EP0216644A1 - Guiding device for sewing three-dimensional soft work pieces upon sewing machines - Google Patents

Guiding device for sewing three-dimensional soft work pieces upon sewing machines Download PDF

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Publication number
EP0216644A1
EP0216644A1 EP86401500A EP86401500A EP0216644A1 EP 0216644 A1 EP0216644 A1 EP 0216644A1 EP 86401500 A EP86401500 A EP 86401500A EP 86401500 A EP86401500 A EP 86401500A EP 0216644 A1 EP0216644 A1 EP 0216644A1
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EP
European Patent Office
Prior art keywords
fabric
wheel
signal
edge
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86401500A
Other languages
German (de)
French (fr)
Other versions
EP0216644B1 (en
Inventor
Christian Huau
Pierre Jean Alphonse Facon
Alain Pelleray
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ALAIN ROULEAU EN PATRICK ROULEAU BEIDEN TE TOULOUS
Original Assignee
Bertin et Cie SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FR8511859A external-priority patent/FR2585684B1/en
Priority claimed from FR8511858A external-priority patent/FR2585683B1/en
Application filed by Bertin et Cie SA filed Critical Bertin et Cie SA
Priority to AT86401500T priority Critical patent/ATE46726T1/en
Publication of EP0216644A1 publication Critical patent/EP0216644A1/en
Application granted granted Critical
Publication of EP0216644B1 publication Critical patent/EP0216644B1/en
Expired legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B35/00—Work-feeding or -handling elements not otherwise provided for
    • D05B35/10—Edge guides
    • D05B35/102—Edge guide control systems with edge sensors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H43/00—Use of control, checking, or safety devices, e.g. automatic devices comprising an element for sensing a variable
    • B65H43/08—Photoelectric devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H7/00—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles
    • B65H7/02—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors
    • B65H7/14—Controlling article feeding, separating, pile-advancing, or associated apparatus, to take account of incorrect feeding, absence of articles, or presence of faulty articles by feelers or detectors by photoelectric feelers or detectors
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B35/00—Work-feeding or -handling elements not otherwise provided for
    • D05B35/10—Edge guides
    • D05B35/107—Fixed or adjustable pin holding the work, e.g. for circular or spiral stitching
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B73/00—Casings
    • D05B73/04—Lower casings
    • D05B73/12—Slides; Needle plates
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
    • D05D2207/00—Use of special elements
    • D05D2207/02—Pneumatic or hydraulic devices
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
    • D05D2209/00—Use of special materials
    • D05D2209/04—Use of special materials with high friction
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
    • D05D2209/00—Use of special materials
    • D05D2209/08—Use of special materials elastic, e.g. rubber spring
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
    • D05D2303/00—Applied objects or articles
    • D05D2303/02—Tape
    • D05D2303/04—Tape elastic

