Patent ID: 6698640
Filing Date: 2004-03-02
Classification: B27F

Abstract:
A motor-operated stapler wherein a bundle of sheets to be stapled is held by both a magazine which houses therein a staple forming mechanism and a plurality of staples and a clincher base which is movable in a direction generally perpendicular to a bundle of sheets and which is driven by a drive source provided on the magazine side, a staple is driven out from said magazine into said bundle of sheets, and leg portions of the staple projecting downward through said bundle of sheets are bent along said bundle of sheets by a pair of clinchers mounted on said clincher base, and includinga clincher pivotal movement control means to increase a force for clinching the staple at the bottom surface of the bundle by said clinchers, irrespective of the thickness of said bundle of sheets when the leg portions of the staple are bent along the bottom surface of the bundle of sheets; a clincher pivoting mechanism for moving said clinchers pivotally, said clincher pivoting mechanism comprising clincher links installed on said clincher base to pivot said clinchers moving the ends vertically, driven cam surfaces formed respectively on said clincher links and extending in the thickness direction of said bundle of sheets to be stapled, fulcrums which convert swing motions of said driven cam surfaces into pivotal motions of said clinchers; and driving cams installed on the side which holds the magazine, said driving cams coming into contact with said driven cam surfaces of the clincher links and being rotated by said drive source provided on the magazine side, and wherein said pivotal movement control means are constructed so that when the thickness of said bundle of sheets exceeds a predetermined value, the distance between an abutment position and each of said fulcrums is increased relatively.