US2257451A - Ironing member - Google Patents

Description

Sept` 30, 1941. w. A. BARNES 2,257,451

IRONINCT MEMBER Filed April 25, 1958 2 Sheets-Sheet l //////////4/7////////////ll \\\\\\\\\\i\\\\\\\\\\\\\ 1N V EN TOR.

Sept 30, 1941- w. A. BARNES 2,257,451

IRONING-fMEMBER Filed April 25, 1938 2 Sheets-Sheet 2 lll'llllllllllilil'l 'lrlll/ INVENTOR.

Patented Sept. 30, 1941 UNITED STATES PATENT OFFICE IRONING MEMBER William A. Barnes. Mansfield, Ohio Application April 25, 1938, Serial No. 204,111

(Cl. 38-74l 17 Claims.

does my invention relate to the provision of an ironing member of lighter weight, higher thermal distributing efficiency, smoother finish and lower cost of manufacture. By ironing member I mean in particular that part or parts of the ironing means or mechanism, which provides thel ironing surface and which when heated is pressed against the articles to be ironed, and which also provides heat transferring and distributing means betweenthe heat source and the ironing surface.

Some ironing members, especially those to be used with electrically heated hand flat irons, have been made from forged steel in order to secure malleability, smoother interior finish where the ironing member comes into contact with the electrical insulation of the heating element, and less costly exterior polishing.l Also steel plates have been laminated and spot welded or riveted together to form ironing members but such an assembly does not give good heat conductivity, or good heat distribution and eventually because of the constant heating and cooling in service the plates warp apart resulting in even less satisfactory heat transfer properties than were possessed when the iron was new. I wish to set forth the objects of my invention, which are:

To provide an ironing member for an electrical or fuel heated ironing means which can be manufactured at less cost than the usual cast iron, forged steel, cast aluminum or cold rolled steel ironing members which have been manufactured heretofore.

A prime object of my invention is to provide an ironing member for an electrical or fuel heated ironing means which will be built up from stamped sheet metal parts such as cold rolled steel, and of high surface finish and which high finish will be preserved throughout the subsequent operations of bonding the sheet metal parts together, in order that the cost of grinding and polishing may be kept to a minimum.

Another object of my invention is to provide an ironing member for an electrical or fuel heated ironing means which may be fabricated from a number of sheet metal parts bonded together by a metal of lower melting point and of higher heat conductivity than the metal of the sheet metal parts, but of a melting point substantially higher than any heat to which the ironing member will ever be subjected in use and which bonding together may be done in an atmosphere protective to the surface of the parts.

Still another object of my invention is to provide an ironing member for an velectrical or fue] heated ironing means which will transmit the heat generated by the heat source to the ironing surface of the ironing member with greater eiliciency, speed and evenness of heat distribution than has ever before been attained in structures of reasonable cost when used for ironing members.

Another object of my invention is to provide an ironing member for an electrical or fuel heated ironing means made from laminations of sheet metal of material of relatively low heat conductivity alternating with -and in intimate thermal contact with, films or sheets of a metal of relatively much greater heat conductivity, in order that the usual uneven heating effect of the heat source may be distributed and dispersed over the ironing surface in a more uniform temperature distribution than has ever been attained heretofore in ironing members of similar mass.

Another object of my invention is to provide an ironing member for an electrical or fuel heated ironing means in which the heat generated by the heat source will be efficiently and uniformly transmitted to the ironing surface but in which will be Vprovided a relatively tortuous thermal path of poor conductivity to those portions of the ironing member supporting contacting or retaining the cover shell and other portions of the ironing means assembly which it is desired to heat as little as possible. f

Another object of my invention is to provide an ironing member for an electrical or fuel heated ironing means which may be fabricated from a number of stamped sheet metal parts assembled together and held in assembled relationship by spot'welding and later processed by a method which will bond the adjacent surfaces of the metal parts together by a metal of high heat conductivity such as copper and which bonding will be substantially continuous over a major portion of the area of the adjacent parts, that the assembly may be bonded together into an integral structure of great rigidity and thermal unity.

Another object of my invention is to .provide an ironing member for an electrical or fuel heat ed ironing means which will be lighter in weight because a smaller proportion of the metal of the ironing member will constitute heat storage mass than heretofore and a greater proportion will constitute heat transferring and distributing mass.

Another object of my invention is to provide an ironing member for an electrical or fuel heated ironing means made up of an assembly of metal parts bonded into an integral structure by a method which will so smoothly close the exposed joints of the assembly that these joints when polished and plated will become practically invisible or be so subdued in visibility as to become decorative rather than objectionable in appearance.

An important object of my invention is to provide an ironing member for an electrically heated ironing means in which the surface of the ironing member in contact with the insulation of the heating element is made of a metal having a surface smooth in comparison to a cast surface. that the heating element may be pressed into a more intimate and efficient heat transferring relationship therewith without danger oi' damaging the insulation of the heating element by the roughness and unevenness of the metal surface.

A salient object of my invention is to provide an ironing member for an electrical or fuel heated ironing means in which the heat absorbing surface of the ironing member is of greater area than the heat dispensing ironing surface, and which heat absorbing surface may include means adapted to intercept heat radiated from the heating source in a plane substantially parallel to the plane of the ironing member. Such means commonly consisting of a projecting member integral with the ironing member and adapted to conduct the heat thus intercepted to the ironing surface.

A further salient object of my invention is to complete in one operation the bonding together into an integral structure ironing member a combination of means which heretofore have necessitated a number of separate and diverse operations and parts to provide for.

Another object of my invention is to provide an ironing member for an electrically heated ironing means in which the ironing member is provided with upwardly projecting portions integrally a part of said ironing member and in good heat conducting relationship with the ironing surface of the ironing member, the upwardly projecting portions being adapted to be bent over upon a pressure plate and heating element assembly in order to bind the assembly into intimate heat conducting contact to the said ironing member and to achieve a more efficient heat transferring relationship than has ever before been attained in such structures, also that the projecting portions be of a nature to be efficient in absorbing heat from the pressure Yplate and in distributing same uniformly over an area of the ironing surface equal to or greater than the area of the heating element.

