GB2227238A - Laminate production - Google Patents

Abstract

A laminate production machine includes a projector (e.g. a low-power laser 14) which directs a light beam 36 towards a desired location of a stock reel to be spliced, the stock reel being axially adjustable so that a light spot projected on its surface can be aligned with the reel edge or some other convenient feature to indicate that the reel is in a desired location. A further projector 12 may be provided whose beam 34 can be moved in synchronism with beam 36 and aligned with the edge of a running web to which the reel is to be spliced. The projectors 12, 14 may be mounted at a convenient location on the machine frame, with the beams 34, 36 being moved by means of mirrors 18, 20 slidable relative to a scale 25 marked in reel deckle sizes. Further mirrors such as 38 may be provided for re-directing the light beam(s). <IMAGE>

Description

LAMINATE PRODUCTION The invention relates to the control of laminate production machines, particularly those making corrugated board, which at its simplest has upper and lower facings and a corrugated sheet between.

The machines run at high speed drawing stock from as many different stock rolls as there are layers in the product, and have splicers operating on the run to replace exhausted rolls, or to switch to an alternative roll, e.g. of different width.

They are well known but one is shown in outline in Fig. 1 of the drawings, with two paper stock rolls P the right hand one of which is being drawn on, left and right splicing heads R, paper idler roll 1 and capstan roll 2, and dancer roll 3.

The dancer roll allows for the brief halt in paper supply while the leading end of the new stock roll is spliced to the end of the paper from a roll about to become exhausted or which is no longer required and that roll is freed.

In production, some edge trimming of laminate is accepted but it must be minimised for efficiency and economy. To that end stock rolls are mounted on joggers by which they can be moved axially to line up with laminate being produced, and/or with slitters or other processing apparatus designed to operate upon the running web at specific locations across its width. Registration is still however done by judgement and on a big machine with the laminate running overhead at 200 m/min and stock rolls at floor level weighing tonnes it is no easy matter.

We have sought to improve control and have seen that a light beam can offer no-contact indication of the required position of the edge of a stock roll to be spliced in, accurate over the required distance on the machine and allowing the stock roll to be placed very closely. At its simplest therefore the invention provides a laminate production machine including a projector for directing a light beam towards a desired location of a stock reel to be spliced, the stock reel being axially adjustable such that a light spot produced by the projector upon the surface of the reel is alignable with a visual feature of the reel surface to indicate that the stock reel is in the desired location.

The reel edge conveniently forms the visual feature with which the light spot is aligned. The beam is conveniently disposed to be in a plane normal to the axis of the stock reel. The diameter of a particular reel then has no effect on the beam aim needed to relate the position of the reel edge to the position of the edge of the laminate.

In order to be able to splice in stock reels of different widths, the projector may be made adjustable parallel to the reel axis, and may carry an indicating mark registrable with a number of indicia fixed with respect to the machine frame and which correspond to a number of desired stock reel locations.

To be able to splice a fresh stock reel accurately to an existing running web, the projector may again be made adjustable parallel to the reel axis, but in addition or as an alternative to the indicating mark and fixed indicia, the machine may be provided with a second projector, aiming a light beam towards the running web. A light spot produced by the second light beam projector upon the surface of the running web can be aligned with a visual feature of the web surface (conveniently its edge) to indicate that the first light beam is correctly aligned with respect to the reel axis to indicate that the stock reel is in the desired location.

For convenience in co-ordinating the two light beams, the second light beam may also be projected in the plane normal to the axis of the stock reel and which contains the first light beam.

In principle one light beam could be divided to give the two required but it is convenient to have two sources, for example two low-power lasers. It is also convenient to direct the beams across the machine initially, using mirrors or other optical elements to deflect them into what may be called the operating plane. The source or sources can then be stationary in a central position on the machine out of harm's way and readily shielded to protect operatives. The mirrors for deflecting the beam or beams into the operating plane can be carried on a scale rider which also carries the indicating mark referred to above, the fixed indicia in this case being in the form of a co-operating scale marked with the various laminate widths under production.The term 'projector' as used in this specification is to be understood as referring to the light source(s) and any optical elements used for directing the light beam(s) to the required location.

The number and particular arrangement of the optical elements used are not material to the invention, so long as the projector fulfils its function as broadly stated above.

The invention, as applicable for example to the machine of Fig. 1, is illustrated by way of example in specific forms in Figs. 2-4 of the drawings in which: Figs. 2a and 2b schematically show isometric views of alternative laser beam paths for a machine according to the present invention, the machine transverse, vertical and longitudinal axes being indicated by x, y and z respectively; Fig. 3a is a cross-sectional view on line III-III in Fig.

2a showing the scale, scale rider and moving mirrors; Fig. 3b is a perspective view of an embodiment of the invention including a unitary subframe for mounting the projector components, and Fig. 4 is a cross-sectional view of a laser beam aperture cover which may be used in the present invention.

