US Patent 8142068 Mixing apparatus

The invention provides mixing apparatus which has a container base and a container lid with the lid carrying mixing means extending through the lid with at one end a mixing element and at the other end a drive connection to a drive motor. When the drive is operated the mixing element mixes the contents of the container, usually when the container inverted. The lid has a rim portion with a circumferential slot and the top edge of the container is located into the slot when the lid is assembled with the container whereby to improve connection between the lid and the container during mixing. The lid within the rim portion carries the mixing means and, during mixing, the assembly is held to lock the assembly together.