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This application is a divisional of copending C~n~d; ~n Patent application Serial No. 382,666 filed July 28, 1~81 and assigned to AMP
Incorporated.
The communications industry has long been in need of an optical waveguide splice which meets stringent optical and mechanical performance criteria, which is inexpensive to manufacture, physically compact, and field applied wi~hout specialized tooling. Despite availability of numerous interconnection technologies~ no previous splice technique is totally successful to date in satisfying all of the industry's requirements.
One splicing technology requires heat fusion of optical fibers.
~le resulting splice minimizes optical signal attenuationa but is best suited for laboratory application and not field application.
One ~1;gr ~nt technique known in the art, embodies three or more elongate cylindrical rods which mutually are positioned to define there-between an intestitial passageway for receiving a pair of waveguides. The rods are radially clamped toge~her and against the waveguides by any one oE a number of methods, and the ends of the waveguides are restrained wi~hin the interstitialspace, so that the axes of the waveguides assume colinear po~itions. To improve their grip on the waveguides the surfaces of the rods are either rigid or resilient. ~he axes of the rods remain straight to minimize constrictions along the intersti~ial space~
It is an object of the present invention to provide a field appliable connector for optical coupling of a pair of waveguides.
A further object of the present invention is to provide a field appliable connector for positive mechanical coupling and optical splicing of a pair of optical waveguides. Still further, an object of the present ~ 2 --~5~66 invention is to provide a field appliable and field repairable connector for coupling optical waveguides. Yet a further object of the present invention is ~o provide a field appliable splice for coupling a pair of waveguides which is physically compact, readily applied, and readily released to facilitate repair or replacement of parts.
According to a broad aspect of the present invention, there is provided a connector for colinear axial alignment of a pair of optical waveguides, comprising: at least three elongate resilient rod members in parallel relationship defining an interstitial passageway therebetween, each of said rod members having a larger diameter at first and second opposite ends thereof, and a smaller diameter segment intermediate said ends, said passageway admitting respective waveguides therein from each said end, with forward end surfaces of said waveguides positioned in an opposed adjacent loca~ion intermediate of said rod members length; means for radially influencing said smaller diametered rod se~ments inwardly into peripheral engagement agains~ said waveguides, whereby both said waveguides are engaged by and cla~ped between said rod members in colinear axial alignment with each other.
According to a more preferred embodiment of the invention~ the connector is for splicing a pair of waveguides, and comprises, three profiled rods adapted with larger diametered end portions and smaller diame-~ered central portions extending between the end portions. A radially compressive tubular body recelves the three rods therethrough, and construction collars are provided for radially compressing the tubular body and deflecting inwardly the central portions of the three rods, constr~cting the interstitial passageway between the rods with a tapered, biconical profile ~s~
for funneling the two waveguides upon their entry into and traverse along the passageway, Once the ends of the waveguides oppose each other, *he collars are caused to compress further the tubular body and deflect the three rods to engage and peripherally clamp upon respective waveguides, thereby forcing the waveguides to assu~le positions of colinear axial alignment. The collars can be released and reapplied to accommodate repair or replacement of any one of the waveguides.
The invention and that of Canadian patent application serial No.382,666 will now be described in greater detail with reference to the accompanying drawings, in which; Figure 1 is an exploded perspective view of the subject connector, in conjunction with a shipping wire intended as a mandrel prior to utilization of the connector in a field application. Figure 2 - 3a -~L~9~ 6 is a perspective view of thc connector and mandrel illus-trated in Figure 1 a in the completed assembly condition.
Figure 3 is a perspective viel~ of a pair of optical ~aveguides in readiness for splicin~ by the subject connec-tor. Figure 4A is a longitudinal section view through theoptical splice in a preliminary assembly condition.
Figure 4B is a transverse section view taken along the line 4~-4B of ~igure 4A, illustrating the alignment rod configuration and mandrel in a preliminary assembly condi- - -tion. Figure SA is a longitudinal section view through thesubject connector, ~ith the mandrel replaced by the pair o optical waveguides. Figure 5B is a transverse section view takell along the line 5B-SB of Figure 5A illustrating the alignment rod configuration with respect to an optical waveguide~
Figure 6A is a longitudinal section vie~ through the subject connector, with the crimping collars moved inward toward each other in a completed assembly condition.
Figure 6B is a transverse section view taken alon~
the line 6B-6B of Figure 6A, illustrating the alignment rod configuration in a inal assembly condition, and the optical waYe~uides lleld therebet~een. Figure 7 is a trans-verse section view througll a second embodiment of the present illvention. Figure 8 is a transverse section vie~ tllrou~h a third embodiment of tlle present invention.
Referring to Figures 1, 2 and 4A, a prcerred em-bodiment of the subject invention compriges three elongate cylindrical rods t2), of resilient metallic or plastics material, each of whicll has larger diamcter end por-tions (4), conical tips ~6~, and a smaller dia~ne~er central por-tion tS) integrally joined to -the larger diameter portions ~4) at integral steps (10), an elongated tubular, elasto-meric body (12) having an axial passage~ay (14) extending tlleretllrough, and an extcrnal profile comprising a first stcp ~16), a second step ~18), doubly tapered protube~ance in t~lC
~form of cone sections (20) projectin~ ~adially out~ard of the peril)llcry of the tubular body (12), a~ially dirccte(l slots (22) scparating adjacent cone sectiolls (20) and a pair Or collars (26) 6~
having respective bores (28), each being truncated conical for a purpose to be explained in greater detail belol~. A
cylindrical shipping wire ~30) serves to limit constriction of the connector during sllipment and prlor to assembly of optical waveguides in ~he connector.
