Note: Descriptions are shown in the official language in which they were submitted.
ELC 75/9
BACKGROUND OF THE INVENTION
This învention relates to electrical connectors of the type having
coupling nuts for coupling and decoupling an electrical connector assembly.
This invention is more particularly related to an improved thread type
electrical connector assembly that provides greater axial movement between
the mateable parts when the coupling nut is rotated 360 so that the coupling
and mating of the assembly is accomplished as quickly as possible; it also
provides minimal radial and axial deflection between the two halves of a
connector assembly when they are connected together.
There is a continual need to improve electrical connectors to meet
the rigid performance standards existing in the Aerospace field. Electrical
connectors should be easily and quickly coupled and decoupled with the use of
acceptable force. Further, the wear of a connector assembly should be as
minimal as possible so that the connectors have a long life. This minimizes
the expense of replacement and the loss of the use of electrical equipment
during replacement of failed or worn connector assemblies. Further, to couple
together connector assemblies quickly and properly, it is important that for
each revolution of a coupling nut a maximum axial movement is obtained.
Further, the electrical connector when coupled should remain securely coupled
when subject to extensive vibration. Considering all these problems and
requirements it is important to balance each of them to obtain the maximum
advantages and the minimum disadvantages.
Another problem associated with mating electrical connector
assemblies is that radial and axial deflection of the male and female electri-
cal contacts should be minimized when the coupling nut is mated to a connector
shell so as to minimize the wear on the electrical pin and socket contacts
within the shells when they are initially mated.
One example of an electrical connector that provides for quick
coupling and decoupling of a connector assembly is shown in U.S. Patent
2,98~,811, issued May 16, 1961 to W. F. Hennessey, Jr., et al and entitled
i;
"Electrical Connector". This patent illustrates a bayonet lock type electrical
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conrlector which has a coupling nut which, instead of threads,
has one or more grooves in it for mating with pins on a
connector shell thereby permitting quick coupling and
decoupling of tlle electrical connector assembly. A dis-
advantage associated with this type of electrical connector
is that the bayonet pins, which reduce radial deflection
from that which occur in a threaded coupling nut, take the
brunt of the forces generated during coupling and vibration.
Therefore, the pins are subjected to wear. For instance,
the pins would break, partially, or completely shear off
allowing the coupling nut to lose its retaining function
and allow the two halves of the electrical connector to
separate. Therefore, there has always been a need for an
electrical connector which: (1) could be quickly coupled
and decoupled; (2) when subject to vibration, would remain
securely connected together; (3) required an acceptable
amount of force.to connect together; (4) had minimum wear
of the engageable connector parts; ~5) traveled a maximum
distance axially for each revolution of the coupling
nut; and (6) had minimal radial deflection of the
electrical contacts when the coupling nut was engaged and
tightened to mate and draw the electrical contacts to~ether,
thereby minimizing wear of the metal components of the
connector ~assembly and the threads themselves.
SUMMARY OF THE I~VENTION : -
This invention provides a quickly connectable and
dlsconnectable electrical connector assembly (with an
acceptable amount of coupling force) that travels a maximum
axial distance for each revolution of a coupling nut while
minimlzing radial and axial deflection of the electrical
contacts within the assembly thereby minimizing wear of
~ the electrical contacts and the coupling threads.
¦ The i.nvention is a separable electrical connector
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having first and second shells connectable in alignment
with the first shell having an enlarged portion located
intermediate of its length, the enlarged portion having
a forwardly-facing shoulder and a rearwardly-facing
shoulder and the second shell having a surface adapted
to seat on the forwardly-facing shoulder of the first
shell when the first and second shells are-connected.
lnterfitting keying means are provided on the shells to
allow their axial approach and retreat while preventing
; 10 rotation relative to each other. An insulating insert
; is mounted within each shell. Cooperating pin and socket
; type electrical contacts are provided, the pin contacts
being mounted in one of the inserts and the socket contacts
being mounted in the other insert, the pin and socket
contacts connectable in mated relationship. Means are
`- provided for connecting the first and second shells
together in seated relationship, the means comprising: a
sleeve rotatably mounted on the first shell the sleeve
including a forwardly-facing surface located and adapted
~0 to seat on the rearwardly-facing shoulder of the first
shell; means for retaining the sleeve against axial removal
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~ in either direction from the first shell; and -interfitting
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thread means in the sleeve and on the second shell, each
of the thread means comprising three separate and distinct
threads whereby when the first and second shells are !~ -'
placed in axial alignment with the keying means interfitting
and the sleeve is rotated in one direction, the three
thread.s in the sleeve interfit with the three threads on
the second shell connecting the pin and socket contacts
in a secure mated relationship with the surface of the
second shell seated on the forwardly-facing shoulder of
the first shell and the surface of the sleeve seated on
-the rearwardly-facing shoulder of the first shell.
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The Eoregoing arrangement provides an electrical
connector that is quickly connectable and disconnectable
with an acceptable amount of rotational force while
minimi~ing the radia] and axial deflection associated
with an electrical connector when the coupling nut
initially engaged is coupled to one of the connector shells.
Accordingly, it is an object of this invention
to provide an improved electrical connector that has a
long and reliable life when subjected to the rugged
~ 10 environment encountered in Aerospace applications.
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ELC 75t9
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It is another object of this invention to provide an electrical
connector that cannot be easily cross-threaded, i.e., misthreaded.
It is still a further object o~ this invention to provide a coupling
nut that has the same basic turning requirements to couple and uncouple a
connector assembly as does a bayonet type electrical connector assembly.
The above and other objects and features of the invention will
become apparent from the following detailed description taken in conjunction
with the accompanying drawings and claims which form a part of this specifica-
tion. Further, the use of reference numerals is for the purpose of clarifica-
10 tion only and is not intended to limit the invention to the specific structure
referenced and shown.
