GB2341399A - Carding : opening and cleaning fibres before flats : mounting of flats - Google Patents

Abstract

A cylinder assembly, co-operating with clothed carding cylinder 1 between a lickerin and carding flats, has clothed stripper cylinder 12 lifting fibre from cylinder 1 and transferring it to clothed worker cylinder 5 co-acting with stationary flats 14 and knives (15, not shown) to pre-open and clean the fibre before returning it to cylinder 1. Two brackets are provided, one either side of cylinder 1, to reposition the main carding flats, e.g. the back-bowl of revolving flats, further round the cylinder to accommodate the cylinder assembly, which, with the brackets, may be provided for retro-fitting. Further pairs of cylinders 12, 5 may be used. It is claimed that the fibre pre-treatment reduces the number of revolving flats required.

Description

2341399 "Booster for Cardinq Machine" The present invention relates to

carding machines comprised of main cylinder, lickerin, doffer and flats and particularly to a booster arrangement for such carding machines. The flats may.be revolving, stationary or'a combination of both. Where the flats are revolving, they are suppo-rted and guided by a "back bowl bracket" at the entry point of the flexible bend. The cloths of the main cylinder and of the flats perform the carding process.

In the spinning industry it is well known that the quality of carding depends to a large extent on the preparation of the fibres before they enter the main carding zone between flats and main cylinder. A pre-opened and uniform fibre mass is favourable for the carding process. The success of quality and production enhancements of a card strongly depend on the achievement of these conditions.

Various approaches have been taken to improve card quality. One approach makes use of enhanced lickerin devices. The fibre mass passes through a lickerin system of more than one cylinder. Examples are shown in U.S. 4, 274,177 (1981) and WO 92/16676 (1992). Those patents describe three cylinders that form the system of feeding and lickerin. Although advantageous these systems also have 2 considerable draw-backs: they are expensive and cannot be retrofitted to existing cards.

Another approach uses the well-known worker and stripper concept. Patents US 4,011,631 (1977) and US 4,271,564 (1981) describe one or more pairs of cylinders that are placed adjacent to the main cylinder. Both cylinders of a pair turn in opposite direction to the main cylinder. One of the rollers, called the "stripper", removes fibres from the main cylinder. The fibres then pass on the second roller, called the "worker". The worker carries around its surface multiple segments with attached cloths and with mote knives. Such configurations are also shown in the literature (for example R.O. Herzog, Technologie der Textilfaser, Berlin 1927). The cited patents give details of the curved segments, the extraction channel and the blades. However such designs are not readily applicable or retrofittable to standard cards.

The present invention seeks to improve on the known worker and stripper concept in combination with a flexible system of stationary flats and mote knives.

Accordingly the present invention provides a booster for a carding machine for processing staple fibres such as cotton, wool, or synthetics, including a main cylinder and a back-bowl bracket carrying revolving flats, the booster comprising one or more pairs of worker and stripper cylinders, the, or each, worker being surrounded by stationary flats with cloths and mote knives, and mounting 3 means for the back bowl bracket which is so arranged as to increase the space between the lickerin and the back bowl bracket whereby the actual configuration of stationary flats and of mote knives around the worker may be varied according to the specific need of the carding proce ss.

Preferably the said worker and stripper are directly driven from the main cylinder by a system of belts so as to ensure a synchronous speed with the main cylinder especially when starting and stopping the card. Alternatively electric motor drives may be employed.

Additional carding elements may be provided at the entry or exit points.

The gaps between the main cylinder, worker and stripper rollers may be arranged so as to be adjustable. The wire point direction of the cloths (carding point) may be varied to suit different applications or machine setups. Internal or external suction may additionally be provided to hold the moving fibres. The worker cylinder preferably rotates in the opposite direction to the main cylinder. The stripper cylinder may rotate in the direction of the main cylinder or in the opposite direction. The system of the invention is applicable to standard cards and provides for setting and driving the important elements, while the actual configuration of flats and mote knives may be readily adapted according to the specific needs. Any contact between the several cloths is prevented and hence dangerous and damaging accidents are eliminated.

4 Some embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which:

Figure I is a side view of one embodiment together with its drive mechanism; Figure 2 is a side view showing flat supports, and flat and mote knife design, Figure 3 is a cross-section and front view of flat and mote knife support, Figure 4 is a side view of a further embodiment together with its drive mechanism.

Figure 5 is a side elevation showing a first type of support bracket; and Figure 6 is a side elevation showing a second type of support bracket.

