Abstract: A mixing apparatus having a rotatable drum with a horizontal axis of rotation and an input and a discharge end. The drum supports a number of first mixing wings which upon rotation of the drum in the mixing direction convey the material to be mixed towards the input end and upon rotation in the opposite direction towards the discharge end. There are also a number of second mixing wings having a V-shaped cross-section forming a chute-shaped first side directed towards the discharge end and a roof-like second side. The second mixing wings are attached to the first wings in such a position that the chute-shaped first sides are below the first wings to carry material falling off the first wings towards the input end when the drum rotates in the mixing direction, and so that the roof-like second sides are below the first wings as a consequence of the rotation of the drum in the discharge direction so that the material falling down on the second sides leaves the second wings sideways.

Abstract: A mixer for mxing concrete and comprising an annular mixing tub. A rotor is situated at the center of the mixing tub above the same. The rotor is rotatable by means of driving means and carrying agitating means including a number of agitators. They extend down in the mixing space of the mixing tub and are provided with means for feeding of liquid to the mixture. The rotor has the shape of a preferably circular case with its outer border extending substantially to the inner border of the annular mixing tub and including an inner space. The periphery of the case carries a number of tubular arms each extending substantially in a radial direction and carrying said agitators with said inner space in the center of the case in connection with conduit means for the supply of liquid and by means of said respective tubular arms to the liquid feeding means of the agitators.