CN111971234A

CN111971234A - Child-resistant closure

Info

Publication number: CN111971234A
Application number: CN201980021792.1A
Authority: CN
Inventors: 史蒂芬·法拉格
Original assignee: Obrist Closures Switzerland GmbH
Current assignee: Obrist Closures Switzerland GmbH
Priority date: 2018-01-26
Filing date: 2019-01-25
Publication date: 2020-11-20
Anticipated expiration: 2039-01-25
Also published as: EP3743351B1; BR112020015171A2; MX2020007809A; WO2019145495A1; CN111971234B; EP3743351A1; BR112020015171B1

Abstract

A child-resistant closure for a container is provided. The safety cap comprises nested outer (15) and inner (25) caps each having a top panel (16) and a side skirt (17) depending generally from the periphery thereof. The outer cap generally loosely surrounds the inner cap to allow relative rotational and axial movement therebetween. The outer cap and the inner cap have respective drive formations which are brought into driving engagement when the caps are moved axially towards each other to a first axial position. The outer cap includes a plurality of spring members (18) for axially moving the inner and outer caps away from each other to a second axial position. The inner cap includes a top plate provided with a plurality of ramps (30), the spring member providing a biasing force to retain the outer and inner caps in a second axial position and drivingly engaging the ramps in the second axial position to simultaneously drive the outer and inner caps in a tightening direction, but freely slide over the ramps in a loosening direction. Downward pressure on the outer cap is used to overcome the bias of the spring fingers to move the cap to a first axial position to allow the safety cap to be unscrewed using the inner cap drive structure and the outer cap drive structure. The outer surface of the inner cap side skirt includes a plurality of full height axial ribs (20) for allowing venting when the outer and inner caps are initially assembled together. The inner cap drive structure includes a plurality of castellations upstanding from the inner cap top plate, and each full-height axial rib is connected to one of the castellations.

Description

Child-resistant closure

Technical Field

The present invention relates generally to child-resistant closures for containers. More particularly, the present invention relates to a child-resistant closure with an improved apply/release drive mechanism.

Background

It is well known for child-resistant closures to include two nested closure members. Typically, the outer cap member and the inner cap member are provided with cooperating sets of lugs which engage one another when the outer closure is rotated in a direction to remove the safety cap from the container. A plurality of spring fingers on the inner surface of the top panel of the outer closure member urge the outer closure member away from the inner closure member and resist engagement of the lugs. The outer surface of the top plate of the inner closure member is formed with a ramp that cooperates with the spring fingers of the outer cap member so that when the outer cap member is rotated relative to the inner cap member in a direction that applies the safety cap to the container, the spring fingers engage the ramp to cause the cap members to rotate together. When the outer cap member is rotated in the opposite or unscrewing direction, the spring finger slides over the ramp to prevent accidental or unintended removal of the closure. The cooperating lugs engage one another to release the inner closure member from the container only when the safety cap is rotated in a unscrewing direction and an axial force is simultaneously applied to the outer closure member.

Disclosure of Invention

The present invention seeks to provide improvements in or relating to such a safety cap.

According to one aspect of the present invention there is provided a child-resistant closure for a container, the closure comprising nested outer and inner caps each having a top panel and a side skirt depending generally from the periphery thereof, the outer cap generally loosely surrounding the inner cap to allow relative rotational and axial movement therebetween, the outer and inner caps having respective drive formations capable of entering into driving engagement when the caps are moved axially towards each other to a first axial position, the outer cap comprising a plurality of spring members for moving the inner and outer caps axially away from each other to a second axial position, the inner cap comprising a top panel provided with a plurality of ramps, the spring members providing a biasing force to retain the outer and inner caps in the second axial position and drivingly engaging the ramps in the second axial position to simultaneously drive the outer and inner caps in a tightening direction but freely slide over the ramps in a loosening direction, downward pressure on the outer cap moves the cap against the bias of the spring fingers to a first axial position to allow the safety cap to be unscrewed using the inner cap drive structure and the outer cap drive structure, wherein the outer surface of the inner cap sides includes a plurality of substantially full height axial ribs for allowing venting when the outer cap and the inner cap are initially assembled together, wherein the inner cap drive structure includes a plurality of castellations upstanding from the inner cap top plate, and wherein each full height axial rib connects to one castellation.

