Device for handling tubular knitted articles, in particular socks and the like

Abstract

The device comprises: a tubular member (15) with an inlet end and an outlet end (15A), associated with suction means and inside which a tubular article (T) is sucked towards the outlet end; a moving pick-up element (21, 23) to engage a first end (P) of the tubular article (T) and remove it from the tubular member, said pick-up element which can be moved towards the outlet end; a shaped block (43), cooperating with the inner wall of the tubular member (15), to define a constriction with variable conformation at the outlet end of the tubular member. The constriction is suitable to define a narrow and elongated section of passage of the tubular article, in which said tubular article is forced to take a spread arrangement at least at the second end.

Description

TECHNICAL FIELD

The present invention relates to a device for handling tubular knitted articles, such as stockings, socks or the like, and in particular to prepare the article for subsequent handling operations, such as opening one of the ends thereof, in particular the end formed by the elastic edge.

STATE OF THE ART

In the production of tubular knitted articles, such as stockings or socks, circular knitting machines are used to produce tubular articles, with an elastic edge defining the end from which the sock is put on, and with a toe end which will be closed by sewing or linking. In some of these machines the toe is closed before the sock or other textile article is unloaded therefrom. In machines which are more conventional and of simpler construction, on the other hand, the sock or other article is unloaded in the form of a semi-finished article with the toe open. The semi-finished articles are then collected in containers, from which an operator picks them up one at a time to insert them over transport tubes that convey the article towards a sewing machine. There are also automatic mechanisms for handling the article and inserting it in the suitable position over the tube for transport towards the sewing machine. An example of devices of this type is described in U.S. Pat. No. 5,040,475.

One of the problems encountered in automated handling of semi-finished articles to be inserted over tubes for transport towards sewing machines, is represented by the difficulty in opening the end edge correctly. For this purpose various mechanisms have been studied.

For example, EP-A-0882829 describes a pneumatic system, in which the semi-finished article is sucked into a tube with a narrow section, positioned at the end of which is a rod-shaped member which is inserted into the end edge of the textile article, causing it to open. A stretching member then engages the elastic edge and stretches it to insert it over the transport tube.

Prior art solutions adopted to pick up the elastic edge of the tubular textile articles, such as socks or the like, have not provided satisfactory results.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the present invention is therefore to provide a particularly efficient device and method to prepare the elastic edge of a tubular textile article, such as a sock, a stocking or the like, to be subsequently stretched and inserted over a tube for transport towards a sewing machine or for other processing operations.

More generally, an object of the present invention is to provide a device particularly suitable to prepare a tubular knitted article, such as a stocking or sock, for subsequent handling operations, or for automatic recognition and subsequent handling operations.

In substance, therefore, according to a first aspect of the invention, a device is provided to handle tubular knitted articles comprising: a tubular member with a first end and a second end, associated with suction means and inside which a tubular article, comprising a first end portion and a second end portion, is sucked; a moving pick-up element to engage a first end portion, or first end, of the tubular article and remove it from said tubular member, said pick-up element which can be moved towards said second end of the tubular member; a shaped block, cooperating with the inner part of the tubular member, to define a constriction with variable conformation at the second end of the tubular member, said constriction being suitable to define a narrow and elongated section of passage of the tubular article, in which said tubular article is forced to take a spread arrangement at least at the level of the second end.

The first end and the second end of the tubular member can be composed respectively of an inlet end and of an outlet end for the tubular article.

According to an advantageous embodiment, the shaped block has a surface portion opposite a portion of the inner surface of the tubular member and substantially parallel thereto, to define a constriction with a cross section with an arched shape. The constriction has an approximately crescent conformation and can be modified during operation in the various operating steps, as will be explained hereunder.

Advantageously, the device can be provided with a suction mouth movable towards the second end of the tubular member, through which a flow of air is generated in said tubular member, oriented from the first end to the second end, to draw the tubular article. Advantageously, to block the tubular article in the most suitable position, an interception element can be inserted in the suction mouth, which prevents tubular articles from entering said suction mouth and which forms a stop for the tubular articles drawn by the flow of air.

The pick-up element, for example a mechanical gripper or the like, and the suction mouth can form a single unit movable parallel to the axis of the tubular member, although other solutions would also be possible, such as with independent units supporting the two elements. Integration in a single unit has clear advantages in terms of constructional simplicity and movement control.

According to an advantageous embodiment, the pick-up element, the shaped block and the suction mouth are arranged and produced so that when the suction mouth is moved towards the second end of the tubular member, the pick-up element is interposed between the shaped block and said suction mouth.

