Patent ID: 7537042

Claim:
An operating mechanism providing an opening force to a garage door, said operating mechanism comprising: at least one helical side drum having a plurality of concentric graduations of increasing diameter along its length, said side drum capable of rotation relative to a fixed axis, said side drum operatively connected to a garage door by a first cable; at least one cable drum coaxially mounted relative to said side drum for simultaneous rotation therewith; at least one gas spring operatively connected to said cable drum by a second cable; wherein said side drum and said cable drum are rotatable in a first direction to close said garage door so that said first cable is unwound from said graduations of said side drum to lower said garage door and said second cable charges said gas spring and a second direction to open said garage door so that said first cable is wound onto said graduations of said side drum to raise said garage door and said second cable discharges said gas spring to assist in opening said door.