ITUB20155766A1 - MACHINE AND METHOD TO IRON TUBULAR MESH MANUFACTURES - Google Patents

Description

MACHINE AND METHOD FOR IRONING TUBULAR KNITTED ARTICLES

DESCRIPTION

FIELD OF THE INVENTION

The present invention relates to the sector of machines for the Hindu hosiery and knitwear stripe. More specifically, the invention relates to improvements in machines for handling tubular knitted products, such as stockings, socks and the like. Embodiments described herein relate in particular to methods and devices for handling, orienting and ironing tubular knitted articles with an elastic edge.

ANTERIOR ART

In the knitwear and hosiery industry, circular knitting machines are used for the production of tubular-shaped garments, for example stockings and socks, which have an elastic edge at one end and a toe, normally closed by a seam or a linking at the bottom. opposite end. These artifacts are packaged after ironing and folding. Socks are commonly loaded onto so-called ironing templates to be ironed by heat and assume the flat shape which then allows them to be packaged. The loading of the ironing templates is normally done manually and is a particularly onerous job also from a physical point of view, as the operator must take the individual tubular knitted articles, and load them on the ironing template and orient them correctly, before the drafting template advances through a heat treatment chamber or an oven where the tubular knitted product is subjected to heating and ironing.

Tubular knitted products, such as in particular stockings and socks, have a shaped shape and are characterized by fabric pockets that form the toe and heel. These parts of the tubular knitted article must be oriented correctly with respect to the shape of the ironing template, since otherwise it will not be possible to package the article correctly. In particular, depending on the type of product, the orientation can be made so that the two longitudinal folding lines are on the back and on the sole of the foot. In other cases, the fold is carried out in such a way that the two longitudinal fold lines are located on the sides of the foot.

The orientation must be done before loading the tubular product on the ironing template, which requires a considerable intervention of labor, or the use of very complex machinery, which is able to carry out an orientation of the tubular product to knit before loading on the form of ironing.

There is therefore a need to create machines and methods that allow for a simplification of the aforementioned operations, reducing the use of manpower and lightening the operator's tasks.

SUMMARY OF THE INVENTION

According to one aspect, a machine is described for ironing tubular knitted articles, such as for example stockings and socks, comprising in combination: at least one tubular shape with a longitudinal axis; a heat treatment chamber, in which the tubular shape can be inserted to subject the tubular knitted product to a heat treatment; a pick-up device for picking up and loading tubular knitted articles on the tubular shape.

The tubular shape, hereinafter also referred to as the drawing shape, can have a substantially cylindrical shape. Preferably, the tubular shape has a circular cross section, because this allows to obtain particular advantages, described below in greater detail. However, the possibility of using tubular shapes with a non-circular cross section, for example elliptical, is not excluded. In this case, the difference between the major axis and the minor axis of the ellipse defining the cross section of the shape is preferably contained for example equal to or less than 30%, preferably equal to or less than 20% or even more preferably equal to or less than 10% .

The tubular knitted product invested on the tubular shape is stretched uniformly, without concentration of tension and deformation of the yarn, as is the case, however, in the flat shapes of the current art. The more uniform the cross section of the tubular shape, the greater the uniformity of the distribution of tension in the yarn that forms the tubular knitted product. For this reason, in some respects it may be preferable to use tubular shapes with a circular section.

The use of tubular shapes, preferably with an approximately circular or slightly elliptical section, also allows greater ease of angular orientation of the tubular product. In fact, when using flat ironing templates it is necessary to invest the tubular knitted article in a very precise angular position with respect to the edges of the flat shape. In particular, it is necessary to precisely orient the toe and heel pockets, so that at the end of the ironing operations the folding line, obtained at the edges of the shape, has a very precise position with respect to the heel.

Vice versa, using a tubular shape, once the tubular knitted product has been invested on the tubular shape, it is possible to carry out an angular orientation of the tubular knitted product with respect to the axis of the tubular shape, in order to proceed then, after the angular orientation, to a final stretching step, for example by squeezing the tubular knitted article between two conveyor belts pressed against each other.

The machine can provide a device for angular orientation of the tubular shape. Furthermore, the machine can comprise a plurality of stations, for example to carry out loading operations of the tubular knitted article on the shape, angular orientation, heat treatment in the heat treatment chamber; unloading and eventual final ironing. Advantageously, it can be envisaged that the tubular shape is mounted on a conveyor that transfers it from one to the other of a plurality of handling, processing or treatment stations of the tubular knitted product, including any loading and unloading stations.

The heat treatment chamber can comprise a heating battery, for example by means of electric resistances and an air circulation system, preferably closed or partially closed, so as to reduce energy consumption. A blower can be provided to circulate the air in the closed circuit. To reduce the risk of fire, filters can be provided that retain impurities, such as dust or fibers, avoiding contact with electrical resistances.

The air temperature can be maintained for example between 50 ° C and 100 ° C, preferably between 60 ° C and 90 ° C and even more preferably around 75-85 ° C.

The air can be dry. In other embodiments, the use of humid air is not excluded.

In some embodiments, the residence time of the knitted tubular article in the heat treatment chamber can range from 10 seconds to 60 seconds, preferably from 20 seconds to 30 seconds.

With process parameters of this type, thanks to the significantly lower temperature than that used in normal ironing machines, the advantage is obtained of reducing or preventing the dissolution of the softeners used in dyeing, obtaining a finished product of better quality.

To increase the productivity of the machine, it is possible to provide for more than one tubular shape to be mounted on the conveyor, for example a number of tubular shapes equal to or greater than the number of machine stations.

The conveyor can be a flexible conveyor, for example a chain or a belt. In other embodiments, the conveyor can be rigid, for example a rotating table or carousel.

