U.S. patent number 3,757,278 [Application Number 05/190,507] was granted by the patent office on 1973-09-04 for subminiature coaxial contact.
This patent grant is currently assigned to AMP Incorporated. Invention is credited to William Ludlow Schumacher.
United States Patent |
3,757,278 |
Schumacher |
September 4, 1973 |
SUBMINIATURE COAXIAL CONTACT
Abstract
A subminiature coaxial contact is provided with a cavity in one
end for receiving a center conductor of a small-size coaxial cable
and has a dielectric sleeve movably positioned thereon being
initially disposed intermediate the ends thereof. The contact is
insertable into one end of a connector housing having a shoulder
stop therein against which the dielectric sleeve registers so that
upon continued insertion the dielectric sleeve is caused to
slidably traverse the contact until it is positioned against the
end of the coaxial cable insulating sheath. The dielectric sleeve
thus may serve as a positioner or stop for use with a crimping tool
so that crimping occurs on the extreme end of the contact whereby
bending is at a minimum and also is operative to positively locate
the contact in a predictably fixed position in the housing while
simultaneously aligning the same diametrically in spaced relation
within a small bore therein.
Inventors: |
Schumacher; William Ludlow
(Camp Hill, PA) |
Assignee: |
AMP Incorporated (Harrisburg,
PA)
|
Family
ID: |
22701629 |
Appl.
No.: |
05/190,507 |
Filed: |
October 19, 1971 |
Current U.S.
Class: |
439/585; 29/828;
439/848; 29/874 |
Current CPC
Class: |
H01R
9/0518 (20130101); Y10T 29/49123 (20150115); Y10T
29/49204 (20150115) |
Current International
Class: |
H01R
9/05 (20060101); H01r 017/06 () |
Field of
Search: |
;29/629 ;174/75C,88C,89
;339/6C,89C,9C,91P,94C,126J,177R,177E,183 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Staab; Lawrence J.
Claims
What is claimed as new and desired to be secured by Letters Patent
of the United States is:
1. A method of terminating coaxial cable, comprising the steps
of:
trimming a coaxial cable to expose a predetermined length of a
center conductor thereof from one end of a surrounding insulating
sheath;
inserting said center conductor into a forward end portion of a
center conductor contact having a rear end portion of reduced
diameter and a slidable dielectric member disposed on the rear end
of said forward end portion;
crimping the forward end of said forward end portion of said center
conductor contact against said center conductor;
inserting said crimped center conductor contact and said slidable
dielectric member into an electrically conducting connector
housing;
receiving said dielectric member against a stop inside said
connector housing;
further inserting said center conductor contact into said connector
housing and causing said dielectric member to slidably traverse
said forward end portion of said center conductor contact so as to
be disposed over said crimped forward end of said forward end
portion;
stopping said dielectric member against an end of said coaxial
cable insulating sheath; and
crimping the outer braid of said coaxial cable into electrical
contact with the outer periphery of the end of said connector
housing receiving said center conductor contact.
2. A coaxial connector comprising:
a first elongate center conductor contact having a cavity in one
end portion for receiving a center conductor of a coaxial cable and
a reduced diameter male contact member on the other end portion,
said one end portion being crimpable at one end thereof on said
center conductor;
a first dielectric sleeve movably disposed on said first center
conductor contact and initially being positioned at another end of
said one end portion adjacent said male contact member;
a connector housing having means therein for defining a series of
at least three stepped bores of decreasing diameter from a front
end of said connector housing for receiving said center conductor
contact, thereby forming at least two spaced shoulder stops
therein;
said first dielectric sleeve being slidable in the first of said
series of stepped bores and engageable with the first of said at
least two shoulder stops from said front end of said connector
housing upon insertion of said first center conductor contact
therein, and upon further insertion being slidably displaced on
said one end portion of said first center conductor contact toward
the crimpable end thereof;
a second dielectric sleeve disposed on said male contact member of
said first center conductor contact being smaller in diameter than
said first dielectric sleeve on said one end portion thereof and
further being slidable in the second of said series of stepped
bores and engageable with the second of said at least two shoulder
stops from said front end of said connector housing;
a second elongate center conductor contact having a cavity in one
end portion for receiving a center conductor of another coaxial
cable and a reduced diameter female contact member on the other end
portion, said one end portion being crimpable at one end thereof on
said center conductor;
a third dielectric sleeve movably disposed on said second center
conductor contact and initially being positioned at another end of
said one end portion adjacent said female contact member;
a second connector housing having means for defining at least a
pair of stepped bores of decreasing diameter from a front end of
said second connector housing for receiving said second center
conductor contact, thereby forming at least one shoulder stop
therein;
said third dielectric sleeve upon insertion of said second center
conductor contact into said second connector housing being
engageable with said at least one shoulder stop and upon continued
insertion of said second center conductor contact being caused to
be displaced on said one end portion toward the crimpable end
thereof;
a collar disposed in the rear bore of said second connector housing
and projecting slightly therefrom;
spring contact members on the rear end of said first connector
housing for engagably receiving the rear end of said second
connector housing with said projecting collar being slidable in the
rearmost of said series of stepped bores in said first connector
housing so as to engage said male contact member in said female
contact member; and
stop means in the rear end of said first connector housing for
limiting the insertion therein of said second connector housing.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to coaxial cable connectors
and more particularly to an improved method and apparatus for
connecting subminiature coaxial cables.
