US Patent 7603778 Folding knife having two modes of operation

A knife having two modes of operation includes a blade member, a first side plate, a second side plate, a spacer, a mode lever, and a linear spring. The spacer is disposed between the first and second side plates in an upper area thereof. A pivoting end of the blade member is pivotally retained between first ends of the first and second side plates. The mode lever is pivotally retained between the second ends of the first and second side plates, below the spacer. The linear spring is pivotally retained between the first and second side plates, below the spacer such that one end thereof engages one of two positions on the mode lever. A release button must be depressed to allow the blade member to pivot outward into an extended position in either mode.