U.S. patent number 3,877,769 [Application Number 05/408,445] was granted by the patent office on 1975-04-15 for circuit board socket.
This patent grant is currently assigned to E. I. du Pont de Nemours and Company. Invention is credited to Quentin Berg, deceased, Dauphin Deposit Trust Co., co-executor.
United States Patent |
3,877,769 |
Berg, deceased , et
al. |
April 15, 1975 |
Circuit board socket
Abstract
A circuit board socket is provided with a silicone rubber seal
to prevent flux, solder, or other impurities from entering the
interior contact areas. Viscous liquid silicone rubber is applied
to an opening communicating with the interior of the socket and
flows completely into the opening prior to curing to form an
effective seal. After the silicone rubber sets, it may be easily
pierced by a lead inserted through the opening into the body of the
connector for establishing electrical contact with a spring in the
interior of the socket.
Inventors: |
Berg, deceased; Quentin (LATE
OF New Cumberland, PA), Dauphin Deposit Trust Co.,
co-executor (New Cumberland, PA) |
Assignee: |
E. I. du Pont de Nemours and
Company (Wilmington, DE)
|
Family
ID: |
23616325 |
Appl.
No.: |
05/408,445 |
Filed: |
October 23, 1973 |
Current U.S.
Class: |
439/83; 439/519;
439/276; 439/389 |
Current CPC
Class: |
B23K
35/224 (20130101); H01R 12/58 (20130101); H05K
3/308 (20130101); H05K 3/3452 (20130101) |
Current International
Class: |
B23K
35/22 (20060101); H05K 3/34 (20060101); H05K
3/30 (20060101); H05k 001/02 () |
Field of
Search: |
;339/17,18,60,61,94,93,96,114-118,278 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Parsons, Jr.; Marion
Assistant Examiner: Lewis; Terrell P.
Attorney, Agent or Firm: Hooker; Thomas
Claims
What I claim as my invention is:
1. An improved circuit board socket of they type adapted to be
positioned within a circuit board hole and subsequently soldered to
printed circuitry on the board, the socket including a hollow metal
body, a mouth in the body communicating with the interior of the
body, spring contact means within the body located to engage a lead
inserted into the interior of the body through said mouth, means
for tightly sealing said mouth comprising a portion of liquid
viscous material flowed into said mouth and cured within the mouth
to form a solid sealing plug, said means completely closing at
least one section extending across the mouth, and an adherent
connection between said means and the body at the mouth.
2. A circuit board socket as in claim 1 wherein said means
comprises a plug of silicone rubber.
3. An improved circuit board socket as in claim 2 wherein said
socket includes a spring member extending from the interior of the
socket outwardly through said mouth and said plug completely
surrounds said member.
4. An improved circuit board socket as in claim 3 including an
adherent connection between said plug and the interior
circumference of said mouth and a non-adherent connection between
said plug and said member.
5. An improved circuit board socket of the type adapted to be
positioned within circuit board hole and subsequently soldered to a
printed circuity on the board, the socket including a hollow metal
body, an opening in the body communicating with the interior of the
body, spring contact means within the body, a penetrable resilient
seal closing said opening without substantial stresses normal to
the interior surface of the body, and an adherent connection
between said seal and body.
6. An improved circuit board socket of the type adapted to be
positioned in a circuit board hole and subsequently soldered to
printed circuitry on the board, the socket including an elongate
hollow metal body closed at one end and having a mouth
communicating with the interior of the body at the other end; a
spring contact comprising a U-shaped strip of spring metal confined
within the interior of the body with the bight portion of the
spring contact located adjacent the closed end of the body and with
the arms of the spring contact extending from the bight portion
toward the mouth of the body, contacts on the arms located adjacent
the bight portion and bowed toward each other to engage a lead
inserted through the mouth and between the arms; a flux and molten
solder sealing plug comprising a portion of liquid viscous material
flowed into said mouth and cured within the mouth to form a solid
sealing plug intimately conforming to the interior configuration of
the socket at the mouth, said sealing plug completely closing at
least one section extending across the mouth so as to seal the
opening at the mouth against flux and molten solder while
permitting insertion of a lead through the mouth and between the
arms to engage said contacts; and an adherent connection between
said sealing plug and the interior surface of the mouth.
