U.S. patent number 3,569,915 [Application Number 04/759,910] was granted by the patent office on 1971-03-09 for grounding foil.
This patent grant is currently assigned to International Telephone and Telegraph Corporation. Invention is credited to Arvin L. Langham, Stanley J. Sorensen.
United States Patent |
3,569,915 |
Sorensen , et al. |
March 9, 1971 |
GROUNDING FOIL
Abstract
The invention comprises a grounding foil member having one or
more cavities therein, formed of tangs for securing circuit
elements such as filters thereto by means of direct contact. The
outer edge of the foil member which contacts the inner shell of a
conductor is formed of flaps bent at an angle. Each of the flaps
deflect upon entering the shell which completes the electrical
circuit between the filter and the shell through the ground foil.
The filter may be removed from the ground foil and the ground foil
from the shell with relative ease and with no soldering
required.
Inventors: |
Sorensen; Stanley J. (Sylmar,
CA), Langham; Arvin L. (Phoenix, AZ) |
Assignee: |
International Telephone and
Telegraph Corporation (New York, NY)
|
Family
ID: |
26266554 |
Appl.
No.: |
04/759,910 |
Filed: |
September 16, 1968 |
Current U.S.
Class: |
439/607.12;
333/182; 439/857 |
Current CPC
Class: |
H01R
13/7197 (20130101); H01R 13/652 (20130101) |
Current International
Class: |
H01R
13/658 (20060101); H01R 13/719 (20060101); H01r
023/06 (); H01r 023/08 () |
Field of
Search: |
;339/95,147,14,143,136,177,258 (A)/ ;339/19 ;174/35,78,87,65
;333/78,79 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Moore; Richard E.
Claims
We claim:
1. In combination a grounding foil retaining removable electrical
elements within a conductor and providing a ground connection
between said elements and said conductor; said grounding foil being
of resilient sheet metal and comprising:
a foil member whose outer dimensions are slightly smaller than the
confines of said conductor, said foil member having a plurality of
tabs extending therefrom resiliently engaging the inner surface of
said conductor;
means on said foil surface defining a plurality of cavities each
formed from a plurality of short tangs, said tangs deflecting over
said electrical element with said electrical element inserted in
said cavity; and
said tangs being angularly disposed with respect to a plane
defining the surface of said foil adjacent said tangs prior to
insertion of said elements in said cavity.
2. A grounding foil in accordance with claim 1 wherein the outer
edge defined by said tabs is slightly greater than said inner
dimension of said conductor, said tabs deflecting upon insertion of
said foil into said conductor, thereby providing a constant
pressure and contact between said foil and said conductor.
3. A grounding foil in accordance with claim 1 wherein each of said
cavity tangs acts independently of the other tangs of a cavity
applying constant pressure to the outer surface of an electrical
element; and upon removal of said electrical element from said
cavity, said tangs being capable of returning to their normal
position.
4. A grounding foil in accordance with claim 1 wherein said
grounding foil is a thin flat member and is mounted in said
conductor in a plane perpendicular to an axis defined by said
conductor.
5. A grounding foil in accordance with claim 4 wherein said
grounding foil is made of beryllium copper plated with silver.
Description
GROUNDING FOIL
The invention relates in general to grounding foils and more
particularly to a device for mounting an element in a conductor
having a ground connection therebetween.
BACKGROUND OF THE INVENTION
Filters are used in coaxial lines to attenuate unwanted signals
such as radio frequency interference signals commonly called RFI
signals. Normally such a filter is a low pass filter which shunts
the unwanted signals to ground. Most coaxial line filters are
soldered to a ground plane and then the ground plane is then
soldered, swaged or welded to the shell or outer conductor of the
coaxial line. Alternatively, a leaf spring may be soldered to the
filter or a spring may be installed in each filter cavity and then
potting used to hold the filters in the connector. Still another
approach is to solder the filter to the contact and insert the
filter into the ground plane and finally soldering this
filter-contact assembly to the ground plane.
Drawbacks to the above mentioned techniques are numerous. For
example when a filter is soldered to the ground plane, the
connector assembly and filters become extremely difficult to rework
or change. In effect, once the filter is soldered to the ground
plane, the connector becomes a nonrepairable assembly. Further, the
quality of the ground connection between the filter and the ground
plane is not known until the assembly of the connector is completed
and tested. Thus, when the ground connection is poor, the connector
assembly must undergo extensive reworking in order to obtain a good
ground contact. Moreover, component and assembly costs are high due
to the physical soldering of the filters and jig boring or die
casting is required to manufacture the ground plane.
In order to overcome the attendant disadvantages of prior art
filter connections, the grounding foil of the present invention
eliminates the need for soldering the filter to the ground plane.
