US3787796A

US3787796A - Low cost sealed connector and method of making same

Info

Publication number: US3787796A
Application number: US00298416A
Authority: US
Inventors: J Barr
Original assignee: Deutsche ITT Industries GmbH
Current assignee: TDK Micronas GmbH; ITT Inc
Priority date: 1972-10-17
Filing date: 1972-10-17
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22

Abstract

A low cost sealed electrical connector and method of making the same in which a conductor terminating in an electrical contact is slidably mounted in the rear end of a passage in a connector body and a radially deformable sealing element surrounding the conductor is forced into the annular space between the conductor and the wall of the passage to provide a seal therebetween. Preferably, the sealing element is attached to the conductorcontact assembly prior to inserting the assembly into the connector body. The invention may be used in any application where it is desired to seal a conductor within a wall or body. A special form of a sealing element is disclosed which assures a moisture-tight seal between the conductor and the body in which it is mounted.

Description

United States Patent 1191 Barr [ LOW COST SEALED CONNECTOR AND METHOD OF MAKING SAME [75] Inventor: John E. Barr, Brea, Califv [73] Assignee: International Telephone and Telegraph Corporation, New York, NY.

22 Filed: Oct. 17, 1972 21 Appl. No.: 298,416

[ 51 Jan. 22, 1974 24,441 12/1914 Great Britain 339/103 R Primary ExaminerJoseph H. McGlynn Attorney, Agent, or Firm-Thomas L. Peterson [57] ABSTRACT A low cost sealed electrical connector and method of making the same in which a conductor terminating in an electrical contact is slidably mounted in the rear end of a passage in a connector body and a radially deformable sealing element surrounding the conductor is forced into the annular space between the conductor and the wall of the passage to provide a seal therebetween. Preferably, the sealing element is attached to the conductor-contact assembly prior to inserting the assembly into the connector body. The invention may be used in any application where it is desired to seal a conductor within a wall or body. A special form of a sealing element is disclosed which assures a moisture-tight seal between the conductor and the body in which it is mounted.

12 Claims, 6 Drawing Figures LOW COST SEALED CONNECTOR AND METHOD OF MAKING SAME BACKGROUND OF THE INVENTION This invention relates to method and means for providing a low cost seal between a conductor and a body in which the conductor is mounted and, more specifically, to a low cost seal for an electrical connector.

DESCRIPTION OF THE PRIOR ART There are generally two different types of electrical connectors, namely, sealed and unsealed. The term, sealed, as used herein refers to the ability of a connector, that is, the mated plug and receptacle members, to prevent the intrusion of moisture or other contaminants into the area of the connector containing the electrical contacts.

There are presently available a number of electrical connectors which are of the sealed type. However, methods to achieve scaling in these connectors are expensive and have functional limitations which render the connectors unacceptable for some applications. In one form of such a sealed electrical connector, an elastomeric sealing member is faced on each end of the respective parts of the connector. The central sealing member is referred to in the art as an interfacial seal. To function, this seal must be held in a compressed condition against the mating surfaces of the connector parts. This requires some form of positive coupling or latching between such parts. Loss of this pressure between the parts will allow moisture entry into the connector. In another form of a sealed connector, the entire body of the connector is formed of elastomeric material. The central seal is provided in this type of connector by a deformable lip on either the plug or receptacle member of the connector.

The rear seal in each of these connectors is provided by a radially inwardly directed deformable lip adjacent the rear end of the passages in the connector. After a contact is mounted in a'passage, the lip will form a seal around the insulation coating on the conductor connected thereto. This arrangement has the disadvantage that when the contact is inserted into the connector body through the rear sealing member portion of the body, sharp edges on the contact sometimes scar the sealing rib thereby preventing a complete seal from being formed.

SUMMARY OF THE INVENTION It is the principal object of the present invention to provide an improved method of providing a seal between a conductor and a body in which the conductor is mounted.

Another object of the invention is to provide an improved conductor-contact assembly which may be inserted through the rear of a connector body and sealed thereto without damage occurring to the seal.

According to the principal aspect of the present invention, there is provided a method of mounting a conductor in a passage of a connector body in sealing relationship therewith. Initially, there is provided a conductor terminating in electrical contact having a maximum cross section less than that of the rear of the connector body passage. The conductor is inserted into the rear of the passage until the contact reaches the forward end thereof. A radially deformable hollow sealing element which surrounds the conductor is then forced into the annular space between the conductor and the wall of the passage to provide a seal therebetween. Preferably, the sealing element is attached either to the connector body or the conductor-contact assembly prior to inserting the assembly into the connector body. In the preferred embodiment, the sealing element is carried by the conductor-contact assembly by means of a forwardly extending tongue on the sealing element which is held between the crimp barrel of the contact and the conductor insulator cover.

