METHOD AND APPARATUS FOR PROCESSING FIBROUS MATTER
This invention relates to a method and apparatus for processing fibrous matter.
The invention is applicable generally to textile processing and in particular to the assembly and subsequent processing of fibres. An application of the invention of some interest is to open-end processes such as the later steps in the rectilinear combing cycle in which a tuft is detached from a beard and laid onto the tail of the preceding tuft. The subsequent discussion concentrates on this application but this is not intended to be limiting on the broad scope of the invention.
In the rectilinear combing system, tufts are separately detached from a beard at the end of the incoming fibrous matter onto a reciprocating apron. The beard is first gripped by the nipper jaws and then pressed onto a rotating cylindrical comb. The nipper jaws are then lifted and opened as the apron carriage moves towards the beard. The contrarotating detaching rollers at the input end of the apron carriage detach a tuft from the beard through a rectilinear comb, known as the top comb, and thence through the roller nip onto the outwardly moving apron. The carriage now moves away to allow the new beard to be presented to the cylindrical comb. During the time when the carriage is away from the circular comb, the apron reverses and partially rewinds the tuft through the detaching rollers. Consequently, when the carriage returns to grasp the new circularly combed beard and detach the next tuft, the leading edge of the new tuft is some distance behind the leading edge of the previous tuft. In this way, and by sequential operation, a continuous combed web is formed from the discontinuous tufts, which is then delivered off the apron through a nip defined by contrarotating exit rollers mounted on the output end of the apron carriage.
The rectilinear combing system just described has been in general use for some years. One aspect of the system that has changed with time is the means of controlling the tail of the tuft to substantially prevent contact with the cylindrical comb and thus prevent undesirable additional loss of fibre as noil. An early arrangement involved a curved baffle, known as a sword, that reciprocated over the top of the detaching rollers
and tucked the tail underneath a lower fixed sword. Space requirements for the swords were such that the apron carriage stroke was set at around 80-90mm. Later machines replaced the sword with a vacuum suction slot underneath the detaching rollers, but the presence of the slot, and of other earlier devices, since discarded, in the space between the beard and the detaching rollers meant that a substantial stroke was still required for the apron carriage. In fact, in one range of commercial combing machines, the apron carriage stroke has remained at about 80 to 90 mm.
An important factor that limits the maximum speed of operation of the machine is the magnitude of the stroke of the apron carriage and a reduction in the stroke would allow higher speeds to be achieved. Indeed, reduction of the stroke is theoretically possible with modem rectilinear combing machines given the current absence of working mechanisms in the space between the circular comb and the detaching rollers.
Nevertheless, the minimum feasible stroke is still of the order of 35mm because of the need to provide pneumatic tuft tail control to prevent the tuft tails from being caught by the cylindrical comb. Even if the stroke could be further reduced, there is another problem that would even then militate against higher speeds, namely the severe buffeting of the web on exit from the apron assembly. As the speed of the machine is increased above 200 r/min there is a marked deterioration in the quality of the web due to the collisions between the web and the trumpet through which the web is typically gathered for downstream gilling. The rapid forwards and backwards motion of the apron itself is also thought to contribute to the deterioration of the web, and to development of entanglements in subsequent gilling and drawing.
German patent 652469 and related United States patent 2092186 to Schmitt, disclose an arrangement for a combing machine in which successive tufts are detached from the beard onto an apron that moves continuously but intermittently in the one direction. The tufts are successively fed to an exit roller set that reciprocates towards and away from the exit end of the apron. A continuous web is formed by laying the leading edge of each tuft into the tail of the preceding tuft at the exit roller set.
Experiments with the configuration disclosed by Schmitt have revealed that a sliver formed from combed web by condensing through a guide, or even a crimper box, has insufficient tenacity to be reliably drawn out of a can by the subsequent gill. In essence, the intermingling of the fibres achieved during overlaying of the successive tufts at the output end of the apron is inadequate. A further problem with the Schmitt system is that the exiting web is not fixed with respect to "ground" in that it is itself reciprocating with the exit roller set. The aforementioned buffeting problem still therefore arises at the desirable higher speeds of operation. Thus, while the Schmitt proposal seems to address some of the known problems with conventional rectilinear combing, it has not led to any practical substitute that would allow combing to be effected at the higher speeds achievable at other stages of wool processing.
French patent 488470 to Schleifer describes a processing apparatus in which tufts of wool or the like are extracted and assembled after effecting head to tail reversal thereof so that the tails proceed the heads.
It is an object of the present invention to provide one or more developments in the assembly of fibrous matter that can be applied to textile combing to at least in part alleviate the outstanding problems with the aforedescribed known systems.
