Door closer assembly

A door closer assembly for automatically moving a door in a closing direction, the door positioned within a door frame and hinged along one edge to the door frame for movement between a closed position and an open position, the door closer assembly comprising:

• a housing having a first end and a second end and defining an interior cavity;
• a pinion journaled in the housing for rotation about an axis, the pinion including gear teeth and at least a portion of the pinion extending from the housing and adapted to be connected to turn with the door;
• a piston having a first end and a second end, the piston slidably disposed in the cavity in the housing and dividing the cavity into a first variable volume chamber between the first end of the housing and the first end of the piston and a second variable volume chamber between the second end of the housing and the second end of the piston, the piston having an opening defined by rack teeth for engaging the gear teeth on the pinion for cooperating with the pinion for converting rotation of the pinion into linear movement of the piston relative to the housing;
• spring means disposed in the housing between the second end of the housing and the second end of the piston for urging the piston and rotating the pinion toward the first end of the housing in the door closing direction;
• a passage defined in the housing for permitting flow of fluid between the first variable volume chamber and the second variable volume chamber in response to movement of the piston relative to the housing;
• a valve disposed in the passage, the valve regulating an amount of fluid that flows through the valve, the amount of hydraulic fluid flowing through the valve controlling a force generated by the door closer assembly on the door, the valve comprising a valve shaft for bi-directional rotation about an axis through an arc between a first angular orientation where a surface of the valve shaft blocks fluid flow through the passage and corresponding to a closed position of the passage and a second angular orientation where at least a portion of the surface of the valve shaft is spaced from the passage allowing fluid flow through the passage and corresponding to an open position of the passage, the surface of the valve shaft defining a partial circumferential groove for allowing fluid flow through the passage between the first angular orientation and the second angular orientation of the valve shaft;
• a first sensor for measuring an angular position of the door;
• a second sensor for measuring a position of the valve;
• and
• a controller for controlling the position of the valve,
• wherein upon rotation of the pinion in a door opening direction the piston moves toward the second end of the housing forcing fluid from the second variable volume chamber through the passage to the first variable volume chamber and compressing the spring means for storing energy, the spring means urging the piston toward the first end of the housing for forcing fluid from the first variable volume chamber through the passage to the second variable volume chamber and rotating the pinion in a door closing direction, and
• wherein the controller controls the position of the valve based on the sensed angular position of the door and the position of the valve for determining the amount of hydraulic fluid flowing through the valve.