crowns are spaced apart from each other so that the teeth of the crown of the outer cap can be embedded easily between the teeth of the cap crown internal when the outer cap is under pressure axial then to a primer of rotation.

• parallélépipède s'achevant à leur extrémité d'engagement mécanique par deux plans obliques, symétriques, séparés l'un de l'autre par un plan horizontal,
• parallélépipède ou cylindre s'achevant à leur extrémité d'engagement mécanique par un hémisphère ou un tronc de cône. Cette forme particulière des dents est conçue de telle manière que le bouchon externe, lorsqu'il n'est pas soumis à une pression axiale, mais seulement soumis à un mouvement de rotation, puisse tourner dans un sens ou dans l'autre sans entraíner le bouchon interne, les dents de la couronne du bouchon externe pouvant glisser sur les dents de la couronne du bouchon interne, si elles sont en contact avec elles, sans s'encliqueter les unes dans les autres ;
• le nombre de dents présentes dans chaque couronne dépend essentiellement du diamètre de ces couronnes : le nombre préférentiel de dents est d'au moins quatre dents par couronne. D'une manière préférentielle, le rapport du nombre de dents au diamètre en mm de la couronne est compris entre 0,15 (4/24) et 0,5 (12/24).

The teeth of the crowns for snapping the outer cap with the inner cap have a shape of:

• parallelepiped terminating at their end of mechanical engagement by two oblique planes, symmetrical, separated from each other by a horizontal plane,
• parallelepiped or cylinder terminating at their mechanical engagement end by a hemisphere or a truncated cone. This particular shape of the teeth is designed such that the outer cap, when not subjected to axial pressure, but only subjected to a rotational movement, can rotate in one direction or the other without causing the inner cap, the teeth of the crown of the outer cap can slide on the teeth of the ring of the inner cap, if they are in contact with them, without snapping into each other;
• the number of teeth present in each crown depends essentially on the diameter of these crowns: the preferred number of teeth is at least four teeth per crown. In a preferred manner, the ratio of the number of teeth to the diameter in mm of the ring is between 0.15 (4/24) and 0.5 (12/24).

According to the invention, the cap guiding means externally with respect to the inner cap, to ensure excellent coaxiality, may be present on one and / or the other of the cylindrical side walls of the one and the other plugs, on the outer surface of the plug internal and / or on the inner surface of the outer cap.

The guiding means may consist of blades with square, rectangular, triangular and others, presented on all or part of the height of the cylindrical sidewall and implanted according to generators of said wall.

When these guide means intervene only for this only guide function, they are present on one and / or the other of the cylindrical side walls external and internal plugs and their height intervenes on all or part of the height of said side walls.

According to the invention, these guide means may have simultaneously two functions, the first being guidance, the second being that of a means of training internal plug in the only direction of screwing, by the outer cap.

• dans le sens à tendance centripète, quand les lames sont sur la surface interne de la paroi latérale cylindrique du bouchon externe,
• dans le sens à tendance centrifuge, quand les lames sont sur la surface externe de la paroi latérale cylindrique du bouchon interne.

So that these two functions can be provided simultaneously, the blades, constituting the guide means and drive in the direction of screwing, are present preferably over the entire height of the cylindrical side walls of the two plugs. These blades have in section substantially in the form of a triangular section wave, rectangular, whose origin is located on a generatrix of the cylindrical side surfaces, and whose end is oriented in an oblique plane:

• in the centripetal direction, when the blades are on the inner surface of the cylindrical side wall of the outer cap,
• in the direction of centrifugal tendency, when the blades are on the outer surface of the cylindrical side wall of the inner cap.

So when the outer cap is rotated in the direction of screwing, without any pressure axial, the ends of the guide blades of the cap the outer end come into abutment with the ends of the blades of guiding the inner plug and driving the plug internal in the direction of screwing.

On the other hand, when the outer cap is subjected to rotation in the direction of unscrewing out of any axial pressure, the oblique planes of the guide blades of the outer cap slide on the oblique planes of guiding blades of the inner cap without causing said internal cap in the direction of unscrewing.

Apart from the only elastic means, which is achieved independently of the plugs or overmoulding of one of the two stoppers, using a material different from that implemented for plugs, external plugs and internal thread, the screw thread, the latching means and guiding are simultaneously performed by injection molding with a polymer material conventionally used for such products.

