Drive between an autoleveller and a coiler

Abstract: A drive between an autoleveller output (1) and a coiler (6) in a carding and deposition assembly comprises slack take-up means (16), and means (16, 18) for varying the length of the sliver path (17). In a belt drive, the slack take-up is effected on both sides of the belt drive by facing pulleys (10, 14). These may be resiliently biassed, either by a helical tension spring (14), by the belt elasticity and pulley geometry, or other suitable means.

Description: This invention relates to a drive between an autoleveller and coiler head, as are found in carding and deposition assemblies for the production of sliver. In these assemblies, sliver is produced as the carded web is doffed from the carding cylinder, at which point the sliver is subjected to autolevelling. This procedure introduces very short-term draft rate variations between two or more pairs of drafting nip rollers in the sliver path. Its purpose is to cause the sliver quality to become more consistent by variably stretching it to remove inconsistencies in sliver weight. The sliver is then conventionally passed to a coiler head, which lays the sliver in epicycloidal loops in a can, in a manner known per se. FR-A-2152591 discloses a combination of a card with a autoleveller and a coiler where the coiler is driven at a substantially constant speed by a direct mechanical transmission from one of the drafting rollers of the autoleveller, linked to the doffer of the card. A sliver reservoir is provided to accommodate mis-match between the rigid linking of the coiler to the autoleveller and the need for absorption of the mis-match between sliver delivery from the card and sliver delivered to the coiler. EP-A-0376002 discloses a comber having an autoleveller 11 and a coiler 23 but with no disclosure of the drive to the coiler 23. The present invention provides a drive for use between an autoleveller and a coiler characterised by the features of claim 1. In the claims and description the terms upstream and downstream in relation to portions of the drive belt refer to the path of movement of the belt past the belt drive pulley driven by the autoleveller. The purpose of the drive between the autoleveller and the coiler head is to provide a sufficiently constant drive for the same quantity of sliver to be coiled as is output from the autoleveller, in the long-term, as well as to isolate the coiler head inertia from the autoleveller, which would otherwise increase the response time of the autoleveller intolerably. Preferably, the slack take-up means are biassed to take up the increase in path length of the downstream portion of the drive belt. Advantageously, the high and low tension portions of the drive belt may be taken up by the slack take-up member via one or more dancing pulleys. Further, the slack take-up member may carry a sliver assisting pulley for guiding a sliver along a sliver path, the sliver-assisting pulley being adapted to co-operate with the sliver path so as to vary the sliver path length between the autoleveller and the coiler in accordance with the motion of the slack take-up member. With this feature the slack in the sliver about the sliver assisting pulley may be maintained substantially constant. This allows the sliver assisting pulley to be shaped so as to avoid creasing or buckling of the sliver (a delicate substantially cylindrical structure) as it passes in a catenary loop from the autoleveller to the coiler. The invention will further be understood from the following description when taken with the accompanying drawings which are given by way of example only and in which: Figure 1 is a schematic side elevation of a belt drive according to the present invention. Figure 2 shows a second embodiment of the invention. Fig 1 shows a first embodiment of a belt drive according to the invention. The drive between the autoleveller output pulley 1 and the coiler head tube wheel 6 is via drive belt 15. The belt passes via a belt deflecting pulley 2 and over a belt tensioning spring loaded pulley 3. The drive belt then passes through a slack take-up assembly 16 and onto the first belt deflecting pulley 5 of the coiler head tube wheel. After the tube wheel 6 itself, the drive belt passes to a second tube wheel belt deflecting pulley 7 and is deflected up to a calender roller drive pulley 8. The drive from pulley 8 is used to drive calender rollers 13, 13'. The drive belt then passes around a can drive input pulley 9 and back up to the slack take-up assembly 16 where it is passed over pulley 10 and then returns to the autoleveller pulley 1 via a belt deflecting pulley 11. The slack take-up assembly 16 comprises two belt pulleys 4, 10 on a common frame member, and a spring 14, in this case a helical tension spring although any resilient biassing means may be used. The slack take-up assembly 16 may however comprise two coaxial pulleys. The slack take-up assembly 16 is movable in the vertical direction as shown by the arrows. The drive