Bobbin thread depletion detector for sewing machine
US3991692A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1975 |
| Grant date | Nov 16, 1976 |
| Priority date | — |
| Expiry date | Sep 18, 1995 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B59/02
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A bobbin thread depletion signal for lock stitch sewing machines or the like. The bobbin, which is constructed so that one of the end flanges is free to slide axially along the hub, is horizontally mounted in the machine bobbin carrier. When thread is wound on the bobbin, the slideable flange is forced outward against a stop and is positioned in the field of an electronic sensor, such as an oscillator coil, the inductance of which is altered by a proximity of the slideable flange. When the thread is removed from the hub, the slideable end flange will drop from the environment of the sensor toward the stationary flange thereby producing an inductance change that is detected by electronic sensor circuitry that signals the sewing machine operator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.