Abstract: An opening-closing device for a Western style toilet seat and seat cover is disclosed, in which a pair of hinge cases are mounted at a predetermined spacing at the rear upper end of a Western style toilet bowl; in either of the pair of hinge cases a rotating shaft for the seat and a rotating shaft for the seat cover are rotatably mounted; on the rotating shaft for the seat in either hinge case, the seat mounting section is rotatably mounted, and on the rotating shaft for the seat cover in the hinge case, the seat cover mounting section is rotatably mounted; and a rotation control mechanism is mounted on the rotating shaft for the seat and the rotating shaft for the seat cover, to thereby prevent sudden drop of the seat and seat cover, At this time, the rotation control mechanism may be a cam mechanism using a compression spring, a torsion spring, a rotation camper, or a friction mechanism.

Abstract: In order to control the rotational torque of opening/closing bodies, such as seats and lids for Western-styled lavatory stool, allowing them to be easily opened, stopped and held stably in an opened state, and preventing them from dropping abruptly when they are closed, the present invention provides an opening/closing device with a pair of brackets fitted on two sides at the upper end of the rear part of a lavatory stool and a pair of cases, one for each of the pair of brackets, for bearing and holding one side of a corresponding bracket. A holder housing receives each of these cases, and has a fitting part for a lavatory lid, and is disposed rotatably between the pair of brackets. A pair of supporting members for the lavatory is positioned outside the brackets, and is borne and held by the cases.

Abstract: A hinge mechanism for a toilet bowl seat or seat lid has improved control of rotation due to torque exerted by a cam member working with a compression spring and slider, such that the torque varies depending on the angle of the seat or seat lid to the plane of the toilet bowl. The slider and cam member are mounted on a shaft having an axially directed oval hole in which a complementary shaped hinge pin is received to connect the seat and the seat lid to the mechanism. A stop mechanism prevents the shaft from turning beyond a predetermined angle.