WO2022029669A1

WO2022029669A1 - Method for winding a strip around a product of cylindrical shape and relative winding machine

Info

Publication number: WO2022029669A1
Application number: PCT/IB2021/057184
Authority: WO
Inventors: Stefano Petri
Original assignee: Stefano Petri
Priority date: 2020-08-07
Filing date: 2021-08-05
Publication date: 2022-02-10
Also published as: EP4192740A1

Abstract

A winding machine (1) for wrapping a cylindrical product (R) with a strip of web material (C) comprises a winding station (4), feeding means (32) for feeding the cylindrical products (R) to the winding station, an unwinding device (3) for unwinding a spool (B) from which a web material is unwound, a cutting system (29) for separating the web material unwound from said spool (B) so as to obtain a strip of web material (C) of suitable length; a conveyor belt (2) suitable for bringing the strip of web material (C) tangent to the cylindrical surface of said cylindrical product (R); a securing device (30, 30') suitable for securing said strip of web material (C) on itself and characterized by the presence of mechanical means for temporary grip (5, 5') suitable for acting on said inlet flap (C1) to favor the wrapping of the strip of web material (C) around the cylindrical product (R) without the use of glue or other permanent adhesion systems.

Description

METHOD FOR WINDING A STRIP AROUND A PRODUCT OF CYLINDRICAL SHAPE AND RELATIVE WINDING MACHINE

TECHNICAL SECTOR

[0001] The present invention relates to a method for winding a strip of web material around a cylindrical product, said method being implemented using a single machine known as a winding machine, also designed for securing the strip itself.

[0002] The invention also relates to a relative winding machine suitable for wrapping a cylindrical product with a strip of web material.

BACKGROUND ART

[0003] Rolls of paper are produced by processing lines where the rewinding machines produce wraps of paper in cylinders up to 5.5 m in length, to then be cut into smaller lengths and then packaged in packages with plastic material. Winding the rolls, and more generally all the cylindrical products, exiting the rewinding machines, allows to obtain, after the cutting step, cylindrical products with a wrapping protection on the entire external cylindrical surface. This protection protects them from contamination, especially after they have been unpacked from the large plastic packaging and put in smaller quantities near the point of use. An example of this use is in hotels, hospitals and similar communities, where the strip of paper around rolls of paper also offers the possibility of showing a print with information, brands, etc. The machines for performing the winding function are made by rolling the cylindrical product itself on a strip of web material, such as paper, which has previously received two lines of glue at its ends, orthogonal to the direction of progression of the cylindrical product and lying on a support plane. Thereby, during the rolling of the cylindrical product, the strip sticks on the cylindrical product itself, which is transported and wound until the second line of glue is suitable for keeping the strip closed. The time of the rolling step of the cylindrical product above the support plane depends on the diameter of the cylindrical product and must be added to the time of laying the winding paper above a support plane. The winding paper, moreover, having a length to cover the entire length of the cylindrical product, requires a time for spreading over the support plane which negatively affects productivity. The invention described in patent EP1348630A1 seeks to solve the problem of the production speed of the winding of a cylindrical product, doubling the spreading and rolling systems. In fact, a spool is provided, whose paper intended for winding, is turned and portioned to be directed on a first rolling plane P1 and subsequently be directed on a second rolling plane P2. In turn, for cylindrical products, a device is provided which alternatively conveys them on different transit paths and corresponding to the same planes P1 and P2. Even the systems which distribute the glue lines are double and in general the concept of having two overlapped devices which perform the same function in order to increase productivity is exploited. The winding paper is spread on the planes P1 and P2, both by unwinding the spool and by using perforated conveyor belts, on which an air suction system operates to avoid the natural fluttering effect of the paper during movement. This method, in addition to having limits on the control of the paper strip with the suction means, is disadvantageous for the noise and energy costs of the same. Finally, it is easy to intuit that this invention is very expensive and complex for having doubled the various devices which operate to alternatively wind the cylindrical products. Finally, the machines which use this winding method have the great defect of having the first row of glue, necessary for connecting the paper strip on the cylindrical product, which compromises the quality of the cylindrical product itself. This defect is less tolerated when the cylindrical product concerns quality products and not only rolls of paper.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a winding machine for any cylindrical product, such as rolls of paper, with a strip of web material which is closed with glue. In particular, an object is to propose a winding machine which uses only a distribution of glue on the strip of web material, or in any case uses only one closing means, intended to keep the strip of web material closed on the cylindrical product, thus avoiding glues which can contaminate the cylindrical product itself.

Another object of the present invention is to have a winding machine which is fast in order to ensure high productivity.

Another object of the present invention is to propose a winding machine which can close the strip of web material also on the base surfaces of the cylindrical product, obtaining a complete packaging thereof.

Another object is to propose a winding machine with a small footprint. Lastly, another object is to propose a winding machine with a simple operating logic and which is economically advantageous.

Another object of the present invention is to propose a winding method of cylindrical products which allows a permanent securing means to be used only at the flap of the strip which remains externally visible following the winding.

