EP0204058B1 - Process and apparatus for automatically positioning the toe end of a stocking at the open end of an everting tube for sewing purposes - Google Patents

Description

The invention relates to a method and a device for automatically placing, in any predefined position, the two tubular stockings of a pantyhose on the tubes of a pneumatic turning device of a machine for sewing sticky spikes, in order to allow the correct and precise sewing of these points.

We know that in sewing machines the tips of tubular stockings the tube of the pneumatic turning device is used to support the turned bottom and two lateral fins, sliding longitudinally with respect to said tube, are used to slide towards the sewing machine sewing bottom point.

In addition, following patent GB 1 577 758, an automatic device is known for placing the end of the seam stocking in a predefined position of the tube of the pneumatic turning device, which comprises a position sensor (eg a fixed photocell), capable of recognizing a detail (eg the open end) of the bottom, as well as devices for grasping the bottom at the level of the lateral fins of the turning device, for sliding it along of the tube, first in front, that is to say towards its open end, in such a way that said bottom detail exceeds the sensor, then in reverse and this until said bottom detail arrives in a position corresponding to that of the sensor, which then controls the opening of the gripping machines.

This known device uses gripping machines which close on the bottom always in the same position relative to the tube and which advance the bottom always in a stroke of the same length; and since the open end of the bottom, at the end of the turning of the latter on the tube, results in a position which varies along a very wide margin, said gripping devices always close on the bottom to a certain distance from the end of it. Consequently, during advancement from the bottom towards the free end of the tube, even if it takes place at low speed, numerous folds form in the bottom termination zone, which is outside of the gripping devices; To eliminate these folds, you must then pull the bottom back at low speed.

The main objective of the present invention is to eliminate the above-mentioned drawbacks. The invention, as characterized by the claims, solves the problem of sliding the two stockings of a pantyhose over the two finned tubes of a pneumatic turning device, from any initial position of each stocking towards the same predefined end position for both stockings, with a single and rapid approach run.

In accordance with the invention, it is planned to use a mobile steering carriage parallel to the axis of the tubes of the turning device and carrying two probes detecting the position of the tips of the stockings, at the end of their turning, as well as two pairs of pliers making it possible to slide the sewing tip from the stockings along the lateral fins of the tubes of the turning apparatus, from their position at the end of the turning to that predetermined for sewing the points; when, during the course of the carriage towards the free end of the tubes, each of the probes individualizes a given point detectable on the corresponding bottom, it then commands the pair of corresponding pliers to close on the bottom, so as to slide it towards and until the end of the carriage stroke to which the predetermined position for sewing corresponds; once it has reached said end position, the carriage stops while each pair of pliers remains closed on the corresponding bottom; then, when a central machine control unit, e.g. a rotary cam programmer, which regulates the various operational phases of the machine, has made a turn, it controls the opening of the clamps to leave the stockings in the predefined sewing position and allow the tubes to advance one step wearing the stockings, so that you can start a new cycle.

The advantages obtained thanks to the present invention essentially consist in the fact that it is possible to operate the prior turning of the stockings on the tubes of the turning device at a speed higher than that obtained hitherto; that the stockings literally slide to the predetermined position in a single approach run; in this case each stocking is always grasped at the height of its open end, whatever its starting position; in that the sliding of the two stockings is carried out at a very high speed and with the woven fabric of the stocking held in the stretched position; in that it is possible to modify the release position of the stockings; in that the relaxation of the stockings is done at a standstill and therefore without the risk of error due to inertia.

