Procedure for combing textile fibres, and circular comb to perform such procedure

Abstract

 Procedure for combing textile fibres, such combing being performed by rotary combs (11) on lap (16) fed by containers (1.7) in motion below such rotary combs (11), in which procedure each rotary comb (11) acts on a tract of such lap (16) and such tract is displaced progressively in the direction of the width of the lap.
Circular comb (11) which performs such procedure and cooperates with containers (17) in substantially straight reciprocal motion, such comb (11) including a plurality of needles (111) and being arranged with its axis of rotation (12) awry in relation to the direction of feed of the lap (16).

Description

[0001] This invention concerns a procedure for combing textile fibres. To be more exact, the invention concerns a procedure for combing the head of the lap by means of circular combs, the lap consisting of several slivers of textile fibres.

[0002] Such slivers may be merely arranged alongside one another or may be arranged in layers or partially in layers above one another.

[0003] The invention also concerns a circular comb able to perform the procedure of the invention and having optimized geometric parameters.

[0004] Common procedures for combing the lap are known. The known procedures for combing the head of the lap which employ circular combs have the axis of rotation of such combs parallel to the plane containing the head of the lap.

[0005] In such traditional procedure of rotary combing the lap is engaged at every moment along its whole crosswise extent with a generating line of the circular comb. The result is that practically all the fibres of the head of the lap are affected by the combing operation at one and the same time.

[0006] There is therefore a vigorous action on the fibres which might cause the removal also of fibres longer than the minimum usable length, that is to say, fibres are removed which are longer than a given limit threshold of usability, and therefore the yield of the operation is reduced.

[0007] Patent US 3,718,944 is known and discloses a combing machine that employs circular combs. Such combs have a cylindrical shape and are inclined in relation to the direction of feed of the lap; the purpose of this is to provide, according to that invention, the required correspondence between the respective curvatures of the cylinder wall and of the clamping groove within which the lap is fed. In fact, the clamping groove too is curved since the whole machine has a circular shape. This invention, therefore, has purposes wholly different from those of our present invention, and moreover the inclined arrangement of the combs is made necessary in it because of the cited requirement of parallelism and correspondence of the curvatures of the clamping groove and of the side surface of the cylindrical combs.

[0008] Our present invention has the purpose of removing only those fibres having a length less than a given threshold by means of a gradual action performed progressively along the width of the head of the lap.

[0009] The invention has the aim of pre-arranging the material for spinning in the best manner. According to the invention, yarns are obtained at the end of the processing which have a greater breakage length and an improved suitability for spinning.

[0010] The progressive nature of the operation enables a better successive mixture of fibres to be obtained.

[0011] The above purposes are attained by providing a combing process in which the lap is made to pass progressively below circular combs, which are arranged to have their axis of rotation inclined in relation to the plane containing the head of the lap.

[0012] According to tests conducted by the present applicant such inclination will preferably be between 5° and 40° and will advantageously be about 18° (from 17° to 19°).

[0013] In this way, as we said earlier, there will be a progressive action on the fibres of the head of the lap, together with a removal only of the less well bonded fibres and a better parallelization of the fibres themselves than can be obtained in traditional processes.

[0014] A combing operation performed according to the invention entails a smaller loss of good fibres, that is, of fibres suitable for successive spinning since they are longer than a given threshold of usability; it also entails an optimum parallelization of the fibres.

[0015] The invention provides also for the ability to employ auxiliary means, such as mechanical or pneumatic means, electrostatic fields, etc., to assist such action of parallelization of the fibres.

[0016] It has been found from studies conducted by the present applicant that the best combing results are obtained by inclining the needles of the comb suitably.

[0017] It is possible to have needles inclined in relation to the radial direction of the comb or to the generating line of the comb, or to both the radial direction and the generating line.

[0018] Inclination in relation to the radial direction, according to the invention, will be between 30° and 50° and preferably about 40° (from 39° to 41°).

[0019] Inclination in relation to the generating line will be between 60° and 90° and preferably about 75° (from 74° to 76°).

[0020] The invention provides also for the use of combs having a variable number of needles or card clothings and a surface arrangement according to lay-outs intended to obtain the best combing results in each case.

