WO2017145185A1

WO2017145185A1 - Device and process for controlling the discharge of logs from a rewinding machine

Info

Publication number: WO2017145185A1
Application number: PCT/IT2016/000304
Authority: WO
Inventors: Fabio Perini
Original assignee: Futura S.P.A.
Priority date: 2016-02-26
Filing date: 2016-12-22
Publication date: 2017-08-31
Also published as: ITUB20161108A1

Abstract

Device for controlling the output speed of paper logs (2) outgoing from a rewinding machine, comprising means for slowing down the logs (2) rolling along an output plane (6). The device (1) comprises at least two deceleration rollers (3a, 3b, 3c, 3d), arranged above said output plane (6) at a distance from the latter such as to intercept each log passing along said output plane (6) and connected to motor means adapted to drive them according to at least two different angular speeds (V3a, V3b, V3c, V3d), such that each log (2) is slowed down along the output plane (6) up to a predetermined value.

Description

TITLE

Device and process for controlling the discharge of logs from a rewinding machine.

DESCRIPTION

The present invention relates to a device and a process for controlling the discharge of logs from a rewinding machine.

The rewinding machines are used to wrap a predetermined amount of paper or other web material around a tubular core, usually made of cardboard, said "core", so as to produce reels, in jargon called "logs", having a predetermined diameter as a function the conformation of the final product.

The winding of the web material on the core is generally made in a winding unit provided with a pair of winding rollers by means of which the logs are held and rotated about the longitudinal axis of the core up to the required diameter. Rewinding machines or rewinders of this type are described, for example, in US 2003/0001042 Al, US 6,565,033 and WO 01/64563. After completing the winding, the log must be downloaded from the rewinder to direct it towards further processing steps (cutting, trimming, etc.). For this purpose, the log is released from the winding rollers and is made to roll along an exit plane of the winding unit. Since the release of the log takes place without a preventive slowing down of the winding rollers, it rolls with an excessive speed compared to that required by the processing units located downstream along the production plant. Therefore, it is necessary to slow down the logs leaving the rewinder .

EP-1520814 discloses the problem related to the slowdown of the logs leaving the rewinders avoiding the damaging of the logs and discloses a solution foreseeing the use of a braking roller having a yielding and elastic outer surface.

WO2015/040644 discloses a device for controlling the discharge of logs outgoing from a rewinding machine, comprising a body placed downstream of a surface along which the logs move along an output direction, said body rotating with a predetermined angular speed about an axis parallel to the logs and perpendicular to said output direction. The rotating body has at least one pocket adapted to receive and temporarily housing a log) that enters in the same pocket while moving along the output direction. The body rotates about said axis in a direction (opposite to the output direction .

The main object of the present invention is to provide a device and a method for controlling the discharge of logs from a rewinding machine using different modes to decrease the output speed of the logs.

The present invention eliminates the problems related to the control of the speed with which the logs move downstream of the rewinding machine by providing a device and a method having the features indicated in the independent claims. Other features of the invention are the subject of the dependent claims. Among the advantages of the present invention there are the following: the speed of the logs may be accurately reduced in a gradual way; the logs are not damaged when they are subject to deceleration; the logs retain a correct orientation while they move, i.e. they remain with their longitudinal axes parallel to that of the winding rollers and that of the deceleration rollers; the device can be applied to existing rewinding machines; the construction and operation of the device are simple and intuitive and, therefore, require low costs for manufacturing, setup and maintenance.

These and other advantages and features of the present invention will be best understood by anyone skilled in the art from the following description and with the help of the attached drawings given as a practical exemplification of the invention, but not to be considered in a limitative sense, wherein:

^■ Fig. 1 is a schematic side view, with details not to scale and represented in a simplified manner, relating to a possible example of embodiment of a device in accordance with the present invention;

^■ Fig. 2 is a schematic side view similar to Fig.l but showing the device in a different operating phase .

In the accompanying drawings there is schematically represented a winding station (5) of a rewinding machine of a known type which therefore will not be described in detail. The winding station (5) comprises winding rollers and feed rollers for feeding and winding a paper web, of the known type and marked with the reference numeral (50) in the drawings. The function of the rollers (50) is that, previously described, to wrap a web material around a core to form a so-called log.

From the winding station (5), the log (2) is allowed to roll along the output or discharge plane (6) of the machine, along the direction indicated by the letter "F" in the drawings. Each log is allowed to roll by gravity along the plane (6) due to the downward inclination of the latter. The output speed of log (2) could be excessive for the operations to be carried downstream in the production process.

According to the example shown in the drawings, at the end of the output plane (6) there is a conveyor (4), provided with seats (40) adapted to receive the logs to be transferred downstream. In particular, according to this example, said seats (40) are sequentially provided by the conveyor (4) at the end of the output plane (6), so as to accommodate the logs (2) coming from the winding station (5) located upstream. The conveyor (4), thanks to corresponding motor means (not shown in the drawings) , performs a rotation (V4) around its longitudinal axis thus performs the transferring the logs (2) downstream of the output plane (6).

