Mixing device

A mixing device comprising, in combination:

• a vessel having a bottom, a side wall defining a vessel axis and a top, all defining a closed space of circular cross section for receiving material to be mixed, said top having a central opening therein;
• a mixing shaft projecting through said opening into said closed space at an inclination to said vessel axis to present an inner end within said vessel reaching to adjacent said bottom and an outer end outside said vessel;
• flexible sealing means joining a section of said shaft between its ends to said cover whereby hermetically to isolate said space and establish a pivot substantially on said vessel axis;
• blade means on the inner end of said shaft and including portions radially offset therefrom;
• and
• drive means connected to said outer end of the shaft for orbiting said outer end without causing rotation of said shaft whereby said inner end of the shaft sweeps a conical path within said vessel, said portions of the blade means being radially offset from said conical path sufficiently to reach into close proximity with said side wall of the vessel, said drive means comprising a drive shaft aligned with said vessel axis, an arm fixed to said drive shaft and bearing means rotatably connecting said outer end of the mixer shaft to said arm in offset relation to said drive shaft, said blade means being fixed to said inner end of the mixer shaft and including means engaging said outer end of the mixer shaft preventing rotation thereof, the means last mentioned comprising a bracket pivoted about an axis normal to said vessel axis and having a slot extending in the direction of the bracket axis, said outer end of the mixer shaft being non-rotatably guided in said slot.