OPERATING MECHANISM FOR MOBILE ELEMENT

摘要

Disclosed is an operating mechanism for a mobile element, comprising: a first fixed-side gear part and a second fixed-side gear part which are provided on a support body side; a mobile-side gear part and a pinion gear which are provided on a supported part of the mobile element; and guide means for providing positioning such that the mobile-side gear part meshes with the first fixed-side gear part, and the pinion gear meshes with the second fixed-side gear part. The first fixed-side gear part is formed along the arc of a first imaginary circle and the teeth tips thereof are directed towards the centre of this first imaginary circle. The second fixed-side gear part is provided adjacent to the first fixed-side gear part in the centre of the first imaginary circle and is formed along the arc of a second imaginary circle other than the first imaginary circle, and the teeth tips thereof are directed towards the centre of the second imaginary circle.