Title of Invention	SPINDLE FOR A SPINNING OR TWISTING MACHINE, WITH A PLASTICS CENTERING TUBE, HAS A METAL REINFORCEMENT RING AT THE ZONES SUBJECT TO RADIAL FORCES TO PREVENT A STRESS OVERLOAD ON THE TUBE
Abstract	This invention relates to a spindle for spinning or twisting machines, said spingle (1) having a rotating spindle shaft (2), which is supported in a spindle bearing housing (5) by means of a neck bearing (3) and a step bearing (4), which comprises a step bearing sleeve (10), which is arranged in a radially flexible centering tube (12) made of flexible plastic material, said centering tube (12) being fixed in the area of the neck bearing (3) at the spindle bearing housing (5) and being supported in the area of the step bearing (4) by means of a dampening spiral (15) on the spindle bearing housing (5). The centering tube (12) is reinforced in at least one area (13, 21, 23) in which radial forces may act on it by means of at least one metallic reinforcing ring (18, 19, 20).

Title of Invention

SPINDLE FOR A SPINNING OR TWISTING MACHINE, WITH A PLASTICS CENTERING TUBE, HAS A METAL REINFORCEMENT RING AT THE ZONES SUBJECT TO RADIAL FORCES TO PREVENT A STRESS OVERLOAD ON THE TUBE

Abstract

This invention relates to a spindle for spinning or twisting machines, said spingle (1) having a rotating spindle shaft (2), which is supported in a spindle bearing housing (5) by means of a neck bearing (3) and a step bearing (4), which comprises a step bearing sleeve (10), which is arranged in a radially flexible centering tube (12) made of flexible plastic material, said centering tube (12) being fixed in the area of the neck bearing (3) at the spindle bearing housing (5) and being supported in the area of the step bearing (4) by means of a dampening spiral (15) on the spindle bearing housing (5). The centering tube (12) is reinforced in at least one area (13, 21, 23) in which radial forces may act on it by means of at least one metallic reinforcing ring (18, 19, 20).

