Process and device for recognizing a residual amount of the hook thread in a sewing machine
US5651324A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 1996 |
| Grant date | Jul 29, 1997 |
| Priority date | — |
| Expiry date | Mar 22, 2016 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B59/02
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
In a process and device for monitoring a residual amount of hook thread in a double thread lockstitch sewing machine, a bobbin is used, which is divided into a large clamber and a small chamber due to the arrangement of a middle flange, wherein the small chamber accommodates the residual amount of thread. An abrupt reduction in the speed of rotation of the bobbin, n.sub.S, takes place dating sewing at the time of the transition from the principal to the residual amount of thread as a consequence of the abrupt change in the thread pull-off site in the bobbin. The jump (abrupt change) in the speed of rotation is measured and is processed info a display signal
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.