Inventor
LUDWIG RICHARD H
US6 patents
Patents
6 patentsUS4785914ANov 22, 1988
Elevator system leveling safeguard control and method
WESTINGHOUSE ELECTRIC CORP55 citations93
US4436185AMar 13, 1984
Elevator system
WESTINGHOUSE ELECTRIC CORP14 citations71
US4648488AMar 10, 1987
Elevator system
WESTINGHOUSE ELECTRIC CORP3 citations61
US4463833AAug 7, 1984
Elevator system
WESTINGHOUSE ELECTRIC CORP6 citations60
US4317506AMar 2, 1982
Elevator system
WESTINGHOUSE ELECTRIC CORP5 citations60
US4638889AJan 27, 1987
Elevator system
WESTINGHOUSE ELECTRIC CORP6 citations57