US2871589A

US2871589A - Electric iron

Info

Publication number: US2871589A
Application number: US560990A
Authority: US
Inventors: Fred C Schwaneke
Original assignee: DORMEYER CORP
Current assignee: DORMEYER Corp
Priority date: 1956-01-24
Filing date: 1956-01-24
Publication date: 1959-02-03
Anticipated expiration: 1976-02-03

Description

Feb. 3, 1 959 F. c. SCHWANEKE ELECTRIC IRON 3 Sheets-Sheet 1 Filed Jan. 24, 1956 g oE 8. h w w ow Q. 767 i, I 4/ a. h 4. q rt 8. a 8 L y A ($20 0n 0 we. 8 5 Q on. 3. W 2 mm. Nn Q/ J m 2 m m N9 02 8 Q om vm mm mm Feb. 3, 1959 F. c. SCHWANEKE ELECTRIC IRON Filed Jan. 2 1, i956 3 Sheets-Sheet 2 INVENTOR:

Feb. 3, 1959"" F. c. sHwANEKE 2,871,589

ELECTRIC IRON v Filed Jan. 24, 1956 I 3 Sheets-Sheet 3 IN VEN TOR:

FRED C. SCHWANEKE ELECTRIC IRON Fred C. SchwanekeyChicago, Ill., assignor to Dormeyer Corporation, Chicago, Ill., a corporation of Illinois Application January 24,1956, Serial No. 560,990 I 8 Claims. (Cl. 38-77) This invention relates to electric irons, and more particularly to thermostatically-controlled irons operable either dry or with steam discharging through openings in the sole plate, as shown in application Serial No. 425,814, of which the present application is a continuation-in-part.

It is necessary, in steam-ironing many of the modern synthetic fabrics, to use temperatures as low as the boiling point of water, which is impossible with conventional steam irons in which the sole plate becomes alternately too hot and too cold in seeking the low temperature. Accordingly, the present invention contemplates a construction and control means which will reduce the swing or differential between high and low temperatures in the sole plate in achieving a desired temperature of as low as 200 F. thermostat setting, either with or without steam and without water-spotting of the fabrics.

By separating the sole plate into two members, one containing the heater and the other forming the sole plate member with the ironing surface thereon, as described. in the aforementioned copending application, the effective heat transfer contact from the heater member to the sole plate member can be determined both as to areaand location sothat a sufiicient amount of heat is available for vaporizing the water dropped into the heater containing member without overheating the sole plate member. Furthermore, an improved thermostat responsive to the temperature of both members can call for more heat if either member is deficient, it being appreciated that extra heat developed in the heating member passes to the sole plate member under controlled transfer if not used for water vaporization.

In providing this, an improved thermostatic control is bodies being controlled are part of the control'and the.

control is instantly effective both to apply heat andcut ofi heat within close limits. 1 i

A further object of the invention is to locate the electrical components of the thermostat where the electrical connections and assembly parts are readily accessible,

for assembly, repair and replacement of parts. 7

Another object of the invention is to provide a handle for the iron which permits grasping and manipulation of the iron closer to the point and is secured to the rear housing thereof by means of a hollow vertical post which protectively houses the thermostat controls with a lever extending forwardly through the wall of the port for selective adjustment of the thermostat.

A further object of the invention is to provide an uninterrupted space for a layer tank' for water within the top valve construction shown in Fig. 1.

ired Sttes Patent ()fii cc ,if 3,

access from above the iron being located at the rear thereof at a considerable savings in material and labor,

Another object of the invention is provision of a manually operable thermostat control lever. having. a readily attachable spring construction for removably engaging the thermostat shaft for rotation thereof in obtaining to desired temperature setting for the iron without damaging strain-upon the shaft under anyconditions of use so that raising or lowering the lever into contact with the handle slot during turning, orblows, or the application of excessive force, will cause no damage.

Another object of the invention is the provision'of a handle and post arrangement in which 'theextension cord and collar means therefrom extend vertically through said handle near the rear thereof for electrical connection directly with the thermostat and heater means, with the cord being held in spaced relation to the thermostat lever within the handle and maintained in a position above the handlewhich will permit both right and left-handed users to operate the iron with equal ease.

