Patent ID: 7151226

Claim:
An opening and closing device comprising: a stationary member; a movable member coupled to said stationary member so as to be rotatable in opening and closing directions; an urging section for urging said movable member in the opening direction in an open state and urging said movable member in the closing direction in a closed state; a reversing section for reversing, in the closed state, a direction that said urging section urges said movable member so that the urging direction changes from the closing direction to the opening direction; and a movable casing connected to said movable member, said movable casing being operable to rotate in accordance with movement of said movable member, wherein: said urging section comprises: said movable member urged by a spring having an end pressed by said movable casing, said movable member including a movable cam disposed along a side of said movable member; and a stationary cam at a first end of a slide member, said stationary cam being opposed to said movable cam, for resiliently contacting said movable cam, said slide member being disposed between said movable member and said stationary member; said movable member is being arranged so as to be urged in one of the opening and closing directions according to which portion of said stationary cam is in resilient contact with said movable cam; said reversing section comprises: a release member including a release cam resiliently contacting a support cam disposed on a second end of said slide member, said release member being disposed between said slide member and said stationary member; and a reversing member inserted into a hollow part of said slide member, said reversing member including a reversing cam; and wherein said movable casing, said spring, said movable member, said slide member, said reversing member, said release member and said stationary member are shaped into a cylinder and arranged along an axis of said cylinder, and due to rotation of said release member, said release cam is disconnected from said support cam, said slide member slides axially, said movable cam is disconnected from said stationary cam and comes into resilient contact with said reversing cam, and consequently, said movable member is urged in the opening direction.