US3849916A

US3849916A - Self-cleaning steam iron

Info

Publication number: US3849916A
Application number: US00305574A
Authority: US
Inventors: W Davidson; K Toft
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1972-11-10
Filing date: 1972-11-10
Publication date: 1974-11-26
Anticipated expiration: 1991-11-26
Also published as: NL7314984A; IT999106B; GB1445166A; JPS5620039B2; FR2206403B1; AU6190173A; DE2356062C3; AU473627B2; DE2356062B2; DE2356062A1; FR2206403A1; JPS49133696A

Abstract

The invention is directed to a self-cleaning steam iron with means to purge the iron through soleplate ports by a substantially large water tank opening separate and distinct from the usual water valve. Other valve means permits the water in the tank to be suddenly emptied onto a hot soleplate so additional steam is created and flushes out the iron. An improved means is provided to avoid expelling water out the soleplate ports by providing a high steam takeoff through a continuously open conduit. The conduit also acts as a pressure control valve and is designed to repel loose foreign particles.

Description

Unite States Patent Davidson et al.

[ SELF-CLEANING STEAM IRON [75] Inventors: William E. Davidson, Ontario; Kaj

, Toft, Upland, both of Calif.

[73] Assignee: General Electric Company,

. Bridgeport, Conn.

[22] Filed: Nov. 10, 1972 [21] Appl. No.: 305,574

[52] U.S. Cl. 38/77.83 [51] lint. Cl. 006i 75/06 [58] Field of Search 38/771, 77.5, 77.8, 77.83

[56] References Cited UNITED STATES PATENTS 3,238,649 3/1966 Denton 38/7783 3,69l,660 9/1972 Gronwick et al. 38/7783 3,728,805 4/1973 Gowdy 38/7783 3,747,241 7/1973 Davidson 38/7783 Primary Examiner-Patrick D. Lawson Attorney, Agent, or FirmGeorge R. Cullen; George R. Powers; Leonard J. Platt [5 7 ABSTRACT is provided to avoid expelling water out the soleplate ports by providing a high steam takeoff through a continuously open conduit. The conduit also acts as a pressure control valve and is designed to repel loose foreign particles.

6 Claims, 3 Drawing Figures SELF-CLEANING STEAM IRON BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains to a steam iron and, more particularly, to a self-cleaning steam iron. of the general type shown in US. Pat. No. 3,747,241 of common assignment, where a large separate opening in the internal water tank can be suddenly emptied and a resultant gush of water and steam purges the iron. The present invention improves such an iron by providing a high takeoff point in the boiler cavity for the steam to pre vent pickup of condensed water on initial operation of the iron and to provide a simple pressure control in order to generate pressure to assist in the self-cleaning operation.

2. Description of the Prior Art With the advent of irons using water for either steam or spray purposes or both, it is customary to provide a water tank above the soleplate and use a water valve to provide controlled and metered water drippage into a steam boiler where it flashes to steam and is directed out ports in the soleplate to steam the article. This is a flash boiler steam iron and is typical of most steam irons today. Additionally, spray attachments, either powered by steam or manual, have been added to such irons to supply a fine spray from the water tank to spray onto the garment. Generally, distilled water is used in such steam irons because of the fineness of the various water passages and orifices which are subjected to clogging due to the mineral deposits from ordinary faucet tap water which vary from one locality to another. Also, a normal home softener may provide undesirable salt deposits that can also clog passages. In addition, the steam ports in the soleplate tend to collect lint from the ironing operation and this lint may find its way into the internal passage structure when the iron is upended and subsequently cause brown spotting. In hostile hardwater localities, the tap water contains minerals which can collect and produce loose flakes and deposits that plate out on the iron components and clog the fine passages in the iron. These generally consist of lime or calcium carbonate as well as other chemicals in solution in the tap water or in relatively large flake-form in the water. Various screens have been used to keep the fine passageways clear of flakes but eventually even these screens can plug up. Additionally, some constructions have provided means whereby brushes or other cleaning implements may be used at least partially to free the passages of obstructing impurities but these may re- SUMMARY OF THE INVENTION Briefly described, the present invention is directed to an improved steam iron which is self-cleaning. A basic iron having a water tank and steam generating soleplate with ports is provided with steam control means including a valve to start and stop a metered flow of water from the tank to a soleplate steam generating boiler cavity and a coverplate is provided over the soleplate to define steam passages between the coverplate and soleplate. A substantially large, separately controlled opening is provided in the tank communicating directly with the inner surface of the soleplate and means are provided so the tank water may be suddenly dumped onto the soleplate to rapidly generate steam and empty quickly through the soleplate ports as steam and water to purge the iron. To this combination of the US. Pat. No. 3,747,241, there is provided an improvement in the form of a continuously open conduit through the coverplate which conduit may act as a pressure control orifice that is spaced separately from the steam control means and which has an entrance in the boiler cavity above the low point of the coverplate for a high steam takeoff. The orifice is formed in an upwardly directed cone and may have screening means to assist in shedding foreign particles. The extension of the orifice above the low point of the coverplate for the high takeoff prevents any condensation in a cold iron from being carried through the conduit and out the ports so condensation is trapped until the iron heats up when it is vaporized to pass through the conduit and out the ports. Thus, the main object of the invention is to provide an improvement to a self-cleaning iron which prevents the carry through of condensation that may form if the iron is not cleaned after every operation.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view, partially in section and broken away, showing general parts of a manual spray iron with the invention;

