Coaxial cable connector and related methods

Information

  • Patent Grant
  • 6769933
  • Patent Number
    6,769,933
  • Date Filed
    Wednesday, November 27, 2002
    22 years ago
  • Date Issued
    Tuesday, August 3, 2004
    20 years ago
Abstract
A cable gripping component is provided for gripping a coaxial cable. The cable gripping component includes a housing including a sleeve portion having a terminus forming a first end housing. The housing has an inner surface defining an interior channel. The inner surface includes a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area. Related methods are disclosed.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to connectors for coaxial cables and related components and methods, including, for example, rigid coaxial cables such as those used for trunk and distribution lines in such applications as cable television and the like, and related components and methods.




2. Description of the Related Art




Of the various coaxial cable designs, each has shared elements, e.g., including an inner or center conductor surrounded by an insulating material, typically referred to as the core, and an outer conductor surrounding the insulating layer. In some coaxial cables, such as with flexible coaxial cables, the outer conductor comprises a braided conductive material. These flexible coaxial cables typically include an outer insulator material, sometimes referred to as a jacket, that surrounds and encases the outer conductor. In other coaxial cables, for example, rigid coaxial cable, the outer conductor is a solid, conductive material, and the outer conductor commonly constitutes the exterior of the coaxial cable, without any need for an outer insulator or jacket.




Coaxial cable connectors must firmly and securely connect the coaxial cable to a terminal. Moreover, it is usually desirable, if not necessary, to ensure that the connector provide a seal so as to avoid exposure or contamination of the interior of the connector to moisture, particulate matter, and/or other undesirable material to which portions of the connector and/or cable may be exposed.




One concern with some commercially available connectors is that the tightening of the connector during installation causes an undesirable twisting of the coaxial cable, leading to unwanted stress on the cable that can cause wear and/or malfunctions.




To address these concerns, some connectors include a gripping and/or sealing component, for example, such as a ferrule, to contact and grip the cable at its exterior, whether it be an outer insulator or jacket or an outer conductor in cable designs that exclude the jacket. This ferrule or like component grips the cable exterior so that the cable is firmly secured with respect to the connector, and so that infiltration of environmental substances such as those noted above can be limited or avoided. The gripping component typically is housed within a larger housing component that also forms a part of the connector.




An example of a commercially available connector for connecting a coaxial cable to a terminal is shown in FIG.


11


. The connector shown in

FIG. 11

, generally designated as


200


, comprises a back nut assembly


202


, a main nut assembly


204


, and a body


206


. A coaxial cable end (not shown) is inserted into a distal end


210


of connector


200


, at a distal portion of back nut


202


. A conductive pin


212


extends from a proximal end


214


of connector


200


, at a proximal portion of body


206


. A ferrule


220


is disposed in the interior of back nut


202


. Ferrule


220


contacts the exterior of the coaxial cable. A pair of compression rings


222


and


224


are positioned within back nut


202


at proximal and distal ends of ferrule


220


, respectively. The proximal compression ring


222


retains the ferrule


220


in place in the interior of the back nut


202


, while the distal compression ring


224


prevents the ferrule


220


from moving distally.




When such a connector is in a disassembled state, for example, as possibly provided when new and ready for use, the gripping component, e.g., the back nut


202


, and in some cases the ferrule


220


, may be provided as a separate component or components, thereby requiring separate handling, which increases the likelihood of being misplaced or lost. Moreover, during installation the ferrule must be correctly inserted into the housing and retained while the remainder of the connector is installed and tightened in place. Thus, the cable gripping component often is partly or fully responsible for twisting the cable, which can place unwanted stress on the cable and connector through its interaction and cooperation with the associated housing.




OBJECTS OF THE INVENTION




Accordingly, an object of the present invention is to provide a connector and related components and methods that facilitate efficient pre-assembly handling.




Another object of the invention is to provide a connector and related components and methods that limit or prevent unwanted twisting of the cable during installation.




Another object of the invention is to provide a connector and related components and methods that are relatively efficient and cost effective.




Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims.




SUMMARY OF THE INVENTION




To achieve the foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described in this document, a cable gripping component is provided for gripping a coaxial cable. The cable gripping component comprises a housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel. The inner surface comprises a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area.




The cable gripping component further comprises a ferrule disposed within the interior channel for contacting the coaxial cable. The ferrule comprises an outer surface that includes a raised portion. The interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.




The weakened area may comprise at least one groove, and preferably a plurality of grooves, which preferably is or are disposed on the inner surface of the sleeve portion.




The cable gripping component also preferably comprises a compression ring disposed within the interior channel between the ferrule and the inner surface of the housing. Preferably, the ferrule comprises a beveled mating surface, and the compression ring comprises a beveled mating surface for mating with the beveled mating surface of the ferrule.




The ferrule preferably has a terminus that extends beyond the terminus of the housing. The ferrule also may be loosely held within the interior channel. The ferrule also preferably may be rotatable within the interior channel.