• La figure 1 est une vue en perspective du bouchon externe.
• La figure 2 est une vue en perspective d'un moyen élastique selon l'invention.
• La figure 3 est une vue en perspective du bouchon interne selon l'invention.
• La figure 4 est une vue en perspective d'un moyen de fermeture d'un réservoir contenant une matière adsorbant l'humidité.
• La figure 5 est une coupe verticale du dispositif selon l'invention se composant des bouchons externe et interne.
• La figure 6 est une coupe horizontale selon B-B du dispositif selon l'invention.
• La figure 7 est une vue interne du bouchon externe du dispositif selon l'invention.
• La figure 8 est une coupe verticale du bouchon externe du dispositif selon l'invention.
• La figure 9 est une vue en perspective d'une dent appartenant au moyen d'encliquetage selon l'invention.

The invention will be better understood thanks to the numerical description of the figures below, these figures having only an illustrative non-limiting character of a particular device of the invention.

• Figure 1 is a perspective view of the outer cap.
• Figure 2 is a perspective view of an elastic means according to the invention.
• Figure 3 is a perspective view of the inner cap according to the invention.
• Figure 4 is a perspective view of a means for closing a reservoir containing a moisture adsorbent material.
• Figure 5 is a vertical section of the device according to the invention consisting of external and internal plugs.
• Figure 6 is a horizontal section along BB of the device according to the invention.
• Figure 7 is an internal view of the outer cap of the device according to the invention.
• Figure 8 is a vertical section of the outer cap of the device according to the invention.
• Figure 9 is a perspective view of a tooth belonging to the latching means according to the invention.

According to FIGS. 1 to 4, the closure device of security according to the invention consists of an external cap (1), a resilient memory means (20), a inner cap (40) and a closure means (60) of a reservoir of hydrophilic material, absorbing moisture internal container (not shown).

• la première de ces fonctions est celle de guider coaxialement le déplacement du bouchon externe (1) par rapport au bouchon interne (40), quand est appliquée, puis relâchée la pression axiale sur le bouchon externe (1) ;
• la deuxième de ces fonctions est celle de participer à un moyen d'entraínement en rotation du bouchon interne dans l'unique sens du vissage du dispositif, en l'absence de toute pression axiale sur le bouchon externe. Comme l'illustre la figure 6, les lames (6) ont sensiblement, en coupe, une forme rectangulaire allongée, dont l'inclinaison selon la trace du plan (7) donne une orientation (selon la flèche), dans le sens à tendance centripète et forme un angle "α" avec le plan de tangence (8) à la naissance de la lame (6).

The outer cap (1) consists of a cylindrical side wall (2) and an upper end wall (3), closing the cylindrical side wall. On the inner surface of its upper end wall (3) is a latching means (Figure 7) formed of a ring (4) having a smaller diameter than the plug, having twelve teeth (5). On the internal surface of the cylindrical side wall are placed (FIGS. 5, 6, 7) centering means consisting of blades (6) playing simultaneously, in this illustrative case, two functions:

• the first of these functions is that of coaxially guiding the displacement of the outer plug (1) relative to the inner plug (40), when is applied, and then released the axial pressure on the outer plug (1);
• the second of these functions is to participate in a means of rotational drive of the inner plug in the only direction of screwing the device, in the absence of any axial pressure on the outer plug. As shown in Figure 6, the blades (6) have substantially, in section, an elongated rectangular shape, the inclination according to the trace of the plane (7) gives an orientation (according to the arrow) in the direction of tendency centripetal and forms an angle "α" with the plane of tangency (8) at the birth of the blade (6).

The inner cap (40) also consists of a wall cylindrical side (41) and end wall upper (42) closing the cylindrical side wall. Sure the outer surface of the upper end wall (42) is a latching means (Figure 3) formed a ring (43), of a diameter smaller than that of the internal cap, but identical to the diameter of the crown (4) placed on the inner surface of the end wall upper outer cap (1). The crown (43) has the same number of teeth as the crown (4).

• la première de ces fonctions est celle de guider coaxialement le déplacement du bouchon externe (1) par rapport au bouchon interne (40),
• la deuxième de ces fonctions est celle de participer à un moyen d'entraínement en rotation du bouchon interne dans l'unique sens du vissage du dispositif, en l'absence de toute pression axiale sur le bouchon externe. Comme l'illustre la figure 6, les lames (45) ont sensiblement, en coupe, une forme triangulaire dont la trace du plan de face (46) donne une orientation (selon la flèche) dans le sens à tendance centrifuge et forme un angle "β" avec le plan de tangence (47) à la naissance de la lame (45).

