Field of the Invention

The present invention relates to a flexible plastic container for liquid and a method of dispensing a predetermined volume of liquid from a container.

The present invention has been developed primarily for bottles dispensing laundry liquids. However, the intention is not limited to that particular use and also finds application in bottles dispensing a wide range of liquids, including but not limited to car wash liquids and polishes, sauces, dessert toppings, cordials, hand and body liquid soaps, shampoos, liquid medications, liquid fertilisers, disinfectants, washing up detergents, and industrial products.

Background of the Invention

Many liquids are packaged in flexible plastic bottles, typically manufactured using blow moulding. To dispense liquids from these bottles, typically either the closure is opened and the bottle manually squeezed, and the liquid flows out by displacement, and the displaced liquid replaced with incoming air when the pressure is released, or alternatively the bottle is inverted, and the liquid flows out under gravity. Neither of these approaches allows the user to accurately or repeatedly dispense a predetermined volume of liquid.

There are several known approaches for accurate dispensing of liquids from flexible plastic bottles. One approach is to use a measuring cup screw cap closure known as a drainback - see for example US Patent Nos. 2,061,685, 4,917,268, and 5,108,009. There are several disadvantages with this approach. The first is the need to carefully dispense a measured amount of the liquid into the cap, which requires time, a certain level of manual dexterity, and is difficult for people with poor eyesight. Another is that the remaining liquid in the cup often drips down the container and forms an unsightly and sticky residue on the outside of the bottle. Additional inserts into the neck of the bottle used to reduce dispensing and drip problems are known - see US Patent No. 3,628,697, but this incurs additional cost. It has been found that 53% of USA consumers do not use the appropriate amount of laundry liquid, often avoiding the use of the supplied measuring caps and overusing the more concentrated and expensive modern laundry liquids, which can lead to laundry liquid residues building up inside washing machines. Another approach for dispensing accurate doses of liquids from bottles has been to utilise a pump pack. Pump packs are expensive, and are not suitable or reliable for many liquids.

Another approach is to use a multi-chamber container. These are also expensive, difficult to operate, and are also not suitable for many liquids.

Object of the Invention

It is the object of the present invention to substantially overcome or at least ameliorate one or more of the above known disadvantages.

Summary of the Invention

Accordingly, in a first aspect, the present invention provides a flexible plastic container for dispensing liquids, the container including:

at least first and second opposed walls; and

a first inwardly directed protuberance associated with, or forming part of, at least the first wall and adapted to contact the second wall in response to squeezing together of the first wall and the second wall in order to cause a predetermined internal volume change in the container.

The container preferably includes a second inwardly directed protuberance associated with, or forming part of, the second wall and adapted to contact the first wall, or the first inwardly directed protuberance, in response to the squeezing together of the first wall and the second wall in order to cause the predetermined internal volume change in the container.

The container preferably includes a pair of the first inwardly directed

protuberances associated with, or forming part of, at least the first wall, each adapted to contact the second wall in response to squeezing together of the first wall and the second wall, wherein one of the first pair causes one predetermined internal volume change in the container and the other of the first pair causes another predetermined internal volume change in the container.

The container preferably includes a pair of second inwardly directed

protuberances associated with, or forming part of, the second wall adapted to respectively contact the first wall, or the pair of the first inwardly directed protuberances, in response to the squeezing together of the first wall and the second wall, wherein one of the second pair causes a predetermined internal volume change in the container and the other of the second pair causes another predetermined internal volume change in the container. The first inwardly directed protuberance(s) is/are preferably in the form of a first outwardly concave or inwardly convex indentation(s) in the first wall, most preferably formed or moulded into the first wall.

The second inwardly directed protuberance(s) is are preferably in the form of a second outwardly concave or inwardly convex indentation(s) in the second wall, most preferably formed or moulded into the second wall.

In a second aspect, the present invention provides a method of dispensing a predetermined volume of liquid from a container, the container including an outlet, at least first and second opposed walls and a first inwardly directed protuberance associated with, or forming part of, at least the first wall, the method including squeezing together the first wall and the second wall until the first inwardly directed protuberance contacts the second wall.

The container preferably includes a second inwardly directed protuberance associated with, or forming part of, the second wall and the method preferably includes squeezing together the first wall and the second wall until the second inwardly directed protuberance contacts the first wall, or the first inwardly directed protuberance.

In an third aspect, the present invention provides a flexible plastic container for dispensing liquids, the container including at least first and second opposed walls, the first wall including a first inwardly directed indentation adapted to contact the second wall in response to squeezing together of the first wall and the second wall in order to cause a predetermined internal volume change in the container.

