Automatic back-tack mechanism
US3949691A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 25, 1975 |
| Grant date | Apr 13, 1976 |
| Priority date | — |
| Expiry date | Apr 25, 1995 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B27/22
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An automatic back-tack feed control mechanism for the work feed regulating system of a sewing machine which feed regulating system includes a rock shaft and a feed block adapted to influence movement imparted to a feed dog for transporting work fabric transversely of the work surface of the machine according to a selected stitch length. A stitch length selector dial located on the machine includes a reverse feed button connected through a rock arm ultimately to the rock shaft so as to tilt the feed block for reverse feed motion of the feed dog for back tacking. At one preselected stitch length, back tacking is automatic for a predetermined number of stitches since the depression of the reverse feed button actuates a latch lever which locks the rock arm in a reverse feed position until a ratchet mechanism also set in motion by depression of the reverse feed button causes disengagement of the latch lever and rock arm whereby the feed dog is again placed in a forward feed mode. Camming means are also provided so that manual, non-automatic, back tacking can be performed at other selected stitch lengths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.