FR2917718A1 - POSITIONER OF BANDS OF PROFILES. - Google Patents

Abstract

The present invention relates to a device (70) for positioning closure strip strips (10) with respect to the longitudinal edges of a tubular thermoplastic film (11), characterized in that it comprises at least one radial abutment (1). external.

Description

-1- POSITIONER OF BANDS OF PROFILES

  The invention relates to a device for positioning strips of closure profiles pre-fitted with sliders relative to the longitudinal edges of a thermoplastic film and intended in particular for closing a bag, in a forming machine, welding and optionally filling bags. in automatic. The relative positioning of the closure profile strips pre-fitted with sliders with respect to the edges of the film is a major difficulty posed by the production of bags on such automatic forming and welding machines, insofar as the strips of profiles and film slide on a forming neck. However, the welding step is fundamental if it is desired that a bag is provided with a closure that is able to enclose the contents hermetically. But if the strips are too close radially to the forming neck (that is, if they overlap the edges of the film too much), the jaws of the welding device may close on the sliders, or the film disrupts their displacement. And conversely, if the strips are too far radially from the forming neck, the welding device can weld the edges of the film together, and not on the strips of closure profiles. Finally, if they are not brought parallel to the direction of travel of the thermoplastic film, the longitudinal edges of the film are partially welded together. It is therefore necessary to find a means for satisfactorily balancing and positioning strips of closure profiles pre-fitted with sliders relative to the forming neck and the longitudinal edges of the thermoplastic film. Various solutions have already been proposed. One of them, described in the document WO 02/092434, implements complementary closure profiles, pre-fitted with sliders and comprising separate lateral support webs which extend beyond -2- closing profiles. A loop is made in a film intended to form the wall of the bag, and the assembly formed by the profiles and the webs is fixed in a concave part of the loop, on the surface of the film which corresponds to the outer surface of the bag.

  This method makes it possible to ensure a correct welding of the strips of closure profiles on the longitudinal edges of the film.

  An objective of the device of the invention is to provide another solution, less complex to implement, in order to properly position the closure strips and the sliders relative to the edges of the film.

  This object is achieved within the scope of the present invention by means of a device for positioning strips of closure profiles with respect to the longitudinal edges of a tubular thermoplastic film, characterized in that it comprises at least one outer radial abutment.

  Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings in which:

  • Figure 1 shows a schematic perspective view of a bag manufacturing machine capable of using the positioning device according to the present invention,. FIGS. 2 to 4 are a sectional representation of three variants of a first possible embodiment of a device according to the invention,

  . Figures 5 and 6 are a sectional representation of two variants of a second possible embodiment of a device according to the invention.

  Identical references in these figures designate identical elements.

  The invention applies to the manufacture of sachets 80 for example on an automatic machine for manufacturing, preferably filling and closure of sachets of the type illustrated schematically in FIG. 1. Such a machine comprises:

  Means for supplying a strip of closure profiles 21,

  Means 22 for supplying slider chains, a station 20 for sequentially operating the individual laying of each slider on said strip,

  A station 30 intended to ensure the closing of the bands, that is to say the engagement of the two sections of the closing band, after placing the sliders,

  Supply means 24 for a thermoplastic film 11,

  A forming neck 3, associated with a filler neck 40, which conforms the film from a flat initial state to a tube,

  A device 70 for positioning the closure strip 10 with respect to the adjacent longitudinal edges of the film 11, associated with longitudinal welding jaws 5, and

  Transverse welding jaws associated with cutting means 60.

  The invention applies to all types of closure strips 10 (in particular closure strips comprising two complementary male and female sections, hook profiles, etc.).

  Each closure band 10 is fixed on a lateral support web which is integral therewith. Where appropriate, the support web is common and serves as an anti-tamper wall 13.

  Similarly, the sliders 12 may be subject to numerous variants. Preferably, each slider is composed of a sole which carries, on one side, two lateral wings and a central separation rib, which define two convergent / divergent corridors according to the direction considered, each corridor being intended to receive one of the The profiles of the sliders 12 on the closure profile strips 10 preferably correspond to the size of the bags 80 to be formed.

  The invention also applies to the manufacture of empty bags 80 for subsequent filling.

  Different embodiments can be envisaged.

First embodiment

  The positioning device 70 is preferably placed on the forming neck 3 of the bag 80. It comprises:

  • A U-shaped guide 1, extending longitudinally with respect to the forming neck 3, comprising an upper wall and two lateral wings.

  The lateral wings are arranged so as to form a U with the upper wall and thus define a corridor.

  Two lateral guiding plates 4, made of plastic or metal, preferably fixed on the guide 1, parallel to its wings, and a rectangular insert 2, which extends radially from the forming neck 3 and parallel to the lateral plates guide 4, metal.

  The insert 2 is positioned between the lateral guide plates 4, under the corridor of the guide 1 and at a distance from its upper wall, so that there remains a space between each lateral face of the insert 2 and each plate 4. on the one hand, and between the insert 2 and the guide 1 on the other hand.

