Cordless blind
US7228797B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2000 |
| Grant date | Jun 12, 2007 |
| Priority date | — |
| Expiry date | May 5, 2023 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06B9/322
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A cordless blind includes a headrail, a bottom rail suspended from the headrail by a first cord and a second cord, a wall covering disposed between the headrail and the bottom rail, and a drive actuator. The drive actuator includes a spring motor, a spool coupled to the spring motor, a first tensioning mechanism, and a second tensioning mechanism. The first and second tensioning mechanisms are configured to impact a resistant force on movement of the first and second cords. The drive actuator may include a spool, a spring motor, a biasing element configured to provide a force biased against movement of the bottom rail, and a bias relief mechanism that is configured to provide for selective application and relief of the biasing force by the biasing element. The drive actuator may include a constant biasing element, a generally rigid strap, a mandrel, a biasing member, and a traction wheel including a plurality of cogs extending from the circumference of the traction wheel such that movement of the strap rotates the traction wheel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.