According to an advantageous embodiment, the shaped block can be provided with a movement according to a direction inclined with respect to the axis of the tubular member to move towards and away from a portion of the inner surface thereof. It would also be possible for the shaped block to be provided with a movement orthogonal to the axis of the tubular member.

To handle the tubular article after the elastic edge thereof has been flattened and prepared for subsequent pick-up, the device can be provided with a stretching device, arranged and controlled to engage a spread end portion of the tubular article, when the latter has been almost fully removed from the tubular member, and to open out said end portion.

According to another aspect, the invention relates to a device of the aforesaid type, wherein said suction means, said tubular member and said pick-up element are controlled and arranged to partially insert a tubular article into said tubular member through the second aperture of said tubular member, and to remove it therefrom, said shaped block being arranged in a position for maximum aperture of the second end of the tubular member when said article is partially inserted in said tubular member and in a position of maximum constriction of the cross section for passage of the tubular article, when the latter is removed again from the tubular member.

The device can also have a dual station, with two tubular members, arranged and produced to flatten or spread two different end portions of the same tubular article in sequence and separately.

According to a different aspect, the invention relates to a method for preparing the elastic edge of a tubular knitted article, such as a stocking or a sock, for subsequent handling to be opened and stretched, comprising the steps of:

• • providing a tubular member having a first end and a second end;
  • arranging at least a part of the tubular article inside said tubular member, with an end portion of said tubular article in proximity to said second end of the tubular member;
  • producing in said tubular member, in proximity to said second end, a narrow and elongated section of passage;
  • removing the tubular article from the tubular member spreading said first end portion of said article by making it pass through said narrow and elongated section.

The narrow and elongated section can be constricted when the article has been more or less completely removed from the tubular member, to block and engage it at the level of two opposite sides of the elastic edge.

According to a further aspect, the invention relates to a device for flattening or spreading at least one portion of a tubular article, comprising: a tubular member, inside which said tubular article can be at least partially inserted; a moving shaped block to modify the cross section of said tubular member, said moving block being controlled to take at least a first position of maximum aperture of the cross section of the tubular member and a second position of maximum constriction of the cross section of said tubular member, said second position defining a cross section elongated in a transverse direction with respect to the direction of movement of said tubular article in said tubular member.

A suction system can be associated with the tubular member, to at least partially insert the tubular article into the tubular member by suction. The suction system can be reversible, to generate a flow of air inside said tubular member in one direction or in the opposite direction alternatively.

In an advantageous embodiment, a pick-up element can advantageously be associated with the end of the tubular member through which the tubular article is removed, to engage the article and move it with respect to said tubular member. The pick-up element can be provided exclusively to remove a tubular article passing through the tubular member. Otherwise, the pick-up member can be moved towards the tubular article at the inlet end of the tubular member, so that this article is sucked inside a certain portion of the tubular member. Subsequently, the same pick-up element can gradually remove the tubular article from the tubular member by pulling it through the constricted cross section, to flatten it, or spread it transversely to the longitudinal moving direction.

If the tubular member is associated with suction systems that insert each tubular article into the tubular member by suction, an interception element can advantageously be provided to block a tubular article sucked through said tubular member.

According to yet another aspect of the present invention, a method is provided to spread or flatten at least a portion of a tubular knitted article, wherein the tubular article is inserted at least partially into a tubular member and is fed in a direction substantially parallel to the longitudinal extension thereof through a cross section with a narrow and elongated passage in a transverse direction with respect to the direction of feed of the tubular article.

In a particular embodiment of the method according to the invention, a portion of the tubular article is inserted in a tubular member; the cross section of at least one part of said tubular member is modified to produce a narrow passage which is elongated in a direction transverse with respect to the longitudinal extension of the tubular article; and said at least one portion of the tubular article is forced to pass through said narrow and elongated passage.

In an improved method, the tubular article is sucked inside the tubular member; a first end of said tubular article is engaged by a pick-up element; and said pick-up element is moved away from the tubular member, thus pulling the tubular article through said narrow and elongated cross section of passage.

According to an embodiment of the method according to the invention, the tubular article is sucked inside the tubular member; a first end of the tubular article is engaged by a pick-up element; and said pick-up element is moved away from the tubular member pulling the tubular article through said narrow and elongated cross section of passage.

