Note: Descriptions are shown in the official language in which they were submitted.
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INSULATED WATER-TIGHT CONNECTOR ASSEMBLY
INCLUDING A SET SCREW DRIVER AND PLUG
[00011
FIELD OF THE INVENTION:
[0002] The present invention is directed to a submersible set screw electrical
connector.
More particularly, the present invention relates to a connector employing an
insulated and water-
tight set-screw driver.
BACKGROUND OF THE INVENTION:
[0003] Set screw electrical connectors are commonly used to connect or splice
distribution cabling to a bus bar. Such connectors generally include a
rectangular aluminum or
conductive alloy body having a series of openings therein sized to accommodate
a transformer
stud, prepared cabling and the associated set screws securing the stripped
conductors or the
cables to the connector. These connectors are often found in locations that
are exposed to
moisture or are underground. Thus, the connector should provide for water
tight connection.
[0004] U.S. 5,533,912 discloses a typical design for a set screw electrical
connector that
prevents water from entering therein. This design encapsulates the connector
body with
somewhat flexible water-impervious material. The encapsulation includes a
series of hollow
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sleeves which project from the connector body. Certain of the sleeves are
designed to accept the
cabling therein while others are sized to accommodate the metal set screw.
Once the set screw is
tightened against the stripped wire conductor, a removable plug or cap is then
inserted into this
sleeve to seal the opening. A drawback of this typical design is the
likelihood that one or more
plugs will be lost or not inserted and thus the entire connector will be
compromised. Another
drawback is that when the user tightens the set screw, there is the risk of
electrical shock hazard
because the tool employed by the user is usually metal and such a tool will
readily conduct
electricity directly to the user or to any object coming into contact with the
tool during
installation if the cable is energized.
[00051 U.S. 6,764,354 discloses a variation of the above in that it
incorporates a wholly
plastic set screw having a threaded lower body portion, a round intermediate
body portion and a
hex head. The lower body portion is threaded into the connector to secure the
cabling in place
while the round intermediate body portion forms a seal with the encapsulating
material.
Obviously, one drawback to this design is the great difference in strength
between the metal
threads of the connector and the plastic threads of the set screw. Stripping
of the plastic threads
is likely and thus inadequate compression of the bare conductor will result.
This can cause
arcing within the connector that will lead to failure. Also, by eliminating
the metal set screw,
there is less electrical contact between the bare conductor and the electrical
connector.
SUMMARY OF THE INVENTION:
[0006J It is therefore an aspect of the present invention to provide a set
screw electrical
connector which incorporates a metal set screw while simultaneously
electrically insulating the
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user (and anything else in contact with the user's tool) from this set screw
during insertion and
rotation.
[0007] Another aspect of the present invention is to provide an electrical
connector with
a metal set screw so that greater electrical contact between the connector and
the bare conductor
is possible.
[0008] A further aspect of the present invention is to eliminate the need for
separate
plugs or caps to seal the set screw openings thereby eliminating the chance
that they will be lost
or damaged which would render the connector unsuitable for wet locations.
[0009] A further aspect of the present invention is to provide an electrical
connector
wherein once the set screw is properly tensioned, no further operation is
needed to also make the
connector watertight.
[0010] The present invention provides a set screw electrical connector
assembly
including an electrical connector housing having at least one set screw portal
which is sized to
accept the set screw therein. A set screw drive plug is formed of electrically
insulated material
and is configured to engage and drive the set screw into the connector.
[0011] In a preferred embodiment of the present invention, the set screw is
formed of
metal and the electrical connector includes a waterproof sleeve which
encircles the set screw
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portal and extends outwardly away from the connector. The set screw drive plug
forms a seal
with the waterproof sleeve.
[0012] In a method aspect of the present invention, a method of sealing a set
screw
within a set screw connector is provided. The method includes partially
threading a set screw
within a set screw portal of the set screw connector and thereafter fully
driving the set screw into
the set screw connector via a set screw drive plug which is electrically
insulated.
[0012.1] In accordance with another aspect of the present invention there is
provided a
method of sealing a metal set screw within a set screw electrical connector
comprising the steps
of: providing an electrical connector having a waterproof sleeve encircling a
set screw portal
extending outwardly from the connector; partially threading an electrically
conductive set screw
within the set screw portal; positioning an electrically insulative set screw
drive plug in the
portal; driving the set screw drive plug into the set screw to drive the set
screw into the
connector; and forming a seal between the set screw drive plug and the sleeve
as the set screw
drive plug drives the set screw into the electrical connector.
BRIEF DESCRIPTION OF THE DRAWINGS:
[0013] Figure 1 is an exploded plan view, partially in section, of the
connector assembly
of the present invention in its unassembled state.
[0014] Figure 2 is a plan view, partially in section, of the connector
assembly of Figure 1.
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[0015] Figures 3-5, are respectively, top, side, and bottom views of the set
screw driver
used in the connector assembly of Figure 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT:
[0016] An electrical connector assembly 1 of the present invention is shown.
Referring
to Figures 1 and 2, electrical connector 10 is shown encased within waterproof
housing 12. Both
connector 10 and housing 12 are of typical material and construction.
