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

Abstract

A set (1) for removing and / or collecting a fabric (F) produced by a circular weft knitting machine (100) comprising a knitting assembly (T) and a base (B); the removal and / or collection group 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 unfold and spread a fabric (F) produced by the circular knitting machine and continuously wind it on the collection roller (10); the operating mechanism comprises: a plurality of electric shafts (10; 30); 60; 70; 80) each configured to selectively rotate about a respective axis of rotation; a plurality of motor groups (20; 40); 50; 75; 85); each electric shaft is individually associated to a respective motor group and is independently driven by the respective 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 textiles, 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 different numbers of drop points, such as 1, 2, 4, 6, 8 or more knitting drop points.

[0007] The invention preferably, but not exclusively, belongs to the technical field of circular weft knitting machines of the type indicated in the industry by the term "unrolling". 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 comprises a take-off and collecting group capable of collecting the fabric manufactured by the machine in a single layer, usually by winding it on a reel. 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 stretching (or "unrolling") of a tubular fabric (if - in most cases - the circular knitting machine manufactures tubular fabric continuously), or alternatively, it can be manufactured directly "in unrolling mode", 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 developed 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 manufactured tubular fabric, or can be derived from the machine in a single layer as an "unrolled" fabric that is already a single layer: the term "unrolling" is therefore used to identify this type of machine. Sometimes, a knitting machine of the "unrolling" type can include only a collecting unit, that is, without a take-off function: for example, in such a machine, the take-off is carried out directly on the needle bed; in this case, the fabric manufactured 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 "unrolling" type can be defined as a circular weft knitting machine in which the manufactured fabric is collected "in an unrolled 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, when referring to an "unfolded" knitting machine in the description and claims of the present patent application, a knitting machine having the above-mentioned "unfolded" machine features is specifically indicated, which unambiguously identify and define this type in the reference field and are clearly understandable 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 according to the object of the present invention is of the "unfolded" type should be understood as a precise technical feature, which constitutes a limitation and should not be interpreted as just one example of a large number of existing types of knitting machines, into which the further technical features described in the claims will be incorporated.

[0010] The invention also falls within the technical field of conventional circular knitting machines, i.e. knitting machines in which the needle-carrying mechanism produces a tubular fabric which is collected by a take-off and collection group which is still in tubular form (i.e. not unfolded). In this case, the take-off and collection group collects the fabric "in double layer", i.e. in a "flat" tubular form (but not unfolded in a single layer); the tubular fabric produced by the machine is usually collected by winding it on a collection reel.

[0011] Circular knitting machines of both the conventional and "unfolding" type are 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-up and collection groups. The base also serves to securely fix the machine in its operating position.

[0012] This type of machine is typically provided with a needle holding mechanism, ie, a needle holding cylinder or plate, having a diameter between 30 and 40 inches, but there are also examples having a smaller diameter (eg, 24 inches), or greater than 40 inches.

[0013] 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 includes a cutting mechanism for longitudinally cutting the tubular fabric emerging from the needle holding mechanism, so that it is "unfolded" and can therefore be wound in a single layer on a collection reel.

[0014] Conventional knitting machines (non-expanding type) are equipped with a needle holding mechanism, i.e., a needle holding cylinder or needle holding plate, which can have a diameter of various specifications; so-called "large diameter" machines can have a needle holding mechanism with a diameter of between 30 and 40 inches, but can also be smaller (for example 24 inches), or greater than 40 inches.

[0015] The take-off and collection group usually also includes other mechanisms, such as flattening devices for the tubular fabric, spreading devices for unwinding the fabric after cutting, tensioning rollers for controlling the path of the fabric towards the collection roller, as well as actuators and mechanical synchronization devices for the movement of the various mechanisms.

[0016] 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 spread and stretched 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 toward both ends.

[0017] The take-off and collection group is usually mounted on the machine, below the needle-carrying mechanism (in a collection space specially designed for this type of group), and is able to rotate integrally with the needle-carrying mechanism to follow its fabric production process and collect the fabric on a reel.

[0018] The known type of removal and collection group is usually connected to the needle holding mechanism of the knitting assembly by a connection device (directly or indirectly), and the connection device is configured to transmit the movement of the needle holding mechanism to the removal and 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 or bolts.

[0019] 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 supporting means (comprising, for example, bearings) that support its weight and at the same time allow it to rotate; the lower supporting means can be driven (for example, by a motor) to determine the rotation of the entire frame.

[0020] 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.

[0021] In solutions of known type, the take-off and collecting group generally comprises motion-generating and transmission means, whose function is to drive the various mechanisms responsible for the handling of the fabric, in order to control the advancement of the fabric on its path from the needle-carrying cylinder to the collecting reel.

[0022] Known take-off and collection groups generally comprise an electric motor positioned at a determined position and a series of mechanical transmissions for rotating the various fabric processing rollers (collection roller, spreading roller, tensioning roller, etc.).

[0023] These mechanical transmissions typically include belts, chains, pulleys, and epicycloidal gearboxes. Summary of the invention

[0024] When collecting fabrics produced by circular weft knitting machines, in particular (but not exclusively) of the "unfolded" type, ie in a single layer, the Applicant has noticed certain limitations and drawbacks and believes that the known solutions could be improved in several respects.

[0025] First, in known take-off and collection groups, motion generation and transmission devices do not allow effective control of the various fabric processing rollers. Specifically, the control of the various rollers is usually imprecise and poorly executed, and therefore does not allow accurate regulation of fabric collection.

[0026] Furthermore, in the known take-off and collection groups, the various reels are hardly synchronizable due to the design of the motion generation and transmission, ie the motor and the mechanical transmission.

[0027] Thus, the known take-off and collection groups are not always able to wind the fabric efficiently and evenly on the collection roll: in particular, the known elements of the take-off and collection groups can generate undesirable folds, wrinkles and / or overlaps on the fabric wound on the collection roll, which can damage the fabric, affect its quality, complicate the subsequent finishing or packaging processes performed on the fabric, or even require further conditioning operations on the fabric on the collection roll. For example, the performance limitations of the known take-off and collection groups can determine a reduced effectiveness in spreading the outer edges of the fabric, which tend to "curl" or wrap around themselves in the longitudinal direction, forming on each side what is known in technical terms as a "cigarette".

[0028] Another disadvantage of known take-off and collection groups is represented by the fact that these groups usually require the insertion of freewheels or brakes at the ends of the chains transmitting the movement to the various rollers, in order to prevent the rollers from rotating backwards in an undesired manner. This is because, for example in the absence of electrical power supply, the rollers may determine a torque opposite to the normal direction of rotation (for example due to inertia or tension in the fabric), and this may cause mismatches between the various rollers and / or errors in the collection of the fabric.

[0029] Another drawback of the known take-off and collecting groups is represented by 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 originating from the knitting assembly (for example the position, angular speed, mutual positioning of the various rollers), and it is generally impossible 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, can introduce defects into the collected fabric, and generally makes it difficult to coordinate the operations performed by the take-off and collecting group with those performed by the other parts of the knitting machine, in particular by the knitting assembly that manufactures the fabric.

[0030] Furthermore, in the known removal and collection groups, the motion generation and transmission devices are usually power-intensive, subject to high wear and difficult maintenance operations.

[0031] Likewise, the known removal and collection groups are characterized by a complex construction and high costs for implementation and maintenance.

[0032] In this case, in its various aspects and / or embodiments, the basic object of the present invention is to provide a removal and / or collection group for a circular knitting machine (specifically, but not limited to the "unfolding" type), a circular weft knitting machine, and a method for collecting fabrics produced by a circular weft knitting machine, which may be able to solve one or more of the above-mentioned shortcomings.

[0033] Another object of the present invention is to provide a take-off and / or collecting group and a circular weft knitting machine that allow an improved control and an improved management of the collection of the fabric produced.

[0034] Another object of the present invention is to provide a take-off and / or collecting group and a circular weft knitting machine which can be operated in an innovative way with respect to known solutions.

[0035] Another object of the present invention is to provide a take-off and / or collecting group for a circular weft knitting machine which has high technical characteristics.

[0036] Another object of the invention is to provide a take-off and / or collecting group for a circular weft knitting machine that can be calibrated and controlled with a high degree of precision.

[0037] Another object of the invention is to provide a take-off and / or collecting group and a circular weft knitting machine characterized by reduced power consumption compared to known solutions.

[0038] 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 which allows easy maintenance and replacement operations of its parts.

[0039] Another object of the invention is to provide a removal and / or collection group which is characterized by high operating reliability and / or low susceptibility to failures and malfunctions.

[0040] Another object of the invention is to provide a take-off and / or collecting group and a circular weft knitting machine capable of preventing the formation of dislocations and / or wrinkles in the collected fabric and / or tangling of the lateral edges of the fabric.

[0041] Another object of the present invention is to provide a take-off and / or collecting group and a circular weft knitting machine which enable uniform and smooth winding of the fabric onto the collecting reel.

[0042] Another object of the present invention is to provide a take-off and / or collecting group and a circular weft knitting machine which are able to effectively unfold and spread the fabric.

[0043] Another object of the invention is to provide a take-off and / or collecting group and a circular weft knitting machine which have improved properties with respect to known solutions, for example in terms of productivity and / or quality and uniformity of the knitted goods produced.

[0044] Another object of the present invention is to provide a taking-off and / or collecting group which is versatile and adaptable to different textile needs and to different fabric types and sizes.

[0045] Another object of the invention is to provide a take-off and / or collecting group and a circular weft knitting machine, which are characterized by a simple and rational structure.

[0046] 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 realizing a take-off and / or collecting group, in particular for (but not limited to) circular weft knitting machines of the "unfolding" type.

[0047] These and other objects, which will become clearer in the following description, are essentially achieved by a taking-off and / or collecting group for a circular knitting machine (specifically, but not limited to, the "unfolding" type), a circular weft knitting machine, 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.

[0048] In the present description and the appended claims, the terms "upper", "lower", "above", "below", "horizontally", "vertically" 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.

[0049] In this specification and the appended claims, the terms "axial", "longitudinal", "circumferential", and "radial" sometimes refer to a certain axis defined for a certain element or component.

[0050] Various aspects of the invention are listed below.

[0051] In its first aspect, the invention relates to a take-off and / or collecting group for fabric produced by a circular weft knitting machine.

