US2316907A

US2316907A - Electric pressing iron

Info

Publication number: US2316907A
Application number: US283860A
Authority: US
Inventors: Wallace Stanley
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-07-11
Filing date: 1939-07-11
Publication date: 1943-04-20
Anticipated expiration: 1960-04-20

Description

prll 20, 1943. S WALLACE 2,36,907

ELECTRIC PREssING IRON y Filed July 11. 1939 3 sheets-sheet 1 mh mb Qmmwm@ whim@ www @Q SMN 9@ m MQ n@ S h Q Q .c m

. 5in/z5 'Zzjcz ce BY W35 QAM ATTORNEYS. d

April 20, 1943. s. WALLACE ELECTRIC PRESSING IRON 5 sheets-Sheet 2 Filed July l1, 1939 INVENTOR.

April 20, 1943. s. WALLACE ELECTRIC PRESSING IRON 3 Sheelgs-Sheet 3 Filed July 11. 1939 Patented Apr. 20, 1943 UNITED STATES PATENT OFFICEv ELECTRIC PRESSING IRON Stanley Wallace, Chicago, Ill.

Application July 11, 1939, Serial No. 283,860

Z Claims.

The present invention relates in general to electric pressing irons, and more in particular to an iron o! this character which is provided with means for generating steam which is injected into the goods while the iron is in use. The main object of the invention is to provide a new and improved steam iron.

In some respects the steam iron disclosed herein may be considered as an improvement on the iron shown in my copending application, Ser. No. 143,031, filed May 17, 1937.

The inventionincludes a considerable number of improvements which cooperate in producing a steam iron which is entirely safe, free from trouble, and more satisfactory to use than steam irons heretofore available. The invention and the various features thereof will be described in detail hereinafter, reference being had to the accompanying drawings, in which:

Fig. 1 is a sectional view of the complete steam iron, taken on the line I-l, Fig. 2;

Fig. 2 is a section through the boiler, taken on 'the une 2 2, Fig. i;

Fig. 3 is partly a top view and partly a section of the sole plate, the section being on the line 3 3, Fig. 1;

Fig. 4 is a section through the terminal housing taken on the line 4-I, Fig. 1;

Fig. 5 is a section through the Water tank and water control valve. taken on the line 5 5, Fig. 1;

Fig. 6 shows a modification and is a side view of the back part of the iron, with a part of the water tank in section to show a different form of water control valve mechanism;

Fig. 'l shows another modication, and is a section through a part of the boiler and the Water control valve; and

Fig. 8 shows a modified form o cap which may be used for the water tank, in case a continuous supply of water to the tank is desirable.

' Referring to the drawings, the sole plate 2, Figs. 1 and 3, maybe somewhat similar in construction to the one shown in my co-pending application. It' has a recess 3 extending from the toe along both sides to receive the lower edge of the cover. On the upper side of the sole plate there is a recess 4, in which the thermostatic control mechanism is mounted, as will be described presently. The reference numeral 5 indicates a channel constituting a steam passage, the shape of which is clearly shown in Fig. 3. Outlets such as 6 extend from the steam passage to the face of the iron.

The 'boiler lis shown in Figs. 1 and 2. It isa one-piece casting, and has a main steam-generating cavity 8, which may be filled with copper wool or similar material. Access to the cavity 8 is had through two openings at the top which are normally closed by threaded plugs I3 and I4. Partitions 9 and I0 extend from opposite sides part way across the cavity 8, and the latter partition is enlarged at lI to provide room for the opening I2 in which the shaft |38 of the adjusting device for the thermostatic control mechanism is located. Near the forward end of the boiler a hole is drilled up from the bottom and is tapped to receive the threaded tubular member I5. The lower end of member I5 lies in the opening i6 leading to the steam passage 5. A gasket 24 surrounds member I5 and is compressed between the boiler and sole plate, where it prevents the leakage of steam.

The boiler l is secured to the sole plate 2 by means of a machine screw Il in front and by two machine screws such as i8, Fig. 1, at the rear. The latter screws pass down `through holes I9 and 20, Fig. 2, in the boiler, and are threaded into tapped holes 2i and 22, Fig. 3, in the sole plate.

The heating element 23 is clamped between the sole plate 2 and the boiler l. This element is of any suitable and known construction.

