Patent ID: 7225774

Claim:
A valve timing control apparatus for an internal combustion engine, comprising: a rotary member rotated by a crankshaft of the engine; a housing fixed to one of the rotary member and a camshaft of the engine, the housing having a housing body and shoes protruding from an inner circumferential surface of the housing body to define actuation spaces therebetween; a vane rotor disposed in the housing and fixed to the other of the rotary member and the engine camshaft, the vane rotor having a rotor body and vanes protruding from an outer circumferential surface of the rotor body into the respective actuation spaces to divide the actuation spaces into circumferentially alternating first and second hydraulic chambers: a fluid supply/drain block through which hydraulic fluid is supplied to and drained out of the first and second hydraulic chambers; a plurality of spring units arranged in at least either the first hydraulic chambers or the second hydraulic chambers to bias the vane rotor in a rotational direction with respect to the housing; and a rotation restriction mechanism capable of restricting a relative rotation of the housing and the vane rotor to prevent contact of the mutually facing surfaces of the shoes and the vanes within the hydraulic chambers in which the spring units are arranged.