Patent ID: 8220160
Filing Date: 2012-07-17
Classification: A45F,B25H,B26B

Abstract:
1. A utility knife, comprising: a handle body having sidewall portions defining a guide channel; a blade shuttle mounted for extension and retraction movement within the guide channel and being movable between a non-use position such that a blade mounted on the blade shuttle is enclosed in the guide channel, and an extended position such that a portion of the blade projects from the guide channel; a hand-grip lever coupled to the handle body at a fulcrum for pivotal movement between an at-rest position in which the blade shuttle is in the non-use position, to an in-use position in which the blade shuttle is in the extended position, the hand-grip lever rotatably coupled to the blade shuttle through a transmission comprising a pin coupled to the hand-grip lever such that a distance from the fulcrum to the pin stays substantially fixed as the hand-grip lever pivots between the at-rest and in-use positions; a biasing member urging the hand-grip lever to the at rest position, the biasing member being compressible and extendable and coupled between the handle body and the hand grip-lever; a guide post disposed between the handle body and coupled to the hand-grip lever, wherein the biasing member is disposed around the guide post and confined for compression and expansion between the handle body and the hand-grip lever in response to pivoting movement of the hand-grip lever; and a selector dial attached to the guide post, wherein the selector dial is adjustable to vary the tension on the biasing member.