Patent · US Expired

Thread monitor for the bottom thread in the bobbin of a sewing machine

US4732098A · kind A · utility

8Cited by

5References

2Claims

0Family size

Assignee

PFAFF INDUSTRIES MASCHINEN AG · DE

Inventors

Bernhard Mertel · Enkenbach-Alsenborn, DE
Erich Willenbacher · Karlsruhe, DE

Key dates

Filing date	Jun 3, 1986
Grant date	Mar 22, 1988
Priority date	—
Expiry date	Jun 3, 2006

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD05B59/02
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

A sewing machine with a lockstitch rotary hook containing a bobbin, has a thread monitor with which light signals of a radiation source are conducted to a light receiver via inlet and outlet openings in parts of the rotary hook and in at least one of the flanges of the bobbin. For determination of a predeterminable thread and length, the hub which connects the flanges of the bobbin comprises a truncated cone-shaped region, in the surface of which the outlet opening extending substantially parallel to the axis of the hub ends.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.