Gas injector in which one of a plurality of nozzles can be selectively driven for elevation

摘要

In a gas injector according to the invention, a forward section of the same is formed by a cylindrical portion which collectively contains and holds a plurality of nozzles and gas supply pipes and a nozzle guide portion which has an opening of a size to allow only one of the nozzles to protrude outwardly at an end thereof and which is formed like a taper extending from said cylindrical portion to said opening, and a rear section of the gas injector has a mechanism capable of selectively driving said plurality of nozzles for elevation through said gas supply pipes.