WO2008028575A1 - Device for reversing tubular articles, particularly for circular knitting machines provided with a station for closing an axial end of the tubular article - Google Patents

Device for reversing tubular articles, particularly for circular knitting machines provided with a station for closing an axial end of the tubular article Download PDF

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Publication number
WO2008028575A1
WO2008028575A1 PCT/EP2007/007484 EP2007007484W WO2008028575A1 WO 2008028575 A1 WO2008028575 A1 WO 2008028575A1 EP 2007007484 W EP2007007484 W EP 2007007484W WO 2008028575 A1 WO2008028575 A1 WO 2008028575A1
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WO
WIPO (PCT)
Prior art keywords
reversing tube
article
dial
reversing
tube
Prior art date
Application number
PCT/EP2007/007484
Other languages
French (fr)
Other versions
WO2008028575A8 (en
Inventor
Tiberio Lonati
Fausto Lonati
Ettore Lonati
Original Assignee
Sangiacomo S.P.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sangiacomo S.P.A. filed Critical Sangiacomo S.P.A.
Publication of WO2008028575A1 publication Critical patent/WO2008028575A1/en
Publication of WO2008028575A8 publication Critical patent/WO2008028575A8/en

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Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04B—KNITTING
    • D04B9/00—Circular knitting machines with independently-movable needles
    • D04B9/40—Circular knitting machines with independently-movable needles with provision for transfer of knitted goods from one machine to another