The rear part of the boiler, through which the screws I8 pass, is of reduced thickness, as seen from Fig. l. This part oi the boiler comprises two sections 50 and 5I which are joined at the rear by a transversely-extending solid section 52. This construction provides a large opening 53 through which pass the electrical connections to the thermostatic control mechanism. The sections 50 and 5I are hollow, being provided with channels 54 and 55. respectively, which communicate with the main boiler cavity. The transverse section 52 drops down sharply at the rear of the sole plate 2, as seen in Fig. 1, and has a rearwardly-extending section 56. rI'he part 56 merges into the two corner members 5l and 5B which are of slightly increased thickness and are rounded off at the rear, as seen in Fig. 2. The construction just described is of utility in connecting the boiler with the water tank, as will be explained presently.

The boiler is concealed beneath a cover 60, which is cast integrally with the water tank 6I. The shape of this casting can be seen from Figs. 1, 4, and 5, also Fig. 6. The cover portion conforms generally to the shape of the main part of the boiler. It is substantially dat on top, with slightly sloping sides, and is brought to a point in front. The lower edge of the cover ts in the groove 3 of the sole plate 2. Above the rear part of the boiler the cover rises at an angle of about 70 degrees and merges into the water tank. The tank lies to the rear of and partly above the level of the boiler, as seen in Fig. 1. The forward part of the tank extends over the rear depressed portion of the boiler and is recessed in front, as seen in Fig. 4, to provide a housing for the terminal strip.

The combined cover and tank casting is as-r sembled to the boiler and sole plate, as shown in Fig. 1, and is secured in place by means of two screws 62 and 63, which pass through the cover part and are threaded into the boiler, and also by means of two large hollow screws or studs |54 and 65, which pass through the

rearwardlyprojecting members

51 and 58 of the boiler and are threaded into the bottom of the tank.

There are two passages leading from the water tank to the boiler, one for the admission of water and the other for equalizing the pressure between the boiler and the space above the water level in the tank. These passages extend through the

hollow screws

64 and 65.

Describing the pressure-equalizing passage,

Y there is an opening 66 drilled slantingly upward through the overhanging part 52 of the boiler to tap the channel 55. This opening is plugged by a tapered screw 68. Another drilled opening 61 connects the opening 66 with the annular space surrounding the shank or unthreaded portion of the hollow screw 64. The latter is crossdrilled at 1| to afford a communication between the annular space referred to and the hollow interior of the screw, in which is tightly fitted the tube 12. This tube may be made of soft copper and is flexible enough so that the screw 64 can be inserted and tightened up without difficulty with the tube in place. 'I'hus it will be seen that a continuous passage is provided from channel 55 by way of drilled openings 66 and 61, the hollow screw 64 (cross-drilled as explained) and the tube 12 to the space above the water level in the tank. Leakage is prevented by a gasket inserted between the tank and part 58 of the boiler and another gasket 69 beneath the head of screw 64.

The water passage extends through the hollow screw 65, and communicates with the channel '54 of the boiler. From the screw 65 to the channel 54 the water passage is exactly the same as the pressure-equalizing passage just described, and includes the drilled openings 66' and 61', shown in dotted lines in Fig. 2. From the screw 65 in the direction ofthe tank, the Water passage includes a manually-controlled shuto' valve 16, Fig. 5, and an automatic shutoff valve 84, Fig. 1.

The manually controlled valve is located in a rounded shoulder 13, Figs. 1 and 5, formed in the wall of the tank. In this shoulder a sloping opening 14 is drilled from the outside and is tapped to receive the threaded portion 18 of the valve 16, the tapered end of which lies in the ne opening which connects the opening 14 with the space above the end of the hollow screw 65. The opening 14 is counter-bored to a large diameter near the top and is tapped to receive the packing gland 11. By means of the latter the packing 19 is compressed around the shank of valve 16`to prevent leakage. The valve 'i6 is rotated by means of knob 80. By turning this knob in a clockwise direction, the tapered end of the valve may be advanced to completely close the opening 15. Turning the knob in the opposite direction will back off the valve and open it to any desired extent.

The automatic shutoff valve is centrally located in the bottom of the tank, and is shown in Fig. 1. There is a downwardly-projecting annular rim 83 on the outside of the bottom wall of the tank. which is bored out to receive the disk 9|. This disk is provided with a. central upwardly-extending cylindrical member 85, which is threaded tightly into -a tapped opening in the bottom of the tank. vThe member has a central opening therein through which passes the valve stem 86, the said opening being faced oil on top to provide a seat for the valve 84. The valve stem 66 has a threaded connection with a stud which is riveted at the center of the diaphragm 81. This diaphragm is clamped between the disk 9| and the closure member 89, the latter having a short threaded cylindrical portion which enters the tapped interior wall of the annular rim 63. A gasket is provided above and below the diaphragm to prevent leakage. The coil Spring 88 normally is under a certain amount of compression, pressing inwardly on the diaphragm 81. Valve 84 is normally open. The vent 90 maintains the lower side of the diaphragm at atmospheric pressure.

