PACK FOR FILMS FOR DOMESTIC USE, IN POLYETHYLENE, ALUMINIUM, OVENPROOF PAPER AND THE LIKE, WOUND ON A ROLL

Abstract: A pack for films (2), in particular for domestic use, in polyethylene, aluminium, ovenproof paper and the like, wound on a roll (3), which provides exceptional ease of manupulation when replacing the exhausted roll with a new roll, and comprises a box (4) that has a tubular cover (5) that is closed at the ends by opposite end-pieces (6, 7) equipped with conical bosses (26, 27) for supporting the roll (3).

Description: PACK FOR FILMS FOR DOMESTIC USE, IN POLYETHYLENE, ALUMINIUM, OVENPROOF PAPER AND THE LIKE, WOUND ON A ROLL. DESCRIPTION The present invention relates to a pack for films, in particular for domestic use, in polyethylene, polypropylene, aluminium, ovenproof paper and the like, wound on a roll, of the type, comprising a box, having a tubular cover of predefined length, closed at the end by opposite end-pieces. In particular the end-pieces are equipped with bosses for supporting the roll. An example of such a pack is described in the Italian application for registration of a utility model MI92U000515 of the same Applicant. Though advantageous in various respects and widely used, the known packs of this type leave some¬ thing to be desired from the standpoint of their ease of manipulation when replacing an exhausted roll with a new roll. Thus, the rolls, generally in the form of a cardboard tube, have widely varying dimensions, so that it can happen that the box has to hold them with excessive or insufficient clearances. In both cases, use of the pack becomes uneven, because the roll is not properly supported inside the cover or it is held with excessive friction. The problem on which the present invention is based is to devise a pack of the type, specified, which overcomes the aforementioned shortcomings. This problem is solved by a pack of the type specified, in accordance with Claim 1. Further characteristics and the advantages of the pack according to the present invention will become clear from the following description of a preferred application, which is given for guidance and is non- limitative, and refers to the appended drawings, in which: - Fig. 1 shows a perspective view, with parts detached and in partial section, of a pack according to the invention, - Fig. 2 shows a sectional view of the pack in Fig. 1, along line II-II and - Fig. 3 shows a sectional view of the pack in Fig. 1, along line III-III. - Fig. 4 shows a perspective view of a pack according to the invention, in accordance with another example of application. Referring to the drawings, 1 denotes throughout a pack according to the invention, for a film 2, for domestic or semi-industrial use, for example for use in an association, in a restaurant and the like. Film 2 is wound on a roll 3, also called a tube or core, made of cardboard, having a predetermined diameter, for example 30 mm and having a predetermined length, for example 300 mm. The film 2 can be made of various materials, for example plastics, such as polyethylene, polypropylene and polyvinyl chloride, or other materials such as aluminium or ovenproof paper. The pack 1 comprises a box 4, substantially cylindrical, with axis x-x, having a tubular cover 5, closed at the ends by opposite end-pieces 6 and 7. The cover 5 is provided, on its entire length, with a longitudinal slit 8, which has longitudinal edges 9 and 10 and a size of angle A between 20 and 40° and preferably of 30°, so as to permit reliable gripping of the film by the new roll but without weakening the cover. A longitudinal lip 11 projects beyond the cover 7, from its generating line G-G, parallel to edge 9 of slit 8. The lip 11 has a free edge 12 which is sharpened and serrated. The free edge 11 is shaped according to a broken line. In particular, the lip 11 has a projection S from the cover 5 which varies continuously from a predetermined minimum value Smin, at mid-length of the cover, and a predetermined maximum value Smax, at the ends of the cover. The projection Smin is chosen between 1 and 7 mm and is preferably 4 mm. The maximum projection Smax is chosen between 6 and 12 mm and is preferably 9 mm. Relative to a radial plane passing through the generating line G-G, the lip 11 has an inclination B which varies continuously from a minimum value B in at mid-length and a maximum value Bmax at the ends of the cover. The value Bmin is preferably chosen to be equal to zero whereas the inclination Bmax is preferably 20° . The pack also comprises holding means 13 for holding the ends of the film. The holding means 13 comprise a shoulder 14 formed in the tubular cover 5 and which has a predetermined size of angle C, formed between the edge 9 of the slit and the generating line G-G from which lip 11 starts. The size C is chosen between 70 and 90° and is preferably 80°. The holding means 13 are completed by three teeth 15, 16 and 17 extending along the said shoulder parallel to