Definitions

  • the present invention relates to a device for reversing tubular articles, particularly for circular knitting machines provided with a station for closing an axial end of the tubular article.
  • Circular machines particularly hosiery knitting machines, are known which are equipped with an apparatus which allows to close, by linking or sewing, an axial end of the article at the end of its production on the machine.
  • the apparatus that closes an axial end of the articles is integrated in the machine that manufactures the articles, and the closure of an axial end of the articles is performed directly on the machine, interrupting the production of articles during the operation for closing the axial end of an article.
  • the apparatus that closes an axial end of the articles is arranged in a sewing or linking station which is separate from the machine for producing the articles and is generally arranged laterally with respect to the production machine.
  • the article, at the end of its production is removed mechanically from the manufacturing machine and is transferred, after being positioned appropriately, into the sewing or linking station, in which there are mechanical elements which prepare the axial end of the article and close it by means of a sewing or linking head.
  • This second type of machines unquestionably has the advantage of not interrupting production activity except for a limited time required to remove the article from the machine.
  • the sewing or linking for closing the axial end of the article must be performed on the reverse side of the article, which, as is known, in single-cylinder circular machines is formed right way out.
  • the sewing or linking station there is generally a reversing device which turns the article inside out before sewing or linking an axial end thereof and then turns the article right way out again at the end of the sewing or linking.
  • An apparatus for sewing or linking an axial end of a tubular article manufactured by means of a single-cylinder circular machine and capable of sewing or linking on the reverse side of the article is disclosed for example in US Patent 7,107,797 and in WO 2004/035894.
  • Such an apparatus substantially comprises a dial provided with a plurality of points directed with their tip downwardly and arranged along a cylindrical surface which matches the arrangement of the needles of the circular knitting machine for hosiery to be served.
  • This dial is arranged so that its axis is vertical and is supported by means of an arm which can move on command so as to place the dial above and coaxially with respect to the needle cylinder of the machine, placing each point above a needle of the machine.
  • the last row of knitting formed is held on the needles that produced it and is then transferred, loop by loop, from a needle to the corresponding point of the dial, which is also provided with means which are capable of retaining the loops of knitting of the article on the points during the transfer of the article from the manufacturing machine to the sewing or linking station.
  • a reversing device which is composed substantially of a reversing tube, which has a vertical axis and can move on command along its own axis so that it is inserted, starting from its upper end, through the dial so as to reverse the article on its outer lateral surface, as will become better apparent hereinafter.
  • the dial is composed of two half-dials, one of which can be turned over below the other half-dial about a diametrical axis of the dial so as to make the end of its points face below the end of the points of the half-dial that has not been turned over.
  • an apparatus of this kind works by taking, by means of the dial, the article right way out from the machine that produced it, keeping it hanging at its axial end to be closed and moving the dial to a coaxial position above the upper end of the reversing tube in a lowered position.
  • the reversing tube is then raised so that its upper end passes through the dial so as to progressively cause the eversion of the tubular article on the outer lateral surface of the reversing tube starting from its upper end. In this manner, the article is inside out and is arranged above the dial. Once the eversion of the article on the lateral surface of the reversing tube has been completed, the upper end of the reversing tube is engaged and the reversing tube is raised further so as to bring its lower end to a slightly higher level than the points of the dial.
  • the overturning half-dial of the dial is then turned over about the diametrical axis with respect to the half-dial that cannot be turned over, so as to make each one of its points face from below a corresponding point of the half-dial that has not been overturned, and the loops of knitting carried by the points of the overturned half-dial are transferred to the points of the half-dial that has not been overturned, said points thus carrying two loops of knitting each.
  • the overturning half-dial is returned to the position in which it is coplanar with respect to the half-dial that has not been overturned, and each pair of loops of knitting is passed from one point of the half-dial of the dial that has not been overturned to the point of another half-dial which faces from below the half-dial of the dial that is not overturned.
  • a sewing or linking head cooperates with the points of this other half-dial, which has received a pair of loops of knitting on each of its points, and sews or links the pairs of loops of knitting supported by each point so as to close the axial end of the article.
  • auxiliary means which are constituted by two contrarotating rollers, which are arranged above the dial in the sewing or linking station and can engage the portion of the article that is everted onto the outer lateral surface of the reversing tube and can be actuated with a rotary motion about their axes and with opposite directions of rotation so as to complete the eversion of the article onto the outer lateral surface of the reversing tube.
  • the problem of the complete insertion of the article within the reversing tube to return it right way out after closing the axial end of the article has proved to be more complex.
  • the rod used to insert the closed axial end of the article into the lower end of the reversing tube is supported by a support or tube holder, which defines an axial abutment for the lower end of the reversing tube and is also used to lift the reversing tube when the first reversing of the article is performed to turn it inside out.
  • the aim of the present invention is to solve the problem described above by providing a reversing device for tubular articles particularly for circular knitting machines provided with a station for closing an axial end of the tubular article which ensures correct reversing of the articles even when such articles have a particularly substantial length and/or are highly extensible.
  • an object of the invention is to provide a device which has precise and reliable operation.
  • a device for reversing tubular articles particularly for circular knitting machines provided with a station for closing an axial end of the tubular article, comprising a reversing tube which has a substantially vertical axis and can move on command along its own axis from at least one lowered position, in which it is arranged, with its upper end, below a dial which has a substantially vertical axis and is adapted to retain the tubular article so that it hangs from said dial with a first axial end thereof, to at least one raised position, in which it passes through said dial and is arranged so that its upper end lies above said dial in order to evert at least partially the tubular article onto the outer lateral surface of the reversing tube starting from the upper end of said reversing tube, and vice versa; auxiliary means being provided along the path of motion of said reversing tube, above said dial, and
  • Figure 1 is a schematic sectional view of the lower portion of the reversing device, taken along a plane which passes through the axis of the reversing tube;
  • Figure 2 is a schematic sectional view of the upper portion of the reversing device, taken in a manner similar to Figure 1 ;
  • Figures 3 to 17 illustrate the operating sequence of the reversing device, shown schematically in a front elevation view. Ways of carrying out the Invention
  • the device according to the invention is designed to be positioned generally at a processing station in which it is necessary to perform a first reversal of a tubular article 60 to allow the execution of particular knitting with the article inside out and then a second reversal to make the article 60 available right way out again or vice versa.
  • a requirement of this kind is observed for example in closing an axial end of a tubular article, particularly the toe of a sock, if this closing operation is performed by sewing or linking on the reverse side of the article by transferring the article, produced with a circular knitting machine for hosiery, from the production machine to a sewing or linking station which is arranged laterally or otherwise in the vicinity of the production machine by means of a dial 50 which is capable of supporting the article 60 so that it hangs from the dial 50 by means of its axial end to be closed.
  • the reversing device according to the invention is conceived to equip an apparatus of the type disclosed in US Patent 7,107,797 and in WO 2004/035894.
  • An apparatus of this kind has an arm 51 which is supported by a supporting structure so that it can rotate about a vertical rotation axis which is spaced laterally with respect to the machine for producing the articles 60 and supports the dial 50 in a region which is spaced from such rotation axis.
  • the dial 50 is composed of two half-dials 52a, 52b, which lie mutually side by side along a diametrical plane of the dial 50 and are provided in a downward region with points 53 which have tips directed downwardly and are arranged so as to correspond to the needles on the machine for producing the article 60.
  • the dial 50 is further provided with means which are capable of retaining the article 60 engaged with the points 53 during and after its transfer from the production machine to the linking or sewing station.
  • the dial 50 is provided with elements for transferring loops of knitting from the points 53 of the overturning half-dial 52b to the points 53 of the fixed half-dial 52a.
  • the apparatus served by the reversing device according to the invention in order to close an axial end of the article, is provided, in the sewing or linking station, with a sewing or linking head, not shown for the sake of simplicity, which can cooperate directly with the points 53 of the fixed half-dial 52a or with the points 55 of an additional half-dial 56, which is arranged below the fixed half-dial 52a and is provided with points 55, which are directed with their tip upwardly and are capable of receiving the loops of knitting retained by the points 53 of the fixed half-dial 52a.
  • the arm 51 by utilizing its ability to rotate about an axis which is parallel to the axis of the needle cylinder of the machine that produces the article, once the production of the article 60 has ended and once the last row of knitting is retained on the needles of the production machine, arranges the dial 50 above and coaxially with respect to the needle cylinder so that each of its points is positioned upwardly at each needle of the machine.
  • the last row of knitting of the article 60, produced by the needles and retained on the needles that produced it is passed, loop by loop, from a needle to a point 53 of the dial 50, which again by utilizing the ability to rotate of the arm 51 that supports it is moved laterally to the machine at the sewing or linking station.
  • the article 60 Before removal from the production machine, the article 60 is in the right way out condition inside the needle cylinder of the machine, and the movement of the dial 50 laterally to the machine achieves the extraction of the article 60 from the needle cylinder, in the case of short articles, or the partial extraction of the article 60 from the needle cylinder in the case of significantly long articles.
  • the arm 51 which supports the dial 50, can also perform a translational motion along its axis of rotation in order to lift and lower the dial 50.
  • the arm 51 in the sewing or linking station, is positioned at a centering arm 57, which is provided with centering pins 58, 59 which are mutually opposite and are designed to keep the arm 51 positioned correctly in the sewing or linking station while allowing a vertical movement of said arm 51 and therefore of the dial 50 which it supports.
  • the reversing device comprises a reversing tube 2, which has a substantially vertical axis 2a and can move on command along its own axis 2a in order to pass from a lowered position, in which it is arranged, with its upper end, below the dial 50 arranged in the sewing or linking station, which holds the tubular article 60 so that it hangs from the dial 50 with a first axial end which constitutes the axial end to be closed of the article 60, to at least one raised position, in which it passes through the dial 50 and is arranged with its upper end above the dial 50 so as to evert the tubular article 60 at least partially onto the outer lateral surface of the reversing tube 2 starting from the upper end of said reversing tube 2, and vice versa.
  • Auxiliary means 3 are arranged along the path of motion of the reversing tube 2, above the dial 50, can engage the article 60, partly everted onto the outer lateral surface of the reversing tube 2, and can be actuated to complete the eversion of the article 60 onto the outer lateral surface of the reversing tube 2.
  • the device further comprises expulsion means which act on the article 60 in order to introflect it inside the reversing tube 2, inserting the first axial end of the article, which is disengaged from the dial 50, in the lower end of the reversing tube 2.
  • the device comprises means for positioning the reversing tube 2 in an expulsion position, in which it is arranged so that its lower end lies proximate to the auxiliary means 3, which can be actuated to entrain the article 60, which is everted onto the outer lateral surface of the reversing tube 2, toward its lower end, to assist the action of such expulsion means.
  • the reversing tube 2 is mounted on a tube holder
  • the tube holder 10 which is substantially cylindrical, is arranged coaxially to the reversing tube 2 and has, in an intermediate region of its extension, an axial shoulder 20 against which the lower end of the reversing tube 2, fitted around the portion of the tube holder 10 that lies above the axial shoulder 20, can rest.
  • the tube holder 10 is provided as the body of a pneumatic cylinder inside which there is chamber 1 1 which has a vertical axis and accommodates, so that it can slide axially, a piston 12 provided with a stem 12a which protrudes downwardly from the tube holder 10.
  • the tube holder 10 can slide axially within a guiding cylinder 14, which in turn is arranged, along a portion of its axial extension starting from its lower end, internally and coaxially to a supporting cylinder 15.
  • the supporting cylinder 15 is rigidly fixed, at its upper end, to the supporting structure 17 of the device and the guiding cylinder 14 is fixed to the supporting cylinder 15.
  • the guiding cylinder 14 has an axial slot 14a, with which two tabs 44 engage slidingly, said tabs being fixed to the tube holder 10.
  • the coupling of the tabs 44 to the axial slot 14a prevents the rotation of the tube holder 10 about its own axis while allowing the tube holder 10 to perform an axial translational motion with respect to the guiding cylinder 14.
