Claims
1. A circuit breaker comprising:
a housing having a window opening;
a contact section disposed in said housing, said contact section comprising a fixed contact and a movable contact which comes into contact with or separates from said fixed contact;
a handle having an operation portion, said handle being disposed so that said operation portion is exposed to the outside of said housing, said handle being supported to said housing so as to be rotatable between a close position for which said movable contact is made contact with said fixed contact and an open position for which said movable contact is separated from said fixed contact;
a link mechanism configured to make said movable contact come into contact with or separate from said fixed contact according to a rotational operation of said handle;
a trip mechanism configured to, in response to detection of an anomalous current flowing through said contact section in a closed state, make a trip-operation of causing said contact section to open for breaking the electrical connection;
a handle spring consisting of a torsion coil spring having a first arm latched with said handle and a second arm, said handle spring being disposed to resiliently urge said handle in a direction of rotating from said close position to said open position;
an indication member having: a trip-indication portion for indicating that said trip-operation has been performed; an off-indication portion for indicating an off-state of said contact section; and an on-indication portion for indicating an on-state of said contact section, wherein said indication member is supported to said housing rotatably within a range: from an on-position at which said on-indication portion faces said window opening; to a trip-position at which said trip-indication portion faces said window opening; through an off-position at which said off-indication portion faces said window opening; and
a bias spring configured to apply a pressure to said indication member to urge said indication member in a direction from said on-position to said trip-position,
wherein said indication member further has a latch projection configured to be engaged with said second arm of said handle spring when said indication member is located at said off-position, whereby said latch projection restricts a rotation of said indication member toward said trip-position.
2. The circuit breaker as set forth in claim 1, wherein said link mechanism is configured to, in response to said trip-operation, displace said second arm of said handle spring in a direction of disengaging said second arm from said latch projection, whereby said indication member rotates to said trip-position from said on-position.
3. The circuit breaker as set forth in claim 2,
wherein said link mechanism comprises a thrust bar and a latch member, said

thrust bar having a first end which is rotatably supported to said handle and a second end, said latch member being rotatably supported to said housing so that said second end of said thrust bar is detachably engaged with said latch member, said latch member being arranged to be engaged with said second end of said thrust bar when said handle is located at said close position,
wherein said latch member is configured to, during said trip-operation, rotate to disengage said thrust bar from said latch member, and
wherein said second end of said thrust bar rotates, in response to the rotation of said latch member during said trip-operation, about said first end of said thrust bar to come in contact with said second arm of said handle spring, thereby displacing said second arm of said handle spring.
4. The circuit breaker as set forth in claim 1, wherein said bias spring is consisted of a torsion coil spring.
5. The circuit breaker as set forth in claim 1, wherein said latch projection is configured to be engaged with said second arm of said handle spring, whereby said latch projection forbids the rotation of said indication member toward said trip-position.
6. The circuit breaker as set forth in claim 1,
wherein said handle spring has: a coil portion formed by winding a metal material into a spiral shape with a first end and a second end; said first arm extending from said first end of said coil portion; and said second arm extending from said second end of said coil portion,
wherein said second arm of said handle spring has: a first portion extending from said second end of said coil portion; a second portion extending from a tip of said first portion in a direction intersecting with said first portion; and a third portion extending from a tip of said second portion in a direction intersecting with said second portion, and
wherein said latch projection comes in contact with said second portion.
7. The circuit breaker as set forth in claim 6, wherein said latch projection is configured to
be engaged with said second portion from a direction that said indication member rotates
from said on-position to said trip-position.