Figure 1 shows the main cylinder 1 together with a driving pulley 2 mounted on the shaft of the main cylinder. A belt 3 drives the pulley 4, which is attached to the I worker cylinder 5. The direction of rotation of the worker I cylinder 5 is designated by the arrow 6. The direction of rotation of the main cylinder 1 is given by the arrow 7. main cylinder 1 and worker cylinder 5 are rotating in opposite directions. The diameter of the worker cylinder 5 is approximately 120 to 200 mm. A pulley 8 is attached to shaft 11 of the worker cylinder 5. This pulley 8 drives a belt 9 and the pulley 10, which drives the stripper cylinder 12. Stripper cylinder 12 rotates in direction 13. The stripper cylinder 12 therefore rotates in the same direction as the worker cylinder 5 and in opposite direction to the main cylinder 1. The diameter of the stripper cylinder 12 is approximately 90 to 15Omm, and it will be appreciated that carding machine speed can be increased/decreased by changing the respective diameters of the pulleys. The direct belt drive 3 and 9 is important to ensure the synchronous start and stop of the cylinders 1, 5 and 12. An unsynchronous start and stop will cause a breakage of the web (not shown) delivered by the card. This might happen especially in the case of a power-failure and would result in all cards of a mill losing a substantial part of their production and needing attention of operators during the restart procedure.

The stripper roller may be provided with a cover (not shown). Around the worker cylinder 5 several stationary flats 14 and mote knives 15'a-re positioned. The stationary flats 14 further open and equalise the fibre mass and the mote knives 15 extract trash, dust and short fibres.

The fibre flow is normally as follows: fibres are transported by the cloth 16 on the main cylinder 1 to the stripper cylinder 12.. The stripper cylinder-12 takes up fibres, transports them to the worker cylinder 5 and finally those fibres are returned to the main cylinder 1.

Fibre flow can be changed as desired by changing direction of rotation of worker cylinder/stripper cylinder In all cases main cylinder direction remains unchanged.

6 Figure 2 shows the details of the working elements which actually improve the carding quality. The cloth 16 on the main cylinder 1 is directed the conventional way, which is in the direction 7 of the rotation, moving along the "front side". For particular applications, however, the direction-fflay be changed as required. The cloth 17 on the stripper 12 is directed against the direction of rotation 13, i.e. moving along the "backside". The cloth 18 of the worker cylinder 5 is directed in the direction 6 of the movement, meaning along the "front side". The cloth 17 has approximately 300 to 450 ppsi (peaks per square inch). The cloth 18 has approximately 550 to 1000 ppsi. The stationary flats 14 carry cloths 19 with approximately 140 to 450 ppsi. The interaction between these cloths 19 and the cloth 18 of the working cylinder 5 leads to the favourable opening and equalising effects.

Instead of the stationary flats 14 mote knives 15 may be installed. The number and positioning of the mote knives 15 will be chosen according to the specific situation. The basic widths of the mote knives 15 and the stationary flats 14 are the same and this makes it possible to fix any combination of stationary flats 14 and mote knives 15.

The mote knife 15 carries an extraction blade 20. The mote knife,15 and the stationary flats 14 are attached to the frame body 27 by means of screws 26 and can be adjusted by means of screws 26a/26.

7 Figure 2 also shows the arrangement of mote knife assembly 40, mote knife holder 41, mote knife suction cover 42 and additional carrier 43. This is connected, in use, to the central suction system so as to remove motes at the preliminary opening stage of the fibres.

A stripper roller cover 45 is also provided to assist in fibre flow control, and the stripper roller and worker roller are so arranged that an area of the top cover sheet 44 is available for the installation of additional stationary flats or mote knives as required to improve performance.

Figures 2 and 3 show the two frame bodies 27 and 28 which space the worker and stripper cylinders 5 and 12. Those frame bodies 27 and 28 are mounted on the shafts 11 and 30 in such a way that the very critical distances of the surfaces of the revolving cloths 16, 17 and 18 are automatically defined and any contact between them is prevented. This is achieved by suitable setting the circumferences of the frame bodies 28 and 27 which both touch each other and the flexible bend 29. The flexible bend 29 is part of every standard carding machine and guides the revolving flats around the main cylinder. Any direct contact of the cloths is dangerous and might result in severe machinery defects. Additional covers 31, 31a, 32, 32a and 36, 36a guide the fibres and keep them stuck to the adjacent cloths.

Figures 1 and 3 shows other important details of the 8 assembling of the cylinders 5 and 10 to the card. The main body of the support 33 for the cylinders 5 and 10 is screwed to the frame of the card 34.

Attached to the main body of the cylinder support 33 is the frame body 27 which sits directly on the flexible bend 29. Two bearings 35 hold the shaft 11 of the worker cylinder 5. The shaft 11 is driven by the pulley 4 and the belt 3. In addition, this shaft 11 drives the stripper cylinder through pulley 8 and belt 9.

Figure 4 shows an alternative embodiment of the invention. The basic function is as shown in Figure 1 but the stripper cylinder 12 now operates in the same direction 37 a's the main cylinder 1. The cloth 17 on the stripper cylinder 12 remains the same as in Figure 1. The drive mechanism may be a tangential belt 38 together with a pulley 39.

Referring to Figure 5, support arms or brackets 46 are fixed on each side of the carding frame by means of mountings 50 previously used for mounting the back-bowl bracket 47 which carries a set of revolving flats. The back-bowl bracket can thus be moved back to the fixing positions indicated at 48 which also enables the number of working revolving flats to be reduced. Windows 51 in the support arm must then be provided to allow access to the flexible bend adjusting bolts, but this is somewhat difficult with the design of support arm shown in Figure 5, which also has a further drawback that the back-bowl end of 9 the support arm itself remains unsupported.

