Hand-held tool for scoring and severing an optical fiber

Abstract: A hand-held tool (10) is provided for scoring and severing an optical fiber (36). An elongate, generally hollow body (18) has a longitudinal axis extending lengthwise thereof and defines a graspable handle for the tool. A plunger (22) is reciprocally mounted in the hollow body for movement in a path generally in the direction of the longitudinal axis. An optical fiber is supported at one end of the body transverse to the longitudinal axis, and a deflector (48) places the optical fiber under tension. A scoring probe (58) is operatively associated with the plunger (22) and movable therewith towards the fiber for scoring and severing the fiber extending across the path of movement of the scoring probe. An actuator lever (12) is pivotally mounted on the body, operatively associated with the plunger, with a finger depressible portion exposed exteriorly of the body, for manual actuation while grasping the body to move the plunger and scoring probe towards the tensioned optical fiber.

Description: The invention relates to a tool for scoring and severing a portion of a free end of an optical fiber according to the preamble of claim 1. In a known tool of that kind (EP-A 0 287 474) tension is applied to the fiber during the scoring or scribing step so that the optical fibers can be easily severed to produce ends with smooth surfaces. The known device uses plate members as the body, and a frame-like slide means is slideably supported by the body. The hollow of the frame-like slide means is faced on the one side by the fiber support means and on the other side by the fiber tensioning means which consist of leaf springs forming a clamp which can be opened and closed by actuacting the actuator means. The optical fiber to be scored has to be inserted into the fiber support means and through the hollow of the frame-like slide means into the clamping means of the fiber tensioning means. The fiber tensioning means draws the fiber along the periphery of a round member so that a bent is produced for the optical fiber. The scoring means is arranged at the frame-like slide facing the hollow thereof and can be moved inwardly and rewardly by actuating the actuator means. The tool is somewhat complex and needs a relative long free end of the optical fiber for being clamped by the tool before being scored. Therefore, the need for a simple hand-held tool for scoring and severing optical fibers during field work still exists. Such a tool should be simply manufactured and simply and reliably used to properly severe optical fibers. The invention is directed to satisfying that need. It is an object of the present invention, which is defined in claim 1, to provide a new and improved simple hand-held tool for scoring and severing an optical fiber, particularly during field work. In the exemplary embodiment of the invention, the tool includes an elongate, generally hollow body having a longitudinal axis extending lengthwise thereof and defining a handle for the tool. Plunger means are mounted in the hollow body for reciprocal movement therewithin in a path generally in the direction of the longitudinal axis. Fiber support means are provided at one end of the body for supporting an optical fiber transverse to the longitudinal axis. Scoring means are mounted on the plunger means and movable therewith towards the fiber support means for scoring and severing an optical fiber extending across the described path. Actuator means are mounted on the body, operatively associated with the plunger means and exposed exteriorly of the body remote from the one end, for manual actuation while grasping the body to move the plunger means and scoring means axially towards the fiber optic support means. As disclosed herein, the actuator means include a depressible finger portion formed by one end of an actuator lever pivotally mounted to the body on a pivot axis transverse to the longitudinal axis, with the finger depressible portion being exposed exteriorly of the body. Oblique cam means are operatively associated between the actuator lever and the plunger means for converting generally transverse movement of the actuator lever to generally axial movement of the plunger means. Preferably, the fiber support means include means for applying a tensile force along an axial direction of the fiber. The tensile applying means is in the form of a deflector offset from the axis of the optical fiber in a direction away from the plunger means and scoring means and against which a free end of the fiber is engageable to establish a concave bend in the fiber facing the scoring means. Other features of the invention include means for adjusting the position of the deflector to vary the extent of the bend in the fiber, adjustable stop means for locating the position of the fiber transversely of the longitudinal axis, and adjustable stop means for limiting movement of the plunger means and scoring means toward the fiber support means. In addition, spring means are provided for biasing the plunger means away from the fiber support means. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. Brief Description of the Drawings The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: FIGURE 1 is a fragmented side elevational view of a hand-held tool for scoring and severing an optical fiber, incorporating the concepts of this invention; FIGURE 2 is a fragmented, axial or longitudinal section, on an enlarged scale, of the tool shown in Figure 1, rotated 90° from the depiction of Figure 1, and illustrating the plunger means and scoring means in an inoperative or retracted position; and FIGURE 3 is a view similar to that of Figure 2, with the plunger means and scoring means advanced to severe an optical fiber. Detailed Description Referring to the drawings in greater detail and first to Figure 1, a hand-held tool, generally designated 10, is designed for grasping by a user's hand while the user depresses an actuator lever 12, as by the user's thumb, to score and severe an optical fiber which is positioned through a forward opening or access area 14 of the tool. Actuator lever 12 is pivoted, as by a pivot pin 16, inside an elongate, generally hollow housing 18 defining a longitudinal axis extending lengthwise thereof, i.e., right-to-left in the drawings. In essence, body 18 forms a tubular housing for most of the operative components of the tool, with the top of actuator lever 12 exposed exteriorly of the housing as shown in Figure 1, for depressing by a user's thumb or finger to the position shown in phantom which effects the scoring and severing of the optical fiber. By designing the overall tool in such an elongate or tubular fashion, it is extremely easy to grasp and use during field work. Referring to Figure 2 in conjunction with Figure 1, elongate body 18 actually is fabricated in two parts, as shown, simply for manufacturing and assembly purposes. The body may be fabricated of plastic material, for instance. A cylinder liner 20 is disposed within body 20 and may be of a more durable material for slidably receiving a plunger 22 at an inner end and a slide member 24 at a forward end. Plunger 22 has an oblique cam surface 26 engageable by the free end of actuator lever 12, the cam surface being at an angle or oblique to the longitudinal axis of the body. Consequently, when a user depresses actuator lever 12 inwardly in the direction of arrow "A" (Fig. 1), this transverse movement is converted to longitudinal movement of plunger 22 in the direction of arrow "B" (Figs. 1 and 2) to move the plunger forwardly toward fiber receiving opening 14. Spring means are located between plunger 22 and slider 24 for biasing those components away from the fiber receiving end of the tool, or opposite the direction of arrow "B". Specifically, a first spring 28 is sandwiched between the forward end of plunger 22 and a head portion 30 at the rear end of slider 24. A second spring 32 surrounds the inner end of slider 24 and is sandwiched between the head portion 30 thereof and a shoulder 34 formed on the inside of cylinder liner 20. First spring 28 is a stronger spring than second spring 32 and defines the force of scoring to severe an optical fiber. Second spring 32 is provided to automatically retract slider 24 and plunger 22 rearwardly, opposite arrow "B", when actuator lever 12 is released. Generally, fiber support means are provided at the front end of body 18 for supporting an optical fiber in a direction generally transverse to the longitudinal axis of the body. Actually, as shown in Figure 2, an optical fiber 36 has been stripped of its cladding 38, and it is the cladding which is positioned within opening 14 at the front end of the tool. This is understandable when considering the very fragile nature of an optical fiber. Cladding 38 easily can be grasped and manipulated by a user to insert the optical fiber through opening 14 to project beyond the inner end of the opening. Stop means in the form of a headed bolt-like member, generally designated 40, is provided for locating the position of the optical fiber transversely of the longitudinal axis of the body. More particularly, member 40 is threaded into body 18, as at 42, and has an enlarged head portion 44. The head portion defines a stop shoulder 46 against which the distal end of cladding 38 can abut. With member 40 being threaded into the body, the transverse position of head 44 can be adjusted to thereby adjust the position of the optical fiber. The fiber support means also include means for placing the optical fiber under tension, i.e., applying a tensile force along an axial direction of the optical fiber. More particularly, a deflector 48 is provided on the end of a rod 50 located in a bore 52 in body 18. A set screw 54 is threaded through body 18 for allowing adjustment and then fixing the position of deflector 48 in a direction generally parallel to the longitudinal axis of the tool, i.e., transverse to the axis of fiber 36. Although deflector 48 is shown pointed in Figures 2 and 3, it should be understood that the deflector actually is widened in a direction perpendicular to the drawings to define a wide edge which easily can engage fiber 36. As a user inserts fiber 36 (by means of cladding 38) into opening 14 in body 18, the user simply uses one of his fingers to lightly deflect fiber 36 so that the fiber moves beyond tip 56 of deflector 48. The deflector should be adjustably located to effect a bend in fiber 36 which is concave in a direction facing inwardly of the tool. The amount of the bend determines the tension placed in the fiber, and the amount of tension can be varied by the position of deflector 48 which is adjustable by set screw 54. Scoring means in the form of a scoring probe 58, having a diamond scoring head 60, is secured to slider 24 for movement therewith in the direction of arrow "B" to engage, score and thereby severe tensioned optical fiber 36, as shown in Figure 3. As with deflector 48, although scoring probe 58 and diamond head 60 are shown in the drawings to be somewhat narrow, the scoring probe and diamond head actually are widened in a direction perpendicular to the drawings to provide a diamond edge sufficiently wide to ensure engagement with fiber 36. The scoring probe is secured to slider 24 by a press fit into a groove 62 on the underside of the slider as viewed in the drawings. A set screw 64 is threaded into body 18 and has a flat head 66 which underlies widened scoring probe 58 to ensure that the probe does not twist should it loosen for some reason. In operation, a user grasps the tool by its tubular body 18 comfortably in one hand of the user. The user's other hand is used to grasp the optical fiber by its cladding 38 and to insert the optical fiber into opening 14 