BOX CUTTER WITH GRIP-ACTUATED BLADE EXTENSION

摘要

An automatic blade-retracting box cutter utility knife has a handle with ergonomic hand grip proportions for comfortable gripping and handling during repetitive cutting operations. A blade-actuating hand-grip lever is mounted on the housing for movement about a pivotal axis. A blade shuffle is mounted for longitudinal sliding reciprocal movement in the housing from a rear retracted end position in which the blade is wholly received in the housing, to a front extended end position in which the blade is extended forward from the housing. The blade shuttle is extended in response to gripping actuation of the hand-grip lever. Extension and retraction forces are transferred from the hand-grip lever to a compression spring and to the blade shuttle via a power transmission assembly that includes a torque plate that is mounted for clockwise and counterclockwise rotation on the housing. Top access to a working blade and a replacement blade stored on the shuttle is provided for blade loading and security. Dual edge guide members are mounted for independent extension and retraction movement. A depth of cut adjustment dial is integrated with the power transmission assembly. Depth of cut, or blade extension, is set by limiting pivoting travel of the gripping lever during hand grip actuation.