  In order to achieve the objective of the invention, the film 11 is made to scroll and conform around the forming neck 3, so that the free longitudinal ends of the film 11 are applied against the rectangular insert 2 by the plates. lateral guiding 4 (these free longitudinal ends of the film 11 being inserted between the lateral guide plates 4 and the insert 2). Plating the longitudinal edges of the film 11 against the insert by the two guide plates 4 ensures a good positioning of the film 11 and its holding in position at the time of welding.

  Simultaneously, profile strips 10 pre-fitted with sliders 12 (for example by means of a slider laying device located upstream on the machine), preferably closed, are brought and placed on the film, between the insert 2 and the passage formed by the U-shaped guide 1, with overlapping of the lateral support ribs of the profile strips 10 on the longitudinal edges of the film 11, as illustrated in FIG. 2. The closure profile strips 10 are then oriented so that the sliders 12 are positioned between the insert 2 and the U-shaped guide 1, and that the webs are directed towards the forming neck 3.

  The pre-fitted profiled strips 10 are then precisely maintained in radial position relative to the forming neck 3 and to the longitudinal edges of the film 11, on the one hand by the U-shaped guide 1 which serves as an external radial abutment, and on the other hand. secondly by the insert 2 which serves as internal radial abutment.

  And the insert 2, by its positioning between the two longitudinal edges of the film 11 during welding, prevents their mutual welding.

  Furthermore, the length of the guide 1 U is preferably at least equal to the distance between two sliders 12. The sliders thus constitute two supports, and ensure the stability and balance of the closure strips 10 during welding.

  Preferably the guide plates 4 are fixed to the U-shaped guide 1 only at their longitudinal ends, so as not to impede the passage of the longitudinal welding jaws 5.

  In a variant, the U-shaped guide 1 further comprises two protrusions 1a and 1b, extending from the free end of the flanges towards the interior of the passage, parallel to the upper wall, so as to support the sliders 12 during the welding of the strips (see for example Figures 5 and 6).

  In this way it is even more possible to maintain the profile strips in radial position.

  In another variant, it is expected that the projections 1a and 1b extend longitudinally from the inner surface of the wings, or non-parallel to the upper wall.

  When the closure profile strips 10 are carried by a common support side veil 13, which serves as an opening indicator and burglar-proof wall, the upper surface of the insert 2 conforms to the shape of the veil 13. For example, the surface is concave, or V-shaped, as shown in Figures 3 and 4.

  Second embodiment In this embodiment, the positioning device 70 is again placed preferably on the forming neck 3 of the bag. He understands :

  A U-shaped guide 1 extending longitudinally with respect to the forming neck. The guide 1 comprises an upper wall, two side walls, and where appropriate two projections 1a and 1b.

  The wings are arranged so as to form a U with the upper wall and thus define a corridor, and the projections 1a and 1b extend from the free end of the wings towards the interior of the corridor, parallel to the upper wall as illustrated in FIG. 5, two lateral guiding plates 4, made of plastic or metal material, fixed along the U-shaped guide 1, and

  Two metal guide pins 6 parallel to each other and extending radially from the forming neck 3.

  Each finger comprises at least one guide groove 7, formed longitudinally in its inner face (namely the face facing the other finger).

  The guide fingers 6 are positioned between the lateral guide plates 4, under the guide 1 and at a distance from its upper wall, so that there remains a space between each finger 6 and a guide plate 4 of a part, and the fingers 6 and the guide 1 on the other hand.

  Preferably the guide plates 4 are fixed to the U-shaped guide 1 only at their longitudinal ends, so as not to hinder the passage of the longitudinal welding jaws 5.

  Alternatively, it is expected that the projections 1a and 1b extend from the inner surface of the wings (as shown in Figure 6), or non-parallel to the upper wall of the guide 1. As illustrated on FIG. 5, thicknesses or ribs 14 are formed longitudinally on the outer face of the support webs of the profiled strips 10. Their shape and dimensions are complementary to those of the grooves 7 for guiding the fingers 6, so that said extra thicknesses or ribs 14 are able to be introduced and held radially in the grooves 7, while being able to move in the direction of travel.

  In order to achieve the objective of the invention, the film 11 is made to scroll and conform around the forming neck 3, and each longitudinal edge of the thermoplastic film 11 is placed between the outer wall of one of the guide fingers. 6 and the corresponding lateral guide plate 4. The two guide plates 4 then hold the edges of the film 11 pressed against the guide fingers 6.

  At the same time, the extra thicknesses or ribs 14 are engaged in the guide grooves 7 of the lateral guide plates 6. The closure strips 10 are also positioned in such a way that the sliders 12 are guided in the corridor formed by the U-shaped guide 1. and rest on the projections 1a and 1b, so that they are maintained at a predetermined fixed distance from the forming neck 3. This ensures the radial positioning of the profiled strips 10 on which the sliders are mounted relative to the longitudinal edges of the movie 11.

