The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 1983
Filed:
Aug. 28, 1981
Helmar Holl, Karlsruhe, DE;
Rolf Kessler, Karlsruhe, DE;
Dorina Nahmaschinen GmbH, , DE;
Abstract
A method and a device for the formation of an overcast seam using a zigzag sewing machine are disclosed. After the formation of a first loop in an overstitch position of the needle bar, the needle bar, while the needle thread is slackened and the fabric is moved by one stitch length, changes to a second overstitch position in which another thread loop is made. Thereupon, the needle thread, leading from the first to the second thread loop, is pulled out to form a loop in the first overstitch position while the fabric is fed by another stitch length, the loop being offered to the needle for the stitching and released after stitching. The oversew mandrel of the device for implementing the method includes a double lever loop stripper. One arm of the double lever supplements the oversew mandrel and serves as the thread loop stripper. The other arm has a slide surface which projects into the path of motion of the needle fastening screw in the first overstitch position of the needle bar. The arm of the double lever supports a holding member for the thread loop, interacting with a thread loop retaining projection of the oversew mandrel. The device is disposed in its own housing connected to the fabric presser of the sewing machine.