In accordance with another aspect of the invention, a connector is provided for a coaxial cable. The connector comprises a cable gripping component comprising a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel. The inner surface comprises a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area.




The connector further comprises a ferrule disposed within the interior channel for contacting the coaxial cable. The ferrule comprises an outer surface that includes a raised portion. Interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.




The connector according to this aspect of the invention also comprises a coupling component attached to the first end of the cable gripping component. Preferably but optionally, the ferrule contacts the coupling component.




The cable gripping component of this connector may further comprise a compression ring disposed within the interior channel between the cable gripping component housing and the ferrule. Preferably, the compression ring does not contact the coupling component. It is preferred that the ferrule and the coupling component have mutually mating beveled surfaces.




In accordance with another aspect of the invention, a method is provided for providing a cable gripping component for a coaxial cable. The method comprises providing a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel, wherein the inner surface comprises a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area.




The method also comprises providing a ferrule comprising an outer surface that includes a raised portion, and inserting the ferrule into the interior channel. It further comprises crimping the sleeve portion to provide interfering engagement between at least a portion of the retention surface and the raised portion, whereby at least a portion of the ferrule is prevented from exiting the interior channel. It also may comprise inserting the ferrule into the interior channel so that the ferrule is capable of rotating within the interior channel.




The method in its preferred implementation further comprises providing a coupling component and attaching the coupling component to the first end of the cable gripping component.




In accordance with another aspect of the invention, a method is provided for attaching a connector to a coaxial cable. The method comprises providing a cable gripping component for a coaxial cable, wherein the cable gripping component comprises a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel. The inner surface comprises a retention surface is disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area. The retention surface is disposed between the terminus and the weakened area. In accordance with this method, the cable gripping component further comprises a ferrule disposed in an interior channel of the housing. The ferrule comprises an outer surface that includes a raised portion, wherein the inner surface narrows from the weakened area to the retention area and at least a portion of the ferrule is prevented from exiting the interior channel by the retention surface and the raised portion of the ferrule outer surface.




The method further comprises positioning the cable gripping component on the coaxial cable so that the ferrule contacts the coaxial cable, and providing a coupling component and attaching the coupling component to the first end of the cable gripping component. In its presently preferred implementations, the method comprises providing a compression ring within the cable gripping component to contact the ferrule.











BRIEF DESCRIPTION OF THE DRAWINGS




The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments and methods of the invention and, together with the general description given above and the detailed description of the preferred embodiments and methods given below, serve to explain the principles of the invention. Of the drawings:





FIG. 1

is side cutaway view of a connector according to a presently preferred embodiment of one aspect of the invention. The connector comprises a cable gripping component according to another aspect of the invention, and is coupled to a coaxial cable;





FIG. 2

shows a side cutaway view of a cable gripping component in the form of a back nut assembly for the preferred embodiment of

FIG. 1

, and according to another aspect of the invention;





FIG. 3

shows a side cutaway view of the back nut assembly housing or back nut for the back nut assembly of

FIG. 2

;





FIG. 4

shows an end view of the compression ring for the back nut assembly of

FIG. 2

;





FIG. 5

shows a side cutaway view of the compression ring of

FIG. 4

taken along line


5


—


5


of

FIG. 4

;





FIG. 6

shows an end view of the ferrule for the back nut assembly of

FIG. 2

;





FIG. 7

shows a side cutaway view of the ferrule of

FIG. 6

, taken along line


7


—


7


of

FIG. 6

;





FIG. 8

shows a side cutaway view of a presently preferred embodiment of a tool for use in modifying the proximal end of the back nut assembly housing to retain the ferrule during an uncoupled state of the connector of

FIG. 1

;





FIG. 9

shows a side cutaway view of the back nut assembly of

FIG. 2

with the tool of

FIG. 8

in position to modify the proximal end of the back nut assembly;





FIG. 10

shows a side cutaway view of a back nut assembly according to a second preferred embodiment of the invention; and





FIG. 11

shows a connector according to a prior art design.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS AND METHODS




Reference will now be made in detail to the presently preferred embodiments and methods of the invention as illustrated in the accompanying drawings, in which like reference characters designate like or corresponding parts throughout the drawings. It should be noted, however, that the invention in its broader aspects is not limited to the specific details, representative devices and methods, and illustrative examples shown and described in this section in connection with the preferred embodiments and methods. The invention according to its various aspects is particularly pointed out and distinctly claimed in the attached claims read in view of this specification, and appropriate equivalents.




In accordance with one aspect of the invention, a connector is provided for a coaxial cable, for example, useful in connecting a coaxial cable to a terminal. The coaxial cable may be one of a number of types of coaxial cables known in the field. These may include, for example, flexible coaxial cable, commonly used, e.g., in interior applications such as cable television (“TV”) and the like. In the presently preferred embodiments and implementations, the coaxial cable comprises a rigid cable having a center conductor, an insulating material (i.e., a core), and an outer conductor, typically without an outer insulator surrounding the outer conductor. Such coaxial cables are commonly used, for example, as trunk or distribution lines in cable TV systems and the like.




