Fiber optic scribe and cleave tool and method

A method for breaking or severing a rod of brittle fiber material, such as glass optical fiber, to produce a mirror end surface thereon, normal to its longitudinal axis and free of imperfection, is described wherein a linear section of the fiber, usually stripped of its outer protective coating or cladding, is supported and held at and between spaced zones and sequentially subjected to gradually increasing axial tension while its exterior surface is scored by a rotatable cutter or scoring wheel moving in and along a plane normal to the longitudinal axis of said section to effect its separation or cleavage along said plane. An adjustment system to accommodate different sizes and types of fiber optic materials is provided for regulating the axial tension imposed on said section, the angle of attack and scoring pressure exerted by the cutter wheel, the distance of the plane of severance relative to the mounting zone for an optical fiber connector fitting and the holding or radial gripping force exerted on the fiber. The sequential steps of tensioning and scribing or scoring the fiber also are selectively reversable. A manually actuatable tool for accomplishing the foregoing events is also described wherein the program of holding, tensioning, scoring and cleaving of the fiber is carried out independently of manually applied tool operating force.

This invention relates to an improved method for scribing and cleaving 
fiber optic materials and to tool means for carrying out the method. 
BACKGROUND OF THE INVENTION 
The relatively widespread and ever increasing utilization of high quality 
fiber optic materials, usually glass or optical plastic, for use in 
optical wave guide communication systems, data processing and other signal 
transmission systems has created a demand for satisfactory and efficient 
means of interjoining terminal ends of adjacent fiber lengths without 
appreciable loss of signal energy through the junction. It has been found 
that such terminal ends of the fibers transmit light energy signals with 
minimum loss of signal when the end of the fiber itself is optically flat 
with a mirror smooth surface lying in a plane perpendicular to the 
longitudinal axis of the fiber filament. 
In the early stages of employing fiber optic filaments, a variety of 
methods and techniques were developed, many involving rough, imprecise 
cutting of the fiber using scissors, side cutters, or similar cutting 
tools which, however, produced a ragged, crooked, cracked or 
non-perpendicular optically irregular surface on the fiber filament. These 
rough end surfaces were then cast in epoxy of plastic and ground and 
polished to a perpendicularly oriented, optically correct surface. In 
still other instances, hand-held or cumbersome bench mounted tools, 
involving fiber scribers and cutters, usually fixedly mounted and made of 
hardened metal or diamond sharpened to a conical or chisel formation, have 
been used for scoring the fiber materials. In such prior tool 
developments, the fiber is normally supported on its bottom side over a 
supporting surface while it is being scored. In still later developments, 
it was discovered that by bending the fiber over a curved surface during 
the scoring operation, sufficient tension was imposed on the fiber 
filament to produce a relatively clean cleavage or break surface thereon. 
However, in the bending-tensioning operations because part of the fiber 
filament is under compression while the remainder thereof is under 
tension, an optically inferior surface results at the break plane through 
the filament. These inferior surfaces are normally compensated for by 
using an optical refractive matching fluid or by grinding and polishing 
the same to correct the defects. 
By and large, past efforts in this art have failed to develop a 
consistently dependable system for achieving an optically perfect end 
surface in and along the fracture plane of the glass or other rigid fiber 
optic material. One of the difficulties in such past efforts has centered 
about the utilization of rigid scribing instruments such as a fixedly 
mounted ground diamond point which, when moved across the surface of the 
glass fiber, produces a torsional load on the fiber, creating unwanted 
forces in the fiber body susceptible of producing errant fractures which 
are damaging to an optically perfect break surface. Additional 
deficiencies in such prior known score and cleave tools reside in their 
inability to accommodate fibers of differing diameters and 
characteristics, the incapabability, as mentioned, of providing uniformed 
tensile stress along the axis of the fiber to effect a clean mirror and 
optically perfect break surface, the inability to regulate the radial 
forces with which the fiber is gripped and held in a tool and the lack of 
any means for regulating the scoring pressure and attack angle of the 
scribing instrumentality employed, whether it be a ground diamond or 
hardened metal. In other instances, particularly in the hand held or hand 
operated tools, the operating forces applied by the operator's hand to 
effectuate the sequence of events, are reflected in and vary the forces 
imposed on the fiber itself. This is particularly undesirable inasmuch as 
uniformity of cutting conditions are required to obtain a consistently 
repeatable capability of cleaving the fibers with optically correct end 
surfaces. 
Typifying some of the prior developments embodying the general features as 
hereinabove discussed are the following U.S. patents: U.S. Pat. No. 
3,934,773 issued to Chinnock et al; U.S. Pat. No. 3,981,422 issued to J. 
