The present invention relates to a circular knitting machine for hosiery or the like and to a method for producing a tubular manufacture.

In the field of the production of tubular knitted manufactures with circular knitting machines for hosiery or the like, in some cases there is the need to transfer the manufacture from the machine used for the production of the manufacture to another production unit in order to perform further processes on the manufacture which cannot be performed on said machine or which it is not economically convenient to perform on said machine.

In particular, in the field of the production of hosiery items, in recent years, techniques for the automated closing of their toe by means of a series of stitches or by looping have been developed. Some of these techniques are based on the removal of the manufacture from the machine used for its production and on its transfer to a station for further processing, separate from the production machine, so as to close the toe of the hosiery item in the further processing station while the machine is used to produce another hosiery item. These techniques have the advantage, with respect to other techniques that are based on closing the toe of the hosiery item directly on the machine used for its production, of not impairing excessively the productivity of the machine.

The transfer of the hosiery item, or more generally the tubular manufacture, from the machine used for its production to the station in which the closing of an axial end of the manufacture or more generally a further processing of the manufacture is to be performed, is generally performed by means of a pickup device which, by means of pickup elements, grips individually the loops of knitting of the manufacture from the needles of the machine and retains them during the transfer of the manufacture.

In some techniques for closing the toe of hosiery items the pickup device is used also to support the manufacture during the execution of the further processing, while in other techniques the pickup device is used only to transfer the manufacture, since once it reaches the station in which the further processing is to be performed it transfers, usually again individually, the loops of knitting previously picked up from the needles to another device which has the function of supporting the manufacture during the execution of the further processing, such as for example a handling device.

In both of these techniques, very often the sewing or looping operation is performed on the manufacture in a turned condition so that the stitching or looping chain is scarcely visible on the right side of the manufacture, i.e., on the side that is normally visible when the manufacture is worn.

For this reason, in sewing or looping stations intended to perform these techniques for closing an axial end of tubular knitted manufactures there is generally a turning device which has the function of turning the manufacture, which is picked up in the right-side-out configuration from the machine that produced it, before subjecting it to the sewing or looping operation, and of optionally turning it again to bring it to the right- side-out configuration after the sewing or looping operation.

One of the most widespread types of turning devices for this type of use is based on the use of a tubular body which faces in a lower region the manufacture, which is supported by means of a pickup device or by means of a handling device at its axial end to be closed and is arranged substantially vertically with the axial end facing upward. The tubular body is also arranged so that its axis is vertical so as to face, with its upper axial end, the hanging manufacture. The inside of the tubular body is then connected to suction means so as to aspirate the manufacture, through its upper axial end; said manufacture remains in any case retained, at its axial end to be closed, by the pickup device or by the handling device. The tubular body is therefore lifted so as to cross, with its upper axial end, the axial end of the manufacture that is engaged with the pickup device or with the handling device. As a consequence of this crossing, the manufacture is everted on the outer lateral surface of the tubular body and is extracted progressively from the upper axial end of the tubular body, turning it. In the case of tubular manufactures of considerable weight, such as for example in the case of hosiery items of high thickness and/or of great length, difficulties can be encountered in being able to ensure a correct insertion of the tubular manufacture in the tubular body.

The aim of the present invention is to solve the problems described above, by providing a circular knitting machine for hosiery or the like that ensures the correct insertion of the tubular manufacture, even of considerable weight and length, in the tubular body.

Within this aim, an object of the invention is to provide a circular knitting machine for hosiery or the like that is highly reliable and precise in operation.

Another object of the invention is to provide a circular knitting machine for hosiery or the like that is structurally simple and can be provided at competitive costs.

This aim and these and other objects which will become more apparent hereinafter are achieved by a circular knitting machine for hosiery or the like and by a method for producing a tubular manufacture according to the independent claims, optionally provided with one or more of the characteristics of the dependent claims.

Further characteristics and advantages of the invention will become more apparent from the description of a preferred but not exclusive embodiment of the circular knitting machine for hosiery or the like, according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a top view of the machine according to the invention; Figure 2 is an enlarged-scale view of the traction device of the circular machine according to the invention;

Figure 3 is a schematic front view of a circular machine, in which the pickup device is arranged in a pickup position in an upward region and coaxially with respect to the needle cylinder; Figure 4 is a view, similar to the one of Figure 3, in which the pickup device is in an intermediate position between the pickup position and the release position;

Figure 5 is a view, similar to the preceding ones, in which the pickup device is arranged at the further processing station in the release position; Figure 6 is a view, similar to Figure 5, during the preparation step of the traction device;

Figure 7 is a view, similar to Figure 6, during the actuation step of the traction device;

Figure 8 is a view, similar to Figure 7, during the actuation step of the suction device;

Figure 9 is a schematic front view of the machine, in which the tubular manufacture is ready for turning.

