Methods and apparatus for a composite bicycle front sprocket are disclosed herein. One embodiment discloses a composite bicycle front sprocket assembly having an outer assembly of a first material. The bicycle front sprocket assembly also has a center assembly of a second material. The center assembly is disposed at least partially within the outer assembly. The center assembly is irremovably coupled with the outer assembly. The center assembly is irremovably coupled with the outer assembly without an external fastening device to irremovably couple the center assembly with the outer assembly.

Methods and apparatus for a composite bicycle front sprocket are disclosed herein. One embodiment discloses a composite bicycle front sprocket assembly having an outer assembly of a first material. The bicycle front sprocket assembly also has a center assembly of a second material. The center assembly is disposed at least partially within the outer assembly. The center assembly is irremovably coupled with the outer assembly. The center assembly is irremovably coupled with the outer assembly without an external fastening device to irremovably couple the center assembly with the outer assembly.

A method for manufacturing an insulator for a spark plug includes a molding process of forming a cylindrical molded product having an axial hole that extends in a direction of an axial line, by means of injection molding using a mold that has a columnar cavity therein and a bar-shaped member disposed in the cavity and extending in the direction of the axial line. In this method, the molding process includes an injection step of injecting a material containing a ceramic. In the injection step, the material is injected into the cavity from a plurality of injection openings that are opened at an inner circumferential surface, of the mold, that forms the cavity. The plurality of injection openings include two or more injection openings located at different positions in the direction of the axial line, or two or more injection openings located at different positions in a circumferential direction.

A method for manufacturing an insulator for a spark plug includes a molding process of forming a cylindrical molded product having an axial hole that extends in a direction of an axial line, by means of injection molding using a mold that has a columnar cavity therein and a bar-shaped member disposed in the cavity and extending in the direction of the axial line. In this method, the molding process includes an injection step of injecting a material containing a ceramic. In the injection step, the material is injected into the cavity from a plurality of injection openings that are opened at an inner circumferential surface, of the mold, that forms the cavity. The plurality of injection openings include two or more injection openings located at different positions in the direction of the axial line, or two or more injection openings located at different positions in a circumferential direction.

Embodiments of the present invention provide an osseointegrative implant and related tools, components and fabrication techniques for surgical bone fixation and dental restoration purposes. In one embodiment an all-ceramic single-stage threaded or press-fit implant is provided having finely detailed surface features formed by ceramic injection molding and/or spark plasma sintering of a powder compact or green body comprising finely powdered zirconia. In another embodiment a two-stage threaded implant is provided having an exterior shell or body formed substantially entirely of ceramic and/or CNT-reinforced ceramic composite material. The implant may include one or more frictionally anisotropic bone-engaging surfaces. In another embodiment a densely sintered ceramic implant is provided wherein, prior to sintering, the porous debound green body is exposed to ions and/or particles of silver, gold, titanium, zirconia, YSZ, α-tricalcium phosphate, hydroxyapatite, carbon, carbon nanotubes, and/or other particles which remain lodged in the implant surface after sintering. Optionally, at least the supragingival portions of an all-ceramic implant are configured to have high translucence in the visible light range. Optionally, at least the bone-engaging portions of an all-ceramic implant are coated with a fused layer of titanium oxide.

A second mold is placed on a planar surface of a first mold to form a first mold cavity, which is filled with a first material slurry containing a first material powder and the molded slurry is caused to set, thereby forming a first molded part on the planar surface of the first mold. A third mold is placed on the planar surface of the first mold from which the second mold is removed and on which the first molded part is formed, thereby forming a second mold cavity. The second mold cavity is filled with a second material slurry which contains a second material powder different from the first material powder so as to mold the slurry in contact with the first molded part. The molded slurry is caused to set, thereby forming a second molded part on the planar surface of the first mold.

A second mold is placed on a planar surface of a first mold to form a first mold cavity, which is filled with a first material slurry containing a first material powder and the molded slurry is caused to set, thereby forming a first molded part on the planar surface of the first mold. A third mold is placed on the planar surface of the first mold from which the second mold is removed and on which the first molded part is formed, thereby forming a second mold cavity. The second mold cavity is filled with a second material slurry which contains a second material powder different from the first material powder so as to mold the slurry in contact with the first molded part. The molded slurry is caused to set, thereby forming a second molded part on the planar surface of the first mold.

Disclosed is a sintering process for ceramic sheets. After biscuit firing and glazing, a green body is placed in a kiln, wherein the temperature of the kiln is controlled such that: when the kiln temperature is 100-400° C., the temperature rise duration is 1-2 hours when the kiln temperature is 400-900° C., the temperature rise duration is 2-3 hours; when the kiln temperature is 900-1100° C., the temperature rise duration must reach 3 hours or more; when the kiln temperature is 1100-1350° C. the temperature rise duration is controlled to be 3-4 hours; and after the temperature reaches 1350° C., heat-preservation cooling is conducted; when the temperature drops to 1230-1270° C., the temperature is raised again to 1290-1310° C.; when the temperature drops again to 880-920° C., the kiln cover is opened for cooling, and the finished product is taken out.

Disclosed is a sintering process for ceramic sheets. After biscuit firing and glazing, a green body is placed in a kiln, wherein the temperature of the kiln is controlled such that: when the kiln temperature is 100-400° C., the temperature rise duration is 1-2 hours when the kiln temperature is 400-900° C., the temperature rise duration is 2-3 hours; when the kiln temperature is 900-1100° C., the temperature rise duration must reach 3 hours or more; when the kiln temperature is 1100-1350° C. the temperature rise duration is controlled to be 3-4 hours; and after the temperature reaches 1350° C., heat-preservation cooling is conducted; when the temperature drops to 1230-1270° C., the temperature is raised again to 1290-1310° C.; when the temperature drops again to 880-920° C., the kiln cover is opened for cooling, and the finished product is taken out.

A fiber optic ferrule assembly is provided, which comprises a ferrule and an optical fiber received in the ferrule. The ferrule and the optical fiber are directly joined together, so as to fix the optical fiber in the ferrule. At least a part of the ferrule is directly over-molded on the optical fiber by injection molding or shrunk on the optical fiber. In the embodiments of the present invention, the ferrule is directly over-molded or shrunk on the optical fiber, so that the ferrule and the optical fiber are directly joined together. As a result, the optical fiber is stably fixed in the ferrule.