A lift’s Otis 6850BJ floor selector, 24 Sep 2011, a fascinating contraption! The ring with switches ran vertically up or down depending on the lift’s direction – the selector was mechanically connected by metal tape to the lift car itself. The shaft with the copper blades rotated at the same time and when the ring of switches became in contact with the blades, they slowed the lift down one by one, with the last switch stopping the lift completely. This contact only occurred if there was a call for that floor on the relays in front of the selector. 24 Sep 2011.