STEAM IRON WITH INCREASED WATER HEAD
FIG2c shows a schematic side view of the embodiment shown in FIG2b having been moved into its operational orientation  FIG2d shows a schematic side view of the embodiment shown in FIG2c after some of the water has been turned into steam
Referring to FIG2c, with the water inlet 29 sealed closed, the garment steaming device 1 is moved back into its operational orientation A in which the steam generator 5 extends horizontally. Because the orifice 21 connected to the second fluid path inlet 8 is below the water level in the first water chamber 2, the air in the first water chamber 2 becomes trapped. The air in the first water chamber 2 is sealed under pressure by the hydraulic head achieved by the water in the second water chamber 3 being at a greater vertical height from the steam generator 5 than the water in the first water chamber 2. The larger the height of the water level in the second water chamber 3 from the first fluid path 6 the larger the hydraulic head. As shown in FIG2c, water may be in the vent pipe 10 when the garment steaming device 1 has just been filled and will contribute to the overall water head.  Referring now to FIG2d, as steaming continues water from the first water chamber 2 is directed through the first fluid path 6 and into the steam generator 5. The air in the first water chamber 2 remains sealed and under pressure caused by the hydraulic head achieved in the second water chamber 3. Therefore, the water that exits the first water chamber 2 into the steam generator 5 is replaced by water from the second water chamber 3. As steam is continually generated, the water level in the second water chamber 3 becomes lower which results in a lower hydraulic head and therefore, a slowing steam rate as the difference in pressure between the first fluid path 6 and the steam generator 5 decreases. As the water level in the second water chamber 3 becomes lower air enters via the vent pipe 10 at atmospheric pressure.
schematic side view
15
first end
5
steam generator
10
pipe
14
plate
['1. A steam iron (1) comprising: - a first water chamber (2); - a second water chamber (3) situated in a heel portion (4) of the steam iron (1); - a steam generator (5) situated below the first water chamber (2) in an operational orientation (A) of the steam iron (1); - a first fluid path (6) connecting the first water chamber (2) and the steam generator (5); and - a vent pipe (10) connected to a top part of the second water chamber (3) by its first end (11) and open to the atmosphere at its second end (12), the second end (12) of the vent pipe (10) extending at least as far as the maximum water level height of the first water chamber (2) when the steam iron (1) is in a non-operational orientation (B); -  characterized in that  a second fluid path (7) connects a bottom end of the first water chamber (2) to a lower part of the second water chamber (3) in the operational orientation (A), the cross-sectional diameter of the second fluid path (7) is in the range of 2 mm to 15 mm, and the second water chamber (3) is arranged wholly above the first water chamber (2) in the operational orientation (A), so that so long as there is water in the second water chamber (3) a water level height of the second water chamber (3) is higher than a water level height of the first water chamber (2) in said operational orientation (A), so that the water head in the first fluid path (6) generated by the fluid coupling the second water chamber (3) and the first water chamber (2) is increased to obtain an increased steam rate when the steam iron (1) is in the operational orientation (A).']