Stitch-forming machine with a transducer and a control device

US5237944A · kind A · utility

Assignee

• G.M. Pfaff Aktiengesellschaft · DE

Inventors

• Erich Willenbacher · Karlsruhe, DE
• Bernhard Mertel · Enkenbach-Alsenborn, DE
• Rainer Spickermann · Pirmasens, DE
• Walter Sinn · Medard, DE

Key dates

• Filing date: Jun 25, 1991
• Grant date: Aug 24, 1993
• Expiry date: Jun 25, 2011

Classification

• Technology area (CPC D): Textiles; Paper
• CPC primary: D05D2205/16
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A stitch forming machine is provided including a transducer for determining the tension present in a thread, wherein the thread tension assumes a higher value during stitch formation and the transducer provides a signal representing the tension level. The control is provided for evaluating the signal corresponding to the tension level. The control includes a comparator device for comparing a peak of the signal representing the tension level, which peak can be used to detect a malfunction, with a limit signal, corresponding to a limit tension. The comparator sends a signal to a switching device when a signal peak drops below the limit signal. The switching device may be connected to a shut-off device of the drive motor of the machine as well as one or more display elements. In this way, the machine may be stopped and the display element associated with a limit tension, below which the tension dropped by a switching device. The comparator may, according to another aspect of the invention, only provide a signal for energizing a switch depending upon a stitch formation phase associated with a signal peak which drops below a limit signal.