U.S. patent application number 11/641595 was filed with the patent office on 2007-06-21 for metal spool.
This patent application is currently assigned to Ziemek Cable Technology GmbH. Invention is credited to Gerhard Ziemek.
Application Number | 20070138333 11/641595 |
Document ID | / |
Family ID | 38172351 |
Filed Date | 2007-06-21 |
United States Patent
Application |
20070138333 |
Kind Code |
A1 |
Ziemek; Gerhard |
June 21, 2007 |
Metal spool
Abstract
The invention specifies a metal spool for receiving metallic
winding material (5) in the form of a wire, which spool comprises
two flanges (1, 2) in the form of circular disks, arranged parallel
to one another and having the same diameter and an elongate core
(3) connecting the flanges and having a circular cross section and
smaller radial dimensions in comparison with the flanges (1, 2),
the mid-axis of which core corresponds to the mid-axes of the
flanges (1, 2). A winding space (4) for receiving the winding
material (5), is delimited by the core (3) and the two flanges (1,
2). The dimensions of the winding space (4) in the direction of the
mid-axis of the spool can be enlarged at an increased temperature.
In addition, means are provided to bring the dimensions of the
winding space (4) back to the initial position when the temperature
returns to room temperature.
Inventors: |
Ziemek; Gerhard;
(Langenhagen, DE) |
Correspondence
Address: |
WARE FRESSOLA VAN DER SLUYS &ADOLPHSON, LLP
BRADFORD GREEN, BUILDING 5
755 MAIN STREET, P O BOX 224
MONROE
CT
06468
US
|
Assignee: |
Ziemek Cable Technology
GmbH
|
Family ID: |
38172351 |
Appl. No.: |
11/641595 |
Filed: |
December 18, 2006 |
Current U.S.
Class: |
242/578.3 |
Current CPC
Class: |
B65H 75/241 20130101;
B65H 2701/5114 20130101; B65H 75/14 20130101 |
Class at
Publication: |
242/578.3 |
International
Class: |
B65H 75/24 20060101
B65H075/24 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2005 |
DE |
102005060279.7 |
Claims
1. A metal spoool for receving metallic winding material in the
form of a wire, comprising: two flanges in the form of circular
disks, arranged parallel to one another, and an elongate core
connecting said flanges and having a circular cross section a
smaller radial dimension in comparison with radial dimensions of
the flanges, the mid-axis of said core corresponding to mid-axes of
the flanges, a winding space for recieving the winding material
being delimited by the core and the two flanges, said flanges and
core arranged so that the distance between the flanges can alterd
elastically by forces acting on them, wherein the dimensions of the
winding space in the direction of the mid-axis of the spool can
enlarged at an increased temperature, in comparsion with and
initial position at room temperature by forces which are brought
about by different coefficients of thermal expansion of the winding
material, on the one hand, and of the core of the spool, on the
other hand, and means for bringing the dimensions of the winding
space back to the initial position when the temperature returns to
room temperature.
2. The spool as claimed in claim 1, wherein the enlarging of the
dimensions of the winding space between room temperature and the
increased temperature is equal to a length el in accordance with
the following equation
el=l.sub.o1.times..DELTA..delta.(.alpha..sub.w-.alpha..sub.c),
where the variables: l.sub.o1=length of the core at room
temperature .DELTA..delta.=difference between the room temperature
and the increased temperature .alpha..sub.w=coefficient of thermal
expansion of the material for the winding material
.alpha..sub.c=coefficient of thermal expansion of the material for
the core.
3. The spool as claimed in claim 2, wherein the core is in the form
of a tube, which is corrugated all the way round transversely with
respect to its axis at least in one section of the tube.
4. The spool as claimed in claim 2, wherein the core is attached
fixedly to one flange of the spool and is connected to the other
flange via a spring mechanism.
5. The spool as claimed in claim 2, wherein the core comprises two
tubes which are arranged concentrically with respect to one another
and bear against one another and of which one is fixed to one
flange and the other is fixed to the other flange and which are
connected to one another by a spring mechanism which is effective
in the axial direction.
6. The spool as claimed in claim 1, wherein an intermediate flange
is arranged in the winding space between the two flanges at least
in the vicinity of one flange, which intermediate flange is mounted
displaceably on the core and is connected to the flange in whose
vicinity it is arranged via springs acting in the axial direction
of the core.
7. The spool as claimed in claim 6, wherein outwardly protruding
bolts, which pass through holes in the associated flange, are
attached to the intermediate flange in the axial direction of the
core.