According to another aspect of the invention, there is provided an improved sealing element comprising a collet which is formed with a longitudinally extending slot through one wall thereof defining therebetween opposed wall faces. A radially extending deformable rib is formed on one of the faces between the ends of the collet. When the sealing member is forced into the annular space between the conductor and the wall of the passage in the connector body receiving the contact, the collet will contract and the rib will deform providing a seal between the faces of the slot. The rib will also expand radially providing pressure for a seal against the conductor insulator and the wall of the passage in the connector body.

Other aspects and advantages of the invention will become more readily appreciated by reference to the following detailed description when considered in connection with the accompanying drawing in which like reference numerals designate like or corresponding parts throughout the various views.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a partial longitudinal sectional view through mated receptacle and plug members of a connector embodying the features of the present invention;

FIG. 2 is a side elevation of one end of a conductorcontact assembly which is utilized in making the connector illustrated in FIG. 1.

FIG. 3 is an enlarged perspective view of the preferred sealing element utilized in the present invention;

FIG. 4 is a longitudinal sectional view taken along line 44 of FIG. 3;

FIG. 5 is a sectional view similar to FIG. 4 showing a modified form of the sealing element of the invention; and

FIG. 6 is a partial sectional view of another embodiment of the invention in which an insulated conductor is sealed within a wall.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference is now made to the drawings in detail, particularly FIG. 14, which illustrate the preferred form of the invention as it is applied to an electrical connector, generally indicated 10. The connector comprises mated receptacle and

plug members

12 and 14, respectively. The plug member 14 is formed with a pair of cylindrical forwardly extending projections 16 which are slidably received in mating recesses 18 formed in the receptacle 12. The bodies of the plug and receptacle are formed of a suitable insulating material, such as a thermoplastic. Although two projections 16 and recesses 18 are shown, it will be apparent that any number may be provided depending upon the particular application of the connector.

Sealing ribs 20 are formed on each of the projections 16 of the plug member 14. Although two ribs are shown on each projection, any number of ribs may be provided. These ribs are dimensioned so that they have an interference fit with the walls of the recesses 18 so that an effective moisture-proof seal is formed at the forward ends of the plug and receptacle members of the connector when the two parts are mated together as illustrated in FIG. 1.

The ribs 20 provide a central seal between the plug and receptacle members of the connector which is high efficient and inexpensive. The seal is particularly advantageous in that it is not sensitive to the axial position of the plug member within the receptacle member. An interfacial seal as utilized in prior art connectors canot allow for any axial displacement between the connector parts and still provide an effective moisture barrier as in the present invention.

The plug member 14 of the connector is provided with a pair of longitudinally extending passages 22, each of which is coaxial with a respective one of the projections 16. The passages extend from the forward end 24 of the projections to the rear end 26 of the plug body. The receptacle connector 12 is likewise formed with a pair of longitudinally extending passages 28 which pass through the receptacle body and are aligned with the passages 22.

Female contact elements 30 are mounted in the projections 16 of the plug. Male contact elements 32 which are mounted in the passages 28 in the receptacle connector member extend into the recesses 18 for sliding engagement into the female contact elements 30 when the connector members are mated. The manner in which the

contact elements

30 and 32 are connected to their respective conductors and the the manner in which the conductors are sealed within their respective connector members are identical. Thus, for the purpose of this description, only the mounting of the female contact elements 30 to their conductors and the sealing of such conductors in the plug connecter member will be described.

Each passage 22 includes a forward end 34 and a rear end 36 which are separated by an inwardly extending flange 38 which defines a restricted bore interconnecting the ends 34 and 36 of the passage. The contact 30 embodies at its rear end a barrel 40 which is crimped upon the insulation cover 42 of an insulated electrical conductor, generally indicated 44. The insulation cover 42 encloses a plurality of wires 46 which are attached to the contact by crimping intermediate section 48 thereof. Forward of the crimped section 48 is an outwardly extending flange 50 on the contact 30 which abuts against a rearwardly facing shoulder 52 formed bythe flange 38. The contact is formed with a pair of spring tines 54 the rear ends of which engage a forwardly facing shoulder 56 provided by the flange 38. The tines 54 and flange 50 of the contact cooperate with the shoulders provided by flange 38 of the plug body to retain the contact in the body. A sealing element or collet 60 positioned in the rear end 36 of passage 22 serves to seal the insulated conductor 44 in the rear of the plug body.

