AU725139B1 - Improvements in child resistant caps - Google Patents

Description

PATENTS ACT 1990 COMPLETE SPECIFICATION.

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Priority Related Art: Name of Applicant: TO BE COMPLETED BY APPLICANT Vere Athol Williamson, Address of Applicant: 27 Anzac Street, GREENACRE NSW 2190 Actual Inventor: AS ABOVE Address for Service: ANDERSON-TAYLOR ASSOCIATES, Registered Patent Attorneys of 10 Harrison Avenue BONNET BAY N.S.W. 2226 Complete Specification for the invention entitled: IMPROVEMENTS IN CHILD RESISTANT CAPS The following statement is a full description of this invention, including the best method of performing it known to me: -1- This invention relates to safety caps which prevent the inadvertent opening of bottles or other containers by children. More particularly it is concerned with caps comprising an inner closure member which removably seals the mouth of a container and an outer cowling which fits over the closure member.

With known prior art child resistant safety caps the cowling is normally fitted over the closure member in such a way that it may be moved from a first position at which it is freely rotatable relative to the closure to a second position at which it engages this member. A biasing mechanism is also provided which urges the cowling to its disengaged position.

The nature of the operation however is such that the cowling must be depressed and held in engagement not only to unscrew the inner closure member but also to tighten it onto the bottle.

While it is known (for example in the case of US patent 5316161) to provide a cap in which the outer cowling need not be depressed to screw the closure member onto the bottle the use of cantilevered spring pawls in such caps leads to weakness and failure of the biasing mechanism.

It is an object of the present invention to ameliorate the aforementioned disadvantage and accordingly.a child resistant safety cap is disclosed having a threaded inner closure member adapted to removably seal the mouth of a container, a cowling fitted over the closure member and movable relative to said closure member between a first position wherein said cowling engages lugs on said closure member when turned in a first rotational direction only to screw said closure member onto said mouth and a second position at which.said closure member is.engaged by said cowling in a second opposite rotational direction to enable said closure member to be unscrewed and an inclined cam surface on one of said closure member and cowling which engages a shoulder'on the other of said closure member and cowling to biase said cowling to said first position and said shoulder being squared off whereby upper and lower surfaces thereof intersect with an outer shoulder surface at substantially right angles.

Preferably said shoulder means rides up said cam surface as said cowling is moved to said second position.

The currently preferred form of the invention will now be described with reference to the attached drawings in which: Figure 1 is a schematic elevational view of the inner closure member.

Figure 2 shows a cross-sectional elevational view of the closure member of figure 1, Figure 3 shows a plan view of the closure member of figure 1, Figure 4 shows a cross-sectional elevational view of the cowling, Figure 5 shows an underside view of the cowling, Figure 6 shows a cross-sectional view of the assembled cap with an eyedropper incorporated therein, and Figures 7, 8 and 9 show side, elevation and crosssectional views of a second embodiment of the invention.

Referring first to figures 1, 2, 3 and 6 the closure member indicated generally as 1 is provided with screw threads 1A around the inside of the skirt 2 to mate with corresponding threads 3 on a medicine bottle 4. A series of lugs 5 are formed around the top surface 6 of the closure member. Each lug preferably comprises substantially vertical end faces and 5B, inclined top surface 5C and horizontal top surface into which the inclined surface 5C merges.

Turning now to the cowling 7, as best shown in figure 4 this is shaped to fit over the closure member and is formed with a series of teeth 8 around the inner face 9. These teeth are positioned and shaped to engage the aforementioned lugs 5 in the assembled cap. More specifically, each tooth preferably comprises substantially vertical end faces 8A and 8B, an inclined bottom surface 8C and a horizontal bottom surface 8D into which the inclined surface 8C merges.

With this embodiment there are also central apertures 9A and 9B in the closure member and cowling to accomodate an eyedropper 9C.

With the cowling 7 fitted onto the closure member 1 in the position shown in figure 6 the end faces 8A of the teeth engage the end faces 5A of the lugs. Clockwise torque is thereby transmitted from the cowling -to the closure member to enable the cap to be screwed onto the bottle 4. Rotation inthe opposite direction however causes the inclined surfaces 8C of the cowling teeth to slide over the inclined lug surfaces 5C of the closure member so that no significant anticlockwise torque, is transmitted. Therefore, once the cap is screwed onto the bottle it cannot be subsequently removed so long as the cowling and closure member are in the position shown in figure 6. To remove the cap the cowling must be pushed down so that a shoulder 10 formed around the outside of the closure member rides up inclined cam surfaces 11 on the inside of the cowling and the vertical teeth end faces 8B engage the vertical lug faces 5B. In this depressed position the cowling grips the closure member so that anticlockwise torque can turn it off the bottle. To accomodate this downward movement the cowling and/or the closure member are stressed to deform resiliently.

