EP0123810B1 - Child-resistant closure - Google Patents

Abstract

A child resistant closure for bottles is provided that permit closure withdrawal by exerting an axial force and a simultaneous rotating movement. For this purpose, a clutch is provided between an inner cap and an outer cap of the closure with at least one elastic flexible clutch element which is ineffective in its rest position and which is deformable upon application of an axial downward force. In this manner, a sufficient friction lock is generated between the two caps, so that the outer cap takes along the inner cap during screwing on and unscrewing off. In the absence of the axial force the outer cap will slide over and not turn the inner cap.

Description

The invention relates to a closure for containers, in particular bottles, with the features mentioned in the preamble of claim 1. The closure is particularly childproof.

Childproof lock of this type is known from CB-A-1 361 195. Between the cover plates of both caps of this closure, an elastic disc is inserted as a torque-transmitting element, which extends over the entire surface of the cover plate of the inner cap. When screwing on as when unscrewing, an axial force directed from the outer cap against the inner cap must be applied so that a sufficient friction torque (a frictional engagement) arises between the two caps for the screwing process. There are no elastic elements that could keep the two caps apart in the idle state.

If an axial force is applied, it increases from a value of zero to a value at which it should be able to apply a frictional torque that is sufficient for the screwing process. The axial force acts on the inner cap from the start and thus increases the contact pressure of the cover plate of the inner cap via its seal at the mouth, for. B. a bottle. This causes a friction between the cover plate of the inner cap and the mouth that increases with the axial force and which counteracts a screwing process. As a result, it is uncertain that the frictional torque caused by the axial force between the two caps will ever be sufficient to unscrew the inner cap against the friction caused between the inner cap and the mouth. This is due to the fact that the axial force acts on the entire surface of the cover plate of the inner cap, while for the screwing process essentially only the portion of this force is essential which acts on the outer edge of the inner cap. The situation becomes particularly unfavorable when a user presses against the center of the outer cap with one finger and tries to loosen the cap with the other fingers. Then the braking torque should weigh the opening torque, so that the cap cannot be unscrewed.

Closures according to the present invention are to be screwed onto the mouths of containers, in particular bottles, by automatic closing machines. The maximum torque to be exerted by the capping machine must be set with a small tolerance so that on the one hand each of the mouths is tightly closed, but on the other hand the inner cap is not screwed down too tightly. In the latter case, it could be destroyed as soon as it was screwed on or would be difficult to loosen again.

With closures according to the above-mentioned document, as with other known closures, a childproof lock is only achieved in the closed state if the inner cap is screwed onto the mouth with a sufficiently large torque. If, on the other hand, the inner cap is screwed on only slightly or only a part of its rotation path, it can be unscrewed again with these known closures, since the coupling elements transmit a torque which is still sufficient for this.

The invention is intended to provide a closure in which no or only a negligibly small frictional torque is generated when the axial force is exerted, while on the other hand the axial force is deflected into a substantially radially acting force which serves to generate a frictional torque which is mainly affects the circumference of the inner cap. A securing effect, in particular child safety), should be achievable regardless of the torque with which the inner cap was screwed on, so that it becomes immaterial to what size the maximum torque of a capping machine is set or how much a consumer screws the cap.

This object is achieved by the invention according to claim 1. (The claim wording is referred to below).

According to the invention, the at least one deformable wall, which can also be designed as a membrane, is elastically bendable and has a section which, during the axial movement, lies against a section of the other cap and transmits a radial force from the one to the end cap. As a result, the desired friction torque is generated without disturbing braking torque.

As a result of its shape, the wall has the property of a return spring, in such a way that when the axial force decreases, it reverses a previous axial displacement of the one relative to the other cap and thus disengages the friction clutch. There is sufficient axial play between the two caps in the idle state. The childproof lock results from the fact that in the idle state the outer cap can be freely rotated on the inner cap. The childproof lock is also guaranteed if the inner cap has only been screwed on partially or very loosely. Both when screwing in and when unscrewing, the outer cap must be moved axially against the mouth. Only then will the wall be deformed sufficiently so that it will take the inner cap with it under friction. The frictional engagement can be dimensioned such that the maximum torque that can thereby be transmitted is sufficient on the one hand for firmly screwing the inner cap, but on the other hand is not sufficient to destroy the closure if, for. Legs Capping machine is set so that it could transmit excessive torque. If too much torque is transmitted to the outer cap, it slips on the outer cap and the deformable wall after overcoming the frictional torque.

