MACHINE AND METHOD FOR WINDING REELS OF WEB MATERIAL

Abstract

The rewinding machine comprises: a first winding member (3) and a second winding member (9) defining a winding cradle (19); a winding rod inserter (25) for introducing a winding rod (A1; A2) in the winding cradle (19) to wind a reel (B1) of web material (N) on said winding rod. The inserter (25) is arranged and designed for introducing the winding rod (A2) against the first winding member (3) towards the winding cradle (19) and the second winding member (5) is designed and arranged to allow a previously formed reel (B1) to be unloaded from the winding cradle (19).

Description

TECHNICAL FIELD

The present invention relates to winding or rewinding machines for producing rolls or reels of web material, such as paper, tissue paper, non-woven fabric and the like. The invention also relates to improvements to the winding methods for producing rolls or reels of web material.

STATE OF THE ART

In the paper converting industry and in other continuous web material processing industries there is the need for producing reels or rolls of wound web material constituting intermediate products for subsequent converting operations. In the paper converting field, in particular, it is provided for a single or multiple ply of cellulosic material, for example tissue paper, to be unwound and wound again on reels. For producing large diameter reels, designed to be subsequently unwound and rewound in small diameter logs that, cut orthogonally to their axis, producing single rolls for final consumption, start-stop rewinding machines are used, i.e. machines wherein the feed of the web material is interrupted or substantially slowed down when a reel has been completed to allow insertion of a new winding rod, around which the subsequent reel is formed, in the machine.

These rewinding machines usually have a winding cradle formed by two winding rollers with substantially parallel axes. A winding rod or tubular winding core, around which the reel is formed, is inserted in the nip formed between the two rollers. The reel is formed above the nip between the rollers with a gradual increase in diameter. In some cases a third movable winding-roller is also provided, which is gradually raised as the reel diameter increases. Once winding has been finished, the feed is interrupted, the formed reel is unloaded from the winding cradle, the web material is severed to form a tail of the finished reel and a head for starting winding around a subsequent rod, the head is anchored to a new winding rod and this latter is driven into rotation in the winding cradle to start formation of the subsequent reel.

DE-A-3207461 schematically discloses a rewinding machine of this type. WO-A-2007/048872 describes a rewinding machine of the above mentioned type, wherein the first winding member comprises a roller and the second winding member comprises a belt or a series of belts, driven around two guide rollers. No means for unloading the reels are described.

U.S. Pat. No. 4,456,190, IT-B-1130631, U.S. Pat. No. 4,635,867, U.S. Pat. No. 4,552,316 and DE-A-3151256 disclose rewinding machines of the above mentioned type, wherein the reel is unloaded by a side pusher that pushes the reel laterally to make it roll outside the winding cradle. A separate insertion means inserts a new rod or tubular winding core. In these machines the subsequent winding rod or core is introduced in the winding cradle from the top, i.e. it is put on the winding rollers.

U.S. Pat. No. 5,577,684, GB-A-2065081, U.S. Pat. No. 4,974,786, U.S. Pat. No. 4,516,735, U.S. Pat. No. 3,918,654 and U.S. Pat. No. 5,911,384 describe rewinding machines of the above mentioned type, wherein a single pivoting member, arranged on a side of the winding cradle, not only unloads the formed reel to move it away from the winding cradle, but also inserts a new winding rod or core in said cradle from the top.

U.S. Pat. No. 3,841,578 discloses a rewinding machine with a pair of winding rollers defining a winding cradle. The machine further comprises a side roller, which pushes the reel, once it has been completed, to move it away from the winding cradle. Once the reel has been at least partially ejected from the winding cradle, the winding rollers are moved away from each other. The reciprocal movement away of the two winding rollers allows the insertion from the bottom of a new winding rod. This winding rod passes across the nip defined between the two rollers, which at are then moved towards each other again to support the new winding rod or core and to start winding of a new reel around the new core inserted from the bottom upward.

U.S. Pat. No. 4,842,209 and US-A-2004/0159737 disclose rewinding machines of the above mentioned type, wherein the new winding core is inserted from the bottom after having moved the winding rollers, defining the winding cradle, away from each other. In these machines one of the two winding rollers also provides for a series of belts driven around the same roller and around a third guide roller. The reel is wound by maintaining it always in contact with the first and the second winding roller. Once winding has been finished, the reel is moved away from the winding cradle and brought in contact with the belts entrained around the second winding roller. The belts act as a transfer element for transferring the reel from the winding cradle towards an unloading area. When the formed reel is on the belts, the winding rollers can be moved away from each other in order to insert, through the nip defined between them, the new winding core, which is lifted from the bottom upward. Once the end position of the winding rod or core has been achieved, the winding rollers are moved towards each other again to allow starting winding of the new reel.

One of the critical aspects of these machines is the continuity of the winding process. The high dimension of the formed reels and the operation complexity of unloading the reels and inserting new winding rods often require for the web material feed to be completely stopped once a reel has been completely wound, in order to allow: the insertion of a new winding rod or core, the severing of the web material, the anchoring of the head thereof on a new winding rod or core, the start of the winding of the new reel.

These start and stop cycles entail production losses as well as stresses in the production line.

In winders for producing very large diameter reels, for example winders arranged downstream of the continuous paper machines, winding means are provided with a single winding roller and a pair of guides. The reel is formed around a winding rod, which is pressed against the winding roller and is supported on the horizontal rectilinear guides extending from the winding roller towards a reel unloading area. Usually a winding rod inserter is provided in these winders, which brings the winding rod against a single winding roller to wind a reel. The whole winding cycle is performed through this single winding roller, against which the reel is pushed by a pair of slides engaging the ends of the winding rod and gradually moving away from the winding roller as the reel diameter increases. Examples of this kind of machines are described in WO-A-2009/049867; EP-A-0943569; DE-A-19944295; EP-A-1571109; EP-A-1245515; U.S. Pat. No. 6,145,778; EP-A-1071627; GB-A-2188619; U.S. Pat. No. 6,047,916.

U.S. Pat. No. 2,989,262 discloses a machine comprising a first winding roller and a second winding roller, which define a winding cradle. The machine also comprises a winding rod inserter for introducing a winding rod in the winding cradle at the start of each cycle. A reel of web material is wound around the winding rod. The inserter is arranged and designed so as to introduce the winding rods against the first winding roller towards the winding cradle. Once a reel has been completely wound, the web material is severed, the machine is stopped, the reel is unloaded from the winding cradle and subsequently the new winding rod is inserted to start a new winding cycle of a new reel.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a new rewinding machine and a new winding method that overcome, wholly or partially, one or more drawbacks of the known machines.

According to one aspect, the invention relates to a rewinding machine comprising: a first winding member and a second winding member defining a winding cradle; a winding rod inserter for introducing a winding rod in the winding cradle and for winding a reel of web material on said winding rod, as well as a system of roller(s) suitable to control the reel diameter increase. The inserter is advantageously arranged and designed so as to introduce the winding rod against the first winding member towards the winding cradle; and the second winding member is designed and arranged to allow a previously formed reel to be stopped and unloaded from said winding cradle. In this way, while a formed reel is unloaded from the winding cradle, a new winding rod is inserted towards the winding cradle and starts to wind around itself a second reel of web material as a result of the contact with only one of the two winding members. The two winding members can be thus controlled independently of each other, the first one to start winding a new reel and the second one to stop and unload a reel that has been completed during the previous winding cycle. The cycle of unloading the reel and starting winding a new reel is therefore faster and can be performed without stopping the machine. The feed speed of the web material is preferably reduced during the reel unloading, but it is not stopped. The speed reduction is substantially lower than the reduction necessary in other known rewinding machines, with consequent advantages from a productivity viewpoint too.

In particular, the object of the present invention is a rewinding machine comprising:

• • at least a first winding member and a second winding member defining a winding cradle;
  • a winding rod inserter for introducing a winding rod in the winding cradle to wind a reel of web material on said winding rod, said inserter being arranged and designed so as to introduce said winding rod against the first winding member towards said winding cradle;
    characterized in that: the second winding member has a variable configuration and, if necessary, a variable speed according to a law different from that of the speed of the first winding member, and is designed and arranged to allow a reel, formed around a first winding rod, to be unloaded from said winding cradle, through a change in the configuration of said second winding member; and that said inserter, said first winding member and said second winding member are controlled such that said reel of web material wound around said first winding rod is unloaded from said winding cradle through a change in the configuration and, if necessary, in the speed of the second winding member, whilst said inserter moves a second winding rod, that can be previously brought to the line speed, towards the first winding member and said first winding member brings said second winding rod into rotation.

In advantageous embodiments the first winding member comprises a first winding roller. According to preferred embodiments of the present invention, the second winding member can comprise a flexible element, for example a belt or a series of belts, entrained around a second winding roller and a guide element, for instance a roller or a series of pulleys.

