Abstract: It is provided a surface-treated steel sheet that can be produced without using hexavalent chromium and has excellent sulfide staining resistance and coating secondary adhesion. It is a surface-treated steel sheet having: a Sn plating layer; a metallic Cr layer disposed on the Sn plating layer; and a Cr oxide layer disposed on the metallic Cr layer, on at least one surface of a steel sheet, and the surface-treated steel sheet has a water contact angle of 50° or less and a total atomic ratio of K, Na, Mg, and Ca adsorbed on the surface to Cr of 5% or less.

Abstract: A child seat includes: a base member; a seat body switchable at least between a forward facing state and a sideways facing state in a bed shape on the base member; a prop or strut member attached to a front end of the base member and extending to a position where the prop member abuts on a floor of an automobile; and a rigid bar-shaped support member supported by the prop member so as to be displaceable between an upper position and a lower position. A side engagement portion is provided in a side surface of the seat body. The side engagement portion engages with the support member when the support member is brought to the upper position in the sideways facing state in the bed shape.

Abstract: A child seat includes: a base member; a seat body switchable at least between a forward facing state and a sideways facing state in a bed shape on the base member; a tension member attached to a front end of the base member and extending to a position where the tension member abuts on a floor of an automobile; and a support member supported by the tension member so as to be displaceable between an upper position and a lower position. A side engagement portion is provided in a side surface of the seat body. The side engagement portion engages with the support member when the support member is brought to the upper position in the sideways facing state in the bed shape.

Abstract: A detachable child safety seat comprises a base member, a seat body mounted on the base member detachably, an upper locking mechanism to lock or unlock a stand wall of the base member and a backrest of the seat body, a lower locking mechanism to lock or unlock a bottom wall of the base member and a seat of the seat body, and a synchronization mechanism to connect the upper locking mechanism to the lower locking mechanism so as to synchronize locked states or unlocked states of both locking mechanisms.

Abstract: A detachable child safety seat comprises a base member, a seat body mounted on the base member detachably, an upper locking mechanism to lock or unlock a stand wall of the base member and a backrest of the seat body, a lower locking mechanism to lock or unlock a bottom wall of the base member and a seat of the seat body, and a synchronization mechanism to connect the upper locking mechanism to the lower locking mechanism so as to synchronize locked states or unlocked states of both locking mechanisms.