Patent Grant
7335059
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 corrugated outer conductors, for example.
A typical coaxial cable connector for such a coaxial cable includes a tubular housing or body to make an electrical connection to the outer conductor of the coaxial cable 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 is incorporated herein by reference.
One important consideration in reducing the costs of connectors may be the number of connector components that are manufactured and then assembled to produce the connector. Another consideration in connector design may be accommodating the axial movement of the back nut and end of the cable into the connector housing as the back nut is tightened so that good electrical contact is maintained.
Published U.S. Patent application No. 2005/0118865 to Henningsen discloses a coaxial connector including a back nut that threads onto the rear of a connector body. The connector body carries a dielectric spacer at its front end that, in turn, carries a center contact for electrically connecting to the inner conductor of the coaxial cable. The cable end is prepared by manually passing it through the back nut and then manually flaring the outer conductor. The flared portion of the outer conductor is ultimately gripped between a ramp on the rear end of the connector body and a corresponding ramp on the back nut. Unfortunately, flaring the outer conductor requires an additional manual step that needs to be done properly to ensure good contact with the outer conductor.
In view of the foregoing background, it is therefore an object of the present invention to provide a coaxial cable connector that provides robust contact to the outer conductor and that may advantageously do away with the additional step of separately manually flaring the outer conductor.
These and other objects, features and advantages in accordance with the present invention are provided by a coaxial cable connector comprising a connector housing defining a radially outer ramp portion, an insulator member defining a radially inner ramp portion aligned with the radially outer ramp portion, and a back nut defining an opposing ramp opposite at least the outer ramp portion. Accordingly, the radially inner and outer ramp portions may flare an end of the outer conductor as the coaxial cable is advanced into the connector housing. In addition, at least the radial outer ramp portion may cooperate with the opposing ramp to clamp the flared end of the outer conductor therebetween to provide effective mechanical and electrical contact.
The back nut may have a gripping surface on an interior thereof for gripping and advancing the coaxial cable into the connector housing as the back nut is tightened onto the connector housing. For example, the gripping surface may comprise a threaded surface.
The radially inner ramp portion may define a smooth continuous ramp surface in some embodiments. The radially outer ramp portion may define a smooth continuous ramp surface in some embodiments, or alternatively the radially outer ramp portion may define a stair-stepped non-continuous ramp surface in other embodiments. Along these lines, the opposing ramp of the back nut may define a smooth continuous ramp surface, or may define a radiused point-contact ramp surface.
The coaxial cable connector may further comprise a contact carried by the insulator member for connecting to the inner conductor of the coaxial cable. The coaxial cable connector may also further comprise at least one sealing ring adjacent the back nut.
Another aspect relates to a method for making a coaxial cable connector for a coaxial cable comprising an inner conductor, a dielectric layer surrounding the inner conductor, and an outer conductor surrounding the dielectric layer. The method may comprise forming a connector housing defining a radially outer ramp portion and forming an insulator member to be positioned in the connector housing and defining a radially inner ramp portion aligned with the radially outer ramp portion. Additionally, the method may comprise forming a back nut defining an opposing ramp opposite at least the outer ramp portion so that the radially inner and outer ramp portions may flare an end of the outer conductor as the coaxial cable is advanced into the connector housing. At least the radial outer ramp portion may cooperate with the opposing ramp to clamp the flared end of the outer conductor therebetween.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments s et 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 and prime and multiple prime notation are used to indicate similar elements in alternative embodiments.
Referring now initially to
The end of the coaxial cable 40 is prepared so that the inner conductor 41 extends axially outwardly beyond the end of the outer conductor 43. In addition, portions of the dielectric foam layer 42 are also removed so that the inner surface of the outer conductor 43 is also exposed. The outer insulating jacket 44 is also stripped back a distance so that outer end portions of the outer conductor 43 are also exposed.
The connector 20 includes an internally threaded back nut 26 threaded onto the externally threaded rearward end of the connector housing 27. A forward Oaring 30 and a rearward 0-ring 31 are provided to seal respective forward and rearward interfaces adjacent the back nut 26 and prevent moisture ingress as will be appreciated by those skilled in the art.
