Container and closure cap

Abstract

A push-and-turn container and closure cap combination provided. Cap (1) has an inner skirt (3) with H (10) is a screw thread (4) which co-operates with a screw threaded neck (11) of the container, and a sprung outer skirt (5) which surrounds inner skirt (3). Container (10) has a locking ring (15) with two slots (16,17); cap (1) has two lugs (7,8) which engage in slots (16,17) when the cap (1) is fully screwed on to the container (10) and the outer skirt is in a first, rest position thereby preventing the cap from being unscrewed. Outer skirt (5) can be moved to a second, stressed position in which lugs (7,8) disengage from slots (16,17) to allow partial unscrewing until lugs (7,8) are aligned with the opposite slot (17,16). The resilient component of the outer skirt (5) urges it back to the first, rest position and lugs (7,8) pass through slots (16,17) due to axial movement of inner skirt (3) during the partial unscrewing. Thereafter cap (1) can be fully unscrewed from the container.

Description

[0001] The present invention relates to a container and closure cap and in particular to a container having a child resistant closure cap.

[0002] Child resistant container caps for disinfectant containers and the like are often of the well known squeeze-and-turn type in which the cap has a skirt which must be squeezed at two diametrically opposite points to disengage stops which are formed on the skirt and the container to permit rotation of the cap for removal. This type of cap can be manufactured simply and cheaply because they can be moulded as a one-piece construction.

[0003] Child resistant caps for pharmaceuticals often use an arrangement in which a cap must be pushed downwardly to permit removal. These arrangements are generally rather complicated and consequently expensive to manufacture. Caps which can be operated by pushing down rather than by being squeezed are preferred by the elderly, however, who find the squeezing action more awkward.

[0004] Many push-and-turn caps use an inner cap which closes the container and an outer cap which must be pushed down to engage the inner cap before the caps are then unscrewed together. However, the use of two caps necessitates an assembly step in production and generally increases the complexity of the design.

[0005] Document U.S. Pat. No. 3,830,391 describes a one-piece closure and a container, in which the closure has inner and outer walls joined by a resilient bridge. The outer wall has locking lugs which engage stop members on the container. In order for the lugs to pass the stop members the outer all must be pushed down and then held down whilst the closure is unscrewed to the point at which the inner wall as moved axially enough for the lugs to spring above the top members when the outer wall is released.

[0006] The present invention seeks to provide a child resistant container and closure cap which can be operated by pushing down on the cap but which is nevertheless of simple and inexpensive construction.

[0007] Accordingly there is provided a container and a closure cap therefor, the container having a screw-threaded neck, the cap having an end panel for closing the neck, an inner skirt depending from the end panel and having a screw thread for co-operation with the neck thread, and an outer skirt surrounding the inner skirt and being resiliently connected thereto, one of the container and the closure having a locking ring with at least one slot therein, the other having at least one lug which engages in a slot when the cap is fully screwed on to the container and the outer skirt is in a first, rest position, thereby preventing the cap from being unscrewed, the outer skirt is movable to a second position in which the resilient connection is stressed and in which the lug is disengaged from the slot to allow the closure to be partially unscrewed until the lug is aligned with the slot, characterised in that the locking ring is adapted to prevent movement of the outer skirt back to the first position during partial unscrewing such that when the lug is aligned with the slot the resilient connection urges the outer skirt back to the first position and the lug passes through the slot due to axial movement of the inner skirt during the partial unscrewing, thereafter the cap can be fully unscrewed from the container.

[0008] The resilient connection may comprise a bridge portion which extends between the inner and outer skirts. By arranging the bridge to join the skirts at the closed end of the cap the bridge can form part of the end panel and movement between the skirts involves a simple flexing of the bridge.

[0009] A plurality of slots and lugs may be provided; in a preferred embodiment the locking ring has two slots and there are two lugs, both of which are substantially diametrically opposed to each other. This arrangement balances the stresses placed on either side of the cap during use. The number of slots and lugs does not have to be equal.

[0010] In the first position the outer skirt may be axially displaced of the inner skirt at their point of connection to the end panel, the bridge portion thereby being inclined. By having an inclined bridge portion in the first, rest position this presents a raised area on which to press. This allows for pressing on the cap using the palm of the hand, making applying the required pressure easier.

[0011] The resilience of the bridge portion may be provided by the material of the portion itself. For example the portion may be formed from an elastomeric material such as polypropylene. The bridge portion does not have to be formed from the same material as the rest of the cap, although for simplicity of manufacture this may be the case. The closure cap may therefore be a one-piece construction.

[0012] The slots may be longer than the lugs whereby to allow a smooth, continuous unscrewing action as described in more detail below.

