United States Patent [19]
`Anila
`
`[11]
`[45]
`
`4,156,554
`May 29, 1979
`
`COAXIAL CABLE ASSEMBLY
`Inventor:
`Sharanjlt S. Aujla, Bramalea, Canada
`Assignee: International Telephone and
`Telegraph Corporation, New York,
`NY.
`Appl. No.: 894,411
`Filed:
`Apr. 7, 1978
`
`Int. Cl.2 ........................................... .. HOIR 17/04
`US. Cl. ...................... .. 339/ 177 R; 174/89
`Field of Search ..................... .. 339/177 R, 177 E;
`174/75 C, 88 C, 89
`
`[54]
`[75]
`[73]
`
`[21]
`[22]
`[51]
`[521
`[58]
`
`[561
`
`Attorney, Agent. or Firm—A. Donald Stolzy
`[57]
`ABSTRACT
`A coaxial cable and an electrical connector therefor
`including a back-nut threaded to a body to receive a
`female ?tting. The body has a stop for the back-nut. The
`back-nut has an internal shoulder. The body has an
`internal frusto-conical surface. A conductive ferrule is
`also provided. A cylindrical member clamps a cylindri
`cal portion of the ferrule to the cable outer conductor.
`The ferrule has a shoulder. The ferrule also has a slotted
`frusto-conical surface to fit against the frusto-conical
`surface of the body. The slots form spring projections
`that are held in pressure contact with and in good elec
`trical contact with the said body surface. The back-nut
`shoulder pushes the ferrule toward the body as the
`back-nut is threaded thereto. The back-nut has a ?ange
`behind which a gasket gland is retained. The clamping
`member is held in axial compression between the ferrule
`shoulder and the gasket gland. The gasket gland then
`provides a seal between the back-nut and the cable, the
`cable being surrounded by the flange.
`
`6 Claims, 8 Drawing Figures
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`1
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`References Cited
`'
`U.S. PATENT DOCUMENTS
`
`.
`
`2/1972 Stevens et al. ................. .. 339/177 R
`3,639,890
`6/ 1972 Nepovim ......... ..
`3,668,612
`3,781,762 12/1973 Quackenbush ................. .. 339/177 R
`FOREIGN PATENT DOCUMENTS
`
`778781 7/1957 United Kingdom .............. .. 339/177 R
`1490421 11/1977 United Kingdom .............. .. 339/177 R
`Primary Examiner-Neil Abrams
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`CORNING EXHIBIT 1029
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`US. Patent May29, 1979
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`Sheet 1 of3
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`4,156,554
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`US. Patent May 29, 1979
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`Sheet 2 of 3
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`4,156,554
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`U.S. Patent May 29, 1979
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`Sheet 3 of 3
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`4,156,554
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`COAXIAL CABLE ASSEMBLY
`
`BACKGROUND OF THE INVENTION
`This invention relates to an electrical assembly and,
`more particularly, to a coaxial cable with a radio fre
`quency interference (RFI) proof and/or weather proof
`connector.
`
`PRIOR ART STATEMENT
`Two searches were made. The following is an incom
`plete list of the patents cited in the search. However,
`this list includes what are believed to be the pertinent
`patents.
`'
`
`4,156,554
`2
`conical external surface around said cable end portion,
`said ?rst portion being axially slotted to form resilient
`prongs; a back-nut surrounding said ?rst and second
`ferrule portions; a conductive body to which said back
`nut is threaded; said body having a frusto-conical inter
`nal surface to mate with said ferrule frusto-conical sur
`face, said back-nut being so threaded and constructed
`that said prongs lie in pressure contact with said body
`surface to make good electrical contact therewith; and
`securing means to hold said cable jacket and outer con
`ductor and said ferrule second portion in ?xed positions
`relative to each other and in pressure contact and in
`electrical contact with each other.
`
`Inventor
`Dupre et al.
`O'Keefe et al.
`O'Keefe et al.
`Brishka
`Hutter et al.
`Nepovim
`
`U.S. PatfNo.
`2,958,845
`3,281,756
`3,297,979
`3,432,798
`3,646,502
`3,671,926
`
`In Dupre et al., see tapered pin 8.