The closure according to the invention therefore transmits no torque at all in the idle state and, when the outer cap is fully depressed, a torque up to a certain maximum size, which depends solely on the shape and the elastic spring force of the deformable wall.

Further bindings of the invention

According to claim 2, the deformable wall can be formed as a membrane which is connected to one cap and has a portion which is closely adjacent to the other cap in the idle state without frictional engagement occurring. When the axial movement is exerted, a section of the membrane that was previously straight or only slightly curved, viewed in longitudinal section, is curved or more strongly curved. As a result, the membrane now exerts a radial force, so that the desired frictional engagement occurs, which is required to take the inner cap with it.

According to claim 3, both caps can be locked together in a simple manner so that the outer cap can not be lost.

The elastic membrane can be part of one of the caps or a separate ßauteil, which is placed on the one cap, in particular inner cap. This gives the possibility of a free choice of material for the membrane and caps. A separate membrane allows a low axial height of the closure.

According to claim 4, a channel-shaped section of a membrane, which is part of one of the caps, connect the jacket to the cover plate and protrude into an annular space of the other cap. When the axial force is exerted, the membrane jams in this annular space and thereby creates the frictional connection.

According to claim 5, the deformable wall can have the shape of a hollow truncated cone. When the outer cap is pressed down, this wall is deformed in such a way that the cone angle increases. The open end of the wall then presses against a second coupling element in the form of an annular projection, depending on the design, either inwards or outwards. The deformable wall and the annular projection jam against each other so that the desired frictional engagement is achieved. The jacket of the outer cap can also serve as an annular projection.

According to claim 7, at least one pair of elastically bendable walls can be provided in the form of hollow truncated cones, which are arranged on the cover plates of both caps and which engage in one another at rest without frictional engagement. The walls have cone angles of different sizes and, when the axial force is exerted, lie against one another with elastic deformation. The force caused by the elastic deformation ensures the necessary friction. This further development achieves closures of small diameter.

If two pairs of such walls are arranged concentrically to one another according to claim 9, then both a small diameter and a low overall height of the closure can be achieved.

If, according to claim 10, the mantles of both caps themselves are designed as walls in the form of hollow truncated cones, particularly simple injection molds for producing the caps result.

Definitions: Terms such as "top", "bottom", "depress" and the like refer to the position of a closure according to the invention, the inner cap of which is screwed onto the mouth of an upright bottle.

According to claim 11 you get particularly easy to manufacture elements of the friction clutch.

Exemplary embodiments with further features of the invention are described below with reference to the drawings.

• Figur 1 bis 7 zeigen Ausführungsformen mit je einer biegsamen Membran mit einem rinnenförmigen Abschnitt.
• Figur 8 und 9 zeigen Ausführungsformen, bei denen die Kupplung eine Wand in Form eines hohlen Kegelstumpfes aufweist.
• Figur 10 bis 12 zeigen Ausführungsformen mit Paaren von Wänden in Form hohler Kegelstümpfe, die als Kupplungselemente wirken.
• Figur 13 zeigt eine Ausführungsform, bei der die Kappenmäntel selbst derartige Wände bilden.

All figures are axial sections (Figure 9 only the right half) through the inner cap, outer cap and coupling elements. All figures show on the left the resting end, in which the outer cap and inner cap are freely rotatable on one another, and on the right the state of entrainment, achieved by depressing the outer cap against the inner cap, causing frictional engagement by the coupling elements.

• Figures 1 to 7 show embodiments each with a flexible membrane with a channel-shaped section.
• Figures 8 and 9 show embodiments in which the coupling has a wall in the form of a hollow truncated cone.
• Figures 10 to 12 show embodiments with pairs of walls in the form of hollow truncated cones which act as coupling elements.
• Figure 13 shows an embodiment in which the cap sleeves themselves form such walls.

Figure 1 shows a mouth 1 of a bottle with an external thread. An inner cap 3 of a closure according to the invention with an internal thread is screwed onto this. Instead of the normal screw thread shown in all figures, bayonet threads could also be provided. The inner cap 3 has a jacket 3a and a cover plate 3b. A downwardly projecting ring seal 5 attaches to this. An outer cap 7 with jacket 7a and cover plate 7b is over the Inner cap 3 put over. It has a hollow cylindrical projection 9 which engages through a central opening 11 in the inner cap. The approach has on its outer edge an outer bead 13 which snaps out after being pressed forcibly and anchors the outer cap to the inner cap. The opening 11 of the inner cap is sealed by a cap 15.

