Buttonhole sewing machine
US4134346A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1977 |
| Grant date | Jan 16, 1979 |
| Priority date | — |
| Expiry date | Oct 27, 1997 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B57/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A sewing machine for sewing buttonholes in a workpiece comprises a stationary lower part and an arm having one end pivotally mounted on the lower part and having an opposite end which carries a rotary hook which cooperates with a reciprocating needle carried in the lower part. The arm is pivotal relative to the base part to move the arm from a fixable sewing position with said hook spaced by a predetermined distance from the needle at a stitch-forming area to a rest position in which it is spaced away from the stitch-forming area. A thread-monitoring device is located adjacent the needle for monitoring the thread and detecting any breakage thereof. The machine includes a buttonhole cutting mechanism which is connected to the drive means so as to periodically cut the workpiece. A clamp is carried by the upper arm and it has a lower portion which rests on a resilient support which is biased upwardly by a spring. The upper part of the clamp carries a rod which is biased downwardly by a spring having a lower characteristic than the spring biasing the arm upwardly, and it engages over a presser frame to urge the frame into engagement with the workpiece. A locking mechanism is associated…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.