FIG. 2 is a partial perspective of the upper portion of the coverplate showing the invention; and

FIG. 3 is a partial enlarged view of a screening means as applied to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention is described in connection with a manual spray steam iron although it is applicable to power sprays and it should be understood that the invention can be applied to steam irons of the flooded boilertype as shown in US. Pat. No. 3,156,054, non-flash boiler type shown in US. Pat. No. 2,810,218, both of common assignment, or the more common flash boiler-type described herein with or without a spray attachment. Referring first to FIG. 1, there is shown a steam iron that includes soleplate 10 having plural steam ports 12 and outer shell 14 connected in any suitable manner to handle 16 all in known fashion. Soleplate 10 may be cast aluminum with an electrical heating element 18 cast in position. The heating element is generally of the sheath type and extends in a loop beginning at the rear of the iron along one side to the forward end and then rearwardly along the other side. Thus, substantially uniform heat distribution is provided to the soleplate.

The iron includes means for generating steam by providing interior water tank 20 which may have a vertical outer suitably shaped riser tube means 22 in the forward portion for housing various operating mechanisms or this may be omitted. For steam, soleplate 10 has a steam generating cavity or boiler 24 to receive metered water. Steam control means is provided and includes well-known water valve structure, generally indicated at 26, to start and stop a metered flow of water from the tank to steam generating cavity 24 and activated by means such as button 28 through connected spring-biased vertical stem 30 and water is thus metered through an orifice 31 from the water tank to the boiler as indicated in the referenced patents and well-known in the art. The resulting steam is distributed and directed through passages 32 that are formed with overlying coverplate 34 and lie between the coverplate and soleplate as seen in FIG. 1. The steam then passes out ports 12 onto the fabric in a well-known manner. A manual .power spray attachment 36, controlled by suitable means such as diaphragm pump 38, is operated by control button 40. Temperature control 42 operates to thermostatically control the heat generated in the soleplate. The structure thus far described is wellknown.

As previously disclosed in said US. Pat. No. 3,747,241, in order to purge or clean the iron through the soleplate there is provided a substantially large separately controlled opening, generally indicated at 44, disposed in the bottom of the water tank separate and spaced from water valve structure 26. This is defined as a substantially large opening in that it is intended to include any additional unrestricted flow opening that rapidly empties the tank or dumps it and functions other than as any small restrictive flow metering orifice such as that controlled by valve 26 and which thus bypasses the water valve structure completely. This opening is conveniently placed in the area of the usual steam cavity at dome 46 where the generated steam is normally accumulated and admitted to passages 32 by a normal pressure control valve, as

shown in US. Pat. No. 3,041,756, which allows a controlled pressure build-up within the iron before the steam is permitted to enter passages 32 and be distributed through ports 12. The large opening 44 is separately controlled and is normally closed by a springpressed plunger assembly 48 that is actuated by means of button 50 on the side of the iron. The button actuates stem 52 to uncover separate opening 44 and dump the entire contents of the tank onto the inner surface of the soleplate above heater l8 whereupon the suddenly generated steam blows out the passages 32 and ports 12 to cleanse these areas of any lint or flakes all as fully described as the subject of said US. Pat. No. 3,747,241.

