Finisher with a punching function

A finisher which punches a sheet comprising:

• a plurality of punching rods for making holes in a sheet;
• a selector which selects a punching rod to be operated from said plurality of punching rods;
• a driving mechanism which energizes said punching rod selected by said selector;
• and
• a controller which determines a punching rod to be selected by said selector in accordance with a length and width of a sheet to be punched and controls said selector based on the determination.

A punching method used in a finisher having a plurality of punching rods for making holes in a sheet, the method comprising steps of:

• receiving a sheet to be punched;
• entering a size of the sheet to be punched;
• automatically selecting a punching rod to be operated from said plurality of punching rods based on a length and width of the sheet to be punched;
• and
• energizing said punching rod selected in said selecting step.

A finisher which punches a sheet comprising:

• a plurality of punching rods for making holes in a sheet;
• a drive shaft;
• a plurality of cam pairs each pair including a circular cam and an eccentric cam positioned adjacent to each other in an axial direction of the drive shaft with each cam being fitted around the drive shaft;
• and
• an electronic switching mechanism configured to reciprocally move the drive shaft in the axial direction to selectively position one of either the circular cam and the eccentric cam of each cam pair to face a respective punching rod, wherein
• the drive shaft rotates, rotating the plurality of cam pairs, and
• positioning the eccentric cam to face a respective punching rod converts the rotary movement of the drive shaft into linear movements of the respective punching rod while positioning the circular cam to face the respective punching rod results in no movement of the respective punching rod during rotary movement of the drive shaft.