In a first aspect of the invention, it has been realised that the observed difficulty with the Schmitt proposal in achieving adequate cohesion in the subsequently formed fibre assembly may arise in part from the maintenance of the traditional presentation of the heads of successive tufts into the tails of the next preceding ufts. It has been appreciated that the leading ends of the fibres are distributed over a relatively small longitudinal region in the head of a tuft, whereas the trailing ends of the fibres are distributed over a much longer region of the tuft, broadly referred to as the tail of the tuft. The concept of the first aspect of the invention is to assemble the tufts in such a way that the previously trailing ends become leading ends with regard to the output of the machine. It has further been discovered that by assembling tufts in this fashion it is possible to directly subject the assembled tufts to a following drafting process, without need for an intermediate storage step, such as by directing the assembled tufts to a can
from which the assembly is subsequently withdrawn for drafting.
In this first aspect, the invention therefore provides a method of processing fibrous matter comprising: (a) assembling the fibrous matter by a process including conveying the fibrous matter as successive fibrous segments each having a head and tail relative to an initial direction of travel, and laying each segment onto a preceding segment to form an output assembly of the fibrous matter, wherein each segment, after it is detached, is laid tail- first onto the preceding segment, whereby to form said output assembly; and (b) submitting the output assembly to drafting without intermediate storage.
Each fibrous segment may be inverted as it is laid tail-first onto the preceding segment. Altematively, or additionally, the segments may be caused to change their direction of travel before, during or after being laid into the preceding segment.
In its first aspect, the invention also provides apparatus for processing fibrous matter comprising:
(a) apparatus for assembling fibrous matter including: means for conveying the fibrous matter as successive fibrous segments each having a head and tail relative to an initial direction of travel; and laying means for laying each fibrous segment tail-first onto a preceding segment whereby to form an output assembly of the fibrous matter; and
(b) means for drafting the output assembly delivered from the apparatus for assembling, without intermediate late storage of the output assembly.
The laying means may further reverse each fibrous segment as it is laid tail-first onto the preceding segment. Additionally or alternatively, the apparatus may further include means to cause the segments to change their direction of travel before, during, or after being laid onto the preceding segment.
The language "laid tail-first" herein means either that the tail is the first part of the fibrous segment to be laid onto the preceding segment, and/or that, as the output
assembly progresses forward after formation, the tail of each fibrous segment forms the leading end of the segment and overlies or interlies the preceding segment in the output assembly.
In a second aspect, the invention provides a method of processing fibrous matter comprising:
(a) assembling the fibrous matter by a process including conveying the fibrous matter as successive fibrous segments each having a head and tail relative to an initial direction of travel, and laying each fibrous segment onto a preceding segment to form an output assembly of the fibrous matter, wherein each segment, after it is formed, is laid onto the preceding segment whereby to form said output assembly with the head of each segment forming the rear of the output assembly until overlaid by a succeeding segment; and
(b) submitting the output assembly to drafting without intermediate storage.
In the second aspect, the invention further provides apparatus for processing fibrous matter comprising:
(a) apparatus for assembling fibrous matter including: means for conveying the fibrous matter as successive fibrous segments each having a head and tail relative to an initial direction of travel; and laying means for laying each fibrous segment tail-first onto a preceding segment whereby to form an output assembly of the fibrous matter with the head of each segment forming the rear of the output assembly until overlaid by a succeeding segment; and (b) means for drafting the output assembly delivered from the apparatus for assembling, without intermediate late storage of the output assembly.
The invention still further provides, in a third aspect, a method of processing fibrous matter comprising: (a) assembling the fibrous matter by a process including conveying the fibrous mater as successive fibrous segments each having a head and tail relative to an initial direction of travel, and laying each fibrous segment onto a preceding segment to form
an output assembly of the fibrous matter, wherein each segment, after it is formed, is reversed and/or inverted and or reverse rotated front to back before or as it is laid into the preceding segment; and
(b) submitting the output assembly to drafting without intermediate storage.
By "reversed" is meant that the relative positions of the head and tail are reversed. "Inverted" means the tail is lifted or otherwise moved past the head, or vice- versa, to rum the fibrous segment end-to-end. "Reverse rotated" means the segment is rotated or revolved around any axis to reverse the relative positions of the head and tail.
In its third aspect, the invention also provides apparatus for processing fibrous matter comprising:
(a) apparatus for assembling fibrous matter including: means for conveying the fibrous matter as successive fibrous segments each having a head and tail relative to an initial direction of travel; and laying means for laying each fibrous segment tail-first onto a preceding segment whereby to form aa output assembly of the fibrous matter, which laying means is effective to reverse and/or invert each segment before or as it is laid into the preceding segment; and
(b) means for drafting the output assembly delivered from the apparatus for assembling, without intermediate late storage of the output assembly.
