GB2350375A - Dispensing helically wound tape - Google Patents

Abstract

Tape dispensed from a helically-wound spool 31 passes over and oscillates on smooth, arcuate guide 40, and then passes around pin 41 and roller 42. The arrangement reduces the transverse motion of the tape due to its helical winding. The tape, with similarly-adhesive tape 14, runs to coat and protect an extrusion formed on an extrusion line.

Description

2350375 DISPENSING TAPE FROM A SPOOL This invention relates to

tape-dispensing apparatus for tape wound helically on a spool, to a method of applying adhesive tape or film to at least one surface of an elongate body, and to film-coating apparatus using such tape- dispensing apparatus. The invention is particularly useful with low tack self-adhesive tape for the surface protection of plastic window profiles or other profiles immediately after extrusion. In this particular application of the invention, the film is used to protect the profile from damage and scratches during handling, window fabdcation and installation and the film is removable cleanly once the work has been completed.

Low tack self-adhesive film is presently supplied as a tape in roll form and is applied to one or both sides of the plastic profile using small laminators attached to the extrusion line. This suffers from the disadvantage that the roll lengths are limited, particularly for very narrow widths of tape, and are subject to distortion by dishing or telescoping, causing frequent roll changes and rejects. This problem is even greater when the profiles are laminated at high speed with imitation woodgrain veneers which then need subsequently to be given a protective coating of the low tack film. The high speed of tape travel exacerbates the aforementioned problems.

Some of these problems are mitigated used "spool wound" products, i.e. by winding the tape helically on to a spool, which may be cylindrical, and dispensing it from that spool for subsequent application. The roll lengths can then be 10 or more times those of conventional rolls. However, dispensing the tape from helically wound spools requires "de-spooling" i. e. compensation for the harmonic motion transverse to the tape travel direction, in order to orientate the tape correctly for lamination in a straight path to the profile surface or other surface. The tape must be travelling in a generally straight path, with minimal transverse motion. We are 1 not aware of the use of spool winding for this type of tape for the coating of profiles. Thus it is the object of the present invention to enable spool winding to be used in this application, and possibly also in broader applications.

A conventional system for applying self-adhesive tape from rollers to an extruded profile is illustrated in Figure 1 of the accompanying drawings.

Conventional rolls 5 and 6 are mounted on horizontal spindles 7 and 8 and the self adhesive tape is applied respectively to top and bottom surfaces of the profile 3 as it passes horizontally in the direction 110 through the nip of two rollers 9 and 10 which serve to apply the tape to the profile surface. The overall extrusion apparatus 1 incorporates the tape-dispensing system which stands on the floor 2, allowing the profile 3 to pass through it.

Replacing the conventional rolls with helically-wound spools would simply not work, because of the harmonic transverse motion of the tape. For most purposes it is impractical to separate the spools a sufficient distance from the application rollers 9, 10 to reduce the transverse motion effectively, for example by placing the spindles some distance above the top panel 4 of the system. Not the least of the problems would be the inaccessibility of the spindles and the need to lift the spools a substantial vertical distance. A further problem is the irregularity introduced into the resistance to tape unwinding from the spool, arising from the effect of gravity on the spool, and we consider that this arises from the horizontal axis of the rollers and that changing to spools would be better with the use of vertically-mounted spools. However, changing from the conventional horizontal mounting arrangement to a vertical mounting arrangement whilst correctly aligning the tape for application to the profile is not possible without major changes to the conventional system of Figure 1.

2 A further object of the invention is therefore to enable spools to be used effectively, but to integrate the tape-dispensing system into the extrusion line for the profiles, where necessary. It would be advantageous to provide a self-contained, preferably free-standing, unit for location within the extrusion line, such that the profile can pass through the dispensing system without interference. Portability between extrusion lines would be a great advantage also. This means that mechanical fastenings to the extrusion machine should be minimised or eliminated, in preferred solutions to this problem.