Definitions

  • the invention relates to an assembly for guiding sheets of flexible material intended to form a three-dimensional assembly, said assembly comprising a drive device formed by at least one support plate, a drive wheel pressing a sheet to be guided on the support plate, drive wheel control means, and a sheet edge position detector for controlling the drive device, said detector comprising at least one photoelectric detector disposed in front of the edge, serving guiding the piece of fabric and the electronic circuits, transforming the signal delivered by the photoelectric detector into a control signal from the drive device.
  • the assembly of flexible parts in a three-dimensional shape is mainly encountered in the clothing industries. Indeed, the confection of clothes consists in assembling pieces of fabric more or less deformable to form a surface intended to cover a volume. The assembly is carried out for fabrics, whatever their texture, by sewing. Two cases can arise depending on whether or not the pieces can be superimposed before sewing.
  • Conventional sewing machines generally include a mechanism providing the inter-looping of the sewing thread (s) and a mechanism for advancing the fabric.
  • This advance mechanism consists of an elliptical movement claw and a presser foot between which the fabric passes.
  • the longitudinal amplitude of the claw movement determines the length of the stitch and is generally adjustable.
  • the parts to be assembled are guided relative to their edges which the operator superimposes as exactly as possible.
  • Actuators can take many forms, however it seems that only claw and wheel actuators have had some developments, with a preference for the latter, the implementation of which is easier.
  • the wheel actuators of the known technique can be divided into two groups: those with free wheel and fixed direction, and those with controlled wheel and fixed direction.
  • French Patent No. 2,241,648 describes an actuator of the first group whose free wheel makes an angle with the direction of advance of the piece of fabric so as to impart thereto a rotational movement, limited by the abutment of the edge of the fabric along a guide whose curvature corresponds to the orientation necessary for the formation of a three-dimensional assembly seam, the second piece of fabric, possibly being guided by the same device.
  • This process has a certain number of drawbacks among which it is necessary to point out a use limited to fabrics sufficiently rigid so that their edge can be effectively guided by the guide, and the need to have as many guides as there are tailoring models and sizes.
  • the guiding device furthermore comprises means for adjusting the pressure of the wheel on the cloth so as to ensure a contact pressure which depends, among other things, on the material, the thickness and the weaving.
  • the position detector comprises at least one photoelectric detector disposed in front of one of the faces of a plate intended to separate, to allow their positioning, two pieces of fabric to be assembled by sewing.
  • the photoelectric detector is made up of two pairs of light-emitting diodes and photo-transistors.
  • the reference position from which the position of the edge of the fabric is checked, is that for which the edge is centered between the two diodes.
  • a second similar photoelectric detector is mounted on the other side of the separation plate to detect the edge of the second piece of fabric.
  • the electrical signals supplied by the photoelectric detectors are sent into an electronic processor device which matches the signals received for each piece of fabric with reference values stored in memory and acts on the drive circuits of the motors of a device for guiding pieces of fabric.
  • Controlling the rotation of the wheel by the position sensor based on an all-or-nothing response, produces relatively large trajectory changes and short amplitudes which create wrinkling of the fabric when loading steering and does not allow not get curved seams of small radius.
  • the analog device no more than the logic system (all or nothing) does not allow the treatment of fabrics of irregular transparency such as lace, tulle, or printed fabrics with strong variations in density.
  • the openwork fabrics have, after cutting, very jagged edges and, in the case of tulle, in the case of threads separated by spaces greater than their diameter.
  • the presence of gaps inside the fabric in the field of the photoelectric detector prevents the use of simple analog sensors measuring the level of obscured surface.
  • the scrolling of the edge of an openwork fabric in front of a supposed sensor capable of detecting the precise position of the apparent edge and not of the cut will give an analog signal reproducing the fluctuations of this apparent edge. These fluctuations are due to the displacement of the line that cut in front of the sensor and to the presence of gaps in the fabric along this line. We must therefore be able to distinguish these two causes in order to reconstruct the cutting line that the seam must follow.
  • the subject of the invention is a guide assembly the drive device of which comprises a drive wheel which can be oriented as a function of the desired curvature, the speed of rotation of which is mechanically controlled by its orientation and the edge position detector of which allows , from the detection of the apparent edge of the fabric, to reconstruct the cutting line parallel to which the seam is to be executed.
  • Figures 1 to 3 show a sewing machine equipped with a guide assembly comprising a a training device M and an edge detector N.
  • the drive device is shown on a larger scale in FIG. 2, mounted on a machine head containing the mechanism for actuating the needle rod 2 at the end of which is fixed the needle 3 and the lowering mechanism and presser foot lifter 4.
  • the head further includes the mechanism for feeding and guiding the needle thread (not shown).
  • the table 5 (FIG. 3) carries the needle plate 6 in which are provided openings for the passage of the feed means constituted by the claw 7 and a needle passage hole 8.
  • the claw is animated with an alternating movement which causes the teeth to periodically protrude from the plate simultaneously with their movement from the front to the rear of the machine (for an observer looking at the machine according to FIG. 1), the return of the claw s performing, the teeth being below the plate.
  • the table also carries the stitch formation mechanism by interlocking the needle thread with the bobbin thread.
  • the pieces of the fabric to be assembled by sewing are introduced once positioned on the needle plate where they are held by the pressure of the lifting presser foot.
  • the synchronization of the various movements of the mechanical parts of the machine is designed so that when the needle passes through the parts of the fabric to loop the sewing threads, these are kept stationary.
  • the claw protrudes from the needle plague and presses the fabric against the presser foot and drives it backwards, bringing between the foot presser and needle plate a length of fabric corresponding to the length of the stitch.
  • the drive device is positioned in front of the needle plate, and comprises a spherical wheel 9 which presses on one of the pieces of fabric to be guided.
  • the wheel is freely movable around an axis 10, parallel to the surface of the fabric, fixed by one of its ends on a wing 11 of a bracket 12 whose other wing 13 is fixed to a shaft 14, mobile around its axis in bearings 15, 16 fixed to a fixed frame 17.
  • the shaft 14 and the axis 10 of the wheel are, according to the embodiment, perpendicular and the axis of the shaft 14 passes through the center of the spherical wheel.
  • the shaft 14 is provided with an angular position measuring device 18 consisting, for example, of a circular potentiometer and carries at its free end rotation control means consisting of a servo motor 19 controlled by an electronic edge detection device which will be described later.
  • the stators of the potentiometer and servo-motor are fixed by a spacer 20 to the fixed frame 17.
  • the wheel 9 is rotated about its axis 10 by a roller 21 whose axis 22 is in a plane containing the axis 10 of the wheel, preferably in the - horizontal plane orthogonal to the shaft 14.
  • the roller occupies a fixed position relative to the frame 17 on which it is held by a bearing.
  • the roller is rotated by a mechanical transmission consisting at least in part of a set of pulleys 23, 24 and belt 25.
  • This set is itself driven by a transmission 26 connected directly or indirectly to a power take-off 27 on the main shaft of the machine.
  • the speed of rotation thus communicated to the roller is linked to that of the machine and therefore is a function of the speed of advance of the parts under the seam forming mechanism.
  • the roller 21 drives the spherical wheel 9 in circles whose diameter depends on the orientation of the latter. As the piece of fabric is always driven at the same point situated on a large circle of the wheel, the speed at this point will vary inversely proportional to the diameter of the circle along which the roller will drive the wheel.
  • FIG. 4 makes it possible to understand the principle of the variation of the drive speed as a function of the position of the wheel in front of the roller whose speed is considered constant.
  • the spherical wheel 9 is oriented in a first position I (in solid lines) oriented so that its plane of symmetry is coincident with the plane of symmetry of the roller 21.
  • the synchronous mechanical drive of the movement of the main shaft of the machine is replaced by a servomotor 230 (shown in broken lines) making it possible to communicate to the wheel, via the roller, a tangential speed producing a drive of the part to be guided at a speed of which a component parallel to the direction of movement of the claw is constant and equal to the speed of advance of the parts to be assembled.
  • the guide assembly comprises a separation device 28 consisting of a support plate 29 comprised between two support plates 30 , 31 disposed respectively above and below the plate 29 and at a distance from the support plate, corresponding approximately to the thickness of the pieces of fabric 32, 33 to be assembled.
  • the support plates carry an opening 34 ensuring the passage of the wheel of the device for driving the piece of fabric, the wheel being in abutment against said piece of fabric.
  • the drive device to a guide assembly of a sewing machine, provision is made for guiding each of the pieces of fabric to be assembled.
  • the piece of fabric 33 passing between the support plate 31 and the support plate 29 is guided by a device at all points similar to the first, which is suggested in FIG. 2 by a portion of wheel 35 shown in phantom, arranged possibly opposite the first with respect to the support plate.
  • the pieces of fabric are guided, as known, by their edges: at least one of the edges being cut along the curve, projected onto the plane of the fabric, of the desired assembly and serving as a reference.
  • the guide assembly also includes an edge detector B which comprises edge detection means formed by a proportional photodetector 36 which will be described later.
  • the signals provided by the photodetector 36 are sent to an electronic device which detects the source signals and generates a signal which is sent to a comparator one of whose inputs receives a reference signal taking into account the orientation of the wheel given by the potentiometer 18.
  • the resulting signal controls a servo device comprising the servomotor 19 which controls the orientation of the wheel 9 in front of the roller 21.
  • Figure 5 is a geometric construction for understanding the operation of the guide device.
  • the straight lines D and E correspond respectively to a straight seam obtained by keeping constant the distance e from the straight edge E of the piece of fabric to the needle Ao
  • This piece of fabric is driven by the claw disposed upstream of the needle, at a speed Vo which is represented in intensity and direction by the vector Vo applied approximately to point A, as will be explained later.
  • the tracking of a curved line is done by superimposing a rotational movement of the fabric in advance given by the claw.
  • the supposedly rigid fabric has a velocity field which can be expressed by rotation around an instantaneous center of rotation 0 1. , 0 2 , 0 3 ...
  • This instantaneous center is located at l intersection of all the perpendiculars to the velocity vectors at each point of the fabric.
  • the perpendicular XX 'to the speed vector Vo given by the claw is a constant whatever the curvature of the seam since this speed is tangent to the seam by definition.
  • the instantaneous center of rotation is therefore always on this perpendicular. We will assume that this perpendicular passes through needle A, which is not true only approximately.
  • the angle ⁇ is the angle made by the diametrical plane of the wheel passing through the point of application B, it is also the angle made by the horizontal axis of the wheel with the line XX ', the point d intersection O 1 being an instantaneous center of rotation.
  • the point O 1 is the center of a curve C 1 of radius equal to O 1 F, F being the point of intersection of the edge of the fabric with the line XX '.
  • a modification of the radius of curvature of the seam will be obtained by modification of the orientation and intensity of the speed vector V1 .
  • the curve C 2 will be obtained by the application of a new speed vector V2 which will cause a displacement of the instantaneous center of rotation in O 2 .
  • the orientation of the wheel is limited on either side of the direction BH to an angle less than 45 ° depending on the importance of the horizontal axis around which spin the wheel. According to other embodiments, this angle can be greater or less, depending on the size of the spherical part of the wheel.
  • An example of the latter case corresponds to the vector V3 .
  • the edge detector P must be positioned so that the photodetector cells are on either side of the theoretical path of the edge of the part to be guided. Their position determines the distance "e" between the seam and the edge of the fabric. If the seam must have a succession of different curvatures, the position of the cells must theoretically be modified according to the progress of the seam to keep e constant. An equivalent result can be obtained using a row of cells of which only the two cells surrounding the theoretical path of the edge for the desired curvature are activated. In practice, the precision sought often does not require this correction.
  • training point B is dictated by the seam to be made and depends on the distance from this point to the nearest edge. Depending on the curvature of the seam, it can be on the other side of the straight line D passing through the needle.
  • the angular position of the drive wheel 9 is marked by the potentiometer 18 while the position of the edge of the fabric is marked by the edge position detector B comprising, - according to the embodiment shown, the photoelectric detector 36 disposed in an enclosure 37 fixed to the arm of the machine .
  • a mirror 38 transmits the light beam on the polished support plate 29 on which it is reflected.
  • the reflected beam falls on the photoelectric sensor consisting of a strip of diodes mounted on an integrated circuit, in a pitch of 0.1 mm.
  • the strip used, in the described application has 64 diodes, which allows a range of sight of 6.4 mm deemed sufficient.
  • the size of the diodes (0.1 mm) was chosen so that their width is less than the diameter of the threads constituting the fabric and in particular those constituting the mesh network of tulle or lace. The place of the thread can therefore be detected to the nearest 0.1 mm, which is sufficient to obtain a sewing precision of ⁇ 0.5 mm.
  • the light rays which fall on the fabric are diffused with a weak intensity while those which! fall alongside or in the gaps are reflected and concentrated by the optics towards the diode array.
  • the result is a set of weak signals in front of the fabric and strong outside.
  • the state of the various diodes 36 (FIG. 7) is observed by a cyclic scan clocked by signals 40 from a clock and defined by synchronization signals 41 from a multiplexer 42 to form a video signal.
  • the timing diagrams of the signals, shown in FIG. 8, correspond, in order to simplify the diagram, to a strip of ten photodiodes, while the embodiment uses a strip of 64 photodiodes.
  • each level represents the illumination of a photodiode.
  • the diagram corresponds to three successive scans I, II, III triggered by the three synchronization signals A, B, C and a single movement of the fabric, which explains the modification of the signal between each synchronization.
  • the low levels correspond to a hole in a mesh of a lace.
  • a threshold 43 is defined against which the signals are compared.
  • the comparator 44 which receives the threshold signal and the video signal, separates the levels and makes it possible to obtain an all-or-nothing signal 45.
  • comparator 44 is sent to a bi-stable flip-flop circuit 45.
  • the first presence of the fabric encountered generates a signal. which switches the bistable to state 1 shown in FIG. 8, it is only returned to state 0 at the end of scanning, that is to say on the arrival of the next signal of synchronization A.
  • a gate circuit 46 controlled by the output signal of the bistable allows a number of pulses of the clock signal 40 proportional to the position of the first photodiode marked by the edge of the fabric to pass.
  • a counting circuit 47 triggered by a synchronization signal 41, determines the number of pulses contained in each output signal of the bistable passing through the gate circuit 46, between two synchronization signals 41. The result of the counting is then transferred in a transfer register 48 by a transfer control circuit 49, which also ensures the reset of the counter 47, controlled by the synchronization signal after time shift.
  • the count value previously obtained is translated into voltage by a digital analog converter 50.
  • a signal proportional to the distance separating the edge of the fabric from the end of the bar is thus obtained.
  • This edge signal faithfully follows the shape obtained after cutting, including the contour of the gaps cut by the cutting line in the openwork fabrics.
  • a second signal processing is necessary to reconstruct the cutting line, and will consist in making a peak-to-peak tracking of the edge signal, so as to skip the gaps.
  • the analog signal obtained in the first processing is sent to a correction circuit 51 which transforms it into a peak signal.
  • This correction is obtained from two time constants, a short one which quickly takes the maximum value, a longer one which allows the minimum acceptable curve to be followed by guiding the fabric.
  • the signal obtained at the output of the correction circuit 51 is sent to a framing circuit 52 where it is calibrated and exits in the form of a signal e 2 .
  • the signal from the angular position sensor 18 is also sent to a framing circuit 53 where it is calibrated in the form of a signal e 1 .
  • the signals e 1 and e 2 are sent in a comparison and control circuit 54 and (FIG. 9) consisting, according to the example, of at least three comparator circuits 55, 56, 57 (for example SIEMENS TCA 965) of which the outputs are associated with three relays 58, 59, 60.
  • the circuit 58 makes it possible to limit the speed of the servomotor 19 by interposing a series resistor R, and the circuits 59 and 60 define the direction of rotation ROT + and ROT- and l 'engine stop by presence at its terminals of the same polarity.
  • the comparator 55 receives the signal e 1 which it compares to two maximum and minimum byte values. These two values are sent to the comparator 57 which receives the values of e 1 and e 2 .
  • One of the relays. 59 of the motor circuit is actuated by the signal e 1 > e 2 + ⁇ 1 , ⁇ 1 being the tripping value, the other relay 60 is actuated by the signal e 1 ⁇ e 2 - ⁇ 1 .
  • the motor finds the same polarity at its terminals and remains stationary, otherwise it turns in one direction or the other.
  • Comparator 56 compares the absolute value of the difference in signals e 1 and e 2 with a trigger value ⁇ 2 to put or remove a speed limitation resistor on the motor circuit.
  • the tangential speed of the drive wheel varied automatically with its orientation, that is to say that the drive device included a spherical wheel driven by a roller 21 at constant speed, as previously described.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)

Abstract

L'ensemble est formé d'un dispositif d'entraînement (1) et d'un détecteur de position de bord (36). Le dispositif comporte une roue d'entraînement (9) sphérique mobile selon deux axes perpendiculaires. Un galet d'entraînement (21) commande la rotation de la roue dans un plan vertical et un arbre (14), sa rotation dans un plan horizontal. Des moyens de mesure de position angulaire (18) et des moyens de commande de rotation (19) sont prévus à l'extrémité de l'arbre (14) qui porte l'axe de la roue. Le détecteur est formé d'une barrette de diodes photo-électriques (36), d'une source lumineuse (38) et de circuits électroniques délivrant un signal de commande du dispositif d'entraînement.The assembly consists of a drive device (1) and an edge position detector (36). The device comprises a spherical drive wheel (9) movable along two perpendicular axes. A drive roller (21) controls the rotation of the wheel in a vertical plane and a shaft (14), its rotation in a horizontal plane. Angular position measuring means (18) and rotation control means (19) are provided at the end of the shaft (14) which carries the axis of the wheel. The detector consists of a strip of photoelectric diodes (36), a light source (38) and electronic circuits delivering a control signal from the drive device.