  • the stem 12a is fixed, proximate to its lower end, to a base 13, which is fixed to an external cylinder 16 which is arranged externally and coaxially with respect to the supporting cylinder 15 and can slide axially with respect to it.
  • Two ducts extend within the stem 12a and are connected, at their upper end, respectively to the region of the chamber 11 that is arranged above the piston 12 and to the region located below the piston 12. These two ducts can be connected selectively to a duct for supplying air under pressure or to a discharge so as to lift or lower the tube holder 10 with respect to the piston 12.
  • the tube holder 10 can be likened to the body of a double- acting pneumatic cylinder in which the stem 12a is fixed while the body, constituted indeed by the tube holder 10, can slide upwardly or downwardly with respect to the stem 12a of the piston 12 as a consequence of the feeding, with air under pressure, of the chamber 11 through one of the two ducts which lie within the stem 12a.
  • the base 13 is connected to the stem 18 of the piston of a pneumatic cylinder 19 which is arranged so that its axis is vertical and is connected, by means of its body, to the supporting structure 17.
  • the actuation of this pneumatic cylinder 19 lifts or lowers the base 13 and consequently the tube holder 10.
  • the auxiliary means comprise two rollers 22 and 23, which are shown partially in cross-section in Figure 2 and are arranged so that their axes 22a, 23a are horizontal and parallel to each other and on mutually opposite sides with respect to the axis 2a, so as to face diametrically mutually opposite regions of the outer lateral surface of the reversing tube 2 in the first lifting position.
  • the rollers 22 and 23 are supported at the end of a corresponding supporting arm 24, 25, which is pivoted, about a corresponding pivoting axis 26, 27, with an intermediate region of its extension, to the supporting structure 17.
  • a pneumatic cylinder 28 acts on the other end of the supporting arms 24 and 25 and can be actuated to produce, by utilizing the pivoting of the arms 24, 25 about the axes 26, 27, the movement of the rollers 22, 23 toward the outer lateral surface of the reversing tube 2, which is inserted between the rollers 22 and 23, or to move the rollers 22, 23 away from the outer lateral surface of the reversing tube 2.
  • the rollers 22, 23 can be actuated with a rotary motion about the corresponding axes 22a, 23 a, for example by means of electric motors of a known type, which are not shown for the sake of simplicity, with mutually opposite direction of rotation and with a tangential speed which is directed downwardly in the regions of the rollers 22, 23 that face each other.
  • the lateral surface of the rollers 22, 23 has a circumferential groove, so as to wrap around the outer lateral surface of the reversing tube 2.
  • the positioning means comprise engagement means which can engage the reversing tube 2 proximate to its upper end and can move on command along a vertical direction so as to lift the reversing tube 2 until the reversing tube 2 is in the expulsion position. More particularly, a connecting tube 30 is arranged above and coaxially to the reversing tube 2.
  • This connecting tube 30 has a telescopic structure, with an upper part 31 which is fixed to the supporting structure 17 of the machine and a lower part 32 which can move on command along a vertical direction with respect to the upper part 31 so as to fit coaxially on the upper end of the reversing tube 2 in the raised position or disengage from the upper end of the reversing tube 2.
  • the lower part 32 of the connecting tube 30 is provided with engagement means, which can engage a portion of the reversing tube 2 which is proximate to its upper end.
  • Such engagement means comprise a movable pivot 33, which is arranged so that its axis is perpendicular to the axis 2a of the reversing tube 2 and is actuated by a corresponding pneumatic cylinder 34 which is connected to the lower part 32 of the connecting tube 30.
  • the movable pivot 33 can be inserted into or removed from a seat 35, which is defined in the end portion of the reversing tube 2 which can be inserted in the lower part 32 of the connecting tube 30.
  • the engagement means are completed by a sensor 36, which is capable of detecting the presence of the upper end of the reversing tube 2 inside the lower part 32 of the connecting tube 30 with the seat 35 positioned correctly in alignment with the movable pivot 33.
  • the lower part 32 of the connecting tube 30 is connected to the end of the stem 38 of the piston of a pneumatic cylinder 45 which has a vertical axis and is connected, by means of its body, to the supporting structure 17.
  • the pneumatic cylinder 45 is a pneumatic cylinder of a known type with a controlled stroke, in that it can lower or lift the lower part 32 of the connecting tube 30, stopping it in a plurality of positions.
  • the reversing tube 2 has an opening 39 on its lateral surface which extends, starting from the upper end of the reversing tube 2, along a portion of its axial extension so as to receive internally the article 60, as will become better apparent hereinafter.
  • the upper end of the connecting tube 30 is connected to a suction tube 40, which can be connected to a pneumatic suction device of a known type so as to produce suction through the connecting tube 30 and therefore through the lower end, in the direction of the upper end of the reversing tube 2 which is coupled thereto.
  • means for pushing the everted article onto the lateral surface of the reversing tube 2 toward the lower end of the reversing tube are provided.
  • Such pusher means comprise a sleeve 42, which is partially inserted coaxially in the lower part 32 of the connecting tube 30 and protrudes from the lower end of the lower part 32 with a portion which ends, in a downward region, with a border 42a which has an enlarged outside diameter.
  • This sleeve 42 can slide axially with respect to the lower part 32 of the connecting tube 30 by way of the action of a pneumatic cylinder 43 which has a vertical axis and is interposed between the lower part 32 and the sleeve 42.
  • the sleeve 42 in addition to pushing the article 60, which is everted on the lateral surface of the reversing tube 2, also at least partially blocks the opening 39 defined in the lateral surface of the reversing tube 2 starting from its upper end, as will become better apparent hereinafter.
  • the reversing device 1 in the inactive condition, preferably is in the configuration shown in Figures 1, 2 and 3, i.e., with the reversing tube 2 rested against the tube holder 10 and raised into the second lifting position, since the stem 18 of the pneumatic cylinder 19 is retracted into the body of said pneumatic cylinder 19 (the base 13 is raised) and the chamber 11 is supplied with air under pressure in its region located above the piston 12.
  • the reversing device When the reversing device must receive an article 60 to be reversed, it is actuated so as to arrange itself in the configuration shown in Figure 4, in which the reversing tube 2, by introducing air under pressure into the region of the chamber 11 located below the piston 12 and by way of the actuation of the pneumatic cylinder 19, is moved to the lowered position, and the lower part 32 of the connecting tube 30, by means of the pneumatic cylinder 45, is raised.
  • the article 60 in the right-way-out configuration, hanging by its upper end from the points 53 of the half-dials 52a, 52b of the dial 50, is picked up, as already described above, by the machine that produced it and moved, by means of the arm 51, into the sewing or linking station at the reversing device 1.
  • the arm 51 is inserted, with a portion thereof provided with a centering seat, between the centering pins 58, 59 and is raised by engaging it with the centering pin 58 until it is brought into abutment against an upper shoulder defined by the centering arm 57.
  • the dial 50 is positioned above and coaxially with respect to the reversing tube 2.
  • the movement of the arm 51 in the sewing or linking station has extracted the article 60 partially or completely from the needle cylinder of the circular machine that produced it.
  • the article 60 is diverted, so as to achieve an optimum arrangement thereof, by interference with a sock guard lever 46, which is activated and arranged below the position assumed by the dial 50 on board the reversing device 1.
  • the reversing tube 2 With the dial 50 thus positioned, the reversing tube 2, by introducing air under pressure into the region of the chamber 11 arranged above the piston 12, is raised into the first lifting position. As a consequence of this lifting, the reversing tube 2 crosses, with its upper end, the dial 50 until it is arranged, with such upper end, above the rollers 22, 23, as shown in Figure 5. The crossing of the dial 50 by the upper end of the reversing tube 2 produces the progressive eversion of the article 60, which is still engaged with the points 53 of the dial 50, onto the lateral surface of the reversing tube 2 starting from its upper end.
  • rollers 22, 23, by way of the actuation of the pneumatic cylinder 28, are moved toward the outer lateral surface of the reversing tube 2 so as to engage the everted article 60 and are actuated with a rotary motion about their own axes 22a, 23a, with mutually opposite directions of rotation, so as to push the article 60 downwardly along the outer lateral surface of the reversing tube 2.
  • the actuation of the rollers 22, 23 completes the eversion of the article 60 onto the lateral surface of the reversing tube 2 even in the case of articles which have a considerable length or are elastically extensible, as shown in Figure 6.
  • the actuation of the rollers 22, 23 can be dependent upon the detection performed by a known type of sensor 61, which is shown in Figure 4 and faces the outer lateral surface of the reversing tube 2 directly above the axis of the rollers 22, 23 and is capable of detecting the presence or absence of a portion of the article 60 on the region of the outer lateral surface of the reversing tube 2 which it faces in order to interrupt the actuation of the rollers 22, 23 as soon as the article 60 has been pushed by the rollers 22, 23 below such region.
  • a known type of sensor 61 which is shown in Figure 4 and faces the outer lateral surface of the reversing tube 2 directly above the axis of the rollers 22, 23 and is capable of detecting the presence or absence of a portion of the article 60 on the region of the outer lateral surface of the reversing tube 2 which it faces in order to interrupt the actuation of the rollers 22, 23 as soon as the article 60 has been pushed by the rollers 22, 23 below such region.
  • the article 60 rises within the reversing tube 2, entering through the opening 39 and exiting from the upper end of the reversing tube 2.
  • the article 60 is inside out and arranged above the dial 50, which is engaged with its axial end to be closed by sewing or linking.
  • the lower part 32 of the connecting tube 30 is raised, by means of the pneumatic cylinder 45, so as to bring the reversing tube 2 into a third lifting position, in which it is arranged so that its lower end is at the level of the dial 50, slightly above the points 53.
  • the base 13 and the tube holder 10 are lowered respectively by means of the pneumatic cylinder 19 and by introducing air under pressure into the region of the chamber 1 1 that is arranged below the piston 12, as shown in Figure 8.
  • the sleeve 42 is lowered so as to push, with its edge 42a, the article 60 toward the lower end of the reversing tube 2 and the overturning half-dial 52b is turned over below the fixed half-dial 52a so as to make the tip of its points 53 face the tip of the points 53 of the fixed half-dial 52a, as shown in Figure 9.
  • the loops of knitting supported by the points 53 of the overturning half-dial 52b are transferred, for example as disclosed in US Patent 7,107,797 and in WO 2004/035894, to the points 53 of the fixed half-dial 52a and the overturning half-dial 52b is returned to a coplanar position, to the side of the fixed half-dial 52a.
  • each point 53 of the fixed half-dial 52a supports two loops of knitting.
  • the lower part 32 of the connecting tube 30 is lowered, by means of the pneumatic cylinder 45, to the level at which it had engaged the reversing tube 2 so that the lower end of the reversing tube 2 lies slightly above the points 55 of the half-dial 56, while the arm 51 is lowered, passing over the centering pin 59 and stopping against a lower shoulder which is defined by the centering arm 57, as shown in Figure 10.
  • the fixed half-dial 52a is made to face and approach, with the tip of its points 53, the tip of the points 55 of the half-dial 56 and the pairs of loops of the article 60 are transferred from the points 53 of the fixed half-dial 52a to the points 55 of the half-dial 56.
  • the sleeve 42 is raised by means of the pneumatic cylinder 43 and a sewing or linking head, of a known type and not shown for the sake of simplicity, is activated and cooperates with the points 55, for example as disclosed in the patents cited above, joining the pairs of loops of knitting carried by said points, thus closing the article 60 at its axial end that had been engaged by the dial 50, as shown in Figure 11.
  • the base 13 is then also raised, by means of the pneumatic cylinder
  • the pneumatic cylinder 43 is activated and lowers the sleeve 42 along the reversing tube 2.
  • the sleeve 42 acts on the article 60, pushing it downwardly along the outer lateral surface of the reversing tube 2.
  • the lowering of the sleeve 42 also closes almost entirely the opening 39 of the reversing tube 2, as shown in Figure 14.
  • the lower part 32 of the connecting tube 30 is then raised further, again by way of the pneumatic cylinder 45, placing the reversing tube 2 in the expulsion position, in which it is arranged so that its lower end, at the level of the rollers 22, 23, lies preferably at the horizontal plane of arrangement of the axes 22a, 23a of such rollers 22, 23.
  • rollers 22, 23 are moved toward the reversing tube 2 so as to engage the article 60 and are actuated with a rotary motion about their own axes 22a, 23 a, with mutually opposite directions of rotation, so as to assist the descent of the article 60 along the outer lateral surface of the reversing tube 2 toward its lower end, facilitating the introflection of the article 60 inside the reversing tube 2 which, by reversing the article 60 again, returns it to the right-way-out configuration inside the reversing tube, as shown in Figure 15.
  • the suction tube 40 is preferably connected to a suction device which, by generating a rising air stream within the reversing tube 2, further facilitates completion of the introflection of the article 60 within the reversing tube 2.
  • the tube holder 10 is then lowered again so as to free the arm 51 and the dial 50, which can be returned above the machine for producing the articles in order to pick up a new article 60 to be then taken to the sewing or linking station, while the rollers 22, 23 are again moved away from the outer lateral surface of the reversing tube 2, as shown in Figure 16, and the sleeve 42 is raised as shown in Figure 17.
  • the reversing device has been conceived in particular to equip a sewing or linking station for closing an axial end of tubular articles of the type disclosed in US Patent 7,107,797 and in WO 2004/035894, it can also be used with other apparatuses which support a tubular article which hangs from a dial by an axial end to be closed even in a different manner and with different means with respect to the ones shown in US Patent 7,107,797 and in WO 2004/035894.