The tubular shapes are preferably arranged with their axes parallel to each other. In the case of a rotating conveyor, the axis of rotation of the conveyor can be parallel to the axes of the tubular shapes.

In some embodiments, the tubular knitted product invested on the tubular shape can be angularly oriented by sliding it on the surface of the tubular shape, for example by placing on it external radial pads that rotate around the axis of the tubular shape, dragging the product by friction knitted tubular by rotating it.

However, in order to obtain a more delicate treatment of the tubular knitted product, avoiding inducing tensions in its textile structure, according to some embodiments of the machine described here, the tubular shape, or each tubular shape with which the machine is equipped, can be mounted rotatable around its longitudinal axis. The tubular knitted product can then be angularly oriented with respect to the axis of the tubular shape by rotating the entire tubular shape, with the tubular knitted product invested on it, around the longitudinal axis of the tubular knitted product.

In this way, any tension induced in the textile structure of the tubular product, whether due to compression or due to friction, is avoided.

The machine can comprise a wet or dry heat treatment chamber, or capable of performing different heat treatments, for example both dry and wet, for example depending on the type of yarn of which the tubular knitted product is made. , or other characteristics of the latter. It is not excluded the possibility of providing a multiple heat treatment chamber, or more heat treatment chambers, preferably placed in sequence, in each of which different operating parameters, such as different degrees of temperature and / or humidity, can be used, for example.

In some embodiments, the machine further comprises a final drafting and removal unit, for removing the tubular knitted articles from the tubular shape and pressing them, stretching them, during extraction or removal from the tubular shape. The final drawing and removal unit can be advantageously positioned in the vicinity of the heat treatment chamber, in such a way that the tubular knitted article is handled by the final drawing and removal unit when the fibers of the yarn that it is composed of are still hot, and possibly damp. In this way, a final stretching effect is obtained, for example by squeezing the tubular knitted product between two opposing conveyor belts, pressed against each other.

In order to facilitate the removal of the tubular knitted article from the tubular shape, in some embodiments it can be provided that the tubular shape, or each tubular shape, comprises an extractor which can be extracted and retracted with respect to one end of the tubular shape. The knitted tubular product can be inserted on the tubular shape so that the closed tip of the knitted tubular product covers the distal end of the tubular shape, i.e. the end which is distant from the point where the tubular shape is engaged to for example to a conveyor that moves it through the various stations of the machine. The extractor is extracted from the distal end of the tubular shape, thus pushing the tubular knitted product from the inside of its tip, and starting to remove it from the tubular shape. The two conveyor belts can thus more easily engage the tubular knitted product between two opposite branches of them, which press against the extractor.

According to a further aspect, a method for ironing a tubular knitted product is described, comprising the steps of:

- insert a tubular knitted product to be ironed on a tubular shape; - subjecting the tubular knitted article to a heat treatment when it is on the tubular shape;

- remove the knitted tubular product from the tubular shape.

The method can also advantageously comprise the step of carrying out a final drawing operation on the tubular knitted article while it is being removed from the tubular shape.

Further details of possible embodiments of the device, machine and method of the present invention are described below with reference to the attached drawings and in the claims, which form an integral part of the present description.

In the following description, the ironing machine and the relative method are described in combination with a device which automatically opens the elastic edge of the tubular knitted articles and automatically places them on the tubular shape. This allows to obtain particular advantages in terms of cycle automation. However, it is not excluded to combine the tubular shape, hereinafter also referred to as ironing shape, with a different system for loading the tubular knitted articles, or also to load the tubular knitted articles manually. In this case, the operator's work is in any case simplified, as he does not have to manually orient the tubular knitted product.

Basically, the machine and the method described here allow to divide the ironing operations of the tubular knitted article into two phases: in a first phase, performed on the tubular shape, the tubular knitted article is subjected to heat treatment, without being folded . Only subsequently, the tubular knitted article is picked up and removed from the tubular shape, and squashed or pressed to be folded, for example by means of two opposing conveyor belts.

This way of proceeding allows multiple advantages. In addition to the aforementioned simplification of the orientation step of the tubular knitted article, it is possible to iron the tubular knitted article by arranging the fold in any position with respect to the fabric bags (heel and toe), according to the production requirements. For this purpose, no type of mechanical intervention or adjustment is necessary, but only a correct setting of the orientation organs.

The tubular shape, preferably with a circular section, of the ironing templates allows the tubular knitted article to be oriented in any predefined angular position, so as to then fold the drafting of the tubular knitted article along fold lines oriented in any position with respect to the heel. For example, the fold lines can be made in such a way as to extend along the back and the sole of the foot, folding the heel pocket and the toe pocket of the tubular knitted product in half. In other operating modes, the orientation can be done so that the fold is made along the sides of the foot. The orientation can be performed by rotating the tubular shape and identifying, through any angular reading system, the angular position of the tubular product with respect to a reference system. The angular reading system can be configured to "see" the position of the toe and / or heel fabric bag, or, more simply, a drawing or an optical clue can be provided on the tubular knitted product, easily identifiable by a vision system. The optical clue can be achieved, for example, during knitting on a circular knitting machine, in a precise angular position with respect to the fabric bags.

