Removal and / or collection group of fabrics manufactured by circular weft knitting machine

Abstract

A set (1) for taking down and / or collecting a fabric (F) produced by a circular weft knitting machine (100), said circular weft knitting machine (100) comprising a knitting assembly (T) and a base (B); the take-off and / or collection group (1) comprises a frame (2) rotatably mounted to the circular knitting machine, and an operating mechanism (3) supported by the frame, the operating mechanism comprising a collection roller (10) and configured to unwind and spread a fabric (F) produced by the circular knitting machine so as to wind it in a single layer and continuously around the collection roller (10); the operating mechanism comprises a first motor group (20) which is associated at the collecting roller and acts on a rotational axis (11) of the collecting roller, so that the collecting roller is axially motorized, i.e. Rotated about the rotational axis by the first motor group.

Description

Technical Field

[0001] The object of the present invention is to provide a take-off and / or collecting group for fabrics produced on a circular weft knitting machine.

[0002] More specifically, the invention relates to a take-off and / or collecting group for a circular knitting machine provided with an operating mechanism capable of collecting the fabric on a collecting reel in a controlled manner.

[0003] Another object of the invention is a circular weft knitting machine comprising a taking-off and / or collecting group as described above.

[0004] Furthermore, the invention relates to a method for collecting a fabric produced by a circular weft knitting machine by means of a take-off and / or collecting group. Background Art

[0005] The invention firstly relates to the technical field of circular weft knitting machines.

[0006] In this document, a "knitting machine" generally refers to a circular knitting machine suitable for manufacturing knitted goods, which is provided with at least one needle holding mechanism or needle holding cylinder, which is rotatably mounted in the support structure of the machine and supports a plurality of needles that can move parallel to the rotation axis of the needle holding cylinder to produce weft knitted fabrics. In addition, the knitting machine is also provided with a plurality of yarn feeding points or knitting "doffing points", from which the yarn is fed to the needles of the machine. For example, such a knitting machine can be a single needle bed or double needle bed type. The circular knitting machine can include a different number of drop points, for example 1, 2, 4, 6, 8 or more knitting drop points.

[0007] More specifically, the present invention relates to the technical field of circular knitting machines, of the type indicated in the industry by the term "unrolled". This type of knitting machine is provided with at least one needle-holding mechanism, a cam device for controlling the movement of the needles and, in particular, a take-off and collecting group capable of collecting the fabric produced by the machine in a single layer, usually by winding it on rollers. The single layer of fabric originating from the needle-holding mechanism and collected by the take-off and collecting group can be obtained by cutting and spreading (or "unrolling") the fabric in a tubular form (if - in most cases - the machine produces the fabric in a continuous form), or, alternatively, it can be produced directly "in unrolled form", i.e. as a single continuous fabric layer (of a determined width). In other words, the take-off and collecting group collects (by winding it on a reel) a single-layer fabric instead of a cylindrically unfolded tubular fabric: a single-layer fabric has a continuous "strip" configuration (or cloth or sheet) of a certain width and can be opened by continuous cuts parallel to the longitudinal development direction of the fabric produced, or can be derived from the machine in a single layer as an "unfolded" fabric that is already a single layer: the term "unfolding" is therefore used to identify this type of machine. Sometimes, knitting machines of the "unfolding" type include only a collecting unit, that is, without a take-off function: this is the case, for example, of knitting machines that carry out the take-off directly on the needle bed; in this case, the fabric produced by the needle-holding mechanism enters the collecting unit, which is responsible for winding it on a reel (usually through a winding device). In any case, a machine of the "unfolding" type can be defined as a circular weft knitting machine in which the fabric produced is collected "in an unfolded manner", that is, as a single layer by winding it on a collecting reel.

[0008] The circular weft knitting machine of the technical field of the present invention can be of single-needle-bed type (with a single needle-holding cylinder) or double-needle-bed type (with a needle-holding cylinder and a needle-holding plate).

[0009] Therefore, in the description and claims of the present patent application, when referring to an "unfolded" knitting machine, a knitting machine having the above-mentioned "unfolded" machine features is specifically indicated, which clearly identify and define this type in the reference field and are obvious to a person skilled in the art. Therefore, the terms used in the claims must be correctly interpreted based on the information of these technical reference fields. In particular, the feature that the machine of the present invention belongs to the "unfolded" type should be understood as a precise technical feature, which constitutes a limitation and should not be interpreted as just an example of many existing types of knitting machines, into which the further technical features described in the claims will be incorporated.

[0010] A circular weft knitting machine of the "unfolding" type is provided with a base which constitutes the supporting structure of the knitting machine, which supports and houses all the machine parts, in particular the knitting assembly (comprising the needle holding mechanism, the plurality of needles and the command means for these needles) and the take-off and collection group. In addition, the base also allows the machine to be securely fixed in its operating position.

[0011] The unfolded machine typically has a needle holding mechanism, ie, a needle holding cylinder or needle holding plate, between 30 and 40 inches in diameter, but there are also examples with smaller diameters, such as 24 inches, or greater than 40 inches.

[0012] In machines of the "unfolding" type for manufacturing tubular fabrics (i.e., without directly producing the fabric "in an unfolded manner"), the removal and / or collection group comprises a cutting device for longitudinally cutting the tubular fabric emerging from the needle holding device, so that it is "unfolded" and can therefore be wound in a single layer on a collection reel.

[0013] The take-off and collection group usually also includes other devices, such as flattening devices for the tubular fabric, spreading devices for unwinding the fabric after cutting, tensioning rollers for controlling the advance of the fabric towards the collection roller, as well as actuators and mechanical synchronization devices for the movement of the various devices.

[0014] Of particular importance among the devices that determine the advance of the fabric toward the collection roll is a roll called a spreading roll, also called a spiral roll or a tensioning roll, which intercepts the fabric upstream of the collection roll and is configured to gradually spread the fabric (in terms of width) and eliminate wrinkles and folds so that the fabric is wound as widely as possible over its entire width when it reaches the collection roll. Patent document WO0050678 shows an example of a spreading roll with this purpose: this roll has two spiral embossing elements that extend in opposite directions from the center of the roll to both ends.

[0015] The take-off and collection group is usually mounted on the machine, below the needle-holding mechanism (in a collection space specially designed for this type of group), able to rotate integrally with the needle-holding mechanism to follow its fabric production process and collect the fabric on a reel.

[0016] The known type of removal and collection group is usually directly or indirectly connected to the needle holding mechanism of the knitting assembly by a connection device, which is configured to transmit the movement of the needle holding mechanism to the removal and / or collection group so that it can move (i.e. rotate) synchronously with the needle holding mechanism. For example, the connection device includes one or more brackets connected to the knitting assembly by fastening means such as screws and / or bolts.

[0017] Examples of take-off and collection groups for knitting machines of the "unfolding" type are shown in the patent documents EP0456576, EP0696658 and WO0050678. In more detail, these take-off and collection groups have a frame that supports all the mechanisms of the take-off and collection group and is arranged below the knitting assembly in the machine. The entire frame rotates integrally with the needle-holding mechanism and is placed on the lower base of the machine by means of support means (comprising, for example, bearings) that support its weight and at the same time allow it to rotate; the support means at the bottom can be driven (for example, by a motor) to determine the rotation of the entire frame.

[0018] Document WO 2014191868 A1 in the name of the applicant describes a take-off and collecting group for a circular knitting machine of the “unfolding” type.

[0019] In solutions of known type, the take-off and collection group usually comprises an idle collection roller, i.e. free to rotate about its own axis. Its rotation is provided by a pair of motorized rollers on which the collection roller is laid. The unrolled fabric to be wound on the collection roller is clamped between the collection roller itself and the two motorized rollers below. The rotation of the motorized rollers drives both the advancement of the fabric and the rotation of the collection rollers, on which the fabric is gradually wound. The collection roller is thus essentially driven tangentially (by contact) by the driven roller responsible for the rotation. Contact is always maintained between the collection roller and the motorized roller to support the advancement of the fabric: it is therefore obvious that, as the amount of fabric wound on the collection roller increases, the diameter of the collection roller also increases, and therefore its position must change; in particular, the collection roller automatically moves vertically as its diameter increases, while the motorized rollers continue to rotate in the same position.

[0020] In known solutions, the motorized reel generally has a constant peripheral speed; the collecting reel is idle and therefore its angular speed varies with increasing diameter, ie with increasing amount of collected fabric.

[0021] Furthermore, given the configuration of the rolls, the fabric is squeezed more when the weight of the collection roll increases: in essence, the wound fabric "squeezes itself" more due to the increased weight of the collection roll. This determines that the fabric is stretched to a greater or lesser extent depending on the diameter of the collection roll. Therefore, the fabric wound on the collection roll does not usually present a perfect "cylindrical" roll shape, but rather a very variable roll shape, for example, being narrower or wider at different points along the lateral extension and in different radial sections. In some cases, the fabric tends to increase in size as the diameter of the collection roll increases.

[0022] In other known solutions, a motorized roller which continuously rotates the collection roller can be placed above the collection roller or to the side of it; in any case, the driving action of the motorized roller is tangential to the collection roller. Summary of the invention

[0023] In collecting knitted fabrics produced by circular weft knitting machines, in particular of the “unfolded” type, ie in collecting single-layer fabrics, the Applicant has noticed certain limitations and drawbacks and has considered that the known solutions could be improved in several respects.

[0024] First, as indicated above, the known take-off and collection groups are not able to wind the fabric efficiently and evenly on the collection roll: in particular, the known take-off and collection groups may cause unwanted folds, wrinkles and / or overlaps in the fabric wound on the collection roll, which may damage the fabric, affect its quality, complicate the subsequent finishing or packaging of the fabric, and may even require further conditioning operations of the fabric on the collection roll. The performance limitations of the known take-off and collection groups generally determine that they are less effective in spreading the outer edges of the fabric, which tend to "curl" or wrap around themselves in the longitudinal direction, forming what is known as a "cigarette" on each side in technical terms.

[0025] Therefore, uneven winding of the fabric on the collecting roll is the main disadvantage of circular knitting machines of the "unrolling" type.

[0026] The applicant has also noted that in the known removal and collection groups, the different elements cooperating with the fabric from the needle holding mechanism to the collection roller, namely the spreading device, the spreading roller, the removal roller, the tensioning roller and the collection roller, are not arranged in an ideal manner relative to each other, resulting in misalignment and / or wrinkles on the fabric, the side edges of the fabric being entangled, and determining that the winding of the fabric on the collection roller is uneven and flat.

[0027] Another limitation noted in known take-off and collecting groups is the small volume or flow rate of the collecting reel in terms of the length of fabric that can be accumulated. Considering that circular knitting machines of the "unrolling" type are usually operated for large-scale production, i.e. they achieve long periods of continuous work, weaving very long lengths of fabric, the saturation of the collecting reel forces a machine stop (for the replacement of the reel itself), which has a negative impact on the knitwear production, both in terms of time and cost. The maximum flow rate of the collecting reel depends on the free space inside the take-off and collecting group, which can increase as the fabric is wound; in the known solutions, this free space is limited due to the elements present and their way of operation.

[0028] Another disadvantage of the known take-down and collection groups is that the motorized rollers of the laying collection rollers introduce an unwanted overvoltage into the fabric during collection, which overvoltage may vary depending on the type of fabric and the friction between the fabric and the motorized rollers. This overtension is also transferred to the already collected fabric layer (i.e. to the previously wound collection roller). Furthermore, it should be taken into account that with the increasing amount of fabric wound onto the collection roller, the weight of the collection roller itself also increases, and therefore the friction between the fabric and the motorized roller also increases (because the weight is unloaded onto the roller): in this case, the overvoltage introduced into the fabric due to the action of the motorized roller also increases. In the case of a high weight / friction on the motorized roller, the motorized roller may simultaneously move several layers (or flaps) of fabric wound onto the collection roller, for example two, three or more layers (i.e. the last outer layer plus the other layers wound previously). This is obviously undesirable, since the motorized roller should only act on the last layer of fabric wound onto the collection roller.

[0029] Another drawback of the known take-off and collecting groups is the difficulty in controlling the collection of the fabric; in fact it is difficult to know precisely the state of the different mechanisms that collaborate with the collection of the fabric obtained from the knitting assembly, and it is generally not possible to have precise parameters representing the operating state that the take-off and collecting group is in. This can lead to errors in the collection of the fabric, introduce defects to the collected fabric, and generally make it difficult to coordinate the operations performed by the take-off and collecting group with those performed by the rest of the knitting machine, in particular by the knitting assembly that manufactures the fabric.

[0030] Likewise, the known removal and collection groups are characterized by a complex construction and high implementation and maintenance costs.

[0031] In this case, in its various aspects and / or embodiments, the object of the present invention is to provide a removal and / or collection group for a circular knitting machine (particularly of the "unfolding" type), and a method for collecting fabrics produced by a circular weft knitting machine, which are able to solve one or more of the above-mentioned disadvantages.

[0032] Another object of the invention is to provide a take-off and / or collecting group, a circular weft knitting machine of the “unfolding” type and a method of collecting fabric that allow improved control and improved management of the collection of the fabric produced.

[0033] Another object of the present invention is to provide a take-off and / or collecting group, a circular weft knitting machine of the “unfolding” type and a method for collecting fabric that can be operated in an innovative way compared to known solutions.