Another object of my invention is to provide an ironing member for an electrically heated ironing means in which provision for a thermally responsive element is made wherein the thermally responsive element will be relatively more responsive to the temperature of the material being ironed than to the temperature of the main portions of the ironing member by reason of the thermally responsive element being positioned thermally intimate to the ironing surface and thermally remote to the main mass of the ironing member.

Another object of my invention is to provide an economical and practicable method of manufacturing ironing members for electrical or fuel heated ironing means which may be made thick around the edge or periphery and thin throughout the interior portions through which the heat is to be conducted from the heat source to the ironing surface and which also will have less mass about the thick periphery than in the thinner portions, thus increasing the proportion of heat transferring to heat storage mass.

Another object of my invention is to provide an ironing member for an electrical or fuel heated ironing means in which the ironing surface may be made of a metal which is harder or which can be made harder by subsequent treatment, than the remaining metal of the ironing member, so as to prevent scratching of the ironing surface on buttons or metal clothing fasteners and the subsequent pulling of threads from the fabric of soft and satin like materials.

Another object of my invention is to provide an ironing member for an electrical or fuel heated ironing means in which threaded or other attaching means for holding the ironing member to other parts of the ironing means assembly, may be more cheaply and satisfactorily provided for than has heretofore been possible in ironing member structures.

Another object of my invention is to provide an ironing member made up of sheet metal parts bonded together into an lintegral structure by a bonding metal of relatively high heat conductivity and one in which the inequalities of heat flow from part to part due to the varying degree of physical contact between adjacent parts and variation of spacing between closely adjacent parts are corrected and made substantially uniform, and heat transfer from part to part greatly facilitated.

Another object of my invention is to provide an ironing member made up of sheet metal parts, the individual parts of which are so designed as to facilitate the bonding together of the parts by fusing a metal of lower melting point upon the assembled parts in a controlled atmosphere furnace. The design of the parts being such as to prevent loss and outflow of the melted bonding metal, and to facilitate the flow of the melted bonding metal into the desired regions of the assembly and between the adjacent parts as desired that complete bonding may be achieved with the greatest possible economy of bonding metal.

Another object of my invention is to reduce the temperature of the heat source of my ironing means required to attain a given ironing surface temperature; by providing a heat transfer member of less mass and greater heat conductivity; by providing a more intimate physical contact between the heating element and the heat absorbing member; by providing a path of good heat conductivity for conducting the heat from the remote side of the heating element to the ironing surface; by providing means in the structure of the ironing member for evening out the thermal inequalities of the heating element and the inequalities of thermal contact between the heating element and the heat absorbing member; by providing heat absorbing parts of large area in proportion to the heat dispensing ironing surface and integrally and molecularly bonding the heat absorbing, heat transferring and heat dispensing parts of the structure together by a metal of high heat conductivity, and by reducing by means of tortuous thermal paths, the loss of heat from the heat transferring and ironing surface members to the cover shell and external atmosphere. By thus reducing the temperature gradient between the heating element and the ironing surface, I attain a further object of longer heating element life.

Other objects of my invention and a fuller understanding thereof may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings in which like parts are designated by like reference characters and in which:

Figure 1 is a plan view of a flat iron sole plate which as an ironing member embodies my invention in one form.

Figure 2 is a cross sectional view of the sole plate shown in plan view in Figure 1 on a line running through the center from the rear on the left to the point on the right.

Figure 3 is another cross sectional view of the sole plate shown in plan view in Figure 1 and on a line running through the widest portion of ,20

Figure 1, that is, A to B and looking towards the point of the sole plate.

Figure 4 is a plan view of another form of my ironing member invention. This is also a flat iron sole plate in which the location of the thermal responsive member is shown.

Figure 5 is a cross sectional View of the sole plate shown in plan in Figure 4 along the line C to D and in which the thermal responsive member is shown by means of dotted lines.

Figure 6 is another cross sectional view of the sole plate shown in plan in Figure 4 but along the line E to F and looking to the point of the sole plate.

Figure 7 is an enlarged partial cross section of the same view as Figure 6 and in which I show how I fasten a thermally responsive member in lace. p Figure 8 is another enlarged partial cross section view similar to Figure 6 and in which I show another species of the structure shown in Figure 6.

Figure 9 shows two plates, one of which embossed, and which are assembled ready for spot welding into a fixed assembly previous to fusing the bonding metal into place.

Figure 10 shows the plates of Figure 9 spot welded and the space remaining between the plates after spot welding and which space I ll with a bonding metal vsuch as copper.

Figure 1l shows a plan View of a fiat iron sole plate form of my ironing member in which I have provided means for holding the heating element to the sole plate, the holding means being an integral part of the structure.

Figure 12 shows a side elevation of Figure ll and illustrates how I may use flat plates in building up my ironing member.

Figure 13 shows a cross sectional view of the sole plate of Figures l1 and 12 with the electric heating element in place.

Figure 14 shows how I combine the heat gathering or element holding means of Figure 13 with the sole plate structure of Figure 8.

Figure l5 is a plan view of an ironing member for an ironing machine, which machine may be either of the conventional roll type or of the socalled fiat plate or presser type.

Figure 16 shows an end elevation of the ironing member of Figure 15.

Figure 17a shows a cross section of my ironing member as built for use in an ironing machine and as adapted to be heated by a fuel fed heating element. Figure 17h shows same as adapted to be heated by an electric heating element. Figures 18a and 18h show a construction similar to that shown in Figures 17a and l'Ib excepting that the structure is especially designed to carry the heat over a wider surface than that of the heating element itself. Figures 19a and 19h show my invention as adapted to be heated by other typesof heating elements than those previously shown.

Having given above a general description of my invention I will now proceed to a detailed description of same.

