ACTUATOR OF DISK APPARATUS, INTERMEDIATE PRODUCT OF ITS ARM, AND THEIR PRODUCTION METHOD

摘要

In manufacturing an arm body having arm portions and used for an actuator in a disk unit, a thermoplastic resin in the molten state is injection molded into the arm so that at least the arm portions are simultaneously and integrally molded with the arm body. The resin is simultaneously and in parallel filled in cavities corresponding to the arm portions to be molded. Resin connection portions typified by a common sprue and runners are formed between the arm portions. In order to simultaneously and in parallel fill the resin in the cavities in the mold, the resin is ejected from the position corresponding to the distal end portion of any arm portion to be molded in the mold. An intermediate product of this arm has at least one resin connection portion which connects the arm portions to each other. After this intermediate product is heat treated, the resin connection portion is cut for removal thereby to obtain an arm. <IMAGE>