In one or more embodiments of any of the above aspects of the invention, the fibrous segment is preferably laterally compressed or condensed. Lateral compression, or condensation, of the segment prior to laying is not essential but may facilitate the reversal and intermingling process. Moreover, in such embodiments the compression/condensation, laying and any reversal, inversion or rotation steps could occur in any order depending on the particular construction adopted.
In a fourth aspect, the invention provides a method of processing fibrous matter comprising:
(a) assembling the fibrous matter by a process including conveying the fibrous matter as successive fibrous segments and laying each segment onto a preceding segment to form an output assembly of the fibrous matter, wherein each segment, is laterally compressed or condensed before or as it is layed onto the preceding segment; and
(b) submitting the output assembly to drafting without intermediate storage.
The invention still further provides, in its fourth aspect, apparatus for processing fibrous matter comprising: (a) apparatus for assembling fibrous matter including: means for conveying the fibrous matter as successive fibrous segments; laying means for laying each successive fibrous segment onto a preceding segment to form an output assembly of the fibrous matter: and means to laterally compress or condense each segment before or as it is layed onto the preceding segment; and
(b) means for drafting the output assembly delivered from the apparatus for assembling, without intermediate late storage of the output assembly.
In another aspect, the invention provides a method of processing fibrous matter comprising assembling the fibrous matter by a process including conveymg the fibrous matter as successive fibrous segments each having a head and tail relative to an initial direction of travel, monitoring segment quality at an inspection station, and then laying each segment onto a preceding segment to form an output assembly of the fibrous matter, wherein each segment, after it is detached, is laid tail-first onto the preceding segment, whereby to form said output assembly.
As employed herein, the term "fibrous segment" includes but is not restricted to tufts, eg combing tufts.
In any of the aspects of the invention, the fibrous matter may initially be formed into successive fibrous segments in an open-end process, eg by detaching successive tufts from an input fibrous beard. In this application, the apparatus may include
detachment means to detach successive tufts from an input fibrous beard. It is further preferred, in each aspect of the invention, that assembly of tufts of sections be effected without use of overlapping rollers.
In an embodiment of the invention, in any of its aspects, the tuft laying means comprises a travelling surface having means to engage and retain the head of each tuft in rum, and means to sweep the tuft up and over onto the travelling surface so that the tuft proceeds forward inverted and tail-first.
In each of its aspects, the apparatus may be incorporated in a textile combing machine incorporating a plurality of comb members, and feed means for delivering an input fibrous beard. The method, in each of its aspects, may be practised as part of a textile combing process.
In any of its aspects, the fibre segments or tufts may be formed or detached and then retained or stored for later laying to form the output assembly. The invention also provides, in an optional application, for fibrous segments, either in compressed or non- compressed form, to be collected as separate units or as a plurality of units, from a plurality of combs, and transported to an appropriate later stage for assembly into a continuous sliver.
The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 is a diagrammatic side-elcvational view of combing apparatus including a first embodiment of fibre assembly apparatus in accordance with the invention, shown at a particular stage in the combing cycle, and in which each tuft is laterally compressed and then reversed and laid tail-first onto the preceding tuft; and
Figure 2 is a cross -section on the line 2-2 in Figure 1, and includes two further fragmentary cross-sectional views A and B as indicated;
Figure 3 is a diagrammatic view similar to Figure 1 of combing apparatus including a second embodiment of fibre assembly apparatus according to the invention, in which each tuft is not laterally compressed but is instead inverted as it is laid tail- first onto the preceding tuft;
Figure 4 is an oblique view of part of the apparatus of Figure 3;
Figure 5A to 5C depict diagrammatically successive stages in the laying and inversion of a tuft in the apparatus of Figures 3 and 4;
Figure 6 is a modified form of the apparatus shown in Figures 3 and 4 in which there is no apron between the detaching rollers and the pinned roller;
Figures 7a to 7c illustrate the transfer of a tuft onto the pinned roller during operation of the apparatus shown in Figure 6;
Figures 8a to 8f are diagrammatic fragmentary side views of a further modified form of fibre assembly apparatus according to the invention, in which tufts are inverted;
Figures 9a to 9c are diagrammatic fragmentary side views of another modified form of fibre assembly apparatus according to the invention, in which tufts are inverted;
Figure 10 is a diagrammatic fragmentary side view of a further embodiment of the invention;
Figure 11 is a diagrammatic fragmentary side view of another modified form of fibre assembly apparatus according to the invention, in which fibrous tufts are laterally compressed;
Figure 12a to 12d are diagrammatic plan views illustrating the operating sequence of the apparatus of Figure 11; and
Figure 13 is a view like Figure 11, but illustrating initial tuft feeding.
