US2602873A - Thermostat switch for automatic flatirons - Google Patents

Description

July 8, 1952 F. E. FlNLAYsoN 2,602,873

THERMOSTAT SWITCH FOR AUTOMATIC FLATIRQNS original Filed June 15, 194e 2 SHEETS- SHEET 1 l l I /5 l99925 4749.

His AttOT-Tje `Iuly 8, 1952 F. E. FlNLAYsoN THERMOSTAT SWITCH FOR AUTOMATIC FLATIRONS 2 SHEETS--SHEET 2 Original Filed June l5, 1946 Inv@ ntOr-w Ffrem K E Fivw lags'om;

His Attofe'g.

Patented July 8, 1952 THERMOSTAT SWITCH FOR ATOMATIC FLA'IIRONS Frank E. Finlayson, Gntario, Calif.,vassignor to General Electric Company, a corporation o New York original application June 15, 1946, serial No. 676,909. Divided and this application May 31, 1950, Serial No. 165,216

3 Claims.

This invention relates to flatironsfmore particularly to electrically heated ilatirons. and it has for its object the provision of improved means for controlling the ilatiron temperature.

More particularly, this invention'contemplates improvements in thermostatic means for controlling the iron heating means to hold preselected soleplate temperatures, and it comtemplates an improved organization of elements resulting in an inexpensive, reliable and easily adjustable thermal control device; more especially, one which includes a manually operable adjustable control element located at the front upper part of the iron.

The present application is based upon and is a division of my earlier application, Serial No. 676,909, led June 15, 1946, and assigned to the same assignee as the instant application. The thermostatic switch mechanism in the atiron will be claimed here.

For a more complete understanding of this invention, reference should be had to the accompanying drawings in which Fig. 1 is a vertical side elevation of an electrically heated atiron embodying this invention, parts shown in section so as to illustrate certain structural details; Fig. 2 is a plan view of certain of the elements shown in Fig. 1; Fig 3 is a perspective view illustrating the heating means, a signal lamp and the electrical parts and connections for effecting energizing circuits for these elements; Fig. 4 is a plan view of a part of the thermostatic switch structure; Fig. 5 is an elevation of the part shown in Fig. 4; and Fig. 6 is an elevation of another element used in the thermal control.

Referring to the drawings, this invention has been shown in one form as applied to an electrically heated atiron comprising a soleplate I having at its bottom the usual pressing surface II, which plate will be made of any suitable metal, such as aluminum, and which preferably will be cast from the metal. The soleplate has the usual shape provided with a point I2 at the forward end, and having a slightly rounded heel edge 12a opposite the point. The soleplate is heated by means of an electrical heating element which preferably is of the sheathed type, and comprises a helical electrical resistance conductor I3 (Fig. 1) mounted within a tubular sheath I4 and imbedded in and held in spaced relation to the sheath by a compacted mass I5 of electrically insulating and heat conducting material, such as compacted granular magnesium oxide. Connected to opposite ends of the resistance conductor I3 and `projecting from the two ends of the sheath are terminals I6 and I1. The heating element has roughly thel shape of a U (Fig. 2), and it is arranged in the soleplate I0 with its bght located at the pointed end I2 of the iron and its terminals I6 and Il at the heel end of the iron. And, preferably, the heating elementis cast within the body of the soleplate, as shown,-

the metal of the plate cast about the upper part of the element forming an upright rib I8.

The soleplate is covered by lmeans of a shell I9., which has its lower edge resting upon a ledge formed on the opposite sides of the soleplate, and which is secured by means of Va pair of transversely-spaced screws 20a tapped into upright bosses 20h formed on the soleplate. The shell slopes downwardly from its forward end to the rear, and at the rear it is provided with a down-turned wall 2| which is spaced to the rear;

of the soleplate heel edge Iza, as shown, and which constitutes a heel rest for the iron. The space between the heel edge I2a and the downturned wall 2| is closed by means of a plate 22 attached tothe soleplate by means of screws 23 and projecting outwardly therefrom to engage the inner surface of the wall 2l.