[0034] Another object of the present invention is to provide a take-off and / or collecting group for a circular weft knitting machine of the “unfolding” type which allows increasing the amount of windable fabric on the collecting reel.

[0035] Another object of the present invention is to provide a take-off and / or collecting group for a circular weft knitting machine of the “unfolding” type, having high technical characteristics.

[0036] Another object of the present invention is to provide a take-off and / or collecting group, a circular weft knitting machine of the "unfolding" type and a method for collecting fabric that prevents the formation of dislocations and / or wrinkles in the collected fabric and / or prevents the side edges of the fabric from being entangled.

[0037] Another object of the invention is to provide a take-off and / or collecting group, a circular weft knitting machine of the "unfolding" type and a method for collecting fabric, making it possible to achieve uniform and flat winding of the fabric on the collecting reel.

[0038] Another object of the present invention is to provide a take-off and / or collecting group, a circular weft knitting machine of the "unfolding" type and a method for collecting fabric, capable of effectively unfolding and spreading the fabric.

[0039] Another object of the invention is to provide a taking-off and / or collecting group, a circular weft knitting machine of the "unfolding" type and a method for collecting a fabric having improved properties relative to known solutions, for example in terms of productivity and / or quality and uniformity of the knitted goods produced.

[0040] Another object of the present invention is to provide a take-off and / or collection group and a method for collecting fabrics which is versatile and can be adapted to different fabric requirements and to different fabric types and sizes.

[0041] Furthermore, the object of the present invention is to propose a solution for realizing a take-off and / or collecting group for a circular weft knitting machine of the “unfolding” type, enabling easy maintenance and replacement operations of its components.

[0042] Another object of the invention is to provide a take-off and / or collecting group for a circular weft knitting machine of the “unfolding” type, characterized by high operating reliability and / or low susceptibility to malfunctions and failures.

[0043] Another object of the invention is to provide a take-off and / or collecting group and a circular weft knitting machine of the "unfolding" type characterized by a simple and rational structure.

[0044] Another purpose of the invention is to create an alternative solution with respect to the known art and / or to open up new design areas for the realization of a take-off and / or collecting group of a circular weft knitting machine, in particular of the “unfolding” type.

[0045] These and other objects, which will become clearer in the following description, are essentially achieved by a removal and / or collection group for a circular knitting machine (particularly of the "unfolding" type), a circular weft knitting machine of the "unfolding" type, and a method for collecting fabrics manufactured by a circular weft knitting machine, according to one or more of the attached claims, as well as by the following aspects and / or embodiments, which may also be combined differently with the above-mentioned claims.

[0046] In the present specification and the appended claims, the terms "upper", "lower", "lower", "below", "horizontal", "vertical" are relative to the positioning of the removal and / or collecting group and the knitting machine during normal operation, for example, with the central rotation axis of the needle holding mechanism placed vertically.

[0047] In this specification and the appended claims, the terms "axial", "longitudinal", "circumferential", and "radial" will from time to time refer to a defined axis of a defined element or component.

[0048] Various aspects of the invention are listed below.

[0049] In its first aspect, the invention relates to a take-off and / or collecting group for fabric produced by a circular weft knitting machine.

[0050] In one aspect, the removing and / or collecting group comprises:

[0051] - a knitting assembly provided with at least one needle holding mechanism in the form of a needle holding cylinder or a needle holding plate rotating about a central axis, a plurality of needles movably mounted to the at least one needle holding mechanism, and a command mechanism suitable for selectively actuating the plurality of needles and suitable for allowing the manufacture of a fabric;

[0052] - a base constituting a supporting structure of the knitting machine and configured to support the knitting assembly, the base defining a housing space below the knitting assembly;

[0053] In one aspect, the removing and / or collecting group comprises:

[0054] - a frame configured to be mounted in a rotatable manner to the circular knitting machine in the receiving space;

[0055] - an operating mechanism operatively associated with and supported by the frame and comprising at least one collecting reel arranged along the axis of rotation and extending longitudinally between two ends, the operating mechanism being configured to at least unwind and spread the fabric produced by the circular knitting machine or also to finally extract it from the needle holder so as to wind it in a single layer and continuously on the collecting reel;

[0056] In one aspect, the operating mechanism comprises at least one first motor group, which is associated at the collecting roller and acts on the axis of rotation of the collecting roller, so that the collecting roller is axially motorized, i.e. rotated about the axis of rotation by the first motor group. In one aspect, the first motor group acts directly on the axis of rotation of the collecting roller.

[0057] In one aspect, the driving torque required for the rotation of the collection roller is generated by the first motor set directly at the collection roller.

[0058] In one aspect, the collection roller actuated by the first motor group is suspended in a frame so as to be suspended in the take-off and / or collection group so that the entire surface of the fabric wound on the collection roller does not come into contact with the operating mechanism or other elements of the take-off and / or collection group.

[0059] In one aspect, the collection roller, during use, has its axis of rotation maintained in a fixed position relative to the frame during all steps of collecting the fabric, regardless of how much fabric is wound around the collection roller.

[0060] In one aspect, the first motor group is fixed at one of the two ends of the collection roller and from this position rotates the collection roller directly on the axis of rotation.

[0061] In one aspect, the removal and / or collection group comprises at least one sensor of non-contact type (non-contact), associated to a frame or operating mechanism and configured to measure the distance value between the sensor itself and the surface of the collection roller, determining the amount of fabric wound in a single layer on the surface.

[0062] In one aspect, the take-off and / or collection group is configured to process the measurement of the radius of the collection roller according to the distance value measured by the contactless sensor.

[0063] In one aspect, the non-contact sensor can be, by way of example: a laser sensor, a time-of-flight sensor, an infrared sensor, an ultrasonic sensor, an optical sensor, a sensor with a camera, an inductive sensor, a capacitive sensor, a magnetic sensor; an LVDT sensor.

[0064] In one aspect, the determined amount of the single layer of fabric can be equal to zero, corresponding to an empty state of the collection roll, or greater than zero, corresponding to a state where fabric is wound around the collection roll.

[0065] In one aspect, the contactless sensor is positioned below the collecting reel, preferably in a fixed position relative to the collecting reel. In this case, the sensor rotates with the removal and / or collection group during use of the knitting machine.

[0066] In one aspect, the non-contact sensor is preferably mounted to the frame of the removal and / or collection group.

[0067] In one aspect, the contactless sensor is oriented towards the rotation axis of the take-up roller, ie has a detection direction intersecting the rotation axis of the take-up roller.

[0068] In an alternative aspect, the contactless sensor is located in a fixed position relative to the collecting roller and maintains this fixed position also when the knitting machine is in use and removed and / or the collecting group is rotated. Preferably, the contactless sensor is located in a fixed position on the base.

[0069] In one aspect, a collection roll:

[0070] - has an outer collecting surface corresponding to the outermost layer of the fabric wound onto the collecting reel;

[0071] - during collection of the fabric, having at any instant a radius of the collecting roller corresponding to the radial distance between the outer collecting surface and the axis of rotation;

[0072] - during the collection of the fabric, instantaneously has an angular velocity of rotation about the axis of rotation;

[0073] - During the collection of the fabric, there is instantaneously a tangential speed, ie a linear speed at the outer collecting surface.

[0074] In one aspect, the tangential velocity instantaneously equals the product of the radius of the collection roll and the angular velocity.

[0075] In one aspect, the tangential velocity:

[0076] - preferably constant value throughout the collection of the fabric;

[0077] - sometimes having a preferred constant value during the discrete steps of collecting the fabric;

[0078] - The tangential speed is based on the rotation speed of the needle holding mechanism that makes the fabric;

[0079] - corresponds substantially to the linear speed of advance of the fabric in the take-off and / or collecting group, and to the linear amount of fabric wound on the collecting reel per unit time.

[0080] In one aspect, the first motor set is configured to gradually reduce the angular velocity of the collection roller as the radius of the collection roller increases so as to maintain a constant tangential velocity of the collection roller.

[0081] In fact, since the tangential speed is equal to the product of the radius of the collection roller and the angular speed, as the radius of the collection roller increases, the angular speed must decrease in order to keep the tangential speed constant.

[0082] In one aspect, the take-off and / or collection group is configured to measure the distance value by means of a contactless sensor and to process the measurement of the radius of the collection roller in real time, ie instantly, thereby continuously monitoring the measurement of the radius of the collection roller.

[0083] In one aspect, the removal and / or collection group defines a connection path for the fabric flowing out of the knitting assembly, which ends on a collection roll. Specifically, the removal and / or collection group defines a connection path starting from the upper opening of the frame and ending in the collection roll.

[0084] In one aspect, the collection roll comprises:

[0085] - a rod extending between two ends and around which the fabric collected by the take-off and / or collecting group is wound, so that a roll of fabric is formed around the rod;

[0086] - Two supports placed at the two ends of the rod and configured to support the rod in rotation.

[0087] In one aspect, the frame comprises two housing seats at the first lateral portion and the second lateral portion, the housing seats being configured to receive the collection roll at its two ends.

[0088] In one aspect, each receiving seat includes a receiving channel configured for loading and unloading the collection roll.

[0089] In one aspect, loading the collection roll occurs by inserting the two supports into the two receiving channels, while unloading the collection roll occurs by withdrawing the two supports from the two receiving channels.

[0090] In one aspect, each receptacle is configured to receive a respective fastener configured to retain the position of a support member of the collection roll in the receptacle in use.

[0091] In one aspect, the first motor group comprises:

[0092] - a first electric motor, preferably a stepper motor;

[0093] - Mechanical transmission means mounted downstream of the first electric motor and acting directly on the rod of the collection roller in order to cause it to rotate selectively.

[0094] In one aspect, a mechanical transmission is provided between the first motor and the rod of the collection roller.

[0095] In one aspect, the mechanical transmission ends in a shaft carrying a motor mechanism configured to transmit the controlled rotational movement directly to the rod of the collection roll.

[0096] In one aspect, the rod of the collection roller comprises a guide mechanism directly engageable with the motor mechanism for receiving a controlled rotational movement therefrom and rotating the rod of the collection roller.

[0097] In one aspect, the guide means is integral with the shaft of the collection roller, preferably at one end thereof.

[0098] In one aspect, the guide mechanism is coaxial with the rod of the take-up roller.

[0099] In one aspect, the guiding institution:

[0100] - when the collecting roller is mounted on the frame, i.e. when the support of the collecting roller is inserted into the housing of the frame, it engages on the motor mechanism;

[0101] - when the collecting roller is removed from the frame, i.e. when the support of the collecting roller is withdrawn from the housing of the frame, it is disengaged from the motor mechanism,

[0102] In one aspect, the first motor group is mounted (preferably in a fixed position during removal and / or use of the collection group) to the first lateral portion or the second lateral portion of the frame. In this way, when the collection roller is mounted to the frame, the motor mechanism is in a fixed position relative to the frame and is ready to receive the guide mechanism.

[0103] In one aspect, the first motor group comprises:

[0104] - a first electric motor of the stepper type provided with an output shaft;

[0105] - A mechanical transmission device comprising:

[0106] - Headless screw drive / helical belt gear, comprising:

[0107] a headless screw connected to and rotated by the output shaft of the first electric motor, and

[0108] - A helical belt gear meshing with the headless screw and mounted on (eg coupled to) a shaft carrying the motor mechanism.

[0109] In one aspect, the operating mechanism comprises at least one spreading roller or tensioning roller mounted to the frame in an upstream position relative to the collection roller (preferably immediately upstream). The spreading roller is configured to interact with the fabric advancing toward the collection roller so as to spread the fabric before being wound on the collection roller.

[0110] In one aspect, the spreading roller extends longitudinally between two lateral ends in a direction substantially parallel to the rotation axis of the collection roller and is configured to rotate about its rotation axis.

[0111] In one aspect, the spreading roller is mounted to the frame in a movable manner, for example in a rotatable or translatable or rotatable-translatable manner, and is configured to be able to vary the operating distance separating it from the collecting roller.

[0112] In one aspect, the operating distance corresponds to the linear distance between the rotation axis of the spreading roller and the corresponding rotation axis of the collecting roller.

[0113] In one aspect, the operating mechanism comprises a second motor set acting on the spreading roller for selectively moving it so as to increase or decrease the operating distance separating it from the collection roller, preferably keeping the spreading roller parallel to the collection roller.

[0114] In one aspect, under the action of the second motor group, the movement of the spreading roller is rotation or translation or rotation-translation.

[0115] In one aspect, the spreading roll:

[0116] - has an outer operative surface which contacts the fabric during its transport towards the collecting reel and acts on the fabric itself for expanding and spreading it;

[0117] - having a radius of the spreading roller which has a constant value and corresponds to the radial distance between the outer operating surface and the axis of rotation of the spreading roller.

[0118] In one aspect, the spreading roller is configured to move during collection by varying the operating distance separating it from the collection roller so as to instantaneously maintain a constant optimal separation value equal to the distance between the outer operating surface of the spreading roller and the outer collection surface of the collection roller.

[0119] In one aspect, the second motor group is configured to move the spreading roller based on a measurement of the radius of the collection roller processed from the distance value measured by the non-contact sensor by varying the operating distance separating the spreading roller from the collection roller so as to keep the optimal separation value constant in real time.

[0120] In one aspect, the second motor group is configured to gradually increase the operating distance as the radius of the collection roll increases, thereby keeping the optimum separation value constant during collection of the web.

