Patent attributes
It is an object of the present invention to increase durability of a driving tool. A representative driving tool comprises an elongated operating member that drives in a driving material and a drive mechanism that drives the operating member. The drive mechanism comprises a rotating flywheel and the flywheel includes an inner wheel and an outer wheel which are concentrically disposed to each other. The inner circumferential surface of the outer wheel is fitted on an outer circumferential surface of the inner wheel. The outer circumferential surface of the outer wheel directly contacts the operating member and thus, the rotational force of the flywheel is transmitted from the inner wheel to the operating member via the outer wheel and the drive mechanism linearly moves. A frictional force between the outer circumferential surface of the inner wheel and the inner circumferential surface of the outer wheel is set to be smaller than a frictional force between the outer circumferential surface of the outer wheel and the operating member. With such construction, when the operating member contacts the rotating flywheel, slippage is caused between the inner wheel and the outer wheel such that only a smaller frictional force may be produced between the inner wheel and the outer wheel. Therefore, stress which acts upon the inner wheel and the outer wheel can be alleviated and as a result, wear of the flywheel and the operating member can be reduced to increase the durability.
