Method for manufacturing double-gear trains

摘要

A method and apparatus for manufacturing double-gear trains in which gears of double-gear trains are molded already in engagement with one another. Upper and lower gear molding cavities are formed in upper and lower molds between which is sandwiched an intermediate mold. Apertures are formed in the intermediate mold for molding shafts which join gear pairs. Thin wall dividing portions are provided between adjacent gears which are molded in engagement with one another. A molten resin introducing cavity is formed between an outer mold and the upper mold. Coupling pieces may also be molded simultaneously with the formation of the double-gear train.