• La figure 1 représente, schématiquement, la vue en plan d'une machine à coudre les pointes de collant de dames, de type carrousel à plusieurs bras, tournant pas à pas, muni d'un dispositif pour mettre les bas en position sur les deux tubes d'un appareil de retournement pneumatique, réalisé conformément à la présente invention;
• la figure 2 représente, en perspective, le détail des deux tubes à ailettes d'un appareil de retournement de la machine de la figure 1, avec les deux bas placés dans la position correspondant à la fin de leur retournement;
• la figure 3 représente la vue en plan d'un dispositif conforme à l'invention relatif aux deux tubes de l'appareil de retournement de la figure 2, en position de fin de course à vide;
• la figure 4 représente la vue frontale du dispositif de la figure 3;
• la figure 5 représente la vue latérale gauche du dispositif de la figure 3;
• la figure 6 représente la section selon A-A de la figure 3;
• la figure 7 représente la vue en plan du dispositif de la figure 3 en position de début de glissement du bas;
• la figure 8 représente la vue frontale du dispositif de la figure 7;
• la figure 9 représente la vue latérale gauche du dispositif de la figure 7;
• la figure 10 représente la vue en plan du dispositif de la figure 3 en position de fin de glissement des deux bas;
• la figure 11 représente la vue frontale du dispositif de la figure 10;
• la figure 12 représente la section selon B-B de la figure 11;
• la figure 13 représente le détail d'une variante du cinématisme de la figure 12.

The invention is explained in more detail in the following pages, with the aid of the drawings which represent an exemplary embodiment thereof.

• Figure 1 shows, schematically, the plan view of a sewing machine for ladies' tights, of the carousel type with several arms, turning step by step, provided with a device for placing the stockings in position on both tubes of a pneumatic turning device, produced in accordance with the present invention;
• 2 shows, in perspective, the detail of the two finned tubes of a turning device of the machine of Figure 1, with the two bottoms placed in the position corresponding to the end of their turning;
• FIG. 3 represents the plan view of a device according to the invention relating to the two tubes of the turning device of FIG. 2, in the end of empty travel position;
• Figure 4 shows the front view of the device of Figure 3;
• Figure 5 shows the left side view of the device of Figure 3;
• Figure 6 shows the section along AA of Figure 3;
• FIG. 7 represents the plan view of the device of FIG. 3 in the position of start of sliding from below;
• Figure 8 shows the front view of the device of Figure 7;
• Figure 9 shows the left side view of the device of Figure 7;
• Figure 10 shows the plan view of the device of Figure 3 in the end of sliding position of the two bottoms;
• Figure 11 shows the front view of the device of Figure 10;
• Figure 12 shows the section along BB of Figure 11;
• FIG. 13 represents the detail of a variant of the cinematism of FIG. 12.

• (a) de mettre un chariot, qui est alternativement mobile en direction parallèle à l'axe des tubes de l'appareil de retournement et qui porte deux sondes photoélectroniques permettant de déceler un point-indice des bas d'un collant retournés sue les tubes correspondants ainsi que deux paires de pinces qui peuvent se refermer sur les ailettes latérales correspondantes des deux tubes pour faire glisser les bas dans la position prédéterminée de couture, dans une position préétablie par rapport aux tubes, position telle que lesdites pinces en arrivent à se trouver, à la fin du retournement des bas sur les tubes, au-dessus des bras et en retrait par rapport aux pointes qui doivent être cousues;
• (b) de fermer partiellement les pinces et ensuite d'explorer les bas le long d'une de leurs génératrices et de détecteur, au moyen desdites sondes photoélectroniques, la position d'un point-indice donné sur chacun des bas, qui sont tenus immobiles sur le tube correspondant;
• (c) de refermer sur chaque bas, à la hauteur des ailettes du tube correspondant et sur commande de la sonde photoélectronique correspondante, lorsque cette dernière a décelé le point-indice donné du bas, deux pinces correspondantes desdites deux paires de pinces;
• (d) de déplacer lesdites deux paires de pinces ainsi refermées, ensemble avec l'extrémité à coudre des bas, le long des ailettes des tubes vers l'extrémité libre de ceux-ci et jusqu'à la fin de la course de retour du chariot;
• (e) d'arrêter le chariot à la fin de sa course de retour et de tenir les pinces fermées;
• (f) d'ouvrir les pinces juste avant le début du nouveau cycle.