Combing apparatus 10 depicted in Figures 1 and 2 includes a reciprocable apron carriage 12, extending between a first or combing and detachment station 70 and a second or tuft laying station 80. At station 70, there is a rotatable cylindrical comb 14, a vertically aligned rectilinear top comb 16, and a feed mechamsm 18 including a feed comb 19 for delivering fibrous matter 8, eg wool sliver, to a pair of upper 20 and lower 21 nipper jaws above comb 14. Apron carriage 12 includes a frame (not shown) that mounts an apron 13 defined by the upper run of a continuous belt 25, and front detaching rollers 22 at station 70.
Station 80 includes the rear end of apron 13 and a pair of contrarotatable rollers
82, 83 that are mounted to the machine frame (not shown) and define a nip 84 through which tufts are collected from apron 13 and delivered to a support bed 100 defined between upper and lower sets of rollers 101,102. Rollers 82,83 and support bed 100 are translational ly fixed with reference to the machine frame.
In operation, fibrous matter 8, eg wool sliver, is continuously delivered to nipper jaws 20, 21. The exposed end of the fibre, known as the beard 8a, is lowered by the nipper jaws for a combing treatment by rotating cylindrical comb 14 (Figure 2). The apron carriage 12 is then moved towards the beard and a tuft 9 is detached from the beard through top comb 16 and the nip 23 onto apron 13 at contrarotating detaching rollers 22 (Figure 1).
The newly detached tuft 9 now lies on the apron behind the detaching rollers 22.
The apron carriage 12 then retracts away from the nipper jaws 20, 21 as the jaws descend to bring the new beard into the cylindrical comb. At this point the illustrated apparatus departs from conventional operation, in which the apron and detaching rollers would reverse to bring the tail of the tuft back through the nip and down around to a suction slot. The apron assembly would then again move forward into position to detach the next tuft, which would be laid onto the tail of the preceding tuft as they are both drawn through the nip of the detaching rollers.
With the illustrated apparatus, in contrast, apron 13 does not reverse but instead maintains motion to convey the tuft to the second station 80 and through rollers 82,83 into support bed 100. A pusher including a transverse set of rods 105, of the cross- section indicated at B in Figure 2, is arranged to cyclically project along the spaces 106 between the rollers from one end of the support bed 100 to compress each tuft into what might be termed a "sausage" 110 at the other end of the bed. The sausage is pneumatically conveyed from this position along a shaped duct 112 and layed within a head 113 over the upper surfaces of a set 120 of pinned rollers 122. Rollers 122 are arranged in sets 124 to 127, with three of the sets (124 to 126) defining aligned nips 128. The fourth set 128 is upwardly offset and is oppositely rotated so as to draw the tail 111 of each sausage 110 back down through an upper nip 129 as it is fed backwards by the rollers of sets 124 to 126. In this way, the successive tufts are laid into each other to form an output fibre assembly in the form of a web which is drawn around through nips 128 to a three roller exit set 130 that operates at a high draft over the aligned roller set 124-126. The total draft may typically be 6 to 8 and is determined by the degree of overlap of the tufts. The pins 123 of rollers 122 generally face backwards, ie opposite to the direction of rotation and are intermingled at the nips, as seen in Figure 2.
The surfaces of roller 122 may, as well as being pinned, be provided with a multitude of holes through which air is drawn to hold the tufts and web onto the roller surfaces. Aspiration in this way may improve control of tuft head pick-up.
The use of a pin drafter, such as is provided by pinned rollers 122, assists in breaking up of the tuft structure by individualising the fibres. This is facilitated by presenting the tufts tail-first because the trailing ends of the fibres, which are the leading ends in the reversed tufts, are spread over a greater length of the tuft, as pointed out earlier.
In Figure 1, for purposes of illustration the full space between rollers 82, 83 and the near end of the apron 13' as is practically required is not shown.
SUBSTTΓUTE SHEET (Rule 26)
The embodiment illustrated in Figures 3 and 4 differs from the first in that the multi-roller support bed is replaced by an assembly 200 for inverting the detached tufts as they are laid tail-first onto the respective preceding tuft.
Assembly 200 includes a large cylindrical pinned roller 202, downstream of, ie behind apron 13', a train of tuft sweeping bars 204 arranged to periodically traverse the gap 206 between apron 13' and roller 202, and a drafting roller set 210 associated with the rear of pinned roller 202.
Rollers 22' reciprocate towards and away from nipper jaws 20',21 ' to detach tufts
9' from the beard 8a' of wool sliver 8' onto apron 13', as described in connection with the first embodiment. Apron 13' conveys the tuft to an output nip 84 between the apron at support roller 83' for the apron and an optional overlying stripping roller 82'. An optional cover plate 250 or upper apron assists in guarding and consolidating the tufts as they are conveyed to nip 84' The upper apron, if employed, could incorporate stripping roller 82'.