Considering first my invention as I apply it tothe manufacture of sole plates for electrically orfuel heated flat irons, reference is made to Figure 1 which shows the general shape and outline of such a sole plte and to Figure 2 which shows the same in cross section. The bosses I and i in the upper plate 2 provide a location suitable for threads where they will not be filled with bonding metal and where they will permit of the screw members passing all the way thru them for a secure hold. The upper plate 2 is formed usually from a smooth cold rolled steel sheet, into a shape suitable to receive the heating element. The bottom plate 3 is a simple fiat plate, usually stamped from the smoothest obtainable grade of sheet steel and preferably assembled to the upper plate with the burr of the die cut edges upward so that the edge to move over and in contact with the fabrics to be ironed will possess a slight radius. The bottom plate is fastened to the under side of the upper plate 2, preferably first by spotwelding as at 4 and by then introducing a bonding metal be tween the adjacent surfaces of the plates 2 and 3 whereby these plates are molecularly joined together over a large area. I introduce the bonding metal, which is usually copper, preferably in the form of pieces of wire, wrapped about or upon, or enclosed within the assembly, in such position that when heated the bonding metal will melt upon, and be drawn by capillary attraction and alloying affinity into the interstices between all closely adjacent or contacting metal surfaces.

In Figure 3 I show a cross section of my sole plate as shown in Figure l and Figure 2, and along the line A to B of Figure l. It will be seen that by using smooth sheet metal for the plates 2 and 3 that I provide a smooth surface to receive the heating element at 6, also a short path for the transfer of heat to the under surface of the plate 3, which is the ironing surface, and which surface is smooth so that it does not require grinding or polishing previous to plating. Also it will be noted that the intervening bonding layer 5, which is preferably of copper, and which is by the methods set forth herein, intermolecularly bonded to the adjacent surfaces of the parts 2 and 3, forms a heat transferring member of great efficiency, also that this bonding layer distributes the heat over the ironing surface with much greater uniformity, because of its high heat conductivity, than would be the case if the plates '2 and 3 were one integral part as a casting or forging. I also attain another object -in the structure shown in Figure l, Figure 2, and

Figure 3, in that I secure an edge of considerable thickness to my ironing member, which gives the finished iron a desirable appearance. This edge is hollow, hence it absorbs very little heat away from the ironing surface, and conducts less heat up to the cover shell, which normally will rest upon the upper surface of the edge ridge at l.

In Figure 4 I show a plan view of another species o: my invention and in which I disclose provision for a thermal responsive element. The space for this element is indicated on the plan by 8. The metal clip to hold same is shown at 8 and this clip is bonded to the bottom plate of the assembly. The thermally responsive element itself does not form any part of this invention. as such elements are common to this art, but the means which I show at 9 to hold same to the sole plate proper is a part of this invention as will be brought out later in this specification. This thermal responsive element in the usual bimetal strip form is shown in dotted lines at I0. At II, I show how I may close the point of my sole plate by welding a seam up the turned back portion at the point.

Figure shows a cross sectional view of my ironing member along the line C to D, from the point on the left to the heel on the right, as shown in plan in Figure 4. At I2 is shown a relatively thin external shell, preferably made of a smooth finish cold rolled steel, such as is known in the trade as number 3 finish. Into this shell is inserted the filler member I3 of relatively thicker metal, and which metal should be smooth but not necessarily of as smooth a finish as for the external shell. 'I'he parts I2 and I3 are bonded together over their large adjacent surfaces by the bonding layer 5 as are the plates 2 and 3 of Figure 1, Figure 2 and Figure 3.

The numeral 5 will be used throughout this specification to indicate the bonding material used between the principal parts of my inven. tion and which bonding material will usually be of copper fused into place at a temperature slightly above the melting point of the copper, and preferably under the fiuxing and surface preserving action of a non-oxidizing atmosphere during the bonding operation. This operation will hereinafter be referred to as the brazing operation.

At I4 in Figure 5, I show a threaded boss to provide a means for attaching the pressure plate which normally clamps the heating element to the sole plate and also to provide means to hold the cover shell and handle assembly to the sole plate and element assembly. At I5 I show a threaded tab or projection which will provide i facilities for the mounting of the terminals to the electric heating element and for the thermal responsive switching mechanism. At 9, in Figure 5, is shown a section of the clip designed to retain the thermal responsive element in intimate thermal relation to the sole plate. At I0 is shown in dotted lines the usual bimetal strip thermal responsive element as it will normally be positioned in the finished appliance.

In Figure 6 I show a cross section of the ironing member of Figure 4 along the line E to F of Figure 4 and looking to the rear of the ironing member as indicated by D in Figure 4. It will be seen that heat may be imparted to the upper surface of the filler plate I3 at I5 and I5 by heat from either an electrical or fuel fed heat source. The plate I3 possesses the necessary heat absorbing mass, the bonding layer 5, the necessary heat transferring, distributing and evening properties and the thin outer shell I2 the desired smoothness of ironing surface, so that the assembled and bonded structure comprises an extremely eiiicient, satisfactory and economical ironing means structure. It will be noted that the thin outer shell I2 is formed up about the edges to give the desired appearance of a thick sole plate edge. and also that this thin upstanding portion forms a tortuous thermal path of low heat oonductivity between the sole plate and the cover shell which will normally rest upon the turned in flange at It. I have thus provided an extremely efficient means for transferring most emciently and uniformly, the maximum percentage of heat from the heat source to the ironing surface and have also provided means to reduce the heat conductivity or heat leakage to the cover shell. where the least possible amount of heating is desired.

In Figure 7 I show how I hold the thermal responsive element III to the ironing surface plate by means of the clip 9. I prefer to insert a small plate I'I over the thermal responsive element Il and then to bend the upturned edges of the clip I down over and upon the plate Il to hold the bimetal thermal responsive element in place. The plate I 1 may be dispensed with if desired. I prefer to retain it as by so doing a more uniform clamping effect is obtained upon the bimetal. It will be noted that the clip 9 is bonded to the external shell I2 without being in contact directly with the filler plate Il. hence the bimetal strip will be more responsive to the thermal changes in the ironing surface of the external shell than to similar changes in the filler plate I3. 'Ihis is a much desired result which has heretofore been impossible of attainment becanse of the necessity of providing considerable mass heretofore, under and around the thermal responsive member in order to provide enough metal for screw threads, for screws to attach the bimetal, or for the provision of bosses which could be swaged down upon the bimetal to hold it to the sole plate. This large mass of metal near the thermal responsive element has had the effect of making the thermal responsive element more responsive to the heat source than to the ironing surface temperature, and has resulted in undesirable thermal control characteristics. It is not practicable to cast or forge a section thin enough to make it possible to obtain the thermal characteristics which I attain by the means above described.