Further advantageous features and embodiments of the invention are indicated in the appended claims and will be described in greater detail hereunder, with reference to a non-limiting example of embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

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

FIG. 1 is an overall axonometric view of a machine for handling socks or other tubular textile articles incorporating the device according to the invention;

FIG. 2 is an enlargement of a detail in FIG. 1;

FIG. 3 is an enlargement of the device according to the invention with the non-relevant parts removed;

FIG. 4 is a view of the device in FIG. 3 according to a different angle and with further parts removed;

FIG. 5 is a longitudinal section of the device according to the invention;

FIG. 6 is a plan view according to VI-VI in FIG. 4;

FIG. 7 is an axonometric view of the stretching device which engages the elastic edge of the article flattened by the device according to the invention;

FIGS. 8A and 8E illustrate an operating sequence of the device;

FIGS. 9 to 14 are various views of a modified embodiment of the device according to the invention;

FIGS. 15A-10F illustrate an operating sequence of the device in FIGS. 9 to 14 and of a further device, placed successively to the first device.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

FIGS. 1 to 8 describe in detail an embodiment of the invention, wherein each tubular article is picked up from a container and fed to the device for spreading or flattening an end portion (hereinafter also called end) of the article. Each article is picked up so that it reaches the flattening or spreading device always facing in the same direction. When the article is a sock, it always reaches the tubular member of the spreading or flattening device with the toe facing forward and with the edge facing backward, i.e. with the toe as the leading portion and with the edge as the trailing portion with respect to the direction of feed. However, as will be apparent hereunder, this is not necessary.

FIG. 1 shows a machine as a whole, wherein the device according to the invention can be utilized. The machine, known per se, does not form the subject matter of the present invention and will therefore be described very briefly and limited to what is required to understand the function and the objects of the device forming the subject matter of the present invention, which however could also be applied and used in machines or apparatus differing from the one illustrated herein. The machine in FIG. 1, indicated as a whole with 1, comprises a container 3, inside which tubular knitted articles, such as socks or the like, are placed randomly. A pick-up member 5 picks up the articles individually and lifts them according to the arrow f5 to take them to the inlet of a suction duct 7 through which the individual articles are sucked inside an intermediate standby station 9, where they are spread through suitable pneumatic suction.

The inlet and outlet section 9A of the station 9 is connected, as well as to the feed duct 7 of the articles from the container 3, also to an unloading duct 11 for incorrectly oriented articles, said duct 11 terminating with a device 13 known per se, from which the socks or other tubular knitted articles are unloaded back into the container 3. The section 9A of the station 9 also communicates with a tubular member 15, the upper end of which is associated with the device of the present invention, indicated as a whole with 17 and described in greater detail hereunder.

The tubular articles could also be fed, for example, directly to the inlet of the tubular member 15 through a pneumatic transport duct coming from one or more circular knitting machines.

Represented schematically at the side of the tubular member 15 is a transport tube 19, on which the individual tubular articles are placed by inserting the elastic edge thereof over the outer surface of the transport tube 19. The transport tube 19 is fixed to a conveying device, not shown and of a type known per se (e.g. a carousel mechanism), to transfer the tubular article, which is inserted each time over the transport tube 19, towards a sewing station (not shown).

A device, shown as a whole at 21, stretches the elastic edge of each tubular article to insert it over the outer surface of the transport tube 19. Several transport tubes 19 can be provided on a conveyor or transport device to serve, for example, a machine with several stations, in which various handling operations on the tubular article are carried out to prepare for subsequent sewing, which can take place in the last of the stations of this machine (not shown). The various preparatory operations are carried out keeping the article on the respective transport tube.

Greater details of the members associated with the upper end of the tubular member 15 can be seen in the enlargement in FIG. 2 and, with regard to the device 17 of the present invention in particular, also in the subsequent FIGS. 3 to 7.

The tubular member 15 has an inlet end connected to the inlet section 9A of the station 9 and an outlet end, indicated with 15A in FIG. 5, through which the individual tubular knitted articles which are inserted into the tubular member 15 are removed to be subsequently fed towards the transport tube 19. The handling device 17 of the present invention is associated with the outlet end 15A of the tubular member 15.

This device has a pick-up member composed, in this specific embodiment, of a mechanical gripper with a fixed element 21 cooperating with a moving element 23. An actuator 25 controls movement according to the double arrow f23 of the moving part (in the form of a slider) of the pick-up element. The movement according to the double arrow f23 moves the slider 23 towards and away from the fixed part 21 of the gripper.

The gripper 21, 23 forming the pick-up unit is supported by a vertically moving element, indicated as a whole with 27, provided with a movement according to the double arrow f27 parallel to the axis X of the tubular member 15. The unit 27 is provided with the movement according to the double arrow f27 by means of a belt 29 controlled by a motor 31 (FIG. 1). The moving unit 27 forms a suction mouth 33 which can be made to communicate with a suction duct 35, along which an opening and closing gate valve 37 is positioned. The suction mouth 33 produced in the moving unit 27 is inferiorly delimited and partially closed by a grid, a mesh or another equivalent interception element, indicated with 37, which is positioned directly above the moving cursor 23 of the gripper 21, 23. As will be explained hereunder, the purpose of the grid or other interception element 37 is to prevent the tubular articles sucked through the tubular member 15 from being sucked inside the suction mouth 33 and the suction duct 35.