R. Moore; U.S. Pat. No. 4,017,013 issued to Hawk et al; U.S. Pat. No. 
4,027,814 issued to Gloge et al; U.S. Pat. No. 4,074,840 issued to 
Fulenwider et al; and U.S. Pat. No. 4,168,026 issued to Lucas et al. The 
scribe-and-cleave methods and instrumentalities disclosed in the above 
listed patents generally include the steps of scribing or scoring and 
applying tensile stress to the fiber for purposes of propagating the 
scribe or score plane diametrically through the fiber which is commonly 
supported by a backing member or anvil having or movable into a curved 
configuration to facilitate the application of the tensile forces. 
BRIEF SUMMARY OF THE INVENTION 
In recognition of the above-noted deficiencies and shortcomings of prior 
developments in the art of scribing and cleaving optic fibers, the present 
invention is directed to improvements in prior known instrumentalities and 
the methods of separating optic fibers by scribing and cleaving the same. 
Briefly, the current invention modifies the prior scribe and cleave 
techniques or methods by gripping a linear section of the fiber between 
spaced holding zones, scribing the fiber at a desired location between 
such holding zones by means of a rotatable cutter or scribing wheel and 
selectively placing said linear section under axial tension load to 
facilitate the cleavage and separation of the fiber along a plane 
perpendicular to its longitudinal axis and coincident with the plane of 
the scribing wheel. Cleavage and separation of the fiber ends is effected 
by the tension load applied to the linear section and desirably to that 
end at least one of the holding zones is movable away from the other. In 
order to accommodate the utilization of the method with fibers of various 
characteristics and diameters, tool means are provided having means for 
regulating and adjustably varying the tension imposed on the section to be 
cleaved as well as adjusting and regulating the angle at which a rotatable 
scribing wheel attacks the exterior of the fiber and the amount of 
scribing pressure applied to the fiber by such wheel. In addition, 
adjustable means are provided for regulating the radial forces applied to 
the fiber for holding or gripping the same at the spaced locations. Such 
tool preferably is manually operable, lightweight and portable for use in 
the field. However, the same is easily adapted for bench-mounted 
application. Means also are provided in the tool for regulating the 
location of the fiber cleavage so as to accommodate the adaption of the 
fiber to various connector devices available for interjoining abutting 
ends of optic fibers in providing terminal connection thereof. This 
feature permits the separation or cutting of the fiber at precise 
locations selected in accordance with the requirements of the particular 
connector fitting employed. 
It is a principal object and purpose of this invention to provide an 
improved method of scoring and cleaving optic fibers so as to effectuate 
optically perfect end surfaces thereon. 
It is a further object of this invention to provide a tool for carrying out 
the method set out in the preceding object which is capable of utilization 
in the field or as a bench-mounted instrumentality. 
It is still another object of this invention to provide a tool for scoring 
and cleaving optic fibers as set out in the preceding objects which is 
readily portable and manually operable in an easy and convenient manner. 
It is a further object of this invention to provide a scoring and cleaving 
tool for effectuating optically perfect end surfaces on optic fibers which 
is fully adjustable to accommodate optic fibers of various characteristics 
and diameters and which is dependable in operation to provide repeated 
separations or cleavages of optic fibers having the same characteristics 
with uniform results. 
A still further important object of this invention is to provide a tool for 
scribing and cleaving optic fibers which is capable of separating optic 
fibers at specified and precise locations, for the purpose of 
accommodating different types of fiber optic connector devices. 
It is an additional object of this invention to provide an improved fiber 
optic scribing and cleaving tool which is relatively simple in its 
construction, economical to manufacture and dependable in operation. 
Having described this invention, the above and further objects, features 
and advantages thereof will be recognized by those familiar with the art 
from the following detailed description of a preferred embodiment 
illustrated in the accompanying drawings and presenting the best mode 
presently contemplated for enabling those with skill in the art to 
practice this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Scribe and Cleave Method 
With initial consideration of the improved method of this invention, 
references is made to FIGS. 1 through 4 of the drawings illustrative of 
the procedure and program steps involved therein. 
As indicated in FIG. 1, a section of optical fiber 20, in this case 
stripped of its outer protective coating, is disposed between spaced 
holding zones Z.sub.1 and Z.sub.2, depicted as including cooperating pairs 
of gripper means 21, 22 and 23, 24. In mounting the fiber 20 in and 
between such holding zones, the portion or section thereof to be cleaved 
is disposed in a linear condition, unsupported except for its engagement 
at the spaced holding zones. 
It will be noted that the gripper pairs 23, 24 is subjected to a force P, 
furnished as by spring means 25, tending to urge or move the gripper pair 
23, 24 of zone Z.sub.2 in a direction away from the gripper pair 21, 22 of 
zone Z.sub.1. Thus, at least one of the holding zones, according to the 
method of this invention, is movable relative to the other. It also will 
be noted that the force P, acting to separate the holding zones, is 
opposed by a counterforce f also shown as acting on the movable gripper 
pair 23, 24. Desirably, movement of the holding zone Z.sub.2 relative to 
the other stationary holding zone Z.sub.1 is generally along the linear 
axis of the exposed fiber filament 20. 
