US3188757A - Steam and dry flatiron - Google Patents

Description

2 Sheets-Sheet 1 June 15, 1965 B. A. DENTON STEAM AND DRY FLATIRON original Filed Dec. 28, 1960 June I5, 1965 B. A. BENTON 3,188,757

STEAM AND DRY FLATIRON Original Filed Dec. 28, 1960 2 Sheets-Sheet 2 ing element is cast integrally into mim1m, an aluminum alloy, or other suitable highly heat vconductive metal. The modernv tendency also is to pro- 4vide a lightweight low-mass soleplate 'which' heats very rapidly. F or satisfactory operation with such a soleplate having, for example, thirty square inches of ironing surtotal length of the twelve or thirteen inches, it is necessary sheathed heating element having a high output per unit :the .heating element nexus of the element as located `fof the iron. Such a construction reduces the lheat applied to the reduced area at the pointed end of the United States Patent O 3,188,757 STEAM AND DRY FLATRON Bryce A. Denton, ntario, Calif., assigner to General Electric Company, a corporation of New York Continuation of application Ser. No. 78,942, Dec. 28, 1960. This application June 17,1963, Ser. No. 290,273

2 Claims. (Cl. 38-77) This invention relates to electrically heated atirons, of

fthe type adapted to be operated selectively as a dry iron or as a steam iron, and in which liquid lmay be converted to vapor more or less instantaneously upon deposit of liquid into a heated steam generating cavity in regulated ,small quantities.

'.flatirons, the ironing pressure is controlled predominantiy Lby the weight of the iron itself and the arca of the flatiron soleplate. The interval of time of application is primarily a function of the speed with which the operator moves the iron 4over the fabric. This factor, while varying from user to user, must be accepted rby the manufacturer of iiatirons on the basis of a xed, though possibly estimated average. Correspondingly, the only realvariable with respect to a modern automatic electrically heated atiron is the temperature at which the ironing or smoothing surface is operated.Y For example, the more delicate synthetic fiber fabrics, such as acetates or fabrics made with the trademarked fibers called Dynel, may require temperatures as low as 220 F.A Rayon, nylon, and fabrics made from'synthetic bers such as those sold under the trade name Dacrom can stand temperaturesin the range of 275, F. to 300 F.; while wool, cotton, and linen typically are described as requiring ironing temperatures of 340 F., 405 F., and 455 F., respectively.

The typical well-'known shape for a atiron soleplate provides a pointed toe end and a broad heel end, such shape having been found satisfactory by the typ-ical user. In modern practice, the iiatiron s-oleplate is heated bylan electric heating element, preferably of the sheathed form. The most emcient heat transfer occurs when such a heata soleplate made of alufaceit has been found that the heating element should provide a capacity in the order of 1100 Watts. Since the heating element usable may only'be to provide such a length. For this reason, the electrical Wire embedded y-within the tubular sheath is coiled, for example in the form ofa helix.

It 1s well known in flatiron practice that the helix or coil yof the heating element may be `stretched or compressed *pto reduce or increase, respectively,

lelement per unit length.

the heat output of 'the Thus, in accordance with vone construction used widely and successfully, the helix of has been stretchedat the bightmor adjacent 'the pointed end wattage of np ICC iron. Such a construction is shown, for example, in yFinlayson Patent 2,582,773, issued January l5, 1952, and assigned to the General Electric Company, assignee of the instant application. The express purpose of such a Construction as shown by the patent, is to provide a uniform Itemperature over the entire soleplate when the iron is used as a dry iron, with no steam generation.

Other congurations of the heating element coil have been used for optimum performance in connection with steam iron operation. The typical approach in this instance is to provide concentrated heat adjacent the flash steam generator so that this area of the heated soleplate will always :be over a minimum temperature in the order of 230 F. lt has been found from experience that maintenance of a temperature lower than 230 F. tends to. result in occasional iiooding of the flash steam generating cavity, such as when lan excessive quantity of water suddenly ows onto this area. Flooding is a most unsatisfactory operating condition, for the reason that discrete drops of Water are suddenly expelled through the soleplate, possibly staining or damaging the fabric being ironed.

