WO2015049627A1

WO2015049627A1 - Circular knitting machine

Info

Publication number: WO2015049627A1
Application number: PCT/IB2014/064932
Authority: WO
Inventors: Ettore Lonati; Fausto Lonati; Tiberio Lonati
Original assignee: Santoni S.P.A.
Priority date: 2013-10-02
Filing date: 2014-09-29
Publication date: 2015-04-09
Also published as: ITBS20130138A1; CN104514076A

Abstract

A circular knitting machine (1 ) for knitwear or hosiery, comprising a bearing structure, at least a needle-bearing organ or needle cylinder rotatably mounted in the bearing structure; a plurality of needles supported by the needle cylinder and mobile parallel to a rotation axis of the needle cylinder for producing a knitted fabric; a dial group (3) arranged above the needle cylinder. The dial group (3) comprises a support ring (4) solidly constrained to the bearing structure and coaxial to the needle cylinder, a thread transport and cutting group, or "cutter" (4a) rotatably mounted externally of the support ring (4) and a plurality of pneumatic activating devices (5) arranged on the support ring (4), each comprising one or more respective pneumatic actuators and one or more respective solenoid valves configured and predisposed to activate or deactivate the pneumatic supply of the pneumatic actuators. The dial group (3) comprises at least a first pathway of pneumatic supply (6) provided with a single main inlet (7) for pneumatic supply, positioned in the dial group and destined to be connected to a compressed air source of the knitting machine; the first pneumatic supply pathway (6) being configured for pneumatically supplying the pneumatic actuators of at least a first group of devices of the plurality of pneumatically activating device (5) present in the dial group (3).

Description

DESCRIPTION

"Circular Knitting Machine"

The present invention relates to a circular knitting machine. In particular, the invention relates to a circular knitting machine characterised by a specific structure of the dial group of the machine and a specific configuration of the part of pneumatic supply of the devices comprised in the dial group. The present invention further relates to a method for pneumatic supply of the dial group of a circular knitting machine.

The present invention relates to the technical sector of circular knitting machines, seamless type machines, hosiery machines and the like.

In the present description, the term "knitting machine" is meant in general to relate to a circular knitting machine for production of textile articles and provided with a plurality of thread feeding points, in which the thread is supplied to the needles of the machine. The knitting machine can be for example of a single-bed or a double-bed type. Circular knitting machines can comprise a variable number of thread feeders, for example 2, 4, 6, 8 or more.

In the present description the expression "dial group" is intended to mean a portion of the knitting machine arranged superiorly of the needle-bearing organ and provided with organs and devices able to cooperate with the needles of the knitting machine and with the threads present in the thread feeders so as to enable production of fabric.

In the sector of circular knitting machine, various types of realization of the dial group are known, together with the devices connected thereto. In general, the dial group is typically provided with a fixed support ring (or plate), mounted to the bearing structure of the knitting machine, a transport and cutting organ of the threads (known in the sector as a cutter) mounted externally of the support ring so as to be able to rotate about it, and a plurality of pneumatic devices positioned on the support ring.

The plurality of pneumatic devices usually comprises at least a hook control group provided with one or more command cams, able to interact with the hooks of the knitting machine, and a plurality of pneumatic actuators actuating the command cams.

In addition, the plurality of pneumatic devices can comprise clamps groups, typically equal in number to the thread feeders of the machine; each clamps group comprises one or more mobile clamps, able to retain or block a thread supplied to the needles of the knitting machine, and pneumatic actuators which move the clamps.

The dial group can further comprise cutting devices, or "knives", each provided with a pneumatically-activated cutting organ able to cooperate with the cutter so as to carry out the cut of the threads transported by the cutter. In addition, the dial group can comprise thread-aspirating devices which aspirate the threads of one or more feeders and the relative fluff. Lastly, the dial group can comprise further auxiliary devices, such as a blower device for opening the tongues, or a regulating device of the hook positions, or hook regulating cam, also provided with respective pneumatic actuators.

In substance, the dial group comprises internally thereof a grouping of numerous devices, some modularly repeated for each thread feeder, others shared among a plurality of feeders, or present singly.

The known knitting machines are further provided with a control board (or central unit) which comprises the electronic components able to govern the functioning of the whole knitting machine, i.e. to manage the rotation of the needle cylinder and the functioning of the devices comprised in the dial group and the feeders. In particular, the control board must be able to singly command all the devices present in the dial group: for this purpose it comprises a plurality of solenoid valves for commanding all the pneumatic actuators moving the hook control group, the clamps, the cutters (or knives) and any auxiliary devices present (such as the tongue-opening blower and the hook regulating cam). In practice, a respective solenoid valve is associated to each pneumatic actuator present in the dial group, the solenoid valve being located in the control board, which manages the pneumatic supply enabling activation of the corresponding pneumatic actuator.

To complete the pneumatic supply and control functions of the dial group, the known knitting machines further comprise a complex group of connections between the control board and the dial group itself. In fact, each pneumatic device of the dial group requires connecting pneumatically with the control board, so as to receive therefrom the compressed air required for the functioning of the plurality of pneumatic actuators present in the dial group. For this purpose, a pneumatic tube branches from each solenoid valve present in the control board, which pneumatic tube singly reaches a respective pneumatic actuator which is a part of a particular device of the dial group. The control board, by acting on each solenoid valve, is able to command as required the activation of each pneumatic actuator, and therefore to controlledly manage each pneumatic device of the dial group. A source of compressed air is present in the control board of the knitting machine, which source supplies all the pneumatic tubes.

The Applicant has found that the known knitting machines are not without drawbacks and can be improved in various ways, in particular with reference to the structural complexity thereof and the management of the dial group.

A drawback typical of the known solutions is represented by the fact that as described above it is necessary to predispose a plurality of pneumatic supply tubes which extend internally of the machine so as to connect the pneumatic devices of the dial group to the processing board. Overall the number of pneumatic connections can be very high: each single pneumatic actuator requires a tube for the compressed air, and the dial group can comprise tens of pneumatic actuators. Each pneumatic tube must be connected to the control board, where the solenoid valves are located.

The large number of pneumatic connections creates a series of drawbacks:

- it makes the pneumatic cabling operations of the machine complex and difficult, in particular the dial group;

- it increases the cost of the knitting machine;

- it increases the time required for manufacturing the knitting machine;

- it can lead to errors in the cabling and mounting of the machine;

- it makes the detecting of faults and/or malfunctioning difficult, and in general complicates the operations of maintenance of the knitting machine, in particular the dial group;

- it increases the probability of faults and malfunctioning, as a high number of tubes are present positioned in an environment subjected to vibrations, oil, dust, etc;

- it complicates the overall structure of the machine, which is occupied by a plurality of pneumatic tubes;

- it makes the structure and the programming of the control board complex, as it has to manage a very high number of pneumatic connections.