`' In O’Keefe et al., 3,281,756, see “crimped” in column
`2, line 5.
`In O’Keefe et al., US. Pat. No. 3,297,979, see “a
`housing crimping sleeve 32” in column 3, line 26.
`In Brishka, see “a clamp gasket” in line 19 of column
`
`2.
`
`In Hutter et al., see “a standard crimp ferrule 54” in
`lines 38-39 of column 2.
`In Nepovim, see FIG. 3 and the ?rst full paragraph in
`column 6.
`The need for effective shielding of coaxial intercon
`nections has increased signi?cantly with the rapidly
`expanding use of electronic equipment for communica
`tions and data processing systems. In addition, govern
`ment speci?cation BP23 has now placed more stringent
`limits on the amount of signal that can lawfully leak out
`of or leak ,into a cable interconnect system. The signal
`which leaks into such a system is called radio frequency
`interference (RFI). RFI leaks into the system through
`poor shielding of connectors for coaxial drop cables. In
`this regard, existing ?ttings known as ‘F’ ?ttings offer
`very little protection against destructive corrosion
`brought about by the ingress of today’s polluted atmo
`sphere at the connecting region and around the compo
`nents. The operation of such a degraded connection in
`the high signal level and freuqency ranges ultimately
`becomes a prime source of RFI. Resulting from the
`described conditions, the frequent replacement of mal
`functioning components is necessary. This then in
`creases costs and maintenance.
`
`SUMMARY OF THE INVENTION
`According to the present invention, there is provided
`an electrical assembly comprising: a coaxial cable hav
`ing an end portion, a center conductor, a dielectric
`surrounding said center conductor, an outer conductor
`which may be comprised of a braid, a foil, or a hollow
`tube surrounding said dielectric, an insulating jacket
`surrounding said outer vconductor, and said outer con
`ductor being stripped away from said dielectric over
`said cable end portion; a conductive ferrule having a
`passageway therethrough somewhat larger in size than
`said dielectric, said cable end portion projecting
`through said passageway, said ferrule having ?rst and
`second axial portions, said ?rst portion having a frusto
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`BRIEF DESCRIPTION OF THE DRAWINGS
`In the accompanying drawings which illustrate exem
`plary embodiments of the present invention:
`FIG. 1 is a side elevational view of a cable and con
`nector assembly;
`,
`FIG. 2 is a longitudinal sectional view of the assem
`bly shown in FIG. 1, and taken on the line 2-—2, shown
`therein;
`,
`FIG. 3 is an exploded elevational view, partly in
`section, of the assembly shown in FIGS. 1 and 2;
`FIG. 4 is an end elevational view of a ferrule shown
`in FIG. 3, and taken on the line 4—4 shown therein;
`FIG. Sis an exploded subassembly, partly in section,
`of the cable and connector shown in FIGS. 1-4;
`FIG. 6 is a longitudinal sectional view of an alterna
`tive embodiment of the present invention;
`FIG. 7 is a side elevational view, partly in section, of
`a seizing collet shown in FIG. 6; and
`FIG. 8 is an end elevational view of the collet taken
`on the line 8—8 shown in FIG. 7.
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`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`The present inventionmay be employed in, for exam
`ple, the CATV industry as a new and improved ‘F’
`?tting for aerial installations of a communication chan
`nel between the distribution trunk and the subscribers’
`premises. Other uses are, of course, possible. The pres
`ent invention provides and RFI-proof and weather
`proof connector system resulting in reduced CATV
`system operating costs and maintenance.
`The accompanying drawings illustrate two embodi
`ments. One embodiment is shown in FIGS. 1-5. The
`other is shown in FIGS. 6-8. Both embodiments are
`identical except that a female ?tting 29 in FIG. 6 is
`omitted in FIG. 1, and a seizing collet 10’ is employed in
`FIG. 6, whereas a retention sleeve 10 is employed in
`FIG. 2 in lieu of the collet 10'.
`FIGS. 2 and 6, respectively, have bodies 11 and 11’,
`back-nuts l2 and 12’, ferrules 13 and 13’, and sealing
`rings (O-rings) 14, 15 and 14', and 15’. Back-nuts 12 and
`12’ have ?anges 40 and 40', respectively, that retain
`gasket glands 19 and 19', respectively, in FIGS. 2 and 6,
`respectively. Back-nut 12' is also provided with a ta
`pered section 12" complimentary to the tapered sectio
`10" of the seizing collet 10'.
