Circular weft knitting machine and ventilation method of circular weft knitting machine

Abstract

A circular weft knitting machine comprises a ventilation group (12) arranged on a central axis (X-X) of the knitting machine (1). The ventilation group (12) comprises: a rotatably supported shaft (13) rotatable about a respective axis of rotation (Y-Y) coinciding with or approaching the central axis (X-X); a plurality of fans (28) mounted on the shaft (13); and the motor (15) is connected with the mechanical transmission device (16). The mechanical transmission (16) is operably paired with the shaft (13), and the motor (15) and the mechanical transmission (16) are configured to rotate the shaft (13) in accordance with alternating movement about a respective axis of rotation (Y-Y).

Description

Technical Field

[0001] The present invention relates to a circular weft knitting machine. The present invention also relates to a ventilation method for a circular weft knitting machine. In particular, the present invention relates to a ventilation group for a circular weft knitting machine. Background Art

[0002] As is known, circular weft knitting machines can be used to manufacture various types of textiles, for example for manufacturing clothing or other types of textiles.

[0003] The circular weft knitting machine includes a knitting assembly, on which is mounted at least one needle holding mechanism (needle holding cylinder and / or needle holding plate), the needle holding mechanism being provided with a group or more organized needles arranged along a circular path to form a corresponding circular needle bed.

[0004] The knitting assembly also includes devices for controlling the movement of the knitting needles to form a fabric that is at least partially tubular. These devices include an action triangle arranged around the needle holding cylinder and / or towards the needle holding plate and operably connected to the knitting needles. The knitting assembly is equipped with a plurality of ring-dropping sinkers, which are arranged to cooperate with the knitting needles to form a knitted fabric. The ring-dropping sinkers are movably arranged in radial seats in an annular body (sinking plate crown seat) arranged around the needle holding cylinder. The circular knitting machine includes a base, which constitutes the supporting structure of the knitting machine itself. Specifically, the base constitutes the ground bearing mechanism of the circular weft knitting machine. The base is also used to support the knitting assembly mounted on the base.

[0005] During the weaving process, the tubular fabric manufactured by the weaving assembly continues to move downward, that is, it falls into the lower space defined by the base structure and is collected by a special device. The circular weft knitting machine is equipped with a main motor connected to the needle holding mechanism, which is used to determine the rotation of the needle holding mechanism around its central axis. The rotation of the needle holding mechanism determines the movement of the knitting needle and other knitting machine mechanisms through interaction with the cam to achieve the purpose of weaving the fabric. For example, documents WO2020250075A1 and WO2020212817A1 under the name of the same applicant describe such a knitting machine.

[0006] In known knitting machines such as those mentioned above, a ventilation group is usually mounted radially inside the needle holding cylinder and is provided with a fan. The ventilation group comprises a shaft which can rotate freely about an axis of rotation coinciding with the main axis of the needle holding cylinder. The fan is located at the ends of arms extending radially relative to the axis of rotation and is provided with corresponding motors for rotating the blades of the fan. The ventilation group has a dual function, firstly to blow away the dust generated by the yarn from the knitting machine bed and the fabric being woven, and secondly to cool the knitting machine device.

[0007] In known knitting machines, sliding contacts are used to transmit power from the machine base to the motor of the fan. The fan is oriented so that the thrust generated by the rotation of the blades, in addition to the air flow to the needle holder and other parts of the knitting machine, can also generate a torque to rotate the ventilation group around the above-mentioned rotation axis. Summary of the invention

[0008] In the above-mentioned field of circular weft knitting machine technology, the Applicant has noticed that ventilation groups of known type do not ensure that the ventilation performance remains constant over time.

[0009] In fact, the Applicant has noticed that the sliding contacts gradually wear over time and that the friction between the shaft of the ventilation group and the bracket to which it is fixed also gradually decreases over time, which can cause the shaft, which is moved only by the torque generated by the fan, to rotate faster and faster and lose control. Wear is thus multiplied and frequent interventions for maintenance operations are necessary.

[0010] The applicant has also noted that known ventilation groups do not allow for the control of ventilation during the fabric production process.

[0011] In fact, since the fan rotates only by the thrust generated by the fan, it is impossible to control the speed in a way that is coordinated with the woven knitted fabric.

[0012] Therefore, the object of the present invention is to propose a circular weft knitting machine and a method for ventilating a circular weft knitting machine that are able to overcome the above-mentioned limitations and disadvantages.

[0013] A basic object of the present invention in its various aspects and / or embodiments is to propose a circular weft knitting machine capable of ensuring ventilation performance over a long period of time.

[0014] Another object of the invention is to propose a circular weft knitting machine which makes it possible to control ventilation, optionally in a manner coordinated with the weaving of the knitted fabric.

[0015] Another object of the invention is to propose an electronically controlled ventilation group.

[0016] Another object of the invention is to propose a ventilation group which is reliable and requires only low maintenance.

[0017] Another object of the invention is to propose an efficient and effective method for ventilating a circular weft knitting machine.

[0018] The above-mentioned objects and other objects can basically be achieved by a circular weft knitting machine and a ventilation method for a circular weft knitting machine according to the following aspects and / or embodiments and / or the appended claims.