Pinned roller 202 has multiple longitudinal rows 212 of pins 213. The roller is positioned to receive and engage the head 9a of a tuft 9' (Figure 5A) as it projects through nip 84'. The traversal of bars 204 is timed so that as the head of a tuft being drawn through rollers 22', is caught on a row 212 of pins 213, a bar 204 (Figure 5A), rising about roller 202 and travelling faster than the roller surface (eg two times faster), lifts the tuft behind the head and sweeps it up and over (Figure 5B), ie flips it, onto the roller. In this way, the tuft is reversed and inverted, and advances on roller 202 tail 9b first (Figure 5C). As it is flipped over it is layed onto the preceding tuft 9" ahead of it on the bed of pins 213. The head of the next tuft is caught by a trailing row of pins 213 and the tuft is again flipped over onto the roller and laid onto tuft 9' to continue the formation of a web 7. Apron carriage 12 and detaching rollers 22' have meanwhile moved back to collect a further tuft from the beard 8a.
Typically, the tuft heads will be spaced at about 1 cm intervals on the pinned roller 202 as web 7 is formed. The web 7 continues to be drawn on by pinned roller
202 and is then drafted through roller set 210. To ensure a non-slip grip of the heads of the tufts by the rows of pins, and to ensure sustained control of the web, necessary in order to facilitate a correct drafting action at roller set 210, the pins 213 are preferably radial or inclined outwardly rearwardly relative to the direction of travel of the roller surface, most preferably the latter. Drafting set 210 is preferably a two-on- one system, with a speed six to eight times higher than the pinned roller.
The tuft sweeping bars 204 are tubes fixed at suitable intervals between a pair of chains 220 (Figure 3, not shown in Figure 4) driven with appropriate timing along a closed path about sprocket 225 coaxial with roller 202, and a remote sprocket 227 on the other side of the drafting roller set. A multiplicity of sprockets can be used to change the path of the bars 204 to provide greater access for threading the drafting rollers 210'. This aπangement requires an angled exit path for the drafted web. Another alternative is a closed path with a return between the detaching rollers and the pinned roller: the bars are timed to return back through the gap behind detaching rollers 22' at an appropriate opportunity between tufts.
The bars 204 are arranged in spaced sets 230. Each set has a leading subset of four bars 204a at close intervals equal to the sprocket pitch, and then three trailing bars 204b at twice the sprocket pitch. This assists in optimum control and overlying of the tuft as it is swept up and flipped. The close spacing of leading bars 204a prevents a later part of the advancing tuft being caught on pins 213, whereupon the tuft would wrap around the bars. Such close spacing is unnecessary after the first few bars, but the regular trailing bars 204b prevent the rear of the tail dropping onto the pins 213 as it emerges from nip 84'.
The embodiments of Figures 3 and 4 may be more suitable for longer fibre materials such as wool, than for shorter fibres such as cotton. For example, the mean fibre length of cotton, about 20 mm, may be too small for a tuft to reliably bridge the gap to the pinned roller 202.
In the embodiment of Figures 3 and 4, it would be possible to employ means other than bars 204 for the purpose of sweeping over the tails of tufts. For example, an air jet may be so employed.
In the modification of Figure 6, in which like parts are indicated by like but primed or double primed reference numerals, apron carriage 12' is dispensed with and pinned roller 202' receives the tufts directly from the nip of the detaching rollers 22'. The path of bars is shown at an angle so that the arc of the pinned roller is maximised to receive longer tufts. In the absence of an apron, at least the lower of detaching rollers 22' would need to be coated or covered with a compliant sleeve in order to provide an effective nip. The sequence of tuft inversion with the apparatus of Figure 6 is similar to that of Figure 3, and is illustrated in Figures 7 A to 7C.
A possible advantage of the embodiments of Figures 3 to 7 relative to that of Figures 1 and 2 is that, in the former, at least the bulk of the tuft is substantially under sustained control throughout the process. Sustained control is a desirable objective in textile processes, which are inherently more robust if the fibre can be held positively during all stages of manipulation.
Figure 8a to 8f illustrate a further arrangement for reversing tufts at cylindrical contrarotating detaching rollers 22. The detaching rollers 22 are in this case mounted, for example on a suitable sub-frame, for bodily rotation about an axis parallel to the roller axes. In the example illustrated, this rotation is about an axis located at the nip 23 between the detaching rollers, although this is not essential.
