Patent ID: 6098555
Filing Date: 2000-08-08
Classification: D05B

Abstract:
A chain-off forming apparatus for cover stitch sewing machines, adapted to introduce double chain stitch chain-off's, which are formed below a needle plate by the intertwining of threads on a plurality of needles and a thread on a looper in accordance with the actions of said needles and said looper occurring when fabrics to be sewn are not fed, onto the portion of an upper surface of said needle plate which is behind needle points, and feed out the chain-off's continuously with the chain-off's held between rear feed dogs on the rear side of the needle points and a chain-off thread gripper, wherein:said needle plate is provided with a thread positioning spreader which is adapted to engage, in a position behind the needle points while the fabrics to be sewn are not fed, the connected needle threads and looper thread with each other at predetermined intervals when said needles are moved into substantially triangular spaces formed by the looper thread connected to said looper double chain stitches from previously formed on feeding the fabrics to be sewn and needle threads hung on said looper, and which is adapted to have said looper enter the loops formed by the needle threads when said needles are moved back, feed double chain stitch chain-off's, remove the intertwined needle threads from said looper, and maintain the intertwined needle threads and looper thread in an engaged state.