A method for packaging a casing

Abstract: A method of packaging a casing (100) for a disc comprises covering an opening and cut outs (5,6) with a sheet shaped member (204) and applying a film in a tubular form so that superposed portions are formed on lateral sides of the casing and heating the superposed portions to fuse the ends of the film.

Description: The invention relates to a packaging method to package a casing such as a disc cartridge comprising a recording disc, such as an optical disc or a magneto-optical disc, contained in a main cartridge body. A so-called sleeve casing has been proposed as a casing for packaging a disc cartridge comprising a recording disc and a cartridge main body housing the disc or a tape cassette comprising a tape reel holding a recording tape and a cassette housing the tape reel therein. Such a sleeve casing 401 is shown in Figures 1 to 3 of the accompanying drawings and is formed by a sheet-shaped member of a synthetic material, such as polypropylene (PP) or polyethylene terephthalate (PET), bent into a box one side of which is open at 404 to provide a pouch-shaped structure, as shown in Fig.1. A cassette 405 as above-mentioned, having a recording medium housed therein, can be introduced via the opening 404 and held within the sleeve casing 401. In general, the sleeve casing 401 is of a size just large enough to accommodate the cassette 405 having the recording medium therein to hold the cassette by the force of friction between the outer surface of the cassette and the inner surface of the sleeve casing. The sleeve casing 401 has cut-outs 402, 403 at forward ends of the major surfaces of the casing in continuation to the opening 404 to assist taking out of the cassette from the sleeve casing 401. Since the sleeve casing is formed by bending a sheet-shaped member formed of paper or synthetic resin, it cannot be increased in thickness beyond a certain limit in order to retain its foldability, thus rendering it difficult to develop a sufficient toughness. There may be occasions wherein the sleeve casing 401, shown in Figs.1 to 3, ready to be sold with a disc cartridge contained therein, is to be packaged with a film member of synthetic resin, such as an overlap film. This packaging is performed by so-called caramel wrapping in which the sleeve casing 401 is introduced into the inside of an overlap film which is connected at opposite sides, and both end faces of the overlap film are folded inwards to form superposed portions which are heat-welded together to complete the wrapping. The heat welding is carried out by applying a heated ironing member, such as a heated metal plate, on the superposed portions of the overlap film. The overlap film is subsequently heat shrunk so as to be tightly affixed to the outer surface of the sleeve casing 401. Since the overlap film is ultimately heat shrunk into tight contact with the outer surface of the sleeve casing 401, if any irregularities are present on the surface of the overlap film, the overlap film tends to be creased around these irregularities. These creases not only detract from the appearance of the casing but also tend to be caught by the fingers of a person handling the casing to produce rupture or severance of the heat-welded portions. Since the above-mentioned cut-outs 402, 403 are formed in the sleeve casing 401, the outer lateral surface of the casing presents a step when the cassette such as a disc cartridge is accommodated in the casing, as shown in Figs.2 and 3. That is, the major surfaces of the sleeve casing 401 present steps corresponding to the thickness of the casing as indicated by arrow d in Fig.2. Also, on the front side of the casing, there are formed ribs on both lateral sides of the cut-outs 402, 403 corresponding to the amount of projection beyond the major surfaces of the sleeve as indicated by arrow S in Fig. 3. According to the invention there is provided a packaging method for a casing, having an opening, a cut-out extending from the opening into the casing and a pair of grooves formed in each of the opposite lateral sides of the casing. comprising the steps of applying a bent into a U-shape sheet member so as to cover at least the opening and the cut-out, applying heat-shrinkable film so that ends thereof are at superposed positions offset from the grooves in the lateral sides of the casing, heating the superposed ends to fuse together the superposed ends of the film; and heating the film to shrink the film onto the casing at least partially covered by the bent into a U-shape sheet member. By applying a bent into a U-shape sheet material to cover up the open side and the cut-outs of the casing before covering the casing with an overlap film, the casing to be packaged can present a planar outer surface in its entirety, so that creases may be prevented from being produced in the film after completion of packaging. The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which: Fig.1 is a perspective view showing the shape of a conventional sleeve casing; Fig.2. is an enlarged partial perspective view showing irregularities on the outer lateral surface of a conventional sleeve as casing shown in Fig.1; Fig.3 is an enlarged partial plan view showing irregularities on the outer lateral surface of a conventional sleeve casing as shown in Fig.1; Fig.4 is a sectional view showing a casing for a disc cartridge packaged with an overlap film by a method according to the invention; Fig.5 is a sectional view showing a state in which the overlap film is shifted to one side from the state of Fig.4 when the casing for the disc cartridge is wrapped with the overlap film; Fig.6 is a sectional view showing a state in which the overlap film is shifted to the opposite side from the state of Fig.4 when the casing for the disc cartridge is wrapped with the overlap film; Fig. 7 is a sectional view showing heating irons packaging the casing with an overlap film; Fig 8. Is a view similar to Figure 7 but showing a state in which the overlap film is shifted to one side from the state of Fig. 7 when the casing for the disc cartridge is wrapped with the overlap film; Fig. 9 is a view similar to Figure 7 but showing state in which the overlap film is shifted to the opposite side from the state of Fig. 7 when the casing for the disc cartridge is wrapped with the overlap film; Fig. 10 is a perspective view showing a label member about to be applied to the casing in packaging a casing with an overlap film according to the invention; Fig. 11 is a perspective view showing the state in which a casing for a disc cartridge is packaged with an overlap film; and Fig.12 is a perspective view showing a modified shape of the label member. A casing 100 accommodating a disc cartridge can be packaged with an overlap film 201 by a packaging method as shown in Figs.4 to 11. The overlap film 201 is a thermally contractible film which is contracted on being heated and which is melted on being heated further. Referring to Figs 10 to 12, for packaging, a label member of paper 204 which is to be a sheet-shaped member, is applied over the front end of the casing 100 so as to cover up cut-outs 5 and 6. The label member 204 is bent at its mid part into U-shape and applied to the casing 100 to cover up a top plate section and a bottom plate section of the casing 100. The two parallel bent portions of the label member 204 are located at substantially the mid positions of the label member 204 and are spaced apart from each other by a distance corresponding to the thickness of the casing 100. With the label member 204 applied over the casing 100, the latter presents a planar outer lateral surface. Meanwhile, the label member 204 is used as a so-called index label. The label member 204, used as index label, is made up of a label coated with an adhesive and a release paper to which the label is bonded. The wrapping is what is termed a caramel wrapping. First, the casing 100 is introduced into the inside of an overlap film 201 obtained by interconnecting two opposing edges of two film halves. Both end parts of the overlap film 201 in the tubular form are bent inwards to form superposed sections 202, 203, as shown in Fig.4. These superposed sections 202, 203 are heated and fused together by heat welding by a pair of heating ironing members 301, 302 making up a wrapping unit. These superposed sections 202, 203 are formed on the outer lateral surfaces of the lateral sides of the casing 100. The heating ironing members 301, 302 are formed of metal and mounted in opposition to each other. These ironing members 301, 302 are heated to a predetermined temperature and moved relative to each other to change the distance therebetween. These ironing members 301, 302 are provided with recesses 303, 304 in the opposite lateral sides, respectively. These recesses 303, 304 are contoured to conform to the profile of the lateral surfaces of the casing 100 so that both lateral sides of the casing 100 may be introduced up to the bottom of the recesses. Since the ridges of the lateral surfaces of the casing 100 are rounded, both corners of the recesses 303, 304 are also rounded to present a cylindrical shape. The recesses 303, 304 are profiled to permit the ridges of the casing 100 to be inserted therein. The result is that, if the overlap film 201 is shifted in one or the other direction so that the overlap film 201 has its one end extending over the entire lateral surface of the casing 100 to reach the opposite side, that is the top plate section or the bottom plate section, the extended portion of the overlap film may still be heated by the ironing members 301, 302 so as to be heat welded, as shown in Figs.5 and 6. The overlap film 201 is heated and shrunk so as to be tightly applied to the outer surface of the casing 100 to complete the wrapping, as shown in Fig.11. Since the casing 100 presents a planar outer surface, the overlap film 201 may be tightly applied to the outer lateral surface of the casing 100 on which the label member 204 is applied previously. Meanwhile, the superposed portions 202, 203 of the overlap film 201 are applied to cover up lateral grooves 7, 8, as shown in Fig.4. The portions of the superposed parts 202, 203 lying over the lateral grooves 7, 8 are not thrust fully by the ironing members 301, 302 so that there is a risk that these portions will not be fused together. It may be a occurrence that the overlap film 201 is partially positioned towards one or the other sides of the casing 100, as shown in Figs.5 and 6. In these cases, one of the superposed parts 202, 203 becomes narrower in width than the lateral grooves 7, 8, as indicated by arrow R in Figs.5, 6. However, since the lateral grooves 7, 8 are offset more towards the top plate section than the mid position of the lateral member, the superposed portions 202, 203 are not positioned over the lateral grooves 7, 8, so that the superposed portions 202, 203 are fused together reliably. It is noted that the sheet-shaped member employed in the packaging method may also be a label member 205 which will cover only the front side of the casing 100, as shown in Fig.12, instead of covering both the top plate section and the bottom plate section, as described above. The label member 205 has two parallel folding lines and is bent into U-shape. The folded portion is offset towards one lateral side from the centre of the label member 205 and the flaps are spaced part from each other by a distance corresponding to the thickness of the casing 100. The casing 100 presents a planar outer surface when it is sheathed by the label member 205.

