Foldable agitator

1 . 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.

2 . The foldable agitator of claim 1 , further comprising:

a shaft coupled to the plurality of body coupler parts; and

an inner stem positioned to form a dual stem structure, the inner stem being rotatably coupled with the piston.

3 . The foldable agitator of claim 1 ,

wherein an inner stem is rotatably connected to the piston, and

wherein the inner stem is coupled to an upper portion and a lower portion of the piston to form a multi-level structure.

4 . The foldable agitator of claim 1 ,

wherein an impeller is coupled to each of the plurality of impeller arms, and

wherein width at a longitudinally central portion of the impeller is greater than a width of a proximal end portion of the impeller connecting with the coupling body.

5 . The foldable agitator of claim 1 ,

wherein the piston insertion part comprises a plurality of movement slots, each corresponding to a respective one of the plurality of impeller arms,

wherein the piston comprises heads and a plurality of insertion modules, each of the plurality of insertion modules being movably inserted in each of the plurality of movement slots, the heads being coupled to both ends of the plurality of insertion modules, and

wherein the pressing protrusion is positioned on one lateral surface of each of the plurality of insertion modules.

6 . The foldable agitator of claim 1 ,

wherein each of the plurality of body coupler parts comprises a coupling member, and

wherein each of the plurality of impeller arms comprises an arm pressing part and an arm coupling part, the arm pressing part being inserted in the insertion slot and rotatably coupled to the coupling member, the arm coupling part extending at a predetermined angle from one end of the arm pressing part to determine an unfolding angle of an impeller, the arm coupling part being coupled with the impeller.

7 . The foldable agitator of claim 1 ,

wherein each of the plurality of body coupler parts comprises an insertion member and a coupling member, the insertion member defining the piston insertion part, the coupling member being disposed on a lateral side of the insertion member and having a respective one of the plurality of impeller arms coupled thereto, and

wherein adjacent ones of the coupling members are separated by a gap, the gap being the insertion slot.

8 . The foldable agitator of claim 7 ,

wherein an upper support member and a lower support member are positioned on an outer side surface of the coupling body, and

wherein opposite end portions of each of the upper support member and the lower support member support the coupling members.

9 . The foldable agitator of claim 8 ,

wherein the upper support member comprises a first body support surface and a second body support surface,

wherein each of the plurality of impeller arms comprises a first arm support surface and a second arm support surface, the first arm support surface being configured to contact the first body support surface, the second arm support surface being configured to contact the second body support surface,

wherein the first arm support surface is configured to contact the first body support surface in a direction toward a center of the coupling body, and the second body support surface and the second arm support surface are configured to contact each other in a rotational direction of the foldable agitator.