OVERHEAD POCKET, AND METHOD FOR THE PRODUCTION THEREOF

Abstract: The invention relates to an overhead pocket for storing and showing overhead pictures or images, said pocket (1) being rectangular in shape and comprised of transparent plastic film. An outwardly foldable flap (2) is disposed along at least one of the longitudinal edges of the pocket and fastened to said pocket with the aid of adhesive tape (3). The adhesive tape (2) includes along the edge of the flap (2) a groove (5) which forms a fold weakening. The invention also relates to a method and to an arrangement for producing such an overhead pocket.

Description: OVERHEAD POCKET, AND METHOD FOR THE PRODUCTION THEREOF The present invention relates to an overhead pocket. The invention also relates to a method and to an arrangement for manufacturing an overhead pocket in accordance with the invention. Overhead pockets in which overhead pictures or images can be kept and displayed without needing to take them out of the pocket are known to the art, for instance from U.S. Patent Specifications 4,402,585 and 5,622,420. These overhead pockets have fastened to their longitudinal edges flaps that can be folded out to cover the light gap that forms outwardly of the side edges when using overhead transparencies of A4-size on a generally square projection surface. The outwardly fold- able flaps are normally fastened with the aid of adhesive tape. When folding these flaps outwards with the flaps on the upper side of the pocket, there is a risk that the flaps will bend back as a result of tension forces in the tape that strive to return the tape and therewith the flaps to its/their original state. If, on the other hand, the overhead pocket is positioned with the flaps facing downwards towards the projecting surface, there is a danger that adhesive on tape that is situated precisely in the folded part will ad- here to the glass plate, the projecting surface, of the overhead projector. This danger becomes greater when the overhead apparatus is used for a comparatively long time and the temperature of the glass plate increases accordingly. It is therefore an object of the present invention to provide an overhead pocket with which the aforesaid problems associated with known overhead pockets are avoided. This object of the invention is fulfilled with an overhead pocket that includes outwardly foldable flaps which are fastened with the aid of adhesive tape that is provided with a groove that extends along the edge of the flap. Another object of the invention is to provide a method for the manufacture of such an overhead pocket in which the aforesaid problems associated with known overhead pockets are avoided. This object of the invention is achieved with a method of manufacturing such an overhead pocket in which a flap and adhesive tape are mounted on the overhead pocket and a groove is formed in the adhesive tape along the edge of the flap with the aid of a grooving roller. Still another object of the invention is to provide an arrangement for use in the manufacture of such an overhead pocket so that the aforesaid problems associated with known overhead pockets will be avoided. This object of the invention is achieved with an arrangement that includes a grooving roller for creating a groove along the edge of the pocket, in the manufacture of such an over- head pocket. According to a further development of the inventive concept, at least part of the groove may be perforated. According to a further development of the inventive concept, the groove is imperforate in regions closest to the short ends of the overhead pocket. The invention will now be described in more detail with reference to non-limiting embodiments of the invention, illustrated in the accompanying drawings in which Fig. 1 illustrates an inventive overhead pocket schematically and from above; Fig. 2 is a schematic illustration of an arrangement for manufacturing overhead pockets in accordance with the invention; and Fig. 3 is a schematic side view of an arrangement constructed in accordance with the invention. An inventive overhead pocket is shown in Fig. 1. The overhead pocket 1 typically includes a double-folded plastic foil that forms the actual pocket. The overhead pocket is suitably of standard size, e.g. of A4-size, although it may, of course, have other sizes. Two outwardly foldable flaps 2 are attached to the long sides of the pocket. These flaps may either consist of light-impermeable material or of material that is fully or partially light permeable. The flaps 2 are fastened to the pocket 1 with the aid of elongate adhesive tapes 3. These tapes will conveniently extend in one piece along the full length of the pocket 1 and are fastened with approximately half their width to the pocket 1 and half their width to the flap 2. The flap 2 and the tape 3 may have punched in one long side of the pocket holes 4 that enable the overhead pocket to be placed in a folder, in a known manner. To enable the flaps 2 to be folded out more easily and to ensure that they will remain in their outwardly folded positions, the adhesive tape 3 is provided with a groove 5 along the edge of its respective flap 2. The groove will preferably extend at least along a major part of the length of the tape, optionally along its full length. The groove 5 may also be perforated with holes that fully penetrate the tape 3 along parts of its length, in accordance with the invention. According to one particularly advantageous embodiment of an inventive overhead pocket that includes a perforated adhesive tape, the perforations terminate short of the ends of the overhead pocket 1, as shown at 6, so that the tape 3 will obtain positive attachment to the material in the overhead pocket on the short sides of said pocket. In the manufacture of an overhead pocket of the kind to which the invention relates, two strips of material that form outwardly foldable flaps are attached to one side of the folded plastic foil forming the overhead pocket with the aid of longitudinally extending adhesive tapes, in a known manner. Fig. 2 illustrates schematically an arrangement for manufac- turing an inventive overhead pocket. Only that part of the manufacturing process that relates to the invention is shown in the Figure. In the stage of manufacture shown in Fig. 2, the web of mate- rial forming the body of the overhead pockets has already been folded and provided with flaps 2 on both of its longitudinal edges, said flaps 2 being fastened with the aid of adhesive tapes 3. The web is guided accurately in its cross- direction in a manner not shown and passes beneath two roll- ers 7 which are adapted for rolling abutment with the tape 3 precisely at the edge of the flap 2 on respective sides of the overhead pocket. This rolling abutment of the roller 7 with the tape 3 produces a groove 5 that extends along the adhesive tape adjacent the edge of the flap 2. Perforations can be made along the edge of the flap, by providing the roller 7 with cutting edges that will cut through the tape along parts of its length, so as to further facili- tate folding of the flap and ensuring that the flap will remain in its outwardly folded position. Fig. 3 is a side view of a roller 7 for use in producing a groove 5 that includes perforations along the transition of the adhesive tape 3 to the flap 2. Extending around parts of the circumference of the roller 7 are cutting edges 8 that cut through the adhesive tape 3. The cutting depth of the cutting edges is suitably chosen so that only the adhesive tape will be penetrated and so that the strip of material forming the overhead pocket will be left essentially untouched by the cutting teeth. According to one preferred embodiment of the invention, the circumference of the roller 7 corresponds exactly to the length of the overhead pocket and also includes a gap or interruption 9 in the array of cutting teeth 8, so as to avoid perforation, penetration, of the adhesive tape 3 at the ends of the overhead pocket. Alternatively, the roller cir- cumference may correspond precisely to a multiple of the length of the overhead pocket, wherewith said circumference will then include a corresponding number of gaps or interruptions in the cutting teeth arrangement. An adhesive tape comprised of polypropylene film is consid ¬ ered best suited for use in the invention, and will conveniently be transparent. Naturally, it is possible within the scope of the invention to use adhesive tapes that are comprised of other materials, provided that said materials have the properties desired in accordance with the invention, i.e. effective adhesion, small stretch, flexibility and non- smearing, not even when heated.

