Patent ID: 8677561
Filing Date: 2014-03-25
Classification: E05F,E05Y,Y10T

Abstract:
1. An automatic door closer comprising: a main housing mounted on a door and having a shape of a cylinder having a closed lower portion; a damper housing disposed along an inner periphery of an upper portion of the main housing so as to divide an interior of the main housing into an upper chamber and a lower chamber, the damper housing having oil charged thereinto and a fixed vane formed at one side of the inner peripheral surface thereof in such a manner as to be projected toward a center thereof, a cover adapted to be fixedly coupled to the upper periphery of the main housing so as to maintain a sealing state with the damper housing; an activating shaft having one end extended to an outside through the cover in such a manner as to be rotatably supported and the other end rotatably supported against a bottom surface of the main housing through the damper housing, the one end extended to the outside being connected to a door frame through a link; a rotary vane formed integrally to the outer periphery of the activating shaft so as to divide the interior of the damper housing into first and second chambers, together with the fixed vane; a return spring mounted in the lower chamber in such a manner as to be compressed at a time when the door is open and to provide a returning force of returning the activating shaft to an initial setting position at a time when the door is closed; damping means adapted to control opening and closing speeds of the door and to selectively provide a damping function if the activating shaft and the rotary vane are rotated in a closing direction of the door by means of the returning force of the return spring; and further comprising closing speed-controlling means by angle for reducing the damping force generated by the damping means, according to a predetermined opening angle of the door, when the activating shaft and the rotary vane are rotated in the closing direction of the door so as to control the closing speed of the door according to the predetermined opening angle of the door, the closing speed-controlling means by angle comprises at least one accelerating groove formed on the bottom surface of the damper housing to form at least one accelerating section in the circumferential direction, and the section where the accelerating groove is not formed is set as a delaying section delaying the closing speed of the door.