A safety device for a container having a screw-on closure

Abstract

 A safety device (1) for a container having a screw-on closure (3) comprises a cylindrical cap (4) having an axial direction (A) and radial directions (R) perpendicular to the axial direction (A). The cap (4) comprises fastening means for fastening the cap (4) on the screw-on closure (3) and closure engagement means arranged to interact with the screw-on closure (3), wherein the cap (4) is arranged to assume a neutral position and an operational position when fastened to the closure (3) and wherein interaction between the closure engagement means and the screw-on closure (3) is disabled in the neutral position and enabled in the operational position.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of closures and containers, and more particularly to a safety device for a container having a screw-on closure.

BACKGROUND

[0002] Numerous child-resistant mechanisms for preventing access to containers for storing dangerous substances such as prescription drugs, over-the-counter medications, pesticides, and household chemicals or the like are known. These locking mechanisms may take several forms, but a common design is a closure having an outer cap and an inner cap combined together. The caps are provided with interengaging ratchet teeth making it possible to turn the caps as a unit in a closing direction but permitting relative rotation of the caps upon rotation of the outer cap in an opening direction unless the outer cap is simultaneously deflected axially relative to the inner cap. WO2011/005924, US 4,598,833, and US 4,241,840 all provide examples of such a design.

[0003] Most known safety closures are intended to be applied to bottle type containers made from either glass or plastics, which have a relatively large diameter neck, whereby the above described arrangements with complementary engaging ratcheting teeth can be adapted with respect to the size of the components thereof.

[0004] However, there are situations when child-resistant packaging is not necessary or even desirable. For example such closures can be a problem for some aged individuals with poor eye sight or people with disabilities, or in circumstances when the flexible container will only be handled by adults, such as for example in hospitals.

SUMMARY OF THE INVENTION

[0005] The present invention is directed to a child-resistant safety device for a container having a screw-on closure and being intended to contain dangerous or harmful contents such as prescription creams, cosmetics, over-the-counter medications, glues, paints, household chemicals, or the like.

[0006] The safety device comprises a cylindrical cap having an axial direction and radial directions perpendicular to the axial direction. The cap comprises fastening means such as snap-on fastening means for fastening the cap on the screw-on closure of the container and closure engagement means arranged to interact with the screw-on closure, when said cap is fastened on said screw-on closure. When fastened on the screw-on closure, the cap and screw-on closure together form a tamper resistant closure arrangement wherein the cap is arranged to assume a neutral position or an operational position and wherein interaction between the closure engagement means and the screw-on closure is disabled in the neutral position and enabled in the operational position.

[0007] The safety device is provided separately from the container of potentially dangerous or hazardous substances. This means that a user is given the option of creating a child-resistant closure on the container by applying the safety device on a screw-on closure which is already present on the container.

[0008] By means of the invention, hazardous substances may be sold in easy-to-open containers that have been provided with a conventional screw-on closure by a manufacturer of the container. The container may be used without making any modification to the original screw-on closure. Such option may be appreciated for instance by elderly and handicapped persons with reduced mobility and strength in their hands who may find tamper-resistant closures difficult to manipulate. Easy-to-open packaging is also efficient and preferred in work-environments such as in hospitals and other medical care facilities as well as in other all-adult environments.

[0009] However, in any instance where a child may gain access to a container with hazardous contents, the container may be selectively child-proofed by application of a safety device of the invention on the screw-on closure. Child-proofing may, for instance, be carried out by personnel in a pharmacy or by the end user as found suitable. The safety device may easily be applied onto an existing screw-on closure, without the need to remove or open the screw-on closure. This is advantageous as it allows the container to be provided with the safety device without extensive manipulation or risk of compromising the contents in the container. In case of the screw-on closure being provided with a perforation member for breaking a protective membrane over the dispensing opening in the container, the safety device can be applied to the screw-on closure after the perforation member has been used to break the seal on the container. This is a considerable advantage as compared to pre-fabricated tamper-proof closures.

[0010] The optional safety device of the invention allows for cost and material savings as the safety device may be used to make a container closure tamper resistant only when tamper resistance is needed.

[0011] The optional safety devices of the invention may be manufactured in a range of sizes adapted to standard sizes for tube and bottle closures.

[0012] The fastening means for fastening the safety device on a screw-on fastener is preferably a snap-on fastener. Snap-on fasteners are well known in the art and allow for easy attachment of the safety device on a screw-on closure, such as a screw on cap on a bottle, tube or similar container by simply pressing the device down onto the closure until the safety device snaps into locking engagement with the closure. The snap-on fastener is preferably designed to provide irreversible fastening of the safety device on the screw-on closure. By irreversible fastening as used herein is implied a connection between the safety device and the screw-on closure which can only be broken by damaging or destroying the safety device.

