Note: Descriptions are shown in the official language in which they were submitted.
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SEAL FOR A CABLE CONNECTOR
The present invention relates to a seal for a
connector of the type used to connect elongated members,
such as electrical cables to a fixed partition of an
enclosure. More specifically, the invention relates to
a seal for gripping and grounding a cable in a connector
housing.
Seals for connectors of electrical cables are well
known. The seals are used to prevent liquids leaking
through a partition or housing at the point where the
cable passes through, provide grounding and also to make
it difficult to pull the cable out of the connector once
the installation is made. One type of seal commonly used
that prevents the cable from being pulled out of the
connector is one made of substantially firm elastomeric
material. Elastomeric seals, however, have to grip the
cable thus can only be used with a limited range of
cable size since elastomeric material has little compress
sublet. This results in a different size of seal for
each range of cable size for a specific connector. This,
of course, increases inventory costs.
It is a purpose of the present invention to provide
a seal for a cable connector that can be used with a wider
range of cable sizes. Thus the number of seals that have
to be carried in inventory can be reduced. It is another
purpose of the present invention to provide a seal for an
electrical connector that has superior grounding and hold-
in properties for cables.
In accordance with the present invention an
improved seal is provided for sealing a cable in a con-
nectar housing, the seal has a tubular body made from firm elastomeric material, the body having means formed
therein that allows greater compressibility of the seal
than known hereto before.
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The present invention also provides an electrical
cable connector for sealing a cable passing through a
partition which includes a rigid tubular housing having a
seal therein made from a firm elastomeric material. The
seal having a curved lip and means formed therein that
allows greater compressibility of the seal than previously
known such that the curved lip swivels inwards in the
housing to contact and ground a cable therein, and the
body of the seal grips and seals to the outer jacket of
the cable.
The seal body is of a generally tubular shape having
a cylindrical inner surface, a frusto-conical outer surface
extending from a small end having a curved lip at the small
end where the outer surface and inner surface join. A large
end surface is provided on the tubular body at the other end
of the body joining the inner surface and the outer surface.
Recesses are formed in the tubular body between the inner
surface and the outer surface. These recesses permit the
curved lip of the tubular body to have more inward or swivel-
lying movement and also allow the tubular body to be compressed or squeezed thinner than normal to accommodate a wider range
of cable sizes than before.
The present invention provides a seal for sealing a
cable in a connector, the seal having a substantially
tubular body made from resilient elastomeric material, the
body comprising a cylindrical inner surface, a frusto-conical
outer surface extending from a small end having a curved lip
at the small end where the outer surface and the inner
surface join, a large end surface on the tubular body at
the other end of the body joining the inner surface and
the outer surface, and recesses formed in the tubular body
between the inner surface and the outer surface.
The present invention also provides an electrical
cable connector for sealing a cable passing through a
partition, comprising a rigid tubular housing with
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external attachment means for attachment to an aperture
in the partition, the tubular housing having a passage
there through for a cable, and a curved shoulder within
the passage, a substantially tubular seal made from
firm resilient elastomeric material, the seal having a
cylindrical inner surface, a frusto-conical outer surface
extending from a small end, having a curved lip at the
small end where the outer surface and the inner surface
join, a large end surface on the tubular seal at the other
end of the seal joining the inner surface and the outer
surface, and recesses formed in the seal between the inner
surface and the outer surface, the seal fitting within
the housing with the curved lip against the curved shoulder,
and a threaded cover fitted on an external thread on the
housing to push against the large end surface of the seal
so that the curved lip of the seal is compressed and
adapted to contact the cable in the housing.
In other embodiments, grounding fingers may be
fitted over the curved lip of the seal. The fingers are adapted
to contact and ground the cable when the threaded cover is
tightened to the housing. In another embodiment, the seal
is formed of conductive elastomeric material for grounding
purposes.
In drawings which illustrate embodiments of the
invention,
Fig. 1 is a cross-sectional view through one embody
immunity of an electrical cable connector according to the
present invention.
Fig. 2 is a perspective view of a seal for the
connector shown in Fig. 1.
Fig. 3 is a sectional view through the seal shown
in Fig. 2.
Fig. 4 is an end view of the seal shown in Fig. 2.
Fig. 5 is a side view of a grounding finger.
An electrical connector 10 is shown in Fig. 1
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having an electrical cable 11 connected therein. The
connector 10 is shown fitting in an aperture in a
partition wall 12 and is arranged to grip and seal the
partition 12. The connector 10 has a rigid generally
tubular connector body 20 which at one end has an
exterior threaded portion 21 passing through the
aperture in the partition 12. A flange gasket 22 is
positioned adjacent an exterior shoulder 23 of the con-
nectar body 20 so that it is between the shoulder 23 and
the partition wall 12. A lock nut 24 on the exterior
threaded portion 21 grips and seals the connector 10 to
the partition 12. Optionally, a threaded bushing 25
may also be used acting as a second lock nut. Whereas
a lock nut 24 and bushing 25 are shown herein, the
threaded portion 21 may fit directly into a threaded
opening of an enclosure.
