Method and device for positioning strips and rolls in order to connect same to an unwinding machine

Abstract

A method and device for positioning strips and rolls in order to connect same to an unwinding machine. The method is characterised in that it consists in physically representing the position at which the side of the roll (3) must be positioned in relation to the longitudinal axis of the machine, on the outside diameter of the roll with the aid of a light beam emitter (6) that emits light that is visible to the operator and without the use of an active receiver. The invention is especially suitable for machines used for the continuous unwinding of strips of material and, in particular, for machines used to unwind rolls of paper or card in order to feed a downstream machine.

Description

This invention relates to the field of continuous rolling and unrolling machines for web materials, especially machines for unrolling paper or cardboard spools, for purposes of feeding a downstream machine, and its object is a process for positioning webs and spools for purposes of connection on an unrolling machine.

The object of the invention is likewise a device for implementing this process.

To continuously feed a machine placed downstream from a machine for unrolling paper or cardboard spools, the web of a spool that is ending must be joined to the end of a web of a new spool without the downstream machine, which can be, for example, a printing machine, being stopped.

For this purpose, a spool in the course of unwinding is placed on one of the two spindles of an unrolling machine.

To accomplish joining without stopping the downstream machine, a new spool is placed on standby for a second unrolling spindle of said unrolling machine. The start of the web of this new spool must be positioned such that it is correctly aligned both laterally and angularly with the web that is ending.

Currently, new spools and webs are prepositioned by the operator using graduated scales located on the spindle that bears the spool and on the preparation zone of the start of the web waiting to be joined. Thus, when, for example, the spool has a known width of 600 mm, the operator will slide the spool onto the spindle until the end of the mandrel, of cardboard or another material, of the spool is located next to a corresponding 600 mm reference corresponding to the graduated scale of the spindle that bears said spool, such that the side of the core of the spool is placed as exactly as possible opposite the corresponding 600 mm reference, i.e., is aligned with this reference.

Then, the operator will unroll a sufficient length of the new web that he will arrange opposite the 600 mm reference of the graduated scale of the holding zone of the start of this new web. In this way, apparently correct alignment is obtained between the new spool and the unrolling machine, and the new web will be able to unwind in the unrolling machine without the risk of running skewed.

However, if the new spool has a shape defect, for example when the side at the level of the outside diameter of the spool is not vertically plumb with the side at the level of the inside diameter, then the start of the new web can be placed, in the preparation zone of the start of the web, skewed relative to the longitudinal axis of the machine. This results in malfunctions, especially of longitudinal folds that can cause tears of the web in unwinding or can damage the main part of the production line.

To eliminate this type of defect, using a mechanical frame to feel the side of the spool at the level of its larger diameter in order to correctly position the spool on the unwinding machine is known. This type of device with a frame must be able to take into account a large range of diameters and values of fabric width, which greatly complicates construction and thus the cost of the unrolling machine. Moreover, there may be risks of product deterioration, often expensive and delicate, when the feelers come into contact with the spool.

U.S. Pat. No. 6,007,017 likewise discloses a process for positioning a web, in which the position of the web is measured by means of distance sensors, the acquired values being compared to a reference and the web being moved to make the acquired values coincide with the reference. This document relates to a process for automatic control requiring the use of distance sensors that can notify a control element of the position of the web. These distance sensors can be light wave or ultrasonic transmitter-receivers.

These sensors, however, do not emit a beam of visible light allowing the marking of a position, i.e., allowing an operator to perfectly locate a vertical plane in which the edge of a spool must be positioned, without intervention of specific control means.

Moreover, U.S. Pat. No. 5,133,511 describes a positioning process consisting in measuring the position of a web by means of a position sensor and a CCD camera that, depending on the number and the position of the activated pixels of the sensor, notifies a control and adjustment element about the position of the web. This process uses a light source that is a lamp that illuminates the zone filmed by the CCD camera and is not suited to the marking of a position by delivering a line of light.

