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Patent Searching and Data


Title:
A COVER FOR A DOCUMENT-SAFE SECURING OF A PLURALITY OF LOOSE LEAVES, A METHOD FOR PRODUCING THE COVER, AND THE USE OF THE COVER
Document Type and Number:
WIPO Patent Application WO/1985/002147
Kind Code:
A1
Abstract:
The cover (1) for a document-safe securing of a plurality of loose leaves comprises a cover sheet (11). This cover sheet comprises a plurality of bending lines (2) extending parallel to the back (3) and dividing the cover sheet (1) into a front (5) a back (7) cover member as well as into equally great coherent folding portion (4, 41, 6, 61) situated between said front and back cover members and finally into a back (3). The back comprises a bending line (2) or a portion (3) between two bending lines (2) outside the folding portions. The folding portions (4, 41, 6, 61) comprise on the back a self-sealing material only binding correspondingly provided surfaces. By the use of the cover (1) said cover is folded along the back (3) with the self-sealing material facing outwards. Then the loose leaves are inserted and knocked up agaist the back (3) whereafter they are secured to the cover (1) in the folding portions (4, 6) adjacent the back (3). The cover (1) is folded so as to make the folding portions (4, 41, 6, 61) contacting each other in pairs, and subsequently said portions are pressed together whereby the front (5) and the back (7) cover member, extends forward from the back (3) outside the folding portions (4, 41, 6, 61) and the loose leaves.

