US2582773A - Soleplate structure for electric steam irons - Google Patents

Description

F. E. FINLAYSON 2,582,773

SOLEPLATE STRUCTURE FOR ELECTRIC STEAM IRONS 2 SHEETSSHEET 1 Jan. 15, 1952 Original Filed Sept. 11, 1946 Fig. I.

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Patented Jan. 15, 1952 SOLEPLATE STRUCTURE FOR ELECTRIC STEAM IRONS Frank E. Finlayson, Ontario, Califi, assignor to General Electric. Company, a corporation of New York Original application September 11, 1946, Serial No. 696,298, now Patent No. 2,557,732, dated June 19, 1951. Divided and this application December 9, 1947, Serial No. 790,525

2 Claims. 1

This invention relates to pressingirons having means for generating steam during the ironing or pressing operations, and it has for its object the provision in a device of this character of an improved soleplate structure for generating steam and for conveying it to the pressing surface of the iron, while presenting an evenly heat-v ed pressing surface.

This application is a division of my copending application, Serial No. 696,298, filed September 11, 1946, now Patent No. 2,557,732, patented June 19, 1951, and is assigned to the same assignee of that application.

' For a more complete understanding of this invention, reference should be had to the accompanying drawings in which Fig. 1 is a vertical central sectional view taken through an electrically heated fiatiron embodying this invention; Fig. 2 is a plan view of certain parts of the flatiron of Fig. 1; Fig. 3 is a sectional view taken through the line 3-3 of Fig. 2 and looking in the direction of the arrows; Fig. 4 is an expanded perspective viewillustrating certain elements of the soleplate structure used in the iron of Figs.

1-3; and Fig. 5 is a partial cross-sectional view taken on the line 5-5 of Fig. 1.

Referring to the drawings, this invention has been shown in one form as applied to a pressing iron comprising an iron body i having a soleplate structure 2, a reservoir and valve structure 3, and a handle structure 4.

The soleplate structure 2 comprises a soleplate 5 having the-usual shape, that is, it has a pointed front end 6, a slightly rounded heel end 1, and a pair of curved sides 8 joining the two ends. It

also is provided with a smooth flat bottom 9', con- The plate will be stituting the pressing surface. made of any suitable heat conducting material, such as aluminum, and preferably, it will be cast from the material.

The soleplate 5 is heated by means of an electrical heating element H) which preferably is of the sheathed type cast within the plate. Briefly, it comprises a helical resistance conductor I! mounted in an outer tubular metallic sheath I2 and supported in spaced relationwith reference to the sheath by an electrically insulating heat conducting mass l3, formed of compacted powdered magnesium oxide. This heating elementis roughly in the shape of a hairpin, as shown most clearly in Fig. 2, the nexus or bight l4 being located at the pointed or point end of the soleplate and the two legs extending backto the rear thereof where their end sections l 5'emerge from the rear. Terminals l5a project from these end sections. The two legs as they progress back follow in general the curved sides 8 of the soleplate, as clearly shown in Fig. 2.

The turns of the resistance conductor l I located in the .bight M are spaced further apart than are those in the two side legs so that a uniform temperature is produced over the entire soleplate when the iron is used as a dry iron, that is, with no steam generation. This arrangement is shown by Fig. 5.

The top surface iii of the soleplate is flat and parallels the flat pressing surface 9, a shown. The surface l6 deviates from its fiat plane character only at the rear where the two ends l5 0f the heater legs are located and where the soleplate is provided with upraised bosses I! to house these ends which incline upwardly, a shown in Fig. 1; at the center where a steam generating cavity I8 is depressed from the surface; and at the rear where a depressed cavity I9 is provided. Because of this, the soleplate lends itself to easy milling and finishing operations. Furthermore, the substantially uniform thickness of the soleplate aids in maintaining a more uniform temperature over the entire pressing surface.

The steam generating cavity [8 is located about midway between the two ends 6 and I of the soleplate; that is, in that section of the plate which has the area of greatest heat concentration. This location tends to avoid a chilled spot in the pressing surface under the cavity I8 whenv the relatively cold water is fed into it. If the cavity were at the nose of the iron, as in certain ones heretofore known, and where the heat concentration is relatively low, cold spots would develop in the pressing surface because there is not sufficient heat to keep up the temperature when the cold water is fed to the generator and moreover, a cold spot in the central area is not so detrimental as one at the nose.

