End connector for coaxial cable

An end connector for coaxial cables having inner and outer spaced concentric sleeves, the outer sleeve having axially spaced endless sealing rings along its inner wall surface portion adjacent to one end to which the end of the coaxial cable is inserted, and axially spaced serrations or gripping edges are disposed on the external wall surface of the inner sleeve in confronting relation to the ribs so that when the coaxial cable is inserted into the connector with the outer conductor and jacket in the annular space between the sleeves the outer sleeve can be crimped inwardly to cause the ribs to advance into uniform sealed engagement with the jacket. The depth of the ribs can be controlled according to the diameter or size of cable to which it is connected.

BACKGROUND OF THE INVENTION 
This invention relates to fittings for connecting coaxial cables to a 
selected device, such as, a post or terminal customarily used in cable 
television; and more particularly relates to a novel and improved end 
connector for electrically and mechanically connecting a fitting in sealed 
engagement with a coaxial cable. 
Coaxial cables are generally characterized by being made up of inner and 
outer concentric conductors separated by a dielectric insulator and 
encased or covered by an outer jacket of rubber or rubber-like material. 
Numerous types of end connectors have been devised to effect a secure 
mechanical and electrical connection to the end of the coaxial cable and 
in such a way that the inner conductor and dielectric insulator extend 
through an inner sleeve of the connector while the outer conductor and 
jacket are inserted into an annular space between the inner sleeve and an 
outer concentric sleeve. The outer concentric sleeve is then crimped in a 
radial inward direction to securely clamp the end of the cable within the 
connector, and a fastener on the opposite end of the connector is then 
connected to the post or terminal. Representative of end connectors that 
have been devised for this purpose is that disclosed in U.S. Pat. No. 
5,073,129 to Szegda which employs a combination of external ribs and 
internal serrations along the crimping sleeve in order to assure a 
reliable electrical connection and mechanical coupling between the cable 
and end connector. U.S. Pat. No. 4,400,050 to Hayward similarly employs a 
plurality of serrations along an internal surface of the crimping sleeve 
but which are specifically intended and designed to engage the outer 
conductor of the cable which is doubled over the external surface of the 
jacket and is concerned more with establishing firm gripping engagement 
with the end of the cable. Other patents of interest are U.S. Pat. Nos. 
3,355,698 to Keller, 3,363,222 to Karol, 4,553,806 to Forney et al, 
4,668,043 to Saba et al, 4,684,201 to Hutter, 4,755,152 to Elliot et al 
and 4,806,116 to Ackerman. 
There is a continuing need for a one piece end connector which is capable 
of establishing uniform sealed engagement between the connector and 
coaxial cable and which is conformable for use with different sized cables 
but nevertheless achieves the necessary weather-tight seal as well as 
secure mechanical coupling between the elements while avoiding the 
necessity of using separate sealing members or materials. 
SUMMARY OF INVENTION 
An object of the present invention is to provide for a novel and improved 
connector fitting for coaxial cables. 
It is another object of the present invention to provide for a connector 
fitting capable of effecting sealed engagement with one end of a coaxial 
cable in a novel and improved manner and in such a way as to obviate the 
use of separate seals or sealing compounds. 
It is a further object of the present invention to provide for a novel and 
improved connector fitting for coaxial cables which is interchangeable for 
use with different diameters of cables and is deformable by crimping into 
uniformly sealed engagement with one end of the cable. 
It is an additional object of the present invention to provide for a novel 
and improved connector fitting having an outer smooth crimping surface for 
ease of engagement and uniform clamping by a crimping tool into sealed 
engagement with one end of a coaxial cable; and wherein the connector 
fitting is conformable for use with a range of different sizes and 
diameters of cables. 
In accordance with the present invention, an end connector has been devised 
for connecting an end of a coaxial cable to a terminal or post wherein the 
cable is a standard cable having radially inner and outer, generally 
cylindrical conductors separated by an annular dielectric, an outer 
tubular jacket of rubber or rubber-like material encasing the outer 
conductor and with a portion of the outer conductor being exposed at the 
end of the cable, the connector comprising radially inner and outer spaced 
coaxial sleeves, the inner sleeve being sized for insertion of the inner 
conductor and annular dielectric therein, the outer sleeve being sized for 
insertion of the outer conductor and jacket through one end of the 
connector between the inner and outer sleeves, at least one endless 
circular rib extending circumferentially around an inner wall surface 
portion of the outer sleeve adjacent to the one end of the outer sleeve, 
the rib engaging an external surface of the jacket only when the cable is 
fully inserted into the connector and the outer sleeve is deformed 
radially inwardly until the rib effects sealed engagement with the jacket, 
and means are provided for connecting the connector to the terminal or 
post. 
