Stapling apparatus, sheet finishing apparatus, and image forming apparatus equipped with the sheet finishing apparatuses

A stapler apparatus comprising:

• a support tray for stacking sheets in a bundle,
• a head unit arranged relative to the support tray and having staple drive means for applying a staple to the sheet bundle on the support tray,
• an anvil unit arranged relative to the support tray for bending the staple applied to the sheet bundle,
• staple operating means for moving the head unit to and away from the anvil unit,
• a cover member for opening and closing an operating space between the head unit and the anvil unit,
• a solenoid operatively connected with the cover member by a spring which is configured to absorb a thickness of the bundle of sheet;
• and
• control means electrically connected to the staple operating means for preventing operation of the staple operating means when the cover member is not located at a predetermined closed position.