Circular knitting machine for hosiery and the like, and method for producing tubular products

Abstract

A circular knitting machine with a needle cylinder configured to make a tubular product includes a pick-up device that shuttles between a pick-up position arranged coaxially around the needle cylinder for picking up the tubular product and a position for releasing it at a station laterally spaced from the needle cylinder. The station is provided with an everter having a lower part forming an access entrance. The lower part of the everter is configured to coaxially receive the tubular product for turning it over. The circular knitting machine includes a pulling means adapted to act on the outer surface of the tubular product in command to convey a portion of the tubular product to a storage area. The everter is associated with a suction means to transfer a portion of the tubular product conveyed to the storage area through the access entrance towards the lower part of the everter.

Description

[Technical Field]

[0001] The present invention relates to a circular knitting machine for hosiery and the like, and to a method for producing tubular products. [Background technology]

[0002] In the field of manufacturing tubular knitted products using circular knitting machines, such as for hosiery, it is sometimes necessary to transfer the product from the knitting machine to a separate manufacturing unit for further processing of the product that cannot be performed on the knitting machine used to manufacture the product or that is not economically advantageous to perform on the knitting machine.

[0003] In particular, in the field of hosiery manufacturing, techniques have been developed in recent years for automatically closing the toe of a hosiery product by a series of stitches or looping. Some of these techniques are based on removing the product from the knitting machine used to produce the hosiery product and transferring it to a station for further processing away from the knitting machine that produced it, so that the toe of the hosiery product is closed at the station for further processing while the knitting machine that produced it is used to produce another hosiery product. These techniques have the advantage of not significantly impairing the productivity of the knitting machine over other techniques that are based on directly closing the toe of a hosiery product on the knitting machine that is used to produce the hosiery product. Summary of the Invention [Problem to be solved by the invention]

[0004] The transfer of hosiery products, or more generally tubular products, from a knitting machine used to manufacture such products to a station for closing the axial ends of the product, or more generally for further processing of the product, is typically performed by a pick-up device in which pick-up elements individually grasp the knitted loops of the product from the needles of the knitting machine and hold these knitted loops while the product is being transferred.

[0005] In some techniques for closing the toe of hosiery products, the pick-up device is also used to support the product while further processing is carried out, while in other techniques the pick-up device is used only to transfer the product, as when it reaches the station where further processing is carried out, it usually separately transfers the knitting loops already picked up from the needles again to another device, e.g. a processing device, which has the function of supporting the product while further processing is carried out.

[0006] In both of these techniques, the sewing or looping operation is often performed inside out relative to the product so that the stitching or looping chain is largely invisible on the surface of the product, i.e., the side that would normally be visible when the product is worn.

[0007] For this reason, sewing or looping stations configured to perform these techniques to close the axial ends of tubular knitted products are typically provided with a turning device which turns the product, picked up right side out from the knitting machine that produced it, before performing the sewing or looping operation on the product, and optionally turns the product again after the sewing or looping operation to return the product to a right side out.

[0008] One of the most widespread types of turning-over devices for this type of application is based on the use of a tubular body, which is supported by a pickup or processing device at the axial end to be closed and positioned substantially vertically in its lower region, with said axial end facing upward. The tubular body is further positioned so that its upper axial end faces the suspended product, with its axis vertical. Therefore, the interior of the tubular body is connected to a suction means so that, in any case, the product still held by the pickup or processing device at the axial end to be closed is sucked through the upper axial end. The tubular body is thus raised so that its upper axial end crosses the axial end of the product engaged with the pickup or processing device. By crossing in this way, the product is turned over on its outer surface, and the product is gradually removed from the upper axial end of the tubular body as it is turned over.

[0009] In the case of tubular products of considerable weight, for example thick and / or long hosiery products, it can be difficult to ensure that the tubular product can be inserted reliably and accurately into the tubular body.

[0010] The object of the present invention is to solve the above-mentioned problems by providing a circular knitting machine for hosiery and the like which reliably and accurately inserts tubular products into tubular bodies even when the tubular products are of considerable weight and length.

[0011] Within this spirit, the object of the present invention is to provide a circular knitting machine for hosiery and the like which is reliable and precise in its operation.

[0012] Another object of the present invention is to provide a circular knitting machine for hosiery and the like which is structurally simple and can be offered at a competitive price. [Means for solving the problem]

[0013] This intention, as well as these and other objects that will become more apparent hereinafter, are achieved by a circular knitting machine for hosiery or the like and a method for producing tubular products according to the independent claims, optionally with one or more of the features of the dependent claims.