A further drawback of known knitting machines is the slow speed of the controls, as the pneumatic actuators of the dial group are supplied via pneumatic tubes singly connected to the control board, in which the respective command solenoid valve is located: the pneumatic groups of the dial group having a greater distance from the control board introduce a delay in the activation of the pneumatic actuators with respect to the instant at which the respective solenoid valves are activated. This reduces the activating velocity of the organs of the dial group, and overall limits the performance obtainable by the knitting machine.

In this situation the aim underpinning the present invention, in its various aspects and/or embodiments, is to disclose a circular knitting machine which is able to obviate one or more of the cited drawbacks.

A further aim of the present invention is to provide a knitting machine characterised by a small number of pneumatic connections destined to the dial group, in particular with respect to the known solutions.

A further aim of the present invention is to disclose a knitting machine characterised by mounting times, in particular pneumatic cabling times, that are faster than with the known solutions. A further aim of the present invention is to provide a knitting machine able to reduce the possibility of mounting errors.

A further aim of the present invention is to disclose a knitting machine characterised by high reliability of functioning and/or by a smaller predisposition to faults and malfunctioning.

A further aim of the present invention is to disclose a knitting machine characterised by a high degree of facility in the maintenance operations.

A further aim of the present invention is to disclose a knitting machine characterised by a simple and rational structure.

A further aim of the present invention is to disclose a knitting machine able to afford a more efficient and effective control of the dial group and the devices thereof.

A further aim of the present invention is to provide a knitting machine characterised by a versatile control of the devices of the dial group, so as to be easily adaptable to the various production requirements.

A further aim of the present invention is to disclose a knitting machine able to activate the devices of the dial group with greater velocity and precision with respect to the known knitting machines.

A further aim of the invention is to provide a knitting machine with improved performance, in particular able to improve the control and increase productivity, for example in terms of quantity of knitting produced by the time unit and/or the complexity of the knitting produced.

A further aim of the present invention is to disclose a knitting machine characterised by a production cost that is modest with respect to the performance and quality provided.

These aims and others besides, which will more fully emerge during the course of the following description, are substantially attained by a circular knitting machine and/or by a method for pneumatically supplying the dial group of a circular knitting machine, according to one or more of the appended claims, each of which taken alone (without the relative dependencies) or in any combination with the other claims, as well as according to the following aspects and/or embodiments, variously combined also with the above-mentioned claims.

In a first aspect, the invention relates to a circular knitting machine for knitwear or hosiery, comprising:

- a bearing structure;

- at least a needle-bearing organ or needle cylinder rotatably mounted in the bearing structure;

- a plurality of needles supported by the needle cylinder and mobile parallel to a rotation axis of the needle cylinder so as to produce a knitted fabric;

- a dial group arranged above the needle cylinder.

In an aspect, the dial group comprises: - a support ring (or plate) solidly constrained to the bearing structure and coaxial to the needle cylinder;

- a thread transport and cutting group, or "cutter", rotatably mounted externally of the support ring;

- a plurality of pneumatic activating devices arranged on the support ring, each comprising one or more respective pneumatic actuators and one or more respective solenoid valves configured and predisposed to activate or deactivate the pneumatic supply of the pneumatic actuators.

In an aspect, the dial group comprises at least a first pathway of pneumatic supply provided with a single main inlet for pneumatic supply, positioned in the dial group and destined to be connected to a compressed air source of the knitting machine, the first pneumatic supply pathway being configured so as to pneumatically supply the pneumatic actuators of at least a first group of devices present in the dial group.

In an aspect, the knitting machine comprises a plurality of thread feeding points, or feeders, in which the thread is fed to the needles of the machine, the feeding points being positioned circumferentially about the needle-bearing organ and distanced angularly to one another.

In an aspect, the plurality of pneumatically-acting devices of the dial group comprises at least a hook control group mounted to the support ring and comprising a body of the hook control group, one or more command cams movably mounted to the body and destined to interact with one or more hooks of the knitting machine, and a plurality of pneumatic actuators movably housed in the body and configured so as to controlledly move the one or more command cams, the mobile cam device comprising a plurality of solenoid valves mounted and connected directly to the body of the hook control group, each solenoid valve being configured and predisposed to activate or deactivate the pneumatic supply of a respective pneumatic actuator of the hook control group or another actuator located on the dial group, with the aim of activating the respective pneumatic actuator selectively.

In an aspect the plurality of pneumatically-acting devices of the dial group comprises a plurality of clamp groups, equal in number to the plurality of feed points and each singly dedicated to a respective feed point, each clamps group comprising at least a mobile clamp configured so as to retain or selectively block a thread supplied to the needles of the knitting machine, at least a pneumatic actuator configured so as to controlledly move the at least a clamp, and at least a solenoid valve located in the clamp group and configured and predisposed to activate or deactivate pneumatic supply of a respective pneumatic actuator of the clamp group or a further actuator located on the dial group, with the aim of selectively activating the respective pneumatic actuator. In an aspect the dial group comprises a second pneumatic supply pathway provided with a respective single main pneumatic supply inlet, positioned in the dial group and destined to be connected to a compressed air source of the knitting machine, the second pneumatic supply pathway being configured so as to pneumatically supply the pneumatic actuators of a second group of devices, distinct from the first group of devices, of the plurality of pneumatically activated devices present in the dial group.

In an aspect the first the first group of devices comprises at least two clamps group of the plurality of clamp groups. In an aspect, the first group of devices comprises the whole plurality of clamps groups of the dial group.

In an aspect the second group of devices comprises at least the clamps groups of the plurality of clamps groups not comprised in the first group of devices.

In an aspect the first group of devices comprises said at least a needle control group. In an aspect the second group of devices comprises the at least a needle control group.

In an aspect the first supply pathway pneumatically supplies all the devices of at least a determined type, for example the clamps groups.

In an aspect the second supply pathway pneumatically supplies all the devices of at least a determined type, for example the hook control group.

In an aspect the first group or second group of devices pneumatically supply all the devices of at least a determined type, for example the cutting devices and/or the blowing devices and/or the hook adjusting cam.

In an aspect the dial group comprises exactly a single first serial pneumatic pathway, configured so as to pneumatically supply all the pneumatic actuators present in the dial group.

In an aspect the first group of devices comprises the whole plurality of pneumatically-activating devices of the dial group, the dial group comprising exactly a single first serial pneumatic pathway, configured so as to pneumatically supply all the pneumatic actuators present in the dial group.

In an aspect the hook control group comprises a pneumatic supply inlet enabling the inlet of a compressed air flow into the hook control group, and at least a first pneumatic supply outlet, enabling exit of a compressed air flow from the hook control group, and each clamp group comprises a respective pneumatic supply inlet, enabling inlet of a flow of compressed air into the clamp group and at least a respective outlet of pneumatic supply enabling exit of a flow of compressed air from the clamp group.

