GB2029806A

GB2029806A - Web Splicing Apparatus

Info

Publication number: GB2029806A
Application number: GB7930061A
Authority: GB
Original assignee: ANNONI E; STEFANONI R
Current assignee: ANNONI E; STEFANONI R
Priority date: 1978-09-12
Filing date: 1979-08-30
Publication date: 1980-03-26
Also published as: GB2029806B; IT1098584B; IT7827540A0; DE2936460A1

Abstract

This apparatus allows tape, preferably adhesive tape, to be unwound from one reel (5) and its expiring end joined to the leading end of tape drawn of a replacement reel (25) without stopping the machine. Tape 7 from the first reel 5 passes over two rollers 9, 10. When this reel is nearly empty, tape from a second reel 25 is unwound via rollers 29, 30 onto a launching roller 31. When the speed of the two tapes at these two pairs of rollers is equal, the tapes are pressed together by units 12, 13, 32 and 33. If the tape is not adhesive tape, a glue may be required. Cutters 14, 35 then operate to isolate the new train of tape from the expiring reel and from the launching roller. <IMAGE>

Description

SPECIFICATION An Unwinding Machine This invention relates to an unwinding machine suitable for tapes, especially tape films, and preferably those previously rendered adhesive on at least one face.

When producing adhesive tapes of different sizes, it is necessary to start from film reels of relatively large diameter, which are then unwound, cut to measure and tape rewound in suitable cutters.

Due to the high speed of these machines, the shutdown times for replacing the empty reel and jointing with the already unwound end are large and therefore contribute considerably to the total cost of the finished product.

Machines having two reels which are alternately unwound by independent unwinding means are known, and these require shutdown only for the time to join the unwound end or terminal and the start of the spare reel. The reel that is now empty can be replaced while the spare reel is unwound. These machines still, however, require shutdown and, moreover, the joint has to be made at a stationary machine.

We have now devised an unwinding machine for tapes or tape films, preferably adhesive, which can automatically effect a jointing between the tape of one reel (generally one which is about to run out) and that of another reel, hereinafter referred to as a spare reel, without shutting down or stopping the machine. The new machine can produce a joint having a superimposed section of highly reduced length, devoid of folds, and accordingly not liable to discards in the rolls of finished tape that will be issued from the cutter.

The invention will now be further illustrated with reference to the accompanying drawing, which shows a schematic side view of a preferred machine.

A machine 1 comprises two standards or uprights 2 in the form of opposing plates which are connected by tie rods 3. Two openable upper bearings 4 carry the top reel 5 and are mounted on upper guides 6 to aid in loading and unloading.

Similarly, two openable lower bearings 24 carry bottom reel 25 and are mounted on lower guides 26.

The unwinding means for the top reel 5 comprise an upper reacting roller 8 and two smooth idle rollers 9 and 10, referred to as first and second upper rollers, respectively.

In the drawing, a tape 7 is shown which is unwound from reel 5 and, by passing beneath rollers 8, 9 and 10, is carried to be wound on another reel (not shown). The upper launching roller 11, to be discussed below, is connectable to the machine motor and is disconnected from the tape being unwound from reel 5.

Similarly, at the bottom of the machine there are provided a reacting roller 28, a first lower knurled idle roller 29 and a second knurled idle roller 30, as well as a lower launching roller 31, which is also connectable to the machine motor.

Under the operative condition shown, the reel 5 is being unwound and tape 7 is rewound on a suitable shaft, while reel 25 is stationary and acts as a spare reel. The pairs of smooth and knurled idle rollers define two planar, parallel and opposing path sections at the tape outlet from the machine, separated by a certain distance, and the tape end of reel 25 is attached by the launching roller 31.

The smooth rollers 9 and 10 and knurled rollers 29 and 30 have associated cutting and pressure units comprising eccentrical pressures 12, 1 3, 32 and 33, having blades or other cutting devices 14, 1 5, 34 and 35 mounted on them.

During the operation of the machine, the cutting and pressure units are disconnected from the rollers and held at rest position remote from the tapes as shown in the figure of the accompanying drawing. When a suitable sensor or meter monitoring diameter of the moving reel 5 detects a pre-determined value indicating that the reel is nearly empty, the launching roller 31 is operated causing reel 25 to rotate. The detector may, for example, be a photoelectric detector applied at bearings 4 which uses reflection of a light beam impinging on the reel mass or body.A suitable speed sensor or detector, for example a speedometer dynamo, determines when the proper running driving speed has been attained, that is when the tape driven by roller 31 also has the same speed as tape 7 and simultaneously operates said cutting and pressing units 12-14 and 33-35.

