Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Publication of DE254034CpublicationCriticalpatent/DE254034C/de
Verfahren und Vorrichtung zum Herstellen von Reissverschluessen mit zwei ineinandergreifenden, schraubenfoermigen Drahtspulen sowie nach diesem Verfahren hergestellter Reissverschluss
Feed dog for double lock-stitch machine - has thread tensioning element which is fastened on outside of a collar on a top bobbin and features a clamp and guide device