The use of tubular shapes also allows to perform heat treatment operations in conditions of uniform tension of the yarn, without areas of concentration of tension and / or deformation of the knitted fabric. The textile fibers are uniformly arranged over the entire surface of the tubular knitted product.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by following the description and the attached drawing, which shows practical non-limiting embodiments of the invention. More specifically, in the drawing:

Fig. I illustrates a schematic plan view of a machine for effecting the stretching of tubular knitted articles such as stockings or socks, equipped with an elastic edge at one of the ends of the article;

Fig. 2 shows a diagram of the pneumatic duct for feeding the tubular knitted articles to the drawing members;

Figs. 3 and 4 show axonometric views of the device for opening the elastic edge of the tubular knitted article and of the pick-up which transfers the tubular knitted articles onto the ironing templates;

Figs. 5 and 6 show two sections according to the longitudinal planes orthogonal to each other of the device and relative pick-up of Figs. 3 and 4;

Fig. 7 illustrates an axonometric view of an ironing template;

Figs. 8A and 8B show longitudinal sections of the upper and lower ends of the drawing template of Fig. 7;

Figs. 9A and 9B illustrate the assembly for rotating the ironing templates in two different operating conditions;

Fig. 10 illustrates an axonometric view and the zone of entry of the ironing templates into the heat treatment chamber;

Figs. 11A and 11B show in a side view the station for taking the tubular knitted articles ironed from the ironing templates;

Figs. 12A to 12S show an operational sequence of opening the elastic edge of a tubular knitted article and loading the tubular knitted article onto a drawing template;

Figs. 13A to 13D illustrate unloading steps of a tubular knitted article in a situation of non-opening of the elastic edge.

DETAILED DESCRIPTION OF FORMS OF CONSTRUCTION

The following detailed description of exemplary embodiments refers to the accompanying drawings. The same reference numerals in different drawings identify the same or similar elements. Also, the drawings are not necessarily to scale. The following detailed description does not limit the invention. Rather, the scope of the invention is defined by the attached claims.

Reference throughout the description to "an embodiment" or "the embodiment" or "some embodiment" means that a particular feature, structure or element described in connection with an embodiment is included in at least one embodiment of realization of the described object. Therefore the phrase "in an embodiment" or "in the embodiment" or "in some embodiment" at various points along the description does not necessarily refer to the same or the same embodiments. Furthermore, the particular features, structures or elements can be combined in any suitable way in one or more embodiments.

Fig. 1 schematically illustrates in a plan view a machine 1 for effecting the ironing of tubular knitted articles, such as stockings and socks, provided with an elastic edge. Schematically, the machine 1 comprises a rotating carousel 3 with a substantially vertical axis of rotation 3A. On the rotating carousel 3 there are tubular ironing templates 5 arranged around the rotation axis 3A of the carousel 3. The number of ironing templates 5 can vary, for example according to the size of the machine 1. More details on the ironing templates 5 will be described later. It is noted from now that in the embodiment illustrated the ironing shapes 5 have a circular cross section, rather than flat as vice versa provided in the drawing machines of the prior art.

Associated with the machine 1 is a pneumatic duct indicated as a whole with 7 for feeding single tubular knitted articles to the ironing machine 1, of which more details will be described below.

The ironing machine 1 comprises a plurality of stations and more particularly a first station 9, in which tubular knitted articles coming from the pneumatic duct 7 are opened by spreading, that is, by annularly widening the elastic edge, and loaded onto the tubular ironing shapes 5. The ironing machine 1 also comprises a second station 11 for orienting the ironing template 5 around an axis of vertical rotation (B-B) of the ironing template 5, substantially parallel to the rotation axis 3 A of the carousel 3. With 12, a device for angular orientation of the ironing shapes 5 is generally indicated. The ironing machine 1 also comprises an actual ironing station 13, comprising an oven or heat treatment chamber 15, which can extend over a portion of circular crown around the axis of rotation 3A of the carousel 3. A station 17 is also provided for extracting or withdrawing the individual tubular products from the shapes drawing 5 and feeding to a packaging machine, not shown.

Fig. 2 illustrates in greater detail the configuration of the pneumatic duct for feeding the individual tubular knitted articles towards the machine 1. The pneumatic duct 7 comprises an inlet end 7A and an outlet end 7B, the latter in flow communication with a device for opening the elastic edge of tubular knitted articles, which will be described in greater detail with reference to subsequent Figs. 3 to 6. Between the inlet end 7A and the outlet end 7B the pneumatic duct 7 has a series of elements that divide the pneumatic duct 7 into sections. Starting from the inlet end 7 A, a first closing gate 21, a first air intake 23 and a first passage sensor 25 are arranged along the pneumatic duct 7 to detect the passage of the long-meshed tubular product in the pneumatic duct. 7, a first suction mouth 27, a second gate 29, a second air intake 31, a second passage sensor 33. A branch line 35 is associated with the pneumatic duct 7, ending with an exhaust bell 37 in communication of fluid, through a third gate 39, with a second suction mouth 41, for the purposes described below.

Each air intake 23 and 31 has a respective opening and closing gate valve 23A and 31 A, respectively. The suction mouth 27 has its own opening and closing gate 27A. In the illustrated embodiment, the individual tubular knitted articles are inserted manually with a predetermined orientation inside the inlet end 7A of the pneumatic duct 7 and are conveyed to the outlet end 7B of the pneumatic duct 7, to be inserted in the device to open the elastic edge of the tubular product and allow it to be subsequently loaded onto the ironing template 5.

The feeding sequence of the individual tubular knitted products inside the pneumatic duct 7 will be described with reference to the sequence of Figs. 12A- 12S.

The device for opening the elastic edge of the tubular knitted article is located in the station 9 of the machine 1, where the tubular knitted article is conveyed by the pneumatic duct 7 and is loaded onto one of the ironing templates 5 of the machine I.

The structure of the device for opening the elastic edge of the tubular knitted article is illustrated in detail in Figs. 3 to 6. The device is indicated as a whole with 43. The device 43 is connected by means of a fitting 7C to the pneumatic duct 7. The fitting 7C is arranged approximately coaxially to a hollow body 45, with a longitudinal axis A-A. Between the hollow body 45 and the tubular fitting 7C there is a feeder, indicated as a whole with 47.