Description

L'invention concerne un ensemble de guidage de feuilles de matériau souple destinées à former un assemblage tridimensionnel, ledit ensemble comportant un dispositif d'entrainement formé d'au moins une plaque d'appui, une roue d'entrainement appuyant une feuille à guider sur la plaque d'appui, des moyens de commande de la roue d'entrainement, et un détecteur de position du bord de la feuille pour la commande du dispositif d'entraînement, ledit détecteur comportant au moins un détecteur photoélectrique disposé devant le bord, servant au guidage de la pièce d'étoffe et des circuits électroniques, transformant le signal délivré par le détecteur photoélectrique en un signal de commande du dispositif d'entraînement.The invention relates to an assembly for guiding sheets of flexible material intended to form a three-dimensional assembly, said assembly comprising a drive device formed by at least one support plate, a drive wheel pressing a sheet to be guided on the support plate, drive wheel control means, and a sheet edge position detector for controlling the drive device, said detector comprising at least one photoelectric detector disposed in front of the edge, serving guiding the piece of fabric and the electronic circuits, transforming the signal delivered by the photoelectric detector into a control signal from the drive device.

L'assemblage de pièces souples selon une forme tridimensionnelle se rencontre principalement dans les industries de l'habillement. En effet la confection de vêtements consiste à assembler des pièces d'étoffe plus ou moins déformables pour former une surface destinée à recouvrir un volume. L'assemblage est réalisé pour les étoffes, quelle que soit leur texture, par couture. Deux cas peuvent se présenter selon que l'on peut ou non superposer les pièces préalablement à la couture.The assembly of flexible parts in a three-dimensional shape is mainly encountered in the clothing industries. Indeed, the confection of clothes consists in assembling pieces of fabric more or less deformable to form a surface intended to cover a volume. The assembly is carried out for fabrics, whatever their texture, by sewing. Two cases can arise depending on whether or not the pieces can be superimposed before sewing.

Dans le premier cas, c'est une couture classique, qui, lorsqu'elle est faite, laisse les pièces assemblées, planes. Dans le second cas, on est obligé de guider séparément chacune des pièces sous l'aiguille et une fois la couture exécutée on ne peut plus mettre les pièces assemblées à plat sans qu'il se produise des plis sur au moins une des pièces. Cet assemblage donne une surface tridimensionnelle et se retrouve, par exemple, dans les bonnets de soutiens-gorge.In the first case, it is a classic seam, which, when made, leaves the assembled pieces, flat. In the second case, it is necessary to guide each of the pieces separately under the needle and once the sewing has been carried out, the assembled pieces can no longer be laid flat without folds occurring on at least one of the pieces. This assembly gives a three-dimensional surface and is found, for example, in the cups of bras.

Les machines à coudre classiques comportent généralement une mécanique réalisant l'entre-bouclage du ou des fils de couture et une mécanique d'avance de l'étoffe. Cette mécanique d'avance est constituée d'une griffe à mouvement elliptique et d'un pied presseur entre lesquels passe l'étoffe.Conventional sewing machines generally include a mechanism providing the inter-looping of the sewing thread (s) and a mechanism for advancing the fabric. This advance mechanism consists of an elliptical movement claw and a presser foot between which the fabric passes.

L'amplitude longitudinale du déplacement de la griffe détermine la longueur du point de couture et est généralement réglable.The longitudinal amplitude of the claw movement determines the length of the stitch and is generally adjustable.

Le guidage des pièces à assembler se fait par rapport à leurs bords que l'opérateur superpose le plus exactement possible.The parts to be assembled are guided relative to their edges which the operator superimposes as exactly as possible.

Normalement une machine à coudre n'est capable de réaliser qu'une couture droite. Pour obtenir une couture courbe il faut superposer à l'avance, donnée par la griffe de la machine, un mouvement de rotation autour de l'aiguille. Ces modifications de trajectoire doivent être menées simultanément sur chacune des pièces à assembler.Normally a sewing machine is only able to make a straight seam. To obtain a curved seam it is necessary to superimpose in advance, given by the claw of the machine, a rotational movement around the needle. These trajectory modifications must be carried out simultaneously on each of the parts to be assembled.

On connaît des machines automatiques permettant de réaliser une couture à une distance donnée d'un bord courbe d'une pièce d'étoffe. Ces machines comportent un actionneur qui vient en contact de la pièce à guider et lui imprime un mouvement dont une composante a pour effet de la faire tourner autour de l'aiguille.Automatic machines are known which make it possible to sew at a given distance from a curved edge of a piece of fabric. These machines include an actuator which comes into contact with the part to be guided and gives it a movement, a component of which has the effect of causing it to rotate around the needle.

Les actionneurs peuvent revêtir de nombreuses formes, toutefois il semble que seuls les actionneurs à griffes et à roue ont eu quelques développements, avec une préférence pour ces derniers dont la mise en oeuvre est plus aisée.Actuators can take many forms, however it seems that only claw and wheel actuators have had some developments, with a preference for the latter, the implementation of which is easier.

Les actionneurs à roue de la technique connue peuvent être répartis en deux groupes : ceux à roue libre et direction fixe, et ceux à roue commandée et direction fixe.The wheel actuators of the known technique can be divided into two groups: those with free wheel and fixed direction, and those with controlled wheel and fixed direction.

Le brevet français No. 2.241.648 décrit un actionneur du premier groupe dont la roue libre fait un certain angle avec la direction d'avance de la pièce d'étoffe de manière à imprimer à celle-ci un mouvement de rotation, limité par la butée du bord de l'étoffe le long d'un guide dont la courbure correspond à l'orientation nécessaire à la formation d'une couture d'assemblage tridimensionnel, la deuxième pièce d'étoffe, étant éventuellement guidée par un même dispositif.French Patent No. 2,241,648 describes an actuator of the first group whose free wheel makes an angle with the direction of advance of the piece of fabric so as to impart thereto a rotational movement, limited by the abutment of the edge of the fabric along a guide whose curvature corresponds to the orientation necessary for the formation of a three-dimensional assembly seam, the second piece of fabric, possibly being guided by the same device.

Ce procédé présente un certain nombre d'inconvénients parmi lesquels il faut signaler une utilisation limitée à des étoffes suffisamment rigides pour que leur bord puisse être effectivement guidé par le guide, et la nécessité d'avoir autant de guides que de modèles de confection et de tailles.This process has a certain number of drawbacks among which it is necessary to point out a use limited to fabrics sufficiently rigid so that their edge can be effectively guided by the guide, and the need to have as many guides as there are tailoring models and sizes.

Ces inconvénients ne se retrouvent pas avec un actionneur à roue commandée, tel que décrit, par exemple, dans le brevet français No. 2.518.134. La roue, dont l'axe de rotation est parallèle à-la direction d'avance du tissu, est susceptible d'être mise en rotation dans un sens ou dans l'autre selon l'information transmise par un détecteur de position des bords de la pièce d'étoffeo Le dispositif de guidage comporte en outre des moyens de réglage de la pression de la roue sur l'étoffe de manière à assurer une pression de contact fonction entre autre de la matière, de l'épaisseur et du tissage.These disadvantages are not found with an actuator with a controlled wheel, as described, for example, in French patent No. 2,518,134. The wheel, whose axis of rotation is parallel to the direction of advance of the fabric, is capable of being rotated in one direction or the other according to the information transmitted by a position detector of the edges of the piece of cloth The guiding device furthermore comprises means for adjusting the pressure of the wheel on the cloth so as to ensure a contact pressure which depends, among other things, on the material, the thickness and the weaving.

Le détecteur de position comporte au moins un détecteur photoélectrique disposé devant une des faces d'une plaque destinée à séparer, pour permettre leur positionnement, deux pièces d'étoffe à assembler par couture.The position detector comprises at least one photoelectric detector disposed in front of one of the faces of a plate intended to separate, to allow their positioning, two pieces of fabric to be assembled by sewing.

Le détecteur photoélectrique est composé de deux paires de diodes luminescentes et de photo-transistors. La position de référence, à partir de laquelle on vérifie la position du bord de l'étoffe, est celle pour laquelle le bord est centré entre les deux diodes. Ainsi on a dans la position de référence, la lumière émise par la première diode et réfléchie par la plaque de séparation qui est interrompue par l'étoffe avant d'être reçue par le photo-transistor correspondant tandis que celle émise par la deuxième diode et réfléchie par la plaque est reçue par le photo-transistor correspondant. Un deuxième détecteur photo-éléctrique semblable est monté sur l'autre face de la plaque de séparation pour détecter le bord de la deuxième pièce d'étoffeoThe photoelectric detector is made up of two pairs of light-emitting diodes and photo-transistors. The reference position, from which the position of the edge of the fabric is checked, is that for which the edge is centered between the two diodes. Thus, in the reference position, there is the light emitted by the first diode and reflected by the separation plate which is interrupted by the fabric before being received by the corresponding photo-transistor while that emitted by the second diode and reflected by the plate is received by the corresponding photo-transistor. A second similar photoelectric detector is mounted on the other side of the separation plate to detect the edge of the second piece of fabric.

Les signaux électriques fournie par les détecteurs photo-électriques sont envoyés dans un dispositif électronique à processeur qui corpare les signaux reçus pour chaque pièce d'étoffe avec des valeurs de référence stockées en mémoire et agit sur les circuits d'entraînement des moteurs d'un dispositif de guidage des pièces d'étoffe.The electrical signals supplied by the photoelectric detectors are sent into an electronic processor device which matches the signals received for each piece of fabric with reference values stored in memory and acts on the drive circuits of the motors of a device for guiding pieces of fabric.

La commande de la rotation de la roue par le détecteur de position, basée sur une réponse par tout ou rien, produit des modifications de trajectoire relativement importantes et de courtes amplitudes qui créent un froissement de l'étoffe lors du chargement de direction et ne permet pas d'obtenir des coutures courbes de faible rayon.Controlling the rotation of the wheel by the position sensor, based on an all-or-nothing response, produces relatively large trajectory changes and short amplitudes which create wrinkling of the fabric when loading steering and does not allow not get curved seams of small radius.

L'utilisation d'un détecteur photo-électrique faisant appel à un faisceau lumineux large permettrait la mesure du taux de surface occultée et fournirait en conséquence un signal analogique qui serait proportionnel à la position du bord à deux conditions : que l'étoffe soit de transparence uniforme et que le rayon lumineux soit réparti uniformément selon une zone allongée perpendiculaire au bord de l'étoffe.The use of a photoelectric detector using a wide light beam would allow the measurement of the occulted surface rate and would consequently supply an analog signal which would be proportional to the position of the edge under two conditions: that the fabric be uniform transparency and that the light ray is distributed uniformly according to an elongated area perpendicular to the edge of the fabric.

Le dispositif analogique, pas plus que le système logique (tout ou rien) ne permettent de traiter des étoffes de transparence irrégulière telles que la dentelle, le tulle, ou les étoffes imprimées à fortes variations de densité.The analog device, no more than the logic system (all or nothing) does not allow the treatment of fabrics of irregular transparency such as lace, tulle, or printed fabrics with strong variations in density.