[0021] The invention provides for a possible doffing cylinder arranged so as to correspond with each circular comb and having the purpose of cleaning from the needles the fibres removed from the lap and deposited on the needles.

[0022] This invention is therefore obtained with a procedure for combing textile fibres, such combing being performed by rotary combs on lap fed by containers in motion below such rotary combs, in which procedure each rotary comb acts on a tract of such lap and such tract is displaced progressively in the direction of the width of the lap, thus providing a progressive combing action on the lap.

[0023] The invention is also embodied with a circular comb which performs the above procedure and cooperates with containers in substantially straight reciprocal motion, such comb including on its outer surface a plurality of needles and being arranged in its working position with its axis of rotation awry in relation to the direction of feed of the lap.

[0024] We shall now describe as a non-restrictive example some preferred embodiments of a device able to perform the combing procedure of the invention, with the help of the attached figures, in which:-

Fig.l shows diagrammatically a device performing the combing according to the procedure of the invention;

Fig.2 shows the feed of the laps below the combing heads;

Figs.3, 4 and 5 show possible embodiments of rotary combs;

Fig.6 gives an axial view of a comb with needles inserted;

Figs.7a and 7b give two views of a small needle-holder plate with needles fitted.

[0025] In Fig.1 a combing device or combing head according to the invention bears the reference number 10. Such device comprises a rotary comb 11, which is arranged, according to the invention, with its axis 12 awry in relation to the direction 33 of feed of lap 16.

[0026] The lap 16 is made to pass below the comb 11 in such a way as to receive a progressive combing action, as can be seen in Fig.l.

[0027] In this example the lap 16 is fed from containers 17, which are made to pass below the comb 11 in succession. In the example shown such containers 17 are moved by a chain conveyor 32.

[0028] Such method of movement can be of any type and.likewise the containers 17 can also be of any type, this being unimportant for the purposes of the invention.

[0029] The comb 11 is driven by an electric motor through a universal joint 14 and, in this example, through a bevel gear pair 15 in an appropriate sheath. The universal joint 14 serves to obviate tearing of the lap if the latter sticks or suddenly resists the motion of the comb 11.

[0030] The bevel gear pair 15 comprises also a motion output including a sprocket wheel 19, which drives a gear wheel 20 through a chain 18.

[0031] A transmission shaft 24 supported on bearings 23 is driven by means of a pair of gear wheels 21-22, which gear up the number of revolutions.

[0032] The shaft 24 drives a pulley 25, which in turn actuates a driven pulley 26 by means of a belt 27.

[0033] Motion is transmitted by the pulley 26 through a shaft 28 supported by a bearing 29 to a doffing cylinder or brush 30. Such doffing cylinder or brush 30 has the task of cleaning from the rotary comb 11 any residues of fibres deposited on the rotary comb as a result of the combing action on the lap 16. Such fibres removed from the comb 11 by the brush 30 are then aspirated and discharged through an aspiration intake 31.

[0034] The rotary comb 11 is cleaned efficiently in this way and can thus be in the best condition to work on the lap 16.

[0035] Both the comb 11 and the brush 30 are supported at one end on their respective shafts in this example but could also be fitted so as to be supported at both ends.

[0036] In a variant which is not shown here, a separate drive system can be provided for the comb 11 and the brush 30; in such a case two electric motors will be required, possibly working with a variable number of revolutions so as to obtain a variable cleaning action on the comb 11 by the brush 30 as required.

[0037] Likewise, in such variant the speed of rotation of the comb 11 can be made variable so as to obtain a combing action having the required gradual nature and force.

[0038] The speed of rotation of the comb 11 can be correlated with the speed of movement of the container 17 in the direction 33 and also with the feed of the head of the lap 16 from the container. In fact, the lap is caused to protrude from the container by some millimetres for the combing process.

[0039] Fig.2 shows the lay-out of the devices 10 along the path of the containers 17; in this example two devices 10 are shown but such devices can be in any required number.

[0040] Thus the lap 16 passes successively below the various combs 11 and undergoes a series of progressive combing actions, according to the invention, at the tracts which are successively subjected to the action of the various combing heads 10.