In the arrangement of Figures 8a to 8f, detaching and combing of the tufts 9 from beard 8a is effected generally as previously described, first by engagement of the beard with upper and lower nipper jaws 20, 21, by means of which the beard is lowered for combing by rotating comb 14. Detachment of tufts 9 is then effected through top of comb 16 by advancing the rotating detaching rollers 22 so that beard 8a is gripped at the nip 23 by the rotating detaching rollers 22. The beard 8a is however caused to pass through nip 23 only a relatively small amount, say 30 mm, before rotation of the
detaching rollers is terminated, and the detaching rollers are moved away from the nipper jaws 20, 21 (Figures 8a and 8b). Typically, the translational movement of the rollers away from the nipper jaws may be of the order of 35 mm, giving a total tuft withdrawal length of the order of 70 mm.
During or after the described translation of the detaching rollers, bodily rotational movement of the detaching rollers occurs about the beforementioned axis located at nip 23. The movement is shown in Figures 8a through 8e as occurring over about 180°, but rotation could be by other amounts. As this movement occurs, a transverse bar 810 is moved on the path 820 shown. Bar 810 engages the underside of the tuft 9 at a location between the tail 9b of the tuft and nip 23, and sweeps the so engaged trailing part of the tuft upwardly and away from the nipper jaws. The combined action of bodily rotation of the detaching rollers, and engagement and movement by the bar 810 causes the tuft to be flipped over so that it proceeds tail first, being deposited on a pin bed 830, similar to that on a gill box, which carries the assembly to a set of drafting rollers (not shown).
Finally, rollers 22 are rotated to free the now trailing head 9a of tuft 9 from the detaching rollers (Figure 8f).
On completion of the above steps, the detaching rollers may be reverted to the position shown in Figure 8a, ready for detaching and reversing the next tuft, although this is not essential. For example, in the described arrangement, bodily rotations of 180° always leave the two detaching rollers in appropriate positions for a fresh cycle of operation.
At a suitable time before a following cycle of operation, bar 810 is moved back to its starting position either back along path 820 or on a different path.
In the arrangement of Figures 8a to 8f, there is some danger that tuft tails may be forced into the root ends of pins of the comb 16 during the flipping operation. In order to prevent this, a plate 822 is positioned immediately forward of the comb 16, and before rollers 22. This extends downwardly to a sufficient extent to prevent the tail of
the tuft from moving upwardly to the point where it would likely be caught on the comb.
The arrangement of Figure 9a to 9c is similar to that of Figure 3, in that it employs a large cylindrical pinned roller 202, downstream of, ie behind apron 13, a train of tuft sweeping bars 204 being arranged to periodically traverse the gap 206 between apron 13 and roller 202, and a drafting roller set 210 associated with the rear of pinned roller 202.
Tufts 9' are drawn through rollers 82', 83' and fed to the pinned roller 202 to be engaged by pins 213 thereof, the bars 204 being effective to flip tufts 9' onto the pins to effect reversal.
In the case of Figures 9a to 9c, however, the feeding of tufts 9' to roller 202 is facilitated by forming the upper roller 22' with a perforate surface 910. Internally of the upper roller 22' there are provided two air feed ducts 912, 914. Suction is applied to duct 912 so that air is drawn inwardly from the exterior of the upper roller 22' through perforations thereof which are for the time being during rotation of the upper roller 22' positioned adjacent duct 912. On the other hand air is blown outwardly through duct 914 and exteriorly of the upper roller 22' through perforations in the upper roller 22' which are for the time being adjacent duct 914. As shown, duct 912 is arranged to effect suction at a zone immediately at the point of leaving of tufts 9' from the nip between rollers 22' and duct 914 is arranged to exhaust directed air through the periphery of the upper roller 22' at a location past the suction zone, reckoned in the direction of travel of the tufts 9' from between the rollers 22' (that is to say reckoned in the direction from right to left in Figures 9a to 9c). The direction and rate of flow the air is selected to control the transfer of the tuft into pins.
In the arrangement of Figures 9a to 9c, then, as the tufts emerge from the nip between the rollers 22' they are at first sucked and held against the surface of the upper roller 22' so that the heads 9a' tend at first to move somewhat upwardly (Figure 9a).
Then, as the head 9a' of each tuft enters the zone of outward exhaust from duct 914 this
is blown off the surface of the upper roller 22' to enter into a space between pins 913 on roller 202. Once the head of the tuft has entered the pins 913, bars 204 sweep the tail in front of the head as previously described and reverses the tuft onto roller 202.
The arrangement of Figures 9a to 9c has the advantage that the tuft is introduced onto the roller 202 more reliably and also in a favourable fashion. That is to say, the tuft is at first introduced between pins 213 in a more positively controlled manner and more parallel to the pins than in the arrangement of Figure 3.
