U.S. patent number 3,678,444 [Application Number 05/106,838] was granted by the patent office on 1972-07-18 for connector with isolated ground.
This patent grant is currently assigned to The Bendix Corporation. Invention is credited to George M. Hubbard, William P. Stevens, William D. Wagner.
United States Patent |
3,678,444 |
Stevens , et al. |
July 18, 1972 |
CONNECTOR WITH ISOLATED GROUND
Abstract
A chassis mountable coaxial cable connector assembly having an
isolated ground. A connector pin is attached to the center wire of
the coaxial cable with insulation surrounding the connector pin to
prevent unwanted signal attenuation to a housing of the connector
assembly. The housing is connected to the shielding braid of the
coaxial cable with the shielding braid and housing forming a
floating type ground. The cable connector assembly includes a
unitary constructed flanged cylinder with a threaded portion for
mounting the connector assembly in a chassis and, simultaneously,
isolating the housing from the chassis.
Inventors: |
Stevens; William P. (Franklin,
IN), Hubbard; George M. (Franklin, IN), Wagner; William
D. (Franklin, IN) |
Assignee: |
The Bendix Corporation
(N/A)
|
Family
ID: |
22313536 |
Appl.
No.: |
05/106,838 |
Filed: |
January 15, 1971 |
Current U.S.
Class: |
439/551;
439/578 |
Current CPC
Class: |
H01R
24/52 (20130101); H01R 2103/00 (20130101) |
Current International
Class: |
H01R
13/00 (20060101); H01R 13/646 (20060101); H01r
017/04 (); H02b 001/02 () |
Field of
Search: |
;339/6C,89C,9C,91P,94C,126J,177,130,64 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Staab; Lawrence J.
Claims
We claim:
1. A coaxial connector with an isolated ground, said coaxial
connector comprising:
a connector pin for mating with a connector to allow an electric
signal to feed therethrough;
a conductive housing axially surrounding said connector pin;
means between said conductive housing and said connector pin for
electrically isolating said housing from said pin, said isolation
means being formed of two parts and fixed with reference to said
housing;
a unitary, non-conductive cylinder having a radially extending
flange on one end and a threaded section on the other end and being
radially disposed about said conductive housing;
a nut engageable with said threaded section to securely mount said
coaxial connector in a hole in a chassis with said non-conductive
cylinder electrically isolating said conductive housing from the
chassis;
an end portion of said conductive housing being deformed radially
outwardly into engagement with said non-conductive cylinder to
secure said cylinder in position on said housing; and
terminal means on said conductive housing providing for an
electrical connection thereto to establish a floating electrical
ground with respect to said connector pin.
2. The coaxial connector as recited in claim 1 wherein:
said non-conductive cylinder is made of a hard-molded,
non-conducting resilient material.
3. The coaxial connector, as set forth in claim 1 wherein said
unitary, non-conductive cylinder is made from a plastic that will
withstand at least 15 inch-pounds torque and 30 pounds pull when
mounted.
4. The coaxial connector set forth in claim 1 and further
including:
a first annular electrically non-conductive member interposed
between said conductive housing and said connector pin and defining
one of said two parts of said isolation means;
a second annular electrically non-conductive member defining the
other of said two parts and interposed between said conductive
housing and said connector pin; and
fastening means operatively connected to said conductive housing
and engageable with said second annular non-conductive member for
holding said first and second annular non-conductive members in
fixed relative positions with respect to said conductive
housing.
5. The coaxial connector set forth in claim 1 wherein:
said terminal means in a tab integral with said conductive housing
and extending axially therefrom.
Description
BACKGROUND OF THE INVENTION
Previous to the present invention, many different types of floating
ground connectors have been devised. One method of providing a
floating ground for a chassis mountable coaxial connector consists
of putting an insulating member in a hole through which the chassis
mountable coaxial connector extends. The coaxial connector is then
tightened to the insulating member with such force to retain the
coaxial connector in place. The insulating member prevents the
coaxial connector from touching the chassis through which it
extends.
Another method that is very undesirable when a floating shield is
needed would be for a coaxial connector to terminate the shield
before reaching the coaxial connector housing. Another connection
external to the connector housing would extend through, or around,
the chassis and be connected to a shielding on the other side of
the chassis through or around which the coaxial connector extends.
Obviously, very high noise spikes can be radiated to the coaxial
cable center conductor at the point which extends through the
chassis thereby causing noise problems.
Another method that has been used to provide an isolated ground for
a coaxial connector has been the enclosing of the center pin within
a first insulator, then inserting the pin and insulator into the
connector housing. The connector housing has a second insulating
member interposed between it and a mounting bracket. During the
manufacturing of the coaxial connector, one has to be very careful
not to short the mounting bracket to the connector housing. If such
occurs, the floating ground no longer exists, and radiated noise
problems can occur. Because of the low voltage between the
connector housing and the chassis, a short between the connector
housing and the chassis may not be detected until it causes a
failure in the system in which the connector is being utilized.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a chassis
mountable coaxial connector having an isolated ground that is more
economically manufactured and reliable than the previous
design.
It is a further object of the present invention to eliminate the
need for additional isolation elements to prevent an electrical
connection between a chassis mountable coaxial connector and a
chassis into which the connector is mounted.
It is a still further object of the present invention to provide a
chassis mountable coaxial connector having a single component that
provides both functions of isolating the connector from the chassis
and, simultaneously, securing the connector in the chassis.