As best seen in FIG. 3, the collet 60 comprises a generally cylindrical body which is formed with a longitudinally extending slot 62 which passes through one wall thereof to provide opposed faces 64 and 66. The rear of the collet is formed with a radially outwardly extending flange 68 while the forward end of the collet is chamfered to provide a frusto-conical lead surface 70 which facilitates insertion of the collet into the passage 22. As best seen in FIG. 4, the interior wall of the collet includes a flared forward portion 72 and flared rear portion 74, said portions joining intermediate the forward and

rear ends

76 and 78, respectively, of the collect to provide an inner reduced diameter section 80. Alternatively, as seen in FIG. 5, the passage extending through the collet 60 may be cylindrical in configuration, and the reduced diameter portion may be in the form of a radially inwardly extending rib as seen.

A generally radially extending rib 82 is formed on the face 64 of the collet 60 generally intermediate the

ends

76 and 78 thereof, that is, adjacent the section 80 of the collet. More than one rib 82 may be provided if desired. The collet is preferably formed of a thermoplastic material so that the rib 82 is deformable.

The collet is also formed with a forwardly extending integral, flexible tongue 84. The purpose of the tongue 84 can be best seen with reference to the conductorcontact assembly, generally designated 86, illustrated in FIG. 2. In this assembly, the tongue 84 is held between the crimp barrel 40 of the contact and the insulation cover 42 of the conductor 44. The assembly 86 is formed by first inserting the collet 60 on the insulated conductor 44 which is stripped of its insulation cover at its forward end to expose the wires '46. Thereafter, the contact is positioned on the conductor 44 with crimp barrel 40 surrounding the end of the insulation cover 42 and the tongue 84 of the collet 60 positioned therebetween. The intermediate section 48 of the contact and the barrel 40 are then crimped to secure the contact to the wires 46 and the insulation cover 42, respectively, thus causing the tongue 84 to be tightly gripped between the barrel and the insulation cover.

At this point, it should be noted that several important dimensional relationships are required between the contact 30, collet 60, and the passage 22 extending through plug connector member 14. First, the maximum cross-section of the contact 30 is less than the cross-section of the rear end 36 of passage 22 so that the contact may be slidably inserted into the passage without scarring the surface of the passage. The diameter of the rear end 36 of passage 22 is also such that when the collet 50 is forced into the passage around the insulated conductor 44, the collet will contract or radially deform to such an extent that the rib 82 on the collet will engage face 66 thereon and will deform to effect a moisture-tight seal between the opposed faces 64 and 66. Of course, the forward end 76 of the collet must have sufficiently small diameter to allow such end to enter into the annular space between the conductor 44 and wall of the passage 22. In addition, the diameter of the central reduce section 80 of the collet is slightly greater than the outer diameter of the insulated conductor 44, yet sufficiently small so that when the collet is forced into the passage 22, the section 80 thereof will squeeze the insulator coating 42 as indicated at 90 in FIG. 1.

In mounting the conductor-contact assembly 86 into the plug connector member 14, the contact 30 is introduced into the rear end 36 of passage 22 and is moved forwardly until the tines 54 engage the shoulder 52 on flange 38. Further forward movement of the contact will cause the tines 54 to contract until they pass beyond the flange 38 and reach the position illustrated in FIG. 1 where the tines spring outwardly and engage the shoulder 56 on the flange 38, thus locking the contact in the plug body. During such forward movement of the contact 30 in the plug body, the frusto-conical lead surface 70 of the collet 60 enters the rear end 36 of pas sage 22. After the contact 30 is properly positioned in the plug body, a suitable tool, not shown, is positioned behind the collet 60 and moved forwardlyto force the collet into the passage 22 until the flange 68 engages the rear surface 26 of the plug body. This movement of the collet relative to the contact 30 causes the tongue 84 to fold or crimp as seen in FIG. 1. Forcing the collet into the passage causes the collet to radially contract, thus squeezing the insulated cover 42 on the conductor 44 at the point 90 which is a localized area of high pressure loading thereby effecting moisture-tight seal therebetween. The slot 62 in the collet is simultaneously sealed by deformation of the rib 82 located at the point of maximum compression of the collet. The rib 82 also deforms radially providing pressure for a seal at the inside diameter of the collet against the insulation cover 42 of the conductor and on the outside diameter of the collet at the wall of the passage 36. Thus, it is seen that the collet 60 provides a moisture-tight seal between the conductor 44 and the wall of passage 36 of the plug body. In addition to performing a moisture-seal function, the collet also provides two other benefits. First, the collet provides a wire strain relief to assist in retaining the contact 30 in the plug body and reduces or eliminates wire mechanical loads at the contact retention area, namely, at

points

40 and 48. Second, the proximity of the seal to the contact in the plug gives a second point of support for the contact and assists in positioning and stabilizing this member in the plug.

