Driving tool

A driving tool, comprising:

• a piston configured to move in a driving direction by a pressure of a gas;
• a driver that (i) extends from the piston in the driving direction and (ii) comprises a plurality of engaged portions spaced along the driving direction;
• and
• a lift mechanism configured to move the driver and the piston in a direction opposite to the driving direction, wherein:
• the lift mechanism comprises:
• a rotation shaft having a first axis of rotation;
• a biasing member;
• and
• a wheel (a) configured to rotate integrally with the rotation shaft, (b) having a second axis of rotation and (c) including
• a plurality of engaging portions (i) spaced along a periphery of the wheel and (ii) configured to engage the plurality of engaged portions;
• the rotation shaft
• is configured to support the wheel so as to allow the wheel to move relative to the rotation shaft in a radial direction from the rotation shaft between an initial position, in which the first axis of rotation and the second axis of rotation are co-axial, and an eccentric position, in which the first axis of rotation and the second axis of rotation are spaced and parallel;
• the biasing member having a biasing force and configured to apply an entirety of the biasing force on the wheel in a direction from the eccentric position toward the initial position;
• and
• the lift mechanism and the driver are configured such that:
• when the driver moves in the direction opposite to the driving direction, the wheel is at a first state or at a second state;
• when the wheel is in the initial position and the first state, at least one of the plurality of engaging portions engages at least one of the plurality of engaged portions and the wheel is movable toward the eccentric position;
• and
• when the wheel is in the eccentric position and the second state, the plurality of engaging portions engages the plurality of engaged portions.