`-
`As shown in FIGS. 2 and 6, the connectors to the
`cable assemblies are indicated at 16 and 16’, respec
`tiv’ely. In FIG. 2, a coaxial cable 17 is inserted through
`a rear wall bore 18 of back-nut 12, a gasket gland 19,
`and the tubular retention sleeve 10.
`The ferrule 13 is provided with an axially slotted
`frusto-conical front portion 13" and a reduced diameter
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`cylindrical rear portion 13"’. Cable 17 has a dielectric
`the connector body 11. From the connector body 11 to
`the mating female ?tting 29 in either of the embodi
`21, a center conductor 22, an outer conductor 23, and a
`polyvinyl chloride outer jacket 24, or one made of any
`ments of FIGS. 2 and 6 or to the female ‘F’ ?tting,
`grounding is achieved by means of a conductive sealing
`conventional material. The ferrule 13 has a central bore
`ring inside the bodyv as well as through the body itself.
`20 to to permit passage of the dielectric 21 and center
`(0) The weather-proof construction of the embodi
`conductor 22. The cable 17 is assembled to the ferrule
`13 by inserting the ferrule tubular rear portion 13"’
`ments disclosed herein protects contacting surfaces
`from degrading due to atmospheric corrosion. Electri
`between the dielectric 21 and the outer conductor 23
`cal integrity is therefore maintained for a long period of
`until the cable jacket 24 and the outer conductor 23
`reach ferrule front portion 13". The cable dielectric 21
`time.
`(d) On prior art ‘F’ ?ttings, any cable bending occur
`and center conductor 22 extend outside the front face of
`ring at the relatively sharp edge on a ferrule rear por
`the ferrule 13 (the left face as viewed in FIG. 2). Cable
`retention is accomplished by forming tubular retention
`tion would ultimately result in a severely damaged
`sleeve 10 into a hexagon crimp over the portion of the
`cable outer conductor and dielectric. Contrary to this,
`cable jacket 24 overlapping the tubular rear portion 13'”
`the present invention causes the back-nut 12 to act as a
`bending stress relief member by allowing the cable
`of the ferrule 13.
`As shown in FIG. 6, cable retention may also be
`bending to occur away from the edge of the ferrule rear
`accomplished by using wedge shaped, axially slotted
`portion 13"’. The mechanical and electrical integrity of
`seizing collet 10’. The seizing collet 10' may be made
`the interconnection are thus maintained. An indepen
`from either metallic or non-metallic materials such as
`dent stress relief device such as a kellums grip, etc., can
`also be incorporated by making slight modi?cations to
`plastics, etc.
`The bodies 11 and 11' have center bores 11" and 11"’,
`the rear entry of the ferrule.
`respectively, in FIGS. 2 and 6, respectively. Center
`(e) On the whole, the present invention offers a struc
`turally superior interconnect system.
`bores 11" and 11”’ accomodate cable dielectrics 21 and
`21’, respectively. Bodies 11 and 11' have front portions
`(f) The connector of the present invention is more
`25 and 26, respectively, with internal threads 27 and 28,
`closely matched to the nominal impedance of the coax
`respectively, to permit connection to the output termi
`ial cable and hence provides superior overall electrical
`characteristics.
`nals on taps/couplers and similar devices that utilize
`female ‘F’ ?ttings. The rear portion of the body is pro
`(g) Where the present invention relates basically to
`vided with external threads to allow coupling to the
`metallic structural members, it must be noted that with
`back-nut, and has a conical inside surface complemen
`the inclusion of suitable conductive additives, non-met
`tary to the frustum pro?le of the ferrule 13.
`. allic materials such as elastomers and plastics may be
`In FIG. 2, body 11 is ?rst installed on a female ?tting
`used for the back shell and body components, etc., de
`scribed herein.