Another object of the invention is the provision of a handle for the iron which is further simplified by constructing the valve adjustment means for determining the flow of water into the steam chamber unitarily with the iron housing and by forming the inlet valve for thewater tank unitarily with the valve adjustment means in the housing to be assembled and inserted in place easily and readily. V p

Other objects and advantages of the invention will become apparent as the description proceeds in accordance with the drawings, in which:

"Fig. 1 is a vertical longitudinal sectional view of the iron embodying the invention; 1

Fig. 2 is a plan view partly insection of the two part sole plate with the thermostat elements in place;

Fig. 3 is a fragmentary side elevation of the iron;

Fig. 4 is a transverse vertical sectional view taken along the line 44 of Fig. 2; V

Fig. 5 is a horizontal sectional view taken along the line 55 of Fig. 1; and v 1 Fig. 6 is an enlarged view partly in section of the Referring now to Fig. 1, the iron embodying the invention comprises a sole plate assembly 10, a housing 11 thereon having a tank 12 therein, a valve device 14 at the front end of the housing, a handle 13 secured to the housing at the rear thereof, a manual lever 15 extending forwardly at the base of the handle post 16, and an extension cord 17 extending vertically from the post 16, by which electricity is supplied to the heating components of the iron as controlled by a thermostat construction indicated vgenerally at 18.

In the preferred embodiment of the invention, the sole plate 10 is made up of essentially two members and the heat control: the bottom member 20 of a metal such as aluminum having good heat conductive and expansion characteristics with or without a polished thin layer of stainless steel 19 bonded on the bottom thereof; a heater carrying member 21, also made of high heat conductive metal such as aluminum, with a preferably high coefiicient of expansion, and the thermostat assembly 18. The housing 11 covers the sole plate and preferably is coextensive therewith except at the rear where it extends beyond to form a connection box opening.

The bottom member is made substantially uniform in thickness throughout the major portion thereof, but has an upwardly projecting flange 24 surrounding its marginal edge shaped to mate with the lower marginal edge of the finishing housing 11. Within this marginal flange 24 a channel or cavity is defined at 25 that is U-shaped in its plan View, as bounded by a continuous upstanding wall 26. Leading from the cavity 25 are steam openings 27 through the bottom wall that terminate in enlargements 28, to form a part of conventional grooves 36 on the bottom of the lower member where the face is highly polished for ironing purposes. Steam is ejected through the openings 27 along the grooves 36 when steam is being generated.

The heater carrying element 21 has a lower marginal flange 3i which follows the inside contour defined by the Walls 26 of the cavity 25 in snug relationship, and the lower face of the heater carrying member 21 may also be provided with a plurality of

lands

32 and 33 whose lowermost faces are coplanar with the flat bottom of the cavity 25. The outermost land 32 preferably defines the overall size of the heater carrying member in a horizontal direction, whereas the innermost flange 33 defines a path through which the steam passes to reach the openings 27.

The bottom area of the

lands

32 and 33 defines pre determined heat transfer contacting areas between the metal stock of the member 21 and the metal stock of the sole plate 29. However, it is within the scope of the invention to form the lands 3n and 33 and the sole plate 26 integrally since limiting the heat exchange for controlling the supply of heat to the sole plate will be maintained by this construction also.

Above the pathway 34 the heater 35, which is a U-shaped, metal-encased resistance heater of high wattage, (approximately 1060 watts), is embedded in a boss 36 of extra thickness on element 21, which follows the heater in its shape. The heater is cast in this boss at the time the heater carrying member 21 is die-cast so that an intimate heat exchange contact is present throughout their interface and the ends of the heater extend outwardly as at 37 and 37 at the rear end of the element 21 where leads 33 and 38 may be used to connect the heater to the thermostat control means, as will be hereinafter further described.

