DESCRIPTION "BLOWING CONTROLLING DEVICE FOR RECTILINEAR COMBS OF A

COMBING MACHINE"

[0001] The invention regards a blowing controlling device for rectilinear combs of a combing machine.

[0002] In a fibre processing line for the production of yarn, after the initial opening and cleaning phase of the fibre, a carding process is executed by a carding machine, following which the fibre is in the form of a sliver.

[0003] After possible processing on a lap machine, in which several separated slivers are united to obtain a lap, the sliver or lap is combed by a combing machine to obtain a web in which the fibres are highly parallelized and cleaned. [0004] Combing is carried out by circular combs that are dedicated to the combing of the heads of the entering lap strands, and by means of rectilinear combs, dedicated to the combing of the tail of the exiting lap strands. The combs parallelize the fibres, remove the short fibres and separate the impurities and fibrous knots. [0005] During combing, the short fibres, impurities and fibrous knots collect on the teeth of the circular combs or the teeth of the rectilinear combs. It is well known that this accumulation negatively influences the quality of the combing and often results in the malfunctioning of the combs and sometimes even breakage. [0006] The cleaning of the combs was once manually performed by the personnel. [0007] Whereas in modern machines the circular combs are generally cleaned by a brushing wheel connected to the comb, while the rectilinear combs have a compressed air blowing device; the blowing device is controlled by a suitable control device which controls the flow of compressed air in a predetermined moment and a predetermined duration.

[0008] Some embodiments for the said control devices are known. For example, some solutions are illustrated in documents EP-A1 -0351443 and EP-A1 -0633333.

[0009] However, it was found that known solutions have some disadvantages, due to the complexity of programming the control device, for example the selection of the blowing start moment in relation to the combing cycle, and a delay of the blowing device response to the presence of the blow signal from control device.

[0010] The purpose of the present invention is that to make a blowing controlling device on rectilinear combs of a combing machine that overcomes the said disadvantages with reference to the prior art and at the same time satisfy the requirements.

[0011] The purpose is achieved by a control device made in accordance with the following claim 1. The dependent claims describe embodiments of the invention.

[0012] Features and advantages of the control device according to the present invention will be evident from the description below, given by way of example but not limited, in accordance with the following figures, wherein:

[0013] - figure 1 illustrates a diagram of a control device in accordance with the present invention, according to a first embodiment;

[0014] - figure 1a illustrates a side view of a control disc of the control device of figure 1 , according to a variant of the embodiment;

[0015] - figure 2 illustrates a diagram of the control device, according to a further embodiment;

[0016] - figure 2a illustrates a side view of a comb shaft of the combing machine on which is applied the control device of figure 2;

[0017] - figure 3 illustrates an operational diagram of the control device, according to an embodiment;

[0018] - figure 4 represents a diagram of the control device, in accordance with a further embodiment;

[0019] - figure 5 represents a diagram of the control device, in accordance with yet a further embodiment.

[0020] With reference to the attached figures, 1 shows a pinching device of a combing machine, to which is fed a fibre lap.

[0021] The pinching device 1 comprises a lower jaw 2 and an upper jaw 4, incident to the lower jaw 2 to pinch the lap between the tips.'

[0022] The pinching device 1 also comprises a pincer support 6 that holds the lower jaw 2, and an arm 8, hinged to the pincer support 6, which holds the upper jaw 4.

[0023] Downstream of the pinching device 1 , the combing machine comprises at least one pair of detaching rollers 10, 10', 12, 12', arranged one downstream of the other; the combed lap passes through the rollers of a pair.

[0024] Furthermore, the combing machine comprises a rectilinear comb 9, usually fastened to the pincer support 6, alongside the upper jaw 4, opposite the lower jaw

2, or rather positioned between the upper jaw 4 and the detaching rollers 10, 10',

12, 12".

[0025] The rectilinear comb 9 comprise a comb body 9' and teeth 9", protruding from the comb body 9' and suitable to penetrate into the body of the web moving from the pinching device 1 to the detaching rollers.

[0026] The rectilinear comb 9 has also at least one blowing nozzle in the comb body 9' to blow compressed air between the teeth 9".

[0027] Below the pinching device 1 , the combing machine comprises a circular comb 14 mounted in rotation on a combs shaft 16.

[0028] The circular comb 14 comprises a disc 18 and a curved sector 20 equipped

with a plurality of needles 22 on the surface and peripherally positioned to the disc

18.

[0029] During the rotation, the needles 22 penetrate the head of the lap strand, combing it.

[0030] The movement of the pinching device 1 is mechanically correlated to the rotation of the circular comb.

[0031] Preferably the combing machine 1 comprises a brushing wheel, motorised for example, next to the disc 18 of the circular comb, opposite the disc 18 in relation to the pinching device.

