DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

[0034] A detailed description will be given below of a particularly advantageous embodiment of the invention, complete with accessories and elements which may also, in part, be omitted. The embodiment illustrated is of the type having tubular winding-up cores on which the individual rolls are formed, but, as stated previously, the machine may also be designed for winding-up without a tubular core.

[0035] The rewinder, generally designated 1, comprises side frames 3 on which is mounted a winding-up cradle, generally designated 5, and comprising in the example shown a trio of winding-up rollers 7, 9 and 11. The first winding-up roller 7 forms, together with the second winding-up roller 9, a gap 13 through which the weblike material and the roll pass at the start of the phase of formation around the respective winding-up core A.

[0036] The first winding-up roller 7 receives the weblike material N from an unwinder (not shown). The third winding-up roller 11 is mounted on an arm 15 oscillating about an axis 17 in order to adapt to the increase in size of the roll being formed. Downstream of the winding-up cradle is disposed an unloading chute 21 with a roll-stopping device 23 controlled by an actuator 25, which intervenes to stop the movement of the rolls and unload, in a controlled manner, the individual rolls delivered to the winding-up cradle along the chute 21.

[0037] Below the first winding-up roller 7 extends a curved rolling surface 25 along which the winding-up cores A roll in the first phase of winding-up of the weblike material N, in accordance with a technology known and described in detail in WO-A-94/21 545, to which reference is made for more descriptive details. Reference 27 designates an element for severing the weblike material, which rotates in a controlled manner about an axis of rotation 29 and interacts with the first winding-up roller 7 to perform the severing of the weblike material at the end of the winding-up of each roll, so as to generate a final free edge, which is eventually wound onto the roll just completed, and an initial free edge which is caused to adhere to the next winding-up core.

[0038] The winding-up cores A are fed to the winding-up cradle 5 by means of a feeder 31 which comprises a re-emergence guide for the cores A, designated 33. The tubular cores A are inserted into the re-emergence guide 33 from below, sliding or rolling along a base surface 35 of a hopper 37 in which is also located an agitator 39 that prevents the cores from becoming jammed. The cores are unloaded individually onto the unloading surface 47 and retained in the waiting position by an elastic blade 49.

[0039] A rotating inserter 51, synchronized with the rotation of the severing means 27, acts to push each tubular core A into the channel defined by the rolling surface 25 and the first winding-up roller 7, at the start of each winding-up operation.

[0040] Above the surface 47, in alignment with the holding position of the cores A before insertion into the channel between the rolling surface 25 and the first winding-up roller 7, are disposed a plurality of first nozzles 53 which apply to the temporarily wafting tubular core A the adhesive necessary for the adhesion of the initial free edge of the weblike material. As an alternative to the gluing system, other systems may be used, for example suction or electrostatic systems or others known in the art.

[0041] Along the path of the weblike material N coming from the unwinder (not shown) is disposed an embossing and laminating unit generally designated 61 and comprising a first embossing cylinder 63 rotating about an axis of rotation 63A and a second embossing cylinder 65 rotating about an axis of rotation 65A. The two embossing cylinders, made for example from steel or another hard material, have surface tips or protuberances which perform the embossing of the material.

[0042] Interacting with the first embossing cylinder 63, which is in a position approximately vertically above the second embossing cylinder 65, is a first pressure roller 67 supported by an arm 69 hinged at 71 and pressed against the embossing cylinder 63 by means of an actuator 73. Interacting with the second embossing cylinder 65 is a second pressure roller 75 supported by an arm 77 hinged at 79 and pressed against the embossing cylinder 65 by means of an actuator 81. As can be seen in FIG. 1, the three axes of rotation, of the embossing cylinders and of the pressure roller 67, are approximately vertically one above the other, in other words they lie in a common vertical plane shown by the line P-P. Conversely, the axis of rotation of the pressure roller 75 is offset and is located, relative to the plane in which the axes of rotation 63A, 65A of the embossing cylinders 63, 65 lie, on the opposite side from the winding-up cradle. A particularly compact configuration is thus obtained.

[0043] The first and second embossing cylinders 63, 65 and the respective pressure rollers 67 and 75 are supported by the same side frames 3 that support the members forming the winding-up cradle.