A rotatable scribing wheel 26, mounted to move vertically, as about a pivot 
fulcrum 27 (indicated at the right side of FIG. 1), is aligned in a plane 
AA disposed at right angles to the lengthwise axis of the fiber 20. The 
wheel 26 is also movable linearly in and along such plane AA to effect its 
scribing operation. It will be understood from diagrammatic FIG. 1 that as 
the scriber wheel 26 moves about its pivot fulcrum 27, the same is biased 
toward the fiber by means of an adjustable spring 28. This serves to 
regulate and adjustably change the pressure with which the wheel 26 
engages the fiber 20. In addition, the angular dispostion and vertical 
location of wheel 26, relative to the body of the fiber 20 at initial 
engagement, is adjustable to regulate the angle of attack or engagement of 
the scriber wheel with the fiber 20 in operation. 
To initiate the scribing and cleaving activity according to this invention, 
the conditions indicated in FIG. 2 are brought about by shifting the 
gripper pairs 21, 22 and 23, 24 in a manner to engage and radially grip 
the fiber 20 therebetween, thus defining two separated or spaced holding 
zones Z.sub.1 and Z.sub.2. In this regard, it is not essential to the 
practice of this invention that each of the spaced holding zones each 
constitute a pair of movable grippers as indicated. At least one of the 
holding areas or zones for instance may constitute means for merely 
longitudinally anchoring the fiber 20, as by abuttingly engaging the outer 
cladding or protective outer coating to hold the fiber against axial 
movement. 
In the condition of events indicated in FIG. 2, force P is exerted on the 
now closed gripper members 23, 24 and is initially opposed by the 
counterface f, preventing movement of zone Z.sub.2 relative to zone 
Z.sub.1. However, at this stage, the fiber 20 is in a linear state 
extending between the two gripping zones. So-held, the fiber 20 is in 
position for attack by the scribing wheel 26 disposed at a desired angle 
of attack depending on its adjusted vertical position. 
FIG. 3 depicts the event of scoring the fiber 20 by the rolling activity of 
the scriber wheel 26. As illustrated, with the fiber 20 stretched between 
the spaced holding zones, the scriber wheel 26 moves in and along the 
plane AA engaging the exterior of the fiber and rolling upwardly and over 
its exterior with scoring force in this illustrated case; acting so as to 
minimize rotation or torque load on the fiber. Meanwhile, the force f, 
opposing the tensioning force P may remain equal to the force P, as in the 
FIG. 2 situation, or may be suddenly or gradually reduced, increasing the 
effect of force P and the tensile forces on the fiber 20 during the actual 
scribing and scoring operation. As previously mentioned, due to the 
adjustability of the scribing wheel 26, both as to elevational position 
relative to the longitudinal axis of fiber 20 to produce a desired attack 
or approach angle of the wheel with the fiber, and regulation of the 
spring means 28 for applying scoring force to the wheel, the angle of 
attack and the scribing pressures are selectively varied to satisfy fiber 
material and diameter requirements. 
Once the scribing wheel has passed over the exterior of the fiber 20, 
completing its scribing and scoring cycle, the force f opposing the 
tensioning force P on fiber 20 is fully released, permitting force P to 
move the second holding zone Z.sub.2 (comprising the gripper members 23, 
24 in the illustrated case) away from the holding zone Z.sub.1 and cutting 
plane AA of the scribing wheel. As a result, the fiber 20 is cleaved or 
separated into two sections 20a and 20b, the latter moving with the second 
holding zone Z.sub.2. This completes the scribing and cleaving operation 
according to the improved method of this invention. Since the separating 
force P is adjustable, it may be optimized for a variety of fibers or 
fixed optimally for a single given fiber. 
It will be observed with respect to the activity of the scribing wheel 26 
that depending on the adjusted position of the angle of attack, it is 
possible to scribe a substantially 180.degree. path about the exterior of 
the fiber 20. Such 180.degree. scribing path is not essential to the 
successful scribing and cleaving operation, although it is helpful in 
certain classes of materials utilizing for optic fibers, particularly at 
larger diameters. Further, while the force f (FIG. 3) has been described 
as being equal to or less than the force P at and during the scribing 
operation, this is a matter of choice and selection, again depending on 
the characteristics of the particular optic fiber being treated. For 
example, it may be desirable in certain instances to avoid any particular 
tension loads on the fiber during the scribing operation, such as when the 
fiber material is extremely brittle and easily fractured. In that event, 
the scribing movements by the wheel 26 will normally suffice to effect the 
desired planar fracture therethrough. In other instances, however, it has 
been found desirable to actually place the fiber 20 under tension load 
during and throughout the scribing operation. In that event the force f is 
gradually lessened permitting a gradual increase of tension forces in and 
along the fiber 20 as the scribing wheel approaches and attacks the 
exterior of the fiber. In either event, once the scribing function is 
completed, it is necessary, that sufficient tensile force to applied to 
the fiber to effect the cleavage and separation of the fiber ends at and 
along the scribing plane as illustrated in FIG. 4. 
