| 摘要 |
<p>471,087. Mercury switches. BRITISH THOMSON-HOUSTON CO., Ltd. Oct. 29, 1936, No. 29459. Convention date, Oct. 29, 1935. [Class 38 (v)] In a rotatable mercury switch in which, in the closed position, mercury 5 passes through a hole 6 in an insulating partition 3 so as to connect two metal end caps 1, 2, the caps are provided over part at least of their internal surface with a coating of platinum. The platinum does not oxidize when the caps 1, 2 are fused to the thin fillet of glass 4 joining them, and it makes good contact with the mercury so that the switch has a minimum resistance. The platinum may consist of a thin coating on a piece of metal 8 welded to each of the caps or it may take the form of a coating on a pin welded to each cap, or it may be deposited from solution or by plating &c. The piece 8 is preferably arranged out of alignment with the opening 6 so that when the device is rotated to break the circuit, the piece remains submerged. The switch may be filled with hydrogen. Specifications 454,342 and 471,079 are referred to.</p> |
