GB2161795A - Adhesive tabs - Google Patents

Abstract

The free end (15) of a roll of paper for a printing press is held against the body (16) of the roll, prior to splicing to the trailing end of a spent roll, with a tearable adhesive tab. The tab has a central portion (6) with a transverse break line (7), and adhesive-backed top and bottom portions (1, 2). Guide lines (13, 14) are marked on the tab above the break line for alignment with the edge of the free end of the roll. <IMAGE>

Description

SPECIFICATION Adhesive tabs This invention relates to a tearable adhesive tab for securing the leading end of a roll of sheet material to adjacent such material on the body of the roll.

Tabs of this kind are used in the printing industry where paper is fed continuously from successive rolls to a printing press. As one roll becomes depleted an adjacent fresh roll is set in rotation and, when effectively spent, the trailing end of the first roll is spliced to the leading end of the fresh roll by contact with a coating of paste or glue previously applied by hand to the fresh roll. The leading end of the fresh roll is prevented from unwinding prior to splicing to the expiring roll by means of an adhesive tab of the abovementioned kind, which is constructed so as to tear readily after splicing has been completed.

It is important to ensure that the glue or paste does not extend beyond the leading end onto the body of the roll such as to give rise to incorrect splicing and consequent disruption of continuous paper feed. However, this can be difficult with known tabs in so far as the limit of paste or glue application is not clearly defined with regard to that portion of the leading end which is covered by the tab.

An object of the present invention is to provide a tab which can firmly attack the leading end in position yet which is readily tearable subsequent to splicing and with which the abovementioned problem can be avoided or at least appreciably reduced.

According to the invention therefore there is provided a tearable adhesive tab for securing the leading end of a roll of sheet material to adjacent such material on the body of the roll, said tab having a central portion with a transverse break line (as hereinafter defined) terminating at or adjacent to side edges of said central portion, and top and bottom portions respectively above and below said central portion and having ahdesive on rear faces thereof for attachment respectively to said leading end and said adjacent material, guide markings for said leading end being provided above said break line. By break line is meant any structure which constitutes a slit or narrow elongate gap or which is adapted readily to form such a structure (comprising a line of perforations or the like). In the former case the break line must terminate spaced from the side edges.In the latter case the break line may extend up to the side edges if desired.

With the arrangement of the invention the tab can securely hold the leading end yet can readily tear, when required, by separation along the break line and by rupture of any short linking portions between the ends of the break line and the edges of the central portion. By use of the guide markings, it is possible to locate the leading end relative to the label so that glue or paste applied over the leading end and label can be readily confined thereto as required. Moreover, the arrangement can be such that a flap is defined between the markings and the break line so that any overlap which does occur is separable on the flap with the leading end when the tab is torn.

Most preferably the said break line constitutes perforations (or like line of weakness) whereby the abovementioned flap can be retained in position smoothly on the roll surface prior to tearing. In particular, curling of the flap after application of the glue or paste thereto can be prevented.

The tab may be of any suitable shape although preferably it is oval or circular or of similar shape having a continuous wholly or largely convex periphery.

The break line may be of any suitable conformation but preferably is arcuate (or angled) so as to be upwardly concave (or open). Preferably also the break line terminates at each end at positions slighly spaced from the respective side edges of the central portion of the tab.

The said guide markings may comprise two opposed guide lines which run inwardly from the said side edges of the central portions. In the case where the said leading edge to be retained by the tab is folded to an angled shape (in accordance with conventional practice), the guide lines may be correspondingly angled particularly so as to intersect at a point on a longitudinal centre line of the tab above the said break line.

The adhesive applied to the rear of the tab may be a contact adhesive which is protected before use with a peel-off backing. The adhesive may extend over any area of the tab, as appropriate, within and, if desired, beyond the said top and bottom portions.

The invention will now be described further by way of example only and with reference to the accompanying drawings in which: Figure 1 is a plan view of one form of a tab according to the invention; Figure 2 shows the tab in a position of use on a roll of paper.