Claims: CLAIMS 1. An overhead pocket for storing and showing overhead pictures or images, wherein the pocket (1) is rectangular in shape and formed from transparent plastic film, and wherein there is provided along at least one of the longitudinal edges of the pocket an outwardly foldable flap (2) which is attached to said pocket by means of adhesive tape (3) , characterised in that the adhesive tape (3) includes along the edge of the flap (2) a groove (5) which functions to form a fold weakening. 2. An overhead pocket according to Claim 1, characterised in that the groove (5) is perforated at least partially. 3. An overhead pocket according to Claim 2, characterised in that the groove (5) is imperforated in a region (6) nearest the short sides of the pocket (1) . 4. A method of producing an overhead pocket where at least one flap (2) is attached along a longitudinally extending edge of the pocket (1) by means of adhesive tape (3), characterised by pressing a longitudinally extending groove (5) in the adhesive tape (3) along the edge of the flap (2) . 5. A method according to Claim 4, characterised by perforating the groove (5) at least partially along its length. 6. A method according to Claim 5, characterised by interrupting perforation of the groove at the short ends of the pocket. 7. A method according to any one of Claims 4-6, characterised in that the groove/the perforations is/are produced by means of a roller (7) which is pressed against the adhesive tape (3) adjacent the edge of the flap (2) . 5 8. An arrangement relating to the manufacture of an overhead pocket where at least one flap (2) is fastened along one longitudinal edge of the overhead pocket (1) with the aid of adhesive tape (3), characterised in that the arrangement w includes a roller (7) which is adapted to run along the adhesive tape (3) adjacent one longitudinally extending edge of the flap (2) and which functions to press against the adhesive tape such as to form a longitudinally extending groove. 15 9. An arrangement according to Claim 8, characterised in that the roller (7) includes cutting teeth (8) around parts of its circumference for forming a line of perforations . 0 10. An arrangement according to Claim 9, characterised in that the circumference of the roller corresponds exactly to the length of the pockets produced, or to a multiple of said lengths, and includes an interruption (9) in the array of cutting teeth (8) so as to provide for the adhesive tape 5 (3) on the pocket an abutment surface that is void of perforations (6) adjacent the short ends of the overhead pocket (1) .

Inventors: BENGTSSON RAYMOND, REINIKAINEN HARRI, TOLVERS TOMMY, BENGTSSON, RAYMOND, REINIKAINEN, HARRI, TOLVERS, TOMMY
Applicants: BENGTSSON RAYMOND, PLASTUS KREATIV AB, REINIKAINEN HARRI, TOLVERS TOMMY, BENGTSSON, RAYMOND, REINIKAINEN, HARRI, TOLVERS, TOMMY
Application year: 2000
Main classification: G03B21
IPC codes: G03B21