Yet another object is to propose a winding method which allows to increase the productivity of a winding machine.

According to a first aspect of the present invention, the objects set forth above and still others are achieved by means of a method for winding a strip of web material around a cylindrical product, said method being actuated by means of a winding machine which comprises: a winding station comprising means of rotation for bringing said cylindrical product in rotation around its own axis; means for feeding the cylindrical products for feeding cylindrical products one at a time in succession to said winding station; an unwinding device for unwinding web material from a spool; a cutting system for separating the web material unwound from said spool so as to produce said strip of web material of appropriate length; a conveyor belt suitable for carrying the web material unwound from said spool and, after cutting by means of said cutting system, carrying said strip of web material at said winding station in an extended configuration; a securing device suitable for securing on itself said strip of web material wrapped around said cylindrical product; said method comprising the steps of: feeding a cylindrical product to said winding station through said cylindrical product feeding means, feeding a strip of web material to said winding station by means of said unwinding device, cutting system and conveyor belt, so that an inlet flap of said strip of web material is substantially tangent to the cylindrical surface of said cylindrical product; actuating said means of rotation to rotate said cylindrical product around its own axis of rotation with said inlet flap of the strip of web material which follows the rotation of said cylindrical product with consequent winding of said strip of web material around said cylindrical product, with said actuation of the means of rotation which is maintained at least one complete turn so that said strip of web material completely wraps the cylindrical surface of said cylindrical product; actuating the securing device so that an outlet flap of said strip of web material is made integral with the surface of the strip of web material wound on said cylindrical product; expulsion of the wrapped cylindrical product; said method being characterized in that following the activation of said means of rotation, said inlet flap follows the rotation of said cylindrical product due to the actuation of mechanical means for temporary grip suitable to act on the base surfaces of said cylindrical product so as to guide said inlet flap to rotate coaxially to said cylindrical product and with a radius of rotation equal to the radius of the cylindrical product itself and with the same angular speed.

Advantageously, said step of feeding a strip of web material to said winding station through said unwinding device, cutting system and conveyor belt, occurs by feeding said strip of web material according to a first direction parallel or inclined with respect to the axis of rotation of said cylindrical product until said strip of web material is aligned with said winding station with reference to a direction of progression of said cylindrical products through said feeding means; and thereafter conveying said strip of web material according to a second direction orthogonal to the axis of rotation (XX) of said cylindrical product, with said steps of parallel or inclined and orthogonal feeding occurring at least partially simultaneously on two strips of web material fed in succession, so that said two strips are at least partially overlapped during the aforementioned respective progression steps.

According to another aspect of the present invention the aforesaid objects are achieved by means of a winding machine suitable for winding a cylindrical product with a strip of web material, said winding machine comprising: a winding station comprising means of rotation for bringing said cylindrical product in rotation around its own axis; means for feeding the cylindrical products for feeding said cylindrical products one at a time in succession to said winding station; an unwinding device for unwinding web material from a spool; a cutting system for separating the web material unwound from said spool so as to obtain said strip of web material of appropriate length; a conveyor belt suitable for carrying the web material unwound from said spool and, after cutting by means of said cutting system, carrying said strip of web material at said winding station in an extended configuration with an inlet flap of said strip of web material positioned substantially tangent to the cylindrical surface of said cylindrical product; a securing device suitable for securing on itself said strip of web material wrapped around said cylindrical product; said winding machine being characterized in that it comprises mechanical means for temporary grip adapted to act on said inlet flap near the base surfaces of said cylindrical product so as to guide said inlet flap to rotate coaxially with said cylindrical product, with a radius of rotation equal to the radius of the cylindrical product itself and with the same angular speed.

Advantageously, the mechanical means for temporary grip comprise: gripping ends suitable to grip and secure said inlet flap near the base surfaces of said cylindrical product, support and actuation devices, said gripping ends being mounted on said support and actuation devices in a rotating mode with respect to an axis corresponding to the axis of rotation of the cylindrical product in said winding station.

Still advantageously, the support and actuation devices comprise translation devices suitable for translating said gripping ends in the direction of said axis of rotation of the cylindrical product.

Still advantageously, said gripping ends comprise suction means designed to hold said inlet flap onto said gripping ends with the support and actuation devices comprising powered actuation means designed to rotate said gripping ends coaxially to said cylindrical product.

Alternatively, the gripping ends comprise first pressing means intended to press said inlet flap onto the surface of said cylindrical product and said gripping ends are freely rotatable with respect to the axis of rotation so that the latter and said inlet flap can be rotated by the rotation of said cylindrical product. In the aforementioned case, advantageously, the strip of web material has a length in the direction of said axis of rotation greater than the length of said cylindrical product and is arranged centered with respect to the latter so that two protruding sections are generated on said strip of web material with respect to the ends of said cylindrical product, and the winding machine is characterized in that said first pressing means are actuated in the direction of said axis of rotation to press a relative protruding section against the base surface of said cylindrical product and in that it comprises auxiliary pressing means intended to press against the external surface of said protruding sections to bend them towards the relative base surfaces of said cylindrical product.