In preferred and modified forms of the invention, a plurality of axially 
spaced ribs are provided adjacent to the entrance end of the outer sleeve, 
each rib having an inner rounded surface deformable into a portion of the 
jacket until the jacket occupies a circumferentially extending space 
between each adjacent pair of the ribs, and the inner sleeve has external 
projections along an external wall surface of the inner sleeve adjacent to 
the one end. The outer sleeve is given an external smooth surface whereby 
to facilitate crimping with a circular crimping tool which will uniformly 
reduce the diameter of the outer sleeve and cause the ribs to advance into 
uniform sealed engagement with the jacket. In the preferred form, the ribs 
are given a depth greater than one-half of the wall thickness of the outer 
sleeve to accommodate smaller sized coaxial cable; and in a modified form, 
the depth of the ribs can be reduced to less than the wall thickness of 
the outer sleeve in order to accommodate the larger diameter cable. Both 
preferred and modified forms of invention are specifically adaptable for 
use with a crimping tool of the type set forth in my co-pending 
application for patent Ser. No. 992,524, entitled "Crimping Tool" and 
which is specifically for use in reducing the end of the connector or 
fitting into a generally conical configuration snugly engaging the end of 
the cable as opposed to the hexagonal type of crimping tools. 
The above and other objects of the present invention will become more 
readily appreciated and understood from a consideration of the following 
detailed description of preferred and modified forms of the present 
invention when taken together with the accompanying drawings in which:

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
Referring now to the drawings, a conventional form of coaxial cable C is 
made up of an inner conductor 10, a dielectric insulator 11, outer braided 
conductor 12 and dielectric jacket 13 composed of rubber or rubber-like 
material. In accordance with well-known practice, in order to effect 
connection of the cable to a post or terminal, the end of the inner 
conductor 10 is exposed by removing a limited length of the dielectric 
insulator 11, and a limited length 15 of the conductor 12 is peeled back 
from the insulator 11 and doubled over the outer jacket 13 as designated 
at 12'. The standard cable C, including those used in the cable television 
industry, has different outer diameters, principally on account of 
different thicknesses employed in the outer braided conductor 12. For 
instance, an RG Series 59 cable may be on the order of 0.035" smaller in 
diameter than an RG 6 cable, and each series cable may vary approximately 
0.025" owing primarily to the difference in thickness of the braided 
conductor layer 12. 
In accordance with the present invention, as shown in FIGS. 1 to 3, an end 
connector 20 is of the type having an inner sleeve 21 including a sleeve 
body 22, an external shoulder or flange 23 at its forward end and a 
rearward extension 24 of reduced diameter and wall thickness in relation 
to the sleeve body 22. An outer sleeve 26 has a body 27 with an internal 
flange or shoulder 28 in surrounding relation to the sleeve 22 and a 
rearward extension 30 of reduced diameter and thickness in relation to the 
body 27 and in outer spaced concentric relation to the inner sleeve 
extension 24 so as to form an annular space 31 therebetween. External 
surface 39 of the extension 30 is a smooth, non-ribbed continuous surface 
to facilitate gripping and crimping in a manner to be described. A 
fastener 32 at the forward end of the end connector 20 has a radially 
inwardly directed flange 34 at its rearward end which is interposed 
between the external flange 23 of the inner sleeve and the outer sleeve 
body 27 and which normally is freely rotatable with respect to the inner 
and outer sleeve members. The fastener 32 is internally threaded as at 36 
throughout its greater length and is provided with external flats 38 to 
facilitate engagement by a hand wrench or other tool for the purpose of 
threading onto an externally threaded terminal or post. When the fastener 
is threaded or made up onto the terminal or post, it will effectively 
wedge the external flange 22 of the inner sleeve against the end of the 
post. 
An important feature of the present invention resides in the manner in 
which sealed engagement is established between the connector 20 and cable 
C. To this end, endless rings 40 extend circumferentially around inner 
wall surface 41 of the extension 30 adjacent to its rearward end which 
defines the entrance for insertion of the outer jacket. The endless ribs 
or protuberances 40 are disposed at uniform, axially spaced intervals so 
as to be define grooves 42 therebetween, the grooves 42 being of a width 
substantially equal to the width of the ribs 40. Further, both the ribs 40 
and grooves 42 are of rounded or circular cross-sectional configuration so 
that when crimped inwardly in a manner to be described will cause the 
elastic material of the jacket 13 to fill the grooves 42 and effectively 
form O-rings between the jacket 13 and the rings 40. The rings 40 are 
formed only along the crimping zone which is that length of the rearward 
extension 30 adjacent to its rearward end and spaced far enough from the 
opposite forward end of the extension 30 as to avoid contact or engagement 
with the braided conductor 12. 