While the collet has been shown as being a split cylindrical body, the present invention can also be practiced by employing simply a continuous cylindrical collet, that is, one without the slot 62. In this case, the collet must be formed of a sufficiently deformable material so that when the collet is forced into the annular space between the conductor 44 and the wall of passage 36, it will contract to provide a moisture-tight seal therebetween. Such a collet could be frictionally retained on the conductor 44 prior to inserting the conductorcontact assembly in the plug body, thus eliminating the tongue 84. Moreover, both the split and continuous collets may be retained upon the plug body 14 by a suitable plastic strip (not shown) rather than upon the conductor 44 as seen in FIG. 2 prior to inserting the conductor-contact assembly into the passage 22. However, the attaching of the collet 60 on the conductor 44 is most practical when the contact 30 is of the crimptype, as shown. The mounting of the collet on the conductor is significant in mass production as the contact and collet can be attached to the wires of the conductor 44 in a single operation. The collet also becomes permanently attached to the conductor and, thus, does not require special handling when it is desired to form the seal between the conductor and the plug body. Moreover, this arrangement permits the installation of the conductor-contact assembly 86 into the passage 36 of the plug body in one operation. However, the advantages of providing a good seal can still be obtained in accordance with the present invention by simply utilizing the collet 60 disconnected from the assembly 86.

In addition, the collet 60 of the present invention may be utilized for sealing conductors in other than electrical connector assemblies. For example, as seen in FIG. 6, the collet may be utilized to seal a conductor or cable 94 in a wall 96.

Although I have herein shown and described my invention in what I have conceived to be the most practical preferred embodiments, it is recognized that departures may be made therefrom within the scope of my invention which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent structures and methods.

I claim:

1. An electrical contact assembly for mounting in an electrical connector insulator comprising:

a conductor having an insulation cover thereon except for an end portion thereof:

a contact member secured to said end portion;

a sealing element surrounding said conductor adjacent to said contact member;

said sealing element formed with an elongated, forwardly extending flexible tongue thereon;

said contact member embodying a barrel crimped to said insulation cover adjacent to said end portion of said conductor; and

the forward end of said tongue only being held between said barrel and said insulation cover.

2. An electrical contact assembly for mounting in an electrical connector insulator comprising:

a conductor having an insulation cover thereon except for an end portion thereof;

a contact member secured to said end portion;

a sealing element surrounding said conductor adjacent to said contact member and being retained on said conductor;

said sealing element comprising a hollow body formed with a longitudinally extending slot through the wall thereof defining opposed faces; and

a generally radially extending deformable rib formed on one of said faces.

3. An assembly as set forth in claim 2 wherein:

a portion of the interior wall of said hollow body between the ends of said body has a cross-section less than that at said ends.

4. An assembly as set forth in claim 3 wherein: said sealing element is formed of a plastic material.

5. An electrical contact assembly for mounting in an electrical connector insulator comprising:

a contact member secured to said end portion;

said sealing element comprising a generally cylindrical body formed of a plastic material, said body being formed with a longitudinally extending slot through the wall thereof defining opposed faces;

a generally radially extending integral rib formed on one of said faces;

a portion of the interior wall of said body between the ends thereof having a cross-section less than that at said ends;

an integral forwardly extending tongue on said body;

said contact member embodying a barrel crimpedto a section of said insulated conductor; and

said tongue being held between said barrel and said section.

6. A seal assembly comprising:

a base member having a passage therethrough;

an insulated conductor extending through said passage;

a sealing element surrounding said conductor in sealing relation therewith, the outer surface of said element being in sealing engagement with the wall of said passage;

a generally radially extending deformable rib formed on one of said faces.

7. An assembly as set forth in claim 6 wherein:

8. An assembly as set forth in claim 6 wherein:

said base member comprises an electrical connector insulator embodying said passage; and

said conductor having an electrical contact mounted thereon, said contact being retained in said passage.

9. An assembly as set forth in claim 8 wherein:

said passage is elongated;

said sealing element is mounted in one end of said passage; and

the cross-section of said one end of said passage is greater than the maximum cross-section of said contact.