The coaxial cable comprises an exterior to which the connector typically would be fastened or secured. In the case of a flexible coaxial cable, for example, the exterior of the cable may comprise the outer insulator, the outer conductor, or both. In the case of a rigid cable as generally described above, the cable exterior may comprise the outer conductor.




Terminals with which such connectors may be used may include, for example, the end of another coaxial cable, a junction box, a transformer, or other electrical component.




A connector


10


according to presently preferred embodiment of this aspect of the invention is shown in FIG.


1


. Although merely illustrative of this aspect of the invention, connector


10


preferably is designed for use with a rigid coaxial cable


12


having an inner conductor


14


, a core insulator


16


, and an outer conductor


18


, e.g., as is used in trunk or distribution lines for cable TV and like applications. Connector


10


is adapted for use in coupling one end


20


of coaxial cable


12


to a terminal (not shown), such as one of those described above. A portion of the core insulator


16


at cable end


20


is removed, as generally indicated at


22


. A portion of outer conductor


18


at cable end


20


also is removed, as generally indicated at


24


, so that inner conductor


14


of cable


12


extends longitudinally beyond core insulator


16


and outer conductor


18


. To illustrate spatial relationships with respect to this embodiment, connector


10


and cable


12


at its end


20


may be assumed to lie substantially along a longitudinal axis L which defines a longitudinal direction.




In accordance with this aspect of the invention, the connector comprises a cable gripping component. This cable gripping component, individually or in combination with other components, also comprises another aspect of the invention. The cable gripping component can provide a means for gripping the exterior of the coaxial cable. As implemented in connector


10


of the preferred embodiment, the cable gripping means comprises a cable gripping component in the form of a back nut assembly


30


and associated components as herein described, and equivalents of these. The connector according to this aspect of the invention further comprises a coupling component attached to a first end of the cable gripping component. In connector


10


, back nut assembly


30


operates in conjunction with a coupling means or coupling component that comprises a main nut assembly


32


and a body assembly


34


and their associated components, and equivalents of these. The coupling component couples the connector to the terminal.




Back nut assembly


30


, shown separately in

FIG. 2

, comprises a is housing or back nut


40


including a sleeve portion


41


at a terminus


42


forming a first or proximal end of the housing


40


. Terminus


42


would be positioned toward the terminal in relative terms. Housing


40


also includes a distal end


44


positioned away from the terminal and toward the remainder of cable


12


in relative terms. Back nut assembly housing


40


has an inner surface


45


defining an interior channel


46


extending to the proximal end


42


of back nut housing


40


. The inner surface


45


of the back nut


40


comprises a proximal end inner surface portion


45




a


, an intermediate inner surface portion


45




b


, and a distal end inner surface portion


45




c


. The distal end inner surface


45




c


is sized and shaped to receive the coaxial cable


12


. Sleeve portion


41


forms at least part of proximal end inner surface portion


45




a.






Inner surface


45


of sleeve


41


comprises a retention surface disposed on the sleeve portion proximate the terminus. This sleeve portion includes a weakened area, wherein the retention surface is disposed between the terminus and the weakened area. This weakened area can provide a relatively predictable and controllable location for a bend in the sleeve


41


to aid in reducing the dimension of the inner surface


45


at the retention area and at terminus


42


.




As specifically implemented in the presently preferred embodiment, inner surface


45


of back nut housing


40


includes a retention surface


52


disposed on sleeve portion


41


proximate terminus


42


. A weakened portion or weakened area


48


is provided to facilitate bending of the sleeve portion


41


at that point. In one embodiment, the weakened portion is a region of thinner wall thickness relative to one or more adjacent wall thicknesses of the tubular wall of the sleeve portion


41


. In another embodiment, the weakened portion comprises a tapered wall thickness. Preferably, the inner surface of sleeve portion


41


comprises at least one groove


50


disposed near or adjacent to proximal end


42


, preferably at a predetermined longitudinal distance from terminus


42


, of the back nut housing


40


. The weakened area


48


in this instance preferably comprises a plurality of grooves, more preferably at least three grooves. Three grooves


50


are present in the embodiments illustrated in the FIGS. These grooves preferably are disposed immediately adjacent to one another. We have found that for one set of preferred embodiments, the removal of tubular wall material and/or absence of tubular wall material in the sleeve portion


41


to form one or more grooves can provide adequate structural strength and/or rigidity to the proximal end of the back nut


40


while also providing a weakened area which facilitates controlled radially inward bending during crimping of the sleeve portion


41


.




Retention surface


52


in this embodiment is disposed at or near the proximal end or terminus


42


of the back nut assembly housing


40


, and preferably adjacent to the proximal end


42


of back nut


40


. Prior to assembly of the back nut assembly


30


, the interior channel


46


at proximal end inner surface portion


45




a


preferably is cylindrical, including the portion comprising retention surface


52


, as shown in FIG.