Flooding of the steam genera-tor cavity .has proved to be a particularly troublesome problem in connection with modern irons designed for ironing the delicate-synthetics.

1 As explained above, when the synthetic fabrics are ironed,

`a relativelylow temperature setting or adjustment is selected for the flatironthermostatic switch. Under these circumstances, the steam generating cavity tends also to operate at a lower temperature, and possibly at such a low temperature that iiooding will result if liquid is allowed .to flow into the steam generating cavity at a rate to provide sufficient steam for satisfactory steam ironing.

In the past, the design of flatiron soleplates, including the heating element configuration and thermostat mountl ing, have been'selected on the basis of steady state koperating conditions. For example, a flatiron is allowed to come up to temperature, followed by several on-otf cycles of the thermostatically controlled switch. Measurements of soleplate temperatures are thereupon taken at several locations, and the concentration of the heating element is ladjusted as necessary to provide a substantially uniform temperature over the entire soleplate. Howevenethis approachv to ilatiron construction overlooks' the serions problems which'may be created by transient temperature variation conditions at different points on -a atiron soleplate. For example, when an iron has been operating --for a period of time'asadry iron and is then switched to siteam'io'n operation, there is a sudden dro-p in temperature'iin' the steam generating cavity,"caused\by theeva'poration of Aliquid and the cooling of this area"by,the liquid.' If the temperature drops too rapid-ly, the cavity isflooidpd as described above.V Therefore, suflicient heat must bes'upplied to this cavity to maintain it` at the. proper operating temperature; however, when this is done, an excessive rise lin temperature adjacent the heel of theiron likely .will

.occun Most of the steam irons which employ an instantaneous -or ilash steam generator are arranged to. cease steaming Vautomatically whenever the iron is up-endedonto its .heel rest. 4.In other words, when the iron is up-ended onto its vheel rest, liquid ceases owing to the steam generator. lHowever, the change inoperating condition yis not. immediately sensed by the temperature responsive member which operates the thermostatic switch. Therefore, as a transient condition, certain portions of the .flatiron soleplate tend to overheat until the iron again Ireaches a steady state condition. -If the operator should decide to again apply the iron with a portion of the soleplate in suchan overheated condition, there is appreciable risk of damage, particularly when ironing a delicate fabricsuch as, one of the synthetics.Y 1,.

Correspondingly, one of the objects of this invention the applied, V'comprising i a smo v l Y y Y is 't'o provide a atiron operable selectively as a dry iron or a steam iron with electric heating 4element and an 'automatit temperature control, so arranged to minimize abnormal transient temperature conditions. n f

A further object of this invention is to provide a iiatlron capable of operation for steam ironing delicatesynthetic f fabrics, without risk of scorching or melting the bers v from which the fabric is made.

Still another object Iof this invention is to provideV an iron with an automatic adjustable temperature control, 'operablefor steam Vor dry ironing, and providing a more uniform heat over'the surface of the soleplate under ally operating and transient conditions, and in all temperature ranges.

A further object `is to provide such an all-purpose "fiatiromuse'ful fr dry ironing, steam ironing, andfany other ironing tasks, at a minimum manufacturing cost, and which maintains reliably uniform operating temperatures over the surface of the soleplate under all steady rstate as wellas transient conditions.` y Brieily stated, Vin accordance with oneaspect of this invention, a combination steam anddry iron includes a cast-in elongated sheathed electrical heater, U-shaped to f conform generally with the configuration of the soleplate with the nexus or bight of the heating element adjacent the pointed end of theiron and legsof the heating element extending adjacent the side edges rearwardlytoe The soleplate has Aa new...

