Foldable agitator

A foldable agitator comprising:

• a coupling body defining a central longitudinal axis;
• a plurality of impeller arms rotatably coupled to an outer peripheral portion of the coupling body;
• and
• a piston inserted in the coupling body, the piston being movable along the central longitudinal axis, the piston being configured to unfold or fold the plurality of impeller arms simultaneously in response to a movement of the piston along the central longitudinal axis,
• wherein the coupling body comprises a plurality of body coupler parts and a piston insertion part, the plurality of body coupler parts being arranged around the piston insertion part, each of the plurality of body coupler parts having each of the plurality of impeller arms coupled thereto, the piston insertion part having the piston movably inserted therein,
• wherein an insertion slot is defined between adjacent ones of the plurality of body coupler parts,
• wherein the piston comprises a pressing protrusion positioned to be movable within the insertion slot, and
• wherein a proximal end portion of each of the plurality of impeller arms is coupled to the outer peripheral portion of the coupling body at the insertion slot and is configured to be rotated within the insertion slot by linear movement, along the central longitudinal axis, of the pressing protrusion within the insertion slot.