Automatic thread wiper for sewing machines

A thread wiper for a sewing machine, comprising

• a compact unit adapted to be mounted on the back of an arm of a sewing machine and including a spring biased pneumatic cylinder having a piston, and a solenoid valve operatively connected to said pneumatic cylinder,
• a downwardly biased presser foot,
• linkage means mounted in the sewing machine for lifting said presser foot upon actuation thereof,
• means for actuating said linkage means via extension of said piston in said pneumatic cylinder upon stopping stitching operation of the sewing machine,
• a needle having an eye and thread extending therethrough, said needle being mounted in said sewing machine, said thread having a thread tail beginning at the eye of the needle and extending between said presser foot to a cut-off thread end therebelow when said presser foot is in a lifted position,
• a holder mounted on said presser foot,
• an air jet tube connected from said solenoid valve to said holder means and extending to an open free end of said air jet tube at an upper portion of the sole of said presser foot adjacent and facing said thread tail,
• means for deactivating said solenoid valve and retracting said piston in said pneumatic cylinder, and releasing said actuating means, so that said downwardly biased presser foot is released and descends, and simultaneously the exhaust from said pneumatic cylinder jets through said air jet tube, exiting at said open free end thereof, lifting said entire thread tail including said cut-off thread end above the presser foot so that the thread tail is out of the way for the initiation of sewing.