| 摘要 |
<p>PCT No. PCT/SE95/00883 Sec. 371 Date Feb. 3, 1997 Sec. 102(e) Date Feb. 3, 1997 PCT Filed Jul. 24, 1995 PCT Pub. No. WO96/05001 PCT Pub. Date Feb. 22, 1996An apparatus for extracting gases comprises a rotatable reeling drum, a suction hose, a cut-off throttle, a position changing device, and a pivoting means. The position changing device cooperates with the pivoting means to open the cut-off throttle during initial rotation of the reeling drum in a direction of unwinding the suction hose and close the cut-off throttle within a first revolution of the reeling drum in a direction of winding the suction hose.</p> |