Full Text	FIELD OF THE INVENTION The present invention relates to a spindle for spinning or twisting machines) said spindle having a rotating spindle shaft, which is supported in a spindle bearing housing by means of a neck bearing and a step bearing, which comprises a step bearing sleeve, which is arranged in a centering tube made of flexible plastic and being radially movable in the area of the step bearing, said centering tube being secured in the area of the neck bearing in the spindle bearing housing and being supported in the area of the step bearing by means of damping spiral on the spindle bearing housing. BACKGROUND OF THE INVENTION A spindle of this type is prior art in German published Patent 19 60 224. The centering tube of this spindle is made of a flexible plastic, so that the inert vibrational properties inherent in this material can be taken advantage of in order to achieve a particularly smooth running of the spindle shaft. A plastic centering tube of this type has damping properties which take up the vibrations particularly quickly, which damping properties combine with the damping forces of the damping spiral, so that a particularly smooth running of the spindle is achieved. FR 2831896 discloses a centering and retaining assembly which consists of two sleeves (3,4), made wholly or partly from plastic, that fit together, one carried on a rotating shaft and the other receiving a tubular support. The sleeve (4) receiving the support has expanding peripheral fingers (4a) with inner ramps (4b) able to co-operate with a matching surface (3b) on the other sleeve (3). At least one of the sleeves is able to move lengthwise, while a spring (7) between the two sleeves urges them away from one another so that they lock the support. A centering tube made of plastic is, however, more susceptible to the introduction of outside forces, as the plastic has a natural tendency to set, that is, it deforms permanently. OBJECT OF THE INVENTION It is an object of the present invention, while retaining the above mentioned advantages of the known centering tube, to eliminate any excessive loading of the centering tube. SUMMARY OF THE INVENTION This object has been achieved in accordance with the present invention in that the centering tube is provided with a metal reinforcing ring in those areas in which radial forces are introduced. Such reinforcing rings must, of course, be so narrow that they do not impair the favourable damping and vibrational behaviour of the plastic. Reinforcing rings, however, in'particular when they are designed as steel rings, are above all desirable in those areas to which a press fit is arranged. The press tension can be increased using such reinforcing rings, without the press tension crossing over to the plastic centering tube. The reinforcing rings reduce the stress in the plastic and prevent any creeping processes. It is hereby favourable when the relevant reinforcing rings are applied to the side of the centering tube facing away from the press fit. A reinforcing ring of this type can, for example, be arranged to the point of fixation of the centering tube in the spindle bearing housing.A further reinforcing ring can be arranged to the area of the step bearing housing. Yet another reinforcing ring can be arranged to the damping spiral. The bending stress can in particular be thus reduced, so that in the area of the step bearing flexural strengths of between 13 and 17 N/mm are achieved. As the centering tube can also stretch under an axial load, a stop is preferably arranged to the centering tube to prevent axial overloading. These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawing. DETAILED DESCRIPTION OF THE DRAWING The spindle 1 according to the present invention, arranged vertically and designed as a ring spindle, comprises a spindle shaft 2 which is driven to rotate, said spindle shaft 2 being supported in a neck bearing 3 in the form of a roller bearing and also being supported in a two-part step bearing 4. The neck bearing 3 and the step bearing 4 are located in a spindle bearing housing 5, which has a closed bottom 6. The spindle bearing housing 5 comprises essentially a sleeve 7 containing the bottom 6, as well as a bearing head 8 which takes up the neck bearing 3 , said bearing head 8 being inserted into the sleeve 7 from above by means of a press fit 9. An oil bath is located in the area of the step bearing 4 inside the spindle bearing housing 5. The step bearing 4 comprises a step bearing sleeve 10, which takes up the radial forces, as well as a thrust plate 11, which takes up the axial forces. The step bearing sleeve 10 is supported in a centering tube 12, which in turn is secured by means of a press fit 13 in the bearing head 8. The centering tube 12 consists of a preferably glass-fibre reinforced plastic, which makes the centering tube 12 flexible to a desired degree and permits radial movements of the centering tube 12 in the area of the step bearing 4. Between the cylindrical inner contour of the sleeve 7 and the cylindrical outer contour of the centering tube 12, an annular gap 14 is located, which takes up a damping spiral 15 in the known way. The damping spiral 15 is entirely arranged in the oil bath. By means of cross bore holes 16 in the centering tube 12, the annular gap 14, which comprises the damping spiral 15, is connected with the oil bath of the step bearing 4. The damping spiral 15 is supported upwards on the bearing head 8. The centering tube 12 is supported on a supporting area 23 on the damping spiral 15, and on a supporting area in the area of the step bearing 4. The spindle 1 is secured, together with a plurality of further, adjacently arranged spindles in a spindle bank 17 (shown only by a dot-dash line) in the known way. A drive wharve (not shown) is further arranged to the spindle 1, whereby all drive wharves can be driven by a continuous drive belt extending in machine longitudinal direction . Many advantages arise out of the fact that the centering tube 12, as is generally known, is made of a flexible plastic. For example, the favourable vibrational behaviour of the plastic can be used to achieve a particularly smooth running of the spindle shaft 2. A plastic centering tube 12 of this type, applied for the purposes of centering, possesses an additional advantage over the known steel centering tubes in that it has damping properties which take up the vibrations quicker, which damping properties combine with the damping forces of the damping spiral 15 to achieve a particularly smooth running of the spindle 1. There is, however, a tendency for introduced stress, in particular bending stress, to trigger creeping processes in the pllstic centering tubes 12, that is, that the plastic "sets".This is, of course, to be avoided, if the advantages of the centering tube 12 made of flexible plastic are not to be cancelled out by the above mentioned disadvantages. It is therefore provided in accordance with the present invention', that the centering tube 12 is provided in those areas, in which radial forces are introduced, with a metal reinforcing ring 18,19,20 made of steel. Areas in which radial forces are introduced are, for example, the press fit 13 between the centering tube 12 and the bearing head 8, also the press fit 21 for the step bearing sleeve 10 secured in the centering tube 12 as well as the supporting area 23 of the centering tube 12 against the damping spiral 15. A reinforcing ring 18,19,20 made of steel is therefore applied to these areas 13, 21 and 23, which permits increased press stresses, without triggering any possible creeping processes in the plastic. Thus significantly higher press stresses are possible than in prior art. As can be seen in the drawing, the reinforcing rings 18 and 19 are applied to the side of the centering tube 12 facing away from the respective press fit 13,21. As the thrust plate 11 is taken up by the centering tube 12, axial forces are also passed into the centering tube 12. In order to avoid axial overloading, a stop 22 is arranged at a short distance to the thrust plate 11.When the centering tube 12 stretches because of axial overloading, it can be supported axially on the stop 22 of the bottom 6 of the spindle bearing housing 5. WE CLAIM: 1. A spindle for spinning or twisting machines, said spindle (1) having a rotating spindle shaft (2) which is supported in a spindle bearing housing (9) by means of a neck bearing (3) and a step bearing (4) , which comprises a step bearing sleeve (10) which is arranged in a radially flexible centering tube (12) made of flexible plastic material, said centering tube (12) being fixed in the area of the neck bear- ing (3) at the spindle bearing housing (5) and being supported in the area of the step bearing (4) by means of a dampening spiral (15) on the spindle bearing housing (5), characterized in that the centering tube (12) is reinforced in at least one area (13,21,23) in which radial forces may act on it by means of at least one metallic reinforcing ring (l8, 19, 20). 2. A spindle as claimed in claim 1, wherein the at least one reinforcing ring (18, 19, 20) is a steel ring. 3. A spindle as claimed in claim 1 or 2, wherein a metallic reinforcing ring (18) is arranged inside the centering tube (12) at the location (13) where the centering tube is fixed at the spindle bearing housing (5). 4. A spindle as claimed in any one of claims 1 to 3, wherein at least one metallic reinforcing ring (19, 20) is arranged between the dampening spiral (15) and the centering tube. 5. A spindle as claimed in claim 4, wherein a reinforcing ring (19) is associated to the step bearing sleeve (10). 6. A spindle as claimed in claim 4 or 5, wherein at least one reinforcing ring (20) is arranged in the area of the upper end of the dampening spiral (15). 7. A spindle as claimed in any one of the claims 1 to 6* wherein the centering tube (12) has a flexural strength between 13 and 17 N/mm in the area of the step bearing (4). 8. A spindle as claimed in any of the claims 1 to 7, wherein the spindle bearing housing (5) is provided with a stop (22) for limiting axial stretching of the centering tube (12). This invention relates to a spindle for spinning or twisting machines, said spingle (1) having a rotating spindle shaft (2), which is supported in a spindle bearing housing (5) by means of a neck bearing (3) and a step bearing (4), which comprises a step bearing sleeve (10), which is arranged in a radially flexible centering tube (12) made of flexible plastic material, said centering tube (12) being fixed in the area of the neck bearing (3) at the spindle bearing housing (5) and being supported in the area of the step bearing (4) by means of a dampening spiral (15) on the spindle bearing housing (5). The centering tube (12) is reinforced in at least one area (13, 21, 23) in which radial forces may act on it by means of at least one metallic reinforcing ring (18, 19, 20).