As more particularly shown in Fig. l, the stock of the heater carrying element 21 on the included side of the curve of the heater is shaped or cored out to provide a steam generating chamber at 39. The walls 43 of this chamber are designed to give maximum surface contact with fluid present therein and have an exit through a narrow slot 40 and 40' on each side thereofinto a diverging passageway 41 and 41' on each side of a diverting island 42 which causes the fluid to follow many turns at which the steam is forced to come into violent contact with the walls 43 of the steam generating chamber. ultimately, the two streams pass into

openings

44 and 45 to channel 34 in the cavity 25.

The cover 22 is made of a low heat conductive metal such as stainless steel and preferably covers only the steam generating chamber and labyrinth as held in place by screws 46 in sealed relationship around the margin in the steam chamber. Directly above the steam chamber 39 the cover is provided with an upset annulus 47 on top of which rests a heat insulating washer 48 preferably made of silicone rubber so that conduction of heat upwardly is blocked at this point.

Preferably the fluid engaged area of the walls 43 is equal to or greater than the coplanar area of the

lands

32 and 33. Thus the fact that the amount of heat transmitted from the heater member to the sole plate is limited by the

lands

32 and 33 insures that the sole plate member will not become overheated in response to surplus heat generated in the heater member in the first instance. Thus this heat will remain available to the steam generating chamber and with both steam and dry applications will gradually penetrate and infuse the sole plate member to provide an unusually even heat therein.

Because of the relatively low temperature differential between maximum and minimum heat conditions in the sole plate for any given thermostat setting, it is highly desirable to provide sensitive heat control means so that 4 such maxima and minima will be sufiicient to actuate the on-ofi" mechanism of the thermostat. In accordance with this objective, thermostat control means are provided which magnify the effect of a given temperature change by utilizing a thermally responsive member of high coefficient of expansion having much greater length than the usual control means. The sole plate itself is used to provide the elongate member, and since it is the heat in the sole plate which it is desired to measure, there is no problem of heattransfer or heatloss such as would occur when the heat from the sole plate is utilized to actuate a separate thermally responsive element.

The thermostat 18 is mounted at the back of the iron so that the greatest length of the sole plate will be used for control purposes, andycomprises a pair of

spring blades

50 and 52 mounted in parallel axial relation by means of insulating ceramic washers 54, 56 and which are secured to the sole plate 26 by a bolt 60. An adjustment sleeve or shaft 62 is threadedly engaged in a collar 63 mounted on a bracket 64 for adjusting the position of the upper blade 50 relative to the blade 52, so that

contacts

66 and 68 on the respective blades can be brought into a predetermined spaced relationship. A manually operable lever 15 is' provided for this purpose as will be hereinafter further described. 7

The changes in length or expansion in the sole plate resulting from temperature variations therein are translated into force for moving the lower blade 52 and contact 68 into circuit-making or circuit-breaking contact with blade 50 and contact 66 by means of a bowed spring 72 carrying a ceramic button 74. A comparison or control rod 76 for this purpose is secured to end 70 of the spring 72. The other end of the spring is fastened tothe extreme back end of the sole plate member 2% by a clamping bolt 78 threaded in a boss 86. The control rod 76 extends to the front of the iron and by a rivet 79 is secured to the heater carrying member 21, in intimate relation along the steam chamber 39.

The spring 52 is biased downwardly slightly to be in constant engagement with spring 72 and button 74. Thus the expansion of the sole plate 20 in response to temperature increases will cause the less expanding rod 76 to draw or flatten the spring and lower the level of button 74 to move blade 52 awayfrom blade 50. During cooling phases in the sole plate member 26 the opposite effect will occur, i. e. the spring 72 will be permitted to recover. Relatively small changes of temperature will therefore serve to make or breakfcontact in the thermo stat, depending on the initial calibration thereof, because the effect of expansion or contraction of the aluminum over a major portion of the sole ,plate will produce a. quite substantial change in the relative lengths involving the rod 76 and even small changes can actuate the spring 72 efiectually.

