Blocking device and system for mechanical lock

A control device for use in a cylinder lock comprising,

• a. a housing defining a cylindrical passage;
• b. a cylindrical plug that fits into said passage for rotational movement relative to said housing;
• c. a keyhole through the front end of said plug;
• d. a means between said plug and said housing for blocking the rotational movement in one axial position of said plug and for unblocking the rotational movement in another axial position thereof;
• e. said plug having at least one longitudinal groove and a multiple of rotary members each supported for rotation about an axis transverse to said longitudinal groove;
• and
• f. blocking bars extending in a longitudinal direction of said cylindrical passage between said plug and said housing and which prevent said rotation of said rotary members in response to said cylindrical plug being rotated in said housing by moving in a radial direction of said cylindrical passage.