Knapsacks used for school and entertainment are nowadays more and more widely spreaded due to the comfort and ease of handling that they provide to their users for transporting various types of objects, leaving their hands free.

Since such knapsacks are used in the majority of times for transporting books and school material (in addition obviously to other types of material), problems occur due to their weight, that can sometimes be excessive with respect to the person wearing them, but above all that is often scarcely balanced inside the knapsack itself. Such problem of a scarce balancing of the transported loads is particularly felt when the users are children or boys: their body structure, in fact, is reduced with respect to the one of an adult user, and the presence of high internal unbalanced loads brings about a displacement of the barycenter for the child/boy + knapsack assembly towards the outside of the user body. Such barycenter displacement on one hand compromises the person's balance, and on the other hand is harmful for his or her health, since it obliges the user to curve his or her back forwards to re-establish such a posture as to bring back the barycenter itself into a balance position.

No arrangements are present in the art that allows optimising the weight of the material being transported in the knapsacks in order to enable a minimum displacement of the user barycenter with respect to a"rest"condition, that is when the user does not wear the knapsack.

Object of the present invention is solving the above prior-art problems by providing an improved knapsack that allows concentrating the weight of the material transported inside the knapsack (or at least of the heavier material) into the minimum displacement position for the final barycenter, that is into the position nearest to the back of the user wearing the knapsack.

A further object of the present invention is providing a knapsack in which the concentration arrangement for the weight of the transported material is realised to guarantee the maximum flexibility of use, being able to be well adapted to all types and sizes of the transported material.

The above and other objects and advantages of the invention, as will appear from the following description, are obtained by a knapsack as claimed in Claim 1. Preferred embodiments and non-trivial variations of the present invention are claimed in the dependent Claims.

The present invention will be better described by some preferred embodiments thereof, given as a non-limiting example, with reference to the enclosed drawings, in which: -Figures 1 and 2 are perspective views of a first embodiment of a knapsack according to the present invention with the holding means in a rest and working position, respectively; -Figures 3 and 4 are perspective views of a second embodiment of a knapsack according to the present invention with the holding means in a rest and working position, respectively; -Figures 5 and 6 are perspective views of a third embodiment of a knapsack according to the present invention with the holding means in a rest and working position, respectively; and -Figure 7 is a perspective view of a fourth embodiment of a knapsack according to the present invention.

With reference to Fig. s 1 and 2, a first preferred embodiment of the knapsack 1 of the present invention is shown. The knapsack 1 is of a known type adapted to transport any type of objects, and in a widespreaded application thereof it is adapted to transport school material (books, exercise books, pencil cases, etc.), such material being generally defined by reference number 2. Both the type of knapsack, and the material contained therein, and the application for which such knapsack can be employed, are not obviously limited to the ones being shown, that, for ease of explanation, show a knapsack adapted to transport books and school material.

The knapsack 1 of the invention, in the type shown, comprises a main compartment 3 in which the material whose weight and sizes are greater is usually placed, and a series of smaller compartments, only one of which is shown, with reference number 5, such compartment 5 being for example adapted to contain pencil cases, snacks or material with a lower encumbrance and weight. The knapsack 1 is composed of a cover 7 adapted to close the knapsack 1 through common closing means (for example of the common snap-arms type, not shown). The knapsack 1 is equipped with a side 8 that abuts against the user back, and that is generally formed of a more resistant material than the remaining sides of the knapsack 1: such side 8 is usually realised with a padding in order to make the contact with the user back more comfortable and with ribs that facilitate its resiliency, substantially conforming it to the back of the wearer.

The knapsack 1 of the present invention provides that internal holding means 9 for the transported material are placed (for example by connecting them through sewing or other connection processes) on such side 8 in contact with the back.

In the drawing Figures, such holding means 9 are composed of elastic means, for example of the type used in the past to keep mutually held together the books to be transported, or in any case of a band of elastic material whose thickness, sizes and shape are variable according to the applications.

Obviously, the holding means 9 are in no way limited to the embodiment shown: for example, a plurality of mutually parallel elastic bands could be provided, or a pair of mutually crossed elastic bands in the shape of an"X", or other suitable holding arrangements. Moreover, the holding means 9 could be realised in a non-elastic material and could be of a shape that can be opened and closed, using for example a common buckle (not shown) or two cooperating Velcro@ straps (not shown).

