WO2001068470A1

WO2001068470A1 - Closure device for the diffusion of aroma

Info

Publication number: WO2001068470A1
Application number: PCT/GB2001/000902
Authority: WO
Inventors: Brian Slade
Original assignee: Brian Slade
Priority date: 2000-03-16
Filing date: 2001-03-01
Publication date: 2001-09-20
Also published as: AU2001235834A1

Abstract

A container closure (10) is provided with a device for dispensing a dose of aromatic material each time the container (2) is opened. The material is held in a body (30) in an enclosure (20) bounded by a diaphragm (16) mounted on the closure. The enclosure is almost sealed but it has a restricted external communication (40). When the closure is secured to the container the diaphragm is displaced to increase the enclosure volume. Aromatic material diffusing into the increased volume is released through the restricted communication when the container is opened and the diaphragm returns to its original position. By these means it is possible to compensate for loss of aroma from the container contents as a result of continual opening of the container.

Description

CLOSURE DEVICE FOR THE DIFFUSION OF AROMA

This invention relates to devices for releasing a volatile material as a gas or vapour. It is a feature of many types of prepackaged consumer products that an aroma of the product is noticeable when the product container is first opened. If the contents of the container are consumed only gradually, however, for many products the continual reopening of the container results in this effect being considerably weakened or even lost, long before the container has been emptied, because the contents are exposed each time it is opened.

It is an object of the present invention to provide means that can at least mitigate this effect.

According to one aspect of the invention, there is provided a container closure device having means for release of a volatile material in the use of the container, the closure device carrying a substrate or body holding the material and having a boundary member defining an enclosure occupied by said substrate or body and by a free space, said boundary member being movable to vary the free space in the enclosure, restricted communication from the enclosure permitting air with taken-up volatile material to be expelled when said space is contracted, and air to be admitted to take up further volatile material when said space is expanded.

Preferably the boundary member is arranged to be moved by the displacement of the closure device relative to the container to open and close the container, thereby automatically releasing some of the volatile material into the surrounding each time the container is opened. Typically, the volatile material will be chosen to match the aroma that is sensed when the container is first opened. That is to say, for a jar of coffee, a volatile material giving a coffee smell will be used so that even after repeated opening has allowed much if not all of the original aromatic substances in the contents of the container to be dissipated, the user will experience an aroma similar to that released when the container was first opened. In the case of a cleaning product, the chosen material may be a fragrance that is a component of the original contents of the container so that even as the fragrance mixed into the container contents is exhausted, the aroma continues to be released each time the container is opened to mask the less attractive smell that the active cleaning components may have. There may be instances, however, when matching is not required, for example when the original contents of the container are not themselves aromatic.

For many applications, a closure device according to the invention will be arranged so that the enclosure free space is contracted when the container is opened. It is however possible to arrange the operation in a reverse manner, the space contracting on closure to expel volatile material into the main body of the container, and expanding on opening, where that is appropriate.

More generally, the ability to release doses of a volatile material may be employed in other applications than with the closure devices of containers, and in another aspect of the invention there is provided a device for release of a volatile material from a substrate or body holding said material, the device comprising an enclosure within which said substrate or body is received and which has a restricted communication with the exterior, said enclosure also having a free space which is contractable from a first larger volume in a dormant or priming phase of the operation of the device, to a second smaller volume in an active or discharge phase, whereby a fluid carrier medium, such as air, is brought into contact with said substrate or body to take up material therefrom in the priming phase and a volume of said medium is emitted through said restricted communication, with volatile material it has taken up, in the discharge phase as the volume contracts. Embodiments of the invention will be described in more detail by way of example with reference to the accompanying drawings, in which:

Figs. 1 and 2 are cross-sectional views of a container with a screw-top closure cap comprising a dosing device according to the invention, the respective figures illustrating the device in alternative positions, and

Fig. 3 is a similar view showing a modified form of the dosing device.

Referring to Figs. 1 and 2, the container body 2 shown only partially can be entirely conventional. It has a cylindrical mouth 4 with a screw thread 6 on its external face. A closure cap 10 has a peripheral wall 12 with a mating screw thread 14 on its inner face to secure it to the container mouth 4 in order to seal the contents of the container.