In the illustrated embodiment, the feeder 47 comprises a pair of rollers 49 rotating around axes 49A substantially parallel to each other and orthogonal to the axis A-A of the hollow body 45. In Figs. 3 and 4, 51 indicates an electric motor which controls the rotation of at least one and preferably both rollers 49 of the feeder 47. The rotation of the rollers 49 can be controlled in a clockwise or anti-clockwise direction according to the phases of manipulation of the knitted tubular product, as described in greater detail below. The rollers 49 are counter-rotating, so that a tubular knitted product inserted in the groove defined between the rollers can be made to move forward or backward according to the direction of rotation of the rollers 49.

In some embodiments an actuator, for example a cylinder-piston actuator 89, can be provided to move the rollers 49 of the feeder 47 away and approach each other with an orthogonal movement to the rotation axes 49A of the rollers.

The end part, that is, closer to the rollers 49, of the tubular fitting 7C can be equipped with holes 7D which place Γ inside the tubular fitting 7C in flow communication with a suction mouth 91, for the purposes that will be clarified hereinafter.

The hollow body 45 has an internal volume 53 delimited by a wall 55 which can have a substantially axial-symmetrical shape with respect to the axis A-A. The internal volume 53 of the hollow body 45 can have a first converging portion 53A and a second diverging portion 53 B. The two portions 53 A and 53B of the internal volume 53 of the hollow body 45 can have a substantially frusto-conical shape and be joined in an intermediate position of the longitudinal extension of the hollow body 45. In the illustrated embodiment, the converging portion 53 A has a greater longitudinal development, approximately double with respect to the longitudinal development of the diverging portion 53 B. In other embodiments, the length of the two converging portions 53A and diverging 53B may be different from those shown.

The hollow body 45 has an inlet opening 45A and an outlet opening 45B for the tubular knitted product. The inlet opening 45A and the outlet opening 45B are preferably coaxial and longitudinally spaced along the axis A-A of the hollow body 45. The cross section of the internal volume 53 and of the inlet openings 45A and outlet 45B can be circular .

The wall 55 of the hollow body 45, delimiting the internal volume 53 has an entrance edge 55A surrounding the entrance opening 45A and an exit edge 55B that surrounds the exit opening 45B.

A suction arrangement is associated with the hollow body 45. In the illustrated embodiment, a first suction chamber 57 develops around the hollow body 45 which forms part of the suction arrangement and which can be delimited by a wall 59. The first suction chamber 57 is equipped with one or more suction openings 58 , see in particular Fig. 6. In the illustrated embodiment, suction openings 58 are provided which are diametrically opposite to each other. The possibility of having a different number of suction ports is not excluded.

The first suction chamber 57 has a downward-facing air passage, which can be selectively opened and closed by means of a closing member 61 which can form an opening wall. The closing member 61 can comprise a plurality of foils, for example two foils 61A and 61B, movable with respect to each other.

In the drawing, the double arrows f61A and f61B indicate the opening and closing movement of the two plates 61 A, 61B to open and close the first suction chamber 57. With 63A and 63 B two actuators are indicated, for example two pneumatic cylinder-piston actuators or hydraulic ones which serve to control the movement of the two laminae 61A, 61B forming the closing member 61. In other embodiments, the closing member 61 may have a different shape, for example it may comprise a single lamina, or it may be made in the form of an openable and closable diaphragm, like an optical diaphragm.

In Figs. 5 and 6 the closing member is shown in a closed arrangement, in which the two plates 61A and 61B form a wall which is opposite the outlet opening 45B of the hollow member 45, at a certain distance from the edge 55 B. The distance between the trailing edge 55B of the wall 55 and the surface of the foils 61 A and 61 B facing the hollow member 45 is such as to leave a gap I between the trailing edge 55 B of the wall 55 and the closing member 61. Through the interspace I, which essentially forms an annular opening surrounding the longitudinal axis A-A of the hollow member 45, the first suction chamber 57 is in flow connection with the internal compartment 53 of the hollow body 45 .

In proximity to the outlet opening 45B and the outlet edge 55B, the hollow body 45 is provided with radial suction ports 65 which are part, together with the suction chamber 57, of the suction arrangement. In the illustrated embodiment, the ports 65 have a substantially circular section, but this is not binding. They consist of through holes which extend through the entire thickness of the wall 55. The ports 65 are preferably placed as close as possible to the trailing edge 55 B and in any case in the diverging portion 53B of the internal volume 53. The ports 65, arranged circumferentially or annularly around the longitudinal axis A-A, place the internal volume 53 of the hollow member 45 in flow communication with the first suction chamber 57.

Forks 67 can be arranged between the rollers 49 of the feeder 47 and the inlet opening 55 A of the hollow member 55 which can approach and move away from each other under the control of linear actuators, for example cylindro-piston actuators 69. The f67 indicates the opening and closing movement of the forks 67.

Under the hollow member 45 there is a pr elevator indicated as a whole with 71, 11 pr elevator 71 is shown in two different operating positions in Figs. 3 and 4. In the embodiment illustrated, the picker 71 has a retractor that can consist of four fingers 73 that can be joined to each other or spread apart, that is, spaced from each other. In Figs. 5 and 6 the fingers 73 of the picker 71 are shown in the position of mutual approach, ie of minimum distance with respect to the longitudinal axis A -A. In Fig. 4 the fingers 73 are, conversely, shown in a spread position. Actuators 75 carried for example by a plate 77 can be provided to control the spreading and approaching movement of fingers 73.

In the illustrated embodiment, the pickup 71 further comprises a second suction chamber 79, in flow communication with one or more suction mouths 80. The second suction chamber 79 is carried by the plate 77.

The plate 77 forms a slide and can be equipped with shoes 81 (see in particular Figs. 3 and 4) which are engaged in sliding on linear guides 83 having a longitudinal development substantially parallel to the longitudinal axis A-A. The movement according to 77 of the slide 77 along the guides 83 can be controlled by a motor 85 (Figs. 3 and 4).