Accordingly, the present invention provides tape-dispensing apparatus for tape wound helically on a spool, comprising a rotary support for mounting the spool, a de-spooling tape guide for substantially reducing motion of the tape transverse to its path of travel resulting from it being unwound from axially different places on the spool, and means for dispensing the tape along a flat output path. Such apparatus may be incorporated in filmcoating apparatus comprising means for conveying an elongate body, such as a window profile, along a path which may be generally horizontal and may extend through the tape-dispensing apparatus.

The invention also provides a method of applying adhesive tape or film to at least one surface of an elongate body using apparatus according to any of the preceding claims, comprising de-spooling the tape from the spools as it passes to the output path or paths and applying the tape or tapes to the corresponding surface or surfaces of the elongate body as the body passes through the tape dispensing apparatus.

Further, the invention provides a method of dispensing tape wound helically on a spool comprising pulling it over a fixed, smooth, curved guiding surface so that its path of travel bends through at least a right-angle and the plane of the tape, originally parallel to the spool axis, turns through an acute angle; then over at least 3 one further stationary or moving guide to complete the turn of the tape's plane from its original plane through a full right-angle, so that it is normal to the spool axis; the tape path length between the spool, the curved guiding surface and the further guide or guides being sufficient, in relation to the amplitude of axial harmonic motion of the tape exiting the spool surface, the radius of the spool and the speed of tape travel, to dampen substantially that transverse harmonic motion of the tape; and the curved guiding surface being sufficiently long, transverse to the tape in use and in the direction of the spool axis, to allow the tape to slide along it with the said transverse harmonic motion at an intermediate amplitude.

Further still, the invention provides a corresponding tape-dispensing apparatus for tape or film wound helically on a spool, comprising a fixed, smooth, curved guiding surface arranged to guide the tape from the spool so that it bends at least through a right-angle and the plane of the tape, originally parallel to the spool axis, turns through an acute angle; then over at least one further stationary or moving guide to complete the turn of the tape's plane from its original plane through a full right-angle, so that it is normal to the spool axis; the tape path length between the spool, the curved guiding surface and the further guide or guides being sufficient, in relation to the amplitude of axial harmonic motion of the tape exiting the spool surface, the radius of the spool and the speed of tape travel, to dampen substantially that transverse harmonic motion of the tape; and the curved guiding surface being sufficiently long, transverse to the tape in use and in the direction of the spool axis, to allow the tape to slide along it with the said transverse harmonic motion at an intermediate amplitude.

In order that the invention may be better understood, a preferred 25 embodiment will now be described, by way of example only, with reference to the accompanying schematic drawings, in which:

4 Figure 1 shows a conventional tape-dispensing system from upper and lower rollers; Figure 2 shows a tape-dispensing apparatus embodying the invention, in place of the conventional tape-dispensing system of Figure 1 but incorporated in the 5 same extrusion line; Figure 3 is a perspective view of the tape-dispensing apparatus of Figure 2 from above and from the front left; Figure 4 is a front elevation of the tape-dispensing apparatus of Figure 3, with the mast partly broken away; Figure 5 is a partial perspective view from above and from the front right of the tape-dispensing apparatus of Figures 3 and 4, omitting some components for the sake of clarity; Figure 6 is a front elevation of a curved guiding surface of the tapedispensing apparatus of Figures 3 to 5, with a modification to the subsequent tape guides; and Figure 7 is a left side elevation corresponding to Figure 6.

