US3912101A

US3912101A - Childproof closure

Info

Publication number: US3912101A
Application number: US508566A
Authority: US
Inventors: Adrien Patrick Rayner; Christopher James Niebuhr Tod; Michael James
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-03-22
Filing date: 1974-09-23
Publication date: 1975-10-14
Anticipated expiration: 1992-10-14
Also published as: AU7937975A

Abstract

The Specification discloses a childproof screw closure for a container, comprising an inner closure member and an outer closure member which shrouds the inner closure member and is held captive on the same. The outer closure member is axially movable on the inner closure member and has projections arranged so that when the outer closure member is axially depressed against a bias, they engage projections on the inner closure member and thereby enable the closure to be unscrewed. To enable the closure to be screwed up irrespective of the relative axial positions of the inner and outer closure members, the skirt of the outer closure member is formed with ratchets which are biassed resiliently against knurls formed on the periphery of the skirt of the inner closure member. Preferably the skirt of the outer closure member is locally reduced in thickness on either side of each ratchet so as to provide the desired characteristics for the ratchets.

Description

Rayner et a1.

Oct. 14, 1975 CHILDPROOF CLOSURE Inventors: Adrien Patrick Rayner, Huntsmoor Lodge, Iver, Buckinghamshire; Christopher James Niebuhr Tod, 2 Maudlyn House, Steyning, Sussex; Michael James, 11 Connaught Ave., Shoreham-By-Sea, Sussex, all of England Filed: Sept. 23, 1974 Appl. No.: 508,566

Foreign Application Priority Data Mar. 22, 1974 United Kingdom 12957/74 June 28, 1974 United Kingdom 28709/74 us. C1. 215/220; 215/9 rm. c1. B65D 55/02 Field of Search 215/9, 219, 220

References Cited UNITED STATES PATENTS Primary ExaminerGeorge T. Hall Attorney, Agent, or FirmKenyon & Kenyon Reilly Carr & Chapin [5 7] ABSTRACT The Specification discloses a childproof screw closure I for a container, comprising an inner closure member and an outer closure member which shrouds the inner closure member and is held captive on the same. The outer closure member is axially movable on the inner closure member and has projections arranged so that when the outer closure member is axially depressed against a bias, they engage projections on the inner closure member and thereby enable the closure to be unscrewed. To enable the closure to be screwed up irrespective of the relative axial positions of the inner and outer closure members, the skirt of the outer closure member is formed with ratchets which are biassed resiliently against knurls formed on the periphcry of the skirt of the inner closure member. Preferably the skirt of the outer closure member is locally reduced in thickness on either side of each ratchet so as to provide the desired characteristics for the ratchets.

lb 7) H US. Patent Oct. 14, 1975 Sheet 3 of3 3,912,101

CHILDPROOF CLOSURE This invention relates to closures of the type which are normally known as childproof closures and which are hereinafter to be referred to by that name. By a childproof closure is meant a closure which is designed to prevent a child from gaining access to the potentially harmful contents of a bottle or the like which is closed by the closure.

According to the present invention from one aspect there is provided a childproof closure comprising an inner closure member having a crown and a depending skirt with cam formations for cooperation with complementary cam formations on a container to be closed, and a plastics outer closure member shrouding the inner closure member and having a crown to overlie at least part of the crown of the inner closure member and a skirt to overlie the first said skirt, the outer closure member being captive on the inner closure member and being at least in part axially moveable on the inner closure member and biassed to a position in which the outer closure member is freely rotatable on the inner closure member in the sense to disengage the closure from the said container, there being provided means on the inner and outer closure members which are mutually engageable on depression of the outer closure member or the said part thereof against the bias to provide a positive drive between the closure members enabling disengagement of the closure from the container, a plurality of projections formed on the outer periphery of the inner closure member skirt and a plurality of ratchets in the form of thin tongues of plastics material which project integrally and inwardly from the outer closure member skirt into engagement with the inner closure member skirt and which are engageable behind the said projections so as at all times to enable a positive drive to be effected between the members, in the sense to engage the closure on the container and irrespective of the axial position of the outer closure member on the inner closure member, each ratchet being arranged so as to ride resiliently over the said projections when the outer closure member is turned in the sense to disengage the closure from the container.