In Figure B I show a section of the edge of still another species of my ironing member. This is similar to the structure shown in Figure 6 excepting that in Figure 8 I turn up the edge of the nller plate I8 in order that it may be more eillcient as a heat intercepting and absorbing member. It will be observed that any heat source above the plate Il will have such heat as it would radiate over the edge of the corresponding plate I3 in Figure 5 or Figure 6, intercepted, absorbed and conducted to the outer shell I9 by the upturned edge of the plate Il. This result is attained without the conduction of any greater amount of heat up the edge ofthe outer shell. In fact the upturned edge of the shell Il shields the edge of the outer shell from the heat radiation and thus reduces the heatloss to the outer shell and hence to the cover shell.

It is desirable that the parts of my ironing means assemblies be fastened together in assembled relationship before and during the brazing operation. I provide for this in some cases by the means shown in Figures 9 and 10. In Figure 9 I show a plate with a small extruded portion which makes contact with the second plate. This assembly is placed between the electrodes of a spot weider at the extruded point and current and pressure applied. The extrusion is fused and the plates welded together as shown in Figure 10.

It is old in the art to spot weld plates. and even ironing members together. It is also common to weld such plates by means of projections. It is usually the object of such welding to join the plates together with the least possible amount of open space remaining between the plates. However. practice has shown that it is not practicable to simply spot weld such plates together for use as ironing members. Where the plates are welded without the aid of projections they arch apart between the welds. The greatest amount of arch being in the thinner plate. Even when welded with projections and with considerable current and pressure, an appreciable space will remain between the plates intermediate the welds. I'he amount and shape of spacing will vary from less than that shown in Figure 'to quite an appreciable arch. Imperfect heat transfer from plate to plate results, also expansion and contraction strains between plates because of the difference of temperatures and eventually oxidation and the formation of scale on the surfaces between the plates. This results in still less satisfactory heat transfer with warping of the plates and eventually a breaking apart of the plates at or near the welds. The presence of air spaces between the plates or of a scaly surface on the adjacent metal surfaces being a most effective retardant to good heat conduction.

I bond the plates of my ironing member to each other by heating the assemblies, together with a bonding metal, in a furnace having a protective, non-oxidizing or fluxing atmosphere, to a temperature slightly above that of the melting point of the bonding metal, Usually the assembly will be made of cold rolled steel parts and the bonding metal will be copper.

The wetting and alloying action of the liquid copper for the steel surfaces in the presence of the protective or iluxing atmosphere is very great and appreciable areas of adjacent, either contacting or slightly spaced steel surfaces will be completely wetted and joined together by a solid layer of copper molecularly bonded to the steel on either side of the copper layer.

I iind that by thus bonding the plates of my ironing member together that even the slight scale and discoloration adjacent the spot Welds is removed by the reducing action of the protective and iluxing atmospheres, and even in case any rust may be present on the surface of the steel that that too will be reduced to metallic iron. Thus a perfectly clean surface is obtained at all times on the surface of the steel and a perfect bond secured between the plates and the copper.

Since copper possesses many times the heat conductivity of steel, I have found that I can increase the total heat transferring ability of a series of laminated steel plates and copper bonding lms until such heat transferring ability is appreciably greater than a solid mass of forged steel of the same dimensions and very much greater than a cast iron mass of equal dimensions. This is a very great improvement in heat conductivty over simple laminated steel structures or laminated steel structures spot welded together. Such structures have always shown a heat conductivity much less than solid masses and furthermore in practice such heat conductivity as was possessed by these structures was uneven. I have also found that when the copper layer is appreciable in thickness so as to con- I stitute two to eight or more per cent of the total thickness, that it acts as a heat evening or distributina means by which uneven heating of an electric heating elementl or spots of heat concentration will be evened out into a well distributed and uniformly heated ironing surface by the time that it has been conducted thru the steel and copper laminations.

In instances where there are appreciable spaces or considerable voids between the adjacent parts of my ironing means assembly, comparatively large amounts of bonding metal may be required in order to bond the assembly into a solid mass. Also variation by warping or otherwise in successive, supposed to be identical, assemblies may cause a very wide variation in the amount of bonding metal required to produce a perfectly bonded assembly. When melted in the fluxing atmosphere the bonding metal is very fluid and unless the design of the assembly has been properly worked out, large amounts of the bonding metal may be lost by flowing away from the assembly, or the metal may form in droplets on the exterior of the assembly and solidify there where it will have to be ground olf before plating. In any event the bonding metal being usually a more costly material than that used for the balance of the assembly, it is highly desirable to prevent it being wasted or being used in yexcessive quantities.

