EP0623522A1 - Child proof screw cap - Google Patents

Abstract

The present invention relates to a plastic screw cap for container closures having a child-resistant safeguard, having an inside cap (1) with an internal thread (13) which can be screwed onto a neck or the nozzle of a container to receive a closure, and having an outside cap (2) which can be turned freely, at least in the opening direction, relative to the inside cap (1), engagement elements (7, 8, 9, 10) being provided between the inside and the outside cap (1, 2), which engagement elements which can be engaged non-positively in the opening direction only when exerting a force which is to be applied in addition to the tangential force bringing about the opening moment and is not to act solely tangentially. In order to provide a closure or a plastic screw cap with the features mentioned at the beginning, which has a high functional reliability regardless of the type of contents used and is easy to actuate, it is proposed according to the invention that the bases (3, 4) of the inside cap (1) and the outside cap (2) engage in one another by means of a cylindrical projection (5), arranged concentrically to the closure axis, on the one base (3, 4) and a cylindrical cutout (6), likewise arranged concentrically to the closure axis, on the other base (4, 3), the cutout (6) having a slightly larger diameter than the projection (5). <IMAGE>

Description

The present invention relates to a plastic screw cap for container closures with child protection, with an inner cap, the internal thread of which can be screwed onto the neck or the socket of a container for receiving a closure, and with an outer cap which can be freely rotated in the opening direction with respect to the inner cap, and outer cap engaging elements are provided which interlock positively and preferably also form-fit when the closure is screwed on, while engaging elements can only be positively engaged when the engaging elements are screwed on when the tangential screwing force acting on the outer cap is exerted, in addition to the tangential force acting on the outer cap so that the inner cap is rotated with the outer cap. The nozzle can optionally be a part to be attached separately to the container.

Such closures or screw caps, generally referred to as "closures with child protection", are known in the prior art in various variations. The inner cap itself is generally not accessible and is encompassed by the outer cap, and securing elements also ensure that the outer cap cannot be easily removed from the inner cap. In a variant of the known, child-resistant fasteners, in addition to rotating the outer cap in the opening direction, an additional axial pressure must be exerted on the outer cap so that the outer cap and inner cap engage in a non-positive manner and with the rotation of the outer cap also the inner cap, which forms the actual, threaded cap, is taken in the opening direction. For this purpose, for example, an asymmetrical toothing is provided on the inside of the cap bottom of the outer cap and on the outside of the cap bottom of the inner cap, wherein when the outer cap is turned in the closing direction, steep flanks of the two toothings come to rest against each other, so that a positive engagement occurs and the inner cap is easily taken along when the outer cap is rotated in the closing direction, while conversely when the outer cap is rotated in the opening direction, relatively flat tooth flanks lie against one another or at least one of the toothings has a flat flank in this direction which is slightly above the opposite tooth flank or the projection slides away from the other part when the outer cap is only rotated in the opening direction. Sufficient flank pressure is required to prevent these tooth flanks from sliding open, thus creating a frictional engagement between the outer and inner caps.

In another variant, the more or less resilient cylinder jacket of the outer cap is pressed in in the radial direction, preferably from opposite sides, with a corrugation on the inside of the jacket of the outer cap and a matching corrugation on the outside of the jacket of the inner cap in the radially indented areas comes into engagement with each other, so that in this so-called "ovalizing" of the outer cap, a connection is established between the outer cap and the inner cap both in the opening and in the closing direction. Such closures are intended to prevent small children from coming into contact with contents of the containers which are dangerous for them, such as medication, cleaning agents, alcohol, etc., it being assumed that children at a certain age are already able to use simple screw closures to open by turning, but at the same time have no experience and also do not have the sufficient strength and dexterity to exert an additional, non-tangential force on the (outer) closure cap in addition to the mere unscrewing movement, but in particular neither recognize nor know that one additional strength in certain direction to be able to open the shutter.

It goes without saying that the outer cap and inner cap must have a certain amount of guidance relative to one another, so that, for example, opening of the closure is not possible solely because of a more or less accidental tilting of the outer cap with respect to the inner cap, so that the engagement elements also without exerting any additional force are in engagement with one another in such a way that the closure can be screwed on. If the guidance is inadequate, it could otherwise also happen that the engagement elements do not engage correctly with one another even when the screws are screwed on, so that the screwing of such closures would also be difficult. The outer cap is therefore guided on the inner cap generally via the cylindrical outer wall of the inner cap and the cylindrical inner wall of the outer cap.

