| 摘要 |
A door accessory, such as a door hinge, includes a hydraulic retarding device for cushioning the closing action of a door. The hydraulic retarding device has a cylinder body which confines a fluid receiving space to receive hydraulic fluid therein. One end of a piston rod extends into the fluid receiving space and has a valve unit provided thereon. The valve unit includes a piston which is formed with perforations and which forms a clearance with the cylinder body and a valve ring which is loosely sleeved on the piston rod. The piston rod is operably associated with the door movement so that the valve ring does not block the perforations on the piston during a door opening action, thereby permitting faster fluid flow inside the fluid receiving space and providing little or no resistance to the movement of the piston rod, and so that the valve ring blocks the perforations on the piston during a door closing action, thereby permitting fluid to flow only through the clearance so as to retard the movement of the piston rod. |