However, the invention also contemplates an anticipation effect which will indicate the direction of temperature change in the sole plate and permit heat to be applied or turned off in accordance with the tendency towards a cooler or hotter sole plate respectively. Thus the heater containing member 21 is provided with a central axial channel 82 for receiving rod 76 in heat exchange contact therewith and a continuation of this channel is provided by means of a ridge 84 formed integrally with the sole plate member 20 having a channel 86 therein. Although the rod 76 does not respond to thermal changes with any great degree'of contraction or expansion, as stated, yet some change is effected thereby, which is suliicient t; change. the elevation of button 74 significantly. This amounts to an anticipation of the direction of temperature change and is particularly desirable with the iron ofthe present invention and is achieved by virtue of the fact that a greater portion of rod 76 contacts the sole plate alongridge 84 than the heater container member. Thus where the sole plate'is relativelywarm but the heater carrying member is cool a-relative elongation of rod '76 will be produced which will counteract to an-extent the elongation in the sole plate proper-and serve to maintain the button 74 in a closer proximity to its circuit closing position than would'occur if rod 76 wereinsulated from the sole plate. Consequently, reactivation of the heater will be produced more quickly. j

On the other hand, thecondition of a relatively cool sole plate member 20 andhotheater-containing member 21 will activate the thermostat to turn ofl? the heat and let the heat be conducted into t-he bottom member to warm it and to prevent .the sole plate from reaching an undesirably low temperature range ,at' such times. Also, where the sole plate is cool and heater-containing member 21 is hot, heat used to vaporize water will leave the heater member and the'thermostat is more quickly ready to supply more heat before the'heater member is unduly chilled and the heater will be turned relatively quickly in antici- .pation'of the effect to :beproduced in the sole plate by less heat available from member 21. i

It will be; appreciated that the same effect will be produced where heater-carrying member 21 is formed integrally with member 20 by elimination of

interfaces

32 and 33 and such'an embodiment is also-within thescope of the invention.

The position of the thermostat 18 at the back of the iron not only eliminates the need for constructing a verpending on which side of the iron the cordwas inserted} In the present invention the iron is equally ambidextrous. The cord 17 extends vertically a substantial distance above the top 90 of the post 16a's held by means of a strain ele-- ment 92 whose base is's'ec'ured in an aperture-94 by means of shoulders 96 and '98. 'A strain relieve clip 100 prevents Withdrawalof the cord, the inner end of the cord being received through an aperture 104 in the housing 11.

Terminal leads 106 and 108 are connected into the heater'circuit through the thermostat 18, the lead 106 being welded to a contact ear 110 which is connected to heater terminal 37 by the 'wire 38','while lead 108 is welded to spring blade 50 of the thermostat. 'The lower spring blade 52 is connectedito terminal 37 of the heater via contact bar 112 andwire38, a wire 114 extending between this contact bar and blade 52.-" Consequently, when the,

contacts

66 and 68 are brought together, the heater circuit is completed. 1

The. position of thermostat 18 and its electrical connections at the rear of the iron makes for easy repair and replacement of-p'arts through an opening 120 below the overhangvof the finishing housing 11 and the rear end of the lower member 20, where. a .closure plate 122 is mounted in place byascrew 124 threaded into a bracket 126 that is secured in place by the, bolt 60 which holds washers 54, 56and58 in place. n Bolt 60 also holds an other bracket 1 28 in place which receives a screw 130-that holds the post 16 in place as at 132, in axial relation with the pin 62, and the upper end, of the pin extends into the chamber 102 in the post and is protected against damage by the outer walls of the post. The post is recessed or slotted at its front side immediately. above the housing 11 to receive therethrough the lever 15, whose construction will now be described. t J I With conventional thermostatic controls, one of the problems is thatvthe operating handle or lever can be bration. The present construction avoidsgthisbyprovid- 7 ing a removable spring connection between the lever 15 6 and pin 62, so that blows or pressure on the 'lever will not be transmitted to the pin. However, the connection is such as to prevent play between these elements horizontal- 1y. The lever has a J-shaped spring member 134, as best shown in Fig. 5, which is formed with slightly offset

bars

136 and 138 adapted to engage with a nut 140 on pin 62 and in

parallel notches

142 and 143. The ends 144 and 146. of the lever are flared outwardly slightly to permit the lever to be moved easily onto the pin. A handle 148 of plastic or the like is provided at the forward end of the lever, preferably by molding around the bend of the spring 134, slightly above the housing 11'so that axial movement of the pin effected by moving the lever 70 through a predetermined amount of angular rotation will not cause the lever to press against the housing, which could effect the calibration.