In Figure 4, Figure 5, Figure 6, Figure 7, Figure 8, Figure 14, Figure 15, Figure 16, Figure 1'7, Figure 18 and Figure 19 I have shown structures each having a turned up edge designed to retain the molten bonding metal within the assembly and thus to prevent waste. In Figure l, Figure 2 and Figure 3 are shown structures designed to fit tightly together about the peripheral edge, thus to prevent loss of the molten bonding metal to the outside of the assembly and to encourage the ow of the bonding metal to the interior portions of the assembly, Of the remaining views, Figure 11 and Figure 12 show well portions in the assembly and into which the major portion of the bonding metal will be placed and to which it will be confined until it is melted. From this interior well it will, upon melting, flow outward between the laminations of the assembly, drawn by the capillary attraction and alloying aillnity of the interstices and adjacent edges of the metal parts. Hence it will be seen that my structures are extremely economical of bonding material and the quantity of bonding material used is utilized most efficiently and effectivelyl It has been described above how spot welding the laminations of an ironing member together results in arches between the welds and voids between the adjacent parts. In closing these voids and lling them with bonding metal a varying quantity of the bonding metal will be required from assembly to assembly due to the natural variations in the extent of the voids or oi the warping. Sufficient bonding metal must be supplied to ll the maximum voids and in the case of those assemblies having little or no voids there will be an excess of bonding metal. In order to prevent the loss of this material or its ilow to the exterior of the assembly, where it would necessitate extra work to remove, I provide spaces within the assembly where the excess may gather, and without harm to the subsequent functioning of the ironing member. In particular will this excess gather in the hollow portions about the periphery of the structures shown in Figure 1, Figure 2 and Figure 3. Also it will collect in the inner corner of the upturned angular side about the periphery of Figure 4, Figure 5,

Figure 6, Figure '7, Figure 8 and Figure 14, where it will be useful in further distributing the heat and in mechanically reinforcing the edge of the assembly.

It is well known that even heating of the ironing surface of an ironing means is very desirable. In the early history of the electric fiat iron great importance was attached to the so called "scorch print test whereby the unevenness of heating of the entire ironing surface of a flat iron was shown very graphically by setting the iron on a sheet of paper and bringing it to a heat which would cause it to scorch the paper. The evenness of color of the scorch was an indication of the A evenness of the heating of the ironing surface.

' riilce the evenness of scorch in favor of other desirable features, especially quick heating. In the early stages of the art it was customary to have to wait eight or even ten minutes for an iron to come up to ironing temperature. With modern irons having thin sole plates and high wattage heating elements it is customary to attain a suitable ironing temperature in one to two minutes. Even with carefully distributed heating elements, very great unevenness of temperature at the ironing surface results from such quick heating and in the use of such an iron wide variations of temperature in the ironing surface will result from the contact of that surface with textiles of varying weight and degree of dampness.

Most thin sole plate, quick heating irons are equipped with thermostatic controls, and such controls do not respond readily to either hot or cold regions of the ironing surface but instead, even at best respond according to an average temperature of the ironing surface. In the case of bimetal actuated automatic controls. the thermal response characteristics are even worse because of the high thermal lag common to bimetals, and which further accentuates any uneven heating characteristic in the ironing member.

By my invention, I overcome the above dimculties and undesirable characteristics. By providing between the plates of my ironing member, appreciable thicknesses of a metal having from four to ten times the heat conductivity possessed by the metal `of the plates, I provide a lateral path of high heat conductivity, crosswise of the normal direction of heat ilow, by which the heatY is encouraged to flow from the hotter to the cooler portions of the ironing member before it comes to the surface in contact with the material to be ironed. Thus my ironing member will give faster heating and more even heating of the ironing surface than a solid steel forged ironing member of similar dimensions and much faster and more even heating than a cast iron ironing member of similar dimensions.

By forming projections on one or more of the parts of my ironing member and spot welding the parts together at these projections with the correct current and pressure a structure as shown in Figure 10 is obtained in which the parts are fastened together and yet suitably spaced to permit the introduction of the desired thickness of bonding metal.

I do not spot weld the parts of my ironing member assembly together either to secure strength of assembled structure or to secure good heat conductivity, but rather for two other very different purposes, which are; i'irst, to properly space the adjacent surfaces of the assembled parts so that the desired amount and thickness of bonding metal may be introduced between the adjacent surfaces; and second, to hold the adjacent assembled parts in assembled position during the brazing operation when the bonding metal becomes fluid. Most bonding metals and in particular copper, have a pronounced lubricating action between the adjacent steel surfaces when melted. Such assemblies as I propose, if not spot welded, or similarly fastened, would become displaced even to the sliding of the parts completely apart, during the brazing operation.

I am also aware that there are other ways in which the plates of my ironing member may be welded together in which the projections of Figure 9 and Figure 10 are not used. I may use small slugs of metal, or pieces of wire which will be quickly heated and fused into the adjacent surfaces of the plates, holding them together with sumcient strength for my purpose, but I find that such slugs or pieces of metal become displaced before the welding operation and cause diillculties with the assembly.

In Figure l1, I show a plan view of another species of my invention. In this species of my ironing member I provide a means at |20, integral with the ironing member by which I hold the heating element and pressure plate in most excellent heat conducting relationship with the ironing surface. In Figure l2, I show a side elevation of the structure shown in plan in Figure ll. It will be seen that in this species I have built up my ironing member by a series of flat plates |2|, |22, |23, |24, superimposed one upon the other with constantly decreasing area towards the top. Upon the uppermost plate I place a stamped metal shell |2|I, of a shape corresponding to the shape of the heating element and having upturned edges. 'I'he assembly is bonded together as has been described above, the bonding metal as shown by 5 joining all plates and the superimposed element retaining shell into one integral structure, after which the edges where the laminated plates form a series of steps may be ground and polished to a smooth bevel.

In Figure l1 at |25 I show retaining means for a thermal responsive element, whereby such an element may be held in close thermal relationship with the ironing surface. The structure here shown is similar to that shown at 8 in Figures 4, 5, 6 and 7. In this case however the retaining means 8 is fastened to the lower plate |2| making up the lower of the series |2|, |22, |23 and |24 which comprises the main mass of the ironing member. 'I'he retaining means is shown located at the bottom of a well formed by openings in the plates |22, |23 and |24.

At |26 I show a threaded means for receiving the screw which holds the cover shell, element terminal mechanism and thermal control switch mechanism to the ironing member. These mechanisms form no part of my invention, are common to such structures and hence are not shown herewith. The threads are tapped in the upper plate |24 only and ie plates |22 and |23 are cut away under the threaded hole in order that screw fastening means may pass clear thru the threaded hole |20 without obstruction and have clearance for imperfect end threads and for variation in the length of the fastening screw. This construction is a variation of that shown at I in Figures 1, 2 and 3.