It is an even further object of the present invention to provide a
chassis mountable coaxial connector with an isolated ground that
insures against the radiation of unwanted noise by including a
sleeve portion that accomplishes both functions of mounting to a
chassis and isolation from the chassis.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional view of a chassis mountable coaxial connector
having an isolated ground.
FIG. 2 is an exploded perspective view partially in section of the
chassis mountable coaxial connector shown in FIG. 1.
FIG. 3 is an end view of the unitary constructed flanged cylinder
of FIG. 1 that provides isolation and mounting of the coaxial
connector.
FIG. 4 is a sectional view taken along line 4--4 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a coaxial connector
assembly, represented generally by reference numeral 10, having an
isolated ground as will be subsequently described. By referring
jointly between FIGS. 1 and 2, the female connector assembly 10
will be described in detail. A connector housing 12 encloses a
connector pin 14 surrounded by two sections 16 and 18 of insulating
material that prevents electrical attenuation between connector
housing 12 and pin 14. Insulation portion 16 is molded on pin 14
with the ribs 20 preventing subsequent rotation of the connector
pin about its longitudinal axis. Thereafter, insulating portion 18
is slid over the mating portion of the connector pin 14 as shown in
the assembly drawing. The two insulating portions have mating
flanges 22 and 24. A rubber seal 26 which seats into a groove 28 of
the connector pin 14 is used as a sealing means between insulating
portions 16 and 18. After insulating portions 16 and 18 and rubber
seal 26 are located on connector pin 14, they are all
simultaneously inserted into the connector housing 12 in the manner
as shown in FIG. 1. Thereafter, a ring 30 bonds the connector
assembly together. The ring 30, which is of a force fit type, could
be replaced by any other suitable means of holding the connector
assembly within the housing 12.
To provide a means for mounting the connector housing 12 containing
the connector pin 18 and insulation portions 16 and 18, a flanged
cylinder 32, which will be subsequently described in more detail,
is slid over the rear end of the connector housing 12. Looking at
FIG. 1, the left-hand portion of connector housing 12 is the front
and the righthand portion is the rear. After the flanged cylinder
32 is pushed on the connector housing 12 to abut the connector
housing shoulder 34, all of the rear portion 36 of the connector
housing 12, except a connecting tab 38, is flared outward to retain
the flanged cylinder 32.
Upon insertion of the coaxial connector assembly 10 in a properly
sized hole of the chassis, a washer 40 will encircle the flanged
cylinder 32 adjacent the chassis. The chassis will be secured
between flange 42 and retaining nut 44 which is threadably
connected to a threaded portion 46 of flanged cylinder 32.
After mounting the coaxial connector assembly 10, a corresponding
male coaxial connector can mate the chassis mounted coaxial
connector assembly 10. A bevelled surface 48 is provided in the
front of connector housing 12 to allow easy insertion of the mating
connector. A protection flange 50 of insulating portion 18
surrounds tines 52 of connector pin 14. As a mating male connector
is inserted, the tines 52 will flare outward to receive the male
connector. Once properly mated, the outer casing of the mating
connector may have slots (not shown) to receive projections 54 of
connector housing 12 thereby locking the two connectors into a
mating configuration. Many other types of locking devices between
mating coaxial connectors may be used such as a locking thread,
screw connection.
Referring now to FIGS. 3 and 4 in conjunction, the flanged cylinder
32 is shown in more detail. The flange 42 of the flange cylinder 32
has a wall 56 for abutting against the chassis into which the
coaxial connector assembly 10 is mounted. Also, the smaller
cylindrical portion 58 has a flat surface 60 for butting against a
flat surface in the hole cut in the chassis (not shown) into which
the coaxial connector assembly 10 is mounted thereby preventing
rotation with respect to the chassis. The present invention shows
the flange cylinder 32 as being connected to the connector housing
12 by flaring the rear portion 36 outward against bevelled surface
62 of the flanged cylinder 32. However, it should be emphasized
that the present invention which uses a unitary constructed flanged
cylinder 32 for both mounting and insulation purposes can be molded
to the connector housing 12 or secured by any other suitable means.
With newer and better plastics becoming a common part of our
technology, the flanged cylinder 32 can be made from a plastic that
will insulate the connector housing 12 from the chassis into which
it is mounted and, simultaneously, be rugged enough to withstand
the previous tests required for earlier type connectors. For
example, all coaxial connector assemblies similar to that shown in
FIG. 1 must withstand 15 inch-pounds of torque and 30 pounds pull
as a minimum requirement. By proper design of the flanged cylinder
32, larger forces can be withstood without any damage to the
coaxial connector assembly 10. It should be obvious to those
skilled in the art that many other designs are possible wherein the
flanged cylinder 32 is replaced by other configurations of suitable
material that will provide the insulating and the mounting function
as required in chassis mountable coaxial connectors. With the
increase in technology, it is also possible that materials other
than plastic could be used to make the flanged cylinder 32 having
the insulating capabilities, plus the strength, needed for mounting
a coaxial cable connector with an isolating ground.
The present coaxial connector assembly 10 does not show a
feedthrough type of coaxial connector but the present design could
be modified to give an isolated feedthrough connector. The rear
portion of the coaxial connector assembly would have to have a
means for clamping the coaxial cable in place and, simultaneously,
connecting a shielding braid to connector housing 12. In such a
configuration, the connecting tab 38 will no longer be required.
The present design was primarily intended for use in instrument
panel where the panel itself would provide the necessary shielding
for the signal processing inside the panel. The floating ground
feature of the present invention helps eliminate the problem of
voltage potentials between different ground points for the coaxial
cable, or commonly called ground loop currents.
* * * * *