However, such closures are not equally suitable for all types of filling goods. For example, there are swellings or fillers which produce a more or less strong internal pressure, by means of which the inner closure cap is expanded or expanded. This can lead to the fact that the outer cap can no longer be freely rotated with respect to the inner cap in the opening direction, so that the closure loses the childproof function. Although you can z. B. in the closures to be ovalized provide a greater clearance between the engagement elements and ensure the guidance of the caps to one another, for example by overlapping flanges, but this does not rule out on the one hand that the flanges come into positive engagement with one another when the inner cap swells, and on the other However, this also makes it difficult to actuate the closure because the outer cap must then be ovalized more, which requires more force or requires the use of a relatively soft material, which involves the risk of deliberate or accidental separation of the outer cap from the inner cap.

Compared to this prior art, the present invention has for its object to provide a closure or a plastic screw cap with the features mentioned, which has a high degree of functional reliability regardless of the type of filling material used and is easy to operate.

This object is achieved in that the screw cap mentioned at the outset additionally has the features that the bottoms of the inner cap and outer cap have a cylindrical projection arranged concentrically to the closure axis on one floor and a cylindrical recess likewise arranged concentrically to the closure axis on the other floor interlock, the outer diameter of the recess being slightly larger than the outer diameter of the extension.

In this way it is achieved that the guidance of the outer cap on the inner cap no longer has to take place via the cylindrical walls of the outer cap and inner cap, which also have to perform other tasks, but one assigns this management function to separate, specially designed elements, namely the cylindrical approach and the corresponding recess, which interlock with a little play. It goes without saying that the term "cylindrical" may also include a hollow cylinder, so that also an embodiment in which the recess is designed, for example, in the form of a circular circumferential groove, while a circular engagement is a circular engagement which fits into the groove circumferential web, which in other words forms a (hollow) cylindrical extension, is provided, falls under the wording of claim 1 described above.

An embodiment of the invention is preferred in which the cutout extends through the bottom of the associated cap and, moreover, in particular such an embodiment in which the cutout on the bottom of the outer cap and the cylindrical extension is designed as an outer, cylindrical extension of the bottom of the inner cap. However, the recess can also easily have the form of a depression in the respective cap base without reaching completely through it, for example in the form of a circular hole.

The engaging elements are preferably provided on the end face on the outer and inner cap, i.e. on the one hand on the outside of the bottom of the inner cap and on the other hand on the inside of the bottom of the outer cap, facing each other so that they can engage and are also located radially outside the cylindrical projection and the recess.

At the end of the outer and inner cap facing away from the respective cap base, retaining elements are expediently provided, which prevent the outer and inner caps from being pulled apart. These retaining elements can have the shape of projecting shoulders, for example, in that the inner wall of the outer cap projects inwards near the edge of the cap, while conversely a shoulder or a projection projects outwards from the outer wall of the inner cap near the edge. Preferably, shoulders or projections of this type are at least partially circumferential To provide flanges, of course in the area of these projections or flanges the inner diameter of the outer cap is smaller than the outer diameter of the inner cap in the area of the projections or flanges, and these flanges or projections have ramps or inclined surfaces on their sides facing away from one another in the assembled state, that make it easier to put the two caps together. It may also be expedient if at least the inwardly projecting flange of the outer cap is interrupted over two opposite sectors in the range of approximately 10 to 60 °, with corrugations being provided on the inner circumferential surface of the outer cap at least in this area, which during ovalization of the Outer cap by pressing opposing wall sections, these corrugations engage with corresponding corrugations on the outer circumferential surface of the inner cap and thus establish a non-positive connection between the outer and inner caps. The omission of the flange in this area to be compressed makes it easier to press the corrugations of the outer cap onto that of the inner cap, although this feature is not essential.

In addition, the flanges or projections on the outer cap and the inner cap are positioned in the axial direction so that the inner cap accommodated in the outer cap has sufficient axial play, so that the teeth on the end faces or bottom surfaces also do not exert any axial force when screwing on Pressure can easily slide over each other. The axial play must therefore correspond at least to the height of the engagement elements or teeth on the bottom of the inner cap or outer cap.

It is also advantageous if the outer cap has corrugations on its outside precisely in the areas where corresponding corrugations are also provided on the inside for engagement with the inner cap. In this way, the user recognizes the areas in which the outer cap is to be grasped and compressed in order to bring it into firm engagement with the inner cap. The corrugations on the outside of the outer cap also make it easier to apply the torque required to open and close the closure.