Preferably each ratchet is integrally rooted on the plastics material of the outer closure member skirt, which is locally reduced in thickness adjacent the ratchet root on at least one side thereof.

In accordance with the invention from a second aspect there is provided a said outer closure member for a closure as defined above.

In order that the invention may be more fully understood several embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic section on a diametral plane of a closure in accordance with the invention when in position on a bottle for medicinal pills;

FIG. 2 is a diagrammatic view showing the outer closure member forming part of the clsoure of FIG. 1 when free of the inner closure member forming the other closure part and at two different vertical sections, the part to the right of the central axis XX being taken on the line llA-llA of FIG. 3 and the part to the left of that axis being taken on the line llBllB of that figure;

FIG. 3 is a quadrant of the outer closure member as seen on the horizontal section represented by the line III-III of FIG. 2;

FIG. 4 is a view corresponding to FIG. 2 of another outer closure member in accordance with the invention;

FIG. 5 is a top view, partly broken away, of the outer closure member of FIG. 4; and

FIG. 6 is a section, to an enlarged scale, of a part of FIG. 5.

Throughout the drawings, the same reference numerals are used to indicate like or analogous parts.

Referring now to FIGS. 1 to 3, a closure for the screw-threaded neck 9 (FIG. 1) of a glass bottle for medicinal pills is formed of an inner closure member 1 and an outer closure member 2 which is fitted onto the inner closure member and is held captive thereon as is to be described.

The inner closure member is conventional. It is integrally moulded in one piece from high density polyethylene and comprises a generally plane crown 3 and a depending generally cylindrical skirt 4 both of which are essentially rigid. The skirt 4 is internally formed with screw threads 7 to engage the screw-threads 8 of the bottle finish. Externally the skirt is regularly formed with vertical knurls 10 separated by grooves 43; one each of the knurls and of the grooves is respectively visible in full lines to the right and left of the inner closure member as seen in FIG. 1. At their bottom ends the knurls merge with an outwardly projecting bead 24 formed circumferentially around the bottom free edge of the skirt exterior.

The crown 3 is integrally formed at its underside with a dependant annular ring 18 which resiliently engages the annular top surface 17 of the bottle finish so as to prevent contamination of the bottle contents by moisture etc., whilst also providing frictional resistance to rotation of the closure cap on the bottle for the purpose later to become apparent. The ring 18 is of thin material; it is angled inwardly of the cap in the direction towards its free edge, so that, as is apparent from FIG. 1, it is deformed upwardly by its engagement with the bottle when the closure is screwed home.

Externally the crown 3 is formed with radial continuations of the knurls 10 and the grooves 43. The crests of the knurl continuations form part of the top surface 23 of the crown; the groove continuations decrease progressively in depth in the direction towards the centre of the crown so that the knurls terminate at a circular locus 25 centred on the central axis XX of the closure. In a modification the continuations of the knurls and grooves have a component of direction circumferentially of the cap.

The outer closure member 2 is integrally moulded in one piece from high density polyethylene and comprises a crown 5 and a dependant skirt which overlie, respectively, the crown 3 and skirt 4 of the inner closure member 1.

The outer closure member is held captive on the closure cap by engagement of a bead 13 under the bead 24 of the inner closure member. The bead 13 is formed continuously around the skirt 6 inner periphery, adjacent the free bottom edge of the outer closure member.

The crown 5 of the outer closure member has a thickness which is substantially smaller than that of the skirt 6. Whereas the skirt 6 has substantial rigidity, the crown 5 is readily deformable axially of the closure.

The crown is chamfered at 35 around its periphery; at its centre it carries a boss 29 in the form of an openbottomed cylinder which depends from the underside of the crown 5 at its top end and which at its bottom end engages the top surface 23 of the inner closure member at a circular free edge 41. The relative dimensions of the inner and outer closure members are chosen so that when as shown in FIG. 1, the outer closure member is held captive on the inner closure member by engagement of the

beads

13 and 24, the crown 5 is upwardly and resiliently deformed by upward pressure exerted by the boss 29 in cooperation with the crown 3; this deformation, however, is insufficient to completely remove the concavity with which the crown 5 is formed during moulding (FIG. 2).

