Information
-
Patent Grant
-
6808416
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Patent Number
6,808,416
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Date Filed
Thursday, April 4, 200222 years ago
-
Date Issued
Tuesday, October 26, 200419 years ago
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Inventors
-
Original Assignees
-
Examiners
Agents
- Barley, Snyder, Senft & Cohen, LLC
-
CPC
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US Classifications
Field of Search
-
International Classifications
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Abstract
The invention relates to a coaxial cable connector having a conductive outer shell comprising a mating section and a cylindrical sleeve. The cylindrical sleeve has a cable receiving end having an annular projection with a larger external diameter than the cylindrical sleeve. A coaxial cable is stripped to expose portions of an outer conductor, a dielectric, and a central conductor. The central conductor terminates within a signal pin. A ferrule is positioned over the outer conductor. The outer conductor is folded back over the ferrule. An insulative cylinder is positioned over the dielectric. When a crimping die is applied to the cylindrical sleeve, the crimping die first contacts the annular projection. The annular projection rolls inward and toward the mating section of the conductive outer shell. The annular projection contacts the ferrule pushing the ferrule toward the mating section to create a forward bias inside the cylindrical sleeve.
Description
FIELD OF THE INVENTION
The present invention relates to coaxial cable connectors and, more particularly, to a coaxial connector having an improved crimp section.
BACKGROUND OF THE INVENTION
Coaxial cable connectors are commonly used to terminate coaxial cables. These connectors typically include a conductive outer shell comprising a mating section, a signal pin and a cylindrical sleeve that receives and mechanically secures a stripped end of a coaxial cable. The coaxial cable has a center conductor for transmitting a signal. The center conductor is surrounded by a dielectric. An outer ground or shield conductor in the form of a pliant wire braid encircles the dielectric. The outer conductor is encased in a protective jacket.
To secure the coaxial cable in the connector, a stripped end of the coaxial cable is inserted into a receiving end of the cylindrical sleeve. The exposed center conductor is electrically connected to the signal pin contained within the connector. As the coaxial cable is inserted into the cylindrical sleeve, an inner tubular member, that may comprise raised barbs, is forced between the dielectric and the outer conductor of the coaxial cable. The outer conductor is received in a space between the cylindrical sleeve and the inner tubular member and may be folded back over the end of the protective jacket. This method and arrangement is disclosed in U.S. Pat. No. 5,499,934 issued to Jacobsen et al. and U.S. Pat. No. 5,525,076 issued to Down. A conventional crimping tool is then used to apply a crimp to the outside of the cylindrical sleeve securing the outer conductor jacket of the coaxial cable between the inner tubular member and the cylindrical sleeve.
A known alternative method for securing a coaxial cable in a connector is commonly used when larger connectors terminate smaller coaxial cables. In this method, a ferrule and an insulative cylinder, respectively, are positioned over the stripped coaxial cable before insertion into the cylindrical sleeve. The exposed center conductor is electrically connected to the signal pin within the connector. The outer conductor of the coaxial cable is then folded back and over the ferrule so that the outer conductor is received in a space between the cylindrical sleeve and the ferrule when the coaxial cable is inserted into the cylindrical sleeve. A conventional crimping tool is then used to apply a crimp along the outside diameter of the cylindrical sleeve to secure the outer conductor jacket of the coaxial cable between the ferrule and the cylindrical sleeve.
In these connectors, a compressive force applied by the crimp secures the internal components of the connector. This retention alone, however, is inadequate when external pulling forces are applied to the coaxial cable. For example, when an external force is exerted on the coaxial cable in a direction opposite from the connector body, the compressive forces are unable to prevent outward movement of the internal components. When the internal components become displaced, the integrity of the connector is jeopardized. Gaps created between the internal components also allow moisture and other foreign matter to enter the connector and may result in pin stubbing upon mating, further deteriorating the electrical performance of the connector.
It is therefore desirable to develop a coaxial connector with a rigid construction that improves coaxial cable retention and electrical performance by providing additional physical restraint of the internal components of the coaxial connector.
SUMMARY OF THE INVENTION
An object of the present invention is to develop an improved crimp section for a coaxial cable connector. This and other objects of the invention are achieved by a coaxial connector having a conductive outer shell comprising a mating section and a cylindrical sleeve. The cylindrical sleeve has a cable receiving end for receiving a cable, at least one ferrule located inside the cylindrical sleeve and an annular projection positioned on the cable receiving end of the cylindrical sleeve. The annular projection has a larger external diameter than the cylindrical sleeve. When a crimping die is applied to the cylindrical sleeve, the crimping die first contacts the annular projection, causing the annular projection to roll inward and toward the -mating section of the conductive outer shell to securely forward bias the cable and ferrule within the cylindrical sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example with reference to the accompanying figures in which:
FIG. 1
is an exploded perspective view of the coaxial connector.