The speed of the logs (2) moving along the plane (6) must be suitably controlled. Obviously, the conveyor unit (4) schematically shown in the drawings is only an example of a possible unit arranged downstream of the winding station (5) to better highlight that it is necessary a control device controlling the speed of the logs.

In accordance with the present invention, the device

(1) for controlling the discharge of logs from a rewinding machine comprises a plurality of deceleration rollers (3a, 3b, 3c, 3d) , arranged above the discharge plane (6), at a distance substantially corresponding to the diameter of the logs (2) . In practice, the rollers (3a, 3b, 3c, 3d) are positioned at a height that allows to intercept the logs rolling on the discharge plane (6) to adjust their speed according to the angular speed of the rollers, as it will be better described hereinafter.

Advantageously, the deceleration rollers (3a, 3b, 3c,

3d,) may have an outer yieldable and elastic surface.

This allows to impart a specific speed to each log without damaging the latter. Alternatively, some of said rollers, in particular the rollers (3c, 3d) more distant from the winding station (5), may be provided with a coating of tungsten carbide which increases the surface hardness to facilitate the engagement of the logs that in the meantime have been partly decelerated by the preceding deceleration rollers (3a, 3b) .

Each deceleration roller (3a, 3b, 3c, 3d) is connected to corresponding motor means (not shown in the drawings) which determines the rotation thereof around its longitudinal axis, which axis is parallel to that of the logs (2) and parallel the axis of the rollers (50) of the winding station (5) . The longitudinal axes of rollers (50) and (3a, 3b, 3c, 3d), the longitudinal axis of the logs (2), and the rotation axis of the conveyor (4) are mutually parallel and are orthogonal to the plane of the sheet in the drawings. With reference to the example shown in the drawings, the logs (2) and the conveyor unit (4) rotate clockwise, while the deceleration rollers (3a, 3b, 3c, 3d) rotate counterclockwise.

According to the invention, the angular speed of the last roller (3d) , that is, the roller disposed further downstream, is less than the angular speed of the first roller (3a), i.e. the roller disposed further upstream. This results in a gradual decrease of speed which brings the logs (2) at a predetermined output speed at the end of the plane (6) above which the deceleration rollers (3a, 3b, 3c, 3d) are positioned. The rollers (3a, 3b, 3c, 3d) can be in different number from that of the example illustrated, in which they are four in number; for example, said rollers may be two in number.

The speeds at which the rollers (3a, 3b, 3c, 3d) rotate (and at which, consequently, they intercept and slow down the logs) can be differentiated according to the production needs, i.e., for example, the type of material used to manufacture the logs , the type of treatment to be performed downstream, the production rate of the production plant, etc.

For example, the speed (V3a) of the first roller (3a) can be higher than that (V3b) of the second roller (3b); in turn, the speed (V3b) of the second roller (3b) can be higher than that (V3c) of the third roller (3c); and in turn, the speed (V3c) of the third roller (3c) can be higher than that (v3d) of the fourth roller (3d) .

The possible sequence of rotational speeds described above can be expressed as: (V3a)> (V3B)> (V3c)> (v3d) .

For example, the first deceleration roller (3a) can reduce the speed of the logs (2) of approximately 10% in relation to the speed of the logs exiting from the winding station, the second deceleration roller (3b) of about 30%, the third deceleration roller (3c) of about 60%, and the fourth deceleration roller (3d) of approximately 90%. In this way, it is possible to decelerate the logs in successive deceleration steps, thus avoiding or at least drastically reducing damages to the logs (2) subjected to deceleration.

The rotation speed of two adjacent deceleration rollers may be the same; in practice, two successive, i.e. adjacent, deceleration rollers may have an identical angular velocity, provided that the deceleration roller positioned further downstream along said direction (F) rotates more slowly than the first deceleration roller positioned further upstream. Possible speed sequences of the deceleration the rollers may be the following, where the sign indicates a same speed between:

(V3a) = (V3b) > (V3c) = (v3d) ;

(V3a) > (V3b) = (V3c) > (v3d) ; (V3a) = (V3b)> (V3c) > (v3d) ;

(V3a) > (V3b)> (V3c) = (v3d) .

Therefore, the speed of the logs along the discharge plane switches from a higher value to a lower value either directly or through an intermediate value. The transition from the initial value of the speed of the logs rolling on the plane (6) to the final predetermined value performed by imposing one or more intermediate values makes the deceleration more gradual. A more "direct" deceleration, performed for example with only two deceleration rollers, may be preferred for particular production requirements (depending, for example, on the type of material used for manufacturing the logs, the minimum production rate of the plant, etc .. ) .

According to another possible alternative, the angular velocity of the first roller (3a) may be such as to slow down the logs or may maintain it unchanged such that the deceleration is actuated downstream. A process realized according to the invention therefore provides that the logs (2) released from the winding station and that roll along an unloading plane (6) are slowed down by means of at least two rollers (3a, 3b, 3c, 3d), arranged above said plane (6) at a distance such as to interfere with the logs rolling on said plane (6) along an output direction (F); the rollers (3a, 3b, 3c, 3d) are rotated according to at least two different speeds (V3a, V3b, V3c, V3d) such as to intercept each of the logs (2) and decelerate them along the unloading plane (6) up to a predetermined output speed value.