Ward the heel of the soleplate. 4,portion and a heel portion of Cornpa'raleA ured at the smoothing'or ironrig'jr- 412m Eh? neas 'generating cavity is` locatif? j. r ff .s sa@ he solely-late, n?, within t e nose portion of Hwy-f ,...no the temperature sensing Yelement of .oimostatic switch assembly Vis mounted 'adjacentihe steam generating cavity, to i to changes in temperatu'rewhen liquidV is introduced into the cavity. YThe heating element itself is constructed k'to emanate vless heat per unit length in the legs therecfrwhicn y uportiorrof thesoleplatdvcnjrpared to the heat bncentrationemitted per unit length' are positioned in the heel along the heater thefnfose/po'xrtion of the iron. This construction materially reduces the transient temperature Yoversh'oots at varitns critical points o frth'eironing surface- The Subj f/rnatter which I regard as my invention is;V

'partvill'llarlyV 'pointed out anddistifnctly claimed in theiconlltlmgrprtlon of this speci'ica'tiont My invention, however,"both as to organizati best be understoodby reference to the following description taken 1n connection with' the alpgymgrr Wings artially in section, of a soleplate assembly inV accord- 'ance Withrthe present invention. Referring Vnow to the drawings, in FIG. 1 is shown a typical Iiatiron of the type 'to which this invention may be .Y

othing member or soleplate 1,

a cover 2 enclosing various components vwithin the iron, :and an operatlng handle 3 molded from a thermalinsulating material. Electricpower may be supplied to theriro'n through a conventional cord (not shown) which Aenters 'the iron through the handle by means of acord lift bushing 4. In order to adapt the iron for application tozvarious fabrics, a temperature'select'or 5 is provided adjacent the top forward portion of handle 3 for convenience of the operator in selecting the desired operating temperadure. Also, the iron is provided with a push buttont6 or Y the equivalentV which can be operated, for example, by an up-and-down motion, to convert the'iron from dry toV steam operationV or vice versa in a manner to be described.

Thermostatic switchesfor controlling operating tem-fV of course, well' known in the jperature of a atiron are,

lari., .In vthis particular embodiment, the temperature andere? v respond asvquickliy aso'ssible i *on-'and method of operatiorn, together with further objects and ra'dvantzrtgesthereof,

with certainsurfaces broken,

plan view, with certain surfacesbroken away Y responsive element is in the form of a bimetallic blade 7 rmly Vsecured tothe flatiron soleplate 1 by means of a bolt 8. Such bimetallic blades, in a well known manner, exhibit the characteristic of deforming or bending responsive Yto heat; In this particular instance, blade 7 is mounted so that it will bend or deform downwardly responsive toV increasing temperature of the soleplate. Adjacent the outerV end of the bimetallic blade 7 isa second bimetallic blade 9 of shorter length fortemperature 30 compensation purposes. This 'short bimetllic blad'il is oriented to deflect upwardly responsive to increasing teni- .perature In accordance with well-established practice, this compensating blade evens out the variations in tem- .perature while theiron is'coming up to steady'state operat- V ing. condiitons. Motion of this compound'bimetallic blade assembly is transmittedy to the electrical switch arm, presently to be described, by means of a U-shaped bracket 10 secured to the outer end of compensating bimetallic blade 9. Bracket Itl,in turn, may include an adjusting screw l1 usable for factory calibration of the thermostatic switch assembly. e Y l In `accordance withv this embodiment, the, electrical Yswitch itself is made up of a rstarm of resilient mate'-L rial, secured as by rivets i3 and 14 (FIG. 2 to an elec1 V aan insulating bleek is. The end ef resilient it l conductors may fsied. The opposite end of this resilient arm 12 s Y secured-te a rigid er snbstantlallyrgd Contact arm 17, with a suitable eleetr'al'lnsulatng member is' eneomf passing the corresponding 'entre er beta fesnent ann 1 2 and Contact Yand "Contact arm 17,111 turn, extends' Y' rearwardly 'ndin'cludes on its ppositefr'e'je lectric'al contactl? atlante` to oop 'ate with a .lixedponf- 'ta-fzs noameapnrhiend 'pf a substantially and sans nalstripglf, Conveniently, the rigid Contact arm Zlmay also be rirottiitedy to insulatorblock 15, for example by Vrivets 22' and f This insulator block l5 is shown in FIG. 2' as secured to a rigid frame `2 4 adapted to be 'boltedor otherwise secured to the soleplateby.r suitable fasteningdevices Zagd 26. Bythis means, the insulator remains 'ef tnermevgblegcntat aria an1 the re llient arm, is positioned to overlie a temperature selecl10n Cam 27.. .Thambasamapprvprately slonedtq face, which upon rotation thereof adjusts thepositiorltit contact arm 17 with 'respeettothe insulating tip 28 which progeets fronrcalibraticnscrew :t1 carried bythe bracket 10 0f hmperature' resimnsivemember;v VCam 27', for VA flmerature selection, is rotatable by a shaft or other suitable connectingdevice 29, which shaft'extends upwardly through the Vbody of the-'iron 'and the front handle sup- /fport for adjustmentor rotation bythe temperature selectorV knob 5; This temperature adjustment control mechanism is, of course', appropriately calibrated sc that selecmay be moved froman olf position to suc- Vso tor knob 5 n Y l cessive positions to adjust. the thermostatic switch asseme bly to maintain progressivelyfhigher temperatures of the sol'eplate Vup. to the highest operating temperature. In accordance with usual practice, Va dial plate 30 cooperable with knob 5 may be calibrated with the names of different typesof fabrics, commencing at the'low temperature `erid with designations of various synthetics and continuing through rayon, wool, and cotton, up tolinen at Vthe hightemperature end of the scale.V

