Patent Description:
The field of converting relates to all machines performing a process of winding and unwinding a strip of material onto and from coils. Such machines perform the function of transporting the strip between one coil and another of generally different sizes in a fast and defect-free manner.

Such converting operations can consist in i) producing coils of small widths and diameters from parent coils produced in large sizes for reasons of process economy; ii) processing the material to add certain features, such as printing, lamination, or film deposition; and iii) rewinding a previously produced coil to eliminate defects.

The end product of the process is an intermediate step in the processing chains of all materials, such as paper, plastics, aluminum, and laminates, made in the form of films, generally of a thickness between a few microns and one millimeter. Converting machines are used in multiple industrial fields, including the food packaging and automotive industries, for example.

However, in some application fields, a highly delicate and/or brittle, very thin and/or loosely cohesive, and thus easily flaky, material needs to be subjected to converting. In these cases, managing the converting activity can be problematic and negatively affect the operational speed of the entire process.

A problem generally characterizing the converting machines is the difficulty in automating the change of the rewinding coil, which, being smaller than the feeding reel, must be changed during the processing. Such a change can occur without interrupting the process when a buffer section is arranged upstream, but still normally requires substantial human intervention. The same problem occurs when the strip tears (as is the case when the material is particularly brittle or delicate), so the winder must be changed and the rewinding must be restarted.

The need is thus felt to provide a machine for converting coils, especially but not solely coils of delicate and/or brittle material, which preserves high productivity and minimizes possible interruptions caused by material breakage and performs all the converting steps automatically.

Such a problem is solved by a machine for converting coils of delicate and/or brittle material as defined in the appended claims, the definitions of which are an integral part of the present description. Document <CIT> discloses an exemplary machine suitable for converting coils of a material into coils of smaller size according to the preamble of claim <NUM>.

In particular, the invention is defined by claim <NUM> and relates to:.

Preferably the accompanying member comprises a semicircular portion having a first end and a second end, a hinge being placed in an intermediate position between said ends, on which hinge a retaining element is hinged, comprising, in turn, an arc-of-circle-shaped portion and a protruding portion, which extends along a direction substantially perpendicular to a tangent of the arc-of-circle-shaped portion, wherein a holding roller is placed at the junction point between said arc-of-circle-shaped portion and said protruding portion, and an idle roller is placed at the distal end of the protruding portion; and wherein the protruding portion comprises a suction/blowing grille, which is alternately in flow communication with suction means or with a fan or source of compressed air; the retaining element being tiltable between a retracted position and a lowered position, in which the arc-of-circle-shaped portion of the retaining element coincides with a sector of the semicircular portion of the accompanying element.

Preferably the accompanying member comprises a tilting arm which distally comprises a holding roller and which is movable between a non-operating position and an operating position, in which the holding roller insists on a winding shaft.

Preferably the cutting member comprises a blade located on a side of the cutting member which, in an operating condition, faces the movable accompanying member and is configured to abut on a surface of the latter when cutting the strip.

Preferably the cutting device comprises a body which extends along a longitudinal axis and comprises a holding roller at one end and, adjacent thereto, a cutting device, which protrudes along a direction substantially perpendicular to the body and carries said blade at its distal end.

Preferably the carriage comprises a tilting arm carrying a holding roller at one end, the tilting arm being movable between a non-operating position and an operating position in which the holding roller abuts against the feeding roller.

Preferably the carriage comprises a longitudinal strip cutting assembly, configured to cut the strip fed to the winding unit according to its length, so as to reduce its width and ultimately obtain two or more coils of rewound material, said longitudinal cutting assembly comprising a crosswise supporting bar comprising one or more cutting devices, wherein each cutting device comprises a vertically sliding blade, the blade preferably being a discoidal blade rotating in an idle manner, and wherein the crosswise supporting bar is movable along a track arranged diagonally on the carriage, between a raised position and a lowered position, the longitudinal cutting assembly further comprising a contrast cylinder, on which the strip is intended to slide and which, in operating condition, is tangential with the blade of the cutting device.

Preferably the winding unit comprises an idle roller placed laterally and at a higher position with respect to the feeding roller, said idle roller being configured to outline a path of the strip, or of the plurality of strips originated by the longitudinal cutting unit, so that it faces the accompanying member and is included between the latter and the cutting member.

Preferably the feeding roller and the winding shafts are motorized and wherein the movements of accompanying member, accompanying element, tilting arm, retaining element and cutting member are actuated by electric or pneumatic actuators.

Further features and advantages of the present invention will become more apparent from the description of some exemplary embodiments thereof, given below by way of non-limiting indication, with reference to the following figures:.