It will therefore be appreciated that by virtue of its own arrangement and its engagement with the inner closure member, the outer closure member 2 is held captive on the inner closure member 1 in a positive manner which allows a user to depress the skirt 6 of the outer closure member axially in relation to the skirt 4 of the inner closure member by pressing on the annular portion 16 of the crown 5 lying radially outside the boss 29. The purpose of this movement will later become apparent.

Referring now to FIGS. 2 and 3 in particular, in addition to the continuous bead 13 the skirt 6 of the outer closure member is internally formed with alternate lugs 11 and ratchets 19 of which nine of each are provided. The lugs are rigid and regularly disposed around the skirt 6 at a 40 pitch. The ratchets are flexible (as is later to be described); like the lugs, they have a 40 relative pitch.

The lugs 11 are vertical and carried on respective bearing lands 33 which are generally rectangular and project inwardly from the base inner surface 34 of the skirt 6. The lands merge with the underside of the chamfer 35 at their top ends; from there they extend vertically downwardly by approximately two-thirds of the skirt length. The lands are of such a thickness that, as can be seen at the right hand side of FIG. 1, they engage the crests of the knurls forming part of the generally cylindrical outside surface of the skirt; they thereby at all times maintain satisfactory axial alignment of the outer closure member on the inner closure member.

The lugs 11 are relatively short in length. They merge with the chamfer 35 at their top ends and there from extend downwardly for a distance which is slightly shorter than the spacing of the

crowns

3,5 when the outer closure member is in its relaxed (but captive) condition as shown in FIG. 1.

The ratchets 19 are thin vertical pieces of plastics material which are of constant thickness and are coextensive in the vertical sense with the lands 33; they are joined to the undersurface of the chamfer 35 at their top ends. Along their outer edges the ratchets are rooted at the base inner surface 34 of the skirt 6 so as to be inherently biassed away from the surface 34 and into contact with the skirt 4 of the inner closure member.

The outer surface 36 of the skirt 6 is generally cylindrical but is formed at regular intervals with nine isosceles-triangular depressions 37 each of which extends up the skirt 6 with its apex in radial and longitudinal correspondance with the root of a respective ratchet 19. As can particularly be seen from FIG. 3, each depression provides reduced thickness neck portions adjacent the root of its associated ratchet 19 on either side thereof. As will later become apparent, these neck portions form integral hinges for the ratchets.

To assemble the closure intitally the outer closure member 2 is pressed axially over the inner closure member 1 until its bead 13 rides over the bead 24 and thereafter snaps resiliently underneath that bead to hold the outer closure member captive on the inner closure member as described above.

To screw the assembled closure onto a medicinal bottle it is then merely required to rotate the outer closure member in the normal clockwise direction. As can be seen from FIG. 3, each ratchet 19 is inclined in relation to the cap radius through its root. The sense of this inclination is such that the clockwise rotation of the outer closure member drives the ratchets into engagement behind knurls 10 of the inner closure member skirt 4 at the radially extending free edges 38 of the ratchets. It will accordingly be seen that the ratchets l9 enable a positive connection to be effected between the

members

1,2 so as to enable the closure to be screwed up in the normal manner irrespective of the axial position of the outer closure member on the inner closure member.

If, however, an attempt is made to undo the closure by merely turning the outer closure member in the normal anticlockwise direction, the ratchets 19 ride over the knurls 10 so allow free relative rotation between the closure members; the outer closure member is therefore turned without effecting any rotation of the closure. It will be appreciated that for this to occur the previously described frictional resistance between the ring 18 (FIG. 1) and the top surface 17 of the bottle finish must be sufficient to withstand the torque frictionally generated by the ratchets as they move over the knurls.

In order to undo the closure it is necessary first to axially depress the portion 16 of the outer closure member 2 as previously described, sufficiently to move the lugs 11 into the top ends of grooves 43 on the skirt 4. The positive drive thereby effected between the two members then enables simultaneous rotation of the outer closure member in the anticlockwise direction to unscrew the closure and so gain access to the contents of the bottle.