The present invention isY of particular importance with respect vtoits application toa combination steam and dry iron in whichsteam is generated in a so-called flash steam Y generator. A typical form of such a steam generating sys- Vtern is lillustratedy in FIG; 1 andincludes a liquid reservoir 70 31 enclosed within cover This reservoir may be sup- Y ported in anysuitable manner .within the iron, and typically is supported at itsforward endby a steam dome y32, preferably made of stainless steel to reduce heat transfer to the liquidY carriedvwithiri reservoir 31175 Steam dome 32 forms a part of a boiler cover plate 33 secured to sole'plate 1 and giiincludesa terminal screw overlying and enclosing a steam generating ,cavity 34 formed in the soleplate. To provide communication between the liquid reservoirandthe steam generating chamber, an orifice member 35 isy employed with a restricted passageway 36, through which liquid may flow at a slow rate, such as drop by drop. Cooperating with orifice member 35 is a valve stern 37 arranged suitably to be operated by steam control push button 6. Valve stem 37 is normal-ly biased in an upward-ly direction by a cornpression spring 38, so that liquid may flow through the restricted orifice 36v into the steam generating cavity. A clean-out pin 39 is provided on the end of the valve stern yto project through orifice 36 when push button A6 is depressed to terminate or shut off liquid flow from the reservoir into the steam generator. This liquid supply and steam generating system may also include a pressure balancing tube 4i) t0 equalize the pressure between the steam generating cavity and the upper portion of reservoir 31. Also, appropriate means is provided for filling the reservoir with liquid, typically in the form of a funnel member 41 in the forward portion of the front handle support communicating with the interior of the reservoir.V For further details with respect to' this liquid supply and steam generating system, reference is made to Patent No. 2892,* 272, issued lune 30, 1,959, and assigned to thc General Electric Company, assignee of the present invention.v

