FIELD OF THE INVENTION

The present invention relates to spinning machines, more particularly air suction compacting system arranged downstream of the conventional drafting arrangement in Ring spinning machines.

According to the invention, the spinning machine is having an air suction nozzle along with perforated apron belt used for condensing the drafted fibre webs delivered from the drafting arrangement.

BACKGROUND OF THE INVENTION

Generally the ring spinning machine has an object of attenuating the fibre web fed and to provide the specific density fibre web called as yarn in delivery.

A creel arrangement is provided in the feeding zone where plurality of roving bobbins arranged to feed the roving to the drafting zone of the ring spinning machine.

In drafting zone, a drafting arrangement is arranged downstream of the feeding zone. The drafting arrangement of ring spinning machines are provided with set of bottom and upper drafting rollers. The bottom drafting rollers are of steel rollers, both ends supported by bearings and brackets, which are extended across the length of the machine. These bottom drafting rollers are connected to each other through gear train, so as to get prescribed drive ratio between each of them. The upper drafting rollers are rubber covered and.which are held in guide arms for loading them over the bottom rollers. The material supplied in the form of roving are processed by the drafting arrangement and delivered to the twisting zone in the form of yarn and wound as coils over a tube placed in the rotating vertical spindles.

In the present compact yarn manufacturing process, a condensing zone comprises an air suction tube arranged downstream of the drafting unit. The air suction tube is having a suction slot extended in the fibre web delivering direction. The suction slot extended over suction nozzle whereby the fibre web is very narrow so that fibres are bundled and condensed in the condensing zone and as soon as the fibre web leaves the nipping line, twist is being imparted in the fibres and the yarn is wound over the tubes placed in spindles. So that the spun yarn is more even, higher strength and less hairiness.

In conventional spinning machines, while the roving passes through the drafting rollers, a guide condenser means are provided. If the roving travels on a single path, considerable wear of cots / aprons and roving breaks also occur, thus leads to reduction in the life of the cot / aprons. To prolong the service life of cots / aprons the guide condensing roving bars are continuously traversed to allow the roving to pass across a predetermined width.

The speed of said traversing can be predetermined based on the yarn count to be processed.

In the compact yarn manufacturing process, the effectiveness of the condensing is extremely influenced by the location of the fibre web fed over the suction slot. This is extremely critical and thus traversing of guide condensers are to be ceased or reduced to minimum to obtain constant quality and performance. This leads to the quick wear out of cots than conventional yarn spinning process and the top roller cot buffing cycle is shorter.

OBJECTS OF THE INVENTION

The principal object of the present invention is to provide an improved suction nozzle arrangement having effective condensing of drafted fibre webs in a ring spinning machine.

Another object of this invention is to provide an improved suction nozzle arrangement having asymmetrically formed suction slots over the condensing zone, thus extending the service life of cots in a ring spinning machine.

A further object of the invention is to provide an improved suction nozzle arrangement, simple in construction, ease of operation, better performance, user friendliness and to fulfil the requirement.

SUMMARY OF INVENTION

In the drafting unit (1), a fibre web (3) is drafted to the desired degree of fineness and transported in the transport direction A. The condensing unit (4) is arranged directly downstream of the said drafting unit (1). The condensing unit (4) comprises a both end sealed hollow profile called as suction nozzle. (5) having two condensing zones (5a, 5b), which belongs to the spindle of two spinning stations (6a, 6b). Downstream of said condensing unit (4), nipping rollers (8a, 8b) are arranged in a known way.

According to the feature of the invention, condensing zones (5a, 5b) consist of an individual suction slots (7a, 7b) provided on nozzle (5) wherein these slots (7a, 7b) are made offset on both sides from the mid plane (13). The position of slots (7a, 7b) is asymmetry from the center (13) of the nozzle (5) ie X Y . The fibre strand (3) during continuous running slightly abrades the cot thus necessitating buffing of the top roller cot.

In this slot (7a, 7b) offset design nozzle arrangement (5), when the top roller is reversed, the fibre path with respect to top roller gets shifted and the fibre strand (3) is controlled by a new top roller surface. This prolongs the top roller buffing cycle.

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 of the drawings schematically illustrates the air suction compacting system along with improved suction nozzle arrangement of this invention.

Figure 2 of the drawings schematically illustrates the improved suction nozzle arrangement along with asymmetrical suction slot of this invention.

