Adjustable bobbin thread run-out indicator
US4178866A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 19, 1978 |
| Grant date | Dec 18, 1979 |
| Priority date | — |
| Expiry date | Jun 19, 1998 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B59/02
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A lock stitch sewing machine having a bobbin thread run-out indicator which is adjustable to permit initiation of the indication with a selected length of bobbin thread remaining on the bobbin. A bobbin case is supported in a rotating loop taker against rotation therewith and partially extending therefrom. The bobbin is fashioned with two flanges joined by a hub and is carried in a cavity in the bobbin case, the cavity being arranged so that one flange of the bobbin also extends partially from the rotating loop taker. A fibre optic is arranged in the sewing machine frame to extend a light ray through an opening in the bobbin case above the rotating loop taker but in between the flanges of the bobbin, adjacent the hub thereof, and through an opening in the opposite side of the bobbin case to a light sensor. The light sensor is carried so as to be shiftable normal to the direction of the light ray. Lateral shift of the light sensor causes the light sensor to receive rays from the fibre optic which are spaced at variable distances from the hub of the bobbin, thereby providing for low thread indication with selected length of bobbin thread remaining on the bobbin hub.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.