In some embodiments the first and the second winding roller are arranged with parallel, preferably horizontal axes. In preferred embodiments, the distance between the centers of the rollers is fixed, i.e. not variable during the normal operating cycle. The winding rods are preferably moved towards the winding cradle, defined by the two winding rollers, from the same side on which the reel is formed, i.e. without passing through the nip between the two winding rollers. The web material is preferably fed around one of the winding rollers, again without passing through the nip between the two winding rollers.

In some preferred embodiments of the present invention the first winding roller and the second winding roller are motorized through distinct motors advantageously controlled by a control unit to change the rotation speeds of the two winding rollers differently one from the other during the winding cycle.

To unload the formed reel from the winding cradle, the second winding member has preferably a variable arrangement in shape and/or position and/or speed. In some preferred embodiments of the invention, when the second winding member comprises a winding roller and a flexible element or member entrained around the winding roller and around another guide member, the arrangement can be such that the flexible member or element tilts to unload the reel. For example it can be lowered to transfer the formed reel from the winding cradle towards an unloading station. Tilting can be performed around the axis of rotation of the second winding roller.

In some embodiments, with the first winding roller guiding surfaces can be associated, against which the inserter rests said winding rods.

In some embodiments the guides are advantageously arranged and designed to define a winding rod-introduction trajectory, extending around the first winding member and moving gradually towards said winding member from a non-contact position to a contact position of the winding rod with the web material driven around said winding member. The guides can be driven to put the new rod into rotation, so as to have a substantially synchronous speed with the web material before the contact thereto. In other embodiments the inserter can comprise one or two jaws or other engaging members for engaging the winding rods, controlled so as to impart to the winding rod a trajectory of gradual movement towards the first winding member and to control the rod in the first winding phase of the web material. The jaws or other engaging members and/or the winding rods can be designed so as to allow the winding rod to rotate around its own axis when the rod is still engaged with the inserter but into contact with the first winding member, which imparts a winding rotational movement to the winding rod.

In preferred embodiments of the invention, the first winding member, the second winding member and the inserter are controlled such that, while a completed reel is unloaded from the winding cradle by a movement of the second winding member, said inserter brings a winding rod to co-act with the first winding member to engage and start winding the web material around said winding rod. The inserter is advantageously controlled to maintain said winding rod resting on said first winding member for a first winding phase of the web material around said winding rod, before said winding rod starts to rest on the second winding member.

The invention also relates to a rewinding machine comprising at least a first winding member comprising, or formed by, a first winding roller and a second winding roller defining a winding cradle; and, in addition, a winding rod inserter for introducing a winding rod towards the winding cradle to wind a reel of web material around the winding rod. The inserter is arranged and designed so as to introduce the winding rod against the first winding roller towards the winding cradle; and the second winding member comprises a second winding roller, a guide element and a flexible element entrained around the second winding roller and around the guide element. The second winding member designed in this way can change in configuration, i.e. in the reciprocal position of the parts composing it, to unload a previously formed reel from the winding cradle. The first and the second winding roller advantageously form the winding cradle wherein the main part of the winding cycle occurs.

In some embodiments the rewinding machine comprises a first winding member, comprising a first winding roller, and a second winding member, comprising a plurality of further winding rollers, preferably with variable center-to-center distances. In some embodiments the winding rollers forming the second winding member define a cluster of winding rollers. The cluster of winding rollers forming the second winding member can be advantageously controlled and arranged so as to be in contact with a reel of web material. In some embodiments, at least some of said winding rollers forming said second winding member are movable so as to move a completed reel away from the first winding member and towards an unloading area, for instance towards an unloading station, which can comprise a pivoting cradle receiving the reel and transferring it towards a pick-up area. According to some embodiments, the winding rollers forming the second winding member are advantageously controlled so as to maintain in rotation the reel being completed and to continue winding the web material around the reel, while said reel is transferred towards the unloading area and the inserter moves a new winding rod towards the first winding member. The first winding member and the second winding member advantageously comprise independent motors to rotate a first winding roller, being part of or constituting the first winding member, and a second roller, being part of the second winding member, at speeds independent of each another.

The speed of the winding members can change from a steady-state speed, or winding speed, to an exchange speed or replacement speed, at which the reel being completed moves away from the first winding member towards an exchange area. The second winding member can be controlled so as further to slow down from the exchange or replacement speed to a reduced speed, at which the reel being completed is brought. This reduced speed is lower than the exchange speed. When the reel rotates at a reduced peripheral speed, lower than the exchange speed, at which the web material is temporally fed, a loop can be formed, which facilitates the step of severing the web material and starting winding a new reel on a new winding rod.

In some embodiments the second winding member comprises a cluster or set of winding rollers comprising a second winding roller, a third winding roller and a fourth winding roller. In advantageous embodiments the first winding roller and the second winding roller are arranged with a preferably fixed center-to-centre distance, and form therebetween a nip or seat for resting and rotating the reel being wound. In some embodiments an auxiliary winding roller is arranged between the first winding roller of the first winding member and the second winding roller, forming part of the second winding member. The auxiliary winding roller can have a fixed axis or a movable axis to follow the diameter increase of the reel being formed.

In some embodiments, when the second winding member comprises a cluster of winding rollers comprising a second, a third, and a fourth winding roller, said third winding roller and said fourth winding roller are arranged and controlled such as to move the first reel away from the first winding member and to transfer it towards said unloading area. The transfer can occur by maintaining the reel in contact with the second winding roller. In other embodiments the third winding roller is controlled such as to move away from the reel whilst the fourth winding roller is displaced to transfer the reel from the winding area towards the unloading area. In some embodiments at least some of the rollers forming the second winding member are controlled such as to slow down and then to stop the reel rotation.

If the second winding member comprises a cluster of winding rollers, in some embodiments one of said winding rollers of the cluster remains in a fixed position, whilst at least one other of said winding rollers of the cluster is used to displace the reel, making it roll on the winding roller, which remains in fixed position. The rotation speed of at least some of the rollers of the cluster of rollers forming the second winding member is controlled to slow down and then to stop the reel rotation. Slowing down can occur in two steps: in a first step, slowing down of the reel rotation corresponds to a reduction in the feed speed of the web material and therefore to it corresponds also a slowing down of the first winding member. In a second step the first winding member continues to move at the feed speed of the web material, whilst the rollers of the second winding member further slow down and then stop the rotation of the formed reel.

In some embodiments the second winding member comprises a cluster of winding rollers comprising a second winding roller, a third winding roller, and a fourth winding roller, which are controlled to slow down and then to stop the rotation of said first reel, whilst the inserter brings a second winding rod against the first winding roller, starting winding a second reel around said second winding rod in contact with said first winding roller, whose rotation is not stopped during the replacement phase.

Preferably, the winding rod inserter is associated with angular acceleration means for the winding rods to drive each winding rod into rotation before it is brought in contact with the web material. Each winding rod is advantageously accelerated by said angular acceleration means, so as to have a peripheral speed substantially equal to the feed speed of the web material when the winding rod comes in contact with the web material.

In advantageous embodiments, winding starts by holding the web material between the new winding rod and the first winding member, whilst the peripheral speed of the first winding member and of the winding rod are substantially equal and nearly corresponding to the feed speed of the web material.

According to a different aspect, the invention relates to a method for producing reels of web material around winding rods, comprising the steps of:

• • winding a first reel of web material around a first winding rod in a winding cradle comprising a first winding member and a second winding member,
  • once said first reel of web material has been wound, unloading said first reel of web material from said winding cradle, inserting a second winding rod in said winding cradle, and winding a second reel of web material around said second winding rod;
    wherein the first reel of web material is unloaded from the winding cradle through a change in the arrangement of the second winding member, while the second winding rod is driven into rotation by moving it towards the first winding member.

According to some embodiments of the invention the first reel of web material is unloaded from said winding cradle by making the second winding member pivot from a winding position to an unloading position.

In one embodiment, the method according to the present invention comprises the steps of:

• • slowing down the winding speed;
  • modifying the arrangement of the second winding member from a winding position towards an unloading position thus moving the first reel away from the first winding member and towards an unloading area;
  • bringing the second winding rod against the first winding member, causing the second rod to start rotation, and starting to wind the web material around the second rod to form the second reel;
  • bringing the second winding member towards said winding position again and bringing the second reel under formation around the second winding rod in contact with said second winding member.

According to a further aspect of the present invention a rewinding machine is provided, comprising: a first winding member and a second winding member defining a winding cradle; and a winding rod inserter for introducing a winding rod in said winding cradle to wind a reel of web material on said winding rod. Advantageously, the second winding member has a variable configuration to unload a formed reel from said winding cradle; and the inserter is arranged and controlled to transfer said winding rod along a movement path towards said first winding member, along said path the web material being engaged to said winding rod to start winding around said winding rod driven into rotation by said first winding member.

