FIELD OF THE INVENTION
The present invention relates to the spindle for a spinning and twisting machines in particular to an apparatus of the type in which the vibration induced by the spindle blade is dampened with metal foam.
BACKGROUND AND SUMMARY OF THE INVENTION
Spindle used in a ring spinning and twisting machine, comprises a spindle blade assembled in the conical upper part of the spindle which is rotatably supported in the bottom part and driven by the drive system of the ring spinning and twisting machine in any one of the known way. The spindle blade of the upper part is rotatably supported by a neck bearing and a foot bearing. The neck bearing is positioned in a tube-like neck bearing housing which is rigidly fitted to an outer housing. The bottom portion of the outer housing is closed and so designed that it can be fitted on the spindle rail in a known way and vertically aligned.
The foot bearing comprises a radial bush bearing provided to take the radial force and an axial foot bearing to take up the axial force which are generated due to the rotation of the upper part of the spindle. The bottom portion of the spindle blade is disposed on the axial foot bearing. The radial bush bearing is fitted to a centering sleeve and the centering sleeve carrying the radial bush bearing and the axial foot bearing is fitted to the neck bearing housing. The centering sleeve is provided with annular helical grooves. Between the annular outer contour of the centering sleeve and the hollow cylindrical inner contour of the outer housing the oil spool is placed vertically. The oil spool is retained in its required position by means of a spacer. The annular helical grooves provided on the centering sleeve

provides an orbital variable spring action to the centering sleeve which is transmitted to the oil spool for vibration damping. The spindles of the above mentioned type which are provided with vibration damping means are generally known, these known constructions have at least partly the disadvantage that depending upon the dimensions and construction of the supporting means.
In order to reduce the vibrations and running noises of spindles, it is known from the prior art, to mount the spindle bearing housing by means of rubber-elastic damping elements on a spindle rail. Although this achieves a reduction in the generating of noise, it is connected with other functional disadvantages. It is an important disadvantage that there is the risk that the rubber-elastic damping element yields more and more as the time goes by so that the spindle will be skewed.
It is also known from the prior art, the spindle blade is dampened by oil spool positioned vertically in the region between the centering sleeve and the hollow cylindrical inner contour of the outer housing. As a consequence, frequent replacement of oil has been necessary. This Implies a complicated disassembling and assembling of the outer housing. Also the oil would be capable of protecting only to a certain limit of structure borne noise.
According to the present invention there is provided a textile spindle assembly provided with an improved damping arrangement comprises a spindle bottom part and a spindle upper part, the said spindle bottom part comprises an outer housing fitted with the spindle insert assembly having the neck bearing and a combination foot bearing fitted to a centering sleeve of the said spindle insert assembly, the said spindle upper part comprises a spindle blade with a conical part and a wharve member rigidly fitted on its upper portion wherein a metal foam is arranged in between the annular gap

of the cylindrical inner contour of the said outer housing and the cylindrical outer contour of the said centering sleeve. The metal foam is used in place of the known oil spool.
OBJECT OF THE INVENTION:
It is an object of the invention to reduce the vibration of the spindle due to the higher rotating speed of the spindle upper part.
It is an another object of the invention to reduce the noise generated by spindle due to the higher rotating speed of the spindle upper part.
It is yet another object of the invention to enhance the life of the neck and foot bearing of the spindle.
Still another object of the invention to enhance the rotational speed of the spindle.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein.
Fig 1 is an axial sectional view of a spindle constructed according to the present invention.