Mounted on the top of the shell is a handle 24, formed of any suitable material, but preferably it will be molded of an electrically insulating material, such as a phenolic condensation product.

The handle is provided with a hand-grasping portion 25 running from the front to the rear of the iron, and with a forward skirtl section 26 and a rear upright sectionZ'I formed integrally with-the hand-grasping portion. The rear section 2l constitutes a support for the rear end of the hand-grasping portion 25 and is secured tothe rear end of the shell by a'pair of screws 28 spaced apart transversely of vthe shell (only one being shown in Fig. 1) preferably, and as shown, the screws will pass through'upright bosses 29 (Fig. l) formed upwardly from the material of the shell and which function to spacethe rear handle support 21 from the shell,y and thereby thermally insulate it from the shell.Y

The forward'end of the hand-grasping portion 25 isv supported by means oiv a metallic upright bracket 30 having roughly the shape of a Z; This bracket, as shown, extends vvupwardly into a cavity 25a provi-ded bythe skirt 26. The lower arm 30a of this bracket rests upon abaille plate 3I which is mounted on the top wall of the shell I9. It is secured to the baile plate by means of a rivet 32 and is prevented from moving about the axis of the rivet by' meansv of a down-turned section 33 which is received'lin an aperture` providedforit in the baille plate. The baille plate 3l, in turn, is secured to the top wall of the shell by means of a pair of transversely spaced rivets 34 (only one shown) positioned on opposite sides of the rivet 32, and extending through -downwardly extending bosses 34a formed in the baiie and spacing vit from the shell. The baiie is held in spaced relation with the shell by means of the down-turned bosses 34a around the rivets and which are formed from the material of ywhich the baffle is made. The upper arm 35 of the Z-shaped bracket 30 bears against a seat 36 provided atthe top of the recess a and it is secured to the handle by means of a self-tapping screw 31. The bracket is provided with a vertical strengthening rib 35h extending along its length, as shown.

The function of the forward skirt section 25 of the handle is to conceal the front handle support it is, as shown, in the form of an apron extending downwardly from the forward end of the hand grasping portion 25. This apron at its lower rearl end38 curves back over the top of the shell, as shown. The rear handle section 21 'is provided with a similar apron 39. extending forwardly toward the apron 38, as shown, and the space betwen the ends of the two aprons-38 and 39 is lled by means of a metallic plate 45. The plate 40 is formed of la metal which is inherently resilient and it is caused to resiliently engage the two aprons 3'8 and 39, whereby it is secured to the handle; each apron preferably andas shown is lprovided with reduced end extensions 4|, while'thebafe plate 40 is given a complementary shape `in cross section whereby it may be snapped over the two reduced sections. To remove the plate, it is merely necessary to insert a screw ldriveror some other similar instrumentunder one side and pry it up to spring it away. When the plate is assembled, as shown in Fig. 1, its top surface merges in a smooth line with the curved aprons.

Part of the handle structure just described is described and claimed in my Patent 2,443,448, assigned to the assignee of the instant application.

The heating element is controlled by means of a thermostat 42 which is arranged to respond to the temperature of the soleplate so as to hold a substantially'` constant temperature in the plate. This thermostat comprises a supporting frame having a U-shaped base plate 43. The bight of the base is secured to kthe top surface of the soleplate by means of a pair of screws 43a. At the outer edges of the two legs of the base plate are upright walls 44 which extend rearwardly from the bight, across the Atop of the soleplate. Preferably, the section of the soleplate under these rearwardly extending walls is cored out so as to form a cavity 45 (Fig. 1)

Secured under the bights of the base plate 43 is a bimetallic temperature responsive bar 45 formed of two metals having dissimilar temperature coefficients of expansion rigidly secured together lengthwise in any suitable way, as by Welding. Preferably, and as shown, this bar will be formed of two reversed sections in order to minimize temperature overshoot in the fashion described and: claimed in the U. S. Patent to R. A. Winborne, No. 2,128,869, dated August 30, 1938. The thermostat bar 46 has its left-hand end, as viewed in Fig. l, secured to the base plate 43 and its opposite end extended over the cavity 45. Clamping the thermostat bar 46 to the base plate 43 is a clampingblock 41 formed of a material having a very; good` heat conductivity. Such aS plate lil kand thebirnetal bar.

