FIELD OF THE INVENTION

This invention relates to a self-sealing balloon.

BACKGROUND TO THE INVENTION

Balloons in various shapes and sizes are sold for use at many social gatherings (e.g. children's and Christmas parties) and are used in larger quantities at many promotional or sporting events. Traditionally, balloons are inflated either by blowing into them by mouth or by filling them with helium gas from a large cylinder. The neck of the balloon is then knotted to prevent gas escaping. The knotting operation requires great dexterity and becomes all the more tiresome when large quantities of balloons need to be inflated and sealed at, for example promotion events.

Furthermore, a gas-tight seal can never be achieved simply by tying a knot in the neck of a balloon, since there will always remain a minute passage through which gas can escape.

One known method of overcoming the problem of knotting balloons is to use a plug or spring clip. Spring clips are typically applied to the twisted end of the balloon's neck to pinch or squeeze the end thereby halting gas escape.

However, irrespective of the force applied by the spring clip, minute passages still exist in the neck allowing gas to escape. Plugs on the other hand are inserted into the neck of the balloon, but these are unsatisfactory as they rely on a force fit which in turn requires very high manufacturing tolerances to provide a gas-tight seal. Furthermore, the use of plugs and spring clips is in general too expensive and too heavy to be of practical use.

It is now common to seal Mylar balloons by heat. The

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balloon's neck is subjected to hot pressing which locally melts the neck and forms a seal. This requires expensive machinery and is unsuitable for use with the normal elastomeric toy balloons, since these melt destructively under this treatment.

United States specifications, 4,560,360 (Isaacs et a_l) and 4,516,949 (Schwartz) describe a balloon sealing method in which a seal is made by bringing together opposed inner surfaces of the neck of a balloon which surfaces have previously been coated with a suitable adhesive. Premature sealing is prevented by means of an interior protective insert or strip. In both cases, a tube is inserted into the neck between the protective inserts to allow for the inflation of the balloon. Such balloons are expensive to manufacture since they require extra elements such as protective inserts or strips. Furthermore, considerable manual dexterity is required to remove the inserts or strips once a balloon is inflated.

The present invention provides a balloon which can be easily sealed by the use of an adhesive, which can be manufactured at low unit cost, which does away with the need for interior protective sheets and which can be adapted to all types of balloons.

SUMMARY OF THE INVENTION

According to the invention there is provided a balloon comprising a body and a neck characterised in that at least a portion of the neck is turned inside out (i.e. everted) and at least an outer annular part of said portion is coated with a contact adhesive such as, for example, an untreated latex.

The balloon can be sealed after inflation, simply by unfolding the neck of the balloon with a pulling action and

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by pinching the neck. The seal produced is entirely gas tight. The balloon does not require any protective strips, since contact adhesive is, in general, non-adhesive except with itself and premature sealing is prevented by the folding of the neck of the balloon. The balloon has the additional advantage in that it can be reused, since it is possible to break the seal by pulling the opposed surfaces of the neck apart.

Preferably, a tube is received within the neck of the balloon. This prevents collapse of the neck during inflation and also eases folding down the neck of the balloon during manufacture. The tube may be of a plastics material and may optionally be removed once the balloon is inflated. Plastics tubing is cheap and thus this part may be disposable.

Preferably, the tube extends out of the neck of the balloon. This prevents spittle affecting the contact adhesive, if the balloon is to be mouth inflated. The tube may also be easily removed it it extends out of the balloon. Such a tube is preferably provided with means adapted to form a substantially gas-tight connection with a gas source. Preferably, these means are one part of a bayonet fitting. This arrangement allows for a simple gas tight connection to be made to a suitable gas source such as a helium cylinder.

The outer annular part coated with contact adhesive may be provided with a removeable protective strip to prevent ^" a collection of the balloons packaged loose together sticking together. The strip may simply be ^' removed from the exterior of the balloon's neck prior to inflation. Alternatively, there may be provided an assembly comprising a plurality of balloons each having a tube extending out if its neck wherein the tubes are attached to, or integral with a common member at spaced apart intervals. For example, the tubes may form

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an integral injection moulded comb provided with frangible portions for the ready removal of individual balloons.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention is now described, by way of example only, with reference to the accompanying drawing which shows, in cross-section, a detail of the neck of a toy balloon comprising inflatable body 1 and a neck 2. A tube 3 is received within and extends from the neck 2. A portion 4 of the neck 2 is folded inside out (i.e. everted) and an outer annular part 5 of the portion 4 is coated with a contact adhesive (i.e. an adhesive which bonds to itself).

The tube 3 is optionally provided with members 6 which act as the male fitting parts of a substantially gas-tight bayonet fitting for attachment to a gas source such as a helium gas cylinder.

Having inflated the balloon, either by mouth or from a gas source, the tube 3 is removed and the neck portion 4 unfolded. The annular adhesive coated part 5 is then brought together by a pinching action. This seals the neck of the balloon.

When the balloon needs to be deflated, the seal can be broken without damage to the rest of the balloon, by carefully pulling the neck portion apart. This is particularly advantageous, since the balloons can then be re-used?

It will be appreciated that the present invention has been described by way of example only and modifications of detail can be made within the scope of the invention. For example, the balloons of the present invention may be inflated by any suitable gas source using any suitable fitting. The balloons can also be inflated by mouth.

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It will also be appreciated that the invention can be adapted for use with any balloon such as, for example, bladders, footballs and bicycle inner tubes.