GB2032972A - Opening Roller for Open-end Spinning Machines - Google Patents

Abstract

An opening roller for open-end spinning machines comprises a cylindrical roller body having a saw- tooth wire wound helically onto its outer surface, the wire having a base region wider than that portion of the wire which is toothed, the wire being wound under tension onto the outer surface of the roller body and fixed at its ends to the roller body. Base regions of adjacent turns of the sawtooth wire are separated from one another by a gap. The radio of the height H to the width B of the base region is less than 1 preferably in a range 0.4 to 0.6. The height of the base region is preferably less than 0.5 mm and desirably equal to the maximum thickness of the tooth region. <IMAGE>

Description

SPECIFICATION Opening Roller for Open-end Spinning Machines This invention relates to an opening roller for open-end spinning machines comprising a cylin'drical roller body and a sawtooth wire wound helically onto the outer surface thereof which has a base region widened in relation to the teeth and which is wound under tension onto the outer surface and fixed at its ends to the roller body, the base regions of adjacent turns of the sawtooth wire being separated by a gap from one another.

One known opening roller of this type (German Auslegeschrift No. 2,364,544) uses standard commercial sawtooth wires of the kind used for example in cards for carding fibrous material.

Standardised sawtooth wires such as these are obtainable with base regions between 1.3 and 1.5 mm in height.

It has been found that opening rollers such as these give a yarn of poorer quality, i.e. a yarn characterised by irregularities in the form of thick and thin zones, in relation to opening rollers of the type in which the base region of the sawtooth wire is embedded in a helical groove. An investigation into the cause of these irregularities has shown that the parallel position of the fibres separated by the opening roller is inadequate.

The object of the present invention is to provide an opening roller of the type mentioned at the beginning which avoids the occurrence of yarn irregularities.

It has surprisingly been found that this object may be achieved by using a sawtooth wire in which the ratio of the height to the width of the base region is less than 1.

The ratio of the height to the width of the base region should preferably be from 0.4 to 0.6. In this connection, it is of advantage for the height of the base region to be less than 0.5 mm.

Alternatively, the height of the base region may be equal to the maximum thickness of the tooth region, i.e. equal to the thickness of the tooth region where it adjoins the base region.

Several examples of embodiment of the invention are described in detail in the following with reference to the accompanying drawings, wherein: Figure 1 is an axial longitudinal section through an opening roller.

Figure 2 is a section through a sawtooth wire on the line Il-Il of Figure 4.

Figure 3 is a sectional view corresponding to Figure 2 of another embodiment of a sawtooth wire.

Figure 4 is a plan view of part of a sawtooth wire in the direction of the arrow in Figure 2.

The opening roller shown in Figure 1 comprises a roller body 1 with a cylindrical, smooth outer surface 2 which is delimited at its ends by peripheral shoulders 3. in the vicinity of each peripheral shoulder, a groove 4 is milled or sawn into the outer surface, extending over only a small part of the periphery. A sawtooth wire 5 is wound in helical turns onto the outer surface 2, the beginning of the sawtooth wire being anchored in one groove 4 and its end in the other groove 6 so that the sawtooth wire lies under tension on the roller body.

The cross-sectional profile of the sawtooth wire illustrated in Figure 2 (on the line Il-Il of Figure 4) shows that the base region 7 has a width B which is approximately twice the height H. The tooth region 8 is of standard design and construction.

Figure 3 shows the cross-sectional profile of another sawtooth wire in which the base region 9 has a height corresponding to the thickness of the tooth region 10. A profile such as this may be obtained by canting the base region through 900 starting from a wire of rectangular profile. In this case, the ratio of the height to the width of the base region 9 may readily be freely selected.

Figure 4 is a side elevation of the sawtooth wire, the boundary between the tooth region 10 and the base region 9 being shown in chain lines.

Sawtooth wires with such a low ratio of the height to the width of the base region are not commercially available. However, sawtooth wires of this type used as a covering for opening rollers where the base region is not embedded in grooves of the roller body enable a considerably better yarn quality to be obtained than standard commercially available sawtooth wires.

Claims

1. An opening roller for open-end spinning machines comprising a cylindrical roller body and a sawtooth wire wound helically onto the outer surface thereof which has a base region widened in relation to the teeth and which is wound under tension onto the outer surface and fixed at its ends to the roller body, the base regions of adjacent turns of the sawtooth wire being separated by a gap from one another, characterised in that the ratio of the height to the width of the base region is 41.

2. An opening roller as claimed in Claim 1, characterised in that the ratio of the height to the width of the base region amounts to between 0.4 and 0.6.