4 aluminum. This block is provided with a central longitudinal channel-like passageway 48 in which the bimetal bar is mounted. The forward part of this block is clamped to the bimetallic bar46 .and to vthe baseplate 43Y by means of a rivet 49. The thermostatbar is further secured to the base plate by a rivet 50 spaced rearwardly from the rivet 49, and which is not fastened in y any way to the block.

vThe heat conducting clamping block is used to provide a good heat transfer between the soled Y The positioning of the thermalbar-.ES below the base plate 43 and the use of the' clamping block 41 is important because it Vpermitsthe thermostat to be set or calibrated as a .unit outside of the iron and later assembledvwith the iron by means of the screws 43a without seriously disturbing the calibration, which disturbance most likely would occur if the bimetallic bar were located under the frame withoutthe 4clamping yblock .due to irregularities inthe tsol'eplate which Awould .result in tipping or'cocking of the thermostat assembly. On the other-.hand'if the thermostat were located on topuof `the base plate to overcome this tipping, ythen there would not be vsuch good heat transferbetween the soleplate and the bimetal bar.

The thermostatic switch further comprises a switch lhaving a contact 5| and a Ycooperating Contact 52. The contact 5l is mounted upon an electrically conducting arm 53 formed of a relatively` stiff spring material. rear end is rigidly secured by means'of a rivet to and under a ltransverse section 54 of the ,supporting frame which 'joins the rearends of the upright walls v44 of the base plate, and it is electrically :insulated from this plate `by suitable materiaLsuch as sheet mica. 'The contact 52 is mounted upon a switch arm 55, likewisefmade of spring material, .but whichA has not the spring strength of the arm 53. The arm 55 is supported at the rear uponL the 'top' of the plate section 54 by means offa `rivet and is electrically insulated from the 'plate 'by mica. The two switch arms 53and 55 are spaced `apart transversely and are in substantiallyparallel relation, but the forward end of the arm 53 is provided with a lateral offset 56 extending to the arm55 so as to bring its contact 5l 'into Aabutting relation with the contact`52.

The switcharm53 biases its Contact 5l .upwardly,'whereas. the arm 55 biases its contact 52 downwardly; but the switch arm 53 bears against an adjustablestop 56a so that the contact 5l normally is a fixed or stationary contact; the contact 52 is .the movable one and is operated to open .and close'the switch responsiveiy to the deflection of the bimetal bar 4B as it heats and cools. yThe bar 4.6 is constructed and arranged so that its free end moves upwardly as it heatsl up and moves downwardly when it cools.-

Mounted on this free end of the bimetal bar is an upright switch actuator V51. As more clearly shown in Figs. 4' and 5, this actuator is laterally positioned with reference to the bimetal bar so that it lies directly under the spring arm 55. The actuator 51 is inthe form of a tube closed at its upper end and is mounted upon the upright arm cfa right angle 'bracket 58, the other arm of which is Secured in any suitable way to the end of the thermostat, as by welding.` The actuator 51 is formed of a suitable refractory electrically insulating material, and it is secured to the bracket 58 bymeansof a lsuitable cement.