[0052] In one aspect, the removal and / or collection set comprises:

[0053] - 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, provided with a plurality of needles movably mounted to the at least one needle-holding mechanism, and provided with a command mechanism suitable for selectively actuating the plurality of needles and suitable for allowing the manufacture of a fabric;

[0054] A base constituting the supporting structure of the knitting machine and configured to support the knitting assembly, the base defining a housing space below the knitting assembly.

[0055] In one aspect, the removal and / or collection set comprises:

[0056] - a frame configured to be mounted in a rotatable manner to the circular knitting machine in the receiving space;

[0057] - an operating mechanism, which is operatively associated with the frame and supported by the frame and includes at least one collecting roller arranged along the rotation axis and extending longitudinally between two ends, and is configured to at least unfold and spread the fabric produced by the circular knitting machine, or also to finally extract it from the needle holding mechanism so as to continuously wind it on the collecting roller.

[0058] In one aspect, the operating mechanism comprises:

[0059] - a plurality of electric shafts, each electric shaft being configured to selectively rotate about a respective axis of rotation;

[0060] -Multiple motor groups.

[0061] In one aspect, each electric axle is individually associated to and independently actuated by a respective motor set.

[0062] In one aspect, the motorized shaft represents an element, which is part of an operating mechanism, configured to handle, ie, contact, manipulate and move, the fabric from the needle holder mechanism to the collection roll.

[0063] In one aspect, the expression "a plurality of electric axles" refers to at least two (or more) electric axles.

[0064] In one aspect, the expression "a plurality of motor groups" refers to at least two (or more) motor groups.

[0065] In one aspect, each of the plurality of motor groups includes a modular type gear motor, ie, a gear motor that is repeated in each of the motor groups.

[0066] In one aspect, the gear motor comprises:

[0067] - an electric motor, preferably a stepper motor;

[0068] - Headless screw / helical toothed wheel mechanical transmission (worm drive) placed downstream of the electric motor and actuated by it.

[0069] In one aspect, the motors of the gear motors of all motor groups in the plurality of motor groups are the same or equivalent in size and / or power (eg, drive torque) to each other.

[0070] In one aspect, the mechanical transmissions of the gear motors of all motor groups in the plurality of motor groups are identical or equivalent to one another in terms of size and / or gear ratios and / or component sizing.

[0071] In one aspect, the plurality of electric axles comprises:

[0072] - a collecting reel configured to collect the fabric produced by the circular knitting machine by continuously winding it and transporting it in a take-off and / or collecting group;

[0073] - At least one transfer roller (or take-off roller) rotatably mounted to the frame in an upstream position relative to the collection roller and configured to draw off and / or tension the fabric (so as to allow optimal winding, i.e. without wrinkles) and guide it along a coupling path towards the collection roller.

[0074] In one aspect, the collection roll is configured to collect by continuously winding the following fabrics thereabout:

[0075] - a single-layer fabric which, in the case where the knitting machine is of the "unfolding" type, has the configuration of a continuous belt of a certain width and is obtained by:

[0076] - obtained by unrolling the tube, by carrying out successive cuts parallel to the longitudinal layout of the tubular fabric produced; or

[0077] - obtained in a single and continuous layer directly from a knitting assembly which has manufactured a single layer of fabric as an “unfolded” fabric;

[0078] or

[0079] - Double-layer fabric, ie as a flattened tubular fabric (with two flaps facing the fabric) and wound on a collecting reel, in cases where the knitting machine is not of the "unfolding" type and keeps the fabric in a tubular shape when it is wound on the collecting reel.

[0080] In one aspect, the plurality of motor groups comprises:

[0081] a first motor group acting directly on the collection roller so that the collection roller is axially motorized, ie the collection roller is rotated by the first motor group about its own axis of rotation;

[0082] - A second motor group acting directly on the transport roller so that the transport roller is axially motorized, ie the transport roller is rotated by the second motor group about its own axis of rotation.

[0083] In one aspect:

[0084] -Each motor group acts directly on the corresponding electric shaft;

[0085] -Each motor group consists of its own modular gear motor.

[0086] In one aspect, the drive torque required for the rotation of each electric shaft is generated directly at the electric shaft by the respective electric machine set.

[0087] In one aspect, in a gear motor:

[0088] - the electric motor is of the stepper type and comprises a drive shaft integrally connected to the headless screw of the mechanical transmission in order to rotate the headless screw;

[0089] - The helically toothed wheel of the mechanical transmission is geared to the headless screw and mounted (eg coupled) on an output shaft of the mechanical transmission.

[0090] In one aspect, the output shaft of the mechanical transmission is ultimately connected to the corresponding electric shaft through the interposition of other mechanical mechanisms (eg, gears) so as to rotate the corresponding electric shaft.

[0091] In one aspect, an electric motor included in a motor group has:

[0092] - the body of the electric motor;

[0093] - Rotation generating means housed in the body.

[0094] In one aspect, a drive shaft caused to rotate by the generating means is provided with:

[0095] - a front part which projects from the front side of the body and is connected at the front side to a mechanical transmission placed downstream;

[0096] - A rear portion which projects from a rear side of the body opposite to the front side.

[0097] In one aspect, the front and rear portions of the drive shaft are integral with each other (ie, rotate in unison), and are preferably one-piece (ie, the drive shaft is a one-piece component).

[0098] In one aspect, the rear portion of the drive shaft protruding rearwardly from the body of the electric motor is configured to be manually actuated - selectively - for manually controlling the rotation of the drive shaft and thereby - cascadingly - controlling the rotation of the headless screw, the rotation of the toothed wheel and the rotation of the electric shaft placed downstream of the mechanical transmission.

[0099] In one aspect, actuation of the rear portion of the drive shaft is accomplished by using a special tool.

[0100] In one aspect, the electric motor includes a transducer configured to measure the position and angular velocity of the drive shaft.

[0101] In one aspect, the transducer is a hollow encoder, placed around the drive shaft and provided with a central hole for allowing the rear portion of the drive shaft to pass through and exit from the rear side of the body of the motor. The hollow encoder then allows the rear portion of the drive shaft to be arranged, manually actuable if necessary, for manually moving the motor shaft. On the other hand, in motors of known type, conventional encoders occupy the rear side of the motor and do not allow access to the drive shaft, and therefore also do not allow actuation of the drive shaft.

[0102] In one aspect, the encoder includes one or more Hall effect sensors (eg, three sensors) for measuring the angular position and angular velocity of the drive shaft.

[0103] In one aspect, at least one transfer roller extends longitudinally in a direction generally parallel to the rotational axis of the collection roller and is configured to rotate about its longitudinal rotational axis.

[0104] In one aspect, the motorized axle includes at least one pair of delivery rollers (or take-off rollers).

[0105] In one aspect, the plurality of motorized shafts include at least one spreading roller or tensioning roller rotatably mounted to the frame in an upstream position relative to the collection roller (preferably immediately upstream) and configured to interact with the fabric advancing toward the collection roller so as to spread and expand the fabric before being wound onto the collection roller.

[0106] In one aspect, the plurality of motor groups comprises a third motor group acting directly on the spreading roller so that the spreading roller is axially motorized, ie the spreading roller is rotated about its rotation axis by the third motor group.

[0107] In one aspect, the plurality of motorized axles comprise a spreading roller positioning mechanism movably mounted to the frame and 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.

[0108] In one aspect, the plurality of motor groups include a fourth motor group that acts directly on the positioning mechanism so that the positioning mechanism is axially motorized, ie the positioning mechanism is rotated about its rotation axis by the fourth motor group.

[0109] In one aspect, under the action of the fourth motor group, the positioning movement of the spreading roller is rotation or translation or rotation-translation.

[0110] In one aspect, the plurality of electric axles comprises:

[0111] - A pair of flattening rollers preferably rotatably mounted to the frame substantially at the upper opening of the frame of the take-off and / or collecting group and configured to flatten or approximate the fabric originating from the braiding assembly as a closed tubular fabric.

[0112] In one aspect, the plurality of motor groups comprises:

[0113] A fifth motor group acting directly on at least one of the pair of leveling rollers so that the roller is axially motorized, ie the roller is rotated about its axis of rotation by the fifth motor group.

[0114] In one embodiment, the rollers of the pair of leveling rollers are arranged parallel to each other. In another embodiment, the leveling rollers may include a pair of rods arranged parallel to each other. The rollers / rods are arranged side by side so as to define a substantially rectilinear passage for the fabric therebetween, thereby determining a substantial leveling of the fabric in a tubular shape along its diameter, the fabric having two layers close to or substantially in contact with each other.

[0115] In one aspect, each electric axle comprises:

[0116] - a respective rod extending longitudinally between two ends and configured to determine a specific movement for the transport of the fabric in the take-down and / or collection group;

[0117] - At least one support configured to support the rod in rotation, preferably two supports placed at the two ends of the rod.

[0118] In one aspect, in each electric axle, the respective rod has an axis of rotation coinciding with its longitudinal arrangement.

[0119] In one aspect, each motor group may include one or more additional mechanical mechanisms downstream of the corresponding (modular) gear motor, interposed between the mechanical transmission and the corresponding electric shaft. The additional mechanical mechanisms are configured to appropriately connect the mechanical transmission with the electric shaft and may include, for example:

[0120] - a toothed wheel;

[0121] -gear;

[0122] - Angular drive.

[0123] In one aspect, a collection roll:

[0124] - has an outer collecting surface corresponding to the outermost layer of the fabric wound onto the collecting reel;

[0125] - 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;

[0126] - during the collection of the fabric, instantaneously has an angular velocity of rotation about the axis of rotation;

[0127] - During the collection of the fabric, there is instantaneously a tangential speed, ie a linear speed at the outer collecting surface.

[0128] In one aspect, the first motor set is configured to vary the angular velocity of the collection roller in order to always keep the tangential velocity of the collection roller properly regulated, ie under control, during collection of the web.

[0129] In one aspect, the take-off and / or collecting group defines a coupling path for the knitted fabric exiting from the knitting assembly, the path ending on a collecting reel.

[0130] In one aspect, the spreading roll:

[0131] - 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;

[0132] - 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.

[0133] In one aspect, the spreading roller is configured to move during collection by varying the operating distance separating it from the collecting roller so as to instantaneously keep constant an optimal separation value equal to the distance between the outer operating surface of the spreading roller and the outer collecting surface of the collecting roller.

[0134] In one aspect, the removal and / or collection group comprises at least one control unit configured to command the operation of the operating mechanism.

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

[0136] - command the motors of the motor group to control the operation of each electric shaft;

[0137] -Ultimately enabling different groups of motors to communicate between themselves in order to coordinate electric shaft operation.