By means of the movement according to the double arrow 77 of the slide 77, the pick-up organ 71 can be moved from one to the other of the two positions illustrated in Figs. 3 and 4 and also brought to an even lower position than that illustrated in Fig. 4, to load the single tubular knitted articles onto the ironing templates 5 according to an operating cycle which will be described with reference to the sequence of Figs. 12A to 12S.

Figs. 7 and 8 show a tubular drawing shape 5 in an axonometric view and in a longitudinal section, respectively. In the illustrated embodiment, the drafting template 5 comprises an outer jacket 93 having a substantially cylindrical shape, which can be supported, for example by means of bearings 95, on a central support 97 which extends inside the jacket 93 along a longitudinal axis B-B of the ironing template 5. The central supports 97 of the various ironing templates 5 carried by the rotating carousel 3 can be fixed with respect to the rotating carousel 3. In advantageous embodiments, the outer jacket 93 is integral with an inner sleeve 99 which forms a friction wheel 101, protruding radially with respect to the cylindrical jacket 93. The support 97 is integral with a tubular body 103 with a flange 105 for anchoring the support 97 to the rotating carousel 3.

The described conformation allows the jacket 93 forming the external surface of the ironing shape 5 to rotate around the longitudinal axis B-B on the bearings 95 with respect to the internal support 97.

Coaxially to the support 97 and to the outer jacket 93, inside the drawing shape 5, and preferably inside the support 97, develops a stem 107 which ends with a flat extractor 109, for example approximately rectangular, which can protrude axially from a closure disk 111 upper of the drafting template 5, fixed with respect to the support 97. The stem 107 is provided with an axial extraction and retraction movement according to the double arrow fi 07 to extract the extractor F 109 through the closure disk 111. In some embodiments, the stem 107, which can be hollow internally, can have a lower end 107A opposite the extractor 109, to which a feeler 115 cooperating with a cam or with an actuator that controls the movement according to the double arrow is fixed fi 07 for extraction and retraction of the stem 107 and of the extractor 109.

The friction wheel 101 is configured to cooperate with a driving friction wheel 121, visible in particular in Figs. 9A and 9B, of the angular orientation device 12 for angularly orienting the ironing templates 5. The friction wheel 121 is arranged in the station 11 of the ironing machine 1 and has the purpose of controlling the rotation of each ironing template 5 around the own axis of rotation B-B longitudinal in order to angularly position the external jacket 93 and the tubular knitted product invested on it, with respect to the internal support 97 and therefore to the extractor 109. As schematically indicated in Fig. 1, the station 11 comprises an optical or other reader schematically indicated by 123, which detects the angular position of the drawing shape 5 with the tubular knitted article inverted thereon, to angularly orient the tubular knitted article, arranging it as required for the subsequent packaging operation .

In some embodiments the motorized friction wheel 121 can be rotated by an electric motor 123, by means of a pair of pulleys 125, 127 and a belt 129. In some embodiments the friction wheel 121, the motor 123 and the transmission members 125, 127, 129 can be carried by a slide 131 sliding along a guide 133 oriented in a radial direction with respect to the rotating carousel 3. As can be easily understood from the comparison between Figs. 9A and 9B, a movement according to the double arrow 31 of the slide 131 can bring the motorized friction wheel 121 alternatively into a position of contact with the friction wheel 101 of a drafting template 5 (Fig. 9A) or into a position withdrawn, in which the motorized friction wheel 121 does not interfere with the passage of the ironing templates 5 moved along a circular trajectory by the rotating carousel 3 which rotates around the axis 3 A according to the arrow f3.

Fig. 10 shows in an axonometric view the inlet zone of the heat treatment chamber or oven 15 arranged in the ironing station 13 of the ironing machine 1. The heat treatment chamber 15 comprises an inlet 15A, which can be closed by elastic sheets 132 deformable upon passage of the ironing templates 5, so as to allow the ironing templates 5 to enter, avoiding excessive heat loss through the inlet opening 15A. A similar arrangement can be provided on the opposite side of the ironing templates from the heat treatment chamber 15.

In Fig. 10 ducts 134, 135 for the circulation of hot air, an impeller 137 for the circulation of hot air, and a filter 139 are schematically indicated. The air heating can take place through electrical resistances, not shown. In some embodiments the heat treatment can occur dry, while in other embodiments moist air or steam can be used. The residence time of the ironing templates 5 and of the tubular knitted items in the heat treatment chamber may vary according to the temperature inside the heat treatment chamber. For example, with temperatures of the order of about 75 ° -85 ° C, the residence time can be 20-30 seconds.

In some embodiments, not shown, the knitted tubular product M can be moistened before entering the heat treatment chamber 15. For this purpose, a specific station can be provided, for example equipped with nebulizers that spray nebulized water on the tubular product. knitted M.

In the station 17 of the ironing machine I a final drafting unit and removal of the tubular knitted article of the ironing templates 5 can be arranged, which final drafting unit removes the tubular knitted articles from the tubular knitting templates 5 afterwards. the heat treatment in the heat treatment chamber 15, and unloading them on an outlet conveyor 141 (Figs. HA, 11B) which transports the stretched tubular knitted articles to a packaging machine, not shown.

Figs. 11A and 11B show the final drafting and removal assembly of the stretched tubular knitted articles. The group is indicated as a whole with 151. The final drafting and removal assembly 151 can comprise two conveyor belts 153, 155 driven by a motor 157 and conveyed around a return wheels 159, 161 carried by arms 163, 165. As can be seen from the comparison between Figs. HA and 11B, the arms 163 and 165 are movable, for example oscillating to assume a first position (Fig. HA), in which the conveyor belts 153, 155 are spaced apart, at least in the area of the deflection wheels 159, 161, and a side-by-side position in which the conveyor belts 153 and 155 are side-by-side at least along a substantially vertical straight section (Fig. 11B). The alternating oscillation movement according to the double arrows fi 63 and f 165 of the arms 163 and 165 can be controlled by means of an actuator 169, and by means of tie rods 171, 173, which join the two oscillating arms 163, 165 to a rotating member 175 equipped with an alternating rotation movement detectable by the comparison of Figs.