In an aspect, the hook control group further comprises a second pneumatic supply outlet enabling exit of a flow of compressed air from the hook control group. In an aspect the main pneumatic supply inlet is located on the hook control group, coinciding with the pneumatic supply inlet and is connected to the compressed air source of the knitting machine via a pneumatic inlet conduit. In an aspect the main pneumatic supply inlet coincides with the pneumatic supply inlet of the hook control group.

In an aspect the only serial pneumatic supply pathway develops in a ring on the dial group about the rotation axis of the cylinder, the only pneumatic supply pathway comprising a pneumatic conduit or a sequence of portions of pneumatic pathway comprising a pneumatic conduit or a sequence of portions of pneumatic conduit connecting, in series, the hook control group and all the clamps groups of the dial group, so that along the single pneumatic supply pathway each clamps group is connected pneumatically with the preceding clamps group and with the successive clamps group.

In an aspect the sequence of portions of conduit of the single pneumatic pathway of the dial group comprises a plurality of connecting conduits connecting adjacent clamps groups.

In an aspect the hook control group comprises the main pneumatic supply inlet of the dial group. In an aspect the only pneumatic supply pathway of the dial group comprises:

- a first connecting conduit connecting the first pneumatic supply outlet of the hook control group with the pneumatic supply inlet of a first clamps group;

- a plurality of connecting conduits, each connecting the pneumatic supply outlet of a clamps group with the pneumatic supply inlet of the successive clamps group, starting from the first clamps group receiving pneumatic supply from the hook control, up to a final clamps group of the dial group, each connecting conduit being interposed and shared between two adjacent clamps groups;

- preferably, a final connecting conduit, connecting the pneumatic supply outlet of the last clamps group with a second pneumatic supply outlet of the hook control group, the final pneumatic supply conduit completing and ring-closing the only serial pneumatic pathway.

In an aspect the plurality of pneumatic activating devices of the dial group comprises a plurality of cutting devices, or "knives", arranged on the support ring and each comprising a respective pneumatic supply inlet, a respective pneumatic actuator and a respective cutting organ configured so as to selectively cooperate with the cutting group so as to perform a cut of one or more threads transported by the cutting group.

In an aspect said sequence of portions of the single serial pneumatic supply pathway of the dial group further comprises a plurality of branch conduits equal in number to the plurality of cutting devices, each branch conduit connecting an auxiliary outlet for pneumatic supply of a clamps group of a determined feed point with the respective pneumatic supply inlet of a determined cutting device.

In an aspect the needle-bearing organ can be, equivalently, a needle plate. In an aspect the knitting machine is a circular knitting machine for knitwear, seamless knitwear, hosiery or the like. In a further independent aspect, the present invention relates to a method for pneumatic supply of the dial group of a circular knitting machine, the method comprising following steps:

- predisposing a circular knitting machine for knitwear or hosiery, comprising:

- a bearing structure;

-a plurality of needles supported by the needle cylinder and mobile parallel to a rotation axis of the needle cylinder so as to produce a knitted fabric;

- a dial group arranged above the needle cylinder and comprising:

- a support ring solidly constrained to the bearing structure and coaxial to the needle cylinder;

- a thread transport and cutting group rotatably mounted externally of the support ring;

- a plurality of pneumatic activated devices arranged on the support ring (4), each comprising one or more respective pneumatic actuators and one or more respective solenoid valves configured and predisposed to activate or deactivate the pneumatic supply of the pneumatic actuators;

- predisposing a pathway of pneumatic supply provided with a single main inlet for pneumatic supply;

- connecting the main inlet to a source of compressed air of the knitting machine;

- by means of the pneumatic supply pathway, pneumatically supplying the pneumatic actuators of the plurality of the pneumatically activated plurality of devices present in the dial group.

Each of the above aspects of the invention can be taken alone or in combination with any one of the claims or other described aspects.

Further characteristics and advantages will emerge more clearly from the detailed description of some embodiments, among which also a preferred embodiment, by way of non-exclusive example, of a circular knitting machine according to the present invention and a method for pneumatically supplying the dial group of a circular knitting machine according to the present invention. The description will be set down in the following with reference to the appended drawings, provided by way of non-limiting example, in which:

- figure 1 is a perspective view of a possible embodiment of a circular knitting machine according to the present invention, with some parts removed; in particular the dial group of the knitting machine is shown;

- figure 2 is a plan view from above of the dial group of figure 1 ;

- figure 3 is a further perspective view of the dial group of figure 1 ; - figure 4 is a further plan view (from above) of the dial group of figure 1 , with some components removed (in particular the thread-aspirating mouths) with the aim of showing specific devices of the dial group (in particular the clamps groups and the hook control group) and the pneumatic supply part;

figure 5 is an enlarged view of a portion of the dial group of figure 4, in particular showing the hook control group, two clamps groups and a cutting device;

figure 6 is an enlarged view of a portion of the dial group of figure 3.

With reference to the figures, reference number 1 denotes in its entirety a circular knitting machine according to the present invention, while numeral 3 denotes in its entirety the dial group of the knitting machine. In general, the same reference number is used for identical or like elements, possibly in the variant embodiments thereof.

Figure 1 illustrates a possible embodiment of a knitting machine according to the present invention, with some parts removed. In particular, the illustration of the machine is focussed on the dial group 3 and on the devices connected thereto, so as to enable comprehension of the present invention. The base of the knitting machine, the section comprising the processing board, the knitting head comprising the needle-bearing organ, the needles themselves and other parts of the machine are not illustrated in detail in the figures, as they are of known type and conventional. From the point of view of textile technology, the functioning of the whole knitting machine (for example the functioning of the knitting head, the cooperation between needles and threads, etc.) is not described in detail, as it is known in the technical sector of the present invention.

The circular knitting machine for knitwear or seamless knitwear or hosiery, comprises a bearing structure, at least a needle-bearing organ or a needle cylinder rotatably mounted on the bearing structure, and a plurality of needles supported by the needle cylinder and mobile parallel to a rotation axis of the needle cylinder so as to produce a knitted fabric. The needle cylinder can have a variable diameter according to knitting needs; for example the diameter can be 4 inches, 8 inches, 16 inches, 24 inches. The needle-bearing organ can equivalently be a needle plate. The machine further comprises a plurality of thread feeding points 8, or feeders, in which the thread is supplied to the needles of the machine. The feeders 8 are positioned circumferentially about the needle-bearing organ and distanced angularly from one another. Figure 1 shows a knitting machine comprising, by way of example, eight feeders, distributed angularly and uniformly about the needle cylinder. The knitting machine can comprise a variable number of feeders, for example 2, 4, 6, 8, 10, 12, 16 or more.