[0013] The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings in which:-

[0014] FIG. 1 is a perspective view of a closure cap;

[0015] FIG. 2 is a perspective view of a container for use in conjunction with the cap of FIG. 1;

[0016] FIG. 3 is a perspective sectional view through the container of FIG. 2 shown with the cap of FIG. 1 fully screwed on;

[0017] FIGS. 4A to 4D are schematic vertical sections through the container and closure cap shown in FIG. 3 illustrating the operation of the cap; and

[0018] FIG. 5 is a diagrammatic side view of a container according to an alternative embodiment.

[0019] Referring first to FIG. 1 there is shown a child resistant closure cap generally indicated 1 and having a circular end panel 2. An inner skirt 3 depends from the end panel 2 and is formed with an internal screw thread 4. An outer skirt 5 also depends from the end panel 2, radially outwardly of the inner skirt 3 and this creates a hollow interspace between the two skirts 3, 5. At the open end of the outer skirt 5 two diametrically opposed lugs 7, 8 project towards the interior of the cap. The outer skirt is resiliently connected to the end panel by an annular bridge portion 20 (shown most clearly in FIG. 3).

[0020] A container for use with the cap of FIG. 1 is shown in FIG. 2 and is generally indicated 10. The container 10 has a cylindrical neck 11 formed with an open end and an external screw thread 12 for cooperation with the screw thread 4 on the closure cap 1. The neck 11 is joined to the main body 13 of the container by a shoulder 14. At the base of the neck 11 in the region it joins the shoulder 14 an annular locking ring 15 extends perpendicular to the main axis of the container 10. The locking ring 15 is provided with two diametrically opposed elongate slots 16, 17 which correspond to the lugs 7, 8 of the closure cap 1.

[0021] The interaction of the closure cap 1 and the container 10 is shown more clearly in FIG. 3. When the closure cap 1 is fully screwed on to the container 10 the lugs 7, 8 are engaged in the slots 16, 17 which prevents the cap 1 from being unscrewed.

[0022] The annular bridge portion 20 is shown to comprise a base 21 formed from material which is relatively thin compared to the inner 3 and outer 5 skirts and a plurality of radially extending mutually spaced ribs 22 which extend from the panel 2 to the outer skirt 5. The localised thinning increases the relative elasticity of the bridge portion 20 and reduces stress during use. The bridge portion 20 acts as a spring to provide a sprung outer skirt 5 as described below.

[0023] Whilst the knurling provided by the ribs 22 is undesirable from the point of the yield of the outer skirt spring, it provides gripping friction to allow opening of the closure using the palm of the hand, with no squeeze force required.

[0024] The operation of the closure cap 1 and container 10 will now be more particularly described with reference to FIGS. 4A to 4D. In FIG. 4A the closure cap is shown fully screwed on to the container as illustrated in FIG. 3. The bridge portion 20 is shown to be upwardly inclined and the lugs 7, 8 are shown to be engaged in their respective slots 16, 17. In this position the closure cap 1 cannot be rotated with respect to the container because of the engagement of the lugs 7, 8 in the slots 16, 17.

[0025] Referring now to FIG. 4B, the outer skirt 5 has been moved to a second position in which the lugs 7, 8 have been disengaged from their slots 16, 17 and are now below the level of the locking ring 15. In this position it will be seen that the bridge portion 20 has moved and is now in a stressed condition.

[0026] With the lugs 7, 8 disengaged from the slots 16, 17 the closure cap 1 can now be partially unscrewed, as the lugs 7, 8 can pass under the locking ring 15. The bridge portion is resiliently biassed to the first position but is unable to urge the outer skirt upwardly due to the engagement of the lugs 7, 8 under the locking ring 15. As the closure cap 1 is unscrewed the inner skirt 3 begins to move axially as a result of the screw thread arrangement. The position of the outer skirt 5 is unchanged (because of the engagement of the lugs under the locking ring) but the bridge portion 20 becomes further stressed as shown in FIG. 4C.

[0027] The partial unscrewing of the closure cap 1 continues until the lugs 7, 8 are rotated approximately 180° and they begin to align with the opposite slot 17, 16. When the lugs 7, 8 are fully aligned with the slots 17, 16 the resilience of the bridge portion 20 urges the outer skirt 5 back to the first position and the lugs 7, 8 pass through the slots 17, 16 due to the axial movement of the inner skirt during the partial unscrewing. Once the lugs 7, 8 have passed through the locking ring 15 the closure cap 1 can be fully unscrewed from the container 10.