During the riding movement of the ratchets 19 over the outer surface of the skirt 4 as described in the penultimate paragraph, the neck portions 40 provided by the depressions 37 act as integral hinges allowing the ratchets 19 to rock on their roots. In conjunction with a small and inconsequential degree of flexing of the ratchets themselves this rotation accommodates the reciprocating radial movements of the ratchet tips as they pass alternatively over the knurls 10 and grooves 43 of the .skirt 4.

In this respect it will be noted that the ratchets are thicker than they otherwise could satisfactorily be from the point of view of their ability to flex in the absence of the depressions 37. The thickness and, therefore, the rigidity of the ratchets is, in fact, chosen to satisfy the function of the ratchets to provide the positive drive required, as previously described, to screw the closure onto the bottle. The provision of the neck portions 40 by means of the depressions 37 therefore reconciles the conflicting requirements for the ratchets to be of high rigidity when required to provide positive drive for screwing up, but to be highly flexible when required to ride over the knurls to prevent unathorised unscrewing.

In the embodiment of FIGS. 4 to 6 the ratchets 19 are in a modified form to that of the ratchets of FIGS. 1 to 3. In contrast with the first embodiment the skirt 6 of the outer closure member 2 is not locally reduced in thickness on either side of each of the ratchets; instead, the necessary characteristics of resilience and capability to deform are provided in the ratchets themselves. In FIGS. 4 to 6 each ratchet 19 comprises a root portion 20 outstanding orthogonally from the skirt wall, and a thicker and essentially rigid inner closure member engaging portion 21 which is inclined in the appropriate direction, that is to say, in the clockwise sense required for the ratchet to engage the knurls 10 for screwing-up the closure. The thickness of theroot portions 20 is suitably chosen to give the required characteristics for the ratchet operation.

A further way in which the second embodiment differs from that of FIGS. 1 to 3 is that the boss 29 is closed at its bottom rather than its top end. It therefore forms a well 42 having a bottom 12 engaging the crown 3 of the inner closure member 1, and side walls 15 which are slightly convergent towards the bottom 12.

In a modification of the arrangement of FIGS. 1 to 3, a well such as is shown at 12 in FIGS. 4 to 6 replaces the boss 29; correspondingly, a boss such as is shown at 29 can replace the well 12 in the arrangements of FIGS. 4 to 6.

In further modifications of the described embodiments: the integral sealing ring 18 is replaced by a separate wad of suitable material; the crown 5 of the outer closure member is made plane and essentially rigid and the boss 29 or well 42 is replaced by integral spring fingers on the crown 3 and/or 5 by a spring or springs separately provided; and the lugs 11 are omitted and replaced by formations on the underside of the crown 5 which are arranged for engagement with the knurl continuations at the top of the crown 3 or with other formations specially provided.

Although in the embodiment described with reference to FIGS. 1 to 3 the depressions 37 are shown and described as isosceles triangular and centred symmetrically on the root of the associated ratchet 19, for some applications it may be found desirable to make the depressions of a different crosssectional shape and/or to make them assymmetrical with respect to the ratchet roots.

In a further possible modification of the first embodiment grooves or slots, preferably part-cylindrical, are formed in the interior surface 34 of the skirt 6 immediately adjacent the roots of the ratchets 19 so as locally to reduce the skirt thickness and form a residual hinge for the ratchet. Only one such groove or slot may be provided for each ratchet; alternatively two grooves or slots may be provided, one on each side of the ratchet root. With the provision of these grooves or slots the depressions 37 may be omitted if desired.

Although the invention has been described in relation to an inner closure member of plastics material, the inner closure member of a closure in accordance with the invention may be of metal.

The invention is in no way limited in application to glass bottles for medicinal pills as particularly described; it may be used in relation to other types of container (which may be of glass, plastics and/or metal),

and for other types of product, sealed or otherwise, which are dangerous to a child.

In the latter respect it will be noted that in each of the described embodiments the outer .closure member completely shrouds the inner closure member so that access to the bottle contents can only be achieved through the agency of the lugs 11. The simultaneous depression and rotation of the outer closure member necessary to achieve unscrewing is not within the capabilities of a child, so that only an adult who knows the required combination of movements can gain access to the bottle contents.

