US3257636A

US3257636A - Electrical connector contact

Info

Publication number: US3257636A
Application number: US237024A
Authority: US
Inventors: Arden D Van Horssen
Original assignee: United Carr Inc
Current assignee: United Carr Inc
Priority date: 1962-11-13
Filing date: 1962-11-13
Publication date: 1966-06-21
Anticipated expiration: 1983-06-21
Also published as: DE1490071A1; DE1490071B2; GB1047890A

Description

June 21, 1966 A. D. VAN HORSSEN 3,257,636

ELECTRICAL CONNECTOR CONTACT 2 Sheets-Sheet 1 Filed Nov. 13. 1962 n e a RP m. 0 NH W n WW D n e d ml A Attorneys Jum 21, W66 A. D. VAN HORSSEN 3,257,636

ELECTRICAL CONNECTOR CONTACT 2 Sheets-Sheet 2 Filed Nov. 15. 1962 INVENTOR Arden D. Van Horssen Attorneys Ow mm United States Patent 3,257,636 ELECTRICAL CONNECTOR CONTACT Arden D. Van Horssen, Minneapolis, Minn., assignor, by

mesne assignments, to United-Carr Incorporated, Boston, Mass, a corporation of Delaware Filed Nov. 13, 1962, Ser. No. 237,024 8 Claims. (Cl. 339-218) This invention relates to electrical connector contacts and more particularly to a single-piece socket contact assembly and the method of making the same.

A common problem in the electrical connector art is the bonding of contacts to a connector insert whereby a hermetic seal may be maintained from one side of the insert to the other. The insert provides the means for maintaining the contacts in permanent relative positions with respect to the connector shell so that the contacts of the mating connector will properly engage to complete the electrical connections.

Contact metals used which have desirable electrical conductivity characteristics are usually difficult to bond to the insert materials such as glass and the like. A reliable and positive bond is necessary for result-ant hermetic seals. Likewise, metals which glass and similar materials will bond to, have, at times, undesirable electrical conductivity characteristics.

One solution to the problem is to divide the contact element into at least two parts, one of which has the desired electrical conductivity properties and the other which the insert material will easily bond to. One result is a coaxial arrangement where the inner member is the electrical conductor and the outer member or shroud is the part in sealed contact with the insert.

An object of this invention is to provide a unitized electrical contact assembly in which the parts may be effectively bonded together to form a solid hermetically sealed structure which is not susceptible to failure when subjected to critical environmental conditions.

Another object of this invention is to provide a unitized contact construction which may be molded into a glass insert or the like of a connector, whereby a hermetic seal will be maintained from one side of the insert to the other.

A further object is to provide a structure as set forth above which requires a minimum of cost and effort to fabricate.

A still further object is to provide a simple method of fabricating an electrical contact assembly, as set forth above which requires a minimum of skill but results in a maximum of reliability.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views and in which:

FIGURE 1 is a partially cross-sectioned elevational view of a socket contact positioned in a glass insert,

FIGURE 2 is an enlarged full cross sectional end view of the socket contact taken on line 22 of FIG- URE 1,

FIGURE 3 is a side view of the socket contact alone, portions thereof being removed beyond the broken line. This view also shows an initial deposit of solder,

FIGURE 4 is a side view of the socket contact, shown in FIGURE 3, having the deposit of solder sized by a shearing tool,

FIGURE 5 is a side view showing the insertion of the socket contact into the shroud, and

FIGURE 6 is a partial view similar to that of FIG- URE 1 but showing the relation of the elements prior to the soldering operation.

Ice

Referring more particularly now to FIG. 1, the contact 10 has two principal :parts; the shroud or sleeve 11 which is bonded directly to the glass insert 12, and the socket contact 13.

The shroud 11 consists of a metallic tubing 14 which has a closed entry end 15. End 15 is formed by spinning the end material 16 at the socket end 17, to substantially a right angle position as shown. If necessary, the shroud opening 18 may be reamed out to a smooth and axially aligned position at the same time the chamfered entry portion 19 is machined.

The shroud 11 is provided with a crimp ring 20 which is also spun into the circumference of the shroud. The purpose of the crimp ring 20 will be set forth in greater detail subsequently. As seen from FIG. 1, the shroud is interference fitted at the terminal end 21 to the socket contact 13. The interference fit will also be more fully described subsequently.

It is found that a typically desirable metal composition, which may be used for a shroud and which will adhere with a hermetically sealed bond to the glass insert 12, is a nickel alloy having a nickel to iron ratio of substantially 52 percent nickel and 48 percent iron. The ratio may of course be varied to meet the optimum characteristics of adhesion to glass at the interface of surface 22 of the glass and surface 23 of the sleeve 11. The ratio may also dictate the machinability and ease of soldering as well.