BRIEF DESCRIPTION OF THE DRAWINGS
.
Figure 1 is a cut away view of the three main portions of an
electrical connector assembly.
Figure 2 is a cut away view of an electrical connector assembly
when connected together.
Figure 3 is an end view of the coupling nut taken along lines
III-III of the coupling nut shown in Figure 1.
Figure 4 is a cut away view of connected electrical connector
20 assembly shown in Figure 2 taken along lines IV-IV. ~:
Figure 5 is an end view of one-half of the electrical connector
assembly shown in Figure 1 and taken along lines V-V.
DESCRIPTION OF THE PREFERRED EMBODIMENT
::
I Referring now to the drawings, Figure 1 illustrates a cross-sectional
; exploded view of an electrical connector assembly which incorporates the
principles of the invention. An electrical connector assembly comprises a first
shell 100, a second shell 200, and a coupling nut 300 mounted on one o~ the
shells 100 for connecting the shells together. The typical components of one-
.
half of an electrical connector assembly include a ~irst shell 100 containing
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ELC 75/9
537~
one or more Female type (socket) electrical contacts 170 retained within the
shell 100 by inserts 110, 120, 130. The outside of the first shell 100
generally includes a rear portion that is threaded for receivin~ a moisture
sealing and/or strain relief nut (not ~hown) and a forward portion that
includes one or more axially extending projections or keys for orienting the
first shell with a second shell 200.
The second shell 200 contains one or more male type (pin) electrical
contacts 270 that mate with the socket contacts 170 of the first shell 100
retained within the second shell 200 by one or more inserts 230. The male
pin type contacts may also be retained in the same manner as the female socket
type contact 170 of the first shell 100 are retained. Within the forward
portion of the second shell 200 there are one or more ax-ially extending recesses -~
or keyways 201 that are engageable with the key 101 on the first shell 100.
The keys 101 on the first shell 100 and the keyways 201 in the second shell 200
operate as keying means to locate the first and second shells in their proper
positions so that when there are a plurality of male and female contacts they
engage in a predetermined manner. On the forward portion of the outside o~
the second shell 200 there are a plurality of threads 210 ~or receivlng the
threads 310 of the coupling nut 300.
The coupling nut 300 is rotatably mounted on the first shell 100
by a snap ring 400 which is snapped into a groove 102 in the first shell 100
thereby captivating the rear end portion 305 of the coupling nut 300 between
the rearwardly facing shoulder 103 of the first shell 100 and the snap ring
400. The coupling nut 300 includes, on the inside forward portion, threads
310 that are mateable with the threads 210 on the outside forward surface of
the second shell 200.
Figure 2 illustrates an electrical connector assembly wherein the
two halves of the electrical connector assembly are coupled together. The
coupling nut 300 has been threaded onto the second shell 200 drawing together
the pin contacts 270 into the socket contacts 170. This figure also illustrates
how the male or female electrical contacts 170 may be removably retained within
the connector shell. In this embodiment a plastic insert 110 has forwardly
ELC 75/9
extending fingers 111 that engage the rearwardly facing shoulder 171 of the
socket contact 170. ~y insertion of a proper tool the forwardly extending
fingers 111 may be radially deflected, thereby allowing the socket contact
170 to be removed from the inside of the first shell 100. Also included in
this connector assembly is a rubber grommet 500 that forms an annular seal
between the first shell 100 and the second shell 200 when the coupling nut
(300) draws the two shells together and compresses the gasket or grommet 500.
Figure 3 illustrates an end view of the coupling nut 300 taken
along lines III-III of Figure 1. This view illustrates the threads 310 within
the coupling nut 300. It is essential to the invention that the threads 310
be comprised of at least three separate threads 311, 312, 313. Preferably,
each of the threads 311, 312, 313 begin at approximately 120 from the other.
This symmetrical spacing minimizes the problem of cross-threading that would be
present when less than three threads are used and minimizes radial deflection
to a degree that results in negligible wear on the threads and the electrical
contacts.
Figure 4 illustrates a cross-sectional view of the connector assembly
shown in Figure 2 taken along lines IV-IV. The coupling nut 300 which is
rotatably mounted to the first shell 100 may be rotated in either direction.
Preferably, when the coupling nut is rotated in direction A and -the threads
are mated with the threads 210 on the second shell 200, the two shells 100,
200 of the connector assembly are drawn together engaging the electrical contacts
270, 170 and compressing the gasket 500.
Figure 5 is a cross-sectional view of the second shell 200 taken
along lines V-V of Figure 1. The threads 210 on the outside forward portion
of the second shell 200 are comprised of three separate threads 211, 212, 213
which are also symmetrically arranged one from the other at approximately 120
apart.
Referring now to the drawings in general, the connector assembly would
be coupled together in the following manner: First the keying means 101, 201
of the first and second shells 100, 200 are aligned and then the threads 310 of
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ELC 75/9
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the coupling nut 300 are engaged with the threads (210) of the second shell
200. By rotating the coupling nut 300 in direction A, the male contacts 270,
which have been aligned with the female contacts 170 by the keying means 101,
201 are drawn together into mated relationship. The coupling nut is rotated
in direction A until the rubber gasket 500 is compressed to form a moisture
proof seal between the first and second shells 100, 200.
While a preferred embodiment of the invention has been disclosed
it will be apparent to those skilled in the art that changes may be made to
the invention as set forth in the appended claims, and, in some cases~ certain
features of the invention may be used to advantage without corresponding use
of other features. Accordingly, it is intended that the illustrative and
descriptive materials herein be used to illustrate the principles of the
invention and not o limit the scope thereof.
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