Patent Grant
7488209
The present invention relates to the field of cables and connectors, and, more particularly, to a connector for coaxial cables and associated methods.
Coaxial cables are widely used to carry high frequency electrical signals. Coaxial cables enjoy a relatively high bandwidth, low signal losses, are mechanically robust, and are relatively low cost. One particularly advantageous use of a coaxial cable is for connecting electronics at a cellular or wireless base station to an antenna mounted at the top of a nearby antenna tower. For example, the transmitter located in an equipment shelter may be connected to a transmit antenna supported by the antenna tower. Similarly, the receiver is also connected to its associated receiver antenna by a coaxial cable path.
A typical installation includes a relatively large diameter cable extending between the equipment shelter and the top of the antenna tower to thereby reduce signal losses. For example, CommScope, Inc. of Hickory, N.C, and the assignee of the present invention, offers its CellReach® coaxial cable for such applications. The cable includes a smooth wall outer conductor that provides superior performance to other cable types. The smooth outer wall construction also provides additional ease of attaching connector portions to the cable ends in comparison to other coaxial cable types, such as including corrugated outer conductors, for example.
A typical coaxial cable connector for such a coaxial cable includes a tubular housing or body to make electrical connection to the cable outer conductor and a center contact to make electrical connection to the inner conductor of the coaxial cable. The center contact may include a tubular rearward end to receive the inner conductor of the coaxial cable. An insulator assembly supports the center contact concentrically within the housing. The insulator assembly may typically include multiple cooperating parts.
A typical connector may also include a gripping member or ferrule that is positioned onto the end of the outer conductor and adjacent the outer insulating jacket portion of the coaxial cable. The ferrule is axially advanced into the housing as a back nut is tightened onto the rearward end of the housing. One or more O-rings may be provided to environmentally seal the connector to prevent the ingress of water, for example, into the connector.
Representative patents directed to coaxial cable connectors include U.S. Pat. No. 6,396,367 B1 to Rosenberger; U.S. Pat. No. 6,024,609 to Kooiman et al.; U.S. Pat. No. 6,607,398 B2 to Henningsen; and U.S. Pat. No. 6,217,380 B1 to Nelson et al. The entire contents of each of these patents are incorporated herein by reference.
U.S. Pat. No. 7,011,546 to Vaccaro, assigned to the assignee of the present invention and incorporated herein by reference, discloses a connector, having significant advantages over the prior art. The connector includes a housing, a back nut threadingly engaging a rearward end of the connector housing, a ferrule gripping and advancing an end of the coaxial cable into the connector housing as the back nut is tightened, and an insulator member positioned within a medial portion of the connector housing. In addition, the insulator member has a bore extending therethrough and includes a forward portion, a rearward portion, a ring portion connecting the forward and rearward portions together, and a tubular outer conductor support portion extending rearwardly from the rearward portion for supporting an interior surface of the outer conductor of the end of the coaxial cable. The ring portion may have a reduced strength portion defining a crush zone to facilitate movement of the rearward portion toward the forward portion as the back nut is tightened onto the connector housing.
CommScope has made another connector similar to the Vaccaro patent wherein the insulator member 5 is tuned to match impedances between the connector and the cable end. More particularly, as understood with reference to
In view of the foregoing background, it is therefore an object of the invention to provide a coaxial connector having an insulator member that may be readily manufactured and that effectively matches the impedance between the coaxial cable end and the connector.
These and other objects, features and advantages in accordance with the present invention are provided by a coaxial cable connector comprising an insulator member including a forward portion, and a rearward portion extending rearwardly from the forward portion. The rearward portion may comprise a tubular outer conductor support portion for supporting an interior surface of the outer conductor of the end of the coaxial cable. In addition, the tubular outer conductor support portion may comprise a sidewall having a plurality of spaced apart hollow cavities extending therein. These cavities may advantageously provide the impedance matching and may be readily formed during manufacturing of the insulator member, such as by molding, for example.
The connector may further include a housing having forward and rearward ends and a medial portion therebetween, and a back nut threadingly engaging the rearward end of the connector housing. The insulator member may be positioned within the medial portion of the connector housing. A contact may be carried within the bore of the insulator member for connecting to the inner conductor of the end of the coaxial cable.
The rearward portion of the insulator member may further comprise a rearward disk portion coupling the tubular outer conductor support portion to the forward portion and having a plurality of openings extending therethrough aligned with and in communication with respective hollow cavities of the tubular outer conductor support portion. In some embodiments, each of the plurality of elongate hollow cavities may extend only partway into the sidewall of the tubular outer conductor support portion. Each of the hollow cavities may have a cylindrical shape, for ease of molding, for example.
The insulator member may have a longitudinal axis, and the hollow cavities may be elongate hollow cavities extending generally parallel with the longitudinal axis of the insulator member. The elongate hollow cavities may be equally angularly spaced about the longitudinal axis of the insulator member. In addition, the sidewall of the tubular outer conductor support portion may have a constant uniform inner diameter and/or a constant uniform outer diameter.