The invention also concerns a winding method comprising the steps of:

• • arranging a first winding roller and a second winding roller to define a seat or cradle for supporting and rotating the reel being wound;
  • arranging a third winding roller and a fourth winding roller with movable axes;
  • winding a first reel in said support and rotation seat in contact with at least said first winding roller and said second winding roller;
  • continuing winding said first reel of web material between said first winding roller, said second winding roller, said third winding roller, and said fourth winding roller;
  • moving said first reel of web material away from said first winding roller maintaining it into rotation through at least said second winding roller and said fourth winding roller and reducing the rotation speed of the reel from a winding speed to a replacement speed, lower than the winding speed;
  • bringing said second winding rod against said first winding roller and engaging the web material between said first winding roller and said second winding rod,
  • severing the web material between the second winding rod and the first reel;
  • starting winding a second reel around said second winding rod;
  • moving the first reel of web material away from the second winding roller;
  • bringing the second reel in contact with said second winding roller.

According to some embodiments of the method according to the invention, it is provided for said first reel of web material to be moved away from said first winding roller while maintaining it into rotation by means of said second winding roller, said third winding roller, and said fourth winding roller.

Whilst the first reel is moved away from the first winding roller, the third winding roller is preferably moved away from the first reel and the first reel is transferred towards the unloading area by means of the fourth winding roller.

In some embodiments of the method according to the invention it is provided that the rotation speed of the first reel is reduced by slowing down the second winding roller, the third winding roller and the fourth winding roller; that the third winding roller and the fourth winding roller are moved away from the first reel; said third winding roller and said fourth winding roller are accelerated until the winding speed and said second winding rod and the reel being formed around it are engaged with said third winding roller and said fourth winding roller.

In some embodiments the winding method provides the steps of: forming a loop of web material between said first reel and said second winding rod slowing down the rotation speed of said first reel; and of holding said loop of web material between said second winding rod and said first winding member and causing the severing of the web material between said first reel and said second winding rod.

According to a further aspect of the present invention, a rewinding machine is provided, comprising: a first winding member and a second winding roller defining a winding cradle; a winding rod inserter for introducing a winding rod in said winding cradle to wind a reel of web material on said winding rod, said inserter being arranged and designed so as to introduce said winding rod against the first winding roller towards said winding cradle; a plurality of further winding rollers with movable axes arranged and controlled to unload a reel from said winding cradle whilst said inserter brings a new winding rod against said first roller to start winding a new reel of web material. The winding rollers can be advantageously controlled to slow down the reel and subsequently to stop it. Advantageously, the winding rollers hold the reel between the second winding roller and said further winding rollers during the phase of moving away from the cradle, slowdown and stopping; preferably the second winding roller remains fixed, i.e. it doesn't rotate, until winding starts around the new rod maintaining the new rod in contact only with the first winding member, for instance by using the inserter.

In some embodiments of the invention a rewinding machine for producing reels of web material wound around winding rods is provided, comprising a first winding roller, a second winding roller defining with said first winding roller a winding cradle; an inserter for introducing winding rods in said winding cradle; a cluster of further winding rollers with movable axes, co-acting with said first winding roller and said second winding roller to maintain in rotation a first reel being formed and to move said first reel away from said winding cradle, to slow down said first reel and lastly to stop said first reel, whilst said inserter introduces a new winding rod towards the first winding roller, said first winding roller starting winding a new reel around said new winding rod. The machine can advantageously provide for severing means for severing the web material. In some embodiments the severing means comprise air blows. The winding rollers can be controlled to generate a loop of web material, which is engaged around the new winding rod. The loop of web material can be formed by changing the rotation speeds of the winding rollers, and in particular by slowing down the second winding roller with respect to the first winding roller.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by following the description below and the attached drawing, which shows a non-limiting practical embodiment of the invention. More in particular:

FIGS. 1 to 5 show a schematic side view of a rewinding machine according to the invention in an operating sequence comprising the formation of a complete reel, its unloading, and the introduction of a new winding rod to start formation of a second reel;

FIGS. 6 to 14 schematically show a machine according to the invention in a different embodiment and a sequence of the operations performed during a winding cycle;

FIGS. 15 to 23 show the machine of FIGS. 6 to 14 in a different embodiment of the winding and replacing cycle of a formed reel with a new winding rod;

FIGS. 24 to 32 show a further variant of the operation of the machine of FIGS. 6 to 14; and

FIGS. 33 to 40 show a third embodiment of a machine according to the invention and a related winding and replacing cycle of a formed reel with a new winding rod.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The rewinding machine, indicated in its entirety with number 1, comprises a first winding member 3 and a second winding member 5. In some embodiments the first winding member 3 is constituted by, or comprised of, a winding roller rotating around a substantially horizontal axis 3A. The rotation of the roller is controlled by an electric motor, schematically indicated with number 7.

In some embodiments, the second winding member 5 comprises a second winding roller 9 rotating around a substantially horizontal axis 9A substantially parallel to the axis 3A of the winding roller 3. The winding rollers 3 and 9 form a nip therebetween and define a winding cradle.

In some embodiments the winding roller 9 is driven into rotation by a second motor 8, distinct from the motor 7. The motors 7 and 8 are preferably connected to a central control unit 10, with which also the other members of the machine are interfaced to perform the winding cycle described below. The control unit 10 can be a programmable microprocessor unit, preferably connected to a panel, a display, a touch screen, a keyboard, or other user interface means.

In some embodiments one or more belts 11 are advantageously provided, entrained around the winding roller 9 and around a roller 13, connected to the roller 9, for instance through a pair of arms 15. In some preferred embodiments of the invention the arms 15 are supported coaxially to the roller 9 and therefore pivot around the axis of rotation 9A of the winding roller 9. Pivoting can be controlled by a hydraulic or pneumatic cylinder-piston actuator, or by a rotating actuator, for example by an electric motor. The actuator controlling the pivoting movement of the arms 15 is not shown for the sake of simplicity of representation. Also this actuator can be controlled by the central control unit 10.

The winding cradle formed by the winding rollers 3 and 9 is labeled as a whole with number 19. At every winding cycle a winding rod is inserted in said cradle 19 to form a reel, with a procedure described later on.

Around the winding roller 3 the web material N is fed, coming from a downstream station and passing around a bow roller 21 to enlarge transversally the web material N. The winding roller 3 can be wholly or partially covered with a material having a high friction coefficient to draw the web material and impart the rotation movement to the reel being formed in the winding cradle 19. In a similar manner also the roller 9 can be wholly or partially covered with a material with high friction coefficient. In some embodiments the roller 9 has annular grooves, inside which the belts 11 are guided. These latter can be in turn covered with, or produced in, a material with high friction coefficient.

Adjacent to the rewinding machine 1, a station 2 is arranged for receiving the single reels formed by the rewinding machine 1, and from this station the reels are then unloaded towards a storage area, a further processing line or other. As it will be clearly apparent from the description below, the reels are unloaded from the cradle formed by the rollers 3 and 9 on the station 2 through a pivoting movement of the arms 15 and of the belts 11 around the axis 9A of the winding roller 9.

A double guide 23 extends around the first winding roller 3. More in particular, two guides 23 are provided at the two ends of the winding roller 3, each of which has a curved guiding surface with a profile gradually moving towards the cylindrical surface of the winding roller 3 to allow the winding rods to move gradually towards said roller. The winding rods, indicated with A1, A2, are fed one after another by a winding rod inserter 25 for introducing the rods in the winding cradle 19. The inserter 25 can be designed in a known manner and has engagement members for engaging the ends of the winding rods A and is provided with a rotation movement around the axis 3A of the winding roller 3.

The machine described above operates as follows.

FIG. 1 shows an initial winding phase of a first reel B1 around a first winding rod A1. In this phase the web material N is fed around an upper portion of the cylindrical surface of the winding roller 3 and winds around the rod A1 to form a reel B1 in contact with the winding rollers 3 and 9. The rotation speed of the rollers 3 and 9 is substantially equal and it can achieve very high values, in the order of 1500-2000 m/min. It should be understood that these and other speed values in the present description are indicated purely by way of non-limiting example.

As the diameter of the reel B1 increases, the reel centre moves away from the pair of winding rollers 3 and 9 and the reel periphery starts touching the upper branch of the belts 11 contributing to impart the rotation movement to the reel and thus to increase the diameter thereof. The contact between belts 11 and reel B1 being formed allows a more regular winding.