[0014] Further features and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a circular knitting machine for hosiery or the like according to the invention, shown by way of non-limiting example in the accompanying drawings, in which: [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a plan view showing a knitting machine according to the present invention. [Figure 2] 1 is an enlarged view of a tensioning device for a circular knitting machine according to the present invention; [Figure 3] 1 is a schematic front view of a circular knitting machine in which the pick-up device is arranged coaxially with respect to the needle cylinder and in a pick-up position in the upper region. [Figure 4] 4 is a view similar to FIG. 3, but with the pick-up device in an intermediate position between the pick-up position and the release position. [Figure 5] 1 is a view similar to the previous one, in which the pick-up device is positioned at a further processing station in a release position; [Figure 6] FIG. 6 is a view similar to FIG. 5 during the preparation step of the tensioning device. [Figure 7] 7 is a view similar to FIG. 6 during the actuation process of the tensioning device. [Figure 8] 8 is a view similar to FIG. 7 during the operating phase of the suction device. [Figure 9] 1 is a schematic front view showing the knitting machine ready to turn the tubular product inside out. DETAILED DESCRIPTION OF THE INVENTION

[0016] Referring to the drawings, a circular knitting machine for hosiery and the like according to the present invention, generally designated by reference numeral 1, comprises at least one needle cylinder 2 having a cylinder axis 100 and configured to produce a tubular product 101.

[0017] Advantageously, the circular knitting machine 1 can be a double-cylinder circular knitting machine or a hosiery knitting machine, as shown in the drawings.

[0018] Of course, nothing prevents the application of the inventive concept that is the subject of this application to single-cylinder circular knitting machines.

[0019] Advantageously, the circular knitting machine 1 comprises a lower needle cylinder whose axis 100 is oriented vertically and an upper needle cylinder arranged in an upper region coaxially with the lower needle cylinder. The needle cylinder has a plurality of axial grooves on its side, each of which accommodates a needle, and the needles are operable to move back and forth along the corresponding axial groove to form a knitted article.

[0020] The lower and upper needle cylinders contain, in a manner known per se, an ejection device therein for removing the product. For example, the ejection device comprises a tubular suction element coaxial with the needle cylinder. This tubular suction element is movable along an axis 100 relative to the lower needle cylinder so that it can protrude with a part of its extension from the upper end of the needle cylinder 2.

[0021] The needles are actuated in a manner known per se by means of, for example, cams, not shown for the sake of simplicity, arranged around the needle cylinder, which cams are engageable with the heels of the needles which project radially from the sides of the needle cylinder as a result of the rotation of the needle cylinder about its own axis 100 relative to said cam. The circular knitting machine 1, which is essentially a knitting machine of known type, will not be described further for the sake of simplicity.

[0022] The circular knitting machine 1 is equipped with a pickup device 10 adapted to reciprocate between a pickup position arranged coaxially around one or more needle cylinders 2 for picking up the tubular product 101 from the needle cylinder at its axial end, and a position laterally spaced from the needle cylinder 2 for releasing the tubular product 101 at a station 40 for further processing of the tubular product 101.

[0023] The further processing station 40 preferably comprises a sawing or looping station.

[0024] By way of example, the pick-up device 10 has an annular pick-up body 11 which supports pick-up elements which are radially slidable relative to the pick-up body 11. The pick-up body 11 can be arranged coaxially around the needle cylinder 2 such that the pick-up elements laterally face corresponding needles of the circular knitting machine 1, respectively.

[0025] The pickup device 10 has actuation means acting on the pickup elements to move them towards or away from the axis of the pickup body so as to engage or disengage each pickup element from the opposing needle, each pickup element being adapted to pick up a knitted loop of the product 101 held by the needle.

[0026] Of course, nothing prevents the provision of pick-up elements to engage between the knitted loops if non-loop sewing is subsequently carried out.

[0027] More specifically, the pickup body 11 is arranged with its axis vertical and is fixed to the end of a horizontally arranged arm 12. The arm 12 is connected at its opposite end to a sleeve having a vertical axis 102. The sleeve is fitted coaxially around the hollow shaft and is integral with the hollow shaft during rotation about its axis. The hollow shaft is supported by a support structure so as to be rotatable about its axis 102; the support structure may be constituted by the support structure of the knitting machine 1 itself or by an autonomous support structure that may be optionally associated with the support structure of the knitting machine 1.

[0028] It is preferable that the rotation of the arm 12 can be stopped at at least one standby position or intermediate position provided between the above-mentioned pick-up position and release position.

[0029] The two or three positions that the pick-up body 11 can assume after activation of motor means, constituted for example by an electric motor, are controlled by respective sensors which detect fiducials placed on each part during their relative movement.

[0030] The circular knitting machine 1 is provided with a further processing station 40, a turning device 20 having a lower part 22 which forms an access opening 21 in its upper region.