The apparatus shown in the drawings is intended to dispense self-adhesive tape of a width between 15 mm and 40 mm from a pair of helically-wound spools 30,31 to the top and bottom respectively of the profile 3 of Figures 1 and 2, which is conveyed along a horizontal path through the tape-dispensing apparatus between its top panel 4 and the floor 2, and more particularly above the spools. The tapedispensing apparatus is a self-contained, free-standing, portable unit which rests on the floor and can be moved between extrusion lines. It requires no mechanical fixings, and can be located manually at the appropriate position in the extrusion line as shown in Figure 2. As shown most clearly in Figure 3, the unit has a generally rectangular footprint defined partly by the peripheries of the largest spools 30,31 intended to be mounted on two turntables 34,35 respectively, with the spools 30,31, located at opposite corners of the rectangle. As will be explained in greater detail below, the tape is "de-spooled" by various guiding surfaces generally or, more preferably, wholly within the rectangular footprint, and it is arranged to be dispensed along twin parallel output paths again within the footprint, for application to the profile 3 using applicaticm rollers 9,10 of a laminator as in the conventional arrangement. Thus the apparatus achieves the objective of replacing the conventional rolls of Figure 1 with spools as shown in Figure 2, with interchangeable modules. There is no need to make any adjustments to the conventional extrusion lines, nor to re-position the application rollers 9,10, and there is no interference between the profile 3 and the tape-dispensing apparatus or the tape as it is being dispensed.

For this application, the tape is self-adhesive on one side only, and is 50 or microns thick. Tape of this type is available from 30 to 100 microns thick.

Alternatives include the use of tensilised tape for extra strength, allowing the thickness to go down for example to 18 microns. The film need not be self adhesive, and it need not be plastics: it could for example be a thin wood foil.

The bottom tape 13 is taken from a spool 31 towards the front and the right hand side of the module, whose platform 21 rests on the floor 2. The top tape 14 is dispensed from spool 30 towards the back and left-hand side, by way of a rather longer path using a mast 22 to take the tape over the extrusion line. As shown in Figure 2, but omitted from Figures 3 to 5, horizontal rollers 11 and 12 guide the top and bottom tapes 14, 13 through approximately 45" into the nip of the application rollers 9, 10.

Each spool 30,31 is located on a corresponding spool turntable 34,35 using three locating pins 32,33. The spool turntable 35 rotates on a spindle 36 (Fig. 4) on 6 conventional bearings, and is adjustably braked by an adjusting screw 37 with a manual brake knob 38; a similar arrangement is provided for the back spoof turntable 34, with its brake knob 39 (Fig. 3). The spindles may be electrically powered for larger spools, but this is not considered necessary for the arrangement illustrated. The tape is tensioned to suit the particular coating application, the degree of self-adhesion, and other parameters, using the brake knobs 38, 39.

The bottom tape 13 exits the spool 31 from near the centre of the footprint of the unit, as shown in Figure 3, with the spool 31 rotating anti-clockwise. It is arranged to turn through an angle of approximately 120-140, when viewed from above, around a fixed, generally toroidal, smooth guiding surface 40. This guiding surface stands in a generally vertical plane, and is supported by a vertical plate, so that it resembles a shark's fin. The active surface of the guide 40 is in fact the lower half of what is in effect a curved metal pipe, and in this example the curve is generally circular, although other configurations are envisaged. For example, for the highest tape transport speeds, the curved surface could be terminated at the top and/or the bottom with a bend in the opposite direction to ensure that the tape does not run off the guide, so that the overall shape would be a letter'S' or a lefter'W' for example. Where the tape is self-adhesive on one side, it has to be the smooth side of the tape which engages the guide 40.

The plane of the tape as it exits the spool 31 is vertical, but this has to be turned through an acute angle, in this example by approximately 45-60", using the guide 40. As best shown in Figures 3 and 5, the tape 13 wanders on the vertical axis, i.e. transverse to its path, as it exits the spool, with a transverse harmonic motion corresponding to the helical winding. The horizontal distance between the spool 31 and the guide 40 is such that the angle to the horizontal of the tape path as it approaches the guide 40 varies in the range of about 20" to 50. As the tape 7 wanders up and down, it is able to slide smoothly up and down the guide 40, and this minimises distortion of the tape. The smooth surface of the guide 40 therefore has to be arcuate in both horizontal and vertical planes and over a sufficient angle to accommodate the tape as it turns about both axes. Further, in order to accommodate spools of different sizes, the guide 40 is made sufficiently tall for the largest possible size spoof.