`such as ?tting 29 in FIG. 6. In FIG. 2, back-nut 12 is
`then threaded onto the body 11. In so doing, the frus
`I claim:
`tum pro?le of the ferrule 13 is brought into contact with
`I. An electrical assembly comprising: a coaxial cable
`the inside conical surface of the body 11 and, at the
`having an end portion, a center conductor, a dielectric
`same time, the gasket gland 19 (19’ in FIG. 6) is com
`surrounding said center conductor, and an outer con
`ductor surrounding said dielectric, an insulating jacket
`pressed between the crimp sleeve 10 and the rear inner
`shoulder of the back-nut 12.
`surrounding said outer conductor, and said outer con
`ductor being stripped away from said dielectric over
`In the case of FIG. 6, the base of the frustum of the
`ferrule 13' pushes against the seizing collet 10’. The
`said cable end portion; a conductive ferrule having a
`collet 10’ compresses the gasket gland 19. Collet 10’ also
`passageway therethrough somewhat larger in size than
`said dielectric, said cable end portion projecting
`seizes on the cable jacket 24'. Tightening either of the
`through said passageway, said ferrule having ?rst and
`back-nuts 12 or 12’ continues until a positive stop is
`second axial portions, said ?rst portion having a frusto
`reached at, for example, 31 and/or 32. See, however,
`conical external surface around said cable end portion,
`FIG. 6 also. This ensures that the frustum of ferrule 13
`in FIG. 2 is properly seated in the cavity of body 11.
`said ?rst portion being axially slotted to form resilient
`The degree of gasket gland compression which is pro
`prongs; a back-nut surrounding said ?rst and second
`duc'ed effects a reliable seal between the cable 17 and
`ferrule portions; a conductive body to which said back
`the connector 16 without damaging the gasket gland 19.
`nut is threaded, said body having a frusto-conical inter
`The frustum of the ferrule 13 is slotted to allow defor
`nal surface to mate with said ferrule frusto-conical sur
`mation of the conical surfaces while consistently main
`face, said back-nut being so threaded and constructed
`taining a positive ground for the cable 17. Grounding
`that said ferrule prongs lie in pressure contact with said
`contact pressure at the conical surface is automatically
`body internal surface to make good electrical contact
`provided when the back-nut 12 is tightened to the posi
`therewith; and securing means to hold said cable jacket
`tive stop. When properly assembled and mated, ade
`and outer conductor and said ferrule second portion in
`quate sealing is achieved between the body 11 and the
`?xed positions relative to each other and in pressure
`back-nut interface, and between the body 11 and the
`contact and in electrical contact with each other,
`mating female ‘F’ ?tting.
`'
`wherein said securing means includes a member sur
`Some outstanding advantages that can be derived
`rounding said cable jacket and outer conductor and said
`from the present invention over prior art devices are as
`ferrule second portion in a manner to clamp the same
`together, and wherein said back-nut has a ?ange close
`follows:
`to and surrounding said cable and forming an annular
`(a) The back-nut 12 herein acts as an enclosure of the
`pocket therein, a sealing gasket gland in said pocket
`cable 17 to connector interconnect area, thereby offer
`ing increased shielding effectiveness against RFI.
`close to said ?ange and said cable, said ferrule having a
`(b) The assembly of the present invention gives posi
`shoulder, said member being annular and in axial com
`pression between said ferrule shoulder and said gasket
`tive grounding of the outer conductor 23 of cable 17 to
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`gland to cause said gasket gland to provide a seal be
`tween said back-nut and said cable.
`2. The invention as de?ned in claim 1, wherein said
`body has a stop to limit axial movement of said back-nut
`when said back-nut is threaded to said body.
`3. The invention as de?ned in claim 2, wherein said
`back-nut has a shoulder to engage said ferrule shoulder
`for pressing said ?rst portion into said body.
`4. The invention as de?ned in claim 3, wherein a ?rst
`O-ring seal is positioned between said back-nut and said
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`body, said body having a second O-ring to seal to a
`female ?tting.
`5. The invention as de?ned in claim 4, wherein said
`body has a hole therethrough somewhat larger than said
`dielectric, said cable end portion extending through said
`hole.
`6. The invention as de?ned in claim 5, wherein said
`cable includes an outer jacket surrounding said outer
`conductor, said ferrule second portion including a cyl
`inder clamped by said securing means between said
`outer conductor and ‘said dielectric, said securing means
`surrounding said outer jacket.
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