Inventors:
KLOEFT HENRIK (DK)
Application Number:
PCT/DK1984/000103
Publication Date:
May 23, 1985
Filing Date:
November 09, 1984
Export Citation:
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Assignee:
KLOEFT HENRIK
International Classes:
B42D3/00; (IPC1-7): B42D3/00; B42F13/00
Foreign References:
DE1179182B1964-10-08
DE2332464A11974-01-10
US4351546A1982-09-28
Download PDF:
Claims:
Claims :
1. A cover (1) for a documentsafe securing of a plurality of loose leaves (16), c h a r a c t e r ¬ i s e d in that it comprises an integrally formed cover sheet (11) which is provided with a plurality of bending lines (2) extending parallel to the back (3) of the cover and positioned on the location where it is desired to fold the cover sheet into a cover (1) , said bending lines dividing the cover sheet (11) into a front (5) and a back (7) cover member completely or partially covering the loose leaves (16) , as well as into equally great coherent folding portions (4, 4' 6, 6') situated in pairs between said front.and back of the cover, whereby the folding portions two and two can be made forming at least one inward fold (9) at the folding of the cover (1) , said inward fold being of a substantially Vshaped cross section, as well as a back (3) formed by a single bend ' ing line (2) or of a portion (3) between two bending lines outside the folding portions, and whereby a layer of selfsealing material has been applied onto the outer side of the folding portions, said material being of the type only binding correspondingly treated surfaces and not other materials after the application.
2. A cover as claimed in claim 1, c h a r a c t e r i s e d in that it comprises only one pair of co¬ herent folding portions (4, 4') preferably positioned between the back (3) of the cover and the front cover member (5) thereof.
3. A cover as claimed in claim 1, c h a r a c t e r i s e d in that it comprises two pairs of coherent folding portions (4, 4' 6, 6') positioned on both sides of the back (3) of the cover.
4. A cover as claimed in claim 1, 2 or 3, c h a OMH _ r a c h t e r i s e d in that it comprises one or more, preferably two, strips (12, 14) of cover material orient¬ ed transversely to the back (3) of the cover (1) and partly separated from the remaining cover material by short intersections (8, 8', 10, 10*) thereof transverse¬ ly to two coherent folding portions (6, 6'_) , and which in the folding portions (6, 6') comprise at least two pairs of through holes (13, 13*, 15, 15') symmetrically provided in pairs about a bending line (2) separating the two coherent folding portions (6, 6'), said strip (12, 14) being of such an extension or said strips (12, 14) being of such an extension and mutually spaced in the longitudinal direction of the back (3) as well as said pairs of through holes (13, 13', 15, 15') being "mutually spaced in the longitudinal direction of the back (3) in such a manner that an insertion of the completely folded cover into a file is allowed.
5. A cover as claimed in claim 4, c h a r a c t ¬ r i s e d in that it comprises a selfsealing material on the inner side of the folding portions (6, 6!) in the separated strips (12, 14) and optionally on the entire inner side of the folding portions (41, 61) positioned farthest from the back (3) and on equally great abutting portions of the front (5) and back (7) cover members.
6. A method for producing a cover (1) for a document safe securing of loose leaves (16) as claimed in one or more of the preceding claims 13, c h a r a c t e r ¬ i s e d by forming in a length of material or in a sheet parallel bending lines (2) indicating the back (3) of the cover and defining two by two equally great coherent folding portions (4, 4*, 6, 6') between the back (3) and the front (5) and/or back (7) cover" member of the cover, and by cutting or punching out the individual cover sheets (11) as well as applying selfsealing material in the folding portions (4, 4', 6, 6') on the side oJ__the material forming the outer side of the cover.
7. A method as claimed in claim 6, c h a r a c t ¬ e r i s e d by forming short intersections (8, 8', 10, 10') in the cover, said intersections extending from the back (3) and crossing two coherent folding portions (6, 6'), which provides one or more, preferably two strips (12, 14) of the cover material coherent with the remain¬ ing cover but separated therefrom along the intersect¬ ions, and by forming in the part of the folding portions (6, 6') positioned in the separated strip(s) (12, 14) at least two pairs of through holes (13, 13' 15, 15') sym¬ metrically situated in pairs about the bending line (2) separating the coherent folding portions (6, 6*), said strip(s) (12, 14) being of such an extention and mutual ly spaced in the longitudinal direction of the back (3) as well as said pairs of through holes (13, 13', 15, 15') being mutually spaced in the longitudinal direction of the back (3) in such a manner' that an insertion of the completely folded cover into a file is. allowed, and whereby the selfsealing material is optionally applied in the separated strips (12, 14) onto the inner side of the cover material in the folding portions (6, 6') and furthermore optionally onto the entire inner side of the folding portions (4', 6') positioned farthest from the back (3) and onto an equally great adjacent portion of the neighbouring cover members (5, 7) .
8. The use of the cover as claimed in one or more of the preceding claims 13 for a documentsafe securing of a plurality of loose leaves, c h a r a c t e r i s e d by folding the cover sheet (11) along the bending line(s) (2) forming or defining the back (3) in such a manner that the selfsealing material faces outwards, and by • positioning the loose leaves (16) to be bound in the cover (1) and knocking said leaves up against the back (3) in which position the loose leaves are secured in any OMH manner known per se such as for instance by means of staples together with the portions (4, 6) of the cover (1) adjacent the back (3) , whereafter the cover is folded in such a manner that the outer sides of the folding portions (4, .4', 6, 61) are made contacting each other in pairs and pressed together so that the _selfsealing material binds them together while forming an inward fold (9) covering the securing and subsequently the front (5) and/or the back (7) cover member are folded forward again whereby the cover members extend about the folding portions and the loose leaves from the back and forward.
9. The use of covers as claimed in claim 8, and whereby the cover material comprises separated strips (12, 14) and selfsealing material as claimed in claim 4 or 5> c h a r a c t e r i s e d by loosening the strips (12, 14) folded inwards upon the folding of the cover (1) .and subsequently folding said strips outwards to form doublelayer flaps (18) projecting from the back (3) of the cover and comprising through holes (13, 13', 15, 15') .
10. The use of the cover as claimed in claim 8 or 9, c h a r a c t e r i s e d by transferring an imprint to one or both sides of the cover sheet after the applica¬ tion of the selfsealing material and prior to the fold ing of the cover (1) by means of a printing machine, an offset machine or a photoprinting machine.
11. The use of the cover as claimed in claim 8, 9 or 10 as a cover with replaceable loose leaves, c h ¬ r a c t e r i s e d by using as selfsealing material a material of the detachable reclosing type such as burrotape, and by performing a perforation of the cover with loose leaves on at least two locations and using a replaceable through split for the assembling instead of using staples (17) . O PI flNATlO ι&.
Description:
Title: A Cover for a Document-safe Securing of a Plural¬ ity of Loose Leaves, a Method for Producing the Cover, and the- Use of the Cover.

Technical Field

The invention relates to a cover for a document-safe se¬ curing of a plurality of loose leaves.