belt paths immediately adjacent the slack take-up means are arranged to be parallel with the direction in which the slack take-up assembly is movable. A path for the sliver 17 is defined by sliver assisting pulleys 18 to 21. A sliver assisting pulley 18 is arranged to be moved by the slack take-up assembly 16 and may preferably be arranged to be co-axial with belt pulley 4. More particularly, the effective diameters of the two pulleys 4 and 8 are preferably the same, and the two drivingly connected. Advantageously, the sliver assisting pulleys 18-21 are shaped so as to cause minimal disruption to the delicate cylindrical structure of the sliver. The sliver assisting pulley 19 is arranged so that the sliver path between the sliver pulley 19 and sliver pulley 18 is substantially parallel to the drive belt path between belt pulleys 3 and 4. Sliver assisting pulley 19 may be disposed above belt pulley 3, or coaxial with it, and adjusted so that its effective peripheral speed is equal to that of belt pulley 3. A sliver deflecting pulley 20 is disposed somewhat above the belt drive mechanism and defines a part of the sliver path which is substantially parallel to the drive belt path between belt pulleys 4 and 5. The sliver path further includes a last sliver deflecting pulley 21 and calender rollers 13, 13' which draw the sliver into the coiler head. In use, the autoleveller output pulley 1 is driven with the final draft roller shaft 30 of an autoleveller in the anticlockwise direction as shown in Figure 1. The drive is therefore transmitted to the tube wheel 6 of the coiler head, the tensions imposed on the drive belt 15 by the drive from the autoleveller differing in the upstream and downstream portions 22 and 23 respectively, of the belt drive. This difference in belt tensions and variations in the difference cause the slack take-up assembly 16 to move either up or down, as shown in Figure 1, with or against the return force of the biassing means 14. In steady state operation, the coiler head is driven at a speed dependent on that of the autoleveller output pulley 1. Due to the operation of the autoleveller, the rate at which the sliver 17 is output from the autoleveller varies, in order to maintain the sliver quality. The rate at which the autoleveller output pulley 1 rotates therefore varies as a function of the instantaneous rate at which the autoleveller is drafting, and therefore the rate at which the sliver 17 is fed out. Since the drive between the autoleveller output pulley 1 and the coiler head 6 is cushioned by the action of the slack take-up assembly 16, the response of the coiler head to changes in the speed of rotation of pulley 1 is somewhat delayed. The effect of e.g. the downward movement of the slack take-up assembly 16 is to allow the coiler head to lag behind the autoleveller output pulley 1 in its response to the autoleveller speed changes. The downward movement of the slack take-up assembly 16 causes the downward movement of sliver assisting pulley 18, thus lengthening the sliver path; this causes the excess of sliver in the path due to the lag of the coiler head and the excess of the sliver produced by the autoleveller to be taken up. Put another way, the speed of the sliver between sliver pulleys 18 and 20 is in one-to-one relation to the belt speed between belt pulleys 4 and 5. By appropriate choice of the sliver speed through the calender rollers 13, 13' and the rate of rotation of the coiler head tube wheel 6, the rate of arrival of sliver at the calender rollers 13, 13' may be kept proportional to the rate of rotation of the calender rollers themselves. Clearly, the system may be adapted for the coiler head, to rotate at other speeds, or to deposit sliver at different rates with the movement of the sliver the assisting pulley 18 parallel to that of the slack take-up assembly 16 being geared, e.g. by simple lever gearing. A second embodiment of the invention, shown in Fig 2, involves the introduction of a variable speed motor 24 in the drive system between pulley 9 and a can drive pulley 12, on which a can to be filled by the sliver from the coiler head is positioned. In this embodiment, the spring 14 is not used, but the variable speed motor is adapted to operate in response to a position sensing device 25 disposed between the machine frame and the slider of the slack take-up assembly 16. Thus, by appropriate control of the motor in accordance with output of the position sensor 25, the inertia of the can and the coiler may be masked from the autoleveller output, and thus the autoleveller mechanism. The motor 24 need not be disposed only between the pulley 9 and the can drive but may be at any position in the system provided it is on the side of the slack take-up assembly remote from the autoleveller between pulleys 4 to 10. The control for motor 24 is effective to introduce variations in the tensions of the upstream and downstream portions of the belt so as to return the slider of the slack take-up means to a central position.

