| 摘要 |
PROBLEM TO BE SOLVED: To ensure liquidtightness by forming a site corresponding to a contact part with a temporary ink storage member of an annularly elastic material in the state that an external pressure is not applied of a convexly curved surface and forming an annular elastic material installing part of the storage member of a concavely curved surface. SOLUTION: An annularly elastic material 6 is mounted at a rear part of a temporary ink storage member 2, sandwiched between the member 2 and an inner wall of a barrel, and elastically deformed to be liquidtight and airtight. The material 6 is a so-called O-ring made of silicone rubber of a circular section. Accordingly, a contact part 6a of the material 6 with the member 2 is formed in a convexly curved surface, and an annularly elastic material installing part 2d of the member 2 is formed in a concavely curved surface having slightly larger curvature than that of the part 6a. Thus, even if dimensional unevenness occurs in an inner diameter of the barrel of a part where the material 6 is installed or a profile of the material 6 itself, radial deformation of the material 6 is extremely small, and hence liquidtightness and airtightness around the material 6 are always ensured. |