Scribe and Cleave Tool 
In order to carry out the program of the above-described method, a tool 
means 30, illustrative of one type of manually operable device capable of 
performing the various method steps described, is set forth in FIGS. 5-9 
of the drawings, to which reference is now made. 
As there shown, the tool means 30 comprises a generally planar or 
plate-like support means 31 on which are mounted laterally spaced right 
and left hand fiber supporting assemblies 32 and 33 comprising the 
above-noted clamping means 21, 22 and 23, 24. Disposed centrally of the 
support means 31 is an actuator means 35 carrying a scriber assembly 36 
having a pivotally mounted scriber arm supporting the scriber wheel 26 at 
one end. Means 35 and the scriber assembly are movable with longitudinal 
reciprocating action generally along a plane passing through the central 
longitudinal axis of the support means 31. Fiber guide means 37 are 
provided on one side of the support means 31 for guiding an optic fiber 20 
into operative alignment with the two holding zones Z.sub.1 and Z.sub.2 
and more particularly with the clamp means 21-24 of assemblies 32 and 33. 
Suitable means for reciprocably activating the actuator means 35 are 
provided comprising, in the illustrated cases, a pivotally mounted, 
manually operated, bell crank handle operator means 38 having a rotatable 
roller means 39 at the outer end of one leg thereof, for engaging the 
actuator 35. Advancing movement of the actuator means 35 is opposed by an 
adjustable return spring means 40. A fixed handle means 41 is also mounted 
on the support means 31 for cooperation with the bell crank 38 whereby the 
latter may be manually actuated through squeezing action of an operator's 
hand to move actuator 38 toward the fixed handle means 41. 
Having described the major components of the tool means 30, the specifics 
thereof will now be set forth. 
The support means 31 is formed as a rectangular generally planar metal base 
plate 45 having an upstanding wall portion 46 at one outer end thereof. An 
elongated opening 47 is formed through the base plate 45, substantially 
centrally thereof, for purposes of mounting the actuator block 35 thereon. 
As shown best in FIG. 6 of the drawings, opening 47 is undercut and 
laterally enlarged along its underside to provide aligned shoulders 48, 48 
along its lateral sides, for reasons which will appear presently. 
The end wall portion 46 is provided with a central threaded opening 
(unnumbered) aligned with the slotted opening 47 and with a recessed 
channel 47a formed in the top face of plate 45. The return spring means 40 
is disposed in and along this channel and engages the block 35 at one end. 
An adjustment screw and spring guide 49 (see FIG. 7) engages the other end 
of spring means 40. The screw 49 fits into the opening in wall portion 46 
and operatively adjusts the compressive force exerted by spring 40 against 
the actuator means 35, as desired. In so regulating the spring 40, the 
manual force required to pivotally actuate the bell crank means 38 is 
correspondingly regulated to fit the the operator's grip and feel. 
However, the forces applied to the bell crank 38 are entirely independent 
of the scribing and cleaving forces developed by the tool 30 and are in no 
way applied to the fiber per se. 
Turning now to the two fiber supporting assemblies 32 and 33 (which include 
the two holding zones Z.sub.1 and Z.sub.2 of FIGS. 1-4), such assemblies 
may be identical, although in the particular illustrated embodiment there 
are slight variations therebetween, as will appear presently. 
The right hand assembly 32, as is best illustrated in FIG. 5 of the 
drawings, comprises an elongated metal member having a generally 
rectangular parallelopiped shaped body, designated 50. Body 50 is 
distinguished by a transverse recess or cut-away area 51, milled or 
otherwise formed inwardly of its upper surface 52 and located adjacent one 
outer end of the body 50. An elongated cylindrical bore 53 is formed 
inwardly of the other or inner end of body member 50 for reception of a 
compression spring means 54, a cylindrical gripper plunger member 55 and a 
threaded adjustment screw 56. The plunger slides axially along this bore 
toward an opposing wall of the recess area 51 which forms the gripper 
means 21; the outer end face of the plunger comprising the gripper means 
22. Regulation of the force exerted by the plunger against the gripper 
face 21 is effected by adjustably threading the screw means 56 toward and 
away from the plunger 55 to vary the compression of the intervening spring 
means 54. Since the other end of the plunger 55 also comprises the gripper 
means 22, adjustment of spring 54 thereby adjusts the holding force 
exerted on an optic fiber by the gripper means 21, 22. If desired, such 
gripper force may be cushioned by providing an elastomeric covering over 
the vaces 21, 22. 