The handle 13 is simplified by forming the valve construction 14 in the housing 11 rather than in the handle tank is depressed to provide a low'point 152.' An opening through this low point receives the threaded end 154 of a kerf-headed sleeve nut 156 whose shoulder at 158 engages the upper face of the depression 152 and as turned by a screwdriver clamps the bottom portion of the depression against seal 48 and draws down upon the side wall of the tank element 12 to locate and hold the marginal edges of the finishing housing against the flange 24 of the sole plate 20. At its threaded portion 154 sleeve nut 156 hasan opening therethrough of reduced diameter as at 160 to provide a valve port above which side openings 162 are provided through the wall of the sleeve nut at the lowest possible point to permit water present in,

the tank 12' to reach the valve port 160. Accordingly, entry of water into the vaporization chamber 39 can be controlled at the valve port 160 by means of a needle valve 164 having a tapered lower end 166 that is raised and lowered to vary adjustably the area of the valve opening.

The means for adjustably positioning valve 164 in the iron include a dial head 172 which is secured to the top of the valve 164 with an integrally formed lower face or shoulder 174 defining a helical cam 174a for raising and lowering the valve as when the" head 172 is turned a suitable number of degrees. A depending annular flange 168 is formed at the top of the housing above the chamber 39 and is provided with an inwardly turned shoulder 170 at the lower edge thereof which cooperates with the helical cam 17411. For this purpose the shoulder 170 defines a helical surface mating with the helical cam 174a to split it one full turn like a conventional nut made of sheet metal. A high part of the helical surface is shown in broken lines as being on the near side of the vertical section plane taken in Fig. 6 and starts at 170a and the lower part ends at 17011 as also shown in broken lines depicting structure and the near side of the vertical section plane depicted in Fig. 6. The end a serves also as a stop against continued rotation of the knob 172 in a counter-clockwise direction when the valve 160 is A closed. The lug 174 is disposed between the ends of cam 174a when the valveis in closed position, and is preferably beveled to ride easily onto the cam 'where' the head I 172 is rotated slightly to open the valve.

In order to bias the valve 164 downwardly, a helical the housing 11 at 184. 1 In order that the valve 14 can also serve as an inlet part for filling tank 12, the bracket 182 is apertured both at 186 for slidably receiving valve 166 andat 188, the latter aperture being of a diameter suitable for draining the cup 190 formed by bracket 182.

In utilizing the inlet port, the dial head 172 is grasped and the dial is lifted until the valve stem 164 locks with bracket 182 by means of a notch 191 formed in the stem at predetermined distance below the dial head. When in the position thus obtained, the dial head is spaced above the housing a suflicient distance to permit water to be poured into the cup 190.

When the tank 12 has been sufficiently filled, release of the dial head will seal the tank for normal operating use. By simply turning the handle, the correct number of drops per minute can be released into steam chain or.

39 and it is preferred that indicia be provided on the top of the valve together with an index on the housing itself.

A baflle 922 is provided at the rear of the depressed portion 152. This bafile acts to retain water in the forward end of the tank when this water has been depleted to the extent that its level in the tank is below the upper edge 194 of the baflie. This serves to isolate a small reserve supply of water when the level is dangerously low by confining it to the depressed portion 152 even when the iron is upended momentarily while in use. The shape of the baffle encourages water to enter the depressed portion while the iron is in use and discourages escape of the reserve supply from the depression.

The mode of assembly of the iron is substantially as described with respect to the aforementioned copending application Serial No. 427,814. The cover 11 without handle 16 in place is brought into position to seat on flanges 24 at the marginal edges thereof. The sleeve nut 156 is thereupon inserted in place with seal 48 under compression to form a heat block at that point, and the nut 156 is tightened. Valve stem 164 is then lowered into place with spring 176 on retainer 178 and bracket 132 is fastened to housing 11.

Handle 16 is then secured to the rear of housing 11 by means of screw 13% with the leads of cord 17 accessible in the opening at the rear of the housing, and "the electrical connections are made and plate 122 fastened by means of screw 124.