To further reduce distortion and to complete the turn of the plane of the tape 13 through a right-angle to a flat horizontal disposition, a fixed pin 41 is secured transverse of the tape path, and at an intermediate angle of about 10-15" to the horizontal as shown in Figure 4. The pin 41 is secured to the shark's fin guide 40, generally perpendicularly to its plane, and is positioned roughly midway between the active surface of the guide 40 and a further roller 42 which is mounted horizontally.

The tape 13 reaches the roller 42 with a substantially reduced transverse harmonic motion, and perfectly flat in the horizontal plane. The tape runs round the roller 42 whence it travels vertically, as shown in Figure 2, to pass around the horizontal roller 12 for subsequent application to the profile 3.

The top tape 14 is handled similarly, but has necessarily a longer path to travel. It exits the spool 30 which rotates clockwise, and passes around a similar ushark's fin" stationary curved guide 50 through an angle of approximately 130-150, and then around a pin 51 corresponding to pin 41. The tape is then flat and horizontal, with much reduced transverse harmonic motion, once it reaches a horizontal roller 52 at the back right-hand corner of the unit, roller 52 having a function similar to roller 42.

In order to raise the tape above the level of the profile 3, a telescopic mast 22 of adjustable height supports a horizontal roller 28 and a vertical roller 27 above the horizontal roller 52, and within the footprint of the unit. A fixed arm 24 supports 8 at its end a swinging arm 25 on a pivot 26, and the vertical roller 27 depends from the end of the swinging arm. The horizontal roller 28 depends from the top of the telescopic mast 22. Thus the tape 14 passes vertically from the lower horizontal roller 52 to an upper horizontal roller 28 and then horizontally, being turned through a right-angle, to the vertical roller 27, and thence horizontally, after a right-angled bend in a horizontal plane to the horizontal roller 11 of Figure 2. The path length from the lower horizontal roller 52 over the further downstream rollers serves to reduce still further the transverse harmonic motion of the tape. Nevertheless, the smooth arcuate guide 50 still has an important function in reducing transverse motion even for this top tape 14.

It will be appreciated that a similar arrangement can be used where only one tape is required, or where the tape is not self-adhesive. The registration of the dispensing unit with the extrusion unit rollers 9, 10 allows some degree of tolerance, enabling the unit to be positioned manually and to rest without any fixture on the floor of the apparatus.

Additional dispensing units of this type can of course be used for multiple profiling purposes, and other turntables can be installed on the same platform 21 as required, for example for protecting side surfaces of the profile 3.

For tapes wider than 40 mm, for example up to 50 mm, we have found it desirable to use a series of three pins 41 a, 41b and 41 c of equal length in place of the single pin 41, as shown in Figures 6 and 7. These three pins are angled progressively so as to guide the tape smoothly as it exits the shark's fin guide 40 (or 50) and completes its turn through 9W from a vertical to a horizontal orientation.

The drawing is approximately to scale, and the heights of the pins 41a to 41c are respectively 115mm, 85mm and 45mm. The tops of the pins 41 a to 41 c respectively are at horizontal spacings of 45mm, 70mm and 11 Omm from the 9 vertical surface of the "shark's fin" 40 (or 50). In this preferred example, the pins are also bent into a curved configuration, the angle of the curve increasing progressively from the lowest pin 41 c through to the highest pin 41 a, as shown in Figure 6. This minimises distortion arising from the transverse motion of the tape, because it allows the tape to slide transversely up and down the pins. Thus the effect of the curve of the pins is similar in principle to that of the curve of the toroidal smooth surface of the guide 40.