[0019] In a first aspect, the invention relates to a circular weft knitting machine comprising:

[0020] A base that can be placed on the ground and a knitting assembly mounted on the base; the knitting assembly comprises: a needle holding mechanism having a central axis and a plurality of grooves arranged around the central axis, a plurality of knitting needles being accommodated in the grooves, and an action device mounted on the base, wherein the needle holding mechanism can move around the central axis relative to the action device, wherein the action device can be operably matched with or suitable for matching with the knitting needles, and is used to determine or allow the knitting needles to move along the grooves, so as to form a knitted fabric by the knitting needles;

[0021] A ventilation group arranged on the central axis;

[0022] The ventilation group includes:

[0023] a shaft supported in a rotatable manner so as to rotate about a corresponding rotation axis coinciding with or close to the central axis;

[0024] at least one fan, optionally a plurality of fans, mounted on the shaft;

[0025] An electric motor is connected to a mechanical transmission, wherein the mechanical transmission is operatively paired with the shaft, and the electric motor and the mechanical transmission are configured to rotate the shaft according to an alternating motion about a corresponding axis of rotation, ie, to oscillate about the axis of rotation.

[0026] In a second aspect, the present invention relates to a method for ventilating a circular weft knitting machine, comprising:

[0027] The shaft supporting at least one fan is rotated alternately around a corresponding rotation axis, wherein the rotation axis coincides with or is close to a central axis of a needle holding mechanism of a circular weft knitting machine.

[0028] In one aspect, the method of the preceding aspect or one or more of the following aspects is driven by a knitting machine of the preceding aspect or one or more of the following aspects, and vice versa, the knitting machine of the preceding aspect or one or more of the following aspects is configured to drive the method of the preceding aspect or one or more of the following aspects.

[0029] The Applicant first demonstrated that the knitting machine according to the invention allows direct control of the rotation of the shaft, since this rotation is controlled by the thrust of the motor and not by the fan.

[0030] The applicant has also verified that the knitting machine and / or method according to the invention can power one or more fans without using sliding contacts, since the shaft itself does not rotate continuously. Thus, the typical problems of sliding contact wear and speed loss control in known knitting machines are solved.

[0031] The applicant has also demonstrated that alternating motion allows for more efficient ventilation of the knitting machine, since the shaft supporting the fan or fans rotates in a direction consistent with the needle holding mechanism for a certain period of time and in an inconsistent direction for a period of time, which enables the air flow generated by the single or multiple fans to reach the gaps in the knitting machine, which is not possible with the typical continuous rotation and always rotating in the same direction in the ventilation groups of known knitting machines.

[0032] Furthermore, the motor drive also enables the direction of one or more fans to be adjusted in the most efficient ventilation manner, since it is no longer necessary to adjust the direction of one or more fans in order to generate the torque to drive the ventilation group.

[0033] Other aspects of the invention are described below.

[0034] In one aspect, the motor and transmission are configured to, or the method includes, rotating the shaft by a first angle in a rotational direction (eg, clockwise) and rotating the shaft by a second angle in an opposite rotational direction (eg, counterclockwise).

[0035] In one aspect, the first angle and the second angle are equal to each other.

[0036] In one aspect, the first angle and the second angle are less than 360°.

[0037] In one aspect, the first angle and the second angle are less than or equal to 180°.

[0038] In one aspect, a knitting machine includes an electronic control unit.

[0039] In one aspect, the electronic control unit is part of or connected to a central processing unit of the knitting machine.

[0040] In one aspect, the electronic control unit comprises one or more central processors and electronic devices, also located in different parts of the knitting machine, adapted and / or configured / capable of electronically controlling parts of the knitting machine and / or the entire knitting machine.

[0041] In one aspect, the motor includes a hollow encoder that is located around the drive shaft and has a central hole to allow the rear portion of the drive shaft to pass through and protrude from the rear side of the motor body. In this way, the hollow encoder can access the rear portion of the drive shaft, and the drive shaft can be manually operated if manual movement of the motor axis is required. On the other hand, in known types of motors, the conventional type of encoder is located on the rear side of the motor and cannot access the drive shaft, and therefore cannot drive it.

[0042] In one aspect, the electric motor is connected to an electronic control unit.

[0043] In one aspect, the electronic control unit is configured to, or the method includes: rotating the shaft by stepwise commanding the motor.

[0044] In one aspect, the electronic control unit is configured to, or the method includes: counting the number of steps corresponding to the first angle.

[0045] In one aspect, upon finishing counting the number of steps corresponding to the first angle, the electronic control unit is configured to, or the method includes: reversing the direction of rotation and counting the number of steps corresponding to the second angle.

[0046] In one aspect, the electronic control unit is configured to, or the method includes: continuing to reverse the rotation direction while the knitting machine is in operation and counting the number of steps corresponding to the first angle and the second angle.

[0047] In one aspect, the electronic control unit is configured to, or the method includes: adjusting the rotation speed of the shaft according to the rotation speed of the needle holding mechanism.

[0048] The Applicant has demonstrated that the connection of the electric motor to an electronic control unit ensures precise management of the rotation of the shaft and therefore of the ventilation.

[0049] In one aspect, a knitting machine includes a proximity sensor mounted proximate to a shaft.

[0050] In one aspect, the proximity sensor is mounted on a base of the gearbox or on a base of an annular body fixed to the gearbox.

[0051] In one aspect, the proximity sensor is configured to, or the method includes: reading an angular position of a shaft about a corresponding rotation axis.

[0052] In one aspect, the proximity sensor is operably connected to the electronic control unit.

[0053] In one aspect, the proximity sensor is configured to, or the method includes: sending a signal to an electronic control unit, the signal indicating detection of an element present on the shaft.

[0054] In one aspect, the electronic control unit is configured to, or the method includes: issuing a command to the motor according to the signal.

[0055] In one aspect, when the knitting machine is switched on and / or started, the electronic control unit is configured to, or the method includes: commanding the motor to rotate the shaft in a rotation direction.