Background Art

US-PS No. 4,351,546 discloses a similar cover for secur¬ ing loose leaves. This cover comprises a clip binder with resilient sides for the securing of the leaves and a folded cover. The cover comprises a back of an inward¬ ly inverted V-shape or an M-shape, and in this back the clip binder is inserted from the outer side of the cover and into the open V and about the outward central fold of the M, respectively. In both cases the back of the clip binder faces outwards and the folding portions of the cover surrounding the sides of the clip binder are glued onto the clip binder. This cover is encumbered with the drawbacks that it depends on the use of the above clip binder which is relatively expensive and complicated to insert in the cover. Furthermore, the use of the em¬ bodiment of the cover where the clip binder is positioned in the folding portion of an inwardly inverted V-shape implies that initially a cutting must be performed of the cover along the point of the inward fold before the leaves can be inserted in the clip binder. The embodi¬ ment including the M-shaped fold implies that it is dif¬ ficult to position the loose leaves uniformly in the bottom of the clip binder unless the cover has been cut up along the outward central point in the bottom of the clip binder before said loose leaves are inserted in the clip binder. Furthermore, this cover is not document- safe as the individual loose leaves can be removed and

other leaves inserted unnoticably. The presence of the clip binder furthermore makes the cover unfit for insert¬ ion in a ring file.

DE-AS No. 1,179,182 discloses a portfolio for loose leaves provided with holes. This portfolio also com¬ prises a cover with a fold of an M-shape in principle in the back as well as a clip binder inserted from the back about the central fold into the M and comprising two transverse pins for the securing of the loose leaves in said holes. The folding portions along the outer side of the clip binder are secured to the clip binder through gluing or in another manner. Such a portfolio is only suitable for loose leaves provided with holes. It is not document-safe and the clip binder wit pins used is relatively expensive to manufacture. Furthermore it is not fit for insertion into a ring file. Both this port¬ folio and the above cover are encumbered with the draw¬ back that they are too complicated to assemble, which make them unfit in practice for being assembled by the user. Consequently, they must be delivered completely assembled with the imprint optionally desired on the cover. The latter reduces their field of application or means in many cases that the covers must be used without being provided with imprints in advance.

Furthermore a self-sealing cover is known which comprises a single folded piece of board or plastic material. This piece is provided with an inner adhesive border extending on both sides of the fold and covered by a strip of cover paper or cover sheet. At the binding, the loose leaves are secured together, the cover paper is removed from the adhesive border, and the leaves secured together are positioned parallel to the cover edges in such a manner that they touch almost half the adhesive border, where¬ after the cover is closed about the material and the adhesive border is pressed firmly against said material.

The drawbacks of this cover are that the system including an adhesive border and a protective strip is unsuitable to carry out both during the manufacture and in use. Furthermore, the bundle of paper is only secured to the cover by the adhesive. Upon application of the adhesive and the protective strip, the cover cannot pass an- off¬ set or photoprinting machine in a satisfactory manner so as to transfer imprints. In addition, the bundle of papers can only be inserted in a ring file provided the entire cover with paper bundle is perforated or provided particular securing means are mounted on the cover.

Disclosure of Invention

■ The object of the invention is to provide a cover of the type stated in the preamble of claim 1 as well as a method of the type stated in the preamble of claim 6, and furthermore a use of the type stated in- the preamble of claim 8, whereby a hidden securing of the loose leaves to the cover is used, and whereby the cover is inexpens¬ ive to manufacture and easily can be provided with in- dividual signs and imprints upon the application of the self-sealing material without the use of tools beyond generally available office equipment. The cover accord¬ ing to the invention is characterised in that it com¬ prises an integrally formed cover sheet which is pro- vided with a plurality of bending lines extending parallel to the back of the cover and positioned on the location where it is desired to fold the cover sheet into a cover, said bending lines dividing the cover sheet into a front and a back cover member completely or part- ially covering the loose leaves, as well as into equally great coherent folding portions situated in pairs between said front and back of the cover, whereby the folding portions two and two can be made forming at least one inward fold at the folding of the cover, said inward fold being of a substantially V-shaped cross section.

as well as a back formed by a single bending line or of a portion between two bending lines outside the folding portions, and whereby a layer of self-sealing material has been applied onto the outer side of the folding portions, said material being of the type only binding correspondingly treated surfaces and not other materials after the application. In this manner a cover is ob¬ tained which is inexpensive to manufacture and which is suited for a document-safe binding of loose leaves in- volving a completely or partially hidden securing of said leaves to the cover. Furthermore, the user can easily provide the cover with individual imprints and signs by way of usual office equipment such as offset machines or photoprinting machines, and in addition the user can easily assemble the- cover for instance by means of staples while using a usual office stapling machine.