It will be appreciated from a consideration of the engineering principles of the guides 40 and 50, the pin 41 and the alternative pins 41a to 41c, that these arrangements could be replaced with any appropriate smooth guiding surface, whether continuous or in discrete sections. Further, the curve in the vertical plane need not be circular: it could be parabolic or some other complex shape, and it could be terminated with a different curvature for ensuring that the tape is maintained on the guide even at high speed.

Further, it will be appreciated that the angles through which the tape path turns when viewed from above will depend on the situation of the spools, which depends on the application required. Clearly the harmonic transverse motion can most easily be eliminated with the longest path lengths, and the tape can be handled most quickly and easily with bends through the least angles, but this conflicts, as in the present case, with the desire for compactness and for the avoidance of interference with the extrusion line, as well as for compatibility with existing systems, and for portability and speed of change during production.

In the extrusion process illustrated in part in Figures 1 and 2, the laminated profile 3 may be cut as required, downstream of the laminator.

The examples of the invention illustrated here are also applicable to the despooling of any form of spool-wound tape or film, not necessarily for coating elongate bodies.

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Claims (31)

1. Tape-dispensing apparatus for tape wound helically on a spool, comprising a rotary support for mounting the spool, a de-spooling tape guide for substantially reducing motion of the tape transverse to its path of travel resulting from it being unwound from axially different places on the spool, and means for dispensing the tape along a flat output path.

2. Tape-dispensing apparatus according to Claim 1, in which the flat output path is generally horizontal, and the rotary support is for mounting the spool on a vertical axis.

3. Tape-dispensing apparatus according to Claim 1 or 2, comprising two such parallel rotary supports for corresponding spools, with corresponding flat output paths.

4. Tape-dispensing apparatus according to Claim 3, in which the two output 15 paths are spaced parallel.

5. Tape-dispensing apparatus according to Claim 3 or 4, comprising a mast supporting tape guides above both rotary supports for guiding the tape from one of the spools to an upper, horizontal flat output path, in which the other output path is horizontal and is lower than the upper output path but is still above the spool rotary supports.

6. Tape-dispensing apparatus according to Claim 5, comprising means for applying the tape from the upper and lower hohzontal output paths to corresponding opposite faces of an elongate body travelling through the tape-dispensing apparatus.

7. Tape-dispensing apparatus according to any of Claims 1 to 5, comprising means for applying the tape from the or each flat output path to a corresponding face of an elongate body travelling through the tapedispensing apparatus.

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8. Tape-dispensing apparatus according to any preceding claim, in the form of a free-standing unit.

9. Tape-dispensing apparatus according to any of Claims 3 to 6, whose footprint is substantially a rectangle bounded by the vertical spoof rotary supports at opposed corners, and in which the output paths above the rotary supports are generally horizontal and fall within the footprint.

10. Film-coating apparatus comprising means for conveying an elongate body along a path, and apparatus according to Claim 5 or 6 for applying film tape from the spool or spools, to a surface or surfaces of the body.

11. Film-coating apparatus according to Claim 10, in which the path for the elongate body is generally horizontal and extends through the tapedispensing apparatus.

12. Film-coating apparatus according to Claim 11, in which the tapedispensing apparatus is a modular, free-standing unit which accommodates the tape-applying means generally above the spool rotary supports.

13. A method of applying adhesive tape or film to at least one surface of an elongate body using apparatus according to any of the preceding claims, comprising de-spooling the tape from the spools as it passes to the output path or paths and applying the tape or tapes to the corresponding surface or surfaces of the elongate body as the body passes through the tape dispensing apparatus.

14. A method according to Claim 13, further comprising extruding the elongate body and conveying it generally horizontally to the tapeapplying means.

15. A method according to Claim 14, comprising the subsequent step of cuffing the elongate body and tape at a point downstream of the tapedispensing apparatus.

