Abstract: A telescopic extraction arm (1), having an outer tube (4) and an inner tube (6) displaceably and rotatably fitted therein. Via balancing rings (14, 16) fixed on each tube respectively, which are kept a pre-determinable distance apart by a stop member (18) arranged in the outer tube (4), the tubes can be easily displaced and locked in relation to one another with a negligible degree of the “drawer effect” occurring in conventional telescopic arrangements.

Abstract: The invention relates to a telescopic extraction arm (1), which has an outer tube (4) and an inner tube (6) displaceably and rotatably fitted therein. By means of balancing rings (14, 16) fixed on each tube respectively, which are kept a pre-determinable distance apart by a stop member (18) arranged in the outer tube (4), the tubes can be easily displaced and locked in relation to one another with a negligible degree of the “drawer effect” occurring in conventional telescopic arrangements.

Abstract: An arm (2) on which to mount an extractor and other equipment, the arm (2) is hinged by its inner end (9) to a support (17) with the intermediary of a mounting bracket (14), so as to be allowed to pivot essentially in the horizontal plane. A retaining device (18) acts between the arm (2) and the mounting bracket (14) to retain the arm in the set pivotal position. The retaining device (18) includes a rod (24) which carries friction washers (23) and which may be actuated by an actuator (20) via a rotationally mounted yoke (38) in order to move the friction washers (23) from their retaining frictional engagement with a plate (34) connected to the mounting bracket (14) and thereby allow the arm (2) to be pivoted as desired. The power actuator (20) is remote-controlled by a control unit positioned on the extraction hood of the extractor.

Abstract: An external middle joint for an extraction arm has one first half and a second half, an inner tube and an outer tube, the inner tube being connected to a fan mounted on a wall, the outer tube having an extraction hood. The first half is connected to the outer end of the inner tube and the second half is connected to the inner end of the outer tube. Each half has a connecting piece connecting the first half to the outer end of the inner tube and connecting the second half to the inner end of the outer tube. A length of hose interconnects the outer end of the inner tube and the inner end of the outer tube, so that a continuous channel is formed from the fan to the extraction hood. Each half has two legs extending on either side of the hose, each leg being articulated to the corresponding leg of the opposite joint half by means of bolt connections. The latter have a bolt which is non-rotationally mounted in one of the legs of the other joint half and which support a knob.