U.S. patent number 3,742,426 [Application Number 05/145,371] was granted by the patent office on 1973-06-26 for fire resistant pluggable contact and receptacle.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to John Henry Huber, Robert Volinskie.
United States Patent |
3,742,426 |
Huber , et al. |
June 26, 1973 |
FIRE RESISTANT PLUGGABLE CONTACT AND RECEPTACLE
Abstract
An electrical connector adapted for connecting a coaxial cable
to the firing system of aircraft-carried rockets is provided which
features a plug contact member for crimpingly engaging a coaxial
cable, a receptacle having a substantially tubular shell threadably
engageable with an aircraft housing, a cap member at one end to be
positioned inside the housing, a non-conductive member movably
disposed in the shell for preventing rocket exhaust flow into the
receptacle, a spring disposed between the non-conductive member and
the cap member and an elongate contact pin extending axially
through the cap member and the non-conductive member to engage the
coaxial cable center conductor upon insertion of the plug contact
member into the receptacle, and means for normally securing the
plug contact member within the receptacle.
Inventors: |
Huber; John Henry (Harrisburg,
PA), Volinskie; Robert (Hershey, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
|
Family
ID: |
22512801 |
Appl.
No.: |
05/145,371 |
Filed: |
May 20, 1971 |
Current U.S.
Class: |
439/141 |
Current CPC
Class: |
H01R
13/635 (20130101); H01R 13/453 (20130101) |
Current International
Class: |
H01R
13/633 (20060101); H01R 13/635 (20060101); H01R
13/44 (20060101); H01R 13/453 (20060101); H01r
011/08 (); H01r 013/54 () |
Field of
Search: |
;339/26,42,45,91,94,75,177,136,181,200,201,203,213,253,255,259
;174/DIG.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1,958,357 |
|
Jun 1970 |
|
DT |
|
169,521 |
|
Nov 1951 |
|
OE |
|
Other References
"Coaxial Cable Connector", F. P. Cefarelli & R. T. Evans, p.
1587 IBM Technical Disclosure Bulletin, Vol. 10, No. 10, Mar.
1968..
|
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Lewis; Terrell P.
Claims
What is claimed as new and desired to be secured by letters patent
of the united states is:
1. An electrical connector useful for connecting a coaxial cable
from a rocket to the firing system of an aircraft or the like which
comprises:
a. a loading socket shell having a bore therethrough, and a cap
member secured to one end thereof, said bore having a shoulder stop
therein;
b. a non-conductive member slidingly disposed in said bore in said
shell;
c. a compression spring positioned in said bore between said
non-conductive member and said cap member and adapted to urge said
non-conductive member away from said cap member;
d. an elongated contact pin axially disposed through said bore and
extending through said cap member at one end and said
non-conductive member at another end;
e. a conductive plug adapted to be inserted into said bore and
having a compressible shoulder thereon for engaging said shoulder
stop in said bore whereby said plug is retained therein, said plug
further adapted for being connected to said coaxial cable at one
end; and
f. a tubular conductive receptacle positioned in said plug and
adapted for being crimped to the center conductor of said coaxial
cable at one end and for telescopingly receiving said elongated
contact pin at another end thereby effecting an electrical contact
between said coaxial cable and said contact pin.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to electrical connectors and more
particularly to a connector for coaxial cables of the type known in
the art as "breakaway" connectors wherein a plug of the connector
is held firmly within a receptacle, yet the parts are so
constructed that when a sufficient separating force is applied, the
connection is almost instantly released.
Breakaway connectors of the character described are widely employed
in military guided missiles and similar areas, wherein they
function to maintain electrical communication between external
control apparatus and the missile until the instant of departure,
such as for connecting the coaxial cable from an aircraft
electrical control system to the firing system of aircraft-carried
rockets, yet are violently jerked apart when the rockets are fired.