DESCRIPTION OF THE INVENTION
The spindle assembly according to the invention will be described in greater detail with reference to the accompanying figure!
The spindle assembly comprises a spindle bottom part and a spindle upper part.
The spindle insert assembly(1) comprising neck bearing(2), combination foot bearing(3) provided with radial foot bearing(3a) and an axial foot bearing(3b), centering sleeve(4) and the metal foam(5). The outer housing(7) fitted with the spindle insert assembly(l) form the spindle bottom part, which rotatably support the spindle upper part. The spindle insert assembly(l) is vertically assembled from the top into the outer housing(7) having a closed bottom. The outer housing(7) of the spindle bottom part is fastened to the spindle rail which extends in the machine in the longitudinal direction. For this purpose, the spindle rail comprises at every spinning or twisting station a cylindrical hole, through which the respective outer housing(7) of the bottom part of the spindle is placed and fastened.
The spindle upper part comprises the spindle blade(6), conical part and the wharve member. An endless driven belt provided tangentially drive the wharve member and there by the upper part of the spindle. The arrangement is such that the endless belt lies in the area above the neck bearing(2), which thus indirectly takes up the belt tension. The spindle blade(6) of the spindle upper part is rotatably supported in the spindle bottom part of by neck bearing(2) and radial foot bearing(3a) and axial foot bearing(3b) of combination foot bearing(3).
In order to dampen the vibration and the noise exerted due to the higher rotating speed of the upper part of the spindle, the metal foam(5) is

provided. The metal foam(5) being constructed in the shape of a hollow cylinder and being arranged in between the annular gap of the cylindrical inner contour present in the outer housing(7) and the cylindrical outer contour present in the centering sleeve(4). The metal foam(5) is retained at a pre determined position by suitable means. The radial foot bearing(3a) and an axial foot bearing(3b) are arranged inside of the centering sleeve(4). The radial foot bearing(3a) takes up the radial load and the axial foot bearing takes the axial load(3b) of the spindle upper part. Between the cylindrical inner contour of the centering sleeve(4) and the cylindrical outer contour of the spindle blade(6) an annular gap is present which is filled with the lubricating oil. The lubricating oil being provided to lubricate both the foot bearing and the neck bearing in case the neck bearing is an antifriction bearing. The centering sleeve, having helically grooved slots which provide an orbital variable spring action.
The metal foam(5) is made out of mixture of metal powder of foaming alloy and foaming agent with suitable porous structure and structure density. The metal foam(5) can be made from Aluminium, Zinc as primary base material and or with alloying elements for example Aluminium and Silicon, Aluminium and Magnesium and Silicon or any other metallic material and its combination which will provide the required damping effect. To suit up with the application the foaming materials and combination are selected based on the density, strength, elasticity and dampening requirements. The meal foam(5) can be injection moulded, or can be extruded in the form of hollow cylinder and cut to the required size or can be rolled and joined in the form of hollow cylinder.

WE CLAIM
1. Textile spindle assembly provided with an improved damping
arrangement comprises :
a spindle bottom part and a spindle upper part,
the said spindle bottom part comprises an outer housing(7) fitted with the spindle insert assembly(1) having the neck bearing (2) and a combination foot bearing(3) fitted to a centering sleeve (4) of the said spindle insert assembly(1),
the said spindle upper part comprises a spindle blade(6) with a conical part and a wharve member rigidly fitted on its upper portion wherein
a metal foam(5) is arranged in between the annular gap of the cylindrical inner contour of the said outer housing(7) and the cylindrical outer contour of the said centering sleeve(4).
2. Textile spindle assembly with an improved damping arrangement as claimed in claim 1, wherein the said metal foam(5) is made of mixture of metal powder of foaming alloy and foaming agent.
3. Textile spindle assembly with an improved damping arrangement as claimed in claim 1 and 2, wherein the said metal foam(5) is made from Aluminum, Zinc as primary base material and / or with alloying elements.

4. Textile spindle assembly with an improved damping arrangement as
claimed in claim 1 to 3, wherein the said metal foam(5) is injection
moulded.
5. Textile spindle assembly with an improved damping arrangement as
claimed in claim 1 to 4, wherein the said metal foam(5) is extruded in
the form of hollow cylinder and cut to the required size.
6. Textile spindle assembly with an improved damping arrangement as
claimed in claim 1 to 5, wherein the said metal foam(5) is rolled and
joined in the form of hollow cylinder.
7. Textile spindle assembly with an improved damping arrangement
substantially as herein before described with reference to the
accompanying drawings.