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

Abstract

A device (1) for reversing tubular articles (60), particularly for circular knitting machines provided with a station for closing an axial end of the tubular article. The device comprises a reversing tube (2) which has a vertical axis (2a) and can be inserted with its upper end through a dial (50) from which the article (60) to be reversed hangs, by means of an axial end, so as to evert at least partially the tubular article (60) onto the outer lateral surface of the reversing tube (2) starting from the upper end of the reversing tube. Auxiliary means (3) are arranged along the path of motion of the reversing tube (2), above the dial (50), and can engage the article (60), which is partially everted onto the lateral surface of the reversing tube (2), and can be actuated to complete the eversion of the article (60) onto the reversing tube (2). The device comprises expulsion means which act on the article (60) to perform its introflection inside the reversing tube (2), inserting its axial end, disengaged from the dial (50), in the lower end of the reversing tube (2). Means are provided for positioning the reversing tube (2) in an expulsion position, in which it is arranged so that its lower end lies proximate to the auxiliary means (3), which can be actuated to entrain the article (60) which is everted on the outer lateral surface of the reversing tube (2) toward its lower end in order to assist the action of the expulsion means.

Description

DEVICE FOR REVERSING TUBULAR ARTICLES5 PARTICULARLY FOR CIRCULAR KNITTING MACHINES PROVIDED WITH A STATION FOR CLOSING AN AXIAL END OF THE TUBULAR ARTICLE Technical Field
The present invention relates to a device for reversing tubular articles, particularly for circular knitting machines provided with a station for closing an axial end of the tubular article. Background Art Circular machines, particularly hosiery knitting machines, are known which are equipped with an apparatus which allows to close, by linking or sewing, an axial end of the article at the end of its production on the machine.
In some types of machines, the apparatus that closes an axial end of the articles is integrated in the machine that manufactures the articles, and the closure of an axial end of the articles is performed directly on the machine, interrupting the production of articles during the operation for closing the axial end of an article.
In other types of machines, the apparatus that closes an axial end of the articles is arranged in a sewing or linking station which is separate from the machine for producing the articles and is generally arranged laterally with respect to the production machine. In these kinds of machines, the article, at the end of its production, is removed mechanically from the manufacturing machine and is transferred, after being positioned appropriately, into the sewing or linking station, in which there are mechanical elements which prepare the axial end of the article and close it by means of a sewing or linking head.
This second type of machines, with respect to the first type, unquestionably has the advantage of not interrupting production activity except for a limited time required to remove the article from the machine. To achieve a satisfactory aesthetic result, the sewing or linking for closing the axial end of the article must be performed on the reverse side of the article, which, as is known, in single-cylinder circular machines is formed right way out. For this reason, if the article is taken from the machine and transferred to the sewing or linking station right way out, at the sewing or linking station there is generally a reversing device which turns the article inside out before sewing or linking an axial end thereof and then turns the article right way out again at the end of the sewing or linking. An apparatus for sewing or linking an axial end of a tubular article manufactured by means of a single-cylinder circular machine and capable of sewing or linking on the reverse side of the article is disclosed for example in US Patent 7,107,797 and in WO 2004/035894.
Such an apparatus substantially comprises a dial provided with a plurality of points directed with their tip downwardly and arranged along a cylindrical surface which matches the arrangement of the needles of the circular knitting machine for hosiery to be served. This dial is arranged so that its axis is vertical and is supported by means of an arm which can move on command so as to place the dial above and coaxially with respect to the needle cylinder of the machine, placing each point above a needle of the machine.
At the end of the production of the article on the circular machine, the last row of knitting formed is held on the needles that produced it and is then transferred, loop by loop, from a needle to the corresponding point of the dial, which is also provided with means which are capable of retaining the loops of knitting of the article on the points during the transfer of the article from the manufacturing machine to the sewing or linking station.
In the sewing or linking station there is a reversing device, which is composed substantially of a reversing tube, which has a vertical axis and can move on command along its own axis so that it is inserted, starting from its upper end, through the dial so as to reverse the article on its outer lateral surface, as will become better apparent hereinafter.
The dial is composed of two half-dials, one of which can be turned over below the other half-dial about a diametrical axis of the dial so as to make the end of its points face below the end of the points of the half-dial that has not been turned over.
In practice, an apparatus of this kind works by taking, by means of the dial, the article right way out from the machine that produced it, keeping it hanging at its axial end to be closed and moving the dial to a coaxial position above the upper end of the reversing tube in a lowered position.
The reversing tube is then raised so that its upper end passes through the dial so as to progressively cause the eversion of the tubular article on the outer lateral surface of the reversing tube starting from its upper end. In this manner, the article is inside out and is arranged above the dial. Once the eversion of the article on the lateral surface of the reversing tube has been completed, the upper end of the reversing tube is engaged and the reversing tube is raised further so as to bring its lower end to a slightly higher level than the points of the dial.
The overturning half-dial of the dial is then turned over about the diametrical axis with respect to the half-dial that cannot be turned over, so as to make each one of its points face from below a corresponding point of the half-dial that has not been overturned, and the loops of knitting carried by the points of the overturned half-dial are transferred to the points of the half-dial that has not been overturned, said points thus carrying two loops of knitting each.
At this point, the overturning half-dial is returned to the position in which it is coplanar with respect to the half-dial that has not been overturned, and each pair of loops of knitting is passed from one point of the half-dial of the dial that has not been overturned to the point of another half-dial which faces from below the half-dial of the dial that is not overturned. A sewing or linking head cooperates with the points of this other half-dial, which has received a pair of loops of knitting on each of its points, and sews or links the pairs of loops of knitting supported by each point so as to close the axial end of the article. Once closure of the axial end of the article has been completed, such end is inserted in the lower end of the reversing tube by means of a rod and the inside of the reversing tube is subjected to pneumatic suction at its upper end so as to cause the progressive entrainment of the tubular article into the reversing tube starting from its lower end, thus achieving a new reversing of the article, which is returned to the right- way-out configuration and removed from the sewing or linking station.
The use of apparatuses of this kind has revealed problems in reversing articles which have a significant length or elastic articles which are highly extensible. With articles of this kind, it is in fact difficult to achieve a complete eversion of the article onto the outer lateral surface of the reversing tube to turn it inside out and it is subsequently difficult to achieve the complete transition of the article inside the reversing tube to return it right way out.
The problem of the eversion of the article onto the outer lateral surface of the reversing tube has been solved by providing auxiliary means, which are constituted by two contrarotating rollers, which are arranged above the dial in the sewing or linking station and can engage the portion of the article that is everted onto the outer lateral surface of the reversing tube and can be actuated with a rotary motion about their axes and with opposite directions of rotation so as to complete the eversion of the article onto the outer lateral surface of the reversing tube.
The problem of the complete insertion of the article within the reversing tube to return it right way out after closing the axial end of the article has proved to be more complex. In known types of apparatuses, the rod used to insert the closed axial end of the article into the lower end of the reversing tube is supported by a support or tube holder, which defines an axial abutment for the lower end of the reversing tube and is also used to lift the reversing tube when the first reversing of the article is performed to turn it inside out. Because of this fact, during the insertion of the rod inside the reversing tube through its lower end, the upward stroke of the rod cannot be increased beyond a certain limit, since it would make the axial abutment of the tube holder engage the lower end of the reversing tube, blocking it and thus blocking the article that is being reversed. For this reason, with a reversing device of the type described above, very often it is not possible to achieve the complete reversing of particularly long or highly extensible articles to return them right way out after closing one of their axial ends. Disclosure of the Invention The aim of the present invention is to solve the problem described above by providing a reversing device for tubular articles particularly for circular knitting machines provided with a station for closing an axial end of the tubular article which ensures correct reversing of the articles even when such articles have a particularly substantial length and/or are highly extensible.
Within this aim, an object of the invention is to provide a device which has precise and reliable operation.
Another object of the invention is to provide a device which can be manufactured at competitive costs. This aim and these and other objects, which will become better apparent hereinafter, are achieved by a device for reversing tubular articles, particularly for circular knitting machines provided with a station for closing an axial end of the tubular article, comprising a reversing tube which has a substantially vertical axis and can move on command along its own axis from at least one lowered position, in which it is arranged, with its upper end, below a dial which has a substantially vertical axis and is adapted to retain the tubular article so that it hangs from said dial with a first axial end thereof, to at least one raised position, in which it passes through said dial and is arranged so that its upper end lies above said dial in order to evert at least partially the tubular article onto the outer lateral surface of the reversing tube starting from the upper end of said reversing tube, and vice versa; auxiliary means being provided along the path of motion of said reversing tube, above said dial, and being engageable with the article, which is partially everted onto the lateral surface of said reversing tube, and actuatable to complete the eversion of the article onto the outer lateral surface of the reversing tube, expulsion means being provided which act on the article for its introflection inside said reversing tube, inserting said first axial end of the article, disengaged from said dial, in the lower end of the reversing tube, characterized in that it comprises means for positioning said reversing tube in an expulsion position, in which it is arranged so that its lower end lies proximate to said auxiliary means which can be actuated to move the article which is everted onto the outer lateral surface of said reversing tube toward its lower end in order to assist the action of said expulsion means. Brief description of the drawings
Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the reversing device according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a schematic sectional view of the lower portion of the reversing device, taken along a plane which passes through the axis of the reversing tube;