According to the present invention, the method for automatically placing the tubular stockings of a pantyhose on the tubes of a pneumatic turning device of a machine for sewing the pantyhose spikes, and which comprises the mechanical return of the stockings of the interior of the tubes with their inversion on the tubes and the forced sliding of the bottom on the lateral fins of the tubes, allows, successively:

• (a) to put a carriage, which is alternately movable in a direction parallel to the axis of the tubes of the turning device and which carries two photoelectronic probes making it possible to detect an index point of the stockings of a tights returned on the tubes corresponding as well as two pairs of pliers which can be closed on the corresponding lateral fins of the two tubes to slide the stockings into the predetermined sewing position, in a predetermined position relative to the tubes, a position such that said pliers come to be , at the end of the turning of the stockings on the tubes, above the arms and back from the points which must be sewn;
• (b) partially closing the clamps and then exploring the stockings along one of their generators and detector, by means of said photoelectronic probes, the position of a given index point on each of the stockings, which are held stationary on the corresponding tube;
• (c) to close on each bottom, at the height of the fins of the corresponding tube and on command of the corresponding photoelectronic probe, when the latter has detected the given index point from the bottom, two corresponding pliers of said two pairs of pliers;
• (d) moving said two pairs of pliers thus closed, together with the sewing end of the stockings, along the fins of the tubes towards the free end thereof and until the end of the return stroke of the cart;
• (e) stop the carriage at the end of its return stroke and keep the clamps closed;
• (f) open the clamps just before the start of the new cycle.

The stroke making it possible to place the carriage in its initial position is carried out towards the center of the carousel during the advancement of one step of the carousel, with said clamps open and said probes inactive, while the stroke for exploration and sliding of the down towards the free end of the tubes takes place during the stopping of the carousel and with the clamps which at the start of said stroke are partially closed, but without touching the fabric of the stockings.

Said index point of the stockings can obviously be the limit between the reinforcement of the point and the rest of the bottom or the end of the bottom or even a particular sign, such as a dark colored thread, previously inserted in the woven of the bottom.

• - une paire de tubes de retournement 10 horizontaux, placés côte à côte et faisant partie d'un bras d'un carrousel 1 à plusieurs bras, tournant, pas à pas, dans le sens contraire aux aiguilles d'une montre autour de son propre axe central, vertical. Ledit carrousel fait partie d'une machine à coudre les pointes de collant, à plusieurs stations (A-B-C-D1-D2-E), dans laquelle la station A est prévue pour l'alimentation automatique des collants en position retourné, position qui est obtenue grâce à un dispositif 2 qui ne fait pas l'objet de la présente invention; la station B permet le rappel des jambes du collant de l'intérieur des deux tubes 10, en en complétant le retournement vers l'extérieur de ces tubes, au moyen de deux rouleaux rotatifs 12 correspondants, connus comme tels; la station C permet de placer les deux bas 3 dans une position prédéterminée sur les tubes 10, au moyen du dispositif objet de la présente invention; les stations D1, D2 permettent de coudre la pointe 31 de l'un (le droit) et de l'autre (le gauche) bas du collant, séparément; au moyen de deux machines coupe-couture 4 correspondantes, connues comme telles: lesdites machines coupe-couture 4 effectuent en même temps la couture du bas droit et du bas gauche de deux collants différents; la station E permet de redresser et d'éloigner, à main droite, le collant terminé, au moyen d'engins pneumatiques, connus comme tels;
• - un chariot 5, mobile en phase par rapport aux mouvements du carrousel 1, sur un rail 6 horizontal, disposé en dessous des deux tubes 10, arrêtés à la station C; ledit chariot 5 porte dans sa partie supérieure trois étriers 50, à profil vertical en forme de C, justaposés, orientés de manière parallèle auxdits tubes 10 et reliés entre eux par des traverses 51, de manière à laisser le passage libre pour les tubes 10 pendant la rotation, pas à pas, du carrousel 1.

The device for carrying out said method, in accordance with the invention comprises, in combination:

• - a pair of horizontal turning tubes 10, placed side by side and forming part of an arm of a carousel 1 with several arms, rotating, step by step, counterclockwise around its own central, vertical axis. Said carousel is part of a sewing machine for sticky points, at several stations (ABC-D1-D2-E), in which station A is provided for the automatic feeding of the tights in the inverted position, which position is obtained thanks to a device 2 which is not the subject of the present invention; station B allows the legs of the pantyhose to be brought back from the inside of the two tubes 10, by completing the turning towards the outside of these tubes, by means of two corresponding rotary rollers 12, known as such; the station C allows the two stockings 3 to be placed in a predetermined position on the tubes 10, by means of the device which is the subject of the present invention; the stations D1, D2 make it possible to sew the tip 31 of one (the right) and the other (the left) bottom of the tights, separately; by means of two corresponding sewing machines 4, known as such: said sewing machines 4 carry out at the same time the sewing of the right bottom and the left bottom of two different tights; station E makes it possible to straighten and move away, on the right, the finished tights, by means of pneumatic devices, known as such;
• - A carriage 5, movable in phase relative to the movements of the carousel 1, on a horizontal rail 6, arranged below the two tubes 10, stopped at station C; said carriage 5 carries in its upper part three stirrups 50, of vertical profile in the shape of C, justaposited, oriented in parallel to said tubes 10 and interconnected by crosspieces 51, so as to leave free passage for the tubes 10 during rotation, step by step, of the carousel 1.

Each pair of contiguous stirrups 50 is associated with two horizontal jaws 52 and 52 ′, articulated on the upper and lower arm respectively, of the corresponding stirrups 50 and connected together by means of a system of levers 53 to form two corresponding clamps (52, 52 ') which close longitudinally and on either side on the lateral fins 11 of each tube 10, partially, under the effect of two return springs 54, and, on the contrary, open under the 'action of a pneumatic cylinder 55'. Clamps 52, 52 'are closed in two stages, since the console 53' of the lever 53 is intercepted not only by the rod of the pneumatic control cylinder 55 '(which is actuated by the central control unit) , but also by that of a second pneumatic control cylinder 55 (which is actuated by one of the probes) and which is of shorter length than that of the cylinder 55 ', so that when the rod of the cylinder 55' is lowered and as long as the cylinder rod 55 remains raised, the clamps 52, 52 ′ are only partially closed.

With the upper crossmember 51 are associated two photoelectronic probes 56, aligned with one another in transverse direction, above the tubes 10, each of the probes being located in withdrawal with respect to the two ends of the jaws 52 of the corresponding tube 10: the position of each probes 56 in direction parallel to the axis of the tube 10 corres laying can be adjusted at will in relation to the index point 30 given from the bottom 3 and with the desired sewing position of the bottom.

Each of said probes 56 is connected to a corresponding cylinder 55, so as to effect, separately, the closing of the corresponding clamps (52, 52 ') on the fins 11 of the two tubes 10 when, after each bottom 3 has been explored separately under the effect of the movement of the carriage 5, the index point 30 given of each stocking has been detected.

The reciprocating rectilinear movement of the carriage 5 is derived from a reduction gear with a general motor of the machine, with the interposition of a complex of oscillating sliding cranks (6, 7) and of a connecting rod 8 so that, at each operating cycle of the stitch sewing machine, the carriage 5 performs a faster run to empty and a slower return run, operative; the end of the return stroke, that is to say the operative stroke, of the carriage 5 being determined by a stop flap 57 whose position is adjustable in the direction of travel of the carriage 5. Said connecting rod 8 is composed of a tubular rod whose head 82 is articulated on the slide 6 and whose foot 81, which is articulated to the carriage 5 by means of a pivot 5 ', is sliding in the rod 8 and connected to it by means of a grip 83, held in place in a corresponding buttonhole, the length of which determines the maximum excursion of the foot 81. An antagonistic spring 9, located between the head 82 and the foot 81 of the connecting rod 8, participates in the movement telescopic of the foot 81 in the rod 8: when the carriage 5, at the end of the return stroke, is stopped against the stop 57 and as long as the slide 7 has not reached its corresponding dead center, the foot 81 retracts into the rod 8, while, when the slide 7 has passed its neutral point and the spring has relaxed, the foot 81 extends until the carriage 5 'is put in the starting position, thus causing the next forward travel of the carriage to start.

As an alternative to the cinematism (6, 7, 8) oscillating with the slide, and with reference to FIG. 13 of the attached drawings, provision is made for using a system of levers (70, 80) whose end 72 is articulated on the carriage 5 and the end 83 of which turns on a cam 91 mounted on the shaft of the aforementioned general motor reducer, a system whose profile is designed so as to allow the carriage 5 to stop in correspondence with the end of his return run.

