Motor control system for one stitch sewing control of a sewing machine
US4161920A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1977 |
| Grant date | Jul 24, 1979 |
| Priority date | — |
| Expiry date | Jul 7, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/293
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control system for one stitch sewing control of a sewing machine is disclosed. Motor speed is controlled by controlling the trigger phase of motor drive thyristors. Two needle position detectors are employed to detect the arrival of the sewing needle at predetermined halt positions. A pair of motor speed indication signal generator circuits, a pair of memory circuits and a start pulse generator circuit are employed. When the one stitch sewing mode is selected and the foot controller is forced down, the first memory circuit memorizes the start of one stitch sewing and energizes the first motor speed indication signal generator circuit so as to drive the motor of the sewing machine at a predetermined sewing speed. When the first needle position detector detects the arrival of the sewing needle at the lowered halt position, it deenergizes the first memory circuit and the first motor speed indication signal generator circuit, and energizes the second memory circuit for energizing the second motor speed indication signal generator circuit so as to drive the motor at a predetermined lower sewing speed. When the second needle position detector detects the arrival of the sewing nee…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.