Within the cap 10 a diaphragm 16 is mounted close to, but spaced from the inner top face of the cap to form an enclosure 20 within the cap. The diaphragm 16 has an annular rib 22 with a wedge-form cross-section that is gripped in a sealing manner in an annular groove 24 formed between a pair of concentric ribs 26 projecting from the inner wall, so locking the diaphragm to the cap. Within the space enclosed between top wall of the cap, the diaphragm 16 and the rib 22, and lying close to the rib, is a toroidal body 30 which has been impregnated with a volatile aromatic material. With the cap 10 unscrewed or removed from the container the diaphragm 16 springs to the upwardly convex dome-like form shown in Fig. 1. When the cap is screwed down onto the container mouth 4, the outer rim 16a of the diaphragm, beyond the rib 22, is engaged by the top face of the container mouth and is displaced upwards, the diaphragm then being held flexed in the downwardly convex form shown in Fig. 2. The free space 32 of the enclosure 20 is thus substantially increased by the deformation of the diaphragm when the container is closed. When the cap 10 is removed again, the internal stresses in the diaphragm 16 return it to the position shown in Fig. 1. Material diffusing from the body 30 into the enclosed free space 32 can escape only through a very small restricted orifice 40 in the diaphragm 16, so that there will be little leakage of the material while the diaphragm remains fixed in either of the positions illustrated. However, when the cap is screwed down to seal the container, the volume of the free space 32 is increased as the diaphragm is flexed downwards, drawing air into the enclosure 20 through the orifice 40. While in this dormant or priming state, volatile material continues to diffuse from the body 30 into the air trapped in the enclosure until an equilibrium state is reached. When the cap 10 is unscrewed again, the diaphragm 16 snaps over to the original upwardly convex position shown in Fig. 1 in an active or discharge phase and the contraction of the space expels air through the orifice 40, with the volatile material it now carries.

Each time the user opens the container, a further dose of the volatile material from the body is thereby released into the atmosphere.

Once the free space 32 has been contracted there is minimal diffusion of the volatile material from the enclosure through the orifice 40. It is not critical therefore if the cap is not replaced immediately, although volatile material from the main body of the container can then escape freely.

Since the diaphragm 16 undergoes the same displacement between the primary and discharge states each time the cap 10 is replaced and removed, a similar amount of the volatile material will be released on each occasion. The orifice 40, which may be no more than a pinhole, is small enough to allow only a negligible rate of leakage while the diaphragm position remains fixed.

In the example of Fig. 3, parts corresponding to those already described are indicated by the same reference numbers. Cap 10a differs from the cap 10 only in that it is provided with an internal annular shoulder 48. In place of the toroidal body 30 there is now a disc-form body or substrate 50 impregnated with the volatile material and the disc is covered by a semi- permeable membrane 52 sealed to the inner of the pair of annular ribs 26.

The use of the membrane 52 to enclose the body carrying the volatile material can prolong the shelf life of the device. The shoulder 48 limits the deflection of the diaphragm to a pre-set position when the lid is screwed down and allows an increased sealing pressure to be applied at the rim of the diaphragm. Each of these modifications can of course be employed independently of the other.

As a further, unillustrated modification, it may also be arranged in a container closure so that the volatile material is released into the main volume of the container when it is sealed and the enclosed space is expanded when the closure member is released, if required.

It will be understood that a dispensing device according to the invention can be arranged in many other ways than that shown in the illustrated example. For example, when embodied in a container closure, that closure may take other forms than the screw cap shown. It may also be constructed as a low cost stand- alone device, eg. to provide samples of a fragrance. Using a snap-over diaphragm as in the illustrated examples, such a device can be operated by squeezing between finger and thumb.

Claims

1. A closure device for a container, having means for release of a volatile material in the use of the container, the closure device carrying a substrate or body holding the material and having a boundary member defining an enclosure occupied by said substrate or body and by a free space, said boundary member being movable to vary the free space in the enclosure, restricted communication from the enclosure permitting air with taken-up volatile material to be expelled when said space is contracted, and air to be admitted to take up further volatile material when said space is expanded .

2. A device according to claim 1 wherein the boundary member is displaced by the action of opening or closing the container to release said volatile material .

3. A device according to claim 1 or claim 2 wherein said boundary member is arranged to contract said space when the container is open and to expand the space when the container is closed.

4. A device according to any one of claims 1 to 3 wherein the boundary member comprises a diaphragm or plate member having a first relaxed position and a second constrained position when engaged in the closure of the container.

5. A device according to any one of claims 1 to 4 wherein a peripheral region of the plate member is engageable by a mouth of the container over which the closure member is applied.

6. A device according to claim 5 wherein said body or substrate is in the form of a ring member concentric with the container mouth.

7. A device according to claim 6 wherein the plate member is supported on the closure device by spacing means adjacent said ring member.

8. A device according to any one of the preceding claims wherein the substrate or body is enclosed by a semi-permeable membrane.

9. A container provided with a closure device according to any one of the preceding claims .