Figure 2 is a schematic sectional view of the upper portion of the reversing device, taken in a manner similar to Figure 1 ; Figures 3 to 17 illustrate the operating sequence of the reversing device, shown schematically in a front elevation view. Ways of carrying out the Invention
The device according to the invention is designed to be positioned generally at a processing station in which it is necessary to perform a first reversal of a tubular article 60 to allow the execution of particular knitting with the article inside out and then a second reversal to make the article 60 available right way out again or vice versa.
A requirement of this kind is observed for example in closing an axial end of a tubular article, particularly the toe of a sock, if this closing operation is performed by sewing or linking on the reverse side of the article by transferring the article, produced with a circular knitting machine for hosiery, from the production machine to a sewing or linking station which is arranged laterally or otherwise in the vicinity of the production machine by means of a dial 50 which is capable of supporting the article 60 so that it hangs from the dial 50 by means of its axial end to be closed.
In particular, the reversing device according to the invention is conceived to equip an apparatus of the type disclosed in US Patent 7,107,797 and in WO 2004/035894.
An apparatus of this kind has an arm 51 which is supported by a supporting structure so that it can rotate about a vertical rotation axis which is spaced laterally with respect to the machine for producing the articles 60 and supports the dial 50 in a region which is spaced from such rotation axis.
The dial 50, as disclosed in the patents cited above, is composed of two half-dials 52a, 52b, which lie mutually side by side along a diametrical plane of the dial 50 and are provided in a downward region with points 53 which have tips directed downwardly and are arranged so as to correspond to the needles on the machine for producing the article 60. The dial 50 is further provided with means which are capable of retaining the article 60 engaged with the points 53 during and after its transfer from the production machine to the linking or sewing station. One of the two half-dials, in the illustrated case the half-dial 52a, is fixed, while the other half-dial 52b can be turned over on command about a diametrical axis 54, below the fixed half-dial 52a, so as to make each of its points 53 face with its tip the tip of a point 53 of the fixed half-dial 52a. Moreover, the dial 50, again as disclosed in the patents cited above, is provided with elements for transferring loops of knitting from the points 53 of the overturning half-dial 52b to the points 53 of the fixed half-dial 52a.
The apparatus served by the reversing device according to the invention, in order to close an axial end of the article, is provided, in the sewing or linking station, with a sewing or linking head, not shown for the sake of simplicity, which can cooperate directly with the points 53 of the fixed half-dial 52a or with the points 55 of an additional half-dial 56, which is arranged below the fixed half-dial 52a and is provided with points 55, which are directed with their tip upwardly and are capable of receiving the loops of knitting retained by the points 53 of the fixed half-dial 52a.
In practice, according to what is disclosed in the patents cited above, the arm 51, by utilizing its ability to rotate about an axis which is parallel to the axis of the needle cylinder of the machine that produces the article, once the production of the article 60 has ended and once the last row of knitting is retained on the needles of the production machine, arranges the dial 50 above and coaxially with respect to the needle cylinder so that each of its points is positioned upwardly at each needle of the machine. Subsequently, the last row of knitting of the article 60, produced by the needles and retained on the needles that produced it, is passed, loop by loop, from a needle to a point 53 of the dial 50, which again by utilizing the ability to rotate of the arm 51 that supports it is moved laterally to the machine at the sewing or linking station. Before removal from the production machine, the article 60 is in the right way out condition inside the needle cylinder of the machine, and the movement of the dial 50 laterally to the machine achieves the extraction of the article 60 from the needle cylinder, in the case of short articles, or the partial extraction of the article 60 from the needle cylinder in the case of significantly long articles.
The arm 51, which supports the dial 50, can also perform a translational motion along its axis of rotation in order to lift and lower the dial 50.
The arm 51 , in the sewing or linking station, is positioned at a centering arm 57, which is provided with centering pins 58, 59 which are mutually opposite and are designed to keep the arm 51 positioned correctly in the sewing or linking station while allowing a vertical movement of said arm 51 and therefore of the dial 50 which it supports.
As regards additional details concerning the dial 50 and the technique for closing an axial end of a tubular article 60, reference is made for the sake of completeness to the patents cited above.
The reversing device according to the invention, generally designated by the reference numeral 1, comprises a reversing tube 2, which has a substantially vertical axis 2a and can move on command along its own axis 2a in order to pass from a lowered position, in which it is arranged, with its upper end, below the dial 50 arranged in the sewing or linking station, which holds the tubular article 60 so that it hangs from the dial 50 with a first axial end which constitutes the axial end to be closed of the article 60, to at least one raised position, in which it passes through the dial 50 and is arranged with its upper end above the dial 50 so as to evert the tubular article 60 at least partially onto the outer lateral surface of the reversing tube 2 starting from the upper end of said reversing tube 2, and vice versa. Auxiliary means 3 are arranged along the path of motion of the reversing tube 2, above the dial 50, can engage the article 60, partly everted onto the outer lateral surface of the reversing tube 2, and can be actuated to complete the eversion of the article 60 onto the outer lateral surface of the reversing tube 2. The device further comprises expulsion means which act on the article 60 in order to introflect it inside the reversing tube 2, inserting the first axial end of the article, which is disengaged from the dial 50, in the lower end of the reversing tube 2.
According to the invention, the device comprises means for positioning the reversing tube 2 in an expulsion position, in which it is arranged so that its lower end lies proximate to the auxiliary means 3, which can be actuated to entrain the article 60, which is everted onto the outer lateral surface of the reversing tube 2, toward its lower end, to assist the action of such expulsion means. More particularly, the reversing tube 2 is mounted on a tube holder
10, which is substantially cylindrical, is arranged coaxially to the reversing tube 2 and has, in an intermediate region of its extension, an axial shoulder 20 against which the lower end of the reversing tube 2, fitted around the portion of the tube holder 10 that lies above the axial shoulder 20, can rest. The tube holder 10 is provided as the body of a pneumatic cylinder inside which there is chamber 1 1 which has a vertical axis and accommodates, so that it can slide axially, a piston 12 provided with a stem 12a which protrudes downwardly from the tube holder 10.
The tube holder 10 can slide axially within a guiding cylinder 14, which in turn is arranged, along a portion of its axial extension starting from its lower end, internally and coaxially to a supporting cylinder 15. The supporting cylinder 15 is rigidly fixed, at its upper end, to the supporting structure 17 of the device and the guiding cylinder 14 is fixed to the supporting cylinder 15. The guiding cylinder 14 has an axial slot 14a, with which two tabs 44 engage slidingly, said tabs being fixed to the tube holder 10. The coupling of the tabs 44 to the axial slot 14a prevents the rotation of the tube holder 10 about its own axis while allowing the tube holder 10 to perform an axial translational motion with respect to the guiding cylinder 14. The stem 12a is fixed, proximate to its lower end, to a base 13, which is fixed to an external cylinder 16 which is arranged externally and coaxially with respect to the supporting cylinder 15 and can slide axially with respect to it.
Two ducts extend within the stem 12a and are connected, at their upper end, respectively to the region of the chamber 11 that is arranged above the piston 12 and to the region located below the piston 12. These two ducts can be connected selectively to a duct for supplying air under pressure or to a discharge so as to lift or lower the tube holder 10 with respect to the piston 12. In practice, the tube holder 10 can be likened to the body of a double- acting pneumatic cylinder in which the stem 12a is fixed while the body, constituted indeed by the tube holder 10, can slide upwardly or downwardly with respect to the stem 12a of the piston 12 as a consequence of the feeding, with air under pressure, of the chamber 11 through one of the two ducts which lie within the stem 12a.
The base 13 is connected to the stem 18 of the piston of a pneumatic cylinder 19 which is arranged so that its axis is vertical and is connected, by means of its body, to the supporting structure 17. The actuation of this pneumatic cylinder 19 lifts or lowers the base 13 and consequently the tube holder 10.
In practice, by acting on the pneumatic cylinder 19 so that the base 13 is lowered and by supplying with air under pressure the region of the chamber 11 arranged above the piston 12, it is possible to place the reversing tube 2, which rests against the shoulder 20, in a first lifting position, in which it passes through the dial 50 and is arranged so that its upper end lies above the dial 50. By then acting on the pneumatic cylinder 19 so that the base 13 is raised, one achieves an additional lifting of the reversing tube 2, which still rests against the shoulder 20 and is moved to a second lifting position, in which its lower end lies proximate to the half-dial 56. A rod 21 is connected coaxially to the tube holder 10, at its upper end, and is part of the expulsion means cited above, as will become better apparent hereinafter.
The auxiliary means comprise two rollers 22 and 23, which are shown partially in cross-section in Figure 2 and are arranged so that their axes 22a, 23a are horizontal and parallel to each other and on mutually opposite sides with respect to the axis 2a, so as to face diametrically mutually opposite regions of the outer lateral surface of the reversing tube 2 in the first lifting position. The rollers 22 and 23 are supported at the end of a corresponding supporting arm 24, 25, which is pivoted, about a corresponding pivoting axis 26, 27, with an intermediate region of its extension, to the supporting structure 17. A pneumatic cylinder 28 acts on the other end of the supporting arms 24 and 25 and can be actuated to produce, by utilizing the pivoting of the arms 24, 25 about the axes 26, 27, the movement of the rollers 22, 23 toward the outer lateral surface of the reversing tube 2, which is inserted between the rollers 22 and 23, or to move the rollers 22, 23 away from the outer lateral surface of the reversing tube 2.
The rollers 22, 23 can be actuated with a rotary motion about the corresponding axes 22a, 23 a, for example by means of electric motors of a known type, which are not shown for the sake of simplicity, with mutually opposite direction of rotation and with a tangential speed which is directed downwardly in the regions of the rollers 22, 23 that face each other.
Conveniently, the lateral surface of the rollers 22, 23 has a circumferential groove, so as to wrap around the outer lateral surface of the reversing tube 2.
Moreover, the lateral surface of the rollers 22, 23 can be covered with a suitably soft material and/or provided with teeth, so as to increase the grip of the rollers 22, 23 on the article 60 fitted on the reversing tube 2, as will become better apparent hereinafter. The positioning means comprise engagement means which can engage the reversing tube 2 proximate to its upper end and can move on command along a vertical direction so as to lift the reversing tube 2 until the reversing tube 2 is in the expulsion position. More particularly, a connecting tube 30 is arranged above and coaxially to the reversing tube 2. This connecting tube 30 has a telescopic structure, with an upper part 31 which is fixed to the supporting structure 17 of the machine and a lower part 32 which can move on command along a vertical direction with respect to the upper part 31 so as to fit coaxially on the upper end of the reversing tube 2 in the raised position or disengage from the upper end of the reversing tube 2.
