Patent ID: 7389066

Claim:
A method of controlling a force exerted on different removable cartridge units by an image forming apparatus, comprising: providing at least one electrically conductive arm pivotally mounted in said image forming apparatus about a pivot point and biased by a force generating member into contact with a removable cartridge unit having at least one electrically conductive protrusion, said arm including a contact member having a longitudinal extent and wherein said protrusion contacts said arm along said contact member; positioning a first protrusion on a first removable cartridge unit to contact said contact member at a first longitudinal position, said arm thereby exerting a first force on said first cartridge unit; and positioning a second protrusion on a second removable cartridge unit to contact said contact member at a second longitudinal position different from said first longitudinal position, said arm thereby exerting a second force on said second cartridge unit different from said first force.