8. A metal spool for receiving metallic winding material in the
form of a wire, comprising: two flanges in the form of circular
disks arranged parallel to one another, and an elongate core
connecting said flanges and having a circular cross section and a
smaller radial dimension in comparison with radial dimensions of
the flanges, the mid-axis of said core corresponding to mid-axes of
the flanges, a winding space for receiving the winding material
being delimited by the core and the two flanges, wherein the core
comprises a material which has a coefficient of thermal expansion
which is at least approximately the same as the material for the
winding material.
9. The spool as claimed in claim 1, wherein the core is in the form
of a tube, which is corrugated all the way round transversely with
respect to its axis at least in one section of the tube.
10. The spool as claimed in claim 1, wherein the core is attached
fixedly to one flange of the spool and is connected to the other
flange via a spring mechanism.
11. The spool as claimed in claim 1, wherein the core comprises two
tubes which are arranged concentrically with respect to one another
and bear against one another and of which one is fixed to one
flange and the other is fixed to the other flange and which are
connected to one another by a spring mechanism which is effective
in the axial direction.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 USC .sctn.119(a)
to German Patent Application No. DE102005060279.7 which was filed
on Dec. 16, 2005.
TECHNICAL FIELD
[0002] The invention relates to a metal spool for receiving
metallic winding material in the form of a wire, comprising two
flanges in the form of circular disks, arranged parallel to one
another and having the same diameter and an elongate core
connecting these flanges and having a circular cross section and
smaller radial dimensions in comparison with the flanges, the
mid-axis of which core corresponds to the mid-axes of the flanges,
in which spool a winding space for receiving the winding material
is delimited by the core and the two flanges, and in which spool
the distance between the flanges can be altered elastically by
forces acting on them (DE 41 38 189 A1).
BACKGROUND OF THE INVENTION
[0003] These spools have long been known and available on the
market. In the known technology, they are used for winding up
metallic wires which are envisaged, in particular, as structural
elements of electrical cables and lines. Spools in which the
distance between the flanges can be altered are known. For example,
DE 41 38 189 A1, mentioned at the outset, describes a spool in
which transverse stresses occurring when spooling wire which is
subjected to temperature are intended to be compensated for in a
controlled manner. For this purpose, the flanges are arranged on
the core such that they can move in the axial direction. Once the
spooling has come to an end, the spool has its rated dimension
owing to the displacement of the flanges towards the outside. DE 33
12 178 A1 describes a spool having a core comprising two parts, of
which in each case one is attached to one flange. The parts of the
core engage telescopically one inside the other and can be
connected to one another by being latched in different relative
positions for the purpose of setting different core lengths. A
similar spool having a core comprising two parts is described in
U.S. Pat. No. 3,840,198 A, in which the flanges are connected to
one another via spring elements.
[0004] In order to set specific properties for wires which are
intended to be used in cables and lines as electrical conductors,
it is necessary for them to be pretreated. In this case, the wires
are provided with predetermined diameters by means of mechanical
processing and, for example, bending properties which can be set in
a targeted manner by thermal treatment. The thermal treatment takes
place, for example, using so-called "annealing spools" consisting
of metal, in particular of steel, onto which the wires are wound
and, in the wound-on state, are subjected to an annealing treatment
together with the spools. The required mechanical and electrical
properties of the wires can thus be set with a sufficient degree of
accuracy. However, problems often occur when withdrawing the wires,
which have cooled down again after the annealing, from the spools
since the wires can be "caked" to one another by the annealing
process.
[0005] The reason for this fact is essentially that the material of
the wires provided for electrical applications expands to a greater
extent on heating than the material of a spool consisting of a
metal having a high tensile strength, in particular of steel. This
applies, on the one hand, to copper, but in particular to aluminum,
as the conductor material for the wires. In comparison with steel,
aluminum has a coefficient of thermal expansion which is greater by
a factor of approximately 2, while this factor is approximately 1.4
for copper in comparison with steel. The expansion of a wire which
has been wound onto the spool with a large number of turns during
heating in the annealing process is then drastically impeded by the
respective spool. As a result, the turns of the wire not only push
against the flanges of the spool, but they are also pushed against
one another with a considerable amount of force. This results in
the abovementioned caking of the wire turns.
SUMMARY OF THE INVENTION
[0006] The invention is based on the object of designing the spool
outlined at the outset such that caking of the wires during an
annealing process can be ruled out with a high degree of
reliability.
[0007] This object is achieved in accordance with the invention by
virtue of the fact that [0008] the dimensions of the winding space
in the direction of the mid-axis of the spool can be enlarged at an
increased temperature, in particular up to an annealing temperature
required for annealing the winding material, in comparison with an
initial position at room temperature by forces which are brought
about by different coefficients of thermal expansion of the winding
material, on the one hand, and of the core of the spool, on the
other hand, and [0009] means are provided which can be used to
bring the dimensions of the winding space back to the initial
position when the temperature returns to room temperature.