Les étoffes ajourées présentent,après découpe, des bords très déchiquetés et à la limite, dans le cas des tulles, des fils séparés par des espaces supérieurs à leur diamètre. La présence de lacunes à l'intérieur de l'étoffe dans le champ du détecteur photo-électrique empêche l'utilisation de capteurs anlogiques simples mesurant le taux de surface occultée. Le défilement du bord d'une étoffe ajourée devant un capteur supposé capable de détecter la position précise du bord apparent et non pas de la découpe va donner un signal analogique reproduisant les fluctuations de ce bord apparent. Ces fluctuations sont dues au déplacement de la ligne ce découpe devant le capteur et à la présence de lacunes de l'étoffe le long de cette ligne. Il faut donc savoir distinguer ces deux causes afin de reconstituer la ligne de découpe que doit suivre la couture.The openwork fabrics have, after cutting, very jagged edges and, in the case of tulle, in the case of threads separated by spaces greater than their diameter. The presence of gaps inside the fabric in the field of the photoelectric detector prevents the use of simple analog sensors measuring the level of obscured surface. The scrolling of the edge of an openwork fabric in front of a supposed sensor capable of detecting the precise position of the apparent edge and not of the cut will give an analog signal reproducing the fluctuations of this apparent edge. These fluctuations are due to the displacement of the line that cut in front of the sensor and to the presence of gaps in the fabric along this line. We must therefore be able to distinguish these two causes in order to reconstruct the cutting line that the seam must follow.

L'invention a pour objet un ensemble de guidage dont le dispositif d'entraînement comporte une roue d'entraînement orientable en fonction de la courbure désirée, dont la vitesse de rotation est asservie mécaniquement à son orientation et dont le détecteur de position du bord permet, à partir de la détection du bord apparent de l'étoffe, de reconstituer la ligne de découpe parallèlement à laquelle la couture doit être exécutée.The subject of the invention is a guide assembly the drive device of which comprises a drive wheel which can be oriented as a function of the desired curvature, the speed of rotation of which is mechanically controlled by its orientation and the edge position detector of which allows , from the detection of the apparent edge of the fabric, to reconstruct the cutting line parallel to which the seam is to be executed.

Les explications et figures données ci-après à titre d'exemple permettront de comprendre comment l'invention peut être réalisée.

  • La figure 1 représente une vue de face c'une machine à coudre équipée de l'ensemble de guidage, comprenant un dispositif d'entrai- nement et un détecteur de bord, selon l'invention.
  • La figure 2 est une vue à plus grande échelle du dispositif d'entraînement.
  • La figure 3 est une vue selon III-III de la figure 2.
  • La figure 4 est un schéma de principe montrant la variation de vitesse de la roue en fonction de son orientationo
  • La figure 5 montre une construction géométrique de principe expliquant le fonctionnement de l'ensemble de guidage.
  • La figure 6 est un exemple de courbes selon lequel est réalisé un assemblage.
  • La figure 7 représente le schéma synoptique du dispositif électronique destiné à traiter les signaux du détecteur de bord pour le suivi du contour de la découpe et, dans le cas d'étoffes ajourées, à corriger les signaux de ceux des contours des lacunes avant leur utilisation pour la commande du dispositif d'entraînement des pièces d'étoffe.
  • La figure 8 présente les chronogrammes des différents signaux obtenus à la sortie des circuits représentés sous forme de blocs à la figure 2.
  • La figure 9 est un schéma du circuit de commande du dispositif d'entraînement.
The explanations and figures given below by way of example will make it possible to understand how the invention can be implemented.
  • FIG. 1 represents a front view of a sewing machine equipped with the guide assembly, comprising a drive device and an edge detector, according to the invention.
  • Figure 2 is an enlarged view of the drive device.
  • Figure 3 is a view along III-III of Figure 2.
  • Figure 4 is a block diagram showing the speed variation of the wheel as a function of its orientationo
  • Figure 5 shows a geometric construction in principle explaining the operation of the guide assembly.
  • FIG. 6 is an example of curves according to which an assembly is produced.
  • FIG. 7 represents the block diagram of the electronic device intended to process the signals of the edge detector for monitoring the contour of the cutout and, in the case of openwork fabrics, to correct the signals of those of the contours of the gaps before their use for controlling the device for driving the fabric pieces.
  • FIG. 8 presents the timing diagrams of the various signals obtained at the output of the circuits represented in the form of blocks in FIG. 2.
  • Figure 9 is a diagram of the drive device control circuit.

Les figures 1 à 3 représentent une machine à coudre équipée d'un ensemble de guidage comportant un un dispositif d'entrainement M et un détecteur de bord N.Figures 1 to 3 show a sewing machine equipped with a guide assembly comprising a a training device M and an edge detector N.

Le dispositif d'entrainement est montré à plus grande échelle figure 2, monté sur une tête de machine contenant le mécanisme d'actionnement de la tige d'aiguille 2 à l'extrémité de laquelle est fixée l'aiguille 3 et le mécanisme abaisseur et releveur du pied presseur 4.The drive device is shown on a larger scale in FIG. 2, mounted on a machine head containing the mechanism for actuating the needle rod 2 at the end of which is fixed the needle 3 and the lowering mechanism and presser foot lifter 4.

La tête comporte en outre le mécanisme d'amenée et de guidage du fil à l'aiguille (non représenté).The head further includes the mechanism for feeding and guiding the needle thread (not shown).

De manière connue, la table 5 (figure 3) porte la plaque à aiguille 6 dans laquelle sont prévues des ouvertures pour le passage des moyens d'avance constitués par la griffe 7 et un trou de passage d'aiguille 8. La griffe est animée d'un mouvement alternatif qui amène les dents à faire saillie périodiquement de la plaque simultanément avec leur déplacement de l'avant vers l'arrière de la machine (pour un observateur regardant la machine selon la figure 1), le retour de la griffe s'effectuant, les dents étant au-dessous de la plaque. La table porte également le mécanisme de formation du point par entre-bouclage du fil de l'aiguille avec le fil de canette.In known manner, the table 5 (FIG. 3) carries the needle plate 6 in which are provided openings for the passage of the feed means constituted by the claw 7 and a needle passage hole 8. The claw is animated with an alternating movement which causes the teeth to periodically protrude from the plate simultaneously with their movement from the front to the rear of the machine (for an observer looking at the machine according to FIG. 1), the return of the claw s performing, the teeth being below the plate. The table also carries the stitch formation mechanism by interlocking the needle thread with the bobbin thread.

Les pièces de l'étoffe à assembler par couture sont introduites une fois positionnées sur la plaque à aiguille où elles sont maintenues par la pression du pied presseur relevable.The pieces of the fabric to be assembled by sewing are introduced once positioned on the needle plate where they are held by the pressure of the lifting presser foot.

La synchronisation des divers mouvements des pièces mécaniques de la machine est conçue de manière que lorsque l'aiguille traverse les pièces de l'étoffe pour faire le bouclage des fils de couture, celles-ci sont maintenues immobiles. Lorsque cette opération est terminée et que l'aiguille remonte et sort de l'étoffé, la griffe fait saillie de la plague à aiguille et vient appuyer l'étoffe contre le pied presseur et l'entraîner vers l'arrière en amenant entre le pied presseur et la plaque à aiguille une longueur d'étoffe correspondant à la longueur du point.The synchronization of the various movements of the mechanical parts of the machine is designed so that when the needle passes through the parts of the fabric to loop the sewing threads, these are kept stationary. When this operation is finished and the needle rises and leaves the fabric, the claw protrudes from the needle plague and presses the fabric against the presser foot and drives it backwards, bringing between the foot presser and needle plate a length of fabric corresponding to the length of the stitch.

Lorsque le guidage des pièces d'étoffe doit aboutir à la formation d'une couture non rectiligne, il faut déplacer la ou les pièces d'étoffe autour de l'aiguille en prenant celle-ci comme centre de rotation. Ce guidage ne peut être effectué, que lorsque l'aiguille est en position basse, dans la phase de formation du bouclage des fils.When the guiding of the pieces of fabric must result in the formation of a non-rectilinear seam, it is necessary to move the piece or pieces of fabric around the needle by taking this one as center of rotation. This guidance can only be carried out when the needle is in the low position, in the phase of forming the looping of the threads.

Selon la forme de réalisation représentée le dispositif d'entraînement, selon l'invention,est positionné en avant de la plaque à aiguille, et comporte une roue sphérique 9 qui appuie sur une des pièces d'étoffe à guider. La roue est mobile librement autour d'un axe 10, parallèle à la surface de l'étoffe, fixée par une de ses extrémités sur une aile 11 d'une équerre 12 dont l'autre aile 13 est fixée à un arbre 14, mobile autour de son axe dans des paliers 15, 16 fixés à un bâti fixe 17. L'arbre 14 et l'axe 10 de la roue sont selon l'exemple de réalisation perpendiculaires et l'axe de l'arbre 14 passe par le centre de la roue sphérique.According to the embodiment shown, the drive device according to the invention is positioned in front of the needle plate, and comprises a spherical wheel 9 which presses on one of the pieces of fabric to be guided. The wheel is freely movable around an axis 10, parallel to the surface of the fabric, fixed by one of its ends on a wing 11 of a bracket 12 whose other wing 13 is fixed to a shaft 14, mobile around its axis in bearings 15, 16 fixed to a fixed frame 17. The shaft 14 and the axis 10 of the wheel are, according to the embodiment, perpendicular and the axis of the shaft 14 passes through the center of the spherical wheel.

L'arbre 14 est muni d'un dispositif de mesure de position angulaire 18 constitué, par exemple, d'un potentiomètre circulaire et porte à son extrémité libre des moyens de commande de rotation constitués d'un servo-moteur 19 commandé par un dispositif électronique de détection de bord qui sera ultérieurement décrit. Les stators des potentiomètre et servo-moteur sont fixés par une entretoise 20 au bâti fixe 17.The shaft 14 is provided with an angular position measuring device 18 consisting, for example, of a circular potentiometer and carries at its free end rotation control means consisting of a servo motor 19 controlled by an electronic edge detection device which will be described later. The stators of the potentiometer and servo-motor are fixed by a spacer 20 to the fixed frame 17.

La roue 9 est entrainée en rotation autour de son axe 10 par un galet 21 dont l'axe 22 se trouve dans un plan contenant l'axe 10 de la roue, de préférence dans le - plan horizontal orthogonal à l'arbre 14. Le galet occupe une position fixe par rapport au bâti 17 sur lequel il est maintenu par un palier.The wheel 9 is rotated about its axis 10 by a roller 21 whose axis 22 is in a plane containing the axis 10 of the wheel, preferably in the - horizontal plane orthogonal to the shaft 14. The roller occupies a fixed position relative to the frame 17 on which it is held by a bearing.