With reference to the figures, the circular knitting machine for hosiery and the like according to the invention, generally designated by reference numeral 1, comprises at least one needle cylinder 2 which has a cylinder axis 100 and is configured to provide a tubular manufacture 101.

Advantageously, the circular machine 1 can be, as shown in the figures, a double cylinder circular knitting machine or hosiery knitting machine. Nothing forbids, naturally, applying the inventive concept that is the subject matter of the present application to single-cylinder circular machines.

Conveniently, the circular machine 1 comprises a lower needle cylinder, with an axis 100 of the cylinder oriented vertically, and an upper needle cylinder arranged in an upward region and coaxially with the lower needle cylinder. On the lateral surface of the needle cylinder there are multiple axial grooves inside each of which a needle is accommodated which can be actuated with reciprocating motion along the corresponding axial groove in order to form knitting.

The lower needle cylinder and the upper needle cylinder are provided, in a manner known per se, inside them, with a device for drawing the manufacture. By way of example, the drawing device comprises a tubular suction element, which is coaxial with the needle cylinder. This tubular suction element can move along the axis 100 with respect to the lower needle cylinder so as to be able to protrude, with a portion of its extension, from the upper end of the needle cylinder 2.

The needles 2 are actuated in a manner known per se, for example by means of cams, not shown for the sake of simplicity, which are arranged around the needle cylinder and can be engaged, as a consequence of the rotation of the needle cylinders about their own axis 100 with respect to said cams, with the heels of the needles protruding radially from the lateral surface of the needle cylinders. The circular machine 1, being a machine substantially of a known type, is not described further for the sake of simplicity.

The circular machine 1 comprises a pickup device 10 adapted to pass between a pickup position, in which it is arranged coaxially around the needle cylinder or cylinders in order to pick up the tubular manufacture 101 at an axial end thereof from the needle cylinder, and a position for the release of the tubular manufacture 101 at a station 40 for further processing of the tubular manufacture 101 which is spaced laterally from the needle cylinder 2.

Preferably, the further processing station 40 comprises a sewing or looping station.

By way of example, the pickup device 10 comprises an annular pickup body 11, which supports pickup elements which can slide, with respect to the pickup body 11, along radial directions. The pickup body 11 can be arranged coaxially around the needle cylinder 2 so that each one of the pickup elements faces laterally a corresponding needle of the circular machine 1.

The pickup device 10 comprises actuation means which act on the pickup elements in order to actuate their movement toward or away from the axis of the pickup body so as to engage or disengage each pickup element with respect to the needle which it faces and each one of the pickup elements is adapted to pick up the loop of knitting of the manufacture 101 retained on the needle.

Nothing forbids, naturally, to provide that providing for the pickup elements to engage between the loops of knitting if non-looped sewing is to be performed subsequently.

More particularly, the pickup body 11 is arranged so that its axis is vertical and is fixed to the end of a horizontally arranged arm 12, which is connected, with its opposite end, to a sleeve with a vertical axis 102. The sleeve is fitted coaxially around a hollow shaft and is integral therewith in the rotation about its axis. The hollow shaft is supported, so that it can rotate about its own axis 102, by a supporting structure which can be constituted by the supporting structure itself of the machine 1 or by an autonomous supporting structure which can be associated optionally with the supporting structure of the machine 1.

Preferably, there is the possibility to stop the rotation of the arm 12 in at least one waiting position or intermediate position located between the pickup position and the release position mentioned above.

The two or three positions that can be assumed by the pickup body 11 following the actuation of motor means, for example constituted by an electric motor, are controlled by respective sensors which detect references arranged on the respective parts in mutual motion.

The circular machine 1 has, at the further processing station 40, a turning device 20 which has a lower portion 22 which forms in an upper region an access inlet 21.

The lower portion 22 of the turning device 20 extends around a respective axis of extension 103and is designed to accommodate coaxially the tubular manufacture 101 in order to turn it.

The circular machine 1 according to the invention comprises traction means 30 which act on command at the outer surface of the tubular manufacture 101.

The traction means 30 are adapted to convey at least one portion of the tubular manufacture 101 at at least one accumulation region 200.