The switch contacts 5| and A52 are connected in the iron heating'circuit to control its energization by opening and closing. `When the iron is energized but has not as yet been heated up, the top of the actuator 51 is spaced below switch arm 55, as shown in Fig. 1. y thermostat moves upwardly as its v'temperature rises, it will move the actuatorupwardly to close this space and engage the switch arm 55 tomove it upwardly against its downward bias and thereby open the contacts 5| and 521, Whereas when the thermostat cools and deilects downwardly it permits the switch arm 55 to returnthe contact 52 to re-engage contact 5| and thereby reclose the switch. f y

In operation, thereforathe switch arms 53 and 55 carry current for the` iron heating element. These arms preferably Iwill be made of stainless steel or other suitable h eat resisting alloy. Such materials which may be used at flatiron temperatures have high specific resistances, This causes some heating of the springs due to the passage of current. In the case of spring 53, this is not too important, because it is relatively thicker than spring 55 and its resistance, therefore, is less. However, in the case of spring 55, this is important both because with its higher resistance it tends to heat to higher temperatures and because it may conduct heat to the thermal bar through the switch actuator 51. This switch arm, if heated too high, would act as an auxiliary booster heater for the thermostat bar, and cause it to operate with too narrow a temperature amplitude. To obviate this, I shunt the spring arm 55 with a good heat conducting strip '59, which,

as shown, is connected at one end with the switch arm and terminal 66 by the rivet fastening these members together, and at its other end is fastened between the other end of the switch arm and its contact 52. `The shunt is made of brass, aluminum, or other suitable good electrical conductor.

It will be remembered that the switch arm 53 holds the contact 5| in a stationary position, and further that the spring arm 53 is stronger than is the spring of the arm 55. The arm 53, however, is prevented from moving upwardly by means of the aforementioned stop 56a` which is made of electrically insulating material and is mounted within adjusting screw 60, which, in turn, is threaded in one end of a lever 6|. This lever intermediate its ends and at the sides is provided with down-turned ears `|32 which are j ournaled upon a transverse shaft 63 which passes through the ears and the side walls 44 of the base plate and which has its ends pinched or squeezed, as shown in Fig. 2, to prevent' the shaft from working loose. The end of the lever 5| opposite the adjusting screw 60 rests upon an 4adjusting cam S4 by means of which the position of the lever and thereby the position of the stop screw 60 may be adjusted. This adjustment varies the position of the stop 56a and this varies the positional relationship between the switch arm 53 and, consequently, the arm 55 andthe actuator 51. This changes the temperature setting of the control device. Y

It should be noted here that the afore-described connection means -between the clamp plate 41, the bimetal bar'46 and the soleplate I0 is a very important feature because it preserves the calibration of thevthermostat. The commercially available good heat conducting metals, such as aluminum, are relatively soft, and, as a result, there is a tendency rfor therivet 49 to work loose. Even though this occurs, the

But when the rivet 50 remains tight, since itl does not go through the plate 41, and thethermal bar 46 cannot become displaced with reference to the switch which it controls, and, therefore, the adjusted positional relationship between the bimetal bar and the switch arm 55 always remains the same.

The switch 5|, 52 iselectrically-connected in series with ther circuit of the heating resistance |3 of the heating element, and for this purpose there is provided a terminal structure comprising a pair of rigid terminals 65 and 66 of roughly L-shape having their horizontal legs mounted` on the top of the transverse plate 54 of the thermostat frame and their upright legs extended upwardly through an openingv `|51v in the top wall of the shell I9 and into a relatively large cavity 63 provided in the rear handle section 21, as shown. The terminal 65 is electrically insulated from the plate 54 and from both switch arms 53 and 55, whereas the terminal 66, while itis electrically insulated from thejplate v54 and theterminal 65, is in electrical contact with the switch arm 55. The terminal structure further comprises a third rigid terminal bar 69 which islmounted under the plate 54 and projects outwardly toward the rear of the shell from the plate. Thisfterminal E9 also is electrically insulated from the other two terminals and theplate 54, butis in direct electrical engagement with the switch arm 53. The three terminals 65. B6, 69 are secured by means of the rivets which hold the two switch arms on the plate 54. Y ,Y