The converting machine according to the invention, indicated by reference numeral <NUM> as a whole, comprises a loading unit <NUM> of the strip N of material, an accumulation unit <NUM> of the strip N being processed, and a winding unit <NUM> of the strip N on a winding shaft <NUM>, <NUM>' to form respective coils B.

The loading unit <NUM> of the strip N comprises the accompanying system <NUM> for the strip N along the various working steps of the machine <NUM>, i.e., from the loading unit <NUM> to the accumulation unit <NUM> and the winding unit <NUM>. The accompanying system <NUM>, shown in <FIG> with a dotted line, consists of a double chain (diagrammatically shown in the figures with a single line) which develops in a loop along a path P defined by a plurality of idle toothed wheels <NUM> and at least one motorized toothed wheel <NUM>'. The double chain movably supports an accompanying bar <NUM>, which is thus movable along the loop-shaped path P and is configured to drive the strip N to be loaded into the machine <NUM> from the loading unit <NUM> to the winding unit <NUM> and then, after releasing the strip N, to return to the starting point in the loading unit <NUM>.

The accompanying bar <NUM> is preferably cylindrical in shape, i.e., it has a circular section or at least comprises a surface with an arc-of-a-circle-shaped section facing the sliding direction of the double chain. The accompanying bar <NUM> is also made of, or comprises parts made of, a ferromagnetic material so as to be subjected to attraction by a magnet.

The accompanying system <NUM> also comprises a non-motorized magnetic bar, which idly slides along the path P on appropriate guides and is configured to be coupled to the accompanying bar <NUM> during the operating steps of the method of loading a new strip N.

In a first step of loading a new strip N, the strip N from a large coil upstream (not shown) is fed to the loading unit <NUM> of the machine <NUM> by means of a conveyor T and falls vertically positioning itself in the space between the accompanying bar <NUM> and the magnetic bar.

In the next step, the double chain is set in motion along the direction of the arrow, so that the accompanying bar <NUM> comes into contact with an end portion of the strip N until it is sandwiched between the accompanying bar <NUM> and the magnetic bar. The magnetic attraction between the magnetic bar and the accompanying bar <NUM> allows holding the strip N firmly close to one end thereof and leading it along the path P in a gentle manner, i.e., without the use of gripper systems which would damage the strip N and cause it to break.

The accompanying bar <NUM> - magnetic bar assembly together with the strip N continues to travel along said path P. In practice, the strip N is driven by the accompanying bar <NUM> and the magnetic bar through the accumulation unit <NUM>, then into the winding unit <NUM>, where the end portion of the strip N is separated from the rest of the strip N, which then begins to be wound on a winding shaft <NUM>, <NUM>', thus performing the converting operation. The accompanying bar <NUM> and the magnetic bar, associated with the piece S of strip N, continue along the path P to return to the loading unit <NUM>, where the accompanying bar <NUM> is disassociated from the magnetic bar and returns to its initial position. The automatic loading system summarized above is described in detail in the co-pending <CIT>.

The accumulation unit <NUM> is placed between the loading unit <NUM> and the winding unit <NUM> of the strip N on a winding shaft <NUM>, <NUM>'. The accumulation unit <NUM> acts as a buffer store when it is necessary to replace a fully wound coil B in the winding unit <NUM> with a winding shaft <NUM>' to be wound. Such an operation requires a temporary stop of the winding, therefore the accumulation unit <NUM> allows not interrupting the feeding of strip N from the conveyor T during such a stop.

The accumulation unit <NUM> comprises a first movable supporting structure <NUM> for a first series of movable rollers <NUM> and a second movable supporting structure <NUM>' for a second series of movable rollers <NUM>'. Each series of movable rollers <NUM>, <NUM>' comprises a plurality of vertically aligned rollers in a plane parallel to a first and a second straight path stretch. Said first and second straight path stretches are connected by a third upper path stretch, to form as a whole a substantially π-shaped stretch of path P, which encloses said movable supporting structures <NUM>, <NUM>' of the movable rollers <NUM>, <NUM>' underneath.

Each of the movable supporting structures <NUM>, <NUM>' comprises a pair of comb-shaped supports arranged parallel to each other and each comprising a plurality of horizontal arms <NUM>, <NUM>', where the horizontal arms <NUM>, <NUM>' of the first pair of comb-shaped supports face the first straight stretch of path P and the horizontal arms <NUM>' of the second pair of comb-shaped supports face the second straight stretch of the path P.