The filter may be installed and removed with relative ease due to
the physical contraction of the grounding foil. Further, good
contact is maintained at all times on the outside diameter of the
filter and the inside diameter of the outer coaxial conductor.
Since the filter ground foil is not soldered to the shell, a
connector assembly using the grounding foil, can be reworked with
ease. Thus, potting is not required in the connector and other
physical means can be employed to retain the insulators and other
components in the shell. Moreover, the grounding foil can be metal
stamped or metal formed from an electroetching, thus its cost is
relatively competitive in comparison to a conventional ground plane
which is made by jig boring or die cast tooling.
SUMMARY OF THE INVENTION
More particularly, the invention comprises a ground foil member
made of lightweight material such as a single piece of the
beryllium copper which may be plated with silver to reduce the
contact resistance between contact points. Within the foil member
are one or more cavities wherein electrical elements are retained
and grounded by the foil. Each of the cavities are formed from a
plurality of short tangs which are bent to form a funnel. The tangs
taper inward to block or close the inside diameter of each cavity.
Each tang operates independent of the other tangs and when the
electrical element is inserted, they deflect over the outside
diameter of the electrical element. The outer edge of the foil
member has means for securing the ground foil to a conductor
providing a ground connection between the electrical elements and
the conductor.
The advantage of the invention, both as to its construction and
mode of operation, will be readily appreciated as the same becomes
better understood by reference to the following detailed
description when considered in connection with the accompanying
drawings in which like referenced numerals designate like parts
throughout the FIGS.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a perspective view partly in section of a preferred
embodiment of the invention; and
FIG. 2 is a side view, partly in section, of the device of FIG. 1,
disassembled.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is shown in FIG. 1 a filter
ground foil 12 mounted in a shell 14, which may be the outer
conductor of a coaxial line, the shell having a mounting flange 16
which may be secured to a rigid structure by means of a nut (not
shown) passing through the hole 18 in the flange.
The filter ground foil is generally circular in shape and has a
diameter slightly less than the inner diameter of the shell 14 at
the point where the foil is to be mounted. Secured along the outer
periphery of the foil are a plurality of flaps 22 bent at an angle
of 30.degree. prior to insertion into the shell. Each of the flaps
deflect upon entering the connector shell and keep a constant
pressure and contact with the inside of the shell.
A plurality of individual cavities 24 are formed on the grounding
foil. Each of the cavities contain a plurality of short tangs 26
(three are shown for illustration purposes in the drawings) which
are bent initially at an angle of 15.degree. to form a funnel. Each
tang operates independently of the others and when an element such
as a filter 28 is inserted in the funnel formed by the tangs 26,
the tangs deflect over the outside diameter of the filter. Each
tang is limited in the amount of deflection due to the fiber
stresses generated when the tang deflects; however, this deflection
can be increased depending upon the size of the filter and the
deflection required to maintain contact with the filter. Thus, each
tang acts like a spring, applying constant pressure to the outside
diameter of the filter. When the filter is removed, the tangs
return to their normal position, ready to accept another filter of
a different outside diameter tolerance.
The filter 28 used in combination with the ground foil is of
conventional design having a pin 32 at one end and a pin contact 34
at the other end. However, the filter shown in the drawing is for
illustrative purposes only, it being understood that other
arrangements or circuit elements could be used in place of the
depicted filter 28.
Referring now to FIG. 2, there is depicted, the arrangement of FIG.
1 prior to assembly. As can readily be seen, the tangs 26 are in
their normal positions at an angle of 15.degree. with respect to
the main ground foil body prior to insertion of the filter 28.
Further, the flaps 22 are at a 30.degree. angle prior to insertion
of the grounding foil into the shell 14. It should be understood,
of course, that the angles mentioned are merely a matter of design
and not limiting, the exact choice of angles being dependent upon
the exact usage of the grounding foil.
As can readily be seen, the entire assembly and disassembly does
not require soldering or other mechanical methods to maintain good
electrical contact between the shell and the filter through the
grounding foil; and the filters can be replaced, added, or removed
from the connector without difficulty and at relatively minor
costs.
The grounding foil can be used in any filter connector that employs
a circular filter. Of course, with minor modifications, other
shaped filters could be used. Moreover, with slight modification of
the grounding foil, other shaped connectors such as elliptical,
rectangular, or square shapes could be used.
Further, while the grounding foil has been described as being made
of beryllium copper which has been plated with silver, it should be
understood that the grounding foil also could be made out of any
conductive material which can act like a spring, such as brass or
stainless-spring steel. Also, insulating plugs may be utilized
within the member 14 to support the member 28 or as a stop for the
member 12.
It should be further understood that the foregoing disclosure
relates only to the preferred embodiments of the invention and that
it is intended to cover all changes and modifications of the
examples of the invention herein chosen for the purpose of the
disclosure which do not constitute departures from the spirit and
scope of the invention.
* * * * *