Finally, U.S. Pat. No. 4,131,206 also discloses a process for web positioning in which the web is moved laterally until the light flux of a light beam emitted by a light source and detected by a receiver is interrupted. This process implements a photoelectric-type barrier means with an emission source that is not designed to mark a position on the web, but to illuminate a receiver that notifies a control element about the web position.

The object of this invention is to remedy the defects of the known processes and devices by suggesting a process for positioning the webs and spools for purposes of joining on an unrolling. machine and a device for implementing this process that allows perfect alignment between the web that is ending and the new web and unrolling the web without longitudinal folds by implementing a group of operations completely under the control of an operator who verifies the position, without using complex and expensive complementary means for electronic and/or information technology control.

For this purpose, the process according to the invention is characterized in that it consists in marking, at the level of the outside diameter of a spool, by means of an emitter of a beam of light that is visible to an operator and without using an active receiver, the position to which the side of said spool must be positioned relative to the longitudinal axis of the unrolling machine.

The object of the invention is likewise a device for implementing this process that is characterized in that it is composed essentially of at least one emitter of a light beam in the form of at least one linear light beam or at least one light plane of light that is visible to an operator, said emitter working with a passive indexing means, without using an active receiver.

The invention will be better understood, thanks to the following description that relates to a preferred embodiment, given by way of a nonlimiting example and explained with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is a side elevation view of an unrolling machine that is equipped with a device that implements the process according to the invention;

FIG. 2 is a partial perspective view of a device that implements the process;

FIG. 3 is a view analogous to that of FIG. 2 that represents a means of controlling the alignment of the web as it unwinds relative to the longitudinal axis of the unrolling machine, and

FIG. 4 is a view analogous to the one of FIG. 2 showing a variant embodiment of the device that implements the process.

FIG. 1 of the accompanying drawings shows a machine for unrolling paper or cardboard spools for purposes of feeding a machine placed downstream such as a printing machine or the like, this machine being essentially composed of a chassis 1 that supports means 2 of the spool-holder 3 that can move transversely to the longitudinal axis of the machine, and optionally of a device 4 for storing the web and a group 5 for preparation of a new web to be connected and for joining this web to a web that is ending.

To accomplish positioning of the webs and spools for purposes of joining on this unrolling machine, according to the invention, a process is implemented that consists in marking, at the level of the outside diameter of a spool 3, by means of an emitter 6 of a light beam of light that is visible to an operator and without using an active receiver, the position at which the side of said spool 3 must be positioned relative to the longitudinal axis of the unrolling machine.

To implement this process, according to the invention, there is a device that is composed essentially of at least one emitter 6 of a light beam in the form of at least one linear light beam or at least one light plane of light that is visible to an operator, said emitter working with a passive indexing means 7, 71 (FIGS. 2 and 4) provided on the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending, without using an active receiver.

The positioning of the webs and spools for purposes of connection consists in loading the spool 3 onto the free spindle of a spool-holder means 2 to reach a corresponding reference 9 (FIGS. 2 and 4), then optionally to laterally position the emitter 6 relative to the longitudinal axis of the machine, working with the passive indexing means 7, 71, without using an active receiver, on a corresponding reference provided on said passive indexing means 7, 71 in order to align the light beam that is projected by the emitter 6 relative to this passive indexing means 7, 71, to then emit by means of said emitter 6 a light beam of light that is visible to an operator on the new spool 3 that has been placed on the corresponding spindle of the spool-holder means 2 so as to allow the operator to move the spool-holder means 2 laterally in order to match the side of the outside diameter of the spool 3 with the light beam that is projected by the emitter 6 and to align and to prepare the start of the new web.

It should be noted here that the positioning of the emitter 6 is not done systematically, this positioning not being necessary if the new spool has the same width as the spool that is ending.

According to one embodiment of the invention and as shown in FIG. 2 of the accompanying drawings, the passive indexing means 7 is composed of a graduated scale that is mounted on the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending.

