| 摘要 |
It comprises an actuating device (22 to 27) of the obturating member (16) provided with a sliding shaft (22) fast with the obturation member, and carrying two permanent magnets (24, 25) separated the one from the other through a distance defining the variation of the cross-section of the passage of the air channel. It comprises further at least one coil (25, 27) enabling to create a magnetic field. |