Figure 12 further illustrates in side elevation the position and construction of the thermal responsive element retaining means and of the threaded means by means oi' dotted lines.

In Figure 13 I show, by the line I to J, the angle and line to which the grinding of the stepped edge should be carried. This grinding operation may be performed after the assembly is made and before brazing, but I prefer to do it after brazing. If it is done before brazing it is possible that globules or masses of excess copper may gather upon the ground edge making it necessary to refinish same.

In grinding down and polishing the beveled edge after brazing it is to be expected that the copper being soit will show a slightly depressed line after plating and bufling. This line will not ordinarily be distinct enough to be objectionable, in fact, it may be considered as decorative. The

distinctiveness of this line may be varied to suit by the proper thickness of copper. The thicker the layer of copper between the steel plates the more pronounced the line. By proper manipulation of the thickness of the copper and of the grinding and polishing operations the line may be practically obliterated. Especially by grinding or polishing across the laminations of steel and copper may the appearance of the line be made less pronounced. At the right side of Figure 13 I show at |38 how the beveled edge will i In Figures l1, l2 and 13 I have shown how I may4 braze together at one operation, iirst; means for retaining a thermally responsive element to the ironing surface plate of my ironing means, second; means for retaining an electric heating element in close thermal relationship to the ironing member, third; threaded means for holding the cover shell and other mechanism to the sole plate portion of my ironing means, fourth; means for conducting the heat from the element cover or pressure plate to the ironing surface parts, and iifth; means for conducting the heat from the heating element to the ironing surface and of evening out the inequalities of temperature at the ironing surface. I may also make the plate |2| of a material which may be hardened by quenching and complete that hardening as the concluding portion of the brazing operation by quenching the assembly as it leaves the brazing chamber. Or I may make the plate |2| of a material which may be subsequently surface hardened.

In Figure 14 I show another species of my invention in which I provide a shell |39 similar in design and purpose to |20 in Figures 11, 12 and 13. The dotted lines |40 show the position of the upper edge of this shell after it is formed down upon a pressure plate, the upper surface of which would be approximately represented by the dotted line |4| and the heating element by the dotted lines at |42. The numerals |42 and |43 show an ironing surface shell and filler member respectively of a construction similar to that shown in Figures 4, 5,16, I and 8. 'I'he cover shell will rest upon the ironing member at |44 and the completed structure constitutes the most eiiicient form, from the heat economy standpoint, of any of the species of my ironing member shown in this speciiication.

In Figure 15 I show a plan view of a species of my ironing member which is particularly adapted for use with a fuel heated or electrically heated ironing machine of either the roll type or of the so called fiat plate or presser type. The main ironing surface part or shoe part is |45. The heat intercepting and conducting parts are in channel form and shown at |46. The threaded fastening means is shown at |41.

Figure 16 shows an end view of the ironing member shown in plan view in Figure 15. This is shown curved to fit a roll but may also be made flat when so desired for use in the presser type of ironing means.

In Figure 17a I show a species of my invention especially adapted to be used in ironing machines. Here I propose to heat my ironing member by a fuel fed heating source. The burner tube |50 containing the ports |55 thru which the iiames |54 emerge to impi-nge upon the upstanding portions of the ironing member at |56 thus heating the upstanding portions which heat is conducted thru the layer of brazing metal 5 to the ironing surface |48. In 1'7b I show a similar construction adapted to be electrically heated by a compression held heating element. In Figure 18a I show a similar construction adapted to be heated by a ceramic embedded electric heating element. In Figure l8b I show a similar but modified construction whereby the heat from the heating element is distributed laterally over the ironing surface very effectively. In Figure 19a I show a similar construction in which a coil form of electric heating element is supported in insulating blocks |61 and |68 and the heat transferred to the ironing member by conduction' thru the blocks and by radiation. Figure l9b shows how a plurality of coils may be embedded side by side in a ceramic mass to give still better heat distribution. Also Figures 19a and 1917 show at |10 how I propose to support the cover shell |12 by a thin edge extension of the ironing surface and thus to minimize the loss of heat by conduction to the cover shell.

In Figures 19a and 19h I show how I may use a very thin ironing surface part |10 and a heavier filler plate |1| to give me an overall construction not unlike that of Figures 5, 8 and 14. The thin ironing surface part |10 is spaced away from the filler plate |1|, where it is turned up at the edges in order to form a tortuous thermal path of low heat conductivity to the cover shell, shown at |12 in dotted lines, and shown held to the iron ing member by the bolt |13. The cover shell forms no part of this invention. By this construction I reduce to the lowest possible degree known to the art, the loss of heat from the iron ing member to the cover shell and consequently to the handle parts. This isan important fea ture of my invention as the problem of reducing the heat conducted to the cover shell and handle parts of electric fiat irons and ironing machines has been the subject of much experimenting and research. The lower the temperature of the cover shell and handle parts the greater the comfort of using the appliance, especially in hot weather, and the less the heat conducted to those parts the greater amount will be reserved for useful work at the surface of the ironing member.

Means for fastening the parts of Figures 15, 16, 17a and llb, 18a and 18h and 19a and 19h to the supporting, manipulating, and pressure applying arms or to the ironing machine proper are not shown as they do not form any part of my invention.

By reference to Figure 2 and Figure 3 it will be noted that I use a single flat sheet, 3, of metal for the ironing surface of my ironing member. This single sheet may constitute as great a percentage of the total mass of my ironing member as the particular design may call for and I may use a metal or alloy of different characteristics for this part. By using a steel of high carbon content for the part 3, I can heat and quench the brazed assembly and thus secure a very hard surface for the ironing surface of my ironing member, without the necessity of hardening the other portions of the assembly. It is even possible and in fact highly desirable that the quenching take place at the conclusion of the brazing operation and before the assembly has cooled entirely, and without having allowed the assembly to be removed from the protective atmosphere before entering the quenching medium. The above is one manner in which I may provide a hard ironing surface. I also may use a steel or metal alloy for plate 3 capable of being surface hardened by suitable treatment such as case hardening, Chapmanizing, or nitriding. Since most of these surface hardening treatments are inhibited by a coat of copper plating, I may copper plate the shell 2, of my assembly previous to brazing. The copper plating will be of assistance in the brazing operation and will inhibit the surface hardening of part 2 when the brazed assembly is subjected to the surface hardening treatment.