2


. At the appropriate point during assembly of the back nut assembly


30


, sleeve


41


is crimped, bent or otherwise moved radially inward toward longitudinal axis L, as exemplarily illustrated in FIG.


3


.




Referring to

FIG. 3

, the proximal end inner surface portion


45




a


has a first radius R


1


and the intermediate surface portion


45




b


has a second radius R


2


, wherein the first radius is greater than the second radius, and the surface portions


45




a


and


45




b


preferably together form a first shoulder


53


. Distal end inner surface portion


45




c


has a third radius R


3


wherein the second radius R


2


is greater than the third radius R


3


, and the surface portions


45




b


and


45




c


preferably together form a second shoulder


55


. Preferably at least part of surface portion


45




a


that includes the weakened portion


48


has a radius that is greater than the first radius R


1


. Preferably, an o-ring


54


is disposed on the intermediate inner surface portion


45




b


, preferably at or near the distal end of surface


45




b


, and more preferably at the second shoulder


55


. Preferably a thrust washer


56


is disposed adjacent o-ring


54


. A thrust washer


58


preferably is positioned on the proximal end inner surface portion


45




a


, preferably at or near the distal end of surface


45




a


, and more preferably at the first shoulder


53


.




The connector according to this aspect of the invention, and the cable gripping component according to a related aspect of the invention, also comprise a ferrule disposed within the interior channel for contacting the coaxial cable. This contact typically will occur at the exterior of the cable, which in the illustrative embodiments would be at outer conductor


18


. The ferrule comprises an outer surface that includes a raised portion. Interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.




As implemented in the embodiments shown in the FIGS, a ferrule


60


is disposed within the interior channel


46


. Ferrule


60


has an inner surface


61


for contacting the exterior of the coaxial cable at outer conductor


18


.

FIG. 6

shows an end view of one embodiment of a ferrule


60


according to the preferred embodiment. Ferrule


60


is generally C-shaped so as to be capable of being compressed about or with respect to longitudinal axis L. Ferrule


60


includes an outer surface


63


from which extends a raised portion, here in the form of an outer flange


62


. With this arrangement, ferrule


60


is retained in the interior channel


46


by retention surface


52


interferingly engaging outer flange


62


. Ferrule


60


in this embodiment has an axial or longitudinal dimension selected so that a portion of ferrule


60


, e.g., its proximal terminal end or terminus, extends beyond the sleeve


41


and beyond back nut assembly housing terminus


42


after the sleeve has been crimped radially inwardly to reduce the diameter of housing terminus


42


to be smaller than that of ferrule flange


62


. This arrangement also can permit ferrule


60


to be loosely and rotatably held within interior channel


46


when back nut assembly


30


is in an “uncoupled” state, i.e., when back nut assembly


30


has not yet been firmly coupled to the coupling component, e.g., main nut assembly


32


.




A compression ring


64


is disposed within interior channel


46


between ferrule


60


and inner surface


45


of housing


40


, at the distal end


65


of ferrule


60


. Compression ring


64


comprises a first annular portion


66


having a first inner surface


67


with first inner diameter


68


smaller than an outer diameter


70


of ferrule


60


, e.g., so that compression ring


64


is capable of interferingly engaging ferrule


60


and compressing ferrule


60


as the compression ring


64


and the ferrule


60


are driven axially toward one another. Compression ring


64


also comprises a second annular portion


72


having a second inner surface


73


with a second inner diameter


74


larger than outer diameter


70


of ferrule


60


, e.g., to aid in maintaining ferrule


60


in longitudinal alignment within interior channel


46


. Ferrule


60


preferably is at least partially disposed within the second annular portion


72


of compression ring


64


, so that at least a portion of the inner surface


73


of the second annular portion


72


of the compression ring


64


contacts the outer surface


70


of ferrule


60


. Preferably, ferrule


60


comprises a beveled mating inner surface


80


and compression ring


64


comprises a corresponding beveled mating outer surface


82


for mating with the beveled mating surface


80


of ferrule


60


. Referring to

FIG. 2

, the beveled mating inner surface


80


is disposed between the first inner surface of the first annular portion


66


and the second inner surface of the second annular portion


72


. Axial movement (along longitudinal axis L) of the compression ring


64


and ferrule


60


toward one another causes engagement of the mating surfaces


80


and


82


and causes the ferrule


60


to compress radially inwardly toward longitudinal axis L. The bevel on the mating surfaces


80


and


82


can help to avoid point loading between the compression ring


64


and ferrule


60


.




Retention surface


52


retains the ferrule


60


in position within the interior channel


46


of housing


40


when the back nut assembly


30


is in an uncoupled state, e.g., when back nut assembly


30


is not coupled to and engaged with main nut


32


. As shown in

FIG. 2

, when initially manufactured, the portion of the interior channel


46


formed by proximal end


42


of sleeve


41


, including the portion comprising grooves


50


and retention surface


52


, is substantially cylindrical, allowing compression ring


64


and ferrule


60


to be inserted into the interior channel


46


through proximal end


42


of back nut assembly housing


40


. The proximal end


42


of housing


40


then may be crimped, bent, or otherwise moved, preferably substantially radially inwardly toward interior channel


46


, so that retention surface


52


moves toward longitudinal axis L to a point at which the diameter.


