Lid opening and closing apparatus with mechanism for assisting opening and closing of lid

A lid opening and closing apparatus, comprising:

• a base having an open portion,
• a lid having a rotational shaft and supported on the base to be rotatable around the rotating shaft for opening and closing the open portion, and
• connecting means for connecting the base and the lid having one spring disposed between the base and the lid, said one spring being stretched for urging the lid in a closed portion to an opening direction when the lid is pushed to a pushed-in position beyond the closed position, said one spring being stretched for urging the lid in an open position to a closing direction when the lid is closed to a predetermined angle,
• wherein said connecting means further comprises a first link arm having one end part with a support shaft rotatably supported on the base;
• a second link arm having one end part slidably attached to the first link arm and the other end part with a pin, said second link arm being urged in a direction approaching the first link arm by the one spring arranged between the first and second link arms;
• a push arm supported on the base for extending the second link arm further from the first link arm when the lid is pushed to the pushed-in position to thereby stretch the one spring;
• and a guide groove provided in the lid for guiding the pin, said guide groove moving the pin in a direction away from the first link arm when the lid is closed by the predetermined angle from the open position to thereby stretch the one spring.