Clopay Building Products Company, Inc.

George S Carper

Kenneth E Carper

Alan R Leist

Thomas Edward Agin

Tony Y Lin

An overhead door apparatus utilizing a torsion spring counterbalancing mechanism. The counterbalancing mechanism includes a worm drive ring-shaped gear winding mechanism for setting the appropriate torque or number of winds in the spring. A counting mechanism is provided to indicate to the installer the number of winds being given to the spring. The ring-shaped gear is a spur gear which is formed integrally with the fitting or cone which attaches by way of a threaded connection with one end of the spring. Means are also provided for accommodating spring growth and contraction during winding and unwinding using the winding mechanism and during normal raising and lowering of the door. A spring clip gear retainer is disclosed for preventing rotation or creep of the worm drive gear and spur gear during normal raising and lowering of the door.

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Milford, OH, United States of America

George S Carper