SAFE OPENING AND CLOSING DEVICE OF DOOR

摘要

PURPOSE: A safe door opening and closing device is provided to prevent rapid closure motion of a door and to help smooth opening and closing of a door by damping the external force applied on an open door. CONSTITUTION: A cylinder member(60) has a guide protrusion(62) having its inner face contacts with a spiral groove(42) of a door rotary member(40). The outer face of the guide protrusion is received in a guide recessed groove(50a). In door opening, the inner end of the guide protrusion is guided by the spiral groove while its outer end is guided by the guide recessed groove. Thus, the cylinder member ascends. During cylinder member ascent, the hydraulic oil in the cylinder member flows out via a slit(74a) of a cover(74). The outgoing hydraulic oil circulates through a path(80) in the lower end of the cylinder member after passing through a gap between an O-ring(78) and a cylindrical housing(18a) of a door rotary member(18). Thereby, a door is opened smoothly.