Note: Descriptions are shown in the official language in which they were submitted.
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T
BACKGROUND
CABLE CONNECTOR
The present invention relates to electrical connectors for cables, and in
particular to improvements to cable connectors of the type including a first
member that defines a socket and a second member that defines a head
rotatably received in the socket.
Cable connectors of the general type described above have been
commercially successful in a number of applications. See for example the
cable clamping device disclosed in Cornell U.S. Patent 4,357,068, assigned to
the assignee and hereby incorporated by reference in its entirety. The cable
clamping device of the Cornell patent clamps the cable being terminated by
rotating a second member within a socket formed by a first member from a
first position, in which cable-receiving openings of the first and second
elements are aligned, to a second position, in which the cable-receiving
openings are misaligned. The cable clamping device of the Cornell patent
provides the particular advantage that the second member can be inserted
into the socket in either first or second orientations adapted for clamping
first
and second sizes of cable, respectively.
Cornell U.S. Patent 3,990,129, also assigned to the assignee of the
present invention and hereby incorporated by reference in its entirety,
discloses a multi-cable connector for use with a different type of cable
clamping device. The disclosed multi-cable connector includes an elongated
cylinder on which various C-shaped elements are mounted for rotation. Each
of the C-shaped elements defines a cable-receiving opening that can be
selectively aligned or misaligned with a corresponding cable-receiving
opening of the cylinder.
A need presently exists for an improved multi-cable clamping device
that is suited for use with the geometry of the clamping device of the Cornell
'068 patent, yet which can be produced at lower cost with fewer parts and
increased ease of use.
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SUMMARY
By way of introduction, the preferred embodiment described below
includes a first element having a base and a receiver. The receiver defines a
socket that extends along an axis. Multiple second elements are received in
the socket. Each of the second elements includes a respective head and tail.
Individual fasteners fold the second elements in a cable clamping position. In
the disclosed embodiment some of the fasteners that hold the second
elements in the cable clamping position also pass through a mounting plate to
secure the first element and therefore the connector in place and to provide
electrical connection to external circuitry.
The preferred embodiment described below uses fasteners including a
nut that contributes to a low profile for the resulting connector. This nut
includes a threaded portion that is received within the tail of the respective
second element. By recessing a portion of the nut in the tail of the second
element, a relatively long effective length is provided for the fasteners.
This
long effective length is useful in moving the second element from the aligned
to the misaligned positions.
The foregoing paragraphs have been intended by way of introduction,
and are not intended to limit the scope of the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGUF~~ 1 is an exploded perspective view of an electrical connector
that incorporates a preferred embodiment of this invention.
FIGURE 2 is a top view of one of the first elements of FIGURE 1.
FIGURE 3 is a cross-sectional view taken along line 3-3 of FIGURE 2.
FIGURE 4 is a view in the plane of FIGURE 3 showing a second
element mounted in place in the first element.
FIGURE 5 is view corresponding to that of FIGURE 4, showing the
second element in an inverted position with respect to the position of
FIGURE 4.
FIGURE 6 is a top view of a threaded nut included in the embodiment
of FIGURE 1.
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T FIGURE 7 is a side view of the nut of FIGURE 6.
FIGURE 8 is a cross-sectional view taken along line 8-8 of FIGURE 7.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED
EMBODIMENTS
Turning now to the drawings, FIGURE 1 shows an exploded
perspective view of a cable clamping device that incorporates a preferred
embodiment of this invention. The cable clamping device or electrical
connector 10 is mounted to a mounting plate 12. In the embodiment of
FIGURE 1 two connectors 10 are shown, and they are substantially identical
in structure. Each connector 10 includes a first element 14 and a plurality of
second elements 30.
The first element is shown in greater detail in FIGURES 2 and 3, and
the first element includes a base 16 and a receiver 18. The receiver 18
extends upwardly from the base 16 and forms a generally cylindrical socket
20 centered about an axis 22. The socket 22 is not entirely circular in cross-
section, because it defines a relieved area 23 as well as a notch 25. A
plurality of first openings 24 are formed in the receiver 18 so as to be
parallel
to one another and to extend into the socket 20. A plurality of aligned
protruding elements 26 extend upwardly from the base 16, each protruding
element 26 aligned with a respective first opening 24. Additional base
openings 28 are formed in the base 16, as shown in FIGURES 2 and 3.
The first element 14 can be formed as a machined extrusion from any
suitable alloy. In this preferred embodiment the alloy is AI 6082-T6. The
first
openings 24, the final shape of the protruding elements 26 and the base
openings 28 are all formed in machining operations after the basic extrusion
has been cut to length.
As shown generally in FIGURE 1 and more specifically in FIGURES 4
and 5, each second element 30 includes a respective head 32 and tail 34.
Each head 32 is generally cylindrical in shape and sized to fit within the
socket 20 and rotate about the axis 22. Each of the heads 32 forms a
respective second opening 36 that extends somewhat into the respective tail
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34T A window 38 is defined in the tail 34, and the window 38 opens out onto
both sides of the tail 34. The head 32 defines two ridges 40 which cooperate
with the notch 25 of the base 16. Each tail 34 also defines a tail opening 42
generally aligned with one of the base openings 28.
The second elements 30 can be formed as an extrusion of a
conductive alloy such as AI 6082-T6. This extrusion is then machined to form
the second opening 36, the window 38 and the tail opening 42.
As best shown in FIGURES 4 and 5, the second opening 36 is
preferably oriented at a skew angle with respect to the centerline of the tail
34.