[0032] The brushing wheel is suitable to brush needles 22 of the circular comb 18 to separate the tangled fibres and the impurities accumulate between them.

[0033] The combing machine further comprises a blowing device suitable to deliver compressed air on command to the rectilinear comb.

[0034] The blowing device comprises a solenoid valve 40 and a source of compressed air 42 connected to the solenoid valve.

[0035] In other words, the rectilinear comb 9 is operatively connected to the solenoid valve 40 to receive compressed air from it destined to exit from the needles of the comb body 9'.

[0036] Furthermore, the combing machine comprises a control device to activate the blowing device at a predetermined moment.

[0037] The control device comprises a control shaft or a control disc 50 connected to the comb shaft 16 so as to create a desired drive ratio with it.

[0038] Since the rotation of the circular comb 14 is correlated to the movement of the pinching device, the rotation of the control shaft or control disc 50 is also correlated to the movement of the pinching device.

[0039] Furthermore, the control device also comprises at least one sensor 60 and a related signalling element 62, connected to the control disc 50.

[0040] The sensor 60 is suitable to detect the presence of the signalling element 62 in a determined angular position, when the signalling element 62 and the sensor 60 are aligned in a radial manner with the control disc 50 for example, and to send a position signal Sp in the presence of the signalling element 62 in the predetermined position.

[0041] In accordance with a preferred embodiment, the control device comprises a rotating plate 70 that can be angularly positioned in an adjustable manner in relation to the control disc 50. The sensor 60 is connected to the rotating plate 70.

[0042] In accordance with a preferred embodiment, the rotating plate 70 can be accessed by an operator and manually adjusted.

[0043] The angular position adjustment of the sensor 60 connected to the rotating plate 70 allows the presence detection of the signalling device 62 in any angular position and therefore to send a position signal Sp at any moment of the combing cycle.

[0044] In other words, the angular position adjustment of the sensor 60 allows to anticipate or delay the sending of the position signal Sp in relation to a fixed angular reference or in relation to a particular phase of the combing cycle.

[0045] The control device also comprises an enabling unit 80 suitable to send an enabling signal Sa if any enabling conditions occur.

[0046] For example, a first enabling condition foresees that the enabling signal Sa is absent if the combing machine is accelerating, for example in an initial time interval from the start of the machine, of 10 seconds for example.

[0047] In this case, the enabling unit 80 is operating analogue to a timer, which

sends the enabling signal Sa only after the predetermined time interval after the start of the machine.

[0048] A second enabling condition foresees that the enabling signal Sa is absent if the combing machine is performing the cleaning of the circular comb 14.

[0049] In this case also, the enabling unit 80 is operating analogue to a timer that sends the enabling signal Sa only after the predetermined time interval after the start of the machine, because it is possible to determine the in which the said cleaning will take place from the start-up.

[0050] A third enabling condition foresees that the enabling signal Sa is absent id the combing machine receives a stop signal.

[0051] In this case the enabling unit is operating analogue to a switch.

[0052] According to a variant of the embodiment, the enabling unit comprises a

PLC or a microprocessor.

[0053] The control device comprises a first AND logic gate 90 that sends a blowing signal Ss to the solenoid valve 40 if the position signal Sp and the enabling signal

Sa are read on input.

[0054] The solenoid valve 40 provides for the discharge of the blow when the blowing signal Ss is received.

[0055] The sensor 60 is connected to the AND port by means of . an optic connection device, for example digital, an opto-coupler 100 for example, often known as "opto-isolator" or "photocoupler" or "photoMOS ".

[0056] The opto-coupler is suitable to transfer the position signal Sp from the sensor 60 to the AND port 90, by means of an optic route, only in the presence of the position signal Sp; in the absence of the said signal the sensor and the AND port are uncoupled.

[0057] Preferably, the combing machine comprises a plurality of combing heads, each with its related pinching device, circular comb and rectilinear comb; the heads are assembled in two groups. For example, an embodiment foresees a combing machine with eight combing heads divided in two groups of four.

[0058] According to a preferred embodiment, the control device comprises an additional sensor 60', positioned for example on the same rotating plate 70, but on the opposite face in relation to that of the sensor 60.

[0059] Furthermore, the control device comprises a further signalling element 62', positioned on the control disc 50, spaced in an angular manner to the signalling element 62, at 180° for example.

[0060] Furthermore, the control device comprises a further opto-coupler 100' and a further AND logic gate 90'.

[0061] Preferably, the enabling unit 80 is also connected to a further AND logic gate 90' and sends the same enabling signal Sa.

[0062] In a variant of the embodiment, a separate enabling unit is foreseen.

