| 摘要 |
<p>The hose connecting branch (2) contains at least one member, e.g. spring-controlled flap (10) which reduces the corss-sectional area of the branch and can be moved when required to widen the cross-sectional area, at least partly. The flap can be designed, e.g. to swivel about an axis which lies at right angles to the axial direction (11) of the branch. In this way, when the hose or other adaptor is not used, the cross-section can be reduced to throttle the air flow to avoid overheating. When the hose is inserted, the cross-sectional area is suitably widened by the hose movement overcoming the spring force.</p> |
