US Patent 10926032 Audible indicator

The disclosure relates to an audible indicator for use with a drug delivery device comprising a bistable resilient force member capable of residing in two states. In a biased state, the resilient force member is biased and stores energy In a relaxed state, the resilient force member is relaxed. The resilient force member releases the stored energy when transitioning from the biased state into the relaxed state, thereby generating an audible signal.