84


(

FIG. 3

) of the opening


86


formed by retention surface


52


is smaller than the ferrule outer diameter


88


at ferrule flange


62


. The weakened area


48


, shown provided by grooves


50


in this embodiment, permits the proximal end


42


of the back nut assembly housing


40


to bend at a predetermined location, i.e., at the weakened area, so that the retention surface


52


can be moved into the desired location to secure the ferrule


60


easily and reliably within interior channel


46


. Thus, the back nut assembly


30


securely retains the ferrule


60


generally in position, even when the back nut assembly exists as an individual component prior to coupling it with main nut assembly


32


or its equivalent. This arrangement also permits ferrule


60


, prior to coupling back nut assembly


30


with the main nut assembly


32


or its equivalent, to fit loosely within the interior channel


46


, and to rotate within the interior channel. This can be advantageous, for example, in facilitating the coupling of the back nut assembly onto the coaxial cable, and the coupling of the main nut assembly or its equivalent to the back nut assembly while the latter is affixed to the coaxial cable.




With reference to

FIGS. 8 and 9

, bending of the proximal end


42


of back nut assembly housing


40


is preferably accomplished by using a tool


90


. Tool


90


comprises a concavity


92


formed by a distal surface


94


extending circumferentially around its distal base


96


and preferably angled or curved with respect to longitudinal axis L such that, when forced longitudinally and distally toward back nut assembly housing


40


, surface


94


contacts the outer portion of peripheral end


42


of housing


40


and forces a bend at weakened area


48


, urging retention surface


52


inward radially toward longitudinal axis L to create narrowed diameter


84


. Application of the force and consequent deformation are continued until retention surface


52


is at the desired location, e.g., as shown in

FIGS. 1 and 3

. The angle or curve of the surface


94


may be selected as is appropriate to obtain the desired shape of the retention surface


52


. Surface


94


may, for example, be conical in shape, curved, parabolic, etc. Preferably but optionally, surface


94


is substantially conical with an angle with respect to the longitudinal axis L, e.g., of approximately 45 degrees.




The outer surface of back nut


40


includes threads


100


and preferably includes a head configuration


102


, such as a hex or octagonal head, suitable for engaging a device such as a wrench for rotating back nut assembly


30


to engage or disengage threads


100


. Back nut assembly


30


also preferably comprises an external o-ring


104


, for environmental sealing, disposed on the outer surface of back nut


40


.




Advantageously, the proximal portion of ferrule


60


extending proximately from sleeve terminus


41


is sized and configured to abut and frictionally engage a surface on a mating component such as the terminal coupling component. Thus, as the cable gripping component is urged toward the coupling component to be coupled together, the extending portion of the ferrule abuts the coupling component and rotation of the ferrule with respect to the coupling component is at least partially inhibited. This can reduce the amount of twist imparted to the cable as the housing


40


is rotated with respect to the coupling component and as ferrule


60


is compressed against the cable.




Back nut assembly


30


may comprise component designs other than those shown and described herein above. For example, another embodiment of a compression ring


164


is illustrated in FIG.


10


. Compression ring


164


comprises a annular portion


172


with beveled surface


182


. In contrast to compression ring


64


, the annular portion


66


could be reduced or eliminated, where, for example, a single thrust washer


156


could be utilized between the compression ring


164


and o-ring


54


.




The connector according to this aspect of the invention further comprises a coupling component attached to the first end of the cable gripping component. The coupling component comprises a device, component, or assembly capable of coupling to or with the cable gripping means or component, and capable of being coupled to the terminal. The coupling component as implemented in the presently preferred embodiment comprises main nut assembly


32


and body assembly


34


.




Main nut assembly


32


comprises a main nut housing


110


. Housing


110


comprises an inner surface


111


defining a central cavity


112


. A sleeve


114


is inserted into the end


20


of coaxial cable


12


, and sleeve


114


in turn resides in cavity


112


of housing


110


. Sleeve


114


can be configured and adjusted to tune the connector so that its performance can be optimized for the specific application, signal, etc., in a manner known in the art. A resilient positioning component


116


is positioned at the proximal end of sleeve


114


and cavity


112


. Resilient positioning component


116


, which preferably comprises an acetyl material or like substance, can be used to radially position and stabilize the proximal end of inner conductor


14


of cable


12


.