FIG. 2 shows the final winding phase of the reel B1. It is in contact in a limited area of the winding roller 3 and in a limited area of the winding roller 9, as well as along an arc of the upper branch of the belts 11. Once the desired diameter, i.e. the quantity of wound web material set by the operator, has been achieved, the machine performs the replacement cycle for replacing the formed reel B1 with a new winding rod A2. To this end, the speed of the machine is reduced, without however stopping the movement thereof. In some embodiments, starting from the arrangement of FIG. 2, the web material speed is reduced from the steady-state speed (1000-2000 m/min) to a speed of about 100 m/min or, more in general, to a reduced replacement speed.

Subsequently (FIG. 3) the arms 15 are lowered rotating in clockwise direction (in the figure), so as to bring the belts 11 in such a position to allow the reel B1 to roll towards the unloading station 2. In this phase auxiliary small planes 16 integral with the arms 15 are advantageously aligned with an inclined unloading plane 31, with which the unloading station 2 is provided. The reel B1 rolls on the belts 11, on the small planes 16 and lastly achieves the inclined unloading plane 31 to be definitely unloaded in the station 2, taking the position indicated in FIG. 4. To move the reel B1 away from the cradle 19 a pushing member can be used, known and therefore not shown, for example of the type described in the prior art documents cited in the introduction of the present description. In this phase, the web material N is still intact and extends therefore around a portion of winding roller 9, and around a portion of the winding roller 3, crossing the cradle 19.

In this phase the inserter 25 introduces a new winding rod A2, which is driven along the guides 23 from the initial position indicated with A2(X) in FIG. 3 to the final position indicated with A2(Y) in the subsequent FIG. 4. During this movement towards the winding cradle 19 the rod A2 is held at the ends of the inserter 25, which gradually rotates around the axis 3A of the winding roller 3. The shape of the guides 23 is such that at a given point the rod A2 presses against the winding roller 3 holding the web material N between the winding rod A2 and said roller 3. In some embodiments, on the winding rod A2 a winding core made of cardboard is provided, advantageously provided for instance with a strip of double-sided adhesive or with other adhesive means that, thanks to the contact with the web material N and to the pressure on the web material N comprised between the winding rod A2 and the winding roller 3, cause the adhesion of the web material N and the beginning of the material winding, with consequent severing, breaking or interruption of the material in a position comprised between the contact point with the new winding rod A2 and the touching point with the winding roller 9.

Severing can be performed or facilitated through known manual or automatic auxiliary means. Advantageously, in some embodiments the rod can be previously accelerated so as to obtain a peripheral speed nearly equal to the speed of contact with the roller 3.

In this arrangement, whilst the reel B1 is transferred to the station 2, a second reel of web material B2 begins winding around the winding rod A2. In this phase the winding movement is imparted only by the winding roller 3, as the rod A2 is maintained in contact only with this roller due to the engagement with the inserter 25. The winding speed is limited, due to the slowdown of the machine in this replacement phase.

Subsequently (FIG. 4), when the reel B1 has been discharged from the belts 11 and has taken the final position shown in FIG. 4, the arms 15 can be raised again rotating around the axis 9A so as to move to the position of FIG. 4 and the winding rod A2 can be released in the winding cradle 19 contacting also the second winding roller 9 and the belts 11. In this phase the inserter 25 can release the winding rod A2 and return in its starting position, where it takes a new rod A3 for the subsequent replacement cycle.

Winding continues around the winding rod A2 that in this phase touches both the winding rollers 3 and 9 and receives therefore the winding motion by both the winding members 3, 5. These latter can be gradually accelerated until the steady-state speed again. The winding cycle continues with increase in the diameter of the second reel B2 as shown in FIG. 5.

In the meanwhile the inserter 25 is returned to the initial position to receive a third winding rod A3, which will replace, with a cycle similar to that described above, the reel B2 when this latter will be completely wound.

During the unloading phase (FIG. 3), thanks to the fact that the rollers 3 and 9 are actuated by two independent motors 7 and 8, it is possible for the motion of the winding roller 9, and therefore of the belts 11 driven around it, to be controlled according to the unloading needs of the reel B1, if necessary winding again the end part of the web material N, independently of the rotation conditions of the roller 3, that will depend upon the requirements of starting winding around the rod A2.

FIGS. 6 to 14 show a machine according to the invention in a different embodiment and the corresponding sequence of winding and replacing a formed reel with a new winding rod.

The machine, indicated as a whole with number 101, comprises a first winding member comprising a first winding roller 103. The machine furthermore comprises a second winding member, which in turn comprises a second winding roller 105, a third winding roller 107 and a fourth winding roller 109. The set of rollers forming the first winding member and the second winding member defines a winding cradle. As will be more apparent below, the second winding member has a variable conformation, i.e. the arrangement of the rollers defining the second winding member is changed during the winding cycle to allow unloading the formed reel and starting winding the new reel with a substantially continuous operation of the machine.

Adjacent to the first winding roller 103 a so-called bow roller 111 is arranged to feed the web material N eliminating the wrinkles thereof and/or enlarging the longitudinal cuts with which the web material can be subdivided into a plurality of strips that are simultaneously wound around a plurality of winding cores driven on a same winding rod or spindle.

The winding rollers 103, 105, 107 and 109 advantageously have substantially parallel axes of rotation. In some embodiments the rollers 103 and 105 are provided with fixed axes and they have therefore a centre-to-centre distance that doesn't change during all the cycle of winding and replacing a wound reel with a new winding rod. The rollers 103 and 105 advantageously define a nip or seat for resting and rotating the reel being wound.

The winding rollers 107 and 109 forming, along with the winding roller 105, the second winding member, advantageously have movable axes of rotation to perform a series of operations on the reel during the replacement steps, i.e. the steps of unloading the finished reel and inserting the new winding rod, as well as during the initial phase of winding a new reel, as it will be described in greater detail hereunder with reference to the sequence of FIGS. 6 to 14.

In this embodiment the second winding member is therefore substantially configured as a plurality or cluster of winding rollers 105, 107, and 109. The arrangement or conformation of this second winding member is variable, thanks to the fact that the axes of rotation 105A, 107A, and 109A of the rollers 105, 107, and 109 respectively move relative one another thus changing the relative position and the distance between the various rollers of the rewinding machine 101.

The roller 105 and the axis of rotation 105A thereof are preferably fixed with respect to a bearing structure of the machine, whilst the rollers 107 and 109 with the respective axes 107A and 109A of rotation can move one with respect to the other and both with respect to the winding roller 105. The translation movement of the axes of rotation 107A, 109A of the rollers 107 and 109 can be obtained with an adequate system of guides and actuators, not shown in detail in the drawing.

In some embodiments the rollers 103, 105, 107, and 109 can be driven into rotation by two or more independent motors. Independent motors means motors that can rotate with speeds different from one another, advantageously under the control of a programmable central processing unit. The speed of the rollers changes in particular during the phase of replacing a wound reel with a new winding rod. In particular, the rollers 103 and 105 can be advantageously actuated by independent motors, so as to make these rollers rotate with different speeds in at least some phases of the winding cycle.

Instead of independent motors systems can be used to vary the speed of rotation of one or the other of two or more rollers actuated by a common motor. These rotation speed change systems can comprise gear motors and auxiliary motors for adjusting the speed of rotation of the outlet shaft of the gear motor relative to the inlet speed of the gear motor.

Advantageously, to the first winding roller 103 an inserter 113 is associated, mounted so that it can rotate according to the double arrow f₁₁₃ in one direction and in the other around the axis of rotation 103A of the first winding roller 103.

Adjacent to the set of rollers forming the first winding member and the second winding member, a station 102 is arranged for receiving the reels formed in the rewinding machine 101. The receiving station 102 comprises a rest surface 102A fixed to a frame 104. In some embodiments the frame 104 pivots according to the double arrow f₁₀₄ around an axis 104A for example by means of an actuator, for instance a cylinder-piston actuator 106, for the purposes described hereunder with reference to the operative sequence shown in FIGS. 6 to 14. In other embodiments the frame 104 can be provided with a translation or roto-translation movement to move the formed reel away from the rewinding machine 101.

In some embodiments, an auxiliary winding roller 115 is arranged between the winding roller 103 and the winding roller 105 of the second winding member. In some embodiments the auxiliary winding roller 115 has a diameter smaller than that of the first winding roller 103 and of the second winding roller 105. In some embodiments the axis 115A of the auxiliary winding roller 115 is fixed. In other embodiments (described hereunder) the axis of the auxiliary winding roller 115 is movable for instance in a substantially vertical direction.

In some embodiments, one or more series of nozzles are arranged in the space between the first winding roller 103 and the second winding roller 105 to generate air jets. In FIGS. 6 to 14 two series of nozzles 117 and 119 are provided, interposed in the nip between the rollers 103, 115 and between the rollers 115 and 105. The air jets generated by the nozzles 117, 119 facilitate the start of winding a new reel around a new winding rod, as it will be described in greater detail hereunder.