For purposes of regulating and determing the opening and closing movements 
of the gripper plunger 55, the latter is cut away adjacent, but behind it 
gripper end face 22, to provide a substantially semi-cylindrical recess 57 
cooperative with the actuator means 35, as will be explained hereinafter. 
The right hand assembly 32 preferably is stationarily fastened to the base 
plate 31 as by spaced machine screw means 58, 58 which pass through spaced 
openings 59 in the base plate 45 for threaded engagement with cooperating 
openings (not shown) formed inwardly of the bottom side of the body member 
50. 
Turning now to the particulars of the left hand supporting and holding 
assembly 33, it will be recalled that its structural make-up is 
substantially identical to the assembly 32 just described. To that end, 
the same comprises a rectangular parallelopiped body 60 having a cut away 
recess 61 near its outer end which is aligned to oppose the recess 51 of 
assembly 32 in operation. As before, the body 60 of assembly 33 is 
provided with an internal bore 53 which houses a spring means 54 and a 
plunger member 62 having a semi-cylindrical recess 63 near its outer end, 
which comprises the gripper means 24 for cooperation with the opposing 
gripper wall 23 of the recess 61. Adjustment screw means 64 thread into 
the outer end of the central bore 53 in body 60 to adjust the force of the 
internal spring means, thereby regulating the force of engagement between 
the plunger's gripper end 24 and the opposing gripper wall 23, which also 
may be covered with elastomeric material to promote gripping engagement, 
all in the manner as described for assembly 32. 
The principal distinguishing difference of assembly 33 from the right hand 
assembly 32 first described, lies in the provision of a face cam along one 
sidewall thereof. Specifically as best shown in FIG. 5, the sidewall of 
body 60, located closest to the actuator means 35 in operation, is cut 
away to provide a sloping cam surface 65 which intersects adjacent 
sidewall portions 66a and 66b. This sloping surface 65 constitutes a 
linear cam means for effecting pivotal movement of the assembly 33 at 
selected periods of the scribing and cleaving program whereby to impose 
axial tension forces on the fiber section. 
To enable such pivotal activity of the assembly 33 to take place in 
response to activation by the cam means as above described, a pivot screw 
means 67 is employed to fasten and mount the assembly 33 to the base plate 
45; the pivotal axis provided by the screw means 67 being located between 
the sloping cam face 65 and gripper means 23, 24. It goes without saying 
that the location of the pivot axis will determine the extent of arcuate 
movement of the outer end of body 60 in response to operation of the cam 
means 65, as will be described hereinafter. 
From the above description of the two assemblies 32 and 33, it will be 
understood that in the illustrated embodiment, the right hand assembly 32 
is stationarily mounted while the left hand assembly 33 is adapted for 
pivotal movement about a vertical axis, as the tool is oriented in FIG. 5. 
It will be recalled from the description of the method of this invention 
that a force P is applied to at least one of the holding zones to 
effectuate tensioning of the fiber and ultimate cleavage and separation of 
its ends. To this end, the body 60 of the movable fiber supporting 
assembly 33 is provided with a transverse bore 68 located near its outer 
end. Bore 68 lies in a plane coincident with the longitudinal axis of the 
plunger means 62 so that the axis of opening 68 is transverse to the axis 
of plunger 62. Opening 68 is of a diameter sufficient to receive one end 
of spring means 70 (corresponding to spring 25 of FIGS. 1-4) and 
preferably a rigid spring guide rod 71 to prevent buckling of spring 70 in 
operation. The outer or opposite end of the opening 68 is threaded for 
acceptance of an adjustable screw means 72 whereby the compression of the 
spring means 70 may be regulated in accordance with the threaded 
positioning thereof. Both the spring means 70 and the guide rod 71 extend 
toward the opposing end portion of the right hand assembly 32 which also 
is suitably bored to receive the other end of the spring means 70 (see 
FIG. 7). So assembled, it will be understood that the spring means 70 
provides the force P for urging the two assemblies 32 and 33 apart; in 
this instance with and by pivotal activity of the assembly 33. 
Turning now to the particulars of the actuator means 35, as best 
illustrated in FIG. 5 of the drawings such comprises a generally elongated 
base block 75 which may be fabricated and cut or otherwise provided with a 
pair of generally L-shaped right and left hand clamp controller arms 76 
and 77, respectively, which are disposed along the top side of block 75 
and extend forwardly and laterally of its front wall 78. The two clamp 
controller arms 77, 76 are separated by an intermediate, elongated opening 
79 receptive of the scribing assembly 36, as will be explained more fully 
presently. Block 75 also is cut away near its upward rearward corner 
portion to provide a rearwardly extending follower arm 80 to which is 
attached a rotatable follower roller 81 movable about a vertical axis and 
adapted to engage the camming wall portions 65, 66a and 66b of assembly 33 
in operation. The bottom side of the block 75 is formed with an 
intermediately disposed and depending portion 82 formed to fit closely 
within the lateral dimensions of the slotted opening 47 in the base plate. 