In proximity to the outlet end 15A of the tubular member 15, an actuator 39 connected to a bracket 41 is supported. The actuator 39 is designed to control movement according to the double arrow f43 of a shaped block 43, which for this purpose is constrained to the rod 39A of the piston-cylinder actuator 39. The shaped block 43 has a curved edge 45 following the profile of the inner surface of the tubular member 15. By moving the shaped block 43 according to f43, towards or away from the opposite inner surface of the tubular member 15, it is possible to modify the cross section of a constriction of the tubular member 15 delimited by the inner surface of the tubular wall of said member and by said edge 45 of the shaped block 43. This constriction is located under the gripper 21, 23 and the grid or other interception member 37 and the crescent-shaped conformation thereof is shown clearly in the top view in FIG. 6 of the upper end of the tubular member 15.

The device is produced to receive the tubular knitted articles inside the tubular member 15, oriented with the toe to be sewn facing forward (with respect to the direction of feed of the tubular articles indicated with F) and the elastic edge facing backward. When the shaped block 43 is in the retracted position, i.e. with the edge 45 farther away with respect to the wall of the tubular member 15, a relatively wide passage is created, through which the end of the tubular article, which is inserted first into the tubular member 15, can easily pass to reach the grid 37, against which said end stops due to suction through the suction mouth 33 and the suction duct 35.

As will be illustrated in greater detail with reference to the sequence in FIGS. 8A to 8E, the device is produced to grip the toe of the article through the gripper 21, 23 and to remove it from the tubular member 15, making the elastic edge pass through the constriction defined by the edge 45 of the shaped block 43 and by the opposite wall of the tubular member 15, if necessary having constricted -the section of passage by moving the shaped block 23 with the edge 45 thereof towards the inner surface of the tubular member 15. In this way, during removal of the tubular textile article from the tubular member 15, the end composed of the elastic edge thereof is flattened, or more precisely arranged according to a curvilinear position following the shape of the edge 45, to facilitate subsequent pick-up by the stretching member described hereunder.

As can be observed in particular in FIG. 4, the upper surface of the shaped block 43 has a seat 43A, inside which the slider 23, which is positioned in said seat 43A when the unit 27 is in the lowered position, can slide.

FIG. 4 also shows the presence of a gasket 51 which surrounds the upper end 15A of the tubular member 15. The purpose of this gasket is to provide a seal between the suction mouth 33 and the tubular member 15 when the unit 27 is in the lowered position (arrangement in FIG. 5) abutting against said gasket.

Operation of the device described hereinbefore is as follows (see sequence in FIGS. 8A-8E). The tubular textile article indicated with T is sucked inside the tubular member 15 due to suction through the duct 35 and the suction mouth 33, which has been moved to the level of the upper end 15A of the tubular member 15 in a first phase of suction of the article. The article T has previously been correctly oriented in one of the possible known ways, e.g. through an optical detection system associated with the intermediate station 9. Therefore, each article T which reaches the inside of the tubular member 15 has the toe, indicated with P, facing upward and the elastic edge, indicated with B, facing downward. The toe P is abutting against the grid or other interception element 37 when suction is generated inside the tubular member 15 by means of the suction duct 35.

Subsequently, the slider 23 is pushed towards the fixed stop 21, pinching the toe P of the textile article T between the members 21 and 23. The moving unit 27 is raised according to the arrow f27 to remove the tubular article T from the tubular member 15. In this phase suction is maintained inside the tubular member 15 from the outlet end 15A towards the inside thereof, said suction helping to stretch and flatten the tubular textile article T, and in particular the elastic edge B thereof.

Suction towards the inside of the tubular member 15 can be obtained through suction mouths arranged along the various pneumatic ducts of the device, by appropriately closing and opening respective gate valves. In FIG. 1 the suction mouths are indicated with 101, 103, and the gate valves are indicated with 105, 107, 109, 111.

In substance, a section of passage with an arched and approximately crescent-shaped conformation is formed between the shaped edge 45 and the inner surface of the wall of the tubular member 15 through which the tubular article T is forced to pass taking a spread out arrangement, facilitated in this by the inflow of air into the tubular member 15, and follows the (substantially cylindrical) surface of the wall of the tubular member 15.

When the tubular article T has been almost completely removed from the tubular member 15, and the lower end thereof passes in front of a photocell 46 (indicated in FIG. 8C) or other suitable sensor, it can be blocked by causing the shaped block 43 with the shaped edge 45 thereof to press against the wall of the tubular member 15. By mechanically blocking the article T in this way it is prevented from accidentally exiting from the tubular member 15 when suction inside the tubular member 15 is interrupted.