To those skilled in the art it will become apparent from the description herein that I have attained the numerous objects of my invention by the generic and specific structures and methods shown, and in particular:

I have reduced the cost of manufacturing ironing members, by means of an assembly of stamped sheet metal parts having smooth surfaces which require little or no costly grinding or polishing in order to bring to the desired smoothness of surface finish, as do cast or forged structures.

I have further attained the objects set forth by bonding the sheet metal parts together into a unitary structure by a bonding metal of lower melting point than the melting point of the metal of the sheet metal parts and preferably of higher heat conductivity.

I have molecularly bonded the stamped sheet metal parts of my ironing member together over large areas of the adjacent parts, thus providing an integral structure of excellent heat transfer qualities, in contrast to the spot welded, clamped or riveted laminated structures shown in the prior art, which were subject to warping apart, formation of oxide films between laminations, uneven contact and consequent very unsatisfactory heat transfer. I have attained the object of higher speed of heating and greater evenness of temperature at the ironing surface by bonding the stamped sheet metal parts together by means of a bonding metal of much greater heat conductivity than the heat conductivity of the metal of the sheet metal parts. In particular, I have, by this feature of my invention, been able to eliminate hot spots on the surface which comes in contact with the material to be ironed. Such hot spots have always been present, heretofore, in thin ironing members and especially so in thin ironing members with high wattage heating elements. This has been due mainly to the fact that the heating elements did not dissipate the heat uniformly from their areas, either because of uneven heat generation or uneven heat conductivity or heat transfer to the heat absorbing member. By means of interleaving films or sheets of a metal of high heat conductivity, I am able to even out and to make uniform over a large area of ironing surface the uneven heat transfer from the heating source.

Heretofore when it has been desired to secure a uniform heat distribution from a nonuniform heat source, it has been the custom to use heat transfer means of higher resistance to flow of heat, such as a thicker heat transfer member or one of lower heat conductivity. This has resulted in a much higher heat gradient between the heat source and the ironing surface, which in turn is deleterious to the long life of the heating element and also gives a slow heating ironing means.

By replacing the usual solid forged or cast rim at the edge of the ironing member by a hollow sheet metal structure, I have reduced the useless weight of my ironing member and have attained the desirable end of a much higher ratio of active heat transferring mass to heat `storage mass. By the same means, I have attained a thin interior cross section, quick to heat thru, together with a thick appearing rim or edge which is so desirable for sales reasons.

By providing upstanding projections or fins which are integrally united with lthe principal mass of my ironing member and in excellent heat transferring relationship to the ironing surface thereof, I have provided a most emcient means for the absorption of heat from the heat source and for its conduction to the ironing surface. By bending these upstanding portions so as to retain a heating element to the ironing member thereby. I have provided a very efficient means of binding the element into excellent heat transferring relationship to the ironing surface and also of gathering the heat from the opposite side of the heating element and of conducting it to the ironing surface.

In building up the assembly of my ironing member, I secure a reasonably close flt of the exposed seams between the parts, such as may be expected from efncient tools, equipment and workmanship. I find that the bonding metal will flow into the interstices of such seams and illl them up so completely that after the brazing operation has been performed it is usually unnecessary even to polish the seams to secure a sufficiently smooth, continuous and uniform surface for plating.

I may also use other metals than steel for the parts of my assembly or for certain parts of the assembly. Some parts may be of cast iron and others of steel. Forgings, castings and sheet steel parts may be brazed together in the same assembly. Brass may be used instead of steel and may be successfully brazed, either to other parts of brass or parts made of Mone] metal or steel or of several other metals vand alloys. In brazing brass to brass it is usual to use a brass of high melting point for the parts of the assembly and a lower melting point brass for the bonding metal. With different metals and combinations of metals in the assembly, different bonding metals will become advisable, and also the use of fluxes additional to the non-oxidizing atmosphere will be often found helpful. Also the bonding metal may be applied in different forms. Pieces of wire, sheets, foil, pulverized or granulated metals, so-called electrolytic dust of metals may be used. The finely powdered forms may best be applied mixed with lacquer binders and painted or sprayed into place before the heating in the brazing furnace.

I may also apply the bonding metal by plating one or more of the parts of my ironing member assembly with the bonding metal to be used, or I may combine plating of some or all of the parts together with additional bonding metal applied as described heretofore. The plating of the parts with the bonding metal or with some metal which will enter into the bonding functions may also be utilized to prevent the corrosion of the brazed assemblies before they are plated. When the brazed assemblies come from the furnace they are perfectly clean and free from any grease or organic materials on the surface. They are therefore subject to immediate and active attack by any corroding agency. A thin plated coating of such a metal as copper will assist in the brazing operation and also provide a corrosion preventing coating for the assembly until i-t is plated.

Attention is particularly directed to the combination of very desirable ends which I attain in the structures set forth above, and the extreme practicability and economy of manufacture of my ironing member and also the excellent heat transfer characteristics, and the advantageous and efficient assemblies permitted by the structures I have described above.

Altho I have described my invention with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scop'e of the invention as hereinafter claimed.

I claim:

l.. In an ironing member, metal plates adapted to be heated by a heating element and bonded together into substantially parallel relationship over an area similar to the area defined by the heating element by a bonding metal of higher heat conductivity than the heat conductivity of the metal of the said plates.

2. An ironing member comprising, metal plates adapted to be heated by a heating element and bonded together over an area similar to the area of adjacent surfaces of the heating element by a bonding metal having from four to ten times the heat conductivity possessed by the metal of the said plates.

3. An ironing member comprising, metal plates adapted toconduct heat from plate to plate, an interleaving heat spreading and heat evening sheet between the said plates of a metal of higher heat conductivity than the heat conductivity of the metal of the said plates.