Figure 10 shows a further variation in the arrangement of Figure 3 with the pins
213 being oppositely directed as compared with the direction shown in Figure 3. That is to say, in Figure 3, the pins 213 extend somewhat tangentially but "anti-clockwise" from the surface of the roller 202 as compared with the "clockwise" and somewhat tangentially oriented direction of extend of the pins 213 from the surface of the roller 202 in Figure 3. In this case, the roller 202 is reversely rotated as compared with the direction of rotation of the arrangement in Figure 3, that is to say that it is rotated clockwise as viewed in Figure 10. With this arrangement, too, there is further provided a more favourable entry angle of the head of the tuft 9' as it is entered onto the roller 202. The action of placing the tufts onto the roller 202 is otherwise the same as explained in relation to Figure 3 by engagement with bars 204 which are omitted in Figure 10 for clarity.
Aside from the abovementioned variations concerning the method of "flipping" of tufts 9, various other ways of consolidating or sidewardly compressing the tufts as they are detached from the beard 8a may be employed. Figure 11 shows an arrangement having detaching rollers 22 that act also as previously described in conjunction with the nipper jaws 20 and 21 to grip the beard 8a and withdraw a tuft by translational movement of the rollers away from the nipper jaws 20, 21. Here, there is provided, immediately behind the detaching rollers 22, a further pair of rollers 320, 322 aπanged with their axes transverse to the direction of travel of the tuft 9, and which are contrarotated. Rollers 320, 322 may have a sector removed to allow an air flow through the rollers to facilitate capture of the leading edge of the tuft.
As illustrated in Figure 12a through 12d, the tuft 9 as it is passed through these rollers 320, 322, from detaching rollers 22, is subjected to a sidewards movement by effecting relative transverse movement between the rollers, in this case by axial transverse movement of the roller 322. As shown, the effect of this is to cause the leading end 9a of the tuft 9 to be moved transversely relative to the trailing edge whereby to compact the intermediate portion 9c between these and, subsequently, to likewise compact the tail 9b itself. The length of the tuft 9 fed through rollers 320, 322 is preferably arranged to be just less than the shortest fibre length. Figures 12a to 12d show an exemplary extent of the relative transverse movement between rollers 320, 322, from a condition at which the two rollers 320, 322 are generally aligned in the direction of travel of tufts 9 (Figure 12a). Figure 12d illustrates the case where relative sidewards movement has occuπed to the point where the roller 322 is well to one side of the roller 320. The sidewards movement of roller 322 need only be the length of the tuft 9, as illustrated in Figure 12c. At this point, the tuft 9 is delivered from the rollers 320, 322 and, for example, placed on a conveyer 340 for subsequent processing. Figure 13 indicates the end condition at which the sidewards compacted tuft 9 is nearing the end of the cycle shown in Figures 12a to 12d.
Subsequent to the sequence illustrated in Figures 12a to 12d, the rollers 320, 322 are reverted to the condition shown in Figure 12a before receiving the next tuft. Altematively the next tuft may be collected during the return stroke of the roller pair 320, 322. In this case, alternative arrangements would be needed to collect the tuft.
Although not shown in Figures 8a to 8f, Figure 10, and in Figures 11, 12a to 12d and 13, there is provided, in each of these arrangements, drafting rollers such as the roller set 130 shown in Figure 1 for processing of the tufts as they are formed and after reversal has occuπed.
A particular advantage of all of the described arrangement is that, by effecting the described reversal of the orientation of the tufts, the can or balls to which assembled tufts or slivers are customarily directed after combing can be omitted. That is, it is possible to immediately subject the assembled tufts to drafting in the rollers 130
whereas, in under past practice, it has been necessary to effect storage as an intermediate step. This leads to considerable increases in efficiency since the step of storage introduces obvious delays in processing.
This effect arises because, by laying tufts tail-first instead of the traditional head-first, fibres of the separate tufts can be adequately intermingled to achieve the required degree of cohesion. Application of a draft (eg as in the second embodiment or in general by any of the conventional methods) enhances such intermingling. Moreover, the reversed laying of the tufts and the feeding of the web through a pin drafter can effectively eliminate a finisher gilling stage.
The described embodiments also have the advantage that assembly of tufts tail- first is effected without use of overlapping rollers, such as in the aforementioned prior patent to Schliefer where hooks are likely to develop in the assembled tuft structure.
Generally, the described arrangements also avoid overlapping of tufts or sections at rollers because it is difficult to fully control the overlapping process of reversed tufts in this way and particularly if the tufts are made in a rectilinear comb. That is to say, in commonly employed combing operations overlapping at rollers are satisfactory because the leading end of the tuft contains many more fibres and are therefore bulkier making it easier to handle and control. By contrast, the trailing ends of tufts are filamentary and are more difficult to control. Loss of control of the fibres in a tuft during overlapping leading to hooked or misaligned fibres will lead to a significant deterioration in the quality of the sliver.
