Switch devices

A switch device comprising:

• a cylindrical tubular case receiving a switch circuit;
• a rotary shaft supported by the tubular case and rotatable relative to the tubular case;
• and
• a tubular operation member surrounding the tubular case and having the same axis as the tubular case;
• wherein the operation member has a first end and a second end opposite to the first end in an axial direction;
• wherein the first end of the operation member is joined to the rotary shaft, so that the operation member can rotate together with the rotary shaft about the axis;
• wherein the switch circuit is operated as the operation member rotates with the rotary shaft relative to the case;
• and
• a projection protruding radially inwardly from an inner circumferential surface of the operation member and extending in a rotational direction of the operation member;
• and
• wherein the projection has a protruded end having a wedge-like cross section, so that the protruded end can contact an outer circumferential surface of the case in line contact relationship therewith.