US Patent 7451626 Drum-type washing machine

Disclosed is a drum-type washing machine having a tub provided therein for storing wash water with an improved structure, the tub including a center tub formed in a hollow cylindrical form for rotatably providing a drum therein; and a back tub including a base plate for covering a rear side of the center tub, a first bending part bent backward from an outline of the base plate, and overlapped on an inner surface of the center tub, and a second bending part bent frontward from the first bending part, and overlapped on an outer circumferential surface of the center tub.