When the cover according to the invention only comprises one pair of coherent folding portions preferably posi¬ tioned between the back of the. cover and the front cover member thereof, a particularly simple 'and material-saving embodiment is obtained. This embodiment hides the secur¬ ing from one side such as for instance from the front of the cover.

Usually it is, however, preferred that the cover acσord- ing to the invention comprises two pairs of coherent fold¬ ing portions positioned on both sides of the back of the cover, whereby the securing is completely hidden both from the front and from the back of the cover.

According to a particularly preferred embodiment of the cover according to the invention, the cover comprises one or more, preferably two, strips of cover material oriented transversely to the back of the cover and partly separated from the remaining cover material by short intersections thereof transversely to two coherent

folding portions, and which in the folding portions com¬ prise at least two pairs of through holes symmetrically provided in pairs about a bending line separating the two coherent folding portions, said strip being of such an extension or said strips being of such an extension and mutually spaced in the longitudinal direction of the back as well as said pairs of through holes being mutual¬ ly spaced in the longitudinal direction of the back in such a manner that an insertion of the completely folded cover into a file is allowed. As a result, the strip(s) can form one or. more perforated double flaps of the cover material, said flaps projecting from the back of the cover. These flaps can be used for the filing of the cover in a ring file, and in this connection it is an advantage when the cover according to the invention com¬ prises a self-sealing material on the inner side of the folding portions in the separated strips and optionally on the entire inner side of the folding portions posi¬ tioned farthest from the back and on equally great abut- ting portions of the front and back cover members. In this manner the two layers of cover material in the flap can be adhered to one another which increases the stabil¬ ity of the flaps, and furthermore the front and/or back cover member can optionally be adhered to the folding portions so as thereby nevertheless to allow a securing of the flaps although the remaining portion of the front and/or back cover member is omitted. The omission of both non-adhered portions of the cover members results in a document-safe, relatively rigid back cover with perforated flaps allowing an insertion of the cover in a ring file.

The invention furthermore relates to a method of produc¬ ing a cover for a document-safe securing of loose leaves. This method is characterised by forming in a length of material or in a sheet parallel bending lines indicating the back of the cover and defining two by two equally

great coherent folding portions between the back and the front and/or back cover member of the cover, and bu cut¬ ting or punching out the individual cover sheets as well as applying self-sealing material in the folding portions on the side of the material forming the outer side of the cover. In this manner the cover can be manufactured in a rational manner, for instance by forming the bending lines and punching out the individual covers by means of a punching machine in the same process and at a great rate of production. Subsequently, the self-sealing material is applied in a gluing machine or by involving a printing machine provided with a folder unit and coupled to a gluing machine in such a manner that the formation of bending lines, the punching out of the covers, and the application of the self-sealing material can be carried out in one process.- Furthermore it is an essential advantage by the manufacture and besides by the following handling of the dovers to use a self-seal- - ing material only adhering to correspondingly treated surfaces and not to other materials.- It is then unneces¬ sary to have a cover paper covering the self-sealing material to achieve that the individual cover sheets do not adhere to one another during the manufacture and the usual handling of said cover sheets.

According to a particularly preferred method according to the invention, short intersections are furthermore formed in the cover, said intersections extending from the back and crossing two coherent folding portions, which provides one or more, preferably two strips of the cover material coherent with the remaining cover but separated therefrom along the intersections, and at least two pairs of through holes are formed in the part of the folding portions positioned in the separated strip(s) , these holes being symmetrically situated in pairs about the bending line separating the coherent folding portions, said strips being of such an extension and mutually spaced in

the longitudinal direction of the back as well as said pairs of through holes being mutually spaced in the long¬ itudinal direction of the back in such a manner that an insertion of the completely folded cover into a file is allowed, and whereby the self-sealing material is option¬ ally applied in the separated strips onto the inner side of the cover material in -the folding portions and further¬ more optionally onto the entire inner side of the folding portions positioned farthest from the back and onto an equally great adjacent portion of the neighbouring cover members. In this manner it is possible in the same rational manner as above to produce a cover insertable in a ring file by means of perforated double-layer flaps of the cover material, said flaps projecting from the back of the cover. These two layers of the flaps can furthermore optionally be adhered to one another so as to obtain an improved rigidity and strength, and the covers may optionally be produced as narrow back covers with perforated flaps secured by portions of the abutting cover members adhered to the folding portions in such a manner that a document-safe back cover with perforated flaps is also obtained for insertion in a ring file.