[0121] In an alternative aspect, the operating distance corresponds to the linear distance between the outer collecting surface of the collection roller and the outer operating surface of the spreading roller. In this case, the operating distance is the linear spacing between the surfaces of the two rollers and is therefore variable, during the collection of the fabric, depending on the radius of the collection roller; in fact, the radius of the collection roller increases as the fabric is collected.

[0122] In one aspect, the two lateral ends of the spreading roller are mounted to the first and second lateral portions of the frame, respectively, so that the rotation axis of the spreading roller is substantially parallel to the longitudinal axis of the frame.

[0123] In one aspect, the unrolling roller is mounted to the frame by a pair of movable arms. In one aspect, each of the two movable arms extends between a lower end and an upper end, the lower end being hinged to the frame and the upper end being connected to the lateral end of the unrolling roller; the distance between the lower end and the upper end defines the length of the movable arm.

[0124] In one aspect, the second motor group includes an actuator acting on at least one of the two movable arms for determining selective swinging of the two arms clockwise and counterclockwise and moving the spreading roller along an arc trajectory.

[0125] In one aspect, one of the two movable arms is actuated by a second motor set, and the other movable arm is articulated to the frame in an idle mode (i.e., free rotation) such that a rotation (i.e., a swinging motion) of one of the two movable arms corresponds to an equal and corresponding rotation of the other movable arm.

[0126] In a possible embodiment (not shown), the second motor group comprises a wire guide to which the spreading roller is mounted and is configured to move the spreading roller so as to selectively vary the operating distance.

[0127] In one aspect, the operating mechanism comprises at least one transfer roller (or take-off roller) mounted to the frame in an upstream position relative to the collection roller, preferably upstream of the spreader roller.

[0128] In one aspect, the operating mechanism includes a flattening or approximation mechanism of the fabric originating from the braided assembly in the form of a closed tubular fabric.

[0129] In one aspect, the operating mechanism includes a cutting mechanism, which is arranged downstream of the flattening mechanism and is suitable for longitudinally cutting a knitted fabric in a tubular shape produced by a knitting assembly along preferably vertical busbar lines so as to thereby unroll and wind the knitted fabric in a single layer on a collecting reel, as is typically found in circular knitting machines of the "unrolling" type.

[0130] In one aspect, the removal and / or collection group comprises at least one control unit configured to command the operation of the operating mechanism.

[0131] In one aspect, the control unit is connected to the contactless sensor and is configured to:

[0132] - receiving a signal from a contactless sensor, which signal represents a distance value and determines a measurement of the radius of the collection roller; or

[0133] - Receive measurement of the radius of the collection roll directly from a contactless sensor.

[0134] In one aspect, the control unit is connected to the operating mechanism for sending command signals thereto capable of modifying and controlling its operating configuration.

[0135] In one aspect, the control unit is configured to:

[0136] - sending a command signal to the first motor group for gradually reducing the angular speed of the collection roller in order to keep the tangential speed of the collection roller constant;

[0137] - sending a command signal to the first motor group for gradually reducing the angular velocity of the collection roller as the radius of the collection roller increases, so as to keep the tangential velocity of the collection roller constant;

[0138] - sending a command signal to the second motor group for moving the spreading roller based on the measured value of the radius of the collecting roller by varying the operating distance in order to keep the optimum separation value constant during the collection of the web;

[0139] - sending a command signal to the second motor group for gradually increasing the operating distance as the radius of the collecting roller increases, so as to keep the optimum separation value constant during the collection of the web;

[0140] - Sending command signals to the third motor group for rotating the spreading roller at a determined speed, for generating a correct spreading and expanding action of the fabric transported on the spreading roller.

[0141] In one aspect, the control unit of the taking-off and / or collecting group may be shared with the knitting machine, for example it may be located in the base or the knitting assembly and operate the control of the entire knitting machine.

[0142] In one aspect, the take-off and / or collecting group of the fabric under production is arranged downstream of the knitting assembly with respect to the supply direction of the fabric under production.

[0143] In one aspect, the take-off and / or collection group is configured to rotate integrally with the needle holding mechanism, or to rotate in a coordinated manner relative to the needle holding mechanism during fabric manufacturing.

[0144] In one aspect, the circular weft knitting machine can be of the single-bed type (with only one needle holding cylinder) or of the double-bed type (with a needle holding cylinder and a needle holding plate).

[0145] In one aspect, the circular weft knitting machine can be of the type with a rotating needle holding mechanism (with a non-rotating needle control mechanism and a removal and / or collection group that rotates with the needle holding mechanism during fabric manufacturing), or of the type with a fixed needle holding mechanism (with a rotating needle holding mechanism and a removal and / or collection group that is fixed during fabric manufacturing).

[0146] In one aspect, the removal and / or collection group is suspended below the knitting assembly. In one aspect, the removal and / or collection group is suspended on and supported by the needle holding mechanism.

[0147] In various aspects, the removal and / or collection group is laid on a floor or base and is restrained to the needle holding mechanism.

[0148] In one aspect, if the needle holding mechanism is a rotary type, the removal and / or collection group is dragged and rotated by the rotation of the needle holding mechanism during the manufacture of the fabric, and rotates integrally with the needle holding mechanism, i.e., there is no relative rotational movement relative to the needle holding mechanism. Therefore, the motor for moving the needle holding mechanism and the removal and / or collection group can be one, thereby saving space and cost.

[0149] In one aspect, if the needle holding mechanism is stationary, the removal and / or collection group is stationary, ie, does not have any relative rotational movement relative to the needle holding mechanism.

[0150] In one of its independent aspects, the present invention relates to a circular weft knitting machine comprising:

[0151] - a knitting assembly provided with at least one needle holding mechanism in the form of a needle holding cylinder or a needle holding plate rotating about a central axis, a plurality of needles movably mounted to the at least one needle holding mechanism, and a command mechanism suitable for selectively actuating the plurality of needles and suitable for allowing the manufacture of a fabric;

[0152] - a base constituting a supporting structure of the knitting machine and configured to support the knitting assembly, the base defining a housing space below the knitting assembly;

[0153] - Removal and / or collection of groups according to one or more of the preceding aspects.

[0154] In one aspect, the circular knitting machine is of the “unfolding” type, ie configured to produce fabric and to collect the fabric in an unfolded manner, ie as a single layer and continuously, by winding the fabric on collecting rolls of a take-off and / or collecting group.

[0155] In one aspect, the single-layer fabric guided out from the needle holding mechanism and collected by the removal and / or collection group is obtained by:

[0156] - if the braided assembly continuously produces a tubular fabric, obtained by cutting and stretching or "unrolling" the tubular fabric; or

[0157] - directly "in an unrolled manner", i.e. as a continuous single-layer fabric of a defined width;

[0158] In both cases, the take-off and / or collection group collects a single layer of fabric rather than a cylindrically laid out tube by winding it on a collection reel.

[0159] In one aspect, the single-layer fabric has a continuous strip of a specific width and is obtained by:

[0160] - obtained by unfolding the tubular article, by successive cuts carried out parallel to the longitudinal development of the tubular fabric produced; or

[0161] - Obtained directly from a woven component that has manufactured it as an "unfolded", single-layer and continuous fabric.

[0162] In one of its independent aspects, the present invention relates to a method for collecting a fabric produced by a circular weft knitting machine, the method comprising the following steps:

[0163] - Arrangement and operation of circular weft knitting machines:

[0164] - Arrange and operate take-down and / or collection groups;

[0165] - processing the measured value of the radius of the collecting roller according to the distance value measured by the contactless sensor, wherein the radius corresponds to the radial distance between the outer collecting surface corresponding to the outermost layer of the fabric wound onto the collecting roller and the axis of rotation;

[0166] - Automatically modifying the configuration of the operating mechanism based on the measured value of the radius of the collecting reel, which is processed according to the distance values ​​measured by the contactless sensor.

[0167] In one aspect, the step of automatically modifying includes the step of synchronizing the operating mechanisms at determined operating parameters to ensure proper tensioning and proper spreading of the fabric.

[0168] In one aspect, the method comprises the step of varying the angular velocity of the collection roll so as to always keep the tangential velocity of the collection roll properly regulated, ie under control, during collection of the web.

[0169] In one aspect, the step of always properly regulating the tangential velocity comprises:

[0170] - maintaining the tangential speed at a preferably constant value throughout the collection of the fabric;

[0171] - maintaining the tangential speed at a preferably constant value from time to time during discrete steps of collecting the fabric;

[0172] - maintaining the tangential speed at a value that depends on the rotation speed of the needle holding mechanism that makes the fabric;

[0173] - Setting the tangential speed so that it corresponds to the linear speed of advance of the fabric in the take-off and / or collection group and the linear amount of fabric wound onto the collection roller per unit time. In one aspect, the method comprises the step of gradually reducing the angular speed of the collection roller as the radius of the collection roller increases so as to keep the tangential speed of the collection roller constant.

[0174] In one aspect, the method provides that the step of processing the measured value of the radius of the collection roller according to the distance value is performed in real time, ie instantly, so that the measured value of the radius of the collection roller is continuously monitored.

[0175] In one aspect, the method comprises the steps of:

[0176] - arranging in the operating mechanism at least one spreading or tensioning roller, mounted to the frame in an upstream position relative to the collecting roller and configured to interact with the fabric advancing towards the collecting roller in order to spread the fabric before being wound on the collecting roller;

[0177] - moving the spreading roller by varying the operating distance separating the spreading roller from the collecting roller so as to instantaneously keep an optimal separation value constant, based on a measurement of the radius of the collecting roller, which measurement value is processed according to a distance value measured by a non-contact sensor, wherein the optimal separation value is an operating value corresponding to an ideal distance, keeping the spreading roller at an ideal distance relative to the collecting roller for performing an optimal spreading of the fabric from the spreading roller to the collecting roller.

[0178] In one aspect, the method includes the step of rotating the spreading roller about its own rotation axis to cause the fabric on the spreading roller to spread and expand during transportation.

[0179] Other features and advantages will be better understood from the detailed description of preferred embodiments of a take-off and / or collecting group for a circular knitting machine of the "unfolding" type, a circular weft knitting machine of the "unfolding" type and a method for collecting a fabric according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0180] The present invention will be described with reference to the accompanying drawings, which are provided for illustrative purposes only and are therefore not limiting, in which:

[0181] - Figure 1 A perspective view showing one possible embodiment of a taking-off and / or collecting group for an “open” circular knitting machine according to the invention;

[0182] - Figure 2 Shows Figure 1 A top view of the removal and / or collection group;

[0183] - Figure 3 Shows Figure 1 A front view of the removal and / or collection group;

[0184] - Figure 4 Shows Figure 1 Left side view of the removal and / or collection group;

[0185] - Figure 5 Shows Figure 1 A right side view of the removal and / or collection group;

[0186] - Figure 6 Shows Figure 1 Another perspective view of the removal and / or collection set with some of the components removed;

[0187] - Figure 7 Shown from outside Figure 6 an enlarged view of a portion of the removal and / or collection set;

[0188] - Figure 8 Shown from the inside Figure 6 an enlarged view of the portion of the removal and / or collection set;

[0189] - Fig. 9 Shows Figure 1 A rear perspective view of the removal and / or collection group;

[0190] - Fig.10 Shows Fig. 9 An enlarged view of a portion of the removal and / or collection group, in this case the upper and rear portion;

[0191] - Fig.11 Shows Figure 1cross-sectional view of the removal and / or collecting group in the frame; the section is implemented in a vertical plane, orthogonal to the longitudinal axis of the frame and parallel to the central axis of the knitting machine in the case of the removal group installed;

[0192] - Fig.12 Shows Figure 1 A perspective view of a removal and / or collection group, the perspective view being along the Fig.11 The above plane shown is cut;

[0193] - Fig.13 shows a perspective view of an exemplary embodiment of a motor group according to the present invention;

[0194] - Fig.14 Shows Fig.13 Another perspective view of the motor group;

[0195] - Fig.15 Shows Fig.13 a motor group in which, according to the invention, a motorized axis (of an exemplary type) is associated;

[0196] - Fig.16 Shows Figure 1 Another perspective view of the removal and / or collection set with some of the components removed; Fig.16 Also shown (by way of example): a fabric produced by a circular knitting machine and fed to a take-off and / or collecting group; a certain length of this fabric advancing in the take-off and / or collecting group while a determined amount of fabric has been wound in a single layer onto a collecting reel;

[0197] - Fig.17 yes Fig.16 A side view of a removal and / or collection group (including the fabric therein);

[0198] - Fig.18 shows a top view of a possible exemplary embodiment of a circular weft knitting machine according to the invention, Figure 1 The removal and / or collection group in the circular weft knitting machine is rotatably mounted to the circular weft knitting machine; some parts are removed from Fig.18 The knitting machine in is removed; the figure specifically shows the base and knitting assembly of the circular knitting machine except for the removal and / or collection group;

[0199] - Fig.19 Shows Fig.18 Another perspective view of the circular weft knitting machine in FIG. 1 (from the bottom);

[0200] - Fig. 20A perspective view of a possible exemplary embodiment of a circular weft knitting machine according to the invention is shown; in this figure, the knitting machine is shown with a fully assembled weaving assembly, a conical clamping structure is placed above the weaving assembly and closing cages enclose the operating space occupied by the taking-off and / or collecting groups (which are subsequently enclosed within these cages). DETAILED DESCRIPTION

[0201] With reference to the above figures, a taking-off and / or collecting group according to the invention, intended to be installed in a circular weft knitting machine, indicated by reference 100 , is indicated overall by reference 1 .