FIG. 2
is a cross-sectional view of the coaxial connector before cable insertion and crimping.
FIG. 3
is a cross-sectional view of the coaxial connector including a terminated cable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1
shows a coaxial cable connector
10
having an electrically conductive outer shell
12
comprising a mating section
12
a
and a cylindrical sleeve
12
b
. The mating section
12
a
has a centrally located signal pin
15
surrounded by a dielectric
18
. A retaining ring
17
is positioned between the outer shell
12
and the dielectric
18
. The mating section
12
a
may optionally comprise a fastener (not shown) that surrounds the conductive outer shell
12
, such as an internally threaded nut, designed to secure a complimentary receptacle to the mating section
12
a
of the end connector
10
. The cylindrical sleeve
12
b
has a cable receiving end
34
and an annular projection
11
. The cylindrical sleeve
12
b
receives a coaxial cable
20
for termination within the connector
10
. The coaxial cable
20
, shown in
FIG. 1
, has a center conductor
21
for transmitting a signal. The center conductor
21
is a solid or stranded wire that is centrally located within a dielectric
22
. An outer conductor
23
or shield surrounds the dielectric
22
. The outer conductor
23
generally comprises a pliant wire braid that may be woven over a foil sheath. The outer conductor
23
, encircling the cylindrical dielectric
22
, is encased within a protective jacket
24
.
Each of the major components will now be described in greater detail with reference to
FIGS. 1 and 2
. As shown in
FIG. 2
, the conductive outer shell
12
has a mating end
32
and a cable receiving end
34
disposed opposite the mating end
32
. An outer surface
36
extends from the mating end
32
to the cable receiving end
34
. The conductive outer shell
12
consists mainly of a mating section
12
a
and a cylindrical sleeve
12
b
. Within the mating section
12
a
, the outer surface
36
is contoured to have raised portions
40
and recessed portions
42
disposed therebetween. Moving rearward from the mating section
12
a
, an annular ridge
44
is disposed about the outer surface
36
rearward of the raised portion
40
.
The cylindrical sleeve
12
b
is disposed between the annular ridge
44
and the cable receiving end
34
. The cylindrical sleeve
12
b
consists of a generally tubular section having a cylindrical sleeve inner surface
54
and a cylindrical sleeve outer surface
56
. An annular projection
11
is disposed around the cylindrical sleeve outer surface
56
at the cable receiving end
34
. It should be understood by those reasonably skilled in the art that while the annular projection
11
is shown here as having a generally rectangular cross section it could have other geometrical configurations either on the outer surface
56
or the inner surface
54
that may have a similar function as will be described in greater detail below. Also, it should be understood by those reasonably skilled in the art that while the outer surface
36
has been described with a certain contour, that contour may be varied depending on size constraints and securing requirements of a particular application.
Beginning once again at the mating end
32
in
FIG. 2
, the conductive outer shell
12
has a receptacle receiving portion
46
disposed along an inner surface
38
. The inner surface
38
extends from the mating end
32
to the cable receiving end
34
. A ring receiving portion
48
is located along the inner surface
38
rearward of receptacle receiving portion
46
and has a slightly smaller inner diameter than the receptacle receiving portion
46
. A dielectric receiving portion
50
is located rear of the ring receiving portion
48
and has a slightly smaller diameter than the ring receiving portion
48
. The dielectric receiving portion
50
ends at a rear wall
52
that connects with a cylindrical sleeve inner surface
54
. The cylindrical sleeve inner surface
54
is generally cylindrical and has a relatively smaller diameter than the dielectric receiving portion
50
. The cylindrical sleeve inner surface
54
extends from the rear wall
52
back to the cable receiving end
34
.
A dielectric
18
is located within the dielectric receiving portion
50
at the mating end
32
of the connector
10
and has a diameter smaller than the inner surface
38
. The dielectric
18
extends to the rear wall
52
and has a receptacle guide
60
that forms an inner receptacle receiving portion
58
. A signal pin receiving portion
62
extends through the dielectric
18
and extends to an insulative cylinder receiving portion
84
. Located on the signal pin receiving portion
62
is an annular stop wall
64
that transitions to the larger circumferencial area of the insulative cylinder receiving portion
84
.
The signal pin
15
is centrally located within the inner receptacle receiving portion
58
. The signal pin
15
has a coupling portion
15
a
and a signal pin body
15
b
. The coupling portion
15
a
of the signal pin
15
extends to a wall
16
of the signal pin body
15
b
. The signal pin body
15
b
is hollow and has a larger diameter than the coupling portion
15
a.