One of the problems with present breakway connectors is that the
rocket exhaust that flows over the receptacle portion as the rocket
moves away from the aircraft causes such considerable damage to the
receptacle that the receptacle generally must be replaced after
only a few firings. Because of this, the receptacles are now
designed for ready replacement in the aircraft housing or
panel.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an
improved breakaway connector for connecting a coaxial cable to the
firing system of an aircraft-carried rocket having a receptacle
portion which is resistant to rocket exhaust damage and thereby is
designed for extending the life thereof over many rocket
firings.
Another object of the present invention is to provide an improved
connector for coaxial cable having a receptacle and a detachable
plug wherein the parts are so related to each other that the plug
may be instantaneously withdrawn from the receptacle, yet wherein
they are coactive to protect the interior of the receptacle from
the outside environment upon withdrawal of the plug.
A further object of this invention is to provide an improved
breakaway connector having a fire resistant pluggable contact and
receptacle.
The foregoing objectives are achieved by the invention through a
connector assembly comprising a receptacle having a substantially
tubular loading socket shell which may be threadably engaged with
an aircraft housing panel, a cap member fastenable to the shell for
substantially closing one end thereof, a non-conductive member
movably disposed within the tubular shell and sealingly engaging
the interior wall surface thereof, a spring compressed between the
cap member and the non-conductive member and an elongate contact
pin extending through the cap member and through the non-conductive
member. A plug member forming part of this invention has portions
near one end thereof for crimpingly engaging the outer insulative
sheath of a coaxial cable and the inner protective braid thereof,
respectively, and a portion insulatively housing the center
conductor of the coaxial cable being suitably constructed for
permitting insertion into the loading socket shell of the
receptacle to provide contact between the coaxial cable center
conductor and the elongate contact pin. According to one embodiment
of the invention, the plug contact is maintained within the
receptacle by locking a compressible shoulder on the plug behind a
positive stop provided within the loading socket shell. In another
embodiment, the plug and receptacle are kept together by a boot
member which is shrunk down over the crimping tabs of the plug and
over a lip portion of the loading socket shell.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the
present invention will be more fully appreciated as the same
becomes better understood from the following detailed description
when considered in connection with the accompanying drawings,
wherein like reference numerals are used to designate like or
corresponding parts in the several embodiments and in which:
FIG. 1 is an exploded perspective view of a plug member constructed
according to this invention and showing its cooperative relation
with a coaxial cable to which it is adapted to be connected;
FIG. 2 is a longitudinal cross-sectional view of the plug member
illustrated in FIG. 1 being assembled with the coaxial cable;
FIG. 3 is an end view of the assembled plug member;
FIG. 4 is a cross-sectional view of one embodiment of a receptacle
formed in accordance with the present invention;
FIG. 5 is a cross-sectional view of another embodiment of a
receptacle according to this invention; and,
FIG. 6 is a cross-sectional view of a connector assembly
illustrating the plug of FIG. 1, the receptacle of FIG. 5, and a
boot retaining member securing the plug and receptacle
together.
DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
Referring now to the Drawings, and more particularly to FIGS. 1, 2
and 3 thereof, there is shown a plug contact generally designated
by the numeral 10 comprising an elongate crimping member having a
front end portion 11 which is substantially tubular and is axially
split along at least a portion thereof at spaced circumferential
intervals, as indicated at 12. The split front end portion 11
terminates in a generally conical exterior exposure being formed of
a plurality of flat, substantially triangular-shaped parts 13,
shown as four in number, inwardly inclined toward the axis from the
rear to the front, and having formed in each a small dome 15
providing a smooth bearing surface for the plug member 10, as will
be set forth hereinbelow.
The rear end portions of the conical surface-forming parts 13
provide upstanding circumferential locking shoulders 17 at the
junctures thereof with the main tubular exterior surface of the
front end portion 11.