[0138] 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.

[0139] In one aspect, the control unit is configured to:

[0140] - sending a command signal to the first motor group for gradually reducing the angular velocity of the collecting roller as the radius of the collecting roller increases, so as to keep the tangential velocity of the collecting roller constant;

[0141] - sending a command signal to the second motor group for rotating the transfer roller at a determined speed for taking off and / or tensioning the fabric and for guiding it towards the collection roller;

[0142] - sending a command signal to the third motor group for rotating the spreading roller at a determined speed, so as to generate the correct movement for spreading and expanding the fabric transported on the spreading roller;

[0143] - sending a command signal to the fourth motor group for moving the spreading roller by varying the operating distance in order to keep the optimum separation value constant during the collection of the web, based on the value of the radius of the collection roller;

[0144] - Sending a command signal to the fourth motor group for gradually increasing the operating distance as the radius of the collecting roller increases, by keeping the optimum separation value constant during the collection of the web.

[0145] In its independent aspect, the present invention relates to a circular weft knitting machine comprising:

[0146] - 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, provided with a plurality of needles movably mounted to the at least one needle-holding mechanism, and provided with a command mechanism suitable for selectively actuating the plurality of needles and suitable for allowing the manufacture of a fabric;

[0147] - 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;

[0148] - Removal and / or collection of groups according to one or more of the preceding aspects.

[0149] In one aspect, a knitting machine comprises a supply mechanism configured to supply electric power to a motor group.

[0150] In one aspect, the feeding mechanism comprises a plurality of electric drives configured to feed the motors of the modular gear motors of the motor group of the removal and / or collection group.

[0151] In one aspect, all motors of the gear motor are supplied by the electric drive at a low voltage, preferably 48V.

[0152] In one aspect, the electric drive device is a switch mode power supply (switch).

[0153] In one aspect, the circular weft knitting machine is of the “unfolding” type, ie it is configured to produce fabric and to collect the fabric in an unfolded manner, ie as a single layer and continuously, by winding it on collecting rolls of a take-off and / or collecting group.

[0154] In one aspect, the single layer of fabric originating from the needle holding mechanism and collected by the removal and / or collection group is obtained by:

[0155] - if the braided assembly continuously produces a tubular fabric, obtained by cutting and stretching or "unrolling" the tubular fabric; or

[0156] - directly "in an unrolled manner", i.e. as a continuous single-layer fabric of a defined width;

[0157] In both cases, the take-off and / or collection group collects the single-layer fabric instead of a cylindrically laid-out tube by winding it on a collection reel.

[0158] In one aspect, the single-layer fabric has a continuous strip configuration of a specific width and is obtained by:

[0159] - by unrolling the tube, carrying out successive cuts in a direction parallel to the longitudinal layout of the tubular fabric being manufactured; or

[0160] - Obtained directly from a woven component that has been manufactured as an "unrolled", single-layer and continuous fabric.

[0161] In its independent aspect, the present invention relates to a method for collecting a fabric produced by a circular weft knitting machine, the method comprising the following steps:

[0162] - Arrangement and operation of circular weft knitting machines:

[0163] - Arrange and operate take-down and / or collection groups;

[0164] - Actuate each motor group independently.

[0165] In one aspect, the step of independently actuating each motor group includes the step of synchronizing the operating mechanism with determined operating parameters required to obtain:

[0166] - Correct tensioning and correct spreading of the fabric;

[0167] - Correct collection of fabrics.

[0168] Further features and advantages will better emerge from the detailed description of preferred embodiments of a take-off and / or collecting group for a circular knitting machine, a circular weft knitting machine and a method for collecting a fabric according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0169] 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:

[0170] - Figure 1A perspective view showing one possible embodiment of a taking-off and / or collecting group for a circular knitting machine according to the invention;

[0171] - Figure 2 Shows Figure 1 A top view of the removal and / or collection group;

[0172] - Figure 3 Shows Figure 1 A front view of the removal and / or collection group;

[0173] - Figure 4 Shows Figure 1 Left side view of the removal and / or collection group;

[0174] - Figure 5 Shows Figure 1 A right side view of the removal and / or collection group;

[0175] - Figure 6 Shows Figure 1 Another perspective view of the removal and / or collection set with some of the components removed;

[0176] - Figure 7 Shown from outside Figure 6 an enlarged view of a portion of the removal and / or collection set;

[0177] - Figure 8 Shown from the inside Figure 6 an enlarged view of the portion of the removal and / or collection set;

[0178] - Fig. 9 Shows Figure 1 A rear perspective view of the removal and / or collection group;

[0179] - Fig.10 Shows Fig. 9 An enlarged view of a portion of the removal and / or collection set, in this case the upper and rear portions;

[0180] - Fig.11 Shows Figure 1 cross-sectional view of the removal and / or collecting group in the knitting machine; 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;

[0181] - 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 surface shown is cut out;

[0182] - Fig.13shows a perspective view of an exemplary embodiment of a motor group according to the present invention;

[0183] - Fig.14 Shows Fig.13 Another perspective view of the motor group;

[0184] - Fig.15 Shows Fig.13 a motor group in which an electric axis according to the invention (of an exemplary type) is associated;

[0185] - Fig.16 Shows Figure 1 Another perspective view of the removal and / or collection set with some of the components removed; Fig.16 Further 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;

[0186] - Fig.17 yes Fig.16 A side view of a removal and / or collection group (including the fabric therein);

[0187] - Fig.18 shows a perspective view of a possible exemplary embodiment of a circular weft knitting machine according to the invention, Figure 1 The taking-off and / or collecting group in the circular weft knitting machine is rotatably mounted to the circular weft knitting machine; some parts are removed from Fig.18 knitting machine in the figure is removed; the figure specifically shows the base and knitting assembly of the circular knitting machine except for the removal and / or collection group;

[0188] - Fig.19 Shows Fig.18 Another perspective view of the circular weft knitting machine in FIG. 1 (from the bottom);

[0189] - Fig. 20 A 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 shows the complete weaving assembly with all its components, 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 then enclosed within these cages). DETAILED DESCRIPTION

[0190] With reference to the above figures, a taking-off and / or gathering group according to the invention, intended to be installed in a circular weft knitting machine, indicated by reference 100 , is indicated overall with reference 1 .

[0191] The circular weft knitting machine 100 comprises:

[0192] - 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 X, provided with a plurality of needles movably mounted to the needle-holding mechanism, and provided with a command mechanism suitable for selectively actuating the plurality of needles and suitable for allowing the fabric F to be manufactured;

[0193] A base B constituting the supporting structure of the knitting machine and configured to support the knitting assembly T; the base B defines a housing space below the knitting assembly T.

[0194] like Figure 18-20 The needle holding cylinder C in the apparatus is usually mounted vertically on a base B with vertically arranged needles, which protrudes further than the upper edge of the needle holding cylinder.

[0195] From the perspective of textile technology, the structure of the entire circular knitting machine 100 and the functions of the needle holding mechanism C (such as the cooperation between the needle and the thread, etc.) are not described in detail because they are known in the technical field of the present invention.

[0196] Take down and / or collect Group 1 including:

[0197] - a frame 2 configured to be mounted in a rotatable manner to the circular knitting machine 100 in the accommodation space;

[0198] An operating mechanism 3 operatively associated to and supported by the frame 2 and comprising at least one collection roller 10 rotatably mounted to the frame 2 , arranged along an axis of rotation 11 and extending longitudinally between two ends 12 and 13 .

[0199] 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 so as to continuously wind it on the collecting reel 10 .

[0200] The operating mechanism 3 comprises:

[0201] - a plurality of electric shafts (described in detail below and indicated by reference numerals 10 , 70 , 30 , 60 , 80 ), each electric shaft being configured to selectively rotate about a respective axis of rotation;

[0202] - A plurality of motor groups (also described in detail below and indicated with reference numerals 20, 75, 50, 40, 85).

[0203] Preferably, each electric shaft is individually associated to and independently driven by a corresponding motor group.

[0204] Preferably, the motorized shaft represents the elements that are part of the operating mechanism 3 and are configured to handle the fabric F from the needle holding mechanism C to the collecting reel 10, ie to contact, manipulate and move the fabric F.

[0205] The expression “a plurality of electric shafts” refers to at least two (or more) electric shafts, and the expression “a plurality of motor groups” refers to at least two (or more) motor groups.

[0206] Preferably, each motor group comprises a gear motor M of modular type, ie a gear motor M which is repeated in each of the motor groups.

[0207] Preferably, the gear motor A comprises:

[0208] - an electric motor M, preferably a stepper motor;

[0209] - Headless screw / helical toothed wheel mechanical transmission R (worm drive) placed downstream of the electric motor and driven by it.

[0210] Preferably, the motors M of the gear motors A of all motor groups in the plurality of motor groups are the same or equivalent in size and / or power (eg, driving torque) to each other.

[0211] Preferably, the mechanical transmissions R of the gear motors A of all motor groups of the plurality of motor groups are identical or identical to one another in terms of size and / or gear ratio and / or component dimensioning.

[0212] Preferably, the plurality of electric axes comprises:

[0213] a collecting reel 10 configured to collect the fabric F produced by the circular knitting machine 100 by continuously winding it and transporting it in a take-off and / or collecting group 1 ;

[0214] - at least one transfer roller 70 (or take-off roller) rotatably mounted to the frame 2 in an upstream position relative to the collection roller 10 and configured to extract and / or tension the fabric F (so as to allow optimal winding, i.e. without creases) and to guide it along a coupling path towards the collection roller.

[0215] Preferably, the transfer roller 70 extends longitudinally in a direction substantially parallel to the rotation axis 11 of the collection roller 10 and is configured to rotate about its longitudinal rotation axis 71 .

[0216] Preferably, the motorized shaft includes at least one pair of delivery rollers (or take-off rollers) 72 and 73 .

[0217] In a possible embodiment, the electric shaft may further include a plurality of conveying rollers which are arranged in series along the coupling path of the fabric.

[0218] It should be noted that within the scope of the present invention, the collection roll 10 is configured to collect by continuously winding the following fabric around itself:

[0219] - a single-layer fabric F, in the case where the knitting machine is of the "unfolding" type, which has a continuous belt configuration of a certain width and is obtained by:

[0220] - obtained by unrolling the tube, by carrying out successive cuts parallel to the longitudinal layout of the tubular fabric produced; or

[0221] - obtained in a single and continuous layer directly from a knitting assembly T which has manufactured a single layer of fabric as an “unfolded” fabric;

[0222] or

[0223] - Double-layer fabric F, ie as a flattened tubular fabric (with two flaps facing the fabric) and wound on a collecting reel 10, in the case where the knitting machine is not of the “unfolding” type and keeps the fabric in a tubular shape when it is wound on the collecting reel 10.