BRIEF DESCRIPTION OF THE INVENTION

By referring- figure. 1 and 2, the drafting unit (1) of a ring spinning station comprising the front drafting roller pairs (2), the middle and back drafting roller pairs (not shown).

The front roller pair (2) comprises a driven bottom roller (2a), which extends over a plurality of spinning stations and also a top roller (2b) arranged at each spinning station.

In the drafting unit (1), a fibre web (3) is drafted to the desired degree of fineness and transported in the transport direction A.

The condensing unit (4) is arranged directly downstream of the said front drafting roller pairs (2). The drafted fibre web (3) is being delivered to the condensing unit (4) in the untwisted form. The condensing unit (4) comprises a both end sealed hollow profile called as suction nozzle (5) having two condensing zones (5a, 5b), which belongs to the spindle of two spinning stations (6a, 6b). Downstream of said condensing unit (4), nipping roller pair (8) comprises a driven bottom roller (8a), which extends over a plurality of spinning stations and also a top roller (8b) arranged at each spinning station.

The outer contour of the suction nozzle (5) is a stationary sliding surface having suction slots (7a, 7b) over which one perforated apron belt (9) per spinning station is arranged.

The perforated apron belt (9) is provided with suitable guide means (10) for example dead weight or tension fork for smooth running over the outer contour of the suction nozzle (5) and bottom nipping roller (8a). The suction nozzle (5) is connected to a suction source which is not illustrated and thus a suction action is exerted through the perforated apron belt (9) on the fiber web (3) during condensing process. The suction slots (7a, 7b) are preferably designed with wide opening at the beginning so as to cover the entire fibre web from front drafting roller pairs (2) and slightly inclined transversely in transport direction A, so that the fibre web (3) obtains a good wrapping action. The nipping roller (8b) presses the fibre web (3) and perforated apron belt (9) against the bottom nipping roller (8a). The bottom roller (8a) is driven from head stock through drive means. The perforated apron belt (9) transports the fiber web (3) over the suction slots (7a, 7b) of the suction nozzle (5).

According to figure.2, the suction nozzle (5) comprising two condensing zones (5a, 5b) belongs to two spinning stations (6a, 6b), which are arranged left and right side of suction connector (11). Each condensing zones (5a, 5b) consists of an individual suction slots (7a, 7b) extends over the suction nozzle (5) whereby the fibre web (3) became very narrow so that fibres are bundled and condensed in the condensing unit (4) to a greater extent. Then the fibre web (3) is being transported to the nipping rollers (8) which acts as twist block. Downstream of the nipping roller pairs (8), the yarn (3a) is fed in delivery direction B towards the ring spinning spindle (not shown) for twisting.

The guide ribs (12) are arranged at the borders of each condensing zones (5a, 5b) which avoids the transverse movement of perforated apron belt (9) during running.

One compact nozzle (5) is used for two spindles (6a, 6b). According to the feature of the invention, the slots (7a, 7b) provided in nozzle (5) are made offset on both sides (X ? Y), i.e., for example the distance on one side is 32.5 mm (X) and on the other side is 37.5 mm (Y) from mid plane (13) of the nozzle (5) for 70 mm spindle gauge. This invention can be extended to any . spindle gauge. The position of slots (7a, 7b) is asymmetry from the center (13) of the nozzle (5).The fibre strand (3) during continuous running slightly abrades the cot thus necessitating buffing of the top roller. In the slot (7a, 7b) offset design nozzle arrangement (5), when the top roller is reversed, the fibre path with respect to top roller gets shifted and the fibre strand (3) is controlled by a new top roller surface.

This prolongs the top roller buffing cycle. The benefit of the invention leads to prolonged buffing cycle of top rollers by atleast 20 to 30 days depending on count.

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.

We Claim

1. An improved device of compact spinning machine comprising drafting roller arrangement, condensing arrangement provided downstream of drafting arrangement, said condensing arrangement having suction nozzle (5) provided with two slots (7a, 7b), wherein the position of said slots (7a, 7b) is asymmetry from the center (13) of the nozzle (5).

2. An improved device of compact spinning machine as claimed in claiml wherein the distance of suction slots (7a, 7b) from center (13) of the nozzle (5) on one side is 32.5mm and on the other side is 37.5mm for 70 mm spindle gauge.

3. An improved device of compact spinning machine.as claimed in claiml wherein the suction slots (7a, 7b) are preferably having wide opening at the fibre entry side so as to cover the entire fibre web from front drafting roller pairs (2) and inclined transversely in fibre transport direction.