Patent · US Expired

Thread tensioning device having an electromagnet for applying a variable force opposing rotation of a tensioning element

US5363786A · kind A · utility

3Cited by

2References

19Claims

0Family size

Assignee

Durkopp Adler Aktiengesellschaft · DE

Inventors

Klaus Hampel · Bielefeld, DE
Gunter Pries · Leopoldshöhe, DE
Wilfried Goldbecker · Steinhagen, DE

Key dates

Filing date	Dec 15, 1992
Grant date	Nov 15, 1994
Priority date	—
Expiry date	Dec 15, 2012

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD05D2207/05
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

A thread tensioning device comprising a stationary electromagnet mounted on a sewing machine arm and a tensioning wheel having a relatively low mass. The tensioning wheel is rotatable concentric to a longitudinal axis of the electromagnet and is mounted on the electromagnet so as to be moveable only slightly in the direction of the longitudinal axis. A friction disk is positioned at one end of the electromagnet so as to be between the electromagnet and the tensioning wheel. A current flows through an excitation winding in the electromagnet and its value is varied within given limits by a suitable current control device, thereby causing the electromagnet to pull a flat side of the tensioning wheel with corresponding force against an application side of the friction disk, whereby a corresponding variable thread tensioning force is applied to a sewing thread passing through the tensioning wheel to the sewing machine.

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