GB2204194A

GB2204194A - Sealed electrical connector

Info

Publication number: GB2204194A
Application number: GB08809290A
Authority: GB
Inventors: Robert James Kobler
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1987-04-30
Filing date: 1988-04-20
Publication date: 1988-11-02
Anticipated expiration: 2008-04-20
Also published as: GB8809290D0; FR2614735A1; GB2204194B; FR2614735B1

Abstract

An effective seal is provided for an electrical connector (10) by means of a substantially-rigid molded plastic insert (13) received in the housing (11) for the electrical connector (10). A potting compound (19) is injected, preferably through an opening in the base portion (14) of the insert (13), and into the space between the base portion (14) of the insert and the bottom wall of a casing (24) which supports a plurality of spaced-apart terminals (12) encapsulated by the potting compound (19). An interfacial seal (20) comprising an elastomeric sealing member is disposed flush against the base portion (14) of the insert (13), opposite to the potting compound (19). The insert (13) substantially compensates for any indentations in the potting compound (19) resulting from the curing thereof, and provides an essentially flat support surface for interfacial seal (20) when connector (10) is mated to a complementary connector thus enabling an effective seal to be achieved between the two mated connectors and precludes the build-up of moisture in the indentations. <IMAGE>

Description

SEALED ELECTRICAL CONNECTOR AND METHOD OF ASSEMBLY The present invention relates to a sealing means for an electronic connector, and more particularly, to an improved means for assuring a substantially-flat engagement between a flexible substantially-flat elastomeric sealing member and an epoxy potting compound used for encapsulating the terminals within the connector.

In the prior art relating to an electronic connector, wherein a pluralitytof spaced-apart terminals are disposed within a housing for the connector, it is the conventional practice to encapsulate the terminals with a suitable potting compound, such as an epoxy. After the terminals have been so encapsulated, a substantially-flat elastomeric sealing member (referred to in the art as an "interfacial seal") is disposed against the potting compound. The interfacial seal has a plurality of spaced-apart openings to receive the terminals, respectively.

When When the epoxy potting compound cures, its surface is not completely flat, but rather has a plurality of "dimples" or indentations. When the interfacial seal is disposed against the potting compound, some minute crevices or pockets are formed due to the irregular dimpled surface of the potting compound. As a result, it is difficult to obtain a good effective seal; and moisture can accumulate within the crevices or indentations, thereby leading to undesired corrosion of the terminals within the connector.

Accordingly, it is an object of the present invention to alleviate the disadvantages and deficiencies of the prior art by providing an insert for the potting compound, thereby assuring a substantially-flat effective sealing engagement between the potting compound and the interfacial seal.

It is another object of the present invention to provide an insert within which the potting compound is received and cured, together with a means for injecting the potting compound into the insert.

It is yet another object of the present invention to provide an improved sealing engagement, conveniently, and at relatively low manufacturing cost.

In accordance with the broad teachings of the present invention, there is herein illustrated and described, and for use in an electronic connector including a housing having a plurality of spaced-apart substantially-parallel terminals mounted therein, an insert disposed within the housing. The insert has a base portion provided with a plurality of spaced-apart openings to receive the terminals, respectively. The base portion of the insert has first and second sides, and the insert further has a peripheral skirt portion extending from the first side of the base portion thereof. A potting compound encapsulates the terminals within the skirt portion of the insert and is substantially flush against the first side of the base portion thereof. An interfacial seal has a plurality of spaced-apart openings formed therein for the terminals.

The interfacial seal is disposed substantially flat against the second side of the base portion of the insert.

With this structural arrangement, an effective seal is provided, thereby precluding moisture from accumulating within the potting compound.

In a preferred embodiment, the housing has an internal peripheral rib formed therein, such that the skirt portion of the insert is seated on the peripheral rib in the housing. The base portion of the insert has an opening formed therein, such that the potting compound may be inserted from the second side of the base portion of the insert. The terminals are mounted in a casing having a peripheral flange portion secured to the housing, and this peripheral flange portion covers the insert and the potting compound therein. Preferably, the potting compound comprises an epoxy; and the interfacial seal is substantially flat and flexible and is molded from an elastomeric material.

In accordance with another aspect of the present invention, there is provided the combination of a housing having a plurality of spaced-apart substantially-parallel terminals disposed therein, the terminals being carried by a casing having a flanged bottom wall secured to the housing. An insert is disposed within the housing. The insert has a base portion provided with a plurality of spaced-apart openings to receive the terminals, respectively, and the insert further has a peripheral skirt portion extending from the base portion of the insert to the bottom wall of the casing. A potting compound encapsulates the terminals within the skirt portion of the insert and substantially between the base portion of the insert and the bottom wall of the casing, thereby precluding moisture from accumulating within the potting compound.

