Patent ID: 11885293
Assignee: LM WIND POWER A/S
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 3:
4. An extendable wind turbine blade, comprising:
a root end and a tip end, the wind turbine blade extendable along a longitudinal axis running between the root end and the tip end;
an exterior surface with a root region and an airfoil region;
a leading edge and a trailing edge, and a chord line extending between the leading edge and trailing edge;
a first blade segment including a first portion of the exterior surface and a first end;
a second blade segment including a second portion of the exterior surface and a second end, the second blade segment being separate from the first blade segment, the first end and the second end being opposite and facing each other;
a connection device engaged between the first blade segment and the second blade segment, the connection device having a first length when the second blade segment is in a retracted state when the wind turbine blade operates above a threshold;
the connection device having a second length when the second blade segment is in an extended state when the wind turbine blade operates below the threshold;
wherein, in the retracted state, the wind turbine blade has a first length from the root end to tip end and the first portion of the exterior surface is arranged flush with and adjoining the second portion of the exterior surface;
wherein, in the extended state, the wind turbine blade has a second length from the root end to tip end and the second blade segment is arranged with a gap to the first blade segment so that the first portion of the exterior surface and the second portion of the exterior surface are disconnected;
wherein the second length is greater than the first length; and
wherein the connection device comprise a biasing element configured to apply a biasing force that urges the second blade segment away from the first blade segment so that the wind turbine blade is biased towards the extended state.