Door closer with self-powered control unit

A door closer comprising:

• a spring;
• a movable element configured to move in response to movement of a door, the movable element loading the spring;
• a valve configured to control movement of hydraulic fluid around the movable element;
• a drive gear configured to rotate in response to movement of a door;
• a chain arranged to cooperate with the drive gear to produce linear motion in response to rotation of the drive gear in response to the movement of the door;
• a generator responsive to rotational motion to generate electricity to control the valve;
• and
• at least one gear to turn the generator in response to the linear motion of the chain.

A method of operating a door closer in response to movement of a door, the method comprising:

• producing linear motion in response to rotation of a drive gear caused by the movement of the door;
• using a set of clutch gears to turn a generator in only one direction in response to the linear motion, wherein the generator turns in only one direction in response to movement of the door in any direction;
• turning the generator to produce electricity to power a controller;
• and
• controlling a valve in the door closer using the controller.

Apparatus for controlling a door closer in response to movement of a door, the apparatus comprising:

• means for producing linear motion in response to rotational motion caused by the movement of the door;
• means for using a set of clutch gears to turn a generator in only one direction in response to the linear motion, wherein the generator turns in only one direction in response to movement of the door in any direction;
• means for turning the generator to produce electricity to power the apparatus;
• and
• means for controlling a valve in the door closer.