GB191400313A - Improvements in or relating to Electric Switches. - Google Patents

Abstract

313. Wade, H., [Kaisser, C.]. Jan. 5. Mercury switches. - In a switch comprising a mercury container pivoted on an horizontal axis and divided into two or more compartments in communication through openings 9 of variable cross-section, the compartments communicate with one another bv means of tubes 25 adapted to lead the mercury to the opposite ends of the compartment into which each tube penetrates, the flow of the mercury from the end towards the centre of the compartment closing successively a number of external circuits by means of contacts in the container. In the motor controller shown in Fig. 1, one side of the movable container is formed by glass tubes connected to one another by metal rings 2, which form the contacts and are connected to the resistances 17. The container is moved in one or the other direction for starting or stopping the motor by means of electro-magnets 13, 14, the circuits of which are controlled by push-buttons 22, 26. The sparking takes place outside the container in a mercury cup 20, the mercury in which is preferably covered with a layer of oil. The right-hand compartment 24 of the container may be provided with two metal rings connected in series with the electromagnet 13 in order to prevent a re-starting of the motor before the mercury has returned into the compartment 24. A modification adapted for flash advertisements is shown in Fig. 4, in which tubes 45, 46 convey the mercury to the ends of the two compartments, contacts connected to the lamp circuits being placed on both sides of the container. The apparatus is rocked continuously by the electro-magnets 13, 14, as long as the main switch A remains closed. In a further modification adapted for lighting a lamp for a predetermined period, the contacts are placed in one compartment, the outlet tube from which is of larger diameter than the inlet tube. On completing the circuit of one of the actuating electro-magnets by means of a push-button, mercury flows into the compartment containing the contacts and completes the lamp circuit, which remains closed until sufficient mercury has passed to complete the circuit of the restoring electro-magnet.