A connection between the automatic shutoil.' valve and the manually controlled valve is established by means of a drilled opening 82 which passes lengthwise through a raised rib 8| on the inside of the bottom wall of the tank. This rib extends from the shoulder 13 diagonally toward the center of the tank where'it merges into the annular rim 83. The opening 82 connects with the space 81 above the disk 0| and at the other end it taps the opening 14 at a point which is a short distance above the opening 15. The rib 8| is seen clear in Figs. 1 and 4.

The path for the ow of water from the tank to the boiler may now be traced by way of valve 84, Fig. 1, valve stem opening in 85 to space above diaphragm 81, drilled openings in disk 6| near the base of 65, space 81', drilled opening 82, space in opening 14, Fig. 5J valve 16, crossdrilled hollow screw 65, and openings 61' and 66', Fig. 2, to the channel 54 leading into the main boiler cavity. This path can be closed by valve 16, under control of the operator, and may also be closed by valve 84 responsive to an excessive boiler pressure, as will be explained in described the operation of the iron.

The water.tank is filled from the top through an opening which is normally closed by a cap |00. The cap is provided with a gasket so that the opening is sealed with the cap in place.

'I'he handle |02 may bemade of Wood or of some composition material'which is a good heat insulator. It is supported at the'rear on a tapered member |0| which projects forward from the upper part of the water tank, and at the front on a bracket |06 which is secured to the cover by screw 62. The handle is in two parts, the main part |02 and a recessed forward part or forecap |03, which are clamped together and to the bracket |06 and member |0| by means of a long bolt |04. This bolt is threaded into a tapped hole drilled in member |0| and when tightened up holds the parts firmly in place. The recessed forwardpart |03 of the handle partly encloses a bell cranklever ||0 which is pivoted at |01 on an ear forming part of bracket |06. Arm i 09 of the lever serves to control the steam valve 34. The pin or stud |08 on the other arm of asiduo? the lever projects through a slotted opening in the side of handle member |03 and carries a button or knob I II, Fig. 5,4by means of which the'lever is operated.

The construction of the steam valve may now fbe explained. This valve is located at the forward Aend of the boiler, as shown clearly in Fig. 1, in a recess which is formed in the solid toe of the boiler by drilling operations. This recess overlaps the drilled recess for the head of screw |1. The valve includes a main body portion 21, the lower end 28 of which is of reduced diameter and is threaded into the boiler. The member 21 is enlarged at 26 and has a hexagonal head 25 by means of which it may be screwed tightly in place. A gasket is interposed beneath the enlarged rim 26 to prevent leakage. The annular space surrounding the member 21 is connected with the boiler cavity by means o f a drilled hole 35. At the bottom of the recess in which the threaded portion 23 is located a sloping hole 36 is drilled to the interior of the tubular member |5.

The body 21 of the valve has a longitudinal bore to receive the valve stem 33, having a valve 34 at the lower end thereof. Leakage around the valve stem is prevented by suitable packing which is compressed by the gland 3|. The valve is held closed by a coil spring 30, which is tensioned between the outside face of gland 3| and' the nut 23 threaded on the end ofthe valve stem. This nut affords a means for adjusting the spring tension. The valve stem 33 is of reduced diameter toward the lower end, providing a steam passage which is connected with the space surrounding the valve body 21 by cross-drilling the latter at 32.

The steam valve is opened by operating the knob I I on pin |08, which rotates the bell crank lever on its pivot |01 and depresses the valve stem 33 against the tension of spring 30. When the valve is open, steam can pass from the boiler to the sole plate by way of opening 35, annular space surrounding 21, cross-drilling 32 in 21, annular space surrounding lower portion of valve stem,valve 34, opening 36, and tubular member I to the channel 5 in the sole plate.

It will be noted at this point that the steam valve is so arranged as to act as a safety valve. Steam pressure in the boiler tends to open the valve and if an excess of pressure is built up the valve will open automatically, allowing steam to escape into the sole plate until the pressure is relieved. The pressure at which the valve opens depends on the tension of spring 30, which can be adjusted by means of nut 29, as previously mentioned.

ed inwardly-projecting shoulder |4I, seen in Fig. 5. The two conductors of the cord are secured under terminal screws and |26.