7. An improved circuit board socket as in claim 6 wherein the end
of at least one of said arms extends outwardly of the body beyond
said plug.
8. An improved circuit board socket as in claim 7 wherein the end
of said one arm also extends beyond the lip of said mouth.
9. An improved circuit board socket as in claim 6 wherein said plug
is formed of silicone rubber.
10. An improved circuit board socket as in claim 6 wherein said
spring contact extends through said plug and projects outwardly of
the mouth with said plug completely surrounding a portion of the
spring contact.
11. An improved circuit board socket as in claim 10 wherein said
plug includes a tip located between the arms of the spring contact
and spaced from the interior surface of the body; said plug
engaging said arms in non-adherent contact.
12. An improved circuit board socket as in claim 6 wherein the plug
includes a tip located adjacent said contacts and spaced from the
interior surface of the body.
13. An improved circuit board socket as in claim 12 wherein said
plug is formed of silicone rubber.
14. An improved circuit board socket of the type adapted to be
positioned in a circuit board hole and subsequently soldered to
printed circuitry on the board, the socket including an elongate
hollow metal body closed at one end and having a mouth
communicating with the interior of the body at the other end; a
spring contact comprising a pair of opposed spring arms formed of
flat metal stock located within the body and extending along
opposed interior body walls, a connecting portion joining the ends
of the spring arms at the closed end of the body and contacts on
the arms bowed toward each other to engage a lead inserted through
the mouth and between the arms; and sealing means comprising a
portion of liquid viscous material flowed into said mouth and cured
within the mouth to form a solid sealing plug intimately conforming
to the interior configuration of the socket at the mouth to
completely seal the mouth to flux and molten solder.
15. An improved circuit board socket as in claim 14, including an
adherent connection between said means and the interior surface of
the mouth.
Description
This invention relates to an improved circuit board socket of the
type disclosed in United States Patent No. 3,681,738. These type
sockets are mounted in holes extending through circuit boards and
are fluxed and wave soldered to form permanent electrical
connections between the exterior of the socket body and printed
circuitry on the circuit board. The socket includes interior spring
arms for forming a connection with a lead inserted through an
opening in the socket and into engagement with the arm.
In the improved circuit board socket, the opening through which the
lead is inserted for making contact with the interior socket spring
arms is closed by flowing viscous room temperature curing silicone
rubber into the opening so that the material, while still viscous,
completely seals the opening and then cures or vulcanizes
sufficiently to retain its position in the opening, thus positively
sealing the opening and preventing flux, molten solder, or other
contaminents entering the interior of the socket through the
opening. The circuit board socket with a resilient plug or seal
forms an improved barrier to the flow of molten solder into the
interior of the socket body then provided in conventional sockets
using solder resists.
The silicone rubber seal is easily penetrated by a lead inserted
into the interior of the body. The seal has the additional
advantage of tightly surrounding the lead inserted into the socket
and thus preventing contaminents from entering the socket after
insertion of the lead. When the lead is withdrawn, the resilient
seal closes the opening formed by the lead and continues to seal
the opening in the socket.
Other objects and features of the invention will become apparent as
the description proceeds, especially when taken in conjunction with
the accompanying drawings illustrating the invention, of which
there is one sheet.
IN THE DRAWINGS
FIG. 1 is a sectional view taken through a circuit board socket
according to the invention;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a top view of the socket of FIGS. 1 and 2;
FIG. 4 is a sectional view taken along line 4--4 of FIG. 1; and
FIG. 5 is a sectional view of a socket like that in FIG. 1 soldered
in a circuit board hole with a lead inserted into the socket and in
electrical connection with the interior spring arms.
