GB2301817A

GB2301817A - Child resistant closure with dropper bulb

Info

Publication number: GB2301817A
Application number: GB9511589A
Authority: GB
Inventors: Dean Walding
Original assignee: Dragon Plastics Ltd
Current assignee: Dragon Plastics Ltd
Priority date: 1995-06-08
Filing date: 1995-06-08
Publication date: 1996-12-18
Also published as: GB9511589D0; AU5908096A; WO1996041750A1; GB2317884A; GB9725845D0

Abstract

A child resistant closure (10) has an inner member (12) threaded for engagement with a complementary thread of a receptacle (11), and an outer member (14) which is captively engaged with the inner member (12). The outer member (14) is rotatable relative to the inner member (12) about the thread axis, and is arranged to enclose the inner member (12) to prevent access thereto. Engagement means (19,20) are provided for releasable engagement of the outer member (14) and the inner member (12) for rotation of the outer member (14) and the inner member (12) in unison in the opening direction. A resilient dropper bulb (35) within the inner member (12) is adapted to receive a dropper tube (40) extending in use into a receptacle (11). The dropper bulb (35) is arranged to urge the engagement means (19,20) into the released condition. A push button (30) may be provided which is axially movable within an aperture (27) of the outer member, depression of the button causing compression of the bulb and consequential drawing up of liquid in the receptacle into the tube (20). The engagement means (19, 20) preferably require axial movement of the outer member relative to the inner member the members carrying axial ribs (21, 22) providing a ratchet type rotation mechanism.

Description

A CHILD RESISTANT CLOSURE The invention relates to a child resistant closure, particularly a child resistant closure for dropper bottles.

Child resistant closures are typically used for closing bottles containing hazardous substances, notably pharmaceutical and cleaning substances, and are intended to deter children from gaining access to the contents thereof.

Such closures commonly comprise inner and outer members, the inner member being threaded for engagement with a complementary thread on a receptacle such as a container or bottle, and the outer member enclosing the inner member so that the inner member cannot be directly disengaged from a receptacle. The outer member is usually captive on the inner member, and is normally free to rotate relative thereto; complementary dogs of each member are typically provided, and are adapted to engage on axial movement of the outer member relative to the inner member. An integral resilient tab or leaf spring of one of the inner and outer members is arranged to urge the outer and inner members apart and thus to hold the dogs out of engagement in the absence of an axial force.In order to engage the dogs, it is necessary to press firmly onto the outer member to move the dogs of outer member towards the dogs of the inner member. Then the entire closure may be rotated by applying a torque to the outer member with respect to the receptacle.

A ratchet is normally provided which engages the outer member to the inner member when the outer member is rotated on the receptacle in a closing direction, thus enabling the cap to be screwed onto the receptacle without engagement of the dogs. The ratchet slips in the unscrewing direction, so that the closure cannot be opened by a person unable to depress the outer member firmly enough to engage the dogs.

The closure may thus be made sufficiently difficult to remove by persons lacking in physical strength, notably young children.

The inner and outer members are most commonly moulded in plastic. As the resilient tab is usually an integral part of one or other of these components, it is essential to select a material which is appropriate for use as one of the inner and outer members, and which is sufficiently resilient to be useful as the resilient tab. Over repeated use, plastics materials are known to fatigue and to deform plastically. As a result, the resilient tab may become less effective at urging the inner and outer members apart.

Consequently it is possible that the dogs will become easier to engage. A further disadvantage is that the resilient tabs may be awkward to mould without rather expensive tooling, and the cycle time may be long due to the difficulty of ejecting the closure from the mould.

Clearly it would be possible to provide a resilient member between the inner and outer members which was not an integral part thereof. However, a helical spring or the like, while being more appropriate in terms of materials selection, is prohibitively expensive to manufacture and assemble.

According to the invention there is provided a child resistant closure comprising an inner closure member threaded for engagement with a complementary thread of a receptacle, an outer member captively engaged with the inner member, rotatable relative to the inner member about the thread axis and arranged to enclose the inner member to prevent access thereto, engagement means being provided for releasable engagement of the outer member and the inner member for rotation of the outer member and inner member in unison in the closing direction, a resilient dropper bulb being provided within the inner member and suitable for use with a dropper tube extending in use into the mouth of the receptacle, said dropper bulb being arranged to urge the engagement means into the released condition.

