Retaining and releasing device for exhaust-gas extraction nozzle

Retaining and releasing device for an exhaust-gas extraction nozzle, which nozzle (5) is adapted for extracting exhaust gases from upwardly directed exhaust pipes (3) on vehicles (2) when these vehicles are started and driven in premises (1) for said vehicles and which nozzle (5) is movably mounted in said premises (1) for being able to follow the exhaust pipe (3) of the vehicle (2) when said nozzle is attached thereto, whereby the retaining and releasing device (20) is adapted to permit attachment of the exhaust-gas extraction nozzle (5) to the exhaust pipe (3) such that said exhaust pipe (3) can bring said nozzle (5) with it when the vehicle (2) is driven in the premises (1), and whereby said retaining and releasing device (20) is further adapted to permit release of the exhaust-gas extraction nozzle (5) from the exhaust pipe (3) when required as the vehicle (2) leaves the premises (1), characterized in that the retaining and releasing device (20) includes at least one retaining and releasing arm (29) which is movable between a retaining position (D) wherein it permits retention of the exhaust-gas extraction nozzle (5) at the exhaust pipe (3) and a release position (C) wherein it permits release of said exhaust pipe (3) from said nozzle (5), whereby a retaining device (43) is provided to retain the retaining and releasing arm (29) in its retaining position (D) and to release the arm (29) such that said arm can move to its releasing position (C) when the exhaust-gas extraction nozzle (5) reaches a certain position (E) in the premises (1), the retaining device (43) comprising an electromagnet (44) retaining the retaining and releasing arm (29) in the retaining position (D) by means of magnetic force, the electromagnet (44) being remote-controlled to release the retaining and releasing arm (29) by cessation of its magnetic force when the exhaust-gas extraction nozzle (5) reaches a certain position (E) as the vehicle (2) is driven out of the premises (1), whereby the exhaust pipe (3) can be released from the nozzle (5) when the nozzle is prevented from continuing its movement in the same direction as the vehicle (2).