In this way the tubular article T is arranged with the elastic edge B thereof in a perfectly spread out (even if not flat) arrangement, suitable to facilitate subsequent pick-up of the elastic edge B by stretching means described hereunder and illustrated in particular in the detail in FIG. 7, where they are represented apart from the other members of the device. The stretching means can engage the elastic edge B of the tubular article T before it is released by the shaped block 43, or optionally after it has been released, having previously slackened the tension in the tubular article in a longitudinal direction, for example by lower the moving unit 27 slightly towards the tubular member 15.

The stretching device, indicated as a whole with 61, comprises a suction member 63 supported by an actuator 65 integral with a slide 67, movable along a guide 69 by means of a belt 71 controlled by a motor 73. The slide 67 is movable according to the double arrow f67 by means of the motor 73, while the actuator 65 can move the suction member 63 according to the double arrow f63. Schematically indicated with 63A is a connector for a flexible suction duct, through which suction is generated at the level of perforated surfaces of the suction member 63.

Arranged in front of the suction member 63 is a mechanical constraining member 75, of a type known per se, movable according to the double arrow f75 controlled by a piston-cylinder actuator 76. The piston-cylinder actuator 76 is supported by a slide 77 movable according to the double arrow f77 along a guide 79. The movement according to the double arrow f77 is provided by a belt 81 driven about pulleys 83 and 84, of which the pulley 83 receives movement from the motor 73 by means of a shaft 87. In this way the movements according to f67 of the suction member 63 and according to f77 of the gripper 75 are synchronized and coordinated. The movement according to f75 allows the mechanical pick-up member 75 to move towards and away from the suction member 63.

The stretching device 61 is arranged (see in particular FIG. 2) so that it can transfer the members 63 and 75 between a position corresponding to the tubular member 15 and a position corresponding to a group of stretching fingers 91 associated with piston cylinder actuators 93, of a type known per se, the function of which is to insert themselves inside the elastic edge B previously opened by the stretching device 61 and to stretch this elastic edge so that it can be inserted over the transport tube 19, or over a reversing tube 95, according to criteria known per se which do not form the subject matter of the present invention.

Once the tubular article T has taken the position shown in FIG. 8C, the stretching device 61 is carried, with the members 63 and 75 stretched, to the level of the axis of the tubular member 15, and the members 63 and 75 are moved towards each other to engage portions of the opposite surfaces of the flattened edge of the tubular article T. When the members 63 and 75 have been moved towards each other with the elastic edge B of the article T interposed and have been activated to engage the opposite surfaces of said edge, they are moved reciprocally away from each other with a movement of the actuator 76 to stretch the elastic edge of the article T distancing the two sides engaged with the suction member 63 and the gripper 75 respectively. The shaped block 43 has previously been moved away from the inner surface of the wall of the tubular member 15, to allow the elastic edge B of the article T freedom of movement.

Subsequently, or simultaneously to the stretching movement (i.e. to move the gripper 75 away from the suction member 63), the two slides 67 and 77 are made to translate to move towards the group of stretching fingers 91. Through reciprocal movements between the stretching device 61 and the fingers 91, the latter are inserted in the closed position inside the partially stretched edge B and subsequently opened to further stretch open the edge and insert in over the transport tube 19 in a substantially conventional manner.

The device 17 described hereinbefore can also be used if the articles are inserted with random orientation, i.e. with the toe or with the edge as the leading end, without prior orientation. In this case it is advantageous for the device to be double, to flatten first one portion and then the other.

FIGS. 9 to 14 show a device, hereinafter also indicated as spreading device, indicated as a whole with 510, connected to which in 7B is a duct leading from a container of articles placed therein in bulk, analogous to the container 3 shown in FIG. 1. In this case, the articles can enter the duct 7B randomly, i.e. without being previously oriented. The structure of the device 510 is described in detail hereunder with reference to the subsequent FIGS. 9 to 14.

The connector 7B leads into a compartment with a rectangular section 513 defining a tubular member and which has, at the opposite end with respect to the connector 7B, a shutter 515 having the function of modifying the conformation of the section of passage defined by the compartment 513, constricting it in a specific operating phase. The shutter 515 has a moving shutter element or shaped block 515A, controlled to translate according to the double arrow f515 orthogonal to the longitudinal axis of the compartment 513 by means of a piston-cylinder actuator or other suitable actuator indicated with 517. As can be seen in particular in FIG. 13, the shutter 515 has a shape with a semi-circular lower edge, or in general with a curved and convex cross section, approximately the same as the shape of the semi-circular cross section of the end section 513A of the suction compartment 513. When the shutter element 515A of the shutter 515 is in the position shown in FIGS. 9 and 13, it defines with the inner wall of the portion 513A of the compartment 513 a narrow and shaped cross section of passage, extending approximately in a semi-circumference, which (as will be explained hereunder) tends to flatten the tubular article.