The circular knitting machine further comprises a dial group 3 arranged superiorly of the needle cylinder and comprising:

- a thread transport and cutting group 4a, rotatably mounted externally of the support ring 4;

The dial group 3 comprises at least a first pathway of pneumatic supply 6 provided with a single main inlet 7 for pneumatic supply, positioned in the dial group and destined to be connected to a compressed air source of the knitting machine. The first pneumatic supply pathway 6 is configured so as to pneumatically supply the pneumatic actuators of at least a first group of devices of the plurality of pneumatically activating devices 5 present in the dial group 3.

The plurality 5 of pneumatically-activated devices of the dial group preferably comprises at least a hook control group 10 mounted to the support ring 4 and comprising a body 11 of the hook control group 11 , one or more command cams 12 movably mounted to the body 11 and destined to interact with one or more hooks of the knitting machine, and a plurality of pneumatic actuators 13 movably housed in the body 11 and configured so as to controlledly move the one or more command cams 12.

The mobile cam device 10 comprises a plurality of solenoid valves 14 mounted and connected directly to the body 11 of the hook control group, each solenoid valve 14 being configured and predisposed to activate or deactivate the pneumatic supply of a respective pneumatic actuator 13 of the hook control group or another actuator located on the dial group 3, with the aim of activating the respective pneumatic actuator selectively.

The plurality 5 of pneumatically activating devices of the dial group preferably further comprises a plurality of clamp groups 20, equal in number to the plurality of feed points 8 and each singly dedicated to a respective feed point 8, each clamps group 20 comprising at least a mobile clamp 22 configured so as to retain or selectively block a thread supplied to the needles of the knitting machine, at least a pneumatic actuator 23 configured so as to controlledly move the at least a clamps 22, and at least a solenoid valve 24 located in the clamps group 20 and configured and predisposed to activate or deactivate pneumatic supply of a respective pneumatic actuator 23 of the clamps group or a further actuator located on the dial group 3, with the aim of selectively activating the respective pneumatic actuator.

Note that the above-mentioned main inlet 7 of the first pneumatic supply pathway 6 is arranged directly on the dial group, preferably on the support ring 4 or (as shown by way of example in the figures) on one of the devices of the plurality of pneumatically-activated devices; the main inlet of the pathway is supplied by a single pneumatic inlet conduit connected to a source of compressed air of the knitting machine.

In an embodiment (not illustrated), the dial group further comprises a second pneumatic supply pathway provided with a respective single main pneumatic supply inlet, positioned in the dial group and destined to be connected to a compressed air source of the knitting machine. The second pneumatic supply pathway being configured so as to pneumatically supply the pneumatic actuators of a second group of devices, distinct from the first group of devices, of the plurality of pneumatically activated devices present in the dial group, and/or wherein the first group of devices comprises at least two clamps group of the plurality of clamps groups.

The first group of devices preferably comprises at least two clamps groups of the plurality of clamps groups. The first group even more preferably comprises the whole plurality of clamps groups of the dial group.

In a possible variant, the second group of devices (if present) can comprise at least the clamps groups (of the plurality of clamps groups) not comprised in the first group of devices. In this case the clamps groups of the dial group are subdivided into two groups and the two supply pathways are each occupied with supplying the clamps groups of a group.

The hook control group can be comprised in the first group or in the second group of devices, thus being supplied pneumatically by the first or the second supply pathway.

The first supply pathway preferably pneumatically supplies all the devices of at least a certain type, for example all the clamps groups. Likewise, the second supply pathway (if present) pneumatically supplies all the devices of at least a respective determined type, for example all the hook controls (or the hook control alone if there is only one).

In a possible embodiment (not shown), the dial group can further comprise a third device group, distinct from the first and second groups, comprising respective devices of the plurality of pneumatically-activated devices present in the dial group. The third group is pneumatically supplied by a third pneumatic supply group provided with a respective single main inlet, positioned in the dial group and destined to be connected to a source of compressed air of the knitting machine.

Passing to a description of the preferred embodiment, shown by way of example in figures 1-6, the dial group 3 preferably comprises exactly a single serial pneumatic supply pathway 6, configured so as to pneumatically supply all the pneumatic actuators present in the dial group. In other words, the first group of devices comprises the whole plurality 5 of pneumatically- activated devices of the dial group, and the dial group 3 comprises exactly a single first serial pneumatic pathway 6, configured so as to pneumatically supply all the pneumatic actuators present in the dial group.

The hook control group 10 preferably comprises a pneumatic supply inlet 7' enabling the inlet of a compressed air flow into the hook control group, and at least a first pneumatic supply outlet 15, enabling exit of a compressed air group from the hook control group.

The hook control group 10 can further comprise a second pneumatic supply outlet 16, which enables exit of a flow of compressed air from the hook control group.

Each clamps group 20 preferably comprises a respective pneumatic supply inlet 25, enabling inlet of a flow of compressed air into the clamps group, and at least a respective outlet of pneumatic supply 26 enabling exit of a flow of compressed air from the clamps group.

The above inlet 25 and outlet 26 for pneumatically supplying each clamps group are identified by considering a supply pathway that is anticlockwise according to the layout in the figures (in particular figure 4). This means that following the supply pathway 6, the air enters and exits from each clamps group respectively from the connections denoted by reference numerals 25 and 26, which following this direction assume the functions of inlet and outlet: this enables realizing a serial pathway connecting the clamps groups. Alternatively, and entirely equivalently, the supply pathway can develop in a clockwise direction, in which case the connection 26 assumes the function of inlet and the connection 25 assumes the function of outlet of pneumatic supply of the single clamps group.

As shown by way of example in the figures, the main pneumatic supply inlet 7 is preferably located on the hook control group 10 and is connected to the compressed air source of the knitting machine (not illustrated) via a pneumatic inlet conduit 9; in this case the main inlet 7 of the hook control group 10 coincides with the pneumatic supply inlet 7' of the hook control group 10.

The above-mentioned only (and first) serial pneumatic supply pathway preferably develops in a ring on the dial group 3 about the rotation axis of the cylinder, the only pneumatic supply pathway 6 comprising a pneumatic conduit or a sequence of portions of pneumatic pathway 6 comprising a pneumatic conduit or a sequence of portions of pneumatic conduit connecting, in series, the hook control group 10 and all the clamps groups 20 of the dial group 3, so that along the single pneumatic supply pathway each clamps group is connected pneumatically with the preceding clamps group and with the successive clamps group.

