U.S. patent number 3,835,443 [Application Number 05/354,330] was granted by the patent office on 1974-09-10 for electrical connector shield.
This patent grant is currently assigned to International Telephone and Telegraph Corporation. Invention is credited to Bruce K. Arnold, John T. Keith.
United States Patent |
3,835,443 |
Arnold , et al. |
September 10, 1974 |
ELECTRICAL CONNECTOR SHIELD
Abstract
A radio frequency and electromagnetic interference shield for an
electrical connector comprising a helically coiled conductive
spring which is interposed between facing surfaces on the mating
halves of the connector. The spring is coiled in such a manner that
the convolutions thereof are slanted at an oblique angle to the
center axis of the connector members. The axial distance between
said facing surfaces when the connector members are mated is less
than the normal outside helical diameter of the convolutions of the
spring. Thus, mating of the connector members axially flattens the
spring to form an almost continuous metal shield between the
connector members.
Inventors: |
Arnold; Bruce K. (El Toro,
CA), Keith; John T. (Los Angeles, CA) |
Assignee: |
International Telephone and
Telegraph Corporation (New York, NY)
|
Family
ID: |
23392826 |
Appl.
No.: |
05/354,330 |
Filed: |
April 25, 1973 |
Current U.S.
Class: |
439/319;
439/607.02 |
Current CPC
Class: |
H01R
13/6583 (20130101) |
Current International
Class: |
H01R
13/658 (20060101); H01r 013/54 () |
Field of
Search: |
;339/14,75,94,90,136,143,177,256RT |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Moore; Richard E.
Attorney, Agent or Firm: Peterson; Thomas L.
Claims
What is claimed is:
1. In an electrical connector comprising a first connector member
having a first contact therein, a second connector member having a
second contact for electrical connection with said first contact
upon mating of said first and second connector members, said first
and second connector members having a common central axis and being
formed with parallel facing surfaces thereon surrounding said
contacts, and a shielding member interposed between said facing
surfaces for eliminating radio frequency and electromagnetic
interference, the improvement which comprises:
said shielding member comprising a helically coiled conductive
spring having convolutions each of which lies in a slanted plane
that intersects said center axis of said connector members at an
oblique angle;
coupling means other than said spring mounted on one of said
connector members and engageable with the other connector member
for coupling said connector members in mated engagement; and
the axial distance between said facing surfaces when said connector
members are mated by said coupling means is less than the normal
outside helical diameter of the convolutions of said spring,
whereby said spring is axially flattened when said connector
members are mated, thus providing RFI and EMI shielding.
2. An electrical connector as set forth in claim 1 wherein:
said connector members are coaxial cylindrical bodies, said first
connector member having an outwardly extending annular shoulder
thereon forming one of said facing surfaces and the second
connector member having an annular end surface forming the other
facing surface; and
said spring being formed as an annulus interposed between said
annular shoulder and annular end surface.
3. An electrical connector as set forth in claim 1 wherein:
said coupling means surrounds said spring; and
one of said connector members is telescopically mounted within the
other connector member.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a shielding member and,
more particularly, to a radio frequency and electromagnetic
interference shielding member for an electrical connector.
The use of shielding in electrical connectors to eliminate unwanted
radio frequency and electromagentic interference from interfering
with signals being carried by contacts in connectors is well known.
Typically, multifinger strip contacts are soldered, crimped or spot
welded in place. Alternatively, closed loop preforms have been used
as shields but have been relatively expensive and cannot be easily
installed in a connector. Another form of a connector shield is
disclosed in U.S. Pat. No. 3,678,445. This shield has the advantage
over the previous mentioned shields in that it may be installed on
a connector with a simple snap-in operation. Thus, no bonding or
intermediate joining processes are required. However, such shield
embodies spring fingers which are subject to breakage and
fragmentation when exposed to extreme deflection or other
abuse.
Therefore, what is desired is a shield which not only may be easily
installed on a connector but is also relatively immune to damage
when subjected to extreme operating conditions.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a radio
frequency and electromagentic interference shield for an electrical
connector which may be easily installed on a connector and is
relatively rugged.
According to the principal aspect of the present invention, there
is provided a shield which is interposed between facing surfaces of
the mating halves of an electrical connector. The shield comprises
a helically coiled conductive spring which is coiled in such a
manner that the convolutions of the spring are slanted at an
oblique angle to the center axis of the connector members. The
axial distance between the facing surfaces when the connector
members are mated is less than the normal outside helical diameter
of the convolutions of the spring. Thus, when the connector halves
are mated, the spring is axially flattened to provide an almost
continuous metal shield between the mating halves. The coil spring
provides excellent shielding against RFI (radio frequency
interference) and EMI (electromagnetic interference). Because of
the slant design of the spring convolutions, a wiping action
between the spring and the facing surfaces on the connector halves
takes place when the halves are mated. This wiping action assures
positive electrical continuity and thus an effective grounding of
the respective connector halves. The shielding spring of the
present invention is easily installed on a connector, is
inexpensive and rugged. Also, because the spring is flexible, it
may be adapted to many shapes of connector bodies.
