GB2204603A

GB2204603A - Exchangeable insert for an open-end spinning unit

Info

Publication number: GB2204603A
Application number: GB08810431A
Authority: GB
Inventors: Vaclav Safar
Original assignee: Elitex Zavody Textilniho; Elitex Koncern Textilniho Strojirenstvi
Current assignee: Elitex Zavody Textilniho; Elitex Koncern Textilniho Strojirenstvi
Priority date: 1987-05-04
Filing date: 1988-05-03
Publication date: 1988-11-16
Also published as: CS312787A1; DE3813765A1; CS263525B1; GB8810431D0; IT1217477B; IT8820432A0

Description

1 2(11 p n g jj 2, 1) U a "EXCHANGEABLE INSERT FOR AN OPEN-END SPINNING

UNIT"

Description

This invention relates to an exchangeable insert for interposition between a fibre opening portion and a spinning rotor of an open-end spinning unit.

In open-end spinning machines, the development aims to increase the production parameters, above all the RPM of spinning rotors. To avoid an increase in breakage rate, while spinning, the relative axial force acting on the yarn must be kept; consequently, the rotor diameter must be reduced with its increasing RPM, on the well known principles.

The spinning units featuring the vertical axis of the combing roller and the horizontal axis of the spinning rotor require the axis to be positioned above the upper face of the combing roller, in a manner permitting the yarn outlet, likewise situated in the axis of the spinning rotor, above the combing roller. Thus, the space available for locating the fibre outlet to the spinning chamber is limited. The fibre feed to the slide wall must be considered with respect to the diameter of the spinning rotor inlet opening where the fibre outlet must be placed.

Closely related to the diameter of the spinning rotor inlet opening is the diameter of its collecting surface, since the angle of the slide wall and the length of its surface line are defined by the conditions and can be, therefore, modified to a limited extent only.

For these reasons, the above described arrangement of a spinning unit permits to set the diamete:r of the spinning rotor inlet opening to 32 mm or more which results in an obtainable diameter of 40 mm of the collecting surface under favourable spinning conditions of 75 to 85 thousand RPM; 2 this applies to the known existing arrangement in which the upper side of the fibre outlet out of a fibre opening unit to a spinning chamber is orientated horizontally throughout. Up to now, the horizontal position of the upper wall has been adopted for reasons, i.e., from the point of view, of the production technology, especially as far as the pressure casting moulds are concerned.

For higher speeds, feasible around the 100,000 RPM with the collecting groove diameter about 35 mm, he overall arrangement of the spinning unit, especially the mutual position of the axes of the spinning rotor and of the combing roller, would require modifications. However, such a modified spinning unit would be substantially costlier in production and besides, would involve other technical problems concerning for instance the spinning rotor drive.

To solve the existing drawbacks and to do away with the RPM-limits imminent to the existing design of spinning units having the spinning rotor axis perpendicular to that of the combing roller, the invention proposes a modification of the fibre outlet out of fibre opening unit to a spinning chamber; the modification has been successfully tested.

According to the invention there is provided an exchangeable insert for interposition between a fibreopening portion and a spinning rotor of an open-end spinning unit in which the fibre-opening portion comprises a combing roller rotatable about a vertical axis and the spinning rotor is rotatable about a horizontal axis, the insert having therein a fibre supply duct with an inlet section for communicating with the cavity in the fibre-opening portion in which cavity the combing roller is rotatable and an outlet section for communicating with the chamber of the spinning rotor, and the fibre supply duct having an upper wall, when the insert is installed in the open-end spinning unit, which upper wall changes from the horizontal in the 3 ti inlet section to an upward inclination in the outlet section.

The advantage resulting from the arrangement according to the invention consists in the possibility to use, in the advantageous and up-to-now used version of the spinning units hAving a vertical axis combing roller and a horizontal axis spinning rotor, a spinning rotor of a smaller diameter than those applicable in the up-to-now used fibre outlets of the fibre opening units. These uP-to-now versions permit the use of spinning rotors with inlet opening above 32 mm. in diameter, with the corresponding collecting surface diameter of 40 mm and with the applicable RPM range of 75 to 85 thousand. The fibre outlet according to the invention permits to use spinning rotors with a collecting surface diameter of 34 mm. and operational speed of about 100,000 RPM.

A spinning unit under development to reach these parameters, features inclined axis of spinning rotors, thus involving a substantial increase in production costs and some technical risks rendering difficult its application in filed conditions.

From the point of view of both the air and fibre flow, is advantageous an arrangement in which the upper and the opposite lower walls are nearing to each other in the direction towards the output section of the fibre outlet.

The change of the upper wall from the horizontal section to the upwards inclined section at the output of the fibre outlet can be made in various versions.

Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, in which:- Fig. 1 shows, in an oblique view, a part of an openend spinning unit, with a cavity of the fibre opening portion intended to receive the combing roller, and an exchangeable insert interposed between the cavity and the spinning rotor; and 4 Figs. 2 to 4 show, schematically in front view, the walls defining the fibre supply duct leading out of the fibre opening unit and into the spinning rotor.