Referring to Figs. 2 and 3a, there is shown a pair of lasers 12, 14 e.g. low power helium neon gas lasers, such as the Uniphase model 1508-1, available from Laser Lines, Beaumont Close, Banbury, Oxon. The lasers 12, 14 are mounted at a convenient location on a frame member 16 part of which is shown in section in Fig. 2 and which runs transversely of the laminating machine. The lasers 12, 14 direct their light beams parallel to the member 16 to strike a pair of mirrors 18, 20 supported on a movable scale rider 22. The mirrors 18, 20 turn each light beam through 90 into the operating plane running normal to the stock reel axis.

The scale rider is supported by means of a linear bearing 24 to run on a guide track 26. Guide track 26 is mounted on a backing plate 28 which in turn is mounted to the frame member 16 by brackets 30 (only one shown). Linear bearing 24 and guide track 26 may be of the 'Linear Way L' type available from IKO Nippon Thompson, Milton Keynes. A track length of 440 mm provides sufficient adjustment of the beam position to accommodate reels of from 1600-2200 mm in width (deckle).

The lasers and running path of the mirrors 18, 20 are enclosed by a protective cover 32. Scale rider 22 is provided with a pointer 23 which cooperates with a scale 25 supported on the backing plate 28 and graduated in deckle sizes.

As shown in the arrangement of Fig. 2a, both light beams are reflected by the mirrors 18 and 20 respectively to run longitudinally of the machine. When correctly aligned, the upper beam 34 shines directly onto the edge of the running web 35 where it passes around the splicer's dancer roll. The lower beam 36 strikes a long fixed mirror 38 disposed with its axis transverse to the machine, and angled to direct the beam 36 downwardly onto the edge of a stock reel to be spliced.

The alternative arrangement shown in Fig. 2b includes mirrors 18', 20' mounted upon the scale rider and which respectively direct a light beam 34' upwardly onto the running web edge and a light beam 36' longitudinally of the machine onto a long fixed mirror 38'. Mirror 38' is arranged similarly to mirror 38 for directing the light beam downwardly onto a stock reel edge. The arrangements shown in Figs. 2a and 2b are examples only; other arrangements of mirrors for use with a different machine configurations will be apparent.

As an alternative to mirrors, it is possible to use other optical elements, such as fibre optics, for example.

Advantageously, the components of the projector may be carried by a unitary subframe attached to cross member 16, facilitating set-up and adjustment of the apparatus. As shown in Figure 3b, the subframe 41 is mounted to the cross member 16 by brackets 31 and carries the guide track 26, scale rider 22 with its associated mirrors 18 and 20, lasers 12 and 14 and the long mirror 38'. The latter is adjustably mounted by pivots 39. This embodiment provides an optical arrangement corresponding to Figure 2b. Mounting the various components on a single subframe increases the accuracy of the projector, as critical surfaces of the subframe can be accurately machined. Installation time is also decreased, because the entire projector structure can be mounted to the machine by only one pair of brackets and the mirror angles and beam alignment can be pre-set.

In order to protect the lasers 12, 14 against the ingress of dust and moisture, it has been found desirable to furnish them with beam aperture covers as illustrated in Fig. 4. The cover 40 is provided with a threaded spigot 42 which screws into the laser face plate and defines a beam passage 44. An angled coverglass 46 is provided at the outer end of the beam passage 44 and is held in place by a circlip 48. Angling of the coverglass ensures that any spurious beams which it generates are directed well away from the main axis and so do not interfere with the proper functioning of the apparatus.

Claims (7)

1. A laminate production machine including a projector directing a light beam towards a desired location of a stock reel to be spliced, the stock reel being axially adjustable such that a light spot produced by the projector upon the surface of the reel is alignable with a visual feature of the reel surface to indicate that the stock reel is in the desired location.

2. A machine as claimed in claim 1 wherein the light beam is projected in a plane normal to the axis of the stock reel.

3. A machine as claimed in claim 1 or 2 wherein the projector is adjustable parallel to the reel axis and carries an indicating mark registrable with a number of indicia fixed with respect to the machine frame and which correspond to a number of desired stock reel locations.

4. A machine as claimed in any preceding claim wherein the projector means is adjustable parallel to the reel axis in unison with a second projector directing a light beam towards a running web of the material to which the stock reel is to be spliced, such that a light spot produced by the second projector means upon the surface of the running web is alignable with a visual feature of the web surface to indicate that the first light beam is correctly adjusted with respect to the reel axis to indicate that the stock reel is in the desired location.

5. A machine as claimed in claim 4 when dependent upon claim 2 wherein the second light beam is projected in the plane normal to the axis of the stock reel and which contains the first light beam.

6. A machine as claimed in any preceding claim in which the projector includes one or more mirrors redirecting the light beam.

7. A machine as claimed in any preceding claim wherein the components of the projector are mounted on a unitary subframe attached to the machine frame.