[0056] In one aspect, when the knitting machine is switched on and / or started, the electronic control unit is configured to, or the method includes: counting an initial number of motor steps corresponding to an initial rotation angle starting from receiving the signal.

[0057] In one aspect, at the end of counting the initial number of steps, or at the end of rotation of the initial rotation angle, the electronic control unit is configured to, or the method includes: reversing the rotation direction and counting the number of steps corresponding to the first angle.

[0058] In one aspect, the first angle is smaller than the initial rotation angle, so that the proximity sensor does not detect the presence of an element on the shaft again after the knitting machine is switched on and / or started.

[0059] In one aspect, the ratio between the first angle and the initial rotation angle is between 0.95 and 0.99.

[0060] According to the above, the electronic control unit always knows exactly the angular position of the shaft and its speed and can adjust the speed according to other operating parameters of the knitting machine.

[0061] In one aspect, the element present on the shaft comprises or is defined by at least one step on the radially outer surface of the shaft.

[0062] In one aspect, the at least one step is defined by a groove on the radially outer surface of the shaft.

[0063] In one aspect, the groove has an arc-shaped extension, and the at least one step includes two steps disposed at opposite ends of the groove.

[0064] Therefore, the element can be easily realized by machining.

[0065] In one aspect, the knitting machine comprises at least one cable connecting a power supply device of the knitting machine and at least one fan, and optionally comprises a plurality of cables connecting a power supply device of the knitting machine and a fan.

[0066] In one aspect, the at least one cable has a first fixed end associated with the base and a second fixed end constrained to the at least one fan.

[0067] In one aspect, the cable is a power supply cable and / or a cable carrying control signals.

[0068] In one aspect, the ventilation group includes a flexible conduit, which can also be a cable-carrying chain, having a first end fixed to a base and a second end fixed to a shaft; wherein a portion of at least one cable is guided into the flexible conduit, and the flexible conduit bends when the shaft rotates according to an alternating motion.

[0069] The above structure does not require any sliding contacts to power the motor and the one or more fans.

[0070] In one aspect, the ventilation group includes a mechanical end stop for limiting the rotation of the shaft.

[0071] In one aspect, the mechanical end stop device includes a bracket integral with the shaft and protruding from the shaft, and at least one protrusion fixed relative to the base, wherein the bracket is configured to abut against the at least one protrusion at a determined rotation angle.

[0072] In one aspect, the at least one protrusion includes two protrusions extending in radially opposite directions relative to the shaft.

[0073] In one aspect, the mechanical end stop includes a plate supporting at least one protrusion and constrained by the gearbox.

[0074] In one aspect, the gearbox has, or is rigidly connected to, an annular surface orthogonal to the axis of rotation, on which the plate is disposed and constrained.

[0075] Mechanical end stops prevent excessive shaft rotation that could tear the cable and / or flexible conduit in the event of an electronic control failure.

[0076] In one aspect, the plate comprises adjustment means for adjusting the angular position of the plate about the shaft, thereby adjusting the angle of the end stop.

[0077] In one aspect, the adjustment device includes at least one slot in the plate and a set screw passing through the at least one slot and engaging the annular surface.

[0078] The adjustment device can adjust the end stop device according to the length of the cable and / or the flexible conduit.

[0079] In one aspect, the motor is fixedly mounted relative to the base.

[0080] In one aspect, the transmission is fixedly mounted relative to the base.

[0081] In one aspect, the motor is a stepper.

[0082] In one aspect, the transmission includes a gearbox.

[0083] In one aspect, the gearbox is of the headless screw type.

[0084] In one aspect, the gearbox includes a headless screw coaxial with the motor, the headless screw meshing with a helical wheel coaxial with the shaft.

[0085] In one aspect, a first coupling axis of the headless screw gearbox to the motor and a second coupling axis of the headless screw gearbox to the shaft are orthogonal to each other.

[0086] In one aspect, the shaft includes a first portion extending upwardly from the gearbox along the second coupling axis and a second portion extending downwardly from the gearbox along the second coupling axis.

[0087] In one aspect, the ventilation group includes at least one nozzle mounted on a shaft and connected to a source of compressed air.

[0088] In one aspect, at least one flexible tube connects the at least one nozzle to a source of compressed air, and the at least one flexible tube bends when the shaft rotates according to the alternating motion.

[0089] In this way, it is also possible to avoid the use of rotating compressed air distributors, since the sliding contacts would cause the resistance to the rotation of the shaft to vary over time.

[0090] In one aspect, the frame is fixedly mounted on the base and disposed above the weaving assembly.

[0091] In one aspect, the motor and transmission are fixed relative to the frame.

[0092] In one aspect, the frame is supported by struts extending from the base.

[0093] In one aspect, the shaft is rotatably suspended from the frame, optionally via at least one bearing.

[0094] In one aspect, the shaft protrudes from above and below the frame.

[0095] In one aspect, the ventilation group includes at least one rod extending transversely relative to the shaft and having a fan mounted at one end thereof.

[0096] In one aspect, the fan is mounted on the end of a pole by a hinge or connection so that the direction can be manually adjusted and locked in a selected position.

[0097] In one aspect, the ventilation group includes at least one rigid tube extending transversely relative to the shaft and having a nozzle at one end.

[0098] In one aspect, the flexible tube is connected to the rigid tube at an end opposite the nozzle.

[0099] In one aspect, the ventilation group includes a pair of upper rods extending transversely in a direction opposite to the shaft, and each upper rod has a fan mounted at each end thereof.