The heating means for the fiatiron soleplate and for the steam generating cavity is in the form, preferably, of a sheathed tubular heater. Such a heater may be cast integrally into s lleplatey 1, and it has been found that aluminum or an aluminum alloy is particularly suitable for the soleplate casting, in that such a metal is highly conductive of heat. The heating element itself comprises a coiled resistance Wire 42, formed typically in a helix. This resistance wire is held in spaced relation within an outer protective sheath 43 by a mass of highly compacted electrical insulating material 44, such as granulated magnesium oxide. At each end of the heater, the resistance wire is connected in any appropriate fashion to respective terminal pins 45 and 46. As shown in FIG. 2, terminal pin 46 `is connected to a terminal lug 47 for one of the conductors of the electrical power supply. The other terminal pin 4S is connected through a conductor 48 to contact strip `21. Thus, when the thermostatic switch is closed, electrical power can iiow through the resistance wire, the thermostatic switch, and bach to terminal 156, to which .is connected the other side of the line of the power supply. In accordance with modern practice, the entire iron, and especially the soleplate, is made as lightweight as is feasible. It has been found in practice that such a lightweight iron is just as effective as heavier irons for smooth ing fabrics, and can be operated with considerably less fatigue. However, since a lightweight iron provides very little heat storage, it is necessary to provide a high electrical power input to heat the soleplate quickly, and thus make up for heat lost in operation. T he vheating element in this application is, for example, in theneighborhood of l1100 watts. Obviously, it is desirable for the thermostat and heating'elerrientto be arranged tojmaintainjthepref selected temperature Yf orthe soleplate. This consideration alone-would tendto indicate that the temperature-sensitive bladeshouldbe mountedjat the geometric center of the soleplate. However, an iron in accordance With'the present invention includes alsothe steam generating cavity into which liquid is deposited for conversion into steam. As liquid is depositedintothis-cavity, the soleplate inthe area is quickly cooled. It has been found in practice that if the metal in the immediate vicinity of the steam generating cavity drops to a temperature below 230 F., there is substantial risk that the steam generating cavity will flood and discharge droplets of liquid through the soleplate onto the fabric being ironed. Correspondingly, in accordance with this invention, I prefer to mount the thermostat temperature sensing element in close proximity to the steam generating cavity.

As shown,- the steam generating cavity"isfloca t ed in the forward portion of soleplate 1. The reason for this is that an iron should cease steam generation whenever it is upended onto its heel rest. This is accomplished conveniently by arranging the steam generator and the orifice member 35 forwardly in the iron, so that whenever the iron is upended to its rest position, orifice 3 6 will be above the water level. Correspondingly, the soleplate, in accordance with this invention, may be described as consisting of a forward portion, above line A -A of FIG. 2, and a heel portion below the line. The forward portion includesV steam generating cavity 34 as previously described. The iron of this invention is provided with a heating element ofA s uiicient wattage for the heaviest i-roning load expected. For example, one of the heaviest loads would be presented when smoothing a heavy cotton or linen fabric that had been dampened to a substantial extent. Under thes'e circumstances, or under the condition when the iron is initially heating up, it is conceivable that the thermostatic switch would Iremain closed Afor an appreciable period of time. However, for most ironingvoperations, the thermostatic switch cycles between on and off conditions rather'frequently to maintain the preselected ternperature. A

For dry ironing alone, it might be reasoned that the electric heating 'element shouldv provide a substantially uniform wattage output'per square inch of soleplatefarea. For example, such a' wattage ina modern iron might be in the range of 35to 40 watts per square inch of soleplate area. Such considerations might also suggest that the heating element should be stretched 'or arranged to provide less watts per u'nit length at the nose or pointed Tend of the iron, in view of the fact that the area tc bel heated at the nose of the iron per unit length of heating element is correspondingly less than such area per unit length of heating 'element at the heel portion of the iron. Such a construction'is, in fact,-disclosedy and claimed inlatent 2,582,773, Finlayson, issued January l5, 19.52,*and assigned to the General Electric Company, assigneev of this invention. Other arrangements'have been heretofore p'roposed for varying the heat'dissipation per lunit'length of the heating element in yorder to achieve a desired heat distribution pattern.

The present invention is `directed particularly to a steam and dry iro'n suitableV for use 'in the relatively. lowand narrow temperature rangesrequired for'smoothing the various synthetic-fabrics." VForthisapplication,the normal steady state heat distribution patterns becomeof less importance than vthe ltemperature variations at; various points on the soleplate .arising-out of transient conditions. For example, 'one serioustransient condition may occur after the iron has been operatingas a dry .iron for a suiiic'ient length of time for -the ythermostatc switch to arrive at its normal cycle of operations between on and.y oif conditions,^thus maintaining lthe preselected temperature. Then, when .the liquid supply oriiiceis opened and Water is deposited into the steam generating cavity, this ,portion Lof the soleplate is suvddienly chilled. As soon as this change inrtemperature is sensed by the bimetallic element or heatsensing member, thethermostatic` switch' is closed, and remains closed fora sufficient periodo-f time to'v again heat the steam generating'cavityup to the* desined extent.