The basic ion of the iron is also substantially as disclosed in the ccpending application, except that the thermostatic control means as herein described afford an even greater uniformity of heat in the sole plate, which is of especial advantage in the neighborhood of 220.

Consequently, it will be seen from the description of the invention and the discussion of its principles that various and further modifications can be made to accomplish the objects enumerated without departing from the spirit of the invention, the scope of which is commensurate with the appended claims.

What is claimed is: I

1. In an electric steam iron having a sole plate, a heater, a housing secured to said sole plate and a handle having an upstanding hollow support post afiixed to the rear of said housing, an extension cord extending substantially vertically through said post into electrically connected relation with said heater, means for securing said cord in said post, a thermostat secured to said sole plate having an adjustment pin for effecting changes in temperature settings for said iron, said thermostat being disposed at the rear of said iron and said pin extending upwardly into said handle post in axial alignment therewith and a'horizontally extending lever secured to the upper end of said pin for manually imparting angular rotation thereto, said post having a laterally extending slot for receiving said lever therethrough.

2. In an electric steam iron having a sole plate, a heater, a housing secured to said sole plate and a handle having an upstanding hollow support post atfixed to the rear of said housing, an extension cord extending substantially vertically through said post into electrically connected relation with said heater, means for securing temperature settings for said iron, said thermostat being disposed at the rear of said iron and said pin extending upwardly into said handle post in axial alignment therewith and a horizontally extending leversecured to the upper end of said 'pin for manually imparting angular rotation thereto, said post havinga laterally extending slot for receiving said lever therethrough, saidlever comprising a U-shaped spring having offset portions at one end thereof and a handle at the other end with the closed end of the spring embedded therein, the upper end of said pin having oppositely disposed parallel notches formed therein, said offset portions of said spring being adapted to releasably engage in said notches.

3. In an electric steam iron having a sole plate," a heater, a housing secured to said sole plate and a handle having an upstanding hollow support post affixed to the rear of said housing, an extension cord extending substantially vertically through said post into electrically connected relation with said heater, means for securing said cord in said post, a thermostat secured to said sole plate having an adjustment pin for effecting changes in temperature setting for said iron, said thermostat being disposed at the rear of said iron and said pin extending upwardly into said handle post in axial alignment therewith, said sole plate including a heater-containing member at the forward end thereof defining a steam chamber and being formed throughout of a metal of high coefficient of heat expansion, and thermostatic control means comprising a rod of low coefficient of heat expansion secured to said heater-conveying member at one end having a spring element at the other end, said spring element being fastened to the rear of said sole plate and adapted to effect circuit making-and-breaking in said thermostat, said sole plate changing the position of saidspring during axial expansion or contraction thereof in response to tempera ture changes therein.

4. In an electric steam iron having a sole plate, a heater, a housing secured to said sole plate and a handle having an upstanding hollow support post affixed to the rear of said housing, an extension cord extending substan-' tially vertically through said post into electrically con-' containing member at the forward end thereof defining a steam chamber and being formed throughout the metal of high coefiicient of heat expansion, thermostatic control means comprising a rod of low coefficient of heat expansion secured to said heater-containing member at one end and to a spring element at theother end, said spring element being fastened to the rear of said sole plate and adapted to effect circuit making-and-breaking in said thermostat,

said sole plate changing the position of said spring during axial expansion or contraction thereof in response to temperature changes therein, said heater containing member being in limited heat exchange relation with the rest of said sole plate and a ridge'formed integrally with said sole plate extending in axially abutting relationship with said control rod rearwardly of said heater-containing member, said heater containing member being contoured to be in abutting relationship with a forward portion of said control rod, the portion of said rod in contact with said ridge being substantially greater than the portion of said rod in contact with said heater containing member' whereby said rod will respond to the relative temperature in said sole plate and ridge to counteract the effect of said sole plate on said spring and effect an anticipation of a relatively higher or lower temperature in said heater containing member which will be infused into the rest of said sole plate relatively gradually.