The lower part 32 of the connecting tube 30 is provided with engagement means, which can engage a portion of the reversing tube 2 which is proximate to its upper end. Such engagement means comprise a movable pivot 33, which is arranged so that its axis is perpendicular to the axis 2a of the reversing tube 2 and is actuated by a corresponding pneumatic cylinder 34 which is connected to the lower part 32 of the connecting tube 30. By way of the actuation of the pneumatic cylinder 34, the movable pivot 33 can be inserted into or removed from a seat 35, which is defined in the end portion of the reversing tube 2 which can be inserted in the lower part 32 of the connecting tube 30. The engagement means are completed by a sensor 36, which is capable of detecting the presence of the upper end of the reversing tube 2 inside the lower part 32 of the connecting tube 30 with the seat 35 positioned correctly in alignment with the movable pivot 33.
The lower part 32 of the connecting tube 30 is connected to the end of the stem 38 of the piston of a pneumatic cylinder 45 which has a vertical axis and is connected, by means of its body, to the supporting structure 17. The pneumatic cylinder 45 is a pneumatic cylinder of a known type with a controlled stroke, in that it can lower or lift the lower part 32 of the connecting tube 30, stopping it in a plurality of positions.
The reversing tube 2 has an opening 39 on its lateral surface which extends, starting from the upper end of the reversing tube 2, along a portion of its axial extension so as to receive internally the article 60, as will become better apparent hereinafter.
The upper end of the connecting tube 30 is connected to a suction tube 40, which can be connected to a pneumatic suction device of a known type so as to produce suction through the connecting tube 30 and therefore through the lower end, in the direction of the upper end of the reversing tube 2 which is coupled thereto.
Advantageously, means for pushing the everted article onto the lateral surface of the reversing tube 2 toward the lower end of the reversing tube are provided.
Such pusher means comprise a sleeve 42, which is partially inserted coaxially in the lower part 32 of the connecting tube 30 and protrudes from the lower end of the lower part 32 with a portion which ends, in a downward region, with a border 42a which has an enlarged outside diameter. This sleeve 42 can slide axially with respect to the lower part 32 of the connecting tube 30 by way of the action of a pneumatic cylinder 43 which has a vertical axis and is interposed between the lower part 32 and the sleeve 42.
The sleeve 42, in addition to pushing the article 60, which is everted on the lateral surface of the reversing tube 2, also at least partially blocks the opening 39 defined in the lateral surface of the reversing tube 2 starting from its upper end, as will become better apparent hereinafter.
Operation of the device according to the invention is described hereinafter with particular reference to Figures 3 to 17, in which the dial 50 and the arm 51 that supports it, if provided, are shown in phantom lines, while the article 60 is shown in an axial sectional view in order to allow to view the reversing device. The reversing device 1 , in the inactive condition, preferably is in the configuration shown in Figures 1, 2 and 3, i.e., with the reversing tube 2 rested against the tube holder 10 and raised into the second lifting position, since the stem 18 of the pneumatic cylinder 19 is retracted into the body of said pneumatic cylinder 19 (the base 13 is raised) and the chamber 11 is supplied with air under pressure in its region located above the piston 12. In this condition, the lower part 32 of the connecting tube 30 is lowered and fitted onto the upper end of the reversing tube 2 and the rollers 22, 23 are mutually spaced. When the reversing device must receive an article 60 to be reversed, it is actuated so as to arrange itself in the configuration shown in Figure 4, in which the reversing tube 2, by introducing air under pressure into the region of the chamber 11 located below the piston 12 and by way of the actuation of the pneumatic cylinder 19, is moved to the lowered position, and the lower part 32 of the connecting tube 30, by means of the pneumatic cylinder 45, is raised.
Subsequently, the article 60, in the right-way-out configuration, hanging by its upper end from the points 53 of the half-dials 52a, 52b of the dial 50, is picked up, as already described above, by the machine that produced it and moved, by means of the arm 51, into the sewing or linking station at the reversing device 1. The arm 51 is inserted, with a portion thereof provided with a centering seat, between the centering pins 58, 59 and is raised by engaging it with the centering pin 58 until it is brought into abutment against an upper shoulder defined by the centering arm 57. In this manner, the dial 50 is positioned above and coaxially with respect to the reversing tube 2. The movement of the arm 51 in the sewing or linking station has extracted the article 60 partially or completely from the needle cylinder of the circular machine that produced it. During the transfer, the article 60 is diverted, so as to achieve an optimum arrangement thereof, by interference with a sock guard lever 46, which is activated and arranged below the position assumed by the dial 50 on board the reversing device 1.
With the dial 50 thus positioned, the reversing tube 2, by introducing air under pressure into the region of the chamber 11 arranged above the piston 12, is raised into the first lifting position. As a consequence of this lifting, the reversing tube 2 crosses, with its upper end, the dial 50 until it is arranged, with such upper end, above the rollers 22, 23, as shown in Figure 5. The crossing of the dial 50 by the upper end of the reversing tube 2 produces the progressive eversion of the article 60, which is still engaged with the points 53 of the dial 50, onto the lateral surface of the reversing tube 2 starting from its upper end.
At this point, the rollers 22, 23, by way of the actuation of the pneumatic cylinder 28, are moved toward the outer lateral surface of the reversing tube 2 so as to engage the everted article 60 and are actuated with a rotary motion about their own axes 22a, 23a, with mutually opposite directions of rotation, so as to push the article 60 downwardly along the outer lateral surface of the reversing tube 2. The actuation of the rollers 22, 23 completes the eversion of the article 60 onto the lateral surface of the reversing tube 2 even in the case of articles which have a considerable length or are elastically extensible, as shown in Figure 6. The actuation of the rollers 22, 23 can be dependent upon the detection performed by a known type of sensor 61, which is shown in Figure 4 and faces the outer lateral surface of the reversing tube 2 directly above the axis of the rollers 22, 23 and is capable of detecting the presence or absence of a portion of the article 60 on the region of the outer lateral surface of the reversing tube 2 which it faces in order to interrupt the actuation of the rollers 22, 23 as soon as the article 60 has been pushed by the rollers 22, 23 below such region.
It should be noted that during eversion the article 60 rises within the reversing tube 2, entering through the opening 39 and exiting from the upper end of the reversing tube 2. Once the eversion of the article 60 onto the outer lateral surface of the reversing tube 2 has been completed, the article 60 is inside out and arranged above the dial 50, which is engaged with its axial end to be closed by sewing or linking.
The rollers 22, 23 are then moved away from the outer lateral surface of the reversing tube 2, the sock guard lever 46 is deactivated and the lower part 32 of the connecting tube 30 is lowered, by means of the pneumatic cylinder 45, into a position which is adapted to engage the reversing tube 2, while the reversing tube 2, by means of the pneumatic cylinder 19, is raised further into the second lifting position or engagement position. In this manner, the upper end of the reversing tube 2 enters the lower part 32 of the connecting tube 30 and is engaged by the engagement of the movable pivot 33 in the seat 35, as shown in Figure 7.
At this point, the lower part 32 of the connecting tube 30 is raised, by means of the pneumatic cylinder 45, so as to bring the reversing tube 2 into a third lifting position, in which it is arranged so that its lower end is at the level of the dial 50, slightly above the points 53. The base 13 and the tube holder 10 are lowered respectively by means of the pneumatic cylinder 19 and by introducing air under pressure into the region of the chamber 1 1 that is arranged below the piston 12, as shown in Figure 8. By means of the pneumatic cylinder 43, the sleeve 42 is lowered so as to push, with its edge 42a, the article 60 toward the lower end of the reversing tube 2 and the overturning half-dial 52b is turned over below the fixed half-dial 52a so as to make the tip of its points 53 face the tip of the points 53 of the fixed half-dial 52a, as shown in Figure 9. The loops of knitting supported by the points 53 of the overturning half-dial 52b are transferred, for example as disclosed in US Patent 7,107,797 and in WO 2004/035894, to the points 53 of the fixed half-dial 52a and the overturning half-dial 52b is returned to a coplanar position, to the side of the fixed half-dial 52a. In this manner, each point 53 of the fixed half-dial 52a supports two loops of knitting. The lower part 32 of the connecting tube 30 is lowered, by means of the pneumatic cylinder 45, to the level at which it had engaged the reversing tube 2 so that the lower end of the reversing tube 2 lies slightly above the points 55 of the half-dial 56, while the arm 51 is lowered, passing over the centering pin 59 and stopping against a lower shoulder which is defined by the centering arm 57, as shown in Figure 10.
In this manner, the fixed half-dial 52a is made to face and approach, with the tip of its points 53, the tip of the points 55 of the half-dial 56 and the pairs of loops of the article 60 are transferred from the points 53 of the fixed half-dial 52a to the points 55 of the half-dial 56.
At this point, the sleeve 42 is raised by means of the pneumatic cylinder 43 and a sewing or linking head, of a known type and not shown for the sake of simplicity, is activated and cooperates with the points 55, for example as disclosed in the patents cited above, joining the pairs of loops of knitting carried by said points, thus closing the article 60 at its axial end that had been engaged by the dial 50, as shown in Figure 11.
Subsequently, by feeding with air under pressure the region of the chamber 11 arranged above the piston 12, the tube holder 10 is raised and by way of this lifting the rod 21 is inserted in the lower end of the reversing tube 2, engaging the closed end of the article 60, disengaging it from the points 55 of the half-dial 56, and beginning to introflect the article 60 into the reversing tube 2, as shown in Figure 12.
The base 13 is then also raised, by means of the pneumatic cylinder
19, increasing the rise of the rod 21 within the reversing tube 2, which by way of the lifting of the lower part 32 of the connecting tube 30 to which it is engaged is moved with its lower end to the level of the dial 50, as shown in Figure 13.
At this point, the pneumatic cylinder 43 is activated and lowers the sleeve 42 along the reversing tube 2. In this manner, the sleeve 42 acts on the article 60, pushing it downwardly along the outer lateral surface of the reversing tube 2. The lowering of the sleeve 42 also closes almost entirely the opening 39 of the reversing tube 2, as shown in Figure 14.
The lower part 32 of the connecting tube 30 is then raised further, again by way of the pneumatic cylinder 45, placing the reversing tube 2 in the expulsion position, in which it is arranged so that its lower end, at the level of the rollers 22, 23, lies preferably at the horizontal plane of arrangement of the axes 22a, 23a of such rollers 22, 23. The rollers 22, 23 are moved toward the reversing tube 2 so as to engage the article 60 and are actuated with a rotary motion about their own axes 22a, 23 a, with mutually opposite directions of rotation, so as to assist the descent of the article 60 along the outer lateral surface of the reversing tube 2 toward its lower end, facilitating the introflection of the article 60 inside the reversing tube 2 which, by reversing the article 60 again, returns it to the right-way-out configuration inside the reversing tube, as shown in Figure 15. Due to the arrangement of the lower end of the reversing tube 2 at the rollers 22, 23 and to the actuation of such rollers 22 and 23, and to the fact that the lower end of the reversing tube 2 is adequately spaced from the shoulder 20 of the tube holder 10, with the reversing device according to the invention it is possible, in this step, to reverse even articles 60 which are substantially long or are highly elastically extensible.
