Patents by Inventor Wen-Chen Tsai

Wen-Chen Tsai 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).

  • Thread trimming device for a spreader thread in a sewing machine
    Patent number: 6318282
    Abstract: The present invention comprises an air cylinder which is driven by compressed air. When sewing with a spreader thread, the air cylinder drives a movable catcher and a fixed cutter to cut off a spreader thread, which is then clamped by a spring plate to facilitate the next sewing operation. When sewing without a spreader thread, compressed air is used through an air passage to blow the free end of the needle thread cut off by an under trimming mechanism away from the underside of the presser foot after the presser foot is lifted at the end of a sewing operation to facilitate the next sewing operation. The air cylinder in the present invention may also be replaced by an electromagnetic relay, which, when powered up, stretches and retracts the central shaft to drive a movable catcher and a fixed cutter and thereby cut off the spreader thread.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: November 20, 2001
    Assignee: Kaulin Mfg. Co., Ltd.
    Inventor: Wen-Chen Tsai
  • Flat bed sewing machine
    Patent number: D465794
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: November 19, 2002
    Assignee: Kaulin Mfg. Co., Ltd.
    Inventor: Wen-Chen Tsai
  • Cylinder bed sewing machine
    Patent number: D468324
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: January 7, 2003
    Assignee: Kaulin Mfg. Co., Ltd.
    Inventor: Wen-Chen Tsai