Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE I~lVENTION
I= electrical wiring apparatus, unshielded cable comprised
of many separate insulated wires or conductors is frequently
utilized. The cable may be covered with a rubber overwrap
~5 or the like, but in general it is unshielded and the wires
or conductors are s~ructurally unprotected against outside
forces or loads, except as mipht be resisted by their own
strength. Consequently, cable damage can occur because of
bending, pulling, compressing or cutting forces applied on
~10 the cable.
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Shielded cable is comprised of a durable but flexible
tubular conduit that covers or houses the interiorly located
wires or conductors. In such instances, the flexible tubular
conduit or shield carries all mechanical forces of bending,
pulling and compressing, and resists cutting forces, so that
the interior wires or conductors are protected. Connectors
are typically provided at the ends of both unshielded cable
and shielded cable for releasably connecting wires or con-
ductors, both electrically and mechanically, to another like
cable or to a terminal board. End couplings are also used
to lock the mated end connectors mechanically to one another.
A typical end connector for an unshielded cable generally
has an annular body formed of metal or highly durable plastic
which houses an array of end terminals or contact pins, one
for each separate wire or conductor, and these end terminals
or contact pins are designed to cooperate in a telescoping
andlor snug facial fit with similarly arranged terminals or
contact pins of a separate mating end connector. The individual
wires or conductors of the cable are secured to the end
terminals or contact pins by soldering, crimping or the like.
Frequently, a compressible rubber grommet surrounds these
joined components for sealing the cable. The grommet is
squeezed securely over such joined components by means of
a nut being drawn snug up on the connector body against a
tapered plastic compression ring surrounding the grommet.
One form of coupling commonly used to lock the connector
body mechanically to a separate end connector or terminal
board takes the form of an annular sleeve fitted over the
connector body and rotatable thereon, where cooperating
shoulders limit axlal separation of the components. The
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sleeve has mechanical means, such as bayonet locking elements,
threads or the like, which mechanically lock onto a cooperating
coupling sleeve on the mated end connector or terminal board.
The end connector used with a shielded cable generally
provides a tubular extension which cooperates with the flexible
conduit in a telescoping fashion and allows for a mechanical
connection in the form of a bonding and/or crimping collar
to be made between the telescoped components. However, the
actual coupling or connector fitting used with a shielded
cable is entirely different from and is generally incompatible
with the coupling and connector fittings used with unshielded
cable. Consequently, adaptor fittings are generally piggy-
backed onto the conventional unshielded connector fittings
in order to provide for the interconnection of a shielded
cable, which increases the costs and size of the terminal
connector assembly.
SUMMARY OF THE INVENTION
This invention relates to an improved end connector and
coupling assembly to be used with a shielded cable having a
flexible tubular conduit, the assembly being compatible with
normal connector or coupling fittings used for unshielded cable.
The assembly includes a tubular body and a corresponding
plurality of terminal contacts supported within the tubular
body and having exposed ends designed to be joined to the
respective conductors and an adaptor having one end butted flush
against the tubular body and having an opposite end including a
tubular extension in telescoped cooperation with the conduit.
Means is provided for mechanically securing the telescoped
conduit and the tubular extension together. The adaptor has
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a conically tapered interior bore diverging in size in the
direction away from the secured cable and toward the exposed
ends of the terminal contacts. A flexible grommet is provided
and has a corresponding plurality of through holes each
respectively receiving a conductor and a terminal contact end
in lapped relationship. The grommet is slightly oversized
but disposed in the tapered bore of the adaptor. Means
including a locking nut cooperating between the adaptor and
the tubular body is effective to draw the adaptor snug against
the tubular body and effective thereby to compress the grommet
both radially and axially against and over the lapped junctures
between the terminal contact ends and the conductors.