Finally, each of said cylinders 55 is controlled by a single switch, which is in turn actuated by a central control unit, for example. a rotary cam programmer (for the sake of simplicity, the latter is not shown in the attached drawings), making it possible to open the two pairs of pliers (52, 52 ') together and thus leave the two stockings 3 on the two tubes 10, in the predetermined sewing position, just before the start of the next cycle.

According to the invention, it is also planned to use two probes 56 for each tube 10 of the pneumatic turning device, arranged above the tube, near the lateral fins, one associated with a clamp (52 , 52 ') and the other associated with the other clamp, as well as two corresponding cylinders 55 making it possible to actuate the clamps (52, 52') separately, so as to allow the bottom to be grasped on the two fins 11 of the tube 10 at different times and so that the open end of the bottom, which, at the end of the turning over on the tube 10 would be oriented obliquely to the axis of the tube itself, results in the end of the sliding , placed in the predetermined sewing position, that is to say perpendicular to the axis of the tube 10.

Operation takes place as follows. While the carousel 1 advances by one step, the carriage 5 carries out an empty travel, that is to say with the clamps (52, 52 ') open, towards the center of the carousel 1 and when the two tubes 10, with the two bottoms 3 turned over on them, reach station C and stop there, the carriage 5 has already arrived at the end of its outward travel and has stopped. Immediately, the carriage 5, with the clamps 52, 52 'partially closed but without touching the bottom fabric (as shown by the dotted line in FIG. 8), performs its return stroke during which each of the two probes 56 expires longitudinally the corresponding bottom 3 and as soon as each of said probes 56 has detected the given index point 30 which is relevant to it, it actuates the corresponding cylinder 55, thus causing the complete closure of the corresponding clamps (52, 52 '); as a result of which the end 31 of each of the bottoms 3 is driven until the end of the return stroke of the carriage 5; once this is reached, the carriage 5 stops and the clamps (52, 52 ') remain closed; then, just before the start of the successive operating cycle, the central control unit of the machine gives its approval, by means of a switch, to the authorization of the cylinders (55, 55 '), thus determining the instant opening of all the clamps (52, 52 ') and hence the abandonment of the tips of the two stockings 3, in the predetermined stroke position.

Claims (11)

1. A method of automatically positioning the tubular stockings of tights on the two tubes of the pneumatic turning device of a toecloser, the method comprising returning each stocking (3) from the inside of the corresponding tube (10) and turning it round on the outside of the tube and compelling each stocking to slide along the tube side blades (11), characterised in that the method makes it possible to consecutively:

(a) Place a carriage (5), which can reciprocate in a direction parallel to the tubes (10) and which carries two photoelectronic detectors (56) and two pairs of grippers (52, 52') adapted to close on the side blades (11) of the rubes (10), in a predetermined position such that the grippers (52, 52') are open above the stockings (3) but are set back from the stocking toes (31) at the completion of the turning around on the tubes (10);

(b) Partially close the grippers (52, 52') without contacting the stocking fabric, then exploring both stockings along their generatrix by means of the photoelectronic detectors (56) to detect the initial position of a given identifiable feature (30) for each stocking (3) kept stationary on the corresponding tube (10);

(c) Close on each stocking (3), at the height of the side blades (11) of the corresponding tube (10) in response to an instruction from the corresponding photoelectric detector (56) when the same has detected the identifiable feature (30), a pair of corresponding grippers (52, 52') so that the end (31) to be sewn can be slid towards the final sewing position on the corresponding tube (10);

(d) Move both pairs of grippers (52, 52') thus closed, together with the end (31) therebelow of the stocking (3) to be sewn, along the blades (11) towards the free end of the tubes (10) as far as the end of the operative travel of the carriage (5);

(e) Keep the carriage (5) stopped at the end of said stroke by keeping the grippers (52, 52') closed on the stockings (3), and

(f) Open both pairs of grippers (52, 52') immediately before the start of the next cycle and thus leave the end (31) of the stockings (3) which it is required to sew in the predetermined sewing position on the tubes (10).

2. A method according to claim 1, characterised in that the closure of the two grippers (52, 52') on each stocking (3) to shift the same occurs near the free end of the stocking part (31) to be sewn is slid with tension over the whole length of the approach movement towards the predetermined sewing position on the corresponding tube (10).

