| 摘要 |
A door closer includes a casing having a hydraulic cylinder in which a coupling block is received, and a first tunnel and a second tunnel are in communication with the hydraulic cylinder. A passage is in communication between the first and second tunnels so as to allow the hydraulic oil to flow between the two tunnels. The coupling block includes a pivot shaft for being connected to a door. A first rod and a second rod are pivotably connected to the coupling block and respectively inserted in the first and second tunnels. A threaded rod is connected to a distal end of the first rod and a first spring is mounted to the first rod and the threaded rod. A sleeve is threadedly engaged with the threaded rod and an operation rod is securely connected to the sleeve so that when rotating the operation rod, the first spring is adjusted by moving the sleeve relative to the threaded rod. |