The terminals are adapted to be electrically connected to an electrical supply source by means of a twin supply conductor (not shown here) entering into the recess 468 inthe rear handle section 21 through an aperture. in a side wall of this recess, as shownin my application,'Serial No. 676,909. This conductor may also be provided with a sheath-like guard and a strain relief plate which is clamped to thecord, as shown in said application. One conductor 15 .of the supply cord is connected to the terminal 65 by means of a screw 1B and by means ofthe same screw and a conductor 11 is electrically Vconnected with the terminal I6 .of the heating element. The other terminal |1 of the heating element is connected with the terminal 69, which is in" electrical engagement with the switch arm 53, by means of a conductor 18 connected at" one end tothe terminal |1 and at its other end with the terminal B9 by means of a screw 19. The terminal 66, which is in electrical engagement with the switch arm 55, is electrically connected with the other conductor of the'supply cord'by means of a screw (not shown here).

In view of these connections, it will be observed that the switch contacts 5| and 52 are electrically connected in series '.'with the heating element resistance v|3 and with the supply source so that when the switch contacts are in engagement the heating elementA is energized, whereas when they are opened the'` heating element is deenergized. The thermostat 45, in operating the switch contact 52 away from and to return into engagement with contact 5| in response to rise and fall in temperature, operates to hold the desired temperaturein the soleplate.

As hasbeen explained previously, the temperature so held may be varied by varying the position of the contact 5| whichvaries the space between the switchactuator 51and the switch arm 55 and thisk is accomplished by changing the position ofthe `abutment'56a; this, in turn, is 'accomplished' by'setting theV cam' 64 which varies the position ofthe lever 6 1 v ns more fully describedand claimed in my patent application, Serial No. 165,215, led concurrently herewith and assignedto the same assignee, jthe cam 64 comprises a circular disc-like base plate 82 which is arranged to rotate upon Ya support S3 which is formed as an extension of the base platel 43 of the support frame, this support 83 being positioned in elevated relation from the plate 43 by a vertically offset section-84. The support S3 not only supports the cam, but it functions as a bearing for the cam plate 82, and for this purpose it is provided with a plurality of upright rounded bosses 85 which engage the under surface of the cam plate. y `Superimpused upon and secured to the cam plate 82 isa circular cam member 86 shaped to define a cam rise il? on its periphery, as shown in Figs. 1 and 2; it is secured to the cam base plate in -any suitable way, as by spot welding. At Vthe center, the cam member 85 is provided with a cone-shaped depression 88 which extends downwardly through a central aperture provided for it in the base plate 82; and the cam bearing 83 likewiseis provided with a cone-shaped depression-39 at the center. The cam 64 is secured to the extension 83 by means of a spring 80 which is formed integrally with the cam base 82 and extends outwardly from one edge thereof and, thence, is folded thereunder, as shown in Fig. 1. On the end of the spring 9D there is formed a lip Si and also an aperture which is received by an extrusion 92 formed on the frame at the lower end of the depression 89. To assemble the cam with the extension 83, theassembly of the cam and. spring is slipped over, one edge of the extension and the spring snapped over the. extrusion with the aperture in its end receiving the extrusion. The lip helps to snap the spring over the extrusion. 'Ihe action .of the spring Si) holds the cam plate 82 against the protuberances 85 upon which it rides.

As described and claimed in my earlier application, Serial No. 676,909, the cam 64 is rotated by means of a rod 93 which is vertically positioned in the forward end of the iron, and which extends upwardly from the cam structure through openings `i4-and 95 provided for it in the top wall ofthe shell and in the baffle plate 3l, respectively, and thence extends upwardly into the recess 26a provided by the skirt 2G at the forward end of handle 25. At its lower end this shaft is provided with a pair of keys 86 positioned on opposite sides of the shaft and which preferably will beformed by squeezing or pinching out sections'of the shaft. These keys are arranged to operate in complementary slots 9'! providedin the cam plate 8E. They also function to ride upon the top surface of the bottom wall of. the conical depression 89 in the support 83 and thereby support the shaft in its vertical position,