In accordance with the further teachings of the present invention, there is herein illustrated and described, an improved method for encapsulating an electrical connector of the type having a housing and further having at least one terminal disposed therein, the terminal being carried by a casing. A substantially-rigid insert is provided, which is made from an electrically insulating material. The insert is seated within the housing, such that the terminal is received through a respective opening formed in the insert; and the casing is secured to the housing. A potting compound is injected into the housing and into the space between the insert and the casing, such that the potting compound encapsulates the terminal. An interfacial seal (preferably constituting an elastomeric sealing member) is provided and is disposed within the housing.The interfacial seal is substantially flush against the insert and on the other side thereof from the potting compound. As a result, an effective seal is provided between the insert and the interfacial seal, thereby compensating for any indentions formed in the potting compound during the curing thereof, and thereby precluding the accumulation of moisture within the indentions.

In accordance with the still further teachings of the present invention, there is herein illustrated and described, an improved method of assembly for an electronic connector. The method includes the step of providing a casing having a plurality of spaced-apart terminals carried thereby, such that the terminals project above and below a bottom wall of the casing. An insert is provided which has a base portion and further has a skirt portion extending upwardly of its base portion. The skirt portion of the insert is secured to the bottom wall of the casing, such that the plurality of terminals projecting below the bottom wall of the casing extend through a corresponding plurality of openings formed in the base portion of the insert. A housing is provided, and the casing is secured to the housing such that the insert is disposed at least partially within the housing.A potting compound is injected into the space between the base portion of the insert and the bottom wall of the casing for encapsulating the terminals. An interfacial seal is provided and is disposed within the housing and substantially flush against the base portion of the insert on the side thereof opposite to the potting compound.

With this method, an effective seal is provided to compensate for any indentations formed in the curing of the potting compound, thereby precluding the accumulation of moisture within the indentations.

Preferably, the insert is secured to the casing by an adhesive which is conductive, such that upon the application of heat thereto, the insert may be removed from the casing, thereby facilitating testing and repair of the connector.

The invention will now be described, by way of example, with reference to the accompanying partly diagrammatic drawings, in which: Figure 1 is an exploded perspective view, showing the insert in relation to the other components in the assembly of the electronic connector, the broken lines indicating the potting compound.

Figure 2 is a longitudinal section of the electronic connector, with certain parts broken away and sectioned.

Figure 3 is a portion of Figure 2, drawn to an enlarged scale, and showing the effective sealing means between the interfacial seal and the base portion of the insert, thereby compensating for any indentations formed in the potting compound during the curing thereof, and thereby assuring a good effective seal to prevent substantial build-up of moisture.

Figures 4-7 illustrate the sequence of assembly of the major components of the electronic connector assembly.

More specifically, Figure 4 illustrates the insert of the present invention being seated within the housing of the connector assembly.

Figure 5 illustrates the plurality of terminals mounted in a casing having a peripheral flange portion, the flange portion of the casing being secured to the housing, and the casing subsequently covering the insert and the potting compound therein.

Figure 6 illustrates the subsequent step of injecting a potting compound through an opening in the base portion of the insert.

Figure 7 illustrates the further subsequent step of mounting the interfacial seal within the housing of the electronic connector, such that the interfacial seal is disposed substantially flat against the base portion of the insert, thereby providing an effective sealto prevent moisture build-up.

Figure 8 is an exploded perspective view of the casing for the terminals, the epoxy potting compound (shown in broken lines), and the insert of the present invention, respectively, the view corresponding substantially to a portion of Figure 1, but showing how the sleeve for the conventional coaxial cable (not shown herein) is formed integrally with the molded insert (rather than the casing for the terminals).

Figure 9 is a further exploded perspective view, corresponding substantially to that of Figures 4 and 5, but showing the insert of the present invention removably secured to the casing for the terminals prior to assembly with the main housing of the connector, thereby facilitating testing and repair.

Figure 10 is a section view, taken along the lines 10-10 of Figure 9 and drawn to an enlarged scale, and showing an adhesive for removably securing the casing for the terminals to the insert of the present invention.

With reference to the drawings, an electronic connector 10 includes a housing 11 having a plurality of spaced-apart substantially-parallel terminals 12 mounted therein.

