Door operating apparatus with enhanced durability

A door operating apparatus for use with a door pivotably mounted to a door frame, the door operating apparatus configured to permit the door to swing from a closed position to an open position in one of a manual operation and an automatic operation, the door operating apparatus comprising:

• a housing;
• a first rotatable sprocket disposed in the housing and coupled to the door;
• a second rotatable sprocket disposed in the housing and operably connected to the first rotatable sprocket by a roller chain, the second sprocket comprising a bottom face and a top face with a protrusion coupled thereto;
• a drive assembly disposed in the housing and comprising a motor operably connected to a drive arm located proximate the second rotatable sprocket;
• wherein a force applied to the door in the manual operation of the door operating apparatus permits the first and second rotatable sprockets to rotate simultaneously to enable the door to swing to the open position, wherein activation of the motor in the automatic operation of the door operating apparatus allows the drive arm to engage in pivotal movement to contact the protrusion and drive the second sprocket, thereby permitting the drive arm to rotate the first and second rotatable sprockets simultaneously to enable the door to swing to the open position.