Advantageously, the unwinding device is installed on said winding machine in an aligned position with said winding station with reference to a direction of progression of said cylindrical products by means of said feeding means, with said spool being mounted on said unwinding device with its axis parallel to the axis of rotation of said cylindrical product, and the conveyor belt comprises progression and return rolls with their axis parallel to the axis of rotation of said cylindrical product, intended to convey the strip unwound from said spool in a direction orthogonal to said axis of rotation until bringing said inlet flap to a position substantially tangent to said cylindrical product in the winding station.

Alternatively, the unwinding device is mounted on said winding machine laterally behind said winding station with respect to a direction of progression of said cylindrical products through said feeding means, with said spool being mounted on said unwinding device with its axis orthogonal or inclined with respect to the axis of rotation of said cylindrical product, and said conveyor belt comprises: a first guiding unit suitable to lead said web material unwound from said spool to the cutting system for the resulting cut, said strip of web material in a parallel or inclined direction with reference to the axis of rotation of said cylindrical product until said strip of web material is aligned with said winding station with reference to a direction of progression of said cylindrical products through said feeding means, and a second guiding unit suitable to convey said strip of web material in a direction orthogonal to the axis of rotation between the aforesaid aligned position and the position in which said inlet flap is substantially tangent to said cylindrical product.

In the aforesaid solution, advantageously said first guiding unit comprises:

- a feeding unit of facing rolls, arranged downstream of said cutting system to act near an outlet flap, the respective facing rolls moving in reciprocal progression and separation to selectively switch between a driving and a release configuration, and vice versa, of said outlet flap,

- guiding organs comprising opposite surfaces reciprocally placed at a given distance to form a passage channel of said strip of web material in an intermediate position between said inlet flap and said outlet flap, said passage channel having a height allowing two of said strips of web material to be overlapped; and said second guiding unit comprises:

- said guiding organs, and

- second progression organs comprising an element of longitudinal progression arranged to find a counter-posed element of said second progression organs, said element of longitudinal progression and said counter-posed element being arranged to operate with each other at predetermined time intervals, so that in the interaction configuration a strip of web material is interposed between said element of longitudinal progression and said counter-posed element is guided to a progression orthogonal to said axis of rotation to move with said inlet flap in said position substantially tangent to said cylindrical product, whereas in the non-interaction configuration said strip of web material between them is not extended.

In general, in a winding machine according to the present invention, advantageously the securing device consists of a labelling machine arranged to apply adhesive labels on the surface of said wrapped cylindrical product at said outlet flap to secure it to the surface of said wrapped cylindrical product.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages and embodiments of the present invention will be better understood from the following description and with the aid of the accompanying drawings, provided by way of example, but not to be considered as limiting, which show:

Fig. 1 an axonometric view of the winding machine of the present invention.

Fig. 2 a sectional view of the winding machine of the present invention passing through a plane orthogonal to the axis of rotation of the spool of web material.

Fig. 3 a sectional view of the winding machine of the present invention passing through a plane orthogonal to the axis of rotation of the cylindrical product in the winding station, where the securing device is a glue sprayer.

Fig.4 an enlargement of Fig.3 in an area where two strips of web material are overlapped within the conveyor belt.

Fig. 5 the schematic detail of the mechanical means for temporary grip, in the case where a method is used for gripping the strip of web material with suction.

Fig. 6 of the schematic sections depicting two steps of the mechanical means for temporary grip of the strip of web material during the rotation of the cylindrical product, in the case of gripping with suction.

Fig. 7 the schematic detail of the mechanical means for temporary grip, in the case where a pressure method is used to engage the strip of web material. Fig.8 a section of the winding machine of the present invention passing through a plane orthogonal to the axis of the cylindrical product where the securing device is an adhesive label applicator.

Fig.9 a sectional view of the winding machine of the present invention in an embodiment where the spool of the web product has the unwinding axis parallel to the cylindrical product to be wrapped.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figures 1 and 6, the main elements of a winding machine according to the present invention will first be described in a possible embodiment.

