| 摘要 |
<p>1275707 Valves ZENTRA ALBERT BURKLE KG 10 July 1970 [11 July 1969] 33674/70 Heading F2V [Also in Division G3] The position of a valve head 13 (Fig. 2) in a valve 10 for controlling the flow of heated water in a central heating system, is adjusted by increasing or decreasing the temperature and hence volume of an expansion fluid 25 (e.g. liquid or gas) to move a piston 16 fixed to the head. The fluid may be heated by an electrical resistance element 26 or alternatively may be heated or cooled by a Peltier effect device. A thermistor 28, connected in a bridge circuit controlling the element 26, is responsive to the temperature of the fluid and hence to the position of the valve head.</p> |