With continued reference to FIG. 1, the socket contact 13 is axially positioned within the shroud 11. It is in contact with the inner surface 24 at point 25, where the crimp ring 20 is engaged, and at surface 26 of the socket contact shank 27 at the interference fit with the terminal end 21 of shroud 11.

In the case of the socket contact, a highly electrically conductive material is provided. Such a material which is also easily machined is a beryllium copper alloy.

The socket contact shank 27 has a socket 28 formed at the forward end which is defined by spring tines 29, as may be seen from the cross-sectioned portion in FIG. 1. The tines, upon introduction of a pin contact (not shown) through shroud opening 18, are forced outwardly so that a positive contact between the socket and the pin is continually maintained.

Rearwardly of the contact shank 27 at the wire termi- .nal end 30 is a solder pot 31 which has a suflicient forward diameter to form a shoulder 32. The shoulder 32, as seen, is positioned closely adjacent the terminal end 21 of shroud 11 in an abutting relation. The socket contact configuration is more clearly shown in FIG. 3. Solder pot 31 is adapted to receive a terminal wire in the usual manner.

The contact shank 27 is divided into two portions. The larger rearward port-ion 33 is defined by the surface 26 which engages with the shoud in an interference fit as pointed out above. The smaller forward portion 34, positioned between the socket 23 and rearward portion 33, has an annular groove or solder dam 35 (see FIG. 3). The solder dam has a base surface 36 adjoining the outer circumferential surface of the portion 34 by means of chamfered surfaces 37. The solder dam is initially supplied with solder 38 which subsequently is caused to flow into the void or open space. 39 (see FIG. 6) when heat is applied. The open space is partially defined by the inner circumferential surface 24 of shroud 11 and outer surface 40 of portion 34. The crimp ring 20 and shoulder 41 define the longitudinal limits of the annular open space 39 between the shroud 11 and socket contact 13, and consequently the volume of solder flow. The crimp ring serves in a similar capacity to that of shoulder 41 in that it is a deterrent to further solder flow along the surface 40. Thus solder will not be allowed to flow among the 3 tines 29 thereby limiting their flexibility. The crimp ring 20 also serves as a means for aligning the socket contact as it is being assembled into the shroud 11 and then subsequently assures a small annular clearance between the shroud and socket contact for a capillary solder flow during the soldering operation.

In the process of fabricating a single-piece pin contact, the solder dam 35 of socket contact 13 is first provided with the solder 38 (see FIG. 3) in sufiicient over quantity to insure that the desired amount will remain when it is sized or sheared as shown in FIG. 4. The sizing is accomplished by axially forcing the socket contact into the sizing tool 42 whereby the knife edge 43 will shear off excess diametral solder deposit. When the sizing is finally accomplished, the solder has a size and shape which will allow the socket contact to be easily inserted into the shroud. After the solder is sized, a flux solution is applied and the socket contact is then prepared for insertion into the shroud 11.

The shroud is also prepared previous to its interfitting with the socket contact. As pointed out previously, the shroud 11 is provided with a crimp ring 20 and a closed entry end 15 by spinning the material into the configuration shown in FIGURES 1 and 5. By reducing the outer diameter of the shroud, a partial construction is formed on the inside surface 24. The shroud is then sealed in the glass insert 12 in a manner common to the glass sealing art. After the shroud is tightly bonded to the glass, a surface plate of gold, silver, etc., may be deposited on the shroud if desired. A plate finish of the material mentioned will allow better soldering characteristics between the shroud and socket contact and thus a more perfect solder seal is achieved. Finally, the shroud is swabbed with a flux solution which aids in the solder bonding between the two parts.

As shown in FIG. 5, the socket contact 13 is then axially forced into the shroud through the terminal end 21. The crimp ring will cause a slight resistance to the interfitting of the parts which in turn provides some initial hermetic seal prior to soldering. The interference fit between the larger rearward portion 33 and the terminal end 21 of the shroud as pointed out above, also forms an initial seal between the mating parts. The socket contact 13 may be forced into the shroud by inserting a tool 44 into the solder pot 31 and then providing force in the direction of arrow 45. When the shroud and socket contact are moved into their final position, they will appear as in FIGURES 1 and 6, the solder 38 being in close contact with the inner surface 24 of shroud 11.

