| 摘要 |
A door closer for regulating the movement of a door panel with respect to its frame has a body enclosing a chamber and an adjacent cylinder having a head. A piston is reciprocable in the cylinder toward and away from the head and in accordance with the door panel motion. A spring in the chamber urges the piston toward the head. A duct through the piston controlled by a check valve permits liquid flow from the chamber to the cylinder, but not vice versa. A passage in the body extends between the cylinder, near the head, and the chamber. In that passage near the head is a throttle valve for restricting liquid flow, and in the passage near the chamber is a bypass valve for restricting liquid flow and for permitting increased flow under increased liquid pressure. There is also a bore in the body extending between the passage intermediate the throttle valve and the bypass valve and an adjacent part of the cylinder traversed by the piston.
|