[0202] The circular weft knitting machine 100 comprises:

[0203] - a knitting assembly T provided with at least one needle-holding mechanism C in the shape of a needle-holding cylinder or a needle-holding plate rotating about a central axis, a plurality of needles movably mounted to the at least one needle-holding mechanism, and a command mechanism suitable for selectively actuating the plurality of needles and suitable for allowing the fabric F to be manufactured;

[0204] A base B constituting the supporting structure of the knitting machine and configured to support the knitting assembly T, the base B defining a housing space below the knitting assembly T.

[0205] like Figure 18-20 As shown, the needle holding cylinder C is usually vertically mounted on the base B, and the needles are arranged vertically and protrude from the upper edge of the needle holding cylinder.

[0206] From the perspective of knitting technology, the structure of the entire circular knitting machine 100 and the operation of the needle holding mechanism C (eg, the coordination between the needle and the thread, etc.) are well known in the technical field of the present invention and are therefore not described in detail.

[0207] Take down and / or collect Group 1 including:

[0208] - a frame 2 configured to be mounted in a rotatable manner to the circular knitting machine 100 in said accommodation space;

[0209] An operating mechanism 3 operatively associated to and supported by the frame 2 and comprising at least one collection roller 10 arranged along an axis of rotation 11 and extending longitudinally between two ends 12 and 13 .

[0210] The operating mechanism 3 is configured to at least unfold and spread the fabric F produced by the circular knitting machine, or also to finally extract it from the needle holding mechanism C by winding it in a single layer and continuously on the collecting reel 10 .

[0211] The operating mechanism 3 comprises at least one first motor group 20 which is associated with the collection roller 10 and acts on the axis of rotation 11 of the collection roller so that the collection roller 10 is axially motorized, ie rotated about the axis of rotation 11 by the first motor group 20 .

[0212] By the expression "acting on the axis of rotation of the collection roller", it is intended that the first motor group 20 preferably acts directly on the shaft (or rod or cylindrical rod) defining the collection roller 10 and about which the roller itself rotates. In other words, the first motor group 20 preferably operates directly on the collection roller 10 for rotating it about its axis of rotation 11. The driving action of the first motor group 20 takes place directly on an element belonging to the collection roller 10, in particular on an element that is part of the axis of the collection roller or similarly on an element that is integral with the axis of the roller. The driving action of the first motor group 20 that rotates the collection roller 10 about its axis of rotation 11 is not necessarily an action coaxial with the axis of rotation 11, but is generally an action that is directly transmitted to the axis and determines its rotation. For example, the action of the first motor group 20 may take place parallel or at an angle relative to the axis of rotation 11 of the collection roller 10, but in any case it preferably takes place directly on the collection roller 10.

[0213] Preferably, the first motor group 20 is configured to rotate the collection roll 10 at a variable and selectable angular speed.

[0214] Preferably, the first motor group 20 is configured to rotate the collection roll 10 at a variable and selectable angular speed regardless of the rotation speed of the needle holding mechanism C.

[0215] Preferably, for example, under certain operating conditions, the first motor group 20 can be configured to rotate the collection roller 10 at a variable and selectable angular speed in a manner coordinated with the needle holding mechanism C, preferably in a manner coordinated with the rotation speed of the needle holding mechanism C, for example proportionally.

[0216] Preferably, the first motor group 20 may be configured to rotate the collecting roller 10 at a variable and selectable angular speed under the condition that the rotation speed of the needle holding mechanism C is constant.

[0217] Preferably, the driving torque required for the rotation of the collection roller 10 is generated by the first motor group 20 directly on the collection roller 10 itself.

[0218] Preferably, the operating mechanism 3 of the take-off and / or collecting group 1 is free of, ie does not comprise, a motorized roller in contact with the collecting roller 10 and / or the fabric F wound thereon.

[0219] Preferably, the collecting roller 10 driven by the first motor group 20 is suspended in the frame 2 so as to be suspended in the removal and / or collection group 1 so that the entire surface of the fabric F wound on the collecting roller 10 does not come into contact with the operating mechanism 3 or other elements of the removal and / or collection group.

[0220] Preferably, the collection reel 10 is mounted to the frame 2 so that the entire surface of the fabric F wound on the collection reel 10 is free and does not rest on any element.

[0221] Preferably, the collection roll 10 is rotatably mounted to the frame at its two ends 12 and 13 so as to be fully supported by both ends.

[0222] Preferably, during use of the collecting roller 10 , its axis of rotation 11 remains in a fixed position relative to the frame 2 during all steps of collecting the fabric, no matter how much fabric is wound around the collecting roller 10 .

[0223] Preferably, the first motor group 20 is fixed to one of the two ends of the collection roller 10 (in the embodiment of the figures, the end 12 ) and from this position rotates the collection roller directly on the axis of rotation 11 .

[0224] Preferably, the removal and / or collection group 1 comprises at least one contactless sensor S, which is preferably associated with the frame 2 or the operating mechanism 3 and is configured to measure the distance value between the sensor S itself and the surface of the collection reel 10 on which a determined amount of fabric F is wound in a single layer.

[0225] Preferably, the take-off and / or collection group 1 is configured to process the measured value of the radius R of the collection roller 10 as a function of the distance value measured by the contactless sensor S.

[0226] Preferably, the non-contact sensor S can be exemplified as follows:

[0227] - Laser sensor;

[0228] - Time of Flight Sensor (Time of Flight);

[0229] - Infrared sensor;

[0230] - Ultrasonic sensor;

[0231] - Optical sensors;

[0232] -Sensor with camera;

[0233] - Inductive sensors;

[0234] - Capacitive sensors;

[0235] -Magnetic sensor;

[0236] -LVDT sensor.

[0237] Preferably, the determined amount of the single-layer fabric F may be equal to zero, corresponding to an empty state of the collecting roller 10 , or greater than zero, corresponding to a state where the fabric F is wound around the collecting roller 10 .

[0238] Preferably, the taking-off and / or collecting group 1 is configured to modify the configuration of the operating member 3 based on the measured value of the radius R of the collecting roller 10 processed from the distance values ​​measured by the contactless sensor S.

[0239] Preferably, the contactless sensor S is positioned below the collecting reel 10, preferably in a fixed position relative to the collecting reel 10. In this case, the sensor S rotates together with the taking-off and / or collecting group 1 during use of the knitting machine.

[0240] Preferably, the non-contact sensor S faces the rotation axis 11 of the collecting roller 10 , that is, the detection direction thereof intersects with the rotation axis 11 of the collecting roller 10 .

[0241] Preferably, as shown by way of example in the attached figures, a contactless sensor S is mounted to the frame 2 of the removal and / or collection group 1 .

[0242] Alternatively, in an embodiment not shown, the contactless sensor can be located in a fixed position relative to the collecting roller and remain in this fixed position also when the knitting machine is in use and the collection group is removed and / or rotated. Preferably, in this case, the contactless sensor is located in a fixed position on the base. In this case, then, when the knitting machine is in use, the sensor is fixed and does not rotate with the removal and / or collection group.

[0243] The contactless sensor S can be synchronized with the rotation speed of the take-off and / or collection group 1 in order to manage the measurement of the above-mentioned distance value between the sensor itself and the collection roll 10. By way of example, the contactless sensor S can perform a measurement once per rotation of the take-off and / or collection group 1 or at a determined sampling frequency.

[0244] Preferably, the collecting roller 10:

[0245] - has an outer collecting surface 15 corresponding to the outermost layer of the fabric F wound on the collecting reel 10;

[0246] - during the collection of the fabric F, instantaneously has a radius R of the collecting roller corresponding to the radial distance between the outer collecting surface 15 and the axis of rotation 11;

[0247] - during the collection of the fabric F, instantaneously has an angular velocity of rotation about the axis of rotation 11;

[0248] During the collection of the fabric F, there is instantaneously a tangential speed, ie a linear speed at the outer collecting surface 15 .

[0249] Preferably, the first motor group 20 is configured to vary the angular speed of the collecting roller 10 so as to always keep the tangential speed of the collecting roller 10 properly regulated, ie under control, during the collecting of the fabric F.

[0250] Preferably, the tangential speed is instantaneously equal to the product of the radius R of the collection roller 10 and the angular speed.

[0251] The tangential velocity:

[0252] - preferably constant value throughout the entire collecting fabric F;

[0253] - has a preferably constant value sometimes during the discrete steps of collecting the fabric F;

[0254] - is the tangential speed according to the rotation speed of the needle holding mechanism C for manufacturing the fabric F;

[0255] - corresponds substantially to the linear speed of advance of the fabric F in the take-off and / or collecting group 1 , and to the linear quantity of fabric F wound on the collecting reel 10 per unit of time.

[0256] Preferably, the first motor group 20 is configured to gradually reduce the angular velocity of the collection roller 10 as the radius R of the collection roller 10 increases, so as to keep the tangential velocity of the collection roller 10 constant. In fact, since the tangential velocity is equal to the product of the radius R of the collection roller 10 and the angular velocity, as the radius R of the collection roller increases, the angular velocity must be reduced in order to keep the tangential velocity constant.

[0257] Preferably, the taking-off and / or collecting group 1 is configured to measure distance values ​​by means of a contactless sensor S and to process the measured values ​​of the radius R of the collecting roller 10 in real time, ie instantly, thereby continuously monitoring the measured values ​​of the radius R of the collecting roller.

[0258] Preferably, the removal and / or collection group 1 defines a connection path for the fabric F flowing out of the knitting assembly T, which ends on the collection reel 10. Specifically, the removal and / or collection group 1 defines a connection path starting from the upper opening 4 of the frame 2 and ending in the collection reel 10.

[0259] Preferably, the frame 2 is mounted in the knitting machine so as to rotate about a vertical axis which preferably coincides with the central axis X of the knitting assembly T. Preferably, in use, the vertical axis coincides with a direction orthogonal to the support surface of the knitting machine, in particular to the support surface of the base B. Preferably, the extension of the frame 2 along its vertical axis coincides with the height of the frame.

[0260] Preferably, the frame 2 extends along a longitudinal axis 5 between the first lateral portion 6 and the second lateral portion 7. Preferably, the longitudinal axis 5 is orthogonal to the vertical axis. Preferably, the extension of the frame 2 along the longitudinal axis corresponds to the width of the frame. Preferably, the extension of the frame 2 along the longitudinal axis 5, i.e. the width of the frame, corresponds to the size of the larger extension of the frame 2.

[0261] Preferably, the two ends 12 and 13 of the collection roller 10 are mounted to the first lateral portion 6 and the second lateral portion 7 of the frame 2 so that the rotation axis 11 of the collection roller 10 is substantially parallel to the longitudinal axis 5 of the frame 2 .

[0262] Preferably, the collecting roller 10 comprises:

[0263] - a rod 16 extending between two ends and around which the fabric F collected by the take-off and / or collecting group 1 is wound, so that a roll of fabric is formed around the rod 16;

[0264] - Two supports 17 and 18 placed at the two ends of the rod 16 and configured to support said rod in rotation.

[0265] Preferably, the rod 16 is mounted in a rotatable manner to two supports 17 and 18 so that the collecting roller 10 forms a single assembly.

[0266] Preferably, the two supports 17 and 18 are associable to the frame 2 , preferably in a removable manner, so as to allow mounting and removal of the collection roller 10 to and from the frame 2 .

[0267] Preferably, the frame 2 comprises two housing seats 8 and 9 at the first lateral portion 6 and the second lateral portion 7 configured to receive the collection roll 10 at its two ends 12 and 13 .

[0268] Preferably, each housing 8 and 9 is configured to receive a respective support 17 and 18 of the collection roll 10 .

[0269] Preferably, each housing seat 8 and 9 comprises a housing channel configured for loading and unloading the collection roll 10 .

[0270] Preferably, loading the collecting roller 10 takes place by inserting the two supports 17 and 18 into the two receiving channels, while unloading the collecting roller 10 takes place by withdrawing the two supports 17 and 18 from the two receiving channels. Disassembly of the collecting roller 10 from the frame 2 for unloading the collecting roller usually takes place when the roller is fully loaded, i.e. when it has wound around itself the maximum amount of wearable fabric F, or when fabric manufacturing of the knitting machine 100 is completed.

[0271] This maximum amount of wearable fabric is a flow rate value for the collection roller 10 and may correspond to a maximum radius R of the outer collection surface 15 or a maximum weight of the collection roller 10 (eg, based on the type of fabric being collected, size, yarns making up the fabric, etc.).

[0272] Preferably, the receiving channel extends in a direction substantially orthogonal to the longitudinal axis 5 of the frame (and the axis of rotation 11 of the collecting roller). Thus, loading and unloading the collecting roller 10, i.e. the insertion and extraction of the supports 17 and 18 from the receiving channel, takes place with a translational movement of the collecting roller 10 relative to the frame 2 and with a frontal movement relative to the frame 2.

[0273] Preferably, the receiving channel can be oriented at a determined angle relative to a plane orthogonal to the central X axis of the knitting machine 100 , so as to provide a chute for loading and unloading the collecting roller 10 .

