06155327 is referenced by 9 patents and cites 18 patents.

A counterbalance spring adjustment mechanism, particularly adapted for a rollup type upward-acting door which is supported between spaced apart wall brackets on a rotatable shaft. One end of the torsion spring is connected to a hub including a tubular hub member and a circumferential radially extending flange. The tubular hub member is disposed in a bore formed in one of the wall brackets and is retained in assembly therewith by a cylindrical collar. The door support shaft is disposed in a self-lubricating polymer bushing which is supported in the tubular hub member. A reinforcing collar is fixed to the wall bracket and includes a boss formed thereon having a lock pin receiving bore for receiving a lock pin which projects through the bore in the reinforcing collar, through a slot in the wall bracket and through a selected one of a plurality of circumferentially spaced pin-receiving bores in the hub flange for locking the hub in a selected rotative position which determines the torsional windup of the torsion spring.

Title
Counterbalance system adjustment mechanism for rollup door
Application Number
9/325493
Publication Number
6155327
Application Date
June 3, 1999
Publication Date
December 5, 2000
Inventor
Craig S Ward Jr
Plano
TX, US
David M Wells
Arlington
TX, US
Agent
Akin Gump Strauss Hauer & Feld
Assignee
Overhead Door Corporation
TX, US
IPC
A47G 5/02
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