It is likewise possible to implement passive indexing means 71 as shown in FIG. 4 of the accompanying drawings, in the form of a mounting support of the emitter 6, this support being provided with positioning references 71′ corresponding to references 700′ of a scale 700 for verifying the position of the new web of a group 5 for preparation of a new web to be connected and for joining this web to a web that is ending. This support that forms the passive indexing means 71 can be implemented in the form of a guide provided with positioning references by marks or again in the form of a guide provided with a means of digital display of the position.

By way of example, on a machine with transverse location-finding between 0 and 650, the spool 3, for example with a width of 600 mm, can be loaded onto the spindle of the spool-holder means 2 at the corresponding 600 mm reference provided as the reference 9, and the positioning of the emitter 6 will then be done on the corresponding 600 mm reference provided on the graduated scale that forms the passive indexing means 7 (FIG. 2) that is mounted on the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending, and said new web is aligned laterally to match said light beam of visible light that has been emitted by the emitter 6.

Thus, the new web is perfectly aligned relative to the unwinding axis of the machine and with the web that is ending, such that a longitudinal fold cannot form after connection.

An identical result can be obtained by using the passive indexing means 71 shown in FIG. 4 of the accompanying drawings. In such a case, it is sufficient to position the emitter 6 on the mounting support that forms the passive indexing means 71 on the positioning reference 71′ corresponding to the reference 700′ of the scale 700 for verifying the position of the new web of the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending.

The emitter 6 can emit a linear light beam or a light plane, or two intersecting light planes arranged, for example, at 90 degrees from one another, such that the resulting trace that is visible on the periphery of the spool 3 is respectively a point, a line or a cross.

According to another characteristic of the invention, the emitter 6 can be provided with a prism or mirrors for division of its light beam. This results in that a part of the latter can be directed onto the periphery of the spool 3 and in that the other part can be directed to the zone for holding the start of the web in the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending, by passing onto a graduated scale 7 (FIG. 2) located in this holding zone.

According to the invention, and as shown in FIG. 2 of the accompanying drawings, the device can comprise two emitters, one pointed toward the spool 3 and the other toward the holding zone of the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending, these emitters being integral with one another.

According to another variant embodiment of the invention that is not shown in the accompanying drawings, it is likewise possible to use a single emitter 6 with a beam that has an aperture angle such that it forms a light plane encompassing simultaneously the spool 3 and the preparation zone of the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending.

The emitter 6 is preferably selected from among the family of laser diodes, but any other highly convergent light source can be used.

The unrolling machine described relative to this invention is symmetrical to allow the new spool 3 to be located to the right or to the left of the vertical center axis of the machine. Actually, when the spool 3 in the course of unwinding is placed to the right relative to the vertical center axis of the machine, then a new spool 3 is placed to the left of this axis and the end of the web of this new spool is prepared and placed in the holding zone located to the left of this axis, in the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending. Then, when the spool 3 in the course of unrolling reaches the end of the web, the web that is ending is. connected to the new web. To avoid stopping the machine placed downstream from the unrolling machine during this changing of the spool, an accumulator or device 4 for storing the web located above the unrolling machine is used, which is designed to store a sufficient length of the web before proceeding to the connection. For this purpose, the speed of the unrolling machine is temporarily increased relative to the speed of the downstream machine, such that the excess length that has been produced can be stored between the cylinders of the accumulator. Then, the connection operation begins that requires stopping of the web as it unwinds at the level of the connection zone. During this temporary stopping, the downstream machine is supplied with the excess length of the web available in the accumulator 4 that is being progressively unwound. Once connection is completed, the new spool that has been placed to the left of the center axis is unrolled to the site of the former one (FIG. 1). The former spool 3 that is located to the right and that is empty or almost empty is removed and replaced by a new spool 3 that is located this time to the right. The machine operator will proceed to proper positioning of the new web of this spool 3 by means of the positioning device according to the invention, this simply by visual monitoring of the position of the light beam of the visible light that has been emitted by the emitter 6, in combination with the passive indexing means 7 or 71, without using a verification means such as a sensor. Operations follow one another in this way by using the left and right positioning devices of the machine in alternation.