Full Text

FIELD OF THE INVENTION
The present invention relates to a spindle for spinning or
twisting machines) said spindle having a rotating spindle shaft,
which is supported in a spindle bearing housing by means of a
neck bearing and a step bearing, which comprises a step bearing
sleeve, which is arranged in a centering tube made of flexible
plastic and being radially movable in the area of the step
bearing, said centering tube being secured in the area of the
neck bearing in the spindle bearing housing and being supported
in the area of the step bearing by means of damping spiral on the
spindle bearing housing.
BACKGROUND OF THE INVENTION
A spindle of this type is prior art in German published Patent
19 60 224. The centering tube of this spindle is made of a
flexible plastic, so that the inert vibrational properties
inherent in this material can be taken advantage of in order to
achieve a particularly smooth running of the spindle shaft. A
plastic centering tube of this type has damping properties which
take up the vibrations particularly quickly, which damping
properties combine with the damping forces of the damping spiral,
so that a particularly smooth running of the spindle is achieved.

FR 2831896 discloses a centering and retaining assembly which
consists of two sleeves (3,4), made wholly or partly from
plastic, that fit together, one carried on a rotating shaft and
the other receiving a tubular support. The sleeve (4) receiving
the support has expanding peripheral fingers (4a) with inner
ramps (4b) able to co-operate with a matching surface (3b) on the
other sleeve (3). At least one of the sleeves is able to move
lengthwise, while a spring (7) between the two sleeves urges them
away from one another so that they lock the support.
A centering tube made of plastic is, however, more susceptible to
the introduction of outside forces, as the plastic has a natural
tendency to set, that is, it deforms permanently.
OBJECT OF THE INVENTION
It is an object of the present invention, while retaining the
above mentioned advantages of the known centering tube, to
eliminate any excessive loading of the centering tube.
SUMMARY OF THE INVENTION
This object has been achieved in accordance with the present
invention in that the centering tube is provided with a metal
reinforcing ring in those areas in which radial forces are
introduced.

