Patent ID: 6539583
Filing Date: 2003-04-01
Classification: E05D,E05Y,G06F,Y10T

Abstract:
A frictional hinge device comprising:a metallic shaft member having a rotational axis as a rotational center; a support member which rotationally supports said rotational axis at said metallic shaft member; said support member being arranged so that said support member is relatively rotatable in relation with said metallic shaft member, and held at any angular position with a surface friction resistance between said support member and said metallic shaft member; said support member being molded around said metallic shaft member when a powdered synthetic resin is injected into a mold, so as to establish said surface friction resistance between said support member and said metallic shaft member due to a residual stress created therebetween when said synthetic resin cools and shrinks; a hardened layer is provided around said outer surface of said metallic shaft member, said hardened layer having Vickers number (Hv) of 800 or more and said hardened layer having a thickness of at least 5.0 &mgr;m; wherein said surface friction resistance between said support member and said metallic shaft member is adapted to be altered in response to a torque required to hold said support member at a desired angular position by adjusting a hardness of said hardened layer.