Figures 1 , 2 show an axonometry and a section of the winding machine of the present invention, as a whole indicated with 1 , passing through a plane perpendicular to the axis of unwinding of a spool B of web material, and composed of a fixed support structure 11 , where an axis of symmetry YY defines the center of the winding machine 1 itself. Briefly, the winding machine 1 operates as follows: an unwinding device 3 of the spool B of web material intended for wrapping cylindrical products R is installed on the fixed structure 11 , which cylindrical products R are incoming from feeding means 32, pass through a winding station 4, where they are wrapped by a strip of web product C, and are subsequently ejected on an outlet plane 33. The strips of web material C are fed so as to be positioned above the cylindrical product R and with a slight downwards inclination, but could also be positioned below and inclined differently, so as to be brought substantially tangent to the cylindrical product R to be wrapped. The unwinding device 3, together with a system for maintaining the tension of the web product, are known in themselves and do not require an in-depth description, we limit ourselves to saying that in this example for the unwinding device 3 a motorized closed loop belt 26 is used which, through contact with the spool B, allows the rotation thereof. To then maintain the tension of the web product, a movable roll 27 is provided, elastically mounted on the fixed structure 11 . The po- sition 29 indicates a cutting system of the web product which has the task of obtaining in succession the strips of web product C, of determined length and greater than the cylindrical product R, which, as shown in Fig. 4, thanks to the method of the present invention, can be overlapped. The paper cutting system 29 can be obtained with any known technique, and is in this example obtained with a rotating blade operating on a contrast roll. Position 2 indicates a guiding system of the web material C, from the unwinding area of the spool B to a centering position with respect to the axis of symmetry YY. The conveyor belt 2 is, in the area upstream of the paper cutting system 29, composed of a motorized rubberized roll 21 and a contrast roll 20, having the function of carrying the strips of web material C forward, while in the downstream area it is composed of motorized rubberized wheels 22 and contrast wheels 23. The latter, which are mounted on a wheel-holder splint 25, have the function of progressing the strips of web product C in a controlled manner up to the centering with the axis of symmetry YY. The wheel-holder splint 25, being hinged at the fulcrum point 28, by means of the actuation of a pneumatic cylinder 24, has the possibility of detaching the contrast wheels 23 from the upper surface of the strip of web product C, in a precise working step, leaving it free. The conveyor belt 2 is also composed of an element of longitudinal progression 19, indicated in Figures 3, 4, obtained in the form of a roll, which extends parallel to the axis of the cylindrical product R and for a length of about half of its length. It acts on the surface below the strip of web material C and has the function of moving it orthogonally to the axis XX of the cylindrical product R by a predetermined amount. The element of longitudinal progression 19, for performing the aforementioned displacement is, for example, made with an external cover protruding in rubber on about half of its circumference, so that, when it is commanded to rotate, it has both the possibility of coming into contact, through the rubberized part, with the strip of web material C, progressing it by the predetermined amount, and then of exiting from the contact with the strip of web material C itself. In other words, when the element of longitudinal progression 19 carries its rubberized part against the upper strip of web material C, by means of the contrast of the structural element 31 a pressure suitable for driving is obtained, on the contrary when the non-rubberized part of the displacement roll 19 is against the upper strip of web material C, it is possible to insert new strips of web material C which can therefore be overlapped. The support plane 10 and the structural element 31 form a guiding unit and create a passage channel NN therebetween to keep the strips of web material C stable during their progression. The operating steps of the entire conveyor belt 2 will be described below, for now it is sufficient to specify that the assembly of the motorized rubberized roll devices 21 and the motorized rubberized wheels 22 are the elements for controlling the progression of the strip of web material C in the direction parallel to the axis XX of the cylindrical product R, while the element of longitudinal progression 19 controls the progression of the upper strip of web material C in the orthogonal direction and more precisely in the direction of the cylindrical product R.

Fig. 3, with the position 4 indicates the winding station of the cylindrical product R, obtained with a pair of rolls of which a motorized roll 6, driven by the motor 12, and by a movable roll 7 are part. The latter is free to rotate on its axis and is mounted at its ends on a pair of levers 8 which are connected, by means of a fulcrum point, to the fixed structure 11 and in turn are controlled by a pair of pneumatic cylinders 9. The motorized roll 6 has the function of supporting and transmitting the rotation movement to the cylindrical product R while the movable roll 7, has the task of being a support and of creating the outlet conditions of the same cylindrical product R, based on its geometric position. The position 30 indicates a securing device of the strip of web material C, which extends along the entire length of the cylindrical product R, provided with guns for spraying points of glue G and provided with a glue tank Sc provided with a pump. With 32, a feeding means is indicated consisting of a chute plane which allows the cylindrical products R, arriving from the rewinding machines, to reach the winding station 4. On the aforesaid feeding means 32, devices could be added to accelerate the displacement of the cylindrical product R in the winding station 4, i.e., the insertion of devices known as movable blades, but, for greater clarity of the drawings, the insertion thereof is avoided.

- Figure 4 depicts an enlargement of Figure 3 in the area of the conveyor belt 2, where two overlapping strips of web product C are shown and inserted in the passage channel NN. For each strip of web material C, an inlet flap C1 and an outlet flap C2 are indicated. The gripping ends of the mechanical means for temporary grip 5 are indicated with the number 13.