the slit, over the entire length of the slit itself. The teeth 15, 16 and 17 have a stepped angular distribution within the range of the size of angle C of the shoulder. The teeth 15, 16 and 17 have a saw-tooth shape with a convex back 18 and a substantially radial front 19, respectively facing the slit and the lip. Preferably, a gripping zone 20 with a concave back 21 is formed at mid-length of the cover, in a way corresponding to the tooth 17 near the lip, and has a length between 20 and 40 mm and preferably of 30 mm. A corresponding projection 22 is formed in the cover, close to edge 10 of the slit, and its length is substantially equal to the length of the gripping zone 521. The end-pieces 6 and 7, which have respective peripheries 6a and 7a that are lobe-shaped, so that they can be manipulated ergonomically, are connected to the ends of the cover respectively by means of a threaded 10 connector 24 and a bayonet fastening 23. The bayonet fastening 23 has a projection 23a that engages in an L-shaped seat 23b formed in a way corresponding to one end of the cover. The threaded connector 24 has an external thread 1524a machined on the end and an internal thread 24b machined at the end of the cover. Between the end-piece 6 and the cover 5, means for stepped positioning 25 are provided, for angular positioning of the end-piece 6 in a desired angular 20 position. The means for stepped positioning 25 comprise a projection 25a jutting out from the periphery 6a of end-piece 6 and a multiplicity of recesses 25b uniformly distributed in steps along a circumference round the end of the cover. 25 The end-pieces 6 and 7 are equipped with bosses 26 and 27 respectively, which are of substantially conical shape. In particular, bosses 26 and 27 are shaped according to three cylindrical portions 26a, 26b, 26c, 3027a, 27b, 27c respectively, which have gradually decreasing diameter. For each boss there are means for unidirectional constraint 28 which comprise a multiplicity of tabs, all indicated with 29, which jut out elastically compliant 35 in the radial direction, projecting obliquely from each cylindrical portion. Advantageously, the cover is produced in one piece with the lip, with the teeth, with the gripping zone and with the projection, by injection moulding in a suitable plastic, for example talc-filled polypropylene. 5 Similarly, the end-pieces 6 and 7 are moulded in a single piece together with the respective bosses and the respective tabs in the same material. Referring to Fig. 4, 30 denotes another example of a pack according to the invention. The parts of pack 1030 that are structurally and functionally similar to those of pack 1 keep the same reference numbers and are not described in the following. In pack 30, the slit 8 has a V-shaped edge 31, so that the slit has a larger size at mid-length and a 15 smaller size at the ends. Correspondingly, the shoulder 14 has a larger size at the ends and a smaller size at mid-length. The holding means 13 comprise three teeth 32, 33 and 34, extending along the shoulder 14. A first tooth 2032 extends along the edge 31 and follows its V shape. A second tooth 33 and a third tooth 34 have stepped angu¬ lar distribution in the shoulder 14. It should be pointed out that the first tooth 32 has a projection that varies between a minimum 25 projection at mid-length and a maximum projection at the ends. It should also be pointed out that the second tooth 33 has a gripping zone 35 formed at mid-length, which projects from the tooth itself; preferably a 30 recess 36 is formed at an intermediate point of the gripping zone 35. As for the third tooth 34, this, like the first tooth 32, preferably has a projection that varies between a minimum projection at mid-length and a maximum 5 projection at the ends. Each end-piece. 6 and 7 of pack 30 comprises a - 6 - respective boss 37, which is preferably conical, and carries tabs, all indicated with 38, which jut out elastically compliant in the radial direction, and project obliquely from respective generating lines of the boss itself. In operation, the desired replacement of the roll is effected easily and quickly from the moment that the roll finds, as a function of its diameter, perfect accommodation on the cylindrical portion which fits better and is also held in the longitudinal direction by the end-piece with threaded connection to the cover, which will be tightened, leaving a desired axial clearance between the end-pieces and the roll itself. In use, the roll is held in the box with optimum radial and axial clearance, owing to the presence of the tabs on each cylindrical portion of the end-pieces, backward rotation of the roll is made impossible. Consequently, it is practically impossible for the free end of the film to be drawn back inside the slit. The film has its end edge laid gently along the shoulder between the slit and the lip, for the whole surface of the shoulder. This free end is prevented from slipping back