[0044] Interacting with the first embossing cylinder 63 is an adhesive dispenser 83, comprising in this example a distributor 85, a first screened cylinder 87 and a second plate cylinder 89, in contact with the ply of material passed around the first embossing cylinder 63 in order to apply, in a manner known per se, an adhesive to the embossed protuberances of the ply generated on the surface of the embossing cylinder 63. The adhesive dispenser is located above the pressure roller 75.

[0045] Also interacting with the first embossing cylinder 63 is a coupling or laminating roller 91 supported by an arm 93 hinged at 95 and stressed against the embossing cylinder 63 by means of a piston-and-cylinder actuator 97. By means of this, the two plies, separately embossed on the two embossing cylinders 63, 65, are coupled by lamination after the application of the adhesive.

[0046] Two plies of weblike material, designated V1 and V2, are fed to the embossing and laminating unit 61 and are embossed separately, the first between the embossing cylinder 63 and the pressure roller 67 and the second between the embossing cylinder 65 and the pressure roller 75. The ply V2 is then detached from the second embossing cylinder 65 and placed gently on the first ply V1 passed around the first embossing cylinder 63. The two plies, thus placed one above the other, are laminated between the first embossing cylinder 63 and the laminating roller 91 to form the weblike material N. An application of adhesive being provided by the dispenser 83, the lamination results in the two plies V1 and V2 being bonded one to the other.

[0047] In the example of embodiment shown, there is provided along the path of the weblike material N coming from the laminating/embossing unit 61 a ply-bonding unit 101 comprising a cylinder 103 with which interact ply-bonding rollers 105 stressed under pressure against the cylinder 103 by means of one or more expansion boxes 107 which are expanded to high pressure. The ply bonding unit 101 may be used in addition to the embossing unit 61, for example when the latter is operating without adhesive, because it lacks the dispenser 83 or because the latter has been taken out of service. This does not exclude the possibility that the machine lacks the embossing unit 61 and is equipped only with the ply-bonding unit 101 which provides the coupling of the two plies V1, V2, appropriately transported to the ply-bonding unit 101, for example by being passed around the roller 91. It is also possible to arrange that the ply-bonding unit 101 is entirely absent and that the machine is supplied solely with the embossing and laminating unit 61, with the associated adhesive dispenser 83. In this case. the path of the weblike material N will be slightly modified.

[0048] Along the path of the weblike material N, between the ply-bonding unit 101 and the winding-up cradle 5, a perforating unit 111 is provided, comprising a rotating blade-supporting roller 113 and a fixed roller 115 bearing a counter-blade. The perforating unit 111 may be of the traditional type and is not described in detail.

[0049] The weblike material N which passes through the perforating unit 111 is provided with a series of perforation lines orthogonal to the longitudinal course of the weblike material N, which perforation lines subdivide the weblike material N into a series of slips or sheets for subsequent use by the end consumer.

[0050] The perforated weblike material N coming from the perforating unit 111 is passed around a cylinder 117 and, from there, around the first winding-up roller 7 in order to be passed to the winding-up cradle.

[0051] Interacting with the first winding-up roller 7 is a series of spray nozzles 121 which serve to apply an adhesive to the weblike material N in order to perform the sealing of the final free edge of the weblike material at the end of the winding-up of each individual roll, following the severing of the weblike material by the severing member 27.

[0052] As clearly illustrated in FIG. 1, the nozzles 121 (which are provided in appropriate numbers and suitably spaced to ensure correct gluing also of areas over the length of the roll, in other words over the width of the weblike material) are disposed in a manner such as to spray the adhesive onto the weblike material at the desired moment, before said weblike material passes into the channel defined by the winding-up roller 7 and the rolling surface 25, and thus before the member 27 for severing the weblike material acts upon it. In this way, the adhesive, subsequently intended to seal the roll, is applied to the weblike material before the latter is severed.

[0053] Expediently, the nozzles 121 may be mutually spaced relative to one another in a manner such that the adhesive distributed thereby does not affect those areas of the weblike material N with which the severing member 2⁻ is in contact, in a manner such that the latter does not become contaminated with adhesive during each winding-up cycle.

