| 摘要 |
<p>A solenoid actuated bi-stable pilot valve comprises a rockable yoke (11) of magnetic material surrounded by a coil (13) to form an electromagnet. The yoke has rubber valve members (6, 10) at opposite ends which close respective valve orifices, alternately. Like-poled permanent magnets (12) interact with the yoke electromagnet poles to cause the yoke to rock from one position to the other to thereby control operation of a main fluid control valve in the form of a diaphragm valve. In another form (Fig. 3) two similar pilot valves control a main diaphragm valve whereby the main valve may be set to a fully open or closed position or any position therebetween such that the flow rate may be controlled. In order to achieve a greater force to close the pilot valves a polarized magnetic circuit as shown in Figure 3A incorporates a lever (38) to actuate the yoke attached perpendicularly to the yoke at its pivot point. A toilet cistern (20) incorporating main flow control valves with pilot valves according to the invention is also disclosed. The cistern operates electrically by low power replaceable batteries and is controlled by a microcontroller (32) and push button switches (34, 35) and has a low battery warning light and fault signal for cleaning inlet filters. Also disclosed is a float incorporating a magnet which, using the 'Hall Effect', sends electronic signals to the microprocessor for empty, half full and full conditions.</p> |