Depending portion 82, however, is shorter than opening 47 whereby it is 
adapted to slide longitudinally along opening 47 with limited linear 
motion. 
Mounting or fastening the actuator assembly 35 to the base plate is 
accomplished by inserting the depending portion 82 into the slotted 
opening 47 as above-mentioned, and employing two spaced machine screws 83, 
83 and a pair of washers 84, 84 or the like. As best shown in 
cross-sectional FIG. 6, the machine screws 83 fit upwardly through the 
bottom of the slotted opening 47 with the washers 84 thereabout slidably 
underengaging the shoulders 48, 48. Suitable threaded openings are 
provided in the depending portion 81 of the block member to accept the 
mounting screws 83. While other modes of interconnecting the actuator 
assembly 35 and the base plate may be carried out, the above-described 
arrangment provides a simple, slidable interconnection therebetween as 
desired. 
It will be understood that the forward wall 78 of the actuator block 75 
engages the inner end of the return spring member 40 and to that end such 
face wall 78 may include a recessed socket receptive of one end of the 
spring member 40 or a raised boss insertable axially within the coils of 
the spring member to maintain its centralized location on the block 75. 
With the actuator assembly 35 mounted on the base plate as described, it 
will be noted that the rear face wall 85 of block member 75 is disposed 
for engagement by the actuating roller 39 mounted at one end of the bell 
crank 38. Thus, advancing pivotal activity of the bell crank moves block 
75 forwardly in and along the slotted opening 47 compressing return spring 
40. Release of the bell crank results in return movement of block 75 by 
reaction of spring 40. 
Regarding the purpose of the actuator arms 76 and 77 previously noted, such 
arms, in the assembly of means 35 on the base plate, extend laterally from 
the actuator block 75 to invade the semi-cylindrical recesses 57 and 63 
formed on the two gripper plungers 55 and 62, respectively; extending 
across such recesses and interferingly engaging the adjacent end walls of 
the plunger recesses. By this arrangement, movement of the two plungers is 
controlled in response to movement of the clamp actuator arms 77 and 76. 
More specifically, in the open or non-actuated condition of the tool 
whereat the actuator assembly 35 is disposed in a rearwardly or retracted 
position i.e. with the adjacent rear end of the central opening 47 and the 
depending portion 82 abutting, the influence of return spring 40 
transmitted to arms 76 and 77 is sufficient to overcome the plunger 
springs 54, pushing the gripper plungers into their bores. Consequently, 
the gripper members are held in a retracted condition by and with the 
retracted positioning of the centrally disposed actuator assembly 35 and 
more specifically by virtue of their engagement with and by the arms 76 
and 77 thereof. Movement of the actuator assembly 35 forwardly or toward 
the opposite end of the slotted opening 47 releases the plunger members 55 
and 62, permitting the end wall faces 22 and 24 thereon to approach the 
opposing gripper walls 21 and 23, respectively, whereby to radially grip 
and hold an optic fiber 20 in and across the assemblies 32 and 33. 
Turning now to the features and operational aspects of the scriber assembly 
36, it will be recognized that such includes a linear support arm 90 
having a transverse opening 91 intermediate its ends. A threaded opening 
92 is provided adjacent the outer end of arm 90 to receive a machine screw 
93 which passes through a central opening in the scribing wheel 26 for 
purposes of rotatably fastening the latter to the outer end of the arm 90. 
It will be appreciated that the scribing wheel has a sharpened V-shaped 
outer edge or periphery and preferably is made of carbide or hardened 
steel for purposes of producing a finite scribe line across the surface of 
an optic fiber engaged thereby. 
Interconnection of the scriber assembly 36 with the actuator assembly 35 is 
brought about by means of an axle or pivot pin 94 which passes through the 
pivot opening 91 in arm 90 and threads into a transverse bore 95 formed 
through the actuator block 75. Thus the arm 90 with the scriber wheel at 
its outer end is pivotally supported within the elongated opening 79 on 
the upper side of the actuator block 75. 
In order to adjustably regulate the activities of the scribing wheel 26 and 
its supporting arm 90, a pair of adjusting assemblies 98, 98, (see FIG. 8) 
each comprising an engagement member 99, spring means 100 and an 
adjustment screw means 101 are provided to fit into openings extending 
upwardly from the bottom of the actuator block 75, on opposite sides of 
the pivotal axis for the scriber support arm. This relationship is best 
shown in the cross-sectional FIG. 8 of the drawings. It will be 
appreciated from this latter figure that the engagement members 99 
underengage the bottom edge or side of the scriber supporting arm 90 with 
resilient force as applied by their respective spring members 100. 