[0031] The lower portion 22 of the turning device 20 extends about its elongated axis 103 and is configured to coaxially receive the tubular article 101 for turning it over.

[0032] The circular knitting machine 1 according to the invention comprises tensioning means 30 which act on the outer surface of the tubular product 101 in a command manner.

[0033] The pulling means 30 is adapted to convey at least one portion of the tubular product 101 to at least one accumulation area 200 .

[0034] The lower part 22 of the turning-over device 20 is associated with suction means adapted to transfer at least one portion of the tubular product 101 conveyed to the accumulation area 200 towards the lower part 22 of the turning-over device 20 via the access inlet 21.

[0035] Advantageously, the accumulation area 200 is located immediately adjacent the access entrance 21 .

[0036] The pulling means 30 is configured to remove at least one portion of the tubular product 101 towards the end opposite the end associated with the pick-up device 10 .

[0037] The turning-over device 20 has an upper part (not shown) in addition to a lower part 22, and the lower and upper parts are advantageously arranged below and above, respectively, an intermediate area in which a support means 41 for the turning-over tubular product 101 suspended at the axial end of the tubular product 101 is arranged or can be arranged.

[0038] The turning-over device 20 further has a tubular body 23, which can be inserted with its upper axial end from below upward through the axial end of the tubular product 101 suspended from the support means 41 after sucking the tubular product through the upper axial end of the tubular body in order to turn over the tubular product held by the support means 41.

[0039] With reference to the embodiment shown in the drawings, the tensioning means 30 comprises at least one pulling roller 32 associated with a motor means 35 .

[0040] The extraction rollers 32 are advantageously located in the immediate vicinity of the storage area 200 .

[0041] In particular, when the pickup device 10 is in the release position, the outer surface of at least one pull-out roller 32 is adapted to contact the outer surface of the tubular product 101 to pull at least one portion of the tubular product 101 toward the accumulation area 200.

[0042] The tensioning means 30 comprises at least one contrast roller 31, which is preferably arranged on the opposite side of the at least one pull-out roller 32 relative to the tubular product 101 during rotational movement of the at least one pull-out roller 32.

[0043] According to a practical embodiment, the contrast roller 31 is supported by the pick-up device 10 while the withdrawal roller 32 is supported by the turning-over device 20 .

[0044] Naturally, nothing prevents providing different configurations of the tensioning means 30, both with regard to the arrangement of the various elements and with regard to the use of alternative tensioning elements, for example belts or similar elements.

[0045] Advantageously, the tensioning means 30 are functionally associated with sensor means 36 adapted to control the transport of a portion of the tubular products 101 into the accumulation area 200 .

[0046] By way of example, the sensor means 36 is arranged to detect the position of an axial end of the tubular product 101 opposite the axial end of the tubular product 101 associated with the support means 41 .

[0047] The pulling means 30 further comprises a lever 37 supported by the pickup device 10, the lever 37 being configured to convey the tubular product 101 below the contrast roller 31 while the pickup device 10 moves from the pickup position to the release position.

[0048] The lever 37 is preferably actuated by actuation means, for example comprising a pneumatically operated cylinder.

[0049] The lower portion 22 of the turning device 20 may be configured so that it can be commandably tilted relative to the extension axis 103 when the tubular body 23 supported by the lower portion 22 is in the lowered position to facilitate the transfer of the tubular products 101 from the storage area 200 to the access entrance 21.

[0050] With reference to the embodiment shown in the drawings, the accumulation area 200 is located between the tensioning device 30 and the support means 41 .

[0051] Of course, nothing prevents an arrangement in which the accumulation area 200 is instead located between the access entrance 21 and the needle cylinder 2.

[0052] During the suction process, the pulling means 30 is removed from the tubular product 101 .

[0053] The present invention further provides a method for making a tubular product, comprising: - manufacturing a tubular product 101 by means of at least one needle cylinder 2; - picking up the tubular product 101 at its axial end by means of a pick-up device 10; - transferring the axial end of the tubular product 101 from a pick-up position in the at least one needle cylinder 2 to a release position in a station 40 for further processing of the tubular product 101; - pulling at least one portion of the tubular product 101 by means of pulling means 30 acting in command on the outer surface of the tubular product 101 in order to convey at least one portion of the tubular product 101 to at least one accumulation area 200; and - sucking by suction means at least one portion of the tubular products 101 conveyed to the storage area 200 through the access opening 21 towards the lower part 22 of the turning device 20, which is adapted to coaxially accommodate the tubular products 101 in order to turn them over, in order to transfer the tubular products 101; The present invention relates to a method having the following structure:

[0054] Indeed, it has been found that the present invention achieves its targeted aims and objectives by providing a circular knitting machine and a method for manufacturing tubular products that can ensure efficient transfer of tubular products to an everting device even in the case of very heavy or long tubular products.