inside the slit and moreover easy gripping is provided, when removing another portion of film. It should be noted that the projection is retained longitudinally by the thumb of the hand holding the cover, allowing it the possibility of being pushed as far as the slit, and of exerting a braking action on the roll, if desired. When cutting a portion of film that has a predetermined length, with one hand holding the box substantially at mid-length of the cover, and holding the end of the portion of film to be cut with the other hand, the desired cut is effected efficiently, in that with a relative movement of one hand away from the other, one or other of the lateral ends of the film first meets the serrated edge corresponding to one of its ends which projects more, and is raised precisely at the point where the cut is to start. Once started, cutting proceeds easily as the mid- width of the film is approached, and then proceeds towards the opposite lateral end of the film itself, where the serrated edge is still projecting and inclined, so that any backward rotation of the tubular cover is rendered substantially superfluous. The recess promotes gripping of the film, whereas the projection of the teeth, which varies from a minimum projection at mid-length and a maximum projection at the end, promotes on the one hand uniform unrolling of the film from the roll, without tearing, owing to concentration of the pulling force at the ends of the roll, and on the other hand promotes retention of the film on the shoulder, after cutting has occurred by action of the lip. The main advantage of the pack according to the present invention is the fact that it is suitable for receiving rolls of even widely varying dimensions. A further advantage is its reliability and the certainty with which the free end of the film is always made accessible relative to the slit. Yet another advantage of the pack according to the present invention is stable retention of the film outside the slit and the exceptional ease of manipulation when the user grips the free end of the film in order to remove a desired portion of it. Another advantage of the pack according to the present invention is the exceptional efficiency of the serrated edge during cutting of the desired portion of film, along the entire length of the cut itself, or along the entire width of the film. Finally, the pack according to the invention has the advantage that the film unrolls uniformly and without tearing from the roll. obviously, in order to meet contingencies and specific requirements, a person skilled in the art will be able to make numerous changes and variations to the pack described above, though all are within the scope of protection of the invention, as defined by the following claims.

Claims: CLAIMS 1. Pack for films, in particular for domestic use, in polyethylene, polypropylene, aluminium, ovenproof paper and the like, wound on a roll, of the 5 type comprising a box, having a tubular cover of prede¬ termined length closed at the. ends by opposite end- pieces equipped with bosses for supporting the roll, characterized in that the boss of each end-piece is of substantially conical shape. 102. Pack according to Claim 1, characterized in that at least one end-piece is in engagement with the cover by means of a threaded connector. 3. Pack according to Claim 2, characterized in that it comprises means of positioning between the end- 15 piece in engagement with the cover by a threaded connector and the cover for stepped angular positioning of the end-piece relative to the cover. 4. Pack according to Claim 3, characterized in that the means for positioning comprises a multiplicity 0 of recesses formed in the cover and a projection formed in the end-piece, capable of snap engagement in one of the said recesses. 5. Pack according to Claim 4, characterized in that it comprises means for bayonet fastening between an 5 end-piece and the cover. 6. Pack according to Claim 5, characterized in that the boss of each end-piece is shaped according to cylindrical portions with gradually decreasing diameter. 7. Pack according to Claim 6, characterized in 0 that it comprises means for unidirectional constraint associated with at least one boss . 8. Pack according to Claim 7, characterized in that the said means of unidirectional constraint comprise a multiplicity of equi-oriented tabs, 5 projecting from the boss. - 10 - 9. Pack according to Claim 8, characterized in that each end-piece has, externally, an ergonomically shaped periphery. 10. Pack according to Claim 9, characterized in 5 that the periphery is lobe-shaped externally. 11. Pack according to Claim 10, characterized in that each end-piece, the boss and the tabs are made as a single piece by injection moulding of a suitable plas¬ tic, preferably talc-filled polypropylene. 