BRIEF DESCRIPTION OF THE DRAWING
FIGURE 1 is a perspective view of a typical shielded
cable showing a preferred embodiment of the improved connector
and coupling assembly of the present invention secured onto
one end thereof;
FIGURE 2 is a sectional view as seen generally from line
2--2 in Figure l; and
FIGURE 3 is a view similar to Figure 2, except showing
the components in a partly exposed or disassembled manner
for clarity of disclosure.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 illustrates a shielded cable 10 having connected at
its opposite ends (only one end being shown) a connector
and coupling assembly 12 by which the cable 10 may be mechanically
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and electrically connected to a mating terminal board or
like cable (not shown). The cable 10 includes conventional
flexible conduit 14 (Figures 2 and 3) formed for example
by convoluting a single strip or band of durable material
in an overlapping helical fashion to allow for a mechanical
interconnection between adjacent turns 16, although the .
adjacent turns can ride on one another and provide limited
lateral flexing of the conduit. The specific design of the
tubular conduit 16 forms no part of this invention.
Typically provided over the interior conduit 14 is a
braided cover 18 also formed by interlacing in opposite
helical directions a plurality of separate strands of thread
or wire. Again, the particular construction of the braid 18
is not a part of the present invention. An overwrap 20 of an
insulating material such as rubber is applied over the braid
18 and thereby renders the tubular conduit 14 waterproof.
~loused within the conduit 14 are a plurality of separate
axially extended wires or conductors 22, only three being
illustrated and identified with the suffix letters a, b and
c. Again the specific number and type of conductors 22 can
vary and forms no part of this invention. ~owever, the
conductors, by being housed within the conduit 14; are
protected by the conduit against mechanical flexing beyond
a certain limit, and further are protected against transverse.
cutting forces acting on the conduit.
The ends of the conduit 14 and of the conductors 22
cooperate as noted above with the connector and coupling
assembly 12, and the specific manner of cooperation is
generally as follows. The connector and coupling assembly
12 includes a connector 24 which is formed in part by an
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annular adaptor fitting 28 having a tubular end or extension
30. The end 30 is sized slightly larger than the exterior
dimensions of the conduit 12 so it can overlap or telescope
with the conduit. The adaptor fitting 28 further has an in-
terior annular shoulder 32 against which the free end of the
conduit 12 is adapted to abut when the components are tele-
scoped together.
Preferably, the rubber overwrap 20 of the conduit 12
fits over the tubular end 30 of the adaptor fitting 28 when the
conduit is inserted into the fitting end, and mechanical means
are used to secure the telescoped conduit and fittin8 end
together. The connection is achieved by a collar or clamp
34 fitted over the tubular end 30 of the adaptor fitting 28
and crimped or tightened down on the rubber overwrap, which
further might deform the tubular end snuggly against the
conduit 14. Other means of mechanical securement between
the conduit and the adaptor fitting can be used, such as by
bonding with epoxy, soldering or by direct crimping of the
adaptor fitting. The interior conductors 22a, 22b, 22c, etc.
extend past the shoulder 32 (See Figure 2) toward the forward
or opposite end portion of the adaptor fitting 28.
The connector 24 further includes an annular connector
body 40 which has thereon an annular radial shoulder 42 generally
medially of the body, and a series of exterior helical threads
44 formed between the shoulder 42 and the annular end face 45
of the connector body adjacent the adaptor fitting 28. Within
the hollow of the annular connector body 40 is an insulator
46, and a plurality of conductive terminal pins or contacts
48 are arranged and maintained in spaced generally parallel
relationship to one another within appropriate tubular openings
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formed througll the insulator 44. In general, there is provided
a contact pin 48a, 48b, 48c, e~c. for each separate conductor
22a, 22b, 22c, etc. carried within the conduit 10. The end
49a, 49b, 49c, etc. of each contact pin 48 proJects beyond
the radial face 50 of the insulator 46 in the direction
toward the conduit 12.