The lower portion 22 of the turning device 20 is associated with suction means, which are adapted to transfer at least one portion of the tubular manufacture 101 conveyed in the accumulation region 200 toward the lower portion 22 of the turning device 20 through the access inlet 21.

Conveniently, the accumulation region 200 is arranged proximate to the access inlet 21.

The traction means 30 are configured to draw at least one portion of the tubular manufacture 101 arranged toward the opposite end with respect to the end associated with the pickup device 10.

Advantageously, the turning device 20 comprises, in addition to the lower portion 22, an upper portion (not shown), which is arranged respectively below and above an intermediate region at which supporting means 41 for the tubular manufacture 101 to be turned, which hangs at an axial end thereof, are or can be arranged.

The turning device 20 has moreover a tubular body 23 which can be inserted upward from below, with its upper axial end, through the axial end of the tubular manufacture 101 which hangs from the supporting means 41 after aspirating the manufacture through the upper axial end of the tubular body, in order to evert the manufacture, which is retained by the supporting means 41. With reference to the embodiment shown in the figures, the traction means 30 comprise at least one extraction roller 32, which is associated with motor means 35.

Advantageously, the extraction roller 32 is arranged proximate to the accumulation region 200.

In particular, the outer surface of the at least one extraction roller 32 is adapted to make contact with the outer surface of the tubular manufacture 101 in order to induce the traction of at least one portion of the tubular manufacture 101 toward the accumulation region 200 when the pickup device 10 is in the release position.

Preferably, the traction means 30 comprise at least one contrast roller

31 which is arranged, during the rotational actuation of the at least one extraction roller 32, opposite with respect to the respective extraction roller

32 with respect to the tubular manufacture 101.

According to a practical embodiment, the contrast roller 31 is supported by the pickup device 10 while the extraction roller 32 is supported by the turning device 20.

Nothing forbids, naturally, to provide different configurations of the traction means 30 as regards both the arrangement of the various elements and the use of alternative traction elements, such as for example, belts or similar elements.

Advantageously, the traction means 30 are functionally associated with sensor means 36, which are adapted to control the conveyance of the portion of the tubular manufacture 101 toward the accumulation region 200.

By way of example, the sensor means 36 are arranged so as to detect the position of the axial end of the tubular manufacture 101 that is opposite with respect to the one associated with the supporting means 41.

The traction means 30 comprise, moreover, a lever 37 which is supported by the pickup device 10 and is designed to convey the tubular manufacture 101 below the contrast roller 31 during transition of the pickup device 10 from the pickup position to the release position.

Preferably, the lever 37 is actuated by actuation means comprising, for example, a pneumatically actuated cylinder.

The lower portion 22 of the turning device 20 may be provided so that it can be inclined on command with respect to the axis of extension 103 when the tubular body 23 supported by the lower portion 22 is in a lowered position so as to facilitate the transfer of the tubular manufacture 101 from the accumulation region 200 toward the access inlet 21.

With reference to the embodiment shown in the figures, the accumulation region 200 is arranged between the traction device 30 and the supporting means 41.

Nothing forbids, naturally, to provide that the accumulation region 200 is arranged instead between the access inlet 21 and the needle cylinder 2.

During the suction step, the traction means 30 are disengaged from the tubular manufacture 101.

The present invention relates moreover to a method for providing a tubular manufacture comprising:

- a step of production, by means of at least one needle cylinder 2, of a tubular manufacture 101;

- a step of pickup, by means of a pickup device 10, of the tubular manufacture 101 at an axial end;

- a step of transfer of the axial end of the tubular manufacture 101 from a pickup position, at the at least one needle cylinder 2, toward a release position at a station 40 for the further processing of the tubular manufacture 101;

- a step of traction, by virtue of traction means 30 which act on command at the outer surface of the tubular manufacture 101, of at least one portion of the tubular manufacture 101 in order to convey at least one portion of the tubular manufacture 101 at at least one accumulation region 200,

- a step of suction, by virtue of suction means, of at least one portion of the tubular manufacture 101 conveyed at the accumulation region 200, in order to transfer it, through an access inlet 21 , toward a lower portion 22 of a turning device 20 designed to accommodate coaxially the tubular manufacture 101 in order to turn it.

In practice it has been found that the invention has achieved the intended aim and objects, providing a circular machine and a method for producing tubular manufactures capable of ensuring an effective transfer of the tubular manufacture to the turning device even in the case of extremely heavy or long tubular manufactures.

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.

In practice, the materials used, as 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.

The disclosures in Italian Patent Application No. 102021000014318 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.