EP0651087B1 - Machine for automatic cutting at right angles to the thread of textile materials, in particular of textile webs - Google Patents

Description

The present invention relates to a machine for cutting woven materials, in particular strips of fabric, in the transverse or longitudinal direction, and more particularly to cut automatically in line with the thread, that is to say to cut the chain son without cutting the weft threads, or vice versa.

Currently cutting strips of fabric in the width or length direction can be realized in several ways, manually using scissors, this which has the disadvantage of cutting often approximate, or automatically using devices cutting mechanics or more sophisticated devices such as than lasers or high pressure water jets.

Document GB-A-830,436 describes a device for cutting materials such as textiles comprising an axis perpendicular to the fabric cutting axis on which are mounted a plurality of cutting members regularly spaced and acting simultaneously, intended for cut the weft threads at specific locations in the fabric, between two warp threads whose gap is more important. Each cutting member has a blade freely rotating knife and shaped element of boss intended to stretch the fabric just before cutting.

However, the various techniques known to date are more or less precise, while it is important to be able to make straight cuts, ie to cut the chain wires between two wires weft without these being cut, or vice versa, to avoid fraying of the cut edge.

The object of the present invention is to remedy the disadvantages of known devices by proposing a machine which allows cuts to be made automatically in the straight line, even in the case of tight weavings.

The automatic cutting machine which is the subject of the present invention comprises a frame which is pivotally secured around a vertical axis cutting the theoretical cutting axis, a cutting blade rectilinear positioned in a vertical plane, inclined by compared to the horizontal and cutting the horizontal plane in which is the strip of fabric to be cut, its edge cut directed upwards, the blade and the fabric being relative displacement relative to each other in parallel to the theoretical cutting axis, and it is characterized basically in that it includes means of detection of deviations of the swivel blade from the cutting axis, said detection means being mainly consisting of two optoelectronic cells positioning positioned downstream of the cutting axis, and other of it, and intended to detect deviations of the blade relative to the cutting axis.

According to another characteristic of the machine according to the invention the blade is secured to the axis of pivoting of the frame by means of a horizontal arm likely to be temporarily maintained by organs retractable retainers, in a position allowing the blade is in the same vertical plane as the cutting axis theoretical.

According to another characteristic of the machine according to the invention, the axis of the blade and the strip of fabric located downstream of the cutting axis are movable one by relative to each other, perpendicular to the cutting axis, this mobility being slaved to the cells for detecting deviations of the blade from the cutting axis.

According to another characteristic of the machine according to the invention the cutting edge of the blade has two sides of the same inclination and is not very sharp, and the blade tilt is adjustable.

According to an additional characteristic of the machine according to the invention the cutting blade comprises, in rear of the two inclined sides, two shoulders intended for spread the wires parallel to the cutting axis.

According to a first embodiment of the machine according to the invention the cutting blade is carried by a mobile carriage in horizontal translation on the frame, parallel to the cutting axis, and the strip of fabric is movable downstream of said cutting axis, perpendicular to the latter, the strip of fabric being maintained for this purpose tensioned by clamps upstream and downstream of the cutting axis and on either side of it, the clamps located in downstream being movable in a moving horizontal plane in the same direction, perpendicular to said axis, this displacement being controlled by the detection cells.

According to a second embodiment which is a variant of the previous one, the strip of fabric is fixed upstream of the cutting axis, and the carriage is also moving in a moving horizontal plane perpendicular to said axis, this movement being controlled to the detection cells, which are in this case susceptible to a similar displacement.

These two embodiments are specially adapted for cutting a strip of fabric transversely, that is to say to cut the warp threads between two weft threads.

According to a third embodiment of the machine according to the invention the pivot axis of the blade is fixedly fixed to the frame, and the fabric strip is movable moving parallel to the cutting axis. The band of fabric is in this case unwound downstream of the cutting axis and wound upstream, the unwinding roller used for this effect being movable in a moving horizontal plane perpendicular to the cutting axis, this displacement being slaved to the detection cells.

According to a fourth embodiment which is a variant of the previous one, the take-up rollers and unwinder used are fixed and the pivot axis of the blade is movable in displacement in a horizontal plane perpendicular to the cutting axis, this displacement being slaved to the detection cells, which are in this cases susceptible to similar displacement.

These last two embodiments are particularly intended for cutting a strip of fabric in the longitudinal direction.

Cutting a strip of fabric in line with the thread by means of a machine according to the invention takes place from the as follows: the strip of fabric is stretched well flat, held either by the clamps or by the rollers unwinder and rewinder, and is positioned a few millimeters above the lower end of the blade cutting, which is temporarily kept in the same vertical plane as the theoretical cutting axis in order to initiate the chopped off. The wires to be cut mount on the blade and are severed under the combined effect of tension and push, then the blade is released, allowing its pivoting, and moves between the two wires not to cut, too large a spacing of said blade by relation to the theoretical axis, meaning that the two wires do not are not parallel to the cutting axis, being detected instantly by the cells, which control the refocusing of the two threads by moving either the fabric in downstream of the cutting axis, perpendicular to it, or of the pivot axis of the blade in the same direction, according to the embodiment chosen.

