Abstract: A mixer (10) for entraining gaseous fuel into an airstream for induction into an internal combustion engine (12) having a turbocharger (13). The mixer has a housing (16) mounted to a conduit (14) between the turbocharger and the engine. The mixer also has a control ring (32) mounted to the housing that has an annular array of holes (39) through which gaseous fuel, from a supply of gaseous fuel coupled to the housing, is introduced into the airstream passing through the mixer and into the engine.

Abstract: An apparatus 10 for introducing a mixture of air and gaseous fuel into internal combustion engines has a housing 12, in communication with a supply of gaseous fuel, that is mounted to a tubular intake port 11 of the engine carburetor. The apparatus has a control tube 26 which adjustably extends into the housing 12 to positions close to but spaced from the housing to form a gap 50 therebetween. A honeycomb air flow restriction plate 33 is mounted in the control tube. By repositioning the control tube the size of the gap 50 may be altered to adjust the air to gas mixture ratio. During engine operation the restriction plate creates a pressure differential that serves to draw gaseous fuel form the housing about the control tube into the airstream passing through the control tube into the port.