When using the cover according to the invention the cover sheet is folded along the bending line(s) forming or de- fining the back in such a manner that the self-sealing material faces outwards, and the loose leaves are positioned to be bound in the cover and knocked up against the back, in which position the loose leaves are secured in any manner known per se such as for in- stance by means of staples together with the portions of the cover adjacent the back, whereafter the cover is folded in such a manner that the outer sides of the fold¬ ing portions are made contacting each other in pairs and pressed together so that the self-sealing material binds them together while forming an inward fold covering the securing, and subsequently the front and/or the back cover

member are folded forward again whereby the cover members extend about the folding portions and the loose leaves from the back and forward. As a result, the loose leaves can with great certainty, easily and correctly be positioned and secured in the cover, and not until after this procedure the securing is hidden through an ad¬ ditional folding and adhering. Thus it is also possible to alter the sequence or position of the leaves in the cover prior to the adhering without influencing the appearance of the cover. At the same time a great ri¬ gidity of the back is obtained, even when only a few loose leaves are inserted, on account of the extra num¬ ber of adhered layers of cover material in the folds. Furthermore, the folded portions of the cover form a straight edge, about which it is easy to fold the loose leaves when turning over said leaves. The securing of the loose leaves in this cover may furthermore be car¬ ried out substantially quicker than"by the previously known covers, partly because no cover strip to be re- moved is present, and partly because no time-consuming operation is involved in positioning the loose leaves correctly in the cover, said leaves only needing to be knocked up against the back of the cover and subsequent¬ ly fixed relative to said cover at the securing to the cover, for instance by stapling.

According to the preferred use, where the cover material comprises separated, strips and optionally self-sealing material on the inner side of these folding portions and optionally on the entire inner side of the folding port- ions farthest from the back on equally great abutting portions of the front and back cover members,, the strips folded inwards are loosened upon the folding of the cover and subsequently said strips are folded outwards to form double-layer flaps projecting from the back of the cover and comprising through holes. As a result, the cover can be inserted in a ring file without necessitating a

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perforation of the cover with the material bound there¬ in. When no self-sealing material is present on the inner sides of the strips, the flaps can be folded out¬ wards or inwards according to desire.

The use of the cover according to the invention is very flexible as an imprint can be transferred to one or both sides of the cover sheet after the application of the self-sealing material and prior to the folding of the cover by means of a printing machine, an offset machine or a photoprinting machine. This possibility has the interesting perspective that the cover sheets can be delivered completely punched out in planar shape and provided with the self-sealing material, whereafter the user on his own and very quickly can transfer the de- sired imprint in the necessary number printed and then subsequently on his own fold the covers as only very usual office equipment is necessary.

Should a desire exceptionally arise of replacing the loose leaves of the cover, such a procedure can be built in by according to the invention using as self-sealing material a material of the detachable re-closing type such as burrotape, and by performing a perforation of the cover with loose' leaves on at least two locations and using a replaceable through split for the assembling instead of using staples.

Brief Description of Drawings

The invention will be described below with reference to the accompanying drawing, in which

Fig. 1 is an outside view of a cover sheet,

Fig. 2 is a perspective sectional view of a corner of the cover upon the folding thereof about the loose leaves.

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Fig. 3 corresponds to Fig. 2 with V-shaped folds.

Fig. 4 corresponds to Figs. 2 and 3 in the completely folded shape of the cover with a hidden securing from both sides,

Fig. 5 corresponds to Fig.- 4, but only with a hidden se¬ curing from the front,

Fig. 6 is a rear view of a completely folded cover with¬ out loose leaves and with flaps folded inwards, and

Fig. 7 corresponds to Fig. 6, but with flaps folded out- wards.

