GB454342A - Improvements in and relating to mercury switches - Google Patents

Abstract

454,342. Mercury and other conducting-liquid switches. BRITISH THOMSONHOUSTON CO., Ltd., Crown House, Aldwych, London. Dec. 20, 1935, No. 35371. Convention date, Dec. 28, 1934. [Class 38 (v)] A tiltable or rotatable conducting-liquid switch comprises two dished metallic members 1, 2 sealed together by a fillet 8 of thermo-plastic material such as glass to form an enclosure containing mercury or other liquid 5 adapted in one position of the switch to form a conducting bridge between the members 1, 2. In the form shown in Fig. 6, there is in addition a refractory member 3 through a hole 4 in which the mercury passes in the above position. When the switch is rotated about an axis a, b the mercury is split up into two portions separated by the diaphragm 3. In a modification, Figs. 3 and 4 (not shown), the members 1, 2 are separated solely by an annular member of glass and the vessel is tilted about a different axis. Fig. 1 shows a method of mounting the switch, conducting clips 37 gripping the members 1, 2, serving to lead the current to them and forming pivots for the rotation of the switch by a handle 42. Examples are given of metals, alloys and thermo-plastic materials specially suitable for the switch and of a method for manufacturing it, involving the application of suction to the enclosure while the glass fillet is in a plastic state and the introduction of the mercury and of a gas such as hydrogen through a hole 25. Instead of mercury, gallium may be used.