Patent ID: 6843633

Claim:
A particulate material conveying apparatus comprising: an upper segment including an outer impermeable conduit and an inner, permeable conduit spaced from said outer, impermeable conduit to provide an annular plenum therebetween; a first intermediate segment connected to said upper segment for swivel movement relative thereto about a first axis, including an outer, impermeable conduit and an inner, permeable conduit spaced from said outer conduit to provide an annular plenum therebetween, said inner, impermeable conduit communicating with said inner, permeable conduit of said upper segment; a second intermediate segment connected to said first intermediate segment for swivel movement relative thereto about a second axis parallel to said first axis, including an outer impermeable conduit and an inner, permeable conduit providing an annular plenum therebetween, said inner, permeable conduit communicating with said inner permeable conduit of said first intermediate segment; a lower segment connected to said second intermediate segment for swivel movement relative thereto about a third axis, including an outer impermeable conduit and an inner, permeable conduit spaced from said outer conduit providing an annular plenum therebetween, said inner, permeable conduit communicating with said inner, permeable conduit of said second intermediate segment; means for translating the angular displacement of said second intermediate segment relative to said first intermediate segment about said second axis to the angular displacement of said first intermediate segment relative to said upper segment about said first axis under displacement of said lower conduit along a line of travel thereby maintaining said displacement of said lower conduit along said line of travel; and means for supplying air under pressure to at least one of said plenums.