Figur 1

eine doppelte Verschlußklappe in einer Position, in welcher Außen- und Innenkappe gegeneinander drehbar sind,

Figur 2

den Verschluß nach Figur 1 in einer Position, in welcher Außen- und Innenkappe in festem Eingriff stehen und

Figur 3

einen teilweisen Schnitt entlang einer zur Achse senkrechten Ebene durch einen Verschluß gemäß Figur 1 und 2.

Further advantages, features and possible uses of the present invention will become clear from the following description of a preferred embodiment and the associated figures. Show it:

Figure 1

a double closure flap in a position in which the outer and inner caps are rotatable relative to one another,

Figure 2

the closure of Figure 1 in a position in which the outer and inner caps are in firm engagement and

Figure 3

3 shows a partial section along a plane perpendicular to the axis through a closure according to FIGS. 1 and 2.

In FIG. 1 one can see in the right third a section through the inner cap 1 and the outer cap 2 approximately in a plane containing the axis 14 of the closure. In the central area of FIG. 1, only the outer cylinder jacket wall 18 of the outer cap 2 is shown broken away, so that the outer wall of the inner cap 2 can be seen. In the left third of FIGS. 1 and 2, essentially only the outer wall of the outer cap 2 can be seen.

The basic shape of the inner cap 1 and also of the outer cap 2 is that of a cylinder closed on one end face. Deviating from this simple cylindrical basic shape, the bottom 3 of the inner cap 1 has a cylindrical extension: 5, while the bottom 4 of the outer cap 2 has a circular recess 6, in which the cylindrical extension 5 engages appropriately with little play. The inner cap also has an internal thread 13 and on its outside in the vicinity of its open end a circumferential flange 11 with a radially extending contact surface, which in FIG. 1 rests on a radially extending surface of a flange 12 which is at least partially circumferential on inner open end of the cylinder jacket wall of the outer cap 2 is provided.

In the position shown in FIG. 1, in which the radially extending surfaces of the flanges 11 and 12 abut one another and thus prevent further axial pulling out of the inner cap from the outer cap, engaging elements 7 are arranged on the bottom 3 of the inner cap and on the bottom 4 of the outer cap. 8 disengaged. These engagement elements 7, 8 consist of a type of asymmetrical teeth, each with a steep flank and a ramp surface, the engagement elements 7, 8 being arranged and designed such that when the outer cap 2 is rotated in the closing direction, the steep flanks of the teeth 7, 8 with one another Engage while rotating in the opposite direction, ie in the opening direction of the closure, the relatively flat inclined ramp surfaces of the teeth 7, 8 engage with each other. As a result, when the ramp surfaces meet and when the outer cap 2 rotates further in the opening direction, a force is exerted on the outer cap 2 and the inner cap 1, by means of which these are pressed apart in the axial direction in the direction of the position shown in FIG. 1. In other words, the ramp surfaces of the teeth 7, 8 slide on one another and thereby press the outer cap 2 and inner cap 1 in the axial direction Direction apart until the elements 7, 8 have slid over one another. The position of the flanges 11, 12 is selected so that the teeth 7, 8 can no longer engage with one another in the position shown in FIG. 1 of a contact between the flanges 11, 12.

The sliding of the ramp surfaces of the teeth 7, 8 over one another can only be prevented by simultaneously exerting an axial (downward in FIG. 1) pressure on the outer cap 2 when screwing on, which causes the torque and the inclined position of the ramp surfaces of the teeth 7, 8 acting, dispersing axial force compensated. When a sufficient axial pressure is exerted on the outer cap 2, the axial pushing apart of the outer cap and the inner cap can be prevented, so that the inner cap 1 is carried along by the ramp surfaces of the teeth 7, 8, which are not sliding against one another, when the outer cap 2 rotates in the opening direction becomes.