To minimise sliding friction between the shoulder and cam surfaces and prevent binding the shoulder is squared off whereby the upper and lower surfaces 10A and 10B intersect with the outer shoulder surface 10C at substantially right angles.

Once downward pressure on the cowling ceases however it is biased up to the rest position of figure 6 by the shoulder riding back down the cam surface 11. In order to achieve this spring bias the cowling and closure member are formed from a resiliently deformable material. In this case polypropylene may be used although the invention extends to other materials.

The aforementioned biasing mechanism has been found to be much more robust and servicable than the cantilevered spring pawls described in the prior art.

A series of spacing ribs 12 are also preferably moulded around the inside periphery of the cowling to centre it on the closure member. There is also a circular ridge 13 around the base of the cowling. This provides a snap fit engagement for the cowling over the closure member and holds the assembed cap together.

With the second embodiment of the cap shown in figures 7 to 9 the main components that correspond in function to those of figures 1 to 6 are marked by the same numbers but with the addition of an accent There is a tear off ring 14 fitted below the closure member. This ring is moulded as one piece with the closure member and is connected thereto by frangible ribs 15. There are also clips 16 formed around the inside surface of the ring which snap fit over a ridge 17 on the bottle neck during initial fitting of the cap. Once so fitted the ring cannot be removed with normal use and if the cap is unscrewed the ribs 15 must break to thereby provide evidence of, for example, tampering prior to sale It will thus be appreciated that this invention at least .in the form of the example described comprises a novel and useful improvement over existing child resistant caps.

Clearly however the embidiment disclosed is only the currently preferred form of this invention and a wide variety of modifications may be made which would be apparent to a person skilled in the art. For: example the cap may be modified to fit different types of containers and may be adapted for use without an eyedropper by fitting inserts to close the apertures 9A and 9B. The shape and configuration of the cowling teeth. the lugs on the closure member and the biasing cam may also be changed according to design preference For the purposwes of this specification expressions such as "down", "lower". "bottom" and "top" etc. refer to the cap in a position of use as illustrated and are not to be read as necessarily limiting.

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Claims (11)

1. A child resistant safety cap having a threaded inner closure member adapted to removably seal the mouth of a container, a cowling fitted over the closure member and movable relative to said closure member between a first position wherein said cowling engages -lug means on said closure member when turned in a first..rotational direction only to screw said closure member onto said mouth and a second position at which said closure member is engaged by said cowling in a second opposite rotational direction to enable said closure member to be unscrewed and an inclined cam surface on one of said closure member and cowling which engages a shoulder on the other one of said closure member and cowling to biase said cowling to said first position and said shoulder being squared off whereby upper and lower surfaces thereof intersect with an outer shoulder surface at substantially right angles.

2. The cap as claimed in claim 1 wherein in use of said cap pushing the cowling downward onto said container moves said cowling from said first position to said second position.

3. The cap as claimed in claim 2 wherein said lug means comprise a plurality of lugs which are.arranged around a top surface of the closure member -and have inclined surfaces whereby at said first position teeth means on the underside of said cowling engage end faces of said lugs when said cowling is turned in said rotational direction and when said cowling is turned in said opposite' rotational direction said teeth means slide over inclined surfaces of said lugs.

4. The cap as claimed in claim 3 wherein said teeth means comprise a plurality of teeth arranged around an underside surface of said cowling, said teeth having inclined surfaces which at said first position when said cowling is turned in said opposite rotational direction slide over the inclined surfaces of said lugs.

The cap as claimed in .claim 4 wherein at said second- position end faces of said teeth engage said end faces of the lugs when said cowling is turned in either of said rotational directions.

6. The cap as claimed in claim 5 wherein the inclined surfaces of said lugs and teeth merge into horizontal surfaces.

7. The cap as claimed in claim 6 wherein ribs are moulded around the inside periphery of the cowling to centre said cowling on the closure member.

8. The cap as-claimed in claim 7 wherein a ridge is formed around the base of the cowling to provide a snap fit engagement of said cowling over the closure member and hold the assembled cap together.

9. The cap as claimed in claim 8 and including a ring provided below said closure member, said ring being adapted for non-removable attachment about a neck of said container during initial fitting of said cap whereby any subsequent opening of said container prior to sale separates said ring to provide evidence of tampering.

A child resistant safety cap, said.c.ap being substantially as described herein with reference to the drawings.

11. A container which is fitted with a child resistant safety cap as claimed in any one of claims 1 to 9. Dated this day of JULZ 2000 Vere Athol Williamson By His Patent Attorney MICHAEL ANDERSON-TAYLOR V,/ ;1)