BACKGROUND

The present invention relates to a container wherein the volume of the container can be varied so as to minimise the amount of air in the container.

Containers are generally of fixed volume. It is usually necessary to have a number of containers of different sizes as it is well known that food will last longer if its contact with air is minimised. Also having containers larger than is necessary sometimes presents a problem, especially when space is at a premium.

Another problem often encountered is that of aerated drinks going "flat" or losing carbonation when stored. This is a result of the gas escaping from the drink into the neighbouring air.

It is an object of this invention to provide a container having a variable volume which will attempt to overcome the above disadvantages, or which will at least provide the public with a useful alternative choice.

According to one aspect of the present invention there is provided a container comprising an inner flexible member substantially enclosed in a number of interlocking outer sleeves, wherein the volume of the inner flexible member container can be varied by moving at least one outer sleeve relative to another outer sleeve.

The interlocking sleeves can be screw threaded together so that by twisting the sleeves relative to each other the volume of the member can be varied.

The interlocking sleeves can alternatively move relative to each other by means of a ratchet. An upper sleeve can include at least two series of externally projecting teeth. A handle on a lower sleeve can be provided to act as a pawl for each series of externally projecting teeth. To decrease the volume of the container, the upper sleeve can be pushed downwards towards and into the lower sleeve. To release the sleeves and hence to increase the volume of the container, the handles can be used, or the upper and lower sleeves can be rotated relative to each other.

The interlocking sleeves can alternatively move relative to each other by means of a multi-level bayonet connection. The multi-level bayonet connection alternatively is formed by providing in either an upper or lower sleeve opposed grooves, each set of grooves comprising a plurality of transverse grooves connected by a longitudinal groove. At least two pin members can extend from the adjacent lower sleeve or upper sleeve to fit one into each set of grooves in the other sleeve. Rotation of the upper and lower sleeves causes the transverse pins to move in the transverse grooves to the longitudinal groove and hence to vary the volume of the container in a push/pull and twist action.

The inner flexible member can be fixed to the base of the lower sleeve by means of a pin. The inner flexible member can be welded to the upper sleeve.

Alternatively, a lip of the inner flexible member can protrude through an opening in the container, hence providing a seal between the inner flexible member and a cap. This allows the inner flexible member to be removed completely from the outer sleeves.

The inner flexible member can be concertina or balloon-like.

The container can be sealed by means of the cap, the cap including a threaded skirt with a float mounted therein. The float has a skirt mounted thereon or formed integrally therewith and a button section. As the volume of the container is decreased by moving one outer sleeve relative to another outer sleeve, air can escape through a passage between the outer edge of the skirt and inner surface of the cap and threaded skirt. Once a liquid or other flowable material reaches the float, the float rises, gradually shutting off the escape of air when the skirt contacts the inner surface of the cap.

According to a further aspect of the invention, there is provided a variable volume container comprising an exterior casing with an inner flexible bladder, the internal volume of which is adjusted by moving one end of the bladder by any suitable means so that in use the volume of the flexible bladder and the volume of its contents are substantially the same.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the invention will become apparent from the following description which is given by way of example with reference to the accompanying drawings in which:

Figure 1 shows a vertical sectional view of the container according to one embodiment of the present invention;

Fi ^g ure 2 shows a sectional view of one half of the cap according to one embodiment of the present invention;

Figure 3 shows a cross-sectional view of a container according to another embodiment of the invention; and

Fi ^g ure 4 shows a cross-sectional view of a container according to a further embodiment of the invention.

DETAILED DESCRIPTION

In the example seen in Figure 1 , the container 10 includes an inner flexible member 1. This inner member 1 is concertina, and permanently attached to upper sleeve 14. The inner member 1 is attached by a pin 2 to the bottom sleeve 3, allowing the bottom sleeve 3 and inner member 1 to rotate independently. The bottom sleeve 3 and upper sleeve 14 have the same diameters, and both have an internal thread. The height of the bottom sleeve 3 and upper sleeve 14 is substantially one sixth of the height of the container when fully extended.

Bottom sleeve 3 interlocks with section 4. Section 4 is threaded on both sides, so as to interlock with bottom sleeve 3 and centre section 5. A similar section 4' to section 4 fits between centre section 5 and upper sleeve 14. Sections 4 and 4' are substantially one sixth of the container height when fully extended, and centre section 5 is substantially one third of the height of the container when fully extended.

The uppermost internal thread 6 in each section of sleeve 3 and 4 and the lower most internal thread 6' of each section 4' and 14 has a different smaller thread contour to the remaining thread. Conversely, the lower most external thread 7 in each section 4 and 5 and the uppermost external thread 7' in each section 4' and 5 has greater thread contours. The combination of these contours prevents the threaded sections 3, 4, 4', 5 and 14 from separating because of frictional engagement therebetween.

Thus, the threaded sections and sleeves 3, 4, 4', 5 and 14 can be screwed downwards to one third of the container's full height. When the threaded sections 3, 4, 4', 5 and 14 are screwed upwards, the full container height is achieved and the sizes of threads 6 and 7 prevent the sections and sleeves 3, 4, 4', 5 and 14 coming apart.

At the top of upper sleeve 14, there is an external threaded opening 15, onto which a cap 9 fits. The cap 9 includes a threaded skirt 8, skirt 13 and float 1 1. The threaded skirt 8 interlocks with threaded opening 15.

Figure 2 shows part of the cap 9. When the sections and sleeves 3, 4, 4', 5 and 14 are screwed down to reduce the volume of the container 10, air can escape from the container 10 by way of passage 12 between threaded skirt 8 and skirt 13. The lowering of cap 9 causes float 1 1 to come into contact with and float on any liquids or other flowable material in the member 1 . This gradual rising of float 1 1 , and consequentially skirt 13, causes passage 12 to be blocked and the container 10 to be sealed. Any further internal pressure, either from further reducing the internal volume or gases escaping from the liquid, will increase the sealing effect of the cap 9.

If the skirt 13 ever jams up against closure 8, finger pressure on button section 16 will open the cap and allow further air to escape.

Figure 3 shows another embodiment of the invention, wherein the volume of the container is varied by means of a ratchet and pawl mechanism. The upper sleeve 14 has two sets of externally projecting teeth 16. It is to be appreciated that more than two sets may be provided. A pawl handle 17 is provided on the lower sleeve 3. To decrease the volume of the container, the upper sleeve is pushed downwards towards the lower sleeve. The pawl inner end of the pawl handle 17 locks in the teeth 16 to maintain a particular volume for the container. Movement of the handle 17 can release the ratchet mechanism, in order for the volume of the containers to be increased. Alternatively, rotation of the upper and lower sleeve 14, 3 may be used to release the ratchet, so as to increase the volume of the container.

Figure 4 shows yet another embodiment of the invention, wherein the volume of the container is varied by means of multi-level bayonet type connections. The connection in the example has the lower sleeve 3 with two sets of shaped grooves, each set comprising a plurality of transverse grooves 19 connected by a longitudinal groove 20. Upper sleeve 14 has a pin member 21 which fits into grooves 19, 20. By moving (Twisting and pushing/pulling) the upper sleeve 14 relative to lower sleeve 3, or vice versa, the member 21 can move between transverse grooves 19 by means of the longitudinal groove, and hence vary the volume of the container.

It will thus be seen that the present invention provides a container wherein the volume of the container can be varied so as to minimise the amount of air in the container.

Where in the aforegoing description, reference has been made to integers or components having known equivalents, then such equivalents are herein incorporated as if individually set forth.

Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the invention, and in the appended claims.