FR2656290A1 - Device for separating and removing waste cut out from a sheet of material - Google Patents

Abstract

This device for removing the waste from a sheet (11) of material driven along a substantially rectilinear path includes a rotary suction roller (18) arranged transversely to the path on one side of the latter, intended to divert the waste from the said rectilinear path and to drive it onto a branch-off path towards take-up means (28, 29) comprising a guide (28) interacting with the surface of the suction roller (18) in order to detach the waste therefrom. An applicator roller (25) interacts with the rotary suction roller (18) on the other side of the said rectilinear path. The suction roller (18) is connected to a suction source (19) located on a part of its periphery.

Description

DEVICE FOR SEPARATING AND EVACUATING FALLS
CUT FROM A BAND OF MATERIAL.

 The invention relates to the separation and disposal of scraps cut from strip material.

 In the field of ribbons of fibers pre-impregnated with thermoplastic or thermosetting resin, intended for the production of composite laminate materials, the successive sections of ribbon used are obtained by cutting the ribbon according to cutting forms suitable for the destination: between an end cutting of section and a cut at the start of the next section is a drop which should be eliminated from the path of the useful sections.

 The object of the invention is therefore to propose a device which responds to this design, and allows the evacuation of scraps cut from a strip of material entrained on a substantially straight path (at least in part).

 This object is achieved according to the invention thanks to a device comprising a rotary suction roller arranged transversely to the path of the strip on one side thereof, and intended to divert by suction the falling material to entrain it on a branched path.

 Advantageously, means are provided for taking up the falling material on the derived path. These means can comprise a guide cooperating with the surface of the suction roller to detach the falling material, and on the other hand, at least one, but preferably two. , conveyor belt cooperating with the guide just downstream of it.

 Advantageously also, an application roller cooperates with the rotary suction roller on the other side of the rectilinear path. This roller, or another roller arranged downstream, can bring a support, in the form of a linear or endless strip, intended to maintain the material to be preserved.

 In a particularly advantageous embodiment of the invention where it is desired, in a very small volume, to modify at a precise instant the orientation of the strip material, the rotary suction roller is of reduced size (as for its diameter) and it is connected to a suction source arranged on a part of its periphery. In other words, instead of creating the vacuum inside the roller by connecting it to a suction source through the front surfaces of the roller, which due to space limitations would reduce the possibilities of sufficient and uniform suction, the roller is used as an organ through the permeable periphery of which the vacuum is established, thanks to a collecting box cooperating with a portion of said periphery, and connected to a suction device comprising rapid opening and closing means.

 Advantageously, the device according to 1 invention comprises control means which only trigger the aspiration at selected periods, and which can be limited to the appearance at the level of the suction roller of an initial fall cut.

 The device of the invention is particularly well suited to the evacuation of falls from the prepreg fiber strips and can be placed upstream of a station for using the sections of strips or a station for temporarily storing said sections (by winding on coils, for example).

Other characteristics and advantages of the invention will emerge from the following description of an embodiment according to the invention. Reference will be made to the appended drawings on which
Figure 1 is a schematic view of the device in elevation.

 Figure 2 is a top view of a strip of prepreg fibers.

 Figure 3 is a cross section of the suction roller and part of the suction system.

 FIG. 4 is a perspective view of the roller of FIG. 3.

 FIG. 5 illustrates a variant of the device of FIG. 1.

 Figure 6 shows the arrangement of the suction roller.

 The device 10 of the invention is intended to evacuate the scraps of pre-impregnated fibers from a strip 11 driven by means not shown on a partially substantially straight horizontal path, in the direction of arrow 12.

 The strip 11 of commercial prepreg fibers has undergone substantially transverse cuts 13, 14 (FIG. 2), according to programmed shapes using a suitable cutting device not shown. These cutouts 13, 14 form, between two consecutive zones 15, 16 of fibers to be preserved, zones 17 of fibers to be eliminated or dropped.

