Patent ID: 8387210
Filing Date: 2013-03-05
Classification: E05D,E05F,E05Y,Y10T

Abstract:
1. An automatic door closing hinge comprising: a cylinder; an operating rod attached to one end of the cylinder so as to be rotatable and restricted from moving in the longitudinal direction; a first cam groove formed on an outer peripheral surface of the operating rod in the cylinder so as to have a substantially V-shape at opposed positions thereof; first balls disposed in engagement with the first cam groove at opposite positions; a compression ring engaged with the first balls and movable in the longitudinal direction in the cylinder in conjunction with the movement of the first balls with respect to the first cam groove; a compression coil spring disposed between the compression ring and an upper end portion of the cylinder for urging the compression ring toward the other end of the cylinder; a second cam groove formed on the outer peripheral surface of the operating rod in the cylinder so as to have a substantially V-shape at opposed position thereof and disposed under the first cam groove, with upper and lower ends being aligned with those of the first cam groove in the longitudinal direction; second balls disposed in engagement with the second cam groove at opposed positions thereof; a piston engaged with the second balls and movable in the longitudinal direction in the cylinder in conjunction with the movement of the second balls with respect to the second cam groove; and an air damper unit configured to flow out air in the cylinder on the other end side with respect to a bottom portion of the piston gradually according to the movement of the piston toward the other end.