Fiber extraction tool

#A common type of optical fiber connector includes passages that receive optical fiber termini. A retainer clip has tines that abut a shoulder on the terminus body to retain it. The terminus can be removed by sliding a tubular extraction tool into the passage to expand the tines of the clip. The terminus and tube then are rearwardly moved together out of the passage by applying a rearward force to the terminus body. Such rearward force can be applied by pulling on the optical fiber that extends rearward from the terminus, or pushing rearwardly against the tip of the terminus. The optical fibers are very delicate, and a rearward pull on them can damage them. Although the front end of the terminus is usually exposed during terminus extractions so it can be pushed rearwardly, a hand or other instrument that pushes against the front end of the terminus body may scratch the tip of the optical fiber that is usually flush with the front end of the terminus. An extraction tool that released a terminus body from a retention clip and that applied force to the terminus body to remove it, without requiring that tension force be applied to the optical fiber or that the tip of a terminus be pressed rearwardly, would of value.

#In accordance with one embodiment of the present invention, an optical fiber extraction tool is provided which enables extraction of an optical fiber terminus by releasing the terminus body from a retention clip and applying a rearward force to the terminus body, which extracts the terminus without requiring tension forces to be applied to the optical fiber or pushing forces to be applied to the front tip of the terminus. The extraction tool includes inner and outer tubes, with the inner tube having a front portion forming a plurality of fingers with free front ends. The inner tube can be inserted until the fingers of the inner tube lie around a portion of the terminus body that lies behind the rearwardly-facing shoulder of the body that engages tines of the retention clip. Then, the outer tube is moved forwardly to a front position relative to the inner tube, wherein the front end of the outer tube substantially abuts the body shoulder and expands the tines so their tips lie out of line with the body shoulder. In the front position of the outer tube, the outer tube closely surrounds the fingers of the inner tube to prevent them from expanding. As a result, the front ends of the inner tube fingers grip the body so when the outer and inner tubes are moved as a unit rearwardly out of the passage, the front ends of the inner tube fingers pull the terminus body out of the passage. Such removal of the terminus is accomplished by rearward forces applied only to the terminus body at a location rearward of the body shoulder, by the fingers of the inner tube.

#The free front ends of the inner tube are preferably bent to extend at forward and radially inward inclines. It is common to form the terminus body with a neck lying immediately rearward of the body shoulder. The inwardly-incline finger front ends lie in the neck and grasp the neck to pull it out. The outer tube prevents the fingers from deflecting radially outwardly, so they continue to grip the rear of the neck of the terminus body to pull it out.

#FIG. 1 is a sectional view of a portion of an optical fiber connector, shown mated to another optical fiber connector.

#FIG. 2 is an enlarged view of a portion of the connector of FIG. 1, and of an extraction tool, showing the extraction tool in the course of its insertion into position.

#FIG. 3 is a view similar to FIG. 2, but with the extraction tool fully inserted into the passage, and ready for removal of the terminus.

#FIG. 1 illustrates a portion of an optical fiber connector 10 which includes a housing 12 with passages 14 and an optical fiber terminus 20 in each passage. The terminus includes a ferrule 22 with a bore 24 that holds a thin optical fiber element 26. The ferrule and fiber element have tips 30, 32 that are flush and polished. A ferrule 34 of another terminus is coupled to the terminus 20 by abutting their tips. The ferrules lie in an alignment frame 36 that lies forward of housing 12 and that holds a precision tube 40 in which the ferrules are positioned for alignment.

#The terminus 20 includes a body 50. An optical fiber cable or optical fiber 52 has a jacket that is stripped away around the optical fiber element 26. The fiber 52 with the jacket therein lies in a bore 54 of the body, and is fixed therein by a potting compound such as epoxy (not shown). The body has a rearwardly R facing shoulder 60, and the connector includes a retention clip 62 with resilient tines 64. The tines are biased to extend in a forward F and radially inward direction towards the axis 70 of the body. The clip 62 lies in a clip holder 72 that can slide within the passage 14. A spring 74 biases the terminus forwardly against the ferrule 34 of the mating terminus. It is noted that the other terminus does not require a spring 64 or a clip holder. The particular housing 12 includes two parts 76, 78.

#Occasionally, a terminus 20 must be removed from the connector housing. In the past, this was accomplished by inserting a retraction tool in the form of a thin-walled tube, forwardly until the front end of the tube abutted the shoulder 60. The tube expanded the front ends of the retention clip tines 64 so they were out of line with the shoulder 60. That is, the front ends 82 of the tines were further from the axis 70 than the perimeter of the shoulder 60, so the shoulder 60 and the rest of the terminus could be moved rearwardly out of the housing passage 14. Even with the clip tines expanded, a substantial force is required to move the terminus rearwardly out of the housing, especially because the tines 64 press firmly against the outside surface of the body front portion 84. One way to apply such rearward force was to pull the rear of the fiber 52. This had the disadvantage that it could damage the delicate fiber. Another way was to disconnect the connector 10 from the mating other connector and push rearwardly against the tip 30 of the terminus ferrule 22. This has the disadvantage that any force applied to the tip of the terminus could damage the tip of the ferrule or the tip of the optical fiber element by creating even a small scratch. The tips, 30, 32 are precisely polished, and slight damage can be important.