The invention relates to a circuit board socket 10 comprising an
elongate metal cup 12 closed at end 14 and open at lead-receiving
end or mouth 16. The mouth at end 16 is outwardly flared to
facilitate reception of a lead inserted into the interior of the
body 12. The circuit board socket 10 also includes a generally
W-shaped spring member 18 having a pair of opposed spring arms 20
confined within body 12 and inter-connected by bight portion 22
adjacent closed end 14 of the body. Spring curls 24 connect the
ends of the spring arms 20 adjacent mouth 16 with exterior circuit
board hole-engaging spring arms 26 extending along opposite
exterior walls of the body 10. The spring 18 is formed of
relatively high yield strength material and is held within the body
10 by a pair of inwardly directed opposed dimples 28 which extend
into the interior of body 12 within the bight portion 22 of spring
18. As illustrated in FIGS. 1 and 4, portions 30 of the spring 18
extend through flared opening 16 of body 12. Body 12 and spring 18
are essentially identical to corresponding members disclosed in
U.S. Pat. No. 3,681,738.
After the spring 18 has been positioned in body 12 as shown in FIG.
1, an amount of viscous room temperature curing silicone rubber is
applied to the flared open end 16 between the portions 30. The
silicone rubber liquid flows completely around the portions 30 and
up to the interior walls 32 of mouth 16 to form a seal extending
across the entire interior opening of the mouth. The rubber also
flows down between the interior facing surfaces 34 of spring arms
20 to form a sealing plug 36. As illustrated in FIG. 2, the plug 36
extends to body side walls 38 adjacent flared mouth 16 and may
narrow to a tip 40 separated from the side walls at a distance
further away from the mouth 16. After application of the silicone
rubber to the mouth of circuit board socket 10, the rubber is
allowed to cure to solidify the plug in position in the socket as
illustrated. The interior walls of body 12 are dry while the
surfaces of spring arms 20 are coated with a material non-adherent
to silicone rubber. When the viscous silicone rubber plug sets or
cures, it adheres tightly to the dry interior surfaces of body 12
and forms an intimate non-adherent contact with the surfaces of the
spring 18. The contact formed between the plug and both the body
and spring tightly closes mouth 16 and prevents flux, molten
solder, or other impurities from entering the interior contact area
of the circuit board socket 10. See FIG. 4.
Following curing of plug 36, the socket 10 may be inserted within a
circuit board hole 42 of circuit board 44 and wave soldered to form
a soldered electrical connection 46 between the body 10, and arms
26, and printed circuitry 48 on circuit board 44. Prior to wave
soldering, the circuit board with the socket mounted therein is
conventionally moved through a fluxing bath to improve soldering.
The plug 36 prevents any flux or molten solder which could possibly
flow into the open end of mouth 16 from flowing into the interior
of the body 10. In this way, flux and solder, together with other
impurities, are prevented from entering the contact area between
arms 20. Silicone rubber plug 36 is not injured by the flux or the
molten solder.
After completion of the soldering operation, a lead 50 may be
inserted into the socket through mouth 16 and plug 36 as
illustrated in FIG. 4. The silicone rubber is easily ruptured by
the lead end of the pin. The rubber does not adhere to the surfaces
of the contact spring arms 20. During insertion, the end of the
lead removes any rubber from the area of contact with spring arms
20. As illustrated in FIG. 5, the lead 50 may break tip 40 into two
portions.
The rubber plug 36 surrounds and forms an impurity resistant seal
against the lead 50 inserted into the socket. In this way socket
failure is reduced because impurities are sealed away from the
contacts between the lead and the socket. When the lead is
withdrawn the resiliency of the plug closes the opening formed by
the lead and maintains an effective seal.
The exact shape of the plug 36 formed in opening 16 depends upon
the amount of liquid rubber applied to the opening. Thus, in a case
that a greater amount of rubber is applied, it is possible that the
plug would overflow the opening and engage curls 24 and the
exterior surfaces of body 12. Such variations in shape of the plug
do not effect the desired seal, so long as the plug does completely
close the lead-receiving opening 16.
While the invention has been described in connection with a
specific form of circuit board socket, it is not intended to be
limited to circuit board sockets of the specific type disclosed
herein. Obviously, sealing plugs may be applied to openings in
other types of circuit board sockets, whether or not leads are
inserted through such openings.
While I have illustrated and described a preferred embodiment of my
invention, it is understood that this is capable of modification,
and I therefore do not wish to be limited to the precise details
set forth, but desire to avail myself of such changes and
alterations as fall within the purview of the following claims.
* * * * *