In a fourth aspect, the present invention provides a flexible plastic container for dispensing liquids, the container including at least first and second opposed walls, the first wall including a first inwardly directed indentation, the second wall including a second inwardly directed indentation, the first and second indentations adapted to contact each other in response to squeezing together of the first wall and the second wall in order to cause a predetermined internal volume change in the container.

In a fifth, a liquid bottle in accordance with this invention comprises a flexible plastic bottle with one or more pairs of indentations on opposite sides of the bottle. When manually squeezed, these indentations touch, and resistance is experienced by the user. The spacing between these indentations is such that the volume of liquid displaced when the bottle is squeezed from the resting position to when the indentations touch and resistance is experienced by the user is the amount required to be dispensed. If different amounts of liquid are required to be dispensed, then two or more pairs of indentations could be made with different gaps at different locations in the bottle to dispense the different amounts of liquid. Labelling on the bottle and/or markings moulded on the bottle mould would indicate the different areas of the bottle to be squeezed to dispense the desired different amounts of liquid.

Another variation could be for a deeper indentation on only one side of the plastic bottle, with the opposite side of the bottle left undented, making labelling easier. To dispense the required amount of liquid the user would squeeze the bottle until the indentation touches the opposite undented wall of the container and resistance is experienced. An additional advantage of this method is that user may feel the indentation pressing against the undented wall of the container, providing additional feedback to the user that the appropriate amount of liquid' has been dispensed.

If a bottle incorporating indentations in accordance with this invention was required to dispense liquid in the upright position, the closure could incorporate a tube down into the liquid, possibly with a non-return valve.

The indentations in accordance with this invention could be left exposed, or could be covered by the product labelling.

These indentations in accordance with this invention could be made during the manufacture of the bottle, by such means as modifying the shape of the blow mould, or after manufacture of the bottle.

A bottle incorporating indentations in accordance with this invention could also be mechanically squeezed, such as in an automated hand wash dispenser.

Detailed Description of the Drawings

Preferred embodiments of the invention will now be described, by way of examples only, with reference to the accompanying drawings in which:

Fig. 1 is a front view of a first embodiment of a flexible plastic container;

Fig. 2 is a schematic cross-sectional side view of the container shown in Fig. 1 ;

Fig. 3 is a schematic cross-sectional side view of the container shown in Fig. 1, after squeezing to dispense a predetermined volume of liquid;

Fig. 4 is a front view of a second embodiment of a flexible plastic container;

Fig. 5 is a schematic cross-sectional side view of the container shown in Fig. 4;

Fig. 6 is a schematic cross-sectional side view of a third embodiment of a flexible plastic container; Fig. 7 is a schematic cross-sectional side view of container shown in Fig. 6, after squeezing to dispense a predetermined volume of liquid; and

Fig. 8 is a front view of a fourth embodiment of a flexible plastic container.

Detailed Description of the Preferred Embodiments

Fig. 1 is a front view of a first embodiment of a flexible plastic container in the form of an inverted flexible plastic bottle 10 for containing a liquid laundry detergent 11 (see Fig. 2). The bottle 10 is shown held by a hand H. The bottle 10 includes a first protuberance in the form of a first inwardly convex indentation 12 in a first side wall 14. The indentation 12 may be covered by a label. The bottle 10 also includes a flip top closure 16, shown in the open position.

Fig. 2 shows that the bottle 10 also includes a second protuberance in the form of a second, correspondingly located, inwardly convex indentation 18 in a second side wall 20, which is opposed to the first side wall 14. A gap 22 is left between the innermost regions of the indentations 12 and 18 when the bottle 10 is at rest (ie. uncompressed or not squeezed). The extent of the gap 22 is set during the manufacture of the bottle 10, typically using blow-moulding techniques, such that the volume of liquid displaced as the indentations 12, 18 touch and resistance is experienced by the user is a predetermined or the desired amount, as will be explained in more detail below.

Fig. 3 shows the bottle 10 after it is manually squeezed by the hand H such that the innermost regions of the indentations 12 and 18 make contact. The resistance of this contact is felt by the user and they are thus made aware that the sides of the bottle 10 have been inwardly squeezed to the full extent possible. The amount that the bottle 10 can have its internal volume reduced by squeezing before the indentations 12 and 18 make contact is set by size of the gap 22 and the shape of the indentations 12, 18. This in turn results in a predetermined and repeatable volume of liquid being dispensed from the bottle's closure 16, per squeezing action.

