Sewing machine with automatic thread cutter.

摘要

In a sewing machine, when the depressed condition of a foot pedal (16) is changed from a forward depressed condition for high speed sewing to a reverse depressed condition for thread cutting, a braking circuit decreases the rotational speed of the machine motor (11) from a high speed to a low speed. The rotational speed is detected by an encoder (12). When the rotational speed detected by the encoder becomes a threshold medium speed or less, and a needle-down signal is generated from a needle position detector, the CPU (10) of the sewing machine outputs a work fabric feed pitch control start signal to a work fabric feed pitch selector. The work fabric feed pitch selector reduces or nullifies the feed pitch of the work fabric. Under this condition, in response to the next needle-down signal, the CPU operates a thread cutting mechanism to cut the needle and bobbin threads. <IMAGE>