Electrical connectors – Including or for use with coaxial cable – Having screw-threaded or screw-thread operated cable grip
Reexamination Certificate
1999-12-13
2001-04-03
Sircus, Brian (Department: 2839)
Electrical connectors
Including or for use with coaxial cable
Having screw-threaded or screw-thread operated cable grip
C439S578000
Reexamination Certificate
active
06210222
ABSTRACT:
FIELD OF THE INVENTION
The invention is related to the field of telecommunications and coaxial cable connectors, and more particularly to a one piece F connector which maintains a mechanical and fully shielded electrical connection with a coaxial cable end, while also providing a substantial RF and moisture seal.
BACKGROUND OF THE INVENTION
Conventional coaxial cables for the cable television industry, such as those shown in
FIG. 6
, typically include a circular center electrical conductor surrounded by a plastic or foam dielectric insulating layer of substantially constant thickness which forms an annular ring around the center electrical conductor. The outer surface of the dielectric insulating layer is covered by an outer conductor, usually an electrically conductive foil or braid or both of a material such as aluminum, and finally an outer elastomeric jacket surrounds the outer conductor.
So-called “F”-type connectors have historically been utilized to terminate the above types of coaxial cables in order to provide a continuous relationship between the center electrical conductor and the conductive foil or braid (or both) in order to effectively transmit a signal without leakage or loss of signal due to the connector and coaxial cable termination devices. F-connectors can include two, three, four, or more pieces, which are assembled together to retain a cable end. A key feature of some, is a hollow post positioned within a metal sleeve, the hollow post including a barrel portion having a raised barb. The barrel portion has a diameter which is slightly larger than the diameter of the inner dielectric insulating layer such that a prepared cable end having an exposed dielectric layer and center conductor can be positioned within the interior of the barrel. The cable is then compressed to complete the connection.
Several different methods have been employed historically to terminate the cable and complete the above assembly. Each of these methods have inherent problems. For example, one common termination method is to radially crimp the metal sleeve onto the post and barb using a hex-shaped tool. Using this method, six indents are formed, creating gaps in 60 degree intervals between the connector body and the jacket of the coaxial cable. These gaps potentially allow moisture into the connector and cause potential distortion of the coaxial cable. Moisture produces corrosion, effectively reducing signal strength and increasing resistance between the coaxial cable and the connector. In addition, because the afore mentioned leakage termination paths, RF leakage can also invariably occur between the connector and the coaxial cable's inner conductive braid shield.
Rather than using a radial crimping method for securing the coaxial cable to the connector, other F connector types use varied techniques using axial forces. For example, the EZ-F type connector manufactured by Raychem Corporation includes a compression sleeve, made from plastic or metal, in combination with the post, a retaining nut, and an outer sleeve. The compression sleeve is disposed between the post and the retaining nut and is caused to plastically deform into an open annular space defined in the post by application of an axial or longitudinal tool.
In another form of longitudinal crimp cable connector, described in U.S. Pat. No. 5,002,503, a preassembled nut, collar, and post are used in conjunction with an axially movable sleeve which fits within the open end of the collar to create a tight mechanical connection. In all known connectors which utilize longitudinal termination (e.g. use a longitudinal compression tool for termination thereof), the portion of the connector having the rotating nut is held in a stationary position and the portion of the connector body or sleeve accepting the coaxial cable moves axially in a direction toward the rotating nut of the connector. Besides the additional costs associated in the manufacture and assembly of these types of connectors, there are also leakage effects due to loosening of the connector and the cable end given that the forces are applied in the same direction as the assembly of the cable.
SUMMARY OF THE INVENTION
A primary object of the present invention is to overcome the above noted problems of the prior art.
Another primary object of the present invention is to provide a coaxial cable connector which provides a substantial mechanical fit between a coaxial cable and the connector while providing good electrical interconnection between the coaxial cable shielding conductor and the coaxial cable connector with minimal leakage.
Yet another primary object of the present invention is to provide an F coaxial cable connector which is adaptable for both environmental as well as non-environmental uses.
Therefore and according to a preferred aspect of the invention, there is provided a longitudinally compressed coaxial cable connector used for terminating a drop end of a coaxial cable, said coaxial cable including a center electrical conductor, a dielectric layer surrounding said center electrical conductor, a conductive layer surrounding said dielectric layer, and an outer insulating layer, said connector comprising:
an outer tubular sleeve having opposing first and second ends;
an inner post press fitted into one of the ends of said outer tubular sleeve, said inner hollow post comprising an annular flange and an extending barrel portion sized for receiving the dielectric layer and center electrical conductor of a prepared cable end inserted into the other end of said outer tubular sleeve, said barrel portion including a raised barb for separating the conductive layer and the outer insulating layer of the inserted cable end; and
a rotating nut member attached to said inner post, said rotating nut member having an internal threaded portion for receiving input from a cable termination device, and in which said inner post and said rotating nut are movable within the interior of said outer tubular sleeve toward the cable receiving end of the outer tubular sleeve to crimp the inserted cable end and to complete the termination thereof.
According to another preferred aspect of the present invention, there is provided a longitudinally compressed cable connector for terminating a drop end of a coaxial cable, said connector comprising: an outer tubular sleeve having opposing first and second ends; a hollow inner post pressfitted into one of the ends of the outer tubular sleeve, said inner post comprising an annular flange and an extending barrel portion having a diameter sized for receiving a portion of a prepared coaxial cable end inserted into the opposing end of said tubular sleeve, said barrel portion having means for separating portions of said coaxial cable; and a rotating nut fixedly attached to said inner post, said rotating nut having an internal threaded portion for receiving input from a cable termination device wherein said rotating nut and inner post are capable of axial movement in a direction directed toward the cable receiving end of the outer tubular sleeve, said sleeve being stationarily held after insertion of said cable end and in which said outer tubular sleeve includes an opening at the cable receiving end, said opening having a throat for compressing said inserted cable end.
According to yet another preferred aspect of the present invention there is provided a method of terminating a coaxial cable using an F connector, said F connector having an inner post fitted within an outer tubular sleeve, said method comprising the steps of:
i) preparing one end of a coaxial cable by removing an axial portion of at least one outer layer of said cable;
ii) inserting the prepared coaxial cable end into said cable connector wherein insertion causes the axially separated portion to extend through an axial sleeve and separates the outer portion of the remainder of the cable inserted into the connector;
iii) driving said cable until the separated ends of said coaxial cable are placed into a circumferential sealing recess; and
iv) supporting said sleeve in a stationary p
Harrison Gary L.
Langham Arvin L.
McLaughlin William D.
Burr & Brown
Eagle Comtronics, Inc.
Le Thanh-Tam
Sircus Brian
LandOfFree
Coaxial cable connector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Coaxial cable connector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coaxial cable connector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2551005