On the outer surface of the cylindrical side wall (41), are also placed guide means constituted by blades (45) playing simultaneously (in this illustrative case) two functions:

• the first of these functions is that of coaxially guiding the displacement of the outer plug (1) with respect to the internal plug (40),
• the second of these functions is to participate in a means of rotational drive of the inner plug in the only direction of screwing the device, in the absence of any axial pressure on the outer plug. As shown in FIG. 6, the blades (45) have a triangular shape in cross-section, the trace of the face plane (46) giving an orientation (in the direction of the arrow) in the centrifugally inclined direction and forming an angle "β" with the plane of tangency (47) at the birth of the blade (45).

The shape of the teeth (5, 44) of the crowns (4, 43) is rectangular parallelepipedic type (FIG. 9) comprising sidewalls (90, 91) extending to their end of mechanical engagement when snapping by cut sides (oblique planes) (92, 93), separated from each other by a horizontal plane (94).

This form of tooth is such that, in the absence of a axial pressure on the outer cap but during a rotation movement applied to said outer cap, the oblique planes (92, 93) of the teeth (5) of the crown (4) and teeth (44) of the crown (43) can slide on each other (in the case of a rapprochement accidental causing their contact), without the teeth said crowns can snap and cause the drive of the internal plug by the rotation of the outer cap.

Between the upper end walls of the plugs external and internal, is the elastic means with memory form (20) according to the invention (Figure 2). Said means elastic member (20) is of the hollow cylindrical-frustoconical type, component of a circular ring (21), a wall lateral cylindro-frustoconical (22) and a wall perforated upper end with a cross (23) and openings (24).

The diameter of the elastic memory means is less than the internal diameter of the snap rings (4) and (43), so that it is easily inserted.

The elastic means with shape memory, realized by injection molding using a mixture of elastomers thermoplastic, is placed in operating position between the two upper end walls (3) and (42) the traffic jam.

The thickness of the elastic memory means (20) is very slightly greater than the distance between the walls (3) and (42), so that, apart from any axial pressure, the outer cap (1) can be rotated (in the sense of opening) without causing the inner cap (40).

During axial pressure on the outer cap (1), the elastic means with shape memory (20) is compressed, distorts while remaining within the limits of crowns (4) and (43). Compression deformation of the elastic medium with shape memory, flushes the air present in the zone allowing the snapping of the two crowns (4) and (43).

The outer cap can cause the plug to rotate internally, especially in the direction of unscrewing. When the axial pressure ceases, the elastic means with memory of form resumes its initial volume, particularly in recovering its initial volume of air. The two caps, in moving away from each other, disengage: the outer cap can no longer cause the inner cap, in particular, in the direction of unscrewing.

Completing the device according to the invention, a cap (60) is present for closing the tank (48) (forming part of the inner plug (40)) in which is introduces a material having specific properties, such as for example adsorbing the internal moisture at container (not shown) closed by said device.

In the illustrative case previously mentioned of the device according to the invention, closing the device according to the invention is done by means of the blades (6) and (45) abutting when the outer cap (1) is subject to a single rotational movement in the direction of screwing: the blades (6) of the outer cap, driven in the direction of the arrow (49), come into contact with the blades (45) of the inner cap (40) by their face abrupt and drive said inner cap in the direction of the closure.

In the opposite way, the outer cap (4) being subject with a single rotational movement in the unscrewing direction, according to the arrow (50), the blades (6) slide by their plane oblique (7) on the oblique plane (46) of the blades (45): the internal cap is not driven in the movement of unscrewing.

For opening by unscrewing the device according to the invention, the outer cap (1) must be submitted at an axial pressure followed by a rotation in the direction unscrewing. In this context, the outer cap (1) closer to the inner cap by compressing the medium elastic memory shape (20).

The teeth of the crown (4) of the outer cap (1) snap into the teeth of the crown (43) at inner cap (40): the inner cap is then rotated by the outer cap (1) and the Closing device is easily unscrewed and separated container (not shown).

According to another variant (not represented), the device safety closure includes all the means described in the first illustrative case, except that only the blades (6) on the outer cap (1) or (45) on the inner plug (40), blades that intervene to their only guide function. In this case, closure and opening of the device according to the invention are carried out by axial pressure on the outer cap followed by proper rotation, causing snapping crowns (4) and (43) and driving the inner plug (40) in the direction of the application of rotation on the plug external (1).

