| 摘要 |
887,333. Valves. VAILLANT, H., [trading as VAILLANT KOMM.-GES., JOH.]. June 6, 1958 [Aug. 23, 1957], No. 18088/58. Class 135. In a water deficiency safety device for gas water heaters in which the gas valve is operated by e.g. a diaphragm one side of which is connected to a stagnation point, e.g. a Venturi in the water supply channel, a slow ignition valve is built in the connection, this valve adjusting the cross-section of the connection automatically by an adjusting element acted upon by the water supply pressure against a spring. The lifting of the diaphragm to operate the gas valve is retarded by the water above the diaphragm being forced into the left-hand passage 9 and moving a check valve 24 in the form of a washer on to its seat 16<SP>1</SP>. Supply pressure at 18 acting behind piston 14 moves a needle 15<SP>1</SP> into the seat orifice 22 and washer orifice 25 to further restrict the flow of water through passage 9 whereby the opening of the gas valve is retarded. On closing the water outflow valve, flow through the Venturi ceases and the diaphragm moves down to close the gas valve, the downward movement occurring quickly as the needle valve is retracted by its spring 20 and the washer is moved to the left against a stopper and needle valve guide 23 to fully open the seat orifice 22. In a second embodiment the lower passage 9 is connected to the space above the diaphragm, the washer is dispensed with and the needle becomes a blunt plug valve. |