At the lower edge of the inner cap 3 there is an elastically flexible membrane 17 which is turned inside out and is located in an annular space 18 between the inner cap 3 and the outer cap 7. It has a channel-shaped section 17a and then a cylindrical section 17b, which in the rest state is at a short distance from the inner wall of the outer cap 7. The free edge 17c of the membrane is supported on an inner shoulder 19 of the outer cap 7. Here, too, there is little play in the idle state, so that no or no significant torque can be transmitted from the outer cap to the membrane and thus to the inner cap in the idle state.

If the outer cap 7 is pressed down in the direction of the arrow, which is possible until the two cover plates abut against one another, then the inner shoulder 19 presses the cylindrical section 17b of the membrane downward. As a result, the lower part of the cylindrical portion 17b is forced to bend. However, it strives to maintain its original shape, with the result that it presses radially outward against the inner wall of the outer cap 7. This creates the desired frictional engagement. The membrane is dimensioned and made of such a material that a torque is generated under friction, which is sufficient to screw the inner cap tightly enough for secure sealing and to unscrew it again. When using capping machines, this design limits the tightening torque. If the inner cap is completely screwed on and a torque of increasing size continues to be exerted on the outer cap, the outer cap finally rotates around the membrane. This prevents the closure from being destroyed when too much torque is applied.

Figure 2 shows a very similar design. Here, the membrane 17.2 is attached to an outer cap 7.2, which is essentially designed as a cylindrical ring. The free edge of the membrane is supported on an outer flange 21 of the. Inner cap. Both caps are held in a manner known per se by an inner bead 23 of the outer cap, which cooperates with the outer flange 21 and is held together by the membrane. The function is the same as that of the closure according to FIG. 1.

According to Figure 3, a membrane 17.3 is provided, which is a special component. As a result, you have a free choice of any hard material for the caps. You only need to use a plastic with suitable elasticity for the membrane itself. The membrane 17.3 has an inner cylindrical section 17d which sits tightly on a section of smaller diameter of the inner cap 3.3. The membrane is turned inside out, has a channel-shaped section 17a and is supported on the cover plate 17b of the outer cap. The function corresponds to that of the embodiment according to FIG. 1.

The embodiments according to FIGS. 4 and 5 show that closures according to the invention can be combined with a tamper-evident device. The embodiment according to FIG. 4 has an insertable, elastically flexible membrane 17.4 with an inner flange 17e and a cylindrical section 17d which is to be inserted over the inner cap. The membrane has a trough-shaped section 17a and a cylindrical section 17b which is at rest. the inner wall of a substantially cylindrical outer cap 7.4 is closely adjacent without exerting frictional engagement. As in FIG. 1, the upper edge of the membrane abuts an inner shoulder 19 of the outer cap 7.4. The outer cap has an inner flange 25 which merges into a retaining ring 29 in an annular predetermined breaking point 27. This ensures the position in which there is no frictional engagement (Figure 4 left). When used for the first time, the outer cap 7.4 is pressed downward in the direction of the arrow, the locking ring 29 breaking off. The other function is the one described above.

According to Figure 5, a locking ring 29 is also provided, which is blown off when used for the first time. Here the membrane 17.5 is an integral part of the inner cap 3.5. It connects its cylindrical section 3a with an internal thread to its cover plate 3b. The trough-shaped section 17a of the membrane projects into an annular space 31 of the outer cap. A short cylindrical extension 33 of the outer cap projects downward into a narrow annular space 35 of the inner cap and is supported on the bottom thereof. When the outer cap is pressed down, the locking ring 29 is first blown off. The membrane is then bent into the position according to FIG. 5, right, whereby it widens and exerts radial forces both inwards and outwards on the walls of the annular space 31 of the outer cap. This creates the desired frictional engagement.

According to FIG. 6, a membrane 17.6, similar to that according to FIG. 1, is provided. However, it has an annular bead 17f widening downward on its free edge. A ring of axially parallel, inwardly directed ribs 40 is provided on the inner wall of the jacket 7a of the outer cap. In the circumferential direction, these ribs have a width of approximately 2 mm and are separated from one another by spaces of the same width. The Ribs 40 widen (viewed in axial planes) from the bottom up and end in a slightly inclined upward stop surface. After the inner cap has been inserted into the outer cap, the outer bead 17f hooks over the upper edges of the ribs 40 and thus captively secures the outer cap to the inner cap.