The safety cap may further include a plurality of non-full-height axial ribs spaced from the full-height ribs disposed on the inner cap sidewall.

The castellations may be substantially U-shaped in plan.

The castellations may comprise a first radially extending side wall upstanding from the top plate and a second radially extending side wall upstanding from the top plate, the first and second side walls being located at or towards the periphery of the top plate and being spaced apart from each other, the first and second side walls being connected at one end by an arcuate cross wall.

Full height axial ribs may extend from the first side wall of the castellations.

The first side wall may be connected to each assembly rib by an inclined wall portion.

The castellations may be thinned in non-functional areas.

The full-height axial ribs may be spaced apart from each other around the outer surface of the inner cap side skirt, and the circumferential length of the ribs may be less than the circumferential length of the spacing therebetween.

In some embodiments, for each ramp there is provided a respective detent projection projecting above the plane of the top plate and on the path taken by the spring member, which projection, when in driving engagement with the ramp, supports the spring member against deformation of the spring member due to it transmitting force to the ramp face, the profile of the projection matching that of the region of the spring member with which it is in contact.

Each ramp may be generally wedge-shaped.

Each ramp may be generally trapezoidal in plan.

In some embodiments, indentations (indentations) are provided on the inner cap top plate (substantially) once rotated beyond each ramp.

Each ramp may be contoured to substantially continuously support the spring member as it passes over it in the unscrewing direction.

The profile of each ramp may be varied as the height of the ramp increases.

Each ramp may have a variable cross-section sweep (sweep) whose cross-section varies as the height of the ramp increases.

Thus, each ramp may be a feature that scans along a prescribed trajectory.

Each ramp may have a variable cross-sectional scan having a generally constant radial trajectory and a cross-section that varies continuously along the radial scan such that the spring member contacts the ramp to a maximum extent by rotation.

The ramp may be contoured to substantially continuously support the spring member as it passes over it in the unscrewing direction, wherein the ramp has a variable cross-sectional sweep with a generally constant radial trajectory and a continuously varying cross-section along the radial sweep such that the one or more spring members maximally contact the one or more ramps through rotation.

According to another aspect of the present invention there is provided a child-resistant closure for a container, the closure comprising nested outer and inner caps each having a top panel and a side skirt depending generally from the periphery thereof, the outer cap generally loosely surrounding the inner cap to allow relative rotational and axial movement therebetween, the outer and inner caps having respective drive formations capable of entering into driving engagement as the caps are moved axially towards each other to a first axial position, one of the inner and outer caps comprising one or more spring members for moving the inner and outer caps axially away from each other to a second axial position, the other of the inner and outer caps comprising one or more ramps, the spring members providing a biasing force to retain the outer and inner caps in the second axial position and drivingly engaging the ramps in the second axial position to simultaneously drive the outer and inner caps in a tightening direction, but is free to slide over the ramp in the unscrewing direction, the downward pressure on the outer cap moves the cap against the bias of the spring fingers to a first axial position to allow the safety cap to be unscrewed using an inner cap drive arrangement and an outer cap drive arrangement, wherein the outer surface of the inner cap side skirt includes one or more axial ribs for allowing venting when the outer cap and inner cap are initially assembled together.

The outer surface of the inner cap side skirt may include a plurality of full height axial ribs for allowing venting when the outer and inner caps are initially assembled together, wherein the inner cap drive structure includes a plurality of castellations upstanding from the inner cap top plate, and wherein each full height axial rib connects to one castellation.

In some aspects and embodiments, the assembly rib is integrally formed with the inner cap drive structure. This can be used, for example, to strengthen the structure and may allow for lightening of the component by removing material.