A particular advantage of the present invention is that the dropper bulb acts as a resilient member between the inner and outer members. The dropper bulb is normally constructed from material selected for elastic properties which do not deteriorate substantially over a period of time, and thus no compromise in material selection need be made. Furthermore, the material of the inner or outer member can be selected without reference to the integral resilient tab of the prior embodiment.

Preferably, the engagement means comprises complementary dogs of the inner and outer members. In the preferred embodiment, the engagement means is urged into the engaged position by axial movement of the outer member relative to the inner member. Preferably the dropper bulb urges the inner member and outer member apart.

In a preferred embodiment, the dropper bulb is arranged co-axially with the inner member. Ratchet means may be provided to engage the outer and inner members for rotation in unison in the closing direction, while slipping in the opening direction.

The dropper bulb may project through the outer member to allow access to said bulb for the purpose of dispensing drops of a liquid.

Preferably a cap is captively engaged between the dropper bulb and the outer member, and axially movable relative to the outer member, axial movement of the cap being operative to squeeze the dropper bulb for dispensing.

This cap is advantageous as it protects the dropper bulb from accidental piercing or other damage. Furthermore the arrangement permits squeezing of the dropper bulb using only the thumb which may be more convenient and controllable. In particular the tendency to carry a conventional dropper by the bulb may lead to accidental discharge; placing the bulb within the outer member avoids this disadvantage.

Preferably a skirt of the cap partially encloses the dropper bulb.

In a preferred embodiment, the dropper bulb urges the cap into abutment with the outer member, consequently urging the outer member and inner member apart.

Preferably the inner and outer members are of plastics material. The cap may also be of plastics material.

Relief features of the exterior of the outer member may be provided to facilitate gripping thereof by the user.

A particular embodiment of the invention will now be described by way of example only, with reference to the drawing, which shows a partial cross-sectional view of a child resistant closure according to the invention as installed on a screw-threaded neck of a bottle.

Child resistant closure 10 comprises a substantially tubular inner member 12 and a substantially tubular outer member 14. The upper end of the outer member 14 has a continuous radially inwardly projecting flange 15 defining a co-axial circular aperture 27 of diameter smaller than the inner diameter of inner member 12. The inner member 12 and outer member 14 are substantially co-axial. A continuous radial rib 16 projects from the outer surface of the inner member 12, and a continuous radial retaining rib 17 projects inwardly from the inner surface of the outer member 14, proximate the lower end, the ribs 16,17 projecting sufficiently to retain the inner member 12 captive within the outer member 14, and movable axially between the upper flange 15 and the retaining rib 17. The outer and inner members are of resilient plastic. The upper end 18 of the inner member 12 has equispaced castellations 19. Equispaced engagement dogs 20 are disposed on the inner surface of outer member 14 and arranged to engage with castellations 19 for transmission of axially applied torque from the outer member 14 to the inner member 12. Dogs 20 and castellations 19 are selectively engageable and disengageable by relative axial movement of the inner and outer members 12,14.

A plurality of equispaced axial ribs 21 project from the outer surface of the inner member 12 and extend between the radial rib 16 and the upper end 18.

A plurality of similar equispaced axial ribs 22 project from the inner surface of the outer member 14, there being an equal number of axial ribs on each of the inner and outer members 12,14. The axial ribs 22 of the outer member 14 extend from the upper flange 15 towards the retaining rib 17, but terminate short of said retaining rib 17 by a distance at least as great as the maximum movement of the inner member 12 within the outer member 14.

The inner and outer axial ribs 21,22 project sufficiently so as to overlap, and are shaped so as to form a ratchet type mechanism, whereby the axial ribs engage to transfer drive torque between the inner and outer members 12,14 in the closing direction, but to deform and slide over each in the opening direction.

A screw-threaded portion 23 is provided on the inner surface of the inner member 12 and is adapted to engage with a complementary screw-threaded portion 25 of the outer surface of the neck 24 of the bottle 11. A radially extending abutment ring 26 extends inwardly from the inner surface of the inner member 12, at the upper end of the screw-threaded portion 23.

A tubular push button 30 is provided in the aperture 27 with a blind outer end. The outermost portion of the push button 30 is of smaller diameter than the aperture 27, and the remaining portion of the push button 30, distal the blind end, is of larger diameter than the aperture 27, but of smaller diameter than the inner diameter of the inner member 12. A radial shoulder 31 is provided between the two portions of the push button. The push button 30 is held captively between the outer and inner members 14,12, the push button 30 being slidable inwardly of the abutment of the shoulder 31 with the periphery of the aperture 27.