[0224] Preferably, the plurality of motor groups include:

[0225] a first motor group 20 acting directly on the collection roller 10 so that the collection roller 10 is axially motorized, ie the collection roller is rotated by the first motor group 20 about its own axis of rotation 11;

[0226] A second motor group 75 acting directly on the transport roller 70 so that the transport roller 70 is axially motorized, ie the transport roller is rotated by the second motor group 75 about its own axis of rotation 71 .

[0227] Preferably, each motor group acts directly on a corresponding electric shaft.

[0228] Preferably, each motor group comprises its own modular gear motor A.

[0229] Preferably, each motor group is configured to rotate a respective motor shaft at a variable and selectable angular speed.

[0230] Preferably, each motor group is configured to rotate the corresponding motor shaft at a variable and selectable angular speed regardless of the rotation speed of the needle holding mechanism C.

[0231] Preferably, for example under certain operating conditions, each motor group is configured to rotate the corresponding electric shaft 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 the rotation speed of the needle holding mechanism C, for example proportionally.

[0232] Preferably, each motor group is configured to rotate the corresponding electric shaft at a variable and selectable angular speed under the condition that the rotation speed of the needle holding mechanism C is constant.

[0233] Preferably, the drive torque required for the rotation of each electric shaft is generated directly at the electric shaft by the corresponding motor group.

[0234] Preferably, in gear motor A:

[0235] the electric motor M is of the stepper type and comprises a drive shaft integrally connected to the headless screw of the mechanical transmission R in order to rotate the headless screw;

[0236] - The helically toothed wheel of the mechanical transmission R is geared to the headless screw and mounted (eg coupled) on the output shaft of the mechanical transmission.

[0237] The output shaft of the mechanical transmission device R is finally connected to the corresponding electric shaft through the interposition of other mechanical mechanisms (such as gears) so as to rotate the corresponding electric shaft.

[0238] The rotation axis of the headless screw and the rotation axis of the helical toothed wheel are axes that are inclined and orthogonal to each other; therefore, the rotation axis of the output shaft of the motor M and the rotation axis of the output shaft are also axes that are inclined and orthogonal to each other.

[0239] The headless screw is always driven, while the helical toothed wheel is always guided.

[0240] It should be noted that the output shaft of the motor M and the headless screw and the helical toothed wheel of the mechanical transmission R are Figure 13-15 are not visible in the drawings because they are internal components; however, electric motors and mechanical transmissions may be predominantly commercial products in the product catalog, and their internal components are also known in the art.

[0241] It should be noted that the transmission ratio is a function of the number of first threads of the headless screw. For example, if the headless screw has a single first thread, the helical wheel shifts one tooth (advancing or retracting, depending on the direction of rotation of the screw) for each revolution of the headless screw.

[0242] The advantages of headless screw / helical toothed wheel transmissions (gear motors) are that they are compact and therefore take up less space than other types of gear motors and can be directly connected to the shaft to be moved. In addition, such transmissions have low manufacturing costs and high reliability.

[0243] Furthermore, it also allows to obtain high reduction ratios and therefore very high movement reduction rates.With a high rotation speed of the drive shaft of the electric motor, a low rotation speed of the output shaft of the mechanical transmission is obtained (gear reduction).

[0244] An important advantage of using a headless screw / helical toothed wheel transmission (gear motor) is represented by the fact that such a transmission (tendency) is kinematically irreversible, ie a helical toothed wheel could actuate the headless screw with difficulty.

[0245] Technically, the irreversibility of such a mechanical transmission is only achievable with high reduction ratios (e.g. from 70-80 upwards); in any case, the torque required at the output end (toothed wheel) to rotate the input end (headless screw) increases with the reduction ratio and becomes high enough to ensure that an element downstream of the transmission can actuate the transmission in the opposite direction.

[0246] In the context of the present invention, the mechanical transmission R drives the electric shaft downstream thereof (and connected to the helical toothed wheel). Control of the rotation of the electric shaft is achieved by controlling the direction of rotation and the relative speed of the electric motor M driving the headless screw. Therefore, even if a reverse torque occurs on the electric shaft, for example due to weight, inertia or take-off forces on the fabric, this will not cause an undesired rotation of the electric shaft in the opposite direction, because - to achieve this - the headless screw / helical toothed wheel mechanical transmission should reverse the rotation, which we have seen is itself irreversible (at a certain reduction ratio).

[0247] Therefore, the headless screw / helical toothed wheel transmission in the above-mentioned modular gear motor A used in various motor groups ensures a high degree of safety when actuating the electric shaft.

[0248] For example, in the event of a knitting machine stop or a lack of power, the gear motor A prevents the motor shaft from accidentally "returning".

[0249] Preferably, the electric motor M included in the motor group has:

[0250] - a body 55 of the electric motor M;

[0251] - Rotation generating means housed in the body (not visible in the figures, of a known type for example).

[0252] Preferably, the drive shaft rotated by the generating device is provided with:

[0253] a front portion which projects from the front side of the body 55 and at which it is connected to a mechanical transmission R placed downstream (the front portion of the drive shaft is thus not visible in the figure);

[0254] A rear portion 56 which projects from the rear side of the body 55 opposite the front side.

[0255] Preferably, the front and rear portions of the drive shaft are integral with each other (ie rotate in unison), and are preferably one-piece (ie the drive shaft is a one-piece component).

[0256] Preferably, the rear portion 56 of the drive shaft protruding rearwardly from the body 55 of the electric motor is configured to be manually actuated - selectively - for manually controlling the rotation of the drive shaft and thereby - cascadingly - controlling the rotation of the headless screw, the rotation of the toothed wheel and the rotation of the electric shaft placed downstream of the mechanical transmission R.

[0257] Preferably, the rear portion of the drive shaft is manually actuated in order to determine a reverse rotation relative to the direction of rotation of the drive shaft during normal operation of the take-down and / or collection group 1, so as to "move the motor shaft back". This may occur, for example, in order to manually adjust / calibrate the motor shaft (e.g. after a stop), or to recover an undesired rotation that occurred during normal operation of the take-down and / or collection group 1, or also to relieve a situation of excessive pulling of the fabric F during collection.

[0258] Preferably, actuation of the rear portion 56 of the drive shaft occurs by using a special tool.

[0259] Preferably, the electric motor M comprises a transducer 57 configured to measure the position and angular velocity of the drive shaft.

[0260] Preferably, the transducer 57 is a hollow encoder placed around the drive shaft and provided with a central hole for allowing the rear portion 56 of the drive shaft to pass through and exit from the rear side of the body 55 of the motor M. The hollow encoder then allows the rear portion 56 of the drive shaft to be manually actuated if necessary for manually moving the motor shaft. On the other hand, in motors of known type, the conventional encoders occupy the rear side of the motor and do not allow access to the drive shaft and therefore do not allow actuation of the drive shaft.

[0261] Preferably, the encoder comprises one or more Hall Effect sensors (eg three sensors) for measuring the angular position and angular velocity of the drive shaft.

[0262] Preferably, each motor group comprises a corresponding flange 58 mounted on the frame 2 and supporting a corresponding gear motor A.

[0263] Preferably, flange 58 intersects the corresponding drive shaft and supports it for rotation.

[0264] Preferably, the electric motor M of the modular gear motor A is directly mounted on and supported by the corresponding mechanical transmission.

[0265] Preferably, the electric motor M of the modular gear motor A is directly mounted on and supported by the corresponding mechanical transmission R. In this configuration, the entire modular gear motor A is supported by the flange 58 mounted to the frame 2 .

[0266] In a possible embodiment, the plurality of motorized shafts include at least one spreading roller 30 (also called tensioning roller) mounted to the frame 2 at an upstream position 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 toward the collection roller 10 so as to spread the fabric F before being wound on the collection roller.

[0267] Preferably, the spreading roller 30 extends longitudinally between 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 the ends 32 and 33 of the spreading roller.

[0268] Preferably, the plurality of motor groups include a third motor group 50, which acts directly on the spreading roller 30 so that the spreading roller is axially motorized, that is, the spreading roller is rotated around its own rotation axis 31 by the third motor group 50. The third motor group 50 rotates the spreading roller 30 to generate an action for spreading and expanding the fabric transported on the spreading roller.

[0269] It should be noted that removing and / or collecting Group 1:

[0270] - in the case where the knitting machine is of the "unfolding" type and the fabric F is collected in a single layer, a spreading roll 30 is included;

[0271] In the case where the knitting machine is not of the “unfolding” type and the fabric F is collected in a tube, ie in a double layer, the spreading roll 30 is not included.

[0272] Preferably, the plurality of motorized shafts comprise a positioning mechanism 60 for the spreading roller 30, which is movably mounted to the frame 2 and acts 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, thereby preferably keeping the spreading roller 30 parallel to the collecting roller 10.

[0273] Preferably, the plurality of motorized shafts comprises a fourth motor group 40 which acts directly on the positioning mechanism 60 so that the positioning mechanism 60 is axially motorized, ie the positioning mechanism is rotated by the fourth motor group 40 about its own rotation axis 63 .

[0274] Preferably, the positioning movement of the spreading roller 30 caused by the fourth motor group 40 is rotation or translation or rotation-translation.

[0275] Further details and exemplary embodiments regarding the positioning mechanism 60 will be described below.

[0276] Preferably, the plurality of motorized shafts comprise a pair of smoothing rollers 80, which are preferably rotatably mounted to the frame 2 approximately at the upper opening 4 of the frame 2 of the removal and / or collection group 1, and are configured to smooth or approximate the fabric F originating from the weaving assembly T as a closed tubular fabric.

[0277] Preferably, the plurality of motorized shafts comprises a fifth motor group 85 which acts directly on at least one of the pair of leveling rollers 80 so that the roller is axially motorized, ie the roller is rotated about its own rotation axis 81 by the fifth motor group 85 .

[0278] Preferably, the rollers in the pair of leveling rollers 80 are arranged parallel to each other. In a possible embodiment, the leveling rollers may include a pair of rods arranged parallel to each other. These rollers / rods are arranged side by side to define a generally straight path for the fabric between them, thereby determining the general leveling of the fabric having a tubular shape along its diameter with two layers (or flaps) close to or generally in contact with each other.

