Patent ID: 8464606

Claim:
A shift operation device, comprising: a lever shaft configured to be supported in a vehicle: a lever knob provided in an upper end portion of the lever shaft; the lever knob comprising: an outer casing, a core member disposed inside of the outer casing and fixed to the upper end portion of the lever shaft, the core member comprising a reinforcing frame, and a hollow box portion attached to the reinforcing frame; the hollow box portion comprising a sidewall and an outer periphery portion; and a connection member for fixing the core member to the lever shaft; wherein said hollow box portion is provided above the lever shaft, the outer casing comprising an outer periphery portion formed to be thin by disposing the hollow box portion therein, wherein the reinforcing frame of the core member comprises: a cylindrical boss for receiving the connection member therein, the cylindrical boss disposed below the sidewall of the box portion and having a central axis which extends substantially perpendicular to an axial direction of the lever shaft, and a stiffening rib connecting the cylindrical boss and the sidewall, the cylindrical boss having at least one cutout groove formed therein proximate the stiffening rib and denning a first weak portion for receiving a load caused by a deformation of the outer periphery portion, wherein a portion of the cylindrical boss, where the cutout groove is formed, is thinner than other, adjacent portions of the cylindrical boss, and wherein the outer periphery portion is configured to be capable of being deformed by a load operating in the axial direction of the lever shaft.