US Patent 7905469 Gaseous fuel mixing device

A gaseous fuel mixing device includes a body having an air/fuel passageway and a gaseous fuel passageway in fluid communication with the air/fuel passageway, a throttle valve pivotably coupled to the body and positioned in the air/fuel passageway, and an intake unit coupled to the body. The intake unit includes an inlet configured to be fluidly connected with a source of gaseous fuel, a first jet fluidly communicating the inlet and the gaseous fuel passageway, a second jet selectively fluidly communicating the inlet and the gaseous fuel passageway, and a selector valve operable to control a flow of gaseous fuel through the second jet.