The connector 10 has an aperture 30 there through
for the cable 11. The cable 11 has an outer jacket 32
surrounding a metallic Armour 33 for protection purposes,
which in turn surrounds an inner jacket 34 protecting a
plurality of conductor wires 35. The tubular connector
housing 20 has a curved inner surface or curved inner
shoulder 40 within the passage 30 which is used as a stop
for the seal 45. Details of the seal will be described
hereafter. An outside gland nut 46 mates with an external
thread 48 on the outside of the connector body 20 and
pushes the seal 45 against the curved inner shoulder 40
so that the lip of the seal 45 swivels to contact the
Armour 33 of the cable 11, and the body of the seal 45
grips and seals against the outer jacket 32 of the cable
11. A tapered pressure ring 47 may be positioned between
the seal 45 and the gland nut 46.
Details of the seal 45 are illustrated in Figs. 2,
3 and 4. The seal in the form of a bushing is made from
a firm resilient elastomeric material such as a synthetic
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or natural rubber. It has a substantially tubular body
with a cylindrical inner surface 50 and a frusto-conical
outer surface 51 extending from a small end 52 which has
a curved lip 53. The curved lip 53 joins the inner
surface 50 and the outer surface 51 together at the small
end 52. At the other end, which is a large end 55, a
tapered surface 56 extends from the large end 55 and is
designed to mate with the pressure ring 47 or if it is
not used, the gland nut 46.
Apertures 60 are provided in the seal 45 between
the inner surface 50 and the outer surface 51. As shown
in the drawings the apertures 60 are equi-spaced and
extend circumferential about the tubular body from the
curved lip 53. The apertures, which are shown as having
a circular cross section, provide for considerably more
compression of the seal and yet do not break the seal as
they do not extend through the tubular body. The curved
lip 53 is designed to substantially fit the curved inner
shoulder 40 in the connector body 20. When the seal 45
is in place in the connector body 20 and the gland nut
46 is tightened, the curved lip 53 is compressed and
swivels inwards to contact the Armour 33. The apertures
60 are shown as extending axially to the tubular body
of the seal 45, however, as will be understood, the
shape and position of the apertures 60 need not be
restricted to that shown in the drawings but may be formed
in different shapes and even in different directions pro-
voided the curved lip 53 of the seal 45 can swivel to
contact the Armour and -the body of the seal can be come
pressed and deformed to grip and seal different sizes and diameters of cables within the connector.
When the cable 11 has a metallic Armour 33, it is
necessary to ground the Armour 33 and this is done in
two ways. In one embodiment the seal 45 is made of a
conductive elas-tomeric material, thus there is an
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electrical contact between the Armour 33 and the con-
nectar body 20 through the curved lip 53 of the seal
45, creating also a grounding connection to the
partition wall 12. In another embodiment, metallic
grounding fingers 70 as shown in Fig. 5, are fitted
over the curved lip 53 of the seal 45 and these fingers
70 provide a ground connection between the Armour 33
and the connector body 20 of the connector 10. The
grounding fingers 70 also aid in swiveling the curved
lip 53 inwards to contact the Armour 33 or cable 11. As
can be seen in Fig. 3, a ridge 71 and internal circular
groove 72 are included in the inner surface 50 of the
seal and each finger 70 has an abutment 73 at the end
of its straight arm 74 which fits into the groove 72.
Thus the fingers 70 are not pushed out of the seal when
the seal bushing is fitted over the cable 11. The
grounding fingers 70 act to swivel the rest of the lip
inwards at the same time. Three fingers 70 are shown,
however, it will be apparent that more or less could be
used depending upon the diameter and size of the sleeve
45. The ridge 71 guides the Armour 33 and keeps it in
the center of the bushing us well as preventing the Armour
33 from dislodging the fingers 70.
The outer jacket 32 is first stripped off the cable
leaving the Armour 33 exposed as illustrated in Fig. lo
The cable 11 is then inserted through passageway 30 of
the connector, through the seal 45 with the gland nut 46
slackened off. The Armour 33 should not pass right
through the connector 10, and an Armour stop 49 prevents
the Armour 33 from passing completely through the connector.
In other instances, there may not be an Armour stop 49
depending upon the size of cable and size of connector
body for the cable. The gland nut 46 is then tightened
which pushes the seal 45 against the curved shoulder
40, causing the curved lip 52
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to compress and swivel inwards to contact the Armour 33
and the body of the seal 45 to grip and seal. against
the outer jacket 33 of the cable 11. When a small
cable is used, the swivel action of the lip is greater
than when a large cable is fitted in the connector,
however, the apertures 60 provide the flexibility and
compressibility to take into account a wide range of
cable sizes.
While the seal and connector have been described
for use with an electrical cable, it will be apparent
that the connector and seal may also be used with other
types of elongated members such as conduit pipes or
tubes.
Various changes may be made to the embodiments
shown herein without departing from the scope of the
present invention which is limited only by the following
claims.