An insert 13 is disposed within the housing. The insert 13 preferably constitutes a relatively-rigid molded plastic member, and preferably in the form of a small tray as shown more clearly in Figures 1 and 3. The insert 13 includes a base portion 14 having a first side 15 and a second side 16, respectively. The insert 13 further includes a peripheral skirt portion 17 formed integrally with the base portion 14 and extending from the first side 15 thereof. The base portion 14 of the insert 13 has a plurality of openings 18 formed therein to receive the respective terminals 12, as shown more clearly in -Figures 1-3.

A potting compound 19 encapsulates the terminals 12 within the skirt portion 17 of the insert 1 and the potting compound 19 is substantially flush against the first side 15 of the base portion 14 of the insert 13.

The potting compound may be a well-known epoxy material used conventionally for encapsulation of electronic components.

An interfacial seal 20 has a plurality of openings 21 formed therein for receiving the terminals 12. The interfacial seal 20 is preferably a relatively-flexible flat member molded from a suitable elastomeric material; and in the final assembly, the interfacial seal 20 is disposed substantially flush (or flat) against the second side 16 of the base portion 14 of the insert 13.

When the epoxy potting compound 19 cures, it invariably results in a plurality of "dimples", pockets or indentations 22 on the surface thereof, as shown more clearly in Figure 3. Thus, when the interfacial seal 20 is placed against the exposed surface of the cured potting compound 19 (without the benefit of the present invention) an imperfect seal is formed. As a result, moisture may tend to accumulate in the indentations 22 between the potting compound 19 -and the interfacial seal 20, thus possibly contributing ultimately to corrosion of the terminals 12.

However, with the structural arrangement of the present invention, including the insert 13, an excellent seal is provided to preclude the accumulation of moisture within the potting compound 19, thereby precluding the likelihood of corrosion of the terminals 12.

Preferably, the housing 11 has an internal peripheral rib 23 formed therein, as shown more clearly in Figure 4; and the skirt portion 17 of the insert 13 is seated thereon, as shown more clearly in Figures 2 and 3. The base portion 14 of the insert 13 has an opening 30 formed therein, such that the potting compound 19 may be inserted from the second side 16 of the base portion 14of the insert 13 (as hereinafter described with reference to Figure 6). Moreover, the terminals 12 are preferably mounted in a casing 24 having a peripheral flange portion 25 formed integrally therewith. The peripheral flange portion 25 of the casing 24 is secured to the housing 11 by means of a plurality of screws 26. The screws 26 carry locking washers 27 and are received in respective tapped recesses 28 formed in the housing 11.

With reference to Figures 4-7, the sequence of assembly of the electronic connector 10 may be described.

In Figure 4, the insert 13 is positioned within the housing 11, such that the peripheral skirt portion 17 of the insert-13 is received on the peripheral rib 23 formed internally within the housing 11.

Next, and as shown more clearly in Figure 5, the plurality of terminals 12 carried within the casing 24 is received within the housing 11, such that the terminals 12 pass through the respective openings 18 formed in the base portion 14 of the insert 13, and such that the flange 25 on the casing 24 rests upon the housing 11. Thereafter, the flange 25 on the casing 24 is secured to the housing 11 by means of the screws 26 received in the tapped recesses 28 formed in the housing 11.

Thereafter, and as shown more clearly in Figure 6, the epoxy potting compound 19 is injected by means of a nozzle 29. The. nozzle 29 is received through an opening 30 in the base portion 14 of the insert 13, such that the potting compound 19 is received around the terminals 12 and in the space between the bottom wall 31 of the casing 24 and the base portion 14 of the insert 13.

Next, and as shown more clearly in Figure 7, the interfacial seal 20 is received substantially flat against the second side 16 of the base portion 14 of the insert 13 and in a recess 32 formed internally within the housing 11. The terminals 12 project through the openings 21 in the interfacial seal 20, as shown more clearly in Figures 2 and 3, to thereby form the desired effective seal as hereinbefore described.

Alternately, the potting compound could be inserted from the other side of the insert 13, if desired.

Additional epoxy potting compound 33 is injected by a nozzle 29', as shown more clearly in Figure 6, for encapsulating the terminals 12 in the casing 24.

With the benefit of the present invention, an excellent seal is obtained, since the insert substantially compensates for the pockets or indentations 22 resulting from the curing of the potting compound -19, thereby precluding the accumulation of moisture within the electronic connector 10 and the possible corrosion of the terminals 12 resulting therefrom.

