Abstract: To provide a rotary damper in which a viscous fluid does not leak from between an inner end face of a land and an outer circumferential surface of a rotatable member, and a decrease in torque caused by an eccentric rotation of the rotating member is prevented. The rotary damper has a rotatable member being relatively rotatable with respect to a casing, the proximal portion of the rotatable member being accommodated in a chamber of the case; a ridge member extending axially along and projecting radially outwardly from an outer circumferential surface of the proximal portion of the rotatable member, the ridge member having a radially outer end face disposed for sliding contact with an inner circumferential surface of the chamber; and the land extending axially along and projecting inwardly from the inner circumferential surface of the chamber, the land having a face transverse with respect to the rotational direction of the rotatable member.

Abstract: To provide a rotary damper in which a viscous fluid does not leak from between an inner end face of a land and an outer circumferentialsurface of a rotatable member, and a decrease in torque caused by an eccentric rotation of the rotating member is prevented. The rotary damper comprises: the rotatable member being relatively rotatable with respect to a casing, the proximal portion of the rotatable member being accommodated in a chamber of the case; a ridge member extending axially along and projectiong radially outwardly from an outer circumferential surface of the proximal portion of the rotatable member, the ridge member having a radially outer end face disposed for sliding contact with an inner circumferential surface of the chamber; and the land extending axially along and projecting inwardly from the inner circumferential surface of the chamber, the land having a face transverse face transversely with respect to the rotational direction of the rotatable member.

Abstract: A damper device includes a casing, a rotor partly housed in the casing, a viscous fluid filled in the casing around the rotor, and a torque generator for generating a torque during a rotating stroke of the rotor. The torque generator includes a fluid torque adjuster for producing a relatively large torque in at least a terminal range of the rotating strokes in normal and reverse directions of the rotor.

Abstract: A rotary damper has a shaft and a torque control mechanism which are accommodated in a chamber filled with a viscous fluid. The chamber is divided into a first compartment and a second compartment. The torque control mechanism comprises an auxiliary chamber defined by a partition wall disposed adjacent to the chamber in communication therewith, first and second communication holes defined in the partition wall and providing fluid communication between the first and second compartments and the auxiliary chamber, and a check valve for preventing the viscous fluid from flowing in the first communication hole from the auxiliary chamber toward the first compartment.

Abstract: A rotary damper for use with a toilet lid has a damper shaft rotatably supported by a damper housing, a collar of synthetic resin fitted over the damper shaft for rotation therewith, and a casing of synthetic resin fixed to the damper housing and disposed around the collar for rotation relative thereto. The collar has a pair of diametrically opposite axial ridges disposed on the outer circumferential surface thereof and projecting radially outwardly. The casing has a pair of diametrically opposite cantilevered resilient arms defined by respective slits in the circumferential wall thereof. The cantilevered resilient arms have respective axial teeth disposed on the inner circumferential surface of the casing and projecting radially inwardly for engagement with the axial ridges, respectively.

Abstract: A rotary damper for use with a toilet lid has a damper shaft rotatably supported by a damper housing, a collar of synthetic resin fitted over the damper shaft for rotation therewith, and a casing of synthetic resin fixed to the damper housing and disposed around the collar for rotation relative thereto. The collar has a pair of diametrically opposite axial ridges disposed on the outer circumferential surface thereof and projecting radially outwardly. The casing has a pair of diametrically opposite cantilevered resilient arms defined by respective slits in the circumferential wall thereof. The cantilevered resilient arms have respective axial teeth disposed on the inner circumferential surface of the casing and projecting radially inwardly for engagement with the axial ridges, respectively.