Valve timing control system for internal combustion engine

A valve timing control system for an internal combustion engine and a camshaft which is subject to a negative torque in a direction opposite to a direction of rotation thereof and than a positive torque in a direction same as the direction of rotation thereof when the camshaft opens a spring biased valve of the internal combustion engine, the valve timing control system comprises:

• a hollow rotary housing driven by the internal combustion engine;
• a rotary member housed within the hollow rotary housing and secured to the camshaft for rotation therewith;
• a torque transmitting mechanism so constructed and arranged as to transmit a torque from said hollow rotary housing to said rotary member, said torque transmitting mechanism having a first position wherein said rotary member has a first angular position relative to said hollow rotary housing and a second position wherein said rotary member has a second angular position relative to said hollow rotary housing;
• and
• means for shifting said torque transmitting mechanism between said first and second position thereof, wherein said torque transmitting mechanism includes a brakeable strut radially extending from said rotary member into engagement with said hollow rotary housing in such a manner as to allow one-way angular displacement of said rotary member in response to appropriate one of the positive and negative torque which said rotary member is subject to until said strut or said rotary member comes into abutting engagement with one of stops which are rotatable with said hollow rotary housing.