Adjustment of the threadably movable screw means 101 serves to vary the 
compression of the spring means 100 and thus adjust the force with which 
the members 99 engage the scriber support arm. With this arrangement, 
appropriate and selected individual adjustment of the screw means 101 and 
the two assemblies 98, 98 effectively adjusts the vertical position of the 
scriber wheel, accordingly regulating its angle of attack with respect to 
the fiber section 20 to be scribed. In addition, adjustment of the two 
screw means 101 may be appropriately regulated to effect or bring about a 
desired force with which the scriber wheel engages the exterior of the 
fiber 20, thereby regulating its scribing pressure. These two adjustments 
are particularly important in accommodating the tool assembly 30 to the 
scribing and cleaving of optic fibers having various physical 
characteristics, particularly breaking and scribing quality, as well as a 
range of diameters, in accordance with that objective of this invention. 
Turning now to the fiber guide means 37, the features thereof will best 
recognized from FIGS. 5 and 7 of the drawings. As there shown, guide means 
37 comprises a cross shaped guide plate having a medially and normally 
horizontally disposed arm portion 105 which parallels and rides over the 
upper face of the plate 45 of the support means in operation. The vertical 
arm of this cross shaped guide plate comprises a lower depending leg 
portion 106 which fits into a substantially rectangular shaped socket 107 
formed or cut inwardly of the upper face of the support plate 45, adjacent 
one end of wall portion 46 thereof. The guide plate is movable along the 
socket 107 and is positionable therein at selected locations. To this 
latter end, a guide rod 108 and a spring means 109, adapted to surround 
the rod 108, are mounted within the socket to oppose movement of the plate 
toward the stationary support assembly 32. Specifically, guide rod 108 
extends through an opening 110 formed in the depending leg portion 106 of 
the guide plate and supports the spring 109 thereabout which then engages 
the opposing end wall of socket 107 and leg 106 of the guide plate. An 
adjustment screw 111 threads into opening 112 formed inwardly of one edge 
of the support plate 45 to communicate with the socket 107 and engage leg 
106, opposing spring means 109 thereon. By appropriate adjustment of the 
screw means 111, the guide plate may be positioned at desired locations 
relative to the lateral edge of the support plate 45 and/or the stationary 
support asembly 32. 
The other or upwardly extending vertical arm portion 115 of the cross 
shaped guide plate, is distinguished by an enlarged opening 116 which is 
invaded at its upper periphery by an open slot 117 through which the 
stripped optic fiber section 20 may be inserted. If desired, the fiber 
also may be axially inserted through opening 116 to align the fiber in the 
holding means 21-24. Optionally, a fitting collar 120 and sleeve 121, 
comprising part a typical optic fiber fitting, may be attached to the arm 
portion 115 coaxially of the opening 116 therein for receiving the 
stripped end of an optic fiber. As shown, the collar 120 and sleeve 121 
also may be provided with slotted openings 121, 123 through which the 
fiber 20 may be inserted. Generally, however, when the use of the fitting 
collar 120 is employed, the central opening thereof closely receives the 
cladding or protective covering surrounding the optic fiber with the 
stripped fiber section 20 being inserted coaxially through the fitting 
collar, the opening 116 and through the two holding zones Z.sub.1 and 
Z.sub.2 comprising the gripper means 20-24. In this fashion, the scribing 
of the fiber at a finite distance from the end of a selected fitting 
member is possible. Regulating the distance between the end of the fiber 
cladding and the end of the cleaved fiber is readily achieved by the 
adjustable positioning the guide plate relative to the cleaving plane of 
the scribing wheel 26. Thus, the objective of providing a capability for 
adapting the cleaving function to a particular class of fiber optic 
fitting is readily achievable with a tool of the above-described order. 
Having described the makeup of a typical tool 30 according to this 
invention, its use and operation will now be set forth. As will best be 
understood from FIG. 7 of the drawings, with the tool 30 in a relaxed or 
open position as shown, loading of the stripped fiber section 20 into and 
between the holding zones is accomplished by inserting the fiber through 
the guide means 37 and across the outer end of the plungers in the 
supporting and holding assemblies 32 and 33. As illustrated in FIG. 7, 
such assemblies are in substantially parallel interrelationship, being 
held in that condition by virtue of the interengagement of the cam 
follower wheel 81 with the surface portion 66a of the left hand assembly 
33. In this condition, it will be noted that the abutment face 85 of the 
central actuator means 35 is disposed against the actuator roller 39 under 
the influence of the compressive forces exerted by the return spring means 
40. 
