# US 7,743,480 B2 · Method of manufacturing a drum-type washing machine

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- Number: US 7,743,480 B2
- Document ID: US7743480B2
- Status: Granted
- Kind: B2
- Application number: 12/289,335
- Filed: 2008-10-24
- Published: 2009-03-12
- Granted: 2010-06-29
- Earliest claimed: 2003-07-08
- Assignees: LG Electronics Inc.
- Inventors: Sam Je Park; Kwang Soo Kim
- Web page: https://patentgrep.com/patent/US7743480B2

## CPC

- D06F 37/263: {assembled from at least two elements connected to each other; Connecting or sealing means therefor}
- D06F 37/264: {Tubs provided with reinforcing structures, e.g. ribs, inserts, braces}
- D06F 37/269: {for the bearing of the rotary receptacle}
- Y10T 29/49: Method of mechanical manufacture
- Y10T 29/49908: Joining by deforming
- Y10T 29/49915: Overedge assembling of seated part
- Y10T 29/49968: Metal fusion joining
- Y10T 403/4966: Deformation occurs simultaneously with assembly
- D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

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.

## Claims

### Claim 1

A manufacturing method of a drum-type washing machine, comprising the steps of:
forming a center tub formed in a cylindrical form;
forming beads, formed in a bend form, on an outer circumferential surface of the center tub by compressing with a roller in a state that a press is installed on an inside thereof;
forming a back tub including a first bending part formed by a curl manufacturing on an outline of a base plate formed in a circular form;
inserting the back tub to overlap a rear inner circumferential surface of the center tub with the first bending part;
seam welding the center tub with a side of the first bending part; and
forming a second bending part for covering an end of the center tub by curling the first bending part.

### Claim 2 (depends on 1)

The drum-type washing machine as claimed in claim 1, wherein the center tub formed in the cylindrical form is formed by rolling a metal sheet into a cylindrical form, and carrying out a butt welding to a seam.

### Claim 3 (depends on 1)

The drum-type washing machine as claimed in claim 1, further comprising the step of forming a pass through hole simultaneously passing through the bending parts of the back tub and a rear end of the center tub, and fixing a bearing housing to a rear of the back tub by coupling a bolt to a bridge through the pass through hole.