ROTARY SEAMER

TECHNICAL FIELD AND BACKGROUND ART. The present invention relates to a rotary seamer. A seamer is a machine that enables to apply a lid to a container to close it hermetically, connecting the edge of the Hd to the edge of the container by folding them one onto the other. Such containers have cylindrical geometry, e.g. they are constituted by cans. In practice, seaming is achieved by setting the container in rotation around its own axis, in a seaming station in which the container interacts with an appropriately shaped idle pivot, i.e. shaped such as to cause said folding of the edges of the container and of the corresponding lid. The seaming station is pivotally associated to a seaming turret, also called carrousel, because it rotates around its own axis. In particular, the present invention relates to rotary seamers, i.e. seamers in which to the processed containers is imparted a motion of rotation around their own axis and a motion of revolution around the axis of rotation of the seaming turret. The seamer is provided with a machine body, which generally comprises a lower and an upper box.

The lower and upper boxes are load-bearing structures in which the seaming turret, which is the core of the seaming machine, is housed and at the same time they constitute containers for the motorization gears which transmit motion from a motorization to the seaming turret. Hence, said boxes must also contain the lubricating oil for said gears.

Therefore, the structure of the boxes must be rigid, able to be machined

(with machine tools such as boring machines, non-deformable (after machining and in operation), corrosion-resistant and economical.

Currently, seamer manufacturers make the load-bearing structures of cast iron (which, however, is not corrosion-resistant) or using a "mount" made of stainless steel or iron plates coated with sheet stainless steel plates (which, however, are not rigid and non-deformable).

DISCLOSURE OF THE INVENTION.

The object of the present invention is to eliminate the aforesaid drawbacks and to make available a rotary seamer provided with a structure for the protection of the seaming turret which is easy to machine and at the same time provided effective protection also against corrosion.

Said object is fully achieved by the seamer of the present invention, which is characterised by the content of the appended claims and in particular in that said structure comprises:

- an outer jacket;

- an inner jacket;

- a filling element interposed between the inner jacket and the outer jacket.

BRIEF DESCRIPTION OF DRAWINGS.

This and other characteristics shall become more readily apparent from the following description of a preferred embodiment, illustrated purely by way of non limiting example in the accompanying drawing tables, in which:

- figure 1 shows a partially sectioned front view of a seamer according to the present invention;

- figure 2 shows a perspective view of a first detail of the seamer of figure 1; - figure 3 shows a sectioned view, according to the plane shown in figure 2, of the detail of figure 2;

- figure 4 shows a perspective view of a second detail of the seamer of figure 1;

- figure 5 shows a sectioned view, according to the plane shown in figure 4, of the detail of figure 4.

BEST MODE FOR CARRYING OUT THE INVENTION.

In the figures, the reference number 1 designates a seamer according to the present invention, comprising a seaming turret 2 rotating around its own axis and a seaming station 3 pivotally associated to the seaming turret. The reference number 4 designates gear systems which actuate the seaming turret 2 and the seaming station 3.

The number 5 designates a structure for the protection of the seaming turret, also called machine body.

This structure 5 has a dual function. In the first place, the structure 5 contains said gear systems 5, together with the fluids needed to lubricate the gears. In the second place, the structure 5 defines a housing, i.e. a seat, in which is pivotally inserted the seaming turret 2, therefore it constitutes a load-bearing structure.

In particular, the structure 5 comprises, in the preferred embodiment illustrated herein, a first box body 6 and a second box body 7.

The structure 5, originally, is provided with walls comprising:

- an outer jacket 8;

- an inner jacket 9;

- a filling element 10 interposed between the inner jacket 9 and the outer jacket 8.

The inner jacket 9 is preferably made of carbon steel, in particular a medium steel. Said jacket 9 substantially constitutes a frame for said box bodies.

The outer jacket 8 is preferably made of stainless steel, preferably austenitic steel AISI 304. Said outer jacket 8 constitutes an outer coating for the structure 5, i.e. for the box bodies 6 and 7. Preferably, all the edges of the outer jacket 8 are rounded or chamfered and free of slits. The filling element 10 is preferably constituted by cement, in particular expansive fluid mortar for anchoring. Therefore, said filling element is contained in an empty space defined between said jackets.

It should be noted that the inner jacket 9 and the outer jacket 8 are originally welded in liquid tight fashion and fastened together with spacing elements, which are neither welded nor connected with threads. The technical solution according to the present invention offers the following advantages.

The structure 5 is rigid, able to be machined and non deformable because it comprises an inner frame made of carbon steel (appropriately dimensioned); at the same time, it is resistant to a corrosive external environment because it is coated with stainless material. Moreover, the fact that the structure 5 is entirely lined, together with the

absence of sharp edges and slits in the stainless coating, enables considerably to improve the sanitary aspect because the stagnation areas are eliminated which allow the formation of moulds and retaining dirt in general.