Clincher device of stapler

A clincher device of a stapler for bending legs of a staple struck out by a staple driving portion along a rear surface of a sheet of paper to be bound, the clincher device comprising:

• a clincher member including, at an upper end surface thereof, a guide surface for bending and guiding the legs of the staple toward inside;
• a thin plate piece disposed between the guide surface and the rear surface of the sheet of paper;
• the thin plate piece being slidable with respect to the clincher member in a forward direction above the clincher guide surface and in a backward direction wherein a tip end of the thin plate piece is evacuated from a position above said guide surface;
• an operation piece protruding upward from the upper end surface of the clincher device and configured to be operated by the staple driving portion to move downwardly and upwardly with respect to said upper end surface of the clincher device;
• and
• an operating lever interconnecting the thin plate piece and the operation piece, wherein, upon the downward movement of the operation piece, the thin plate piece slides forwardly above the clincher guide surface to guide and bend the legs of the staple along a lower surface of said thin plate piece, and wherein upon upward movement of the operation piece, the thin plate piece slides backwardly.