The described arrangements also minimise fibre disturbance during overlapping, in order to provide retain sliver quality at high levels. With the pinned drafter method, for example, the incoming tuft is able to move into a zone free from fibre that may disturb fibre parallelization. The tuft is then reversed while the head is held securely in the pins, which prevents fibres from becoming misaligned. Similar considerations apply in the case of separate tuft overlapping. In this case the tuft is restrained during collapse so that the fibres in the trailing end are under control during the process.
Many other arrangements are also possible within the broad concept of the first and second aspects of the invention. For example, in the embodiment of Figures 1 and 2, apron 13 might be dispensed with and support bed 100 positioned and adapted to receive the tufts directly from the beard. Also, the upper run of transport rollers 101 can be eliminated and the collapser rods 105 replaced eg by a plate driven by a chain. In general, an alternative arrangement to roller support bed 100 might comprise a feed surface in the form of a primary cylinder provided with a multitude of holes through which air is drawn to hold the tuft onto the cylinder so that it can rotate at high surface speeds and rapidly transport the tuft to a preset position. Other methods could, of course, be used to hold the tuft onto this cylinder, eg electrostatic gripping or belts. Once the tuft reaches the preset position the cylinder stops and the airflow is stopped, leaving the tuft free on the surface of the cylinder. On the side of the transporting cylinder is a scraper that fits closely around the circumference but is free to slide in the transverse direction, ie along the axis of the cylinder. When the cylinder comes to rest the tuft is arranged so that its complete length is spanned by the scraper. For wool, this typically requires that the diameter of the cylinder is about 160 mm. Longer fibres would require a larger diameter whereas shorter fibres would require a smaller diameter. As the scraper moves along the cylinder it collects the tufts and pushes them in turn onto a second naπower cylinder that rotates continuously in the opposite direction.
It will also be appreciated that the lateral compression, or condensation, of the tuft prior to laying is not essential but does facilitate the reversal and intermingling process in the first embodiment. Moreover, the compression/condensation, laying and reversal steps could occur in any order depending on the particular construction adopted. The tuft may be rolled up rather than pushed as in the first illustrated embodiment, or may be lifted off the initial support surface as a planar tuft, eg with some form of suction arrangement, rather than pushed off as a condensed tuft.
The placement of tufts to form an assembly is illustrated, for both embodiments, as taking place broadly horizontally on the upper surface of a rotating cylinder. In general, this placement to form the assembly may take place vertically or horizontally or a combination of both.
Reversing of tufts also provides for greater scope to improve the evenness of the combed sliver by providing an extra gilling at the comb. Normally drafting of combed slivers in the forward direction is less effective because the leading ends of the fibres are aligned. This alignment cannot be disrupted by drafting when the leading ends are presented first. If the tuft is reversed, so that the trailing ends are presented first, the alignment of the previously leading ends is readily disrupted, significantly improving the evenness and tenacity of this sliver.
The separate presence of tufts following detachment from the beard allows the possibility of a new quality control point at the combing station. Tufts may be monitored, eg optically, to detect unacceptable tufts, for example those responding in a manner suggesting the presence of contaminants, and these tufts may then be wholly or partially ejected either in full-width foπn or in laterally condensed form. The rejected tufts could be consolidated into a sliver of lower quality if desired.
A quality control station for the above purposes may be provided for example after the detaching rollers, such to detect defects as the tufts are transported on apron 13.
Another advantage of detaching tufts separately is that the fibre length can be readily measured on the machine during normal operation. The shape of the tuft provides all of the information that is needed to measure mean fibre length and also the variation in fibre length. Tuft shape can be monitored by fitting appropriate sensors to the comb, such as capacitive or optical, from which the required information can be extracted. This capability will provide great assistance to combers by enabling on-line measurement leading to improved quality assurance. Also, there is the possibility of inspecting each tuft for the presence of contammants such as vegetable matter or other non-wool materials, eg bale pack tapes. Once these materials are detected, an alarm can be set or the tuft can be ejected, at substantially lower cost than subsequent removal, which is conventionally either in yam clearing or by hand in fabric mending.
A significant advantage of the illustrated embodiments resides in a simplification of the required associated drive mechanism. In the conventional comb assembly, the apron carriage is reciprocated, and the apron itself moves back and forth on the carriage. This requirement for a reversal of motion of an element within a component that itself reciprocates on a different cycle has meant a complex drive mechanism. Current such mechanisms impose a limit on the throughput speed of combs. With the present invention, however, moving elements of reciprocating components (eg the apron 13, 13') move only in one direction thus eliminating the conventional source of the speed limited complex mechanism. It will of course be understood that the mechanism as such, which is not detailed, is of a conventional type readily apparent to, and well understood by, textile machinery engineers.
The described aπangement has been advanced merely by way of explanation and many modifications may be made thereto without departing from the spirit and scope of the invention, which includes every novel feature and combination of novel features herein disclosed.
Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.