Progressive resistance lifting mechanism for a window covering
US7331370B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2004 |
| Grant date | Feb 19, 2008 |
| Priority date | — |
| Expiry date | May 16, 2025 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06B2009/3222
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A lifting mechanism is provided for a window covering which allows a bottom rail of the window covering to maintain a static position unless raised or lowered by a user. The lifting mechanism is included within either a top or bottom rail of the window covering. The lifting mechanism includes cords which pass from a rail including the lifting mechanism to a rail not including the lifting mechanism and about cord redirectors located within the rail including the lifting mechanism. The lifting mechanism includes spools and associated springs for gathering excess portions of the cord thereon. A progressive resister is coupled to the spools with the progressive resister providing different amounts of resistance to spool rotation depending on the amount of cord upon each spool.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.