SHAPING ROLL FOR DOUBLE COLD WORKING OF SHEET MATERIAL AND APPARATUS AND PROCESS FOR REALISING SAID ROLL

The present invention relates to a shaping roll for double cold working of sheet material.

The invention further relates to an apparatus for realising said roll, as well as to a process for realising the same.

Baskets are realised since many years to be used for power production systems by thermal exchange between smokes and liquids, and particularly to be used for recovery of smoke heat and the purification of the same smokes.

Said baskets, which can be assembled in various ways, are realised by an overlapping of shaped sheets having different shaping for passage of smokes.

Pairs of two sheets are thus comprised of two sheets having different shapes.

Baskets are realised providing the superimposition of double working sheets with plain sheets. Particularly, in many cases, it is necessary realising a double working on one of the sheets of each pair, and particularly a kind of undulation, with a substantially diagonal run, and a juxtaposed straight corrugation, repeating with the wished pitch.

These double working sheets are interposed with flat sheets, on which only an undulation has been realised, in order to obtain the final optimum result of heat recovery and/or smoke purification.

At present, said double working, which is carried out as cold deformation, is obtained by two different lines, employing different rolls, each one making a specific configuration on the sheet. Obviously, said double working involves remarkable drawbacks, among which it is possible mentioning, for example, mechanical stresses to which the material is subjected during the double cold deformation, the needing of a double working line, or as an alternative, of modifying the features of the line, in order to obtain the different configurations, with a consequent increase of working time and costs.

It is thus well evident the needing of having a technology as suggested by the present invention, allowing overcoming all the above- mentioned drawbacks.

Main object of the present invention is therefore that of providing a shaping roll allowing obtaining both an undulation and a corrugation on the sheet by a single cold working, said undulation and corrugation being based on the specific design of the work. . Further object of the present invention is that of providing an apparatus allowing realising said rolls, with the specific configuration of undulation and corrugation, and the specific height of the final use.

Still another object of the present invention is that of providing a process for realising said rolls. It is therefore specific object of the present invention a shaping roll for double cold working of sheet material, characterised in that it provides a toothed configuration extending on the outer surface of the roll, according to a substantially diagonal direction with respect to the roll axis, and a plurality of projections on the outer surface of the roll, substantially extending parallel with respect to the roll axis, and crossing with said toothed configuration extending according to a substantially diagonal direction with respect to the roll axis.

Preferably, according to the invention, said plurality of projections substantially extending parallel with respect to the roll axis is comprised of profiled rods inserted within suitable seats realised on the outer surface of the roll.

Particularly, according to the invention, said seats are shaped in a complementary way with respect to an insertion surface for said rods.

Still more particularly, said seats have a dovetail shape. Always according to the invention, said projections substantially extending parallel with respect to the roll axis are equally spaced on the outer surface of the roll.

Furthermore, according to the invention, said toothed configuration developing on the outer surface of the roll according to a substantially diagonal extension with respect to the roll axis makes an angle with respect to said projections substantially parallel with respect to the roll axis, preferably a constant angle.

The invention further relates to a toothing and hob apparatus modified for realising a shaping roll, comprising a front upright and a rear upright, a rotating table for the vertical support of the roll semi finished product, a vertically movable head, on which the hob or the milling cutter are alternatively mounted, means for rotating the semi finished product

bearing table when working as toothing machine, by using the hob, and means for stepwise rotating the semi finished product bearing table, when working as milling cutter.

Always according to the invention, said apparatus provides roll semi finished product support means having an adjustable height.

It is further object of the present invention a process for realising a roll, comprising the steps of :

- taking a roll with suitable sizes;

- vertically mounting the roll on a toothing - milling apparatus; - applying a suitable hob on the toothing - milling apparatus for realising the toothing configuration on the outer surface of the roll, with a substantially diagonal extension with respect to the roll axis;

- rotating the roll for realising said toothing configuration by a suitable hob, said toothing extending on the outer surface of the roll with a substantially diagonal extension with respect to the roll axis;

- rotating the apparatus according to a mode not allowing the rotation of the roll; - applying the milling cutter on the apparatus

- making a vertical milling along the roll;

- rotating the roll of an angle corresponding to the position of the following vertical milling;

- carrying out the previous step a number of times corresponding to the number of millings to be realised on the roll;

- taking a number of rods corresponding to the number of millings realised on the roll and provided with a shaped face so as to be inserted within said vertical millings and a face suitably shaped on the basis of the work to be carried out by the roll, and inserting the rods within the corresponding vertical millings.

The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein: figure 1 is a perspective view of a first pair of shaping rolls according to the invention;

figure 2 is a perspective view of an apparatus for realising rolls according to the invention; figure 3 is a lateral view of the apparatus shown in figure 1 without the roll to be subjected to working; figure 4 is a perspective view of the apparatus of figure 2 without the roll to be subjected to working; and figure 5 is a lateral view of the apparatus of figure 2. Observing first the enclosed figure 1 , it is shown a pair of rolls, generically indicated by reference number 1. Roll 1 shown is only one of the many rolls that can be realised with the technical features according to the invention. In fact, both the configuration of roll land its height can vary in function of the final use to which it is destined, i.e. the features that must be obtained on the product (cold worked sheet) that must exit from the working by the inventive roll 1. A toothing configuration 2 is provided on said roll 1 , said configuration 2 being, as shown in figure 1 , oriented sloped with respect to the vertical axis of the roll 1.