  The longitudinal welding jaws 5 then weld the longitudinal edges of the thermoplastic film 11 on the lateral webs of the profile strips 10 by closing over the guide fingers 6.

  Preferably, the length of the guide 1 in U is at least equal to the distance between two sliders 12. These sliders then form two supports, and ensure the stability and balance of the closure strips 10 during welding. Alternatively, provision may be made to form the extra thicknesses or ribs on the free ends of the film, and the complementary guide grooves on the outer surface of each finger 6, or that the guide fingers 6 comprise on their surface internal, longitudinal ribs 8 penetrating into complementary grooves 15 formed on the strips of closure profiles 10, as shown in Figure 6. Where appropriate, it is expected to associate the positioning device 70 to a cutting system designed for cutting the longitudinal edges of the film 11 to ensure perfect positioning coincidence of the two longitudinal edges of the film 11 and prevent any disturbance of the displacement of the slider 12. It can further be provided that one of the longitudinal edges of the film 10 11 overflows beyond the closure band 10 and associated sliders 12, to form for example a handle. Of course, the present invention is not limited to the particular embodiments which have just been described but extends to any variant within its spirit.

Claims (27)

  1. Device (70) for positioning strips of closure profiles (10) relative to the longitudinal edges of a thermoplastic film (11) tubular, characterized in that it comprises at least one stop (1) radial outer.   2. Device (70) according to the preceding claim, characterized in that the radial outer abutment (1) is a guide which extends longitudinally with respect to a forming neck (3).   3. Device (70) according to the preceding claim, characterized in that the guide (1) comprises an upper wall and two side walls arranged so as to form a U with the upper wall and thus define a corridor.   4. Device (70) according to one of the preceding claims, characterized in that the strips of closure profiles (10) are provided with a plurality of sliders (12).   5. Device (70) according to one of the preceding claims, characterized in that it further comprises lateral guide plates (4).   6. Device (70) according to the preceding claim, characterized in that the lateral guide plates extend along the stop (1) radial outer.   7. Device (70) according to any one of claims 5 or 6, characterized in that the guide plates (6) are made of plastic or metal.   8. Device (70) according to one of the preceding claims, in combination with claim 4, characterized in that the length of the guide (1) is at least equal to the distance between two successive sliders (12) on the strips of profiles (10) .- 10-   9. Device (70) according to one of the preceding claims, characterized in that the strips of closure profiles (10) comprise a web (13) lateral support common.   10. Device (70) according to the preceding claim, characterized in that the web (13) lateral support common is an opening control.   11. Device (70) according to one of the preceding claims, characterized in that it further comprises an inner radial stop (2).   12. Device (70) according to the preceding claim, characterized in that the radial inner abutment (2) is an insert which extends radially from a forming neck (3).   13. Device (70) according to the preceding claim, characterized in that the insert (2) has a rectangular shape.   14. Device (70) according to one of claims 12 or 13, characterized in that the upper surface of the insert (2) is concave or V-shaped.   15. Device (70) according to one of claims 11 to 14, characterized in that the stop (2) radial internal is metal.   16. Device (70) according to one of claims 1 to 15, characterized in that it further comprises two guiding fingers (6) parallel to each other, and extending radially from a forming neck (3) .   17. Device (70) according to the preceding claim, characterized in that the guide fingers (6) comprise at least one longitudinal guide groove (7) complementary to an extra thickness (14) formed longitudinally on a support web of the strips of closure profiles (10).   18. Device (70) according to claim 16, characterized in that the guide fingers (6) comprise at least one longitudinal rib (8) complementary to a groove (15) formed longitudinally on a support web of the strips of closure profiles (10).   19. Device (70) according to one of claims 16 to 18, characterized in that the guide fingers (6) are metal.   20.Dispositif (70) according to any one of claims 1 to 19, characterized in that the radial outer abutment (1) is a guide which extends longitudinally with respect to a forming neck (3) and that the guide (1) further comprises two longitudinal protrusions (1a, 1b) which extend from the inner surface of the lateral wings of the guide (1).   21.Dispositif (70) according to the preceding claim, in combination with claim 4, characterized in that the sliders (12), which are positioned on the strips of profiles (10), rest on the projections (lb) of the guide ( 1).   22. Device (70) according to any one of the preceding claims, characterized in that the stop (1) outer radial is made of plastic or metal.   23. Device (70) according to any one of the preceding claims, characterized in that it is associated with longitudinal welding jaws (5).   24. Device (70) according to any one of the preceding claims, characterized in that it is associated with transverse welding jaws (60).   25. Device (70) according to any one of the preceding claims, characterized in that it is associated with longitudinal cutting means.   26.Machine manufacturing a bag (80) equipped with a strip of 25 closure profiles (10) provided with sliders (12), characterized in that it comprises a device (70) according to one of the Claims 1 to 25.   27. Bag (80) comprising closure strip strips (10) provided with a slider (12) welded to a thermoplastic film (11) by means of a device (70) according to one of the Claims 1 to 25.