The cover plate 7b is connected to the jacket 7a by webs 42. There are as many webs as there are ribs 40. In the injection mold, a ring of pins is required to produce the ribs 40, which pins are inserted from above through the spaces between the webs 42. The function for screwing on and unscrewing is the one described above.

FIG. 7 shows a similar embodiment in which the membrane 17.7 is only shorter. Correspondingly, the ribs 40.7 are shorter. Here the webs 42.7 connect jacket sections 7a1 and 7a2 of different diameters.

The embodiments to be described now do not have membranes with a trough-shaped section, but as essential coupling parts at least one wall in the form of a hollow truncated cone.

FIG. 8 shows such a wall 50, which attaches to the outer edge of the cover plate 3b of the inner cap and is directed inwards at an angle of 30 ° to 40 °. On the inner wall of the cover plate 7b of the outer cap, an annular projection 52 is provided, which forms an abutment for the free inner edge of the wall 50. In the idle state (left in Figure 8), the two are slightly apart. If the axial force is exerted, the wall 50 folds inwards and presses against the projection 52, which creates the frictional engagement.

As FIG. 9 shows, the wall 50.9 can also be directed outwards. In the entrained state, it then presses from the inside against the inner wall of the outer casing or against an annular projection arranged outside of its free edge, whereby it is compressed.

According to Figure 10, two walls 54 and 56 are provided in the form of hollow truncated cones. Wall 54 protrudes downwards and somewhat inwards from the cover plate of the outer cap. Wall 56 protrudes upwards and somewhat outwards from the cover plate of the inner cap. The cone angles differ by 10 ° to 20 °, so that the wall 54 with its lower edge is most closely adjacent to the wall 56 in the idle state, but without exerting frictional engagement. In the entrained state, both walls 54 and 56 lie close together under the influence of the axial force. The elastic forces caused by their bending produce the desired frictional engagement.

FIG. 11 shows that the arrangement can also be reversed in such a way that the upper free edge of wall 56.11 is most adjacent to wall 54.11. The function is otherwise the same as that shown in FIG. 10.

Figure 12 shows that two pairs of such sloping walls can also be arranged. In the entrained state, the walls of both pairs then lay against each other under elastic tension. The required frictional force is generated here at two radially separate locations. One therefore gets by with a lower overall height for the functionally essential walls and thus for the whole closure.

Figure 13 shows that the mantles of the caps themselves can be designed as walls in the form of hollow truncated cones. The function corresponds to that according to FIG. 10 or 11. For captive holding of the outer cap on the inner cap, a ring 60 is provided at the lower edge of the outer cap, which, after the outer cap has been fitted, engages with an inner bead 62 behind an outer bead 64 of the inner cap.

The closures according to all embodiments are preferably made of plastic.

Reference numerals

• 1 Mündung
• 31nnenkappe
• 3a Mantel
• 3b Deckplatte
• 5 Ringdichtung
• 7 Außenkappe
• 7a Mantel
• 7b Deckplatte
• 9 Ansatz
• 11 Öffnung
• 13 Außenwulst
• 15 Käppchen
• 17 Membran
• 17a rinnenförmiger Abschnitt
• 17b zylindrischer Abschnitt
• 17c freier Rand
• 17d zylindrischer Aufsteckteil
• 17e Innenflansch
• 17f Außenwulst
• 18 Ringraum
• 19 Innenschulter
• 21 Außenflansch
• 23 Innenwulst
• 25 Innenflansch
• 27 Sollbruchstelle
• 29 Sicherungsring
• 31 Ringraum
• 33 zylindrischer Ansatz
• 35 Ringraum
• 40 Rippe
• 42 Steg
• 50 Wand ( = hohler Kegelstumpf)
• 52 ringförmiger Vorsprung
• 54 Wand
• 56 Wand
• 60 Ring
• 62 Innenwulst
• 64 Außenwulst

(Numbers after a point (like 7.2 in the description) refer to the figure of the same number))

