CIRCULAR HOSIERY KNITTING MACHINE FOR MANUFACTURING TUBULAR ITEMS

Abstract

A circular hosiery knitting machine comprising a needle cylinder which can be actuated with a rotary motion about its own axis, arranged vertically, and on the skirt of which there is a plurality of axial grooves, each accommodating a needle, a tubular body being arranged internally and coaxially to the needle cylinder and being adapted to receive the manufactured item during its forming; the tubular body is supported so that it can slide along an axial direction within the needle cylinder; and actuation means which act on command on the tubular body in order to actuate its axial movement with respect to the needle cylinder, the actuation means being associated with means for controlling the speed of the tubular body.

Claims

1-8. (canceled)

9. A circular hosiery knitting machine comprising a needle cylinder which can be actuated with a rotary motion about an axis thereof, arranged vertically, and on a skirt of which there is a plurality of axial grooves, each accommodating a needle, a tubular body being arranged internally and coaxially to said needle cylinder and being configured to receive a manufactured item during forming thereof, said tubular body being supported so that it can slide along an axial direction within said needle cylinder in order to pass from at least one inactive position, in which the tubular body is arranged with an upper end thereof at a same level or at a lower level with respect to an upper end of the needle cylinder, to at least one active position, in which the tubular body protrudes with its upper end from the upper end of the needle cylinder, actuation means being provided which act on command on said tubular body in order to actuate an axial movement thereof with respect to said needle cylinder, wherein said actuation means are associated with control means for controlling a speed of said tubular body along its axial movement from said inactive position to said at least one active position.

10. The circular machine according to claim 9, wherein said actuation means comprise motor means adapted to actuate in a controlled manner the axial movement of said tubular body from said inactive position to said at least one active position.

11. The circular machine according to claim 9, wherein said control means are configured to control the speed of said tubular body along its axial movement from said inactive position to said at least one active position as a function of a corresponding rotation rate of the needle cylinder during needle lifting steps.

12. The circular machine according to claim 9, wherein said control means are associated with programming means.

13. The circular machine according to claim 10, wherein said control means are associated with sensor means associated with said needle cylinder and adapted to control said motor means as a function of the position of said needles.

14. The circular machine according to claim 9, further comprising means for transferring said tubular manufactured item to a station for sewing or looping to close one of the axial ends thereof.

15. The circular machine according to claim 9, wherein said at least one active position comprises a first “tuck stitch” active position and a second “drop stitch” active position.

16. The circular machine according to claim 10, wherein said motor means comprise an electric motor which has an output shaft which comprises a worm screw which meshes with a block that is integral with said tubular body.

Description

[0026] Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the circular hosiery knitting machine for manufacturing tubular items according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

[0027] FIG. 1 is a schematic axial sectional view of the tubular body and of its actuation means of the machine according to the present invention;

[0028] FIG. 2 is a lateral elevation view of the machine portion of FIG. 1;

[0029] FIG. 3 is an enlarged-scale view of a detail of the upper end of the needle cylinder of the machine according to the invention in an operative condition;

[0030] FIGS. 4 to 6 are views of the same detail of FIG. 3 in another operative condition.

[0031] With reference to the figures, the machine according to the invention, generally designated by the reference numeral 1, comprises, in a per se known manner, a needle cylinder 2, which can be actuated with a rotary motion about its own axis 2a, which is vertical, and on the skirt of which there is a plurality of axial grooves 3, each accommodating a needle 4 which can be actuated along the corresponding axial groove 3 in order to produce knitting.

[0032] Internally or coaxially to the needle cylinder 2 there is a tubular body 5 designed to receive the manufactured item 40 during its forming.

[0033] The upper end of the tubular body 5 is preferably wider like an inverted cone.

[0034] The tubular body 5 exits in a lower region from the needle cylinder 2 and can be connected, in a per se known manner, to a suction device in order to draw the manufactured item 40 during its formation.

[0035] The tubular body 5 is supported, so that it can slide along its axis that coincides with the axis 2a, by the supporting structure of the machine and there are first actuation means 10 which act on command on the tubular body 5 in order to actuate its axial movement with respect to the needle cylinder 2.

[0036] The tubular body 5 is movable on command along its axis that coincides with the axis 2a, with respect to the needle cylinder 2, from an inactive position, in which it is arranged with its upper end at the same level or at a lower level with respect to the upper end of the needle cylinder 2, as shown in FIG. 3, to at least one active position, in which it protrudes with its upper end from the upper end of the needle cylinder 2, as shown in FIGS. 4, 5 and 6.

[0037] Preferably, the tubular body 5 is movable on command from the inactive position to multiple active positions, in which it protrudes with its upper end from the upper end of the needle cylinder by mutually different extents.

[0038] By way of example, FIG. 4 shows a first “tuck stitch” active position, FIG. 5 shown a second “drop stitch” active position, and FIG. 6 shows a third “heel bypass” active position.