Advantageously, in some embodiments to the first winding roller 103 guides 123 are associated that, analogously to what has been illustrated with reference to the guides 23 of FIGS. 1 to 5, form a support for the ends of a winding rod A, engaged by the inserter 113, to allow a gradual movement of the rod towards the first winding roller 103.

After having illustrated the main elements of the rewinding machine in this second embodiment, a first winding method that can be performed with this machine will now be described, illustrated schematically in the sequence of FIGS. 6 to 14.

In FIG. 6 a first reel B1 is being wound around a first winding rod A1. The reel B1 is rotating according to the arrow f_B (in counterclockwise direction in the figure) around its own axis. The reel B1 is resting in the seat or cradle formed by the first winding roller 103 and by the second winding roller 105. The rollers 103 and 105 rotate (in clockwise direction in the figure) with a peripheral speed substantially corresponding to the peripheral speed of the reel B1, corresponding to the feed speed of the web material N, according to the arrow f_N. In this phase of the winding cycle also the third winding roller 107 and the fourth winding roller 109 rotate (in clockwise direction in the figure) substantially at the same peripheral speed as the winding rollers 103 and 105. A second winding rod A2 is arranged in the inserter 113 and is temporarily still.

Once the required web material has been wound around the reel B1, the replacing phase starts, involving removal of the reel B1, severing of the web material N, introduction of the second winding rod A2 and start winding of a new reel B2 around the second winding rod A2.

To this end, in an advantageous embodiment, in the arrangement of FIG. 6 a phase already starts of slowdown of the machine, reducing the feed speed of the web material N. At the same time the peripheral speed of the winding rollers 103, 105, 107, and 109 is reduced. Typically, in some embodiments the steady-state winding speed, i.e. the speed outside the replacing phase, can be around 1000-2000 m/min. The machine is slowed down from this winding speed for instance to about 100-200 m/min, preferably 50/150 m/min, for instance about 100 m/min. The speed values must be intended just as non-limiting examples.

FIG. 7 shows the subsequent phase of the replacing cycle. During this phase the reel B1 is moved towards an unloading area through a translation movement of the third winding roller 107 and of the fourth winding roller 109, that move according to the arrows f₁₀₇ and f₁₀₉ respectively. In this phase all the winding rollers are still in rotation and the reel B1 continues winding at a low speed. It is in contact with the second winding roller 105, the third winding roller 107 and the fourth winding roller 109.

To obtain a more gradual and uniform start of the winding of a new reel B2 around the second winding rod A2, this latter is driven into rotation by a member, not shown, preferably until it achieves a peripheral speed equal to the speed of the winding roller 103 and to the feed speed of the web material N during the replacement phase.

In the subsequent phase, shown in FIG. 8, the inserter 113, rotating around the axis 103A of the first winding roller 103, brings the second winding rod 102 gradually towards the winding cradle, and more in particular towards the rest and rotation seat defined by the first winding roller 103 and by the second winding roller 105. In this rotation movement around the axis 103A of the first winding roller 103, the rod rests with its ends on the guides 123 that are suitably shaped to move the axis of the second winding rod A2 gradually towards the cylindrical surface of the first winding roller 103. In this phase the first reel B1 continues rotating at the replacement speed, maintained into rotation by the winding rollers 103, 107, and 109.

According to a preferred embodiment of the invention, at this point a step is performed of forming a loop of web material N to obtain severing of the web material N and to form a tail end that remains wound around the reel B1 and a head end that winds around the second winding rod A2.

FIG. 9 shows the phase of forming the loop and severing the web material. In this embodiment the winding rollers 105, 107, and 109 further slow down, whilst the winding roller 103 continues rotating at the reduced speed to which the machine has been brought during the previous operating phase. Following this slowdown, the quantity of web material between the second winding rod A2 and the contact point of the reel B1 on the second winding roller 105 increases, with consequent formation of a loop of web material, indicated with A_N. In some embodiments the nozzles 117 and 119 are actuated by generating air flows pushing the loop of web material AN upwards, causing tensioning and severing of the web material N in an intermediate position between the second winding rod A2 and the rest point of the reel B1 on the winding roller 105. In combination with, or alternatively to, the air flows, severing of the web material can be obtained by providing an adhesive means on the winding rod A2, for example a strip of double-sided adhesive, a glue, a suction system inside the rod or any other means causing the adhesion of the web material to the outer surface of the winding rod A2. When, due to the gradual rotation of the inserter 113 around the axis 103A, it is brought in contact with the web material N driven around the first winding roller 103, the adhesion occurs of the web material N on the second rod A2, which, rotating in the winding direction, causes the start of the winding of the web material N around the second winding rod A2. With or without the aid of the air flows generated by the nozzles 117 and 119, this causes severing of the web material in an adequate position along the loop A_N formed in the manner described above.

Preferably, as shown in FIG. 10, the subsequent phase of the replacement cycle entails stopping the rotation of the second winding roller 105, of the third winding roller 107 and of the fourth winding roller 109, i.e. of the cluster of winding rollers forming the second winding member. In this phase the web material N continues winding around the second winding rod A2 which remains engaged by the inserter 113 and pressed against the cylindrical surface of the first winding roller 103. This latter gradually accelerates so as to bring the winding speed to the steady-state value (for instance 1000-2000 m/min).

In the illustrated embodiment, in the subsequent phase shown in FIG. 11 the inserter 113 continues rotating around the axis 103A of the first winding roller 103, bringing the second winding rod A2 with the new reel B2 being formed around it in the space defined between the first winding roller 103 and the second winding roller 105. In this embodiment, due to this movement and to the increase in its diameter, the second reel B2 contacts also with the auxiliary winding roller 115 rotating at a peripheral speed corresponding to the feed speed of the web material N and to the speed of rotation of the first winding roller 103.

The third winding roller 107 translates upwards and the fourth winding roller 109 translates horizontally pushing the reel B1 towards the unloading area defined by the station 102. An intermediate plane 130 arranged between the second winding roller 105 and the surface 102A allows the first reel B1, pushed by the fourth winding roller 109, to roll until to be completely in the unloading station 102 (FIG. 12). This movement frees the area above the rest and rotation seat defined by the first winding roller 103 and by the second winding roller 105. In this way the third winding roller 107 and the fourth winding roller 109 can be arranged above the second winding roller 105 and the rest and rotation seat defined by the first winding roller 103 and by the second winding roller 105. The fourth winding roller 109 and preferably also the third winding roller 107 return to the steady-state speed of rotation, with a peripheral speed corresponding to the feed speed of the web material. The second winding roller 105 is also driven into rotation again and gradually accelerated until to achieve the peripheral speed corresponding to the feed speed of the web material.

As shown in FIG. 12, the fourth winding roller 109 moves towards the second reel B2 being formed. Therefore in this phase, whilst the first reel B1 is in the unloading station 102, the second reel B2 winding around the second winding rod A2 is in contact with three winding rollers and more precisely: the first winding roller 103, and the second and fourth winding roller 105, 109 of the second winding member.

In the subsequent FIG. 13 the phase is shown wherein also the third winding roller 107, that has been brought again to a peripheral speed equal to the feed speed of the web material N, contacts the second reel B2 winding around the second winding rod A2. In this phase the reel B2 is in contact with five winding rollers.

The second winding rod A2 has been released by the inserter 113 that can gradually return in the initial position to receive a new winding rod, as shown in the subsequent FIG. 14. This new winding rod can be the rod A1 that has been removed from the reel B1 that, with a pivoting of the frame 104, is unloaded towards a storage area, a transferring system or other.

In the meanwhile the second reel B2 continues winding and the increase in its diameter is allowed by a gradual displacement of the third winding roller 107 and of the fourth winding roller 109, whilst the contact with the auxiliary winding roller 115 is lost. Therefore in this phase the second reel B2 being wound is in contact with the first winding member constituted by the first winding roller 103 and with the second winding member constituted by the cluster of winding rollers 105, 107, and 109. When the reel B2 has achieved the desired diameter, i.e. the required quantity of web material N, the replacement cycle starts again starting from the arrangement of FIG. 6.

In the sequence of FIGS. 15 to 23 a different method is illustrated to perform the replacement cycle of the finished reel B1 with a new winding rod A2 and start winding a new reel B2 on the new winding rod A2 using the same machine illustrated in FIGS. 6 to 14.

FIG. 15 shows the final phase of winding the first reel B1, similarly to FIG. 6. FIG. 16 illustrates the start of the ejection of the formed reel B1. This phase corresponds substantially to the phase of FIG. 7. By comparing FIGS. 7 and 16 it is clear that in this operating mode the third winding roller 107 is moved away from the reel B1 and is not used to perform the phase of slowdown and ejection of the first reel B1. In this embodiment, in order to eject the first reel B1 from the rest and rotation seat only the fourth winding roller 109 is used whilst the third winding roller 107 is raised towards a position from which it will be then brought again near the second winding roller 103.