The cavity l8, as shown, has roughly a T-shape, having a stem Hill to which the water is fed, and a cross bar section l8b extending crosswise of the plate, as shown.

Steam which is generated in the cavity I8 is directed therefrom by means of a cover plate 20 to a series of steam discharge ports 2| spaced along the sides of the soleplate in the spaces between the heating element Ill and the side edges of the soleplate, as shown in Fig. 3, and passing through the soleplate from top surface i6 toits pressing surface 9.

This cover plate 20 'fits to the flat top surface l6, and has in general the shape of this surface in'plan view, as shown. That is, it is provided with curved side edges Zla joined at the front, and which correspond to the soleplate sides 8; with a U-shaped rear edge 2lb which registers with the depression. l9; and with. a pair of end wall edges .2 lo inclining inwardly toward the rear to connect the side edges 2m with the U-shaped end edge 2 lb, and to cause the top plate to clear the bosses IT, as shown mostclearly in Fig. 2. The top plate is secured to the bottom plate by a series of screws 22 directed through it and threaded into tapped holes in the plate.

The cover plate 20 is provided with a depending. marginal wall 23 which follows the edges 2la, 21b and 2lc and which gives, the plate alhollow interior chamber 23a which extends substantially throughout the area of the.-.- plate and therefore has its general shape. This chamber is closed; except as to the ports 2|, and as to an opening 24 in its upper wall through which Water is delivered to the generating cavity I8. The chamber 23a is divided into a series ofchannels by means of a rib 25, and a pair of additionalribs 26. The

rib 25, as shown, has a U-shaped section which.

follows the contour of opening 24, and the legs of which flare out at points 25a. into sections 2517 as they leave the opening, as shown; these flared-- out sections terminate in straight substantially. parallel sections 21 which are spaced from the corresponding legs of the U-shaped rear section of the marginal wall 23 which follow the edge 2 lb. The legs of ribs 25, therefore, follow ingeneral the shapes of the point and side edges of the plate, as shown; and their rearends 250 terminate somewhat short of the rear ends of. cham;---

ber 2311, and flare outwardly at arather sharp.

angle, as shown. The two ribs 26 are connected:

to the depending wall'23 substantiallywhere-its portions extending along side edges 2la join with.

about midway between the side wall 23. andthe:

corresponding adjacent legs-of rib 25 and in gene eral follow the contour of the side-wall. 23, as. shown, but they terminate at points somewhatzin advance of the points 25a where the; legs.of; the rib 25 flare out.

The ribs 25 and 26 partition. the-chamber-23ag. into a series of channels as. follows: A: central cross channel 28 which overlies. the. steam generating cavity l8; a pair'ofidentical.channelsZQ; at the sides of the reentrant. U-shaped back edge 2lb, and which at their forward; ends. connect. with channel 28 and also overlapth-e. endsofl ca.v.- ity section I8b; a pair of channelstfl, generally, parallel with channels 29 and which. are. con:- nected at their rear ends withthe rear" ends: of. these channels by channel sections 3|; and. at their forward ends emerge into a generally U- shaped channel 31a, Fig. 2, atthe nose orspoint. end of the plate; and finally a. pair of identical outside channels 32 which coextendchannels-SU, and which also emerge into. u-shaped; channel 3Ia.

Preferably, and as shown, channel sections 29, 38 and 3| will be-somewhat deeperthan the re-- mainder by providing them: indeep blister-like. sections 3lb of the cover. plate, as shown more. clearly in Fig. 2. Inserted in thesedeeper. sec-.- tions is fine screening Me which prevents drops; of water from passingout of the'generatingcav ity [8.

Steam generated incavity l8,fiows upwardly into centralchannel 28, thence-is turned sharply back into channels 29; thencethrough: connect:-

ing channels 3| and sharply forwardly into channels 30;. and through the channels 30 into the large U-shaped channel 3la. From this channel it. flows. through ports 2lopening into it, and back; through channels 321 and ports 2|, opening into them.