[0274] Preferably, each of the two supports 17 and 18 of the collecting roller comprises a respective bearing. Preferably, each bearing comprises an inner ring integral with the rotating rod 16 of the collecting roller 10, an outer ring receivable in a respective housing seat 8 and 9 of the frame 2 and rolling elements arranged between the inner and outer rings.

[0275] Preferably, each housing (8, 9) is configured to receive a corresponding fastener (8A, 9A in the figures) configured to retain the position of the support (17, 18) of the collection roll 10 in the housing when in use.

[0276] Preferably, the fastener is configured to lock the position of an outer race of a bearing of a respective support member in use.

[0277] Preferably, the first motor group 20 includes:

[0278] - a first electric motor 21, preferably a stepper motor;

[0279] - Mechanical transmission 22 mounted downstream of the first electric motor 21 and acting directly on said rod 16 of the collection roller 10 in order to cause it to rotate selectively.

[0280] Preferably, a mechanical transmission 22 is provided between the first electric motor 21 and the rod 16 of the collection roller 10 .

[0281] Preferably, the mechanical transmission 22 comprises a headless screw transmission, or a gear transmission, such as a pair of bevel gears, or an epicycloidal gearbox.

[0282] Preferably, the mechanical transmission 22 ends in a shaft carrying a motor mechanism 23 configured to transmit a controlled rotational movement directly to the rod 16 of the collection roller 10 .

[0283] Preferably, the motor mechanism 23 is a gear, for example, a first gear wheel 23 .

[0284] Preferably, the rod 16 of the take-up roller 10 comprises a guide mechanism 19 directly engageable with the motor mechanism 23 for receiving a controlled rotational movement therefrom and rotating the rod 16 of the take-up roller 10 .

[0285] Preferably, the guide means 19 are integral with the rod 16 of the collection roller 10, preferably at one end thereof (end 12 in the figures).

[0286] Preferably, the guide means 19 is coaxial with the rod 16 of the collection roller 10 .

[0287] Preferably, the guide mechanism 19 is a gear, for example, a second belt gear 19 .

[0288] It should be noted that since the guide mechanism 19 is integral with (and coaxial with) the rod 16 of the collection roller 10, and since the motor mechanism 23 can be directly geared with the guide mechanism 19 to transmit rotational motion, the action of the first motor group 20 occurs directly on the rotation axis 11 of the collection roller 10, thereby causing the collection roller 10 to rotate directly.

[0289] Preferably, the meshing of the guide mechanism 19 with the motor mechanism 23 occurs by meshing of a first belt gear with a second belt gear.

[0290] Preferably, the motor mechanism 23 and the guide mechanism 19 have respective rotation axes that are parallel to each other.

[0291] Preferably, the guide mechanism 19:

[0292] - when the collection roller 10 is mounted on the frame 2, ie when the supports 17 and 18 of the collection roller 10 are inserted into the housings 8 and 9 of the frame 2, they engage on the motor mechanism 23;

[0293] When the take-up roller 10 is removed from the frame 2 , ie when the supports 17 and 18 of the take-up roller 10 are withdrawn from the housings 8 and 9 of the frame 2 , they are disengaged from the motor mechanism 23 .

[0294] Specifically, mounting the collecting roller 10 to the frame 2 determines the meshing of the second belt gear with the first belt gear, whereas dismounting the collecting roller 10 from the frame 2 determines the separation and distance of the second belt gear from the first belt gear.

[0295] Preferably, the rotation axis of the first belt gear 23 and the corresponding rotation axis of the second belt gear 19 are parallel to each other and to the rotation axis 11 of the collection roller 10 .

[0296] Preferably, the first motor unit 20 is mounted (preferably in a fixed position during removal and / or use of the collecting unit 1) to the first lateral portion 6 (as shown) or the second lateral portion 7 of the frame. In this way, when the collecting roller 10 is mounted to the frame 2, the motor mechanism 23 is in a fixed position relative to the frame 2 and is ready to receive the guide mechanism 19.

[0297] Preferably, the first motor group 20 includes:

[0298] - a first electric motor 21 of the stepper type provided with an output shaft;

[0299] - Mechanical transmission device 22, comprising:

[0300] - Headless screw drive / helical belt gear, comprising:

[0301] a headless screw connected to and rotated by the output shaft of the first electric motor 21 , and

[0302] A helical belt gear meshing with the headless screw and mounted (eg coupled) on the shaft carrying the motor mechanism 23 .

[0303] The rotation axis of the headless screw and the rotation axis of the helical belt gear are mutually skewed and orthogonal; therefore, the rotation axis of the output shaft of the first motor 21 and the rotation axis of the shaft carrying the motor mechanism 23 are also mutually skewed and orthogonal.

[0304] The headless screw is the driving one and the helical gear is the guiding one.

[0305] It should be noted that in Figure 13-15 The output shaft of the electric motor and the headless screw and helical belt gear of the mechanical transmission are not visible in the figure because they are internal components; however, the electric motor and the mechanical transmission can be advantageous commercial products in the catalog, and their internal components are known in the art.

[0306] It should be noted that the gear ratio is based on the number of initial threads of the headless screw. For example, if the headless screw has only one initial thread, the helical wheel will move one tooth (forward or backward depending on the direction of the screw rotation) for each rotation of the headless screw.

[0307] Preferably, the first motor group 20 comprises a flange 24 mounted on the frame 2 and carrying the mechanical transmission device 22 .

[0308] Preferably, the flange 24 intersects the shaft carrying the motor mechanism 23 and supports the shaft for rotation.

[0309] Preferably, the first electric motor 21 is mounted directly to and supported by the mechanical transmission 22. In this configuration, the flange 24 supports the entire first motor group 20 by mounting it to the frame 2.

[0310] Preferably, the operating mechanism 3 comprises at least one spreading roller 30 (also called tensioning roller) mounted to the frame 2 at a position upstream relative to the collection roller 10, preferably immediately upstream along the path of the fabric F. The spreading roller 30 is configured to interact with the fabric F advancing towards the collection roller 10 in order to spread the fabric before being wound on the collection roller.

[0311] Preferably, the spreading roller 30 extends longitudinally between the two lateral ends 32 and 33 in a direction substantially parallel to the rotation axis 11 of the collection roller 10 and is configured to rotate about its rotation axis 31. In other words, the spreading roller 30 is arranged parallel to the collection roller 10 and is configured to expand and spread the fabric towards its ends 32 and 33.

[0312] Preferably, the spreading roller 30 is mounted to the frame 2 in a movable manner, for example in a rotatable or translatable or rotatable-translatable manner, and is configured to be able to vary the operating distance separating it from the collecting roller 10 .

[0313] Preferably, the operating distance corresponds to the linear distance between the rotation axis 31 of the spreading roller 30 and the corresponding rotation axis 11 of the collecting roller 10 .

[0314] Preferably, the operating mechanism 3 comprises a second motor group 40 acting on the spreading roller 30 for selectively moving it so as to increase or decrease the operating distance separating it from the collecting roller 10 , preferably keeping the spreading roller 30 parallel to the collecting roller 10 .

[0315] Preferably, under the action of the second motor group 40, the movement of the spreading roller 30 is rotation or translation or rotation and translation.

[0316] Preferably, the spreading roller 30:

[0317] - has an outer operating surface 35 which contacts the fabric F during its transport towards the collecting reel 10 and acts on the fabric itself for expanding and spreading it;

[0318] - having a radius R of the spreading roller 30 which has a constant value and corresponds to the radial distance between the outer operating surface 35 and the axis of rotation 31 of the spreading roller.

[0319] In one aspect, the spreading roller 30 is configured to move during collection by varying the operating distance separating it from the collection roller so as to instantaneously maintain a constant optimal separation value equal to the distance between the outer operating surface 35 of the spreading roller 30 and the outer collection surface 15 of the collection roller 10.

[0320] Preferably, the optimal separation value is an operating value corresponding to an ideal distance (for example, a value set when setting up the knitting machine), and the spreading roller 30 is maintained at this ideal distance relative to the collecting roller 10 for performing optimal spreading of the fabric F from the spreading roller to the collecting roller.

[0321] Preferably, the second motor group 40 is configured to move the spreading roller 30 based on the measured value of the radius R of the collection roller 10, which is processed according to the distance value measured by the non-contact sensor S, by changing the operating distance separating the spreading roller 30 from the collection roller 10 so as to keep the optimal separation value constant in real time.

[0322] Preferably, the second motor group 40 is configured to gradually increase the operating distance as the radius R of the collecting roller 10 increases, thereby keeping the optimal separation value constant during the collection of the fabric F.

[0323] In fact, as the radius R of the collection roller 10 increases, its outer collection surface 15 approaches the spreading roller 30, so the latter must be gradually distanced. In other words, as the radius R of the collection roller 10 increases, the operating distance (if calculated as the distance between the axes of rotation 11 and 31) required to keep the optimal separation value constant also increases.

[0324] Alternatively, the operating distance may correspond directly to the linear distance between the outer collecting surface 15 of the collection roller 10 and the outer operating surface 35 of the spreading roller 30. In this case, the operating distance is the linear spacing between the surfaces of the two rollers 10 and 30 and is therefore variable, during the collection of the fabric F, depending on the radius R of the collection roller; in fact, the radius of the collection roller 10 increases as the fabric F is collected.

[0325] In this case, the second motor group 40 is configured to selectively move the spreading roller 30 so as to keep constant the operating distance separating it from the collecting roller 10 .

[0326] Preferably, the two lateral ends 32 and 33 of the spreading roller 30 are mounted respectively to the first lateral portion 6 and the second lateral portion 7 of the frame 2 so that the rotation axis 31 of the spreading roller 30 is substantially parallel to the longitudinal axis 5 of the frame 2 .

[0327] Preferably, the operating mechanism 3 comprises a third motor group 50, which acts on the spreading roller 30 to rotate around its rotation axis 31 and causes the fabric on the spreading roller 30 to spread and expand during transportation.

[0328] Preferably, the spreading roller 30 includes two embossing elements 36 and 37, which are spiral or helical (or double helical or double helical), extending from the center of the spreading roller 30 in opposite directions to its two lateral ends 32 and 33; due to the rotation of the spreading roller 30, the embossing elements 36 and 37 operate the gradual spreading and expansion of the fabric F in contact with the spreading roller.

[0329] An embodiment of the spreading roll 30 will now be described in more detail by way of example as shown in the figures.

[0330] Preferably, the spreading roll 30 is mounted to the frame 2 by a pair of movable arms 61 and 62. Preferably, each of the two movable arms 61 and 62 extends between a lower end hinged to the frame 2 and an upper end connected to a lateral end (32 or 33) of the spreading roll 30; the distance between the lower end and the upper end defines the length of the movable arm. Preferably, the two movable arms 61 and 62 are identical to each other.

[0331] The two movable arms 61 and 62 are configured to swing in unison, ie tilt, by rotating about a common swing axis 63 passing through the lower ends of the two arms, which are hinged to the frame 2 .

[0332] The swinging of the two arms 61 and 62 determines the rotational movement of the spreading roller 30 along a circular arc trajectory, the center of which is on the common swinging axis 63 and the radius is equal to the length of the movable arm; when moving along this trajectory, the spreading roller 30 maintains its own rotation axis 31 parallel to the corresponding rotation axis 11 of the collecting roller 10.

[0333] Preferably, the two movable arms 61 and 62 can be selectively swung clockwise and counterclockwise to reduce and increase the operating distance for separating the spreading roller 30 from the collecting roller 10 .

[0334] Preferably, the second motor group 40 includes an actuator 41, which acts on at least one of the two movable arms to determine the selective swinging of the two arms in the clockwise and counterclockwise directions and move the spreading roller 30 along the arc trajectory.

[0335] Preferably, one of the two movable arms (arm 61 in the figure) is actuated by the second motor group 40, and the other movable arm (arm 62 in the figure) is hinged to the frame 2 and is dragged to swing, so that the rotation (i.e., the swinging movement) of one of the two movable arms corresponds to the equal and corresponding rotation of the other movable arm. The two movable arms 61 and 62 always move in a synchronized manner in order to obtain an equidistant (and unstable) structure.

[0336] Preferably, the actuator 41 is an electric motor, more preferably a stepper motor, or a cylinder, such as a pneumatic or oil-operated cylinder.

[0337] Preferably, the second motor group 40 may include a mechanical transmission device 42 associated with the actuator 41, for example, arranged between the actuator 41 and a movable arm moved by the actuator.

[0338] Preferably, the mechanical transmission device 42 is a headless screw transmission device, or a gear transmission device, such as a pair of bevel gears, or an epicycloid reducer.

[0339] In a possible embodiment (not shown), the second motor group may comprise a wire guide to which the spreading roller is mounted and configured to move the spreading roller so as to selectively vary the operating distance. In this case, the variation of the distance between the two rollers occurs by a translational movement (approach or distance of the spreading roller relative to the collection roller) rather than the above-mentioned rotational or rotational-translational movement obtained by the swinging of the two movable arms.

[0340] Preferably, the operating mechanism 3 comprises at least one transfer roller 70 (or take-off roller) mounted to the frame 2 in an upstream position relative to the collection roller 10 , preferably upstream of the spreading roller 30 .

[0341] Preferably, the transfer roller 70 is configured to pull and / or stretch the fabric F (so as to allow optimal winding, ie without creases) and to push it along the coupling path towards the collection roller 10 .