The support arm mounting enables additional space to be created between the back-bowl bracket and the lickerin roller for more stationary flats and the booster.

A further improved design of support arm 46 is illustrated in Figure 6 in which the support arm is positioned further around the machine in the anti-clockwise direction as shown in the figure, compared to that of Figure 5. The support arm has a mounting position 50 at its leading end corresponding to the original mounting of back bowl 47 (which is again relocated), but does not extend so far forward in the clockwise direction, as that of Figure 5. Instead it extends further in the anti-clockwise direction so that its "trailing" end can be bolted to the centre support plate 52, giving a much more robust support arrangement. The support arm is also made deeper in the radial direction so that the windows 51 can be correspondingly larger to improve accessibility of the flexible bend adjusting bolts, and the relatively shorter dimension of the leading end also improves access to the booster assembly.

The preferred embodiments of the invention provide a number of significant improvements in performance.

The drive to the carding machine is taken from the main cylinder, so no significant additional power is required and the power of the carding machine will be used to the maximum possible extent.

- If the carding machine is stopped for any reason, the booster does not stop immediately, but keeps running with inertia of the main cylinder and hence there is no interruption of the web.

since fibres are pre-opened thoroughly dust, trash and fibre fragments are removed to a greater extent, thereafter cleaner and even presentation of fibre to the carding zone is possible. This leads to less load on the revolving flat tops. Further, revolving flat tops will have less tendency towards loading of fibres fragments, dust and trashes, so their working life can be extended.

In an exemplary arrangement it was possible to reduce total number of revolving flat tops in working condition from 32/35 to 25/28. Even with reduced revolving flat tops in working condition, it was possible to improve upon the inherent limitation of revolving flat tops where it removes long fibre i.e. lint along with short fibres. The even and preopened feed to the carding zone by Booster enables a great improvement of selectivity of short fibre extraction by revolving flat tops, which in practical term means even with less flat waste extraction desired short fibre removal is possible. Thus the fibre realisation in the total spinning process can be improved.

Research on working of a carding machine indicates the main function of carding fibre i.e. opening and segregating fibre to an individual form thereby removing impurities, neps etc. present in the fibre mass and parallelisation of the fibres are done mainly in main cylinder - revolving flat tops zone. Further research indicates that in this action zone the greater function is done by the initial 12-14 revolving flat tops as it enters active zone in a clean form. More number of revolving flat tops in the active zone may in fact result in over carding causing fibre rupture and formation of neps. The Booster assembly of the present invention along with reduced number of revolving flat tops in active zone eliminates this chance and thereby reduces neps which.ultimately results in better yarn quality.

Thus, the present invention presents a whole gamut of options to a spinner by overcoming the limitations of the revolving flat top system to a greater extent.

I I

Claims (13)

1. A booster for a carding machine for processing staple fibres such as cotton, wool, or synthetics, including a main cylinder and a back-bowl bracket carrying revolving flats, the booster comprising one or more pairs of worker and stripper cylinders, the, or each, worker being surrounded by stationary flats with cloths and mote knives, and mounting means for the back bowl bracket which is so arranged as to increase the space between the lickerin and the back bowl bracket whereby the actual configuration of stationary flats and of mote knives around the worker may be varied according to the specific need of the carding process.

2. A booster for a carding machine according to claim 1 in which the mounting means comprises a respective support arm mounted on each side of the carding frame.

3. A booster for a carding machine according to claim 1 or claim 2; wherein the said worker and stripper are directly driven from the main cylinder by a system of belts so as to ensure a synchronous speed with the main cylinder especially when starting and stopping the card.

4. A booster for a carding machine according to any preceding claim 1 in which the said stripper cylinder has a 13 - diameter of approximately 90 to 150 millimetres.

5. A booster for a carding machine according to any preceding claim in which the said stripper cylinder has a revolving speed of approximately 250 to 450 rpm.

6. A booster for a carding machine according to any preceding claim in which the said worker cylinder has a diameter of approximately 120 to 200 millimetres.

7. A booster for carding machine according to any preceding claim in which the said worker cylinder has a revolving speed of approximately 780 to 1300 rpm.

8. A booster for a carding machine according to any preceding claim in which the said stripper cylinder has a cloth of approximately 300 to 450 peaks per square inch.

9. A booster for a carding machine according to any preceding claim in which the said worker cylinder has a cloth of approximately 550 to 1000 peaks per square inch.

10. A booster for a carding machine according to any preceding claim in which the said stationary flats have cloths of approximately 140 to 300 peaks per square inch.

11. A booster for a carding machine according to any preceding claim in which the said stripper and worker cylinders are supported by two independent side frames, which are in direct contact with each other and also with the flexible bend, so as to prevent any dangerous contact of cloths.

12. A booster for a carding machine according to any preceding claim in which the said stripper is arranged to rotate in the same direction as the main cylinder.

13. A booster for a carding machine according to any preceding claim in which the said stripper is driven by a tangential belt system.