kiiofwever, 'during this time' when' the therm'ostatic switch Y'is elo-sed, serious overheat''conditions mayl exist temporarily or transiently a't someother point-on Vthe flatiron `'lolelplate, such as the area of the soleplate adjacentthe ee In Vorder to minimize wide temperature variations over the soleplate lunder such transient conditions, it has been found that the soleplate may be considered as including a nose portion with a steam generating cavity therein and a heel portion, these two portions being of generally comparalble areas. In one typical example, the nose portion of the soleplate presented an area of approximately 15 square inches, while the heel portion of the soleplate inits length in the nose portion of the iron, While the helix is stretchedllto reduce thewatt's output per unit'length forV the Vlengths or legs of the heating element in the heel portion of the soleplate. 'In a .typical example, a cncenalegre? tration of 110 watts per inch hasfbeen Vused for the heating element lengt-i1 in thenose 'portieri ef the soleplate, to prio-1 areaoverthe nose portieri of thenlegs of the heating element in the heel soleplate, it has been found that 48 watts materially in reduction, of transient temperature condi-y tions .whieh might lead to damage dwf delicate fabrics.

iiirtiea ef fue per inch helpel With 48 Watts per inch of heatingelemeiit iii the heel por'- f.

tion, the Watts per unit of area of the soleplate is reduced to a value of 12 to 14 Watts per square inch. l y

'lo avoid danger of ooding in the steam generating cavity, itis preferred to moi-int thel temperature' sensitive elementi et fhe. thermestaue switeiiV assernely immedi gtmiyadjan to the stei geiieratf. Withsuii an arf *ran ement.' ther is minimum delai' Betr/ 25 fleiiifil chil ing of the s cam generating cavi't'yvvhen Water is gidture is sensed bythe bimetall-ic blade. lIn otheiFx i/itrdgthe f temperature ysensing element `responds Very quickly to eri-V ergizeV the heating Yelement whenever liquid is introduced normal have been noted directly .uiidr the heating element il; the heei portion of the ifogupon introduction er. aqu-id in the ssteam 4generating.cavityfr AIrifaccordance with the present invention, this temperature overshoot has'been reduced by a nagitd 'iii Vtlie oder of 40 in the' spe-v Ci-eexample described above. At` tlewsiime' time,` the mounting of the temperature sensing element ofthe flier mostaticnswitoh assembly immediately adjacent the ste-ani generating cavity has resulted in la signiiicnt increase in the' lowestitemperature found'to exist in Vthe Vcavity area upon' initiationo-f steam'generatioiti.l This is also'ray very deinite improvement in the sense that the risk of Yaiood- 'ing condition Yis obviated, even foi-.relatively low settings ofthe thermostatic switch. "Therefore, it is now possible Wit-h an iron in =accord-ance with the present invention to steam delicate fabricsg'while the material reduction in the transient temperature overshoot in the heel portion of the iron materially yreduces the risk of damage or scorching of such delicate fabrics.

While the Vpresent invention has been described by reference Vtoparticular embodiments thereof, it is to be un- Y derstood Vthat numerous modifications maybeV madeiby those skilled in `the art wit-houtactually departing from V the invention. It is, therefore, the aim of the appended' claims to .cover al1 such equivalent variations as come 1. steam and dry iron soleplate of high heat conductivity metal comprising a nose por-tion including a steam generating cavity into which liquid may be deposited for substantially instantaneous conversion into steam,.a heel pontion, said heel and nose portions being of generally comparable areas", eingleelongated heating elementV for both steam and Adry ironing extending integrally within the VVsoleplate and following 'the .external con-tour thereof, a

,'thermostafio switch mechanism controlling power input .to .said heatingjele'iient including a heat sensing member mounted centrally on said soleplate at a portion thereof Vwhichdefines a 4Wall of said steam gener-ating cavity to sensei predominantly the temperature of said steam geneitingc a'ity .and Ysecondarily the temperature of said heel portiri, saidlieating'ele'ment being constructed to provide greater liat output per unit length inthe nose portion sorthat .the total heat generated in that portion of the Heating element in the'fnose portion of the soleplate exceeds by. footer inthe order of four or tive to onek the heat output of the portions of the heating element in the heel portion ofthe soleplate.

