Sewing machine having workpiece prepuncturing device
US4077340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 1976 |
| Grant date | Mar 7, 1978 |
| Priority date | — |
| Expiry date | Oct 4, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C66/836
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A workpiece prepuncturing device for use with a sewing machine having drive means for reciprocating a needle and means for feeding a workpiece into association with the needle to sew a stitch comprises a perforating tool which is located at a spaced location from the needle which is comparable to a multiple of the stitch length. The perforating tool cooperates with a counter tool which is mounted on the opposite side of the workpiece and is movable toward and away from the workpiece in timed relationship to the speed of the feed and the reciprocation of the perforating tool. The counter tool is supported in a base portion of the sewing machine by an elastic suspension, and it is in drive connection with the main shaft of the machine which operates the needle and the feed for the workpiece.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.