Selon l'exemple de réalisation représenté, le galet est entraîné en rotation par une transmission mécanique constituée au moins en partie d'un ensemble de poulies 23, 24 et de courroie 25. Cet ensemble est lui-même entrainé par une transmission 26 relié directement ou indirectement à une prise de mouvement 27 sur l'arbre principal de la machine. La vitesse de rotation ainsi communiquée au galet est liée à celle de la machine et par conséquent est fonction de la vitesse d'avance des pièces sous le mécanisme de formation de la couture.According to the embodiment shown, the roller is rotated by a mechanical transmission consisting at least in part of a set of pulleys 23, 24 and belt 25. This set is itself driven by a transmission 26 connected directly or indirectly to a power take-off 27 on the main shaft of the machine. The speed of rotation thus communicated to the roller is linked to that of the machine and therefore is a function of the speed of advance of the parts under the seam forming mechanism.

Le galet 21 entraine la roue sphérique 9 selon des cercles dont le diamètre dépend de l'orientation de celle-ci. L'entraînement de la pièce d'étoffe se faisant toujours en un même point situé sur un grand cercle de la roue, la vitesse en ce point variera d'une manière inversement proportionnelle au diamètre de cercle le long duquel le galet entrainera la roue.The roller 21 drives the spherical wheel 9 in circles whose diameter depends on the orientation of the latter. As the piece of fabric is always driven at the same point situated on a large circle of the wheel, the speed at this point will vary inversely proportional to the diameter of the circle along which the roller will drive the wheel.

La figure 4 permet de comprendre le principe de la variation de la vitesse d'entraînement en fonction de la position de la roue devant le galet dont la vitesse est considérée comme constante.FIG. 4 makes it possible to understand the principle of the variation of the drive speed as a function of the position of the wheel in front of the roller whose speed is considered constant.

On a représenté dans une première position I (en trait plein) la roue sphérique 9 orientée de manière que son plan de symétrie soit confondu avec le plan de symétrie du galet 21. Le galet attaque la roue selon son grand cercle de rayon R pour lui communiquer une vitesse tangentielle, représentée par le vecteur Vo, égale à un coefficient près k à la vitesse constante Vg du galet (k Vg =Vo).The spherical wheel 9 is oriented in a first position I (in solid lines) oriented so that its plane of symmetry is coincident with the plane of symmetry of the roller 21. The roller attacks the wheel according to its large circle of radius R for it communicate a tangential speed, represented by the vector Vo, equal to a coefficient near k at the constant speed Vg of the roller (k Vg = Vo).

Dans une deuxième position II (en trait interrompu) le plan de symétrie vertical de la roue est tourné, par -exemple vers la droite, d'un angle a. l'axe de la roue, perpendiculaire au plan de symétrie, tourne également du même angle en présentant devant le galet 21 un cercle de rayon R1 inférieur à R et égal à R cos a. Il s'ensuit que la vitesse tangentielle au point de contact du grand cercle avec la pièce d'étoffe augmente et devient Y1 = Vo/cos a. Vo peut être considéré comme une composante de la vitesse V1 et a été choisie, pour des raisons qui seront ultérieurement développées, égale à la vitesse d'avance de la griffe et de même direction.In a second position II (broken line) the vertical plane of symmetry of the wheel is turned, for example to the right, by an angle a. the axis of the wheel, perpendicular to the plane of symmetry, also rotates by the same angle, presenting before the roller 21 a circle of radius R1 less than R and equal to R cos a. It follows that the tangential speed at the point of contact of the large circle with the piece of cloth increases and becomes Y 1 = Vo / cos a. Vo can be considered as a component of the speed V 1 and has been chosen, for reasons which will be developed later, equal to the speed of advance of the claw and in the same direction.

Selon une variante, l'entraînement mécanique synchrone du mouvement de l'arbre principal de la machine est remplacé par un servomoteur 230 (représenté en trait interrompu) permettant de communiquer à la roue, par l'intermédiaire du galet, une vitesse tangentielle produisant un entraînement de la pièce à guider à une vitesse dont une composante parallèle au sens de déplacement de la griffe est constante et égale à la vitesse d'avance des pièces à assembler.According to a variant, the synchronous mechanical drive of the movement of the main shaft of the machine is replaced by a servomotor 230 (shown in broken lines) making it possible to communicate to the wheel, via the roller, a tangential speed producing a drive of the part to be guided at a speed of which a component parallel to the direction of movement of the claw is constant and equal to the speed of advance of the parts to be assembled.

Afin de permettre l'orientation aisée de chaque pièce d'étoffe avant leur assemblage l'ensemble de guidage comporte un dispositif de séparation 28 constitué d'une plaque d'appui 29 comprise entre deux plaques supports 30, 31 disposées respectivement au-dessus et au-dessous de la plaque 29 et à une distance de la plaque d'appui, correspondant approximativement à l'épaisseur des pièces d'étoffe 32, 33 à assembler.To allow easy orientation of each piece of fabric before their assembly the guide assembly comprises a separation device 28 consisting of a support plate 29 comprised between two support plates 30 , 31 disposed respectively above and below the plate 29 and at a distance from the support plate, corresponding approximately to the thickness of the pieces of fabric 32, 33 to be assembled.

Les plaques supports portent une ouverture 34 assurant le passage de la roue du dispositif d'entrainement de la pièce d'étoffe, la roue étant en appui contre ladite pièce d'étoffeoThe support plates carry an opening 34 ensuring the passage of the wheel of the device for driving the piece of fabric, the wheel being in abutment against said piece of fabric.

Selon une application du dispositif d'entraînement à un ensemble de guidage d'une machine à coudre, on prévoit le guidage de chacune des pièces d'étoffe devant être assemblées. La pièce d'étoffe 33 passant entre la plaque support 31 et la plaque d'appui 29 est guidée par un dispositif en tout point semblable au premier, qui est suggéré sur la figure 2 par une portion de roue 35 représentée en trait mixte, disposé éventuellement à l'opposé du premier par rapport à la plaque d'appui.According to an application of the drive device to a guide assembly of a sewing machine, provision is made for guiding each of the pieces of fabric to be assembled. The piece of fabric 33 passing between the support plate 31 and the support plate 29 is guided by a device at all points similar to the first, which is suggested in FIG. 2 by a portion of wheel 35 shown in phantom, arranged possibly opposite the first with respect to the support plate.

Le guidage des pièces d'étoffe se fait, comme connu, par leurs bords : au moins un des bords étant coupé selon la courbe, projetée sur le plan de l'étoffe, de l'assemblage désiré et servant de repère. L'ensemble de guidage comporte également un détecteur de bord B qui comprend des moyens de détection du bord formés par un photodétecteur proportionnel 36 qui sera ultérieurement décrit.The pieces of fabric are guided, as known, by their edges: at least one of the edges being cut along the curve, projected onto the plane of the fabric, of the desired assembly and serving as a reference. The guide assembly also includes an edge detector B which comprises edge detection means formed by a proportional photodetector 36 which will be described later.

Les signaux fournis par le photodétecteur 36 sont envoyés dans un dispositif électronique qui détecte la provenance des signaux et génère un signal qui est envoyé dans un comparateur dont une des entrées reçoit un signal de référence prenant compte l'orientation de la roue donnée par le potentiomètre 18. Le signal résultant commande un dispositif d'asservissement comportant le servo- moteur 19 qui commande l'orientation de la roue 9 devant le galet 21.The signals provided by the photodetector 36 are sent to an electronic device which detects the source signals and generates a signal which is sent to a comparator one of whose inputs receives a reference signal taking into account the orientation of the wheel given by the potentiometer 18. The resulting signal controls a servo device comprising the servomotor 19 which controls the orientation of the wheel 9 in front of the roller 21.

La figure 5 est une construction géométrique permettant de comprendre le fonctionnement du dispositif de guidage.Figure 5 is a geometric construction for understanding the operation of the guide device.

Les droites D et E correspondent respectivement à une couture droite obtenue en maintenant constante la distance e du bord rectiligne E de la pièce d'étoffe à l'aiguille AoThe straight lines D and E correspond respectively to a straight seam obtained by keeping constant the distance e from the straight edge E of the piece of fabric to the needle Ao

Cette pièce d'étoffe est entraînée par la griffe disposée en amont de l'aiguille, à une vitesse Vo qui est représentée en intensité et direction par le vecteur Vo appliqué approximativement au point A, comme il sera expliqué ultérieurement.This piece of fabric is driven by the claw disposed upstream of the needle, at a speed Vo which is represented in intensity and direction by the vector Vo applied approximately to point A, as will be explained later.

Le suivi d'une ligne courbe se fait en superposant un mouvement de rotation de l'étoffe à l'avance donnée par la griffe. L'étoffé supposée plan rigide, est dotée d'un champ de vitesse qui peut s'exprimer par la rotation autour d'un centre instantané de rotation 01., 02, 03... Ce centre instantané se situe à l'intersection de toutes les perpendiculaires aux vecteurs vitesse en chaque point de l'étoffe. En particulier, la perpendiculaire XX' au vecteur vitesse Vo donnée par la griffe est une constante quelle que soit la courbure de la couture puisque cette vitesse est tangente à la couture par définition. Le centre instantané de rotation est donc toujours sur cette perpendiculaire. On supposera que cette perpendiculaire passe par l'aiguille A, ce qui n'est vrai qu'approximativement.The tracking of a curved line is done by superimposing a rotational movement of the fabric in advance given by the claw. The supposedly rigid fabric has a velocity field which can be expressed by rotation around an instantaneous center of rotation 0 1. , 0 2 , 0 3 ... This instantaneous center is located at l intersection of all the perpendiculars to the velocity vectors at each point of the fabric. In particular, the perpendicular XX 'to the speed vector Vo given by the claw is a constant whatever the curvature of the seam since this speed is tangent to the seam by definition. The instantaneous center of rotation is therefore always on this perpendicular. We will assume that this perpendicular passes through needle A, which is not true only approximately.