[0055] The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims, and all of the details may further be substituted by other technically equivalent elements.

[0056] In fact, the materials used, and the accompanying shapes and dimensions, can be anything depending on the requirements and current technology, so long as the materials used are suitable for the particular application.

[0057] The disclosures in Italian Patent Application No. 102021000014318 from which this application claims priority are incorporated herein by reference.

[0058] Although reference numbers are added after the technical features recited in any claim, these reference numbers are included only to enhance the comprehension of the scope of the claim, and therefore, such reference numbers do not in any way affect the interpretation of each element identified by such reference numbers as an example.

Claims

1. 1. A circular knitting machine for hosiery, comprising: at least one needle cylinder having a cylinder axis and configured to create a tubular product; a pickup device adapted to reciprocate between a pickup position coaxially disposed around the needle cylinder for picking up the tubular product from the needle cylinder at an axial end of the tubular product, and a release position laterally spaced from the needle cylinder for releasing the tubular product at a further processing station for further processing of the tubular product; Turn-over device and It is equipped with a turning-over device is provided at the further processing station, the turning-over device having a lower portion extending about its elongated axis with an access entrance in an upper region, the lower portion of the turning-over device being configured to coaxially receive the tubular products for turning them over; the circular knitting machine comprises a tensioning means adapted to act in command on an outer surface of the tubular product to convey at least one portion of the tubular product to at least one accumulation area; the turning-over device is associated with suction means adapted to transfer at least one portion of the tubular products conveyed to the accumulation area towards the lower part of the turning-over device via the access opening; the tensioning means comprises at least one pull-out roller associated with a motor means; the tensioning means comprises at least one contrast roller, the contrast roller being disposed on an opposite side of the at least one pull roller relative to the tubular product during rotational movement of the at least one pull roller; Circular knitting machine, wherein the at least one contrast roller is supported by the pick-up device and the at least one withdrawal roller is supported by the turning-over device.

2. 2. The circular knitting machine of claim 1, wherein the accumulation area is located immediately adjacent the access entrance.

3. the turning-over device has the lower and upper parts, the lower and upper parts being respectively arranged below and above an intermediate area in which support means for turning over the tubular product suspended at an axial end of the tubular product are arranged or can be arranged, 3. The circular knitting machine according to claim 1 or 2, further comprising a tubular body that can be inserted from below upward through the axial end of the tubular product suspended from the support means at its upper axial end after sucking the tubular product through its upper axial end in order to turn the tubular product held by the support means inside out.

4. Circular knitting machine according to any one of claims 1 to 3, wherein the at least one withdrawal roller is arranged in the immediate vicinity of the accumulation area.

5. 5. The circular knitting machine according to claim 1, wherein when the pickup device is in the release position, an outer surface of the at least one pulling roller is adapted to contact an outer surface of the tubular product in order to pull at least one portion of the tubular product towards the accumulation area.

6. 6. The circular knitting machine according to claim 1, wherein the tensioning means is functionally associated with sensor means adapted to control the conveyance of the portion of the tubular product to the at least one accumulation area.

7. 7. The circular knitting machine according to claim 1, wherein the tensioning means comprises a lever supported by the pick-up device, the lever being configured to convey the tubular product beneath the contrast roller during the transition from the pick-up position to the release position.

8. 4. The circular knitting machine of claim 3, wherein the lower portion of the turning device can be tilted commandably relative to the extension axis when the tubular body supported by the lower portion is in a lowered position.

9. 4. The circular knitting machine according to claim 3, wherein the accumulation area is disposed between the tensioning means and the support means.

10. 1. A method for making a tubular product, comprising: - manufacturing a tubular product by means of at least one needle cylinder; - picking up the tubular product by means of a pick-up device at an axial end of the tubular product; - transferring the axial end of the tubular product from a pick-up position in the at least one needle cylinder to a release position in a station for further processing of the tubular product; - pulling at least one portion of the tubular product by means of pulling means acting in command on the outer surface of the tubular product in order to convey the at least one portion of the tubular product to at least one accumulation area; - sucking by suction means at least one portion of the tubular products conveyed to the accumulation area through an access opening towards a lower part of an inverting device adapted to coaxially receive the tubular products in order to transfer the tubular products; and the tensioning means comprises at least one pull-out roller associated with a motor means; the tensioning means comprises at least one contrast roller, the contrast roller being disposed on an opposite side of the at least one pull roller relative to the tubular product during rotational movement of the at least one pull roller; The method, wherein the at least one contrast roller is supported by the pick-up device and the at least one pull-out roller is supported by the turning device.

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