| 摘要 |
PURPOSE:To make working cost low and a high working accuracy unnecessary by a method wherein the inner surface of an intermediate block is formed so as to be a flat slidably contacting surface which contacts with the flat surface of outer periphery of a segment opposing to the inner surface. CONSTITUTION:The inner surfaces of respective intermediate blocks 31 are formed so as to be a flat slidably contacting surfaces 33, parallel to the flat surface 19 of a slider 13 of a segment 12 and slanted, while the slidably contacting surface 33 is contacted slidably with a flat surface opposing to the slidably contacting surface 33. All segments 12 are pushed by the wedge effect of slidably contacting surfaces 33 of slanted intermediate blocks 31 and are moved radially and inwardly. In this case, surface contact is effected between the flat surface 19 and the slidably contacting surface 33 and are moved radially and inwardly. In this case, surface contact is effected between the flat surface 19 and the slidably contacting surface 33 through an area more than 80% of the total area, therefore, respective segments 12 move smoothly while keeping constant postures. On the other hand, shearing force is not applied substantially to a bolt 37, connecting the intermediate block 31 and an outer ring 21, as a result, the connection of both parts is kept in a high accuracy. According to this method, the highly accurate mold, which operates smoothly, may be manufactured inexpensively. |
