To clamp one end of a clutch spring in a simple structure by bending one end of this clutch spring to the axial direction of a clutch shaft, using it as an engaging end, and making this engaging end engage with an engaging groove being formed long in a holder part in the axial direction.

Merely turning force to one direction of a lever 1 is made so as to be transmitted to an interval between a holder part 3 and a clutch shaft 4 by a coil-form clutch spring 10 which is made up of a square sectional wire rod. An engaging groove 11 notched inward in the axial direction from one end at the side of the clutch spring 10 is formed in the holder part 3 at sufficient length. An engaging end 12 made up of being bent almost orthogonally so as to project one end of the clutch spring 10 in the axial direction, is engaged with this engaging groove 11. With such a simple structure as merely fitting the one end 12 of the clutch spring 10 in the engaging groove 11 of the holder part 3, an engaging part can be lengthened, aside from being intallable.