Patent ID: 6764394
Filing Date: 2004-07-20
Classification: B08B

Abstract:
An extraction arm (1) for a suction duct, the extraction arm (1) constituting a connection between a junction and a suction device of a localized extraction unit and comprising a telescopic arrangement having at least two tubes moveable in relation to one another, that is an outer tube (4) and an inner tube (6) arranged so that it can move inside the former, characterized in that an intermediate joint (2) connected to the junction is arranged so as to adjustably support the outer tube (4), that the inner tube (6) is supported inside the outer tube, partly by a first balancing ring (10) with internal slide members (12) situated close to the outer end of the outer tube and arranged in the outer tube (4), and partly by a second balancing ring (14) with external slide members (16) situated close to the inner end of the inner tube and arranged on the inner tube (6), that a stop member (18), moveably fitted in the outer tube (4) at a predetermined first distance (A) from the outer end thereof, is arranged between the balancing rings, against which stop member the balancing ring (14) of the inner tube comes to bear when the inner tube (6) is fully extended, and which stop member (18) ensures that the balancing rings (10, 14) are separated from one another at least by a second distance (B).