DIFF Subgroup
F01B 9/023 Full Title
Reciprocating-piston machines or engines characterised by connections between pistons and main shafts, not specific to groups F01B1/00 - F01B7/00 > with crankshaft
F01B 9/023 Reciprocating-piston machines or engines characterised by connections between pistons and main shafts, not specific to groups F01B1/00 - F01B7/00 > with crankshaft