A rear end portion 18 and an intermediate portion 19 are integrally
formed with the front end portion 11 to complete the plug contact
member 10. Both the rear end portion 18 and the intermediate
portion 19 are formed in a substantially semi-tubular
configuration, with the intermediate portion having a smaller
radius of curvature than the rear end portion such that a coaxial
cable 20 may be received therein with an outer protective and
insulating sheath 21 thereof positioned in the rear end portion 18
and an outer braided jacket 22 disposed immediately below the
insulating sheath being positioned in the intermediate portion 19.
The rear end portion 18 is provided with crimping tabs 23 and the
intermediate portion 19 is provided with crimping tabs 24 for
permitting these portions of the plug contact 10 to be crimpingly
engaged with the outer insulation 21 and the braid 22,
respectively, of the coaxial cable 20.
The front end portion 11 of the plug contact 10 is adapted to
receive an inner, or center, conductor 25, being stripped of its
various protective and insulative jackets and extending beyond
these portions of the coaxial cable 20 which are received in the
rear and intermediate portions of the plug contact 10. A tubular
conductive receptacle 26, preferably being slit at spaced
circumferential intervals adjacent one end thereof, and having an
inside diameter substantially equal to the diameter of the center
conductor 25, is crimped about the center conductor and is disposed
in the front end portion 11 of the plug contact 10 with the split
portions being bent radially inward to provide improved contact
with a receptacle contact element, as will be set forth
hereinbelow. Between the receptacle 26 and the front end portion 11
of the plug 10, a non-conductive sleeve 27 is disposed for
insulative purposes.
The plug contact 10 and the insulating sleeve 27 may of course be
constructed from a variety of suitable materials, such as, by way
of example, a soft metal like brass in the case of the plug contact
10 and a silicone tubing in the case of the sleeve 27.
A receptacle for the plug contact 10 for completing a coaxial
connector assembly is shown in FIG. 4, being generally designated
by the numeral 30. The receptacle has a loading socket shell 31
which is externally threaded at 32 along an intermediate portion to
facilitate mounting of the same in a panel and has tiny barbs 33 in
its exterior wall at one end thereof for securably engaging the
shell in a cap member 34 constructed of a soft material, such as,
for example, nylon, when the same is forcefully fitted thereon, the
barbs being angularly pointed in the direction of the opposite end
of the shell to readily permit insertion of the end of the shell
into the cap member, but resisting subsequent separation thereof by
digging into the soft cap inner wall when the elements are urged
away from each other.
A bore 35 is provided in one end of the loading socket shell 31 and
a counter bore 36 of slightly greater diameter is provided in the
other end thereof, thereby forming a shoulder, or stop, 37, shown
being tapered, within the shell 31. A coil spring 38 is disposed
within the receptacle 30, being compressed between the cap member
34 and an annular disc 39 of dielectric material, such as, for
example, Teflon, which fits slidably but tightly within the counter
bore 36 of the loading socket shell 31 and is normally held against
the shoulder 37 under the force of the spring. An elongate contact
pin 40 which is adapted to plug into a coaxial cable socket in the
panel and is designed for ready replacement, if such is required,
may be inserted through an opening in the end wall of the soft cap
member 34 and friction fitted within the central opening of the
annular dielectric disc member 39, so that one end thereof extends
beyond the disc 39 to engage the center conductor 25 of the coaxial
cable 20 upon insertion of the plug contact 10 within the
receptacle 30. The elongate contact pin 40 is provided with an
integral flange 41 being tapered at one end to facilitate pressing
of the pin 40 through the cap member end wall opening and has a
square shoulder at the other end which resists pin movement in the
opposite direction within the receptacle 30 upon engagement with
the inner surface of the cap end wall. Another shoulder on the pin
40 spaced from the flange 41 and positioned adjacent the end of the
pin which is adapted to plug into the panel socket determines the
extent to which the pin 40 should be inserted through the end wall
of the cap member 34.
