| 摘要 |
A hinge type automatic door closer has a cylindrical housing mounted on a door via a door mounting plate, a hinge shaft mounted on a door frame via a door-frame mounting plate. The hinge shaft is inserted within the cylindrical housing. The door closer has a piston engaged around the hinge shaft movable vertically locked to the housing in its rotational movement. When the housing rotates, the piston is moved up and down depending upon a rotational direction of the housing. |
