| 摘要 |
A valve (1) for supplying fuel gas to a gas appliance comprises a valve housing (2) having a valve chamber (3) extending therethrough. Fuel gas is supplied through an inlet port (5) to the valve chamber (3) and from main and secondary outlet ports (6,7) to a burner and a pilot light jet, respectively, of the gas appliance. A primary valving member (35) and a secondary valving member (36) co-operate with a primary valve seat (15) and a secondary valve seat (20), respectively, for isolating the main and secondary outlet ports (6,7) from the inlet port (5). A main carrier member (30) carries the primary valving member (35) and is magnetically coupled to a first secondary carrier member (31) which is driven by a stepper motor (38). A second secondary carrier member (32) is magnetically coupled to the main carrier member (30) for carrying the secondary valving member (36). Electromagnetic coils (60,61) magnetically couple the first and second secondary carrier members (31,32) to the main carrier (30) so that the drive motor (38) can operate the main carrier (30) and in turn the primary and secondary valving members (35,36) for opening and closing primary and secondary communicating passageways (19,25) through the primary and secondary valve seats (15,20). Isolating the coils (60,61) from a power supply causes the first and second carrier members (31,32) to be decoupled from the main carrier (30), and first compression springs (65,66) urge the primary valving member (35) into engagement with the primary valve seat (15) while a second compression spring (80) urges the secondary valving member (36) into engagement with the secondary valve seat (20) the outlet ports (6,7) from the inlet port (5). |
