FULL TENSION SWAGED CONNECTOR

CONNECTEUR EMBOUTI PLEINE TENSION

English Abstract

An improved full tension connector for electrical conductors has a substantially cylindrical outer surface and a stepped series of substantially cylindrical inner surfaces with progressively smaller inside diameters. The design of the connector allows for improved control of the compression of the cable inside the fitting. A series of swages, progressing successively from a light compression to a heavier compression, ensures that the connector will sustain the required tensile load.

French Abstract

Un connecteur pleine tension amélioré pour conducteurs électriques comporte une surface externe essentiellement cylindrique et un ensemble en gradins de surfaces internes essentiellement cylindriques présentant des diamètres intérieurs progressivement plus petits. La conception du connecteur permet une régulation améliorée de la compression du câble à l'intérieur du raccord. Un ensemble de cosses, exerçant une compression progressivement plus importante, assurent que le connecteur saura résister à l'effort de tension requis.

Claims

What is claimed is:
1. A connector for an electrical conductor comprising: a body having a
substantially
cylindrical outer surface; a first substantially cylindrical inner surface
having a first inside
diameter d₁, the first inner surface extending axially from a first end
of the body to a
depth A; a second substantially cylindrical inner surface having a second
inside diameter
d₂ smaller than d₁, the second inner surface extending axially from
the depth A
to a depth B; wherein d_1-d₂ < 0.05".
2. The connector of claim 1 further comprising a third substantially
cylindrical inner
surface having a third inside diameter d₃ smaller than d₂, the third
inner surface
extending axially from the depth B to a depth C; wherein d_2-d₃ <
0.05".
3. The connector of claim 2 further comprising a fourth substantially
cylindrical
inner surface having a fourth inside diameter d₄ smaller than d₃,
the fourth
inner surface extending axially from the depth C to a depth D; wherein d_3-
d. sub .4 < 0 .05".
4. The connector of claim 1 wherein the body is configured as a splice.
5. The connector of claim 1 wherein the body is configured as a dead end.
6. A method of attaching the connector of claim 1 to an electrical
conductor
comprising: inserting an electrical conductor into the connector to at least
depth B;
compressing the outer surface of the connector between the first end and depth
A with a
first compression force; compressing the outer surface of the connector
between depth A
and depth B with a second compression force greater than the first compression
force.

7. A method of attaching the connector of claim 2 comprising: inserting an
electrical
conductor into the connector to at least depth B; compressing the outer
surface of the
connector between the first end and depth A with a first compression force;
compressing
the outer surface of the connector between depth A and depth B with a second
compression force greater than the first compression force; and compressing
the outer
surface of the connector between depth B and depth C with a third compression
force
greater than the second compression force.
8. The method of claim 6 wherein the steps of compressing are performed
using a
swaging tool.
9. The method of claim 7 wherein the steps of compressing are perforated
using a
swaging tool.
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Description