Moreover, in this step the suction tube 40 is preferably connected to a suction device which, by generating a rising air stream within the reversing tube 2, further facilitates completion of the introflection of the article 60 within the reversing tube 2. Once the article 60 has been inserted completely within the reversing tube 2, it is moved away by suction along the suction tube 40.
The tube holder 10 is then lowered again so as to free the arm 51 and the dial 50, which can be returned above the machine for producing the articles in order to pick up a new article 60 to be then taken to the sewing or linking station, while the rollers 22, 23 are again moved away from the outer lateral surface of the reversing tube 2, as shown in Figure 16, and the sleeve 42 is raised as shown in Figure 17.
At this point, the lower part 32 of the connecting tube is lowered to the same level at which it engaged the reversing tube 2 and the tube holder 10 is raised into the second lifting position or engagement position, as already explained, so that the reversing tube 2 again rests against the tube holder 10, returning the device to the condition shown in Figures 1, 2 and 3. In practice it has been found that the device according to the invention fully achieves the intended aim, since it ensures the correct overturning of the articles even if said articles are particularly long and/or highly extensible.
Although the reversing device has been conceived in particular to equip a sewing or linking station for closing an axial end of tubular articles of the type disclosed in US Patent 7,107,797 and in WO 2004/035894, it can also be used with other apparatuses which support a tubular article which hangs from a dial by an axial end to be closed even in a different manner and with different means with respect to the ones shown in US Patent 7,107,797 and in WO 2004/035894.
The reversing device thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; moreover, all the details may be replaced with other technically equivalent elements.
In practice, the materials used, as well as the dimensions, may be any according to requirements and to the state of the art. The disclosures in Italian Patent Application No. MI2006A001720 from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A device for reversing tubular articles, particularly for circular knitting machines provided with a station for closing an axial end of the tubular article, comprising a reversing tube which has a substantially vertical axis and can move on command along its own axis from at least one lowered position, in which it is arranged, with its upper end, below a dial which has a substantially vertical axis and is adapted to retain the tubular article so that it hangs from said dial with a first axial end thereof, to at least one raised position, in which it passes through said dial and is arranged so that its upper end lies above said dial in order to evert at least partially the tubular article onto the outer lateral surface of the reversing tube starting from the upper end of said reversing tube, and vice versa; auxiliary means being provided along the path of motion of said reversing tube, above said dial, and being engageable with the article, which is partially everted onto the lateral surface of said reversing tube, and actuatable to complete the eversion of the article onto the outer lateral surface of the reversing tube, expulsion means being provided which act on the article for its introflection inside said reversing tube, inserting said first axial end of the article, disengaged from said dial, in the lower end of the reversing tube, characterized in that it comprises means for positioning said reversing tube in an expulsion position, in which it is arranged so that its lower end lies proximate to said auxiliary means which can be actuated to move the article which is everted onto the outer lateral surface of said reversing tube toward its lower end in order to assist the action of said expulsion means.
2. The device according to claim 1, characterized in that said expulsion means comprise a rod which can be inserted in the lower end of the reversing tube and can engage said first axial end of the article, which is closed after the insertion of said reversing tube through said dial and disengaged from said dial.
3. The device according to claims 1 and 2, characterized in that said expulsion means comprise pneumatic suction means which can be connected to the upper end of said reversing tube after the eversion of the article onto the lateral surface of said reversing tube.
4. The device according to one or more of the preceding claims, characterized in that said auxiliary means comprise a pair of rollers which have mutually parallel and horizontal axes and face two mutually diametrically opposite regions of the outer lateral surface of the reversing tube in said at least one raised position; said rollers being movable on command toward said reversing tube and away from said reversing tube, respectively to engage or disengage the article everted onto the outer lateral surface of the reversing tube; said rollers being actuatable with a rotary motion about the corresponding axes and with mutually opposite rotation directions to entrain the article along the outer lateral surface of the reversing tube toward its lower end.
5. The device according to one or more of the preceding claims, characterized in that the lateral surface of said rollers has a circumferential slot for wrapping around the outer lateral surface of the reversing tube.
6. The device according to one or more of the preceding claims, characterized in that the lateral surface of said rollers is covered and/or shaped in a manner adapted to increase the grip of said rollers on the article.
7. The device according to one or more of the preceding claims, characterized in that said positioning means comprise engagement means, which can engage said reversing tube proximate to its upper end and can move on command along a vertical direction in order to lift said reversing tube until said reversing tube is in said expulsion position.
8. The device according to one or more of the preceding claims, characterized in that said reversing tube, in said expulsion position, is arranged so that its lower end lies substantially at the horizontal plane of arrangement of the axes of said rollers.
9. The device according to one or more of the preceding claims, characterized in that it comprises first lifting means which can be activated on command in order to transfer said reversing tube from said lowered position, in which it is arranged with its upper end below said dial, to a first lifting position, in which it is arranged with its upper end above said dial, and vice versa.
10. The device according to one or more of the preceding claims, characterized in that it comprises second lifting means, which can be actuated on command to transfer said reversing tube from said first lifting position to a second lifting position, in which it is arranged so that its upper end lies above the position occupied by said upper end in said first lifting position at a height which is suitable for engagement with said engagement means.
11. The device according to one or more of the preceding claims, characterized in that it comprises a connecting tube which is arranged above and coaxially to said reversing tube and has a telescopic structure, with a lower part which can move axially from a lowered position, in which it mates with the upper end of said reversing tube in said second lifting position, to a raised position, in which it is spaced upwardly from the upper end of said reversing tube and vice versa; said lower portion of the connecting tube being provided with said engagement means, which can engage a portion of the reversing tube which is proximate to its upper end.
12. The device according to one or more of the preceding claims, characterized in that said lower part of the connecting tube can move on command in order to move said reversing tube, engaged with said lower part of the connecting tube, from said second lifting position to a third lifting position, in which it is arranged so that its upper end is at a higher level than said second lifting position and its lower end is substantially at the level of said dial and in order to move said reversing tube into said expulsion position or vice versa.
13. The device according to one or more of the preceding claims, characterized in that the upper end of said connecting tube is connected to a pneumatic suction tube.
14. The device according to one or more of the preceding claims, characterized in that it comprises means for pushing the everted article onto the lateral surface of said reversing tube toward the lower end of said reversing tube.
15. The device according to one or more of the preceding claims, characterized in that said reversing tube has an opening on its lateral surface which lies, starting from its upper end, along a portion of the axial extension of said reversing tube.
16. The device according to one or more of the preceding claims, characterized in that it comprises means for partially blocking said opening which can be activated or deactivated on command.
17. The device according to one or more of the preceding claims, characterized in that said means for pushing the article comprise a sleeve which is supported by said lower part of the connecting tube and can be fitted coaxially on said reversing tube starting from its upper end and can move on command along the outer lateral surface of said reversing tube.
18. The device according to one or more of the preceding claims, characterized in that said means for partially blocking said opening are constituted by said pusher means.
19. A method for reversing tubular articles, particularly in circular knitting machines provided with a station for closing an axial end of the tubular article, comprising the following steps: - arranging the article so that it hangs, at an axial end, by means of a dial which has a substantially vertical axis;
- inserting the upper end of a reversing tube, which has a substantially vertical axis, through said dial, moving the upper end of the reversing tube above said dial, causing the at least partial eversion of the article onto the outer lateral surface of the reversing tube, starting from its upper end;
- moving the lower end of the reversing tube to the level of, or directly above, said dial;
- releasing the axial end of the article, disengaging it from said dial; - inserting the axial end of the article, previously retained by said dial, through the lower end of the reversing tube; characterized in that it comprises the following additional steps:
- moving the lower end of the reversing tube to the level of auxiliary means which are arranged above said dial and can engage the portion of the article that is everted onto the outer lateral surface of the reversing tube;
- pushing or pulling the article upwardly by acting on its axial end inserted in said reversing tube, causing its progressive introflection inside the reversing tube starting from its lower end;
- actuating said auxiliary means, in engagement with the portion of the article that is everted onto the outer lateral surface of the reversing tube, to assist its descent toward the lower end of the reversing tube.
20. The method according to claim 19, characterized in that said auxiliary means comprise a pair of rollers, which have mutually parallel and horizontal axes and face two diametrically mutually opposite regions of the outer lateral surface of the reversing tube; said rollers being actuatable with a rotary motion about the corresponding axes and with mutually opposite directions of rotation in order to entrain the article along the outer lateral surface of the reversing tube toward its lower end.
21. The method according to claims 19 and 20, characterized in that after the insertion of the axial end of the article in the lower end of the reversing tube, the reversing tube is moved so that its lower end is at the level of the axes of said rollers.
22. The method according to claims 19-21, characterized in that the axial end of the article retained by said dial is closed before it is inserted through the lower end of the reversing tube.
23. The method according to claims 19-22, characterized in that the insertion of the axial end of the article in the lower end of the reversing tube and its upward pushing are performed by inserting, through the lower end of the reversing tube, a rod which has a substantially vertical axis.
24. The method according to claims 19-23, characterized in that the inside of the reversing tube, at least after the insertion of the axial end of the article previously retained by the dial, is subjected to pneumatic suction at its upper end to generate a flow of air through its lower end toward its upper end.
PCT/EP2007/007484 2006-09-08 2007-08-27 Device for reversing tubular articles, particularly for circular knitting machines provided with a station for closing an axial end of the tubular article WO2008028575A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI2006A001720 2006-09-08
ITMI20061720 ITMI20061720A1 (en) 2006-09-08 2006-09-08 MANUFACTURER OF TUBULAR MANUFACTURED ITEMS, PARTICULARLY FOR CIRCULAR KNITTING MACHINES EQUIPPED WITH A CLOSING STATION OF AN AXIAL END OF THE TUBULAR MANUAL.