 In order to eliminate these drops 17, the device 10 of the invention comprises a cylindrical roller 18 driven in rotation by conventional means not shown, and disposed tangent to the path of the strip 11. The periphery of this roller is permeable to air in order to be able, if a vacuum zone is created inside the roller, to suck through its surface, or on a well delimited part of its surface.

 As seen in Figures 1, 3 and 4, the roller 18 is associated with a suction source 19 disposed on a part of its periphery, and consisting of a fixed cover 20, two walls of which are applied so substantially sealed along two generatrixes of the cylindrical envelope of the roller 18, while two other front walls are applied transversely and substantially hermetically on the roller 18. The interior space of the box 20 is connected by a connector 21 to the source suction 19. I1 is provided at least one shutoff valve controllable on the suction circuit.

 The roller 18, which consists of a perforated, porous or permeable hollow sleeve, internally comprises two fixed waterproof screens 22 mounted against the internal periphery of the roller on two opposite cylindrical sectors, and thereby delimiting two fixed permeability zones 23 and 24 opposite: the first 23 is contiguous to the path of the strip and extends downstream from the tangency contact, over approximately one fifth of the periphery of the roller 18; the second zone 24, extends to the lower part of the roller 18, on the side of the suction box 20. The zone 23 therefore constitutes a suction zone where the air passes from the outside of the roller 18 towards the inside, while the zone 24 lets air pass from the inside of the roller 18 to the suction box 20.

 The roller 18 can be made of perforated steel sheet, and have in an exemplary embodiment a width of 150 mm for an inside diameter of about 20 mm. The roller 18 is closed at its ends by advantageously fixed front faces integral with the screens 22, and provided with a sufficient seal with respect to the roller taking into account the depression prevailing in the roller.

 On the other side of the strip path 11, a roller 25 applies the strip 11 against the roll 18, and moreover makes it possible to bring a support element 26 to the back of the strip 11 and to stick it to it. this by pressure.

 On the path of the strip 11, downstream of the suction roller 18, it is possible to provide another support element 27 intended to protect the other side of the fibers to be preserved.

 The supports 26 and 27 can be linear supports made of paper or plastic, fed from reels, and allowing easy handling of the strip 11 downstream of the fall evacuation device, it can be rewound into a reel if necessary.

 If the strip is used immediately, one or the other of the supports 26 and 27, or both, may consist of endless support strips.

 The discharge device 10 also comprises means for taking up the fiber scraps on the branched path thanks to the suction roller 18. These means include a scraper 28 disposed fixed along a generatrix of the outer casing of the roller 18 to intercept and take off the fibers pressed against the roller 18 by the vacuum: the chosen generator is slightly downstream of the end of the suction zone 23 to facilitate take-off. The scraper 28 leads the fibers to be evacuated in the nip of two endless belts 29 cooperating with each other to cause the falls to a suitable reservoir 30 (or a chopper).

 The operation of the device according to the invention is as follows.

 The strip 11 advances in the direction 12 and undergoes the appropriate cuts 13, 14. A cutting detector member, which can be independent of the cutting means or on the contrary depend on it, detects the arrival of a first cut 13 at the level of the evacuation device, which triggers, by suitable means, the suction through the roller 18.

 As soon as the zone 17 of the strip engages on the roller 18, the suction through the roller forces the fibers to press against the roller. The preceding neighboring fibers, belonging to the zone 15 to be preserved, are entrained by the strip downstream and therefore prevented from deviating from the path. On the contrary, the fibers of zone 17 gradually separate from the downstream strip at the location of the cut 13 and are carried by the roller 18 in zone 23 until they are taken up by the blade 28 and s '' engage in the double evacuation belt, which is driven at a speed slightly higher than that of the strip 11 so as to maintain a slight traction. Once the fibers to be eliminated engaged in this carpet, it is no longer necessary to maintain the vacuum in the roller 18, the whole of the chute 17 continuing its deviated path towards the tank 30. When the next cut 14 engages in the separation and evacuation device, the next area to be kept 16 is will detach from the fall 17, all the better since the support 26 applied under the pressure of the rollers 18 and 25 to the strip 11, tends to maintain the latter on its rectilinear path in the absence of preponderant forces which l would depart from it.

