A lock

摘要

A lock ( 1 ) comprises an electronics module ( 6 ) which in response to receiving an authorisation signal from an electronic key ( 8 ) causes movement of handles ( 4 a; 4 b) to release a bolt ( 19 ) within aperture ( 3 ). Electronic module ( 6 ) is replaceable and is retained in place by a latch ( 16 ) that may be released by actuation of a mechanical lock ( 11 ).