Claims (27)

1. Device for the safe closure by screwing of a container provided with an opening with an outer screw thread, which comprises two coaxial caps made of thermoplastic polymer materials, fitted one inside the other, one external (1), the other internal (40), each formed by a cylindrical lateral wall and by an upper end wall closing the cylindrical lateral wall:

   the outer cap (1) comprising, on its inner surface, engagement means (4) (5) allowing it to drive the inner cap (40) in rotation, by the application of an axial pressure/rotational mechanical torque;

   the inner cap (40) comprising a screw thread on the inner surface of its cylindrical lateral wall and engagement means corresponding to those of the outer cap, on its outer surface, allowing it to be driven in rotation by the outer cap (1) when said outer cap is subjected to an axial pressure/rotational mechanical torque;

   means (45) for guiding the inner and outer caps, providing their coaxiality;

   a resilient means for disconnecting the engagement means (20) from the inner and outer caps when the axial pressure/rotational mechanical torque ceases to be applied on the outer cap,

   characterised in that said resilient disconnecting means

   is placed between the upper end walls of the inner and outer caps,

   and is made of a shape-memory thermoplastic polymer material having a different composition to the compositions of the materials forming the caps themselves.
2. Device for the safe closure by screwing of a container according to claim 1, characterised in that:

   the engagement means (4) (5) of the outer cap (1), allowing the inner cap (40) to be driven in rotation by the application of an axial pressure/rotational mechanical torque, are placed on the inner surface of the upper end wall of said outer cap;

   the engagement means of the inner cap (40), corresponding to those of the outer cap (1), allowing it to be driven in rotation by the outer cap (1) when said outer cap is subjected to an axial pressure/rotational mechanical torque, are placed on the outer surface of the upper end wall of said inner cap (40).
3. Device for the safe closure by screwing of a container according to claim 1, characterised in that:

   the engagement means (4) (5) of the outer cap (1), allowing the inner cap (40) to be driven in rotation by the application of an axial pressure/rotational mechanical torque, are placed on the inner surface of the cylindrical lateral wall of said outer cap (1);