Soldering of the two parts together is the final step. This is accomplished by immersing the whole assembly in an oil, or other non-oxidizing media which will provide an even heat while also preventing any plating from blistering or the surface from oxidizing. The oil is held at a temperature which will quickly cause the solder flow, yet will not overheat the solder. To this end it is desirable to use a solder with a melting point below that of the glass insert. It is also desirable that the solder 38 have a melting point well above the melting point of solders which are used for attaching a wire to the terminal end 30 so that the solder seal will not be broken each time a wire is attached to or detached from the solder pot 31. A solder having a solidus temperature of approximately 514 degrees Fahrenheit and a liquidus temperature of approximately 570 degrees Fahrenheit 'has been found to have satisfactory characteristics in this respect. An oil of approximately 560 degrees Fahrenheit is used wherein the contact 10 is submerged for approximately two minutes. The submersion for two minutes is an optimum time during action for an adequate seal to form and according to the size, etc., of a contact, may be varied in duration. The oil bath is preferably held at a temperature slightly below the liquidus temperature of the solder as the solder will be sufliciently liquid to flow into the i open space 39 yet close enough to the solidus temperature to quickly bond the shroud and contact together upon cooling.

During the soldering operation, the solder will flow into the open space 39 by a capillary action. The chamfered surfaces 37 tend to aid in the capillary movement of the solder thus further insuring a complete circumferential solder seal. As the solder flows into the open space 39, a small annular cavity 46 (see FIG. 1) is formed by the absence of solder. This cavity does not affect the seal however, since the spaces 39 are completely sealed.

Although the drawings have shown the shroud crimp ring within the glass insert it is understood that the crimp ring may be located externally of the glass insert as Well without adversely affecting the final assembled connector contact. 1

Thus it has been shown that a hermetically sealed electrical contact can be sealed in glass while at the same time preserving the desirable electrical conductivitycharacteristics which a contact must have.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts Without departing from the scope of this invention.

What I claim is:

' 1. A unitized electrical contact assembly for an electrical connector comprising,

(a) a shroud adapted to be hermetically bonded to a glass insert of an electrical connector,

. (b) said shroud having a terminal end and an entry end,

(c) said shroud also having an annular constricting means intermediate said ends which reduces the inside circumference thereof,

(d) an electrically conductive socket contact having a forward portion positioned within said shroud and in engagement therewith at said annular constricting means as well as said terminal end,

(e) said contact having the portion between the points of engagement with said shroud in an annular spaced clearance therewith, said annular spaced clearance being larger at a locus longitudinally spaced from the ends thereof,

(f) said socket contact forward portion terminating in a socket adapted to receive a mating pin of a mating connector,

(g) said socket contact also terminating rearwardly and externally of said shroud in a wire terminal end adapted to have a wire secured thereto, and

(h) a deposit of solder positioned between said shroud and said socket contact and Within said annular spaced clearance whereby to solder the two together and form a hermetically sealed bond therebetween,

(i) said engagement of said socket contact with said shroud terminal end and said annular constricting means providing restrictions on either side of said deposit of solder to confine the solder How in the longitudinal direction and within said annular spaced clearance during the time of soldering.

2. A unitized electrical contact assembly for an electrical connector comprising,

(a) said shroud having a terminal end and an entry end,

(0) said shroud also having an annular constricting crimp ring positioned intermediate said ends,

(d) an electrically conductive socket contact having a forward portion positioned within said shroud,

(c) said socket contact also being in engagement with said shroud at said crimp ring and said terminal end whereby said contact will be axially positioned within said shroud with an annu ar spaced clearance extending rearwardly of said crimp ring to said engagement with said terminal end,

(g) said socket contact also terminating rearwardly and externally of said shroud in a wire terminal end adapted to have a wire secured thereto,

(h) said socket contact further having a solder dam positioned between the points of engagement of said socket contact and said shroud and within said spaced clearance, and

(i) a deposit of solder positioned between said shroud and said socket contact within said annular spaced clearance and adjacent said solder darn whereby to solder the two together to form a hermetically sealed bond therebetween.

3. A unitized electrical contact assembly for an electrical connector comprising,

(a) a cylindrical shroud adapted to be hermetically bonded to a glass insert of an electrical connector,

(b) said shroud having a rearward terminal end and a forward end,

(c) said shroud also having an annular crimp ring which forms a constriction on the inner surface of said shroud,

(d) an electrically conductive contact having a forward portion coaxially positioned within said shroud and in an annular spaced clearance therewith,

(c) said contact also having a rearward portion terminating exteriorly of said shroud in a means adapted to have a wire secured thereto,

(f) said forward portion terminating adjacent the forward end of said shroud in an engageable electrical connection,

(g) said forward portion also having a cylindrical segment having a diameter corresponding to the inner diameter of said shroud and in engagement with said shroud at said terminal end to provide a friction fit therebetween and further joining said rearward portion in a shoulder,

(h) said forward portion of said conductive contact being in frictional contact with said constriction,

(i) said forward portion further having a solder dam positioned between said shoulder and said shroud crimp ring and within said annular spaced clearance,

(j) a deposit of solder positioned between said shroud and said conductive contact to solder the two together whereby to form a hermetically sealed bond therebetween.