Claims: A packaging method for a casing (100), having an opening, a cut-out (5, 6) extending from the opening into the casing (100) and a pair of grooves (7, 8) formed in each of the opposite lateral sides of the casing (100), comprising the steps of applying a bent into a U-shape sheet member (204, 205) so as to cover at least the opening and the cut-out (5,6), applying heat-shrinkable film (201) so that ends (202, 203) thereof are at superposed positions offset from the grooves (7, 8) in the lateral sides of the casing (100), heating the superposed ends (202, 203) to fuse together the superposed ends (202, 203) of the film (201); and heating the film (201) to shrink the film (201) onto the casing (100) at least partially covered by the bent into a U-shape sheet member (204, 205).

Inventors: FUKAYA MASAEI, FUNAWATARI TAKATSUGU, HONMA HIROYUKI, TAKAHASHI KENJI, FUKAYA, MASAEI, FUNAWATARI, TAKATSUGU, HONMA, HIROYUKI, TAKAHASHI, KENJI, Fukaya, Masaei, Patents Division, Funawatari, Takatsugu, Patents Division, Honma, Hiroyuki, Patents Division, Takahashi, Kenji, Patents Division
Applicants: SONY CORP, SONY CORPORATION
Application year: 1993
Main classification: G11B33
IPC codes: B29C63, B29C53, G11B33