Exhaust systems for removal of fumes

Claim 1

An exhaust system for removal of fumes, gases, vapors and other contaminants produced in workshops by machines movable in such premises, and at working stations therein, comprising an exhaust system including exhaust fans, ducts, pipes and hoses leading to the sources of contaminant, at least one duct portion being fixedly mounted in said premises and at least one duct portion being movable together with a source of contaminant; a tapping unit associated with each duct portion and adapted to establish communication between said fixed duct portion and said movable duct portion through at least one opening disposed in and extending along said fixed duct portion elastic strips provided along said opening for normally keeping it closed, said tapping unit being capable of moving said strips apart to establish communication between said fixed and said movable duct portions, wherein at least one of said fixed duct portions which presents an opening is disposed along an overhead track suitably suspended in said premises and trolleys supporting said tapping units and the associated movable duct, connectable to the source of contaminant and adapted to run along said overhead track: closure means mounted at the end of said strips which are movable aside, said closure means in nonactuated position being adapted to axially close the space defined by said strips and the peripheral duct surface surrounding said opening, and wherein said tapping unit tapers towards its ends and has outwardly inclined clipper bow or plough-shaped end portions, said end portions being adapted when said tapping unit is moved towards and past the strip ends to move aside said closure means inwardly or outwardly respectively and to adjust the strip ends and said tapping unit for alignment with regard to each other.