US Patent 11222758 Rotary handle construction of an electrical switch

The construction comprises a rotary handle with a first pivot axis, a locking latch with a second pivot axis, a fixed bottom ring, a locking pin movable with the locking latch between a first position in which the rotary handle can be turned in relation to the bottom ring and a second position in which the locking pin prevents turning of the rotary handle in relation to the bottom ring, a shaft adapter rotationally movable against a spring force in relation to the rotary handle. The shaft adapter comprises a protrusion having a locking member which locks the locking pin into the first position when the torsional moment acting on the rotary handle exceeds the spring force acting on the shaft adapter causing a limited rotational movement of the shaft adapter in relation to the rotary handle.