In FIG. 17, corresponding to FIG. 8, the start is shown of the contact between the second winding rod A2 and the web material N. In FIG. 18 the phase is illustrated of severing the web material to form the head end and the tail end. In FIG. 19 the second reel B2 starts winding around the second winding rod A2, whilst the first reel B1 is in contact with the second winding roller 103 and with the fourth winding roller 109 that can stop rotating.

In FIG. 20 the second reel B2 being formed around the second winding rod A2 (still engaged by the inserter 113) is brought in contact not only with the first winding roller 103, but also with the auxiliary winding roller 115. The fourth winding roller 109, moving from left to the right (in the figure) makes the first reel B1 to roll towards the unloading station 102. In FIG. 21 the first reel B1 is housed in the unloading station 102, the fourth winding roller 109 has been brought in contact with the second reel B2 and the third winding roller 107 is near the second winding roller 105 and has passed above and around the completed reel B1.

In FIG. 22 the second reel B2 is winding in contact with the five winding rollers 103, 105, 107, 109 and 115 that are brought again to the steady-state or winding speed (typically 1000-2000 m/min). The inserter 113 has been brought again in the position of receiving a new winding rod, whilst the previously formed reel B1 is moved towards the outlet by pivoting of the structure 104.

In FIG. 23, corresponding to FIG. 14, the second reel B2 being formed around the second winding rod A2 is in contact with the winding rollers 103, 105, 107 and 109, whilst it has lost the contact with the auxiliary winding roller 115 due to the increase in its diameter.

Once the reel B2 has achieved the desired dimension, the replacement cycle starts again starting from the condition of FIG. 15.

In the sequence of FIGS. 24 to 32, a modified embodiment is shown, wherein the auxiliary winding roller 115 is provided with an upwards and downwards translation movement according to the double arrow f_115, so as to remain in contact with the reel being formed until the final diameter is achieved, as shown in FIG. 24. To this end the auxiliary winding roller 115 is gradually raised from the initial position (FIG. 29) until the final position (FIG. 24). Otherwise, the replacement cycle can be substantially equal to that described with reference to the two sequences of FIGS. 6 to 14 or to that illustrated in FIGS. 15 to 23.

In the sequence shown in FIGS. 24 to 32, the third winding roller 107 accompanies the deceleration and the unload of the first reel B1, similarly to what has been described with reference to the sequence of FIGS. 6 to 14, but it must be understood that in this embodiment again the replacement cycle can be modified so that the third winding roller 107 doesn't participate in the translation and unloading phase of the reel B1, but moves away from the reel B1 before the latter starts the slowdown phase.

In summary, and with reference to the sequence illustrated in FIGS. 6 to 14, the cycle shown in the sequence of FIGS. 24 to 32 is as follows.

FIG. 24 shows the completion of winding the reel B1, in contact with the five winding rollers 103, 105, 107, 109 and 115. The feed speed of the web material is equal to the steady-state speed (for example 1000-2000 m/min) corresponding to the peripheral rotation speed of all the winding rollers. Once the desired quantity of web material around the reel B1 has been achieved, the machine is slowed down, bringing the feed speed of the web material as well as the peripheral speeds of the various rollers to the replacement speed. A second winding rod A2 is arranged in the inserter 113.

In FIG. 25 the third winding roller 107 and the fourth winding roller 109 forming part of the cluster of the rollers defining the second winding member start to translate towards the right in the figure, displacing the formed reel B1 towards the unloading section 102, and therefore moving it away from the first winding roller 103 and removing it from the rest and rotation seat defined by the first winding roller 103 and by the second winding roller 105. Preferably in this phase the winding rod A2 engaged by the inserter 113 starts rotating and is brought to a peripheral speed approximately equal to the reduced feed speed of the web material N.

In FIG. 26 the inserter 113, pivoting around the axis 103A of the winding roller 103, brings the second winding rod A2 in contact with the web material N that is held between the winding rod A2 and the cylindrical surface of the first winding roller 103.

In FIG. 27 severing of the web material is shown, if necessary with the aid of the air jets generated by the nozzles 117 and 119. The speed of rotation of the reel B1 is furthermore slowed down by reducing the peripheral speed of the winding rollers 105, 107, and 109 to form the loop A_N of web material between the point of contact of the reel B1 and the winding roller 105 and the new winding rod A2.

In FIG. 28 the second winding roller 105, the third winding roller 107 and the fourth winding roller 109, i.e. the cluster of winding rollers forming the second winding member, stop, whilst the first winding roller 103 starts accelerating, until achieving the winding steady-state speed. The second reel B2 continues winding in contact only with the first winding roller 103, the second winding rod A2 still remaining engaged by the inserter 113 that provides to maintain the second reel B2 pressed against the first winding roller 103.

In FIG. 29 the third winding roller 107 moves away from the reel B1 and starts its movement of passing over the reel B1 to achieve the winding position again. The fourth winding roller 109 pushes the formed reel B1 in the unloading station 102, so that the reel B1 loses the contact with the second winding roller 105. The inserter 113 is furthermore lowered bringing the second reel B2 in contact with the auxiliary winding roller 115.

In FIG. 30 the fourth winding roller 109, which has been accelerated to the winding speed, contats the second reel B2. The reel B2 is therefore in contact with three winding rollers 103, 115 and 109. The inserter 113 can be unreleased from the second winding rod A2 and returns in the loading position, as shown in FIG. 31. In this arrangement also the third winding roller 107, which has returned to the peripheral speed corresponding to the winding speed, is in contact with the second reel B2. Winding of the reel B2 continues in contact with the five winding rollers 103, 115, 105, 107 and 109, until the final diameter is achieved (FIG. 32 and subsequently FIG. 24) to start a new replacement cycle.

FIGS. 33 to 40 show a further embodiment of the machine according to the invention. The same numbers indicate parts identical or equivalent to those in FIGS. 6 to 32.

In this embodiment the rewinding machine comprises a first winding member comprising a first winding roller 103 and a second winding member comprising a cluster of three winding rollers 105, 107 and 109, indicated hereunder as second winding roller 105, third winding roller 107 and fourth winding roller 109. The winding rod inserter is again labeled 113. This embodiment lacks the auxiliary winding roller 115 and a single series of compressed air nozzles 117 can be provided, arranged in the space or nip between the first winding roller 103 and the second winding roller 104 below the plane on which the axis of rotation 103A of the first winding roller 103 and the axis of rotation 105A of the second winding roller 105 are placed.

With reference to the sequence of FIGS. 33 to 40, in a possible embodiment the machine illustrated herein performs a cycle of replacing the formed reel B1 with a new winding rod or core A2 as follows.

In FIG. 33 the reel B1 is in the final winding phase. The rewinding machine starts to slow down from the steady-state speed to the replacement speed. In FIG. 34 the second winding rod A2 is engaged by the inserter 113. In FIG. 35 the third winding roller 107 and the fourth winding roller 109 of the second winding member start to move the reel B1 towards the unloading area in the unloading station 102. The reel B1 is still in contact with the three rollers 105, 107, and 109 rotating at reduced speed. The new winding rod A2 is moved towards the rest and winding seat defined between the first winding roller 103 and the second winding roller 105.

In FIG. 36 the loop A_N of web material is formed with or without the aid of the air flows generated by the nozzles 117. The winding rollers 105, 107 and 109 have furthermore decelerated with respect to the feed speed of the web material N, to allow the formation of the loop as described above.

In FIG. 37 the completed reel B1 is unloaded in the unloading station 102 whilst the third winding roller passes over the reel B1 and the fourth winding roller 109 moves towards the cradle or rest and winding seat formed by the rollers 103 and 105. The second winding rod A2 is brought towards the nip between the rollers 103 and 105 so as to bring the second reel B2 in contact with the first winding roller 103 and with the second winding roller 105.

In FIG. 38 the fourth winding roller is put in contact with the reel B2 that is therefore engaged between the rollers 103, 105 and 109. The inserter 113 can be released and returns in the initial position (FIG. 39), whilst the winding rollers started rotating again at the steady-state speed. The third winding roller 107 is still in raised position.

In the subsequent FIG. 39 also the third winding roller 107 is again in contact with and engaged with the second reel B2 that, in this phase, is wound in contact with the four rollers 103, 105, 107 and 109 rotating at the winding speed.

In FIG. 40 a subsequent phase is shown, wherein the reel B2 is increased in diameter whilst a new winding rod has been engaged by the inserter 113. From this arrangement the completion of the reel B2 is achieved, i.e. the condition of FIG. 33, to start a new cycle of replacing the completed reel with a new winding rod.

FIGS. 41 to 48 show a further embodiment of a rewinding machine according to the invention. The same numbers indicate parts identical or equivalent to those of the previously illustrated embodiment.

