Patent ID: 7974666

Claim:
An opening/closing device comprising: a fixed guide member ( 110 ) fixed to a first member ( 20 ) to be hingedly connected and having a guide center axis ( 10 a ) extending along a center axis of a hinge connection; an operation cam ( 130 ) supported on said fixed guide member to be displaceable with respect to said fixed guide member in a predetermined operation direction by an external operation force; a first rotation cam ( 160 ) rotatably supported on said fixed guide member to be engaged with said operation cam and to be rotated with respect to said fixed guide member around said guide center axis in response to the displacement of said operation cam; a second rotation cam ( 140 ; 240 ; 340 ) supported on said fixed guide member to be displaceable along and rotatable around said guide cent axis in response to the rotation of said first rotation cam; a movable cam ( 150 ; 250 ; 350 ) regulated from being rotated around said guide center axis with respect to a second member ( 30 ) hingedly connected with said first member, and positioned in face-to-face relationship with said second rotation cam and displaceable with respect to the fixed guide member along said guide center axis and rotatable around said guide center axis; urging means ( 170 ) for urging said movable cam toward said second rotation cam in one of an opening operation direction ( 10 e ) to have said second member moved away from said first member and a closing operation direction ( 10 d ) to have said second member moved toward the first member in response to the engagement state of said second rotation cam and said movable cam, and returning means ( 190 ) for returning said first rotation cam to a predetermined operation starting position of said operation cam and for returning said second rotation cam to a predetermined operation starting position where said second member is urged toward said closing operation direction by said urging means; said second member being rotated with respect to said first member toward said opening operation direction through said movable cam by the urging force of said urging means when said operation cam is displaced in said predetermined operation direction by said external operation force, wherein said fixed guide member having inclined guide portions ( 115 ) each inclined at an advance angle in a predetermined inclination direction with respect to the surface perpendicular to said guide center axis to have said second rotation cam rotated around said guide center axis in response to the displacement of said second rotation cam along said guide center axis, and said second rotation cam being driven to rotate by said inclined guide portions under a pressing force from said movable cam to have its engagement state with said movable cam changed and to have the urging direction of the second member by said urging means changed when said operation cam is operated to cause the first rotation cam to be rotated from the operation starting position.