[0100] In one aspect, the ventilation group includes a pair of lower rods extending transversely in a direction opposite to the shaft, and each lower rod has a fan mounted at each end thereof.

[0101] In one aspect, the ventilation group includes a pair of rigid tubes extending transversely in a direction opposite to the shaft, and each rigid tube is equipped with a nozzle at each end thereof.

[0102] In one aspect, the pair of upper rods are located on the first portion of the shaft.

[0103] In one aspect, the pair of upper bars are located above the frame.

[0104] In one aspect, the pair of lower rods are located on the second portion of the shaft.

[0105] In one aspect, the pair of lower rods are located below the frame.

[0106] In one aspect, the pair of rigid tubes are located on the second portion of the shaft.

[0107] In one aspect, the pair of rigid tubes are located below the frame.

[0108] In one aspect, the knitting machine comprises a plurality of guide elements for guiding yarn coming from at least one creel, wherein the plurality of guide elements are arranged above the frame; wherein the at least one fan is directed towards the guide elements.

[0109] In one aspect, the fans of the pair of upper rods are installed above the needle holding mechanism to blow away dust generated when the yarn slides in the guide element.

[0110] In one aspect, a knitting assembly includes a plurality of yarn guides disposed proximate to the knitting needles, wherein at least one fan is directed toward the yarn guides.

[0111] In one aspect, the fans of the pair of lower rods are at least partially placed inside the knitting assembly to cool the needle holding mechanism, yarn guide and knitted fabric forming area, and to blow dust away from the formed knitted fabric.

[0112] In one aspect, at least one nozzle is directed toward the needles.

[0113] In one aspect, the nozzles of the pair of rigid tubes are located inside the needle holding mechanism to cool the needle holding mechanism and the knitted fabric weaving area and to blow dust away from the knitted fabric being woven.

[0114] In one aspect, the ventilation group includes at least one lamp located at the lower end of the shaft; and the at least one cable includes an electrical cable connected to the lamp.

[0115] In one aspect, the ventilation group includes a top light mounted on the lower end of the shaft and accommodating the at least one light.

[0116] In one aspect, at least one fan includes a motor and a blade connected and rotated by the motor, wherein at least one cable is connected to the motor of the at least one fan.

[0117] In one aspect, the electronic control unit is operatively connected to the motor of at least one fan.

[0118] In one aspect, the electronic control unit is configured to, or the method includes: adjusting the speed of at least one fan, in particular the speed of the motor of at least one fan, according to the operating parameters of the knitting machine, in particular the speed of the needle holding mechanism.

[0119] In one aspect, the speed of the motor and blades of at least one fan is programmable.

[0120] In one aspect, the electronic control unit is configured to, or the method includes: adjusting the air pressure of the nozzle according to operating parameters of the knitting machine.

[0121] In one aspect, a knitting machine includes a main motor operatively connected to a needle holding mechanism and configured to rotate the needle holding mechanism about a central axis.

[0122] In one aspect, the electronic control unit is configured as, or the method includes: adjusting the rotation speed of the motor of the shaft of the ventilation group according to the rotation speed of the main motor and / or the needle holding mechanism.

[0123] In one aspect, the shaft speed regulation and / or the at least one fan speed regulation is performed according to a cycle configured to minimize energy consumption.

[0124] In one aspect, the circular weft knitting machine has a single needle bed or a double needle bed.

[0125] In one aspect, the needle holding mechanism includes a needle holding cylinder and / or a needle holding plate.

[0126] In one aspect, the actuation device comprises an actuation cam which is arranged around the needle holding cylinder and / or towards the needle holding plate.

[0127] The features and advantages of the present invention will be further better explained by a detailed description of a preferred, but non-limiting embodiment of a circular weft knitting machine and a ventilation method for a circular weft knitting machine according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0128] The present specification will be described with reference to the accompanying drawings, which are for illustrative purposes only and are not limiting:

[0129] - Figure 1 The overall three-dimensional view of the circular weft knitting machine of the present invention is shown;

[0130] - Figure 2 Shows Figure 1 a knitting machine in which some parts are not shown to better highlight other parts;

[0131] - Figure 3 Shows Figure 1 A magnified view of a portion of

[0132] - Figure 4 Shows Figure 2 A magnified view of a portion of

[0133] - Figure 5 Shows Figure 4 A magnified view of a portion of the image.

[0134] - Figure 6 shows a part of the ventilation group of the knitting machine shown in the above figures;

[0135] - Figure 7 Shows Figure 6 An enlarged view of the portion shown in;

[0136] - Figure 8 Shows Figure 7 a cross-sectional view of the components in the portion shown in ;

[0137] - Fig. 9 Shows Figure 7 The upper part of the middle;

[0138] - Fig.10 Different parts of the ventilation group of the knitting machine shown in the above figures are shown.