The movable supporting structures <NUM>, <NUM>' slide horizontally on appropriate shoes by means of an appropriate drive (not shown). The movable supporting structures <NUM>, <NUM>' are movable in a mutually opposite direction between a retracted position, in which the movable rollers <NUM>, <NUM>' are not in contact with the strip N, and a plurality of extended positions, in which the movable rollers <NUM>, <NUM>' are in contact with the strip N.

The accumulation unit <NUM> further comprises a first series of fixed rollers <NUM> and a second series of fixed rollers <NUM>', facing the first and second series of movable rollers <NUM>, <NUM>', respectively, but vertically staggered with respect thereto. Each series of fixed rollers <NUM>, <NUM>' comprises a plurality of vertically aligned rollers, respectively, in a plane parallel to said first stretch and second stretch of the path P and facing one side of said path stretches opposite to the first and second series of movable rollers <NUM>, <NUM>', i.e., outside of the π-shaped path stretch P, so that said path stretches are placed between said fixed rollers <NUM>, <NUM>' and said movable rollers <NUM>, <NUM>'.

<FIG> shows the machine <NUM> in a normal operational condition. The movable rollers <NUM>, <NUM>' are moved forward to an extended position, introducing themselves between two contiguous fixed rollers <NUM>, <NUM>' and engaging the strip N so as to extend it to form meanders. The movement of the movable rollers <NUM>, <NUM>' from the retracted position to an extended position and vice versa, as indicated by the arrows, allows modulating the total length of the path P as needed, either by lengthening it (movable rollers <NUM>, <NUM>' in a more extended position) or shortening it (movable rollers <NUM>, <NUM>' in a less extended position), so as to act as a storage buffer for the strip N during processing, in case of a processing stoppage or slowdown of the downstream in winding unit <NUM>.

A particular embodiment of the accumulation unit <NUM> is described in detail in the co-pending <CIT>.

The winding unit <NUM> comprises a rotatable disc <NUM>, which supports two winding shafts <NUM>, <NUM>' of the coils B. In turn, the winding shafts <NUM>, <NUM>' are rotatable by means of an appropriate motorization.

The winding unit <NUM> further comprises a feeding roller <NUM> of the strip N to a winding position, with which a movable member <NUM> accompanying the strip N and a cutting member <NUM> are operatively associated.

The winding shafts <NUM>, <NUM>' are placed in opposite positions along a diameter of the disc <NUM>, so that <NUM>° rotation of the disc <NUM> allows taking the first winding shaft <NUM> or the second winding shaft <NUM>' alternatively to said winding position.

<FIG> shows in detail the mechanism of feeding roller <NUM>, movable accompanying member <NUM>, and the cutting member <NUM>.

The feeding roller <NUM>, the movable accompanying member <NUM>, and the cutting member <NUM> are placed on a carriage <NUM>, movable horizontally (as shown by the arrow in <FIG>) between at least one forward or operating position (<FIG>) and a retracted or resting position (<FIG>).

A longitudinal cutting assembly <NUM> of the strip N, also shown in <FIG>, is also placed on the carriage <NUM>. The longitudinal cutting assembly <NUM> is configured to cut the strip N fed to winding unit <NUM> according to its length, so as to reduce its width and ultimately obtain two or more coils B of rewound material N.

The longitudinal cutting assembly <NUM> comprises a crosswise supporting bar <NUM>, to which a plurality of vertical supports <NUM> is fixed, with each of which a cutting device <NUM> can be associated. The number of cutting devices <NUM> is dictated by the number of width reductions of the strip N to be achieved. <FIG> shows a cutting device <NUM> for each vertical support <NUM>, but in other cases, there may also be a single cutting device <NUM> placed in the middle of the width of the crosswise supporting bar <NUM>, so as to divide the incoming strip N into only two strips to be rewound.

The cutting device <NUM> comprises a blade <NUM> vertically sliding by means of a pneumatic actuator (not shown) inside the cutting device <NUM>. The blade <NUM> is a discoidal blade idly rotating on a supporting pin.

The crosswise supporting bar <NUM> is movable, by a pneumatic actuator 35a, along a track <NUM> arranged diagonally on the carriage <NUM>, between a raised position and a lowered position.

The longitudinal cutting unit <NUM> further comprises a contrast cylinder <NUM>, on which the strip N slides and which, in operating condition, is tangential with the blade <NUM> of the cutting device <NUM>. Such an operating condition is achieved by sliding the crosswise supporting bar <NUM> diagonally from the raised position to the lowered position and by sliding the blade <NUM> downward.