1012. Pack for films in particular for domestic use, in polyethylene, polypropylene, aluminium, ovenproof paper and the like, wound on a roll, of the type comprising a box which has a tubular cover of a predetermined length closed at the ends by opposite end- 15 pieces and equipped with a longitudinal slit and with a longitudinal lip projecting from the cover and parallel to the slit, the said lip having a sharpened and ser¬ rated free edge, characterized in that the tubular cover comprises a shoulder with predetermined size of angle 20 formed between the slit and the lip. 13. Pack according to Claim 12, characterized in that the said size of angle is chosen between 90 and 70° and is preferably 80°. 14. Pack according to Claim 13, characterized in 25 that it comprises means for holding the film arranged along the said shoulder. 15. Pack according to Claim 14, characterized in that the said means of holding the film comprises at least one tooth extending in the said shoulder parallel 30 to the slit, the said tooth having a saw-tooth section with a back and a front, turned towards the. slit and the lip respectively. 16. Pack according to Claim 15, characterized in that the back is convex. 3517. Pack according to Claim 16, characterized in that the teeth are three in number and have a stepped angular distribution in the said shoulder. 18. Pack according to Claim 17, characterized in that it comprises a gripping zone, formed at mid-length of the cover, in a way corresponding to the tooth near 5 the lip. 19. Pack according to Claim 18, characterized in that the said gripping zone has a saw-tooth profile with concave back, turned towards the slit. 20. Pack according to Claim 19, characterized in 10 that the said gripping zone has a limited length chosen between 20 and 40 mm. 21. Pack according to Claim 12, characterized in that the gripping zone has a recess formed at an intermediate point of it. 1522. Pack according to Claim 20, characterized in that it comprises a projection extending parallel to the slit from the opposite side of the shoulder, over a short length, to mid-length of the tubular cover. 23. Pack according to Claim 22, characterized in 20 that the lengtii of the projection is chosen between 20 and 40 mm. 24. Pack according to Claim 23, characterized in that the length of the projection is chosen equal to the length of the gripping zone. 2525. Pack according to Claim 12, characterized in that the slit has a size of angle chosen between 20° and 40° and is preferably 30°. 26. Pack according to Claim 12, characterized in that the slit has a larger size at mid-length and a 30 smaller size at the ends. 27. Pack according to Claim 14, characterized in that the said holding means comprise at least one tooth extending in the said shoulder parallel to the slit, the said tooth having a projection that varies between a 35 minimum projection at mid-length and a maximum projec¬ tion at the ends. 28. Pack according to Claim 22, characterized in that the cylindrical cover, the lip, the shoulder, the teeth, the gripping zone and the projection are made in a single piece by injection moulding in a suitable plastic, preferably talc-filled polypropylene. 29. Pack for films in particular for domestic use, in polyethylene, polypropylene, aluminium, ovenproof paper and the like, wound on a roll, of the type comprising a box, with a tubular cover of predetermined length closed at the ends by opposite end-pieces and provided with a longitudinal slit and with a longitudi¬ nal lip projecting from the cover and parallel to the slit, the said lip having a sharpened and serrated free edge, characterized in that the free edge of the lip is shaped according to a broken line. 30. Pack according to Claim 29, characterized in that the lip has a projection from the cover which varies continuously between a predetermined minimum value, at mid-length of the cover, and a predetermined maximum value, at the ends of the cover. 31. Pack according to Claim 30, characterized in that the said minimum value is from 1 to 7 mm and is preferably 4 mm. 32. Pack according to Claim 30, characterized in that the said maximum value is from 6 to 12 mm, and is preferably 9 mm. 33. Pack according to Claim 29, characterized in that the lip projects from a generating line cf the cover and has an inclination relative to the radial plane passing through the generating line, which is turned towards the slit and varies continuously between a minimum value at mid-length of the cover and a maximum value at the ends of the cover. 34. Pack according to Claim 33, characterized in that the minimum value of the inclination is around 20°. 35. Pack according to Claim 33, characterized in that the maximum value of the inclination is around 20°. 36. Pack according to Claim 35, characterized in that the cylindrical cover and the lip are made as a single piece by injection moulding of a plastic, preferably talc-filled polypropylene.

Inventors: GRAFFEI MAURIZIO, GRAFFEI, MAURIZIO
Applicants: GRAFFEI MAURIZIO, GRAFFEI, MAURIZIO
Application year: 1996
Main classification: B65D83
IPC codes: B65H35