Electronic sewing machine and presser foot particularly for buttonhole stitches and process for producing buttonhole stitches utilizing alternately operable sensor
US4878444A · kind A · utility
Inventors
Key dates
| Filing date | Apr 29, 1988 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Apr 29, 2008 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B3/06
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An electronic zigzag sewing machine is provided with a presser foot including a switch lever pivotable between a first and second position. During buttonhole stitching operation the switch lever remains in the first position, but it is shifted to the second position when either one of longitudinal ends of a buttonhole is detected. A photo-sensor is mounted to the presser foot to output a detection signal when the switch lever is in the second position. A pattern number designating a specific stitch pattern of the buttonhole stitches is renewed to the next in response to the detection signal from the photo-sensor. A control system is provided to nullify operation of the photo-sensor during production of bar tacks of the buttonhole stitches so that the pattern number is not renewed in areas of the bar tacks irrespective of output of the detection signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.