11 A and 11B.

As shown in broken lines in Fig, HA, each drawing shape 5 passes under the final drawing and removal assembly 151 with the extractor 109 in the extracted position, which extends between the arms 163, 165. When a tubular knitted product is struck on the drafting template 5 and partially raised by the extractor 109, the closing of the arms 163, 165 causes the conveyor belts 153, 155 to approach the extractor 109 and the pinching and crushing of the tubular knitted product between the The extractor 109 and the two conveyor belts 153, 155, The subsequent actuation of the conveyor belts according to the double arrows fi 53 and f 155 causes the extraction of the tubular knitted article from the drafting template 5 and its feeding towards the outlet conveyor 141. Since the tubular knitted product is still hot due to the heat treatment undergone in the heat treatment chamber 15, the pressure of the two conveyor belts 153, 155 stretches and stabilizes a the fold of the tubular knitted article before it is discharged onto the outlet conveyor 141.

Having described the main members of the drawing machine I, with reference to the sequence of Figs. 12A-12S, a work cycle will now be described in detail for loading a tubular knitted article on a drawing template 5, which will move the tubular knitted article through stations 11-13 and 17 to iron a tubular knitted article. knit and remove it from the ironing template 5 in order to subsequently send it to the packaging machine.

Figs. 12A to 12G illustrate the sequence of introducing a tubular knitted article into the pneumatic duct 7 and advancing the tubular knitted article along said pneumatic duct 7 up to the device 43 to open the elastic edge of the tubular knitted article.

In Fig. 12A the tubular knitted product is schematically indicated by M. It has a closed tip P at a first end and an elastic edge E at a second end. In some embodiments, writings or other elements placed in a determined position with respect to the shape of the tubular knitted product M can be provided on the knitted tubular product M. These elements are schematically indicated with S. The knitted tubular product M can be a sock or a stocking, which can have a heel T. The elements S for angular positioning have a predetermined position with respect to the shape of the toe P and the position of the heel T, if present.

The knitted tubular product M is inserted, for example manually, into the inlet end 7A and sucked into the inside of the pneumatic duct 7. In this operating phase, the first gate 21 is in the open position, the first air inlet 23 is closed by the gate. 23A, while the first suction mouth 27 is open and air is sucked (arrow A) through said first suction mouth 27, so as to generate an air current C1 which from the inlet end 7A reaches the suction mouth 27 .

When the tubular knitted article M is inserted at the inlet end 7 A, it is dragged by the suction towards the first suction mouth 27. The passage sensor 25 detects the passage of the tubular knitted article M and causes the closure of the gate 21, the opening of the first air intake 23 and the cessation, after a predetermined time, of the suction through the first suction mouth 27. The knitted tubular product M continues its feeding stroke along the duct pneumatic 7 due to the effect of inertia after closing the first suction mouth 27, beyond the point where the latter is located, to enter (as shown in Fig. I2C) the section of the pneumatic duct between the first suction mouth 27 and the closing gate 29 which, in this phase, is closed. The gate 29 is subsequently opened, and the tubular knitted product passes through the gate 29 until it passes the second passage sensor 33, which generates a signal when the tubular knitted product M passes, which causes the closure of the first outlet. air 23 and gate 29 (see Fig. 12E). The second air intake 31 is also opened by opening the gate 31 A. The tubular product M continues its advancement towards the device 43 by inertia until it reaches the device 43, arranging itself in the terminal part of the tubular fitting 7C (Fig. 12F) .

In the first section of the pneumatic duct 7, upstream of the gate 29 can enter, in the manner described above, a second tubular article with mesh M, which will be arranged to be subsequently fed to the device 43, when the tubular fabric with mesh M has just been inserted will have been opened along the elastic edge and moved away from the device 43.

In Fig. 12G suction has been activated through the branch 35 of the pneumatic duct 7 by opening the gate 39 and thus generating an air flow represented by the arrow A in Fig. I2G. This flow of air A stretches the knitted tubular product M upstream of the rollers 49 of the device 43. In fact, when the knitted tubular product reaches the lower part of the tubular fitting 7 C, its elastic edge E is captured in the groove between the rollers 49, whose rotation (arrow f49 in Fig. 12H) causes the tubular knitted article to advance, and in particular its elastic edge E up beyond the groove between the rollers 49, downstream of which a photocell or other is arranged detection organ 191,

When the elastic edge E of the knitted tubular product M intercepts the photocell 191, the signal generated by it causes the suction to be activated through the branch 35 the second suction mouth 41, so as to stretch the portion of the tubular product upwards. M upstream of the groove between the rollers 49.

With the tubular knitted product M, stretched by the effect of the suction (arrow A in Figs. 12H and 121), suction can be activated through the first spirating chamber 57. Continuing the rotation according to f49 of the rollers 49 causes the advancement of the elastic edge E of the tubular knitted product M towards the internal volume of the hollow body 45, as shown in the following Fig. 12J. To facilitate this advancement of the elastic edge E, air is sucked in through the suction openings 58, the first suction chamber 57, the ports 65, the interspace I, the internal volume 53 of the hollow body 45, and the inlet opening 45A, as shown by the arrows Al in Fig.12J,

The air current that is generated in the internal volume 53 of the hollow body 45 causes the widening or opening of the elastic edge E of the tubular knitted product M which gradually advances inside the hollow body 45.