The thermostatic control mechanism is mounted on a plate |42, Fig. 1, which is secured at the bottom ofthe recess 4 in the sole plate by means of screws |36 and |31. The control mechanism comprises a bi-metallic element |34, and contact springs |23 and |30, all of which are se- The electrical connections for the iron will now be described briefly. That portion of the front wall of the water tank which lies above the cover is given a U-shaped formation, as seen particularly in Fig. 4, to form a housing for the terminal strip |20, said housing having side walls |2I and |23 and the rear wall |22. The housing projects rearwardly into the tank, as seen in Figs. 4 and 5. The side walls |2I and |23 have vertical slots in which the terminal strip |20 is retained. 'I'his terminal strip is of suitable insulating material, The housing is lined with a sheet of insulating material (not shown) to guard against accidental short circuits, and is closed in front by the plate |24.

The cord for supplying current to the iron enters the housing from the right side through an opening |40, Fig. 1, which is formed in the roundcured to plate |42 by means of screw |35. I'he contact springs are suitably insulated and are provided with contacts |32 and |33 which are normally in engagement. When the bi-metallic element |34 becomes heated, the free end moves upward due to bending of the element and engages the end of screw |43, thereby raising the end of spring |29 to separate contact |32 from contact |33. Screw |43 is adjustable. 'I'he working adjustment during use of the iron is accomplished by means of the lever |40, secured to the shaft |38. This shaft has a cam |38 nea;` the lower end which raises or lowers contact |33 responsive to rotation of shaft |33 in one direction or the other, and thus determines the temperature at which the contacts |32 and |33 are separated by the element |34.

The upper contact spring |29 extends to the rear and is bent upward, passing through the opening 53 in the boiler to the terminal strip where it is secured under screw |26. The other contact spring |30 is connected to one end of the winding of the heating element 23. The other end of the heating winding is comiected to a metallic strip |28, which extends upward along the back of the terminal strip |20 and is bent over around the top of the strip and retained under screw |25. By the described arrangement the heating element 23 is connected in series with contacts |32 and |33.

The operation of the iron will now be described.

VThe knob should rst be turned down to close the water valve 18, after which the cap |00 can be removed and the tank illled with water. The cap is then replaced and screwed down tightly. The cord may then be plugged into a convenient receptacle and the iron will begin to heat up. The thermostatic control knob |40 should be set forl the desired heat value, depending on the type of material to be ironed.

When the iron has become thoroughly heated, the water valve 16 may be opened and water4 will ow from the tank to the boiler by way of the path described. Since the `boiler is hot, steam will be formed at once, but the Water continues to flow into the boiler, due to the pressure-equalizing-passage including tube 12, which maintains the pressure above the water in the tank equal to the back pressure at the water passage. The opening 15 is rather small and when the valve is fully open. allows only enough water to enter the boiler to provide for the maximum steam requirements. The size of the opening can be reduced by adjustment of the valve.

If the steam valve remains closed, the pressure in the boiler will rise gradually, and since the same pressure exists in the tank, the valve 04 will close before long. The spring B6 may be so designed that the valve will close at a pressure of about five pounds. The closure of valve 84 shuts off the supply of Water to the boiler, which tends to prevent an excessive rise in boiler pressure and avoids the waste of water in case there is some delay in beginning work with the iron.

When the ironing operation begins, the operator presses forward on knob |I| with his thumb,

which actuates lever I to open the steam valve 34, and steam begins to iiow through the valve into channel 5 in the sole plate and out through the openings 6 in the toe of the iron. On entering channel 5 the steam flows through the sole plate to the rear and then returns to the toe of the iron before passing out through the openings 6. The passage of the steam through the hot sole plate insures that only dry steam will be delivered to the material being ironed. The steam valve may be operated intermittently or may be held open for substantial intervals as required. As the steam is used, the pressure in the boiler falls, whereupon the valve 84 opens to admit more water. During continuous ironing operations this valve will remain open most of the time, but if any suspension of operations occurs, the valve responds to the resulting rise in steam pressure and shutsof the water. This makes it unnecessary to close the manually operated valve '|6 until the ironing is completed, even if the work is interrupted from time to time.