10. An electrical connector comprising:

mating plug and receptacle connector members each formed with a longitudinally extending passage having a contact mounted in the forward end of said passage;

said plug connector member embodying a forwardly extending projection slidably received in a mating recess in said receptable connector member, said projection being formed with a sealing rib extending about its outer surface and having an interference fit with the wall of said recess;

a conductor extending into each passage and being connected to the respective contact therein;

a separate sealing element surrounding each said conductor adjacent the rear end of said passage, said sealing element being in sealing engagement connector insulator member formed with a passage having a forward end and rear end comprising the steps of:

providing a conductor member terminating with an electrical contact having a cross-section less than that of said rear end of said passage, said conductor member being encircled by a radially deformable hollow sealing element having a forwardly extenidng, elongated flexible tongue thereon secured at its forward end only to said conductor member;

sliding said conductor member through said rear end of said passage until said contact reaches the forward end thereof; and

thereafter forcing said sealing element into the annular space between said conductor member and said rear end of said passage causing said tongue to fold and providing a seal between said conductor member and the wall of said passage.

Claims

1. An electrical contact assembly for mounting in an electrical connector insulator comprising: a conductor having an insulation cover thereon except for an end portion thereof: a contact member secured to said end portion; a sealing element surrounding said conductor adjacent to said contact member; said sealing element formed with an elongated, forwardly extending flexible tongue thereon; said contact member embodying a barrel crimped to said insulation cover adjacent to said end portion of said conductor; and the forward end of said tongue only being held between said barrel and said insulation cover.

2. An electrical contact assembly for mounting in an electrical connector insulator comprising: a conductor having an insulation cover thereon except for an end portion thereof; a contact member secured to said end portion; a sealing element surrounding said conductor adjacent to said contact member and being retained on said conductor; said sealing element comprising a hollow body formed with a longitudinally extending slot through the wall thereof defining opposed faces; and a generally radially extending deformable rib formed on one of said faces.

3. An assembly as set forth in claim 2 wherein: a portion of the interior wall of said hollow body between the ends of said body has a cross-section less than that at said ends.

5. An electrical contact assembly for mounting in an electrical connector insulator comprising: a conductor having an insulation cover thereon except for an end portion thereof; a contact member secured to said end portion; a sealing element surrounding said conductor adjacent to said contact member and being retained on said conductor; said sealing element comprising a generally cylindrical body formed of a plastic material, said body being formed with a longitudinally extending slot through the wall thereof defining opposed faces; a generally radially extending integral rib formed on one of said faces; a portion of the interior wall of said body between the ends thereof having a cross-section less than that at said ends; an integral forwardly extending tongue on said body; said contact member embodying a barrel crimped to a section of said insulated conductor; and said tongue being held between said barrel and said section.

6. A seal assembly comprising: a base member having a passage therethrough; an insulated conductor extending through said passage; a sealing element surrounding said conductor in sealing relation therewith, the outer surface of said element being in sealing engagement with the wall of said passage; said sealing element comprising a hollow body formed with a longitudinally extending slot through the wall thereof defining opposed faces; and a generally radially extending deformable rib formed on one of said faces.

7. An assembly as set forth in claim 6 wherein: a portion of the interior wall of said hollow body between the ends of said body has a cross-section less than that at said ends.

8. An assembly as set forth in claim 6 wherein: said base member comprises an electrical connector insulator embodying said passage; and said conductor having an electrical contact mounted thereon, said contact being retained in said passage.

9. An assembly as set forth in claim 8 wherein: said passage is elongated; said sealing element is mounted in one end of said passage; and the cross-section of said one end of said passage is greater than the maximum cross-section of said contact.

10. An electrical connector comprising: mating plug and receptacle connector members each formed with a longitudinally extending passage having a contact mounted in the forward end of said passage; said plug connector member embodying a forwardly extending projection slidably received in a mating recess in said receptable connector member, said projection being formed with a sealing rib extending about its outer surface and having an interference fit with the wall of said recess; a conductor extending into each passage and being connected to the respective contact therein; a separate sealing element surrounding each said conductor adjacent the rear end of said passage, said sealing element being in sealing engagement with both said conductor and the wall of said passage; said sealing element comprising a hollow body formed with a longitudinally extending slot through the wall thereof defining opposed faces; and a generally radially extending deformable rib formed on one of said faces.

11. A connector as set forth in claim 10 wherein: a portion of the interior of said hollow body between the ends of said body has a cross-section less than that at said ends.

12. A method of mounting an electrical contact in a connector insulator member formed with a passage having a forward end and rear end comprising the steps of: providing a conductor member terminAting with an electrical contact having a cross-section less than that of said rear end of said passage, said conductor member being encircled by a radially deformable hollow sealing element having a forwardly extenidng, elongated flexible tongue thereon secured at its forward end only to said conductor member; sliding said conductor member through said rear end of said passage until said contact reaches the forward end thereof; and thereafter forcing said sealing element into the annular space between said conductor member and said rear end of said passage causing said tongue to fold and providing a seal between said conductor member and the wall of said passage.