The connector may further comprise a ferrule gripping an end of the coaxial cable for advancing the end of the coaxial cable into the connector housing as the back nut is tightened onto rearward end of the connector housing. The forward and rearward portions of the insulator member along with the plurality of hollow cavities may be integrally molded as a monolithic unit. The forward portion of the insulator member may comprise a forward disk portion, and a ring portion coupling the forward disk portion to the rearward portion.
A method aspect is for making a coaxial cable connector. The method may comprise providing a connector housing, and forming an insulator member for positioning within the connector housing. The insulator may comprise a forward portion, and a rearward portion extending rearwardly from the forward portion and comprising a tubular outer conductor support portion for supporting an interior surface of the outer conductor of the end of the coaxial cable. Moreover, the tubular outer conductor support portion may comprise a sidewall having a plurality of spaced apart hollow cavities extending therein.
The present invention will now be described more fully hereinafter with reference to the accompanying drawing, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
Referring initially to
A ferrule 11 is positioned over the end of the outer conductor 53 and adjacent portions of the jacket 54 of the cable 50. The ferrule 11 includes a supporting band portion 13 and plurality of circumferentially spaced apart gripping members 14 carried by the supporting band portion. The ferrule 11 also includes inner tabs 15 and outer tabs 16 carried by each gripping member 14 as shown in the illustrated embodiment. The forward ends of the gripping members 14 wedge tightly between the outer conductor 53 and interior portions of the housing 12. The ferrule 11 may preferably be formed as single monolithic unit to thereby reduce the number of connector components and thereby reduce the overall cost of the connector 10.
The connector 10 includes an internally threaded back nut 17 threaded onto the externally threaded rearward end of the connector housing 12. As the back nut 17 is tightened, the end of the inner conductor 51 is positioned further into a rearward end of a center contact 18. The ferrule 11 is also compressed into secure engagement between the outer conductor 53 and the adjacent interior portions of the housing 12 as will be appreciated by those skilled in the art. A forward O-ring 19 and a rearward O-ring 20 are provided to seal respective forward and rearward interfaces adjacent the back nut 17 and prevent moisture ingress.
Referring now additionally to
The rearward portion 26 includes a tubular outer conductor support portion 31 that supports an interior surface of the outer conductor 53 of the end of the coaxial cable 50. The tubular outer conductor support portion 31 comprises a sidewall 32 having a substantially tubular shape with a chamfered rearward end 33. In addition, the sidewall 32 includes a plurality of angularly spaced apart hollow elongate cavities 34 extending therein. Each of these cavities 34 is generally parallel with the longitudinal axis 28 of the insulator member 22, and extends only partway into sidewall. Of course, in other embodiments the cavities 34 could be through-holes, for example. These cavities 34 advantageously provide additional impedance matching capability and can be readily formed during manufacturing of the insulator member 22, such as by molding, for example. The rearward portion 26 also includes a rearward disk portion 36 coupling the tubular outer conductor support portion 31 to the ring portion 25 of the forward portion 23 of the insulator member. This rearward disk portion 36 also has openings aligned with the cavities 34.
The insulator member 22 may also be desirably formed as a single monolithic unit to reduce the number of components and thereby reduce the cost of the connector 10. For example, the insulator member 22 may be molded from plastic as will be appreciated by those skilled in the art.
The connector 10 is illustratively in form of a female DIN connector. The features and advantages of the connector 10, as described herein, may be used in other connector types, such as N-female, N-male, and DIN-male types of connectors, for example, as will be appreciated by those skilled in the art. The connector 10 may also be suitable for a ⅞-inch coaxial cable of the type commonly used for wireless base stations, for example. Such applications are also described in U.S. Pat. No. 6,217,380 assigned to the assignee of the present invention and the entire disclosure of which is incorporated herein by reference. The cable may be smooth wall or corrugated wall, for example. Other sizes and types of coaxial cable, and other applications are also contemplated by the invention.
One method aspect is for making the coaxial cable connector 10. The method may comprise providing a connector housing 12, and forming an insulator member 22 for positioning within the connector housing. The insulator member 22 may comprise a forward portion 23, and a rearward portion 26 extending rearwardly from the forward portion and comprising a tubular outer conductor support portion 31 for supporting an inner surface of the outer conductor 53 of the end of the coaxial cable 50. Moreover, the tubular outer conductor support portion 31 may comprise a sidewall 32 having a plurality of spaced apart hollow cavities 34 extending therein.
Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6024609 | Kooiman et al. | Feb 2000 | A |
| 6217380 | Nelson et al. | Apr 2001 | B1 |
| 6396367 | Rosenberger | May 2002 | B1 |
| 6607398 | Henningsen | Aug 2003 | B2 |
| 7011546 | Vaccaro | Mar 2006 | B2 |
| 7104839 | Henningsen | Sep 2006 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20080311788 A1 | Dec 2008 | US |
