Door opener

摘要

A door opener and closer that provides motive power for opening and closing a door. A double acting cylinder pivotally mounted on the door is coupled to a roller arm. A roller on the roller arm is captive within a cage mounted to the door frame. The cylinder applies a force on the roller arm in one direction to open the door and in the opposite direction to close the door. The components are mounted in a manner such that none of the components project into the door opening. The door opener and closer eliminates the need for a separate closer. The door may be opened manually with minimum resistance.