Fig.12K shows the effect of the advancement of the tubular knitted product M with its elastic edge E towards the outlet opening 45B of the hollow body 45, under the effect of the continuous suction through the first spirating chamber 57, the radial openings 55 and the interspace I. This suction causes the elastic edge E to initially adhere to the internal surface of the divergent portion 53B of the internal volume 53 of the hollow body 45 and subsequently to enter the interspace I.

When the tubular knitted article M with its elastic edge E is arranged as shown in Fig. 12K, the radial suction ports 65 are substantially closed by the fabric of the tubular knitted article and Γ annular gap I is at least partially blocked by the fabric of the elastic edge E Consequently, the suction inside the first suction chamber 57 determines a pressure reduction, which can be detected by a vacuum switch (not shown). When the vacuum switch detects a certain degree of vacuum, that is an under-pressure with respect to the atmospheric pressure in the first suction chamber 57, this means that the tubular fabric with mesh M is correctly arranged as shown in Fig. 12K, obstructing for the most part the interspace I and the radial suction ports 65. When this degree of depression is reached inside the suction chamber 57, suction can cease.

In the subsequent phase illustrated in Fig. 12L, the rollers 49 stop rotating, retaining in the groove between them the end part, i.e. adjacent to the tip P, of the tubular knitted product M. The closing member 61 is opened and, continuing the suction through the first suction chamber 57, air begins to enter according to the arrows A3 from the outside through the passage of air left open by the removal of the sheets 61 A, 61 B forming the closing member 61 causing the edge elastic E brought into contact with the wall 55 of the hollow body 45 remains adherent to the exit edge 55 B of the wall 55.

In the next step, illustrated in Fig. 12M, the pick-up 71 is raised until its fingers 73 are partially inside the internal volume 53 of the hollow body 45 passing through the outlet opening 45 B. Conveniently, the fingers 73 can be shaped to have a tapered distal portion, which can easily fit into the diverging portion 53B of the internal volume 53 of the hollow body 45. By lifting the pickup 71 to the position shown in Fig. 12M, the second suction chamber 79 is brought, with its own inlet suction, in flow communication with the first suction chamber 57 and with the internal volume 53 of the hollow body 45.

At this point, the intake of air through the suction mouths 80 can be activated. This flow of air, represented by the arrows A4 in Fig. 12N passes through the internal volume 53 of the hollow body 45, entering through the inlet opening 45 A, exits from the internal volume 53 of the hollow body 45 through the outlet opening 45B, penetrates inside the second suction chamber 79 and exits from the suction mouths 80, The flow of air that is generated in the narrow passage left free between the internal surface of the wall 55 of the hollow body 45 and the fingers 73 drags the tubular knitted article M detaching it from the trailing edge 55B and bringing the elastic edge E of the tubular knitted article M to embrace the fingers 73 and slide along them until it reaches the position illustrated in Fig. 12N. The flow of air A4 necessary for this purpose is conveyed towards the bottom of the second suction chamber 79 by a collar 82 approximately coaxial with the fingers 73 of the pickup 71, which collar 82 extends towards the bottom of the suction chamber 79 partially covering the suction mouths 80 so that the flow of air A4 laps the pin formed by the fingers 73 close together and generates the dragging force required to hit the elastic edge E of the tubular knitted product M on the fingers 73 which are in their position of mutual approach.

Fig, 120 shows the device 43 with the pickup 71 in an axonometric view in this operating step. Fig. 12P shows the next phase, in which the closing member 61 returns to its closed position after the pick-up has started its downward stroke (arrow f71 in Fig, 12P) by removing the fingers 73 from the inside of the hollow body 45. A subsequent knitted tubular product MI can at this point enter the groove between the rollers 49, which resume their rotation to start a new processing cycle, while the knitted tubular product M invested on the fingers 73 of the pick-up 71 can be brought down and loaded onto a drawing template 5 which is positioned coaxially to the device 43 and its pick-up 71.

In Fig, 12Q a drawing shape 5 is schematically shown in a coaxial position with the pickup 71, the fingers 73 of which have been brought into a splayed position.

Continuing its downward movement according to the arrow f7I, the pickup 71 loads the tubular knitted article M onto the ironing template 5, having previously spread the teeth 73. The latter are at a distance from each other such as to allow the insertion of the tubular shape 5 between the four fingers 73 spread apart. By continuing to lower the picker 71 according to arrow f71, the fingers 73 are removed from the tubular knitted product M, which is gradually loaded onto the ironing template 5, until it reaches the position of Fig. 12R. Now the tubular knitted article M is completely loaded on the ironing template 5, and the pickup 71 with its fingers 73 is at a lower level than the elastic edge E of the tubular knitted article M loaded on the upper part of the ironing template 5.

Fig. 12S is an axonometric view of the device 43 with the pick-up 7 1 and the drafting template 5 in the position reached in this phase. The picker 71 can at this point reverse its movement returning to a higher level than the distal end of the stretching template 5. The latter can thus advance angularly dragged by the rotating carousel 3 towards the subsequent angular positioning station 11. In station 11, by means of the friction wheel 101 integral with the outer jacket 93 of the ironing template 5 and the motorized friction wheel 121 (Figs. 9A and 9B), the knitted tubular product M can be rotated angularly, together with the outer jacket 93 of the ironing template 5, to bring the tubular knitted article M into the desired angular position with respect to the extractor 109. The latter is, in this phase, completely retracted inside the ironing template 5, under the upper surface of the disc 111. The angular positioning could also be carried out in a step following the stretching inside the heat treatment chamber 15.

