Apparatus for connecting door closer or operator to swing door

A method of using a swing door, comprising the steps of:

• providing the door in one of an open or closed position interposed in a door frame and secured to the door frame by at least one hinge;
• providing a door closer housing mounted to one of the door frame or the door surface;
• providing a linkage arm for pivoting the door between open and closed positions, the linkage arm having a first and second end, the first end mounted to the other of the door frame or the door surface;
• providing a rotatable connector between the linkage arm and the door closer housing, the linkage arm second end engaging with the rotatable connector, the connector having a rotatable body portion in the door closer housing and a head protrusion substantially secured in a female receptor to transmit rotation about a longitudinal axis of the connector to the linkage arm, the connector head protrusion having a curved profile viewed along the longitudinal axis of the connector and the female receptor having substantially straight walls, the female receptor closely conforming in diameter to a diameter of the connector head protrusion profile at a midpoint of the longitudinal axis to enable the connector head protrusion to be slideably secured within the female receptor such that the connector head protrusion and female receptor are rotationally locked about the longitudinal axis of the connector, the female receptor being further movable with respect to the head protrusion to permit limited rotational misalignment of the linkage arm on any axis perpendicular to the connector longitudinal axis;
• urging the door into the other of the open or closed position and rotating the connector about the longitudinal axis of the connector to move the linkage arm;
• and
• permitting limited rotational misalignment of the linkage arm on any axis perpendicular to the connector longitudinal axis during rotation of the connector.