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WO2008028575A1 true WO2008028575A1 (en) 2008-03-13
WO2008028575A8 WO2008028575A8 (en) 2008-06-19

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CN103485060A (en) * 2012-06-08 2014-01-01 浙江伟焕机械制造有限公司 Free lifting system of five-finger sock hat cover
CN108560128A (en) * 2018-07-24 2018-09-21 杨志林 A kind of band dials the tubing stitching devices and method of hosiery machine structure
EP3715511A1 (en) 2019-03-26 2020-09-30 Stäubli Italia S.p.A. Method and device for reversing a tubular knitted article in a circular knitting machine
IT201900009615A1 (en) 2019-06-20 2020-12-20 Santoni & C Spa Reversing device for tubular knitted products and method for overturning a tubular knitted product

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EP1118700A1 (en) * 2000-01-18 2001-07-25 Metalworking And Finance Group International S.A. Method and device for producing tubular knitted articles and for closing their toes
WO2003018903A1 (en) * 2001-08-28 2003-03-06 Golden Lady S.P.A. Device and method for opening the edge of a tubular knitted article or similar
WO2004035894A1 (en) * 2002-10-21 2004-04-29 Fabritex S.R.L. Method and apparatus for joining the edges of a tubular knitted article

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EP1118700A1 (en) * 2000-01-18 2001-07-25 Metalworking And Finance Group International S.A. Method and device for producing tubular knitted articles and for closing their toes
WO2003018903A1 (en) * 2001-08-28 2003-03-06 Golden Lady S.P.A. Device and method for opening the edge of a tubular knitted article or similar
WO2004035894A1 (en) * 2002-10-21 2004-04-29 Fabritex S.R.L. Method and apparatus for joining the edges of a tubular knitted article

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Publication number Priority date Publication date Assignee Title
CN103485060A (en) * 2012-06-08 2014-01-01 浙江伟焕机械制造有限公司 Free lifting system of five-finger sock hat cover
CN108560128A (en) * 2018-07-24 2018-09-21 杨志林 A kind of band dials the tubing stitching devices and method of hosiery machine structure
CN108560128B (en) * 2018-07-24 2024-03-29 浙江嘉志利智能科技有限公司 Tubular fabric sewing device with sock pulling mechanism and method
EP3715511A1 (en) 2019-03-26 2020-09-30 Stäubli Italia S.p.A. Method and device for reversing a tubular knitted article in a circular knitting machine
CN111749001A (en) * 2019-03-26 2020-10-09 斯塔乌布利意大利股份公司 Method and device for reversing tubular knitted articles in circular knitting machines
CN111749001B (en) * 2019-03-26 2023-03-28 斯塔乌布利意大利股份公司 Method and device for reversing tubular knitted articles in circular knitting machines
IT201900009615A1 (en) 2019-06-20 2020-12-20 Santoni & C Spa Reversing device for tubular knitted products and method for overturning a tubular knitted product

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