Inventor
MARR PETER
DE7 patents
Patents
7 patentsUS4252476AFeb 24, 1981
Hydraulically operated mine prop with safety valve
BOCHUMER EISEN HEINTZMANN13 citations72
US4094153AJun 13, 1978
Breast roof support system for longwall mining
BOCHUMER EISEN HEINTZMANN13 citations72
US4008578AFeb 22, 1977
Pit prop assembly
BOCHUMER EISEN HEINTZMANN13 citations71
US4077670AMar 7, 1978
Method and apparatus for advancing and supporting an underground mine gallery
BOCHUMER EISEN HEINTZMANN14 citations69
US4094154AJun 13, 1978
Roof prop apparatus and method for longwall mining
BOCHUMER EISEN HEINTZMANN4 citations61
US4183700AJan 15, 1980
Walking mine support
BOCHUMER EISEN HEINTZMANN4 citations57
US4175891ANov 27, 1979
Auxiliary walking mine support
BOCHUMER EISEN HEINTZMANN0 citations47