Dial indicator

Abstract

Abstract PURPOSE: To prevent the intrusion of the foreign matters with a simple constitution by providing the grooves opposing to each other at the lower part of the outer circumference of the outside support frame as well as on the inner circumference surface of the inside support frame and thus mounting with pressure the circular spring of a polygonal shape. CONSTITUTION: In case outside support frame 14 has the rotary motion to inside support frame 11, the frictional resistance between groove bottom surface 11 j and top part 16 b of circular spring 16 formed into a polygonal shape with a partial cut is larger than that between linear part 16 a of spring 16 and bottom surface 14 j and slope part 14 k of the groove of frame 13. Accordingly, spring 16 has no rotary motion together with frame 14. But the tension of spring 16 is applied evenly to the inner circumference of frame 11, and as a result an appropriate gap is secured between outer circumference surface 14 f of frame 14 and inner circumference surface of frame 11. And thus the rotary friction means the sum of the sliding friction between step surface 14 e of frame 14 and step surface 11 e of frame 11 and the sliding friction between spring 16 and the groove of frame 14. In this connection, the intrusion of the foreign matters can be prevented without imparing the smooth rotary motion of both frames 14 and 11 by controlling properly the tension cuased when spring 16 is mounted into the groove with variation of the vertical angle of spring 16. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Katsutoshi Sekine
• 👤 Takumi Inagawa

Bibliographic Details