3. A method according to claim 1, characterised in that the closure of the two grippers (52, 52') occurs at different times in order that the end of each stocking (3), which is initially oblique, can be so positioned in the predetermined sewing position as to be perpendicular to the axis of the corresponding tube.

4. An apparatus for automatically placing the tubular stockings of a pair of tights on the two tubes of an automatic turning device of a toe-closer, the arms, in the form of two tubes (10), of the toe closer forming a horizontal turret (1), by the method according to claims 1 to 3, and comprising means (12) for returning the legs (3) of the tights from inside the two tubes (10) while completing the turning on to the outside of such tubes, and gripper means (52, 52') for compelling each leg (3) to slid on the lateral blades

(11) of the corresponding tube (10), characterised in that the apparatus comprises a carriage (5) adapted to reciprocate on a horizontal rail (6) in a direction parallel to the tubes (10) when the same are stationary at a station of the toe-closer, the carriage carrying at least two photoelectronic detectors (56) adapted to explore the two stockings (3) lengthwise separately from one another and to detect their predetermined identifying feature (30); two pairs of grippers (52, 52') for gripping the two stockings (3) separately on the blades (11) of the two tubes (10) and sliding the two stockings therealong; two first pneumatic actuating cylinders (55') operated by the central control unit of the machine for opening and, by means of a pair of springs (54), partly reclosing the two pairs of grippers (52, 52'); at least two second pneumatic actuation cylinders (55) for producing with the aid of the springs (54) total closure of the gripper pairs (52, 52'), each of the cylinders (55) being operated by the corresponding detector (56) when the same has detected the identifying feature (30) of the corresponding stocking (3), the central control unit of the machine opening the grippers (52, 52') simultaneously; each stocking (3) is gripped by the grippers (52, 52') whatever its initial position on the corresponding tube (10), simultaneously or not according as the stocking end (31) is positioned on the tube (10) perpendicularly or obliquely relatively to the axis of the tube (1µ); and both stockings (3) are released simultaneously in the predetermined sewing position on the tubes (10).

5. An apparatus according to claim 4, characterised in that the photoelectronic detectors (56) are disposed above the tubes (10) in a line which is perpendicular to the axis of the tubes (10) in an intermediate zone relatively to the jaws (52) of the corresponding grippers (52, 52') and set back from the two ends of the jaws (52) so as to slide with tension the stocking ends (31) to be sewn over the entire length of the corresponding approch to the predetermined sewing position on the tubes (10).

6. An apparatus according to claim 4, characterised in that the position of the detectors (56) can be adjusted in a direction parallel to the longitudinal axis of the tubes (10) in order to select a different identifying feature (30) and to change the predetermined sewing position of the stockings (3) on the tubes (1µ).

7. An apparatus according to claim 4, characterised in that the carriage (5) has three C-shaped vertical stirrups (50) disposed in juxtaposed relationship to one another and parallel to the tubes (10) so as to allow the same to pass through freely during rotation of the turret (1 and the top and bottom jaws (52, 52') of the grippers (52, 52') are pivotally connected to the top and bottom arms of the stirrups (50).

8. An apparatus according to claim 4, characterised in that the top jaw (52) and bottom jaw (52') of each of the grippers (52, 52') are interconnected by means of linkage (53) enabling them to be closed and opened by actuation by a corresponding pneumatic actuating cylinder (55, 55') by means of a return spring (54).

9. An apparatus according to claim 4, characterised in that the carriage (5) reciprocates on the rail (6) as a result of actuation by an oscillating slide link complex (6, 7), with a tubular rod (8) whose base (81) is telescopic, to stop the carriage (5) when the same contacts an operative limit stop (57), the position thereof being adjustable in dependence upon the predetermined sewing position of the stockings (3) on the tubes (10); the carriage (5) moves towards the centre of the turret (1) with the gripper pairs (52, 52') open and while the turret (1) is moving through one step, whereas the return movement in which the stocking (3) slides towards the free end of the tubes (10) takes place while the turret (1) is stationary.

10. An apparatus according to claim 4, characterised in that the reciprocation of the carriage (5) on the rails (6) is controlled by a system of levers (70, 80) and a cam (91) shaped to enable the carriage (5) to stop when the same contacts the end stop (57).

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