Referring to the accompanying drawings, the log (2) released from the winding station (5) moves to the right, along the direction indicated by the arrow (F) until it interferes with the first roller (3a), that is, the roller disposed further upstream . The roller (3a) leads the log (2) to the speed (V3a) which is preferably lower than that of the log (2) entering the deceleration device (1) defined by the rollers (3a, 3b, 3c, 3d) . Subsequently, the log (2) , following the discharge path defined by the discharge inclined plane from upstream to downstream, comes into contact with the second roller (3b) , which leads it to a speed that is not higher than the speed imposed to the same log by the first roller, and, continuing to roll along the discharge plane, the log comes into contact with the third (3c) and the fourth roller (3d) . When the log (2) is downstream of the last roller (3d) it has an output speed that is lower than the speed of the same log leaving the winding station (5), the lower speed being preferred to permit a more correct interaction of the log itself with the unit disposed downstream (according to the example shown in the drawings, the unit disposed downstream is the conveyor unit 4) .

The transition from the initial speed (presented by the logs that leave the winding station 5) to the final speed (presented by the logs once through the deceleration device 1) can be obtained in several successive stages with ever decreasing speed values, or it may involve intermediate stages in which is maintained the same value of angular velocity by the respective rollers (3a, 3b, 3c, 3d) that control the discharge of the logs, according to the production choices made by the manufacturer.

From the foregoing it is evident that: the speed of the logs is reduced in a gradual way and with predictable accuracy; the logs are not damaged in the process of slowing down, also maintaining a proper orientation while they move in the downstream direction; the device can be applied to already existing machines; the construction and operation of the device are simple and intuitive.

Of course, the invention is not limited to the examples described and illustrated in the drawings, but may be greatly varied as regards the nature and arrangement of the component parts without departing from the inventive teaching disclosed above and claimed in the following.

Claims

Device for controlling the output speed of paper logs (2) outgoing from a rewinding machine, comprising means for slowing down the logs (2) rolling along an output plane (6), device (1) characterized in that it comprises at least two deceleration rollers (3a, 3b, 3c, 3d), arranged above said output plane (6) at a distance from the latter such as to intercept each log passing along said output plane (6) and connected to motor means adapted to drive them according to at least two different angular speeds (V3a, V3b, V3c, V3d) , such that each log (2) is slowed down along the output plane (6) up to a predetermined value.

Device according to claim 1, characterized in that said at least two deceleration rollers (3a, 3b, 3c, 3d) are connected to motor means adapted to drive them according to at least two different angular speeds (V3a, V3b, V3c, V3d) such that the log is gradually slowed down along said output plane (6) up to a predetermined value, passing through at least an intermediate speed value between the initial one presented by the logs and the final predetermined speed value.

Device according to claim 1 and / or 2, characterized in that one of said at least two deceleration rollers (3a, 3b, 3c, 3d) arranged further downstream (3d) is moved at a speed (v3d) lower than that of the roller (3a) located further upstream.

Device according to any of the preceding claims, characterized in that said at least two deceleration rollers (3a, 3b, 3c, 3d) have a yieldable and elastic outer surface.

Device according to any one of claims 1 to 3 characterized in that said at least two deceleration rollers (3a, 3b, 3c, 3d) have an outer surface provided with a hardening coating.

A process for controlling the output speed of logs (2) outgoing from a rewinding machine, wherein the logs (2) are slowed down along an output plane (6), characterized in that the slowdown of said logs (2) is performed by at least two deceleration rollers (3a, 3b, 3c, 3d), arranged above said output plane (6) at a distance from the latter such as to intercept each log passing along said output plane (6) and connected to motor means adapted to drive them according to at least two different angular speeds (V3a, V3b, V3c, V3d) , such that each log (2) is slowed down along the output plane (6) up to a predetermined value .

Process according to claim 6, characterized in that said at least two deceleration rollers (3a, 3b, 3c, 3d) are connected to motor means adapted to drive them according to at least two different angular speeds (V3a, V3b, V3c, V3d) such that the log is gradually slowed down along said output plane (6) up to a predetermined value, passing through at least an intermediate speed value between the initial one presented by the logs and the final predetermined speed value.

Process according to claim 6 and / or 7, characterized in that one of said at least two deceleration rollers (3a, 3b, 3c, 3d) arranged further downstream (3d) is moved at a speed (v3d) lower than that of the roller (3a) located further upstream.

Process according to any one of claims 6 to 8, characterized in that said at least two deceleration rollers (3a, 3b, 3c, 3d) have a yieldable and elastic outer surface. Process according to any one of claims 6 to 8, characterized in that said at least two deceleration rollers (3a, 3b, 3c, 3d) have an outer surface provided with a hardening coating.