Main nut assembly


32


preferably comprises a distal fastener means in the form of a distal fastener for fastening to the first or proximal end of the cable gripping means or component housing. The specific design of distal fastener will depend on the design employed for the coupling portion of main nut assembly, or of the corresponding coupling component if a main nut assembly is omitted. In the embodiment of the connector


10


shown in the Figures, main nut housing


110


comprises distal fastening means comprising threads


118


at or near its distal end for engaging threads


100


of back nut assembly housing


40


. Main nut assembly


32


further comprises fastening means such as threads


120


at its proximal end. Means also are provided, for example, in the form of a hex or octagonal external head or surface configuration, for fastening or engaging main nut assembly


32


to back nut assembly


30


and body assembly


34


. This preferably enables one to rotate the assemblies with respect to one another so they are threadably engaged.




Body assembly


34


comprises a body assembly housing


130


which mates with and threadably engages the proximal end of main nut assembly


32


. Fastening means such as threads


132


are provided at the distal end of body assembly housing


130


to engage threads


120


of main nut assembly. Body assembly


34


also preferably comprises a proximal fastener means or a proximal fastener for fastening to the terminal. The proximal fastener will depend upon the specific application, the specific terminal or terminal type, etc. In the embodiment disclosed herein, the proximal fastener comprises threads


134


. Appropriate environmental sealing means, such as o-rings


136


, also may be included at the threaded joints or engagements.




Body assembly housing


130


, comprises a cavity


138


disposed about longitudinal axis L. The proximal end of inner conductor


14


extends through an aperture in positioning component


116


and into cavity


138


. A conductive pin


140


is disposed over this proximal end of conductor


14


to continue a conduction path through the proximal end of body assembly


34


. An insulative actuator


142


is disposed in cavity


138


to receive and guide pin


140


. Actuator


142


in this preferred embodiment comprises an injection molded plastic material, for example, ULTEM 1000, commercially available from General Electric Plastics Co. of Pittsfield, Mass.




In the presently preferred embodiments, the ferrule


60


is disposed such that it contacts the coupling component, and preferably the compression ring


64


does not contact the coupling component. It also is preferable that the ferrule and the coupling component have mutually mating beveled surfaces. In the illustrative embodiment of

FIG. 1

, for example, ferrule


60


includes a bevel


180


on its proximal end, and a bevel


182


is provided on a surface in the interior or main nut housing


110


. Bevels


180


and


182


are configured to mate with one another so that, as back nut assembly


30


and main nut assembly


32


are coupled and thus drawn together axially, these beveled surfaces contact one another and thereby force ferrule


60


onto outer conduct


18


of coaxial cable


12


. Preferably but optionally, these beveled surfaces


180


and


182


correspond in size, shape, angle, etc. with beveled surfaces


80


and


82


of the ferrule and compression ring, respectively, for example, to balance the forces on ferrule


60


and urge the ferrule substantially symmetrically onto the cable exterior.




In accordance with additional aspects of the invention, methods are provided for providing a cable gripping component, and for connecting a coaxial cable. These methods preferably are practiced in connection with coupling a coaxial cable to a terminal. To better illustrate these methods and for ease of illustration, preferred versions will be described with reference to the presently preferred embodiments of the invention as described herein above, although they are not necessarily limited to such embodiments.




The method for providing a cable gripping component according to this aspect of the invention comprises providing a cable gripping housing including a sleeve portion having a terminus forming a first end of the housing. The housing has an inner surface defining an interior channel. The inner surface comprises a retention surface disposed on the sleeve portion proximate the terminus. The sleeve portion includes a weakened area, e.g., preferably comprising at least one groove, wherein the retention surface is disposed between the terminus and the weakened area. In this illustrative version of the method, each of these components is as described above with respect to back nut assembly


30


.




The method according to this aspect of the invention further comprises providing a ferrule comprising an outer surface that includes a raised portion, and inserting the ferrule into the interior channel. The presently preferred implementation of this method comprises providing ferrule


60


as described herein above. The method optionally but preferably comprises positioning a compression ring, and more preferably a compression ring such as compression ring


64


, in the interior channel distally with respect to the ferrule.




The method further comprises moving the retention surface, e.g., crimping the sleeve portion, inwardly toward the ferrule or the longitudinal axis so that the interfering engagement is provided between at least a portion of the retention surface and the raised portion. In the preferred implementation, weakened area


48


of sleeve


41


permits retention surface


52


to constrict, thereby retaining ferrule


60


in the interior channel of the cable gripping component housing by the retention surface and the raised portion of the outer surface of the ferrule. In the presently preferred implementation of the method, this comprises bending or otherwise moving retention surface


52


radially inward toward longitudinal axis L so that it retains ferrule


60


in proximal end cavity


45




a


. As noted above, it is preferred that a plurality of grooves are used, preferably disposed immediately adjacent to one another. It is also preferable that at least three grooves be used. The retention surface preferably is moved using a tool to compress the proximal surface of the cable gripping component housing and to move the retention surface, such as tool


90


as shown in

FIGS. 8 and 9

. In this manner, at least a portion of the ferrule, e.g., its proximal end, is prevented from exiting the interior channel. This method also may yield a cable gripping component in which, when uncoupled with respect to the a coupling component, e.g., such as main nut assembly


32


and its equivalents (e.g., in an uncoupled state), the ferrule is capable of rotating within the interior channel.