An insulative cylinder
14
has an insulative cylinder inner surface
72
; and an insulative cylinder outer surface
66
that extends between first and second ends
68
,
70
. The insulative cylinder inner surface
72
has a diameter smaller than the diameter of the insulative cylinder outer surface
66
. The diameter of the insulative cylinder outer surface
66
is smaller than the cylindrical sleeve inner surface
54
such that a small clearance exists between the insulative cylinder outer surface
66
and the cylindrical sleeve inner surface
54
. The insulative cylinder first end
68
is positioned adjacent to the signal pin body
15
b
. The insulative cylinder second end
70
is positioned adjacent a conductive ferrule
13
.
The ferrule
13
is generally cylindrical and has a ferrule outer surface
74
and a ferrule inner surface
76
, that extends between first and second ends
78
,
80
. The ferrule inner surface
76
has a diameter smaller than the ferrule outer surface
74
, but larger than the insulative cylinder inner surface
72
. The ferrule outer surface
74
has a diameter smaller than the inner diameter of the cylindrical sleeve inner surface
54
, but slightly larger than the insulative cylinder outer surface
66
such that the clearance
19
between the ferrule outer surface
74
and the cylindrical sleeve inner surface
54
is slightly smaller than between the insulative cylinder
14
and the inner diameter
54
. The ferrule first end
78
is positioned adjacent to the insulative cylinder second end
70
and extends to the cable receiving end
34
such that the ferrule second end
80
is positioned slightly forward within the annular projection
11
near the cable receiving end
34
.
Termination of the coaxial cable
20
and assembly of the connector
10
will now be described in greater detail with reference to
FIGS. 1 and 3
. First the dielectric
18
is loaded into the mating section
12
a
from the mating end
32
until it engages the rear wall
52
. The retaining ring
17
is secured in the receiving portion
48
to retain the dielectric
60
.
To prepare the coaxial cable
20
for installation in the connector
10
, a conventional tool is used to strip one end of the coaxial cable
20
as best shown in FIG.
1
. The protective jacket
24
of the coaxial cable
20
is removed to expose the outer conductor
23
. A portion of the outer conductor
23
and a smaller portion of the dielectric
22
are stripped away to expose the center conductor
21
.
The ferrule
13
is positioned over the protective jacket
24
behind the exposed outer conductor
23
. The outer conductor
23
is then folded back over the ferrule
13
as best shown in FIG.
3
. The insulative cylinder
14
is positioned over the section of the coaxial cable its dielectric
22
exposed therebehind. The center conductor
21
is received in the signal pin body
15
b
and terminates behind the wall
16
. Termination of the center conductor
21
to the signal pin
15
may be accomplished by crimping or other suitable means. The terminated signal pin
15
, insulative cylinder
14
, ferrule
13
and cable
20
subassembly is then inserted into the conductive outer shell
12
from the cable receiving end
34
until the pin body
15
b
engages the annular stop wall
64
. The outer conductor
23
is received in a clearance
19
between the ferrule
13
and the inner surface
54
.
A conventional crimping die, such as a hex die (not shown) is then applied to the cylindrical sleeve
12
b
to secure the coaxial cable
20
inside the connector
10
as best shown in FIG.
3
. Because the annular projection
11
at the rear of the cylindrical sleeve
12
b
has a larger external diameter compared to the balance of the cylindrical sleeve
12
b
, as the cylindrical sleeve
12
b
is crimped, the die will first contact the annular projection
11
. As the crimp is applied, the annular projection
11
is forced to roll inward and toward the mating end
32
of the conductive outer shell
12
. As a result, the cable receiving end
34
of the cylindrical sleeve
12
b
has post crimp diameter which is slightly smaller than the balance of the cylindrical sleeve
12
b
. The internal deformation of the cylindrical sleeve
12
b
behind the ferrule
13
causes the internal components including the ferrule
13
, the insulative cylinder
14
, and the signal pin
15
, to be biased forward. The forward biased internal components, as well as the outer conductor
23
are locked in place by the internal surface of the annular projection
11
at the rear of the cylindrical sleeve
12
b.
As the die continues to crimp the cylindrical sleeve
12
b
, the cylindrical sleeve
12
b
is compressed to eliminate the clearance
19
between the ferrule
13
and the cylindrical sleeve
12
b
, securing the outer conductor
23
between the ferrule outer surface
74
and the cylindrical sleeve inner surface
54
. The major components are advantageously biased and retained in the conductive outer shell
12
by a single crimping action.