With reference again to Figure 1, the casing 24 of the electronic connector 10 includes an integrally formed sleeve 34 which is in substantial alignment with an aperture 35 formed in the insert 13 and with an aperture 36 in the elastomeric seal 20, thereby accommodating an interconnection with the coaxial cable (which, being conventional, has been omitted for ease of illustration).

With reference to Figure 8, an alternate embodiment 13' of the insert is illustrated. The insert 13' has a sleeve 37 formed integrally therewith for accommodating the coaxial cable. The sleeve 37 on the insert 13' would thus be used in lieu of the sleeve 34 on the casing 24 (as shown in Figure 1).

With reference to Figures 9 and 10, a further alternate embodiment of the present invention is illustrated, wherein the insert 13 is removably secured to the casing 24 prior to assembly to the housing 11 of the connector 10. The skirt 17 of the insert 13 is secured to the flange 25 of the casing 24 by an adhesive 38.

Preferably, the adhesive38 is a thermoplastic conductive adhesive which may be softened upon the application of heat thereto, thereby allowing the casing 24 with its terminals 12 to be lifted out of the housing 11 of the connector 10. This arrangement facilitates testing of the terminals 12 in the casing 24 prior to assembly within the housing 11 of the connector 11 (during manufacture thereof) and further facilitates a convenient and economical repair and replacement out in the field.

Obviously, many modifications may be made without departing from the present invention.

Accordingly, it will be appreciated by those skilled in the art that within the scope of the appended claims, the invention may be practiced other than has been specifically described herein.

Claims

CLAIMS:

1. An electrical connector comprising: a housing having a plurality of terminals mounted therein; an insert disposed within the housings the insert having a base portion provided with a plurality of openings to receive the terminals, respectively, the base portion having first and second sidesl the-insert further having a peripheral skirt portion extending from the first side (15) of the base portion . thereof; a potting compound encapsulates the terminals within the skirt portion of the insert and substantially against the first side of the base portion thereof; and an interfacial seal has a plurality of openings formed therein for the terminals, the interfacial seal being disposed substantially flat against the second side of the base portion of the insert1 thereby providing an effective seal when the connector is mated with a complementary connector and to preclude moisture from accumulating within the potting compound, '

2. The electrical connector of claim 1, wherein the housing has an internal peripheral rib formed therein, and wherein the skirt portion of the insert is seated on the peripheral'rib in the housing1

3. The electrical connector of claim 1 or 2, 'wherein the base portion of the insert - has an opening formed therein, whereby the potting compound may be inserted from-the second side (16) of the base portion of the insert.

4. The connector of claim 1, 2 or 3 wherein the terminals are mounted in a casing having a peripheral flange portion secured to the housing1 wherein the casing has a bottom wall covering the insert - and the potting compound therein; and wherein a potting compound is disposed within the casing for encapsulating the terminals therein.

5. The electrical connector of claim 1, 2, 3 or 4 wherein the potting compound comprises an epoxy.

6. The electrical connector of claim 1, 2, 3, 4 or 5 wherein the interfacial seal is substantially '--flat and flexible and is molded from an elastomeric material.

7. The electrical connector of claim 1, 2, 3, 4, 5 or 6 wherein said terminals include filter members (12A) disposed thereon.

8. The method of encapsulating an electrical connector having a housing; wherein the connector includes at least one terminal carried by a casing * the method being characterized by the steps of: providing a substantially-rigid insert made from an electrically insulating material, said insert having a base portion and further having a skirt portion - extending upwardly of its base portion, seating the insert within the housing; receiving the terminal (12) through a respective opening formed in the insert; securing the casing to the housing; injecting a potting compound into the housing (11) and into the space between the insert and the casing (24), such that the potting compound encapsulates the terming providing an interfacial seal; and disposing the interfacial seal within the housing and substantially flush against the insert on the other side thereof from the potting --compoundJ such that the terminal projects through the interfacial. sealg and such that an effective seal is provided between the insert and the interfacial seal thereby compensating for any indentions formed in the potting compound k during the curing thereof, and thereby providing an essentially flat support for the interfacial seal X when the connector (10) is mated to a complementary connector and essentially precluding the accumulation of moisture within the indentations.

9. The method of claim 8 wherein said at least one terminal (12) includes a filter member - disposed thereon.

10. The method of claim 8 or 9 wherein said casing is secured to said housing by a thermoplastic adhesive, such that upon the application of heat thereto, the casing may be removed from the housing, thereby facilitating testing and repair of the connector.

11. An electrical connector substantially as herein described with reference to the accompanying drawings.

12. A method of encapsulating an electrical connector substantially as herein before described with reference to the accompanying drawings.