Basically just slows and stops lift in a controlled manner during an emergency or power cut etc. Avoids the passengers being subjected to the discomfort of a conventional sudden high speed stop.
I assume this is what they are referring to although there is a chance they are speaking about a braking device which prevents uncontrolled upward movement of which there are several different types.
If we are talking about a true emergency brake as mentioned above, than...
Read ASME A.17 section 2.19.1 Emergency brake does many things, including ACO and UCM protection. It is a crucial component in maintaining the safe operation of a lift by todays standard.