- In Fig.5 a schematic section of the mechanical means for temporary grip 5 is shown, which are installed symmetrically mirrored with respect to the axis YY of the winding machine 1 , both placed in the direction of the base surface of the cylindrical product R. The mechanical means for temporary grip 5 consist of support and actuation devices for the gripping ends 13, which in this case are suction cups. The support and actuation devices are part of the rotating sleeves 14 in which there is piping to bring the suction force to the gripping ends 13, by means of rotating joints, these not shown in the images for the purposes of greater clarity and because they are common devices known in the art, to bring the air from a fixed point to a rotating point. The sleeves 14 are mounted on the fixed structure 11 so as to be free to slide axially and free to rotate on their axis, which is placed coaxial to the axis of rotation XX of the cylindrical product R in the winding station 4. 17 indicates the motor which transmits the movement of rotation, through the drive gear 18, to the driven gear 15, which is rigidly keyed to the sleeve 14. The pneumatic cylinder 16 is connected with the sleeve 14 so as to be able to move it axially but without constraining it to rotation. Finally, the driven gear 15 is made of an increased width in order to remain engaged on the drive gear 18 even when it is moved axially. The purpose of the sup- port and actuation devices just described is to move the gripping ends 13 towards the base surface of the cylindrical product R and to rotate them coaxially with the axis XX of the cylindrical product R. The rotation of the gripping ends 13 will be synchronized with the speed of the winding station 4 and therefore with the speed of the same cylindrical product R. The strips of web material C, being portioned by a length greater than the length of the cylindrical product R and positioned centered on the same cylindrical product R, allow to have two protruding sections, indicated with C3, free to be held by the gripping ends 13. Alternatively, even if not depicted, the length of the strips of web material C could be coincident with the length of the cylindrical product R and the gripping ends 13 could act on the external side of the strips of web material C by means of slats.

- Figure 6 depicts two working steps of the mechanical means for temporary grip 5, where in Step A the inlet flap C1 of the upper strip of web material C has been positioned, by means of the element of longitudinal progression 19, in a position tangent to the cylindrical product R and the gripping ends 13 are activated in rotation. With Step B a moment of the winding process is shown where the gripping ends 13 have activated the suction force and have accompanied the upper strip of web material C to follow the rotation of the cylindrical product R. Finally, the securing device of the strip 30 is shown, positioned between the motorized roll 6 and the feeding means 32, which has just performed a spraying of glue G, on the inlet flap C1 of the upper strip of web material C .

- Figure 7 shows a schematic section of an embodiment of the mechanical means for temporary grip 5', where in this case the gripping end 13’ consists of a thrust plate, placed almost in the direction of the base surface of the cylindrical product R and capable of rotating, by means of the sleeve 14, coaxially to the axis of rotation

XX of the same cylindrical product R. The support and actuation devices differ from the support and actuation devices of Figure 5 due to the lack of the elements 15, 17 and 18 concerning the drive of the rotation. The function of the gripping ends 13’ is to hold down the protruding sections C3 of the strip of web material C and in particular to keep them bent on the base surfaces of the cylindrical product R, for this feature the gripping ends 13’ could obtain the rotational motion directly through the rotation of the cylindrical product R itself. Actuators are shown in Fig.7, of which a first pneumatic cylinder 3T, supported by the fixed structure 11 , with the function of performing a preliminary bending of the protruding sections C3 of the strip of web material C, so that the gripping end 13' can better intercept them. A second cylinder is then depicted with 34’, placed in the axis of the sleeve 14 in order to then act on the axis XX of the cylindrical product R. Its task is to perform a final fold on the protruding sections C3, towards the inside of the cavity of the tube on which the same cylindrical product R is wound.

- Fig. 8 depicts a section, passing through a plane orthogonal to the axis of unwinding of a spool B, of a section 1” which has an embodiment of the securing device 30” of the strip of web material C. In this case, instead of the securing device 30, suitable for spraying a glue G, a common labelling system 30” is installed on the fixed structure 11 , at the outlet of the cylindrical product R from the outlet plane 33. This labelling system, well known in the art, involves distributing small adhesive portions, often pre-printed with logo or acronym, which in this case, applied on the already wrapped cylindrical product R have the task of keeping the outlet flap C2 secured on the strip of web material C.

- Fig. 9 depicts a sectional view of the winding machine of the present invention T” in an embodiment where the spool B, placed above the fixed structure 11 , has the axis of unwinding parallel to the axis XX of the cylindrical product R. This example has the same type of embodiment described in Figure 3 except that the conveyor belt 2 has only means for moving the strip of web material C in only one direction, i.e. , towards the winding station 4. The conveyor belt 2 has in the area upstream of the paper cutting system 29 the motorized rubberized roll 21 and the contrast roll 20, with an axis of rotation parallel to the axis of the cylindrical product R, and having the function of carrying the web material forward. In the downstream area, the element of longitudinal progression 19, with an axis of rotation parallel to the axis of the cylindrical product R, and which in this case can be entirely rubberized, controls the progression of the strip of web material C, positioning it with the inlet flap C1 tangent to the cylindrical product R.