Among the problems in meeting the high density requirements of
today's electrical connectors suitable for use in the new rack and
panel types as well as in readily available manually disconnectable
connector housings is that of providing a satisfactory subminiature
shield wire, or coaxial, contact, such as one designed for a size
16 cavity with a mated electrical length only slightly over
one-half inch. Generally, such contacts heretofore available have
been readily subject to bending during crimping, which results in
extreme difficulty being encountered in precisely aligning the
contact within an encircling small bore in a connector housing.
Further, because of their size, no satisfactory method has
heretofore been provided for accurately positioning the contact in
a definite axial location within the connector housing.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
new and improved coaxial contact for connecting subminiature cables
in high density connectors.
Another object of the present invention is to provide a novel
apparatus for connecting subminiature coaxial cables having a
connector housing and a coaxial contact which is readily alignable
in spaced relation within a small axial bore of the housing.
Still another object of this invention is to provide a novel
apparatus for connecting subminiature coaxial cables having a
connector housing and a coaxial contact which is accurately
positionable in a fixed location within the housing.
Yet another object of this invention is the provision of a
connector housing and a subminiature coaxial contact which are so
cooperatively constructed as to facilitate ready disposition of the
contact within a bore in the housing at a fixed location therein
and in axial alignment in spaced relation with the wall defining
the housing bore.
It is a further object of this invention to provide a subminiature
coaxial contact which is subject to minimum bending during crimping
and accordingly is more readily alignable in spaced relation within
a small-sized encircling bore of a connector housing.
A still further object of this invention is to provide an improved
method of connecting subminiature coaxial cables in high density
connectors.
A yet further object of the present invention is the provision of
an improved method of connecting subminiature coaxial cables which
insures alignability and accurate positioning of the cable contact
within a bore of a connector housing.
The foregoing and other objects are attained in accordance with one
aspect of the present invention by a subminiature coaxial contact
having a cavity in one end for receiving a stripped center
conductor of a small-size coaxial cable and being provided with a
dielectric sleeve movably positioned thereon and initially disposed
intermediate the ends thereof. The subminiature contact is
insertable into one end of a connector housing have a shoulder stop
therein against which the dielectric sleeve registers so that upon
continued insertion the dielectric sleeve is caused to slidably
traverse the inwardly moving contact until it is positioned against
the end of the insulating sheath disposed about the unstripped
portion of the center conductor of the coaxial cable. The
dielectric sleeve thus may serve as a positioner or stop for use
with a crimping tool prior to inserting the contact into the
connector housing so that crimping occurs on the extreme end of the
contact whereby bending is at a minimum and it is also operative
during insertion into the connector housing to positively locate
the contact in a predictable fixed position therein while
simultaneously aligning the same diametrically in spaced relation
within a small bore of the connector housing. The subminiature
coaxial contact may have a pin contact on the end opposite the
center conductor-receiving cavity or a socket contact, so that when
used together, the respective connector housings of the
subminiature pin contact assembly and the subminiature socket
contact assembly are cooperatively engageable to readily permit the
maintenance of alignment of the pin and socket contacts and to
obtain the shortest posssible mating electrical legnth.