The advantages and features of the present invention will emerge more clearly from the description which follows and which relates to the appended drawing, which represents a single embodiment not limiting.

• la figure 1 représente une vue schématique partielle en élévation de profil d'une machine selon l'invention.
• la figure 2 représente une vue schématique partielle en plan de la même machine, notamment le dispositif de coupe.
• la figure 3 représente une vue schématique partielle en plan de la même machine, notamment le dispositif de maintien de la bande de tissu.
• la figure 4 représente une vue schématique en plan d'une lame de coupe de la machine selon l'invention.
• la figure 5 représente une vue schématique en plan, d'une lame de coupe reliée à un moteur apte à l'animer d'un mouvement de va-et-vient.

In the attached drawing:

• FIG. 1 shows a partial schematic view in profile elevation of a machine according to the invention.
• 2 shows a partial schematic plan view of the same machine, in particular the cutting device.
• FIG. 3 represents a partial schematic plan view of the same machine, in particular the device for holding the strip of fabric.
• FIG. 4 represents a schematic plan view of a cutting blade of the machine according to the invention.
• Figure 5 shows a schematic plan view of a cutting blade connected to a motor capable of animating it back and forth.

If we refer to Figures 1 and 2 we can see that a machine according to the invention comprises a frame 1 on which passes a strip of fabric 2 intended to be cut transversely to the right of the wire along a cutting axis theoretical 20.

The frame 1 comprises a carriage 3 movable in horizontal translation on a slide 30 parallel to the cutting axis 20, and secured to a chain, or belt 31, stretched between two pulleys 32 and 33, one of which 32 is driven in rotation by a geared motor 34, not shown in figure 2.

An arm 4 is pivotally secured, by one of its ends, around a vertical axis 40, at carriage 3, and is crossed at its other end by a second axis 41, parallel to axis 40, at the end of which an idler roller 42 is attached which is inserted with a slight clearance between two guides 43 and 44 positioned on either side on the other side of the vertical plane containing the cutting axis 20, mounted pivoting in a horizontal plane by their end in upstream of the cutting axis on vertical axes, 45 and 46 respectively, the pivoting in spacing of one relative to the other being controlled by two cylinders 47 and 8 secured to the frame 1 and at their other end.

The arm 4 comprises, projecting downwards from its underside 49, a cutting blade 5, positioned in a vertical plane passing through axes 40 and 41, and the edge of which of cut 50 is directed upwards and makes an acute angle with the underside 49 of the arm 4.

The inclination of the blade 5 is adjustable in depending on the nature of the fabric to be cut, allowing the fabric to mount on the cutting edge 50 of said blade, which facilitates the cutting of the wires perpendicular to the axis cutting 20 which come into contact with said edge 50.

The frame 1 also comprises, downstream of the axis section 20, positioned on either side thereof, in look of a mask 14 fixed on the axis 41 of the arm 4, two detection cells 10 and 11.

If we now refer to Figure 3 we can see that the frame 1 also has two pairs 12 and 13 of pliers, respectively 120, 121 and 130, 131, the pair 12 being placed on the edge side 21 of the fabric strip 2 where cut must be started, pliers 120 and 121 positioned close to each other on both sides of the cutting axis 20, and the pair 13 being placed on the other side on edge 22, clamps 130 and 131 also being positioned on either side of the cutting axis 20.

The clamps 120, 121, 130 and 131 are adapted to grab the fabric strip 2 and stretch it, and they are this mobile effect in horizontal translation, under the effect means known per se, the clamps 120 and 121 one by report the other, and the pliers 130 and 131 on the one hand with respect to the other, on the other hand in spacing by compared to clamps 120 and 121, and on the other hand again together perpendicular to the cutting axis, the latter movement being controlled by cells 10 and 11.

Cutting to the right of the wire along the cutting axis 20 of the fabric strip 2 is produced as follows: the strip of fabric 2 is kept stretched by the pairs of clamps 12 and 13, the carriage 3 moves in the slide 30, driven by the belt 31, the arm 4, maintained not pivoting between guides 43 and 44 via the roller 42, allowing the positioning and the maintenance of the blade 5 in the extension of the cutting axis 20 so to initiate the cut between two weft threads.

When the cut is started, arm 4 is released by spacing relative to each other of the guides 43 and 44 under the action of cylinders 46 and 47, while the clamps 120 and 121 move apart to tension the fabric strip 2 on either side of the cutting axis 20, the blade 5, which has become movable in pivoting around the axis 40 via of arm 4, moves between the two weft threads and cuts the chain son, a possible deviation of the blade 5, indicating that the two weft threads are not on the axis section 20, being detected by cells 10 and 11 which in this case control the movement in one direction or in the other of the pair of pliers 13 in order to center the two weft threads in the cutting axis 20.