Such reinforcing rings must, of course, be so narrow that they do not impair
the favourable damping and vibrational behaviour of the plastic. Reinforcing
rings, however, in'particular when they are designed as steel rings, are above
all desirable in those areas to which a press fit is arranged. The press tension
can be increased using such reinforcing rings, without the press tension
crossing over to the plastic centering tube. The reinforcing rings reduce the
stress in the plastic and prevent any creeping processes. It is hereby
favourable when the relevant reinforcing rings are applied to the side of the
centering tube facing away from the press fit.
A reinforcing ring of this type can, for example, be arranged to the point of
fixation of the centering tube in the spindle bearing housing.A further
reinforcing ring can be arranged to the area of the step bearing housing. Yet
another reinforcing ring can be arranged to the damping spiral. The bending
stress can in particular be thus reduced, so that in the area of the step bearing
flexural strengths of between 13 and 17 N/mm are achieved.
As the centering tube can also stretch under an axial load, a stop is
preferably arranged to the centering tube to prevent axial overloading.
These and further objects, features and advantages of the present invention
will become more readily apparent from the following detailed description
thereof when taken in conjunction with the accompanying drawing.
DETAILED DESCRIPTION OF THE DRAWING
The spindle 1 according to the present invention, arranged vertically and
designed as a ring spindle, comprises a spindle shaft 2 which is driven to
rotate, said spindle shaft 2 being supported in a neck bearing 3 in the form of
a roller bearing and also being supported in a two-part step bearing 4. The
neck bearing 3 and the step bearing 4 are located in a spindle bearing
housing 5, which has a closed bottom 6.
The spindle bearing housing 5 comprises essentially a sleeve 7 containing the
bottom 6, as well as a bearing head 8 which takes up the neck bearing 3 ,

said bearing head 8 being inserted into the sleeve 7 from above by means of
a press fit 9. An oil bath is located in the area of the step bearing 4 inside the
spindle bearing housing 5.
The step bearing 4 comprises a step bearing sleeve 10, which takes up the
radial forces, as well as a thrust plate 11, which takes up the axial forces. The
step bearing sleeve 10 is supported in a centering tube 12, which in turn is
secured by means of a press fit 13 in the bearing head 8. The centering tube
12 consists of a preferably glass-fibre reinforced plastic, which makes the
centering tube 12 flexible to a desired degree and permits radial movements
of the centering tube 12 in the area of the step bearing 4.
Between the cylindrical inner contour of the sleeve 7 and the cylindrical outer
contour of the centering tube 12, an annular gap 14 is located, which takes up
a damping spiral 15 in the known way. The damping spiral 15 is entirely
arranged in the oil bath. By means of cross bore holes 16 in the centering
tube 12, the annular gap 14, which comprises the damping spiral 15, is
connected with the oil bath of the step bearing 4. The damping spiral 15 is
supported upwards on the bearing head 8. The centering tube 12 is supported
on a supporting area 23 on the damping spiral 15, and on a supporting area in
the area of the step bearing 4.
The spindle 1 is secured, together with a plurality of further, adjacently
arranged spindles in a spindle bank 17 (shown only by a dot-dash line) in the
known way. A drive wharve (not shown) is further arranged to the spindle 1,
whereby all drive wharves can be driven by a continuous drive belt extending
in machine longitudinal direction .
Many advantages arise out of the fact that the centering tube 12, as is
generally known, is made of a flexible plastic. For example, the favourable
vibrational behaviour of the plastic can be used to achieve a particularly
smooth running of the spindle shaft 2. A plastic centering tube 12 of this type,
applied for the purposes of centering, possesses an additional advantage
over the known steel centering tubes in that it has damping properties which

take up the vibrations quicker, which damping properties combine with the
damping forces of the damping spiral 15 to achieve a particularly smooth
running of the spindle 1.
There is, however, a tendency for introduced stress, in particular bending
stress, to trigger creeping processes in the pllstic centering tubes 12, that is,
that the plastic "sets".This is, of course, to be avoided, if the advantages of
the centering tube 12 made of flexible plastic are not to be cancelled out by
the above mentioned disadvantages. It is therefore provided in accordance
with the present invention', that the centering tube 12 is provided in those
areas, in which radial forces are introduced, with a metal reinforcing ring
18,19,20 made of steel. Areas in which radial forces are introduced are, for
example, the press fit 13 between the centering tube 12 and the bearing head
8, also the press fit 21 for the step bearing sleeve 10 secured in the centering
tube 12 as well as the supporting area 23 of the centering tube 12 against the
damping spiral 15. A reinforcing ring 18,19,20 made of steel is therefore
applied to these areas 13, 21 and 23, which permits increased press stresses,
without triggering any possible creeping processes in the plastic. Thus
significantly higher press stresses are possible than in prior art.
As can be seen in the drawing, the reinforcing rings 18 and 19 are applied to
the side of the centering tube 12 facing away from the respective press fit
13,21.
As the thrust plate 11 is taken up by the centering tube 12, axial forces are
also passed into the centering tube 12. In order to avoid axial overloading, a
stop 22 is arranged at a short distance to the thrust plate 11.When the
centering tube 12 stretches because of axial overloading, it can be supported
axially on the stop 22 of the bottom 6 of the spindle bearing housing 5.

