摘要 |
First calculation section calculates, on the basis of sewing data, a sewing-progressing direction angle for rotating a rotary cylinder to orient an embroidering material, guided by a guide lever of a zigzag sewing head, in a sewing-progressing direction. Second calculation section adds or subtracts a zigzag-swinging angle to or from the sewing-progressing direction angle to thereby calculate a target rotational angle of the rotary cylinder. Swinging mechanism may be provided for swinging the guide lever relative to the rotary cylinder, and a swinging amount corresponding to the swinging angle of the rotary cylinder may be added to a width of zigzag-swinging by the swinging mechanism. Alternatively, every swinging movement necessary for zigzagging the embroidering material may be set by the swinging angle without the guide lever being caused to swing relative to the rotary cylinder. |