The winding machine 1 of the present invention has the following operation: the cylindrical products R coming from the rewinding machines, one at a time in succession, are centered with respect to the axis YY and are conveyed through a feeding means 32 to the winding station 4 where they rest stably between the motorized roll 6 and the movable roll 7. At the same time, the spool B is unwound and portioned by the cutting system 29, obtaining a first strip of web material C. The strips of web material C will be produced at a length greater than the length of the cylindrical product R and in particular at a length which allows to obtain two protruding sections C3 with respect to the cylindrical product R, of a length of about the radius thereof. The strip of web material C just produced, by means of the conveyor belt 2, has the possibility of reaching with maximum speed its centered position point with respect to the axis YY, and thanks to the fact of passing through the series of motorized rubberized rolls 22 and the contrast rolls 23 is kept perfectly controlled during its progression. In addition, the upper strip of web material C, through the passage channel NN, between the support plane 10 and the structural element 31 can remain stable and the fluttering effects thereof are prevented. The spool B does not need to stop in the unwinding of the web product for which a second strip of web material C is produced in succession, which, thanks to the pushing action of compressed air nozzles, not shown in the drawings, overlaps and rests on the first strip of web material C already cut. In the meantime, the opening movement of the wheel-holder splint 25 and the simultaneous rotation of the element of longitudinal progression 19 allow to position the first strip of web material C, i.e., the strip of web material C which rests on the support plane 10, towards the cylindrical product R and in particular to position the inlet flap C1 just tangent on the upper part thereof of the same cylindrical product R. The opening of the wheel-holder splint 25 occurs for the minimum time sufficient to allow the strip of web material C which rests on the support plane 10, to exit between the wheels 25 themselves, due to the element of longitudinal progression 19, and then close and re-check the progression of the next strip of web material C. The actuation of the winding station 4 through the motorized roll 6, allows the rotation of the same cylindrical product R on its axis XX, which takes place simultaneously with the activation of the mechanical means for temporary grip 5. Therefore, the gripping ends 13, due to the suction effect of the suction cups, perform the dragging and guiding of the strip of web material C around the same cylindrical product R. As shown in step B of Figure 6, at the passage of the angular rotation of the gripping ends 13, at the securing device 30, drops of glue G are sprayed over the entire length of the inlet flap C1 of the strip of web material C. Upon completion of the rotation of the cylindrical product R on itself by about one and a quarter turns, the strip of web material C finally closes, attaching by means of the drops of glue G to the other outlet flap C2. The cylindrical product R, just wrapped, exits the winding station 4 through the opening of the movable roll 7 and a quick stop at the rotation of the motorized roll 6, thanks to the thrust effect of the rotation inertia. The steps just described are then repeated, thus obtaining an automatic wrapping of cylindrical products R with a high production speed. When using materials for wrapping where liquid glues cannot be used, the winding machine 1” of the present invention has the possibility of using adhesive labels for securing the strip of web material C around the cylindrical product R. As shown in Fig.8, in this one embodiment variant 1”, there is in fact the securing device 30 for spraying glue G, but the securing device 30” is installed which consists of a device called a labelling machine, diffused and known in the art, with the task of applying precisely a series of adhesive labels distributed with a certain pitch over the entire length of the strip of web material C. The securing device 30” being placed at the outlet of the cylindrical product R between the outlet plane 33 and the movable roll 7, it operates at the passage of the cylindrical product R itself and applies the adhesive labels in step with the end of the outlet flap C2 of the strip of web material C. In Fig. 9 the winding machine T” has an embodiment variant where the spool B is positioned to feed the strips of web product C parallel to the axis XX of the cylindrical product R, i.e. , in the same direction as the winding direction. In this case, using spools B of a width slightly greater than the length of the cylindrical product R, the strips of web material C produced are guided by the conveyor belt 2 to be positioned directly tangent to the cylindrical product R and perform the wrapping process as previously described. This solution, which is simpler from a constructive point of view, can only be used when the cylindrical products R are generally less than 2 meters in length, i.e., when the spools B are not bulky and heavy and therefore difficult to handle. In summary, the embodiment variations are shown to highlight various advantages offered by the present invention. For example, in the embodiment example of Figure 7 , thanks to the activation in sequence of the first pneumatic cylinder 3T and of the second pneumatic cylinder 34’, which operating during the rotation step of the cylindrical product R, allow to completely fold the protruding sections C3 of the strip of web material C. I.e., thanks also to the fact that the cavity of the cardboard tube of the cylindrical product R itself offers an area where the protruding sections C3 can remain stuck, it is advantageously obtained, in addition to the winding, a real packaging of the cylindrical product R. In the winding machine 1 , of the present invention, the drive of the motors, of the pneumatic cylinders and the set of sensors for process control, will be managed by a processor, even if not shown, which is easily programmable by a common technician of the art. From the descriptions made the great advantage of the winding machine 1 is evident, to be able to obtain a cylindrical product R, wrapped by a strip of web material C, with a single distribution of glue or adhesive labels, which serves only for the closure of the end flaps C1 and C2, leaving the cylindrical product R itself clean. This is very appreciated in terms of quality and waste reduction, when, for example, the cylindrical product R is a product such as tablecloths, wallpaper, etc. The advantage of being able to produce a series of strips of web material C, which can overlap, can also be produced with greater speed, without stopping the movement of the spool B is also evident.