   the engagement means of the inner cap (40), corresponding to those of the outer cap (1), allowing it to be driven in rotation by the outer cap (1) when said outer cap is subjected to an axial pressure/rotational mechanical torque, are placed on the outer surface of the cylindrical lateral wall of said inner cap (40).
4. Device according at least one of claims 1 to 3, characterised in that the shape-memory resilient means is detached from both of the surfaces of the upper end walls.
5. Device according to at least one of claims 1 to 3, characterised in that the shape-memory resilient means is integral with both of the surfaces of the upper end walls.
6. Device according to at least one of claims 1 to 5, characterised in that the shape-memory resilient means is produced using at least one of the shape-memory resilient materials selected from the group consisting of at least one elastomer.
7. Device according to claim 6, characterised in that the shape-memory resilient means is produced from materials selected from the group consisting of elastomers of the natural rubber and synthetic rubber type, used individually or in combination.
8. Device according to claim 7, characterised in that the resilient means is preferably produced from materials selected from the elastomer group formed by isobutylene/isoprene, ethylene vinyl acetate (EVA), ethylene propylene (EPR), ethylene propylene diene monomer (EPDM), ethylene acrylic esters (EMA-EEA), fluoropolymers, polybutadienes, copolymers of styrene butadiene (SBR), polyester and polyurethane rubbers, silicones, styrene-butadiene-styrene (SBS) and styrene-isoprene-styrene (SIS) styrene rubbers, used individually or in combination.
9. Device according to at least one of claims 1 to 8, characterised in that the shape-memory resilient means has the shape of a volume of the substantially cylindrical, truncated, cylindrical truncated, cylindrical hemispherical, or hemispherical type, the diameter of which is adapted to that of the device and the height of which is at least equal to the minimum distance required to ensure that the engagement means of the outer and inner caps are not in the engaged position.
10. Device according to claim 9, characterised in that the volume of the shape-memory resilient means is a solid volume.
11. Device according to claim 9, characterised in that the volume of the shape-memory resilient means is a hollow volume.
12. Device according to claim 11, characterised in that the hollow volume of the shape-memory resilient means is open.
13. Device according to at least one of claims 1 to 3 and 5 to 12, characterised in that the shape-memory resilient means is joined to one or other of the upper end walls by bonding or over-moulding.
14. Device according to at least one of claims 1 to 5 and 8 to 13, characterised in that the shape-memory resilient means is produced using a thermoplastic polymer foam.
15. Device according to at least one of claims 1 to 14, characterised in that the thermoplastic polymer material used in forming the inner and outer caps is selected from the group consisting of polyethylenes, polypropylenes, ethylene-propylene copolymers and mixtures thereof, polyamides, polystyrenes (PS), acrylonitrile-butadiene-styrene copolymers (ABS), styrene and acrylonitrile copolymers (SAN), polyvinyl chlorides (PVC), polycarbonate (PC), polymethylmethacrylates (PMMA) and polyethylene terephthalates (PET).
16. Device according to at least one of claims 1 to 2 and 4 to 15, characterised in that when the engagement means are fitted on the inner surface of the upper end wall of the outer cap and on the outer surface of the upper end wall of the inner cap, these means are selected from those consisting of teeth placed in a crown, blades that are square, rectangular or triangular in section, in the radial position, the radial length of which is at most equal to the radius of the surface receiving the engagement means less the radius of the base surface of the geometric volume of the resilient means.
17. Device according to at least one of claims 1 to 15, characterised in that when the engagement means are simultaneously fitted on the opposing surfaces of the cylindrical lateral walls and on the upper end surfaces of the inner and outer caps, the engagement means are successive ribs forming blades extending radially over at least one of the appropriate surfaces of the upper end walls of the caps in the form of a radial fluting, the radial length of which is at most equal to the radius of the surface receiving the engagement means less the radius of the base surface of the geometrical volume of the resilient means.
18. Device according to at least one of claims 1 or 3 and 4 to 15, characterised in that when the engagement means are fitted on the inner surface of the cylindrical lateral wall of the outer cap and on the outer surface of the cylindrical lateral wall of the inner cap, the engagement means are selected from the group consisting of blades that are square, rectangular or triangular in section, present over at least a portion of the height of said lateral wall and fitted along the generatrices, or notched crowns present at the periphery of said relevant surfaces.
19. Device according to at least one of claims 1 to 18, characterised in that the engagement means fitted on the opposing surfaces of the outer and inner caps are of the same morphology or of different morphology.
20. Device according to at least one of claims 1 to 2 and 4 to 16, characterised in that the engagement means placed facing one another on the inner surface of the upper end wall of the outer cap and on the outer surface of the upper end wall of the inner cap are formed on each of these surfaces by a crown of teeth, of which the apparent diameter, which is smaller than that of the caps, is preferably the same for both of the crowns.
21. Device according to claim 20, characterised in that the teeth of the engagement crowns have a parallelepiped shape, ending at their mechanical engagement end with two symmetrical oblique planes, separated from each other by a horizontal plane.
22. Device according to claim 20, characterised in that the teeth of the engagement crowns have a parallelepiped or cylindrical shape, ending at their mechanical engagement end with a hemisphere or a cone frustrum.
23. Device according to any one of claims 20 to 22, characterised in that, preferably, the number of teeth present in each crown is at least four teeth per crown, and the ratio of the number of teeth to the diameter in mm of the crown is between 0.15 and 0.5.
24. Device according to at least one of claims 1 to 23, characterised in that the means for guiding the outer cap relative to the inner cap are present on one and/or the other of the cylindrical lateral walls of both of the caps, on the outer surface of the inner cap and/or on the inner surface of the outer cap.
25. Device according to claim 24, characterised in that the guiding means consist of blades that are square, rectangular or triangular in section, present on the cylindrical lateral wall and fitted according to the generatrices of said wall.
26. Device according to at least one of claims 1 to 23, characterised in that the means for guiding the outer cap relative to the inner cap are also and simultaneously means for driving, in the single direction of screwing, of the inner cap by the outer cap, and are preferably present over the entire height of the cylindrical lateral walls of the two caps.
27. Device according to claim 25, characterised in that the means for simultaneous guiding and driving, in the direction of screwing, of the inner cap by the outer cap are blades having the appearance of a wave that is triangular or rectangular in section, of which the origin is located on a generatrix of the cylindrical lateral surfaces and of which the end is oriented along an oblique plane:

    in the centripetal tendency direction when the blades are on the inner surface of the cylindrical lateral wall of the outer cap,

    in the centrifugal tendency direction when the blades are on the outer surface of the cylindrical lateral wall of the inner cap.

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