[0041] Fig.2 shows also the system of adjustment of the mutual inclination of, and distance between, the comb 11 and lap 16; in this example such adjustment is obtained by providing a supporting shaft 35 for a casing 34 of the device, such casing containing the various elements forming the combing device 10.

[0042] In this example the shaft 35 is solidly fixed to a gear wheel 37, which is driven by a worm screw 38 actuated by hand by means of a knob or handwheel 39. It is possible in this way to obtain an adjustment of the mutual inclination of, and distance between, the comb 11 and lap 16.

[0043] This example also shows a portion of a frame 36 of the combing device, such frame 36 serving to support the device 10 through the shaft 35.

[0044] In any event it is possible to employ an adjustment system which is different from that shown here and which makes use, for instance, of slidable guides to adjust the position of the whole device 10; the whole adjustment system can also be actuated mechanically or pneumatically rather than by hand.

[0045] Fig.2 also shows aspiration ducts 131 to discharge any residues of fibres removed from the combs 11 by the doffing cylinders or brushes 30.

[0046] Fig.3 shows some possible embodiments of circular combs suitable for employment in the device according to the invention.

[0047] Thus the combs can be cylindrical (Fig.3a), or tapered (Fig.3b), or have a barrel-shaped profile (Fig.3c), or have a variously hollowed profile (Fig.3d), depending on the type of action to be applied to the lap 16 and on the gradual nature of such action.

[0048] According to the invention it is also possible to provide combs 11 bearing a variable number of needles 111, for instance in the axial direction of the comb; for example, Fig.3a shows one zone 40 with a small number of needles and another zone 41 with a greater number of needles.

[0049] Various zones having different numbers of needles may be provided, or there may be a progressive variation of the density or number of needles 111 along the comb.

[0050] In the same way such needles may be distributed evenly in a circumferential direction, or a circumference of the comb may contain zones with a greater number of needles and zones with a smaller number, depending on the type of action to be applied to the lap 16.

[0051] Moreover, the needles may be inclined in the radial direction of the comb or may be variously inclined in relation to such radial direction; lastly, the needles 111 may be straight (Fig.4a), or curved (Fig.4b), or be shaped like teeth (Fig.-4c).

[0052] Finally, the needles may be variously inclined in relation to the generating line of the comb, namely with their inclination measured in a plane radial to the cylindrical comb.

[0053] Trials conducted by the present applicant show as being advantageous an inclination "γ" of the needles (see Fig.6), in relation to the radial direction, ranging from 30° to 50° and preferably being about 40° (from 39° to 41°).

[0054] Likewise, an inclination "β" of the needles in relation to the generating line (Fig.7a) is advantageous which ranges from 60° to 90° and is preferably about 75° (from 74° to 76°).

[0055] In the embodiment of Fig.5 the teeth are arranged on a band 211 that can be disposed in a ring, several rings of such band 211 being provided on the periphery of the comb; or else such band can be wound in a spiral about the periphery of the comb 11, as shown in Fig.5.

[0056] The needles 111, whether separate from each other or forming part of a band 211, can be secured to the comb 11 in any known method, for instance by a fixed joint, by welding or by adhesives, or can be fixed by means of suitable clamping inserts; or else specially shaped bars or small plates 311 (Figs.7a-7b) can be provided which bear the needles 111 and are connected by a fixed joint to the body of the comb 11.

[0057] Fig.6 gives an axial view of a comb 11 with needles 111 inserted. In this example the needles are integrally secured to small plates 311 that are inserted into appropriate peripheral slots in the comb.

[0058] This figure shows the inclination "γ" of the needles in relation to the radial direction; the angle "r" here is about 40°.

[0059] Figs.7a and 7b give frontal and plan views respectively of a small plate 311. The needles 111 are secured to such plate by known methods (welding, adhesives, etc.). Fig.7a shows the angle "β" between the needles 111 and the generating line of the comb;.in this case the angle is about 75°.

[0060] Fig.7b shows the small plate 311 with its needles 111 in their working position; the inclination "α" in relation to the plane of the lap can be seen and is about 18° in this example.

[0061] The needles of the circular comb may have a circular or elliptic or polygonal or elongated section, depending on the type of fibres to be processed and/or on the progressive nature of the operation to be obtained.

