Patent ID: 8720068
Filing Date: 2014-05-13
Classification: B26B

Abstract:
1. A hand cutter comprising a housing a blade mounted detachably in the housing, having a cutting edge at the front of the knife, a blade guard assembly mounted pivotally in the housing, said blade guard assembly comprising two arms separated by an angle, the front arm being at the blade end of the knife said front arm of the blade guard assembly protecting the blade in the closed position and exposing the cutting edge of the blade in the open position a nub attached to the housing, forming the pivot point of the blade guard, a guard spring connecting the blade guard assembly to the housing and forcing the blade guard into the closed position, said guard spring, connecting the rear arm of the blade guard assembly to the housing and forcing the blade guard into the closed position a lock piece locking the blade guard in the closed position by preventing the rotation of the blade guard assembly said lock piece fixed to the housing at the rear end of the knife, the front end of said lock piece is moveable sideways with respect to the housing, said lock piece locking the blade guard in the closed position by preventing the rotation of the blade guard assembly when the front end is on one side and allowing the rear arm of the blade guard assembly to rotate back when the front end is on the other side a release assembly comprising a trigger button fixed to the handle unlocking said lock piece when said trigger button is pressed said release assembly further comprising a vertically movable release piece having the form of an arch and being wider at the bottom part on one side, said wider bottom side facing the lock piece, forcing the lock piece sideways when moving the release piece upwards, so that the blade guard can move freely a release spring forcing said release piece downward a trigger assembly comprising a trigger button a torsion spring forcing the trigger button into the released position whenever no pressure is applied to the button a trigger ramp consisting of front arm oriented vertically and a rear arm which is basically horizontal rotatably connected to the trigger button at the connecting point of the two arms a button spring connecting the rear arm of the trigger ramp to the trigger button attempting to maintain a constant distance between the rear arm of the trigger ramp and the trigger button said trigger ramp being pushed upwards when the trigger button is pressed, the front arm of the trigger ramp forcing the release piece upwards when the trigger ramp is moved upwards, said upwards movement of the release piece forcing the lock piece sideways when moving the release piece upwards, so that the blade guard is no longer locked into the closed position and can move freely a torsion spring forcing the trigger button into the released position whenever no pressure is applied to the trigger button a blade holder containing the blade mounted rotatably in the housing, rotating about a pivot point if pressure is applied to the cutting edge of the blade having a decoupling mechanism allowing said lock piece to be decoupled from said release assembly which automatically relocks the blade guard as soon as it returns to the extended position wherein said blade holder has a decoupling extension at the rear end which is in contact with the front arm of the trigger ramp and moves slightly downward when said blade holder is rotated thereby forcing the front arm of the trigger ramp out of the reach of the release piece allowing said release piece to be forced downwards to the original position by the flat spring allowing the lock piece to move sideways back towards the center of the cutter automatically relocking the blade guard as soon as it returns to the extended position.