[0342] Preferably, the spreading roller 70 extends longitudinally in a direction substantially parallel to the rotation axis of the collection roller 10 and is configured to rotate about its longitudinal rotation axis 71 .

[0343] Preferably, the operating mechanism 3 includes at least one pair of conveying rollers (or removal rollers) 72 and 73 .

[0344] In a possible embodiment, the operating mechanism may further include a plurality of conveying rollers arranged in series along the coupling path of the fabric.

[0345] Preferably, the operating means 3 comprise flattening or approximating means 80 of the fabric F in the form of a closed tubular fabric originating from the knitting assembly T. Preferably, these flattening or approximating means 80 are arranged substantially at the upper opening 4 of the frame 2 .

[0346] Preferably, the flattening or approaching mechanism comprises a pair of rollers 81 and 82 arranged parallel to each other. Alternatively, the flattening or approaching mechanism 80 may comprise a pair of rods arranged parallel to each other. These rollers / rods are arranged in close proximity therebetween so as to define a substantially straight transition for the fabric, thereby determining a substantial flattening of the fabric in a tubular shape along one of its diameters, the fabric having two layers close to or substantially in contact with each other.

[0347] Preferably, the operating mechanism 3 includes a cutting mechanism 90, which is arranged downstream of the flattening mechanism 80 and is suitable for longitudinally cutting the knitted fabric in a tubular shape manufactured by the weaving assembly T along a preferably vertical busbar line pair so as to thereby unfold and wind the knitted fabric in a single layer on a collecting reel, as usually occurs in circular knitting machines of the "unfolding" type.

[0348] Preferably, the operating mechanism includes a spreading mechanism 95 for the fabric F, which is directly led out from the needle holding mechanism in a single layer in an unrolled manner or obtained by the action of the cutting mechanism 90. These spreading mechanisms 95 are arranged downstream of the cutting mechanism 90, upstream of the conveying roller 70 (if more than one, upstream of the conveying rollers 72 and 73), and upstream of the spreading roller 30 and the collecting roller 10 along the connection path of the fabric F. The spreading mechanism 95 is configured to unroll the fabric F flowing out of the flattening mechanism 80 and to perform longitudinal cutting by the cutting mechanism 90.

[0349] Preferably, the spreading mechanism 95 includes at least one spreading rod 96, which is preferably mounted to the frame 2 in a fixed manner when the removal and / or collection group is used, and the structure of the spreading rod is set to determine the openings of the two lateral peripheries of the fabric F in a continuously separated manner; the fabric F flows through the spreading rod 96 along its connecting path and is spread on the spreading rod in the form of a single layer of fabric F.

[0350] The spreading rod 96 can be adjusted in its position (for example, before taking down and / or collecting groups start operating); preferably, such registration occurs by translation in a direction parallel to the longitudinal extension (or axis of rotation) of the flattening roller 80 .

[0351] Preferably, the spreading rod 96 is located longitudinally between the first lateral portion 6 and the second lateral portion 7 of the frame 2 .

[0352] Finally, the spreading rods 96 may also not be connected to the lateral portions 6 and 7 of the frame; for example, the spreading rods 96 may be mounted to a suitable supporting structure integral with the frame 2 .

[0353] Preferably, the spreading rod 96 is shaped as a circle "V" as a whole, i.e., has a curved center or a circular arc portion and two straight portions protruding from both sides of the center portion in opposite directions and terminating at the first lateral portion 6 and the second lateral portion 7, respectively. Preferably, the spreading rod 96 is shaped substantially symmetrically about the symmetry plane.

[0354] Preferably, the axis 11 of the collection roller 10 is orthogonal to the plane of symmetry of the spreading rod 96 .

[0355] Preferably, the operating mechanism 3 comprises a coupling structure 97 configured to mount the cutting mechanism 90 and / or the spreading mechanism 95 on the frame 2 .

[0356] Preferably, the operating mechanism 3 of the removal and / or collection group 1 may include other motor groups configured to move relatively moving parts. Preferably, the operating mechanism 3 includes one or more of the following motor groups:

[0357] a respective motor group 75 of the at least one transport roller 70 configured to determine the rotation of the transport roller about the respective axis of rotation 71 ;

[0358] - a respective motor group 85 of the leveling or approximation mechanism 80 , configured to determine the rotation of the leveling or approximation rollers 81 and 82 about relative longitudinal rotation axes;

[0359] a respective motor group 91 of the cutting mechanism 90 , configured to actuate the cutting mechanism and determine the longitudinal opening of the tubular fabric emerging from the braiding assembly T;

[0360] It should be noted that, in particular, Fig.16 and Fig.17 , the connection path of fabric F:

[0361] - the fabric is produced by the needle holder C of the knitting assembly T (in the embodiment shown in the figure, the fabric is in tubular shape) and falls from the inner needle holder itself and then enters the upper opening 4 of the frame 2;

[0362] - The fabric, still in tubular shape, passes through two leveling rollers 81 and 82;

[0363] - gradually cutting the fabric longitudinally by means of a cutting mechanism 90 (in particular a cutter) and in this way opening the tubular fabric;

[0364] - stretching the fabric (just opened by the cutter) by means of the stretching rod 96 so that its left and right flaps are opened;

[0365] - The single-layer (i.e. with flaps) and stretched fabric F is transferred to two transfer rollers 72 and 73, where it is taken off; specifically, the fabric passes behind the rear roller 72, then enters the gap between the rear roller 72 and the front roller 73 from below, passes the front roller 73 and continues to the spreading roller;

[0366] - the fabric F reaches the spreading roll 30 and passes over it, coming into contact with the embossing elements 36 and 37;

[0367] - The fabric F passes from the spreading roll 30 to the collecting roll, where it is wound; the winding can occur by rotating the collecting roll clockwise (in which case the fabric F passes under the collecting roll) or counterclockwise (in which case the fabric F passes over the collecting roll).

[0368] Before reaching the spreading roller 30, the fabric F can optionally pass under a fixed rod 64 connecting the two movable arms 61 and 62 and preferably coaxial with the common swing axis 63. In this case, the fabric F led out from the delivery roller 70 passes under the fixed rod 64, returns, rises above the spreading roller 30, bypasses it and continues to the collection roller 10. If it is desired to wrap more than the spreading roller, that is, to wrap at a greater angle, it can be passed under the fixed rod 64, thus deviating from the trajectory of the fabric.

[0369] The fixing rod 64 located below the spreading roller is configured to mechanically reinforce the structure supporting the spreading roller; this structure also includes two movable arms 61 and 62 .

[0370] Preferably, the position of the cutter can be set during the setting of the take-down and / or collecting group (eg by sliding on dedicated guides), for example, generally according to the dimensions of the tubular fabric produced by the knitting machine.

[0371] The passage of the fabric F over the spreading roller necessarily takes place above the latter (and not below), since the embossing (spiral) elements will correctly act on the fabric, expanding and spreading it. If the fabric passes under the spreading roller, the embossing elements will close the fabric in the opposite way, instead of opening it. Obviously, the spreading roller and its relief can be appropriately modified to operate with opposite directions of rotation, or with different paths of the fabric.

[0372] The removal and / or collection group may include / use at least one control unit configured to control the operating conditions set by the group itself and / or to control the steps of the collection method of the fabric. The control unit may be a single unit or may be formed by a plurality of different control units, depending on design choice and operational needs.

[0373] As a control unit, it is intended to be an electronic component, which may include at least one of the following: a digital processor (CPU), an analog circuit, or a combination of one or more digital processors and one or more analog circuits. The control unit can be "configured" or "programmed" to perform certain steps: this can be achieved in practice by any means that allow the control unit to be configured or programmed. For example, if the control device includes one or more CPUs and one or more memories, one or more programs can be stored in appropriate memory groups attached to the one or more CPUs; the one or more programs contain instructions that, when executed by the one or more CPUs, can program or configure the control unit to perform the operations described with respect to the control unit. Alternatively, if the control unit is or includes an analog circuit system, the circuit of the control unit can be designed to include a circuit system that is configured to process electrical signals when in use so as to perform steps related to the control unit.

[0374] Preferably, the removal and / or collection group 1 comprises at least one control unit configured to command the operation of the operating mechanism 3 .

[0375] Preferably, the control unit is connected to the contactless sensor S and is configured to:

[0376] - receiving a signal representative of the distance value from the contactless sensor S and determining a measured value of the radius R of the collection roller 10; or

[0377] The measured value of the radius R of the collection roller 10 is directly received from the contactless sensor S.

[0378] Preferably, the control unit is connected to the operating mechanism 3 for sending command signals thereto capable of modifying and controlling its operating configuration.

[0379] Preferably, the control unit is configured as follows:

[0380] - sending a command signal to the first motor group 20 for changing the angular speed of the collection roller 10 in order to keep the tangential speed of the collection roller 10 always properly regulated;

[0381] - sending a command signal to the first motor group 20 for gradually reducing the angular velocity of the collection roller 10 as the radius R of the collection roller 10 increases, so as to keep the tangential velocity of the collection roller 10 constant;

[0382] - sending a command signal to the second motor group 40 for moving the spreading roller 30 based on the measured value of the radius R of the collecting roller 10 by varying the operating distance so as to keep said optimum separation value constant during the collection of the fabric F;

[0383] - sending a command signal to the second motor group 40 for gradually increasing the operating distance as the radius R of the collecting roller 10 increases, so as to keep said optimum separation value constant during the collection of the fabric F.

[0384] - Sending a command signal to the third motor group 50 to rotate the spreading roller 30 at a determined speed, so that the fabric F on the spreading roller 30 is correctly spread and expanded during transportation.

[0385] Preferably, the control unit of the taking-down and / or collecting group 1 can be shared with the knitting machine 100, for example, it can be located in the base B or in the knitting assembly T and operate the control of the entire knitting machine.

[0386] Preferably, the taking-off and / or collecting group 1 of the fabric F being manufactured is arranged downstream of the weaving assembly T with respect to the supply direction of the fabric being manufactured.

[0387] Preferably, the removal and / or collection group 1 is configured to rotate integrally with the needle holding mechanism C during the manufacture of the fabric F, or to rotate relative to the needle holding mechanism C in a coordinated manner.

[0388] Preferably, the circular knitting machine 100 may be of a single-bed type (with only one needle-carrying cylinder) or a double-bed type (with a needle-carrying cylinder and a needle-carrying plate).

[0389] Preferably, the circular knitting machine 100 can be of the type with a rotating needle holding mechanism (with a non-rotating needle control mechanism and a take-off and / or collection group that rotates with the needle holding mechanism during fabric production) or of the type with a fixed needle holding mechanism (with a rotating needle holding mechanism and a take-off and / or collection group that is fixed during fabric production). The embodiment shown in the figures is a circular knitting machine with a rotating needle holding mechanism and a take-off and / or collection group that rotates with it.

[0390] Preferably, the removal and / or collection group 1 is suspended below the knitting assembly T. Preferably, the removal and / or collection group 1 is suspended from and supported by the needle holding mechanism C. In this case, preferably, the adjustment is performed by rotating the removal and / or collection group by a predetermined angle relative to the knitting assembly, while, preferably, the group remains suspended.

[0391] In a different embodiment (not shown), the removal and / or collection group can be laid on the ground or base and restrained to the needle holding mechanism.

[0392] Preferably, if the needle holding mechanism C is a rotary type, the removal and / or collection group 1 is dragged and rotated by the rotation of the needle holding mechanism C during the manufacture of the fabric F, and rotates integrally with the needle holding mechanism, i.e., there is no relative rotational movement relative to the needle holding mechanism. Therefore, the motor for moving (i.e., rotating) the needle holding mechanism C and the removal and / or collection group 1 can be one, thereby saving space, cost and energy.

[0393] In a possible embodiment (not shown), if the needle holding mechanism is stationary, the removal and / or collecting group is stationary, ie does not have any relative rotational movement with respect to the needle holding mechanism.

[0394] In a preferred embodiment, as shown, the circular knitting machine 100 is of the “unfolding” type, i.e. configured to produce fabric F and to collect the fabric in an unfolded manner, i.e. as a single layer and continuously, by winding it on a collecting reel 10 of a take-off and / or collecting group 1 .

[0395] The single-layer fabric F guided out from the needle holding mechanism and collected by the removal and / or collection group can be obtained in the following manner:

[0396] - if the braided assembly T continuously manufactures a tubular fabric, it is obtained by cutting and stretching or "unrolling" the tubular fabric; or

[0397] - Directly "in an unrolled manner", ie as a continuous single-layer fabric F of a determined width.

[0398] In both cases, the take-off and / or collection group 1 collects a single layer of fabric F by winding it on a collection reel 10 instead of a cylindrically laid out tube.

[0399] The single-layer fabric F has a continuous strip shape of a specific width and is obtained by:

[0400] - obtained by unfolding the tubular article, by successive cuts carried out parallel to the longitudinal development of the tubular fabric produced; or

[0401] - Obtained directly from a woven component that has manufactured it as an "unfolded", single-layer and continuous fabric.

[0402] As in Fig. 20 As shown by way of example in FIG. 1 , the circular knitting machine can include other components such as:

[0403] - Parts of the braiding assembly, such as covers, cams, thread guides, etc.;

[0404] - A P cone seat structure placed above the braided assembly T;

[0405] A plurality of closing cages G closing the operating space occupied by the removal and / or collection of the groups 1 (the groups thus remain closed inside the cages).

