Note: Descriptions are shown in the official language in which they were submitted.
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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
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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
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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
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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)
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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).
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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~
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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.