 Naturally, in order to ensure correct operation of this cycle, the speeds of the various supply and drive members are regulated and coordinated, for example by means of a digital computer control and speed control controlled by a analog or digital tachometer generator.

 FIG. 5 shows an alternative embodiment of the installation of FIG. 1.

 The device 10 'further comprises means for driving a strip 11' in the direction 12 ', and thus pass over a porous roller 18' associated with a suction duct 19 'disposed tangent to the roller.

 The structure of the roller 18 ′ is detailed in FIG. 6. I1 comprises the porous cylindrical envelope 18 ′ proper mounted in rotation on bearings 40. These are wedged on the end journals of a fixed cylinder 41 secured to elements of the chassis 42. The cylinder 41 is full except in a zone 43 corresponding substantially to the width of the strip 11 ', where the suction must be carried out. In this zone, the cylinder is hollowed out (as seen in section in FIG. 5) at its center, so as to constitute two lateral parts of material forming screens 22 ′, and two hollowed parts respectively forming an inlet zone 23 ′ and an air outlet zone 24 '. Outside these zones 23 ′ and 24 ′, the cylinder 41 is practically contiguous to the porous rotating sleeve 18 ′. In FIG. 6, there is shown a suction zone 43 corresponding to the smallest strip width 11 ′ used ( 25 mm); for different widths (for example 50, 75 or 150 mm), the roller 41 is replaced by another roller whose hollowed out areas 23 'and 24' correspond to the desired width.

 The end of the porous roller 18 'has a toothed profile 44 meshing with a drive pinion 45 and thus allowing the rotation of the roller 18'.

 Returning to FIG. 5, it can be seen that the suction box 20 ′ serves as a support or scraper 28 ′ arranged tangent to the roller 18 ′.

 The strip 11 'is applied against the roller 18' by an applicator roller 25 'mounted in a support 46 allowing the adjustment of the application force. Unlike the embodiment of Figure 1, here the applicator roller 25 'is not used simultaneously to bring a paper support strip 26': this role is assigned to a second roller 47, arranged downstream of the roller 25 'and cooperating with a lower roller 48 which brings it a plastic support strip 27 '. Because the roller 25 'is only an applicator roller driven by friction, not bringing a support strip, the sucked air circulates more freely in this region than in the corresponding region of FIG. 1.

 The fall recovery means comprise, downstream of the scraper 28 ', two rollers 49.50, one of which, the roller 50, is carried by an articulated support 51 whose application force is adjustable by means of a screw 52 mounted in an element of the chassis 42.

Claims (8)

 1. Device for evacuating falls (17) from a strip (11,11 ') of material entrained on a substantially straight path, characterized in that it comprises a rotary suction roller (18,18') arranged transversely to the path on one side thereof, intended to divert the falls (17) from said rectilinear path and to entrain them on a derived path.  2. Device according to claim 1, characterized in that means (28,29) are provided to take up the falls (17) on the derivative path.  3. Device according to claim 2, characterized in that said means (28,29) comprise at least one evacuation mat (29).  4. Device according to any one of claims 2 or 3, characterized in that said means (28,29) comprise a guide (28) cooperating with the surface of the suction roller (18) to detach the scraps (17).  5. Device according to any one of claims 1 to 4, characterized in that a roller (25) applicator cooperates with the rotary suction roller (18) on the other side of said rectilinear path.  6. Device according to any one of claims 1 to 5, characterized in that the suction roller (18,18 ') is connected to a suction source (19,19') disposed on a part of its periphery.  7. Device according to any one of claims I to 6, characterized in that it comprises at least one roller (25,25 ') for applying a linear support (26,26') to the material to be preserved (15 , 16).  8. Device according to any one of claims 1 to 7, characterized in that it is intended for the evacuation of scraps (17) of prepreg fibers cut from a strip (11).