Fiber optic connectors and methods of affixing optical fibers thereto

A fiber optic connector includes a first connector body, an associated first end cap means, a second connector body and an associated second end cap means. A longitudinal groove is provided along a fiber engaging face of the first connector body. A plurality of transverse slots are spaced along the groove. Reference means are associated with the groove for indicating where a face of a first fiber to be coupled should be aligned. The first end cap means has a longitudinal protuberance along a face which engages a portion of the first connector body, the protuberance corresponding in size and shape to the groove. A plurality of transverse inverted fingers are spaced along the protuberance. The second connector body has a longitudinal protuberance along a fiber engaging face with a plurality of transverse inverted fingers spaced therealong. Reference means are associated with the second body protuberance for indicating where a face of a second fiber to be coupled should be aligned. The second end cap means has a raised longitudinal extension with a groove therein along a face for engaging a portion of the second connector body. A plurality of transverse slots are spaced along the second end cap means groove. Upon proper mating of the two connector bodies, body engaging means associated with each connector body engage the corresponding mated body.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to fiber optic connectors, and to methods of 
affixing optical fibers thereto. Accordingly, it is a general object of 
this invention to provide new and improved connectors and methods of such 
character. 
2. Description of the Prior Art 
Spring means and screw means have been used for biasing an optical fiber 
connector against the operative surfaces of a V-groove channel, as set 
forth in greater detail in U.S. Pat. No. 3,902,784, entitled "Apparatus 
for Forming an Optical Fiber Connector," issued to Mark Dakss et al on 
Sept. 2, 1975. Similar material appears in a division thereof, U.S. Pat. 
No. 3,999,841 entitled "Method for Forming an Optical Fiber Connector," 
issued Dec. 28, 1976. 
The presence of a V-groove channel without more, does not assure proper 
alignment of an optical fiber. cl SUMMARY OF THE INVENTION 
Another object of the invention is to provide for new and improved fiber 
optic connectors and methods of affixing optical fibers thereto so that 
such optical fibers are properly aligned. 
Yet another object of the invention is to provide new and improved optical 
connector bodies which can be simply coupled together with the associated 
optical fibers in proper alignment. 
Still another object of the invention is to provide an inexpensive, easy to 
manufacture, optical connector. 
Still yet another object of the invention is to provide for a new and 
improved, easy to assemble, method of affixing optical fibers to optical 
connector parts. 
Another object of the invention is to provide new and improved parts and 
procedures for assembling optical fibers to an optical connector which 
obviate the requirement for high precision parts and critical assembly 
procedures. 
In accordance with one embodiment of the invention, a fiber optic connector 
includes a first connector body, an associated first end cap means, a 
second connector body and an associated second end cap means. A 
longitudinal groove is provided along a fiber engaging face of the first 
connector body. A plurality of transverse slots are spaced along the 
groove. Reference means are associated with the groove for indicating when 
a face of a first fiber to be coupled should be aligned. The first end cap 
means has a longitudinal protuberance along a face which engages a portion 
of the first connector body, the protuberance corresponding in size and 
shape to the groove. A plurality of transverse inverted fingers are spaced 
along the protuberance. The second connector body has a longitudinal 
protuberance along a fiber engaging face with a plurality of transverse 
inverted fingers spaced therealong. Reference means are associated with 
the second body protuberance for indicating where a face of a second fiber 
to be coupled should be aligned. The second end cap means has a raised 
longitudinal extension with a groove therein along a face for engaging a 
portion of the second connector body. A plurality of transverse slots are 
spaced along the second end cap means groove. Upon proper mating of the 
two connector bodies, body engaging means associated with each connector 
body engage the corresponding mated body. In accordance with certain 
features of the invention, the groove on the first connector body can be 
recessed and V-shaped, and the transverse slots spaced along therein are 
rectangular. The protuberance on the first end cap means is extended and 
V-shaped. The fingers on the first end cap means are rectangular and 
V-shaped. The protuberance along the face of the second connector body is 
extended and V-shaped, and the fingers spaced there along are rectangular 
and V-shaped. The groove in the second end cap means is V-shaped. The 
associated transverse slots are rectangular, and are extended to a depth 
beyond the V-shape groove of the second end cap means. 
In accordance with another embodiment of this invention, fibers can be 
affixed to such a connector by orienting one fiber within the first 
connector body longitudinal recessed groove and aligning it so that a face 
thereof is aligned with the first connector body reference means. Epoxy is 
applied to the first fiber within the groove of the first connector body. 