3. An opening roller as claimed in Claim 1 or 2, characterised in that the height of the base region is less than 0.5 mm.

4. An opening roller as claimed in Claim 1 or 2, characterised in the height of the base region is equal to the maximum thickness of the tooth region.

5. An opening roller for open-end spinning machines substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Opening Roller for Open-end Spinning Machines This invention relates to an opening roller for open-end spinning machines comprising a cylin'drical roller body and a sawtooth wire wound helically onto the outer surface thereof which has a base region widened in relation to the teeth and which is wound under tension onto the outer surface and fixed at its ends to the roller body, the base regions of adjacent turns of the sawtooth wire being separated by a gap from one another. One known opening roller of this type (German Auslegeschrift No. 2,364,544) uses standard commercial sawtooth wires of the kind used for example in cards for carding fibrous material. Standardised sawtooth wires such as these are obtainable with base regions between 1.3 and 1.5 mm in height. It has been found that opening rollers such as these give a yarn of poorer quality, i.e. a yarn characterised by irregularities in the form of thick and thin zones, in relation to opening rollers of the type in which the base region of the sawtooth wire is embedded in a helical groove. An investigation into the cause of these irregularities has shown that the parallel position of the fibres separated by the opening roller is inadequate. The object of the present invention is to provide an opening roller of the type mentioned at the beginning which avoids the occurrence of yarn irregularities. It has surprisingly been found that this object may be achieved by using a sawtooth wire in which the ratio of the height to the width of the base region is less than 1. The ratio of the height to the width of the base region should preferably be from 0.4 to 0.6. In this connection, it is of advantage for the height of the base region to be less than 0.5 mm. Alternatively, the height of the base region may be equal to the maximum thickness of the tooth region, i.e. equal to the thickness of the tooth region where it adjoins the base region. Several examples of embodiment of the invention are described in detail in the following with reference to the accompanying drawings, wherein: Figure 1 is an axial longitudinal section through an opening roller. Figure 2 is a section through a sawtooth wire on the line Il-Il of Figure 4. Figure 3 is a sectional view corresponding to Figure 2 of another embodiment of a sawtooth wire. Figure 4 is a plan view of part of a sawtooth wire in the direction of the arrow in Figure 2. The opening roller shown in Figure 1 comprises a roller body 1 with a cylindrical, smooth outer surface 2 which is delimited at its ends by peripheral shoulders 3. in the vicinity of each peripheral shoulder, a groove 4 is milled or sawn into the outer surface, extending over only a small part of the periphery. A sawtooth wire 5 is wound in helical turns onto the outer surface 2, the beginning of the sawtooth wire being anchored in one groove 4 and its end in the other groove 6 so that the sawtooth wire lies under tension on the roller body. The cross-sectional profile of the sawtooth wire illustrated in Figure 2 (on the line Il-Il of Figure 4) shows that the base region 7 has a width B which is approximately twice the height H. The tooth region 8 is of standard design and construction. Figure 3 shows the cross-sectional profile of another sawtooth wire in which the base region 9 has a height corresponding to the thickness of the tooth region 10. A profile such as this may be obtained by canting the base region through 900 starting from a wire of rectangular profile. In this case, the ratio of the height to the width of the base region 9 may readily be freely selected. Figure 4 is a side elevation of the sawtooth wire, the boundary between the tooth region 10 and the base region 9 being shown in chain lines. Sawtooth wires with such a low ratio of the height to the width of the base region are not commercially available. However, sawtooth wires of this type used as a covering for opening rollers where the base region is not embedded in grooves of the roller body enable a considerably better yarn quality to be obtained than standard commercially available sawtooth wires. Claims

1. An opening roller for open-end spinning machines comprising a cylindrical roller body and a sawtooth wire wound helically onto the outer surface thereof which has a base region widened in relation to the teeth and which is wound under tension onto the outer surface and fixed at its ends to the roller body, the base regions of adjacent turns of the sawtooth wire being separated by a gap from one another, characterised in that the ratio of the height to the width of the base region is 41.

2. An opening roller as claimed in Claim 1, characterised in that the ratio of the height to the width of the base region amounts to between 0.4 and 0.6.

3. An opening roller as claimed in Claim 1 or 2, characterised in that the height of the base region is less than 0.5 mm.

4. An opening roller as claimed in Claim 1 or 2, characterised in the height of the base region is equal to the maximum thickness of the tooth region.

5. An opening roller for open-end spinning machines substantially as hereinbefore described with reference to the accompanying drawings.