[0279] Preferably, the leveling roller 80:

[0280] - Oriented orthogonal (or transverse) to the longitudinal axis 5 of the frame 2, in the case where the knitting machine is of the "unfolding" type and the fabric F is designed to be subsequently cut, unfolded and collected in a single layer, (this case is shown in the figures);

[0281] - in the case where the knitting machine is not of the "unfolded" type and the fabric F is collected in a tube, ie in a double layer, oriented parallel to the longitudinal axis 5 of the frame 2 (in this case the flattening roller is rotated 90° with respect to the situation shown in the figures).

[0282] 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 preferably vertical busbar lines, so as to subsequently unfold and wind the knitted fabric in a single layer onto the collecting reel 10, as occurs in a circular knitting machine of the "unfolding" type.

[0283] Preferably, the operating mechanism 3 comprises a motor group 91 of the cutting mechanism, which is configured to actuate the cutting mechanism and determine the longitudinal opening through which the tubular fabric exits the knitting assembly T.

[0284] It should be noted that the taking-off and / or collecting group 1 comprises a cutting mechanism 90 only if the knitting machine 100 is of the “unfolding” type and the fabric F is unfolded and collected in a single layer.

[0285] Preferably, each electric axle comprises:

[0286] - a respective rod extending longitudinally between two ends and configured to determine a specific action for the transport of the fabric F in the taking-down and / or collecting group 1 ;

[0287] - At least one support configured to support the rod in rotation, preferably two supports placed at the two ends of the rod.

[0288] Preferably, in each electric axle, the respective rod has its own axis of rotation coincident with its longitudinal arrangement.

[0289] It should be noted that, preferably, each motor group (of the various motor groups described above) may include one or more additional mechanical mechanisms downstream of the corresponding (modular) gear motor M, which are interposed between the mechanical transmission R and the corresponding electric shaft. These additional mechanical mechanisms are configured to appropriately connect the mechanical transmission R to the electric shaft and may include, for example:

[0290] - a toothed wheel;

[0291] -gear;

[0292] - Angular drive.

[0293] Here is a more detailed description of the collection roll 10 .

[0294] Preferably, the mechanical transmission R of the first motor group 20 ends in a shaft bearing a motor mechanism 23 configured to transmit a controlled rotational movement directly to the rod 16 of the collection roller 10 .

[0295] Preferably, the motor mechanism 23 is a gear, such as a first toothed wheel 23 .

[0296] Preferably, the rod 16 of the collection roller comprises a guide mechanism 19 which can be directly geared to the motor mechanism 23 for receiving a controlled rotational movement therefrom and rotating the rod 16 of the collection roller 10 .

[0297] Preferably, the guide means 19 is integral with the rod 16 of the collection roller 10 , preferably at its ends.

[0298] Preferably, the guide means 19 is coaxial with the rod 16 of the collection roller 10 .

[0299] Preferably, the guide mechanism is a gear 19 , such as a second toothed wheel 19 .

[0300] 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 gear-connected to the guide mechanism 19 for transmitting the rotational movement, the first motor group 20 acts directly on the rotation axis 11 of the collection roller 10, thereby directly rotating the collection roller.

[0301] Preferably, the engagement of the guide mechanism 19 with the motor mechanism 23 is achieved by meshing a first toothed wheel with a second toothed wheel.

[0302] Preferably, the motor mechanism 23 and the guide mechanism 19 have respective rotation axes that are parallel to each other.

[0303] Preferably, the guide mechanism 19:

[0304] - when the collection roller 10 is mounted on the frame 2, it engages on the motor mechanism 23;

[0305] When the collection roller 10 is removed from the frame 2 , it is disengaged from the motor mechanism 23 .

[0306] In particular, mounting the collection roller 10 to the frame 2 determines the meshing of the second toothed wheel with the first toothed wheel, and vice versa, dismounting the collection roller 10 from the frame 2 determines the separation and distance of the second toothed wheel from the first toothed wheel.

[0307] Preferably, the rotation axis of the first toothed wheel 23 and the corresponding rotation axis of the second toothed wheel 19 are parallel to each other and to the rotation axis of the collection roller.

[0308] Preferably, the collecting roller 10 actuated by the first motor group 20 is suspended in the frame 2 so as to be suspended in the removal and / or collecting group 1 and 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 collecting group.

[0309] Preferably, the collection roller 10 is mounted to the frame 2 so that the entire surface of the fabric F wound on the collection roller 10 is free and does not rest against any element.

[0310] Preferably, the collection roller 10 is rotatably mounted at its two ends to the frame 2 so as to be supported exclusively by the two ends.

[0311] Preferably, the collection roller 10 maintains its axis of rotation 11 in a fixed position relative to the frame 2 during all the steps of collecting the fabric, in use, regardless of the amount of fabric wound on the collection roller 10 .

[0312] Preferably, the first motor group 20 is fixed at one of the two ends of the collection roller 10 and, from this position, it rotates the collection roller directly on the axis of rotation 11 .

[0313] Preferably, the collecting roller 10:

[0314] - has an outer collecting surface 15 corresponding to the outermost layer of the fabric F wound on the collecting reel 10;

[0315] - during the collection of the fabric F, instantaneously has a radius Y of the collection roller corresponding to the radial distance between the outer collecting surface 15 and the axis of rotation 11;

[0316] - during the collection of the fabric, instantaneously has an angular velocity of rotation about the axis of rotation 11;

[0317] During the collection of the fabric F, there is instantaneously a tangential speed, ie a linear speed at the outer collecting surface 15 .

[0318] 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.

[0319] Preferably, the tangential speed is instantaneously equal to the product of the radius Y of the collection roller 10 and the angular speed.

[0320] Tangential speed:

[0321] - has a preferably constant value throughout the collection of the fabric F;

[0322] - has preferably constant value during discrete steps of collecting the fabric F;

[0323] - is a function of the rotation speed of the needle holding mechanism C for manufacturing the fabric F;

[0324] - corresponds approximately 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 around the collecting reel 10 per time unit.

[0325] Preferably, the first motor group 20 is configured to gradually reduce the angular velocity of the collection roller 10 as the radius Y 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 angular velocity and the radius Y of the collection roller 10, as the radius Y of the collection roller increases, the angular velocity must be reduced in order to keep the tangential velocity constant.

[0326] Preferably, the taking-off and / or collecting group 1 is configured to process the value of the radius Y of the collecting roller 10 in real time, ie thereby to continuously monitor the value of the radius Y of the collecting roller in real time.

[0327] Preferably, the removal and / or collection group 1 defines a connection path for the fabric F leaving the weaving assembly T and ending 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.

[0328] 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, the vertical axis Z coincides with a direction which, in use, is orthogonal to the support surface of the knitting machine, in particular to the support surface of the base B. Preferably, the layout of the frame 2 along its vertical axis coincides with the height of the frame.

[0329] Preferably, the frame 2 is arranged along the 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 arrangement of the frame 2 along the longitudinal axis coincides with the width of the frame. Preferably, the arrangement of the frame 2 along the longitudinal axis 5, i.e. the width of the frame, coincides with the dimension of the larger arrangement of the frame 2.

[0330] Preferably, the collection roller 10 is mounted with its two ends 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 .

[0331] Here is a more detailed description of the spreading roll 30 .

[0332] Preferably, the spreading roller 30 is mounted to the frame 2 in a movable (eg translatable or rotationally translatable) manner and is configured to be able to vary the operating distance by which it is separated from the collecting roller 10 .

[0333] Preferably, this 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 .

[0334] Preferably, the spreading roller 30:

[0335] - has an outer operative 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;

[0336] Having a radius 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 .

[0337] 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.

[0338] Preferably, the optimum separation value is an operating value corresponding to an ideal distance (set, for example, when setting up the knitting machine), at which the spreading roller 30 is maintained relative to the collecting roller 10 for performing an optimal spreading of the fabric F from the spreading roller to the collecting roller.

[0339] Preferably, the fourth motor group 40 is configured to move the spreading roller 30 based on the measured value of the radius Y of the collection roller 10 by varying 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.

[0340] Preferably, the fourth motor group 40 is configured to gradually increase the operating distance as the radius Y of the collecting roller 10 increases, thereby keeping the optimal separation value constant during the collection of the fabric F.

[0341] In fact, as the radius Y of the collection roller 10 increases, its outer collection surface 15 approaches the spreading roller 30, so the latter must be moved away step by step. In other words, as the radius Y 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 optimum separation value constant increases.

[0342] 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 Y of the collection roller; in fact, the radius of the collection roller 10 increases with the collection fabric F.

[0343] In this case, the fourth 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 .

[0344] Preferably, the spreading roller 30 includes two embossing elements 36 and 37 in the shape of a spiral or helix (or a double spiral or double helix), which are arranged in opposite directions from the center of the spreading roller 30 toward its two lateral ends 32 and 33; due to the rotation of the spreading roller 30, the embossing elements 36 and 37 operate to gradually spread and expand the fabric F in contact with the spreading roller.

[0345] An embodiment of the spreading roll 30 will now be described in more detail by way of example as shown in the figures.

[0346] Preferably, the spreading roll 30 is mounted to the frame 2 by a positioning mechanism 60. Preferably, the positioning mechanism comprises a pair of movable arms 61 and 62. Preferably, each of the two movable arms 61 and 62 extends between a lower end, at which it is hinged to the frame 2, and an upper end, at which it is connected to the 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.

[0347] The two movable arms 61 and 62 are configured to oscillate, ie tilt, in unison by rotating about an axis 63 passing through the lower ends of the two arms, at which they are hinged to the frame 2 .

[0348] The oscillation of the two arms 61 and 62 determines the movement of the spreading roller 30 along a circular arc trajectory having its center on the rotation axis 63 and having a radius equal to the length of the movable arm; during the movement 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.

[0349] Preferably, the two movable arms 61 and 62 can selectively oscillate clockwise and counterclockwise to decrease and increase the operating distance of separating the spreading roller 30 from the collecting roller 10 .

[0350] Preferably, the motor M of the fourth motor group 40 acts on at least one of the two movable arms to determine the selective oscillation of the two arms in clockwise and counterclockwise directions and move the spreading roller 30 along a circular arc trajectory.