At the top of the shaft 83 there is a .pair of oppositely positioned keys 98 similar to the keys 9E and preferably arranged in the same. angular relation vwith reference to theA shaft as are the keys 96. The keys 98 at the top of the shaft eifect a driving connection with an operating lever 99 which is positioned at right angles to the shaft and which extends outwardly through the front wall of the recess 25a, the wall being provided with an elongated transverse slot It@ for, this purpose. The lever 99 on its. inner end is provided with an upwardly .extending inverted cup-shaped protuberance lilll which is provided in its upper wall with slots (not shown,

but similar to slots 91) and which receive the keys 98 to eifect a drivingconnection between the'lever and the shaft. Thus, when the lever 3 9 is operated transversely inthe 'slot Ylfiii, the shaft 93 is rotated in order to adjust the cam..

The upper end of the shaft S3 is journaled in a bearing provided for it in an extension H32 pro--` vided on the-forward end of the upper'arm 35 of the handle support.

On the forward end of the lever 99 which projects from the slot lr, `.there i's attached. an operatingknob |03. y,

Also mounted within slotv |99 is a temperatureindication plate. |04 which is roughly semicircular in shape and which is so constructed and arranged that when it is inserted in the slotvlil a peripheral portion Il thereof is exposed to view, and lupon this exposed portion there are suitable-.indications for soleplate temperature settings for ironing various materials, such as Rayon, Silk, Wool, Cotton and Linen; Also, it has an indication for ,"Off in which position of the leverl 99 the cam vis so' positioned that it moves the contact '5| .downwardly so far that it leaves the contact'52 which will be held in an upper open position by the actuator' 57. The cam rise'surface 8l gradually rises from a high temperatureA setting. position corresponding to Linen to a low temperature position corresponding to Rayon and then has an abrupt rise l5a which is the fOff position; in this position of the cam, the lever Si is operated to, depress the abutment 55a so far downwardly that switch arm '53 separates its contact 5i from contact 52, which latter contact is supported by the actuatory 57 on the thermostat. As the cam is rotated. from the OPE position, it first permits thevarm. 53 to., rise to reclose the contacts and, thence, .as itcontinues to move, increasesthe space Vbetween actuator 5'! and switch arm 55, and therebyv increases the temperature setting. Upright vears i?) and ll5c function to limit motion. of cam 8f3 in assembly and insure proper positioning of the cam.

The indicator plate Hifi is provided with a circular 'opening I B6 which receives the upwardly extending boss IUI vof the lever 9S, and around this boss and sandwiched betweenthe lever sii and the plate 184 is a cup-shaped spring l0? which biases the two members apart and which holds them rmly. in the iron assembly by forcing them against the upper and lower walls of the slot Hill respectively.

It will be understood that to assemblethe shaft 93, the lever 99 and the indicating vplate it@ with their associated par-ts, first the vshell i9 with the handle attached will be separated from the solepl-ate, then the lever 98 will be assembled with the spring |01 and with the temperatureplatemi. in their proper relative positions shown in Fig, l. This assembly will then be inserted into the slot |00. Thenr the shaft S33-will be inserted through the chamber 25a so that its upper end passes through the apertures in the lever and in'dicatu ing plate and so that its keys S8 are received in the slots provided 'for them in the prctuberance lill. The shaft, of course, is forced inwardly until its upper end is received in the-opening provided for. it in the bracket extension ID3. Preferably, means will he provided lfor holding the shaft up in its assembled position. This means comprises aspring member ia of roughly U- shape positioned under and against the lower surface ofthe top Wall of the shell... The legs of ture.'

