| 摘要 |
An automatic thread trimmer for use on a computerized embroidery sewing machine having a work table, a bobbin mechanism below the work table, an arm overhanging the work table with a needle driver therein movable through one cycle for each cycle of operation of the sewing machine needle, and a computerized control connected to the machine for driving the needle driver and shifting the needle according to the computer program. The thread trimmer has a thread catcher positioned below the work table and driven reciprocally across the path of a thread extending through the work table to the bobbin for catching the thread at the end of the movement in one direction and drawing the thread with the thread catching member during movement in the other direction, a cutter adjacent the path of movement of the thread catcher against which the thread catcher draws the thread for cutting the thread during movement in the other direction, a wiper positioned above the work table and reciprocally movable across the path of the thread for removing the thread after it has been cut by the cutting means, a signal producer associated with the needle drive for producing first and second signals, the first when the needle is raised clear of the path of reciprocation of the thread catcher, and the second when the needle is raised clear of the path of reciprocation of the wiper, and a control system discriminating when the signals are only in the order of the first signal and the second signal and thereupon actuating the needle drive and the wiper in sequence.
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