| 摘要 |
An adjustable support for smoke- or fume-exhausters and the like, said support comprising a first and a second parallelogram, each parallelogram being made up of two upper rods and a rigid suction tube, two compensating spring pairs which are respectively associated to one of said parallelograms, lengths of a flexible hose between the first parallelogram and said exhauster, as well as between said first and second parallelograms and between the second parallelogram and the suction hood, the coupling between said first and second parallelograms being realized through transmission plates with four points having a lower arm of a length longer than the diameter of said suction tube. |