acoasvs thismember'st'raddle the/shaft' 93, and at the outer edge of the bight of the U there is an up- -ivardly and outwardly offset'tongue |011) which has its top outwardly extendingpart overlying'the top wall of the shellf. Formed on the inner edge of the bight between the two legs is an upright flexible spring arm Ilc which bearsagainst the shaft and holds it in place.'` Thespring also functions to prevent rattling ofthe `shaft when the ironis in use. Afterthe shaft is assembled, as described, and the spring lilla applied, the handle and shell aremoved into Vassembled relation with vthe soleplate, while the'lower end of the rod 93 is moved into the conical protubera'nce 88 of cam 8-8 which guides it to the central'slots 91 therein, and thencev into the'. conical projection 89 of frame 83 which guides it to itsfcentral aper- If, when the shell is assembled, the keys 96 do not register with the slots 91, the knob |03 will be moved back and forth until they do and when they do the shell-may, be lowered in position on the soleplate, and then Lsecured bythe screws 20a. After this, the cover plate d0 may be snapped in place to cover the screws.

While the knob |93 is used by the operator to adjust the temperature setting, -attimes it-may be desired to change the basiccal-ibration of the thermostat. This may be done readily by adjusting the screw B in which the insulator 56a is supported. This may be done conveniently through an opening.V |09 provided in the top wall of the shellv I9 immediately above the screw and through which a suitable instrument, such as a screwdriver, may be inserted to set the screw. It

will be observed that the screw 60 is accessible when the plate 40 is removed. Preferably, a spring H0 will be provided Vto hold the screw 60 in any position4 in`which it is'adjusted Suitable signal means .are provided for indicating when the thermostat is closed and when it is opened. rI'his means comprises a gas glow lamp lli located within the chamber 68 of the rear handle section 21. This lamp is mounted in a U- shaped bracket H2 having a base H3 at the bottom supporting the base of the lamp, and a pair of prongs H4 at the top resiliently engaging and holding the other end of the lamp. The bracket H2 is attached to the terminal 66 by means of a rivet IIE. One terminal of the lamp is electrically connected with the terminal 6B and thereby to the supply conductor 88 by being clamped between the terminal and the bracket. The other terminal of the lamp is connected with the terminal 69 through a current limiting resistance l i6. In view of this arrangement, it will be observed that when the switch is closed the lamp will be short-circuited and thereby be deenergized, whereas when the switch is open the lamp will be connected in series with heater I3 and across the supply source and thereby energized to light. The lamp is viewed through a window or other opening located in the side wall of the chamber 68 opposite the lamp, as shown in my application, Serial No. 676,909, and which window may be covered by means of a light-distributing lens, also as shown in said application. It will be observed that the lamp is supported on the rigid thermostat terminal B-, and that no other supporting means are required.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention in its broader aspects and I. therefore, aim in the appended claims to cover all 'such changes and modifications asfall within the temperature of said soleplate and a control actuator for said thermostat extendingfrom inside of said body to means outside of said body for moving said control actuator, that improvement in the thermostat comprising an elongated metallic frame in said body extending longitudinally from Vfront to rear ofsaid soleplatameans mounting the forward end of said frame to the upper surface of the soleplate, said' forward end of the frame havinga supportsection extending'forwardly from said' mounting meansand spaced above the upper surface of said soleplate, a pair of spring switch arms secured at one of their lends to the rear end of said frame and projecting forwardly thereof within the confines of said frame, coacting switch contacts on the forward ends of said arms for controlling the energization of said heating element, the contact end of" one of said arms being mounted above the other with the rst arm being biased upwardly and the second arm biased downwardly, the rst bias being relatively stronger than the second',A a lever extending from front to rear of said soleplate pivoted intermediate its ends to said frame intermediate the frame ends, an adjustable motion limiting stop on the rear end of .said lever engaging said first switch arm, a cam rotatably mounted on said forward support section of said frame for movement by said control actuator. said cam eng-aging. the .frontv end of Vsaid lever which is forced against it by the strength of bias of said first spring arm, a biametallic thermostat bar attached at one end to said frame at said frame mounting means in thermal relation with the upper surface of said soleplate, said bar extending toward the rear of said frame, and a contact actuator carried by the free end of said bar for engagement with and operation of said second switch arm to open and close said contacts.