The rib may be connected to a rim of the drive formation which, in use, is in driving engagement with the drive formation on the outer cap.

The ribs may extend along substantially the entire length of the skirt.

Each drive formation on the inner cap may have a respective rib.

In some embodiments, the rim of the inner cap top plate is provided with a plurality of castellations.

The or each rib may be connected to the rim of a respective castellation.

The castellations may be substantially U-shaped in plan.

In some embodiments, the assembly ribs extend from the first sidewall of each of the castellations described above.

The first side wall may be connected to the assembly rib by an inclined wall portion.

The castellations may be thinned in non-functional areas.

The ribs may be spaced apart from one another around an outer surface of the inner cap side skirt, and a circumferential length of the ribs may be less than a circumferential length of the spacing therebetween.

According to another aspect of the present invention there is provided a child-resistant closure for a container, the closure comprising nested outer and inner caps each having a top panel and a side skirt depending generally from the periphery thereof, the outer cap generally loosely surrounding the inner cap to allow relative rotational and axial movement therebetween, the outer and inner caps having respective drive formations capable of entering into driving engagement as the caps are moved axially towards each other to a first axial position, one of the inner and outer caps comprising one or more spring members for moving the inner and outer caps axially away from each other to a second axial position, the other of the inner and outer caps comprising one or more ramps, the spring members providing a biasing force to retain the outer and inner caps in the second axial position and drivingly engaging the ramps in the second axial position to simultaneously drive the outer and inner caps in a tightening direction, but is free to slide over the ramp in the unscrewing direction, the downward pressure on the outer cap moving the cap against the bias of the spring fingers to a first axial position to allow the safety cap to be unscrewed using an inner cap drive arrangement and an outer cap drive arrangement, in which for the or each ramp there is provided a respective detent projection which projects above the plane of the top plate and on the path taken by the spring member, the projection, when in driving engagement with the ramp, supports the spring member against deformation of the spring member due to its passing of its interior to the ramp face, the profile of the projection matching that of the region of the spring member with which it is in contact.

According to another aspect, there is provided a child-resistant closure for a container, the closure comprising nested outer and inner caps each having a top panel and a side skirt depending generally from the periphery thereof, the outer cap generally loosely surrounding the inner cap to allow relative rotational and axial movement therebetween, the outer and inner caps having respective drive formations capable of entering into driving engagement when the caps are moved axially towards each other to a first axial position, one of the inner and outer caps comprising one or more spring members for moving the inner and outer caps axially away from each other to a second axial position, the other of the inner and outer caps comprising one or more ramps, the spring members providing a biasing force to retain the outer and inner caps in the second axial position and drivingly engaging the ramps in the second axial position to simultaneously drive the outer and inner caps in a tightening direction, but is free to slide over the ramp in the unscrewing direction, the downward pressure on the outer cap moving the cap against the bias of the spring fingers to a first axial position to allow the safety cap to be unscrewed using the inner cap drive configuration and the outer cap drive configuration, wherein the ramp may be contoured to substantially continuously support the spring member as it passes over it in the unscrewing direction.

The profile of the ramp may be continuously varied as the height of the ramp increases.

The present invention also provides an inner cap for a child-resistant container closure of the type comprising nested outer and inner caps each having a top panel and a side skirt depending generally from the periphery thereof, the outer cap generally loosely surrounding the inner cap to permit relative rotational and axial movement therebetween, the outer and inner caps having respective drive formations capable of entering driving engagement when the caps are moved axially towards each other to a first axial position, one of the inner and outer caps comprising one or more spring members for axially moving the inner and outer caps away from each other to a second axial position, the other of the inner and outer caps comprising one or more ramps, the spring members providing a biasing force to retain the outer and inner caps in the second axial position and drivingly engaging the ramps in the second axial position to simultaneously drive the outer and inner caps in a tightening direction, but is free to slide over the ramp in the unscrewing direction, the downward pressure on the outer cap moves the cap against the bias of the spring fingers to a first axial position to allow unscrewing of the safety cap using an inner cap drive arrangement and an outer cap drive arrangement, wherein the outer surface of the inner cap side skirt includes full height axial ribs for allowing venting when the outer and inner caps are initially assembled together, wherein the inner cap drive arrangement includes castellations upstanding from the inner cap top plate, and wherein one full height axial rib is connected to one castellation.

