An object of the present invention is to provide a unit capable of improving redispersibility in a concentrated liquid of a polishing composition containing alumina as abrasive grains. There is provided a concentrated liquid of a polishing composition which includes: particulate alumina; colloidal alumina having an aspect ratio of more than 5 and 800 or less; at least one phosphorus-containing acid selected from the group consisting of phosphoric acid, phosphoric acid condensates, organic phosphoric acids, phosphonic acids, and organic phosphonic acids; and water, where a pH of the concentrated liquid of the polishing composition is 2 or more and 4.5 or less.

A tool for chamfering cleaved tips of optical fibers. The tool including conical bores of relatively smooth and hard material terminate at a cylindrical bore that is slightly larger than the fiber core maximum diameter and a fiber centering bore that is slightly larger than the fiber coating maximum diameter. The tool provided such that when a cleaved fiber tip is inserted into the centering bore the sharp edge falls upon the chamfering surface that, when rotated relative to the fiber, gently grinds the edge to the chamfer angle. Chamfering cannot occur on the core face due to the absence of tool surface at this dimension.

A fabrication carrier for fiber optic connectors defines a body configured to removably hold a plurality of fiber optic ferrules. The body allows each of the fiber optic ferrules to be movable along its axis under a bias when the ferrules are mounted to the body. The body can be coupled to a polishing plate for use with a ferrule polishing apparatus in a polishing step. Coupling of the body to the polishing plate allows each of the ferrules to at least partially protrude past a bottom face of the polishing plate for contact with the polishing apparatus. The body of the fabrication carrier is configured as a fixture that can be used in at least one additional fabrication step aside from the polishing step when not mounted to the polishing plate.

An end face polishing device for optical fiber ferrule for polishing an end face of an optical fiber ferrule by applying a polishing pressure between a polishing plate driven by a polishing drive shaft and an optical fiber ferrule held by a holding portion. The end face polishing device has: a bearing portion for allowing the polishing plate to rotate relatively around the polishing drive shaft and to move relatively to the polishing drive shaft in an axial direction; a polishing plate guide supporting portion for movably supporting the polishing plate on a base portion to apply the polishing pressure to the holding portion by allowing the polishing plate to move in the axial direction; a pressing drive source for outputting a driving force to apply the polishing pressure; and a pressing force transmission mechanism for transmitting the driving force output from the pressing drive source as a pressing force in the axial movement direction of the polishing plate.

Carbon atoms of a single-crystal diamond and active abrasives are used to produce a chemical reaction to form carbides under a specific grinding condition of no higher than a graphitization temperature, and a hard abrasive is used to remove the carbides.

Carbon atoms of a single-crystal diamond and active abrasives are used to produce a chemical reaction to form carbides under a specific grinding condition of no higher than a graphitization temperature, and a hard abrasive is used to remove the carbides.

Provided is an optical fiber ferrule polishing jig capable of fixing an optical fiber ferrule and releasing the optical fiber ferrule. An optical fiber ferrule polishing jig 10A has; a base 12a having insertion holes 20 into which optical fiber ferrules 51 can be detachably inserted; pivoting rods 13 which are adjacent to the insertion holes 20 of the base 12a and rotatable around lower end portions 36; fixing pieces 14a installed in installation recesses 19a formed in the base 12a to fix the optical fiber ferrules 51 with respect to the insertion holes 20 by being moved as the rods are pivoted; and a plurality of coil springs 15a installed in the installation recesses 19a to bias the fixing pieces 14a so as to release fixing of the optical fiber ferrules 51 with respect to the insertion holes 20.

An embodiment of the invention of this application provides a polishing pad that eliminates a gap between an optical connector and a polishing film during polishing. A polishing pad of the embodiment is used by being placed between a polishing platen and a polishing sheet in a case of performing spherical polishing of an end surface of an optical connector including an optical fiber and a ferrule. The optical connector polishing pad of the embodiment has rebound resilience higher than 20%. The optical connector polishing pad of the embodiment can be formed from a urethane-based material.

An optical fiber polishing fixture assembly comprises a fixture base and a clamping assembly. The clamping assembly has first and second base portions, a lever, and a biasing member. Each of the first and second base portions has an inner facing side with a slot and an inner facing surface. The slots are adapted to receive bars on opposing sides of a fiber optic connector and cable assembly. The lever has a first end positioned between the inner facing surfaces and a second end extending outward therefrom. The clamping assembly has a locked position, when the first and second base portions are biased toward one another by the biasing member, and an unlocked position, when the lever overcomes a biasing force of the biasing member and separates the first and second base portions.

A combined additive manufacturing method applicable to parts and molds relates to moldless-growth manufacturing of parts and molds, which includes steps of: S1: layering and slicing a three-dimensional CAD (computer-aided design) model of a workpiece to be formed according to shape, thickness and dimensional accuracy requirements of the workpiece, so as to obtain a plurality of layered slice data; S2: planning a forming path according to the layered slice data, and generating layered slice numerical control codes for forming; and S3: deposition-forming a powder material on a substrate layer-by-layer and performing pressure forming or milling forming according to the layered slice numerical control codes in the step S2, which uses a numerically controlled high-speed cold spray gun to spray the powder material to a determined position for deposition-forming. The method of the present invention overcomes thermally induced adverse effects of hot processing and drawbacks of cold spray deposition.