While the present invention has been described in connection with the illustrated embodiments, it will be appreciated and understood that modifications may be made without departing from the true spirit and scope of the invention. For example, the annular projection could be positioned on the cylindrical sleeve inner surface and a similar effect may be achieved. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.
Claims
- 1. A coaxial cable connector, comprising:a conductive outer shell having a mating section and a cylindrical sleeve; the cylindrical sleeve having a cable receiving end; and an annular projection positioned on the cable receiving end of the cylindrical sleeve and having a larger external diameter than a remainder of the cylindrical sleeve; wherein when a crimping die is applied to the cylindrical sleeve, the crimping die first contacts the annular projection, causing the annular projection to bend inward into an interior of the cylindrical sleeve so that the annular projection contacts a ferrule having a smaller diameter than a diameter of the cylindrical sleeve and positioned inside the cable receiving end of the cylindrical sleeve over an exposed outer conduct of a coaxial cable to push the ferrule forward and toward the mating section to create a forward bias within the cylindrical sleeve.
- 2. The coaxial cable connector of claim 1, wherein the outer conductor is folded back over an outer surface of the ferrule.
- 3. The coaxial cable connector of claim 2, wherein the outer conductor is crimped between the ferrule and the cylindrical sleeve.
- 4. The coaxial cable connector of claim 1, further comprising an insulative cylinder having a smaller diameter than a diameter of the cylindrical sleeve wherein the insulative cylinder is positioned over an exposed dielectric of a coaxial cable and the insulative cylinder is inserted into the cable receiving end of the cylindrical sleeve forward of the ferrule.
- 5. The coaxial cable connector of claim 1, wherein the annular projection is positioned on an outer surface of the cable receiving end of the cylindrical sleeve.
- 6. The coaxial cable connector of claim 1, further comprising a dielectric having a circumference smaller than a circumference of the mating section of the conductive outer shell and positioned within the mating section of the conductive outer shell.
- 7. The coaxial cable connector of claim 6, wherein the dielectric receives a pin terminated to a center conductor of the coaxial cable.
- 8. A coaxial cable connector, comprising:a conductive outer shell having a mating section and a cylindrical sleeve; the cylindrical sleeve having a cable receiving end; the mating section having a signal pin surrounded by a dielectric sleeve; a retaining ring interposed between the conductive outer shell and the dielectric sleeve; a coaxial cable having a stripped end exposing portions of an outer conductor, a dielectric, and a central conductor; the signal pin terminated to the central conductor; a ferrule positioned in the cylindrical sleeve and over the exposed outer conductor and having the outer conductor folded back over the ferrule; an insulative cylinder positioned over the exposed dielectric; and an annular projection positioned on the cable receiving end of the cylindrical sleeve and having a larger external diameter than the cylindrical sleeve; wherein when a crimping die is applied to the cylindrical sleeve, the crimping die first contacts the, annular projection, causing the annular projection to bend inward into an interior of the cylindrical sleeve until the annular projection contacts the ferrule pushing the ferrule forward and toward the mating section to create a forward bias within the cylindrical sleeve.
- 9. The coaxial cable connector of claim 8, wherein the annular projection is positioned on an outer surface of the cable receiving end of the cylindrical sleeve.
- 10. A coaxial cable connector having a conductive outer shell, the conductive outer shell having a mating section and a tubular cylindrical sleeve, the mating section having a signal pin, the cylindrical sleeve having a cable receiving end and comprising:an annular projection positioned on the cable receiving end of the cylindrical sleeve and having a larger external diameter than the cylindrical sleeve; an annular stop wall formed in a dielectric sleeve housing the signal pin; and a ferrule having a smaller diameter than a diameter of the cylindrical sleeve and positioned inside the cable receiving end of the cylindrical sleeve for positioning over an exposed outer conductor of a coaxial cable, the ferrule being biased toward the annular stop wall after crimping of the annular projection; wherein when a crimping die is applied to the cylindrical sleeve, the crimping die first contacts the annular projection, causing the annular projection to bend inward into an interior of the cylindrical sleeve until the annular projection contacts the ferrule pushing the ferrule forward and toward the annular stop wall to create a forward bias within the cylindrical sleeve.
- 11. The coaxial cable connector of claim 8, wherein the ferrule is biased toward an annular stop wall formed in the dielectric sleeve.
- 12. The coaxial cable connector of claim 10, further comprising an insulative cylinder for positioning over an exposed dielectric of the coaxial cable, the insulative cylinder positioned inside the cylindrical sleeve and adjacent to the ferrule.
- 13. The coaxial cable connector of claim 10, wherein the external diameter of the annular projection is smaller than the cylindrical sleeve after crimping.
US Referenced Citations (16)