Claims: Apparatus comprising an autoleveller, a coiler, and a belt drive transmitting drive therebetween, characterised in that the belt drive comprises a drive belt (15), portions (22,23) of the drive belt being defined respectively upstream and downstream of the autoleveller; in that it further comprises a slack take-up member (16) co-operating with both of said upstream and downstream drive belt portions for selectively increasing and decreasing the path length of either one (22,23) of said upstream and downstream portions of the belt in response to decreasing or increasing, respectively, of the other (23,22) of said belt portions, for taking up any slack in the drive belt, the slack take-up member (16), having at least one fixed axis belt pulley (4) on a carrier movable along a path such that the increase and corresponding decrease in the path lengths of the respective drive belt portions of the belt occur at substantially the same rate; and in that means (14;24) are provided to drive the slack take-up member along the path in a first direction to respond to an increase in the path length of the downstream portion (23) of the drive belt by shortening that downstream drive belt portion, and in a second direction to respond to an increase of the path length of the upstream portion (22) of the drive belt by shortening that upstream portion. Apparatus according to claim 1 characterised in that the slack take-up member (16) is driven by being biassed towards a central position of said path, preferably by a spring (14). Apparatus according to claim 1 characterised in that the slack take-up member (16) is driven by the elasticity of the drive belt which biasses the slack take-up member to increase and decrease the length of the upstream portion (22) of the drive belt path at a rate lower than that at which the length of the downstream portion (23) of the drive belt path correspondingly decreases or increases. Apparatus according to any one of claims 1 to 3 characterised in that the upstream (22) and downstream (23) portions of the drive belt are taken up via two dancing pulleys (4,10) carried by the carrier of the slack take-up member (16). Apparatus according to any preceding claim wherein the slack take-up means comprise a pulley (4,10) for each of the upstream and downstream portions (22,23) of the drive belt (15); and in that the belt path of both portions are substantially parallel adjacent the pulleys (4,10). Apparatus according to any one of the preceding claims, characterised in that the slack take-up member further carries a sliver assisting pulley (18) for guiding a sliver (17) along a sliver path (19,18,20,21); in that the sliver assisting pulley (18) is adapted to co-operate with the sliver path so as to vary the sliver path length between the autoleveller and the coiler in accordance with the motion of the slack take-up member (16); and in that the sliver speed is substantially equal to the drive belt speed. Apparatus according to claim 6, wherein the paths of the drive belt (23) and sliver (17) are congruent in the neighbourhood of the slack take-up member; and including a movable sliver guide means (18) for varying the length of the sliver path responsive to the slack take-up member such that when the slack in the drive is introduced in the downstream portion (23) of the drive belt the path (17) of the sliver is lengthened, and when slack in the drive is taken up the sliver path (17) is shortened. Apparatus according to claim 1, wherein a variable drive means (24,25) is disposed in the drive, on the side of the slack take-up member (16) remote from the autoleveller, and responsive to the slack take-up member. Apparatus according to claim 8, wherein the variable drive (24) is controlled in response to a sensor (25) on the slack take-up means (16) to substantially isolate from the autoleveller the inertia of the side of the drive remote from the autoleveller. Apparatus according to claim 8 or 9, for a rotating can coiler, wherein the variable drive means (24) is drivingly engaged with the drives (6,8,15) to the coiler can and a can drive pulley (12).

Inventors: HANKINSON JULIAN EDGAR JR, WHITELEY JOHN, HANKINSON, JULIAN EDGAR, JR., WHITELEY, JOHN
Applicants: HOLLINGSWORTH ON WHEELS JOHN D, JOHN D. HOLLINGSWORTH ON WHEELS INC.
Application year: 1992
Main classification: D01G15
IPC codes: D01G15, B65H59, D01G23, B65H51