Patent ID: 8959771
Filing Date: 2015-02-24
Classification: B21D,F24H,Y10T

Abstract:
1. A method of manufacturing a generally rectangular shell from sheet metal for a room air conditioner/heat pump comprising the following steps: stamping a first sheet metal blank to form a predetermined shaped shell with holes and louvers therein; stamping a second sheet metal blank to form a predetermined shaped shell brace; first forming flanges on outer edges of said shell; second forming of said shell into a U-shaped rectangle with said outer edge overlapping at corners of said U-shaped rectangle; painting said shell and said angle brace after said stamping step, but before the next step of inserting; inserting said shell and said shell brace into an assembly machine wherein (a) said shell brace is secured across an open end of said U-shaped rectangle and (b) corners are punched through (1) said overlapping outer edges and (2) said flanges and said shell brace; during said punching, a conical shaped punch on an end of a cylinder moves inward towards a die at each corner of said open end of said U-shaped rectangle so that an outermost layer of said flanges are punched at said each corner to form outer punched holes having a diameter approximately equal to said cylinder, but an innermost layer of said flange or shell brace is punched to form a conical shaped hole aligned with said outer punched hole; inserting screws through said outer punched holes for threaded connection with said conical shaped holes, but not with said outer punched holes, to draw said innermost layer against said outermost layer, said screws providing lateral strength to said generally rectangular shell.