| 摘要 |
<p>1,213,895. Valves. JOH VAILLANT K.G. 18 Sept., 1968 [25 Nov., 1967], No. 44354/68. Heading F2V. [Also in Division F4] A rotary gas switch, in particular for water heaters, is characterized in that a rotary handle 9 is provided with a disc cam 10 and is also provided with a control cam 14, the disc cam cooperating with an inclined surface 13 to displace a cam support 6 sufficiently for the opening of an ignition valve 2. The ignition valve 2 is coaxial with a main gas valve 3 and they are lifted in succession by a shank 4. The shank 4 terminates in the cam support 6. In operation the handle 9 is turned to an " ignition " position (Fig. 4). If the pilot ignition ignites, a current through a thermocouple causes the depression of a spindle 19 and allows a projection 15 on the control cam 6 to be locked by a three-armed bolt lever 16. This result is necessary prior to opening the main valve 3, since the control cam 6 is locked whilst the handle 9 is turned back towards the" off ''position to a " main " position, the cam 14 axially forcing the control cam to open the main valve 3. A spring 8 counteracts the rotation as well as the axial displacement of the control cam 6. If the projection 15 does not lock because the pilot has failed to ignite, the control cam simply returns to the " off" position. In an embodiment a thermal sensing element is connected to an expansion vessel (25) which causes the projection (15) to be released when the desired temperature is reached.</p> |