At the same time, the winding machine 1 offers the advantage of greater productivity, thanks to the operations of the conveyor belt 2, the winding station 4 and the temporary gripping means 5 of the strip of web material C, which occur in parallel steps and not in succession. Finally, the aforementioned advantages remain safeguarded even in the presence of variants or modifications of a practical application nature which can be made by a person skilled in the art to a winding machine as described above, while remaining within the scope of protection defined by the following claims.

Claims

CLAIMS ) Method to wind a strip of web material (C) onto a cylindrical product (R), said method being actuated by a winding machine (1) which includes: a winding station (4) including means of rotation (6, 7) adapted to bring said cylindrical product (R) in rotation around its own axis of rotation (XX); feeding means (32) for the cylindrical products (R) for conveying in succession the cylindrical products (R) to said winding station (4); an unwinding device (3) for unwinding web material from a spool (B); a cutting system (29) to separate the web material unwound from said spool (B) in order to obtain said strip of web material (C) of suitable length; a conveyor belt (2) suitable to transport said strip of web material (C) unwound from said spool (B) in extended configuration to said cutting system (29) and to said winding station (4); a securing device (30, 30') suitable to secure on itself said strip of web material (C) wound around said cylindrical product (R); said method comprising the steps of: feeding of said cylindrical product (R) to said winding station (4) through said feeding means (32) of the cylindrical products (R); feeding of said strip of web material (C) to said winding station (4) by means of said unwinding device (3), cutting system (29) and conveyor belt (2), so that an inlet flap (C1) of said strip of web material (C) is substantially tangent to the cylindrical surface of said cylindrical product (R); actuation of said means of rotation (6, 7) to rotate said cylindrical product (R) around its own axis of rotation (XX) in coordination with said inlet flap (C1) of strip of web material (C), which follows the rotation of said cylindri- cal product (R) having as a result the winding of said web material (C) around said cylindrical product (R), said actuation of said means of rotation (6, 7) operating for at least one complete turn so that said web material (C) completely wraps the cylindrical surface of said cylindrical product (R); actuation of said fastening device (30, 30') so that an outlet flap (C2) of said strip of web material (C) is integral with the surface of said web material (C) wound around said cylindrical product (R); expulsion of the wrapped cylindrical product; said method being characterized in that following the activation of said means of rotation (6, 7) said inlet flap (C1) follows the rotation of said cylindrical product (R) due to the actuation of mechanical means for temporary grip (5, 5') suitable to act on the base surfaces of said cylindrical product (R) in order to rotate said inlet flap (C1) coaxially to said cylindrical product (R) and with a radius of rotation equal to the radius of the cylindrical product itself and with the same angular speed. ) Method to wind a strip of web material (C) onto a cylindrical product (R) according to claim 1 characterized in that said step of feeding said strip of web material (C) to said winding station (4) through said unwinding device (3), cutting system (29) and conveyor belt (2), is obtained by conveying said strip of web material (C) in a first direction parallel or inclined with respect to the axis of rotation (XX) of said cylindrical product (R) until said strip of web material (C) is aligned with said winding station (4) with reference to the direction of progression of said cylindrical products (R) through said feeding means (32); and thereafter by conveying said strip of web material (C) in a direction orthogonal to the axis of rotation (XX) of said cylindrical product (R), with said steps of parallel or inclined and orthogonal feeding occurring at least partially at the same time on two strips of web material (C) fed in succession, so that said two strips are at least partially overlapped during said steps of feeding.) Winding machine (1) for wrapping a cylindrical product (R) with a strip of web material (C), said winding machine (1) including: a winding station (4) including means of rotation (6, 7) adapted to bring said cylindrical product (R) in rotation around its own axis of rotation (XX); feeding means (32) for the cylindrical products (R) for conveying in succession the cylindrical products (R) to said winding station (4); an unwinding device (3) for unwinding web material from a spool (B); a cutting system (29) to separate the web material unwound from said spool (B) in order to obtain said strip of web material (C) of suitable length; a conveyor belt (2) suitable to transport said strip of web material (C) unwound from said spool (B) to said cutting system (29) and to said winding station (4), in extended configuration with an inlet flap (C1) of said strip of web material (C) substantially tangent to the cylindrical surface of said cylindrical product (R); a securing device (30, 30') suitable to secure on itself said strip of web material (C) wound around said cylindrical product (R); said winding machine being characterized in that it includes mechanical means for temporary grip (5, 5') suitable to act on said inlet flap (C1) at the base surfaces of said cylindrical product (R) in order to rotate said inlet flap (C1) coaxially to said cylindrical product (R), with a radius of rotation equal to the radius of the cylindrical product itself and with the same angular speed. ) Winding machine (1) according to the previous claim characterized in that said mechanical means for temporary grip (5, 5’) comprise: gripping ends (13, 13') suitable to grip and secure said inlet flap (C1) in correspondence of the base surfaces of said cylindrical product (R); support and actuation devices (14, 15, 16, 17, 18), supporting said gripping ends (13, 13') in a rotating mode with respect to an axis corresponding to the axis of rotation (XX) of the cylindrical product (R) in said winding station (4). ) Winding machine (1) according to the previous claim characterized in that said supporting and actuation devices (14, 15, 16, 17, 18) include translation elements intended for translating said gripping ends (13, 13') in the direction of said axis of rotation (XX) of the cylindrical product (R). ) Winding machine (1) according to claim 4 characterized in that said gripping ends (13, 13’) include suction means designed to hold said inlet flap (C1) onto said gripping ends (13, 13’) and in that said support and actuation devices (14, 15, 16, 17, 18) include powered actuation means designed to rotate said gripping ends (13, 13’) coaxially to said cylindrical product (R). ) Winding machine (1) according to claim 4 characterized in that said gripping ends (13, 13') include first pressing means () intended to press said inlet flap (C1) onto the surface of said cylindrical product (R) and in that said gripping ends (13, 13') rotate freely around the axis of rotation (XX) so that said gripping ends (13, 13’) and said inlet flap (C1) rotate due to the rotation of said cylindrical product (R). ) Winding machine (1) according to the previous claim in which the length of said strip of web material (C) in the direction of said axis of rotation (XX) is greater than the length of said cylindrical product (R) and centered with reference to said cylindrical product (R) so that two protruding sections (C3) are generated on said strip of web material (C) in correspondence of the ends of said cylindrical product (R), said winding machine (1) being characterized in that said first pressing means () are actuated in the direction of said axis of rotation (XX) to press one of said protruding section (C3) on the base surface of said cylindrical product (R) and in that it comprises auxiliary pressing means (3T, 34') intended to press down said protruding sections (C3) to bend them towards the base surfaces of said cylindrical product (R) located behind. ) Winding machine (1) according to claim 3 characterized in that said unwinding device (3), installed onto said winding machine (1) , is aligned with said winding station (4) with reference to a direction of progression of said cylindrical products (R) through said feeding means (32), said spool (B) being mounted on said unwinding device (3) with its axis parallel to the axis of rotation (XX) of said cylindrical product (R), and in that said conveyor belt (2) includes feed and return rolls with their axis parallel to the axis of rotation (XX) of said cylindrical product (R), intended to convey the strip of web material (C) unwound by said spool (B) in a direction orthogonal to said axis of rotation (XX), therefore bringing said inlet flap (C1) to a position substantially tangent to said cylindrical product (R) in said winding station (4). 0) Winding machine (1) according to claim 3 characterized in that said unwinding device (3) is mounted on said winding machine (1) laterally behind said winding station (4) with respect to a direction of progression of said cylindrical products (R) through said feeding means (32), said spool (B) being mounted on said unwinding device (3) with its axis orthogonal or inclined with respect to the axis of rotation (XX) of said cylindrical product (R), and in that said conveyor belt (2) comprises:

- a first guiding unit suitable to lead said strip of web material (C) unwound by said reel (B) to the cutting system (29) for the resulting cut, in a parallel or inclined direction with reference to the axis of rotation (XX) of said cylindrical product (R) until said strip of web material (C) is aligned with said winding station (4) with reference to a direction of progression of said cylindrical products (R) through said feeding means (32), and

- a second guiding unit () intended to convey said strip of web material (C) in a direction orthogonal to the axis of rotation (XX) between said aligned position and the position in which said inlet strip (C1) is substantially tangent to said cylindrical product (R). ) Winding machine (1) according to the previous claim characterized in that said first guiding element comprises:

- a feeding unit ef facing rolls (22, 23), placed downstream of said cutting system (29) to act on the outlet flap (C2), said facing rolls moving in mutual progression and separation to selectively switch between a driving and a release configuration, and vice-versa, of said outlet flap (C2),

- guiding organs (10, 31) comprising opposite surfaces reciprocally placed at a given distance to form a passage channel (NN) of said strip of web material (C) in an intermediate position between said inlet flap (C1) and said outlet flap (C2), said passage channel (NN) having a height allowing two of said strips of web material (C) to be overlapped; and said second guiding unit including:

- said guiding organs (10, 31), and

- second progression organs (19, 31) including an element of longitudinal progression (19) disposed to find a counter-posed element (31) of said second progression organs, said element of longitudinal progression (19) and counter-posed element (31) being arranged to operate at predetermined time intervals, so that in the interaction configuration a strip of web material (C) interposed between said element of longitudinal progression (19) and said counter-posed element (31) is guided to a progression orthogonal to said axis of rotation (XX) to move with said inlet flap (C1) in a position substantially tangent to said cylindrical product (R), whereas in the non-interaction configuration said strip of web material (C) interposed between them is not extended. ) Winding machine (1) according to claim 3 characterized in that said securing device (30) consists of a labelling machine intended to apply adhesive labels on the surface of said wrapped cylindrical product (R) in correspondence of said outlet flap (C2) to secure said outlet flap (C2) to the surface of said wrapped cylindrical product (R).