In the example of FIGS. 41 to 48 the members are also shown that are intended to rotate and translate the axes 109A and 107A of the rollers 109 and 107. In the illustrated embodiment the winding roller 107 is carried by a slide 107B able to slide along a guide 107C. The guide 107C is pivoted around an axis indicated with 107D, substantially parallel to the axes of the winding rollers. The slide 107B can slide according to the double arrow f_107B along the guide 107C. A similar arrangement is provided for the support of the winding roller 109. The latter is carried by a slide 109B, able to slide in a guide 109C, pivoted around an axis 109D. The slide 109B can slide according to the double arrow f_109B along the guide 109C and this latter can pivot or rotate according to the double arrow f_109C around the axis 109D. The rotation around the axes 107D and 109D can be controlled by an electronically controlled electric motor or other adequate actuator. The translation movement of the slides 107B and 109B along the guides 107C and 109C can be controlled by a screw and nut screw system, with an electrically controlled electric motor that controls for instance the rotation of the nut screw and that can be carried by the guide.

The machine of FIGS. 41 to 48 furthermore comprises, on both the sides of the machine, a system for the axial engagement of the winding rods. In some embodiments the engagement systems comprise, on each of the two sides of the machine, a pair of jaws 201 carried by a cursor 203 which, by means of a threaded bar 205 controlled by an actuator 207 (for instance an electric motor), allows movement in vertical direction according to the double arrow f₂₀₃ of the cursor 203 carrying the jaws 201. As will be explained hereunder with reference to the operating cycle illustrated in the sequence of FIGS. 42, 43, 44, 47 and 48, the jaws 201 follow the increase of the reel B that is in the winding cradle and are opened and closed to receive, hold and unload the winding rods on which the reels of web material N are formed.

The functioning sequence illustrated in FIGS. 42, 43, 44, 47, and 48 is similar to the sequence illustrated in FIGS. 34 to 40 and therefore hereunder the sequence will be described in summary, highlighting only the differences with respect to the previously illustrated functioning cycle.

In FIG. 42 a reel B1 is nearly completed. The rod A1, on which it has been wound, has been already released from the jaws 201 that have been opened. The reel B1 is in contact with the first winding member formed by the winding roller 103 and with the second winding member, formed by the group or cluster of winding rollers 105, 107 and 109 that rotate in the directions indicated by the arrows in the figure. A second winding rod A2 is ready at the inserter 113.

With the already described movement of the winding rollers 107 and 109, the reel B1 is moved from the cradle formed by the winding rollers 103 and 105 to the position of FIG. 47, wherein it is on the surface 102A in the unloading station 102. The winding rollers 107 and 109 make a movement similar to that described above to move the formed reel B1 in the unloading station 102 and to return, firstly the roller 109 and then the roller 107, in contact with a second reel B2 that in FIG. 48 is in the initial winding phase, in contact with the four winding rollers 103, 105, 107 and 109.

The figures clearly show the way to obtain the rotation and translation movement of the rollers 107 and 109 according to the trajectories necessary to unload the reel and start winding a subsequent reel, by means using the slides and the guides 107B, 107C and 109B, 109C.

Differently than in the embodiment disclosed above, in this case the winding rod ends projecting from the reel being formed are engaged by the jaws 201. As already noted, in the phase shown in FIG. 42 the jaws 201 are opened to allow the rod A1 to exit when the reel B1 begins to be translated towards the unloading station 102. In FIG. 43, while the reel B1 is rolling, under the thrust and the control of the rollers 107 and 109, towards the unloading station 102, the two pairs of jaws 201 are made translate downwards near the nip or cradle formed between the winding rollers 103 and 105, to receive the second rod A2, which is engaged in this phase by the inserter 113 and begins to be angularly accelerated until it achieves a peripheral speed approximately equal to the feed speed of the web material N. In this phase the winding rollers can be slowed down from the steady-state winding speed to a lower speed.

FIG. 44 shows the phase of approaching movement of the second rod A2 inside the nip or cradle formed between the winding rollers 103 and 105. FIGS. 45 and 46 show an enlargement of the process for severing the web material N in this phase, with the formation of a tail end LC, that ends to wind on the reel B1, and of a head end LT, that begins to wind around the new winding rod A2, adequately brought to the necessary speed of rotation. The head end LT can be anchored to the second winding rod A2 by using a strip of double-adhesive or in any other manner, for example through suction, electrostatic charges, by applying a liquid glue or simple water, if necessary with starch or other slightly or temporarily adhesive substance, or in any other adequate manner.

A series of compressed air nozzles 117 arranged between the rollers 105 and 107 generate air jets that facilitate the formation of the loop of web material. The peripheral speed of rotation of the reel B1 is slowed down so as to loose the web material N and form the loop and facilitate severing and beginning of winding the new reel.

In FIG. 47 the reel B1 is resting in the unloading station 102, whilst the new reel B2 (not shown in FIG. 47) is in the phase of initial winding, in contact with the winding rollers 103, 105 and 109. The jaws 201 on both the sides of the machine are closed and engage the ends of the winding rod A2. Adequate supports on the rod or on the jaws allow the rod to rotate with respect to the jaws around the axis of the rod.

The winding roller 107 is passing over the already formed reel B1 to move towards the new reel B2 being formed. FIG. 48 shows the position achieved by the winding rollers 103, 105, 107 and 109 in contact with the new reel B2, whose rod A2 is engaged at both the ends by the jaws 201. The inserter 113 has returned to the position in which it receives a second winding rod indicated with A3, which will be inserted in the machine at the subsequent replacement cycle. The reel B1 begins the unloading movement by means of a pivoting motion around the axis 104A due to the effect of the actuator 106. The pairs of jaws 201 begin to be gradually raised due to the effect of the threaded bar 205 following the diameter increase of the new reel B2.

FIGS. 49 to 52 show an operating sequence illustrating a way for obtaining the angular acceleration of a new winding rod, indicated with A2, which is engaged by the inserter 113 and inserted in the winding cradle. The specific embodiment illustrated in FIGS. 49 to 52 corresponds to that shown in the FIGS. 41 to 48. It should be noted that a similar system for angular acceleration of the winding rod can be adopted also in the other embodiments. In the illustrated example the inserter 113 comprises a pair of jaws 113A, 113B suitable to open and close to receive, engage and release the winding rods. The jaws 113A and 113B are connected to actuators 113C and 113D respectively, which control the opening and closing movement of the jaws and the movement of the winding rod towards the guiding surfaces that control the movement thereof towards the winding roller 103. The jaws and the actuators 113C, 113D (in the illustrated example two linear actuators in the form of hydraulic or pneumatic cylinder-pistons, for example) are carried by a rotating equipment 113E, rotating in alternate directions around the axis 103A of the winding roller 103. The rotation movement according to the double arrow f₁₁₃ is imparted through a toothed wheel 250 engaging with toothed sector 113F integral with the rotating equipment 113E. M205 schematically indicates a motor, imparting the rotation to the toothed wheel 250. The motor M250 is suitably controlled by a programmable control unit, to which the other motors and actuators of the machine are interfaced.

The described arrangement is on both sides of the machine, which is therefore provided with a double inserter 113, with two pairs of jaws 113A, 113B on both the sides to engage the opposite ends of the winding rods A1, A2, A3.

In the illustrated embodiment, on each side of the machine a respective wheel 260 is arranged, whose axis is indicated with 260A and is parallel but not coinciding with the rotation axis 103A of the winding roller 103. The wheels 260 are outside the winding roller 103, i.e. flanking it.

With each wheel 260, which advantageously has a substantially smooth circular edge, treated, if necessary, so as to have a high friction coefficient, a toothed wheel 262 is integral, coaxial with each wheel and engaging with a toothed wheel 264, whose rotation is controlled by a motor schematically indicated with M264. Through the motor M264, that can be single for the two toothed wheels 264 on the two sides of the machine, the two wheel 260 are driven into rotation at a controlled speed. Alternatively the wheels 260 can be constituted by smooth or V-shaped pulleys with a plurality of grooves, mounted outside the end of the rollers and between sides of the roller and jaws 113A and 113B driven into rotation by belts drawn by a single axis moved by a single motor.

As it is clear from the sequence illustrated in FIGS. 49 to 52, a winding rod A2 previously inserted in the machine on guiding profiles 266 (FIG. 49) is engaged by the jaws 113A and 113B on the two sides of the machine and is moved, through rotation of the inserter 113 according to f₁₁₃, towards the cradle or nip formed between the winding rollers 103 and 105. In this movement, as the centre of rotation of the inserter 113 doesn't match with the centre of rotation of the wheels 260, the winding rod A2 is moved gradually from a position distanced from the edge of the wheels 260 to a position of contact with the wheels (FIG. 50).