The second element 32 can be inserted into the socket 22 in first and second
orientations. When the second element 30 is in the clamping position, the
degree of misalignment between the second opening 36 and the first opening
24 is greater when the second element is in the first orientation as shown in
FIGURE 4 than when the second element 30 is in the reverse orientation as
shown in FIGURE 5. This allows a single second element 30 to clamp cables
having a wider range of diameters than would otherwise be possible.
As best shown in FIGURE 1, the second elements 30 are moved from
a first position 80 (in which the first and second openings 24, 36 are
generally
aligned) to a second position 82 (in which the first and second openings 24,
36 are misaligned as shown in FIGURES 4 and 5) by fasteners 60. Each of
the fasteners 60 includes a bolt 62, and some of the bolts 62 define out-of-
round surfaces 64 that engage complementary base openings 28 to prevent
rotation of the bolt 62 with respect to the base 16. The fasteners 60 also
include nuts 66, one of which is shown in detail in FIGURES 6, 7 and 8.
Each nut 66 includes a first portion 68 that defines a cylindrical outer
surface 70 dimensioned to fit within the tail opening 42 of the respective
second element 30. Each nut 66 also defines a second portion 72 that
extends above the respective tail 34 and defines an out-of round surface 74
adapted to be engaged by a wrench. A shoulder 75 is disposed between the
first and second portions 68, 72, and the shoulder 74 bears on a washer 84
that in turn bears on the surface of the tail 34. As shown in FIGURE 8, both
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the'first and second portions 68, 72 define a threaded interior surface 76
configured to engage the respective bolt 62.
As shown in FIGURE 1, some of the bolts 88 are shorter bolts that
extend through a single base 16 and a single tail 34. Other bolts 86 are
longer bolts that extend through two tails 34, finro bases 16 as well as the
mounting plate 12. These longer bolts 86 both hold the respective second
elements in the cable clamping position and mount the connector 10 to the
mounting plate 12. Other bolts 90 extend through two bases 16 and the
mounting plate 12 to complete the assembly of the connectors 10 on the
mounting plate 12.
In operation, the connectors 10 are assembled as described above,
with the nuts 66 initially positioned near the ends of the respective bolts.
The
second elements 30 are then rotated clockwise in the view of FIGURES 4 and
5 to bring the second openings 36 in alignment with the first openings 24.
Then cables (not shown) are inserted through the first and second openings
24, 36 into the windows 38. Then a wrench (not shown) is used to rotate the
nuts 66 on the bolts 62. The out-of-round surfaces 64 prevent some of the
bolts 62 from rotating. Rotation of the nuts 66 moves the tails 34 into
contact
with the base 16, thereby bending the clamped cable and applying substantial
compressive forces to the cable. The protruding elements 34 bend the ends
of the cables upwardly out of the window 38. The result is a secure
mechanical tErmination for the cables having excellent electrical contact
between the connector 10 and the clamped cables.
The connector 10 provides the advantage that many cables can be
terminated in a relatively compact space. Because a single first element 14 is
used to mount many second elements 30 to the mounting plate 12, a
substantial reduction in the number for required parts, the cost, and the size
of
the resulting assembly is achieved. Individual ones of the second elements
can be moved between a first, cable-receiving position and the second,
30 cable-clamping position without disturbing the remaining second elements. A
particularly low profile design is provided by using nuts of the type
described
above which are substantially received within the respective tails.
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As another advantage, the first element 14 provides a conductive path
to distribute electrical current to all of the associated terminated cables.
For
this reason, the mounting plate 12 can be made smaller and lighter, and the
mounting plate 12 does not have to extend through the entire length of the
first element 14. As illustrated above, the mounting plate preferably overlaps
some but not all of the second elements, such that the first element is
electrically interposed between the mounting plate and those cables that are
associated with at least the remotely positioned second elements.
Of course, many changes and modifications can be made to the
preferred embodiments described above. More or fewer second elements
can be used with each first element. The improved fastener including the nut
described above can be used in electrical connectors for single cables, as
well as in multiple cable connectors described above. If desired, only a
single
connector 10 can be mounted to each mounting plate 12.
Additionally, many other geometries can be used for the components
described above. It is not essential in all embodiments that the second
opening be arranged at a skew angle with respect to the tail of the second
element. In one alternative design, each second opening 36 is positioned
symmetrically with respect to the tail 34. As another alternative, multiple
openings may be provided in each head 32 and in the portion of the receiver
18 associated with each head 32 such that two or more cables or rods can
simultaneously be terminated with a single second element. See for example
the designs shown in U.S. Patents 5,765,962 and 5,919,065, assigned to the
assignee of the present invention and hereby incorporated by reference.
Sizes, dimensions, proportions and materials can all be adapted as
appropriate for the particular application.
This invention is not restricted to use with extruded components as
shown in the drawings. Other techniques can be used to form the first and
second elements, including the techniques described in U.S. Patent
5,919,065.
As used herein, the term "misaligned" is intended broadly to cover
misalignment in whole or in part. Thus, two openings that are skewed with
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respect to one another by a relatively small angle are still considered
misaligned.
The term "position" is intended to encompass a range of positions.
Thus, the cable clamping position described above can correspond to any one
of a range of positions, depending upon the particular cable being clamped.
The foregoing detailed description has described only a few of the
many forms that the present invention can take. For this reason, this detailed
description is intended by way of illustration and not by way of limitation.
It is
only the following claims, including all equivalents, that are intended to
define
the scope of this invention.