In accordance with the invention herein, it has been found that when the iron is not cleaned after every operation, there is a tendency of condensate to form in the area of the bottom of the steam dome 46. If it is still there when the iron is next used, the condensate may be carried directly out with the steam to issue from ports 12 as droplets onto the fabric an undesirable condition. In order to prevent this, there is provided a high takeoff entrance for the steam in the form of a sep- 1 arate and continuously open conduit 54 that is disposed preferably in the coverplate spaced from the steam control. This conduit connects the generating cavity 24 and passages 32. This basic concept of a continuously open conduit to control pressure generally in an iron is disclosed and claimed in co-pending application Ser. No. 329,365 filed Feb. 5, 1973. That concept, applied to a self-cleaning iron of the type of US. Pat. No. 3,747,241 both of common assignment, is the subject of this application. To prevent the carry-over of condensation with initial steam flow, the entrance to the conduit has a high takeoff in the boiler cavity or, in other words, is disposed above the low point of the coverplate as shown. In structure, the conduit is in the form of an upstanding cone as shown in FIG. I. In addition to the continuous opening to admit steam from generating cavity 24 to passages 32, the conduit may also be designed to replace the normal pressure control valve by providing the conduit with a pressure control orifice 56 designed, in the manual spray iron shown, to create a low internal pressure within the steam generating area. To assure flow, this pressure is communicated to the upper surface of the water in tank 20 by means of balance tubey58 to provide a balanced pressure system whereby the water will flow into cavity 24. The inclusion in conduit 54 of a pressure control orifice substitutes for the usual pressure control valve assembly and thus omits one of the conventional parts. The open conduit 54 may easily be formed directly in coverplate 34. It will be apparent that the low steam pressure within the iron created by orifice 56 with its high entrance assists and aids in the speed of emptying or dumping the water when the tank is emptied through opening 44.

In order to prevent any small particles from being carried through and clogging conduit 54, it is formed with sloping sides and this may conveniently be in the form of an upwardly-directed cone on the outer surface. Any tendency of foreign particles to congregate around orifice 56 is minimized because the sides shed the particles. Additionally, for further protection as seen in FIG. 3, additional means may be placed over the orifice in the form of screen 60 pressed into eyelet 62 which may also be used to create a sharp orifice 56. The screen is cumulative to the sloping sides in repelling any foreign particles.

It will be apparent that the improvement herein to the US. Pat. No. 3,747,241 prevents any water carryover from condensation if the iron is not cleaned. The structure causes the water to lie trapped on top of the coverplate where it will eventually be vaporized on the next heating operation and carried over as pure steam. Additionally, by making the continuously open conduit 54 in the form of a separate pressure control orifice, the normal pressure control valve may be omitted in low pressure applications and thus the open conduit performs a dual function. Finally, by shaping the conduit in the form of a cone and screening it, it will inherently shed any foreign particles that may tend to clog the fine passages.

While there has been shown a preferred form of the invention, obvious equivalent variations are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practised otherwise than as specifically described, and the claims are intended to cover such equivalent variations.

We claim:

1. In a steam iron having a water tank and steam generating soleplate with ports, steam control means including a valve to start and stop a metered flow of water from the tank to a soleplate steam generating cavity, the improvement in means to purge the iron through the soleplate comprising,

a coverplate overlying the soleplate to define steam passages therebetween,

means connecting the cavity and passages to admit steam thereto,

3. Apparatus as described in claim 2 wherein the entrance to said orifice is disposed above the low point of the coverplate.

4. Apparatus as described in claim 3 wherein said orifice is formed with sloping sides to shed foreign particles.

5. Apparatus as described in claim 4 wherein said orifice is formed as an upward cone on its outer surface to shed the foreign particles.

6. Apparatus as described in claim 5 having means over the orifice to screen out foreign particles.

Claims

1. In a steam iron having a water tank and steam generating soleplate with ports, steam control means including a valve to start and stop a metered flow of water from the tank to a soleplate steam generating cavity, the improvement in means to purge the iron through the soleplate comprising, a coverplate overlying the soleplate to define steam passages therebetween, means connecting the cavity and passages to admit steam thereto, said means comprising a separate continuously open conduit through said coverplate, a substantially large separately-controlled opening in said tank communicating directly with the inner surface of the soleplate, whereby the tank water may be suddenly dumped onto the soleplate to empty rapidly through said ports.

2. Apparatus as described in claim 1 wherein said conduit includes a separate pressure control orifice and is spaced from said steam control means whereby said pressure aids in speed of emptying.