Counterbalance mechanism for vertical opening door
US5865235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1997 |
| Grant date | Feb 2, 1999 |
| Priority date | — |
| Expiry date | Jan 23, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE05Y2900/106
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A counterbalance mechanism for a sectional garage door includes an elongated shaft mounted above the door opening and supporting spaced apart cable drums connected to respective cables which are connected at one end to the door for exerting a counterbalance force thereon. Opposed torsion springs are connected to the cable drums at one end, respectively, and to respective hub members which are axially slidable on but nonrotatable with respect to the shaft. The cable drums are provided with detachable bushing members for engagement with the support brackets. The shaft is connected to a non-reversible worm gear drive at one end. The worm gear drive may be actuated to selectively vary the torsional deflection of the counterbalance springs by rotating the worm and a ring gear meshed therewith. The worm gear drive may be detachably mounted on one or the other of shaft support brackets and a lock plate is supported on the shaft and engageable with a bracket to prevent rotation of the shaft when the drive mechanism is removed. The door guide members are engaged with coil compression springs for centering the door between its guide tracks and to minimize skewing of the door during opening a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.