[0406] The closing cage G is mounted (eg pivoted) to the base B in such a way that it can move between at least a closed configuration, in which it prevents access to the operating space, and an open configuration, in which it allows access to the operating space.

[0407] The cage G is suitable for allowing safe operation of the knitting machine 100: in fact, the taking-down and / or collecting group 1 operates by rotating around the operating space, so it is necessary to make this space inaccessible during the operation of the knitting machine to avoid accidental contact with the moving mechanism. On the contrary, the cage must also allow access to the interior of the operating space in order to carry out configuration and maintenance operations on the knitting machine and to load / unload the collecting rolls of the fabric, so it can be opened individually and selectively manually or automatically.

[0408] The method for collecting a fabric produced by a circular weft knitting machine according to the present invention comprises the following steps:

[0409] - Arrange and operate the circular knitting machine 100;

[0410] - Arrange and operate the removal and / or collection group 1;

[0411] - the measured value of the radius R of the collecting roller 10 is processed as a function of the distance value measured by the contactless sensor S, wherein the radius R corresponds to the radial distance between the outer collecting surface 15 corresponding to the outermost layer of the fabric F wound on the collecting roller 10 and the axis of rotation 11;

[0412] - Automatically modifying the configuration of the operating mechanism 3 on the basis of the measured value of the radius R of the collection roller 10 , which is processed according to the distance value measured by the contactless sensor S.

[0413] Preferably, the step of automatic modification comprises a step of synchronizing the operating mechanism 3 at determined operating parameters to ensure the correct tensioning and the correct spreading of the fabric F.

[0414] Preferably, the method comprises the step of varying the angular speed of the collecting roller 10 so as to always keep the tangential speed of the collecting roller 10 properly regulated, ie under control, during the collecting of the fabric F.

[0415] Preferably, the step of keeping the tangential speed always properly adjusted comprises:

[0416] - maintaining the tangential speed at a preferably constant value throughout the collecting fabric F;

[0417] - maintaining the tangential speed at a preferably constant value from time to time during discrete steps of collecting the fabric F;

[0418] - Maintaining the tangential speed at a value that depends on the rotation speed of the needle-holding mechanism C that produces the fabric;

[0419] - Setting the tangential speed so that it corresponds to the linear speed of advance of the fabric F in the take-off and / or collecting group 1 and the linear amount of fabric F wound on the collecting reel 10 per unit time.

[0420] Preferably, the method comprises the step of gradually reducing the angular speed of the collection roller 10 as the radius R increases so as to keep the tangential speed of the collection roller constant.

[0421] Preferably, the method provides that the step of processing the measured value of the radius R of the collection roller 10 according to the distance value is performed in real time, ie instantly, so that the measured value of the radius R of the collection roller 10 is continuously monitored.

[0422] Preferably, the method comprises the following steps:

[0423] - in the operating mechanism 3 there is arranged at least one spreading roller 30, mounted to the frame 2 in an upstream position relative to the collecting roller 10 and configured to interact with the fabric F advancing towards the collecting roller in order to spread it before being wound on the collecting roller 10;

[0424] - moving the spreading roller 30 based on the measured value of the radius R of the collecting roller 10, which is processed according to the distance value measured by the non-contact sensor S, by changing the operating distance separating the spreading roller 30 from the collecting roller 10 so as to keep the optimal separation value constant in an instant, wherein the spreading roller 30 is kept at the ideal distance relative to the collecting roller 10 for performing optimal spreading of the fabric F from the spreading roller to the collecting roller.

[0425] Preferably, the method comprises the step of rotating the spreading roller 30 around its own rotation axis 31 so as to spread and expand the fabric F on the spreading roller during transportation.

[0426] Preferably, the method comprises a step of monitoring the operation of the collection of fabric F, said step of monitoring comprising the following steps:

[0427] - detecting an abnormal variation in the measured value of the radius R of the collection roller 10, which may be an indicator of an abnormality;

[0428] - finally, generating a signal representative of said anomaly;

[0429] Preferably, "exceptions" are intended to be, for example:

[0430] - oscillatory values ​​of the measured values ​​of the radius R, i.e., first increasing and then decreasing (i.e., not strictly increasing over time);

[0431] - Null value for the measurement of radius R;

[0432] - The variation or ovality of the fabric roll (ie the deviation of the diameter from a cylindrical shape).

[0433] Oscillating values ​​of the measured value of the radius R may indicate uneven collection of the fabric F in a certain portion of the collecting roller 10 or the formation of wrinkles or piles of the fabric in a longitudinal portion of the collecting roller.

[0434] Preferably, the monitoring step comprises a step of stopping the collection of fabric F, preferably the entire knitting machine 100, when a signal representative of an anomaly is generated.

[0435] Preferably, the method comprises the following steps:

[0436] - comparing the measured value of the radius R of the collection roller 10 with the maximum radius value;

[0437] After reaching the maximum radius value, the production by the circular knitting machine 100 is stopped.

[0438] The maximum radius value corresponds to the condition of a full collecting reel 10, which must be unloaded from the removal and / or collecting group 1 and replaced by an empty collecting reel (it can also be the same reel from which the reel on which the fabric was previously wound was removed).

[0439] The collecting roller 10 is considered “full” when it has wound a maximum amount of wearable fabric F, ie when the flow rate value of the collecting roller 10 corresponds to the maximum radius of the outer collecting surface 15 or the maximum weight of the collecting roller 10 .

[0440] Preferably, the step of comparing the measured value of the radius R of the collecting roller 10 with the maximum radius value is performed continuously throughout the collection of the fabric F.

[0441] Basically, the method of collecting the fabric corresponds to a program for controlling the operations of the taking-down and / or collecting group 1 .

[0442] The present invention has important advantages.

[0443] Firstly, the Applicant has verified that the present invention allows solving the problems and overcoming the typical limitations of the known solutions mentioned above, thereby achieving the intended purpose. In particular, the taking-off and / or collecting group 1 is characterized by an innovative structure and operation, which provides a specific operating mode of the collecting roller by means of the first motor group, the presence of a contactless sensor and the regulation of the position of the spreading roller. This advantageously allows:

[0444] - Better control and improved management of the collection of manufactured fabrics;

[0445] - prevent the formation of dislocations and / or wrinkles in the collected fabric and prevent the lateral peripheral edges of the fabric from rolling up;

[0446] -Effectively unwind and spread the fabric at all times, thus achieving an even and flat winding of the fabric on the collection roll;

[0447] - achieving improved performances relative to known solutions, for example in terms of productivity and / or quality and uniformity of the collected knitted fabric;

[0448] - Dynamic control (even real-time control) of the mechanisms involved in the processing of the fabric to its collection;

[0449] - Adapting the taking-down and / or collecting groups to different knitwear needs and to different types and sizes of fabrics;

[0450] -Easy to maintain the operating mechanism and replace its own parts;

[0451] - Provide a system with high operational reliability and less prone to malfunctions and failures.

[0452] It should be taken into account that the taking-down and / or collecting group of the present invention also allows to obtain another very important advantage, expressed as the possibility of increasing the maximum amount of fabric that can be wound on the collecting roller. In fact, since the collecting roller is directly motorized axially by the first motor group, it is not necessary to prepare a lower motorized roller, which, in the known technology, makes the collecting roller rotate. This allows to completely free up the space under the collecting roller, which can therefore be larger (compared to the known technology, with the same frame dimensions) without interfering with the other elements of the taking-down and / or collecting group. A larger drum device means more collected fabric: in fact, it must be taken into account that the volume of the drum (fabric roller) increases with the square of the radius, so that allowing to increase the radius of the collecting roller is equivalent to being able to wind more fabric.

[0453] Another advantage of the solution according to the invention is that, thanks to the presence of the contactless sensor and motor group, the length of fabric wound on the collecting roller can be accurately measured, which allows to always know exactly the radius traversed by the collecting roller when winding the fabric, as well as the (angular and tangential) speed of the collecting roller in all operating conditions.

[0454] The solution according to the invention allows to obtain another advantage, expressed as the absence of over-tension introduced in the fabric reel wound around the collecting roller. In fact, the operation of the collecting roller is of the axial (and not tangential) type and there is no lower motorized roller, typical of known solutions, which, as shown above, introduces over-tension in the fabric and can drag in an undesired way more of the fabric layer already wound on the collecting roller. Even if the radius of the collecting roller increases and the weight increases, the solution according to the invention always operates with a high and constant performance and there are no friction, tension or drag problems with the fabric on the collecting roller, even at greater weights.

[0455] The solution according to the invention ensures that the fabric wound on the collection reel has precise and uniform properties in every section, from the beginning to the end of collection; for example, the weight per square meter of the collected fabric remains constant from the beginning to the end of the roll and over the entire width.

Claims

1. A group (1) for taking off and / or collecting fabric (F) produced by a circular weft knitting machine (100), the circular knitting machine include: - a knitting assembly (T) provided with at least one needle holding mechanism (C) in the form of a needle holding cylinder or a needle holding plate rotating about a central axis, provided with a plurality of needles movably mounted to said at least one needle holding mechanism (C), and provided with a command mechanism suitable for selectively actuating said plurality of needles and suitable for allowing the manufacture of a fabric (F); - a base (B) constituting a supporting structure of the knitting machine and configured to support the knitting assembly (T), the base (B) defining a housing space below the knitting assembly (T); The removal and / or collection group (1) comprises: - a frame (2) configured to be mounted in a rotatable manner to the circular knitting machine (100) in the housing space; - an operating mechanism (3) operatively associated with the frame (2) and actuated by the frame (2) The circular knitting machine (100) is supported and comprises at least one collecting roller (10) arranged along the rotation axis (11) and extending longitudinally between two ends (12, 13), the operating mechanism (3) being configured to at least unfold and spread the fabric (F) manufactured by the circular knitting machine (100), or also configured to finally draw the fabric (F) out of the needle holding mechanism (C) so as to be wound in a single layer and continuously on the collecting roller (10); The operating mechanism (3) comprises at least one first motor group (20), which is associated with the collecting roller (10) and acts on the rotation axis (11) of the collecting roller, so that the collecting roller (10) is axially electrified, that is, the first motor group (20) causes it to rotate around the rotation axis (11).

2. The removal and / or collection group (1) according to claim 1, in, The first motor group (20) acts directly on the rotation axis (11) of the collection roller (10), and / or wherein: - the first motor group (20) is configured to rotate the collection roller (10) at a variable and selectable angular speed, and / or - the first motor group (20) is configured to rotate the collection roller (10) at a variable and selectable angular speed, regardless of the rotation speed of the needle holding mechanism, and / or - the first motor group (20) is configured to rotate the collecting roller (10) at a variable and selectable angular speed in a manner coordinated with the rotation of the needle holding mechanism (C), preferably in a manner coordinated with, for example proportional to, the rotation speed of the needle holding mechanism (C), and / or The first motor group (20) is configured to rotate the collecting roller (10) at a variable and selectable angular speed, also under the condition that the rotation speed of the needle holding mechanism (C) is constant.

3. A removal and / or collection group (1) according to claim 1 or 2, in, The operating mechanism (3) of the removal and / or collection group does not have, i.e. does not include, a motorized roller in contact with the collection roller (10) and / or with the fabric (F) wound on the collection roller (10), and / or wherein the collection roller (10) is suspended in the frame (2) so as to be suspended in the removal and / or collection group (1) and so that the entire surface of the fabric (F) wound on the collection roller (10) does not come into contact with the operating mechanism (3) or other elements of the removal and / or collection group, and / or wherein the collection roller (10) is wound on The collecting roller (10) is mounted on the frame (2) in such a way that the entire surface of the fabric (F) is free and does not rest against any element, and / or wherein the collecting roller (10) is rotatably mounted to the frame (2) at its two ends (12, 13) so as to be supported exclusively by said two ends, and / or wherein the first motor group (20) is fixed at one of the two ends (12; 13) of the collecting roller (10) and from this position it rotates the collecting roller (10) directly on the rotation axis (11).

4. The removal and / or collection group (1) according to any one of the preceding claims, comprising at least one sensor (S) of the non-contact type (non-contact type), which is associated with the frame (2) or the operating mechanism (3) and is configured to measure the distance value between the sensor (S) itself and the surface of the collection roller (10), determine the amount of fabric (F) wound in a single layer on the surface of the collection roller, and / or in, The removal and / or collection group (1) is configured to process the measured value of the radius (R) of the collection roller (10) according to the distance value measured by the non-contact sensor (S), and / or wherein, The non-contact sensor (S) is a sensor selected from the following types: a laser sensor, a time-of-flight sensor, an infrared sensor, an ultrasonic sensor, an optical sensor, a sensor with a camera, an inductive sensor, a capacitive sensor, a magnetic sensor, and / or wherein the removal and / or collection group (1) is configured to modify the configuration of the operating mechanism (3) based on the measured value of the radius (R) of the collection roller (10), the measured value being processed according to the distance value measured by the non-contact sensor (S), and / or wherein the non-contact sensor (S) is oriented toward the rotation axis (11) of the collection roller (10), i.e., has a detection direction that intersects the rotation axis (11) of the collection roller (10).