The sequence of portions of conduit of the single pneumatic pathway 6 of the dial group 3 preferably comprises a plurality of connecting conduits connecting adjacent clamps groups. The single pneumatic supply pathway 6 (see in particular figure 4) of the dial group preferably comprises: - a first connecting conduit 31 connecting the first pneumatic supply outlet 15 of the hook control group 10 with the pneumatic supply inlet 25 of a first clamps group 20a;

- a plurality of connecting conduits 32, each connecting the pneumatic supply outlet 26 of a clamps group 20 with the pneumatic supply inlet 25 of the successive clamps group 20, starting from the first clamps group 20a receiving pneumatic supply from the hook control 10, up to a final clamps group 20b of the dial group 3, each connecting conduit 32 being interposed and shared between two adjacent clamps groups;

- a final connecting conduit 33, connecting the pneumatic supply outlet 26 of the last clamps group 20b with a second pneumatic supply outlet 16 of the hook control group 10, the final pneumatic supply conduit completing and ring-closing the only serial pneumatic pathway.

Note that the "first clamps group" 20a and the "final clamps group"20b can be any one of the clamps groups present on the dial group; as shown by way of example in figure 6, with the aim of realising a single pneumatic supply pathway, the first and final clamps groups are the groups that are positioned adjacent to the hook control group, where the first clamps group is the one immediately downstream of the hook control group and the final clamps group is the one immediately upstream of the hook control group.

Overall the pneumatic supply pathway takes on a circular or ring conformation on the dial group. In an embodiment, the first 15 and second pneumatic supply outlet 16 are connected to two opposite branches of the ringed pneumatic supply pathway and enable supplying, in two directions, the whole ring starting from the hook control group; in substance, the compressed air is injected by the two outlets 15 and 16 towards two opposite sides of the dial group, i.e. in the two clamps groups immediately adjacent to and on opposite sides of the hook control group. In this case, the compressed air reaches the hook control group by means of the inlet 7' and is injected into the circuit by both the outlets 15 and 16. This increases the efficiency of the pneumatic supply in the whole pathway, as the air flow is balanced on two sides of the pathway, limiting the difference of pressure in inlet to the single devices supplied.

Equivalently, the compressed air can be, alternatively, injected in the whole circuit by means of a sole outlet (or, there are two outlets, by a single one thereof): in this case the compressed air (received from the hook control group by means of the pneumatic supply inlet 7') is sent to an adjacent clamps group, from this to the next, and so one, up to reaching the final clamps group, which can be newly connected to the hook control group with the aim of closing the ring supply pathway.

The plurality of pneumatic activating devices 5 of the dial group preferably comprises a plurality of cutting devices 40 arranged on the support ring 4 and each comprising a respective pneumatic supply inlet 41 , a respective pneumatic actuator 42 and a respective cutting organ 43 configured so as to selectively cooperate with the cutting group 4a so as to perform a cut of one or more threads transported by the cutting group.

As can be seen in the figures, the cutting group 4a is externally provided with an annular cogging for drawing threads: the cogging comprises a plurality of cogs 4b each of which is able to draw a thread and constituting a cutting blade, while the respective cutting organ 43 of each of the cutting devices 40 constitutes a counter-blade able to selectively cooperate with a cog 4b of the cogging so as to cut a thread borne by the cog of the cogging.

The sequence of portions of the single serial pneumatic supply pathway 6 of the dial group preferably further comprises a plurality of branch conduits 35, each branch conduit 35 connecting an auxiliary outlet 27 for pneumatic supply of a clamps group 20 of a determined feed point 8 with the respective pneumatic supply inlet 41 of a determined cutting device 40.

In a possible further embodiment, the clamps group 20 can comprise a first solenoid valve 24a configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a first clamps 22a of the group.

In a further embodiment, the clamps group 20 can comprise a first solenoid valve 24a configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic activate activating a first clamp 22a of the group and a second solenoid valve 24b configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a second clamp 22b of the group, or alternatively the clamps group can comprise a first solenoid valve 24a configured and predisposed so as to activate or deactivate the pneumatic supply of a pneumatic actuator activating a first clamp 22a of the group and a second solenoid valve 24b configured and predisposed to activate or deactivate the pneumatic supply of the auxiliary pneumatic supply exit 27 of the clamps group 20 so as to selectively activate the pneumatic actuator of a cutting device 40.

In a further embodiment, the clamps group can comprise a first solenoid valve configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a first clamp of the group, a second solenoid valve configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a second clamp of the group and a third solenoid valve configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a third clamp of the group, or alternatively the clamps group can comprise a first solenoid valve configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a first clamp of the group, a second solenoid valve configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a second clamp of the group, and a third solenoid valve configured and predisposed to activate or deactivate the pneumatic supply of the auxiliary pneumatic supply outlet of the clamp group so as to selectively activate the pneumatic actuator of a cutting device or knife.

In substance, each clamps group can comprise a variable number of solenoid valves, for example from one to three, so as to be able to control a plurality of clamps (for example from one to three) or control both clamps and cutting devices (for example one or more clamps and together a respective cutting device).

As shown by way of example in the figures, the dial group 3 comprises a plurality of thread aspirating devices 50, configured to suck the threads on one or more thread feeding points and the relative fluff. The plurality of thread aspirating devices 50 can be equal in number to the plurality of thread feeding points, in which case each thread aspirating device or mouth is singly dedicated to a respective thread feeding point, or (as shown in the figures) can be half in number with respect to the thread feeding points, in which case each thread aspirating mouth is shared between two adjacent thread feeding points.

The plurality of cutting devices 40 is preferably equal in number to the plurality of thread- aspirating mouths 50, each cutting device being arranged adjacently to a respective thread- aspirating device, or it is equal to half in number of the clamps groups.

The plurality of pneumatically-acting devices 5 of the dial group 3 comprises at least a blowing device 60, or "tongue-opening blow", arranged on the support ring 4 and comprising a respective pneumatic supply inlet 61 and a respective compressed air dispensing nozzle 62 configured so as to selectively open one or more tongues of the needles of the needle-bearing organ during the working.

The hook control group 10 preferably comprises a first auxiliary serial pneumatic supply outlet 17 and the sequence of portions of the single serial pneumatic supply pathway of the dial group further comprises a first auxiliary conduit 37 connecting the first auxiliary outlet with the respective pneumatic supply inlet 61 of the blowing device 60.

The plurality of solenoid valves 14 of the hook control group 10, mounted and connected directly to the body 11 of the hook control group 11 , preferably comprises a first auxiliary solenoid valve 14a configured and predisposed to enable or prevent passage of compressed air from the first auxiliary outlet 17 of pneumatic supply towards the blowing device 60, with the aim of selectively activating the exit of compressed air from the dispensing nozzle 62 of the blowing device.

In this way hook control group transmits the pneumatic supply to the blower device and commands inflow of air thereto via a branch of the pneumatic supply pathway 6 and a dedicated solenoid valve.

The plurality of pneumatically activating devices 5 of the dial group 3 can further comprise at least a regulating device of the position of the hooks 70, arranged on the support ring 4 and comprising a respective pneumatic supply inlet 71 , at least a respective pneumatic actuator 72 and a respective regulating cam configured to selectively modify the position of the hooks of the knitting machine during working.