The first end cap means is applied to engage the first connector body so 
that the epoxy joins the first end cap means to the first fiber, and the 
epoxy joins the first fiber to the first connector body. The second fiber 
is oriented within the second connector body V-shaped fingers. The second 
fiber is aligned so that a face thereof is aligned with the second 
connector body reference means. Epoxy is applied to the second fiber 
within the second connector body V-shaped fingers. The second end cap 
means is applied to engage the second connector body so that the epoxy 
joins the second end cap means to the second fiber, and the epoxy joins 
the second fiber to the second connector body.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, there is shown an exploded view of a fiber optic 
connector, partly in sections in accordance with a preferred embodiment of 
the invention. The connector 11 includes a first connector body 12, an 
associated first end cap means 13, a second connector body 14, and a 
second end cap means 16. 
The first connector body 12 has a face 17 upon which a first fiber 18 to be 
coupled will be engaged. A longitudinal recessed V-shaped groove 19 is 
provided along the face 17 of the connector body 12. A plurality of 
rectangular transverse slots 21 are spaced along the groove 19, the slots 
21 extending to a depth exceeding that of the groove 19. The body 12 has 
an engaging section 22 formed as will become more apparent hereinafter. A 
spring clip 23 is affixed to the body 12 as will become more apparent 
hereinafter. Reference means, such as a line 24 or other indicium 
associated with the groove 19, indicates where the face 26 of the fiber 18 
is to be aligned. 
The end cap 13 has a face 26 for engaging a portion of the connector body 
12, as indicated at FIG. 2. A longitudinally extended V-shaped 
protuberance 27 is provided along the engaging face 26, the protuberance 
27 corresponding in size and shape to the recessed groove 19. 
The protuberance 27 is provided with a plurality of rectangular transverse 
inverted V-shaped fingers 28 spaced therealong. The fingers 28 are of such 
a length that they do not exceed the depth of the transverse slots 21. 
The second connector body 14 has a face 29 upon which a second fiber 31 to 
be coupled will be engaged. A longitudinal extended V-shaped protuberance 
32 is provided along the face 29 of the connector body 14. A plurality of 
rectangular transverse inverted V-shaped fingers 33 are spaced along the 
protuberance 32, the fingers 33 extending a distance beyond the 
protuberance 32. The connector body 14 includes a body engaging portion 34 
adapted to engage with the engaging section 22 of the body 12 when the two 
bodies 12 and 14 are brought together and the engaging portions 22 and 34 
are in proper alignment. A spring clip 36 is affixed to the body 14 as 
will become more apparent hereinafter. Reference means, such as a line 37 
or other indicium associated with the protuberance 32, indicates where the 
face 38 of the fiber 31 is to be aligned. 
The end cap 16 has a face 39 for engaging a portion of the connector body 
14, as indicated at FIG. 2. A raised longitudinal extension 41 has a 
V-shaped groove 42 therein along the face 39. A plurality of rectangular 
transverse slots 43 are spaced along, and extend to a depth beyond, the 
V-shaped groove 42. 
Upon proper mating of the two bodies 12 and 14, the first engaging portion 
22 engages with the second engaging portion 34, the first spring clip 23 
affixed to the body 12 engages about the second end cap 16 and clips the 
second connector body 14; the second spring clip 36 affixed to the second 
body 14 engages about the first end cap 13 and clips about the first 
connector body 12. 
The connector 11, in summary, is a snap together device which uses a 
V-groove-winged finger clamp to rigidly align the fibers. It is 
constructed of two halves which are mechanically polarized. Each half is 
composed of a molded plastic body 12 or 14, a molded plastic end cap 13 or 
16, and a spring clip 23 or 36. The body 12, 14 has either a V-groove 19 
or a winged finger 32, 33 (respectively) molded into its entire length. A 
cleaved fiber 18, 13 is placed into this groove and is gauged with respect 
to a reference line 24, 37 on the body 12, 14 with an appropriate tool. 
The end cap 13, 16 which contains a mating finger 27, 28 or V-groove 42 is 
then snapped into place to hold the fiber 18, 31 securely. Fast setting 
epoxy is preferably used to permanently secure the fiber, end cap, and 
body together. 
Once properly attached to the fiber ends, the connector halves (including 
their respective bodies and end caps) need only be snapped together to 
complete the connection. The action of the spring clips 23, 36 is two 
fold: First, they act to press the reference surfaces of the connector 
halves together which align the fibers in the longitudinal direction (end 
separation). Second, they press the fingers and V-groove together which 
align the fibers in both the transverse and angular orientations. 
In accordance with the invention, fiber optic connectors can be easily 
constructed and optical fibers can be conveniently affixed thereto. The 
connectors utilize easily moldable parts which are relatively inexpensive 
to manufacture. Assembly is simplified. High precision parts and critical 
assembly procedures are elminated due to the V-groove-winged finger clamp 
combination. The fiber ends are protected from handling damage, but they 
can be cleaned if necessary after installation. 
Extensive tests of the connectors, indicate that losses predominantly fall 
in the 0.5 dB to 1.0 range for 125 micron diameter, graded index fiber. 
Other modifications to the invention will become apparent to those 
ordinarily skilled in the art, without departing from the spirit and scope 
of this invention as defined by the appended claims.