The tab shown in Fig. 1 comprises an oval piece of paper which has a front surface (as shown) provided with printed markings and information, and a rear surface which is coated with contact adhesive at top and bottom portions 1, 2 thereof.

These portions 1, 2 are distinguished on the front surface by transverse lines 3, 4 extending perpendicularly to the longitudinal centre line 5 of the tab, and are coated throughout their entire areas with the adhesive.

The central portion 6 defined between the two lines 3, 4 is printed with a symmetrically arranged arcuate line 7 which extends at each end up to positions 8, 9 at the opposite side edges 12 of the central portion 6 close to the top line 3. The arcuate line 7 is perforated and/or slit between positions 10, 11 equally spaced from but close to the side edges 12.

At each side within the central portion 6 there is a respective printed guide line 13, 14 extending at an angle downwardly from the positions 8,9. The two lines 13, 14 are so inclined as to intersect, if extended, on the centre line 5 of the tab above the arcuate line 7.

Multiple tabs of the kind so far described are provided on a peel-off backing strip.

In use, where a fresh roll of paper is to be spliced to a depleted roll, one such tab is used as follows.

The leading end 15 of the fresh roll is folded and torn to give a pointed structure. This end 15 is fixed in position by bonding the tab over the end 15 and the adjacent paper 16 on the body of the roll. The tab is arranged so that its centre line 5 extends circumferentially, the top portion 1 overlies and adheres to the leading end 15, the bottom portion 2 overlies and adheres to the adjacent paper surface 16, and the tip of the folded end 15 lies beneath the central portion 6 above the arcuate line 7. This arrangement of the tab is achieved by aligning the guide lines 13, 14 with the edges of the folded end 15.

The leading end 15 is now part-coated with glue or paste using a brush in conventional manner.

The glue or paste is also applied over the tab but only in the region of the top portion 1 and the central portion 6 above the arcuate line 7. The arcuate line 7 is clearly defined whereby it can be readily ensured that the glue or paste is not applied beyond this.

In the usual manner the roll is rotated and the trailing end 15 brought into contact with the expiring roll so that the latter end of this expiring roll adheres to the abovementioned coating of glue or paste. At this point, the tab tears to permit unwinding of the fresh roll. The tearing occurs by breaking of the perforations along the arcuate line 7 between the positions 10, 11 and by final rupture of the short linking sections of the central portion 6 between the positions 10, 11 and the side edges 12 of the central portion 6.

The tab described above is particularly convenient to manufacture and handle having regard to its simple oval shape and simple prominent adhesive areas. Positioning of the tab and subsequent glueing or pasting can be readily effected in an accurate manner and the tab holds the leading end 15 firmly and smoothly in position until ready for unwinding.

Lines shown on the tab in the drawings additional to those specifically described are provided for decorative purposes.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only.

Claims (10)

1. A tearable adhesive tab for securing the leading end of a roll of sheet material to adjacent such material on the body of the roll, said tab having a central portion with a transverse break line (as hereinbefore defined) terminating at or adjacent to side edges of said central portion, and top and bottom portions respectively above and below said central portion and having adhesive on rear faces thereof for attachment respectively to said leading end and said adjacent material, guide markings for said leading end being provided above said break line.

2. A tab according to claim 1, wherein the break line constitutes perforations.

3. A tab according to claim 1 or 2, which has a continuous wholly or largely convex periphery.

4. A tab according to claim 3, wherein said periphery is oval.

5. A tab according to any one of claims 1 to 4, wherein the break line is arcuate so as to be upwardly concave.

6. A tab according to any one of claims 1 to 5, wherein the break line terminates at each end at positions slightly spaced from the respective side edges of the central portion of the tab.

7. A tab according to any one of claims 1 to 6, wherein the guide markings comprise two opposed guide lines which run inwardly from the said side edges of the central portion.

8. A tab according to claim 7, wherein the guide lines are angled so as to intersect, if extended, at a point on a longitudinal centre line of the tab above the said break line.

9. A tab according to any one of claims 1 to 8, wherein the adhesive is applied only to the top and bottom portions and not to the central portion.

10. A tab substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.