| 摘要 |
The invention is a sewing machine (1) comprising a main motor (8) suited to axially rotate a main shaft (3) for moving the vertical needle-holding rod (4), an auxiliary motor (9) mechanically connected to the lower drive wheel (6) and to the roller (71) of the upper presser foot (7), an encoder (10) connected to a cam (43) for the oscillation of the needle-holding rod (4) and suited to detect the motion of said cam (43), that is, of said rod (4), an auxiliary electronic board (11) communicating with said encoder (10) and with said auxiliary motor (9), and wherein said auxiliary electronic board (11) activates said auxiliary motor (9) so as to modulate the speed and/or the rotation direction of said lower drive wheel (6) and of said upper roller (71) according to the motion of said needle-holding rod (4). |