Whichever the final embodiment is, the major purpose of the holding means 9 of the invention is tightening, and therefore"compacting", the transporting material (for example books, exercise books, pencil cases) against the side 8 of the knapsack 1, which side 8 is located, as already seen, in the nearest position to the user back: this helps in minimally displacing the balancing barycenter of the person wearing the knapsack 1, not forcing the user to move and curve his or her back forwards to restore the balance condition.

Moreover, when the knapsack 1 is not completely full of material, the holding means 1 prevent the material from bouncing inside the knapsack 1, often moving towards the outside and therefore going away from the optimum configuration. Finally, when instead the knapsack 1 is completely full of material, the holding means 9 are shaped in such a way as not to occupy precious internal space, providing a minimum encumbrance in the position next to the side 8, as can be better seen in Fig. s 1,3 and 5.

In addition to number, shape, sizes and type of material, the holding means 9 can be realised under several arrangements that allow them to provide the maximum application flexibility. The enclosed Figures show four possible embodiments of the holding means 9, but many other ones are possible, some of which will simply be described hereinbelow, without departing from the functionality of such means 9 and therefore from the scope of the present invention.

In particular, Fig. s 3 and 4 show a second embodiment of the present invention in which the internal holding means 9 are equipped with a gripping member 10 adapted to facilitate the movement of the sealing means 9 away from the side 8 of the knapsack 1 in order to insert the material 2 to be held between the side 8 and the holding means 9. Figures 3 to 7 show a preferred exterior embodiment of the gripping member 10, equipped with an handle 11 to facilitate inserting the fingers of an hand and the tensioning operation for the elastic means 9: in such exterior embodiment, the gripping member 10 further has a rounded shape, in order to avoid any sharp edge that could be dangerous for the users, above all if they are young. Moreover, the gripping member 10 is equipped with at least two slits 12 (the drawings show four of them) through which the holding means 9 are passed, but obviously other arrangements are possible in order to mutually connect holding means 9 and gripping member 10.

Instead, Fig. s 5 and 6 show a third embodiment of the knapsack 1 of the invention, in which the internal holding means 9 are further equipped with an adjusting member 14 for the working length of the holding means 9 themselves. Such length adjusting member 14 is commonly of the buckle type, with a known operation in the art that allows shortening or elongating the holding means 9 according to the amount of material 2 to be held.

Also in this case, it is possible to adopt a different embodiment of the adjusting member 14, that allows realising an equivalent functionality.

Moreover, it is possible to couple the adjusting member 14 to the holding means 9 alone (Fig. s 1 and 2) or to the holding means equipped with other members (as in Figures 3 to 7 or under any combination of members that could be applied to the holding means 9, as clearly appears by reading this specification).

Upon completion of the above description from which it is clearly evident that the present invention is subjected to numerous variations and that therefore what is shown here must be deemed as a purely illustrative and non-limiting example, Fig. 7 shows a fourth possible embodiment of the knapsack 1 of the invention. In Fig. 7, the holding means 9 are further equipped with position-varying members, that are useful because they allow adjusting the height, inside the knapsack 1, at which the holding means 9 are applied: this is important because, for example, it could be necessary to hold pocket books or standard-size books, or even atlasses or encyclopedias, and therefore a material with different heights according to the cases. The position-varying members of the internal holding means 9, in Fig. 7, are composed of a plurality of assemblies composed of a slot 16 and a small hook 18 that are connected on one side to both the ends of each one of the holding means 9 and on the other hand to an internal side (for example the side 8) of the knapsack 1 in a plurality of mutually offset positions along the height of the knapsack 1 itself. It is thereby possible to attach and detach the holding means 9 at the most suitable height to guarantee an optimum held of the material 2.

Also in case of the position-varying members, numerous variations are possible, such as for example a common pair of driving tracks (not shown) in which a respective pair of sliders (not shown) are placed, each slider being placed at one end of each one of said holding means 9 in such a way as to allow the adjustment sliding of the holding means 9 till the desired holding position; moreover, the sliders are equipped with stopper means (not shown) that are adapted to prevent the further sliding of the holding means 9 once having reached the established holding position.

The holding means 9 could also be used, in any one of the above-described embodiment or in other suitable ones, in other internal knapsack compartments, such as the compartment 8 shown in the Figures.