Knife

A knife, comprising:

• an elongated hollow handle having an opening at one end;
• a blade holder longitudinally shiftable in said handle, adapted to receive a blade, and displaceable between an operative position wherein said blade extends from said opening and a retracted position wherein said blade is withdrawn through said opening into an interior of said handle;
• a first longitudinally extending coil tension spring generally parallel to a direction of displacement of said holder within said handle and connected to said holder for retracting said holder from said operative position to said retracted position;
• an extension on said holder projecting rearwardly in said handle generally along said first spring and formed with a locking tooth;
• a locking pawl swingably mounted in said handle for pivotal movement about a pivot axis therein and formed with a detent recess receiving said tooth and having a substantially planar blocking surface substantially tangential to a pivot circle of said surface centered on said axis for engagement by said tooth in said operative position of said holder, thereby retaining said holder in said operative position, said pawl being swingable about said axis away from said tooth to release said tooth from said surface and permit said first spring to retract said holder to said retracted position, said tooth being shaped so as to engage said surface only at an apex of said tooth;
• and
• a second longitudinally extending coil tension spring in said handle connected to said pawl and biasing said pawl toward said extension.