TEXTILE MACHINE FIELD OF THE INVENTION

The present invention relates to spinning preparatory machines, more particularly sliver processing machines such as carding, drawing, combing, lap forming machines having sliver guiding arrangement for assuring efficient sliver transportation during processing.

According to the invention, the sliver guide arrangement is a rotating element provided to guide the sliver in a stretch free manner in the transition process of fibrous material between various machine zones. BACKGROUND OF THE INVENTION

Generally the spinning preparatory machine such as combing machine has row of multiple heads for processing fibre webs, supplied in the rolled form of lap sheets. Combing operation includes the sheet of fibre lap fed via the feed rollers in to the combing section, thereby the fibre webs are held through set of top and bottom nipper pairs and during rotary motion of circular comb, combing action takes place. After combing has been done, the noil-free cotton is collected in the form of fibre web by the pair of detaching roller arrangement and converted as sliver by the trumpet and moved to the common delivery table. All the combed slivers from each head are taken around a rotating sliver guides to enable smooth transportation over the common delivery table towards the drafting arrangement.

Main function of rotating sliver guide is to provide stretch free transportation, i.e. almost nil stretch during transportation between the various machine zones. In the textile yarn manufacturing process, linear density / unit area of sliver is maintained in various process stages in a controlled manner. However the minor variations of surface speeds, frictional characteristics, etc., could not be avoidable. The obstruction in free motion of parts is influenced by various factors such as accumulation of dust, fly, lint, other small waste matters, etc., leads to variation in frictional characteristics. The accumulation of dust particles such as cotton fly is very common in the textile mill and get deposited over a period of working of the machine, this obstruct the free rotation of sliver guides. And continuous production of combed sliver influences greater extent for jamming and catching of fluff particles in the moving parts.

A rotating sliver guide arrangement has been explained in the prior art Indian patent 174085 under application number 424/M AS/1989, referred in figure 1 a and 1 b. There is an individual rotating sliver guide (1 1 1 ) for each combing head used to deflect a sliver in right angle, i.e. a combed sliver coming from a combing head of a combing machine takes approximately right angle on to a delivery table (1 14) and runs towards the drafting arrangement (not shown). The sliver guide comprises a cylindrical outer sleeve (1 12) mounted rotatably on an inner element (1 13). The inner element (1 13) is fixed on the delivery table (1 14) by means of fastener (1 15). The combed sliver (1 17) runs around the sliver guide (1 1 1 ) and supported above the outward projection of the flange (1 16).

In the practical working of the known art, it is observed that the rotation of sliver guide (1 1 1 ) is interrupted during machine running. Since the inner element (1 13) has bigger diameter, the rotating torque generated by the running sliver tension force is not overcoming braking torque caused by the bearing surface friction (created by the rotational friction between sleeve (1 12) and inner element (1 13). Due to the interrupted rotation of the sliver guide, unwanted sliver stretch is created, there by sliver quality is affected.

OBJECTS OF THE INVENTION

The principal object of the present invention is to provide an improved rotating sliver guide arrangement in sliver transportation in a sliver processing machine.

Another object of this invention is that a rotating sliver guide arrangement which is suitable for stretch free transportation of combed sliver

A further object of the invention is to provide a rotating sliver guide arrangement for sliver processing machine, with simple in construction, cost effective and to provide quality sliver SUMMARY OF INVENTION

According to the aspects of present invention, provided an improved rotating sliver guide arrangement (1 ) in a combing machine, said arrangement comprising: The rotating sliver guide arrangement (1 ) comprises a cylindrical sleeve (2) rotatably mounted on a bearing pin (3). The radially outwardly projecting flange (6) is formed at the bottom edge of the cylindrical sleeve (2). The cylindrical outer surface of the sleeve (2) merges with the flange (6) by a curvature (8) of suitable radius, which provides sufficient space to accommodate the running combed sliver (7). The combed sliver (7) runs around the sliver guide (1 ) and supported over the flange (6) .

In the present invention, the probability of rotating the guide is increased such a manner that the rotating torque generated by the sliver force is considerably sufficient for overcoming the braking torque caused by bearing surface friction (created by the rotational friction between sleeve (2) and bearing pin (3)). This is achieved by keeping the bearing pin (3) radius lesser than half of sliver contact surface radius (The radial distance between the rotating axis and the sliver contact point.) to reduce the braking torque.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 a of the drawings schematically illustrate the cross sectional view of rotating sliver guide arrangement along with sliver known in the art.

Figure 1 b of the drawings schematically illustrate the top view of rotating sliver guide arrangement along with sliver of known art.

Figure 2a of the drawings schematically illustrate the side view of rotating sliver guide arrangement along with sliver of present invention. Figure 2b of the drawings schematically illustrate the top view of rotating sliver guide arrangement along with sliver of present invention. BRIEF DESCRIPTION OF THE INVENTION

Rotating sliver guide as per the known art is illustrated in figure 1 a and 1 b, which is explained in detail in the background of the invention. Rotating sliver guide as per the present invention is illustrated in figure 2a and 2b. The rotating sliver guide arrangement (1 ) comprises a cylindrical sleeve (2) preferably made of polymer having a mounting hole at the centre of axis. The cylindrical sleeve (2) is rotatably mounted on a bearing pin (3). There is a radial clearance maintained between the bearing pin (3) and the mounting hole of the cylindrical sleeve (2) to facilitate free rotation. The bearing pin (3) is fixed in upright position through the guide slot (5a) provided on the delivery table (4) by means of fastener (5).

The radially projecting flange (6) is formed at the bottom edge of the cylindrical sleeve (2). The cylindrical outer surface of the sleeve (2) merges with the flange (6) by a curvature (8) of suitable radius. The combed sliver (7) runs around the sliver guide (1 ) and supported on the flange (6) which provides sufficient space to accommodate the running combed sliver. The rotating sliver guide (1 ) is mounted in the guide slot (5a) of the delivery table (4) in an adjustable manner. In order to enable free rotation of cylindrical sleeve (2) on the bearing pin (3), the bottom surface of the flange (6) is spaced apart by a small distance, just above the surface of the delivery table (4).

The free rotation of the sliver guide (1 ) depends on the factors such as running sliver (7) tension force, sliver contact area (9) and bearing pin (3) contact area.

In the present invention, the trouble free rotation of the sliver guide is achieved in such a manner that the rotating torque generated by the sliver force is considerably sufficient for overcoming the braking torque caused by bearing friction. This is achieved by keeping the bearing pin (3) radius lesser than half of sliver contact surface radius (The distance between the rotating axis and the sliver contact point on sleeve) to reduce the braking torque.

It is be given by,

Rb / Rs < 0.5

Where Rb = Bearing pin radius

Rs = Sliver contact radius

The sliver guide arrangement (1 ) as per the invention gives smooth, reliable and trouble free rotation. The advantage being unwanted sliver stretch is avoided and better distribution of draft over the length can be achieved.

Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims.