United States Patent
`
`[19]
`
`[11] Patent Number:
`
`4,979,911
`
`Spencer
`
`[45] Date of Patent:
`
`Dec. 25, 1990
`
`[54] CABLE COLLET TERMINATION
`
`[15]
`
`Inventor: Mark Spencer, Ma:-icopa. Ariz.
`
`[73] Assignee: W. L. Gore & Associates, Inc.,
`Newark, Del.
`
`[21] App]. No.: 385.833
`
`[22] Filed:
`
`Jul. 26, 1989
`
`Int. Cl.5 ........................................... .. I-101R 17/18
`[51]
`[52] U.S. Cl. ................................... .. 439/583; 439/434
`[58] Field of Search
`439/343, 351, 352, 578-585,
`439/675, 668, 669, 433, 434
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`3,042,288 6/1962 Edlen et al.
`3,134,706
`5/1965 Atkins .
`439/509
`4,239,313 12/1930 Schwartz
`..... .. 439/584
`4,331,374
`5/1932 Phillips
`4,638,8'?'7 8/ 1987 Dreyer ................................ 439/584
`
`.
`
`FOREIGN PATENT DOCUMENTS
`
`1494323 11/ 191% United Kingdom .
`
`Primary Examiner—David L. Pirlot
`Attorney, Agent. or F1’:-m--Gary A. Sarnuels
`
`ABSTRACT
`[57]
`A cable collet connector for use in terminating the
`shield conductor of coaxial cables that is quickly and
`easily fitted to a coaxial cable and provides a secure
`mechanical and electrical connection.
`
`1,348.4-34 3/1920 Marshick-1-39/BS]
`1,451,548
`4/1923 Kreicheld ......................... .. 439/851
`
`7 Claims, 1 Drawing Sheet
`
`
`
`CORNING EXHIBIT 1013
`
`CORNING EXHIBIT 1 013
`
`

`
`U.S. Patent
`
`Dec. 25, 1990
`
`4,979,911
`
`Fig.
`
`5
`
`Fig. 2
`
`22
`
`22
`
`34
`
`5
`
`Fig. 3
`
`

`
`·1
`
`CABLE COLLET TERMINATION
`
`4,979,911
`
`2
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 represents a three dimensional perspective
`view of the collet.
`FIG. 2 represents a three dimensional perspective
`view of the hat with a male threaded segment.
`FIG. 3 represents a cross-sectional view of the collet
`and hat combination as fitted to a coaxial cable.
`
`FIELD OF THE INVENTION
`This invention relates to electrical connectors for use
`in terminating coaxial cables, specifically to a connec·
`tor having a collet that is quickly and easily fitted to the
`shield of a coaxial cable.
`The connector provides a secure electrical and me· 10
`chanical connection to the shield of the cable.
`
`5
`
`BACKGROUND OF THE INVENTION
`flie ·mtingOfteiixifuation connectors-tocoaiiiil ca(cid:173)
`bles has heretofore been a laborious and time consum- 15
`ing operation. These coaxial connectors have
`previously been of generally three attachment types:
`they have been soldered to the shield of the coaxial
`cable, they have been connected to the shield of the
`coaxial cable by compressing the tubular form of the 20
`connector to the shield with the aid of a compression or
`crimping tool, or they have been both soldered and
`crimped. The connector fitted to the shield of the
`coaxial cable by soldering functions well, ·being me(cid:173)
`chanically secure. and providing a good electrical con- 25
`nection to the cable shield. However, the process of
`soldering this type of connector to the cable shield is
`typically time-consuming and laborious. When the con(cid:173)
`nector is applied to the shield by crimping or compres(cid:173)
`sion, the connection may be made fairly quickly, 30
`however, there is a great risk of crushing the dielectric
`insulation of the cable and thus compromising or per(cid:173)
`haps ruining the impedance characteristics of the co(cid:173)
`axial cable. This method also creates impedance
`discontinuities which adversely affect electrical per- 35
`formance at high frequency. The third method works
`well, but is complicated and time consuming.
`Previously available coaxial shield connectors have
`been complex, requiring multiple components. Several
`require the use of a ferrule inserted between the cable 40
`shield and the cable dielectric insulation. These com(cid:173)
`plex and difficult to fit components only increase termi(cid:173)
`nation time and expense.
`
`DESCRIPTION OF THE INVENTION WITH
`REFERENCE TO THE DRAWINGS
`The cable collet termination comprises the combina(cid:173)
`tion of two components, an inner tubular component in
`the form of a collet and an outer tubular component
`hereafter referred to as a "hat". The collet, as shown in
`FIG. 1, is made of an electrically conductive material,
`preferably of metal, of tubular construction and bas a
`first (4) and second end (5). Slots (6) and (7) are cut
`through the wall of the tube, are longitudinally disposed
`and extend inwardly at least half and preferably more
`than half the length of the tube. There are at least four
`such slots; more than four slots may be provided. The
`slots are made so as to extend inwardly from alternate
`ends of the collet. In a preferred alternative, slot (7) may
`be wider than slot (6). Another preferred alternative
`incorporates a flange (8) at the first end ( 4) of the collet.
`In still another alternative, the flange (8) at the first end
`(4) of the collet is made so as to both increase the out·
`side diameter and decrease the inside diameter of the
`collet for the width of the flange. The bore of the collet
`is provided with many fine grooves or serrations (9)
`which may be oriented to run circumferentially or more
`preferably in a helical pattern, as in a screw thread. In
`another alternative, the serrations may run longitudi(cid:173)
`nally. The serrations regardless of orientation will pref·
`erably extend for the entire length of the bore of the
`collet. The outer surface of the collet will preferably be
`tapered from end to end so that the outside diameter of
`the collet is larger at the first end than at the second end.
`This taper is preferably of one-half degree to ten de(cid:173)
`grees and is most preferably of one degree.
`With reference to FIG. 2, the compression hat por(cid:173)
`tion of the cable collet termination is a tubular compo(cid:173)
`nent having a first (21) and second end (22), made from
`electrically conductive material, preferably metal. Most
`of the length of the bore of the hat (2) is preferably
`tapered from one end to the other, the taper being of the
`same angle as the taper on the collet (1) portion of the
`assembly. Tue largest diameter of the taper is located at
`the first end (21) of the hat (2), the smallest diameter of
`the taper being located within the bore of the hat and
`most or all of the distance to the hat's second end (22).
`Both the largest and smallest diameters of the taper are
`of such dimensions as to securely bind the collet to the
`cable when a cable termination is completed. Any re(cid:173)
`maining untapered length of the bore of the hat (2) may
`be of constant diameter and of a slightly larger diameter
`than the outside diameter of the insulating jacket (34), in
`order that a short length of the jacketed cable can be
`accommodated within the hat (2). This straight bored
`p,ortion of the hat (2) may be of the same or smaller
`diameter as the smallest diameter of the taper.
`In one preferred alternative, the exterior of the hat (2)
`is threaded (23) at the first end, the threads (23) prefera(cid:173)
`bly extending for about one-third to about one-half of
`the length of the hat (2). This male threaded segment
`(23) will mate to a female threaded segment of the oppo(cid:173)
`site connector necessary to make a completed connec-
`
`45
`
`SUMMARY OF THE INVENTION
`The disclosed electrical connector terminating the
`shield conductor of a coaxial cable comprises the com(cid:173)
`bination of:
`(a) a tubular collet of electrically conductive mate(cid:173)
`rial, having a first and second end, an inner and outer 50
`surface, and a wall, having at least four slots longitudi(cid:173)
`nally disposed and of length less than the length of the
`collet and more than half the length of the collet, the
`~~~~~~d~~~~~u~:s:::~~~~~h=n~~l~: ~:=~ 55
`having serrations on some portion of the inner surface
`of the collet, wherein ·the outer surface of the collet is
`tapered, having a larger outside diameter at the first end
`than at the second end;
`(b) a tubular hat of electrically conductive material
`having a first and second end and an inner and outer
`surface, wherein the inner surface of the hat is tapered,
`having a larger inside diameter at the first end than at
`the second end, the angle of taper being the same as for 65
`the collet, the diametrical dimensions of the taper being
`appropriate to cause compression of the collet when the
`hat is slideably fitted over the collet.
`
`60
`
`

`
`4,979,911
`
`4
`3
`tion of the cable to a device or another cable. The use of
`EXAMPLE
`threads represents a convenient means for connecting to
`A cable collet termination was manufactured for the
`an opposite connector. Any other means providing
`purpose of terminating a microwave coaxial cable. Both
`good mechanical and electrical connection may be used
`5 the collet and hat were manufactured from stainless
`as well.
`steel. The collet was made to be 0.420 inch long, of
`The male threaded segment (23) of the hat is followed
`0.173 inch constant inside diameter and 0.235 inch out-
`by a short segment (24), increasing the outside diameter
`side diameter at the largest end of the external taper, the
`of the hat (2) for a short distance. The flange (24) is
`typically located at about the center of the length of the
`taper being of one degree. Serrations were cut into the
`IO bore of the collet by running a 0.201--48 tap through the
`hat. Its fun.ction is to provide wrench flats (25) for the
`full length of the bore. Eight slots of 0.380 inch length
`were cut through the wall of the collet. They were
`tightening of the hat (2) to the female threaded segment
`uniformly spaced 45 degrees apart and were cut begin-
`of the opposite connector. This configuration allows
`ning from alternate ends of the collet. The four slots
`many industry standard connector interface types to be
`adapted. The remainder of the hat externally is of con- !5 beginning from the first end were cut 0.007 inch wide;
`the four slots beginning from the second end were cut
`stant diameter which, combined with the optional
`straight non-tapered bore of the second end of the hat,
`0.020 inch wide. The collet was made to incorporate an
`provides a relatively thin walled sleeve intended to
`outside flange at its first end, the flange being of 0.250
`cover a short segment of the cable jacket (34). This is
`inch outside diameter and 0.020 inch width. The com-
`only one of several possible configurations. The specific 20 pression hat was made to a length of 0.600 inch with a
`design of the outside of the hat is not important since its
`set of 5/16-32 UNEF-2E external threads extending
`purpose is only to provide a means by which an indus-
`from the first end for a distance of about 0.110 inch. A
`try standard interface or a ne:w interface design may be
`flange of0.085 inch width and 0.355 inch outside diame-
`mechanically attached to the collet termination which is
`ter was incorporated into the exterior of the hat, and
`the subject of this patent.
`25 having 0.3 12 inch wrench flats, the flange located 0.165
`As shown in FIG. 3, these components are utilized in
`inch from the threaded first end of the hat. The remain-
`terminating a coaxial cable by first stripping any insulat-
`ing le~gth of the hat was made to an outside diameter of
`ing outer jacket (34) from the cable so as to expose the
`0.250 mch. The bore of the hat was tapered one degree
`conductive shield (32). The shield (32) may be solder
`from a largest diameter of 0.233 inch at the threaded
`tinned or not depending on the type of shield utilized 30 end. The bore of the opposite end was of constant diam-
`eter of 0.218 inch for a distance of 0.200 inch, at which
`and the quality of fit to the collet that will be appropri-
`point it met the tapered portion of the bore without a
`ate for the service required. A portion of the exposed
`step. The assembly was fitted to a coaxial cable of the
`type available from w. L. Gore and Associates, Inc.,
`shield and underlying insulation are cut and stripped
`away so as to expose the center conductor or conduc- 35 Phoenix, Ariz. in G2S01S01028.0 cable assemblies. The
`tors (33). These conductors may be terminated at this
`termination was made by first stripping the plastic
`point or terminated subsequent to the fitting of the
`jacket from the cable for a distance of 1.0 inch. The
`shield termination.
`exposed shield, consisting of wire braid, was dipped into
`The cable collet termination is assembled by first
`a hot solder pot for tinning. About 0.575 inch of shield
`sliding the hat (2) component onto the cable second end 40 and dielectric insulation were stripped away, exposing
`the same length of center conductor. This exposed cen-
`(22) first and far enough that it is beyond the exposed
`shield (32) and over the jacketed portion (34) of the
`ter conductor was tinned in a solder pot for later tenni-
`cable. The collet (1) is next fitted over the exposed
`nation. The hat was slid onto the cable second end first
`shield (32), second end (5) first, so that the flange (8) is
`and beyond the tinned shield. The collet was fitted over
`flush with the end of the shield (32) and dielectric cable 45 the tinned shield second end first so that the flanged end
`was flush with the edge of the shield and dielectric
`insulation. The hat (2) is then pulled back over the collet
`(1) while maintaining the collet (1) in its fitted position,
`insulation. The collet was maintained in this position
`mating the internal taper of the hat (2) with the external
`while the hat was pushed back over the collet. The hat
`taper of the collet (1). The taper and inside dimension of
`was temporarily made up to a female threaded opposing
`the hat is such that it causes compression of the collet, 50 connector and tightened to 20 inch-pounds to ensure an
`the longitudinal slots in the collet allowing this to oc-
`adequate connection between the cable shield and the
`~~~~~c~re !e::~:~~eca!i';[ ;::~~~:~· ~:e~=~t~~
`cur. Because the collet is alternately slit from opposite
`ends, the compression takes place relatively uniformly
`the center conductor. An adapted SMA interface was
`over the surface of the shield, thus minimizing any ten- 55 then mated to the threaded portion of the hat.
`Four such terminated coaxial cable assemblies were
`dency to crush the insulation of the cable. As the collet
`is compressed, the serrations (9) provided on the inner
`made up utilizing collet cable terminations fabricated as
`surface of the collet bite into the surface of the exposed
`described above on both ends of each cable. The char-
`shield (32) and thus furnish the grip required for a good
`acteristic impedance of a 24 inch length of coaxial cable
`electrical and mechanical connection. In one configura- 60 so terminated was measured at 50 ohms. The mechani-
`cal integrity of each of the four samples was tested by
`tion where the serrations (9) are in the form of threads,
`prior to the complete compression of the collet (1). the
`applying a tensile load to both ends of the termination of
`collet (1) and hat (2) may be rotated on or off the end of
`each cable. The load was applied sequentially to each
`sample in loads of 25, 30, 35, 40, 45 and 50 pounds. The
`the cable, thereby allowing adjustment in the electrical
`phase length of the cable assembly. The collet can be 65 SMA interfaces and the collet/cable area was inspected
`placed in any position that maintains secure mechanical
`for degradation after each pull test; none was found.
`connection in order to adjust the electrical phase length
`Each sample was also tested for voltage to standing
`of the assembly.
`wave ratio (VSWR) after each pull test. All four sam-
`
`

`
`5
`pies measured less than 1.35: l at 18.0 gHz through pulls
`of 45 pounds. At 50 pounds two samples exceeded
`VSWR of 1.35:1 at 18.0 gHz due to cable tensile
`strength failure. The remaining two· samples were still
`below a VSWR of 1.35:1at18.0 gHz after having been 5
`pulled to 50 pounds tension.
`I claim:
`1. An electrical connector for terminating the shield
`conductor of a coaxial cable comprising the combina(cid:173)
`tion of:
`(a) a tubular collet of electrically conductive mate(cid:173)
`rial, having a first and second end, an inner and
`outer surface, and a wall, having at least four slots
`longitudinally disposed and of length less than the
`length of the coll et and more th;m half the length of IS
`the collet, the slots extending through the wall of
`the collet beginning alternately from the first and
`second ends of the collet, having serrations on
`some portion of the inner surface of the collet,
`wherein the outer surface of the collet is tapered, 20
`having a larger outside diameter at the first end
`than at the second end;
`(b) a tubular hat of electrically conductive material
`having a first and second end and an inner and
`outer surface, wherein the inner surface of the hat 25
`is tapered, having a larger inside diameter at the
`first end than at the second end, the angle of taper
`
`10
`
`4,979,911
`
`6
`being the same as for the collet, the diametrical
`dimensions of the taper being appropriate to cause
`compression of the collet when the hat is slideably
`fitted over the collet.
`2. An electrical connector of claim 1 wherein the
`serrations on the inner surface of the collet are int he
`form of a screw thread.
`3. An electrical connector of claim 1 wherein the first
`end of the collet has a flange.
`4. An electrical connector of claim 1 wherein the
`slots through the wall of the collet beginning from the
`first end of the collet are of different width than the
`slots beginning from the second end of the collet.
`5. An electrical connector of claim 1 wherein the
`outer surface of the hat has near the longitudinal mid(cid:173)
`point a flange of increased diameter, the outer surface of
`said flange having two diametrically opposed flat sur(cid:173)
`faces for use with a wrench, said hat having threads on
`the outer surface between the first end and the flange.
`6. An electrical connector of claim S wherein the
`serrations on the inner surface of the collet are in the
`form of a screw thread.
`7. An electrical connector of claim S wherein the
`serrations on the inner surface of the collet are oriented
`to run longitudinally.
`• • • • •
`
`30
`
`35
`
`40
`
`45
`
`50
`
`SS
`
`60
`
`65