Integral with the spreading member 510 is a suction mouth 521, connected to which is a suction duct 523, of which only the initial portion is shown in the drawing.

Cooperating with the spreading member 510 is a mechanism 525 to pick-up the tubular articles which are sucked inside the spreading member 510 and which has the function of pulling each tubular article through the section of passage defined by the inner wall of the end portion 513A of the compartment 513 and by the shutter element 515A described above.

The mechanism 525 is supported by a slide 527, movable according to the double arrow f525 along a guide 529. Movement of the slide 527 is controlled by a belt 531 operated by a motor 533 and entrained around two pulleys. The mechanism 525 is constrained to the slide 527 by means of a piston-cylinder actuator 535 which controls the lifting and lowering movement in a vertical direction according to the double arrow f525X of the mechanism 525. The lifting and lowering movement of the mechanism 525 has the function of positioning said mechanism in line with the spreading member 510 and, alternatively, above the latter. This facilitates and improves the efficiency of flattening of the article when it is made to pass through the shutter 515, as the article is pulled against the shutter element 515A.

The mechanism 525 comprises an approximately box-shaped compartment 539, inside which a vacuum can be created by means of suction through an aperture 541 which is connected with a tubular connector 543 through a suction box 543A. The tubular connector 543 can be connected to the suction mouth 521 of the spreading member 510. This pneumatic connection is implemented by moving according to the arrow f525 the mechanism 525 with its connector 543 towards the suction mouth 521 and therefore towards the spreading member 510 to make the elements 510, 525 take the reciprocal position shown in FIG. 29. In this arrangement suction generated through the suction duct 523 causes suction through the box-shaped compartment 539, the suction compartment 513 and the duct 7, 7B. Inside the box-shaped compartment 539 is a grid 545 composed (FIG. 11) of a series of teeth 545A with a front edge (i.e. oriented towards the spreading member 510) inclined with respect to the horizontal. Associated with this grid formed by the teeth 545A is a retaining pawl 547 the movement of which according to the double arrow f547 is controlled by a piston cylinder actuator 549 supported by the mechanism 525. Combined with the grid 545 formed of the teeth 545A and of the pawl 547, is a presser 551, provided with a vertical movement according to the double arrow f551 controlled by a piston cylinder actuator 553. The presser 551 has a C-shape open towards the grid 545. The purpose of the presser is to constrain the tubular article during the spreading or flattening phase, acting thereon with a sufficiently wide surface to prevent the article from being damaged.

FIG. 15F shows, in a longitudinal section, a further spreading or flattening device, indicated with 510X, which has members equivalent to those described with reference to the spreading member 510, indicated in the figures with the same reference numbers followed by the letter X. The suction compartment 513X with rectangular section is connected to a suction duct indicated with 8B and corresponding to the suction duct 7B. As opposed to a mechanism like the one indicated with 525, the spreading member 510X which is located, for example, in a station adjacent to the one with the device 525, cooperates with a simple conveyor belt or mat 563 provided with a movement according to f563 imparted by a motor 565. The conveyor belt 563 is entrained about rollers which are supported, together with the motor 565 and the other members transmitting motion to the conveyor belt 563, by side panels 567 which move vertically by means of piston cylinder actuators 569, to allow the conveyor belt 563 to move towards or away from the surface 503. This can be composed of a conveyor belt.

The conveyor belt 563 moves each individual article longitudinally, i.e. parallel to the extension thereof, to take each tubular article inside the spreading member 510X and remove it gradually therefrom when the shutter element, equivalent to the shutter element 515A, is in the substantially closed position and suction continues through the slot it leaves open. Partial insertion of the tubular article inside the tubular member formed by the compartment 513X can be obtained by suction combined with the gradual forward movement of the conveyor belt 563 towards the inlet of the tubular member 513X. By reversing the movement of the conveyor belt 563 the tubular article is removed from the end of the tubular member 513X, after the cross section thereof has been constricted by the shutter or shaped moving block 515AX.

In practice, the devices illustrated respectively in FIGS. 9 to 14 and in FIG. 15F can be combined: the tubular article which is removed from the device in FIGS. 9 to 14 is flattened, i.e. spread out, at the level of the end (or end portion) thereof which enters the compartment 513 last, and is spread on the conveyor belt or other supporting surface 503. This moves forward orthogonally to the longitudinal extension of the article, taking it to the level of the device in FIG. 15F, where flattening of the other end or end portion of the article is carried out.