[0013] The circular cap may preferably comprise a circular top wall extending in the radial direction of the safety device and a peripheral skirt extending in the axial direction of the safety device and having a proximal end at the top wall and a distal end remote from the top wall.

[0014] When the circular cap comprises a peripheral skirt, a snap-on fastener may comprise a radially inwardly directed retaining rim arranged on the peripheral skirt at the distal end thereof. When the safety device, and specifically the circular cap of the safety device is pushed down over a screw-on closure, the rim is designed to snap in below an edge on the screw-on closure and retain the safety device on the screw-on closure with the screw-on closure covered by the circular cap of the safety device.

[0015] In order to facilitate application of the safety device on a screw-on closure at least one slit extending in the axial direction may be arranged in the peripheral skirt.

[0016] The materials used to make a safety device of the invention are preferably flexible materials implying that they are capable of being elastically flexed, expanded or compressed under the influence of external forces and that they will substantially return to their original state once the external forces are removed. A "flexible material" is intended to mean a material that can easily be folded or twisted or bent by hand or a material that may be flexed and/or bent repeatedly without rupture or the development of visible defects. Suitable materials include polymeric materials such as different types of plastics that may be shaped by molding techniques such as injection molding.

[0017] However, it is generally preferred to use comparatively rigid plastic materials for the safety devices of the invention. A relatively rigid material will retain its shape during normal use and will not be deformed by the forces required to manipulate the safety device between the neutral position and the operational position or by the forces required to connect the device to a screw-on closure. Furthermore, a rigid material contributes to keeping the safety device firmly secured over the screw-on closure once it has been attached. However, the rigid plastic materials that are useful in a safety device according to the invention preferably have the ability to elastically flex and deform under greater applied forces such as the forces arising during attachment of the safety device on the screw-on closure.

[0018] The closure engagement means may comprise a plurality of ratchet teeth arranged to be brought into engagement with the screw-on closure on a container. Such ratchet teeth are arranged on the inside of the circular cap and may be placed around the periphery of a circular end wall or on a flexible peripheral skirt portion of the circular cap. The ratchet teeth are arranged to be brought into engagement with corresponding elements on a screw-on cap. Such corresponding interengaging elements on a screw-on closure may be any type of commonly occurring features on conventional screw-on closures such as grip-enhancement members, rigidity enhancement members, etc. Screw-on closures are usually designed with a grip-enhancement member in the form of an edge or surface having an angular shape or being provided with multiple ridges and grooves in order to improve grippability by increasing friction between a user's fingers and the surface of the screw-on closure. Such grip-enhancement members are highly suitable as interengaging elements for the purpose of the safety devices of the invention.

[0019] Furthermore, when a screw-on closure comprises a centrally arranged axially extending perforation member, the closure is often also provided with radially extending guiding elements. The perforation member usually has a tapered end with axially extending ridges for piercing of a frangible protective membrane placed over the dispensing opening in the container. Radially extending guiding elements may be provided for ascertaining that the perforation member is correctly guided through the protective membrane during the perforating operation. Hence, a safety closure according to the invention can readily be adapted to interact with elements that are pre-existing on conventional screw-on closures. The safety device may be provided with a closure engagement means comprising a centrally arranged female engagement member configured for interaction with a projecting perforation member on said closure. A centrally arranged female engagement member may be provided instead of or in addition to closure engagement means in the form of ratchet teeth arranged peripherally on the inside of the safety device cap. Alternatively the closure engagement means may comprise an opening centrally located in the circular top wall of the cap, said opening the having a shape that will encircle and interact with a projecting perforation member provided on the screw-on closure.

[0020] A particular problem with prior art safety closures for bottles is to adapt such closures to the neck of a flexible container such as a tube that may be made of aluminum or polymeric materials. Such tubes are commonly used for packaging glues, pharmaceutical creams or cosmetics and others, where the threaded neck of the container is small and the arrangements of complementary engaging ratchet teeth as disclosed above are difficult to readily house in the tube closures. In such instances the safety device may interact with other features on the tube closure, such as a piercing member.

[0021] The safety device may be arranged to be brought from the neutral position to said operational position by axial movement of said cap. This means that when the safety device is attached over a screw-on closure on a container, a user may push down on the safety device to bring the closure engagement means into contact with an interacting element on the screw-on closure and enable opening of the closure by rotating the combined safety device and screw-on closure. Alternatively, operational interaction between the safety device and the screw-on closure may be arranged to take place when pulling on the attached screw-on closure in the axial direction.

