CA1201186A

CA1201186A - Electrical connector

Info

Publication number: CA1201186A
Application number: CA000424704A
Authority: CA
Inventors: David M. Mccormick; Gerald Nieman
Original assignee: Automation Industries Inc
Current assignee: Automation Industries Inc
Priority date: 1982-03-29
Filing date: 1983-03-28
Publication date: 1986-02-25
Also published as: GB8305437D0; DE8304149U1; GB2117575A; FR2524211A1; DE3305156A1; GB2117575B

Abstract

ABSTRACT OF THE DISCLOSURE
The plug of a plug and receptacle connector has an outer hollow cylindrical coupling ring rotatable with respect to the plug body and includes internal threads that cooperate directly with threads on the plug body outer surface. Rotation of the coupling ring serves to drive the plug and receptacle toward or away from each other depending on the direction of rotation thereby connecting and releasing the connector parts, respectively. Resilient inter-face seals compensate for accumulated tolerances of the assembled connector parts thereby obviating the need for a separate threaded coupling nut prevalent in prior art structure.

Description

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Th0 present invention relates generally to an electrical connector and, more particularly, an improved electrical connector of the type having plug and receptacle parts releasably intermateable to interconnect two electric wirc cables.
An exceptionally well-received electrical connector for both domestic, aerospace and military use, is that set forth in United States Letters Patent 4,066,315. As described in that patent, the electrical cable connector has keyed parts which are lockingly intermated by rotation of a coupling ring, the latter including a separate internal nut that drives the connector parts to-gether or apart, depending upon the direction of rotation. Spring-type devices located between the coupling housing and a connector part serve to provide compensation for accumulated tolerances of the different connector components.
These spring-type devices, however, are sensitive to and adversely affected by forces applied to the cable that tend to pull the connector apart. That is, cable load sufficient to deflect the spring devices will also effect separation of the connector parts at the interface resulting in either undesirable contact movement, reduction or even total loss of compression at the interface seal.
The electrical connector described herein includes plug and receptacle parts respectively interconnected to two sets of cable wires via socket and pin contacts. On mating of the plug and receptacle parts the pin contacts are removably received within socket contacts establishing the desired electrical interconnection between the sets of cable wires.
The plug has an outer hollow cylindrical coupling ring which is rotatable with respect to the plug body and includes internal threads that co-operate with threads on the plug body outer surace. When the plug and re-ceptacle are joined together, rotation of the coupling ring serves to drive the plug and receptacle toward or away from each other depending on the direction of rotation thereby connecting and releasing the connector parts, respectively.
In accordance with a first version of the described invention, the plug and receptacle both include resilient inter-face seals which are of sufficient thickness and softness as to provide satisfactory compensation for the accumulated tolerances of the assembled connector parts. In this manner, the need for the separate threaded coupling nut of the referenced patent is obviated.
As a further aspect, the coupling ring and plug body threads can be so made as to mesh loosely thereby providing additional tolerance compensation.
The invention may be summarized as an electrical connec-tor having plug and receptacle parts releasably mateable for electrically interconnecting pin and soc~et contacts respectively carried by the connector parts, comprising: the plug part inclu~
ding a hollow cylindrical metal coupling means received about a plug shell, said coupling means having threads formed on the inner wall surface which mesh with threads formed on the peripheral surface of the plug shell, the threads on said coupling means and plug shell being dimensioned so as to provide substantial relative movement therebetween along a direction parallel to the cylindrical axis of the coupling means; a first insulative means carried by the receptacle within which one of the contacts is mounted, said first means having a soft resilient interface seal

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facing toward the plug during mating; and a second insulative means carried by the plug shell and within the other contacts are mounted, said second means including a soft resilient interface seal facing the receptacle and abutting against the first insula-tive means interface seal during matina of the receptacle parts;
the relative thicknesses and location of said soft resilient interface seals being such that said seals will be in compression on the connector parts being mated together.
The invention will now be described in greater detail with reference to the accompanying drawings, in which:
Figure 1 is a fragmentary partly sectional view of a prior art conn~ctor;
Figuxe 2 is a side elevational view of a connector of the present invention shown in the released mode;
Figure 3 is a partly sectional elevational view of the electrical connector of Figure 2 shown partially mated; and Figure 4 is a partly sectional elevational view similar to Figure 3 with parts shown fully mated.
With reference now to the drawing and particularly Figure 1, a presently available electrical connector of the general type to which the present invention applies is identified generally as at 10 and is seen to include a plug 11 and receptacle 12 which are intermated to interconnect respective sets of cable wires 13 and 14. The plug 11 includes a cylindrical shell-like coupling ring 15 which is free to rotate about the plug. A nut 16 is loca-ted within the coupling ring 15 and resiliently held therein by a spring t ~ 2a-~L2~

