| 摘要 |
In a door closer, there are provided a vertical rotatable shaft (3) associated with the rotation of a door (1) through an arm, two cams (4, 5) installed integral with the shaft, an urging device (8) for rotating the door in closing direction through one of the cams and a cylinder device (12) for braking the door during door closing operation through the other of the cams. Thus, the opening of the door is effected by overcoming the force of the urging device and hence the door can be opened lightly. When the door is released, the force of the urging device (8) is transmitted to the one cam (4) and then to the arm (32), so that the door can be automatically closed. During door closing operation, the cam surface of the other (5) cam pushes the piston rod (11) of the cylinder device (12), whereby the rotation of the other cam and hence the rotation of the shaft integral with the other cam are braked, avoiding severe shocks to the door. |