Best Mode for Carrying Out the Invention

Fig " . 1 illustrates a cover sheet 11 from the outer .side and prepared for folding. A row of parallel bending lines 2 appear, of which the two central bending lines define a back 3, the two outermost lines define a front

5 and a back 7 cover member, respectively, and the inter¬ mediary bending lines divide the portions of every second pair of equally great folding portions 4, 4 1 and 6, β 1 , respectively, said folding portions being positioned between the innermost and the outermost bending lines 2. Transversely to one pair of folding portions 6, 6', two pairs of intersections 8, 8' and 10, 10' are shaped which extend from the back line or the back 3 and a short distance inwards into the back cover member 7. As a result, two strips 12, 14 of the cover material 11 ap¬ pear, which have been freshly cut from said cover mate¬ rial along the intersections 8, 8* and 10, 10' , respect¬ ively. Furthermore, two pairs of holes 13, 13 » and 15, 15', respectively, are shaped in the folding portions 6, β1 of the strips. These holes are symmetrically posi¬ tioned in pairs about the bending line 2 between the fold-

ing portions β, 6' . The distance between the pairs of holes 13, 13' and 15, 15' in the longitudinal direction of the back is adapted to the hoop distance of a standard ring fil . In the areas indicated by dots, the folding portions are coated with a self-sealing material on the outer side of the cover. Fig. 2, 3, and 4 illustrate various steps during the folding of the cover 1 of Fig. 1 about a set of loose leaves 16. The cover of Fig. 2 is folded about the loose leaves 16 with a front cover member 5 facing upwards and with the self-sealing layers facing outwards, and the loose leaves 16 are knocked up against the back 3. Furthermore the reference numeral 17 repre¬ sents a staple clipping the loose leaves 16 together with the cover 1 through the folding portions 4 and 6.

Fig. 3 illustrates how the cover members 5 and 7 are initially folded backwards and subsequently forwards • along the-bending lines defining the- folding portions 4' and 6* . As a result the folding portions are made contacting each other two by two along the outer sides provided .with self-sealing material and while forming inward folds 9 of a V-shaped cross section. Having been pressed together, the folds are secured to one another by the self-sealing material and hide the securing from both sides of the cover, whereby the preferred embodiment of Fig. 4 of the completely folded cover appears.

Fig. 5 illustrates a second embodiment of the cover ac¬ cording to the invention, whereby only the front cover member 5 is folded so as to hide the securing when seen from the front, whereas the back cover member is not folded whereby the securing is visible from . the back.

Fig. 6 illustrates a completely folded cover 1 without loose leaves, whereby both the front cover member 5 and the back cover member 7 are folded inwards at the back side 3 where the intersections 8, 8 1 and 10, 10' appear.

These intersections define the strips 12, 14 used for forming the flaps of the cover. This cover is shown with flaps folded inwards.

Fig. 7 also shows a completely folded cover, seen from the back. This cover comprises flaps 18 folded outwards and provided with through holes 13' and 15*, respectively, interspaced in the longitudinal direction of the back 3 in such a manner that they fit over the hoops of a stan¬ dard ring file.

While manufacturing the cover sheets 11, bending lines 2 are formed in a length of material or a sheet about the back 3 of the cover. Furthermore, intersections and holes for the flaps are punched or cut out and the cover sheets 11 are punched or cut out of the length of mate- rial or the sheet.

When using the cover, the cover sheet 11 is initially bent along the bending lines 2 defining the back 3 in such a manner that the self-sealing material applied onto the outer side of the cover sheet faces outwards. Subsequently, the loose leaves 16 are inserted in the cover and knocked up against the back 3 of said cover. Then the loose leaves are secured to the cover by means of staples 17 inserted through the cover and the loose leaves in the folding portions 4, 6 adjacent the back 3. Now the cover members 5, 7 are initially folded back¬ wards and then forwards along the bending lines 2 defin¬ ing the folding portions 4* , 6' to form the inward V- shaped folds 9, σf. Fig. 3. These folds are then pressed together into the shape illustrated in Fig. 4. If it is desired to use the flaps 18 of the cover for inserting the cover into a ring file, the part of the strips 12, 14 appearing from Fig. 6 is carefully loosened whereafter the portions of the strips 12, 14 folded inwards are folded outwards to form the flaps 18. The strips 12, 14

can be coated with the self-sealing material onto the inner side in the folding portions in such a manner that the two layers of the flaps folded outwards can be made adhering to one another at the pressing together pro- σedure.

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