<FIG> shows the rewinding unit <NUM> in a non-operational condition. The movable accompanying member <NUM> is hinged on the axis of the feeding roller <NUM> and is tiltable between a non-operating position (for example, shown in <FIG>) and an operating position (for example, shown in <FIG> or <FIG>).

The movable accompanying member <NUM> comprises a body 31a having an arc-of-circle-shaped recess 31b of shape and size such as to be coupled to an at least semi-cylindrical portion of the surface of a winding shaft <NUM>, <NUM>'.

The recess 31b comprises a housing which develops along its entire extension and in which an accompanying element <NUM> of the strip N slides. The accompanying element <NUM> is movable between a retracted position and an extended position, in which, by sliding in said housing, it performs a rotation of about <NUM>° about a rotation axis parallel to the rotation axis of the winding shafts <NUM>, <NUM>'.

As better shown in <FIG>, the accompanying element <NUM> comprises a semicircular portion 41a, having a first end <NUM> and a second end <NUM>. A hinge 41b is placed in an intermediate position between said ends <NUM>, <NUM>, on which a retaining element <NUM> is hinged, comprising, in turn, an arc-of-circle-shaped portion 60a and a protruding portion 60b, which extends along a direction substantially perpendicular to a tangent of the arc-of-circle-shaped portion 60a.

A holding roller <NUM> is placed at the junction point between said arc-of-circle-shaped portion 60a and said protruding portion 60b, while an idle roller <NUM> is placed at the distal end of the protruding portion 60b.

The protruding portion 60b further comprises a suction/blowing grille <NUM>, which can be alternately put into flow communication with suction means (not shown) or with a fan or compressed air source (not shown) by means of an appropriate two-way valve.

The retaining element <NUM> is tiltable between a retracted position (for example, shown in <FIG>) and a lowered position (for example, shown in <FIG>), in which the arc-of-circle-shaped portion 60a of the retaining element <NUM> coincides with a sector of the semicircular portion 41a of the accompanying element <NUM>.

A tilting arm <NUM>, which distally comprises a holding roller <NUM>, is also hinged on a hinge <NUM> of the body 31a of the accompanying member <NUM>. The tilting arm <NUM> is movable between a non-operating position (for example, shown in <FIG>) and an operating position (for example, shown in <FIG>), as will be further clarified below.

The cutting member <NUM> is tiltable between a non-operating position (for example, shown in <FIG>) and an operating position (for example, shown in <FIG>).

The cutting member <NUM> is also hinged on the axis of the feeding roller <NUM> by means of a connecting element 32a which extends in a substantially perpendicular direction to the body 32b. The body 32b extends along a longitudinal axis and comprises a holding roller <NUM> at one end, and adjacent thereto, a cutting device <NUM>, which protrudes along a direction substantially perpendicular to the body 32b and carries a blade 51a at the distal end thereof. The cutting device <NUM> is placed on the side of the body 32b which, in the operating condition, faces the movable accompanying member <NUM> and is configured to abut against a surface of the latter when cutting the strip N.

Moreover, a tilting arm <NUM> hinged at one end 52a and carrying a holding roller 52b at the opposite end is also placed on the carriage <NUM>, below the feeding roller <NUM>. The tilting arm <NUM> is movable between a non-operating position (for example, shown in <FIG>) and an operating position (for example, shown in <FIG>) in which it abuts against the feeding roller <NUM>.

The feeding roller <NUM> and the winding shafts <NUM>, <NUM>' are motorized. The movements of accompanying member <NUM>, accompanying element <NUM>, tilting arm <NUM>, retaining element <NUM>, and cutting member <NUM> are actuated by suitable electric or pneumatic actuators.

The strip N of material to be rewound, coming from the accumulation unit <NUM> and reduced in width by passing through the longitudinal cutting unit <NUM>, is slid at an idle roller <NUM> placed laterally and at a higher position with respect to the feeding roller <NUM>. The strip N, possibly divided in width into two or more strips, thus faces the accompanying member <NUM> and is included between the latter and the cutting member <NUM>.

<FIG> show an operational sequence of automatically starting (or restarting) the winding of a coil of material.

As described above, the strip N is driven by the accompanying system <NUM> into the rewinding unit <NUM>. <FIG> shows the step in which the feeding roller <NUM> placed on the carriage <NUM> is in the retracted position and the strip N has already passed over the feeding roller <NUM> and the idle roller <NUM>.