5. In an electric iron having a sole plate, a heater, a housing secured to said sole plate and a handle having an upstanding hollow support post aflixed to the rear of said housing, a thermostat positioned in the rear of said iron and having an adjustment pin threadedly received on said iron for adjusting the heat setting thereof, a horizontal lever secured to the top of said pin for imparting angular rotation thereto, said pin extending upwardly into said post and said post being slotted horizontally for receiving said lever therethrough, said thermostat having an upper spring blade and a lower spring blade mounted in spaced parallel and axial relation on said sole plate, said spring blades being provided with electrical contacts positioned in adjustably close proximity by said pin, means forming a closed heater circuit when said contacts are in abutting relationship, a heater containing member for said sole plate, said sole plate being formed throughout from a metal of high heat expansion coefiicient and thermostatic control means comprising a metal rod of low heat expansion coeficient having an upwardly bowed spring element at one end, said spring element being fastened to the rear of said sole plate, the other end of said rod being fastened to said heater containing member at a forward position in said iron, said lower spring blade being biased downwardly into abutting relation with said upwardly bowed spring whereby said upwardly bowed spring may move said lower spring blade upwardly into circuit-making contact with said upper spring blade upon predetermined t cooling and contraction of said sole plate and permit said lower spring blade to move downwardly into circuitbreaking position upon predetermined heating of said sole plate.

6. The construction according to claim wherein said heater containing member is in limited heat exchange contact with the rest of said sole plate and is constructed to be in abutting relationship with a forward portion of said rod, a ridge formed integrally with said sole plate extending axially rearwardly in heat exchange relation with said rod for a greater extent of said rod than the portion thereof in contact in said heater containing member whereby said rod will contract slightly when the rest of said sole plate is relatively cool despite relatively high residual heat in said heater containing member to cause said upwardly bowed spring to efiect a relatively lower position of said lower spring for quicker circuit breaking in anticipation of infusion of heat from said heater containing member into the rest of said sole plate said rod being relatively expanded slightly when the rest of said sole plate is hot relative to said heater containing member to afford anticipation of cooling in the rest of said sole plate and relatively quick circuit making action of said thermostat.

7. In an electric steam iron having a sole plate, a

heater, a housing secured to said sole plate and a handle having an extension cord' extending into electrically connected relation with said heater, means for securing said cord in said handle, a thermostat secured to said sole plate having an adjustment pin for effecting changes in temperature setting for said iron, said thermostat being disposed at the rear of said iron and said pin extending upwardly into said handle, said sole plate including a heater-containing member at the forward end thereof defining a steam chamber and being formed throughout of a metal of high coefiicient of heat expansion, and thermostatic control means comprising a rod of low coefiicient of heat expansion secured to said heater-conveying member at one end having a spring element at the other end, said spring element being fastened to the rear of said sole plate and adapted to effect circuit makingand-breaking in said thermostat, said sole plate changing the position of said spring during axial expansion or contraction thereof in response to temperature changes therein.

8. In an electric steam iron having a sole plate, a heater, a housing secured to said sole plate and a handle having an upstanding hollow support post afiixed to the rear of said housing, an extension cord extending substantially vertically through said post into electrically connected relation with said heater, means for securing said cord in said post, a thermostat secured to said sole plate having an adjustment pin for effecting changes in temperature settings for said iron, said thermostat being disposed at the rear of said iron and said pin extending upwardly into said handle post in axial alignment therewith, a horizontally extending lever secured to the upper end of said pin for manually imparting angular rotation thereto, said post having a laterally extending slot for receiving said lever therethrough, said thermostat comprising a rod of low coeflicient of heat expansion secured to said heater-conveying member at one end having a spring element at the other end, said spring element being fastened to the rear of said sole plate and adapted to effect circuit making-and-breaking in said thermostat, said sole plate changing the position of said spring during axial expansion or contraction thereof in response to temperature changes therein.

References Cited in the file of this patent UNITED STATES PATENTS 2,146,992 Saunders et a1. Feb. 14, 1939 2,434,136 Walcott Jan. 6, 1948 2,512,062 Huffman June 20, 1950 2,602,248 Finlayson July 8, 1952 2,663,100 Bricker Dec. 22, 1953 FOREIGN PATENTS 465,478 Canada May 30, 1950