It is further provided a plurality of shaped projections or teeth 3, extending according to a substantially parallel direction with respect to the roll 1 axis, and crossing many times said configuration 2.

Roll 1 thus obtained permits realising a double cold working on a sheet, not shown, in order to obtain both an undulation and a corrugation o f the same by a single pass of the roll 1 , thus obtaining well evident advantages both as mechanical features of the final product and as manufacturing time and costs.

Said toothings 3 are preferably comprised of rods that are inserted within suitable grooves, said grooves being shaped complementary with the rear surface of the toothings, and realised on the outer surface of the roll 1 , being in such a way it possible also using rods having a different outer profile, on the basis of the needings deriving from the final use of the roll 1.

As to the configuration of the toothing 2, its profile will be determined by the hob used for its realisation.

Coming now to observe figures 2 - 4, it is shown a particular embodiment of an apparatus, generically indicated by reference number

10, for realising shaping rolls 1 according to the invention, being understood that the same, although included within the scope of the

present invention, must not be used to limit the same invention, the scope of which includes, beside the same apparatus 10 described and claimed, every kind of roll 1 having the described and claimed features, independently from the apparatus and the process by which it is realised. Particularly, apparatus 10 according to the invention must work both as gear cutting machine, and as vertical milling machine, according to the working step of the roll to be obtained.

In the embodiment shown in the drawings, a maximum outer diameter of the toothing of 1000 mm, a height of the toothing of 1420 mm and a maximum modulus of 10 mm.

Apparatus 10 provides a front arm 11 , bearing the hob or milling cutter support 12, and a rear arm 13, providing counter - strut 14 for positioning the semi finished roll 100 in a vertical position, on the base 15.

Said rear arm 13 provides a support 16 with a variable height permitting working rolls 100 of different height.

Consequently, apparatus according to the invention permits toothing gear or toothed shafts height up to 1420 mm.

After having obtained the wished toothing by the suitable hob 17, roll 100 will be subjected to working by the vertical milling cutter. Worm screw 18 of the toothed wheel is detached, said worm screw 18 being integral with the horizontal circular table 15, thus preventing the rotation of the roll 100 during its working. A ratiomotor 20 transmits the rotation motion to the screw 18 ensuring the transmission of the table 15 movement. A divider applied on the rotatable table 15 of the toothing machine permits realising a number of grooves 3 in the roll necessary on the basis of the pitch.

The suitable milling cutter necessary for the milling cutting to be realised replaces hob 18.

Roll 100 to be subjected to working is still and vertically mounted on the table 15. Milling cutter progressively descends and digs the piece.

From the above, it can be understood that a milling machine has been realised having the following features:

- vertical milling machine, rather than horizontal milling machine;

- useful length of 1400 mm, which usually cannot be found in this specific technical field.

Working process of the semi-finished roll 100 in order to obtain roll 1 according to the invention by apparatus 10 is the following:

- semi finished roll 100 with suitable sizes is provided;

- vertically mounting the roll 100 on a toothing - milling apparatus;

- applying a suitable hob on the toothing - milling apparatus 10 for realising the toothing 2 configuration on the outer surface of the roll 100, with a substantially diagonal extension with respect to the roll axis; - rotating the roll 100 for realising said toothing configuration 2 by a suitable hob 17, said toothing extending on the outer surface of the roll 100 with a substantially diagonal extension with respect to the roll 100 axis;

- rotating the apparatus 10 according to a mode not allowing the rotation of the roll 100;

- applying the milling cutter on the apparatusiO;

- making a vertical milling along the roll 100;

- rotating the roll 100 of an angle corresponding to the position of the following vertical milling; - carrying out the previous step a number of times corresponding to the number of millings to be realised on the roll 100;

- taking a number of rods (not shown) corresponding to the number of millings 3 realised on the roll 100, prepared beforehand or in any case in a separate phase.

Said rods have a dovetail shape (male) to be keyed within the dovetail millings (female) of the roll.

After having keyed said rods within the roll dovetail millings, said rods projects of a suitable height, in the part opposite with respect to the dovetail milling, from the outer circumference of the rolls.

Thus obtained roll is again mounted within the toothing - milling apparatus, which is again prepared to work in the toothing mode.

Milling cutter is dismounted from the tool-bearing table, and a special hob is mounted, which is suitable to working of straight undulated shaping of the rod projections.

Then, last roll working phase is carried out by the toothing - milling apparatus in a toothing mode, in order to realise the straight undulated shaping of the rod projections, as described in the above.

It is finally pointed out that pitch of straight undulated toothing can be varied in function of the drawings required by the Clients. As a consequence, a different number of straight undulated toothings can be obtained with the same outer diameter of the roll.

The present invention has been described for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that modifications and/or changes can be introduced by those skilled in the art without departing from the relevant scope as defined in the enclosed claims.