| 摘要 |
A constant pressure mechanism (40) includes: a support shaft (41) including a shaft portion (411) that is provided on a base end of a spindle (20) coaxially with a center axis of the spindle (20) and inserted into a ratchet ring (33) of an operation section (30) and a head (412) of a diameter larger than the shaft portion (411) that is provided on a base end of the shaft portion (411); a ratchet claw (43) that is rotatable around a shaft (432) held by the head (412) and is provided with a sawtooth second projection (434) to be engaged with a first projection (332) on a lateral side thereof, the ratchet claw (43) being disposed within the ratchet ring (33); and a biasing unit (44) that biases the ratchet claw (43) toward the first projection (332). Since the above-described members (41,43,44) are disposed in a space within the ratchet ring (33) orthogonal to the axial direction of the spindle (20), the constant pressure mechanism (40) can be shortened in length along the axial direction of the spindle (20), thereby reducing the size of the micrometer. |