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, in
which like reference numerals designate like or corresponding parts
throughout the several views, and wherein:
FIG. 1 is a perspective view of a subminiature pin center contact
having a pair of dielectric sleeves positioned thereon and a
connector housing for receiving the contact being formed in
accordance with the present invention;
FIG. 2 is a longitudinal cross-section of the connector housing and
the pin center contact shown in FIG. 1 having a stripped center
conductor of a subminiature coaxial cable secured within the
contact and illustrating in part a crimping tool for crimping the
one end of the contact;
FIG. 3 is another cross-sectional view of the apparatus of FIG. 1
showing the contact being inserted into the connector housing with
the one dielectric sleeve registering with a stop therein;
FIG. 4 is another cross-sectional view of the fully assembled
apparatus illustrated in FIG. 1;
FIG. 5 is a perspective view of a socket, or female, center contact
having a movable dielectric sleeve disposed thereon and a connector
housing for receiving the contact being formed in accordance with
the present invention;
FIG. 6 is a longitudinal cross-section view of the connector
housing and the socket contact shown in FIG. 5 and illustrating in
part a crimping tool for crimping one end of the socket contact
when a center conductor of a subminiature coaxial cable is received
therein;
FIG. 7 is a cross-sectional view of the apparatus illustrated in
FIG. 5 showing the socket contact being inserted into the connector
housing with the dielectric sleeve registering against a stop
therein;
FIG. 8 is another cross-sectional view of the apparatus shown in
FIG. 5 when fully assembled; and
FIG. 9 is a cross-sectional view of the pin contact assembly shown
in FIG. 4 and the socket contact assembly shown in FIG. 8 being
inter-engaged for connecting the respective subminiature cables
thereof.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring now to the drawings, and more particularly to FIGS. 1 and
2 thereof, there is shown a male center contact generally indicated
by the reference numeral 10 being formed with one cylindrical end
portion 11 having an axially-extending cavity 12 therein and
another end portion 13 being an elongate pin contact of a smaller
diameter than end portion 11 and extending coaxially from the end
thereof opposite the cavity 12. A dielectric sleeve 14 is slidably
positioned on the end portion 11 of the contact 10 being initially
disposed at the end thereof connected with the pin contact 13 and
another dielectric sleeve 15 is slidably positioned on the pin
contact 13 being initially disposed at the end thereof connected
with the end portion 11 so that the dielectric sleeves 14 and 15
are initially positioned with respective end faces thereof
contacting one another. The dielectric sleeve 14, as shown, has a
larger diameter than that of dielectric sleeve 15. Preferably the
sleeves 14 and 15 are constructed of Teflon, although it is to be
understood that other suitable materials may be employed. A screw
16 is shown being threadably engaged radially into the end portion
11 of the male contact 10 at a longitudinal location thereon which
is initially not covered by the dielectric sleeve 14 for the
purpose of permitting a center conductor of a subminiature coaxial
cable to be fixedly secured within the cavity 12.
The reference numeral 18 generally designates a connector housing
for the male center contact 10 having stepped bores 19, 20 and 21
coaxially formed therein which provide shoulders 22 and 23 at the
points of the respective diameter changes. The periphery of the end
portion of connector housing 18 in which the larger bore 21 is
formed has a plurality of rolled V-shaped serrations 24 formed
therein, the purpose of which will be set forth hereinbelow. At the
other end of the connector housing 18, an integral tubular portion
25 is provided with a plurality of longitudinal slots 26,
preferably being four in number spaced at 90.degree. intervals, so
that the end portion 25 provides a shoulder portion 27 internally
thereof at the juncture with the bore 19 and provides a set of
contact springs, the operation of which will be described in
greater detail further below.
Still referring to FIG. 2, an engaging wall 28 of a crimping tool
29 is shown positioned about one end of the center contact 10. As
is well known, it is important to maintain alignment of the inner
and outer contacts, especialy in small-size coaxial contacts, and
any bending caused by crimping of the center contact becomes a
critical factor in obtaining such alignment in the dielectric
spacer. Thus, in this embodiment, with the dielectric sleeve 14
being located forwardly on the end portion 11 of contact 10, it
acts as a positioner or stop in the crimping tool, so that the
initial location thereof permits the crimp to occur on the extreme
end of the contact. Thus, should any bending action occur in the
crimp area, the effect is at an absolute minimum as compared to a
crimp centered in the contact length.
Referring now to FIG. 3, the inner, or center, conductor of a
subminiature coaxial cable 31 is stripped of its various protective
and insulative jackets and is inserted and fixedly secured within
the cavity 12 of the center contact 10 by screw member 16.
Thereafter, the end portion 11 of the center contact 10 is crimped
to the center conductor and the center contact 10 is inserted into
the connector housing 18. Upon insertion therein, the dielectric
sleeve 14 which snugly fits within the bore 21, engages the
shoulder 23. At this time, the dielectric sleeve 15 is disposed in
the bore 20 of connector housing 18. Since the dielectric sleeve 14
is prevented from being further displaced into the connector
housing by its engagement with shoulder 23, further insertion of
the center contact 10 into the connector housing 18 causes the
dielectric sleeve 14 to move to the rear of the end portion 11 of
the center contact 10 until, as shown in FIG. 4, it is positioned
over the previously crimped area and against the facing annular
wall 32 of the cable insulating sheath 33 at the point to which the
same had been previously stripped from the center conductor prior
to crimping. Thus, in addition to giving axial alignment on the
extreme end of the contact, the dielectric sleeve 14 also acts as a
stop or positioner for the positive locating of the center
contact-cable with respect to the connector housing 18.
Further, the dielectric sleeve 15, during its forced movement
through the bore portion 20 of the connector housing 18 effected
through its engagement with the annular end of end portion 11,
combines with the movable dielectric sleeve 14 being displaced
therefrom to provide maximum axial alignment of the center contact
10 within the housing. Movement of the center contact into the
connector housing 18 also is limited, of course, as shown in FIG.