Pour définir le champ de vitesse voulu, on applique en un point B, autre que l'aiguille A, par l'intermédiaire de la roue 9, une vitesse définie en orientation et intensité par un vecteur V1 par exempleoTo define the desired speed field, at a point B, other than the needle A, is applied via the wheel 9, a speed defined in orientation and intensity by a vector V1 for example

Afin d'éviter une déformation du plan de l'étoffe entre les points d'entraînement A et B, il faut que le vecteur V1 ait une composante V'o de mêmes orientation et intensité que le vecteur Vo appliqué au point A. Cette composante Vo a pour valeur V1 cos a = Vo. L'angle α est l'angle que fait le plan diamétral de la roue passant par le point d'application B, c'est également l'angle que fait l'axe horizontal de la roue avec la droite XX', le point d'intersection O1 étant un centre instantané de rotation. Le point O1 est le centre d'une courbe C1 de rayon égal à O1 F, F étant le point d'intersection du bord de l'étoffe avec la droite XX'.In order to avoid a deformation of the plane of the fabric between the drive points A and B, the vector must be V1 have a component Yo with the same orientation and intensity as the vector Vo applied to point A. This component Vo is worth V1 cos a = Vo . The angle α is the angle made by the diametrical plane of the wheel passing through the point of application B, it is also the angle made by the horizontal axis of the wheel with the line XX ', the point d intersection O 1 being an instantaneous center of rotation. The point O 1 is the center of a curve C 1 of radius equal to O 1 F, F being the point of intersection of the edge of the fabric with the line XX '.

Une modification du rayon de courbure de la couture sera obtenue par modification de l'orientation et de l'intensité du vecteur vitesse V1. Par exemple, la courbe C2 sera obtenue par l'application d'un nouveau vecteur vitesse V2 qui entraînera un déplacement du centre instantané de rotation en O2.A modification of the radius of curvature of the seam will be obtained by modification of the orientation and intensity of the speed vector V1 . For example, the curve C 2 will be obtained by the application of a new speed vector V2 which will cause a displacement of the instantaneous center of rotation in O 2 .

Il est à remarquer que, selon l'exemple de réalisation, l'orientation de la roue est limitée de part et d'autre de la direction BH à un angle inférieur à 45° dépendant de l'importance de l'axe horizontal autour duquel tourne la roue. Selon d'autres réalisations, cet angle peut être plus ou moins grand, suivant l'importance de la partie sphérique de la roue.It should be noted that, according to the exemplary embodiment, the orientation of the wheel is limited on either side of the direction BH to an angle less than 45 ° depending on the importance of the horizontal axis around which spin the wheel. According to other embodiments, this angle can be greater or less, depending on the size of the spherical part of the wheel.

Lorsque le vecteur vitesse est orienté dans la partie droite de la portion du plan limité par la droite BH, les courbes obtenues seront convexes. Lorsqu'il est orienté dans la partie gauche, les courbes obtenues sont concavesoWhen the speed vector is oriented in the right part of the portion of the plane limited by the line BH, the curves obtained will be convex. When oriented in the left part, the curves obtained are concaveso

Un exemple de ce dernier cas correspond au vecteur V3.An example of the latter case corresponds to the vector V3 .

Le centre instantané de rotation est alors en 03 et la courbe concave C3 est obtenue. Il est évident que ce dernier cas a une valeur d'exemple et ne peut s'appliquer qu'à une couture d'assemblage plan et non tridimensionnel. La figure 6 illustre les coutures courbes obtenues avec les différents centres instantanés de rotation.The instantaneous center of rotation is then at 0 3 and the concave curve C 3 is obtained. It is obvious that the latter case has an exemplary value and can only be applied to a flat, not three-dimensional, assembly seam. Figure 6 illustrates the curved seams obtained with the different instantaneous centers of rotation.

Le détecteur de bord P doit être positionné de manière que les cellules photodétectrices se trouvent de part et d'autre du trajet théorique du bord de la pièce à guider. Leur position détermine la distance "e" entre la couture et le bord du tissu. Si la couture doit présenter une successsion de courbures différentes , la position des cellules doit théoriquement être modifiées en fonction de l'avancement de la couture pour garder e constant. Un résultat équivalent peut être obtenu en utilisant une rangée de cellules dont seules les deux cellules entourant le trajet théorique du bord pour la courbure désirée sont activées. Dans la pratique, la précision recherchée ne nécessite souvent pas cette correction.The edge detector P must be positioned so that the photodetector cells are on either side of the theoretical path of the edge of the part to be guided. Their position determines the distance "e" between the seam and the edge of the fabric. If the seam must have a succession of different curvatures, the position of the cells must theoretically be modified according to the progress of the seam to keep e constant. An equivalent result can be obtained using a row of cells of which only the two cells surrounding the theoretical path of the edge for the desired curvature are activated. In practice, the precision sought often does not require this correction.

Le choix du point d'entraînement B est dicté par la couture à faire et dépend de la distance de ce point au bord le plus proche. Il peut suivant la courbure de la couture à faire se trouver de l'autre côté de la droite D passant par l'aiguille.The choice of training point B is dictated by the seam to be made and depends on the distance from this point to the nearest edge. Depending on the curvature of the seam, it can be on the other side of the straight line D passing through the needle.

Cette position est aisément déterminée par l'homme de métier.This position is easily determined by the skilled person.

La position angulaire de la roue d'entrainement 9 est repérée par le potentiomètre 18 tandis que la position du bord de l'étoffe est repérée par le détecteur de position de bord B comportant,-selon la forme de réalisation représentée, le détecteur photoélectrique 36 disposé dans une enceinte 37 fixée au bras de la machine. Un miroir 38 transmet le faisceau lumineux sur la plaque d'appui 29 polie sur laquelle il se réfléchit. Le faisceau réfléchi tombe sur le capteur photoélectrique constitué d'une barrette de diodes montées sur un circuit intégré, suivant un pas de 0,1 mmo La barrette utilisée, dans l'application décrite comporte 64 diodes, ce qui permet une plage de visée de 6,4 mm jugée comme suffisante. La taille des diodes (0,1 mm) a été choisie de manière que leur largeur soit inférieure au diamètre des fils constituant l'étoffe et en particulier à ceux constituant le réseau de mailles du tulle ou de la dentelle. La place du fil peut doncêtre détectée à 0,1 mm près, ce qui est suffisant pour obtenir une précision de couture de ± 0,5 mm.The angular position of the drive wheel 9 is marked by the potentiometer 18 while the position of the edge of the fabric is marked by the edge position detector B comprising, - according to the embodiment shown, the photoelectric detector 36 disposed in an enclosure 37 fixed to the arm of the machine . A mirror 38 transmits the light beam on the polished support plate 29 on which it is reflected. The reflected beam falls on the photoelectric sensor consisting of a strip of diodes mounted on an integrated circuit, in a pitch of 0.1 mm. The strip used, in the described application has 64 diodes, which allows a range of sight of 6.4 mm deemed sufficient. The size of the diodes (0.1 mm) was chosen so that their width is less than the diameter of the threads constituting the fabric and in particular those constituting the mesh network of tulle or lace. The place of the thread can therefore be detected to the nearest 0.1 mm, which is sufficient to obtain a sewing precision of ± 0.5 mm.

Les rayons lumineux qui tombent sur l'étoffe sont diffusés avec une faible intensité tandis que ceux qui ! tombent à côté ou dans les lacunes sont réfléchis et concentrés par l'optique vers la barrette de diode. Il en résulte un ensemble de signaux faibles en face de l'étoffe et forts en dehors.The light rays which fall on the fabric are diffused with a weak intensity while those which! fall alongside or in the gaps are reflected and concentrated by the optics towards the diode array. The result is a set of weak signals in front of the fabric and strong outside.

Ces signaux sont traités pour trouver le bord puis la découpe, en tenant compte du fait que la forme du contour due à des lacunes peut être distinguée de celle due à la découpe par suite de la différence des rayons de courbure (quelques millimètres pour une lacune contre au minimum 30 millimètres pour la découpe) lors du défilement du bord devant la barrette de diodes, défilement dû au mouvement d'avance imprimé à l'étoffe par la griffe.These signals are processed to find the edge and then the cut, taking into account that the shape of the contour due to gaps can be distinguished from that due to the cut due to the difference in the radii of curvature (a few millimeters for a gap against at least 30 millimeters for cutting) when scrolling the edge in front of the diode array, scrolling due to the advance movement printed on the fabric by the claw.

L'état des différents diodes 36 (figure 7) est observé par un balayage cyclique cadencé par des signaux 40 d'une horloge et défini par des signaux de synchronisation 41 d'un multiplexeur 42 pour former un signal vidéo. Les chronogrammes des signaux, représentés figure 8, correspondent, afin de simplifier le schéma, à une barrette de dix photodiodes, alors que la réalisation utilise une barrette de 64 photodiodes.The state of the various diodes 36 (FIG. 7) is observed by a cyclic scan clocked by signals 40 from a clock and defined by synchronization signals 41 from a multiplexer 42 to form a video signal. The timing diagrams of the signals, shown in FIG. 8, correspond, in order to simplify the diagram, to a strip of ten photodiodes, while the embodiment uses a strip of 64 photodiodes.

Sur le signal vidéo, chaque niveau représente l'éclairement d'une photodiode. Le diagramme correspond à trois balayages successifs I, II, III déclenchés par les trois signaux de synchronisation A, B, C et à un seul déplacement de l'étoffe, c'est ce qui explique la modification du signal entre chaque synchronisation.On the video signal, each level represents the illumination of a photodiode. The diagram corresponds to three successive scans I, II, III triggered by the three synchronization signals A, B, C and a single movement of the fabric, which explains the modification of the signal between each synchronization.

Dans le premier balayage I, on peut observer deux niveaux faibles entre des niveaux plus élevés, les niveaux faibles correspondent à un trou d'une maille d'une dentelle.In the first scan I, two low levels can be observed between higher levels, the low levels correspond to a hole in a mesh of a lace.

L'absence de l'étoffe devrait donner un niveau zéro mais pratiquement le niveau n'est pas nul. Afin de séparer nettement les signaux correspondant à la présence ou à l'absence d'étoffe, on définit un seuil 43 auquel sont comparés les signaux. Le comparateur 44, qui reçoit le signal de seuil et le signal vidéo, sépare les niveaux et permet d'obtenir un signal tout ou rien 45.The absence of the material should give a zero level but practically the level is not zero. In order to clearly separate the signals corresponding to the presence or absence of fabric, a threshold 43 is defined against which the signals are compared. The comparator 44, which receives the threshold signal and the video signal, separates the levels and makes it possible to obtain an all-or-nothing signal 45.

La sortie du comparateur 44 est envoyée à un circuit bascule bi-stable 45. Lors du balayage de la barrette, la première présence de l'étoffe rencontrée génère un signai qui fait basculer le bistable à l'état 1 représenté sur la figure 8, celui-ci n'est remis à l'état 0 qu'en fin de balayage, c'est-à-dire à l'arrivée du prochain signal de synchronisation A. On ne fient, par conséquent, compte que du bord de l'étoffe et non des trous ! éventuels. Un circuit-porte 46 commandé par le signal de sortie du bistable laisse passer un nombre d'impulsions du signal horloge 40 proportionnel à la position de la première photodiode marquée par le bord de l'étoffe.The output of comparator 44 is sent to a bi-stable flip-flop circuit 45. When the bar is scanned, the first presence of the fabric encountered generates a signal. which switches the bistable to state 1 shown in FIG. 8, it is only returned to state 0 at the end of scanning, that is to say on the arrival of the next signal of synchronization A. We therefore only rely on the edge of the fabric and not the holes! possible. A gate circuit 46 controlled by the output signal of the bistable allows a number of pulses of the clock signal 40 proportional to the position of the first photodiode marked by the edge of the fabric to pass.

