Apparatus and method for shaping a cylindrical metal tubular component

Claim 1

A shaping device for shaping an end portion of a cylindrical tube made of sheet metal, said device comprising: a generally tubular guide block and an elongate hollow die member disposed in abutting and aligned relationship, said guide block constituting the feed end and the end of the die member opposite to the guide block the finishing end of the device, said guide block and said die member defining therein contiguous from the feed end toward the finishing end of the device a first guide portion having an inner diameter fitting the outer diameter of a tube to be shaped, a cylindrical guide portion also having an inner diameter fitting the outer diameter of the tube, a frustoconical first shaping portion tapered toward said finishing end, said shaping portion having at its wide end an inner diameter equal to the inner diameter of the second guide portion, and a cylindrical second shaping portion having an inner diameter equal to the inner diameter of the first shaping portion at the narrow end thereof, Cooling means jacketing said guide block for cooling a tube portion therein, and heating means jacketing the second guide portion, the first shaping portion and the second shaping portion for heating said second guide portion and the shaping portions to a temperature causing softening of a tube portion therein whereby upon forcing the tube to be shaped into the device from the feed end thereof toward the finishing end the tube end portion when successively entering the first shaping portion and then the second shaping portion is deformed to obtain a frustoconical configuration and a cylindrical configuration of reduced diameter respectively, and the wall thickness of the tube wall at the deformed end portion of the tube is increased so as to compensate for the decrease of the peripheral outline of the tube at the deformed end portion thereof.