[0139] Description of reference numerals:

[0140] 1: Circular weft knitting machine

[0141] 2: Base

[0142] 3: Braided components

[0143] 4: Needle holding mechanism

[0144] 5: Upper support ring or element

[0145] 6: Lower base

[0146] 7: Framework

[0147] 8: Guide element

[0148] 9: Pillar

[0149] 10: Round plate

[0150] 11: Yarn guide

[0151] 12: Ventilation Group

[0152] 13: Axle

[0153] 13A: Part I

[0154] 13B: Part 2

[0155] 14: Bearings

[0156] 15: Stepper Motor

[0157] 15a: Hollow encoder

[0158] 16: Gearbox

[0159] 17: Robotic Arm

[0160] 18: Mechanical end stop device

[0161] 19: Bracket

[0162] 20: Protrusion

[0163] 21: Plate

[0164] 22: Ring

[0165] 23: Slot

[0166] 24: Groove

[0167] 25: Stairs

[0168] 26: Proximity sensor

[0169] 27: Backswing

[0170] 28: Fan

[0171] 29: Motor

[0172] 30: Blade

[0173] 31: Cable carrying chain

[0174] 32: Downswing

[0175] 33: Rigid tube

[0176] 34: Nozzle

[0177] 35: Ceiling light

[0178] 36: Electronic control device

[0179] XX: Central axis

[0180] YY: Rotation axis

[0181] α1: first angle

[0182] α2: Second angle

[0183] αs: initial rotation angle DETAILED DESCRIPTION

[0184] With reference to the above-mentioned drawings, a circular weft knitting machine according to the present invention is generally indicated by reference numeral 1 .

[0185] The circular weft knitting machine 1 comprises a base 2 which constitutes the bearing structure of the knitting machine and can be placed on the ground. A knitting assembly 3 is mounted on the base 2 and is provided with a needle holding mechanism 4 on which a plurality of knitting needles are movably mounted, and a command device for selectively driving the plurality of knitting needles, so as to weave a tubular or partially tubular fabric (the fabric is not shown in the drawings) in a known manner. Figure 1 and Figure 3 The braided assembly 3 is shown in Figure 2 and Figure 4 In the figure, the braided component 3 is not shown to better highlight other components.

[0186] The circular weft knitting machine 1 in the example is a single-needle-bed circular weft knitting machine, but the present invention is also applicable to a double-needle-bed circular weft knitting machine.

[0187] The needle holding mechanism 4 shown in the figure is a needle holding cylinder ( Figure 3 In an embodiment not shown, the needle holding mechanism 4 may include a needle holding plate combined with a needle holding cylinder. The needle holding mechanism 4 has a central axis "XX", a plurality of grooves arranged around the central axis "XX", and a plurality of knitting needles mounted in the grooves. The grooves and knitting needles of the needle holding mechanism 4 are not shown in the figure, because they can be of conventional type and are known in the reference technical field.

[0188] The base 2 comprises an upper support ring or element 5 on which the knitting assembly 3 is mounted so as to enable the needle-holding mechanism 4 to rotate about a central axis "XX". When the knitting machine 1 is properly placed on the ground, the central axis "XX" is vertical. The base 2 comprises a lower base 6 for placement on the ground.

[0189] The action device installed around the needle holding mechanism 4 is used to determine or allow the knitting needle to move along the groove so as to manufacture the knitted fabric by knitting. In the illustrated embodiment, the action device includes an action triangle fixedly mounted on the base 2. Since the action triangle can be of a known type, the details are not shown. The needle holding mechanism 4 is supported by bearings on the support ring 5 and has a gear coaxial with the center axis "XX", which is not shown in the figure. A main motor hidden in the base is connected to the gear of the needle holding mechanism 4, which is used to determine the rotation of the needle holding mechanism 4 around the center axis "XX" and relative to the base 2 and the action triangle. The main motor is connected to the gear through a transmission device, and its function is to transmit the power of the main motor to the gear.

[0190] The knitting machine 1 comprises a frame fixedly mounted on a base 2 and located above a knitting assembly 3. The frame carries a plurality of guide elements 8 for yarn coming from at least one creel (not shown) comprising a series of coils arranged to facilitate unwinding of the yarn. The guide elements 8 are located above the frame and carried by a circular structure supported by the frame ( Figure 1 ).

[0191] like Figure 2 and Figure 4 As shown, the frame is supported by struts 9 extending from the base 2. The frame has a lattice structure placed in a horizontal plane orthogonal to the central axis "XX" and carries a pair of parallel circular plates 10 having a central hole coaxial with the central axis "XX".

[0192] After the yarn extends from the creel and the guide element 8, it will further pass through a plurality of yarn guides 11 near the knitting needles. Figure 3 As shown in the figure, they are arranged in a ring shape above the circular edge of the needle holding mechanism 4, and the needle holding mechanism 4 is provided with a needle (not shown in the figure).

[0193] The knitting machine 1 also comprises a ventilation group 12 arranged at the central axis "XX".

[0194] The ventilation group 12 comprises a shaft 13 rotatably supported on a frame to rotate about a rotation axis "YY" coinciding with the central axis "XX". The shaft 13 is mounted on a bearing 14 between two circular plates 10. The bearing 14 is supported by the lower circular plate of the two circular plates 10 ( Figure 4 , 5 6). The shaft 13 passes through the hole of the circular plate 10 and can rotate around the central axis "XX" relative to the circular plate 10. The shaft 13 is rotatably suspended on the frame.

[0195] The stepper motor 15 connected to the headless screw gearbox 16 is fixedly mounted on the frame and cooperates with the shaft 13 to rotate the shaft 13 around the central axis "XX" ( Figure 6 and Figure 7 ). For example, a gearbox 16 of known type includes a headless screw coaxial with the stepper motor 15, and the headless screw is engaged with a spiral wheel coaxial with the shaft 13. The first coupling axis (horizontal) of the gearbox 16 and the stepper motor 15 and the second coupling axis (vertical) of the gearbox 16 and the shaft 13 are orthogonal to each other. The stepper motor 15 may also include a hollow encoder 15a, which is located around the transmission shaft and has a central hole to allow the rear part of the transmission shaft to pass through and protrude from the rear side of the motor body.