4, by the engagement of the dielectric sleeve 15 with the shoulder
22 at the end of bore 20. Thus, the movable dielectric technique
permits the shortest possible impedance match and only requires a
double stripping of the cable as opposed to the conventional triple
strip.
The outer braid 34 of the coaxial cable 31 may then be received
over the serrated end portion of the connector housing 18 and
electrically secured thereto by a conventional clamping collar
35.
Turning now to FIGS. 5 and 6, a female, or socket, center contact
is generally indicated by the reference numeral 40. This female
center contact 40 has an end portion 41 having an elongate cavity
42 therein for receiving a center conductor 43 of a coaxial cable
which has been stripped of it various protective and insulative
jackets. The other end portion 44 of the female center contact 40
has a slotted socket portion 45 on one end which is adapted to
receive a corresponding pin contact 13 of a male center contact 10.
The end portion 44 of the center contact 40 has a smaller diameter
than the end portion 41 and extends axially therefrom. A dielectric
sleeve 47 is slidably positioned on the center contact 40, being
initially located at the juncture of the end portions 41 and 44.
The dielectric sleeve 47 is preferably constructed of Teflon
although it is to be understood that other suitable materials may
be employed.
The socket portion 45 is designed to offer the maximum frontal
opening target area, so that instead of a standard slotted and
tapered, or pinched tube configuration, the outer surface thereof
is kept straight and inward projections 48, shown in FIG. 6,
provide the contact area. This gives the maximum bellmouth opening
in the front for the best possible alignment within the dielectric
sleeve 47 and the inward projecting surfaces 48 maintain a constant
spring length, contact pressure, as well as consistent location of
the electrical contact area.
A connector housing 50 having a bore 51 in one end and a counter
bore 52 in the other end forming a tapered shoulder 53 therebetween
is provided for receiving the female center contact 40. The
periphery of the one end portion of the connector housing 50 in
which the counter bore 52 is located is serrated as indicated by
reference numeral 54 in the same manner as connector housing 18,
for the same purpose, being to provide good electrical contact of
the outer braid of a coaxial cable when fastened thereto by a
suitable clamping collar. Disposed in the bore 51 in the other end
of the connector housing 50 is a collar 55 which is adapted to
receive the frontal opening target area of the socket portion 45 of
female center contact 40.
As in the earlier description of the male center contact 10, the
stripped center conductor 43 is inserted into the cavity 42 and
with the dielectric sleeve 47 serving as a positioner for the
crimping tool 29, the end portion 41 of the center contact 40 is
crimped about the center conductor 43. Then, upon insertion of the
crimped center contact 40 into the connector housing 50, the socket
portion 45 is positioned in the collar 55 and the dielectric sleeve
47 engages the shoulder 53, as shown in FIG. 7.
Upon further insertion of the center contact 40 into the connector
housing 50, the dielectric sleeve 47 is caused to move to the rear
of the end portion 41 of the center contact 40 until it is
positioned over the previously crimped area and against an end wall
32' of an insulating sheath 33' of a coaxial cable 31', as shown in
FIG. 8. As in the case of the male center contact 10 with its
dielectric sleeve 14, the dielectric sleeve 47 of the female center
contact 40 acts as a stop or positioner for the center
contact-cable location within the connector housing 50, as well as
providing axial alignment on the extreme end of the contact.
The outer braid 34' about the insulating sheath 33' of coaxial
cable 31' is received over the serrated portion 54 of the connector
housing 50 and is electrically secured thereto by a clamping collar
35'.
Turning now to FIG. 9, an assembled version of the male center
contact assembly 10 and the female center contact assembly 40 is
shown. Thus, the end portion of the connector housing 50 having the
collar 55 therein is forceably inserted into the set of spring
contacts 25 of the connector housing 18, with the collar 55
slightly projecting from the end of the connector housing 50 being
received in the bore 19 of connector housing 18 until the end wall
of connector housing 50 having bore 51 therein registers against
the shoulder 27. During this forceable insertion of the end of
connector housing 50 into the spring contact area 25 of connector
housing 18, the pin contact 13 of the male center contact 10 is
slidably received between the projections 48 on the inner surfaces
of the socket portion 45 of the female center contact 40.
Thus, a novel coaxial cable connection technique is provided which
utilizes a movable dielectric for insuring alignment of the male
and female contacts and for positively locating these contacts in
predictable fixed positions within their respective connector
housings, and thus permits the use of subminiature coaxial cables
in high density connectors with improved results. Another feature
of the invention is that a dielectric may be fabricated from low
cost dielectric tubing which is cut to length in order to form the
movable and fixed encircling dielectrics.
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 invention may be practiced otherwise than as
specifically described herein.
* * * * *