[0022] The safety device may be arranged to be brought from the neutral position to the operational position by radial compression of the circular cap. This means that when the device is attached over a screw-on closure on a container, a user may squeeze the safety device to bring the closure engagement means into contact with an interacting element on the screw-on closure and enable opening of the closure by rotating the combined safety device and screw-on closure. Furthermore, the safety device may be arranged to require both an axial movement and a radial compression in order to bring the safety device into the operational position where it can be rotated together with the screw-on closure to open the closure.

[0023] The safety device may comprise gripping means arranged externally on said circular cap. The gripping means may provide the safety device with any suitable external shape, such as square shapes or shapes with more sides than a square, including irregularly shaped exterior surfaces, and surfaces comprising friction-increasing structures such as grooves, ridges, knobs or other aberrations. The safety device may also be used to increase the size and/or shape of smaller screw-on closures in order to improve grippability of such closures.

[0024] Accordingly, the safety device of the invention may be used for providing tamper resistance to a pre-existing screw-on closure on a container. A further use of the safety device of the invention is to improve grippability of screw-on closures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention will be described in greater detail with reference to the appended drawings in which:

Figure 1

shows a perspective view of a tube with a screw-on closure and a safety device before application of the safety device on the screw-on closure;

Figure 2

shows the safety device in Fig. 1 in the process of being fastened onto the screw-on closure;

Figure 3

shows the safety device and the screw-on closure in Figs. 1 and 2 with the safety device fastened onto the screw-on closure;

Figure 4

shows a cross-section parallel to the axial direction through the safety device and the screw-on closure in Fig. 3, and

Figure 5

shows a radial section through the safety device and the screw-on closure in Fig. 3 taken at the proximal end of the safety device.

Figure 6

shows another embodiment of the safety device in 6a, and the safety device in a neutral position in 6b and operational position in 6c.

DETAILED DESCRIPTION

[0026] A safety device 1 of the invention is shown in Fig. 1 together with a container 2 provided with a screw-on closure 3. The container 2 that is shown in Fig. 1 is a flexible tube but a safety device of the invention may be used for selective child-proofing of any type of container having a screw-on closure, such as bottles or cans.

[0027] The safety device 1 comprises a cylindrical cap 4 which has an axial direction A and radial directions R perpendicular to the axial direction. The cap has a radially extending circular top wall 5 and a side wall or peripheral skirt 6 extending in the axial direction A at the periphery of the top wall 5. The skirt has a proximal end 7 located at the top wall 5 and a distal end 8 remote from the top wall 5. The peripheral skirt 6 delimits a cap opening 9 at the distal end 8 of the skirt 6.

[0028] The distal end 8 of the skirt 6 is provided with fastening means for fastening the cap on the screw-on closure 3. In the embodiments shown in Figs. 1-6, the fastening means is in the form of a radially inwardly directed retaining rim 10. Alternative fastening means that may be used in the safety devices of the invention are other types of snap-in elements such as knobs or hook elements.

[0029] The retaining rim 10 is provided with cut-outs 11. The cut-outs 11 divide the retaining rim 10 into flexible tongues 12 which are portions of the rim 10 located between the cut-outs 11. Upon application of an axially directed force, the flexible tongues 12 are caused to flex in the direction of the force allowing the size of the opening 9 defined inside the peripheral skirt 6 to be increased and to accommodate a screw-on closure 3.

[0030] The skirt portion 6 of the cylindrical cap 4 is provided with friction enhancing gripping members 13 which are shown as being grouped ridges on the outer surface of the skirt 6. The shown configuration of the gripping members 13 is not to be considered limiting to the invention as any other type of gripping member or combination of gripping members may be used, such as grooves, ridges, knobs, friction increasing coatings, finger grips, etc. It is also conceivable to make the safety device 1 completely without any particular gripping members.

[0031] The safety device 1 is further provided with closure engagement means. The closure engagement means are intended to interact with the screw-on closure 3 when the safety device 1 is attached on the screw-on closure 3 as described herein.

[0032] The safety device 1 shown in Figs. 1-5 has two different closure engagement means which are designed to interact with different features on the screw-on closure 3. The first closure engagement means is constituted by a plurality of ratchet teeth 16 which are arranged to be brought into engagement with a correspondent element on the screw-on closure 3. The second closure engagement means is constituted by a centrally arranged female engagement 17 member configured receive a corresponding male projecting member on the screw-on closure 3.

