The present invention concerns a thermal bag.

The thermal bag of the present invention is suitable to contain articles (drinks, food, medicines, etc.) in low temperature conditions, in any case lower than the outside temperature; in particular it comprises means suitable to obtain, given the same time that the articles are contained in the bag, a lower temperature, with regard to the inside of the bag, than that which can be obtained with thermal bags currently on the market, with a system that is reasonably priced.

Currently thermal bags on the market allow to keep the articles contained therein in an adequate thermal state for their consumption for on average about 2 hours from when they were inserted in the bag and at their original temperature, for example after having been removed from a fridge or any other container suitable for refrigeration.

To increase the time that the temperature can be maintained in the thermal bag, it is also known to use sacs which contain a suitable cooling gel or liquid and which are normally kept in a freezer or fridge, which once put in the thermal bag together with the articles promote the preservation of the temperature for a longer time. However, the sacs make it more difficult for the user to manage the bag, since the user always has to have available at least one sac, with gel, which has been previously kept in the fridge.

In the state of the art there are electric thermal bags that are supplied with means suitable to preserve the cold, but which need to be powered electrically. They therefore need to be re-charged, so that the user needs an electric power source to be able to do this, as well as sufficient time to allow the bag to reach the desired functioning conditions.

Thermal bags are also known which, in the walls, comprise a sac containing a first reagent and a sac containing a second reagent. The sacs are separated by a breakable or tearable partition and such as to allow the two reagents to mix. The two reagents are chosen so that, in short, their endothermic reaction determines a lowering of the temperature in a zone of the bag.

In documents ES 2007918 A6 and US 2013/318916 Al two types of known thermal bag are described, by means of which, however, it is difficult to obtain an immediate, effective and uniform cooling of the whole bag. In the light of the above state of the art, one purpose of the present invention is therefore to provide a thermal bag that is able to keep the internal temperature at a level equal to or higher than the thermal bags currently on the market, without the use of devices such as gels or electricity.

Another purpose of the present invention is to provide a thermal bag that is easier to manage, in particular that does not need electric connections and is ready to use immediately.

Another purpose of the present invention is to provide a thermal bag that allows an effective and uniform cooling of the articles contained therein.

These purposes are obtained by means of a thermal bag made according to claim 1.

The preferred embodiment of the present invention has at least one of the following aspects.

According to a characteristic aspect of the invention, the first containing mean is a sac or tube in a deformable material, while the second containing mean is a coil, spiral, branched or finger or similar shaped tube positioned under the first containing mean.

Advantageously, the second coil, spiral, branch or finger or similar shaped allows an efficient, rapid and uniform distribution of the cold on the walls of the thermal bag.

Preferably at least one of the walls is at least partly made of a soft and/or deformable material, so that the bag is advantageously foldable and easy to place among other objects when not being used, or to reduce the volume taken up when the volume of a containing compartment inside the bag is not entirely used.

Preferably one of the containing means is disposed in a higher position than another of the containing means, in a condition of use of the thermal bag, so that, in the operating configuration of the separator mean, the two substances can mix together.

Preferably at least one of the containing means is configured to be compressed by a user so as to force the separator mean to assume the operating configuration and take the substances into contact. Preferably the bag has at least two bigger lateral surfaces, each of which has a respective hollow space and each of them being associated to a respective cooling unit.

Preferably the separator mean comprises a separator partition that can be torn. Preferably the first substance comprises water and the second substance comprises a nitrogenous salt.

Preferably the internal wall comprises at least one layer of polyethylene, advantageously virgin white polyethylene, which is a material which is particularly suitable to be in contact with food.

Preferably the external wall comprises at least a layer of polyethylene.

Preferably the external wall comprises an external layer of terephthalate polyethylene and an intermediate layer, facing toward the hollow space and made of expanded polyethylene.

The characteristics of the present invention will become clear from the following description relating to the preferred embodiment thereof: it is to be considered merely by way of non-restrictive example of the more general concepts claimed.

The following detailed description refers to the attached drawings wherein:

- fig. 1 is a perspective view of a bag according to the present invention, in a condition where the separator mean is non-operating;

- fig. 2 is a perspective view of the bag, partly cut-away, to show some internal elements;

- fig. 3 is a section view of a surface that defines an internal space of a bag according to the present invention;

- fig. 4 is a detail of fig. 3 showing a possible structure of a surface of the bag;

- fig. 5 shows a variant of the thermal bag in which the first and second containing mean are housed in an envelope or casing that can be extracted and interchanged.

Fig. 1 shows a thermal bag 1 according to a preferred embodiment of the present invention. The bag 1 is particularly suited for use containing foods, drinks, medicines and/or other articles for which transport is necessary in temperature below ambient temperature. In this form of embodiment, the bag 1 has two bigger surfaces la and lb, which are connected by two smaller surfaces lc and Id, so as to assume a substantially parallelepiped shape.

The bag 1 defines inside itself a containing compartment le and is preferably made of deformable or soft material, that is to say, adaptable to the content disposed therein.

Above, the bag 1 also comprises a pair of handles If and lg, connected for example respectively to the bigger surface la and the bigger surface lb.

The description that follows will refer to this structure of the bag 1, but the inventive concept of the invention is equally applicable to bags of any other shape or structure.

As can be seen in fig. 2, and better shown in figs. 3 and 4, at least in correspondence with the two bigger surfaces la and lb, the cross section of the bag 1 is defined by an outermost wall "A" and an innermost wall "B", which define between them a hollow space 'Ί". The bag 1 has a first containing mean 2a and a second containing mean 2b, which are advantageously both situated inside the hollow space "I", and in fig. 1 are shown by dashes precisely because they are situated inside it.