As previously mentioned, the steam Valve is so constructed that it also operates as a safety valve. The valve is enabled to function in this manner because the steam pressure inside the boiler tends to open the valve against the tension of spring 30. This spring may be so adjusted that the valve will open at a boiler pressure of about eight pounds. With this adjustment the valve ordinarily will not open automatically, because the automatic shutoif valve 84 cuts oi the water supply when the pressure reaches ve pounds. If anything should go wrong with the shutoif valve, however, or if the heat adjustment is too high, the pressure may increase sufcientlyto open the steam valve. It will be seen, therefore, that the iron is entirely safe. The dual functioning steam valve is particularly reliable in performing its function of a safety valve because it is in conthe steam valve permits the flow of steam along the channel 5, which cools the sole plate somewhat and causes the element |34 to turn on the heat again sooner than would otherwise be thel case. Although the steam is hot it still has a somewhat lower temperature than the sole plate, so that the described effect will take place. The effect is greatly enhanced if the operation reaches the critical stage where moist steam begins to leave the boiler, indicating an imperative demand for heat, which is met at once by the loss of heat matic shutoff valve in one structure, or, in other words, to simplify the iron by providing a dualpurpose valve which may be manually controlled and is also controlled automatically responsive to a rise in boiler pressure.

The iron shown in Fig. 6 is the same as the one shown in Figs. 1 5, except that the manually controlled valve '|6 at the side of the tank, together with the shoulder '|3, is entirely omitted and is replaced by a new valve structure at the rear of the tank which incorporates both the manual and automatic control feature. 'Ihere are other minor changes in the tank structure, which will be apparent. That part of the drawing Fig. 6 which is shown in section is on the v line 6 6, Fig. 2.

' downwardlyis bored out to receive'the diaphragm tinuous use under manual control and is always free and operative; or, at least, if anything goes wrong'with it, the fact willv immediately become apparent. This overcomes the objection to a separate safety valve, which operates very infrequently, and may become stuck and remain that way without its condition becoming known.

When the iron is to be put away, the cord is disconnected'and the water is shut off at valve '|6 to prevent flooding of the boiler as the temperature goes down. The tank need not be emptied.

The location of the channel 5in the sole plate is of special importance, particularly when working on certain fabrics, such as silk and rayon; which have to be ironed with a relatively low sole plate temperature, say about 225. This temperof the cup-shaped member I ature is considerably-below the temperature at which the heating element can maintain the iron, and consequently the thermostatic control will come into play from time to time to shut off the heat. The bi-metallic element |34 is located where it is affected by the sole plate temperature, which changes rather slowly due to the large mass of the material of which it is composed. It is desirable to accelerate the change in temperature in the vicinity of the element |34, to give a quicker and more accurate control, and decrease the length of the intervals during which the'heat is off. thus avoiding any danger of water accumulating in the boiler. To this end the channel 5 is directed to the rear of the sole plate close alongside the recess in which the bi-metallic element |34 is located. At any time when the heat is The bottom of the tank 6| is cast With a extending annular rim |50, which |54. The diaphragm |54 is clamped between two gaskets against the shoulder in annular rim |50 by means 52, which is attached to the rim |50 by means of several screws such as |5|. The member |52 is vented at the center s'o that the space inside is at atmospheric pressure. A coil spring |53 is housed in member |52V and presses against the center of the diaphragm |54. The space |55 above the diaphragm is connected by a diagonal passage 82 with the space at the end of the hollow screw Just above the center of the diaphragm |54 there is an opening drilled through the bottom of the tank. This opening is countersunk on the-inside to form a seat for the valve |58. The valve is formed lat the lower end of the rod |51, which continues beyond the valve in the form of a stem |56 of reduced diameter the end of vmanually operated part of the valve comprises off and while the iron is in use, the opening of a shaft |6|, which is rotatable |63. The shaft IBI is threaded at its lower end in an abutment formed in the tank wall. The shaft is surrounded by packing, held in place by the gland |62. The upper section |60 of rod |51 enters a hole drilled in the end of shaft |6|.

When the valve |58 is open, water can ow from the tank through the valve into the space |55 and thence by way of passage 82', hollow screw 65', the drilled openings shown, and the channel 54' to the main boiler cavity. Spring |53 tends to oppose closing of the valve, and its strength may be suicient to prevent 'closing of by means of knob ed. 1 Thel -bottom of the hole in shaft |6| will engage the end of extension |60, whereupon further rotation oi' the knob in the same direction will close the valve. It will be seen therefore, that the valve structure described comprises a valve which will respond automatically to a predetermined rise in boiler pressure to shut of! the water, which can be adjusted by hand to vary the pressure to which the valve responds, and which can be closed by hand at any time. f

'I'he operation of the iron modified according to Fig. 6 is otherwise the same as the operation oi' the main embodiment already described.