Other aspects and advantages of the invention will become more
apparent when the following description taken in connection with
the accompanying drawing.
A BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partial longitudinal sectional view of an electrical
connector embodying the shielding spring of the present invention,
with the convolutions of the springs being shown in their normal
relaxed condition before the connector halves are fully mated;
FIG. 2 is a top plan view of the shielding spring of the present
invention.
FIG. 3 is a transverse sectional view taken generally along line
3--3 in FIG. 1 showing a side view of the shielding spring in its
normal relaxed condition and
FIG. 4 is a sectional view similar to FIG. 3 showing the shielding
spring flattened after the mating halves of the connector have been
fully mated.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing in detail, there is shown in FIG. 1
the connector of the present invention, generally designated 10,
comprising a plug connector member 12 and a receptacle connector
member 14. The plug connector member 12 comprises a cylindrical
barrel 16 which is telescopically positioned in the front end of
the cylindrical shell 18 of the receptacle connector member. A
plurality of socket contacts 20 are axially positioned in
insulators 22 and 24 mounted in the barrel 16, only one such
contacts being illustrated in FIG. 1. Each socket contact 20
receives a pin contact 26 which is mounted in an insulator 28 in
the receptacle connector member 14. A facing seal 30 may be
provided on the front face of the insulator 28.
A coupling nut 32 is mounted on the barrel 16. The forward end of
the nut surrounds the receptacle shell 18. An integral outwardly
extending flange 34 is formed on the barrel 16. An annular member
36 is retained in the coupling nut 32 by a retaining ring 38. A
wave spring 40 is interposed between the flange 34 and the annular
member 36 to bias the coupling nut 32 in the rearward
direction.
One or more projections 42 are mounted in the receptacle shell 18.
Each projection is slidably received in a corresponding internal
helical groove 44 havings its entrance at the end surface 46 of the
coupling nut 32. The barrel 16 and shell 18 have a key-keyway
arrangement (not shown) to prevent rotation with respect to each
other when the coupling nut 32 is actuated. As well known in the
art, by rotating the coupling nut 32 the interaction of the
projections 42 with the grooves 44 causes the coupling nut and plug
connector member 12 to be axially drawn toward the receptacle
connector member 14. For further details of the structure of the
connector 10, reference may be had to U.S. Pat. No. 3,393,927. It
is to be understood that the structure of the connector disclosed
herein is given by way of example only. The shielding member of the
present invention may be utilized in most all forms of axially
mated electrical connectors. While the socket contact 20 is shown
mounted in the plug connector member 12, it will be understood that
the socket contact could be mounted in the receptacle connector
member 14 and the pin contact 26 mounted in the plug connector
member 12. Furthermore, the connector 10 may employ a single pair
of contacts or coaxial conductors rather than a plurality of mated
contacts if desired.
The shielding member of the present invention, generally designated
50, is a helically coiled conductive spring formed as an annulus
which is concentric with the central or longitudinal axis X--X of
the connector 10. The spring is interposed between an annular
shoulder 52 formed by the flange 34 on barrel 16 and the annular
end surface 54 on the receptacle shell 18. As will be apparent, the
spring 50 is positioned on the barrel 16 adjacent to the annular
shoulder 52 prior to coupling of the plug and receptacle connector
members.
As best seen in FIG. 3, the convolutions of the helically coiled
conductive spring 50 are slanted at an oblique angle to the center
axis X--X of the connector members, thereby providing what is
generally known in the art as a "slant spring." Springs of this
type are described in detail in U.S. Pat. Nos. 3,323,785 and
3,468,527. When an axial pressure is applied to the spring, an
axial flattening of the spring occurs due to the folding of the
convolutions upon each other and not due to distorting of the
original diameter of the convolutions.
As illustrated in FIG. 1, the connector members 12 and 14 are
partially mated so that no axial pressure is applied to the spring
50. However, when the connector members are fully mated so that the
forward end 56 of the plug connector member 12 engages the facing
seal 30, the axial distance between the facing surfaces 52 and 54
of the connector members is less than the normal outside helical
diameter of the spring convolutions. Therefore, as seen in FIG. 4,
the spring is axially flattened due to the convolutions folding
over each other, to provide an almost continuous metal shield
between the mating halves of the connector. The spring, therefore,
provides excellent shielding against RFI and EMI. Also, because of
the slant design of the spring convolutions, a wiping action occurs
between the spring convolutions and the surfaces 52 and 54 when the
connector members are mated together. This assures positive
electrical continuity and thus effective grounding of the connector
halves with respect to each other.
The grounding spring 50 is relatively rugged and inexpensive. It
may be installed easily on any configuration of a connector member.
For example, the spring may be mounted on rectangular connector
bodies as well as cylindrical connector bodies. Also, no bonding or
intermediate joining processes are required for holding the
shielding member 50 of the present invention on the connector.
* * * * *