The present invention also provides an inner cap as described herein.

The present invention also provides an outer cap as described herein.

The present invention also provides a lid incorporating a container as described herein.

The different aspects and/or embodiments of the invention may be used separately or together.

The appended independent and dependent claims set out further particular and preferred aspects of the invention. The dependent claims may incorporate features of the independent claims as appropriate, and may incorporate features other than those set out in the claims.

Drawings

The present invention will now be described more particularly with reference to and as illustrated in the accompanying drawings, in which:

FIG. 1 is a plan view of the exterior of a security cover formed in accordance with an embodiment of the present invention;

FIG. 2 is a side view of the exterior of the safety cap of FIG. 1;

fig. 3 is a perspective view of the outer part of the safety cap of fig. 1 and 2;

FIG. 4 is a bottom perspective view of the outer member of the safety cap of FIGS. 1 and 2;

fig. 5 to 9 show top, side, bottom, top and bottom perspective views of the outer part of fig. 1 to 4;

FIG. 10 is a perspective view of an inner member formed in accordance with an embodiment of the present invention;

FIG. 11 is a bottom perspective view of the inner member of FIG. 10;

fig. 12-16 show top, side, bottom, and bottom perspective views of the interior of fig. 10 and 11;

FIGS. 17 and 18 are enlarged views of portions of the inner cap showing the assembled ribs and castellations; and

fig. 19 and 20 are enlarged views of a portion of the inner cap showing the ramp.

Detailed Description

The following example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and practice the systems and processes described herein. Importantly, embodiments can be provided in many alternative ways and should not be construed as limited to the examples set forth herein.

Accordingly, while the embodiments are capable of modification in various ways and take various alternative forms, specific embodiments thereof are shown in the drawings and will herein be described in detail by way of example. It is not intended to be limited to the specific form disclosed. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims. Throughout the drawings and the appropriate detailed description, elements of the example embodiments are identified by the same reference numerals.

The terminology used herein to describe the embodiments is not intended to be limiting in scope. The articles "a" and "the" are singular forms of having one referent, but use of the singular forms herein is not intended to exclude the presence of a plurality of referents. In other words, reference to an element in the singular can be made to one or more elements unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, items, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be understood in accordance with their ordinary practice in the art. It will be further understood that terms of general usage should be interpreted as customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein.

Although illustrative embodiments of the present invention have been disclosed in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments shown, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope of the invention.

The safety cap of this embodiment is comprised of two parts: an outer cap 15 shown in fig. 1 to 9 and an inner cap 25 shown in fig. 10 to 20.

The outer cap 15 is formed with a circular top plate 16 integrally molded with a depending cylindrical skirt 17.

A plurality of finger-like spring members 18 are formed on the underside of the top plate 16 and extend to the interior of the outer cap 15.

The illustrated embodiment shows four curved arcuate spring members 18, but as few as one or two members may function satisfactorily, and more than four members, such as six members, may be employed if desired.

The spring member 18 takes the form of an inclined tab integrally formed with the underside of the top plate 16. The spring member 18 is inclined at an angle of about 45 degrees relative to the outer member 10; however, the tilt angle may be changed as long as a ratchet function, which will be described later, can be appropriately performed. Note also that the spring members 18 are disposed radially inward of the periphery of the plate 16. The spring fingers are curved along their length with substantially the same radius of curvature as the side walls 17.

In addition to the spring member 18, a plurality (eight in this embodiment) of drive lugs 19 are also molded into the underside of the top plate 16 and depend downwardly. The drive lugs 19 are adjacent the outermost portion of the outer cap 15 adjacent the inner diameter of the depending skirt 17. The drive lugs 19 then extend inwardly towards the spring 18, but their edges terminate before reaching the spring member 18. The eight drive lugs 19 are shown by way of example, with a single drive lug also functioning properly; multiple drive lugs may be preferred to allow for multiple different disengagement positions.