The hook control group 10 comprises a second auxiliary pneumatic supply outlet 18 and the sequence of portions of the single serial pneumatic supply pathway of the dial group further comprises a second auxiliary conduit 38 connecting the second auxiliary pneumatic supply outlet with the respective pneumatic supply inlet 71 of the regulating device of the position of the hooks 70.

The plurality of solenoid valves 14 of the hook control group 10, mounted and connected directly to the body 11 of the hook control group, preferably comprises a second auxiliary solenoid valve 14b configured and predisposed to allow or prevent passage of compressed air from the second auxiliary pneumatic supply outlet 18 towards the regulating device of the position of the hooks 70, with the aim of selectively activating the respective pneumatic actuator 71 and controlling the movement of the respective regulating cam.

In this way the hook control group transmits the pneumatic supply to the hook adjusting cam, and commands the inflow of air via a further branch of the pneumatic supply pathway 6 and a dedicated solenoid valve.

In a possible embodiment (not shown), all the devices of a certain type, for example all the cutting devices and/or the tongue-opening blowing devices and/or the hook regulating cam, can be included in a respective devices group, for example first group or the second group or the third group illustrated above. In this way each type of device of the dial group refers to and is supplied by a single pneumatic supply pathway.

In further possible embodiments, the plurality of devices of the dial group can comprise, beyond the first and the second groups of devices, also sub-groups of devices; overall the devices comprised in the groups form the above-mentioned plurality 5 of pneumatically-activated devices which are part of the dial group.

By way of example, the first group might comprise the clamps groups, while the second group might comprise the hook control group, the tongue-opening blower and the hook regulating cams. Alternatively, and still by way of example, the first group might comprise some clamps groups and the cutters, while the second group might comprise the remaining clamps groups and the hook control group. In a further example, the first group might comprise some clamps groups and the cutters, the second group the remaining clamps groups, and the third group the hook control group, the tongue-opening blower and the hook regulating cam.

In general, the pneumatically activated devices present on the dial group can be variously comprised in the groups (first and/or second and/or third and/or further sub-groups) in which the plurality of devices 5 is sub-divided, each group being supplied by the respective pneumatic supply pathway.

The knitting machine preferably comprises a source of compressed air (internal or external of the machine, not shown in the figures as of known type) to which the pneumatic supply pathway 6 of the dial group 3 to which the pneumatic supply pathway 6 of the dial group 3 is connected to receive therefrom a flow of compressed air.

The source can comprise a filter and/or regulating and/or lubricating group of the compressed air injected into the pneumatic supply pathway of the knitting machine.

The dial group 3 preferably comprises an electronic control board 80, for example located on a hook control group, configured and predisposed to command the solenoid valves of the hook control group and the respective solenoid valves of one or more of the clamps groups of the dial group, preferably all the clamps groups of the dial group.

Each clamps group 20 of the dial group preferably comprises a respective electronic interface board 81 connected to the electronic control board 80 of the dial group so as to receive therefrom command instructions for the respective solenoid valves present in the clamps group.

The dial group is preferably provided with a serial control ring comprising a sequence of portions of electric cable connecting, in series, the hook control group and the clamps groups of the dial group, so that along the control ring each clamps group is connected electrically and/or electronically with the preceding clamps group and with the following clamps group. The control ring constitutes a series communication channel shared by the hook control group and the clamps groups of the dial group, by means of which it is possible to send electric supply and control signals to each group.

The knitting machine preferably comprises a central processing unit (not illustrated), to which at least the electronic control board of the dial group is operatively connected; the central processing unit is configured so as to manage the functioning of the knitting machine and to send a set of command instructions to the electronic command board of the dial group.

The serial control ring of the thread feeders is preferably connected, in at least a point thereof, to the central processing unit, so as to receive therefrom electric supply and control signals and to send thereto a plurality of data relating to the devices comprised in each feeder.

It is noted that in the present invention the solenoid valves of the hook control group and the clamps group are positioned directly in the respective group, i.e. are delocalized with respect to the central unit of the knitting machine and located direction in the dial group.

From a pneumatic point of view, the present invention describes a knitting machine having a profoundly different configuration to those of the prior art. In fact, by positioning the solenoid valves at the respective pneumatic actuators (i.e. locating the solenoid valves which command the actuators of the hook control group directly on the body of the group and the solenoid valves controlling the clamps directly on the clamps group) it is possible to serialise the pneumatic supply part, realizing a single pneumatic supply pathway having a circular or ring conformation. In fact, the presence for each device integrating a pneumatic part of the solenoid valves enables eliminating the single pneumatic conduits which, in the prior art, connect each solenoid valve located in the control board point-to-point with the respective pneumatic actuator, and enables carrying compressed air directly to the dial group, where the solenoid valves activate - in place - the respective pneumatic actuators.

The present invention enables delocalising the control of the pneumatic devices of the dial group from the central unit of the dial group, and realizing a single pneumatic supply pathway for the dial group.

The embodiment of figures 1-6 shows a configuration by way of example of a dial group of a knitting machine according to the present invention. It comprises:

- eight thread feeding points;

- a single hook control group provided with two command cams, each activated by two solenoid valves, and two auxiliary solenoid valves for a total of six solenoid valves;

- eight clamps groups, one for each feeding point, each provided with one, two or three solenoid valves, according to whether it controls one or more clamps and possibly a cutting device;

- four thread-aspirating mouths (one for each two feeding devices);

- four cutting devices (one for each mouth, or two for each two mouths), each controlled by a solenoid valve placed on a respective clamps group;

- a single blowing device for tongue opening (controlled by one of the auxiliary solenoid valves of the hook control device);

- a hook-regulating cam (controlled by one of the auxiliary solenoid valves of the hook control device).

On the basis of the type of knitting machine and desired working, the number and position of each of the above-described dial group (for example the number of hook control groups or clamps groups or cutting devices etc.) can be changed. Further, the number and position of the solenoid valves in the groups present in the dial can be changed, as can the internal pneumatic connections of the dial group. The variants are to be considered as part of the scope of the present invention.

The present invention further relates to a method for pneumatic supply to a dial group of a circular knitting machine. The method comprises following steps:

- predisposing a circular knitting machine for knitwear or hosiery, comprising:

- a bearing structure;

- a dial group arranged above the needle cylinder and comprising:

- a plurality of pneumatic activating devices arranged on the support ring, each comprising one or more respective pneumatic actuators and one or more respective solenoid valves configured and predisposed to activate or deactivate the pneumatic supply of the pneumatic actuators;

- predisposing a pneumatic supply pathway of the dial group provided with a single main inlet for pneumatic supply;

- by means of the pneumatic supply pathway, pneumatically supplying the pneumatic actuators of the plurality of pneumatically activated devices present in the dial group.