[0062] If the section is polygonal, for instance quadrangular, there can be a flat or sharp action of the needles on the lap, depending on how the needles have been oriented. Moreover, the needles may be tapered or have a variable section from their base towards their outer end. All these variants and others again are possible without departing thereby from the scope of this invention.

Claims

1 - Procedure for combing textile fibres, such combing being performed by rotary combs (11) on lap (16) fed by containers (17) in motion below such rotary combs (11), the procedure being characterized in that each rotary comb (11) acts on a tract of such lap (16) and such tract is displaced progressively in the direction of the width of the lap, thus providing a progressive combing action on the lap.

2 - Circular comb(11) which performs the procedure of Claim 1 and cooperates with containers (17) in substantially straight reciprocal motion, such comb (11) including on its outer surface a plurality of needles (111) and being characterized in that it is arranged in its working position with its axis of rotation (12) awry in relation to the direction of feed of the lap (16).

3 - Circular comb (11) as claimed in Claim 2, of which the axis of rotation (12) is inclined in relation to the plane of the lap (16) by an angle (α) of between 5° and 40°.

4 - Circular comb (11) as claimed in Claims 2 and 3, of which such inclination (α) ranges from 17° to 19°.

5 - Circular comb (11) as claimed in any of Claims 2 to 4 inclusive, of which such inclination is adjustable (39).

6 - Circular comb (11) as claimed in any of Claims 2 to 5 inclusive, which has a substantially cylindrical shape (Fig.3a).

7 - Circular comb (11) as claimed in any of Claims 2 to 6 inclusive, which has a substantially tapered shape (Fig.3b).

8 - Circular comb (11) as claimed in any of Claims 2 to 6 inclusive, which has a convex shape (Fig.3c).

9 - Circular comb (11) as claimed in any of Claims 2 to 6 inclusive, which has a concave shape (Fig.3d).

10 - Circular comb (11) as claimed in any of Claims 2 to 9 inclusive, of which at least some of the needles (111) are straight (Fig.4a).

11 - Circular comb (11) as claimed in any of Claims 2 to 10 inclusive, of which at least some of the needles (111) are curved (Fig.4b).

12 - Circular comb (11) as claimed in any of Claims 2 to 11 inclusive, which comprises individual needles (111).

13 - Circular comb (11) as claimed in any of Claims 2 to 11 inclusive, which comprises needles (111) arranged on a band (211) (Figs.4c and 5).

14 - Circular comb (11) as claimed in any of Claims 2 to 13 inclusive, which comprises needles (111) having a variable section.

15 - Circular comb (11) as claimed in any of Claims 2 to 14 inclusive, which comprises needles (111) having a section that can at least be likened to an elliptic section.

16 - Circular comb (11) as claimed in any of Claims 2 to 14 inclusive, which comprises needles (111) having a polygonal section.

17 - Circular comb (11) as claimed in any of Claims 2 to 16 inclusive, of which the needles (111) are inclined at least in relation to the generating line of the comb (11), such inclination (C ) being between 60° and 90°.

18 - Circular comb (11) as claimed in Claims 2 and 17, such inclination of the needles (111) in relation to the generating line of the comb (11) ranging from 74° to 76°.

19 - Circular comb (11) as claimed in any of Claims 2 to 18 inclusive, of which the needles (111) are inclined (γ) at least in relation to the radial direction of the comb (11), such inclination being between 30° and 50°.

20 - Circular comb (11) as claimed in Claims 2 and 19, such inclination of the needles in relation to the radial direction of the comb ranging from 39° to 41°.

21 - Circular comb (11) as claimed in any of Claims 2 to 20 inclusive, which comprises a number of needles that can be varied (40-41) along the length of the comb (11).

22 - Circular comb (11) as claimed in any of Claims 2 to 21 inclusive, which comprises a number of needles that can be varied about the circumference of the comb (11).

23 - Circular comb (11) as claimed in any of Claims 2 to 22 inclusive, which cooperates with a doffing cylinder (30) having a coordinated speed of rotation.

24 - Circular comb (11) as claimed in any of Claims 2 to 23 inclusive, which cooperates with an aspiration (31) of air.

Drawing