A retention ring (retention bead)21 is molded on the inner wall of the downwardly depending skirt 17 at an opening near the downwardly depending skirt 17. The ring 21 is continuous around the entire circumference of the depending skirt 17.

The outer cap 15 may be made of any material having sufficient spring force to provide the necessary spring mass for the integrally molded spring member 18, such as polyethylene or propylene.

The inner cap 25 is also formed as an integral unit having a circular top plate 26 and a depending skirt 27 connected thereto.

The interior of the depending skirt 27 is provided with a thread 28 for engagement with a threaded neck finish of a container (not shown).

On the outer surface of the side edge 27, a plurality of full height assembly ribs 20 are provided. The ribs 20 extend axially along the skirt and project outwardly therefrom.

In this embodiment, the ribs 20 extend along substantially the entire length of the skirt 26.

Furthermore, a plurality of (approximately) half height (half height) ribs 22 are provided. In this embodiment, the

ribs

20 and 22 are alternately evenly distributed around the skirt.

The

ribs

20 and 22 allow for relief of the pressure generated when the inner and outer caps are assembled together (see below for details). In addition, the ribs provide additional strength to support the edges of the drive lugs (castellations) for engagement when unscrewing the safety cap. In this embodiment, this additional strength allows the drive lug to be thinner in the nonfunctional area.

The general configuration of the upper portion of the inner cap member 25 may be considered to be castellated. Upwardly or axially extending castellated drive projections 34 are spaced around the periphery of the top plate. In the assembled safety cap, the drive lugs 19 on the interior of the outer cap 15 are dimensioned so that they can engage in the openings between the drive projections 34. This gives the inner cap member 25 a driving force so that it can be driven by the outer cap 15.

The top plate 26 is provided with a plurality (eight in this embodiment) of upstanding castellations 34. Each castellation 34 comprises a first radially extending sidewall 34a upstanding from the top plate and a second radially extending sidewall 34b upstanding from the top plate. The first and second sidewalls are located at a periphery of the top plate and are spaced apart from each other. The first and second side walls are connected at one end by an arcuate cross wall 34 c.

The assembly ribs 20 extend from each of the first side walls 34 a. An assembly rib 20 is connected to the rim of each of the castellations to provide additional strength to support the rim for engagement when unscrewed. In this embodiment, the first side wall 34a is connected to the assembly rib 20 by an inclined wall section 34 d.

Thus, the ribs 20 extend and merge into the inner cap drive lugs, each rib being connected to the leading edge of a respective castellated drive lug (i.e. the edge which is used to provide drive in use).

The weight is removed by thinning the castellations in the non-functional areas 60.

The top plate 26 is also provided with four ramps 30. The ramp 30 is connected by extensions 36 to the arcuate walls 34d of the spaced castellations 34. The ramp is generally wedge-shaped with a curved (curved) front guide surface 30a and a rear abutment surface 30 b.

Behind each ramp 34 (i.e. in its counterclockwise direction) is a shallow groove 31, depression, indentation, or the like.

The design and contour of the shape of the ramps 34 is such that they support the fingers 18 of the outer cap 15 throughout contact with these features.

The ramp portion 30 is shaped and contoured so that it follows the same path that the spring fingers follow in use. The portion has a variable cross-sectional sweep whose cross-section varies with increasing ramp height, i.e., the ramp face is not flat. The trajectory of the portion has a constant radius; the cross-section (in both the X-plane and the Y-plane) along the radius scan varies continuously. This allows the spring fingers to maximally contact the ramp by rotating so that there is no point contact between them at any time. This allows the ramp to be formed with a minimum amount of material while providing maximum contact with the fingers during rotation.

A retention ring 35 is molded into the outer surface of the depending skirt 27. The retention ring 35 extends around the entire circumference of the depending skirt 27 and has a diameter greater than the diameter of the retention ring 21 formed in the depending skirt 17 of the outer cap 15.

