Counterbalance system adjustment mechanism for rollup door
US6155327A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1999 |
| Grant date | Dec 5, 2000 |
| Priority date | — |
| Expiry date | Jun 3, 2019 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06B9/174
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.