Stirring device

A stirring device comprising:

• a hub having a central aperture for mounting on a shaft and a plurality of pivot means circularly spaced in said hub radially outward from said aperture;
• a plurality of elongate vanes pivotally mounted to said hub around a circle to pivot from a folded idle position wherein said vanes extend parallel to the axis of said aperture, outward to working position radially outward from the axis;
• each of said vanes having a mounting hub portion connected to said hub by one of said pivot means, and a distal portion remote from said hub, with a major portion of each vane from the hub portion through the distal portion being skewed with respect to said hub portion to facilitate folding said vanes close to said axis without interference with said axis, and to propel axially a liquid when said vanes are in said working position and rotated in a plane normal to said axis;
• the major portion of each vane when folded having generally parallel inner and outer trailing and leading, respectively longitudinally extending edges;
• and the major portion of each vane, when folded, having an inner surface generally facing said axis and an outer surface generally facing away from said axis;
• the inner edge of each vane, when said vanes are folded, being immediately adjacent the inner surface of a vane next following it around the circle, and the inner region of the major portion having a longitudinally extanding slot opening toward the hub and defining an inwardly extending trailing edge cutting part.