[0054] More expediently, moreover, contamination of the severing member 27 by the adhesive sprayed by the nozzles 121 can be prevented with appropriate timing of the actions of the two members. Specifically, as is known from the prior art, the severing member 27 may be phased, relative to the perforation lines produced by the perforating unit 115 on the weblike material N, in a manner such that the weblike material is severed by tearing at a position between the roll being wound up between the rollers 7, 9 and 11 and the point of contact between the severing member 27 and said weblike material, in other words the point at which the weblike material is pinched between the severing member 27 and the first winding-up roller 7. Since the adhesive applied by the nozzles 121 is to remain on the end part or tail of the weblike material which is being wound up on the roll being completed, the spray nozzles 121, the perforator 111 and the severing member 27 may be mutually phased in a manner such that the severing action performed by the severing member 27 on the weblike material takes place when the perforation along which the weblike material parts as a result of the pinching action of the severing member 27 is located at a sufficient distance from the area of action of said member 27, so that the adhesive previously sprayed by the nozzles 121 onto the weblike material is reliably outside the area of contact between the weblike material and the severing member 27.

[0055] While the foregoing has provided a description of the possibility of using a series of spray nozzles 53 to apply an adhesive to the tubular cores A before the latter are inserted between the rolling surface 25 and the winding-up roller 7, this does not exclude the possibility that the adhesive necessary for anchoring the initial free edge of the weblike material to the winding-up core A is applied by said nozzles 121. To this end, provision may be made for the latter to be actuated twice, once in order to apply the adhesive to the area of weblike material N which, after the severing performed by the severing member 27, will form the tail or final end of the roll, and a second time to the weblike material which will enter into contact with the tubular winding-up core A. In this case also, provision being made for interrupting the delivery of the adhesive by the spraying nozzles 121, it will be possible to prevent contamination of the severing member 27 by the adhesive. In practice, the severing member will act between two linear areas of adhesive, the more forward one in order to seal the finished roll and the more rearward one in order to initiate the subsequent winding-up.

[0056] The use of two series of nozzles 53 and 121 is expedient when the adhesives used for sealing the final edge of the roll and anchoring the initial edge to the core are of different nature and features. This depends on the type of product wound up and/or the winding-up speed.

[0057] FIGS. 2, 3 and 4 show three consecutive phases in the operation of winding-up a roll of weblike material.

[0058] In FIG. 2, the roll R is in an intermediate phase of formation. A new core A, in this example, has already been positioned for subsequent insertion. FIG. 3 shows the phase of completion of the winding-up of the roll, with the separating member which rotates in the direction of the arrow f27 and enters the channel defined between the rolling surface and the upper winding-up roller 7. The nozzles 121 spray the adhesive necessary for the sealing of the final edge. FIG. 3 also shows the phase of delivery of the adhesive to the new core A by the nozzles 53 on the weblike material N before its severing. This delivery may be simultaneous or staggered in time, and in particular advanced, by comparison with the delivery by the nozzles 121. FIG. 4 shows the subsequent phase, in which a new core A has already been inserted into the channel defined between the rolling surface 25 and the winding-up roller 7, in contact with said rolling surface and with the weblike material N passed around the winding-up roller 7. Downstream of the severing member, the weblike material N has been torn to form a final edge LF which eventually becomes wound up onto the roll R, and to which the adhesive C has been applied by the spray nozzles 121. LI designates the initial edge which is wound up onto the new core. The unloading of the roll R from the winding-up cradle takes place in a manner known per se.

[0059] In the example shown, the machine also has a printing unit, generally designated 131 and comprising an inker 133, a screened cylinder 135 and a plate cylinder 137 which bears the plate on which is engraved the design, decoration, text or other information to be printed on the weblike material. In this example, only the ply V1 of the weblike material N is caused to pass onto the return cylinder 139 with which the plate cylinder 137 interacts, while the other ply V2 is passed, without printing, to the embossing unit or, possibly, directly to the ply-bonding unit.

[0060] It is understood that the drawing shows only a simplification of the invention, provided by way of a practical demonstration, and that it may be varied in shapes and arrangements without thereby departing from the scope of the concept underlying said invention.