Upon release of the hand pressure on the bottle 10, the bottle 10 elastically rebounds to its original shape, as shown in Fig. 2, as air enters the bottle 10 replaces the volume of the dispensed liquid.

Figs. 4 and 5 show a second embodiment of a bottle 30, which is constructed and operates similar to the bottle 10. Like features to the bottle 10 are indicated with like reference numerals. However, the first side 14 of the bottle 30 includes two indentations 32a and 34a and the second side 18 includes two correspondingly located indentations 32b and 34b. The respective gaps 36 and 38 between the two indentations pairs 32a and 32b and 34a and 34b respectively are different. The gap 38 is smaller than the gap 36. As a result, squeezing the bottle in the region of the indentation pair 32a and 32b, until the larger gap 36 is closed, will dispense a larger volume of liquid when compared to the smaller amount dispensed by squeezing the bottle in the region of the indentation pair 34a and 34b until the smaller gap 38 is closed. This allows a user to select between dispensing two different (ie. a larger and a smaller) volumes.

The bottle 30 can include a label and/or markings moulded thereon to indicate the different regions of the bottle that are to be squeezed to dispense the different amounts of liquid.

Figs. 6 and 7 show a third embodiment of a bottle 40, which is constructed and operates similar to the bottle 10. Like features to the bottle 10 are again indicated with like reference numerals. However, the bottle 40 includes only one indentation 42 in the first side wall 14. In this embodiment, volume dispensed per squeezing acutation is related to gap 44 between the indentation 42 and the second opposed wall 18. Again, the gap 44 is set during the manufacture of the bottle 40, typically using blow-moulding techniques, such that the amount of liquid displaced before the indentation 42 and the undented wall 18 of the bottle 40 make contact and resistance is experienced by the user, and/or the indention 42 is felt on the undented wall 18 of the bottle 40 by the user, is the predetermined, repeatable and desired amount. The second wall 18 of the bottle 40 is also available for marking or labelling without having to cover or avoid any indentations.

Fig. 8 shows a fourth embodiment of a bottle 50 which is constructed and operates similar to the bottle 10. Like features to the bottle 10 are again indicated with like reference numerals. However, the first side of the bottle 50 includes two indentations 52 and 54. The bottle 50 also includes a closure 56. The closure 56 includes a dip tube 58 into the liquid, a one-way valve 60 and a dispensing spout 62. The closure 56 allows the bottle 50 to effect liquid dispensing when the bottle is squeezed whilst in the upright position. The indentations 52 and 54 are sized to each provide a differing dispensed volume per squeezing action.

The advantages of dispensing liquids using the embodiments of flexible plastic bottles described above include:

• The ability to dispense a desired amount of liquid from a container by the

relatively inexpensive incorporation of indentations into the shape of the flexible plastic bottle during manufacture, and without the need for additional and expensive drainback closures or pump packs. • The ability to easily dispense different amounts of liquid from the same container through incorporating indentations at different areas of the bottle with different gaps. This negates the need to have graduated measuring caps with different doses, or the need to dispense multiple capfuls or pumps.

• The making the use of inverted closures, such flip cap closures, practical for a range of liquids. This also allows for bottles that rest on their closure (known as tottles) to be used, which allows for thicker liquids to always drain to the closure, providing for immediate use without having to wait for the liquid to flow when the bottle is inverted for dispensing, and minimising liquid wastage when the bottle is discarded.

• The limiting nature (ie. until the gap is closed) of the squeezing of the bottle reduces accidental or undesirable overuse of liquids. It will also limit potential excessive deformation of the squeeze bottle, making rupture or permanent deformation of the bottle during use less likely.

• The indentations are likely to be made of the same material as and are integral with the bottle, increasing the recyclability of the package after use.

Although the invention has been described with the preferred embodiments, it will be appreciated by persons skilled in the art that the invention can be embodied in many other forms.

For example, the bottle could be designed and shaped such that the user is likely to squeeze the bottle at or adjacent to the indentations, increasing the accuracy of the liquid dose dispensed.

Also, the shape of the end of the indentations could be shaped such that they suddenly invert when they are brought into contact, providing additional feedback to the user that the required dose of liquid has been dispensed.

Another approach is to allow the indentation to be seen through the clear or translucent undented wall of the bottle, providing a visual indication that the required dose has been dispensed.

Another possible modification is to insert a spring on the end of the indentations to assist the flexible bottle to return to its original shape.