16. A method of dispensing tape wound helically on a spool comprising pulling it over a fixed, smooth, curved guiding surface so that its path of travel bends through 13 at least a right-angle and the plane of the tape, originally parallel to the spool axis, turns through an acute angle; then over at least one further stationary or moving guide to complete the turn of the tape's plane from its original plane through a full right-angle, so that it is normal to the spool axis; the tape path length between the spool, the curved guiding surface and the further guide or guides being sufficient, in relation to the amplitude of axial harmonic motion of the tape exiting the spool surface, the radius of the spool and the speed of tape travel, to dampen substantially that transverse harmonic motion of the tape; and the curved guiding surface being sufficiently long, transverse to the tape in use and in the direction of the spool axis, to allow the tape to slide along it with the said transverse harmonic motion at an intermediate amplitude.

17. Tape-dispensing apparatus for tape or film wound helically on a spool, comprising a fixed, smooth, curved guiding surface arranged to guide the tape from the spool so that it bends at least through a right-angle and the plane of the tape, originally parallel to the spool axis, turns through an acute angle; then over at least one further stationary or moving guide to complete the turn of the tape's plane from its original plane through a full right-angle, so that it is normal to the spool axis; the tape path length between the spool, the curved guiding surface and the further guide or guides being sufficient, in relation to the amplitude of axial harmonic motion of the tape exiting the spool surface, the radius of the spool and the speed of tape travel, to dampen substantially that transverse harmonic motion of the tape; and the curved guiding surface being sufficiently long, transverse to the tape in use and in the direction of the spool axis, to allow the tape to slide along it with the said transverse harmonic motion at an intermediate amplitude.

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18. Tape-dispensing apparatus according to Claim 17, in which the curved guiding surface is generally part-toroidal so as to present a generally cylindrical guiding surface.

19. Tape-dispensing apparatus according to Claim 17 or 18, having a further guide comprising a fixed pin transverse to the tape path and inclined to the spool axis at an angle intermediate the said acute angle, at which the tape exits the curved guiding surface, and the full right-angle which the tape subsequently attains.

20. Tape-dispensing apparatus according to Claim 17 or 18, having a further guide comprising a series of a plurality of fixed pins generally transverse to the tape path and inclined at progressively increased angles from the said acute angle, at which the tape exits the curved guiding surface, to the full right-angle which the tape subsequently attains.

21. Tape-dispensing apparatus according to any of Claims 17 to 20, comprising at least one downstream guide for turning the tape path through another right-angle, the path length between the said further guide and the downstream guide or guides allowing extra dampening of the said harmonic transverse motion of the tape, and allowing for appropriate positioning of the tape for application as required.

22. Tape-dispensing apparatus according to Claim 21, in which the or each downstream guide comprises rollers both parallel and transverse to the tape spool.

23. Tape-dispensing apparatus according to any of Claims 17 to 22, in which there are two such tape spools.

24. Tape-dispensing apparatus according to Claim 23, in which the spools are mounted on parallel spaced rotary supports.

25. Tape-dispensing apparatus according to Claim 24, in which the rotary supports are on vertical axes.

26. Tape-dispensing apparatus according to any of Claims 17 to 25, in which the tape is guided to an output path or paths which is or are horizontal.

27. Tape-dispensing apparatus according to Claim 23, 24 or 25, comprising a mast or gantry supporting downstream rollers for guiding one of the tapes in an 5 output path over the two spools.

28. Tape-dispensing apparatus according to any of Claims 17 to 27, having two spools and corresponding parallel horizontal output paths for the tape, and means for applying the tapes to opposed surfaces of an elongate body passing through the tape-dispensing apparatus.

29. A method according to Claim 16, or apparatus according to any of Claims 17 to 28, in which the or each tape or film is adhesive or tacky on one side, but smooth on the other side, and the apparatus is arranged such that the smooth side of the tape slides against the curved guiding surface.

30. De-spooling apparatus substantially as described herein with reference to 15 the accompanying drawings.

31. A method of dispensing tape substantially as described herein with reference to the accompanying drawings.

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