(57) [summary] [purpose] and has an inner frame and outer frame casing is relatively rotated with each other, and the inner frame and the outside by allowing fitted interposing the O-ring between them within the frame and the outer frame In the dial gauge is configured to frame are attached to achieve the simplification of formation of the groove for the O-ring fitted in the compact and the inner frame side of the entire apparatus. [Configuration] Along the outer peripheral edge of the frame are provided with a step portion or tapered portion of the annular, substantially a plate member is the same as to a part of material in diameter inner frame of the operation display unit, the stepped portion of the inner frame side of the groove being partitioned and formed by fixing the mounting to the end surface, the O-ring is fitted held for coupling the inner frame and the outer frame casing. EFFECT inner frame side O-ring groove in order to fit holding a is composed of the step portion and the plate member of the inner frame, the diameter of the inner frame as compared with the case of forming a groove on the inner frame or the inner frame axial dimension of the can be made small, also it is not necessary to form a groove. In addition, the outer frame also correspond to the size of the inner frame, downsizing can be achieved.
展开▼
