Patent GB-638019-A (GB)
Title: Improvements in and relating to steam irons
IPC: D06F75/18
Filed: 1947-06-02
Abstract: 638,019. Steam irons. BRITISH THOMSONHOUSTON CO., Ltd. June 2, 1947, No. 14568. Convention date, April 4, 1946. [Class 138 (ii)] In a steam iron comprising a soleplate, a flash steam generating chamber, heating means and a water reservoir, the water supply to the generating chamber is controlled by a rearwardly spaced valve which is connected to the nose of the reservoir by an open-ended tube, so that when the iron is up-ended into its rest position the open end of the tube is above the water level and the generation of steam is stopped. As shown, water contained in a reservoir 11 of a steam iron is discharged through a tube 24 and regulating valve 19 into a steam generating chamber 30 located in the soleplate 10. The tube, which lies along the base of the reservoir, has its open end 40 adjacent to the nose of the iron, and may consist of a separate tube, or alternatively, a covered depression in the base as in Fig. 4 (not shown). The regulating valve and steam generating chamber, which are not in vertical alignment, are connected by a tube 29 supported in a layer of thermal insulating material B. The steam generating chamber may be connected by a passage 33 and a distributing space 36 to discharge openings 34, or alternatively, to discharge openings 31. In either case the generating chamber is connected by a pressure equalizing vent pipe 37 to a dome 38 at the top of the reservoir. The regulating valve comprises a screwed adjusting stem 19 with a conical end 20 reciprocating in a tapered bore 21 connecting the upper and lower tubes 24, 29. An electric heating element 48 in the soleplate has its terminals in a compartment 44 at the rear of the iron, the temperature being controlled by a thermostat 15. In use the reservoir is filled with water by removing a plug C. When completely filled the water level is below the opening 39 of the vent pipe. Water discharges to the regulating valve and steam generating chamber through the opening 40 at the front of the iron. When, however, the iron is up-ended on its heel with the soleplate substantially vertical, the water level with the reservoir completely filled will be along the line A-A, the increase in water volume in the dome leaving a small air cavity at the nose of the reservoir. Both the vent pipe opening 39 and the discharge tube opening 40 will be above the water level and steam generation will cease. The drainage tubes 24, 29 are arranged with similar volumetric capacities so that the water remaining in tube 24 will run into tube 29 until both levels are the same. When the iron is replaced in its ironing position the water in the lower tube 29 will give increased steam for commencing ironing and also act as a reserve until circulation of water from the reservoir commences. The spacing of the steam generator from the regulating valve with the connecting tube supported in a heat insulating material is intended to reduce the temperature at the valve and so reduce precipitation of mineral salts from the water at this point. To facilitate cleaning the steam chamber may be made in the form of a removable plug threaded in the base-plate. The adjustments of the thermostat and regulating valve may be co-related. Specification 597,209 is referred to.