Circuit breaker having automatic release linkage

A circuit breaker having an automatic release linkage including a movable conduction unit (3) for selectively conducting a first terminal (2) and a second terminal (1) by contacting the second terminal (1) while being electrically contacted to the first terminal (2), and an open/close linkage including a connection linkage (140) for transmitting a impact force from the movable conduction unit (3) to a trip roller (55) as an operational force,

• the circuit breaker comprising:
• an open lever (190);
• a second link (160) rotatably formed about a latch pin (150a);
• a third link (170) having a meshed lateral cross-sectional surface by being latched with an outer circumferential surface of the open lever (190) while moving relative to the second link (160) by rotatably fixing the trip roller (55);
• and a spring (180) so interposed between the second link (160) and the third link (170) as to apply an elastic force (Fs) toward an operational line (99), wherein a branch force (77p) toward the operational line of an operational force (77) reacts in opposition to the elastic force (fs), and a latched state of a lateral cross-sectional surface of the third link (170) with the open lever (190) is released at all times under any circumstance when the branch force (77p) is greater than the elastic force (fs) by a predetermined level.