The center contact 21 is illustratively supported in the housing 27 by an insulator member 32. The insulator member 32 includes a forward disk shaped portion 33, and an outer annular portion 34 carried by the disk shaped portion and defining a radially inner ramp portion 35. Along the same line as the radially inner ramp portion 35 there is illustratively provided a radially outer ramp portion 36 defined by the rear surface of the connector housing 27. Opposite the radially inner and radially outer ramp portions 35, 36 there is provided a corresponding opposing ramp 39 formed on the opposing portion of the back nut 26. The forward two ramp portions 35, 36 cooperate with the rearward ramp 39 to self-flare an end of the outer conductor 43. In the illustrated embodiment, the radially outer ramp portion 36 and the opposing ramp 39 clamp an end of the outer conductor 43 therebetween as the back nut is tightened onto the housing 27, as will be appreciated by those skilled in the art. In other embodiments, the radially inner ramp portion 35 may participate in the clamping, as will be appreciated by those skilled in the art. More particularly, the back nut 26 illustratively includes an interior threaded portion 45 that grabs onto or grips the outer jacket 44 of the cable 40 so that as the back nut is tightened onto the housing 27, the outer conductor 43 is advanced, flared, and finally trapped between the ramps as described above.
A second application of a connector 20′, including the outer conductor pick-up and self-flaring features is now described with additional reference to
The connectors 20, 20′ described above both illustratively include smooth continuous ramp surfaces 35, 36, 39, 35′, 36′, and 39′. These smooth continuous ramp surfaces may provide adequate mechanical clamping and/or electrical contact for many applications as will be appreciated by those skilled in the art.
Referring now additionally to
Opposite the stair-stepped ramp 36″, the back nut illustratively includes a radiused contact surface 39″ instead of the flat or smooth wall contact surfaces defined by the ramps 39, 39′ as in the connector embodiments 20, 20′ described above with reference to
As will be readily appreciated by those skilled in the art, the stair-stepped ramp 36″ and the radiused contact surface 39″, when used individually or in combination, can effectively engage and deform the outer conductor 43″ for better mechanical and/or electrical contact. Accordingly, passive intermodulation distortion (PIM) may be reduced in the connector 20″. In other words, both PIM performance and PIM stability may be improved.
Those other elements of the connector 20″, not specifically discussed, are indicated with double prime notation and are similar to elements described above with reference to the connector 20 shown in
Referring now additionally to
Yet another method aspect is directed to a method for making the connector 20, 20′, 20″. The method may include forming a connector housing 27 defining a radially outer ramp portion 36 and forming an insulator member 32 to be positioned in the connector housing and defining a radially inner ramp portion 35 aligned with the radially outer ramp portion. Additionally, the method may comprise forming a back nut 26 defining an opposing ramp 39 opposite at least the radially outer ramp portion 36 so that the radially inner and outer ramp portions 35, 36 may flare an end of the outer conductor 43 as the coaxial cable 40 is advanced into the connector housing 27. At least the radial outer ramp portion 36 may cooperate with the opposing ramp 39 to clamp the flared end of the outer conductor 43 therebetween.
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.
This application is based upon and claims priority to now abandoned provisional application No. 60/780,106 filed Mar. 8, 2006 and to now abandoned provisional application No. 60/745,500 filed Apr. 24, 2006. The entire subject matter of these provisional applications is incorporated herein by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3040288 | Edlen et al. | Jun 1962 | A |
| 3963321 | Burger et al. | Jun 1976 | A |
| 5154636 | Vaccaro et al. | Oct 1992 | A |
| 6024609 | Kooiman et al. | Feb 2000 | A |
| 6217380 | Nelson et al. | Apr 2001 | B1 |
| 6396367 | Rosenberger | May 2002 | B1 |
| 6607398 | Henningsen | Aug 2003 | B2 |
| 6955562 | Henningsen | Oct 2005 | B1 |
| 20050079760 | Vaccaro | Apr 2005 | A1 |
| 20050118865 | Henningsen | Jun 2005 | A1 |
| Number | Date | Country |
|---|---|---|
| 1075699 | Nov 1960 | DE |
| 565981 | Oct 1969 | DE |
| 2033463 | Dec 1970 | FR |
| Number | Date | Country | |
|---|---|---|---|
| 20070212937 A1 | Sep 2007 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60745500 | Apr 2006 | US | |
| 60780106 | Mar 2006 | US |
