Powder spray gun for spraying different color powders from a powder channel of a spray gun

Claim 1

A powder spray gun arrangement for spraying different color powders comprising a spray gun including a spray gun body member having a powder dispensing channel for spraying different color powders, a connection mechanism having a number of connections, infeed conduits for different powder-conveying air-mixtures and flushing air connectable with said connection mechanism and through the agency of which there can be delivered through the spray gunpowder dispensing channel for spraying purposes a given selected powder-conveying air-mixture and for cleaning of the spray gun flushing air, said connection mechanism comprising a connection element carrying said connections, said connection element being provided with a respective substantially continuous straight connection channel for each connection, each said connection channel having an outlet opening and said powder dispensing channel having an inlet opening, means for mounting said connection element and said spray gun body member having said powder channel so as to be displaceable relative to one another such that said connection channels of the connection element can be selectively connected by means of their outlet openings with the inlet opening of the powder channel in a certain sequence, and with a predetermined distribution of the feed conduits for the powder-conveying air-mixture and the flushing air at the connections of the element the powder dispEnsing channel is flushed with flushing air during each color-changeover operation, said connection element and said gun body member possessing oppositely situated surfaces at which respectively open said connection channels and said powder channel, said outlet openings of all said connection channels being arranged in a row at the surface of said connection element with a center point located along a line, said connection element and said gun body member being able to be moved relative to one another along said line for adjusting said outlet openings with respect to said inlet opening of said powder channel, and wherein when any one of said outlet openings is adjusted with respect to said inlet opening so as to be in flow communication therewith said gun body member covers by means of its surface said outlet openings of all the remaining connection channels, said inlet opening of said powder dispensing channel being surrounded by a sealing ring by means of which that connection channel which is located in an operable position can be sealed at the region of its outlet opening, said connection element and said gun body member being arranged such that a gap is present between said connection element and said gun body member, leakage air entering from said connection channels into said gap and said gap being continuously flushed by such leakage air.