[0351] Preferably, one of the two movable arms (arm 61 in the figure) is actuated by the fourth motor group 40, while the other movable arm (arm 62 in the figure) is articulated to the frame 2 in idle mode (i.e., free rotation), so that a rotation (i.e., oscillating movement) of one of the two movable arms corresponds to an equal and corresponding rotation of the other movable arm.

[0352] Basically, the positioning mechanism 60 comprises two movable arms 61 and 62 (which represent levers) which are rotated to move the spreading roller; a rotation about an axis of rotation 63 occurs.

[0353] It should be noted that in the motorized shaft constituted by the positioning mechanism 60 of the spreading roller 30, the "corresponding lever" of the motorized shaft is constituted by at least one of the two movable arms 61 and / or 62, specifically by the first movable arm 61 in the exemplary embodiment shown in the figures. The lever of the positioning mechanism 60 determines that a specific action on the fabric F consists of the correct positioning of the spreading roller 30 (precisely supported and moved by the positioning mechanism 60).

[0354] In the electric shaft constituted by the positioning mechanism 60, "at least one support member" (configured to support the rotation of the corresponding rod) is constituted by a support member (such as a bearing) that movably connects the lower end of the movable arm (61 and / or 62) to the frame 2.

[0355] In a possible alternative and functionally equivalent embodiment (not shown), the fourth motor group may comprise a linear guide mounted with the spreading roller 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 is achieved by a translational movement (approach or distance of the spreading roller relative to the collecting roller) rather than by a rotational or rotational-translational movement obtained by oscillation of the two movable arms.

[0356] Preferably, the operating mechanism comprises spreading means 95 of the fabric F obtained in an unrolled manner as a single layer directly from the needle-holding means or by the action of the cutting means 90. These spreading means 95 are arranged downstream of the cutting means 90 and upstream of the delivery roller 70 (or the delivery rollers 72 and 73 if more than one), the spreading roller 30 and the collecting roller 10 along the connection path of the fabric F. The spreading means 95 are configured to unroll the fabric F leaving the flattening roller 80 and to be cut longitudinally by the cutting means 90.

[0357] The taking-off and / or collecting group 1 comprises a spreading mechanism 95 only if the knitting machine is of the “unfolding” type and the fabric F is unfolded and collected in a single layer.

[0358] Preferably, the spreading mechanism 95 comprises at least one spreading rod 96 mounted to the frame 2, preferably in a fixed manner to the removal and / or collection group in use, and the structure of the spreading rod is set to determine the spreading of the two lateral edges of the fabric by gradually moving away; the fabric F passes over the spreading rod 96 along its connection path and is spread on the spreading rod as a single layer of fabric F.

[0359] The spreading rod 96 can be registered in its position (for example before the removal and / or collection group starts operation); preferably such registration is achieved by translation in a direction parallel to the longitudinal arrangement (or axis of rotation) of the flattening roller 80.

[0360] Preferably, the spreading rod 96 is positioned longitudinally between the first lateral portion 6 and the second lateral portion 7 of the frame 2 .

[0361] 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 .

[0362] Preferably, the spreading rod 96 has an overall rounded "V" configuration, i.e., it has an arcuate portion with a curved center or circumference and two straight portions protruding in opposite directions from both sides of the center portion and terminating at the first lateral portion 6 and the second lateral portion 7, respectively. Preferably, the spreading rod 96 has a generally symmetrical configuration relative to the symmetry plane.

[0363] Preferably, the axis 11 of the collecting roller 10 is orthogonal to the plane of symmetry of the spreading rod 96 .

[0364] 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 .

[0365] It should be noted that, referring to Fig.16 and 17 , the connection path of fabric F:

[0366] - the fabric is produced by the needle holder C of the knitting assembly T (in the embodiment of the figures, in tubular shape) and falls inside the needle holder itself and is then passed into the upper opening 4 of the frame 2;

[0367] - The fabric, still in tubular shape, passes through two leveling rollers 80;

[0368] - subjecting the fabric step by step to longitudinal cutting by means of a cutting mechanism 90, in particular by means of a cutter, and in this way unrolling the tubular fabric;

[0369] - The fabric (just unfolded by the cutter) is stretched by the spreading rod 96 so that its two left and right flaps are unfolded;

[0370] - passing the single-layer (i.e. flapped) and stretched fabric F to two delivery rollers 72 and 73 where it is taken off; specifically, the fabric passes behind the rear roller 72, then enters from below the space between the rear roller 72 and the front roller 73, passes over the front roller 73 and continues to the spreading roller;

[0371] - the fabric F reaches the spreading roll 30 and passes over it, contacting the embossing elements 36 and 37;

[0372] - The fabric F is transferred from the spreading roll 30 to the collecting roll where it is wound; the winding can be achieved by means of a clockwise rotation of the collecting roll (in which case the fabric F passes under the collecting roll) or by means of a counterclockwise rotation of the collecting roll (in which case the fabric F passes over the collecting roll).

[0373] Before reaching the spreading roller 30, the fabric F may optionally pass under a fixed rod 64 connecting the two movable arms 61 and 62 and preferably coaxial with the common oscillation axis 63. In this case, the fabric F originating from the transfer roller 70 passes under the fixed rod 64, returns, rises over the spreading roller 30, travels around the spreading roller 30 and continues towards the collecting roller 10. If it is desired to wrap more around the spreading roller, i.e. at a greater angle, a deviation of the fabric trajectory by passing the fabric under the fixed rod 64 can help.

[0374] The fixing rod 64 placed below the spreading roller is configured to mechanically reinforce the structure supporting the spreading roller; this structure also comprises two movable arms 61 and 62 .

[0375] Preferably, the rotation axis 63 of the positioning mechanism 60 corresponds to the longitudinal axis of the fixing rod 64 .

[0376] Preferably, the position of the cutter can be set (eg by sliding on dedicated guides) typically during the taking-off and / or collecting group, eg according to the size of the tubular fabric produced by the knitting machine.

[0377] The passage of the fabric F over the spreading roller necessarily takes place above the spreading roller (and not below) because the embossed (spiral) elements then correctly act on the fabric to expand and spread it. If the fabric passes under the spreading roller, the embossed elements will act in the opposite way, closing the fabric instead of spreading it. Obviously, the spreading roller and its relief can be appropriately modified to operate with rotation in the opposite direction or with a different path of the fabric.

[0378] The taking down and / or collecting group may comprise / use at least one control unit configured to control the operating conditions set by the taking down and / or collecting group itself and / or to control the steps of the fabric collecting method. 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.

[0379] A control unit refers to an electronic component that may include at least one of the following: a digital processor (CPU), an analog type circuit, or a combination of one or more digital processors and one or more analog type circuits. The control unit may be "configured" or "programmed" to perform certain steps: in practice, this may be achieved using any device that allows the control unit to be configured or programmed. For example, in the case where the control unit includes one or more CPUs and one or more memories, one or more programs may be stored in an appropriate memory group attached to the one or more CPUs; the one or more programs contain instructions that, when executed by the one or more CPUs, 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 type circuit, the circuitry of the control unit may be designed to include a circuit system that is configured to process electrical signals in use in order to perform steps associated with the control unit.

[0380] Preferably, the removal and / or collection group 1 comprises at least one control unit configured to command the operation of the operating mechanism 3 .

[0381] Preferably, the control unit is configured as follows:

[0382] - commanding the electric motors M of the motor groups 20, 40, 50, 75, 85 for controlling the operation of each electric shaft 10, 30, 60, 70, 80;

[0383] -Ultimately enabling different groups of motors to communicate between themselves in order to coordinate the operation of the electric shaft.

[0384] Preferably, the control unit is connected to the operating mechanism 3 for sending command signals thereto capable of modifying and controlling its operating configuration.

[0385] Preferably, the control unit is configured as follows:

[0386] - sending a command signal to the first motor group 20 for gradually reducing the angular velocity of the collection roller 10 as the radius Y of the collection roller 10 increases, so as to keep the tangential velocity of the collection roller 10 constant;

[0387] - sending a command signal to the second motor group 75 for rotating the transfer roller 70 at a determined speed, thereby removing and / or tensioning the fabric F and guiding it towards the collection roller 10;

[0388] - sending a command signal to the third motor group 50 for rotating the spreading roller 30 at a determined speed, so as to generate a correct spreading and expansion action for the fabric F transported on the spreading roller 30;

[0389] - sending a command signal to the fourth motor group 40 for moving the spreading roller 30 based on the value of the radius Y of the collecting roller 10 by varying the operating distance in order to keep the optimum separation value constant during the collection of the fabric F;

[0390] - Sending a command signal to the fourth motor group 40 for gradually increasing the operating distance as the radius Y of the collecting roller 10 increases, so as to keep the optimum separation value constant during the collection of the fabric F.

[0391] 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 positioned in the base B or in the knitting assembly T and operate the control of the entire knitting machine.

[0392] The circular knitting machine 100 according to the present invention may include a supply mechanism configured to supply electric power to the motor groups 20 , 40 , 50 , 75 , 85 .

[0393] Preferably, the feeding mechanism comprises a plurality of electric drives configured to feed the electric motors M of the modular gear motors A of the motor group of the removal and / or collection group 1 .

[0394] Preferably, all electric motors M of the gear motor A are supplied with a low voltage, preferably 48V, by an electric drive.

[0395] Preferably, the electric drive means is a switch mode power supply (switch).

[0396] Preferably, the electric drive is connected to and controlled by the control unit.

[0397] 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 feeding direction of the fabric being manufactured.

[0398] Preferably, the taking-off and / or collecting group 1 is configured to rotate integrally with the needle holder during the manufacture of the fabric F, or to rotate in a coordinated manner relative to the needle holder.

[0399] Preferably, the circular knitting machine 100 may be of a single-bed type (with only one needle holding cylinder) or a double-bed type (with a needle holding cylinder and a needle holding plate).

[0400] Preferably, the circular knitting machine 100 can be of the type with a rotary 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 a fixed needle holding mechanism (with a rotary needle control 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 rotary needle holding mechanism and a take-off and / or collection group that rotates with it.

[0401] Preferably, the taking-off and / or collecting group 1 is suspended below the knitting assembly T: preferably, the taking-off and / or collecting group 1 is suspended to and supported by the needle holding mechanism C. In this case, preferably, the adjustment is performed by rotating the taking-off and / or collecting group by a predetermined angle relative to the knitting assembly, while preferably the taking-off and / or collecting group remains suspended.

[0402] In a different embodiment (not shown), the removal and / or collection group can be placed on the ground or on a base and constrained to the needle holding mechanism.