[0010] When using the spool according to the invention, caking of
the turns of a wire wound onto said spool can be ruled out with a
high degree of reliability. The core of the spool can, for example,
itself be designed to be so elastic that, as a result of the
heating during an annealing process, it is extended reversibly
owing to the pressure exerted, for example, on the flanges of the
spool when the wire turns expand. The individual wire turns can
expand relatively unimpeded, however, in all embodiments of the
spool during the annealing process owing to the expansion of the
winding space, and the pressure exerted on these wire turns is as a
result considerably reduced. The corresponding "extension distance"
of the winding space is dependent on the level of the annealing
temperature, of the coefficient of thermal expansion of the
material for the wire wound on and of the size of the spool. It is,
for example, between 2 mm and 10 mm.
[0011] The elasticity of the core existing in the axial direction
can be achieved by spring elements acting in the axial direction
being incorporated, but with particular advantage owing to the use
of a tube as the core, which tube is corrugated all the way around
at least in an axial section transversely with respect to its axis,
preferably over its entire length.
[0012] Caking of the wire turns during an annealing process can
also be ruled out with a high degree of reliability in another
embodiment of the spool when the material of said spool has a
coefficient of thermal expansion which corresponds at least
approximately to that of the material for the wire wound onto the
spool.
[0013] Exemplary embodiments of the subject matter of the invention
are illustrated in the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a view of a spool known in principle.
[0015] FIGS. 2 to 6 show different embodiments of the core of a
spool according to the invention.
[0016] FIG. 7 shows a further embodiment of the spool according to
the invention.
[0017] FIG. 8 shows a section through FIG. 7 along the line
VIII-VIII.
[0018] FIG. 9 shows a detail of the spool shown in FIG. 7 in an
enlarged illustration.
[0019] FIG. 10 shows a further embodiment of the spool.
[0020] FIG. 11 is a graph of the displacement travel of the flanges
over the length of the core at different temperatures.
DETAILED DESCRIPTION
[0021] The spool illustrated in FIG. 1 has two flanges 1 and 2 in
the form of circular disks and having the same diameter. The
flanges 1 and 2 consist of a metal having a high tensile strength,
in particular of steel. They are arranged parallel to one another
in the spool and are connected to one another by a core 3, which
likewise consists of metal and, in the exemplary embodiment
illustrated, is cylindrical. The elongate core 3 could also be
conical. The mid-axes of the flanges 1 and 2 and the core 3
correspond to one another. A winding space 4 serving the purpose of
receiving the winding material is delimited by the flanges 1 and 2
and the core 3.
[0022] The spool according to the invention consists of metal and
is used for receiving winding material in the form of wire, which
is wound on with a large number of turns and likewise consists of
metal--referred to below as "wire" for short. The upper part of
FIG. 1 shows a large number of turns 5 of a wire. Its material
should have a markedly greater coefficient of thermal expansion
than the material for the flanges 1 and 2 and, in a preferred
embodiment, also for the core 3. All parts of the spool therefore
preferably consist of steel, and the wire is preferably a
copper-cladded aluminum wire--referred to below as "CCA wire", for
short. The invention is naturally not restricted to the use of
these materials. However, they are taken into consideration in the
description below.
[0023] A spool which has been fully wound with CCA wire is
introduced into an annealing furnace for an annealing treatment of
the CCA wire and is heated there, for example, to temperatures of
between 400.degree. C. and 600.degree. C. In the process, the turns
5 of the CCA wire expand to a greater extent than the spool or its
core 3. In order that, as a result, the turns 5 of the CCA wire are
not pressed too firmly against one another, the distance between
the flanges 1 and 2, for example, can be extended elastically or
reversibly such that the winding space 4 can be altered in the
direction of the mid-axis of the spool.
[0024] The displacement travel of the flanges 1 and 2 at an
increased temperature or the expansion of the winding space 4 can
be calculated, starting from a length at room temperature and
subsequent return to the initial position at room temperature. The
elements required for the reversible change in length can then have
corresponding dimensions. The displacement travel of the flanges 1
and 2 and therefore the change in length of the winding space 4
between room temperature and the increased temperature is equal to
a length el in accordance with the following equation
el=l.sub.o1.times..DELTA..delta.(.alpha..sub.w-.alpha..sub.c), in
which: l.sub.o1=length of the core at room temperature
.DELTA..delta.=difference between the room temperature and the
maximum temperature .alpha..sub.w=coefficient of thermal expansion
of the material for the winding material .alpha..sub.c=coefficient
of thermal expansion of the material for the core.