[0196] The motor 15 and the gearbox 16 are configured to alternately rotate the shaft 13 around the corresponding rotation axis "YY". The rotation of the stepper motor 15 in a certain direction determines the rotation of the shaft 13 around the rotation axis "YY" in the corresponding direction. The rotation of the stepper motor 15 in the opposite direction determines the rotation of the shaft 13 around the rotation axis "YY" in the opposite direction.

[0197] The gearbox 16 is matched with the first portion 13A and the second portion 13B of the shaft 13. The first portion 13A extends upward from the gearbox 16 along the second coupling axis, and the second portion 13B extends downward from the gearbox 16 along the second coupling axis.

[0198] Thus, the gearbox 16 is located between the first portion 13A and the second portion 13B of the shaft 13, and the assembly consisting of the stepper motor 15 and the gearbox 16 is restrained on the frame by means of an arm 17 fixed to the two circular plates 10 so as not to rotate ( Figure 5 , 6 and 7).

[0199] The bearing 14 is mounted on the second portion 13B, and the two circular plates 10 together with the bearing 14 are arranged at a lower position relative to the assembly consisting of the stepper motor 15 and the gearbox 16 .

[0200] The ventilation group 12 also includes a mechanical end stop 18 for limiting the rotation of the shaft 13. The mechanical end stop 18 includes a bracket 19 integral with the shaft 13 and protruding from the shaft 13, and two protrusions 20 fixed relative to the base 2 and extending in the opposite direction of the shaft 13. The bracket 19 is configured to abut against one protrusion 20 or the other protrusion 20 (related to the direction of rotation) at a determined rotation angle.

[0201] In the embodiment shown, the bracket 19 is "L" shaped, one end of which is restrained on the shaft 13 in the area between the bearing 14 and the gearbox 16. The two protrusions 20 are part of a plate 21 inclined and restrained on the annular surface of the gearbox 16 or fixed relative to the gearbox 16, which is developed around the shaft 13 and is orthogonal to the axis of rotation "YY" ( Figure 5-9 ). In the embodiment shown, an annular body 22 is fixed to the gearbox 16 and is arranged around the first portion 13A, of which the annular surface is a part.

[0202] The plate 21 is provided with grooves 23 which are fixed by means of fastening screws to an annular surface integral with the gearbox 16. These grooves 23 and the corresponding fastening screws constitute adjustment means for adjusting the angular position of the plate 21 around the shaft 13 and thus the end stop angle of the shaft 13 in both directions of rotation.

[0203] One end of the first portion 13A accommodated in the annular body 22 is provided with a groove 24 (such as Figure 8 The groove 24 extends in an arc shape and has two steps 25 ( Figure 8In addition, the annular body 22 also has a radial base, in which a proximity sensor 26, such as a magnetic or capacitive sensor, is accommodated. The proximity sensor 26 ( Figure 7 , 8 , 9) toward the first portion 13A of the shaft 13 at the groove 24 ( Figure 8 sectional view of the ).

[0204] like Figure 6 As shown, the first part 13A carries a pair of upper rods 27, which extend transversely in the direction opposite to the shaft 13 and each of which is equipped with a fan 28 at each end. Each fan 28 includes a motor 29 and a blade 30 connected to the motor 29 and rotated. The fan 28 is mounted on the end of the corresponding rod 27 by a hinge or a connecting piece, so that the direction can be manually adjusted and locked in a selected position ( Figure 6 ).

[0205] In order to transmit power and control signals from a power supply device of the knitting machine 1, which is usually arranged in the base 2, to the motors 29 of the fans 28, cables, not shown in the drawings, connect the power supply device to each motor 29 of the fans 28. The cables may be power supply cables and / or cables for transmitting control signals.

[0206] Part of the cable passes through the cable carrying chain 31 and is supported by the cable carrying chain 31. The first end of the cable carrying chain 31 is fixed to the base 2, in particular to the frame, and the second end is fixed to the shaft 13, in particular to the bracket 19 ( Figure 5 , 6 , 7). The cable then continues to extend inside the shaft 13 and the upper rod 27. When the shaft 13 rotates according to the alternating motion, the cable carrying chain 31 bends, and the above structure does not require sliding contacts to power the motor 29 and the fan 28. In a variant embodiment not shown, a different flexible conduit can be used instead of the cable carrying chain 31.

[0207] The adjustment device of the mechanical end stop device 18 can adjust the end stop device according to the length of the cable and the cable carrying chain 31 to prevent the cable from being torn and / or the cable carrying chain 31 from being broken due to excessive rotation of the shaft 13.

[0208] The present description mainly focuses on the part where the ventilation group 12 is located above the frame. Figure 1 , Figure 2 , Figure 3 and Figure 4 As can be seen in the figure, the ventilation group 12 also includes a lower part located below the frame. Fig.10 The lower part is shown, which comprises the lower part of the shaft 13, and Figure 6 The lower end of the second portion 13B of the shaft 13 shown in FIG. 1 is connected. Fig.10 The lower part of the shaft comprises a pair of lower rods 32 extending transversely in the direction opposite to the shaft, and each of which is provided with a fan 28 at its end. The fans 28 carried by the lower rods 32 are substantially the same as the fans 28 carried by the upper rods 27 described above. The fans 28 on the lower rods 32 are also powered by cables in the cable carrying chain 31.

[0209] In addition, a pair of rigid tubes 33 extending transversely in the direction opposite to the shaft 13 are mounted on the shaft 13, and each rigid tube is equipped with a nozzle 34 at each end thereof. The end of each rigid tube 33 opposite to the nozzle 34 is connected to a compressed air source, such as a compressor controlled by a valve, through a flexible tube. When the shaft 13 rotates according to the alternating motion, the flexible tube bends, and the above structure does not include a rotating compressed air distributor.