Connector 10 may be an
electrically conductive single bar or may be formed of multiple parallel (and
electrically inter-
connected) conductive bars for even more connection options. Housing 12 is an
electrically
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insulative plastic member which may be applied about connector 10 is via
molding. However,
other methods of application are also suitable. As shown in Figures 1 and 2,
the housing 12
covers the connector 10 and additionally forms extending sleeves 18 and 40
which will be
described in further detail hereinbelow.
[0017] During assembly of connector 10, a cable 14 is prepared by stripping or
baring an
end portion of the insulation 15 to expose conductor 16. This prepared cable
14 is then inserted
into a cable sleeve 18 formed by housing 12 and through cable aperture 19
until bare conductor
16 is fully within connector area 20. In this embodiment, to prevent water
from likewise
entering, sleeve 18 is shown as being configured with one or more internal
ribs 22 that engage
and seal around the outside of cable insulation 15. Such ribs 22 are optional
as other means of
preventing water entry are also feasible. Depending upon the degree to which
these ribs 22
extend inwardly within sleeve 18, different sizes of cable 14 can be
accommodated within a
single connector 10.
[0018] Set screw porta124 of connector 10 also opens into connector area 20
with this
portal 24 being threaded so as to accommodate like-threaded set screw 26. Set
screw 26 is
preferably metal so that it can establish electrical contact with bare
conductor 16. Set screw 26
also presses bare conductor 16 against opposite wall 28 of connector 10 for
enhanced electrical
connection.
[0019] Set screw 26 is of typical construction having a female hex drive slot
30 so that a
typical hex tool can be used to tighten set screw 26 against bare conductor 16
within connector
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10. Of course, other configurations of set screw 26/drive slot 30 may also be
employed. The
hex configuration is shown herein as currently the industry typically employs
hex drive slots.
[0020] While the drawings only show one cable aperture 19 and one set screw
portal 24
in connector 10, in practice there would be multiple such openings spaced
along all or a portion
of the length of connector 10. Similarly, insulative housing 12 may be formed
to provide
extending sleeves for each connector aperture and portal so that a multitude
of cable connections
can be made using a single connector assembly 1.
[0021] The present invention employs an insulated drive plug 32 to drive set
screw 26.
Drive plug 32 is typically made of plastic material, but any other
electrically insulating material
such as rubber, for example, so long as it is stiff or hard enough to rotate
set screw 26 under
pressure without significant deformation. Plug 32 may also be made of multiple
materials if so
desired with one material being used for hex drive 34 while another, for
example, is employed in
head region 36. The use of an insulative plug 32 is advantageous in that there
is no electrically
conductive path between bare conductor 16 and the tool employed by the user.
Thus, even in the
situation where a metal set screw 26 is employed within connector 10,
electrical isolation to the
user is provided.
[0022] Drive plug 32 can be a separate component from set screw 26 or the two
may be
permanently attached or secured together such as by an adhesive.
Alternatively, it is also
possible to form or mold drive plug 32 to or with set screw 26.
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[0023] Drive plug 32 would also typically incorporate female hex opening 38
therein but
other configurations are also likely. For example, drive plug 32 and more
particularly head
region 36 could be configured with a male driver such as a hex nut. The user
would simply use a
tool to engage drive plug 32 so as to rotate it and thus push or bias set
screw 26 against bare
conductor 16 within connector 10.
[0024] To make connector 10 watertight, housing 12 would further be configured
with
set screw sleeve 40. This set screw sleeve 40 would typically extend from
connector 10 and
surround set screw porta124. As with cable sleeve 18, the interior of set
screw sleeve 40 could
also be configured with one or more optional ribs 42 that project slightly
inwardly. Optional ribs
42 would be located so as to engage head region 36 of drive plug 32. In this
fashion, by
threading drive plug 32 into connector 10, associated head region 36 would
engage ribs 42 to
thereby form a seal and prevent any moisture from also entering area 20 via
this route. It should
further be noted that a seal could also be formed directly between the smooth
side walls of both
head region 36 and the interior of set screw sleeve 40.
[0025] In operation, a user would insert cable 14 into opening 19 of connector
10 through
sleeve 18 in the normal fashion. The bare conductor 16 would thereby reside in
connector area
20. Drive plug 32, which in most cases would already be partially inserted
within set screw
sleeve 40 (i.e. coming from the manufacturer that way), would then be rotated
by the user who
would most likely employ a standard hex wrench. Under this arrangement, hex
drive 34 of drive
plug 32 would already be in full or partial engagement with hex drive slot 30
of set screw 26.
Continued rotation by the user of the tool will further cause drive plug 32 to
engage bare
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conductor 16 and compress it against opposite wa1128 inside connector area 20
of connector 10.
This places the conductor 16 in secure mechanical and electrical engagement
with connector 10.
Due to the construction of drive plug 32, there is no electrically conductive
path between the user
and bare conductor 16 even if using a metal set screw 26 and a metal tool.
Furthermore, upon
rotating drive plug 32 within set screw sleeve 40, head region 36 would engage
ribs 42 so as to
immediately form a seal between the two thereby preventing moisture from
entering connector
10. Also, there is no need to remove drive plug 32 from connector 10 to
further tighten or
remove set screw 26 as would be the case if connector 10 were sealed by
removable caps or
plugs or the like.
[00261 While select preferred embodiments of this invention have been
illustrated, many
modifications may occur to those skilled in the art and therefore it is to be
understood that these
modifications are incorporated within these embodiments as fully as if they
were fully illustrated
and described herein.
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