Mixer with a fixed drum

A mixer for mixing wet or dry mix constituents to mix concrete silica sand and the like comprising, a fixed drum, an upstanding central pipe mounted fixed defining a central opening at the top of said drum for introducing mix constituents into the interior of the drum, a ring gear disposed supported externally of the drum coaxial with the central pipe for rotation about the pipe and relative to the drum, a motor drive coactive with the teeth of said ring gear for driving it rotationally, a mixing arrangement interiorly of said drum having a depending shaft rotationally supported on the ring gear for rotation therewith, a fixed gear mounted externally of said drum coaxial with and on said pipe, a driven pinion gear on said shaft meshing with said fixed gear for driving said depending shaft rotationally about its axis as said gear transports the mixing arrangement in a circular path in said drum and relative to said fixed gear, and the motor drive having a drive motor, a speed reducer driven thereby, and a drive pinion gear driven by the speed reducer for rotationally driving the ring gear, whereby the mixing arrangement is transported along said circular path and simultaneously driven rotationally by the motor drive.