When moving the retention surface to a position in which it retains the ferrule, it is preferable that the retention surface be bent or moved so that the proximal end interior channel


46


comprises a distal portion, e.g., distally with respect to grooves


50


, having a first substantially cylindrical cross section, and a proximal portion, e.g., at retention surface


52


, having a second cross section different from, and smaller than, the first cross section. In other words, the portion of sleeve


41


This bending or moving of the proximal end of the back nut assembly housing


40


preferably causes the second cross section, e.g., at the retention surface, that comprises a conical cross section, a parabolic cross section, or a curved cross section.




The method for connecting a coaxial cable comprises fastening the coupling component to the terminal using a proximal fastener for fastening to the terminal. This may be accomplished by fastening the connector


10


, comprising the assembled components of back nut assembly


30


, main nut assembly


32


and body assembly


34


as shown in

FIG. 1

, to the terminal, for example, using threads


134


.




In accordance with the presently preferred implementation of the method, once assembled, the back nut assembly


30


can be used as follows. The coaxial cable


12


is prepared as described herein above, e.g., by removing the proximal portions of the core insulator


16


and the outer conductor


18


. Back nut assembly


30


then is placed over the proximal end of cable


12


.




The method for connecting a coaxial cable, in addition to providing a cable gripping component as described herein above, also preferably comprises providing a coupling component and attaching the coupling component to the first end of the gripping component to a coupling component, preferably at a distal to fastener of the coupling component. The presently preferred implementation of this aspect of the method comprises coupling back nut assembly


30


to main nut assembly


32


and body assembly


34


.




In accordance with the preferred implementation of this method, the coaxial cable is coupled to the terminal, e.g., such as an equipment port, as follows. Body assembly


34


is threadably engaged with and tightened to the terminal using threads


134


. Sleeve


114


is inserted into proximal end


20


of cable


12


. Coaxial cable


12


is passed through the cavity of main nut assembly


32


, and center or inner conductor


14


is inserted into pin


140


. The main nut assembly


32


then is threadably engaged with and tightened onto body


34


. Back nut assembly


30


is then threadably engaged with and tightened onto main nut assembly


32


to tighten threads


100


of back nut assembly


30


and mating threads


118


of main nut assembly


32


. As they are tightened, bevels


80


and


82


engage, as eventually do bevels


180


on the proximal end of ferrule


60


and


182


in main nut assembly cavity


112


, to urge ferrule


60


into intimate and gripping contact with the external portion of the cable


12


, which in this preferred but illustrative embodiment comprises outer conductor


18


.




Preferred embodiments and preferred versions of the methods according to the invention can be advantageous, for example, in that use of the arrangement as described herein can permit the ferrule to be attached to and retained with the cable gripping device when in component form, i.e., prior to coupling of the cable gripping device to the coupling component. These aspects of the invention also may be beneficial, for example, in permitting connection of a coaxial cable to a terminal while limiting or eliminating undesirable twisting of and torsion on the cable. The use of a compression ring as described herein also facilitates connector performance by better maintaining the alignment of components, and better facilitating contacting of the ferrule with the cable exterior. The elimination of a proximal compression ring as described herein with respect to the presently preferred embodiments also allows the back nut assembly


30


to be tightened with respect to the main nut assembly while limiting or preventing twisting on the inner conductor


14


, the outer conductor


18


, or other components. of the cable as the connector is being attached to the cable.




Additional advantages and modifications will readily occur to those skilled in the art. For example, the cable gripping component is described herein as an integral component of the connector and, with respect to presently preferred connector


10


, as a component of the connector. The cable gripping component, however, independently of connector


10


, comprises another aspect of the invention. In addition, the preferred embodiments and methods have been described using a particular type of coaxial cable having no outer insulator or jacket. It will be understood by those in the art, however, that the invention is not necessarily limited to such limited applications. Furthermore, the order in which steps of the inventor and its preferred implementations are performed may be varied. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.