In this way, an optimal flattening or spreading effect of both ends of the article is obtained, irrespective of the orientation with which they are fed into the suction duct 7B.

This operating cycle is illustrated schematically in the sequence in FIGS. 15A-15F.

FIG. 15A shows a schematic longitudinal section of the spreading member and of the pick-up mechanism 525 in the coupled position thereof. The tubular article M, such as a stocking or sock, is sucked through the duct 7 and the connector 7B inside the compartment 513 with rectangular section. Suction takes place through the tubular connector 543 and the suction box 543A and then through the aperture 541 and the grid 545, as the connector 543 is connected with the suction mouth 521 and with the suction duct 523. Due to suction, the article M moves forward according to the arrow fM until knocking against the grid 545 (FIG. 15B). Here it is engaged by the retaining tooth or pawl 547 (FIG. 15B). In the example shown the article M has entered the suction duct 7 and then the spreading member 510 with the elastic edge B facing forward and the toe P backward. This orientation is entirely random and depends on how the article has been picked up from the container 1.

To spread the article M, at this point suction in the duct 7 is reversed and the article is sucked into the duct again. If by error two articles enter the compartment 513 simultaneously, one of them is unloaded back into the container 1, as the retaining pawl 547 is dimensioned so that it is unable to retain two articles M. FIG. 15C shows the article M extended towards the duct 7 but held by the pawl 547. To perform flattening and spreading of the article M at this point the shutter element 515A is taken to the closed position thereof, in which it defines a narrow and long section of passage. At the same time the presser 551 is lowered for improved retention of the article M (FIG. 15D). The retaining mechanism 525 is moved away (arrow f525, FIG. 15E) pulling the article M out of the constricted cross section defined by the shutter element 515A. In this phase suction can be activated through the duct 7 which stretches the article towards the inside of said duct. The effect of this operation is to spread the article not only longitudinally, but also, and above all, transversely, thanks to the narrow and elongated shape of the cross section of the passage defined by the shutter element 515A.

A similar process takes place for the opposite end (in this case the edge B) of the article, as schematically illustrated in FIG. 15F, after the article has moved forward by one step along the surface 503 orthogonal to the longitudinal extension thereof.

It is understood that the drawing only shows an example provided purely as a practical embodiment of the finding, which may vary in forms and arrangements without however departing from the scope of the concept on which said finding is based. Any reference numerals in the appended claims are provided to facilitate reading of said claims with reference to the description and to the drawing, and do not limit the scope of protection represented by the claims.

Claims

1. A device to flatten or spread at least one portion of a tubular article, in particular stockings and socks, the device comprising: a tubular member, inside which said tubular article can be at least partially inserted;a moving shaped block to modify the cross section of said tubular member, said moving block being controlled to take at least a first position of maximum aperture of the cross section of the tubular member, and a second position of maximum constriction of the cross section of said tubular member, said second position defining a cross section elongated in a direction transverse with respect to the direction of movement of said tubular article in said tubular member.

2. Device as claimed in claim 1, wherein: said tubular member has a first end and a second end;said tubular member is associated with suction means to suck said tubular article inside said tubular member;a moving pickup element is arranged to engage a first end portion of the tubular article and remove it from said tubular member, said pick-up element being associated with said second end of the tubular member;said shaped block cooperates with the inner wall of the tubular member, to define a constriction with variable conformation at the second end of the tubular member, said constriction defining a narrow and elongated section of passage of the tubular article, in which said tubular article is forced to take a spread arrangement at least at the level of a second end portion thereof;said pick-up member can move towards or away from said second end of the tubular member respectively;said suction means and said tubular member are arranged and produced so that the tubular article enters said tubular member through said first end and said tubular article exits from said tubular member through said second end; andsaid suction means are designed and arranged to generate suction in the two directions inside said tubular member.

3-5. (canceled)

6. Device as claimed in claim 1, wherein said shaped block has a portion of surface opposite a portion of the inner surface of said tubular member and substantially parallel thereto, to define a constriction with a cross section having an arched development.

7. Device as claimed in claim 1, further comprising a suction mouth which can move towards the second end of the tubular member and through which a flow of air is generated in said tubular member which flows from the first end to the second end of the tubular member, wherein an interception element is inserted in said suction mouth to prevent the tubular articles from entering said suction mouth and which forms a stop for the tubular articles drawn by said flow of air, said interception element being a grid or a mesh, said suction mouth and said pick-up element being movable as one unit to move towards or away from the second end of said tubular member, wherein an actuator to control the pick-up element is supported integral with said suction mouth and is movable therewith.