This device according to the invention allows perfect angular positioning between the web as it unwinds and the web in preparation. There can nevertheless be a slight defect of lateral alignment due to a lateral defect on the spool in the course of unwinding.

In order to allow the lateral position of the web to be perfectly maintained relative to the longitudinal axis of the unrolling machine during unrolling of the spool 3, according to another characteristic of the invention, a lateral guide device 8 is added to the positioning device (FIG. 3).

This lateral guide device 8 is located downstream from the connecting zone of the group 5 for preparation of a new web to be connected and for joining this web to a web that is ending and controls the lateral position of the web in the course of unwinding relative to the longitudinal axis of the machine.

According to one characteristic of the invention, the lateral guide device 8 advantageously has the form of a means for controlling the lateral position of the web relative to the longitudinal axis of the machine that notifies a central unit of the lateral position of the web and that is composed of a set of two optical cells 8′, 8″ located next to one another near one edge of the web and spaced slightly laterally relative to the longitudinal axis of the machine. This device 8 can be located to the left relative to the web when an observer is watching the unrolling machine frontally, the machine downstream being located in an extension of the web.

Thus, the correct position of the web is obtained when one of the cells 8′, 8″ is activated. When the two cells 8′ and 8″ are activated at the same time, the web is in the process of moving laterally to the left, viewed in the direction of unwinding, and then the spool 3 should be moved in the corresponding unwinding by means of its spool-holder carriage 2 toward the right in order to re-center the web as it unwinds. The movement of the spool-holder carriages 2 takes place transversely to the longitudinal axis of the unrolling machine by means of electric motors in the conventional manner and is not described in detail. The movement of the spool-holder carriage takes place such that the web is automatically re-centered as it unwinds.

Conversely, if neither of the two cells 8′, 8″ is activated, this indicates that the web is in the course of moving to the right and that then the spool-holder carriage 2 should be moved to the left for re-centering the web. This type of control makes it possible to keep the edge of the web between the two cells.

By combining the lateral guide device 8 with the emitter 6, on the one hand it is possible to maintain an optimum lateral position of the web as it unwinds, and, on the other hand, to ensure that the position of the web of the new spool 3 will be in the alignment of the former web and that it will unroll without forming longitudinal folds.

Moreover, the invention ensures the quality of the webs as they unwind, due to the fact that the guide and positioning means are without contact.

Of course, the invention is not limited to the embodiment described and shown in the accompanying drawings. Modifications remain possible, especially from the standpoint of the composition of various elements or by substitution of technical equivalents, without departing from the protective scope of the invention.

Claims

1. Process for positioning webs and spools for purposes of connection on an unrolling machine, characterized in that it consists in marking, at the level of the outside diameter of a spool (3), by means of an emitter (6) of a light beam of light visible to an operator and without using an active receiver, the position to which the side of said spool (3) must be positioned relative to the longitudinal axis of the unrolling machine.

2. Process according to claim 1, wherein it consists in loading a spool (3) onto the free spindle of a spool-holder means (2) to reach a corresponding reference (9), then optionally to laterally position the emitter (6) relative to the longitudinal axis of the machine, working with a passive indexing means (7, 71) provided on a group (5) for preparation of a new web to be connected and for joining this web to a web that is ending, without using an active receiver, on a corresponding reference provided on said passive indexing means (7, 71) in order to align the light beam that is projected by the emitter (6) relative to this passive indexing means (7, 71), to then emit, by means of said emitter (6), a light beam of light visible to an operator on the new spool (3) that has been placed on the corresponding spindle of the spool-holder means (2) so as to allow the operator to move the spool-holder means (2) laterally in order to match the side of the outside diameter of the spool (3) with the light beam projected by the light source (6) and to align and to prepare the start of the new web.