The external wall "A" is at least partly heat insulating; in the preferred form of embodiment, described in detail in the subsequent paragraphs, it comprises a layer made of insulating material.

With reference to fig. 2, the first containing mean 2a is able to contain a first substance 3 a and the second containing mean 2b is able to contain a second substance 3b.

A separator mean 4, in a non-operating configuration shown in figs. 1-3, keeps the substances 3a and 3b separate. The separator mean 4 is configured so that, following an external action that can be exerted manually by the operator, the separator mean 4 passes to an operating condition, such that the first substance 3 a and the second substance 3b are put in communication.

The first substance 3a and the second substance 3b are different, and are selected so that a chemical reaction between them determines a cooling of the space inside the bag 1, and more particularly of the containing compartment le, in other words, so that the chemical reaction is an endofhermic one. The preferred embodiment of the present invention provides that the first substance 3a is water and that the second substance 3b is a nitrogenous salt or a mix of nitrogenous salts.

Furthermore, in the form of embodiment shown in the drawings, the separator mean 4 is tearable.

To facilitate contact between the substances 3a and 3b and to reduce the operations that have to be done by the user, in this form of embodiment the first containing mean 2a is disposed in an upper position with respect to the other containing mean 2b, when the thermal bag 1 is in a condition of use. In this way, in the operating condition of the separator mean 4, the two substances 3a and 3b can mix.

In particular, the two substances 3a and 3b can mix simply due to gravity, or with the aid of the force of gravity.

Furthermore, at least one of the containing means 2a and 2b can comprise a sac or tube.

The second containing mean 2b, in the preferred form of embodiment shown in figs. 1 and 2, is advantageously shaped like a coil, so that it is distributed on a wider surface defining the containing compartment le of the bag 1, in order to improve the spatial uniformity of cooling of the compartment le. The combination that includes the containing means 2a and 2b, the substances 3a and 3b and the separator mean 4 can be considered a cooling unit. It should be remembered that the bag 1 could comprise at least another cooling unit in correspondence with at least the other bigger surface lb, similarly situated in the respective hollow space.

Moreover, it should be noted that the bag 1 can include one or more cooling units in correspondence with corresponding hollow spaces made in any one of its six sides on side la, lb, Id and le.

To facilitate contact between the substances 3 a and 3b, one of the containing means 2a and 2b could be configured so that an action of compression exerted thereon by the user can put them in communication. In particular, the first containing mean 2a can comprise a deformable tube or sac which, pressed by the user, not only tears the separator mean 4, but also determines a thrust of the water contained therein toward the second containing mean 2b, promoting the mixing of the two substances 3a, 3b.

With reference to the structure of the walls "A" and "B", each of them preferably comprises a layer of polyethylene.

In particular, with reference to fig. 4, the innermost wall "B" comprises an internal layer "si" made of virgin white polyethylene, which is particularly suitable to be in contact with food. The outermost wall "A" advantageously comprises a layer "s2" made of expanded polyethylene, which guarantees good heat insulation.

At least one of the two walls "A" and "B" could also contain several layers. For example, in the preferred form of embodiment, the outermost wall "A" has an intermediate layer "s2", facing toward the hollow space "I", made of heat insulating material, such as expanded polyethylene, and an outermost layer "s3" made of terephthalate polyethylene, defining a protective layer for the intermediate layer "s2". In this structure, at least the external layer "s3" defines the mechanical bearing properties of the bag 1.

The possible application of the present invention extends to containing articles of any type, provided they have to be kept at a lower temperature than ambient temperature.

During use, the user presses the first containing mean 2a, the compression of which causes the separator mean 4 to tear and promotes the mixing of the two substances 3a and 3b, which come into contact also due to gravity.

The present invention achieves the aims proposed, overcoming the disadvantages of the state of the art.

To this end it has its own cooling system, so that thermal efficiency is considerably improved and hence the time for which the articles can be preserved is much longer.

The ease of management for the user is also improved, in that it functions autonomously without requiring external elements, such as artificial energy sources.

It guarantees a good, uniform cooling of the space inside the bag, since due to the positioning of the containing means inside the walls of the bag, the containing means can extend over a wide surface. The thermal bag 1 according to the invention is normally single-use, since once the separator element 4 has been broken or torn, and once the desired cooling has been obtained, it would be necessary to introduce a new containing mean 2b, with a coil or spiral or other shape, and a new sac 2a with the reagents 3 a and 3b to reuse it.

Alternatively (fig. 5), it is possible to provide that the second containing mean 2b', the sac 2a and the separator element 4 are in turn positioned inside an interchangeable casing 5, which can be positioned in the hollow space of the bag 1. In this case, once cooling has been effected, the interchangeable casing 5 can be replaced inside the hollow space by a new casing 5 containing a new containing mean 2b' and a new sac 2a, suitably separated. In order to allow to replace the casing 5, the thermal bag 1 according to the invention provides normal apertures 6 to access the hollow space defined between the walls A and B. The apertures 6 can be closed by elements that allow access to the hollow space or allow to close it, such as zips, Velcro closures or suchlike.

In the variant shown in fig. 5, furthermore, the containing mean 2b' has kinds of fingers that allow it to suitably branch off inside the casing 5, as an alternative to the sinuous coil shape shown in fig. 1. Naturally, it could be provided to use the coil-shaped containing mean 2b in the casing 5 and, vice versa, in the disposable bag shown in fig. 1, it could be provided to use the containing mean 2b' with several branches or fingers.