[0025] The dependence of the length el of the "displacement travel"
on the level of the annealing temperature is shown, for example, in
FIG. 11 for an aluminum wire which has been wound onto a steel
spool. A core having a length of 1000 mm is accordingly extended at
a temperature of 200.degree. C. by 2 mm, while the extension at
400.degree. C. is approximately 4.8 mm, i.e. more than double that
at 200.degree. C. This effect is even more serious at a core length
of 2000 mm. Here, the extension at 200.degree. C. is approximately
3.8 mm and 9.5 mm at 400.degree. C. The respective extension of the
core, which is reversed when the wound spool is cooled to room
temperature, is necessary, as mentioned above, in order that the
wire turns do not cake to one another during annealing and
subsequent cooling. The expansion of the flanges 1 and 2, which
likewise occurs at increased temperature, is so low in relation to
the extension of the core that it is negligible.
[0026] The reversible enlargement of the winding space 4 between
the two flanges 1 and 2 in the axial direction of the core 3 can be
achieved in a different way:
[0027] As shown in FIG. 2, the core 3 may be in the form of a tube
6, which is corrugated all the way round transversely with respect
to its axis over its entire axial length. Since the core 3 is
fixedly connected to the two flanges 1 and 2, it is expanded by the
turns 5 of the CCA wire which are expanding and pressing against
the flanges 1 and 2, with the result that the clear width of the
winding space 4 is increased. When the spool and the CCA wire are
cooled, the core 3 returns to its original length.
[0028] The same effect can be achieved when the core shown in FIG.
3 is in the form of a tube 7, which is corrugated all the way round
transversely with respect to its axis at least in an axial
section.
[0029] In the embodiment of the spool shown in FIG. 4, the core 3
is fixedly connected to the flange 1 and connected to the flange 2
via a spring mechanism 8. Such a spring mechanism, however, can
also be provided in each case between the two flanges 1 and 2 and
the core.
[0030] As shown in FIG. 5, the core can also comprise two tubes 9
and 10, which engage telescopically one inside the other, bear
against one another such that they can move in relation to one
another and are connected to one another via a spring mechanism 11.
The tube 9 is only fixedly connected to the flange 1, while the
tube 10 is fixed to the flange 2.
[0031] In one further embodiment of the spool according to the
invention, the core can also be designed such that there are no
substantial measures for elastically changing its length. As shown
in FIG. 6, the core 12 may consist of aluminum and therefore
substantially of the same material as the CCA wire. It therefore
has at least approximately the same coefficient of thermal
expansion as the CCA wire, with the result that the expression in
parentheses in the above equation in the extreme case is equal to
zero. With this design of the spool as well, no substantial
pressure is applied to the turns 5 of the wire. This embodiment of
the spool is generally designed such that the material of the core
12 has at least approximately the same coefficient of thermal
expansion as the material of the wire which has been wound on and
is to be annealed.
[0032] One preferred embodiment of the spool is shown in FIGS. 7 to
9:
[0033] As shown in FIG. 7, an intermediate flange 14 is mounted on
a core 13 of the spool such that it can be displaced in the axial
direction of the core 13, to be precise in the vicinity of the
flange 2. The intermediate flange 14 likewise consists, for
example, of steel. It is connected to the flange 2 via springs 15.
As shown in FIG. 8, preferably four springs 15 are provided which
are offset with respect to one another uniformly in the
circumferential direction. For the guidance of the intermediate
flange 14, bolts 16 are provided which are attached fixedly to the
intermediate flange 14 and pass through holes 17 in the flange 2,
as is shown in a detail in FIG. 9. As shown in FIG. 8, four bolts
16, which are offset with respect to one another in the
circumferential direction, may be provided. They also prevent the
intermediate flange 14 from tilting on the core 13 during
displacement of said core.
[0034] In the spool shown in FIG. 7, the winding space 4 is
therefore delimited by the flange 1 and the intermediate flange 14.
On expansion of the turns 5 of the wire wound onto the spool, the
intermediate flange 14 moves in the direction of the stationary
flange 2. The springs 15, which are pushed together in the process,
move the intermediate flange 14 back into its initial position if
the temperature returns to room temperature. The spool in the
embodiment shown in FIG. 7 is particularly robust since the flanges
1 and 2 are fixedly connected to the core 13.
[0035] This also applies to the spool illustrated in FIG. 10, in
which a displaceable intermediate flange 18 with springs 19 and
bolts 20, is attached to the core 13, also in front of the flange
1. The same applies for the mode of operation of the intermediate
flange 18 as for the intermediate flange 14.
* * * * *