~ slightly oversized rubber grommet 51 is positioned
within the adaptor fitting 28 and has a plurality of openings
or tubular passages 52a, 52b, 52c, etc. aligned respectively
with the terminals 48. The individual conductors 22 are fed
through the grommet passages 52 and overlap with the ends
49 of the pins 48 and are suitably joined thereto to provide
an electrically continuous connection, as by bonding, soldering,
crimping, compression or the like. The grommet 51 overlies
the junctures of conductors and the ends 49 of the contact
pins 48, holds the conductors 22 in proper orientation
relative to one another and relative to the projected ends
of the pins 48, and further provides snugged overlapping
connections between the individual conductors and the pins.
The adaptor fitting 28 also has an end section 56 located
opposite the conduit from the interior shoulder 32, and further
has therein a bore face that tapers as at 58 in a conical
diverging fashion from the shoulder area 32 in the direction
away from the secured cable to cylindrical interior face 58a,
and across annular shoulder 58b to larger cylindrical face 58c.
The grommet 51 has a cylindrical face 57c, an annular shoulder
57b, and a slightly conically tapered face 57. By slightly
oversizing the grolllmet 51, when the annular end faces 59 and
45 of the respective adaptor fitting 28 and the annular body
40 are abutted against one another, the grommet 51 is compressed
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both axially and radially between the surrounding faces 58,
58a, 58b and 58c of the adaptor fitting, the insulator face
50, and/or inner cylindrical face 45a of the annular body 40,
which there~y causes the grommet to snugly embrace the con-
ductors 22 and the contact pins 48 in a sealed relation.
Further, the end 59 of the adaptor fitting and the end 45
of the annular body abut one another in solid metal-to-metal
contact which provides electron~agnetic shielding of the
conductors or wires even at the interface between these
components.
The connector 24 also includes an annular locking nut
60 which is provided at one end with an inturned annular lip
or flange 62 that butts against a shoulder 64 on the adaptor
fitting 28. The nut 60 is provided with internal threads 66
that cooperate with the external threads 44 formed on the
annular connector body 40. Thus, the locking nut 60 can be
turned down upon suitable engagement of the threads 66 and 44
and be used with the engagement of the lip or flange 62 against
the shoulder 64 to draw the adaptor fitting 28 into firm
metal-to-metal contact at ends 45 and 59. The foregoing
further compresses the grommet 51 in tightly embracing fashion
over the conductors 22a, 22b, and 22c passing therethrough
and the contact pin ends 49 terminating therein.
Also associated with connector and coupling assembly 12
as previously noted is an outer annular coupling sleeve 70
which is designedto fit over the exterior of the connector
body 40 and has an interior shoulder 72 trapped between the
shoulder 42 of the annular body 40 and the annular end face
73 on the locking nut 60. Thus, the coupling sleeve 70 is
axially trapped on the connector body 40 but can rotate ~reely
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relative thereto for providing an exterior connection with
a cooperating coupling or terminal board (not shown~. It is
common, for cx~mple, to have formed on the interior sleeve
face grooves 74 adapted to receive pins (not shown) to provide
separable bayonet connection. However, the specific cooperation
of the coupling sleeves forms no part of the present invention.
The cooperation between the conduit 14 and the connector
24 provides a weather-sealed and electromagnetically shielded
connection, which advantages are achieved by means of a single
locking nut 60 cooperating with the annular connector body 40
and the squeezing in tightly embracing fashion of grommet
51 trapped between the taperçd face 58 of the adaptor fitting
28 and the connector body 40 and the insulator 46. Such
advantages further are accomplished using only conventional
components of a connector for a nonshielded cable, in combination
with the specific adaptor fitting 28 disclosed herein. The
foregoing invention allows for an economical inventorying of
component parts, and eliminates the need for duplication of
parts and/or for increasing the size and cost otherwise
experienced when using a piggy-back type adaptor fitting for
tying nonshielded and shielded cables together. I~oreover,
the foregoing is accomplished without appreciably changing
the specifications and/or operational characteristics of the
connector coupling asse~bly.
Although reference is made to a wire or conductor, and
an electrical wire or conductor is illustrated, it is possible
to use the disclosed inventive concept with only limited
modifications where the conductors are in the form of fiber
rods for transmitting light.
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