What we claim is:

l. A childproof closure, comprising an inner closure member having a crown and a depending skirt with cam formations for cooperation with complementary cam formations on a container to be closed, and a plastics outer closure member shrouding the inner closure member and having a crown' to overlie at least part of the crown of the inner closure member and a skirt to overlie the first said skirt, the outer closure member being captive on the inner closure member and being at least in part axially moveable on the inner closure member and biassed to a position in which the outer closure member is freely rotatable on the inner closure member in the sense todisengage the closure from the said container, there being provided means on the inner and outer closure members which are mutually engageable on depression of the outer closure member or the said part thereof against the bias to provide a positive drive between the closure members enabling disengagement of the closure from the container, a plurality of projections formed on the outer periphery of the inner closure member skirt and a plurality of ratchets in the form of thin tongues of plastics material which project integrally and inwardly from the outer closure member skirt into engagement with the inner closure member skirt and which are engageable behind the said projections so as at all times to enable a positive drive to be effected between the members, in the sense to engage the closure on the container and irrespective of the axial position of the outer closure member on the inner closure member, each ratchet being arranged so as to ride resiliently over the said projections when the outer closure member is turned in the sense to disengage the closure from the container.

2. A closure according to claim 1, wherein the plastics material of the outer closure skirt is locally reduced in thickness adjacent the root of each ratchet, along at least one side of the ratchet.

3. A closure according to claim 1, wherein each ratchet comprises a deformable and resilient root portion, and a substantially rigid further portion to engage the skirt of the inner closure.

4. A closure according to claim 1 wherein the crown of the outer closure member has a rigid cylindrical boss depending therefrom to engage the crown of the inner closure member at its free edge, a portion of the outer closure member crown radially outside the boss being resilient and deformable to allow the said axial movement of the outer closure member on the inner closure member.

5. A closure according to claim 1, wherein the crown of the outer closure member is formed with a well having a closed bottom to engage the crown of the inner closure member, a portion of the outer closure member crown radially outside the well being resilient and deshort lugs formed at intervals around the inside periphery of the skirt of the outer closure member, the lugs b'eing engageable between the knurls by the said axial movement of the outer closure member on the inner closure member.

Claims

1. A childproof closure, comprising an inner closure member having a crown and a depending skirt with cam formations for cooperation with complementary cam formations on a container to be closed, and a plastics outer closure member shrouding the inner closure member and having a crown to overlie at least part of the crown of the inner closure member and a skirt to overlie the first said skirt, the outer closure member being captive on the inner closure member and being at least in part axially moveable on the inner closure member and biassed to a position in which the outer closure member is freely rotatable on the inner closure member in the sense to disengage the closure from the said container, there being provided means on the inner and outer closure members which are mutually engageable on deprEssion of the outer closure member or the said part thereof against the bias to provide a positive drive between the closure members enabling disengagement of the closure from the container, a plurality of projections formed on the outer periphery of the inner closure member skirt and a plurality of ratchets in the form of thin tongues of plastics material which project integrally and inwardly from the outer closure member skirt into engagement with the inner closure member skirt and which are engageable behind the said projections so as at all times to enable a positive drive to be effected between the members, in the sense to engage the closure on the container and irrespective of the axial position of the outer closure member on the inner closure member, each ratchet being arranged so as to ride resiliently over the said projections when the outer closure member is turned in the sense to disengage the closure from the container.

5. A closure according to claim 1, wherein the crown of the outer closure member is formed with a well having a closed bottom to engage the crown of the inner closure member, a portion of the outer closure member crown radially outside the well being resilient and deformable to allow the said axial movement of the outer closure member on the inner closure member.

6. A closure according to claim 1, wherein the said means on the inner and outer closure members comprises knurls formed at intervals around the outside periphery of the skirt of the inner closure member, and short lugs formed at intervals around the inside periphery of the skirt of the outer closure member, the lugs being engageable between the knurls by the said axial movement of the outer closure member on the inner closure member.