3. Process, according to claim 2, wherein the light beam emitted by the emitter (6) has the form of a linear light beam or light plane, or two intersecting light planes.

4. Process, according to claim 2, wherein part of the light beam is directed onto the periphery of the spool (3) and the other part is directed to the zone for holding the start of the web in the group (5) for preparation of a new web to be connected and for joining this web to a web that is ending, passing onto a graduated scale (7 or 700) located in this holding zone and forming the passive indexing means (7) or a scale (700) for verifying the position of the new web.

5. Device for implementing the process according to claim 1 in a machine for unrolling paper or cardboard spools for purposes of feeding a machine placed downstream such as a printing machine or the like, this machine being essentially composed of a chassis (1) that supports means (2) of the spool-holder (3) that can move transversely to the longitudinal axis of the machine, and optionally of a device (4) for storing the web and by a group (5) for preparation of a new web to be connected and for joining this web to a web that is ending, wherein it is composed essentially of at least one emitter (6) of a light beam in the form of at least one linear beam or at least one light plane of light that is visible to an operator, said emitter (6) working with a passive indexing means (7, 71), without using an active receiver.

6. Device, according to claim 5, wherein the passive indexing means (7) is composed of a graduated scale mounted on the group (5) for preparation of a new web to be connected and for joining this web to a web that is ending.

7. Device, according to claim 5, wherein the passive indexing means (71) has the form of a mounting support of the emitter (6), this support being provided with positioning references (71′) corresponding to references (700′) of a scale (700) for verifying the position of the new web of the group (5) for preparation of a new web to be connected and for joining this web to a web that is ending.

8. Device, according to claim 7, wherein the support that forms the passive indexing means (71) is implemented in the form of a guide provided with positioning references by marks or again in the form of a guide provided with a means for digital display of the position.

9. Device according to claim 5, wherein the emitter (6) is provided with a prism or mirrors for division of its light beam.

10. Device according to claim 5, wherein it comprises two emitters, one pointed toward the spool (3) and the other toward the holding zone of the group (5) for preparation of a new web to be connected and for joining this web to a web that is ending, these emitters being integral with one another.

11. Device according to claim 5, wherein there is a single emitter (6) that has one beam that has an aperture angle such that it forms a light plane encompassing simultaneously the spool (3) and the preparation zone of the group (5) for preparation of a new web to be connected and for joining this web to a web that is ending.

12. Device according to claim 5, wherein the emitter (6) is preferably selected from among the family of laser diodes.

13. Device according to claim 5, wherein the emitter (6) is of the highly convergent beam type.

14. Device according to claim 5, wherein a lateral guide device (8) is added to it.

15. Device according to claim 14, wherein the lateral guide device (8) is located downstream from the connecting zone of the group (5) for preparation of a new web to be connected and for joining this web to a web that is ending and controls the lateral position of the web in the course of unwinding relative to the longitudinal axis of the machine.

16. Device according to claim 14, wherein the lateral guide device (8) has the form of a means for controlling the lateral position of the web relative to the longitudinal axis of the machine that notifies a central unit of the lateral position of the web and that is composed of a group of two optical cells (8′, 8″) located next to one another near one edge of the web and slightly spaced laterally relative to the longitudinal axis of the machine.

17. Device according to claim 15, wherein the lateral guide device (8) has the form of a means for controlling the lateral position of the web relative to the longitudinal axis of the machine that notifies a central unit of the lateral position of the web and that is composed of a group of two optical cells (8′, 8″) located next to one another near one edge of the web and slightly spaced laterally relative to the longitudinal axis of the machine.

18. Device according to claim 6, wherein the emitter (6) is preferably selected from among the family of laser diodes.

19. Device according to claim 6, wherein the emitter (6) is of the highly convergent beam type.

20. Device according to claim 6, wherein a lateral guide device (8) is added to it.