CA 02765395 2012-01-25
FULL TENSION SWAGED CONNECTOR
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] This invention relates to the field of power transmission and, more
particularly, to
connectors for high tension power transmission lines.
BACKGROUND
[0002] Connectors play a critical role in the efficiency and reliability of
power transmission
systems. Aluminum cables used for overhead transmission lines require
connectors for splices
and dead end assemblies. Currently available connectors are typically tubular
aluminum devices
that are crimped or swaged onto the cable. In order to achieve a full or
nearly full tension fitting,
prior art connectors require numerous crimps or swages and are therefore
relatively long and
heavy. In addition, the installation tools for prior art connectors are large
and unwieldy. During
the installation of prior art connectors, the length of the fitting and the
size of the tooling may
result in undesired bending of the connector.
SUMMARY OF INVENTION
[0003] The present invention provides an improved connector with a body
having a
substantially cylindrical outer surface and a stepped series of substantially
cylindrical inner
surfaces with progressively smaller inside diameters. The design of the
connector allows for
improved control of the compression of the cable inside the fitting. A series
of swages,
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CA 02765395 2012-01-25
progressing successively from a light compression to a heavier compression,
ensures that the
connector will sustain the required tensile load.
[0004] In comparison to prior art connectors, the present invention
provides a smaller, lighter
full tension connector that can be installed with fewer swages. Installation
of the connector is
quicker and easier than prior art counterparts. Furthermore, the connector is
less prone to
bending during installation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Figure 1 is a partial cross-sectional view of a connector in
accordance with an
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0006] In the following description, for purposes of explanation and not
limitation, specific
details are set forth in order to provide a thorough understanding of the
present invention.
However, it will be apparent to one skilled in the art that the present
invention may be practiced
in other embodiments that depart from these specific details. In other
instances, detailed
descriptions of well-known methods and devices are omitted so as to not
obscure the description
of the present invention with unnecessary detail.
[0007] A connector 10 in accordance with one embodiment of the present
invention is shown
in Figure 1. The connector body 12 has a substantially cylindrical outer
surface. A first
substantially cylindrical inner surface 14 has an inside diameter d1 and
extends axially from the
end of connector body 12 to a depth A. A second substantially cylindrical
inner surface 16 has
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CA 02765395 2012-01-25
an inside diameter d2, which is smaller than d1, and extends axially from
depth A to depth B. A
third substantially cylindrical inner surface 18 has an inside diameter d3,
which is smaller than
d2, and extends axially from depth B to depth C.
[0008] To install the connector 10 onto a cable, the end of the cable is
inserted into the
connector body to depth C. The connector is compressed onto the cable using a
hydraulic
swaging tool. A suitable swaging tool may be, for example, the tool disclosed
in U.S. Patent No.
7,299,674 and commercially available under the CableLok brand from Designed
Metal
Connections of Gardena, California. The design of connector 10 allows it to be
installed on the
cable using a single die set.
[0009] The first swage area at the end of the connector (i.e., between the
end of the
connector body where the cable is inserted and depth A) carries the maximum
load. This has the
minimum compression, thereby minimizing damage to the cable. The second swage
area (i.e.,
between depth A and depth B) holds the load that the first swage area cannot
take and has a
heavier compression to provide better electrical contact. The third swage area
(i.e., between
depth B and depth C) carries less load, but provides the best electrical
contact. When properly
installed, connector 10 can sustain a load of 95% or more of the rated
strength of the cable,
thereby meeting the requirements for class 1 full tension fittings of the
C119.4 ANSI standard.
[0010] As will be appreciated, the specific dimensions of connector 10 are
dependent upon
the dimensions of the cable with which it will be used. The smallest inside
diameter, in this case
d3, is slightly greater than the nominal outside diameter of the cable. The
inside diameter step
sizes (i.e., the difference between d1 and d2 and the difference between d2
and d3) may be less
than about 0.05 inches. The axial length of each step (i.e., the distance from
the end of the
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CA 02765395 2012-01-25
connector body to depth A, from depth A to depth B, and from depth B to depth
C) is determined
primarily by the dimensions of the swaging tool head and may be approximately
1 inch.
Connector 10 has been described as having three swaging segments; however, it
is to be
understood that other embodiments of the invention may have more or fewer
segments.
[0011] Connector 10 may be configured either as a splice connector with a
tubular body
receiving a cable at each end or as a full tension dead end having a suitable
structural coupling.
In one embodiment, connector 10 is fabricated with 6061-T6 aluminum alloy,
although other
alloys may be used. In this embodiment, the connector body is heat treated
(annealed) after
machining.
[0012] It will be recognized that the above-described invention may be
embodied in other
specific forms without departing from the spirit or essential characteristics
of the disclosure.
Thus, it is understood that the invention is not to be limited by the
foregoing illustrative details,
but rather is to be defined by the appended claims.
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Representative Drawing