In the sequence described with reference to Figs. 12A-12S it has been observed that the correct and complete opening of the elastic edge E, as well as its adhesion to the internal surface of the wall 55 of the hollow member 45 is determined through a reading of the pressure in the first suction chamber 57. If the tubular product a mesh fails to position itself correctly, i.e. if its elastic edge E does not cover the intake ports 65 correctly and / or does not fit into the cavity I, a sufficient degree of vacuum, i.e. a sufficient depression with respect to the external ambient pressure. This circumstance is detected by the vacuum switch (not shown).

Since the divarication, i.e. the opening of the elastic edge and of the tubular knitted product M until closing the suction ports 65 and the interspace I requires a certain time, if the pressure inside the first suction chamber 57 does not drop to the below a predetermined threshold within a determined time, this is interpreted by a control unit (not shown) of the ironing machine 1 as a failure or incomplete opening of the elastic edge E of the tubular knitted product M and is consequently a procedure for repeating the opening operation was started, or a unloading cycle of the tubular knitted product which did not open correctly.

In the first case (repetition of the opening operations), the rotation motion of the rollers 49 is reversed until the elastic edge E of the knitted tubular product M is brought back to the photocell 191 and the cycle described with reference to the sequence of Figs, 12H at 12S is repeated.

Alternatively, or if, despite the repetition of the opening operations, a signal of non-opening and spreading of the elastic edge E of the tubular knitted article M is given again, the tubular knitted article M which has not opened correctly can be unloaded. . This can take place according to the sequence illustrated in Figs. 13 A-3E.

In Fig. 13A a situation is schematically represented in which the knitted tubular product has not been correctly arranged inside the hollow member 45. The elastic edge E of the knitted tubular product M has adhered only to a portion of the internal surface of the wall 55 of the hollow body 45, obstructing only some of the suction ports 65 and only a part of the interspace I. The degree of vacuum required to proceed further with the loading operations of the tubular knitted product is not generated inside the suction chamber 57 M on the drawing template 5. As a consequence of this, the motion of the rollers 49 is first interrupted and then reversed, as shown by the arrows f49X in Fig. 13B. At the same time, suction is activated through the second suction mouth 41 opening the gate 39. The flow of air, indicated by the arrow A6 that is generated in the tubular fitting 7C, drags the tubular knitted article M upwards when it is released from the rollers 49. The flow of air A6 drags the knitted tubular product M up to inside the discharge bell 37. From here the knitted tubular product is removed by interrupting the suction by closing the gate 39. Due to the weight of the tubular product with mesh M a lower closing door 37A of the discharge bell 37 opens releasing the tubular knitted product M, for example into an underlying container (not shown).

While the disclosed embodiments of the object illustrated herein have been shown in the drawings and fully described above with details and details in relation to several exemplary embodiments, those skilled in the art will understand that many modifications, changes and omissions are possible. without materially departing from the innovative teachings, from the principles and concepts set out above, and from the advantages of the object defined in the attached claims. Therefore, the actual scope of the innovations described must be determined only on the basis of the broadest interpretation of the attached claims, so as to include all modifications, changes and omissions.

Claims (13)

MACHINE AND METHOD FOR IRONING TUBULAR KNITTED ARTICLES CLAIMS 1. A machine for ironing tubular knitted articles (M), comprising in combination; - at least one tubular shape (5) with a longitudinal axis (B-B); - a heat treatment chamber (15), the tubular shape (5) being insertable in the heat treatment chamber (15) and extractable therefrom; - a pick-up device (71) for picking up and loading tubular knitted articles on the tubular shape (5). 2. Machine according to claim 1, in which the tubular shape (5) is carried by a conveyor (3) configured and controlled to introduce the tubular shape (5) into the heat treatment chamber (15) and extract it from it. 3. Machine according to claim 1 or 2, further comprising an angular orientation device (12) of the tubular shape (5). 4. Machine according to claim 1, 2 or 3, further comprising a final drawing and removal unit (151), for removing the tubular knitted articles from the tubular shape (5). 5. Machine as per claim 4, in which the final drawing and removal assembly (151) comprises a pair of side by side and opposite conveyor belts (153, 155), defining a path for picking up the tubular knitted articles from the tubular shape (5 ). 6. Machine according to claim 4 or 5, in which the tubular shape comprises an extractor (109) which can be extracted and retracted with respect to one end of the tubular shape (5). 7. Machine as per claim 6, in which the extractor (109) has a flattened shape. 8. Machine according to one or more of the preceding claims, comprising a plurality of said tubular shapes (5). 9. Machine according to claim 8, in which said tubular shapes (5) are carried by a common conveyor, preferably in the form of a carousel (3) rotating around an axis preferably parallel to the longitudinal axes of the tubular shapes (5), 10. A method for ironing a tubular knitted product (M), comprising the steps of: - insert a tubular knitted article (M) to be ironed on a tubular shape (5); - subjecting the knitted tubular product (M) to a heat treatment when it is on the tubular shape (5); - remove the tubular knitted product (M) from the tubular shape (5). Method according to claim 10, further comprising the step of carrying out a final stretching operation on the tubular knitted article (M) while it is being removed from the tubular shape (M). Method as per claim 10 or 11, in which the step of removing the tubular knitted article (M) from the tubular shape (5) comprises the steps of: engage the knitted tubular product (M) by means of a pair of opposing conveyor belts (153, 155) pressed against each other; remove the tubular knitted article (M) from the tubular shape (5) by means of the two conveyor belts (153, 155) and iron the tubular knitted article (M) by mutual pressure of the two conveyor belts (153, 155). 13. Method as per claim 12, in which the step of engaging the knitted tubular product (M) by means of the pair of opposing conveyor belts (153, 155) comprises the step of lifting the knitted tubular product from one end of the tubular shape (5) by means of an extractor (109) housed in the tubular shape (5) and extractable therefrom; and press the two conveyor belts (153, 155) against each other with the extractor (109) and the tubular knitted product (M) interposed between the two conveyor belts (153, 155).