摘要 |
<p>A door closer for affording a controlled closing movement to a door including a return spring, an oil hydraulic piston and cylinder means, and a valve for generating a damping force when the door closers, said valve comprises a movable valve member for regulating oil flow through the valve, and a bimetal element connected with the movable valve member in response to the change in the temperature thereby attaining a substantially constant closing speed of the door irrespective to the change in the temperature.</p> |