Patent ID: 7331266

Claim:
A paper punch comprising: a base being hollow and having a top; an open bottom; a cavity defined in the base and communicating with the open bottom; two punch holes defined through the top and communicating with the cavity; two brackets mounted on the top and each bracket having a bottom; two side tabs and each side tab having a front end; a through hole defined through the bottom of the bracket and aligned with a corresponding punch hole in the base; two guide slots defined respectively through the side tabs; and two open pivot slots defined respectively in the front end of the side tabs; and two gaps defined respectively between the bottom of each bracket and the top of the base; two cutters mounted slidably and respectively in the brackets and each cutter having a top end, a bottom end, a blade formed on the bottom end and a mounting hole defined transversely through the cutter; two articulated linkages pivotally mounted respectively on the brackets on the base and each articulated linkage having a lower link mounted pivotally and slidably on a corresponding bracket and having a front end; a rear end; two side tabs and each side tab having a front end and a rear end; two pivot holes defined respectively through the side tabs of the lower link; and two open pivot slots defined in the front end of the side tabs of the lower link; an upper link mounted pivotally on the rear end of each lower link and each upper link having a front end and a rear end, where the rear end is mounted pivotally on the rear end of a corresponding lower link; and a connecting pin respectively extending through the pivot holes in the lower links and the mounting holes of the cutter and slidably mounted respectively through the guide slots in the brackets; and a lever mounted pivotally on the brackets on the base, connected pivotally to the articulated linkages and having a pressing surface having a front edge; two lever arms extending from the front edge of the pressing surface, mounted pivotally to the brackets and each lever arm having a rear end formed on the front edge of the pressing surface and connected pivotally to a front end of a corresponding upper link; a front end connected pivotally to a corresponding bracket; two side tabs; and two pivot holes defined through the side tabs of the lever arm; two pivot pins respectively extending through the pivot holes of the lever arms and respectively mounted slidably through the open pivot slots in the brackets and the lower links; and two springs mounted respectively around the pivot pins of the lever to force the lever to incline upward.