A plurality of serrations or sawtooth edges 44 are formed on external 
surface 24' of the inner sleeve 24 and in facing relation to the rings 40 
in order to grippingly engage the inner wall surface of the braided 
conductor 12. The serrations 44 are angled in a forward direction so that 
their apices 45 extend or face in a forward direction and will resist 
rearward movement of the cable C with respect to the connector 20. 
In order to attach the end connector 20 onto the end of the cable C, the 
cable is inserted into the end connector 20 with the exposed inner 
conductor 10 and insulator 11 extending through the inner sleeve 21 and 
the outer braided conductor 12 and jacket 13 extending through the annular 
space 31 between the reduced rearward extension 24 of the inner sleeve 22 
and the reduced outer extension 30 of the outer sleeve 26. When the cable 
C is fully inserted into the connector 20, the end of the jacket 13 will 
abut the rearward end of the flange 27 on the outer sleeve 26 and the 
inner conductor 10 will project slightly beyond the end of the fastener 
34. Inward radial crimping of the rearward end of the extension 30 is 
effected by the use of a crimping tool, such as, that disclosed in my 
hereinbefore referred to patent application Ser. No. 992,524 and which 
will cause uniform, radially inward reduction in diameter of the rearward 
end, or crimping zone, which is that area surrounding the spaced rings 40, 
into uniform sealing engagement with the jacket 13. In this relation, the 
inner sleeve 24 extends between the outer conductor 12 and dielectric 
insulator 11, and the serrations 44 will be forced into firm engagement 
with the inner surface of the jacket 13. It is important that the outer 
conductor 12 be doubled over the jacket 13 for a distance short of the 
crimping zone as hereinbefore defined so that the rings 40 can make direct 
sealed engagement with the jacket. 
The modified form of invention shown in FIGS. 4 to 6 demonstrates the 
universality of the end connector 10 and specifically its ability to 
accommodate different diameters of coaxial cables. Like parts to those of 
FIGS. 1 to 3 are correspondingly enumerated. The outside dimensions and 
make-up of the end connector 50 are the same as in the preferred form of 
FIGS. 1 to 3; however, in order to more easily accommodate larger diameter 
cable, axially spaced rings 52 along the inner wall surface of outer 
sleeve 30 are made shallower or truncated with respect to the deeper rings 
40 of the preferred form of FIGS. 1 to 3. In addition, the external 
serrations 54 of the inner sleeve 24 may be formed somewhat shallower than 
the serrations 44 of the preferred form. For the purpose of illustration 
and not limitation, for an end connector having an outer sleeve 30 with an 
outer diameter of 0.370" and intended for use with standard RG 59 cable 
has sealing ribs or rings 40 with a depth on the order of 0.017". On the 
other hand, an end connector 50 as shown in the modified form having an 
outer diameter on the order of 0.370"may be given shallower sealing ribs 
52 on the order of 0.004". By reducing the depth of the ribs, ample space 
is afforded for insertion of the thicker braided conductor 12 and outer 
jacket 13. The width of the grooves 53 between ribs may be the same as the 
width of the grooves 42 in the preferred form; and in each case the corner 
edges of the sealing ribs 40 and 52 are radiussed or rounded as 
illustrated so as not to cut or tear the outer jacket 13 of the cable. 
As noted earlier, the end connectors 20 and 50 of the present invention are 
specifically designed for inward radial crimping along the crimping zone 
by means of a crimping tool which will cause uniform inward reduction in 
diameter of the outer sleeve so as to maintain its circular configuration 
as opposed to a hexagonal configuration. It is possible to achieve a 
greater reduction in diameter with a circular crimp than a hexagonal 
crimp, and the inner sealing ribs or rings 40 and 52 cooperate in assuring 
uniform sealed engagement with the jacket 13 of the cable. 
From the foregoing, it will be appreciated that the connector 20 of the 
present invention is conformable for use with different-sized cables; yet, 
it is capable of effecting sealed engagement with the cable in the manner 
described without the necessity of separate seals or sealing compounds. 
The cable can be installed essentially in a one-step operation with the 
aid of a crimping tool to exert the necessary pressure on the rearward end 
of the extension 30 to cause the rings 40 to move into uniform sealed 
engagement with the outer jacket. Once connected, it is a simple matter to 
thread the fastener end 30 onto the post or terminal to complete the 
connection. 
It is therefore to be understood that while preferred and modified forms of 
invention has been herein set forth and described, various modifications 
and changes may be made in the construction and arrangement of elements 
without departing from the spirit and scope of the present invention as 
defined by the appended claims.