In Figure 2 you can see a position of the closure cap, which is normally taken when screwing the closure. In the case of a normal container closure, a closure neck is generally at the top and the closure has the position shown in FIGS. 1 and 2 or may also be slightly inclined relative to the horizontal. The dead weight of the outer cap 2 then ensures in any case that it sinks down onto the inner cap until its teeth 8 rest on the outer surface of the cap base 2 of the inner cap 1. This could, for example, be the position shown in FIG. 2, although the outer cap 2 and inner cap 1 can also assume different angular positions, so that initially the steep flanks of the teeth 7, 8 are not yet in engagement with one another. In any case, with the closure described above, when the closure is screwed on, the position shown in FIG. 2 is reached, in which the steep flanks of the teeth 7, 8 are in engagement with one another, so that when a torque is exerted on the outer cap 2 in the closing direction, the inner cap 1 is definitely taken over the teeth 7, 8.

Both in the state shown in FIG. 1 and in the state shown in FIG. 2, the cylindrical extension: 5 engages in the circular recess 6 of the base 4 of the outer cap 2 and ensures clean guidance when the outer cap is turned relative to the inner cap, in particular when turning in the opening direction if the sloping flanks of the teeth 7, 8 are to slide over one another in the function as child safety devices. Tilting is also avoided by the possibly engaging flanges 11, 12, which allow only a limited axial play between the outer cap and the inner cap.

In addition to the teeth 7, 8 already described, the inner cap 1 and outer cap 2 also have further engagement elements in the form of the corrugations 9 and 10. The inner cap 1 with its corrugation 9 on its outer circumferential surface and the outer cap 2 with its corrugation 10 on its inner circumferential surface are dimensioned such that when the outer cap and inner cap have their normal circular shape, the smallest inner diameter of the outer cap is still greater than the largest outer diameter of the inner cap in the area of the respective corrugations 9, 10. Thus, both in the opening and in the closing direction, the corrugations 9, 10 do not engage with one another, and the outer cap 2 would be freely rotatable in both directions with respect to the inner cap 1, unless it was the further engagement elements 7, 8 take effect. In the normal state, therefore, between the corrugations 9, 10 there is the free space 15 or a game 15 shown in the left partial image in FIG. preferably by gripping the outer surface of the cap 2 from two opposite sides, so that the cap is pressed together, for example, between the thumb and index finger. The state shown in the right part of FIG. 3 occurs, in which the corrugations 9, 10 of outer cap 2 and inner cap 1 are in meshing engagement.

The outer cap 2 preferably also has an external toothing or corrugation 16 in the regions to be compressed, which facilitate gripping and applying a torque and at the same time are a marking for the region to be compressed, since the inner corrugation 10 of the outer cap preferably only extends over two opposite angular sectors extends in the order of 30 to 80 °, so that a compression of the outer cap 2 outside of these sectors would not produce any engagement between the corrugations 9, 10.

It may be expedient, even if this is not shown in the figures, that the flange 12 and possibly also the flange 11 are interrupted in a sector corresponding to the corrugation sector or shortened in the radial direction, which reduces the compression of the outer cap 2 and that in Intervention bringing the corrugations 9, 10 facilitated.

Also in connection with the corrugations 9, 10 on the lateral surfaces, the concentric guidance of the outer cap relative to the inner cap with the help of the cylindrical extension 5 engaging in the recess 6 is of essential importance, namely only by a clean concentric guidance of the left part of the figure 3 shown state of a free space or play between the teeth 9, 10 over the entire circumference of the Inner cap or in the sector areas where both teeth 9, 10 are present can be ensured. The closure according to the invention thus ensures a high degree of functional reliability, the preferred embodiment with a combination of the engagement elements 7, 8 and 9, 10 being preferred.

Since, in the embodiment shown, the recess 6 extends completely through the base 4 of the outer cap 2, a bulging of the cap base 3 in the central region, i.e. Do not disturb in the area of the cylindrical extension 5, since the cap base 4 is left free in this area. A radial expansion of the shell of the cap 1 due to a swelling content of a container or due to the build-up of an internal pressure also does not affect the functionality of the closure, since the game or the free space 15 can in any case be chosen so large that the without compressing the Walls of the outer cap 2 no engagement between the corrugations 9, 10 arises.

Furthermore, in the preferred embodiment of the invention, which is not shown in the figures, a so-called guarantee band is arranged on the inner sealing cap at the lower edge. Such a guarantee tape is typically connected to the lower edge of a screw cap, in this case the inner cap, via a series of tear-off webs and is otherwise designed in such a way that it hooks with a projection on the neck or neck of the container, so that when the cap is unscrewed the guarantee band is held on the container neck, the connecting webs tearing and thus the guarantee band as a whole being torn off or separated from the closure cap. A loose guarantee band is then a sign that the closure has already been opened. The hooking of the guarantee band with the container neck can in principle be achieved in a manner similar to the previously described hooking or securing of the outer closure cap to the inner closure cap via the projections or flanges 11, 12, whereby in the case of guarantee bands it is customary - but not mandatory - is that these consist of individual, interconnected segments and each of the segments has its own small projection, which hooks with a corresponding flange on the neck or neck of a container after screwing on the closure cap in question.