WE CLAIM:
1. A spindle for spinning or twisting machines, said
spindle (1) having a rotating spindle shaft (2) which is
supported in a spindle bearing housing (9) by means of a neck
bearing (3) and a step bearing (4) , which comprises a step
bearing sleeve (10) which is arranged in a radially flexible
centering tube (12) made of flexible plastic material, said
centering tube (12) being fixed in the area of the neck bear-
ing (3) at the spindle bearing housing (5) and being supported in
the area of the step bearing (4) by means of a dampening spiral
(15) on the spindle bearing housing (5), characterized in that the
centering tube (12) is reinforced in at least one area
(13,21,23) in which radial forces may act on it by means of at
least one metallic reinforcing ring (l8, 19, 20).
2. A spindle as claimed in claim 1, wherein the at least
one reinforcing ring (18, 19, 20) is a steel ring.
3. A spindle as claimed in claim 1 or 2, wherein a
metallic reinforcing ring (18) is arranged inside the centering
tube (12) at the location (13) where the centering tube is fixed
at the spindle bearing housing (5).

4. A spindle as claimed in any one of claims 1 to 3,
wherein at least one metallic reinforcing ring (19, 20) is
arranged between the dampening spiral (15) and the centering
tube.
5. A spindle as claimed in claim 4, wherein a reinforcing
ring (19) is associated to the step bearing sleeve (10).
6. A spindle as claimed in claim 4 or 5, wherein at least
one reinforcing ring (20) is arranged in the area of the upper
end of the dampening spiral (15).

7. A spindle as claimed in any one of the claims 1 to 6*
wherein the centering tube (12) has a flexural strength
between 13 and 17 N/mm in the area of the step bearing (4).
8. A spindle as claimed in any of the claims 1 to 7,
wherein the spindle bearing housing (5) is provided with a
stop (22) for limiting axial stretching of the centering
tube (12).

This invention relates to a spindle for spinning or twisting
machines, said spingle (1) having a rotating spindle shaft (2),
which is supported in a spindle bearing housing (5) by means of a
neck bearing (3) and a step bearing (4), which comprises a step
bearing sleeve (10), which is arranged in a radially flexible
centering tube (12) made of flexible plastic material, said
centering tube (12) being fixed in the area of the neck bearing
(3) at the spindle bearing housing (5) and being supported in the
area of the step bearing (4) by means of a dampening spiral (15)
on the spindle bearing housing (5). The centering tube (12) is
reinforced in at least one area (13, 21, 23) in which radial
forces may act on it by means of at least one metallic
reinforcing ring (18, 19, 20).

Documents:

551-KOL-2004-(24-08-2012)-CORRESPONDENCE.pdf

551-KOL-2004-FORM-27.pdf

551-kol-2004-granted-abstract.pdf

551-kol-2004-granted-assignment.pdf

551-kol-2004-granted-claims.pdf

551-kol-2004-granted-correspondence.pdf

551-kol-2004-granted-description (complete).pdf

551-kol-2004-granted-drawings.pdf

551-kol-2004-granted-examination report.pdf

551-kol-2004-granted-form 1.pdf

551-kol-2004-granted-form 2.pdf

551-kol-2004-granted-form 3.pdf

551-kol-2004-granted-form 5.pdf

551-kol-2004-granted-pa.pdf

551-kol-2004-granted-priority document.pdf

551-kol-2004-granted-reply to examination report.pdf

551-kol-2004-granted-specification.pdf

551-kol-2004-granted-translated copy of priority document.pdf

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Patent Number

227619

Indian Patent Application Number

551/KOL/2004

PG Journal Number

03/2009

Publication Date

16-Jan-2009

Grant Date

14-Jan-2009

Date of Filing

08-Sep-2004

Name of Patentee

NOVIBRA GMBH

Applicant Address

DONZDORFOR STR. 4, 73079 SUSSEN

Inventors:

#	Inventor's Name	Inventor's Address
1	GERD STAHLECKER	AUF DER EBENE 30, D-73054, EISLINGEN/FILS

PCT International Classification Number

D01H 7/04

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10348893.6	2003-10-15	Germany