[0039] More particularly, around a lower portion of the tubular body 5 which is arranged below the needle cylinder 2 there is a supporting element 11 which is integral with the supporting structure of the machine, at least as regards its translation along the axis 2a, and is crossed by a cylindrical seat 11a, with an axis that coincides with the axis 2a, which supports, so as to allow sliding along its own axis, the tubular body 5.

[0040] The actuation means 10 are associated with means for controlling the speed of the tubular body 5 along its axial movement from said inactive position to said at least one active position.

[0041] In particular, the actuation means 10 comprise motor means 12 adapted to actuate in a controlled manner the axial movement of the tubular body 5 from the inactive position to the at least one active position.

[0042] Conveniently, the control means are adapted to control the speed of the tubular body 5 along its axial movement from the inactive position to the at least one active position as a function of the corresponding rotation rate of the cylinder during the needle lifting step.

[0043] According to one possible practical embodiment, the control means are associated with programming means.

[0044] The control means may also be associated with sensor means associated with the needle cylinder 2 and adapted to control the motor means 12 as a function of the position of the needles 4.

[0045] According to one practical embodiment, the motor means 12 comprise an electric motor which has an output shaft 12a constituted by a worm screw which meshes with a block 13 that is integral with the tubular body 5.

[0046] Different connection means may be provided between the motor means 12 and the tubular body 11, which are adapted in any case to allow a movement in a controlled manner of the tubular body 5 from the inactive position to the at least one active position.

[0047] The operation of the machine according to the invention, as regards the movement of the tubular body 5, is as follows.

[0048] During normal work of the machine, the tubular body 5 is in the inactive position, shown in FIG. 3, i.e., with its upper end arranged substantially at the same level or at a lower level with respect to the level of the upper end of the needle cylinder 2.

[0049] When one wishes to exert on the manufactured item 40 an action that is directed upward so as to cause its rise along the needle 4, such as for example when one wishes to transfer the loops arranged on the needles 4 from the needles 4 to the grip members of a transfer member, as described above, it is possible to actuate the motor means 12, which cause the lifting of the tubular body 5 at a controlled speed and by the desired quantity.

[0050] FIGS. 4 to 6 shown three different degrees of lifting of the tubular body 5 with respect to the needle cylinder 2.

[0051] When one wishes to return the tubular body 5 to the inactive position, it is sufficient to actuate the actuation means in the opposite direction.

[0052] By way of example, with reference to the type of machine shown in the figures, at the end of the knitting of the manufactured item 40 all the needles 4 are in the so-called “float stitch” or “under sinker” (FIG. 3) position and the tubular body 5 is in its lowest position, the one used during the knitting of the tubular manufactured item 40.

[0053] This position is substantially common for all the types of machines that perform methods intended to perform a closed toe with removal for sewing on devices external to said machine.

[0054] At this point, a cam reaches the active position and begins to lift the needles 4, bringing them to the “tuck stitch” position (FIG. 4).

[0055] According to the present invention, the actuation means 10 are actuated, in a controlled manner, in order to lift the tubular body 5 so as to maintain the loops in a safety condition.

[0056] In fact, if the loops were too low in this step there would be the risk that they might end up under the latch, while if they were too high they might exit from the head of the respective needle 4.

[0057] Once leveling in the “tuck stitch” position has been completed, another cam is actuated and moves the needles 4 to the “drop stitch” position (FIG. 5).

[0058] During this step, the tubular body 5 continues its movement at a controlled speed in order to keep the loops of knitting in the previously described condition.

[0059] Once leveling in the “drop stitch” position has been completed, it is possible to provide for another cam to become active in order to move the needles 4 to the “heel bypass” position (FIG. 6).

[0060] If the “heel bypass” position is actually provided, the tubular body 5 is actuated further in order to perform an upward movement at a controlled speed so as to keep the loops of knitting in the previously described condition.

[0061] When all the needles 4 are in the “heel bypass” position the intervention of the tubular body 5 necessary to keep the loops of knitting in the transfer position is finished.

[0062] The movement sequence of the needles 4 described above is merely an example, although most machines 1 that provide for the transfer of the tubular manufacture perform substantially the same sequence except, in some cases, for the movement in the “heel bypass” position.

[0063] Although the machine according to the invention has been conceived in particular to simplify and increase the speed of the operations for automated transfer of a manufacture of the circular knitting machine that produces it to a machine capable of performing sewing or looping for closing an axial end of said manufacture, particularly for manufacturing hosiery items, it may be used in any case advantageously in any situation which requires a movement of the manufacture along the needles with which it is engaged.

[0064] In practice it has been found that the machine according to the invention fully achieves the intended aim and objects, since by allowing to move the manufactured item along the stein of the needles with which the manufactured item is engaged it simplifies and increases the speed of the operations for the automated transfer of the manufactured item from the knitting machine to a transfer member to be used for performing, externally from said machine, the sewing and looping operation for closing an axial end of said manufactured item.

[0065] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may furthermore be replaced with other technically equivalent elements.

[0066] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art.

[0067] The disclosures in Italian Patent Application No. 102020000006142 from which this application claims priority are incorporated herein by reference.

[0068] 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.