If we then refer to Figure 4 we can see that the cutting blade 5 has two shoulders 51 and 52 located behind the inclined planes 53 and 54 which define the cutting edge 50 and the cutting edge 55 allowing, during the advancement of said blade 5 by through the arm 4, to separate the wires 56 and 57 parallel to the theoretical cutting axis 20, in order to cut the wires 57 'perpendicular to the cutting axis 20 by the cutting edge 55 without it cutting the two wires 56 and 57 bearing respectively on the shoulders 51 and 52. We can also see that blade 5 is double-edged and has two additional shoulders 58 and 59 symmetrically arranged.

If we finally refer to Figure 5 we see that the cutting blade 5 is actuated by a motor 60 according to a reciprocating movement similar to that of a jigsaw. The blade 5 is positioned in a sheath 61 provided, short distance from its end, from a blank 62 revealing said blade 5. The sheath 61 has two shoulders 63, 64, visible on the sectional view along line I-I of the figure, which frame the blade 5 and allow to separate the yarns of fabric 65 between which the cut is made.

Claims (13)

1. Machine for automatically cutting at the right of the yarn of the woven material, especially fabric strips, in a transverse or longitudinal direction, said machine comprising a frame (1) to which a rectilinear cutting blade (5) is rendered integral so as to pivot around a vertical axis (40) cutting the theoretical cutting axis (20), said cutting blade being positioned inside a vertical plane and slanted with respect to horizontal and cutting the horizontal plane containing the fabric strip (2) to be cut, its cutting edge (50) being directed upwards, the blade (5) and the fabric strip (2) being in relative displacement of one with respect to the other parallel to the theoretical cutting axis (20), characterised in that the blade (5) is rendered integral with the vertical axis (40) by means of a horizontal arm (4) whose said vertical axis (40) traverses one of the extremities and which is able to be temporarily supported by retractable holding elements (43, 44) in a position to ensure that the blade (5) is within the same vertical plane as the theoretical cutting axis (20), and secondly in that it includes means (10,11,14) for detecting deviations of the blade (5) with respect to the cutting axis (20), and means (13) for moving the fabric strip (2) downstream of the cutting axis with respect to the vertical axis (40) of the blade (5), this movement being automatically controlled at said means (10,11,14) for detecting the deviations of the blade (5).
2. Machine according to claim 1, characterised in that said detection means (10,11,14) include two opto-electronic cells (10, 11) positioned downstream of the cutting axis (20) on both side of the latter and orientated towards the pivoting arm (4) which is fitted at its extremity with a mask (14) disposed opposite said cells (10,11).
3. Machine according to claim 2, characterised in that the horizontal arm (4) is traversed by a second axis (41) parallel to the axis (40) at the extremity of which a loose roller is rendered integral and is inserted with slight play between the two retractable retention elements (43, 44) constituted by two guides positioned on both sides of the vertical plane containing the cutting axis (20) and mounted pivoting inside a horizontal plane.
4. Machine according to claim 1, characterised in that the vertical axis (40) is rendered integral with a carriage (3) able to move in horizontal translation parallel to the cutting axis (20), the fabric strip (2) being kept upstream of the cutting axis and on both sides of the latter by two mobile clamps (120, 121) spaced with respect to each other, and downstream of said cutting axis (20) by two mobile clamps (130, 131) spaced with respect to each other and with respect to the other two clamps (120, 121).
5. Machine according to claim 4, characterised in that the clamps (130, 131) situated downstream of the cutting axis (20) are mobile inside a horizontal plane by moving in a given direction perpendicular to said cutting axis (20), this movement being Automatically controlled at the detection, cells (10, 11).
6. Machine according to claim 4, characterised in that the carriage (3) is also mobile inside a horizontal plane by moving perpendicular to the cutting axis (20), this movement being automatically controlled at the detection cells (10, 11).
7. Machine according to claim 1, characterised in that the vertical axis (40) of the blade (5) is integral with the frame (1), the fabric strip (20) being taut between two rollers, namely an unwinding roller and a winding roller.
8. Machine according to claim 7, characterised in that the unwinding roller is able to move inside a horizontal plane perpendicular to the cutting axis (20), this movement being automatically controlled at the detection cells (10, 11).
9. Machine according to claim 7, characterised in that the vertical axis (40) of the blade (5) is able to move inside a horizontal plane perpendicular to the cutting axis (20), this movement being automatically controlled at the detection cells (10,11).
10. Machine according to any one of the preceding claims, characterised in that the cutting edge (50) of the blade (5) is less sharp and comprises two slanted planes (53, 54) with identical angles.
11. Machine according to any one of the preceding claims, characterised in that the inclination of the blade (5) is variable.
12. Machine according to claim 10 or 11, characterised in that the blade (5) comprises two shoulders (51) and (52) situated at the rear of the slanted planes (53, 54) defining the cutting edge (50).
13. Machine according to any one of the preceding claims, characterised in that the blade (5) is connected to a motor (60) which actuates it according to an alternative movement similar to that of a piercing saw.

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