Once the fiber has been loaded as above noted, either by abutting the 
cladding thereabout within the fitting collar 120 or against the guide 
plate arm portion 115, to locate the cleavage line at a desired distance 
from the cladding about the fiber, the scribing and cleaving operation is 
ready for initiation. This takes place by squeezing the bell crank 
operator 38 toward the stationary handle portion 41, causing the roller 
means 39 thereon to advance the actuator means 35 toward the fiber section 
20. As this advancing movement commences, the arm portions 76 and 77 
release the two plungers 55 and 62, permitting the outer end faces 22 and 
24 thereof to approach the opposing end walls 21 and 23, respectively. The 
fiber section 20, being located and aligned between such gripper faces 
21-24, is then engaged by the plungers with an adjustable radial force as 
exerted by the associated plunger spring means 54. This serves to hold the 
fiber section 20 in a linear condition unsupported between the assemblies 
32 and 33. The tool is now in the operational condition outlined in FIG. 2 
of the drawings. 
Continued squeezing movement of the operator means 38 toward the stationary 
handle 41 serves to advance the actuator means 35 for purposes of moving 
the scribing wheel 26 into engagement with the fiber 20. At this stage of 
events, depending on the location of the sloping cam face 65 of the 
movable assembly 33, with respect to the follower wheel 81 on the actuator 
assembly 35, the periphery of the follower wheel 81 will start to move 
over the cam face 64 until it engages face 66b on assembly 33. During this 
procedure, the sloping face 65 permits the inner end of the assembly 33 to 
pivot toward the actuator means as urged by the compressive spring means 
70 extending between the two holding assemblies 32 and 33. Such activity 
causes the outer end of assembly 33 to move outwardly (counterclockwise) 
as viewed in FIG. 7 thereby placing the fiber section 20 under tensile 
load. This tensile loading of the fiber is gradual, depending on the rate 
of movement of the wheel 81 along the sloping cam face 65 and the time 
interval required for its movement from wall portion 66a to wall portion 
66 b. This condition of events and happenings is best depicted in FIG. 3 
of the drawings where the scribing function of the wheel 26 takes place 
and the force f which opposes the force P (provided by spring means 70) is 
equal to or less than the force P. Force f, of course, is provided by the 
interengagement of the follower wheel 81 with the cam face portion 66a of 
the assembly 33 whereby the latter is held against the separating force 
imposed by the spring means 70. 
Thus, by way of review, as the inner end of the block member 60 moves 
toward the follower wheel 81, the outer end comprising the gripper 
surfaces 23, 24 moves away from the stationary assembly 32 and grippers 
21, 22 in accordance with the FIG. 4 illustration. This separating 
movement of the gripper assembly 33 effects the desired tensioning, 
fracturing, cleavage and separation of the fiber 20 along the plane of 
cleavage A--A as determined by the scribing wheel 26. 
It will be recalled that according to the procedural steps involved in the 
method of this invention the imposition of tensile forces on the optic 
fiber may be regulated to occur prior to, during and/or immediately after 
the scribing operation effected by the scribing wheel 26. This regulation 
of the force P is brought about by the location and slope of the sloping 
cam face 65 whereby to selectively effect the pivotal actuation of 
assembly 33. Thus, for example, if the sloping face 65 is located closer 
to the outer end of assembly 33 than that illustrated, the pivotal 
activity of the inner end of the block member 60 thereof can be regulated 
to occur after the scribing function of the wheel 26; for example, after 
the wheel has passed totally over and beyond the fiber as illustrated in 
the right hand portion of FIG. 4. In that event, the tensile forces on the 
fiber will not be applied until after the scribing function takes place. 
Conversely, the application of the tensile force P may take place prior to 
or simultaneously with the scribing function, as in the illustrated case 
of FIGS. 3 and 4, which in most cases is the preferable order of events. 
The rate of applying tension force is determined by the slope of cam face 
65, which may be regulated as desired. 
In any case, once the scribing function of the wheel 26 has been completed, 
the fiber section 20 will separate or cleave along the scribing plane of 
the wheel 26 under the force P applied by the compressive spring means 70. 
The exact amount of tensile force applied to the fiber of course is easily 
regulatable by adjustment of the screw means 72, which serves to vary the 
compression of the spring means 70, the source of the tensile force P. 
This feature adapts the tool means 30 of this invention to optic fibers of 
varying characteristics and diameters in accordance with that objective of 
this invention. 
Once the scribing and cleaving functions are completed as indicated in FIG. 
4 for example, release of the operator bell crank 38 by the operator 
effects an immediate return of the actuator means 35 to its at rest 
position as shown in FIG. 7 under the influence of the compressive return 
spring means 40. Here again, the adjustment of the force required to 
effect advancement of the actuator means 35 is readily adjusted by virtue 
of the positioning of the adjustment screw means 48 for varying the force 
of the return spring means 40. 
From the foregoing, it is believed that those familiar with the art will 
readily understand and appreciate the novel advancement and unique 
operating steps presented by the present invention. Further, it will be 
understood that while the illustrative tool means for carrying out the 
method of this invention has been set forth in association with a 
preferred embodiment thereof illustrated in the accompanying drawings, the 
same is susceptible to wide variation, change, modification and 
substitution of equivalents without departing from the spirit and scope of 
this invention as defined in the following appended claims.