Patents by Inventor Mitsuru Ninijima

Mitsuru Ninijima has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Sewing machine automatic thread tension device with thread elongation detector
    Patent number: 4960062
    Abstract: A sewing machine includes an automatic thread tension adjusting device comprising an upper thread tension member arranged in an a thread running path between an upper thread source and a main thread take-up lever. An auxiliary thread take-up lever is arranged in the upper thread running path between the main thread take-up lever and a needle holding the upper thread. A thread engaging part guides the upper thread. A thread presser is arranged laterally of the upper thread running path between the main and auxiliary thread take-up levers and normally clamps the upper thread. A detector detects a predetermined rotation phase of a drive shaft of the machine and thread elongation, respectively, and generates respective electric signals. A control circuit causes the thread presser to release the upper thread in response to the electric signals generated by the detector.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: October 2, 1990
    Assignee: Janome Sewing Machine Co. Ltd.
    Inventors: Susumu Hanyu, Noboru Kasuga, Kazumasa Hara, Mikio Koike, Mitsuru Ninijima