Ribs

20 and 22 extend from ring 35.

The inner cap 25 is itself a separate cover for the container. Thus, the inner cap 25 may be made of a suitable material, not necessarily the same material as the outer cap 15; for example, thermoplastic materials such as polyethylene or polypropylene may be used.

The safety cap 10 is formed by assembling the outer cap 15 and the inner cap 25. To assemble the complete safety cap, the retention ring 21 is pressed against the retention ring 35, during which the depending skirt 17 of the outer cap member 10 is allowed to spring slightly outwardly. The assembly ribs 20 allow for the relief of pressure generated when the inner cap 25 is assembled into the outer cap 15 (and vice versa).

Once the larger diameter retention ring 21 has passed the retention ring 35, the depending skirt 17 springs back inwardly, trapping the inner cap 15 within the outer cap 25. The fit between the outer cap 15 and the inner cap 25 is not tight. There is a significant gap between the interior of the depending skirt 16 and the exterior of the depending skirt 32. Thus, the outer cap 15 can both rotate and slide axially relative to the inner cap 25.

In use, the inner cap 25 is threadably engaged on the externally threaded neck of the container. A sealing ring (not shown) may be provided in the inner cap 25 and will be trapped between the upper part of the neck and the lower part of the top plate of the inner cap 25.

When the outer cap 15 is rotated clockwise, the spring member 18 moves into driving engagement with the respective faces 30 b. Thus, the complete safety cap can be screwed down on the neck of the container, since rotation of the outer cap 15 will cause the spring member 18 to drive the engagement ramp 30 and thus turn the outer cap 15 and the inner cap 25 as a unit in the fastening direction.

Conversely, it can be seen that if the outer cap 15 is rotated in the opposite direction or in a direction which is typical for unscrewing the cap from a container, the spring 18 slides over the ramp 30. The profile of the ramp 30 may be varied as the height of the ramp increases. This allows maximum support to be provided to the spring fingers 18.

Thus, both functions provide a one-way ratchet drive for the inner cap 25. The outer cap 15 is thus free to rotate in the unscrewing direction relative to the inner cap 25. This feature makes the closure child resistant in that it cannot be unscrewed without additional action.

In this embodiment, the shape and contour of the ramps 30 are such that they support the edges/tips of the spring fingers 18 throughout contact with these features.

To remove the cap from the container neck, the outer cap 15 must be pressed down onto the inner cap 25.

The spring member 18 normally serves to retain the outer cap 15 and the inner cap 25 in their axially spaced relationship in which it is not possible to remove the cap from the container. However, the outer cap 15 may be pressed down on the inner cap 25 by the elastic function of the spring 18. Downward displacement of the outer cap 15 causes the drive lugs 19 to engage the spaces between the drive castellations 34.

The alignment of the lugs 19 with the spaces between the drive lugs 34 may not be perfect when the outer cap 15 is pressed down. However, rotating the outer cap 15 slightly in the loosening direction will bring these components into proper driving engagement. With proper engagement with the drive lugs 19, the outer cap 15 can be rotated and the inner cap 25 rotated with it as a unit by this driving engagement.

Once the combined cover is removed from the container and the downward pressure on the outer cap 15 is released, the combined cover will spring back under the influence of the spring member 18, thereby placing the cover in a configuration suitable for re-application. The user can then screw the closure back onto the container neck using the driving combination of the spring 18 and ratchet surface 30 b.

Once back onto the container, the combined lid cannot be removed again without pressing the outer cap 15 down onto the inner cap 25. The alarm sound is generated when a child attempts to remove the assembled closure from the container without pressing down on the inner cap 15. The spring 18 slides over the ratchet lug 29 and hits the top plate 26 creating a loud and unique "click". This sound can be heard at a distance and can act as a warning to parents that a child is fiddling a container whose contents are harmful to them.

