Sewing machine drive control
US3991693A · kind A · utility
4Cited by
5References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1972 |
| Grant date | Nov 16, 1976 |
| Priority date | — |
| Expiry date | Jun 2, 1992 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B59/00
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A direct motor drive system for a sewing machine wherein a low-inertia direct current motor coupled directly to the drive shaft is excited by a low impedence source of variable direct current voltage derived from a rectified alternating current signal at a manually controllable autotransformer. A needle-positioning circuit senses the needle position and either pulses or brakes the motor electrically so that the needle moves to a selected up or down position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.