4. In an ironing member of laminated metal parts bonded together into an integral structure over an area opposite the major part of the ironing surface. a lesser area of relative thinness, attaching means for a thermal responsive means in said area of relative thinness, said attaching means being metallically bonded to the side of said area of relative thinness opposite the ironing surface thereof.

5. In a device of the class described, a combination of heat absorbing means, heat transferring means and sheet metal ironing surface means, said combination of means being bonded together by relatively thin layers of a metal of greater heat conductivity.

6. In a device of the class described, a combination of heat absorbing means, heat transferring means and sheet metal ironing surface means, 'said combination of means comprising a laminated structure adapted to conduct heat across the plane of said laminations, and an interleaving bonding metal of high heat conductivity -between the said laminations, said bonding metal tending to equalize by lateral heat conductivity any uneven heating of the said heat absorbing means.

"I. An ironing member comprising sheet metal parts adapted to be heated by a heating element and assembled together with adjacent heat transferring surfaces of an area similar to the area defined by the heating element, the interstices between the said adjacent surfaces illed by a bonding metal having a heat conductivity greater than the heat conductivity of the metal of the said plates.

8. In a device of the class described, a combie nation of heat absorbing means and sheet metal ironing surface means, said combination of means adapted to be heated by a heating element and comprising a metallic structure laminated over an area similar to the area of the heating element and less than the area of the ironing surface and adapted to conduct heat across the plane of said laminations and an interleaving layer of a bonding metal of relatively high heat conductivity molecularly bonded to the adjacent surfaces of the said laminations, filling the interstices between the said laminations and facilitating the transfer of heat to the said ironing surface.

9. In a device of the class described, a combination of heat absorbing means and sheet metal ironing surface means, said combination of means adapted to .be heated by a heating element and bonded together by a bonding metal having a heat conductivity high relative to the heat conductivity of steel and providing an integral structure thereby, and means comprising a hollow, downwardly opening V shaped section about the edge of said heat absorbing means to retain any excess of said bonding metal.

10. In a device of the class described, a combination of heat absorbing means and sheet metal ironing surface means, said combination of means adapted to .be heated by a heating element and comprising a metallic structure laminated over` an area similar to the area of the heating element and adapted to conduct heat across the plane of said laminations, an interleaving layer of bonding metal of a heat conductivity high relative to the heat conductivity of steel between the said laminations and bonding the said laminations together and means adapted to retain said bonding metal within the said combination of means comprising an integrally formed upstanding edge on said ironing surface means.

11. In a device of the class described, a combination of heat absorbing means and sheet metal ironing surface means, said combination of means adapted to be heated by a heating element and providing a laminated metallic structure of an area Similar to the area of the heating element, an interleaving layer of bonding metal between the laminations, bonding said laminations together and providing a structure of high thermal continunity over an area similar to the area of the heating element, said heat absorbing means formed away from said ironing surface means at the perimeter of the area interleaved with bonding metal and reversely formed to the said ironing surface means at the edge of said ironing surface means and comprising an enlarged section about the perimeter of said combination of means, said enlarged section having a thermal continuity less than that of said laminated metallic structure.

12. In a device of the class described, a combination of heat absorbing means and sheet metal ironing surface means, said combination of means adapted to be heated by a heating element and comprising a metallic structure laminated over an area similar to the area of the heating element, and an interleaving layer of bonding metal molecularly bonded to the adjacent surfaces of the said laminations, said heat absorbing means adjacent the perimeter of the heating element area formed at an angle to said ironing surface means and providing a raised edge portion about the heating element area, said heat absorbing means being reversely formed to reengage the ironing surface means at the edge of said ironing surface means.

13. An ironing member comprising a combination of heat absorbing means and sheet metal ironing surface means, said combination of means adapted to be heated by a heating element and to support a cover shell in spaced relation to said heating element, said combination of means comprising a metallic structure laminated where directly heated by said heating element, said laminations being welded together at spaced intervals and means preventing oxidation of the adjacent surfaces of said laminations intermediate the welds consisting of a layer of brazing metal molecularly bonded to the said adjacent surfaces of said laminations, and a raised portion about the perimeter of said combination of means supporting said cover shell at a position more remote from the ironing surface than is said heat absorbing means.

14. In a device of the class described, a combination of means comprising, an ironing surface means adapted to be heated by a heating element, means for supporting 'a' cover shell in a position more remote to said ironing surface means than is the heating element, including acutely formed extended edges of said ironing surface means,

means for retaining said heating element within the area denned by the said acutely formed extended edges, said means for supporting the cover shell and said means for retaining the heating element being connected to each other by the ironing surface means and by an interleaving layer of bonding metal.

l5. In a device of the class described, a combination of means comprising a heat absorbing means adapted to be heated by a heating element and to support a cover shell in spaced relation to said heating element, an ironing surface means metallically bonded to said heat absorbing means over an area similar to the area of the heating element by a bonding metal having a heat conductivity high relative to the heat conductivity of steel, said heat absorbing means including an inverted- V shaped formed section at the edge thereof adapted to support the edge of a cover shell at a level more remote to said ironing surface means than the metallically bonded portions of said heat absorbing means.

16. In an ironing member, metal heat transferring plates adapted to be heated by a heating element, spacing lugs extending from the adjacent surface of said plates and providing contacting means between the said plates, the areas of surfaces intermediate the contacting means being bonded together by a metal having a heat conductivity high relative to the heat conductivity of steel.

17. An ironing member comprising sheet metal parts adapted to be heated by a heating element and bonded together over an area similar to the area of the heating element by a bonding metal having a heat conductivity high relative to the heat conductivity of steel, a combination of means to provide an ironing surface, means to support a cover shell in spaced relation to said heating element and to retain any excess of said bonding metal, comprising an inverted V shaped formed portion at the edge of said ironing member whereby the point of said inverted V is adapted to support the cover shell and the base of said inverted Visadaptedtocooperatewiththesaidironing surface means to retain any excess of bonding metal.

WILLIAM A. BARNES.

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