| 摘要 |
A device (10) is provided for controlling the mixture of a gas with air in response to a vacuum drawing the air into a venturi (20). Housing (12) has a bore (14) therein for conveying the gas to the venturi (20). A main valve (30) is disposed in the bore (14) for controlling the flow of gas from a pressurized source. Structure forms a third chamber (68) having a control diaphragm (70) which divides the third chamber (86). One side of the diaphragm (70) is connected to the source of the gas, and the other side is connected upstream of the venturi (20). Structure forms a second chamber (60) with an amplifier diaphragm (74) dividing the second chamber (60) which amplifies the variations in pressure. Structure includes a main diaphragm (86) in fluid communication with the second chamber (60) for actuating the main valve (30) in response to amplified variations in the gas pressure. |
