Equipment for superimposing two layers of products to be packaged

Equipment for superimposing layers of products to be packaged (P), comprising: a feed surface (12) associated to a first product-feed device (18); and a pair of preparation surfaces (24, 26) set on top of one another and designed to receive each a respective layer of products to be packaged (P), the preparation surfaces (24, 26) being associated each to a respective feed device (36, 38), the said feed devices (36, 38) being designed to cause synchronized advance of corresponding layers of products (P) along the preparation surfaces (24, 26). Both of the preparation surfaces (24, 26) are mobile so as to bring alternately the respective product-intake end (28, 30) into a position corresponding to the product-output end (16) of the feed surface (12).

BACKGROUND OF THE INVENTION

The present invention relates to a piece of equipment for superimposing two layers of products to be packaged. The invention has been developed in particular with a view to its application to automatic machines for packaging rolls of paper, such as rolls of toilet paper or rolls of kitchen wipes, which are arranged for the formation of packs consisting of two layers of products. The Italian patent No. 1 225 033 describes a piece of equipment designed to form two layers set on top of one another of cylindrical products, such as rolls of paper. The known equipment described in the aforesaid Italian patent application comprises a stationary feed surface for feeding the products, which is associated to a first device for advance of the products. Set downstream of the product-feed surface is an oscillating surface articulated about an axis transverse to the direction of advance of the products. The intake end of the oscillating surface receives the products from the output end of the stationary feed surface, whilst the output end of the oscillating surface moves cyclically between two operating positions. Provided downstream of the oscillating surface are two preparation surfaces set one on top of the other, which receive each a respective layer of products coming from the oscillating surface. The preparation surfaces are associated each to a respective product-feed device, the said devices being synchronized with one another and being set in such a way that the layers of products that advance on the preparation surfaces are perfectly set on top of one another at the output ends of the preparation surfaces.

Starting from the above example of prior art, the present invention has the purpose of providing a piece of equipment for superimposing two layers of products to be packaged that is simpler, more economical and is made up of a smaller number of components than the equipment according to the prior art described previously.

SUMMARY OF THE INVENTION

According to the present invention, the above purpose is achieved by a piece of equipment having the characteristics that form the subject of the main claims.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the drawings, number10designates a piece of equipment for superimposing layers of products P, consisting, for example, of rolls of paper, which advance in a direction parallel to their own longitudinal axis. The equipment10comprises a stationary feed surface12having an intake end14and an output end16. The feed surface12is associated to a feed device18, which may be of any type and is designed to cause advance of the products P from the intake end14towards the output end16. Preferably, the product-feed device18comprises a pair of motor-driven chains20(FIG. 4) which are set laterally with respect to the feed surface12and carry a plurality of transverse rods22that push the products P along the feed surface12.

The equipment10comprises two preparation surfaces24,26set on top of one another and each having a respective intake end28,30and a respective output end32,34. The preparation surfaces24,26are associated each to a respective product-feed device36,38. The product-feed devices36,38may be built in a way similar to that of the feed device18associated to the feed surface12. The reference numbers40,42designate drawing rods which can move in the direction indicated by the arrows44,46to cause the products to advance from the intake ends to the output ends of the preparation surfaces24,26. The preparation surfaces24,26are mobile so as to bring alternately their respective intake ends28,30up to the output end16of the feed surface12. The device25,25′ controls movement of the preparation surfaces24,26. In the embodiment illustrated in the figures, the preparation surfaces24,26can oscillate about respective axes33,35set at the output ends32,34of the preparation surfaces24,26. In an alternative embodiment, which is not illustrated in the drawings, the preparation surfaces24,26, instead of being hinged about an axis, could be translated in a direction orthogonal to the direction of movement of the products.

In the embodiment illustrated by way of example in the figures, two short stationary surfaces48,50are set in the proximity of the output ends32,34of the preparation surfaces24,26. Set immediately downstream of the stationary surfaces48,50is a lifting plate52which can move vertically and is designed to receive two layers of products set on top of one another that are to be packaged in a plastic film, according to modalities in themselves known which do not fall within the scope of the present invention.

During operation, the preparation surfaces24,26are cyclically displaced between the two operating positions, illustrated inFIGS. 2 and 3, in a way synchronized with the movement of the feed devices18,36and38.

The products P coming from the feed surface12are alternately loaded onto the bottom preparation surface24and onto the top preparation surface26. The two layers of products then advance synchronously along the two surfaces24,26and are laid on top of one another on the lifting plate52, as illustrated in FIG.3.

As compared to the machine according to the prior art described in the Italian patent No. 1 225 033, the solution according to the present invention makes it possible to reduce the length of the equipment for forming the layers. In fact, all other conditions being equal, the overall length of the machine may be reduced by an amount corresponding to the length of the oscillating surface that is present in the solution according to the prior art.

Preferably, the distance Δx between the output ends of the preparation surfaces24,26may be adjusted according to the diameters of the rolls to be packaged.