Two-chambered electric mercury switch - has mesh between two electrodes through which mercury passes under pressure

摘要

The electrical switch using mercury as a third contacting electrode connecting two static electrodes is intended for general electrical and communication use esp. telephone line connection matrices. The switch has two plate electrodes (4, 7) spaced apart by a split insulator (5, 6). This insulator traps a mesh (10), the apertures in this are sufficiently fine to prevent mercury from passing through it at normal pressures. An upper compartment (14) above the mesh also contains mercury, enclosed by a completely impermeable membrane (11). When a piston (12) presses this down the mercury makes contact through the mesh completing the circuit.