In the step of predisposing a pneumatic pathway, the pathway is preferably only one for the whole dial group and is configured so as to pneumatically supply all the pneumatic actuators present in the dial group.

The method preferably comprises steps of: connecting the hook control group and all the clamps groups of the dial group in series, by means of a pneumatic conduit or a sequence of portions of pneumatic conduit, so that each clamps group is connected pneumatically along the pneumatic supply pathway with the preceding clamps group and with the successive clamps group.

The invention as it is conceived is susceptible to numerous modifications and variants, all falling within the scope of the inventive concept, and the cited components can be replaced by others that are technically equivalent.

The present invention is able to be used on both new machines and already-existing machines, in the latter case in replacement for traditional parts of pneumatic supply of the dial group.

The invention attains important advantages. Primarily the whole invention enables overcoming some of the drawbacks of the prior art. Further, the present invention leads to a reduction in the number of pneumatic tubes present on the dial group.

Further, the present invention enables a reduction in the time required for mounting the knitting machines and a simplification of the pneumatic cabling operations of the dial group. Further, the present invention enables reducing the costs of manufacture of a circular knitting machine. Further, the present invention enables reducing the risks of mounting errors of the knitting machine. Further, the present invention enables a simplification of the maintenance operations of the machine, and in general improves accessibility of the dial group and the knitting head.

Further, the present invention enables reducing breakdowns and malfunctioning of the knitting machine and/or guarantees a greater efficiency over time, as the presence of pneumatic tubes is limited.

Further, the present invention enables increasing the performance of a knitting machine, as by delocalising the solenoid valves from the central unit of the dial group (directly placing them on the respective device) it is possible to more rapidly control the pneumatic actuators, and therefore carry out the knitting work at higher speeds, in particular when a change of configuration of one or more of the thread guides is required.

Further, the serialisation of the pneumatic devices of the dial group described in the present invention enables making the structure of the dial group modular: the addition or removal of a thread guide can be carried out simply and rapidly.

Further, the present invention enables increasing the control of a knitting machine and/or increasing the versatility of use of the knitting machine for different production requirements. Further, the knitting machine of the present invention is characterised by a competitive cost and a simple and rational structure.

Claims

1. A circular knitting machine (1) for knitwear or hosiery, comprising:

- a bearing structure;

- a plurality of needles supported by the needle cylinder and movable parallel to a rotation axis of the needle cylinder for producing a knitted fabric;

- a dial group (3) arranged above the needle cylinder and comprising:

- a support ring (4) solidly constrained to the bearing structure and coaxial to the needle cylinder;

- a thread transport and cutting group (4a), or "cutter", rotatably mounted externally of the support ring (4);

- a plurality of pneumatic activating devices (5) arranged on the support ring (4), each comprising one or more respective pneumatic actuators and one or more respective solenoid valves configured and predisposed to activate or deactivate the pneumatic supply of the pneumatic actuators;

wherein the dial group (3) comprises at least a first pneumatic supply pathway (6) provided with a single main inlet (7) for pneumatic supply, positioned in the dial group and destined to be connected to a compressed air source of the knitting machine, the first pneumatic supply pathway (6) being configured for pneumatically supplying the pneumatic actuators of at least a first group of devices of the plurality of pneumatically activating devices (5) present in the dial group (3).

2. The circular knitting machine (1) of claim 1 , comprising a plurality of thread feeding points (8), or feeders, in which the thread is fed to the needles of the machine, the feeding points (8) being positioned circumferentially about the needle-bearing organ and distanced angularly to one another, and wherein the plurality (5) of pneumatically-acting devices comprises:

- at least a hook control group (10) mounted to the support ring (4) and comprising a body (11) of the hook control group (11), one or more command cams (12) movably mounted to the body (11) and destined to interact with one or more hooks of the knitting machine, and a plurality of pneumatic actuators (13) movably housed in the body (11) and configured for controlledly moving the one or more command cams (12), the mobile cam device (10) comprising a plurality of solenoid valves (14) mounted and connected directly to the body (11 ) of the hook control group, each solenoid valve (14) being configured and predisposed to activate or deactivate the pneumatic supply of a respective pneumatic actuator (13) of the hook control group or another actuator located on the dial group (3), with the aim of selectively activating the respective pneumatic actuator; - a plurality of clamp groups (20), equal in number to the plurality of feed points (8) and each singly dedicated to a respective feeding point (8), each clamps group (20) comprising at least a mobile clamp (22) configured for retaining or selectively blocking a thread supplied to the needles of the knitting machine, at least a pneumatic actuator (23) configured for controlledly moving the at least a clamp (22), and at least a solenoid valve (24) located in the clamps group (20) and configured and predisposed to activate or deactivate pneumatic supply of a respective pneumatic actuator (23) of the clamps group or a further actuator located on the dial group (3), with the aim of selectively activating the respective pneumatic actuator.

3. The circular knitting machine (1 ) of claim 1 or 2, wherein the dial group comprises a second pneumatic supply pathway provided with a respective single main pneumatic supply inlet, positioned in the dial group and destined to be connected to a compressed air source of the knitting machine, the second pneumatic supply pathway being configured for pneumatically supplying the pneumatic actuators of a second group of devices, distinct from the first group of devices, of the plurality of pneumatically activated devices present in the dial group, and/or wherein the first group of devices comprises at least two clamps groups of the plurality of clamps groups, preferably comprises the whole plurality of clamps groups of the dial group, and/or wherein the second group of devices comprises at least the clamps groups of the plurality of clamps groups not comprised in the first group of devices, and/or wherein the first group or second group of devices comprises the at least a needle control group, and/or wherein the first supply pathway pneumatically supplies all the devices of at least a determined type, for example the clamps groups.

4. The circular knitting machine (1) of any one of the preceding claims, wherein the first group of devices comprises the whole plurality (5) of pneumatically-activated devices of the dial group, the dial group (3) comprising exactly a single first serial pneumatic pathway (6), configured for pneumatically supplying all the pneumatic actuators present in the dial group, and/or wherein the hook control group (10) comprises a pneumatic supply inlet (7') enabling inlet of a compressed air flow into the hook control group, and at least a first pneumatic supply outlet (15), enabling exit of a compressed air flow from the hook control group, and each clamps group (20) comprises a respective pneumatic supply inlet (25, 26), enabling inlet of a flow of compressed air into the clamps group, and at least a respective outlet of pneumatic supply (26, 25) enabling exit of a flow of compressed air from the clamps group and/or wherein the main pneumatic supply inlet (7) is located on the hook control group (10), coinciding with the pneumatic supply inlet (7') and is connected to the compressed air source of the knitting machine via a pneumatic inlet conduit (9).