[0210] A ceiling light 35 is mounted at the lower end of the shaft 13 and contains one or more bulbs (not shown) therein, which are powered by cables in the cable carrying chain 31.

[0211] like Figure 1 , Figure 2 and Figure 3 As shown, a pair of fans 28 of upper rods 27 are located above the needle holding mechanism 4 and are consistent with the height of the guide element 8. The fans 28 of the pair of upper rods 27 are basically directed toward the guide element 8 to blow away the dust generated when the yarn slides in the guide element 8.

[0212] A fan 28 of a pair of lower rods 32 is partially placed inside the knitting assembly 3 and basically faces the yarn guide 11, and is used to cool the needle holding mechanism 4, clean the yarn guide 11 and the knitted fabric forming area, and blow dust away from the formed knitted fabric.

[0213] The nozzle 34 is located inside the needle holding mechanism 4 and faces the knitting needles, and is used to cool the needle holding mechanism 4 and the knitted fabric forming area, and to blow away dust from the formed knitted fabric.

[0214] The knitting machine 1 comprises Figure 7 36. Even if not shown in the figure, the electronic control unit 36 ​​is also configured and / or programmed to manage the knitting machine 1 in the operating steps. Therefore, the electronic control unit 36 ​​is connected to the sensors, actuators and motors of the knitting machine 1.

[0215] In particular, in the context of the present invention, the electronic control unit 36 ​​is connected to the motor 15 of the ventilation group 12, the proximity sensor 26, the power supply unit managing the power of the fan 28, the compressed air source and the main motor determining the rotation of the needle holding mechanism 4. The electronic control unit 36 ​​is part of the CPU of the knitting machine or is connected to the CPU of the knitting machine 1 to move the ventilation group 12 and the needle holding mechanism 4 in a coordinated manner.

[0216] During use, according to the ventilation method of the circular weft knitting machine, when the knitting machine 1 is turned on and / or started, the electronic control unit 36 ​​sends a command to the motor 15 to rotate the shaft 13 in the rotation direction. When the proximity sensor 26 detects one of the two steps 25, it will send a signal to the electronic control unit 36, and the electronic control unit 36 ​​will count the initial number of steps of the motor 15 corresponding to the initial rotation angle "αs" (e.g., equal to 185°). At the end of the initial step count, that is, the initial rotation angle "αs" (not shown in the figure) is rotated, the electronic control unit 36 ​​instructs the motor 15 to reverse the rotation direction of the shaft 13 and count the number of steps corresponding to the first angle "α1" (e.g., equal to 180°). The first angle "α1" is smaller than the initial rotation angle "αs", so the proximity sensor 26 will not detect the step 25 again. In the illustrated case, the ratio of the first angle "α1" to the initial rotation angle "αs" is 180° / 185°=0.973. After the counting of the number of steps corresponding to the first angle "α1" is completed, the electronic control unit instructs the motor 15 to reverse the rotation direction and count the number of steps corresponding to the second angle "α2", and the absolute value of the second angle "α2" is preferably equal to the first angle "α1". The electronic control unit 36 ​​continues to reverse the rotation direction and count the number of steps corresponding to the first angle "α1" and the second angle "α2", so that the shaft 13 performs alternating rotational motion, that is, swings around the rotation axis "YY".

[0217] The electronic control unit 36 ​​can also be programmed to coordinate with the central processing unit to change the speed and / or width of the first angle "α1" and / or the second angle "α2" according to different operating parameters of the knitting machine 1, such as the speed of the needle holding mechanism 4, or adjust the speed of the fan 28 and / or the air pressure ejected from the nozzle.

[0218] In the variant embodiment that belongs to the scope of the present invention, the number and part of fan and / or nozzle can change.For example, in the double needle bed type circular weft knitting machine that is not shown in the drawings, ventilation group 12 only comprises the fan that is arranged on upper rod 27.

[0219] The present invention has important advantages.

[0220] The present invention can solve the jet problem and adjust its intensity in the process of weaving knitted fabrics by the needle holding mechanism through electronic control and coordination.

[0221] The present invention can effectively cool down various mechanisms of a knitting machine.

[0222] The invention can effectively remove dust, so that the dust will not be retained on the knitted fabric being woven, thereby helping to improve the quality of the produced fabric.

[0223] The invention can reliably ensure the ventilation performance of the knitting machine for a long time and only requires a small amount of maintenance on the ventilation group.

Claims

1. A circular weft knitting machine, include: A base (2) that can be placed on the ground and a knitting assembly (3) mounted on the base (2); the knitting assembly (3) comprises: a needle holding mechanism (4) having a central axis (XX) and a plurality of grooves arranged around the central axis (XX), wherein a plurality of knitting needles are accommodated in the grooves, and an action device mounted on the base (2), wherein the needle holding mechanism (4) can move around the central axis (XX) relative to the action device, wherein the action device can be operably paired with or suitable for pairing with the knitting needles, and is used to determine or allow the knitting needles to move along the grooves so as to form a knitted fabric through the knitting needles; a ventilation group (12) arranged on the central axis (XX); Wherein, the ventilation group (12) comprises: a shaft (13) supported in a rotatable manner and rotatable about a corresponding rotation axis (YY) coinciding with or close to the central axis (XX); at least one fan (28) or a plurality of fans (28) mounted on the shaft (13); A motor (15) connected to a mechanical transmission (16), wherein the mechanical transmission (16) is operably paired with the shaft (13), the motor (15) and the mechanical transmission (16) being configured to rotate the shaft (13) according to an alternating movement around a corresponding rotation axis (YY).

