Fiber optic ferrule polishing device

#The invention relates to a polishing device and, more particularly, to a device for polishing fiber optic ferrules.

#Fiber optic connectors typically consist of a ferrule having a fiber optic cable comprising an optical fiber encompassed by a buffer extending therethrough. The ferrule has a substantially flat end face through which projecting segments of the optical fiber are inserted and bonded by an adhesive. To prepare the ferrule for connection, the projecting segments of the optical fiber are polished flush with the surface of the end face of the ferrule. First, the surface of the end face is rough polished to remove the projecting segments. Then, the surface of the end face is final polished to remove processing strain layers or any other surface irregularities.

#Because the polishing is required to be done with high precision in order to insure an optimal optical connection between two abutting end face surfaces, it is known to secure the ferrule in a fixture and position the end face against a grinding or polishing wheel. One such ferrule polishing device is disclosed in U.S. Pat. No. 5,503,590 issued to Saitoh et al. Saitoh et al. teaches an elastic film polishing plate for a fiber optic connector having an adhesive removing ring area along an outer area of a polishing wheel. A rough polishing ring area is disposed inward of the adhesive removing ring area, and a final polishing ring area is located concentrically on the polishing wheel. Each of the ring areas is formed of an elastic film to which an abrasive liquid is applied during rotation. The abrasive liquid is varied in each section in order to achieve either a rough or fine polishing. A plurality of partition rings are each disposed between the each ring section to prevent the abrasive liquids from mixing with each other. This device requires the injection of several abrasive liquids and containment of these various abrasives over various ring areas to achieve either the rough or final polishing desired at that specific ring area. These abrasive liquids are costly and the consumables of the process further add to process costs. Further, this device does not have a continuos abrasive surface to allow a single pass polishing of the end face.

#The invention will now be described by way of example with reference to the accompanying figures in which:

#FIG. 1 is an isometric view of the fiber optic ferrule polishing device.

#FIG. 2 is a schematic view of the attachment of the rings to the disk.

#FIG. 1 shows a fiber optic ferrule polishing device 10 comprising a polishing assembly 20 and a fixture assembly 60 attached to a base 12. The polishing assembly 20 comprises an axially preloaded spindle motor 22 having a spindle 30 extending therefrom that is received in a hub 36. The hub 36 has an attached polishing surface 52 comprising a plurality of rings 50. A shroud 210 is positioned about the hub 36 and the attached polishing surface 52. The fixture assembly 60 comprises a fiber optic ferrule holder 100 attached to a mounting plate 212 that is attached to a mounting structure 76. The ferrule holder 100 has a water injecting recess 102, a ferrule holding recess 105 and an attached holding arm 226. The mounting structure 76 is moveably mounted on a slide base 62 and has a threaded shaft 78 extending therefrom that is received in a motor 80. Alternatively, a linear slide motor assembly may be used instead of the threaded shaft 78 and motor 80.

#The main components of the fiber optic ferrule polishing device 10 will now be described in greater detail beginning with the polishing assembly 20 as shown in FIGS. 1 through 3. Referring to FIG. 1, the axially preloaded spindle motor 22 is contained in a housing 24. A supporting structure 32 extends from a bottom surface 34 of the housing 24 and is attached to a top surface 14 of the base 12. A first end 26 of the spindle 30 extends substantially parallel to the base 12 from a front surface 90 of the housing 24. A second end 28 of the spindle 30 is received in the hub 36.

#Shown in FIGS. 2 and 3, the hub 36 is made out of a material such as steel, aluminum, or other materials having similar properties and comprises a mating portion 38 and a disk 40. The mating portion 38 is substantially cylindrical in shape and is dimensioned for receipt of the second end 28 of the spindle 30. The disk 40 has a front side 42 and a back side 44. A plurality of securing apertures 46 extends through the disk 40 from the front side 42 to the back side 44. The securing apertures 46 are positioned radially from the disk center 92 to the disk outer periphery 94. Attached to the front side 42 of the disk is a plurality of rings 50. Each ring 50 is preferably made out of a magnetic material such as steel and has an attachment surface 54 and a polishing surface 52. A magnetic material facilitates manufacturing in that the rings 50 can be magnetically retained during a grinding operation. The attachment surface 54 has a plurality of threaded ring apertures 56 that correspond to the securing apertures 46 on the back side 44 of the disk 40. The ring apertures 56 are positioned on the attachment surface 54 and do not extend through to the polishing surface 52 of the rings 50. Each ring 50 is formed to slip fit into each other. Cap screws 16 or other suitable fastening means are positioned in the securing apertures 46 on the back side 44 of the disk 40. The cap screws 16 extend through the front side 42 of the disk 40 and are received into the threaded ring apertures 56 of the attachment surface 54.