5. The circular knitting machine (1) of the preceding claims, wherein said single serial pneumatic supply pathway develops in a ring on the dial group (3) about the rotation axis of the cylinder, said single pneumatic supply pathway (6) comprising a pneumatic conduit or a sequence of portions of pneumatic pathway (6) comprising a pneumatic conduit or a sequence of portions of pneumatic conduit connecting, in series, the hook control group (10) and all the clamps groups (20) of the dial group (3), so that along the single pneumatic supply pathway each clamps group is connected pneumatically with the preceding clamps group and with the successive clamps group, and/or wherein the sequence of portions of conduit of the single pneumatic pathway (6) of the dial group (3) comprises a plurality of connecting conduits connecting adjacent clamps groups.

6. The circular knitting machine (1) of any one of the preceding claims, wherein the hook control group (10) comprises the main pneumatic supply inlet (7, 7') of the dial group (3) and said single pneumatic supply pathway (6) of the dial group comprises:

- a first connecting conduit (31) connecting the first pneumatic supply outlet (15) of the hook control group (10) with the pneumatic supply inlet (25) of a first clamps group (20a);

- a plurality of connecting conduits (32), each connecting the pneumatic supply outlet (26) of a clamps group (20) with the pneumatic supply inlet (25) of the successive clamps group (20), starting from the first clamps group (20a) receiving pneumatic supply from the hook control (10), up to a final clamps group (20b) of the dial group (3), each connecting conduit (32) being interposed and shared between two adjacent clamps groups;

- possibly, a final connecting conduit (33), connecting the pneumatic supply outlet (26) of the last clamps group (20b) with a second pneumatic supply outlet (16) of the hook control group (10), the final pneumatic supply conduit completing and loop-closing said single serial pneumatic pathway.

7. The circular knitting machine (1 ) of any one of the preceding claims, wherein the plurality of pneumatic activating devices (5) of the dial group comprises a plurality of cutting devices (40), or "knives", arranged on the support ring (4) and each comprising a respective pneumatic supply inlet (41), a respective pneumatic actuator (42) and a respective cutting organ (43) configured for selectively cooperating with the transport and cutting group (4a) so as to perform a cut of one or more threads transported by the transport and cutting group (4a), and/or wherein the transport and cutting group (4a) is externally provided with an annular cogging for drawing threads, the cogging comprising a plurality of cogs (4b) each of which is able to draw a thread and constituting a cutting blade, the respective cutting organ (43) of each of the cutting devices (40) constituting a counter-blade able to selectively cooperate with a cog (4b) of the cogging for cutting a thread borne by the cog of the cogging, and/or wherein the sequence of portions of the single serial pneumatic supply pathway (6) of the dial group further comprises a plurality of branch conduits (35) equal in number to the plurality of cutting devices (40), each branch conduit (35) connecting an auxiliary outlet (27) for pneumatic supply of a clamps group (20) of a determined feed point (8) with the respective pneumatic supply inlet (41 ) of a determined cutting device (40).

8. The circular knitting machine (1) of any one of the preceding claims, wherein the clamps group (20) can comprise a first solenoid valve (24a) configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a first clamp (22a) of the group, and/or wherein the clamps group (20) can comprise a first solenoid valve (24a) configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a first clamps 22a) of the group and a second solenoid valve (24b) configured and predisposed to activate or deactivate the pneumatic supply of a pneumatic actuator activating a second clamp (22b) of the group, or alternatively the clamps group can comprise a first solenoid valve (24a) configured and predisposed for activating or deactivating the pneumatic supply of a pneumatic actuator activating a first clamp (22a) of the group and a second solenoid valve (24b) configured and predisposed to activate or deactivate the pneumatic supply of the auxiliary pneumatic supply exit (27) of the clamps group (20) for selectively activating the pneumatic actuator of a cutting device (40), and/or wherein the clamps group can comprise a first solenoid valve configured and predisposed to activate or deactivate the pneumatic supply to a pneumatic actuator activating a first clamp of the group, a second solenoid valve configured and predisposed to activate or deactivate the pneumatic supply to a pneumatic actuator activating a second clamp of the group and a third solenoid valve configured and predisposed to activate or deactivate the pneumatic supply to a pneumatic actuator activating a third clamp of the group, or alternatively the clamps group can comprise a first solenoid valve configured and predisposed to activate or deactivate the pneumatic supply to a pneumatic actuator activating a first clamp of the group, a second solenoid valve configured and predisposed to activate or deactivate the pneumatic supply to a pneumatic actuator activating a second clamp of the group, and a third solenoid valve configured and predisposed to activate or deactivate the pneumatic supply to the auxiliary pneumatic supply outlet of the clamps group for selectively activating the pneumatic actuator of a cutting device.

9. The circular knitting machine (1 ) of any one of the preceding claims, wherein the plurality of pneumatically-acting devices (5) of the dial group (3) comprises at least a blowing device (60), or "tongue-opening blower", arranged on the support ring (4) and comprising a respective pneumatic supply inlet (61) and a respective compressed air dispensing nozzle (62) configured for selectively opening one or more tongues of the needles of the needle-bearing organ during the working, and/or wherein the hook control group (10) comprises a first auxiliary pneumatic supply outlet (17) and the sequence of portions of the single serial pneumatic supply pathway of the dial group further comprises a first auxiliary conduit (37) connecting the first auxiliary outlet with the respective pneumatic supply inlet (61 ) of the blowing device (60), and/or wherein the plurality of solenoid valves (14) of the hook control group (10), mounted and connected directly to the body (11) of the hook control group (11 ), comprises a first auxiliary solenoid valve (14a) configured and predisposed to enable or prevent passage of compressed air from the first auxiliary outlet (17) of pneumatic supply towards the blowing device (60), with the aim of selectively activating the exit of compressed air from the dispensing nozzle (62) of the blowing device.

10. The circular knitting machine (1 ) of any one of the preceding claims, wherein the plurality of pneumatically activating devices (5) of the dial group (3) comprises at least a regulating device of the position of the hooks (70), or "hook regulating cam", arranged on the support ring (4) and comprising a respective pneumatic supply inlet (71), at least a respective pneumatic actuator (72) and a respective regulating cam configured to selectively modify the position of the hooks of the knitting machine during working, and/or wherein the hook control group (10) comprises a second auxiliary pneumatic supply outlet (18) and the sequence of portions of the single serial pneumatic supply pathway of the dial group further comprises a second auxiliary conduit (38) connecting the second auxiliary pneumatic supply outlet with the respective pneumatic supply inlet (71) of the regulating device of the position of the hooks (70), and/or wherein the plurality of solenoid valves (14) of the hook control group (10), mounted and connected directly to the body (11) of the hook control group, comprises a second auxiliary solenoid (14b) configured and predisposed to allow or prevent passage of compressed air from the second auxiliary pneumatic supply outlet (18) towards the regulating device of the position of the hooks (70), with the aim of selectively activating the respective pneumatic actuator (71) and control the movement of the respective regulating cam.