device 17 which enables the nut to be moved along the connector longitudinal axis and at the same time remain unitarily related to the coupling ring. The nut has internal threads 18 which cooperate with a complementary set of threads 19 on the peripheral surface of the plug such that when the outer end of the coupling ring is received onto the receptacle, rotation of the coupling ring causes the plug to move toward or away from the receptacle depending upon the direction of rotation.
The spring device 17, which frequently takes the form of a "wavy"
washer, enables resilient movement or positioning of the nut 16 ~and thus the coupling ring) along the connector axis serving as a compensation for connector part tolerances. In the prior art design the contact system ~i.e., pin and socket contacts) is referred to as "rear release" in that the contacts are inserted and extracted from the rear (i.e., cable wire ends) of the connector.
In such connectors a hard dielectric socket interface is used and this necessi-tates the described two-piece coupling to allow for manufacturing tolerances and provide constant interface sealing.
Turning now to Figure 2, the electrical connector of this invention is seen to include in its major elements a receptacle 20 and plug 21 which are fitted together during the connection mode of the connector for interconnecting sets of cable wires 22 and 23. After the receptacle and plug are initially partially joined, a hollow, cylindrical coupling ring 24 is rotated which in a way that will be described causes the plug to be driven against and onto the receptacle to firmly seat pin contacts within the socket contacts. A plurality of generally rectangular keys 25 are circumferentially arranged about the re-ceptacle shell exterior for fitting receipt within a corresponding arrangement of keyways (not shown) located inside the coupling ring 2~ and plug 21 for

- 3 -insuring proper arrangement and mutual location of the connector contacts with respect to each other. As described to this point the present connector is constructed and operates substantially the same as the connector in the refer-enccd United States patent.
With reference particularly to Pigure 3, the receptacle and plug are shown in initial mating stages with the receptacle 20 received within the plug 21 but with the pin contacts 26 not yet received within the socket contacts 27 to effect electrical contact for the cable wires.
The receptacle 20 is seen to consist generally of a hollow cylindrical metal shell having a bore that passes completely therethrough. An insert as-sembly 28 is located within the receptacle bore and includes a grommet 29, an interface seal 30 and a centrally arranged insert body 31, all of which are integrally related together.
The grommet 29 is a generally cylindrical member having a plurality of openings 32 extending therethrough parallel to the cylindrical axis, which openings in use receive the individual cable wires 22. The grommet is construct-ed of a relatively soft and r0silient material such as rubberJ for ex~mple.
Insert body 31 is generally cylindrical and constructed of a relative-ly hard, rigid and highly insulative plastic. A plurality of openings are provided in the body in alignment with the grommet openings 32, which openings are of such cross-section as to retain the socket contacts 27 received therein.
A circumferential flange 34 abuts against a shoulder in the receptacle inner wall to position the insert body.
The interface seal 30 is cylindrical in shape and so dimensioned as to fit snugly within the receptacle bore. A plurality of openings extend through the seal in alignment with the openings in insert body 31 and also those .~ ~

in the grommet. Preferably, the seal 30 is constructed of a relatively soft and resilient insulative material such as rubber, for example.
In assembly, the grommet 29, insert body 31 and interface seal 30 are suitably arranged as a unit with the openings of each aligned and secured within the receptacle by a snap-ring 35. The socket contacts 27 are inserted into grommet openings 32, then through the insert body openings, and finally the interface seal openings so as to extend outwardly of the seal ou~er face 36.
Removal of the socket contacts can be conveniently achieved by pushing them out at the face 36 using a plunger device.
The receptacle also includes a set of threads 37 on its outer peri-phery for conventional connection to cable shielding means, for example. Still further, a rim or flange 38 is provided for wall mounting, if desired.
The plug 21 is a generally cylindrical, hollow metal shell having a set of relatively large threads 39 formed on an outer margin of the end that faces the receptacle during matingO The coupling ring 24 is an oversi~e cylindrical metal shell received onto the plug and which includes an internal set of threads 40 which mesh with the plug threads 39.
A flange 41 at the outer end of the coupling ring 24 extends radially inwardly a limited amount for releasably engaging the receptacle in a manner to be described. At the opposite end of the coupling ring a snap-ring 42 is located within an internal groove 43 to limit rearward threading of the plug by the couping ring. A detent spring 44 provides audible and tactile means for indicating fully mated condition as more fully described in the referenced United States patent. In addition; the detent spring prevents the coupling ring from inadvertently rotating loose.
The inner diameter of the plug bore at the end carrying threads 39 is ~2~