The body of a fibre opening portion is fitted with a feed mechanism comprising a feed roller onto which is pressed a member, not represented and rotatably seated on a pin fixed in an aperture. A recess is provided in the body for the said member, a cylindrical cavity and a coaxial opening being provided to seat the combing roller. A recess in the front wall of the body serves to receive an exchangeable insert separating the cylindrical cavity, serving to lodge the combing roller, from the spinning chamber, the latter being defined substantially by the inner cavity of the spinning rotor and by the front wall of the section of the exchangeable insert. The spinning chamber also houses a separator, not represented, and the functional section of the outlet of the yarn. In some cases, i.e., when the output orifice of the fibre supply duct is situated on the periphery of that section of the insert that projects into the spinning chamber, no separator is used.

The spinning rotor is mounted on a shaft rotatably seated in an antifriction bearing. The exchangeable insert has a cylindrical recess for the combing roller, not represented, and on the cylindrical wall a fibre supply duct whose inlet section consists of a wall tangential with respect to the cylindrical recess, of an upper wall and of an opposite wall for doffing and directing the fibres. The upper wall runs in its initial section horizontally, then considered in the direction of the fibre feed changes and runs obliquely upwards in the outlet section of the fibre supply duct with the outlet orifice at the end of it. The outlet orifice is represented as being provided on the front wall of the exchangeable insert, however, it could be provided on the periphery of the section of the exchangeable insert that projects into the spinning chamber. In such a case, this projecting section would be adequately wider, and 4 i cr 1 no separator would be used. The yarn is fed out of the spinning chamber by an outlet, coaxial with the spinning rotor.

Figs. 2 to 4 show some possible versions of the walls. the angle of inclination of the upper wall, theO(, and the angle of inclination of the opposite wall, thejo, refer both to the horizontal plane, In the version shown in Fig. 2, the upper wall changes in a raising bow, with varying curvature as the case may be, from the horizontal position to the obliquely upwards oriented section near the outlet section with the outlet orifice at the end of it. The opposite wall has a width increasing in the direction towards the outlet section.

In the version shown in Fig. 3, the upper wall changes to the oblique position in an arc with a radius Rl, the arc radius of the opposite wall being R2; this applies only to a part of the total width of the cylindrical recess represented in Fig. 1.

In the version shown in Fig. 4, the upper wall after the inlet section of the fibre outlet, first sinks downwards, under its horizontal position, by the bow, but its outlet section is oriented obliquely upwards, at the outlet orifice lying by a value A higher than its horizontal section.

In each case, the angleoCs inferior to the anglep this applies to any section of the two mutually opposite walls.

The fibre supply duct leading out of the fibre opening unit into the spinning chamber, can be used in all cases in which the fibres flowing from the fibre opening sector to the spinning chamber are directed, doffed on the collecting surface of the spinning rotor to a fibre band, and then twisted to a yarn by the rotation of the sPinning rotor to be subsequently drawn-off and wound up.

6

Claims

1. An exchangeable insert for interposition between a fibre-opening portion and a spinning rotor of an open-end spinning unit in which the fibre-opening portion comprises a combing roller rotatable about a vertical axis and the spinning rotor is rotatable about a horizontal axis, the insert having therein a fibre supply duct with an inlet section for communicating with the cavity in the fibreopening portion in which cavity the combing roller is rotatable and an outlet section for communicating with the chamber of the spinning rotort and the fibre supply duct having an upper wall, when the insert is installed in the open-end spinning unit, which upper wall changes from the horizontal in the inlet section to an upward inclination in the outlet section.

2. An insert according to claim 1, wherein the said upper wall and its opposite wall approach each other in the direction towards the outlet section of the fibre supply duct.

3. An insert according to claim 1, wherein the fibre supply duct has a continuously upwardly orientated curvature in the direction towards the outlet section of the fibre supply duct.

4. An insert according to claim 1, wherein the said upper wall has a raising bow section between the inlet section and the outlet section of the fibre supply duct.

5. An insert according to claim 1, wherein the said upper wall has, after the inlet section, a bow section which extends below the level of the horizontal at the inlet section.

6. An exchangeable insert for interposition between a fibre-opening portion and a spinning rotor of an open-end spinning unit, substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

c 1 1 7

7. An insert according to claim 6 but modified substantially-as hereinbefore described with reference to Fig. 2 of the accompanying drawings.

8. An insert according to claim 6 but modified substantially as hereinbefore described with reference to Fig. 3 of the accompanying drawings.

9. An insert according to claim 6 but modified substantially as hereinbefore described with reference to Fig. 4 of the accompanying drawings.

10. In combination, an insert according to any preceding claim, and an open-end spinning unit in which a fibreopening portion comprises a combing roller rotatable about vertical axis in a cavity and a spinning rotor is rotatable about a horizontal axis, the insert being interposed betwee the fibre-opening portion and the spinning rotor, and the fibresupply duct in the insert intercommunicating between the cavity in the fibre-opening portion and the chamber in the spinning rotor.

Published 1988 at The Patent Office, State House, 6"1 High Holborn, London WC1R 4TP. Further copies maybe obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1/87.