I had them at Fredrick and Nelson (Now Nordstrom) in Seattle OTIS type A, see Unitec poster link below.
http://www.unitecparts.com/wp-content/uploads/2013/03/Unitec-Door-Operator-Poster3.jpgA type on the right (white one)
I had the door link to the hall door come off and had a report of the car flying by the lobby at full speed with the hall doors open. I ran over to find the car doing just that. The weight on the sill trip that opened the hall door was in the closed position (cam retracted), but because the link had detached from the hall door, controller saw it as safe and door closed.
It was a monster with cams, chains, oil checks and a mechanical brake.