Un circuit de comptage 47, déclenché par un signal de synchronisation 41, détermine le nombre d'impulsions contenu dans chaque signal de sortie du bistable transitant par le circuit-porte 46, entre deux signaux de synchronisation 41. Le résultat du comptage est ensuite transféré dans un registre de transfert 48 par un circuit de commande de transfert 49, qui assure également la remise à zéro du compteur 47, commandé par le signal de synchronisation après décalage dans le temps.A counting circuit 47, triggered by a synchronization signal 41, determines the number of pulses contained in each output signal of the bistable passing through the gate circuit 46, between two synchronization signals 41. The result of the counting is then transferred in a transfer register 48 by a transfer control circuit 49, which also ensures the reset of the counter 47, controlled by the synchronization signal after time shift.

La valeur du comptage précédemment obtenue est traduite en tension par un convertisseur numérique analogique 50. On obtient ainsi un signal proportionnel à la distance séparant le bord de l'étoffe de l'extrémité de la barrette.The count value previously obtained is translated into voltage by a digital analog converter 50. A signal proportional to the distance separating the edge of the fabric from the end of the bar is thus obtained.

Ce signal de bord suit fidèlement la forme obtenue après la découpe y compris le contour des lacunes coupées par la ligne de découpe dans les étoffes ajourées.This edge signal faithfully follows the shape obtained after cutting, including the contour of the gaps cut by the cutting line in the openwork fabrics.

Un second traitement du signal est nécessaire pour reconstituer la ligne de découpe, et consistera à faire un suivi crête à crête du signal de bord, de manière à sauter les lacunes.A second signal processing is necessary to reconstruct the cutting line, and will consist in making a peak-to-peak tracking of the edge signal, so as to skip the gaps.

On a constaté que la courbure apparente de l'étoffe au niveau du capteur engendre des variations de signal très lentes devant celles qu'engendrent les lacunes. On peut donc limiter les variations du signal dans le sens du creux des lacunes suivant une valeur de pente correspondant à celle que l'on constate en cas de courbure apparente maximale qui est dans l'exemple de réalisation de 30 mm.It has been found that the apparent curvature of the fabric at the level of the sensor generates very slow signal variations compared to those caused by the gaps. It is therefore possible to limit the variations in the signal in the direction of the trough of the gaps according to a slope value corresponding to that which is observed in the event of maximum apparent curvature which is in the embodiment 30 mm.

Le signal analogique obtenu dans le premier traitement, est envoyé dans un circuit de correction 51 qui le transforme en signal crête. Cette correction est obtenue à partir de deux constantes de temps, une courte qui prend assez vite la valeur maximum, une plus longue qui permet de suivre la courbe minimum acceptable par le guidage de l'étoffeoThe analog signal obtained in the first processing is sent to a correction circuit 51 which transforms it into a peak signal. This correction is obtained from two time constants, a short one which quickly takes the maximum value, a longer one which allows the minimum acceptable curve to be followed by guiding the fabric.

Le signal obtenu à la sortie du circuit de correction 51 est envoyé dans un circuit de cadrage 52 où il est calibré et sort sous la forme d'un signal e2.The signal obtained at the output of the correction circuit 51 is sent to a framing circuit 52 where it is calibrated and exits in the form of a signal e 2 .

Le signal provenant du capteur de position angulaire 18 est également envoyé dans un circuit de cadrage 53 où il est calibré sous la forme d'un signal e1.The signal from the angular position sensor 18 is also sent to a framing circuit 53 where it is calibrated in the form of a signal e 1 .

Les signaux e1 et e2 sont envoyés dans un circuit de comparaison et de commande 54 et (figure 9) constitué, selon l'exemple, d'au moins trois circuits comparateurs 55, 56, 57 (par exemple SIEMENS TCA 965) dont les sorties sont associées à trois relais 58, 59, 60. Le circuit 58 permet de limiter la vitesse du servo-moteur 19 en intercalant une résistance série R, et les circuits 59 et 60 définissent le sens de rotation ROT+ et ROT- et l'arrêt moteur par présence à ses bornes d'une même polarité.The signals e 1 and e 2 are sent in a comparison and control circuit 54 and (FIG. 9) consisting, according to the example, of at least three comparator circuits 55, 56, 57 (for example SIEMENS TCA 965) of which the outputs are associated with three relays 58, 59, 60. The circuit 58 makes it possible to limit the speed of the servomotor 19 by interposing a series resistor R, and the circuits 59 and 60 define the direction of rotation ROT + and ROT- and l 'engine stop by presence at its terminals of the same polarity.

Le comparateur 55 reçoit le signal e1 qu'il compare à deux valeurs de bytée maximale et minimale. Ces deux valeurs sont envoyées sur le comparateur 57 qui reçoit les valeurs de e1 et e2. L'un des relais.59 du circuit moteur est actionné par le signal e1>e2+ε1,ε1 étant la valeur de déclenchement, l'autre relais 60 est actionné par le signal e1<e2-ε1.The comparator 55 receives the signal e 1 which it compares to two maximum and minimum byte values. These two values are sent to the comparator 57 which receives the values of e 1 and e 2 . One of the relays. 59 of the motor circuit is actuated by the signal e 1 > e 2 + ε 1 , ε 1 being the tripping value, the other relay 60 is actuated by the signal e 1 <e 2 -ε 1 .

Si les deux relais sont dans le même état, le moteur trouve une même polarité à ses bornes et reste immobile, autrement il tourne dans un sens ou dans l'autre.If the two relays are in the same state, the motor finds the same polarity at its terminals and remains stationary, otherwise it turns in one direction or the other.

Le comparateur 56 compare la valeur absolue de la différence des signaux e1 et e2 à une valeur de déclenchement ε2 pour mettre ou retirer une résistance de limitation de vitesse sur le circuit moteur.Comparator 56 compares the absolute value of the difference in signals e 1 and e 2 with a trigger value ε 2 to put or remove a speed limitation resistor on the motor circuit.

On a admis dans cet exemple de réalisation que la vitesse tangentielle de la roue d'entraînement variait automatiquement avec son orientation, c'est-à-dire que le dispositif d'entraînement comportait une roue sphérique entraînée par un galet 21 à vitesse constante, telle que décrite précédemment.It was admitted in this exemplary embodiment that the tangential speed of the drive wheel varied automatically with its orientation, that is to say that the drive device included a spherical wheel driven by a roller 21 at constant speed, as previously described.

Il est évident qu'un dispositif qui ne comporterait pas cette particularité nécessiterait un circuit d'alimentation du servo-moteur 230 de la roue d'entraînement, qui soit susceptible de délivrer une tension d'alimentation variable en fonction de l'orientation a de la roue.It is obvious that a device which does not include this feature would require a power supply circuit for the servo-motor 230 of the drive wheel, which is capable of delivering a variable supply voltage as a function of the orientation a wheel.

Claims (7)

