Bottom stop mechanism for a window covering
US6032716A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 13, 1997 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Feb 13, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06B9/322
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An inventive bottom stop mechanism uses one of the lift cords to operate. While the cord is unwinding from the shaft, the cord leaves the shaft along a line tangent to the shaft. As the last turn of cord is unwound from the shaft, and the point of attachment of the cord to the shaft passes that point of tangency, the angle of the cord with respect to the shaft changes. This change in angle of the cord is used to raise a pawl which engages a ratchet wheel to stop the shaft and prevent further rotation in that direction. When the direction of the shaft is reversed to again start winding the cord thereupon, the cord angle returns to its prior value, releasing the stop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.