Proceeding with reference to Figures 2, and 4A, assembly o~ the component parts proceeds as follows. The three elonga~e rods (2) are inserted within the passageway (14), tne body ~12) expanding resiliently to allo~ passage of the rods along the passageway. The sectional dimension of the passageway ~14) is such that the larger diameter end portions (4) of the-rods ~2; are held ~ith their cylindrical peripheries in contacting parallel relationship. In Figure 4B the interstitial passageway defined by and between the rods (2) is designated as numeral (44~ for the purposes of illustration. As shown by Figures 2 and 4A, the cylindrical shipping wire ~30) is inserted between the rods ~2) and along the inters~itial passageway ~44). Thereafter, both o tile crimping collars ~26) are moved along tne body (12~
and establish interference engagement with the second, lar-ger stepped diameter ~18) of the tubular body ~12), exerting radial compression forces upon the tubular body ~12), and further causing inward radial constriction of the passageway (14) and inward radial deflection of the central portions of the rod segments ~8). The presence of the shipping ~ire ~30) limits deflection of the rods and constriction o *he passage-way (~4).
TUrlling IIOW to Figure SA, the wire ~30) is removed ro~n bet~een the rods (2), allo~ing the segments (8) of tlle rocls ~) to deflect radially inward a slight amount. Thereby, the interstitial passageway (44) bet~een the inwardly deflected portions of the rod segments ~8~, assumes a truncated conical profile from each end of the passageway (44) axially toward the center OI the passageway (44). This doubly tapered profile funnels the exposed core lengths (36)~3X) of respec-tive waveguides as the ~i~aveguides are inserted in~o and traversed along the passageway (~4).
S~S
Figure SB is a section vie~ showing that the for-ward ends (40)t42) of the waveguides are loosely const~ained within the interstitial passage~ay ~44).
Proceeding to Pi~ures 6A and 6B, the crimping collars (26~ are further moved along the tubular body, axially toward each other into a final cri~nped assembly condition, ~Yith the truncated bores (23) of the collars radially engaging and de~lecting inward the cones (20) o~ the tubular body ~12), further deflecting radially inward the tubular body (18), and the midportions of the rod portions (8~. These de-flections of the rod segments (8) cause their midportions to engage peripherally against the exposed waveguide cores (36)(38~ exLending theretllrougll, clamping the ~aveguides be-tween all three of the deflected midportions of the rod seg-- 15 ments ~8). Such a condition is illustrated in section by Fig-ure 6B, and it ~ill be noted that the interstitial passageway t44) in the final crimped condition is dimensioned substan-~ially to the diameter of tlle waveguides. Tlle angles of taper in respect to the interior truncated profiles, of the crimp-ing collars (26) and the tapered external surfaces of the retention cones ~Z0), are selected such that tlle crimping collars ~26) w;ll lock against the retention cones (2~), thereby preventing any relaxation of the crimping pressure upon the tubular body ~12). Clamping of the rod segments ~8) upon the exposed waveguides proceeds from ends of the assembly toward ~he middle, and is concentrated at the or~ard ends cf the waveguides between common rod segments, assuring axial align-ment o:E the ~aveguides.
Pigure 7 illustrates another embodim~nt of the ~resent in~ntion, in ~hich the e~ternal profiled eat-lres of the tubular body (12) and the crimping collars (26) are cllanged, as ollows. The tapers ~f the retention cones (20), and the crimping collar bores (28), are steeper than in the alternative embodiment depicted in Figure 7, ancl eliminates loc~ing between the crimping collars (26) and the cones (20). Figure 8 illustrates yet another embodi-ment o t;le present invention in WhiCil tlle external crin~ping profile of the tubular body (12), the protuberances (20), thc collars ~26) ancl thc bores (23) of tne collars ilave rigll~
5~t66 cylindrical sections and profiles. In all other respects~
however, the al~ernative embodiments o~ Figures 7 and 8 are like the preferred embodimen~ described first in orderO
Viewing Figures 5A and 6A it will be apparent that the crimping collars may progressively move along the pro~ile of body (12) by use of relatively simple applicatio tooling. For example a vise-like hand tool may be used for the necessary nlovement of the collars ~26~ into the final crimped condition. Also it will be noted that the collars may be disengaged by their movement outward axially along tlle body ~12) to facilitate repair of the ~aveguides.
Thus the present splice is field appliable by comparatively simple tooling yet is repairable.
Several further observations will be obvious from a combined consideration of Figures 4A SA and 6A. First the oversized end diameters of the rods provide an oversi~ed interstitial passageway for easy guided inse~tion of the ~aveguide therein. SecondlyJ the oversized end diameters of the rods engage one another radially and spaces apart the smaller diameter intermediate rod segments~ thereby enabling de1ection radially the rod segments to for the resultant bi-conical proiled interstitial passageway. Also it will be apparent that the clamping forces exerted by the rods are directed radially upon the ends (40)(42) of the ~aveguides.
The alignment unction achieved by the three rods is ~ptimally loclted at the juncture of the ~aveguide ends ~40)(42) to achiove opt.imal results in coupling efficiency.
The alternative embodlments depicted in Figures 7 and 8, illustrate but several o:E the many variations in crimping proiles ~hich l~ill become apparent to one skilled in the art upon a reading o the teachings herein set forth.
The principles of the subject invention, may ind application in various alternative and obvious ~mbodiments and tne scope and the spirit of the present invention is not to be confined solely to the embodiments herein set fortll.