CA1124347A

CA1124347A - Connector assembly for electrical conduit

Info

Publication number: CA1124347A
Application number: CA347,512A
Authority: CA
Inventors: Willem F. Bakker; Stanley J. Profiri
Original assignee: Breeze Illinois Inc
Current assignee: Breeze Illinois Inc
Priority date: 1979-05-21
Filing date: 1980-03-12
Publication date: 1982-05-25
Also published as: DE3010987C2; GB2050714A; DE3010987A1; GB2050714B

Abstract

ABSTRACT OF THE DISCLOSURE

The end connector and coupling assembly disclosed herein is for a shielded cable having a flexible conduit, but also is compatible with unshielded cables. An annular connector body houses an insulator holding a plurality of arranged terminal contacts to which the cable conductors are connected.
An annular adaptor fitting surrounds the conductors and has one tubular end sized to telescopically receive and be mechanically secured to the cable conduit, and has an opposite tubular end provided with a conically tapered inner bore face diverging in a direction away from the secured cable. A resilient grommet is fitted over the cable conductors and is within the adaptor fitting bore. A conventional locking nut cooperates with an exterior shoulder on the adaptor fitting in order to draw the adaptor fitting snug against the annular body thereby compressing the grommet between the adaptor fitting, the annular body, the insulator and the conductors. A coupling sleeve can cooperate with an exterior shoulder on the annular body to lock the connector assembly mechanically to another connector or terminal board.

Description

~24~7 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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~ ~ 24347 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 _4 WS/~ln '' '''' ~.2~347 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 ws/~ j`
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~!.24~7 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 ' ~ Z43~7 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 - 8 - ~`

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~L~24~47 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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~L~ Z4347 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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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A connector assembly for a shielded cable having a flexible tubular conduit and a plurality of conductors axially extended within the conduit, the connector assembly including 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, 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 to mechanically secure the telescoped conduit and tubular extension together, said adaptor having 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 having a corresponding plurality of through holes therein each respectively receiving a conductor and a terminal contact end in lapped relationship and said grommet being slightly oversized but disposed in the tapered bore of the adaptor, and means including a locking nut cooperating between the adaptor and said tubular body effective to draw the adaptor snug against said tubular body effec-tive thereby to compress the grommet both radially and axially against and over the lapped junctures between the terminal contact ends and the conductors.

2. A connector assembly according to Claim 1, wherein an insulator holds said terminal contacts in axially extended radially spaced relation within said tubular body, said insulator having a radial face against which the grommet is biased as the locking nut draws the adaptor element and said tubular body together.

3. A connector assembly according to Claim 2, wherein one of the ends of each of said terminal contacts projects away from the insulator radial face and in a direction toward the secured conduit.

4. A connector assembly according to Claim 1, wherein at least a portion of the resilient grommet is generally cylindrical in exterior shape, and wherein the through holes in the grommet are generally parallel to one another and to the longitudinal axis of the cylindrical grommet.

5. A connector assembly according to either of Claims 1, 2 or 3 wherein said adaptor has an intermediate shoulder facing away from the connector body and toward the cable, and said locking nut has an inwardly directed radial lip that butts against the shoulder.

6. A connector according to Claim 4 wherein said adaptor has an intermediate shoulder facing away from the connector body and toward the cable, and said locking nut has an inwardly directed radial lip that butts against the shoulder.