U.S. patent number 3,778,752 [Application Number 05/202,320] was granted by the patent office on 1973-12-11 for connector contact including an isolation resistor.
This patent grant is currently assigned to General Motors Corporation. Invention is credited to LeRoy W. Noyes.
United States Patent |
3,778,752 |
Noyes |
December 11, 1973 |
CONNECTOR CONTACT INCLUDING AN ISOLATION RESISTOR
Abstract
A connector contact having two portions which are mechanically
connected and electrically isolated one from the other except for
an electrical path provided through a resistor which acts as a
buffer between an active circuit connected to one portion and a
testing device connected to the other portion.
Inventors: |
Noyes; LeRoy W. (Milwaukee,
WI) |
Assignee: |
General Motors Corporation
(Detroit, MI)
|
Family
ID: |
22749385 |
Appl.
No.: |
05/202,320 |
Filed: |
November 26, 1971 |
Current U.S.
Class: |
439/620.21;
338/220 |
Current CPC
Class: |
H01R
13/6616 (20130101); G01R 1/06 (20130101) |
Current International
Class: |
G01R
1/06 (20060101); H01R 13/66 (20060101); H01r
011/08 () |
Field of
Search: |
;313/136,137
;315/46,49,58 ;324/51,72.5,149 ;339/118,147,276,278C
;338/204,220,221,229,248,273,271 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Moore; Richard E.
Claims
I claim:
1. A connector contact assembly including first and second contact
portions for electrically interconnecting first and second external
circuits respectively, said first portion having a bored end
portion of predetermined external and internal diameter, said
second portion having a lead barrel adapted to be connected to an
electrical lead and of external diameter substantially
corresponding to the external diameter of said bored end portion,
said second portion further including a stub shaft end portion of
less diameter than the internal diameter of said bored end portion
and a shoulder portion of greater diameter than said lead barrel
and interposed between said lead barrel and said stub shaft, a
resistor element affixed to said stub shaft and the seat of said
bored end portion to establish an electrically conductive path
between said first and second portions, and a dielectric material
electrically isolating the sides of said bored end portion from
said stub shaft, said resistors and said shoulder, said bored end
portion having an opening in the sides thereof through which said
dielectric material may be introduced.
Description
The invention herein described was made in the course of work under
contract or subcontract thereunder with the Department of
Defense.
This invention relates to electrical connector contacts and more
particularly to a connector contact including an isolation resistor
as an integral part of its assembly.
In the design of various functional circuits, which are fabricated
into printed circuit boards, test points are often interfaced to
external test equipment in order that primary voltages or current
can be monitored. These test points may be the outputs of a digital
frequency divider or the analog output voltage of an amplifier. In
order to prevent degradation of performance of the active circuit
and to insure that these test points are not accidently grounded by
inadvertently shorting the test point, it is conventional practice
to incorporate a series buffer resistor between the test points and
the external test equipment. This is usually accomplished by
physically placing a resistor of sufficient value on the circuit
board and providing printed circuit runs from the point which is to
be monitored through one end of the resistor and from the other end
of the resistor to the circuit cards motherboard connector. The
motherboard connector wire harness then may be interfaced with the
necessary test equipment via a test connector contact. Thus the
series connection of the buffer resistor between the test point and
the test connector contact is accomplished.
Because of the many test points needed for monitoring the
electronics associated with large electronic systems a separate
circuit board entirely devoted to the buffer resistors is often
required which necessitates additional mounting space within the
structure carrying the electronic system.
It is an object of the present invention to eliminate the need for
such buffer resistor board and the additional mounting space by
providing the necessary buffer resistor as an integral part of the
connector contact.
Other objects and advantages of the present invention will be more
apparent from the following detailed description which should be
read in conjunction with the drawings in which:
FIG. 1 shows a partially cut away view of the connector contact of
the present invention;
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1;
FIG. 3 is a top view taken along lines 3--3 of FIG. 1;
FIG. 4 is an exploded view of the connector contact of the present
invention.
Referring now to the drawings, where like numerals designate
corresponding elements in the various figures, a preferred
embodiment of the present invention is shown to comprise an
inseparable socket contact including a contact portion 10 and a
lead portion 12 for interconnecting a testing device and an active
circuit respectively. The contact portion 10 includes a female
contact 14 adapted to receive a male contact within the confines
indicated in part by the dotted lines 16. The contact 14 has a
bored end portion designated 18 and including a seat 20. The lead
portion 12 includes a lead barrel 22 of outside diameter
substantially the same as the outside diameter of the bored end
portion 18 for mechanically and electrically attaching an electric
lead. The lead barrel 22 includes an opening 24 provided for the
purpose of plating the inside of the barrel 22 with a conductive
and protective material such as gold. The electrical connection
between the lead and the lead barrel 22 is normally obtained by
crimping the barrel 22 to the lead. The portion 12 is also provided
with a seating and retaining shoulder 26 of greater diameter than
the lead barrel 22 and which is adapted to cooperate with suitable
tines located in the connector assembly to thereby releasably
secure the connector contact in the connector assembly. The portion
12 further includes a stub shaft end portion 28 of diameter less
than the internal diameter of the bored end portion 18. A resistor
element 30 is affixed to the stub shaft 28 and the seat 20 by means
of a suitable electrically conductive cement or solder. After
assembly of the portions 10 and 12, a flowable dielectric 32 is
injected through an opening 34 in the bored end portion 18 to
electrically isolate the end portion 18 from the resistor 30 and
stub shaft 28 and flows between the bored end portion 18 and the
shoulder 26 to form a band 36 electrically isolating the portion 18
and the shoulder 26. The resistor 30 thus provides the only
conductive path between the contact 14 and the lead barrel 22 and
serves as a buffer between the active circuit connected to the
portion 12 and the testing device connected to the portion 10.
While the invention has been described with regard to an embodiment
including a female contact portion 10 it will be appreciated that a
male contact could be employed where such is desirable.
* * * * *