Patent ID: 7329065

Claim:
A system for a mixing assembly comprising: a housing; an impeller shaft extending into the housing; a first coupling half mounted to an end of the impeller shaft and having a disc shape with a top substantially flat surface and a bottom substantially flat surface; a powered drive system having an output shaft extending therefrom; a second coupling half mounted to the output shaft; and an orifice in the housing having an orifice diameter, wherein the orifice diameter is greater than the diameter of the second coupling half and smaller than the diameter of the first coupling half, wherein the first coupling half has a plurality of first locking pins extending upwardly from the disc top surface and disposed around a first distance from the center of the first coupling half, and a second set of drive pins extending upwardly from the disc top surface and disposed at a second distance from the center of the first coupling half, wherein the housing further comprises a ledge around the periphery of the orifice, said ledge having a plurality of passageways that can receive the first locking pins, and wherein the second coupling half has a plurality of holes that can receive the second drive pins, and wherein the assembly can be arranged in a first operative position at which the first and second coupling halves mate with each other via engagement of the second drive pins with the holes and wherein the disc top surface and the first locking pins are spaced below the ledge and the disc top surface and the first locking pins do not contact the ledge, and a second inoperative position at which the second coupling half is detached from the first coupling half and the first coupling half is supported in the housing by the ledge via engagement of the first locking pins with the passageways of the ledge, wherein in both the first operative and the second inoperative positions, the disc shaped first coupling half is arranged below the ledge.