It will be observed by reference to Fig. 2, that thevarious channelsjust described lie in a plane directly above and parallel with the highly heated soleplate. Channel 28 lies over a part of the soleplate: between theheater legs and which has a high. degree. of' heat; concentration; channels 29 overlie areas: of the soleplate just inside of the heater. legs; channels 3| pass over into the areas above. the. legs; while channels 30 are directly over the legs, andso is the major part of U- shaped channel 3m; channels 32 overlie areas outside. of. the legs but close to them, all as shown in Fig." 2: The steam therefore emerging from the generating cavity I: follows a tortuous path which lies .in1a. plane abovei the: heated plate. and in.close: relation to: it; It; has. been. found. that itis practically impossible. for any water particles-to. reach the discharge ports 21-. All the waterfedto thecavityl 8 is converted into steam, which issuperheated beforedischarging. throughthesoleplate.

As pointed out previously, water is. fed to the generating chamber I8. through the opening 24 in the top plate 20; andit is fedv from the reser voir section.3-.

The-opening 24 i covered by means of an.in"-- verted cup-shaped cover plate 33 formed of a. suitable poor heat conducting metal, such. as stainless steel. This; cover plate. 33- isv provided with. a: flange 34- which is secured tothecover plateZll and soleplate 5 bythe screws 22.

The reservoir and. valve structure-3, and handle. structure 4 are, described and. claimed in my; above-;-Inentioned acopending application,

What. I.- claim as new. and. desire-to-secureby LettersPatent of;the United States, is:

1..A- steam iron comprising: a. soleplate. provided with apointed front end and-aheelendattherear, with-a fiat pressing; surface onits bot.- tom and with a fiat heating. surface. on-itstop substantially parallel and co-extensive with said pressingsurface, and in addition. providedzwith; aseries. of ports. spaced atintervalsalong its sides and interconnectingsaid pressing andheating surfaces, a U-shaped heating element. embedded; in. said soleplate betweensaid two. surfaces;to apply heat: to. saidsoleplate and to.- the. surfaces'and having its bight at theforward-end of saidsoleplateand its-two legs extending along thesideportions thereof toward therear, said. heating. element: bein formed to emanate less. heat. per unit; length in said bight than in said. legs, said soleplatehaving formed therein a steam. generating cavity in said heating. surface located substantially atthe centerof said soleplaterelatively removed toward the rear from said bight andintermediate said two legs, and acover plate substantially. coextensive with and. covering said. heating surfaces-providedwith means defininga series .of channels: extending from said. cavityfirst. backwardly; and thence forwardly along said heating surfaceinto. a-. generally U-shaped channel locatedalong theforward parts of the sides. of said surface and a-roundits point, and-a pair of. side channelsiat the-rear connected'with the two. legs. of said u-shapedichannel, and said. latter. pairzof'channels; andsaid U.-shaped channel con.- nectingwithsaidports.

2..- A- steam iron. comprising, a. soleplateprovided with a pointed front end and a heel end at the rear and also a flat pressing surface on its bottom and with a flat heating surface on its top substantially parallel and co-extensive with said pressing surface, and in addition provided with series of ports spaced at intervals along its two sides and interconnecting said pressing and heating surfaces, a U-shaped heating element of helically wound resistance wire embedded in said soleplate between said two surfaces to apply heat to said soleplate and to the surfaces and having its bight at the forward end of said soleplate and its two legs extending along the side portions thereof inside of said ports, adjacent turns of. said resistance wire forming said bight being spaced more than corresponding turns of said legs, said soleplate havin formed therein a steam generating cavity in said heating surface located at a point relatively removed toward the rear from said bight and located between said two legs, and a cover plate substantially coextensive with and covering said heating surface provided with means defining a series of channels extending first across a portion of said cavity to receive steam therefrom, thence backwardly in a pair of substantially parallel legs and thence forwardly in a pair of legs substantially parallel with each other and with the legs of said first pair respectively, said last pair at their forward ends emerging into a forward U-shaped channel extendin along the forward parts and sides of said heating surface, and finally a pair of legs extendin from the two legs of said U-shaped channel backwardly along the extreme outer side edges of said heating surface, said last pair of legs and said U-shaped channel communicating with said ports, and said three pairs of legs and said U-shaped channel overlying areas of said heating surface substantially above said legs of said heating element.

FRANK E. FINLAYSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,313,124 Seldin Aug. 12, 1919 1,731,120 Abbott Oct. 8, 1929 2,010,331 Starrick Aug. 6, 1935 2,353,604 Waring et al. July 11, 1944 2,384,839 Kistner Sept. 18, 1945 2,387,281 Morton Oct. 23, 1945 2,419,705 Busch et al. Apr. 29, 1947

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