Accordingly, when placed in use, the receptacle 30 is threaded into
a panel, not shown, which may, as indicated, be carried on an
aircraft, and the tapered front end of the plug contact 10, which
may be secured to a rocket, is inserted into the bore 35 of the
receptacle 30, pushing the dielectric disc 39 back against the
action of the spring 38 until the shoulders 17 on the front end
portion 11 of the plug contact 10 which are slightly compressed
during their passage through the bore 35 passes the shoulder 37
inside the receptacle 30. At this time, the shoulder portions 17
naturally resume or spring back so that when an installing force is
no longer being applied, the spring 38 operates to urge the
shoulders 17 against shoulder 37 thereby positively locking the
plug contact 10 in the receptacle 30, with the contact pin 40 being
engaged by the center conductor 25 through the fingers of
receptacle 26 to establish an electrically conductive path between
the aircraft and the rocket firing mechanism. When the rocket is
fired, it pulls the plug 10 from the receptacle 30 and the exhaust
gas generated by the rocket as it moves away flows over the
receptacle from left to right, as viewed in the Drawings. The
spring 38, however, is immediately operative upon removal of the
plug to push the dielectric disc 39 back to the left against the
shoulder 37, thereby resisting the gas pressure of the rocket
exhaust and preventing damage to the interior of the
receptacle.
Turning now to FIGS. 5 and 6, there is shown another embodiment of
the receptacle 30 in which, instead of retaining the plug 10 in the
receptacle by locking it behind a positive stop, a separate boot
member is utilized for securing the elements together. Thus, the
receptacle 30' comprises a loading socket shell 31' having a
through-bore 50, a cap member 34' secured to one end thereof by
tiny barbs 33' and being adapted to threadably engage a panel on
the aircraft through a threaded portion 32'.
A dielectric skirt 39', which in this case is a cylindrical member
of approximately the same outside diameter as the diameter of the
throughbore 50, has a bore 51 in its inner end for receiving a
compressed spring 38', a central opening through which an elongate
contact pin 40' may be friction-fitted, and a flange 52 extending
radially outward at the inner end for engaging the inner annular
end surface of the loading socket shell 31' to keep from being
ejected the spring 38', and is appropriately positioned within the
shell 31' and the cap member 34'. An o-ring seal 53 is provided in
the bore 50 between the skirt 39' and the loading socket shell 31',
and another O-ring seal 54 is positioned in a groove in the
elongate contact pin 40' to provide a seal between the pin 40' and
the dielectric skirt 39' upon movement of the skirt against the
action of the spring 38'. The outer end surface of the skirt 39' is
provided with a circular groove or cavity 55 and a flared or
outwardly tapered circumerential periphery 56.
In operation, the plug contact 10 is inserted into bore 50 of the
receptacle 30' and is secured therein by a boot member 57 which may
be formed of silicone rubber, for example, and is shrink-fitted
over the crimp tabs 23 and 24 of the plug 10 and a lip 58 on the
outer end of the shell 31'. As in the previous embodiment, the
dielectric skirt 39' is pushed back against the action of the
spring 38' when the plug 10 is inserted, and upon withdrawal of the
plug from the receptacle 30', the spring is operative to push the
skirt 39' forward to prevent damage to the interior of the
receptacle. The forward motion of the skirt 39' is limited by the
flange 52 thereon which engages the inner annular end surface of
the socket shell 31'. Thus, the forward end wall of the skirt 39'
is used to positively receive and flare out the gas pressure from
the rocket exhaust through the annular cavity 55 formed
therein.
In both embodiments, a substantial force is required to separate
the plug from the receptacle, to unlock the plug from the positive
stop in the first case and to free the boot in the second case.
Thus, it may be seen that the fire resistant pluggable contact and
receptacle of the present invention has important advantages over
known prior art structures in that a breakaway connector is
provided wherein the plug may be easily and quickly attached or
detached yet wherein the parts are of such design and construction
that they tend to reduce the chances of damage to the interior of
the receptacle by such external environmental factors as the rocket
exhaust gas.
Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is to be
understood, therefore, that within the scope of the appended claims
the present invention may be practiced otherwise than as
specifically described herein.
* * * * *