A bulb 35 of rubber or similar material has a single aperture 36 enclosed by a rim 37. The rim 37 is shaped to co-operate sealingly with the abutment ring 26, so that in use, the rim 37 seals between the abutment ring 26 and the neck 24 of the bottle 11 in order to contain the contents thereof. The bulb 35 extends within the interior of the push button 30, and resiliently urges the shoulder 31 into abutment with the periphery of the outer member 14, and consequently the dogs 20 and castellations 19 are urged out of engagement with each other.

A dropper tube 40 of known type is engaged sealingly with the bulb 35 axially within the inner member 12. For removal of the child resistant closure 10 from the bottle 11, the outer member 14 must be urged downwards against the resilience of the bulb, so that the dogs 20 and castellations 19 engage. The outer member 14 may then be turned in the opening sense to transmit torque to the inner member 12.

In order to dispense liquid contents from the bottle 11 by use of the dropper, the push button 30 is depressed which causes compression of the bulb 35 and evacuation thereof. Liquid may then be drawn up into the dropper tube 40 by releasing the button 30 and dispensed by further depressions of the button 30.

The inner and outer members 12,14 and the push button 30 are preferably of appropriate plastics material.

Knurling or similar patterns are preferably moulded on the outer surface of the outer member 14, for improved gripping thereof by the user.

The components of the closure may be assembled as follows. Push button 30 is dropped through the aperture 27 of the outer member 14 from the interior; meanwhile the dropper bulb 35 is pressed over the abutment ring 26, and the dropper tube 40 is pushed into the bulb 35. The inner member 12 is then pressed into the outer member 14, snapping the rib 16 of the inner member 12 over the rib 17 of the outer member 14. Alternatively, installation of the dropper tube 40 may be carried out as an optional operation after press-fitting the inner member within the outer member.

Claims

CLAIMS:

1. A child resistant closure comprising an inner member threaded for engagement with a complementary thread of a receptacle, an outer member captively engaged with the inner member, rotatable relative to the inner member about the thread axis and arranged to enclose the inner member to prevent access thereto, engagement means being provided for releasable engagement of the outer member and the inner member for rotation of the outer member and inner member in unison in the closing direction, and a resilient dropper bulb being provided within the inner member and adapted to receive a dropper tube extending in use into a receptacle, said dropper bulb being arranged to urge the engagement means into the released condition.

2. The closure of claim 1 wherein the dropper bulb urges the inner member and outer member apart.

3. The closure of claim 1 or claim 2 wherein the dropper bulb is arranged co-axially with the inner member.

4. The closure of any preceding claim wherein the dropper bulb projects through the outer member to allow access to said bulb for the purpose of dispensing drops of a liquid.

5. The closure of any preceding claim wherein the engagement means is urged into the engaged position by axial movement of the outer member relative to the inner member.

6. The closure of any preceding claim wherein the engagement means comprises complementary dogs of the inner and outer members.

7. The closure of any preceding claim further comprising ratchet means to engage the inner and outer members for rotation in unison in the closing direction, while slipping in the opening direction.

8. The closure of any preceding claim wherein the outer member comprises relief features of the exterior of said member to facilitate gripping thereof by a user.

9. The closure of any preceding claim wherein the inner and outer members are of plastics material.

10. The closure of any preceding claim further comprising a cap captively engaged between the dropper bulb and the outer member, and axially movable relative to the outer member, axial movement of the cap being operative to squeeze the dropper bulb for dispensing.

11. The closure of claim 10 wherein a skirt of the cap partially encloses the dropper bulb.

12. The closure of claim 10 or claim 11 wherein the dropper bulb urges the cap into abutment with the outer member, consequently urging the outer member and inner member apart.

13. The closure of any one of claims 10 to 12 wherein the cap is of plastics material.

14. A child resistant closure substantially as described herein with reference to the accompanying drawing.

Amendments to the claims have been filed as follows

1. A child resistant closure comprising an inner member threaded for engagement with a complementary thread of a receptacle, an outer member captively engaged with the inner member, rotatable relative to the inner member about the thread axis and arranged to enclose the inner member to prevent access thereto, engagement means being provided for releasable engagement of the outer member and the inner member for rotation of the outer member and inner member in unison in the opening direction, and a resilient dropper bulb being provided within the inner member and adapted to receive a dropper tube extending in use into a receptacle, said dropper bulb being arranged to urge the engagement means into the released condition.