Upper feed adjusting mechanism for seing machine
US4987843A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 2, 1988 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Dec 2, 2008 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD05B27/04
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An upper feed mechanism of a sewing machine, in which a horizontal motion mechanism for moving the upper feed dog back and forth is provided with a double lever mechanism composed of a single arm lever, a bifurcate lever and a slider slidably mounted on both levers, and a crank lever mechanism for oscillating the levers. When a crank of the crank lever mechanism is at a top dead point or a bottom dead point, the radial directions of the levers are matched, and when the slider is moved in this state, the upper feed dog varies in the feed amount while the front position or rear position is constant. When a rod for coupling the crank and lever of the crank lever mechanism is pivotally mounted in one of two positions spaced in the peripheral direction with respect to the lever, the upper feed dog fitted and disposed at the presser foot makes an upper feed motion before the needle drop point, and when the rod is mounted in the other position the upper feed dog disposed behind the presser foot makes an upper feed motion behind the needle drop point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.