Door closer assembly

Abstract

A door closer comprises a piston cooperating with a rotating pinion. Upon rotation of the pinion in the door opening direction, the piston moves toward the second end of the housing forcing fluid from a second variable volume chamber through a passage to a first variable volume chamber and compressing a spring assembly for storing energy. The spring assembly urges the piston toward the first end of the housing for forcing fluid from the first variable volume chamber to the second variable volume chamber and rotating the pinion in the door closing direction. A controller controls the position of a valve in the passage based on the sensed angular position of a door and the position of the valve for determining the amount of hydraulic fluid flowing through the valve.

We claim: 
     
         1 . 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 hydraulic 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;   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 the 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 to the second variable volume chamber and rotating the pinion in the 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. 
     
     
         2 . The door closer assembly according to  claim 1 , wherein the controller reads a first angular position of the door from the first sensor and then reads a second angular position of the door from the first sensor. 
     
     
         3 . The door closer assembly according to  claim 2 , wherein the controller determines a difference between the first angular position and the second angular position and determines whether the door is opening or closing based on the difference, and compares the difference with a threshold value. 
     
     
         4 . The door closer assembly according to  claim 3 , wherein when the difference is above the threshold value the controller retrieves one of opening mode threshold data or closing mode threshold data defining desired valve positions based on the sensed angular position of the door and determining a desired valve position from the opening or closing mode threshold data, and comparing the sensed angular position of the valve with the desired valve position and determining if the position of the valve requires adjustment based on the comparison, and wherein the controller controls an adjustment of the position of the valve based on one of the opening mode threshold data or the closing mode threshold data. 
     
     
         5 . The door closer assembly according to  claim 4 , wherein the controller makes no adjustment of the position of the valve when the difference is below the threshold value. 
     
     
         6 . The door closer assembly according to  claim 4 , wherein the opening mode threshold data and the closing mode threshold data are determined by settings on the exterior of the door closer. 
     
     
         7 . The door closer assembly according to  claim 2 , wherein the controller compares the two sensed angular positions of the door for calculating a speed of the door based on the comparison and predicting a next movement of the door based on the calculated speed and at least one previously stored calculated speed, and wherein the controller adjusts the valve based on the prediction. 
     
     
         8 . The door closer assembly according to  claim 1 , wherein the sensors comprise magnetic sensors for sensing a magnetic field that is related to the position of the valve, wherein the controller determines a value indicative of a strength of the magnetic field and maps the value to the position of the valve. 
     
     
         9 . The door closer assembly according to  claim 1 , wherein the sensors comprise ratiometric sensors, a ratio (R) of an input voltage to an output voltage of the ratiometric sensors being related to the position of the valve, wherein the controller maps the R value to the position of the valve. 
     
     
         10 . The door closer assembly according to  claim 1 , wherein the valve comprises a valve shaft for bi-directional rotation about an axis through an arc between a first angular orientation corresponding to the closed position of the door and a second angular orientation corresponding to an open position of the door, wherein rotation of the valve shaft from the first angular orientation to the second angular orientation corresponds to movement of the door in the opening direction and rotation of the cam from the second angular orientation to the first angular orientation corresponds to movement of the door in the closing direction. 
     
     
         11 . The door closer assembly according to  claim 1 , further comprising a gear configured to receive an end of the pinion for rotation of the gear with the pinion, and a generator operatively connected to the gear for generating an electrical pulse responsive to rotation of the gear, the electrical pulse being usable to charge an energy storage device such as a capacitor or a battery for powering the controller. 
     
     
         12 . The door closer assembly according to  claim 11 , further comprising a regulator operatively connected to the controller, the voltage storage device, and the generator, the regulator regulating an output voltage of the energy storage device to maintain a constant voltage level.