Patent attributes
A length adjuster on a wearable device includes an arc-shaped shell and a length fine-adjustment mechanism. A first connection rack, a second connection rack, a gear, a button and a return spring of a gear shaft are provided in the arc-shaped shell. The first connection rack, the second connection rack and the gear are meshed with one another. The gear shaft is connected to a clockwork spring mechanism. The gear shaft and the length fine-adjustment mechanism are in a clutch connection. A unidirectional rotation-prevention structure is provided in the length fine-adjustment mechanism, and the unidirectional rotation-prevention structure allows the length fine-adjustment mechanism to drive the gear shaft to rotate in a rotation direction for enabling a clockwork spring to be stretched, and prevents the gear shaft from rotating in the direction opposite to the rotation direction. The length adjuster is provided with a release mechanism.