such as to permit fitting receipt over the open end of the receptacle 20. An internal groove includes an 0-ring 45 for sealing the connector parts against the ingress of dirt, dust and moisture. An annular spring 46 is located just inwardly of the 0-ring 45 within a suitable groove and functions primarily as a common electrical grounding means for the plug and receptacle. As in the case of the receptacle, conventional threads 47 are provided on the plug outer end for engagement with, say, the incoming cable shield.
A soft and resilient grommet 48 of similar construction to the re-ceptacle grommet 29 is provided for the plug. Also, a rigid insulative plastic insert 49 abuts against the grommet 48 and is similar in function and construc-tion to the receptacle insert body 31. Aligned openings in the plug grommet and insert receive the cable wires 23 therethrough. Still further, a flange 50 on the insert 49 engages an internal shoulder of the plug shell to locate the insert.
A soft and resilient interface seal 51 is secured to the exposed face of insert 49 and includes a plurality of openings 52 aligned with the insert openings and passing completely through the seal. These openings 52 are each so dimensioned as to enclose a pin contact 26 which is mounted within an insert opening and extending into the seal opening. Moreover, the cross-sectional dimensions of the openings 52 are sufficient to permit receipt of a socket con-tact 27 therewithin for mating with a pin contact.
The grommet 48, insert 49 and interface seal 51 are unitarily assem-bled and securely located within the plug shell by a snap-ring 53.
In use, the receptacle and plug are initially equipped with pin and socket contacts arranged in the connector parts as shown in Figure 3. As a first step in mating, the receptacle is slid into the open end of the plug and ;~

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coupling ring, some axial orienting of the parts being necessary to align the receptacle keys 25 (Figure 2) with keyways ~not shown) in the coupling ring flange 41 and the plug shell. With the flange 41 located past the keys~ proper rotation of the coupling ring draws the plug and receptacle together causing the socket contacts 27 to enter openings 52 in plug insert 51 (Figure 3).
Further rotation of the coupling ring in the same direction moves the pins into the sockets and when fully mated the faces of the interface seals abut (Figure

4). Rotation of the coupling ring in the opposite direction releases the plug and receptacle.
In the described connector, manufacturing tolerances are compensated for by the resiliency of the connector parts interface seals 30 and 51 when brought into contact with each other. Accordingly, by this means of tolerance compensation it is possible to replace the two-piece coupling ring construction (i.e., coupling shell and separate included nut) of the prior art with the single-piece coupling ring 24 described herein. This results in substantial manufacturing material and labor savings as well as savings in assembly.
For the ensuing description of an alternate aspect of this invention~
reference is now made to Figure 4. The only difference in construction there over the connector as depicted in Figure 3 is in the coupling ring and plug threads 39 and 40~ respectively. That is, in accordance with this aspect the two sets of threads are formed so that a substantial of movement or "play" can be effected between the coupling ring and plug shell along a direction parallel to the connector longi-tudinal axis. In this manner, still further compensation is provided for accumulated manufacturing tolerances of the connector parts.
Mating and unmating is, otherwise, identical to that of the Figure 3 embodiment.
Although in the preferred forms previously described herein, the sock-~2~

et contacts are shown mounted in the receptacle and the pin contacts within the plug, it is considered within the spirit of this invention to reverse the gender of the contacts. Moreover, although it is considered advantageous to completely enclose each pin contact within a cavity in the interface seal, particularly for relatively small size contacts it may be advantageous to have the socket con-tacts embedded or enclosed within an interface seal and the pin contacts ex-posed.

Claims

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

1. An electrical connector having plug and receptacle parts releasably mateable for electrically interconnecting pin and socket contacts respectively carried by the connector parts, comprising:
the plug part including a hollow cylindrical metal coupling means received about a plug shell, said coupling means having threads formed on the inner wall surface which mesh with threads formed on the peripheral surface of the plug shell, the threads on said coupling means and plug shell being dimensioned so as to provide substantial relative movement therebetween along a direction paral-lel to the cylindrical axis of the coupling means; a first insula-tive means carried by the receptacle within which one of the con-tacts is mounted, said first means having a soft resilient inter-face seal facing toward the plug during mating; and a second insulative means carried by the plug shell and within the other contacts are mounted, said second means including a soft resilient interface seal facing the receptacle and abutting against the first insulative means interface seal during mating of the recep-tacle parts; the relative thicknesses and location of said soft resilient interface seals being such that said seals will be in compression on the connector parts being mated together.

2. An electrical connector as in claim 1 in which said first and second insulative means each include a rigid insert, a soft resilient interface seal and a soft resilient grommet all unitarily assembled and having a plurality of openings therethrough for receiving contacts therein.