24. A combined .steam'and dry iron soleplate cast of a high heat conductivity met-al comprising a nose portion .and a hee-l portion, said nose portion'being a substantial portion' of said soleplate andextending from the tip of said soleplate 'rearwardly more than half of the center line dimension cisaid iron', Said heel portion comprising the remaining'. portion' of saidso-leplate, a steam generating cavity integally cast' in the nose portion of said iron, an upwardly extending" integrally cast in the nose portionof said solepl'atmthe forward surface of said wall providing the rear 'inner surface of Vsaid steam generating yea.'vity, .a single castain 4sheathed heating element in said Y 4soleplate generally Afollowing theexternal contour of said soleplate Vinwardly thereof for providing heat for both steai'riand dry ironing, said heating element being coneentrated throughout its length in the nose portion of said -iior'i and being stretched in .the heel portion of said soleplate so that the total heatgenerated in the portion of the heating element Yinthe nose portion of the soleplate exceeds by .a factor of'..appro'xirnatelyv fourt-o one the heat output of .the portions y of .the heating element in the heel portion of the soleplate,` a thermostatic switch mechanism `for controlling power input to said heating element, said switchv ,mechanism including a heat .sensing member mounted lon said steam generating cavity wall and extendlingrearwardly. to yay position above the. heel portion of f Asaid soleplate to sense both the temperature of said steam generating cavity and the temperature ofthe heel portion .of said soleplate, whereby said iron may be eiectively usedf-or both steam and dry ironing with a minimum transientv temperature over-shoot in said heel portion upon change from dry to steamironing.

References Cited by theExamner j UNITED STATES rarnn'rs` Y` 1,863,284 Y. 6/32y '.Rollman 219-25 2,582,773 1/52k Finlayson 38--77 2,655,746 10/53 McFarland et al. 3f8-77 2,710,469 6/55 Vaneeet'a-l 38-77 2,829,452 i/58 Humphrey 38--77 Within thetrlue spirit and scope-ofthe foregoing disvJORI'DAN FizANKLIN'Primary Examiner.

DAVID J. .WILLIAMOWSKK Examiner.

Claims (1)

1. A STEAM AND DRY IRON SOLEPLATE OF HIGH HEAT CONDUCTIVITY METAL COMPRISING A NOSE PORTION INCLUDING A STEAM GENERATING CAVITY INTO WHICH LIQUID MAY BE DEPOSITED FOR SUBSTANTIALLY INSTANTANEOUS CONVERSION INTO STEAM, A HEEL PORTION, SAID HEEL AND NOSE PORTIONS BEING OF GENERALLY COMPARABLE AREAS, A SINGLE ELONGATED HEATING ELEMENT FOR BOTH STEAM AND DRY IRONING EXTENDING INTEGRALLY WITHIN THE SOLEPLATE AND FOLLOWING THE EXTERNAL CONTOUR THEREOF, A THERMOSTATIC SWITCH MECHANISM CONTROLLING POWER INPUT TO SAID HEATING ELEMENT INCLUDING A HEAT SENSING MEMBER MOUNTED CENTRALLY ON SAID SOLEPLATE AT A PORTION THEREOF WHICH DEFINES A WALL OF SAID STEAM GENERATING CAVITY TO SENSE PREDOMINANTLY THE TEMPERATURE OF SAID STEAM GENERATING CAVITY AND SECONDARILY THE TEMPERATURE OF SIAD HEEL PORTION, SAID HEATING ELEMENT BEING CONSTRUCTED TO PROVIDE GREATER HEAT OUTPUT PER UNIT LENGTH IN THE NOSE PORTION SO THAT THE TOTAL HEAT GENERATED IN THAT PORTION OF THE HEATING ELEMENT IN THE NOSE PORTION OF THE SOLDPLATE EXCEEDS BY A FACTOR IN THE ORDER OF FOUR OR FIVE TO ONE THE HEAT OUTPUT OF THE PORTIONS OF THE HEATING ELEMENT IN THE HEEL PORTION OF THE SOLEPLATE.

Images