while lightly deflecting fiber 36 to pass by the tip 56 of deflector 48 in order to effect a bend in the fiber. Shoulder 46 on head 44 of stop member 40 provides a limit position which the user can feel as cladding 38 abuts the shoulder. The user then depresses actuator lever 12, as by his thumb, to force plunger 22, slider 24 and scoring probe 58 forwardly in the direction of arrow "B", whereby diamond head 60 of the scoring probe scores the fiber at a position shown in Figure 3, and whereupon the tension in the fiber itself effects the severing of a distal end portion 70 (Fig. 3) of the fiber. It is important that a large force not be applied to the fiber. With the fiber under tension, a small score or flow will effect its severing and provide a square and mirror-smooth surface at the severed point. To this end, a set screw 72 (Fig. 2) is threaded through body 18. The set screw has an angled inner end 74 which intersects the longitudinal movement of slider 24 and engages an angled surface 76 at the forward end of the slider. It can be understood that the transverse position of end 74 of set screw 72 provides a limit stop and determines the extent of travel of slider 24 and scoring probe 58. Therefore, adjustment in the stroke of the scoring probe can be effected to ensure that excessive force is not applied by diamond head 60 against the fiber. From the foregoing, it can be seen that a very simple, easily hand-held and manipulatable tool has been provided by this invention. Yet, the simple tool has a full range of adjustments, including means for adjusting the axial position or extent of insertion of the optical fiber in the tool, means for adjusting the bend and, thereby, the tensile force in the fiber itself, and means for adjusting the scoring force on the fiber by adjusting the stroke of the scoring probe. All of the levers and extraordinary numbers of parts of these types of tools heretofore available have been eliminated. It will be understood that the invention may be embodied in other specific forms without departing from the scope of the claims. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.

Claims: A tool (10) for scoring and severing a portion of a free end of an optical fiber (36), comprising an elongate body (18) defining a graspable handle for the tool (10); actuator means (12) arranged on said body (18) for being manually acted upon; silde means (22,24) slidably supported in said body in lengthwise direction thereof for reciprocal movement in cooperation with said actuator means (12); fiber support means (14) at the forward end of the body (18) for supporting protective means (38) of the optical fiber (36) to be scored so that the optical fiber extends transversly to said elongate body (18); fiber tensioning means (48) for placing the end of the optical fiber (36) in tension; scoring means (58) connected to said slide means (22,24) to be driven therethrough, characterized in that said slide means comprise a plunger (22) and a slide (24) said elongate body (18) is formed for a hand-held tool (10) and is generally hollow to take up and guide said slide means (22,24) and said scoring means (58) outwardly and forwardly towards said fiber support means (14), when said optical fiber (36) is to be scored, and in that said fiber tensioning means (48) comprises a deflector which is arranged in the path of said freely extending optical fiber (36) to be scored to engage the optical fiber to establish a concave bend in the fiber portion facing the scoring means so that said optical fiber is bent and tensioned by the deflector means (48) so as to prevent a bent and tensioned fiber portion to said scoring means. The hand-held tool of claim 1 wherein said slide means (22,24) includes a plunger (22) having an oblique cam surface (26) which cooperates with said actuator means (12) for moving said slide means (22,24) together with said scoring means (58) towards said fiber support means (14). The hand-held tool of claim 2 wherein said actuator means (12) comprises an actuator lever pivotally mounted on a pivot axis (16) which extends transversely to and within said elongate body. The hand-held tool according to any of claims 1 to 3 wherein said fiber support means (14) includes stop means (40,42,46) for locating the position of the fiber (36) and its protective means (38), said stop means (40,42,44) being adapted to be adjusted transversely to said elongate body (18). The hand-held tool according to any of claims 1 to 4 wherein said actuator means (12) includes a finger depressible portion exposed exteriorly of said elongate body (18) and which is movable generally transversely to said elongate body (18). The hand-held tool according to any of claims 1 to 5 wherein means (54) for adjusting the position of the fiber tensioning means (48) is provided to vary the extent of the bend in said optical fiber (36). The hand-held tool according to any of claims 1 to 6 wherein said slide means (22,24) comprises a slider (24) and a plunger (22) and wherein spring means (28,32) is provided for biasing the slider (24) and the plunger (22) away from the fiber support means (14) toward said actuator means (12). The hand-held tool according to any of claims 1 to 7 including stop means (74) for limiting the movement of the slide means (22,24) and scoring means (58,60) towards the fiber support means (14). The hand-held tool of claims 8 including means (72) for adjusting the position of said stop means (74) for varying the stroke of the slide means (22,24) and scoring means (58,60). The hand-held tool according to any of claims 1 to 9 wherein said scoring means (58) is a probe having a diamond head (60), the probe being secured to the slide means (22,24).

Inventors: GROIS IGOR, MARGOLIN MARK, GROIS, IGOR, MARGOLIN, MARK
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 1991
Main classification: G02B6
IPC codes: G02B6, B26F3, H02G1