[0403] Preferably, if the needle holding mechanism C is of the rotary type, the removal and / or collecting 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. without any relative rotational movement relative to the needle holding mechanism. Therefore, the motor that moves the needle holding mechanism C and the removal and / or collecting group 1 (i.e. rotates it) can be a motor that saves space, cost and energy.

[0404] In a possible embodiment (not shown), if the needle holding mechanism is of the fixed type, the removal and / or collecting group is fixed, ie without any relative rotational movement relative to the needle holding mechanism.

[0405] In the exemplary embodiment shown in the figures, the circular knitting machine 100 is of the “unfolding” type, i.e. configured to produce a 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 .

[0406] The single-layer fabric F originating from the needle holding mechanism and collected by the removal and collection group 1 can be obtained in the following way:

[0407] - if the braided assembly T continuously manufactures a tubular fabric, it is obtained by cutting and stretching or "unrolling" the tubular fabric; or

[0408] - directly "in an unrolled manner", i.e. as a continuous single layer of fabric F having a determined width;

[0409] 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.

[0410] The single-layer fabric F has a continuous strip structure of a specific width and is obtained by:

[0411] - obtained by unrolling the tube, by carrying out successive cuts parallel to the longitudinal layout of the tubular fabric produced; or

[0412] - A single-layer and continuous fabric is obtained directly through the weaving assembly of the fabric which has been manufactured as an "unfolded" fabric.

[0413] As in Fig. 20 As shown by way of example in the figure, the circular knitting machine may include other components such as:

[0414] - Parts of the braiding assembly, such as covers, cams, thread guides, etc.;

[0415] - A P-type conical retainer structure placed above the braided assembly T;

[0416] A plurality of closing cages G closing the operating space occupied by the taking-down and / or collecting group 1 (thus enclosing the taking-down and / or collecting group inside such cages).

[0417] The closing cage G is movably mounted (eg, hinged) to the base B at least between a closed configuration in which it prevents access to the operating space and an expanded configuration in which it allows access to the operating space.

[0418] The cage G is suitable for allowing safe operation of the knitting machine 100: in fact, the taking-down and / or collecting group 1 is operated by rotating it in the operating space, and it is therefore necessary to make this space inaccessible during the operation of the machine, in order to avoid accidental contact with the moving mechanisms. Conversely, the cage G must also allow access to the interior of the operating space for configuration and maintenance operations on the machine or for loading / unloading the collecting rolls of fabric, since the cage can be deployed individually and selectively, manually or automatically.

[0419] According to the invention, a method for collecting a fabric produced by a circular weft knitting machine comprises the following steps:

[0420] - Arrange and operate the circular knitting machine 100;

[0421] - Arrange and operate the removal and / or collection group 1;

[0422] - Actuating each motor group 20, 40, 50, 75, 85 independently.

[0423] Preferably, the step of independently actuating each motor group comprises the step of synchronizing the operating mechanism 3 with determined operating parameters required to obtain:

[0424] - Correct tensioning and correct spreading of the fabric F;

[0425] - Correct collection of fabric F.

[0426] It should be noted that the method of collecting the fabric corresponds substantially to the process for controlling the operation of the taking-down and / or collecting group 1 .

[0427] The present invention has important advantages.

[0428] Firstly, the Applicant has demonstrated that the present invention allows solving the problem and overcoming the above-mentioned typical limitations of known solutions and subsequently achieving the intended purposes.

[0429] In particular, the taking-down and / or collecting group 1 is characterized by an innovative structure and function which provides for the modularity of the gear motors inside each group of motors actuating the electric shaft.

[0430] Basically, the solution based on the present invention provides:

[0431] - define a series of motorized axes whose purpose is to properly handle the fabric F from the needle holder mechanism C to the collection reel 10;

[0432] - Combine each electric axle with its own individually dedicated motor group;

[0433] - Each electric axis is realized by a gear motor A of modular type, ie repeated in a substantially similar manner in all motor groups.

[0434] This advantageously allows:

[0435] - Better control and improved management of the collection of manufactured fabrics;

[0436] - Dynamically control (even in real time) all the mechanisms involved from processing to collecting the fabric;

[0437] - achieving improved performance with respect to known solutions, for example in terms of productivity and / or quality and uniformity of the collected knitted fabric;

[0438] - prevent the formation of dislocations and / or wrinkles on the collected fabric and prevent the lateral edges of the fabric from rolling up;

[0439] - Always effectively unwind and spread the fabric, so that it can be wound evenly and flatly on the collection roll;

[0440] - Adapting the taking-off and / or collecting groups to different textile needs and to different types and sizes of fabrics;

[0441] -Easy for the operating mechanism to maintain and replace its own parts;

[0442] - Provide systems with high operational reliability and low susceptibility to failure and malfunction;

[0443] The modularity represented by the use of the same gear motor in all the group motors (consisting of electric motors, preferably stepper motors, and of mechanical transmissions, preferably headless screws / helical wheels) represents a major step forward in the design and realization of the take-off and / or collection groups. In fact, modularity allows:

[0444] - Reduction of costs for the realization of movable parts (electric shafts) present in the removal and / or collection groups;

[0445] - Possibility to use components from the catalogue (specifically, electric motors and mechanical transmissions);

[0446] - Makes various gear motors effectively "interchangeable" in that they are suitable for use with various electric axes;

[0447] - Reduction of the storage space required for the production and maintenance of the take-down and collection groups, since the gear motors are repeated in a modular manner in the various motor groups (avoiding the need for each motorized shaft / roller and each roller to have a different actuator suitable only for that shaft / roller);

[0448] - Makes the maintenance of the motor unit simple, convenient and quick.

[0449] Furthermore, the solution of the invention, using modular gear motors and motor groups individually coupled to the motorized shafts, allows to greatly improve the control capabilities of the take-off and / or collection groups and therefore the control of the fabric collection. The controls that can be achieved with the invention are:

[0450] - Advanced and precise, since it allows the status of each electric axle to be known and regulated individually and at all times;

[0451] - Freely programmable and parameterizable;

[0452] -Can be integrated into knitting machines.

[0453] It should be noted that the take-off and / or collection group of the invention also allows obtaining another very important advantage, which is represented by the absence of chains and belts, which is not generally known in the solutions. In the invention, each motor shaft / roller is driven directly, ie rotates directly about its own axis, by its own motor group; each motor group is individually coupled to a single motor shaft and is exclusively dedicated to this motor shaft.

[0454] Another advantage of the invention is represented by the presence of a hollow encoder which allows the rear portion of the drive shaft to be removed from the body of the motor, which can then be manually actuated if necessary, for example for adjusting and calibrating the motorized shaft.

[0455] Other advantages of the invention come from the use of a stepper motor in combination with a headless screw / helical toothed wheel transmission in a gear motor. As indicated above, these advantages consist of the following:

[0456] -Compact shape and few obstructions;

[0457] - Irreversibility of mechanical transmission devices;

[0458] - It is possible to connect directly to the axis to be moved;

[0459] -High reduction ratio;

[0460] -High security and reliability.

[0461] The solution based on the invention allows overall to obtain a removal and / or collection group characterized by a simple and rational structure.

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 comprising: - a knitting assembly (200) 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 and supported by the frame (2) and comprising at least one collecting roller (10) rotatably mounted to the frame (2), arranged along an axis of rotation (11) and extending longitudinally between two ends (12, 13), the operating mechanism (3) configured to at least unfold and spread the fabric (F) produced by the circular knitting machine (100), or It is also configured to finally extract it from the needle holding mechanism (C) and continuously wind it on the collecting roller (10); Wherein, the operating mechanism (3) comprises: - a plurality of electric shafts, each electric shaft being configured to selectively rotate about a respective axis of rotation; -Multiple motor groups; Each electric shaft is individually associated with a corresponding motor group and is independently driven by the corresponding motor group.

2. The removal and / or collection group (1) according to claim 1, wherein: Each of the plurality of motor groups comprises a gear motor (A) of modular type, i.e. a gear motor (A) which is repeated in each of the motor groups, and / or wherein the gear motor (A) comprises: - an electric motor (M), preferably a stepper motor; - a headless screw / helical toothed wheel mechanical transmission (R) (worm drive) placed downstream of said electric motor (M) and driven by said electric motor (M), And / or wherein the electric motors (M) of the gear motors (A) of all the motor groups in the plurality of motor groups are identical or equivalent to each other in terms of size and / or power, and / or wherein the mechanical transmission devices (R) of the gear motors (A) of all the motor groups in the plurality of motor groups are identical or equivalent to each other in terms of size and / or gear ratio and / or component dimensioning.

3. A removal and / or collection group (1) according to claim 1 or 2, wherein: The plurality of electric axes include: - the collecting reel (10) being configured to collect the fabric (F) produced by the circular knitting machine (100) by continuously winding the fabric (F) and transporting it in the taking-off and / or collecting group; - at least one transfer roller (70) rotatably mounted to the frame (2) in an upstream position relative to the collection roller (10) and configured to extract and / or tension the fabric (F) and guide it along a coupling path towards the collection roller (10); And wherein the collecting roller (10) is configured to collect by continuously winding the following fabric around it: - a single-layer fabric (F) which, in the case where the knitting machine is of the "unfolding" type, has a continuous belt configuration of a specific width and is obtained by: - obtained by unrolling the tube, by carrying out successive cuts parallel to the longitudinal layout of the tubular fabric produced; or - obtained in a single and continuous layer directly from said knitting assembly (T) which has manufactured said single-layer fabric as an "unfolded" fabric; or - Double-layer fabric (F), ie as a flattened tubular fabric and wound on the collecting reel (10), in the case where the knitting machine is not of the "unfolding" type and keeps the fabric in a tubular shape when it is wound on the collecting reel.

4. A removal and / or collection group (1) according to any one of the preceding claims, wherein: The plurality of motor groups include: - a first motor group (20) acting directly on the collecting roller (10) so that the collecting roller is axially motorized, i.e. the collecting roller is rotated by the first motor group about its own axis of rotation (11); a second motor group (75) acting directly on the conveyor roller (70) so that it is axially motorized, ie it is rotated by the second motor group about its own axis of rotation (71), and / or where: - Each motor group acts directly on the corresponding electric shaft; - Each motor group consists of its own modular gear motor (A), And / or wherein the first motor group (20) is configured to change the angular velocity of the collecting roller (10) so as to keep the tangential velocity of the collecting roller (10) always properly adjusted, i.e. under control during the collection of the fabric, and / or wherein the first motor group (20) is configured to gradually reduce the angular velocity of the collecting roller (10) as the radius (Y) of the collecting roller (10) increases so as to keep the tangential velocity of the collecting roller (10) constant.

