| 摘要 |
PURPOSE:To conserve the labor of manufacturing and assembling by making accuracy easy to develop and simplifying a structure and to reduce load of rotation by realizing wt. reduction while attaining cost reduction, by squeezing both ends of an equal diameter pipe to form a main body part having a large diameter and shafts parts each having a small diameter coaxial to the main body and respectively extending to the outside from both ends of said main body part while providing an elastic layer to the outer periphery of the main body part. CONSTITUTION:A platen consists of a pipe part 10 and an elastic layer 11. For example, the pipe part 10 is formed by using a tubular material made of aluminum or an aluminum alloy and integrally constituted of a main body part 12 having a large diameter and shaft parts 13 each having a small diameter by a method wherein both ends of the tubular material are squeezed by swaging and both ends or an outer diameter are finished by cutting processing and surface treatment such as alumite treatment, chromium plating or the spraying of a resin is performed if necessary. The elastic layer 11 is formed by a method wherein rubber subjected to extrusion processing is fitted to the outer periphery of the main body part 12 under pressure and surface finishing is applied to the outer surface of the rubber layer by a polishing plate. The pipe part 3 is closed by the shaft parts 13 to form the hollow part 14 in the main body part 12 to make it possible to prevent the leakage of printing sound to the outside. |