It is particularly advantageous according to the present invention that the outer cap and the inner cap are two parts which are not firmly connected and which are to be produced separately from one another, the tear-off band or guarantee band being fastened to the inner cap. This makes it possible, in particular, to produce the outer cap and inner cap in different colors, optionally also from materials with different mechanical properties, so that the Guarantee ring or the guarantee band, which is made with the inner cap in one piece from the same material and in the same color, is clearly visible in a color that is clearly distinguishable from the color of the outer cap and looks out from under the edge of the outer cap and is visible from the outside without the free movement of the To interfere with the outer cap against the inner cap.

Claims (13)

Plastic screw cap for container closures with a child safety lock, with an inner cap (1) with an internal thread (13) that can be screwed onto a neck or the socket of a container for receiving a closure, and one that can be freely rotated in relation to the inner cap (1) at least in the opening direction Outer cap (2), wherein engagement elements (7, 8, 9, 10) are provided between the inner and outer cap (1, 2), which only exert a force in the opening direction that is not exclusively tangential when the tangential force causing the opening moment is exerted Can be frictionally engaged, characterized in that the bottoms (3, 4) of the inner cap (1) and outer cap (2) via a cylindrical projection (5) arranged concentrically to the closure axis on one bottom (3, 4) and also one Cylindrical recess (6) arranged concentrically to the closure axis on the other bottom (4, 3) interlock, the off saving (6) has a slightly larger diameter than the approach (5). Screw cap according to claim 1, characterized in that the recess (6) extends through the bottom (3, 4) of the associated cap (1, 2). Screw cap according to one of claims 1 or 2, characterized in that the recess (6) on the bottom (4) of the outer cap (2) and the shoulder (5) are provided as an outer, cylindrical extension of the bottom (3) of the inner cap (1) are. Screw cap according to one of claims 1 or 3, characterized in that the recess (6) is designed as a circular groove and the extension (5) as an axially short wall section of a hollow cylinder. Screw cap according to one of claims 1 to 4, characterized in that engagement elements (7, 8) on the end face on the inside of the base (4) of the outer cap (2) and on the outside of the base (3) of the inner cap (1) radially outside the recess (6) or the approach (5) are provided. Screw cap according to one of claims 1 to 5, characterized in that near the open ends of the inner cap (1) and outer cap (2) overlapping projections or shoulder surfaces, preferably in the form of radial Flanges (11, 12) are provided. Screw cap according to claim 6, characterized in that the projections or flanges (11, 12) are positioned such that the inner cap (1) held in the outer cap (2) by the projections or flanges (11, 12) within the outer cap (1) has an axial play which corresponds at least to the axial height of one of the engaging elements (7 or 8). Screw cap according to one of claims 6 or 7, characterized in that the surfaces of the flanges 11, 12 facing away from one another in the installed state are inclined surfaces or conical surfaces inclined to the axis (14) of the closure. Screw cap according to one of claims 6 to 8, characterized in that at least the projection or flange (12) provided on the inside of the outer cap has a sector-like interruption. Screw cap according to one of claims 1 to 8, characterized in that corrugations (9, 10) are provided on the outer lateral surface of the inner cap (1) and the inner lateral surface of the outer cap (2), the smallest inside diameter of the outer cap (2) in The area of the corrugations is larger than the largest outer diameter of the inner cap including its corrugations (9). Screw cap according to claims 9 and 10, characterized in that the sector-like interruption of the flange (12) lies in the same sector as the corrugation (10) of the outer cap. Screw cap according to one of claims 1 to 11, characterized in that a guarantee tape is attached to the lower edge of the inner cap (1) via a tearable connection, preferably in the form of webs, which, after the inner cap has been screwed on, is fastened to the neck or neck of the container it is ensured that when the inner cap is unscrewed, the connection between the inner cap and the guarantee tape breaks, so that the latter remains on the neck or neck of the container. Screw cap according to one of claims 1 to 12, characterized in that the outer cap (2) and the inner cap (1) have different colors.

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