<FIG> shows the next step in which the carriage <NUM> is in an operating forward position. In the immediately following step, shown in <FIG>, the accompanying member <NUM> and the cutting member <NUM> are tilted until they abut, so as to cut the strip N, thus generating the piece S which will be removed as described above. It is worth noting that, during the cutting operation, the strip N is bent and stretched by sliding on the holding roller <NUM> and the idle roller <NUM> of the retaining element <NUM>. Similarly, downstream of the accompanying member <NUM>, the strip N is bent and stretched by passing through the holding roller <NUM> of the cutting member <NUM>.

<FIG> shows the step in which the cutting member <NUM> is returned to the non-operating position, while the accompanying member <NUM> holds the end of the strip N to be rewound by virtue of the activation of the suction grille <NUM> and the simultaneous rotation of the tilting arm <NUM> of the carriage <NUM> so as to apply a sealing pressure to the feeding roller <NUM> by means of the respective holding roller 52b. The disc <NUM> (<FIG>) is also rotated clockwise to take a winding shaft <NUM>' close to the accompanying member <NUM>. <FIG> shows the next step in which the accompanying member <NUM> is further rotated to a second operating position so that the arc-of-circle-shaped recess 31b accommodates the winding shaft <NUM>' by positive coupling.

The next step, shown in <FIG>, includes moving the retaining element <NUM> from the retracted position to the lowered position so that the holding roller <NUM> thereof presses against the surface of the winding shaft <NUM>', thus helping to keep the strip N (i.e., the plurality of strips resulting from its longitudinal cut) adhered to the winding shaft <NUM>'.

As shown in <FIG>, the next step includes, according to the arrows shown in the figure, synchronously rotating:.

The strip N (i.e., the plurality of strips resulting from its longitudinal cut) is thus accompanied in the initial winding thereof around the winding shaft <NUM>', being held against its surface by the holding rollers <NUM>, <NUM>, and by the suction of the free end thereof by means of the suction grille <NUM>.

<FIG> shows the next step, in which the suction by the grille <NUM> is suspended and the grille <NUM> is connected to a pressurized air source which provides a release of the free end of the strip, taking it to adhere onto the winding shaft <NUM>'. The winding shaft <NUM>' continues to rotate, thus starting the rewinding operation.

Finally, <FIG> shows the final step in which the accompanying member <NUM> is returned to the non-operating position, and the carriage <NUM> is further moved forward to a further operating position in which it abuts against the winding shaft <NUM>' to keep the strip N in contact therewith.

The converting machine <NUM> according to the present invention thus allows achieving the initially set objects since the winding system described above, in the case of a change of coil or breakage of the strip to be wound, allows for complete automation, without any human intervention, and is also particularly suitable if the strip is made of a particularly brittle material, especially by virtue of the accompanying member.

The machine <NUM> according to the invention allows for an automatic restarting after breakage or coil change without using adhesive tape or glue (of any nature). By avoiding the use of adhesives (thus chemical contaminants), it is also possible to process materials intended for the food industry.

Claim 1:
A machine (<NUM>) for converting coils of a material into coils of smaller size, comprising a loading unit (<NUM>) for loading a strip (N) of material into the machine (<NUM>), an accumulation unit (<NUM>) of the strip (N) being processed, and a winding unit (<NUM>) of the strip (N) on a winding shaft (<NUM>, <NUM>') to form respective coils (B), wherein the winding unit (<NUM>) comprises:
- a revolving disc (<NUM>), which supports two winding shafts (<NUM>, <NUM>') of coils (B);
- a feeding roller (<NUM>) of the strip (N) to a winding position;
- a movable accompanying member (<NUM>) of the strip (N) and a cutting member (<NUM>) associated in an operating manner with said feeding roller (<NUM>),
wherein the feeding roller (<NUM>), the movable accompanying member (<NUM>), and the cutting member (<NUM>) are placed on a carriage (<NUM>), movable horizontally between at least one forward or operating position and a retracted or resting position;
and wherein the movable accompanying member (<NUM>) and the cutting member (<NUM>) are hinged on the feeding roller axis (<NUM>) and are tiltable between a non-operating position and an operating position adapted to operate the crosswise cut of the strip (N), characterized in that the movable accompanying member (<NUM>) comprises a body (31a) having an arc-of-circle-shaped recess (31b) of shape and size such to couple with an at least semi-cylindrical portion of the surface of a winding shaft (<NUM>, <NUM>', wherein the recess (31b) comprises a housing which develops along its entire extension and in which an accompanying element (<NUM>) of the strip (N) slides, the accompanying element (<NUM>) being movable between a retracted position and an extended position, in which, by sliding in said housing, it performs a rotation of about <NUM>° about a rotation axis parallel to the rotation axis of the winding shafts (<NUM>, <NUM>').