5. A removal and / or collection group (1) according to any one of the preceding claims, wherein: - the electric motor (M) is of the stepper type and comprises a drive shaft integrally connected to the headless screw of the mechanical transmission (R) in order to rotate the headless screw; - a helical toothed wheel of the mechanical transmission (R) is geared to the headless screw and mounted on the output shaft of the mechanical transmission (R); - the output shaft of the mechanical transmission device (R) is finally connected to the corresponding electric shaft through the interposition of other mechanical mechanisms such as gears so as to rotate the corresponding electric shaft; And / or wherein each motor group is configured to rotate the corresponding electric shaft at a variable and selectable angular speed, and / or wherein each motor group is configured to rotate the corresponding electric shaft 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 the rotation speed of the needle holding mechanism (C) - for example, proportionally - and / or wherein each motor group is configured to rotate the corresponding electric shaft at a variable and selectable angular speed and under the condition that the rotation speed of the needle holding mechanism (C) is constant, and / or wherein the driving torque required to rotate each electric shaft is generated directly at the electric shaft by the corresponding motor group.

6. A removal and / or collection group (1) according to any one of the preceding claims, wherein: The electric motor (M) included in the motor group has: - a body (55) of the electric motor (M); - rotation generating means housed in said body (55), and / or wherein the drive shaft rotated by the generating device is provided with: - a front portion protruding from the front side of the body, said front portion being connected at said front side to the mechanical transmission (R) placed downstream; - a rear portion (56) which projects from a rear side of the body (55) opposite to the front side, And / or wherein the rear portion (56) of the drive shaft protruding rearwardly from the body (55) of the electric motor (M) is configured to be manually actuated - selectively - for manually controlling the rotation of the drive shaft and thereby - cascadingly - controlling the rotation of the headless screw, the rotation of the toothed wheel and the rotation of the electric shaft placed downstream of the mechanical transmission (R).

7. A removal and / or collection group (1) according to any one of the preceding claims, wherein: The motor (M) comprises a transducer (57) configured to measure the position and angular velocity of the drive shaft, and / or wherein the transducer (57) is a hollow encoder placed around the drive shaft and provided with a central hole for allowing the rear portion (56) of the drive shaft to pass through and exit from the rear side of the body (55) of the motor (M), the hollow encoder allowing the rear portion (56) of the drive shaft to be arranged to be manually actuatable when it is necessary to manually move the electric shaft, and / or wherein each motor group comprises a corresponding flange (58) mounted to the frame (2) and supporting the corresponding gear motor (A).

8. A removal and / or collection group (1) according to any one of the preceding claims, wherein: The plurality of electric axes include: - at least one spreading roller (30) or tensioning roller, rotatably 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 (10) in order to spread and expand the fabric before being wound onto the collecting roller (10), And the plurality of motor groups include: a third motor group (50) acting directly on the spreading roller (30) so that the spreading roller (30) is axially motorized, i.e. the spreading roller is rotated by the third motor group (50) about its own axis of rotation (31), and / or wherein said removing and / or collecting group (1): - comprising said spreading roll (30) in the case where said knitting machine is of the "unfolding" type and said fabric (F) is collected in a single layer; - In the case where the knitting machine is not of the "unfolding" type and the fabric (F) is collected in a tube, ie in a double layer, the spreading roll (30) is not included.

9. A removal and / or collection group (1) according to any one of the preceding claims, wherein: The plurality of electric axes include: - a positioning mechanism (60) of the spreading roller (30), which is movably mounted to the frame (2) and acts 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 by keeping the spreading roller (30) parallel to the collecting roller (10), And the plurality of motor groups include: a fourth motor group (40) acting directly on the positioning mechanism (60) so that the positioning mechanism is axially motorized, i.e. the positioning mechanism is rotated by the fourth motor group (40) about its own axis of rotation (63), and / or wherein the positioning movement of the spreading roller (30) caused by the fourth motor group (40) is rotation or translation or rotation-translation, And / or wherein the spreading roller (30) is configured to be moved by the fourth motor group (40) during the collection by changing the operating distance separating the spreading roller from the collecting roller (10) so as to instantaneously maintain an optimal separation value constant, the optimal separation value being equal to the distance between the outer operating surface (35) of the spreading roller (30) and the outer collecting surface (15) of the collecting roller (10), the optimal separation value being an operating parameter corresponding to an ideal distance, and the spreading roller (30) is maintained 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).

10. A removal and / or collection group (1) according to any one of the preceding claims, wherein: The plurality of electric axes include: - a pair of flattening rollers (80) preferably rotatably mounted to said frame (2) in a manner roughly corresponding to the upper opening (4) of said frame (2) of said taking-down and / or collecting group (1) and configured to flatten or approximate said fabric (F) coming from said knitting assembly (T) in the shape of a closed tubular fabric, And the plurality of motor groups include: a fifth motor group (85) acting directly on at least one of the pair of leveling rollers (80) so that the roller is axially motorized, i.e. the roller is rotated by the fifth motor group (85) about its own axis of rotation (81), and / or wherein said flattening rollers (80) are arranged side by side so as to define a substantially straight passage for said fabric (F) so as to determine a substantial flattening of said fabric having a tubular shape along its diameter, and / or wherein said flattening rollers (80): - in the case where the knitting machine (100) is of the "unfolding" type and the fabric (F) is designed to be subsequently cut, unfolded and collected in a single layer, oriented orthogonally to the longitudinal axis (5) of the frame (2); - wherein said knitting machine (100) is not of the "unfolding" type and said fabric (F) is in tubular form, That is, in the case of double-layer collection, the orientation is parallel to the longitudinal axis (5) of the frame (2).

11. A removal and / or collection group (1) according to any one of the preceding claims, wherein: Each electric axis includes: - a respective rod extending longitudinally between two ends and configured to determine a specific movement of said fabric (F) for transport in said taking-down and / or collecting group; - at least one support configured to support the rod in rotation, preferably two supports placed at the two ends of the rod, and / or wherein, in each electric shaft, the respective rod has its own longitudinal axis coincident with its longitudinal layout, and / or wherein each motor group can comprise, downstream of the respective modular gear motor (A), one or more additional mechanical mechanisms interposed between the mechanical transmission (R) and the respective electric shaft, wherein the additional mechanical mechanisms are configured to appropriately connect the mechanical transmission (R) to the electric shaft and can comprise one or more of the following components: - a toothed wheel; -gear; - Angular drive.

12. The removal and / or collection group (1) according to any one of the preceding claims, comprising at least one control unit, the at least one control unit being configured to command the operation of the operating mechanism (3), and / or where The control unit is configured to: - commanding the electric motor (M) of the motor group (20; 40; 50; 75; 85) to control the operation of each electric shaft (10; 30; 60; 70; 80); - ultimately enabling the different motor groups (20; 40; 50; 75; 85) to communicate between themselves in order to coordinate the operation of the electric shaft (10; 30; 60; 70; 80); and / or where 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 perform one or more of the following operations: - sending a command signal to the first motor group (20) for gradually reducing the angular velocity of the collection roller (10) as the radius (Y) 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 (75) for rotating the transfer roller (70) at a determined speed for removing and / or tensioning the fabric (F) and for guiding it towards the collection roller (10); - sending a command signal to the third motor group (50) for rotating the spreading roller (30) at a determined speed, so as to generate a correct action for spreading and expanding the fabric (F) transported on the spreading roller; - sending a command signal to the fourth motor group (40) for moving the spreading roller (30) based on the value of the radius (Y) of the collecting roller (10) by varying the operating distance in order to keep the optimum separation value constant during the collection of the fabric; - sending a command signal to the fourth motor group (40) for collecting the fabric (F) by During this period, the optimum separation value is kept constant, and the operating distance is gradually increased as the radius (Y) of the collection roller (10) increases.

13. A circular weft knitting machine (100), comprising: - 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 rotatable about a central axis (X), provided with a plurality of needles movably mounted to said at least one needle-holding mechanism, 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 (100) and configured to support the knitting assembly (T), the base (B) defining a receiving space below the knitting assembly; - A taking-off and / or collecting group (1) according to one or more of the preceding claims.

14. The circular knitting machine (100) according to claim 13, comprising a supply mechanism configured to supply power to the motor group (20, 40, 50, 75, 85), and / or wherein: The feeding mechanism comprises a plurality of electric drives configured to feed the electric motor (M) of the modular gear motor (A) of the motor group (20, 40, 50, 75, 85) of the removal and / or collection group (1), and / or wherein, All the electric motors (M) of the gear motor (A) are supplied by the electric drive with a low voltage, preferably 48 V, and / or wherein the electric drive is a switched mode power supply (switch).

15. A method for collecting a fabric (F) produced by a circular weft knitting machine (100), the method comprising the following steps: - Arrange and operate a circular weft knitting machine (100), said circular weft knitting machine comprising at least: - a knitting assembly (T) provided with a needle-holding cylinder or plate around a central axis (X) at least one rotating needle holding mechanism (C), provided with a plurality of needles movably mounted to said at least one needle holding mechanism, and provided with a command mechanism suitable for selectively actuating said plurality of needles and suitable for allowing the fabric (F) to be manufactured; - 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; - Arrangement and operation of 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 with and supported by the frame (2) and comprising at least one collecting roller (10) rotatably mounted to the frame (2), arranged along an axis of rotation (11) and extending longitudinally between two ends (12, 13), the operating mechanism (3) configured to at least unfold and spread the fabric (F) produced by the circular knitting machine (100), or It is also configured to finally extract it from the needle holding mechanism (C) and continuously wind it on the collecting roller (10); Wherein, the operating mechanism (3) comprises: - a plurality of electric shafts (10; 30; 60; 70; 80), each electric shaft being configured to selectively rotate about a respective axis of rotation; - Multiple motor groups (20; 40; 50; 75; 85); wherein each electric shaft is individually associated to a corresponding motor group and is independently actuated by the corresponding motor group; - independently actuating each motor group (20; 40; 50; 75; 85), and / or wherein the step of independently actuating each motor group comprises the step of synchronizing the operating mechanism (3) with determined operating parameters required to obtain: - Correct tensioning and correct spreading of the fabric (F); - Correct collection of said fabric (F).

Images