1.  FIELD OF THE INVENTION
The invention herein pertains to an extra capacity steam iron with its surge boiler in the rear of the iron formed of a walled enclosure with a pyramid-shaped upstanding boss in the enclosure formed to provide a good heat sink and water spreader throughout the enclosure for efficient heat transfer to steam. 
2.  DESCRIPTION OF THE PRIOR ART
Irons having provisions for extra capacity steam on demand are well known.  Generally, such irons employ spaced generators with the main generator for the customary steam and a separate spaced generator which, on demand, may receive a separate charge of water to create a quick volume of steam for touch-up or difficult creases.  In some, the main flow and surge flow come together to pass through a tortuous or conversion passage together and thence to the soleplate ports as in U.S. Pat.  No.  3,599,357; some use a consecutive flow pattern as in U.S. Pat.  No.  3,711,972; some provide confluent flows as in U.S. Pat.  No.  3,828,452, and some use completely separated flows as in U.S. Pat.  No.  3,919,793, of common assignment.  All of these prior arrangements have the surge generator substantially centrally of or forward in the iron because all are designed for the normal conventional size larger household irons.  Recent developments have produced lightweight, smaller, plastic irons, at a lower price while retaining many of the standard features for dry, steam, and surge operations and these smaller irons have presented problems in applying the usual structure to obtain saisfactory results.  A typical iron of this general type is shown in U.S. Pat.  No.  3,986,282 of common assignment.  This iron uses a rear surge generator and has required a revision in design from the usual larger irons simply because there is not enough room in this small lightweight iron for the usual arrangement of parts to supply the various features.  Thus, the main object of the invention is to provide an iron structure for an extra capacity steam iron having a completely different formation of surge generator in order to provide the water spreading characteristics and heat transfer necessary for adequate surge capacity.