Continuing the rotation of the inserter 113 from the position of FIG. 50 towards the position of FIG. 52, by means of the actuator 113C, provided on both the sides of the machine, the ends of the rod A2 are maintained in contact with the circular edges of the two wheels 260. These form therefore the surfaces for guiding the rod and moving it towards the winding roller 103 and towards the cradle between the winding rollers 103 and 105. At the same time the rotation f the wheels 260, controlled by the motor M264, drives in rotation the rod A2, which can be therefore brought to the desired peripheral speed, advantageously equal to or substantially equal to the feed speed of the web material N in the replacement phase.

In this embodiment the wheels 260 form therefore the guiding surfaces for the rod A1, A2, A3 and at the same time the means for angular acceleration of the rod.

It is also possible to obtain these two functions through separate members, for instance the guide through static surfaces and the acceleration through at least one belt or preferably two belts that engage tangentially respectively with the one or the other of the two ends of the winding rod while the rod is moved from the initial position to the final position in the insertion cycle.

As it is clearly apparent from FIGS. 49 to 52, the eccentric arrangement of the wheels 260 on one side and of the winding roller 103 on the other side allows a gradual passage, without particular stresses, of the winding rod A2 from the contact with the wheels 260 (FIGS. 49 and 50) to the position of contact with the winding roller 103 (FIGS. 51 and 52).

It is understood that the drawing only shows an example provided by way of a practical arrangement of the invention, which can vary in forms and arrangements without however departing from the scope of the concept underlying the invention. Any reference numbers in the appended claims are provided for the sole purpose of facilitating reading of the claims in the light of the description and the drawing, and do not in any manner limit the scope of protection represented by the claims.

Claims

1. A rewinding machine comprising:

at least a first winding member and a second winding member defining a winding cradle;

a winding rod inserter for introducing a winding rod in said winding cradle to wind a reel of web material on said winding rod, said winding rod inserter being arranged and designed so as to introduce said winding rod against the first winding member towards said winding cradle, said second winding member having a variable configuration and being designed and arranged to allow a reel, formed around a first winding rod, to be unloaded from said winding cradle, through a change in the configuration of said second winding member, said winding rod inserter, said first winding member and said second winding member being controlled so that said first reel of web material wound around said first winding rod is unloaded from said winding cradle through a change in the configuration of the second winding member, while said winding rod inserter moves a second winding rod towards the first winding member and said first winding member brings said second winding rod into rotation, whereby winding a second reel is started, said first winding member comprising a first winding roller and said second winding member comprising a plurality of further winding rollers controlled to be in contact with the reel of web material, one or more of said further winding rollers being movable such that said first reel moves away from said first winding member towards an unloading area maintaining said first reel in rotation and continuing to wind said web material on said first reel while said first reel is transferred toward said unloading area and said winding rod inserter moves said second winding rod towards said first winding member.

2. A rewinding machine as claimed in claim 1, wherein said winding rod inserter is controlled to maintain said second winding rod resting on said first winding member for a first phase of winding of the web material around said second winding rod, before said second winding rod is brought to rest on the second winding member.

3-11. (canceled)

12. A rewinding machine as claimed in claim 1, wherein said second winding member comprises a second winding roller, a third winding roller and a fourth winding roller.

13. A rewinding machine as claimed in claim 12, wherein said first winding roller and said second winding roller define a rest and rotation nip for the reel in winding phase.

14. A rewinding machine as claimed in claim 12, wherein an auxiliary winding roller is arranged between said first winding roller of the first winding member and said second winding roller of said second winding member.

15. A rewinding machine as claimed in claim 12, wherein said third winding roller and said fourth winding roller are arranged and controlled to move the first reel away from the first winding member and to transfer the first reel towards said unloading area.

16. A rewinding machine as claimed in claim 15, wherein said third winding roller and said fourth winding roller are arranged and controlled to transfer said first reel maintaining said first reel in contact with the second winding roller.

17. A machine as claimed in claim 12, wherein said second winding roller, said third winding roller and said fourth winding roller are controlled to decelerate and subsequently to stop the rotation of said first reel, said winding rod inserter bringing said second winding rod against said first winding roller starting the winding of a second reel around said second winding rod in contact with said first winding roller.

18. A rewinding machine as claimed in claim 1, further comprising guiding surfaces associated with said first winding member, against which the winding rod inserter rests said winding rods.

19. A rewinding machine as claimed in claim 18, wherein said guiding surfaces are arranged and designed to define a trajectory for introducing the winding rods, extending around the first winding member and moving gradually towards said first winding member from a non-contact position to a contact position of the winding rod with the web material driven around said first winding member.

20. A rewinding machine as claimed in claim 19, wherein said winding rod inserter comprises an engaging system for the winding rods close to ends of said winding rods, said engaging system maintaining the winding rods resting against said guiding surfaces.

21. A rewinding machine as claimed in claim 18, wherein said guiding surfaces are movable to impart an angular acceleration to said winding rods.

22. A rewinding machine as claimed claim 1, wherein said winding rod inserter, said first winding member and said second winding member are arranged and controlled so that while said first reel is unloaded from the winding cradle, the second winding rod is brought to cooperate temporarily with only the first winding member, through which the winding of the web material around said new winding rod starts before said new winding rod starts to co-act with the second winding member, while said second winding member unloads said reel.

23. A rewinding machine as claimed in claim 1, wherein said first winding member and said second winding member are controlled so as to decelerate said first reel at the end of winding of the first reel and before an introduction of the second winding rod.

24. A rewinding machine as claimed in claim 1, wherein said winding rod inserter is associated with means for angular acceleration of the second winding rod to drive said second winding rod into rotation.

25. A method for producing reels of web material around winding rods, the method comprising the steps of:

winding a first reel of web material around a first winding rod in a winding cradle comprising a first winding member and a second winding member;

at an end of winding of said first reel of web material, unloading said first reel of web material from said winding cradle, inserting a second winding rod in said winding cradle, and winding a second reel of web material around said second winding rod, said first reel of web material being unloaded from said winding cradle through a change in an arrangement of the second winding member, while said second winding rod is driven into rotation by moving said second winding rod towards the first winding member;

arranging a first winding roller and a second winding roller to define a seat for supporting and rotating one of the first reel and the second reel during winding;

arranging a third winding roller and a fourth winding roller with movable axes;

winding said first reel in said support and rotation seat in contact with at least said first winding roller and said second winding roller;

continuing winding said first reel of web material between said first winding roller, said second winding roller, said third winding roller, and said fourth winding roller;

moving said first reel of web material away from said first winding roller and maintaining said first reel of web material in rotation by means of at least said second winding roller and said fourth winding roller and reducing the rotation speed of the reel from a winding speed to a replacement speed, said replacement speed being less than the winding speed;

bringing said second winding rod against said first winding roller and engaging the web material between said first winding roller and said second winding rod;

severing the web material between the second winding rod and the first reel;

starting winding said second reel around said second winding rod;

moving the first reel of web material away from the second winding roller;

bringing the second reel in contact with said second winding roller.

26-28. (canceled)

29. A method as claimed in claim 25, further comprising the step of:

moving said first reel of web material away from said first winding roller maintaining said first reel of web material into rotation by means of said second winding roller, said third winding roller, and said fourth winding roller.

30. A method as claimed in claim 25, wherein, while the first reel is moved away from the first winding roller, the third winding roller is moved away from the first reel and said first reel is transferred towards the unloading area through the fourth winding roller.

31. A method as claimed in claim 25, further comprising the steps of:

reducing the rotation speed of the first reel by slowing down the second winding roller, the third winding roller and the fourth winding roller;

moving the third winding roller and the fourth winding roller away from the first reel;

accelerating said third winding roller and said fourth winding roller to the winding speed and engaging said second winding rod and the second reel being formed there around with said third winding roller and said fourth winding roller.

32. A method as claimed in claim 25, further comprising the steps of:

forming a loop of web material between said first reel and said second winding rod by slowing down the rotation speed of said first reel; and

holding said loop of web material between said second winding rod and said first winding member and causing the severing of the web material between said first reel and said second winding rod.

33. (canceled)

34. A rewinding machine as claimed in claim 2, wherein said second winding member comprises a second winding roller, a third winding roller and a fourth winding roller.

35. A rewinding machine as claimed in claim 34, wherein said first winding roller and said second winding roller define a rest and rotation nip for one of the first reel and the second reel in winding phase.

36. A rewinding machine as claimed in claim 34, wherein an auxiliary winding roller is arranged between said first winding roller of the first winding member and said second winding roller of said second winding member.

37. A method as claimed in claim 29, wherein, while the first reel is moved away from the first winding roller, the third winding roller is moved away from the first reel and said first reel is transferred towards the unloading area through the fourth winding roller.