[0063] Furthermore, the blowing device comprises a further solenoid valve 40', generally connected to the same compressed air supply 42.

[0064] In the embodiment with combing head units, the first solenoid valve 40 is connected to the rectilinear combs 9 of the heads of the first group (for example, from the first head to the forth head), while the other solenoid valve 40' is connected to the rectilinear combs 109 of the heads of the second group (for example, from the forth head to the eighth head).

[0065] Because the position signal is given in an out-of-phase manner from the first sensor 60 in relation to the other sensor 60' (because the signalling elements 62,

62' are angularly out -of-phase), the blowing of the heads of the first group and on

the heads of the second group is performed in an out-of-phase manner, improving the efficiency of the compressed air supply.

[0066] Furthermore, because there is a transmission ratio between the comb shaft

16 and the control disc 50, the position signal Sp ₁ Sp' is emitted every number of combing cycles equal to the said transmission ratio.

[0067] For example, if the transmission ratio between the comb shaft 16 and the control disc 50 is equal to 4, the position signal Sp, Sp' is emitted every forth combing cycle (and the further position signal Sp' is emitted in an out-of-phase manner in relation to the first position signal Sp).

[0068] According to a further embodiment, the signalling element 62 id connected to the comb shaft 16 (in this case the transmission ratio is equal to 1); sensor 60 is positioned on the rotating plate 70 angularly adjustable in relation to the comb shaft

16 (figures 2 and 2a).

[0069] According to a preferred embodiment, the further signalling element 62' is foreseen, connected to the comb shaft 16, the further sensor 60', positioned on the said rotating plate 70, as well as the opto-coupler 100', the further AND logic gate

90' and the further solenoid valve 40', for the blowing between the rectilinear combs

109 of the heads of the second group.

[0070] In the said embodiment with signalling element connected to the comb shaft, filtering means 82 are foreseen, with input positioning signals Sp, Sp'; the filtering means are suitable to allow the first signal Sp or the second signal Sp' to alternately pass on each turn of the comb shaft.

[0071] Innovatively, the control device according to the. invention allows the programming in a simple manner of the blowing on the rectilinear combs of the combing machine and to limit the delays between the desired emission of the air

and the effective emission.

[0072] Advantageously, in particular, the opto-coupler allows transmitting the position signal from the sensor to the AND logic gate at high speed, while electrically maintaining the components isolated when the position signal is absent.

[0073] Advantageously, the opto-coupler is very reliable, being that there are no moving mechanical parts, which ensures the absence of breakage even in the presence of a great number of cycles.

[0074] Advantageously, the opto-coupler is digital and transmits the on-off signal better.

[0075] It is clear that a man skilled in the art, in order to meet contingent needs may make changes to the control device described above, for example, in accordance with the variations described below.

[0076] According to further variants of the embodiment, the control device also comprises a logic unit 110, such as a PLC or a microprocessor, and an electric motor 120, controlled by the logic unit 110 and mechanically connected to the rotating plate 70, to rotate it (Figures 4 and 5).

[0077] Preferably, the electric motor is a linear motor and operates peripherally to the rotating plate 70.

[0078] According to a variant of the embodiment, the electric motor is connected in line with the rotating plate.

[0079] According to a preferred embodiment, the control device comprises input means 130, for example comprising a keyboard and a monitor, suitable for inputting a predetermined speed value at which the combing machine to work and blowing is optimal.

[0080] The input means 130 are operationally connected to the logic unit 110,

which acquires the inserted speed value, processes it by means of a predetermined program, and controls the motor 120 to adjust the angular position of the sensor 60 in order that the blow is optimal for the desired speed.

[0081] In accordance with a further embodiment, the logic unit 110, according to a predetermined program, controls the motor 120 to rotate the rotating plate 70 so that the sensor 60 is placed in a predetermined angular position and to control the moment of blowing.

[0082] In accordance with yet a further embodiment, the control device comprises a speed sensor suitable to detect the speed of the circular comb; the speed sensor is operatively connected to the logic unit 110 that processes the signal from the sensor and commands the motor 120 for the adjustment of the sensor 60 angular position.

[0083] According to a variant of the embodiment, the enabling unit 80 and logic unit

110 are realized of a single electronic component, such as a single PLC or a single microprocessor.

[0084] Innovatively, the control device allows the simple programming of the optimal blow to the rectilinear combs of the combing machine.

[0085] Advantageously, in addition, the general lay-out of the machine is optimized, because it is not necessary that the rotating plate is accessible to operators.

[0086] According to a further advantageous aspect, the adjustment of the blowing advance can be carried out remotely.

[0087] According to yet a further advantageous aspect, the adjustment of the blowing advance is continued, depending on the instantaneous conditions of combing machine.