1. Ensemble de guidage de feuilles de matériau souple destinés à former un assemblage tridimensionnel, ledit ensemble comportant un dispositif d'entraînement formé d'au moins une plaque d'appui, une roue d'entraînement appuyant une feuille à guider sur la plaque d'appui, des moyens de commande de la roue d'entraînement, et un détecteur de position du bord de la feuille, ledit détecteur comportant au moins un détecteur photo-électrique disposé devant le bord servant au guidage de la feuille et des circuits électroniques transformant le signal délivré par le détecteur en un signal de commande du dispositif d'entraînement,
caractérisé en ce que le dispositif d'entrainement comporte une roue d'entraînement (9) sphérique et mobile librement autour d'un axe (10) parallèle à la plaque d'appui (29) fixé par une de ses extrémités à une extrémité d'un arbre (14), mobile autour de son axe, dont le prolongement approximativement orthogonal à la plaque d'appui passe par le centre de la roue; un galet d'entratnement (21), d'axe parallèle à la plaque d'appui, commandant la rotation de la roue, l'arbre (14) et le galet (21) étant portés par un même bâti (17, 20); des moyens de mesure de position angulaire (18) et des moyens de commande rotation (19) sont prévus à l'autre extrémité de l'arbre (14).1. assembly for guiding sheets of flexible material intended to form a three-dimensional assembly, said assembly comprising a drive device formed of at least one support plate, a drive wheel pressing a sheet to be guided on the plate d support, drive wheel control means, and a sheet edge position detector, said detector comprising at least one photoelectric detector disposed in front of the edge serving to guide the sheet and transforming electronic circuits the signal delivered by the detector into a control signal from the drive device,
characterized in that the drive device comprises a spherical drive wheel (9) which can move freely around an axis (10) parallel to the support plate (29) fixed by one of its ends to one end d 'A shaft (14), movable around its axis, the extension of which is approximately orthogonal to the support plate passes through the center of the wheel; a drive roller (21), with an axis parallel to the support plate, controlling the rotation of the wheel, the shaft (14) and the roller (21) being carried by the same frame (17, 20) ; angular position measuring means (18) and rotation control means (19) are provided at the other end of the shaft (14). 2. Ensemble selon la revendication 1, caractérisé en ce que la roue d'entraînement (9) présente à son point de contact avec l'étoffe, une vitesse tangentielle variable (V1) en fonction du cosinus de l'angle (a) que fait son plan de symétrie, perpendiculaire à son axe, avec le plan de symétrie du galet d'entraînement (21) à vitesse constante (Vg).2. Assembly according to claim 1, characterized in that the drive wheel (9) has at its point of contact with the fabric, a variable tangential speed (V 1 ) as a function of the cosine of the angle (a) what does its plane of symmetry, perpendicular to its axis, with the plane of symmetry of the drive roller (21) at constant speed (V g ). 3. Ensemble selon la revendication 2, caractérisé en ce qu'une composante (V'o) du vecteur vitesse (V1) de la roue d'entrainement (9) est parallèle et égal au vecteur vitesse (Vo) des moyens d'avance (7).3. Assembly according to claim 2, characterized in that a component ( Yo ) of the velocity vector ( V1 ) of the drive wheel (9) is parallel and equal to the speed vector ( Vo ) means of advance (7). 4. Ensemble selon la revendication 1, caractérisé en ce que le détecteur de position du bord de la feuille comporte un détecteur photo-électrique (36) constitué d'un capteur formé par une barrette de diodes photo-électriques et d'une source lumineuse, un faisceau lumineux émis par la source est réfléchi sur une plaque d'appui (29) sur laquelle passe le bord de l'étoffe, un multiplexeur (42) formant à partir des signaux de chaque diode un signal vidéo, un comparateur (43) pour séparer les niveaux du signal vidéo en tout ou rien, un circuit bascule bi-stable (41) passant de l'état 1 par la première présence de l'étoffe rencontrée, à l'état 0 à la fin du balayage de la barrette, un circuit-porte (46) laissant passer un nombre d'impulsions d'horloge proportionnel à la position de la première diode masquée par le bord de l'étoffe, un circuit de comptage (47), un registre de transfert (48) et un convertisseur numérique/ analogique (50), les tensions de sortie correspondant fidèlement au contour du bord observé, un circuit de correction de trous (51) transforme le signal de sortie produit par les étoffes ajourées en un signal crête à crête, un circuit de comparaison et de commande (54) comparant le signal traité provenant du circuit de correction et le signal de position provenant du capteur de position (18) pour commander l'orientation et la vitesse du dispositif d'entraînement. 4 . An assembly according to claim 1, characterized in that the sheet edge position detector comprises a photoelectric detector (36) consisting of a sensor formed by a strip of photoelectric diodes and a light source, a light beam emitted by the source is reflected on a support plate (29) over which passes the edge of the fabric, a multiplexer (42) forming from the signals of each diode a video signal, a comparator (43) for separating the levels of the all-or-nothing video signal, a bi-stable flip-flop circuit (41) passing from state 1 by the first presence of the material encountered, to state 0 at the end of the strip scanning, a gate circuit (46) allowing a number of clock pulses to pass proportional to the position of the first diode masked by the edge of the fabric, a counting circuit (47), a transfer register (48) and a digital / analog converter (50), the output voltages corresponding exactly to the contour from the edge observed, a hole correction circuit (51) transforms the output signal produced by the openwork fabrics into a peak-to-peak signal, a comparison and control circuit (54) comparing the processed signal coming from the correction circuit and the position signal from the position sensor (18) for controlling the orientation and speed of the drive device. 5. Ensemble selon la revendication 4, caractérisé en ce que les photo-diodes constituant la barrette ont un diamètre inférieur à celui des fils constituant les mailles de l'étoffe ajourée.5. Assembly according to claim 4, characterized in that the photo-diodes constituting the strip have a diameter smaller than that of the threads constituting the mesh of the openwork fabric. 6. Ensemble selon la revendication 4, caractérisé en ce que le circuit de comparaison et de commande (54) du moteur comporte trois circuits comparateurs intégrés (55, 56, 57), un premier circuit comparateur (55) reçoit le signal traité (e2) de la barrette de diodes qu'il compare à deux valeurs de butée maximale et minimale (S1, S2) un deuxième circuit comparateur (57) reçoit les deux valeurs de butée précédentes et les signaux (e1, e2) provenant de la barrette de diodes (19) et du capteur de position (18), les sorties des circuits comparateurs (55, 57) donnant deux signaux, supérieur ou inférieur à une valeur de référence (e2) augmentée ou diminuée d'une valeur de déclenchement (ε1), actionnant des relais commandant un servo-moteur (19) d'orientation du dispositif d'entraînement; le troisième circuit comparateur (56) comparant le signal (e1) provenant du capteur de position (18) et le signal (e2) de la barrette de diode (36) à une valeur de référence (ε2) pour introduire une résistance dans le circuit d'alimentation du servo-moteur (19) pour limiter sa vitesse.6. Assembly according to claim 4, characterized in that the comparison and control circuit (54) of the motor comprises three integrated comparator circuits (55, 56, 57), a first comparator circuit (55) receives the processed signal (e 2 ) of the diode array which it compares to two maximum and minimum stop values (S 1 , S 2 ) a second comparator circuit (57) receives the two previous stop values and the signals (e 1 , e 2 ) coming from the diode array (19) and from the position sensor (18), the outputs of the comparator circuits (55, 57) giving two signals, greater or less than a reference value (e 2 ) increased or decreased by one trip value (ε 1 ), actuating relays controlling a servo-motor (19) for orienting the drive device; the third comparator circuit (56) comparing the signal (e 1 ) from the position sensor (18) and the signal (e 2 ) from the diode array (36) to a reference value (ε 2 ) to introduce a resistance in the servo motor supply circuit (19) to limit its speed. 7. Ensemble selon la revendication 3 ou 4, caractérisé en ce que la roue d'entraînement (9) est entraînée en rotation par un servo-moteur (230) et en ce que le détecteur de bord comporte un circuit d'alimentation du servo-moteur (230) délivrant une tension d'alimentation variable en fonction de l'orientation (a) de la roue.7. An assembly according to claim 3 or 4, characterized in that the drive wheel (9) is rotated by a servo motor (230) and in that the edge detector includes a servo supply circuit -motor (230) delivering a variable supply voltage as a function of the orientation (a) of the wheel.
EP86401500A 1985-08-02 1986-07-04 Guiding device for sewing three-dimensional soft work pieces upon sewing machines Expired EP0216644B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86401500T ATE46726T1 (en) 1985-08-02 1986-07-04 CONTROL DEVICE FOR SOFT, NON-FLAT WORKPIECES ON SEWING MACHINES.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR8511859A FR2585684B1 (en) 1985-08-02 1985-08-02 POSITION SENSOR OF THE EDGE OF A FABRIC PART FOR THE CONTROL OF A DRIVE DEVICE
FR8511858A FR2585683B1 (en) 1985-08-02 1985-08-02 DRIVE DEVICE FOR GUIDING ASSEMBLY OF SHEETS OF FLEXIBLE MATERIAL FOR FORMING A THREE-DIMENSIONAL ASSEMBLY
FR8511858 1985-08-02
FR8511859 1985-08-02

Publications (2)

Publication Number Publication Date
EP0216644A1 true EP0216644A1 (en) 1987-04-01
EP0216644B1 EP0216644B1 (en) 1989-09-27

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP86401500A Expired EP0216644B1 (en) 1985-08-02 1986-07-04 Guiding device for sewing three-dimensional soft work pieces upon sewing machines

Country Status (3)

Country Link
US (1) US4730824A (en)
EP (1) EP0216644B1 (en)
DE (1) DE3665894D1 (en)

Cited By (5)

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EP0292135A3 (en) * 1987-05-20 1989-02-15 Porter Sewing Machines, Inc. Method and apparatus for guiding fabric to a sewing machine
WO1992004493A1 (en) * 1990-09-01 1992-03-19 British United Shoe Machinery Limited Automatic sewing machine system
WO1997047797A1 (en) * 1996-06-14 1997-12-18 Patrick Rouleau Device for guiding a sewn material perpendicularly to a presser foot, automatic sewing method and sewing machine
FR2749861A1 (en) * 1996-06-14 1997-12-19 Rouleau Patrick Automatic sewing machine especially for use in stitching fabrics
FR2749862A1 (en) * 1996-06-14 1997-12-19 Rouleau Patrick Automatic sewing machine especially for use in stitching fabrics

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DE3710258A1 (en) * 1987-03-28 1988-10-13 Heidelberger Druckmasch Ag DEVICE FOR TRANSPORTING SHEETS, EXAMPLE PAPER SHEET
DE3804576A1 (en) * 1987-03-28 1988-10-06 Heidelberger Druckmasch Ag DEVICE FOR PROMOTING AND ALIGNING BOWS IN BOW-PROCESSING MACHINES
US4836119A (en) * 1988-03-21 1989-06-06 The Charles Stark Draper Laboratory, Inc. Sperical ball positioning apparatus for seamed limp material article assembly system
JPH0732827B2 (en) * 1989-01-27 1995-04-12 ハムス株式会社 Deflection correction device for cloth edge in octopus seam sewing machine
FR2665191B1 (en) * 1990-07-27 1992-11-20 Rouleau Patrick FABRIC GUIDING DEVICE AND AUTOMATIC SEWING METHOD.
EP0997567B1 (en) * 1998-10-30 2003-01-02 Johannes Sahl Accessory for a sewing machine
US20060070093A1 (en) * 2004-09-30 2006-03-30 Joy Mangano Combination candle centerpiece and side loading music CD player
JP2007014556A (en) * 2005-07-07 2007-01-25 Ykk Corp Overedging machine for cloth piece
US7444951B2 (en) * 2006-11-21 2008-11-04 Ykk Corporation Curved edge sewing systems
US8573145B2 (en) * 2010-03-18 2013-11-05 Stephen Lang Dickerson Feed mechanism that advances fabric
US8850999B1 (en) * 2011-02-10 2014-10-07 Daniel K. Kalkbrenner Sewing machine feed device
DE102015200720B4 (en) * 2014-07-02 2021-05-20 Adient Luxembourg Holding S.À R.L. Feeding device and manufacturing device for sewing blanks of the same contour
DE102017107480A1 (en) * 2017-04-07 2018-10-11 Schmale-Holding Gmbh & Co. Method and device for aligning a surface area of a flexible piece of material

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US3899986A (en) * 1974-03-27 1975-08-19 Stahl Urban Co Apparatus for guiding limp material
DE3043852A1 (en) * 1980-11-21 1982-07-01 Koninklijke Textielfabrieken Nijverdal-Ten Gate N.V., Almelo METHOD FOR DETECTING SIGNAL DEVIATIONS WITH THE AID OF AN INTEGRATING DIFFERENTIAL AMPLIFIER
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0292135A3 (en) * 1987-05-20 1989-02-15 Porter Sewing Machines, Inc. Method and apparatus for guiding fabric to a sewing machine
WO1992004493A1 (en) * 1990-09-01 1992-03-19 British United Shoe Machinery Limited Automatic sewing machine system
WO1997047797A1 (en) * 1996-06-14 1997-12-18 Patrick Rouleau Device for guiding a sewn material perpendicularly to a presser foot, automatic sewing method and sewing machine
FR2749861A1 (en) * 1996-06-14 1997-12-19 Rouleau Patrick Automatic sewing machine especially for use in stitching fabrics
FR2749862A1 (en) * 1996-06-14 1997-12-19 Rouleau Patrick Automatic sewing machine especially for use in stitching fabrics
US5941187A (en) * 1996-06-14 1999-08-24 Rouleau; Patrick Device for guiding a sewn material perpendicularly to a presser foot, automatic sewing method and sewing machine

Also Published As

Publication number Publication date
DE3665894D1 (en) 1989-11-02
EP0216644B1 (en) 1989-09-27
US4730824A (en) 1988-03-15

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