Patent ID: 7527635

Claim:
A surgical knife comprising, a cutter blade including at least one sharp edge and lateral surfaces opposed to each other, between which lateral surfaces the at least one sharp edge is arranged as seen in a direction perpendicular to a thickness direction of the cutter blade, a holder including a longitudinal hole extending in a longitudinal direction of the holder and containing at least a part of the cutter blade, and a guide groove extending in the longitudinal direction and in a thickness direction of the holder to extend from the longitudinal hole and open to a front surface of the holder extending in a front surface direction parallel to the lateral surfaces of the cutter blade, and a slider connected to the cutter blade and movable along the guide groove between a front position for making the cutter blade project from a front end of the holder and a back position for making the cutter blade be contained in the holder, wherein the slider has a slider body holding thereon the cutter blade and being supported in the longitudinal hole, and an operating part swingably coupled to the slider body to be movable with respect to the holder so that a first portion of the operating part in the longitudinal hole is disengaged from the holder to release the slider from the holder and engaged with the holder to fix the slider to the holder at each of the front and back positions, and the operating part has a second portion protruding in the thickness direction from the first portion of the operating part in the longitudinal hole through the guide groove to project from the front surface in the thickness direction and being movable in a radial direction in a plane of the guide groove as seen in the thickness direction, and wherein the slider has an elastic member arranged between the operating part and the slider body to elastically urge the first portion of the operating part against the holder, and has a hinge arranged separately from the elastic member between the slider body and the operating part to swingably couple the operating part to the slider body.