8-11. (canceled)

12. Device as claimed in claim 2, wherein said pick-up element, said shaped block and said suction mouth are arranged and produced so that when the suction mouth is moved towards said first end of the tubular member, the pick-up element is interposed between the shaped block and said suction mouth.

13. Device as claimed in claim 2, wherein said suction mouth cooperates with a gasket extending at least partially around said second end of the tubular member.

14. Device as claimed in claim 1, wherein said shaped block is provided with a movement according to a direction inclined with respect to the axis of the tubular member to move towards and away from a portion of the inner surface of said tubular member.

15. Device as claimed in claim 2, wherein said pick-up element comprises a mechanical gripper.

16. Device as claimed in claim 1, wherein said pick-up element comprises a slider which slides inside a seat produced on the surface of said shaped block facing the pick-up element.

17. Device as claimed in claim 1, further comprising a stretching device, arranged and controlled to engage an end portion in the spread arrangement of the tubular article when the latter has been almost fully removed from the tubular member, and to open out said end portion, wherein said stretching device comprises two members to engage two opposite sides of said end portion of the tubular article, provided with a reciprocal movement towards and away from each other, and with a movement of alignment with respect to the tubular member and of movement away therefrom.

18. (canceled)

19. Device as claimed in claim 1, wherein said suction means, said tubular member and said pick-up element are controlled and arranged to partially insert a tubular article into said tubular member through the second aperture of said tubular member, and to remove it therefrom, said shaped block being arranged in a position of maximum aperture of the second end of the tubular member when said article is inserted partially into said tubular member and in a position of maximum constriction of the cross section of passage of the tubular article, when it is removed once more from the tubular member.

20. Device as claimed in claim 1, further comprising two tubular members to spread two end portions of the tubular articles.

21. Device as claimed in claim 1, wherein a suction system is associated with said tubular member, to at least partially insert the tubular article into the tubular member by suction, said suction system being reversible, to generate inside said tubular member a flow of air alternatively in one direction or in the opposite direction.

22. (canceled)

23. Device as claimed in claim 1, wherein a pick-up element is associated with said tubular member to engage said article and move it with respect to said tubular member.

24. Device as claimed in claim 1, wherein an interception element is associated with said tubular member, to block a tubular article sucked through said tubular member.

25. Device as claimed in claim 1, further comprising two tubular members to spread two end portions of the tubular articles.

26. A method for spreading or flattening at least a portion of a tubular knitted article, the method including the steps of: at least partially inserting said tubular article into a tubular member;when said tubular article is at least partly inserted in said tubular member, narrowing a cross section of passage for said tubular article in said tubular member;moving said tubular article in said tubular member in a direction substantially parallel to the longitudinal extension of said tubular member through said narrowed cross section, said cross section extending in a direction transverse to the direction of feed of said tubular article through said tubular member.

27. Method as claimed in claim 26, wherein said tubular article has a toe end and a elastic edge; including the following steps: arranging the tubular article inside said tubular member, with a toe oriented towards an outlet end of the tubular member;producing in said tubular member, in proximity to said outlet end, said narrowed and elongated section of passage;removing the tubular article from the tubular member spreading the elastic edge of said article by making it pass through said narrowed and elongated section.

28. Method as claimed in claim 27, wherein said narrowed and elongated cross section is constricted when the article has been almost completely removed from the tubular member, to block and engage said tubular article at two opposite sides of the elastic edge.

29. Method as claimed in claim 27, further comprising the steps of: sucking the tubular knitted article to take the toe thereof approximately to the outlet end of the tubular member;engaging the toe of the tubular knitted article;gradually removing the tubular knitted article from the tubular member, maintaining it in tension by suction from the outlet end towards the inside of the tubular member.

30. Method as claimed in claim 29, wherein when the elastic edge of the tubular knitted article has been approximately completely removed from the tubular member, said edge is blocked at the outlet end of the tubular article.

31. Method as claimed in claim 27, wherein the elastic edge of the tubular knitted article is engaged by stretching members after it has been at least partially removed from the tubular member.

32. A method as claimed in claim 26, wherein: said tubular article is sucked inside said tubular member;a first end of said tubular article is engaged by a pick-up element; andsaid pick-up element is moved away from the tubular member pulling the tubular article through said narrow and elongated cross section of passage.

33. Device as claimed in claim 19, wherein said suction means and said tubular member are arranged and produced so that the tubular article enters said tubular member through said first end and said tubular article exits from said tubular member through said second end.

34. Device as claimed in claim 19, wherein said suction means are designed and arranged to generate suction in the two directions inside said tubular member.