[0033] The screw-on closure 3 shown in Figs. 1-6 is a commonly occurring type of screw-on closure having a neck portion 18 extending from a first surface of a base plate 19 and being provided with an inner thread 20 for screwing the closure 3 onto the tube 2 in a conventional manner, as shown in Fig. 1. The screw-on closure 3 is further provided with a cylindrical gripping wall 21 extending from a second surface of the base plate 19 which is opposite to the first surface of the base plate 19. The gripping wall 21 is provided with friction enhancing gripping means 22 in the form of a plurality of alternating grooves and ridges arranged in the axial direction A on the outer surface of the gripping wall 21.

[0034] A star-shaped, pointed perforation member 23 having a tapered end and axially extending ridges is arranged centrally on the second side of the base plate 19. The perforation member 23 is provided to allow a user to perforate a frangible protective membrane placed over the dispensing opening when the tube 2 is delivered to the user. The dispensing opening and the frangible protective membrane are not visible in the figures but are well known features of containers with screw-on closures and do not need to be described in further detail. A user may make the tube operational by unscrewing the closure 3 and turning it in an opposite direction to that shown in Fig. 1 whereafter the perforation member 23 can be pressed down through the protective membrane and into the tube opening. In this manner, the protective membrane is broken and the contents of the tube 2 can be squeezed out through the dispensing opening. In order to ascertain that the perforation member is correctly guided through the protective membrane during the perforating operation, the inside of the gripping wall 21 is provided with radially inwardly extending guiding elements 24.

[0035] After having used the perforation member 23 to perforate the protective membrane, the user may then choose to make the screw-on closure 3 tamper-proof by attaching the safety device 1 on the screw-on closure 3. This is preferably and most easily done after screwing the closure 3 back on the tube 2, but can be made by applying the safety device 1 on the un-screwed closure 3 if so desired.

[0036] With particular reference to Figs. 2-4, when the safety device 1 is pressed down onto the screw-on closure 3 with an axially directed force F₁, the rim 10 at the distal end 8 of the skirt 6 on the safety device 1 is brought into contact with the gripping wall 21 on the screw-on closure 3. The size of the safety device 1 is adapted to the size of the screw-on closure 3 such that the inner diameter of the peripheral skirt 6 is greater than the outer diameter of the cylindrical gripping wall 21 on the screw-on closure 3. However, the diameter of the opening 9 defined inside the rim 10 at the distal end 8 of the peripheral skirt 6 is smaller than the outer diameter of the screw-on closure 3. As the safety device 1 is pushed down onto the screw-on closure 3, a counter force will cause the flexible tongues 12 on the rim 10 to flex upwards. This allows the safety device 1 to be completely pushed down on the screw-on closure 3 until the gripping wall 21 is accommodated inside the cylindrical cap 4 and the flexible tongues can flex or snap back into a non-tensioned state below the base plate 19 of the screw-on closure 3.

[0037] Accordingly, the rim 10 at the distal end 8 of the cylindrical cap 4 and the flexible tongues 12 on the rim 10 constitute snap-on fastening means and retaining members keeping the safety device 1 mechanically attached to the screw-on closure 3 once the safety device 1 has been applied over the screw-on closure 3. Another way of achieving a snap-on fastening function and providing retention of the safety device 1 on the screw-on closure 3 may be by arranging at least one slit, such as 2-10 slits, extending axially in the peripheral skirt 6. The slit or slits permit radial expansion of the peripheral skirt as the safety device 1 is brought down over the screw-on closure 3 and may also provide a snap-back function when a rim or other hook element or elements arranged at the distal end 8 flex back under the base plate 19 of the screw-on closure 3. Such size-adapting snap-on fasteners have the advantage of being relatively size insensitive, allowing the same safety device to fit securely on screw-on closures having slightly different diameters.

[0038] Once the safety device 1 has been attached to the screw-on closure 3, the tube 2 can only be opened by bringing the safety device 1 into an operational position on the screw-on closure 3. This is accomplished by pressing further down onto the safety device 1 until the ratchet teeth 16 which are arranged on the inside of the cylindrical cap 4 at the proximal end 7 of the cap are brought into engagement with the radially extending guiding elements 24 on the screw-on closure 3 and the centrally arranged female engagement member 17 engages with the projecting perforation member 23 on the screw-on closure 3. In this position, the combined safety device 1 and screw-on closure 3 can be rotated as an assembly while continuing to apply a downward pressure on the safety device 1. If no downward pressure is applied to the safety device 1, the safety device 1 will be in a neutral position and rotation of the safety device 1 will not affect the screw-on closure 3.

