Title of Invention

A SPINNING FRAME WITH A SUCTION DEVICE

Abstract

In a spinning frame with a suction device, that amongst other components consists of a sieve drum (13) and a suction insert (20), which together form a mutual frictioning pair, the respective contacting material is being selected in such a way that the material hardness at least on the surfaces of sieve drum (13) and suction insert (20) differs by at least the factor 2. Preferably, the sieve drum (13) is being made of brass and the suction insert (20), at least on its outer surface, is being made of plastic. The suction insert (20) can be made as a compression joint of a casing (25) and a brass insert (28) whereat the casing is being made of plastic and the insert of a light-metal alloy.

Full Text

The invention relates to a spinning frame with a suction device. The patent application DE 196 37 828 1 discloses a suction device of the kind where the suction insert is arranged within the sieve drum by which suction air is being drawn through the perforation of the sieve drum into a central suction device. In practice a suction device is made of light metal cast iron in order to allow cost effective production. For the sieve drum for instance brass is suitable since it can easily be put under tension. It has been experienced that such a material combination under certain circumstances does not result in a sufficient service life of the suction device since a fusion connection can result at least on one of the friction parts during a relative motion of the two parts towards each other. It is the object of the following invention to provide a suction device of such a design, whereat no change occurs at the surfaces of those parts due to motion towards each other. This task is being solved by a suction device of the present invention as described herein. Accordingly the present invention provides a spinning frame with a suction device consisting of a sieve drum and a suction insert being arranged within said drum and which is being connected to a suction installation, characterised in that at least on the facing surfaces of the sieve drum and the suction insert such combinations of materials are being used, whose hardnesses are different by at least the factor 2. The spinning frame is being provided with a suction device consisting of a sieve drum and a suction insert being arranged within said drum and which is being connected to a suction device, characterised in that at least on the facing surfaces of the sieve drum with the suction insert as contact material such combinations of materials are being used whose hardness is different by at least the factor 2, the factor 4 in particular. The sieve drum is preferably made of brass and the suction insert at least on the surface facing the sieve drum is made of plastic. The material combination for the sieve drum and the suction insert can consist of nickel and plastic or at least the inside of brass, the sieve drum can consist of brass and the outside of the suction insert, facing the sieve drum, can consist of Teflon. When using plastic for the manufacturing of the suction insert the production costs can be reduced considerably. A plastic sleeve as outer part of the suction insert can be mounted in a simple way by pressing it onto the inner part, whereat sufficient sealing and a satisfactory concentricity of the component is being achieved. For axial and circumferential positioning to each other the inner and the outer part can be engaged by snap connection. Through the application of materials with different hardness on one side, that is on the outer surface of the suction insert and on the other side, that is on the inner surface of the sieve drum, a fusion connection or erosion of the materials can be avoided. Thus also clogging of the openings or holes in the sieve drum can be prevented. As a preferred material combination brass can be used for the sieve drum and for at least the outer part of the suction insert plastic can be applied. Further preferred material combinations are listed in the following table: Sieve drum Suction insert nickel zinc nickel plastic brass Teflon brass chromium It will be sufficient if the mentioned materials are being applied as surface coating onto the respective parts. In the following the invention is being described in detail by way of the accompanying drawing for an exemplified embodiment wherein show: fig. 1 a cross section through a suction device according to the invention, and fig. 2 a view of a suction insert at right angle to its longitudinal axis. The suction device according to figure 1 consists of a sieve drum 13 which by means of a hub 27 is being mounted onto a shaft 15. On the inside of the sieve drum 13 there is the suction insert 20 arranged which in the shown exemplified embodiment is composed of a casing 25 with a suction trunk 21 and an insert 28. Through the suction trunk 21 the sucked air is being led to a central suction installation. Inside the insert 28 a bearing opening 31 serves for rotatable mounting of the suction insert 20 onto the shaft 15. A connection to a stationary part of the spinning frame serves to secure the insert 28 against rotation on the shaft 15. For the inserts 28 for instance a light metal alloy is being selected, while the casing 25 preferably is made of plastic for instance of polyamide 6.6. During assembly the casing 25 is pressed onto the insert 28, whereat a snap connection 26 serves to secure the parts in their position. The snap connection 26 preferably consists of a recess in the insert 28 and a projection in the casing 25. The casing 25 can be formed as a one-piece part together with the suction trunk 21, or as two single parts which are being connected. In the outer surface of the casing 25 two suction slots 26.1 and 26.2 are being furnished, which according to figure 2, either converge downward in circumferential direction (full line) or diverge (dotted line). From the suction slots 26.1 and 26.2 one groove or two grooves 37 lead preferably in spiral form to the suction trunk 21. With this way of guiding the air accumulation offer instance fibres is being avoided. Between the shaft 15 and the insert 28 within the bearing opening 31 preferably a roller bearing or a combination of roller bearings is being provided. Over its entire circumference , within the area of the suction slots 26.1 and 26.2 the sieve drum 13 is being provided with openings, preferably small holes. The suction device, basically consisting of the components such as the sieve drum 13 and the suction insert 20 is preferably applied in a ring spinning frame as a compacting device, as is for instance disclosed in the above mentioned patent application DE 196 378 28.1. A suction device according to the description can for instance also be applied as a false-twisting device. WE CLAIM: 1. A spinning frame with a suction device consisting of a sieve drum (13) and a suction insert (20) being arranged within said drum and which is being connected to a suction installation, characterised in that at least on the facing surfaces of the sieve drum (13) and the suction insert (28) such combinations of materials are being used, whose harnesses are different by at least the factor 2. 2. Spinning frame as claimed in claim 1, wherein the sieve drum (13) is made of brass and that the suction insert (20) at least on the surface facing the sieve drum (13) is being made of plastic. 3. Spinning frame as claimed in claim 1, wherein at least the inside surface of the sieve drum (13) is being provided with nickel and that the suction insert (20) at least on the surface facing the sieve drum (13) consists of a zinc alloy 4. Spinning frame as claimed in claim 1, wherein the combination of the contact materials for the sieve drum (13) and the suction insert (20) consists of nickel and plastic. 5. Spinning frame as claimed in claim 1, wherein the sieve drum (13) at least on its inside consists of brass and that the suction insert (20) on its outside, facing the sieve drum (13), consists of Teflon or is at least coated with Teflon respectively. 6. Spinning frame as claimed in claim 1, wherein each the sieve drum (13) and the suction insert (20) at their material contacting side at least consist of brass or chromium respectively. 7. A spinning frame with a suction device, substantially as hereinabove described and illustrated with reference to the accompanying drawings.

Documents:

488-mas-99 abstract-duplicate.pdf

488-mas-99 abstract.jpg

488-mas-99 abstract.pdf

488-mas-99 claims-duplicate.pdf

488-mas-99 claims.pdf

488-mas-99 correspondence-others.pdf

488-mas-99 correspondence-po.pdf

488-mas-99 description (complete)-duplicate.pdf

488-mas-99 description (complete).pdf

488-mas-99 drawings.pdf

488-mas-99 form-19.pdf

488-mas-99 form-2.pdf

488-mas-99 form-26.pdf

488-mas-99 form-4.pdf

488-mas-99 form-6.pdf

488-mas-99 others.pdf