5. A removal and / or collection group (1) according to any one of the preceding claims, in, The collecting roller (10): - having an outer collecting surface (15) corresponding to the outermost layer of said fabric (F) wound onto said collecting reel (10); - having, at the moment during the collection of the fabric (F), a radius (R) of the collection roller (10) corresponding to the radial distance between the outer collection surface (15) and the axis of rotation (11); - during the collection of said fabric (F), instantaneously having an angular velocity of rotation about said axis of rotation (11); - during the collection of said fabric (F), instantaneously has a tangential speed, ie the linear speed of said reel at said outer collecting surface (15), and / or wherein the first motor group (20) is configured to change the angular velocity of the collecting roller (10) so as to always keep the tangential velocity of the collecting roller (10) properly regulated, i.e. under control, during the collection of the fabric (F), and / or wherein, The first motor group (20) is configured to gradually reduce the angular velocity of the collection roller (10) as the radius (R) of the collection roller (10) increases, so as to keep the tangential velocity of the collection roller (10) constant.

6. A removal and / or collection group (1) according to any one of the preceding claims, in, The collecting roller (10) comprises: - a rod (16) extending between two ends and around which the fabric (F) collected by the taking-down and / or collecting group is wound, forming a roll of fabric around the rod (16); - two supports (17, 18) placed at the two ends of the rod and configured to support the rod (16) in rotation, and wherein the two supports (17, 18) are preferably removably associable to the frame (2) so as to allow mounting of the collection roller (10) to the frame (2) and removal of the collection roller (10) from the frame (2), And / or wherein the frame (2) comprises two receiving seats (8, 9) at its first lateral portion (6) and at its second lateral portion (7), the two receiving seats being configured to receive the collection roller (10) at its two ends (12, 13), and / or wherein each receiving seat (8, 9) is configured to receive a corresponding support (17, 18) of the collection roller (10), and / or wherein each receiving seat (8, 9) comprises a receiving channel, the receiving channel being configured for loading and unloading the collection roller (10), and / or wherein loading of the collection roller (10) occurs by inserting the two supports (17, 18) into the two receiving channels, and unloading of the collection roller (10) occurs by withdrawing the two supports (17, 18) from the two receiving channels.

7. A removal and / or collection group (1) according to any one of the preceding claims, in, The first motor group (20) comprises: - a first electric motor (21), preferably a stepper motor; - a mechanical transmission (22) mounted downstream of the first electric motor (21) and acting directly on the rod (16) of the collection roller (10) in order to selectively rotate it, and / or wherein the mechanical transmission (22) comprises a headless screw transmission, or a gear transmission, such as a pair of bevel gears, or an epicycloidal gearbox, and / or wherein the mechanical transmission (22) ends with a shaft carrying a motor mechanism (23), the motor mechanism being configured to transmit a controlled rotational movement directly to the rod (16) of the collection roller (10), and / or wherein the rod (16) of the collection roller (10) comprises a guide mechanism (19) which can directly engage with the motor mechanism (23) for receiving the controlled rotational movement therefrom and causing the rod (16) of the collection roller (10) to rotate, And / or wherein the guiding mechanism (19): - when the collecting roller (10) is mounted on the frame (2), i.e. when the supports (17, 18) of the collecting roller (10) are inserted into the receiving seats (8, 9) of the frame (2), they engage on the motor mechanism (23); - when the collecting roller (10) is removed from the frame (2), that is, when the supporting members (17, 18) of the collecting roller (10) are withdrawn from the receiving seats (8, 9) of the frame (2), they are disengaged from the motor mechanism (23), And / or wherein the first motor group (20) comprises: - said first electric motor (21) is of stepper type and provided with an output shaft; - the mechanical transmission device (22), comprising: - Headless screw drive / helical belt gear, comprising: - a headless screw connected to the output shaft of the first motor (21) and caused to rotate by the output shaft, and - a helical belt gear meshing with the headless screw and mounted on the shaft carrying the motor mechanism (23).

8. A removal and / or collection group (1) according to any one of the preceding claims, in, The operating mechanism (3) comprises at least one spreading roller (30) or tensioning roller, which is mounted to the frame (2) in an upstream position relative to the collecting roller (10), the spreading roller (30) being configured to interact with the fabric (F) advancing towards the collecting roller (10) so as to spread the fabric before being wound onto the collecting roller, wherein the spreading roller (30) extends longitudinally between two lateral ends (32, 33) in a direction substantially parallel to the rotation axis (11) of the collecting roller (10) and is configured to rotate about its rotation axis (31), and / or wherein the spreading roller (30) is movable, for example rotatable or The invention relates to a device for distributing the spreading roller (30) to the collecting roller (10), wherein the spreading roller (30) is mounted in a translationally or rotationally translationally movable manner to the frame (2) and is configured to be able to change the operating distance separating it from the collecting roller (10), wherein the operating distance corresponds to the linear distance between the rotation axis (31) of the spreading roller (30) and the corresponding rotation axis (11) of the collecting roller (10), and / or wherein the operating mechanism (3) comprises a second motor group (40) acting on the spreading roller (30) for selectively moving it so as to increase or decrease the operating distance separating it from the collecting roller (10), preferably keeping the spreading roller (30) parallel to the collecting roller (10) by a rotational or translational or rotational-translational movement.

9. A removal and / or collection group (1) according to any one of the preceding claims, in, The spreading roller (30): - has an outer operating surface (35) which contacts the fabric (F) during its transport towards the collecting roller (10) and acts on the fabric itself for expanding and spreading it; - having a radius (R) of the spreading roller (30) which has a constant value and corresponds to the radial distance between the outer operating surface (35) and the axis of rotation (31) of the spreading roller (30), and wherein the spreading roller (30) is configured to move during the collection by varying the operating distance separating it from the collecting roller (10) so as to instantaneously maintain a constant optimal separation value, the optimal separation value being equal to the distance between the outer operating surface (35) of the spreading roller (30) and the outer operating surface (15) of the collecting roller (10), wherein the optimal separation value is an operating value corresponding to an ideal distance at which the spreading roller (30) is maintained relative to the collecting roller (10) for performing optimal spreading of the fabric (F) from the spreading roller to the collecting roller, and / or wherein the second motor group (40) is configured to move the spreading roller (30) based on the measured value of the radius (R) of the collecting roller (10) by changing the operating distance for separating the spreading roller (30) from the collecting roller (10) in a manner that instantaneously keeps the optimal separation value constant, the measured value of the radius (R) of the collecting roller (10) being processed according to the distance measured by the non-contact sensor (S), and / or wherein the second motor group (40) is configured to gradually increase the operating distance as the radius (R) of the collecting roller (10) increases, thereby keeping the optimal separation value constant during the collection of the fabric (F).

10. The removal and / or collection group (1) according to any one of the preceding claims, comprising at least one control unit configured to command the operation of the operating mechanism (3), in, The control unit is connected to the contactless sensor (S) and is configured to: - receiving a signal from said contactless sensor (S), said signal being representative of said distance value and determining said measured value of said radius (R) of said collecting roller (10); or - receiving directly from said contactless sensor (S) said measured value of said radius (R) of said collection roller (10), and / or wherein the control unit is connected to the operating mechanism (3) for sending command signals thereto capable of modifying and controlling its operating configuration, And / or wherein the control unit is configured to: - sending a command signal to the first motor group (20) for changing the angular speed of the collection roller (10) so as to keep the tangential speed of the collection roller (10) always properly regulated; - sending a command signal to the first motor group (20) for gradually reducing the angular velocity of the collection roller (10) as the radius (R) of the collection roller (10) increases, so as to keep the tangential velocity of the collection roller (10) constant; - sending a command signal to the second motor group (40) for moving the spreading roller (30) by varying the operating distance in such a way as to keep the optimum separation value constant during the collection of the fabric (F) and based on the measured value of the radius (R) of the collection roller (10); - sending a command signal to the second motor group (40) for gradually increasing the operating distance as the radius (R) of the collecting roller (10) increases, so as to keep the optimum separation value constant during the collection of the fabric (F).

11. A circular weft knitting machine (100), include: - a knitting assembly (T) provided with at least one needle-holding mechanism (C) in the form of a needle-holding cylinder or a needle-holding plate rotating about a central axis, a plurality of needles movably mounted to said at least one needle-holding mechanism, and a command mechanism suitable for selectively actuating said plurality of needles and suitable for allowing the manufacture of a fabric; - a base (B) constituting a supporting structure of the knitting machine and configured to support the knitting assembly (T), the base (B) defining a housing space below the knitting assembly (T); - a removal and / or collection group (1) according to one or more of the preceding claims; The circular knitting machine (100) is preferably of the "unfolding" type, i.e. configured to manufacture a fabric (F) and to collect the fabric in an unfolded manner, i.e. as a single layer and continuously, by winding the fabric on the collecting reel (10) of the taking-off and / or collecting group (1), the single-layer fabric (F) being preferably obtained in the following manner: - if said knitting assembly (T) continuously manufactures a tubular fabric, it is obtained by cutting and stretching or "unrolling" the tubular fabric; or - directly "in an unrolled manner", i.e. as a continuous single-layer fabric of a defined width; In both cases, the take-off and / or collection group (1) collects a single layer of fabric instead of a cylindrically laid out tube by winding it on the collection reel (10).

12. A method for collecting a fabric (F) produced by a circular weft knitting machine (100), the method comprising: The following steps are involved: - Arrange and operate a circular weft knitting machine (100), said circular weft knitting machine comprising at least: - a knitting assembly (T) provided with at least one needle-holding mechanism (C) in the form of a needle-holding cylinder or a needle-holding plate rotating about a central axis, a plurality of needles movably mounted to said at least one needle-holding mechanism, and a command mechanism suitable for selectively actuating said plurality of needles and suitable for allowing the manufacture of a fabric; - a base (B) constituting the supporting structure of the knitting machine and configured to support the knitting assembly (T), the base defining a housing space below the knitting assembly; - Arrange and operate a removal and / or collection group (1), said removal and / or collection group comprising: - a frame (2) rotatably mounted to the circular knitting machine (100) in the housing space; - an operating mechanism (3) operatively associated to and supported by said frame (2), and comprising at least one collecting roller (10) arranged along the rotation axis (11) and extending longitudinally between two ends (12, 13), the operating mechanism (3) being configured to at least unfold and spread the fabric (F) manufactured by the circular knitting machine (100), or also configured to finally extract it from the needle holding mechanism (C) by winding it in a single layer and continuously on the collecting roller (10); - at least one non-contact sensor (S) associated to the frame (2) or to the operating mechanism (3) and configured to measure the distance value between the sensor itself and the surface of the collecting roller (10), determining the amount of fabric (F) wound in a single layer on said surface; - processing the measured value of the radius (R) of the collecting roller (10) according to the distance value measured by the contactless sensor (S), wherein the radius (R) corresponds to the radial distance between an outer collecting surface (15) corresponding to the outermost layer of the fabric (F) wound onto the collecting roller (10) and the axis of rotation (11); - Automatically modifying the configuration of the operating mechanism (3) based on the measured value of the radius (R) of the collection roller (10), the measured value of the radius (R) of the collection roller (10) being processed according to the distance value measured by the contactless sensor (S).

13. The method for collecting fabric (F) according to claim 12, in, The automatic modification step comprises a step of synchronizing the operating mechanism (3) based on determined operating parameters required to ensure correct tensioning and correct spreading of the fabric (F), and / or wherein the method comprises a step of varying the angular velocity of the collection roller (10) so as to keep the tangential velocity of the collection roller (10) always properly regulated, i.e. under control, during the collection of the fabric (F), and / or wherein the method comprises a step of gradually reducing the angular velocity of the collection roller (10) as the radius of the collection roller (10) increases, so as to keep the tangential velocity of the collection roller (10) constant, and / or wherein the method comprises a step of processing the measured value of the radius (R) of the collection roller (10) in real time, i.e. instantly, according to the distance value, thereby monitoring the measured value of the radius (R) of the collection roller (10) in a continuous manner.

14. A method for collecting a fabric (F) according to claim 12 or 13, The following steps are involved: - at least one spreading roller (30) or tensioning roller is arranged in the operating mechanism (3), mounted to the frame (2) in an upstream position relative to the collecting roller (10) and configured to interact with the fabric (F) advancing towards the collecting roller in order to spread the fabric before being wound onto the collecting roller (10); - moving the spreading roller (30) based on the measured value of the radius (R) of the collecting roller (10), the measured value of the radius (R) of the collecting roller (10) being processed according to the distance value measured by the non-contact sensor (S), by changing the operating distance separating the spreading roller (30) from the collecting roller (10) in such a way as to instantaneously keep the optimal separation value constant, wherein the optimal separation value is an operating value corresponding to an ideal distance, and the spreading roller (30) is kept at the ideal distance relative to the collecting roller (10) for performing optimal spreading of the fabric (F) from the spreading roller (30) to the collecting roller (10).

15. The method for collecting fabric (F) according to claim 12, 13 or 14, comprising a step of monitoring the operation of collecting the fabric (F), said step of monitoring The following steps are involved: - detecting an abnormal variation of the measured value of the radius (R) of the collection roller (10), which abnormal variation may be an indicator of an abnormality, such as: - an oscillating value of said measured value of said radius (R), i.e. first increasing and then decreasing; - a null value for said measured value of said radius (R); - the variation or ovality of the roll of fabric (F), ie the deviation of the diameter from the cylindrical shape, - finally, generating a signal representative of said anomaly; and / or where The method comprises the following steps: - comparing said measured value of said radius (R) of said collecting roller (10) with a maximum radius value; - After reaching said maximum radius value, stopping the production performed by said circular knitting machine (100).

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