[0028] It will be appreciated that if the slots 16, 17 were substantially the same size as the lugs the unscrewing action could not be continuous. Because the slots 16, 17 are considerably longer (in this embodiment approximately twice as long) than the lugs 7, 8 the unscrewing action can be continuous; the additional length of the slots allows the closure cap to be rotated as the lugs 7, 8 move axially through the slots 16, 17. If the slots are the same size as the lugs the unscrewing action would have to be in several stages; the user would have to gently unscrew the closure to the point at which the lugs flicked fully through the slots, during which time no rotation would be possible.

[0029] When the cap is screwed back onto the closure the lugs snap back into the slots; the slots prevent over tightening and serve as an end stop for capping machines.

[0030] In other embodiments (not shown) the locking ring is located on the closure cap and the lugs are located on the container. The principle behind the operation of such a closure is exactly the same as previously described.

[0031] In this embodiment the closure cap is injection moulded in a single piece.

[0032] The container may be made by extrusion blowing using materials such as HDPE or by injection stretch blowing using materials such as PET. The closure cap may be made from HPPE, polypropylene or other elastomeric material.

[0033] Referring now to FIG. 5 there is shown a container 110 according to an alternative embodiment. The basic design and function of the container 110 is the same as the container 10 of FIGS. 1 to 4. In this embodiment the locking ring 115 is slightly upwardly inclined between the slots 116, 117. The inclination makes it easier to unscrew a closure cap (not shown) during the time its lugs pass under the locking ring 115. Without inclination, turning of the cap becomes more difficult as the inner and outer skirts move relative to each other against the resilience of the bridge portion. The inclination of the ring 115 reduces the relative movement of the skirts.

[0034] In addition, the locking ring 115 has a stop 118 adjacent each of the slots 116, 117. The stops 118 have a ramped surface 119 inclined away from the direction of unscrewing, and a sheer face 125 which defines the start of the slot.

[0035] The function of the stops 118 is twofold. First, the face 125 increases the local width of the locking ring 115 which makes it more difficult for the closure cap to be forced open, bypassing the push-and-turn mechanism. Secondly, the ramped surface 119 causes a change in the force required to screw the closure back onto the container just before the lugs engage the slots; the lugs will also pass into the slots with a more definite clicking noise. This informs the user that the container is fully closed.

Claims

1. A container (10) and a closure cap (1) therefor, the container (10) having a screw-threaded neck (11), the cap having an end panel (2) for closing the neck (11), an inner skirt (3) depending from the end panel (2) and having a screw thread (4) for co-operation with the neck thread (12), and an outer skirt (5) surrounding the inner skirt (3) and being resiliently connected thereto, one of the container and the closure having a locking ring (15) with at least one slot (16,17) therein, the other having at least one lug (7,8) which engages in a slot (16,17) when the cap (1) is fully screwed on to the container (10) and the outer skirt (5) is in a first, rest position, thereby preventing the cap (1) from being unscrewed, the outer skirt (5) is movable to a second position in which the resilient connection is stressed and in which the lug (7, 8) is disengaged from the slot (16,17) to allow the closure to be partially unscrewed until the lug (7,8) is aligned with the slot (17,16),

characterised in that the locking ring is adapted to prevent movement of the outer skirt back to the first position during partial unscrewing such that when the lug (7,8) is aligned with the slot (17,16) the resilient connection urges the outer skirt (5) back to the first position and the lug (7,8) passes through the slot (17,16) due to axial movement of the inner skirt (3) during the partial unscrewing, thereafter the cap (1) can be fully unscrewed from the container (10).

2. A container (10) and a closure cap (1) as claimed in claim 1, in which the resilient connection comprises a bridge portion (20) extending between the inner and outer skirts (3,5).

3. A container (10) and closure cap (1) as claimed in claim 1 or claim 2, in which the locking ring (15) has two slots (16,17) and there are two lugs (7,8).

4. A container (10) and closure cap (1) as claimed in claim 2 or claim 3, in which in the first position the outer skirt (5) is axially displaced of the inner skirt (3) at their point of connection to the end panel (2), the bridge portion (20) being inclined.

5. A container (10) and closure cap (1) as claimed in any of claims 2 to 4, in which the resilience of the bridge portion (20) is provided by the material of the portion itself.

6. A container (10) and closure cap (1) as claimed in any preceding claim, in which the slots (16,17) are longer than the lugs (7,8) whereby to allow a continuous unscrewing action.

7. A container (10) and closure cap (1) as claimed in any preceding claim, in which the closure cap (1) is a one-piece construction.

8. A container (10) and closure cap (1) as claimed in any preceding claim, in which at least part of the locking ring 15 is inclined.

9. A container (10) and closure cap (1) as claimed in anyof claims 2 to 8, in which at least part of the bridge portion (20) is knurled.