The above-mentioned unit 12-14 rotates in the direction shown by the arrow cutting the tape 7 and brings it at the same time to press against tape from reel 25, to which it gets attached.

Similarly, rotation of unit 33-35 cuts the tape from reel 5 thus clearing it from the launching roller and, by pressing it against tape 7, connects it to the latter.

Suitable timing of these operations and the width of the pressure sectors will depend on the driving speed, and are chosen to provide complete joining between the tapes of the two reels for a length considerably less than the spacing between the axes of rollers 9, 10 or 29, 30.

Now, reel 25 is unwound by the action of the outrunning tape, and reel 5 is stopped. During the unwinding of reel 25, the following operations are carried out in order to preset the machine for the next reel exchange: opening of bearings 4 and withdrawal of the empty reel by sliding on the saddle 6 (or complete replacement of the bearing assembly with an already preset assembly); partial unwinding of the tape from the new reel until it is attached or anchored to the launching roller 11; and clearing of any tape remaining on the launching roller 31.

When the reel 25 is nearly unwound, a corresponding sensor will operate the launching roller 11, and a further detector will control the operation of units 13-1 5 and 32-34 in a similar way to that described above. The pneumatically controlled reacting rollers 8 and 28 help to prevent tearing and reduce noise, and also avoid the crack of the rolled up tape.

The launching rollers may be knurled to improve adhesion of the tape, while the rollers 9 and 10 are preferably smooth, and rollers 29 and 30 are preferably knurled to facilitate separation of them from the adhesive side of the tape. The cutting control is preferably of the electrical type, having a temporally adjustable control pulse for final setting up.

The cutting and pressing units may be independent of the rollers, or interlocked to them when in use and released immediately after a complete revolution.

Finally, the machine could be used also for non-adhesive tapes (such as tapes to be made adhesive), and in such a case a suitable adhesive or bonding agent may be applied by a spreader at the rollers, operated by the same control for the cutting and pressing units.

Claims

1. An unwinding machine having two tape reels which can be used to join tape from the two reels in tandem, which has: a launching roller for each reel onto which tape from that reel can be wound; two adjacent pairs of rollers, each pair defining a travel path between a reel and its launching roller; means for determining when the tape speeds at the sections are equal; pressers which cause the two tapes at the sections to touch; if necessary, means to cause the two tapes to adhere when they touch; cutters, operable by the means for determining, which can cut one tape each side of the adhered section to isolate tape on the launching roller and, if necessary, to isolate any tape remaining on the spent reel.

2. An unwinding machine according to claim 1, which has means for detecting the load of tape on each reel; the means for detecting being able to control unwinding of tape from a fresh reel onto its launching roller.

3. An unwinding machine according to claim 1 or claim 2, in which the cutters and pressers comprise circular sectors having knives or blades.

4. An unwinding machine according to any one of claims 1, 2 and 3, in which one pair of rollers are smooth and the other pair are knurled, and in which the launching rollers are knurled.

5. An unwinding machine according to any one of the preceding claims, in which the launching rollers can be driven by the main motor of the machine.

6. An unwinding machine for adhesive tapes, comprising a frame on which two tape reels are mounted, which are successively unwound by independent driving means, characterized by comprising for each of the reels a launching roller driving the spare reel under control of a detector for the diameter of the reel being unwound, and first and second rollers for each reel adjacent the outlet of the tape from the machine, defining two opposing straight travel sections, said rollers being provided with cutting units with eccentrical pressing members, and that the first cutting unit relating to the reel being unwound and the second cutting unit relating to the spare reel are simultaneously operated by a speed meter or detector when the speeds for the two reels are the same, respectively for cutting off the tape of the reel being unwound and re!ease the tape of the spare reel from the launching roller, at the same time carrying out the jointing between the tapes along a portion of the opposing travel section by means of said eccentrical pressing members.

7. An unwinding machine substantially as herein described with reference to the accompanying drawing.

8. A method of unwinding tapes from reels, in which tape is unwound from a first reel until nearly empty and tape from this reel is then joined to tape from a second reel; in which tape from the second reel is wound onto a launching roller such that the paths of the two tapes run adjacent, and when the speeds of the two tapes are equal, the tapes are adhered together, and the tape running from the adhered portion to the first reel and that running from the adhered portion to the launching roiler are cut to isolate the new train of tape.

9. A method of unwinding tapes substantially as herein described with reference to the accompanying drawing.