Inventor
HELM PERCY R
5 patents
Patents
5 patentsUS3977530AAug 31, 1976
Crane with gantry backhitch and boom hoist assembly removable as a unit
MANITOWOC CO35 citations92
US4601402AJul 22, 1986
Steerable concentric ring segment supported lift crane
MANITOWOC CO25 citations81
US4358021ANov 9, 1982
Separated ring segment dual pivot lift crane
MANITOWOC CO26 citations81
US4316548AFeb 23, 1982
Concentric ring segment supported lift crane
MANITOWOC CO23 citations81
US4449635AMay 22, 1984
Imaginary pivot lift crane
MANITOWOC CO16 citations72