Patent ID: 8181820

Claim:
A mechanism for opening and closing an opening portion having an outer frame and an outer wall member having an opening portion formed therein, and a lid member for operatively opening and closing the opening portion, which includes: a rotation supporting shaft disposed on the outer side of one end of the outer wall member that faces the opening portion; a lid member's wound section disposed on one end of the lid member and having a head end wound around the rotation supporting shaft, the one end of the lid member being supported pivotally by the rotation supporting shaft surrounded by the lid member's wound section with the other end of the lid member closing the opening portion; and an opening and closing member operated for causing the lid member to open and close the opening portion, the opening and closing member having a head end that is made to slide out of and into the opening portion inside the outer wall member on the outer frame; when the opening portion is closed by the lid member, the head end of the lid member's wound section surrounding the rotation supporting shaft is extended inwardly of the opening portion until it reaches the point that is located closer to the inward direction of the opening portion than the point in which the rotation supporting shaft is located; and the opening and closing member has a protrusion on an outer wall thereof on the side on which the head end of the opening and closing member being made to slide out of and into the opening portion faces opposite the outer frame, the protrusion having a head end directed from an inner side toward an outer side of the outer wall member on the outer frame, wherein when the opening portion is closed by the lid member, the head end of the protrusion and the head end of the lid member's wound section are brought closer to each other, causing them to face opposite each other, and then the opening and closing member is operated so that its head end can be made to slide out of the opening portion, and can be made to engage the side of the lid member located inwardly of the opening portion, causing the one end of the lid member being supported pivotally by the rotation supporting shaft to rotate about the rotation supporting shaft and thereby permitting the opening portion to be opened; and reversely when the opening portion is to be closed from its opened state, the opening and closing member is operated so that its head end can be made to slide back into the opening portion, causing the head end of the protrusion of the opening and closing member to engage the head end of the lid member's wound section and thereby causing the one end of the lid member being supported pivotally by the rotation supporting shaft to rotate about the rotation supporting shaft.