Patent ID: 8201336

Claim:
Retractable knife comprising an elongate handle defining a handle axis; a release button mounted for movements along said handle axis; a blade holder slidingly mounted within said handle responsive to actuation of said release button for sliding movements along said handle between a retracted position and an extended position in which at least a portion of said blade holder extends beyond said handle and having an upper edge, receiving means within said blade holder for receiving at least a portion of a blade provided with one edge formed with a cutting edge and opposing edge formed with a notch; and a manually operable blade lock formed on said portion of said blade holder and comprising a release member rotatably mounted on said blade holder, said release member having a first portion on said blade holder and mounted to be actuated by movement of a finger of the same hand of a user holding said handle along a direction substantially parallel to said handle axis, and a second portion mounted on said first portion for movements with said first portion between a locking position in which said second portion is received within a notch of a blade and a releasing position in which said second portion is removed from the blade notch to a position beyond the notch of the blade, said release member being substantially in the form of a disc having an axis of rotation substantially normal to said handle axis and rotatably mounted on said blade holder for rotation about said release member axis of rotation, said first portion at least partially projecting above said upper edge of said blade holder to always be exposed for engagement by the user in both said blade locking and blade releasing positions when said release member is actuated while said blade holder is extended along said handle axis beyond said handle at a position spaced from said release button in the direction of the blade to be removed, and biasing means for normally moving said release member to move said second portion to said locking position, whereby actuation of said release member by the finger of the user to overcome said biasing means moves said second portion to said releasing position for releasing the blade so that it can be withdrawn from said receiving means.