The real problem, the one of most vital importance from the point of efficiency, was that of the heating element that would do more than heat the center of the sole plate. One of the pioneer manufacturers, after numerous experiments, concluded that, since the point or nose of an iron comes first in contact with the damp goods, naturally it should have first and most heat applied to it. The result was a double heating element in the form of a V, the resistance wire used being symmetrically wound on a flat, thin mica core. This V-shaped element, the point of the V coming up into the nose of the iron, insured a hot point, as well as hot sides, center, back and heel, where the terminals were connected with the switch plug receptacle. Another development which followed was that of an attached stand, eliminating the necessity of lifting the iron on and off a stand many times during the ironing. At first the iron was heavy and clumsy, being built of cast iron, but modern manufacture has made it possible to build the sole plate of cast iron and the top of pressed steel.
Fig. 1.—Pouring Molten Metal into Molds for Casting Iron Sole Plates
Fig. 2.—Workman Polishing Sole Plates
The illustrations show some of the steps necessary before the iron reaches the shipping room. [Fig. 1] shows the workman pouring an earthen ladle of molten metal into the molds in which the sole plates are cast. [Fig. 2] shows the sole plate in the hands of the workman, held against a rapidly revolving polishing wheel, after it has been run through a milling machine and ground to a perfect size. [Fig. 3] shows a huge punch press which cuts the blank of steel that is afterwards drawn to the shape of the iron top. The workman is seen holding in his hand the blank cut from a sheet of steel ([Fig. 4]). The blanks of flat steel of such irregular shape are next passed to a mammoth draw press which draws blanks into the perfect shape to be fitted over the top of the pressure plate which holds the heating element firmly against the sole plate. At the operator’s left hand is a stack of blanks and in his left hand he holds one ready to be placed in the draw press. In his right hand is a top just pulled from the press, and at the extreme right a large truck full of finished tops ready for the polishing wheels.