2. In an electric fiatiron, a soleplate and an electric heating element therefor, and a shell covering said soleplate, a thermostat for controlling said heating element responsively to the temperature of said soleplate and an actuating rod for said thermostat extending up through the front part of said shell with means outside of said shell for rotating said rod, that improvement in the thermostat comprising a U-shaped metallic frame extending from front to rear of said soleplate with the bight of the U toward the front of the soleplate, means mounting the forward end of said frame to said soleplate and said forward end having a forwardly extending support section, a pair of spring switch arms mounted on the rear end of said frame between the legs of the U and projecting forwardly thereof, coacting switch contacts on the forward ends of said arms for controlling the energization of said heating element, one mounted above the other, the first arm carrying the lower contact being biased upwardly, and the second carrying the upper contact biased downwardly and said first bias being relatively stronger than the second, a lever extending from front to rear of said soleplate pivoted intermediate its ends to said frame, a motion limiting stop on the rear end of said lever yengaging said rst switch arm, la cam mounted on said support section for rotation on a generally `vertical axis by said actuating rod, said cam engaging the front end' of said lever which is forced against it by the strength ofv said rst arm, a thermostat bar attachedto said frame at its forward end and supported in thermal relation with said soleplate and extending back rearwardly of -said frame, and a generally vertical actuator carried by the rear end of said Vbar for operating said `second switch arm to open and close said contacts.

3. In an electric iiatiron having a body with a soleplate thereon, an electric heating element in the soleplate, a thermostat in the body for controlling said heating element responsively to the temperature of said soleplate and a control actu- .atorfor said thermostat extending from inside of said body to means outside of said body for moving said control actuator, that improvement in the thermostat comprising an elongated metallicframe in said body extending longitudinally from front to rear of said soleplate, a iiat base section on said frame, means mounting the forw-ard'end of the fiat base section to the upper surface of the soleplate, said forward end of the frame having a support section extending forwardly from said mounting means above the upper surface of said soleplate, a pair of opposed elongated spring switch arms mounted on the rear end of said fra-me and projecting forwardly thereof within the confines of the frame, said arms being spaced laterally-of each other and one lhaving a forward end section laterally offset to lie under the forward end of the second, coacting switch contacts on the forward ends of said arms for controlling the energization of said heating element, said lower offset arm being biased upwardly and said second upper arm being biased downwardly, the first bias being relatively stronger than the second, a lever extending from front to rear of said soleplate pivoted intermediate its ends to said frame intermediate the frame ends, a motion limiting stop on the rear end of said lever extending above and engaging the top of said first switch arm, a cam rotatably mounted on said frame support section for movement by said control actuator, said cam engaging under the front end of said lever, which is forced downwardly against the cam by the upward bias of the rst spring arm engaging the stop, abimetallic thermostat bar attached at one end to said frame at said frame. mounting means and supported thereby in thermal relation with the upper surface of said soleplate, said bar extending back toward the rear of said frame below the second switch arm, and an upwardly extending contact actuator carried by the free end of said bar for engagement with and operation of said second switch arm to open and close said contacts upon motion of said bar.

FRANK E. FINLAYSON.

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

UNITED STATES PATENTS Number Name Date 1,537,035 Heislerv 1 May 5, 1925 1,593,266 Myers July 20, 1926 2,154,043 Gough Apr. 11, 1939 2,235,893 Kuhn et al.- 1- Mar. 25, 1941 2,267,387 Winborne' v -Dec. 23, 1941 2,353,151 Elsenheimer July l1, 1944 2,439,825 Sparklin 7.1.1 Apr. 20, 1948 2,461,562 McLelland et al. Feb. 15, 1949 2,518,503 Sparklin i.- Aug. 15, 1950

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