The safety cap of the present invention assembled by the outer cap 15 and the inner cap 25 can be applied by a conventional capping machine since no manipulation of the cap is required during the fastening procedure.

Although illustrative embodiments of the present invention have been disclosed in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments shown, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A child-resistant closure for a container, said closure comprising nested outer and inner caps each having a top panel and a side skirt depending generally from the periphery thereof, said outer cap generally loosely surrounding said inner cap to permit relative rotational and axial movement therebetween, said outer and inner caps having respective drive formations capable of entering into driving engagement as said caps are moved axially toward one another to a first axial position, said outer cap including a plurality of spring members for axially moving said inner and outer caps away from one another to a second axial position, said inner cap including a top panel provided with a plurality of ramps, said spring members providing a biasing force to retain said outer and inner caps in said second axial position and drivingly engaging said ramps in said second axial position to simultaneously drive said outer and inner caps in a tightening direction, but is free to slide over the ramp in the unscrewing direction, the downward pressure on the outer cap moving the cap against the bias of the spring fingers to the first axial position to allow the safety cap to be unscrewed using the inner cap drive formation and the outer cap drive formation, wherein the outer surface of the inner cap side skirt includes a plurality of substantially full height axial ribs for allowing venting when the outer cap and the inner cap are initially assembled together, wherein the inner cap drive formation includes a plurality of castellations upstanding from the inner cap top plate, and wherein each full height axial rib is connected to one castellation.

2. The safety cap of claim 1, further comprising a plurality of non-full-height axial ribs disposed on the inner cap sidewall alternating with the full-height ribs.

3. A safety cover as claimed in claim 1 or 2, wherein the castellations are substantially U-shaped in plan.

4. A safety cover as claimed in claim 3, wherein the castellations comprise a first radially extending side wall upstanding from the top plate and a second radially extending side wall upstanding from the top plate, the first and second side walls being located at or towards the periphery of the top plate and being spaced apart from each other, the first and second side walls being connected at one end by an arcuate transverse wall.

5. The safety cap of claim 4, wherein the full-height axial rib extends from the first sidewall.

6. The safety cover as claimed in claim 5, wherein the first sidewall is connected to the assembly rib by an inclined wall portion.

7. A safety cover as claimed in any preceding claim, wherein the castellations are thinned in non-functional areas.

8. The safety cap of any preceding claim, wherein the full height axial ribs are spaced from each other around the outer surface of the inner cap side skirt, and the circumferential length of the ribs may be less than the circumferential length of the spacing therebetween.

9. A safety cap as claimed in any preceding claim, wherein for each ramp there is provided a respective detent projection projecting above the plane of the top plate and on the path taken by the spring member, the projection supporting the spring member when in driving engagement with the ramp against deformation of the spring member as it imparts force to the ramp face, the projection having a profile which matches the profile of the region of the spring member which it contacts.

10. A security cover as claimed in any one of the preceding claims wherein each ramp is generally wedge-shaped.

11. A safety cap as claimed in any preceding claim, wherein each ramp is generally trapezoidal in plan.

12. A safety cap as claimed in any preceding claim, wherein an indentation is provided on the inner cap top panel upon rotation beyond each ramp.

13. The safety cap of any preceding claim, wherein each ramp is profiled to substantially continuously support the spring member as it passes over it in the unscrewing direction.

14. A safety cap as claimed in any preceding claim, wherein the profile of each ramp may be varied continuously as the height of the ramp increases.

15. The safety cap of any preceding claim, wherein each ramp has a variable cross-sectional sweep having a generally constant radial trajectory and a cross-section that varies continuously along the radial sweep such that the spring member contacts the ramp to a maximum extent by rotation.

16. The safety cap of any preceding claim, wherein the ramp is contoured to substantially continuously support the spring member as it passes over it in the unscrewing direction, wherein the ramp has a variable cross-sectional sweep with a generally constant radial trajectory and a cross-section that varies continuously along the radial sweep such that one or more spring members maximally contact one or more ramps by rotation.

17. A security cap as claimed in any one of the preceding claims in combination with a container.