4. A unitized electrical contact assembly as set forth in claim 3 wherein said terminal rear end of said shroud is abutted against said shoulder of said conductive contact.

5. In an electrical connector, a combination comprising, 1

(a) an insert, and

(b) at least one unitized electrical contact assembly,

(c) said insert being of a vitreous material,

(d) said unitized electrical contact assembly having an outer shroud of a material capable of being hermetically bonded to said insert,

(e) said electrical contact assembly also having an electrically conductive member partially positioned within said shroud and terminating forwardly therein in an engageable electrical connection means,

(f) said shroud having a crimp ring for forming a constriction at the inner circumference thereof,

(g) said conductive member being held in an axial position by said crimp ring whereby an annular spaced clearance will be provided between said shroud and said conductive member,

(h) a deposit of solder positioned between the opposing circumferential surfaces of said shroud and electrical contact and within said spaced clearance whereby to solder the two together and form a hermetically sealed bond therebetween, and

(i) means in addition to said crimp ring for confining the longitudinal flow of said deposit of solder to said annular spaced clearance, said last-mentioned means also assisting in holding said conductive member in said axial position to maintain said annular spaced clearance.

6. A combination insert and shroud as set forth in claim 5 wherein said crimp ring is longitudinally positioned on said shroud within said insert.

7. A unitized electrical contact assembly as set forth in claim 3 wherein said shroud is of a nickel-iron alloy and said conductive contact is of a beryllium-copper alloy.

8. A unitized electrical contact assembly as set forth in claim 7 wherein said nickel-iron alloy is in a proportion of substantially 52 percent nickel and 48 percent iron.

References Cited by the Examiner UNITED STATES PATENTS 689,684 12/1901 Mueller 285-287 2,040,092 5/1936 leedy 285287 2,251,709 8/1941 Klein 29148 2,270,166 1/1942 'Hiensch et al 29-15555 2,504,625 4/1950 Barnhart et a1. 285287 2,715,216 8/ 1955 Howenstine. 2,961,632 11/1960 Hachmeister et al. 339--218 X 2,961,633 11/ 1960 Kuebler. 3,003,135 10/1961 Purinton 339258 X 3,007,130 10/1961 Martin 339-275 X 3,101,983 8/1963 Van Horssen 339262 X FOREIGN PATENTS 148,457 9/ 1952 Australia.

JOSEPH D. SEERS, Primary Examiner.

R. E. MOORE, Assistant Examiner.

Claims

5. IN AN ELECTRICAL CONNECTOR, A COMBINATION COMPRISING, (A) AN INSERT, AND (B) AT LEAST ONE UNITIZED ELECTRICAL CONTACT ASSEMBLY, (C) SAID INSERT BEING OF A VITREOUS MATERIAL, (D) SAID UNITIZED ELECTRICAL CONTASCT ASSEMBLY HAVING AN OUTER SHROUD OF A MATERIAL CAPABLE OF BEING HERMETICALLY BONDED TO SAID INSERT, (E) SAID ELEECTRICAL CONTACT ASSEMBLY ALSO HAVING AN ELECTRICALLY CONDUCTIVE MEBER PARTIALLY POSITIONED WITHIN SAID SHROUD AND TERMINATING FORWARDLY THEREIN IN AN ENGAGEABLE ELECRICAL CONNECTION MEANS, (F) SAID SHROUD HAVING A CRIMP RING FOR FORMING A CONSTRUCTION AT THE INNER CIRCUMFERENCE THEREOF, (G) SAID CONDUCTIVE MEMBER BEING HELD IN AN AXIAL POSTION BY SAID CRIMP RING WHEREBY AN ANNULAR SPACED CLEARANCE WILL BE PROVIDED BETWEEN SAID SHROUD AND SAID CONDUCTIVE MEMBER, (H) A DEPOSIT OF SOLDER POSITIONS BETWEEN THE OPPOSING CIRCUMFERENTIAL SURFACES OF SAID SHROUD AND ELECTRICAL CONTACT AND WITHIN SAID SPACED CLEARANCE WHEREBY THE SOLDER THE TWO TOGETHER AND FORM A HERMETICALLY SEALED BOND THEREBETWEEN, AND (I) MEANS IN ADDITION TO SAID CRIMP RING FOR CONFINING THE LONGITUDINAL FLOW OF SAID DEPOSIT OF SOLDER TO SAID ANNULAR SPACED CLEARANCE, SAID LAST-MENTIONED MEANS ALSO ASSISTING IN HOLDING SAID CONDUCTIVE MEMBER IN SAID AXIAL POSITION TO MAINTAIN SAID ANNULAR SPACED CLEARANCE.