2. The knitting machine according to claim 1, It is characterized in that The invention comprises an electronic control unit (36), wherein the motor (15) is operably connected to the electronic control unit (36); wherein the electronic control unit (36) is configured to rotate the shaft (13) by stepwise instructing the motor (15); wherein the electronic control unit (36) is configured to: count the number of steps corresponding to the first angle (α1); when the number of steps corresponding to the first angle (α1) is finished, reverse the rotation direction and count the number of steps corresponding to the second angle (α2); when the knitting machine (1) is working, continuously reverse the rotation direction and count the number of steps corresponding to the first angle (α1) and the second angle (α2).

3. The knitting machine according to claim 2, It is characterized in that It includes a main motor, which is operably connected to the needle holding mechanism (4) and is configured to rotate the needle holding mechanism (4) around the central axis (XX), wherein the electronic control unit (36) is configured to adjust the rotation speed of the motor (15) of the shaft (13) of the ventilation group (12) according to the rotation speed of the main motor.

4. The knitting machine according to claim 2 or 3, It is characterized in that It comprises a proximity sensor (26) installed near the shaft (13) and operably connected to the electronic control unit (36), wherein the proximity sensor (26) is configured to read the angular position of the shaft (13) around the corresponding rotation axis (YY) and send a signal to the electronic control unit (36), wherein the signal indicates that an element on the shaft (13) is detected; wherein the electronic control unit (36) is configured to issue instructions to the motor (15) according to the signal.

5. The knitting machine according to claim 4, It is characterized in that When the knitting machine (1) is turned on and / or started, the electronic control unit (36) is configured to: instruct the motor (15) and rotate the shaft (13) in a rotation direction, and count the initial number of steps of the motor (15) corresponding to the initial rotation angle (αs) from the time the signal is received; at the end of the initial step count, reverse the rotation direction and count the number of steps corresponding to the first angle (α1); wherein the first angle (α1) is smaller than the initial rotation angle (αs) so that after the knitting machine (1) is turned on and / or started, the proximity sensor (26) will not detect the element present on the shaft (13) again; wherein the ratio between the first angle (α1) and the initial rotation angle (αs) is between 0.95 and 0.

98.

6. A knitting machine according to any one of claims 1 to 5, It is characterized in that It comprises at least one cable connecting the power supply device of the knitting machine (1) to the at least one fan (28), and optionally, it comprises multiple cables connecting the power supply device of the knitting machine (1) to the fan (28); wherein the at least one cable has a first fixed end associated with the base (2) and a second fixed end restricted to the at least one fan (28); wherein the ventilation group (12) comprises a flexible conduit, optionally a cable carrying chain (31), which has a first fixed end associated with the base (2) and a second fixed end fixed to the shaft (13); wherein a part of the at least one cable is introduced into the flexible conduit, and the flexible conduit bends when the shaft (13) rotates according to the alternating movement.

7. A knitting machine according to any one of claims 1 to 6, It is characterized in that The invention comprises a mechanical end stop device (18) for limiting the rotation of the shaft (13); the mechanical end stop device (18) comprises a bracket (19) which is integral with the shaft (13) and protrudes from the shaft (13) and at least one protrusion (20) fixed relative to the base (2), wherein the bracket (19) is used to abut against the at least one protrusion (20) at a determined rotation angle.

8. A knitting machine according to any one of claims 1 to 7, It is characterized in that The ventilation group (12) comprises at least one nozzle (34) mounted on the shaft (13) and connected to a compressed air source; at least one flexible tube connects the at least one nozzle (34) to the compressed air source, and the at least one flexible tube bends when the shaft (13) rotates according to an alternating motion.

9. A knitting machine according to any one of claims 1 to 8, It is characterized in that The motor (15) and the transmission device (16) are fixedly mounted relative to the base (2).

10. A knitting machine according to any one of claims 1 to 8, It is characterized in that It comprises a frame (7) fixedly mounted on the base (2) and arranged above the weaving assembly (3); wherein the shaft (13) is rotatably suspended on the frame (7), and the motor (15) and the transmission device (16) are fixed relative to the frame (7).

11. A knitting machine according to any one of claims 1 to 10, It is characterized in that The motor (15) is of stepping type, and the transmission device (16) comprises a headless screw gearbox.

12. A method for ventilating a circular weft knitting machine, include: According to an alternating motion, a shaft (13) supporting at least one fan (28) is rotated around a corresponding rotation axis (YY), wherein the rotation axis (YY) coincides with the center axis (XX) of the needle holding mechanism (4) of the circular weft knitting machine (1) or is close to the center axis (XX).

13. The method according to claim 12, It is characterized in that include: The shaft (13) is rotated by a first angle (α1) in a rotation direction, and by a second angle (α2) in an opposite rotation direction; wherein the first angle (α1) and the second angle (α2) are equal to each other and less than 360°, and optionally, the first angle (α1) and the second angle (α2) are less than or equal to 180°.

14. The method according to claim 12 or 13, It is characterized in that include: The rotation speed of the shaft (13) is adjusted according to the rotation speed of the needle holding mechanism (4), and / or the rotation speed of the at least one fan (28) is adjusted according to the rotation speed of the needle holding mechanism (4).

15. The method according to claim 14, It is characterized in that The speed regulation of the shaft (13) and / or the speed regulation of the at least one fan (28) is performed according to a cycle configured to minimize energy consumption.

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