• 1 mouth
• 31 inner cap
• 3a coat
• 3b cover plate
• 5 ring seal
• 7 outer cap
• 7a coat
• 7b cover plate
• 9 approach
• 11 opening
• 13 outer bead
• 15 caps
• 17 membrane
• 17a channel-shaped section
• 17b cylindrical section
• 17c free margin
• 17d cylindrical push-on part
• 17e inner flange
• 17f outer bead
• 18 annulus
• 19 inner shoulder
• 21 outer flange
• 23 inner bead
• 25 inner flange
• 27 predetermined breaking point
• 29 circlip
• 31 annulus
• 33 cylindrical approach
• 35 annulus
• 40 rib
• 42 bridge
• 50 wall (= hollow truncated cone)
• 52 annular projection
• 54 wall
• 56 wall
• 60 ring
• 62 inner bead
• 64 outer bead

Claims (11)

1. Closure, particularly child-proof closure, for mouth pieces of containers especially bottles, with the following features:

a) an inner cap (3 to 3.4) with a screw or bayonet thread corresponding to that of the container mouth piece (1),

b) an outer cap (7 to 7.4) surrounding at least the outer wall of the inner cap (3 to 3.4),

c) a friction clutch provided between both caps having at least one deformable wall (17 to 17.7, 50, 50.9, 54, 56) which upon an axial movement of the outer cap (7 to 7.4) with respect to the inner cap (5 to 5.4) is causing a friction turning moment between both caps,

characterized in that the at least one deformable wall is elastically bendable and has a portion (among others 17b) which upon the axial movement is contacting a portion of the other cap and is transmitting a radial force from one onto the other cap.

2. Closure according to claim 1, characterized by the following features:

a) the deformable wall is a membrane (17ff) while the caps consist of especially harder material;

b) the membrane is interconnected with one of the caps, especially integrally (one-piece- arrangement);

c) the membrane is turned back on itself and is located completely or partially in an annular space (18) between both caps or within the other cap;

d) a turned back part (17b) of the membrane is closely neighbouring a cylindrical or frusto-conical wall of the other cap without producing a frictional force in the position of rest;

e) the free end (17c) of the turned back part of the membrane bears against an at least approximately radial annular surface of the other cap at least when the axial force is applied.

(Figs. 1 to 4, 6 and 7).

3. Closure according to claim 2, characterized by the following features:

a) The free end of the membrane (17.6, 17.7) is provided with at least one radial projection, especially outer bead (17f) which is directed towards the cap not carrying the membrane;

b) this cap has radial projections (rips 40), directed towards the cap carrying the membrane and gripping behind the projection or projections.

(Figs. 6 and 7).

4. Closure according to claim 1, characterized by the following features:

a) The deformable wall is a membrane (17.5);

b) the membrane is a component of one cap (3.5) and unites the skirt (3a) of the cap with its end plate (3b);

c) the membrane is folded over and has a channel section (17a), which extends into an annular space (51) within the other cap;

d) at least one portion of the membrane is, in the position of rest, closely neighbouring a cylindrical or frusto-conical wall of the other cap without generating a frictional force.

(Fig. 5).

5. Closure according to claim 1, characterized by the following features:

a) the deformable wall (50, 50.9) has the shape of a hollow conical frustum;

b) one of the annular ends of this wall is united with the end plate of one of the caps in such a way that the other, open end of this wall is directed towards the end plate of the other cap and an annular projection (52, 7a) therefrom and is closely neighbouring this projection without generating a frictional force.

(Figs. 8 and 9).

6. Closure according to claim 5, characterized in that the skirt of the outer cap serves as annular projection.
(Fig. 9).

7. Closure according to claim 1, characterized by the following features:

a) End plates of the two caps which face each other are each provided with one wall of a pair of elastically deformable walls (54, 56) having the shapes of hollow conical frustums, which, in the position of rest, are closely neighbouring each other;

b) the walls of each pair have cone angles differing by about 10 to 20°, so that in the position of rest the open end of one wall is closely neighbouring the other wall and in that after exerting the axial movement towards the mouth piece both walls lie next to each other in frictional contact.

(Figs. 10 to 13).

8. Closure according to claim 7, characterized in that the walls having the shapes of hollow conical frustums are projecting from the end plates of the caps radially inwards from the skirts of the caps.
(Figs. 10 to 12).

9. Closure according to claims 7 or 8, characterized in that two pairs of such walls are arranged concentrically to each other. (Fig.12).

10. Closure according to claim 7, characterized in that the skirts of the two caps themselves are such walls in the shapes of hollow conical frustums.
(Fig. 13).

11. Closure according to one of the preceding claims, characterized in that at least one of the elements of the friction coupling is axially symmetrical.

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