| 摘要 |
<p>517,730. Mercury switches. BURGESS, A. F. (Adlake Co.). July 1, 1938, No. 19517. [Class 38 (v)] Inside a glass envelope 10 holding mercury 15 is disposed a displacer 16 of glass or quartz carrying a ferro-magnetic armature 17 fixed to it by springs 19 which also act as buffers and which has guide projections 22. The switch is held between poles 23, 24 of an electromagnet which when energized, pulls down the displacer 16 to cause the mercury to bridge contacts 11, 12 made of tungsten, molybdenum or tantalum. To prevent the deleterious effects of current carrying iron on the mercury, the armature 17 and any other parts of ferromagnetic material within the switch are coated with an oxide of iron by being heated in a stream of oxygen or by the Bower- Barff or Russia oxidising processes.</p> |
