This invention relates to a small-sized electric iron which is handy to carry while travelling and which has both a steaming function for smoothing clothes on hangers or a rack and a pressing function which is substantially the same as that performed by an ordinary steam iron.
In general, an instrument called a "steamer" has a function to smooth clothes on a hanger or a rack by jetting steam to the clothes from nozzle ports which are communicated with a water boiling chamber therein, as shown in U.S. Pat. No. 3,690,024. This instrument, however, has no pressing function because it is devoid of a hot pressing plate.
In order to obviate this shortcoming, U.S. Pat. No. 3,733,723 proposes an instrument which has a hot pressing plate, steam jetting ports provided in the hot pressing plate, a contractable water tank and a spring for contracting the water tank such as to forcibly supply the water to a steam generating chamber. This instrument can serve both as a steamer and a steam iron because it has means for supplying water to the steam generating chamber and the hot pressing plate for pressing clothes. This instrument, however, is not suited to a portable design because there is a practical limit in the reduction of the size, due to the use of a boosting type water supply system.
On the other hand, some proposals have been made for irons which employ a simple dripping type water supply system and which can jet the steam even when they are held vertically. Typical examples of such irons are shown in U.S. Pat. Nos. 2,908,092 and 3,986,282. Both of these irons have a water tank and nozzles for dripping water and are capable of jetting steam both when they are used in pressing clothes and when stationed vertically.
The iron proposed by U.S. Pat. No. 2,908,092, however, suffers from a disadvantage in that, since the water dripping nozzles are positioned ahead of the water tank, most of the water in the water tank cannot drip through the nozzles when the iron is used in a vertical position as a steamer. Thus, most of the water supplied to the water tank cannot be changed into steam and a frequent supply of water into the water tank is necessary. Also, when the water level has been reduced almost to a half of the full level, the water splashes up and down in the water tank during the use of the iron, resulting in a discontinuous dripping and, hence, in a steaming failure.
These problems are overcome by the iron disclosed in U.S. Pat. No. 3,986,282 in which the water dripping nozzles are disposed at the rear side of the water tank. In this case, however, the supply of water to the steam generating chamber is inevitably made at the rear portion of the base, i.e., at the rear side of the heater. In general, the rear portion of the base receives less heat than the front portion thereof because the front portion of the base is usually surrounded at its three sides by the heater which is bent in a U-like form. In order to generate the steam efficiently and stably, therefore, it is necessary to supply the rear portion of the base with a sufficient amount of heat to evaporate the water into steam. This in turn requires an increase in the capacity of the heater as a whole, as well as a longer time of supply of electric power to the heater. Consequently, the iron is heated excessively to a dangerous level and a large amount of electric power is wasted.
U.S. Pat. Nos. 2,761,228 and 2,786,287 disclose portable steam irons which have a handle swingably secured to a rear portion of the iron and a water tank detachably secured to the iron body. The portable iron proposed by U.S. Pat. No. 2,761,228, however, as a whole has a considerable size even when the handle is rotated downwardly because the water tank projects to a large extent. When this steam iron is carried by a traveller, therefore, the water tank must be separated from the main body of the iron. The dismounting and carrying of the water tank undesirably increases the total volume to be carried, and requires a specific casing for encasing the main body of the iron and the water tank. The same problem is encountered also by the portable iron proposed by U.S. Pat. No. 2,786,287. In addition, the portable iron of the U.S. Pat. No. 2,786,287 has no means for switching the operation between a steaming mode and a dry mode. Namely, this portable iron operates either in steaming mode or in dry mode, depending on whether the water tank contains water or the water tank is empty, and it is not possible to instantaneously stop and start steaming. In contrast, the portable iron of U.S. Pat. No. 2,786,287 is provided with a change-over device which is provided in the water tank, and is positioned remote from the handle. As a result, a user can not operate the change-over device using one hand while ironing.