[0039] A safety device 1 according to the invention does not need to have two different closure engagement means. Accordingly, each of the described closure engagement means may be used as a sole closure engagement means or in combination as shown in Figs. 1-5. A further option may be that the cylindrical cap 4 comprises an opening 26 centrally located in the circular top wall 5 of the cap 4, said opening 26 having a shape that will encircle and interact with a projecting perforation member 23 provided on the screw-on closure (see Fig. 6 a-c). For example, if the projecting perforation member 23 is star-shaped with a tapered end and axially extending ridges, the opening 26 is also preferably star-shaped and of a size such that when the cap is fitted onto the screw-on closure, and is in operational position, the opening 26 encircles and interacts with the axially extending ridges on the projecting perforation member 23.

[0040] Once the safety device 1 has been attached to the screw-on closure 3, the tube 2 can only be opened by bringing the safety device 1 into an operational position on the screw-on closure 3. This is accomplished by pressing further down onto the safety device 1 until the centrally located opening 26 located in the circular top wall 5 of the cap 4 is brought into engagement with the projecting perforation member 23 on the screw-on closure 3 (see Fi. 6c). In this position, the combined safety device 1 and screw-on closure 3 can be rotated as an assembly while continuing to apply a downward pressure on the safety device 1. If no downward pressure is applied to the safety device 1, the safety device 1 will be in a neutral position and rotation of the safety device 1 will not affect the screw-on closure 3 (see Fig. 6b).

[0041] In order for the cap to not accidentally enter into the operational position, the inside of the top wall 5 is preferably provided with flexible spacer elements 26. Said flexible spacer elements 26 will retain the safety device 4 in the neutral position (see Fig. 6b) until the safety device 1 is pressed down onto the screw-on closure 3 with an axially directed force F₁, thereby forcing the flexible spacer elements 26 to flex towards the inside of the top wall 5 and allow the safety device 1 to enter the operational position (see Fig. 6c). Such flexible spacer elements may also be provided in the safety device shown in Figs. 1-5.

[0042] The above mentioned and described embodiments are only given as examples and should not be limiting to the present invention. Other solutions, uses, objectives, and functions within the scope of the invention as claimed in the below described patent claims should be apparent for the person skilled in the art.

Claims

1. A safety device (1) for a container having a screw-on closure (3) pre-mounted thereon, characterized in that said safety device (1) comprises a cylindrical cap (4) having an axial direction (A) and radial directions (R) perpendicular to said axial direction (A), said cap (4) comprising snap-on fastening means for irreversibly fastening said cap (4) on said screw-on closure (3) and closure engagement means arranged to interact with said screw-on closure (3) when said cap (4) is fastened on said screw-on closure (3) to form a tamper resistant closure arrangement together with said screw-on closure, wherein said cap (4) is arranged to assume a neutral position or an operational position when fastened to said closure (3) and wherein interaction between said closure engagement means and said screw-on closure (3) is disabled in said neutral position and enabled in said operational position.

2. A safety device (1) according to claim 1, wherein said cap (4) comprises a circular top wall (5) extending in said radial direction and a peripheral skirt (6) extending in said axial direction (A) and having a proximal end (7) at said top wall (5) and a distal end (8) remote from said top wall (5).

3. A safety device (1) according to claim 2, wherein said snap-on fastener comprises a radially inwardly directed retaining rim (10) arranged on said peripheral skirt (6) at said distal end (8).

4. A safety device (1) according to claim 2 or 3, wherein at least one slit extending in said axial direction (A) is arranged in said peripheral skirt (6).

5. A safety device (1) according to any one of the preceding claims, wherein said closure engagement means comprises a plurality of ratchet teeth (16) arranged to be brought into engagement with said screw-on closure (3).

6. A safety device (1) according to any one of the preceding claims, wherein said closure engagement means comprises a centrally arranged female engagement member (17) configured for interaction with a projecting perforation member (23) on said closure (3).

7. A safety device (1) according to any one of claims 1-4, wherein said closure engagement means comprises a centrally arranged opening (26) configured for interaction with a projecting perforation member (23) on said closure (3).

8. A safety device (1) according to any one of the preceding claims, wherein said safety device (1) is arranged to be brought from said neutral position to said operational position by axial movement of said cap (4).

9. A safety device (1) according to any one of the preceding claims, wherein said safety device (1) is arranged to be brought from said neutral position to said operational position by radial compression of said cap (4).

10. A safety device (1) according to any one of the preceding claims, wherein said cylindrical cap (4) comprises externally arranged gripping means (13).

11. Use of a safety device (1) according to any one of the preceding claims for providing tamper resistance to a pre-existing screw-on closure (3) on a container.

12. A container having a screw-on closure (3), characterized in that a safety device (1) according to any one of claims 1-10 is applied to said screw-on closure (3).

Drawing