Claims
  • 1. A cable gripping component for gripping a coaxial cable, the cable gripping component comprising:a housing including a sleeve portion having a terminus forming a first end of the housing, the housing having an inner surface defining an interior channel, the inner surface comprising a retention surface disposed on the sleeve portion proximate the terminus, the sleeve portion including a weakened area, wherein the retention surface is disposed between the terminus and the weakened area; and a ferrule disposed within the interior channel for contacting the coaxial cable, the ferrule comprising an outer surface that includes a raised portion, wherein the ferrule extends beyond the terminus of the housing and wherein the ferrule is capable of being compressed against the coaxial cable, and wherein interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.
  • 2. The cable gripping component as recited in claim 1, wherein the ferrule has a terminus that extends beyond the terminus of the housing.
  • 3. The cable gripping component as recited in claim 1, wherein the ferrule is loosely held within the interior channel.
  • 4. The cable gripping component as recited in claim 1, wherein the weakened area comprises at least one groove.
  • 5. The cable gripping component as recited in claim 4, wherein the at least one groove is disposed on the inner surface of the sleeve portion.
  • 6. The cable gripping component as recited in claim 4, wherein the at least one groove comprises a plurality of grooves.
  • 7. The cable gripping component as recited in claim 1,further comprising a compression ring disposed within the interior channel between the ferrule and the inner surface of the housing.
  • 8. The cable gripping component as recited in claim 7, wherein:the ferrule comprises a beveled mating surface; and the compression ring comprises a beveled mating surface for mating with the beveled mating surface of the ferrule.
  • 9. A connector for a coaxial cable, the connector comprising:a cable gripping component comprising a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing, the housing having an inner surface defining an interior channel, the inner surface comprising a retention surface disposed on the sleeve portion proximate the terminus, the sleeve portion including a weakened area, wherein the retention surface is disposed between the terminus and the weakened area, the cable gripping component further comprising a ferrule disposed within the interior channel for contacting the coaxial cable, the ferrule comprising an outer surface that includes a raised portion, wherein interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel; and a coupling component attached to the first end of the cable gripping component.
  • 10. The connector as recited in claim 9, wherein the ferrule contacts the coupling component.
  • 11. The connector as recited in claim 9, wherein the cable gripping component further comprises a compression ring disposed within the interior channel between the cable gripping component housing and the ferrule.
  • 12. The connector as recited in claim 9, wherein the compression ring does not contact the coupling component.
  • 13. The connector as recited in claim 9, wherein the ferrule and the coupling component have mutually mating beveled surfaces.
  • 14. A method for assembling a cable gripping component for a coaxial cable, the method comprising:providing a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing, the housing having an inner surface defining an interior channel, the inner surface comprising a retention surface disposed on the sleeve portion proximate the terminus, the sleeve portion including a weakened area, wherein the retention surface is disposed between the terminus and the weakened area; providing a ferrule comprising an outer surface that includes a raised portion; inserting the ferrule into the interior channel; crimping the sleeve portion to provide interfering engagement between at least a portion of the retention surface and the raised portion, whereby at least a portion of the ferrule is prevented from exiting the interior channel; and providing a coupling component and attaching the coupling component to the first end of the cable gripping component.
  • 15. The method of claim 14, wherein the ferrule insertion comprises inserting the ferrule into the interior channel so that the ferrule is capable of rotating within the interior channel.
  • 16. A method for attaching a connector to a coaxial cable, the method comprising:providing a cable gripping component for a coaxial cable, wherein the cable gripping component comprises a cable gripping component housing including a sleeve portion having a terminus forming a first end of the housing, the housing having an inner surface defining an interior channel, the inner surface comprising a retention surface disposed on the sleeve portion proximate the terminus, the sleeve portion including a weakened area, wherein the retention surface is disposed between the terminus and the weakened area, the cable gripping component further comprises a ferrule disposed in an interior channel of the housing, the ferrule comprising an outer surface that includes a raised portion, wherein the inner surface narrows from the weakened area to the retention area and at least a portion of the ferrule is prevented from exiting the interior channel by the retention surface and the raised portion of the ferrule outer surface; positioning the cable gripping component on the coaxial cable so that the ferrule contacts the coaxial cable; and providing a coupling component and attaching the coupling component to the first end of the cable gripping component.
  • 17. A method as recited in claim 16, further comprising providing a compression ring within the cable gripping component to contact the ferrule.
  • 18. A cable gripping component for gripping a coaxial cable, the cable gripping component comprising:a housing including a sleeve portion having a terminus forming a first end of the housing, the housing having an inner surface defining an interior channel, the inner surface comprising a retention surface disposed on the sleeve portion proximate the terminus, the sleeve portion including a weakened area, the weakened area comprising a plurality of grooves, wherein the retention surface is disposed between the terminus and the weakened area; and a ferrule disposed within the interior channel for contacting the coaxial cable, the ferrule comprising an outer surface that includes a raised portion; wherein interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.
  • 19. A cable gripping component for gripping a coaxial cable, the cable gripping component comprising:a housing including a sleeve portion having a terminus forming a first end of the housing, the housing having an inner surface defining an interior channel, the inner surface comprising a retention surface disposed on the sleeve portion proximate the terminus, the sleeve portion including a weakened area, wherein the retention surface is disposed between the terminus and the weakened area; a ferrule disposed within the interior channel for contacting the coaxial cable, the ferrule comprising an outer surface that includes a raised portion; and a compression ring disposed within the interior channel between the ferrule and the inner surface of the housing; wherein interfering engagement between at least a portion of the retention surface and the raised portion prevents at least a portion of the ferrule from exiting the interior channel.
  • 20. The cable gripping component as recited in claim 19, wherein:the ferrule comprises a beveled mating surface; and the compression ring comprises a beveled mating surface for mating with the beveled mating surface of the ferrule.
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