The modification disclosed in Fig. 'l has for its main object the provision of a temperaturecontrolled water valve, adapted to replace the manually controlled valve such as i6. As an additional improvement the temperature-controlled valve is also controlled by boiler pressure, which enables the automatic shutoff valve 04 to be omitted. Thus the modication about to be described comprises a dual-purpose water valve controlled in accordance with the temperature oi' the boiler and also in accordance with the pressure in the boiler.

The valve is located at the rear of lthe boiler, just behind partition 9, see Fig. 2, and in line with the channel 54 in the rearwardly-extending leg 50. The channel 54 is, however, omitted, and the casting is further modified to include a raised portion 2|3 on the floor of the boiler cavity. The roof of the boiler is made considerably thicker at this point and is bored out from above to receive the ring 203. This ring has a transversely-extending curved arm 206. Above the ring 203 there is assembled a diaphragm 204, which is clamped in place between two gaskets by means of the threaded cup-shaped closure member 2|4, the latter having a hexagonal head at the center by means of which it can be screwed down tightly. The member 2|4 is drilled and tapped at the center to receive the screw 2||. A spring 2|0 is tensioned between this screw and the diaphragm 204.

On the lower side of the diaphragm there is secured a bimetallic element 202 which may be shaped as shown in the drawings. The lower horizontal portion of the element 202 is perforated to admit the body of the valve 209, and the stem of the valve passes up through an opening in arm 206. The valve is urged to its'seat by a light spring 205 secured to arm 206. The element 202 is normally under compression, the end of the element bearing against the edge of the ledge 2|3.

The passage 200 is drilled out from the rear of the boiler and ls plugged at the end by means of a screw 20|. This passage connects with passage 66 at the rear. The passage 200 extends forward past the center of diaphragm 204, and is tapped by an opening drilled down through ledge 2|3 from above. This opening is countersunk to provide a seat for valve 209. The valve is normally held closed by gravity and by the spring 206. Screw 2| is an adjusting screw for varying the boiler pressure to which the valve is responsive and is accessible through an opening 2|2 in the cover 00'.

Describing the operation of this modification briefly, when the tank is iilled no water can pass to the boiler because the valve 209 is closed. When the iron is connected to a source of current, it begins to heat up, likewise the bi-metallic element 202, which gradually loses its tension and eventually bends upward to raise the valve 209. The bi-metallic element should preferably be arranged to open the valve responsive to a. temperature of about 215 degrees. When the water is first admitted, the parts will be cooled down somewhat, and the valve may close, but will soon open again as the heating continues and the water is converted to steam. The valve will therefore feed water to the boiler only at times when the temperature is high enough to convert the water to steam and positively prevents iiooding of the boiler with Water.

As in the case of the main embodiment of the invention, if the steam is not discharged by opening the steam valve, the pressure in the boiler will rise and eventually will exert a force on diaphragm 204, which is sufficient to bend the diaphragm outwardly against the tension spring 2|0. The adjustment of this spring may be such that a pressure of about five pounds is required for operation, as in the previous case. The horizontal portion of the 'bi-metallic element 202 is now resting against the end of arm 206, holding valve 209 open, but when the diaphragm 204 rises it carries along the element 202, or attempts to do so, and the horizontal portion of the element acts about the end of the arm 206 as a fulcrum to close the valve. That is, the diaphragm raises all that part of the bi-metallic element to the right of the fulcrum at the end of arm 206 and consequently the end of the element to the left of the fulorum point is lowered and the valve is closed. When the consumption of steam begins the pressure Within the boiler falls, the diaphragm 204 returns to normal and the valve 209 is opened again, provided, of course, that the temperature has been maintained.

Referring now to Fig. 8, there is shown a cap which may be substituted for the cap |00 of Fig. 1 as a closure for the water tank. The modified form of cap comprises a main threaded body portion 250, having a hexagonal shoulder 252 by means of which it can be screwed tightly into the tapped opening at the top of the tank. The body 250 has a longitudinal bore, in which is located a check valve in the form of a ball 251, held in its seat by a light coil spring 258. A tube 25| is threaded into the lower end of 250. At the upper end of the body member 250 there is inserted a curved tube 255. This tube is provided with a shoulder 254, which is held against the end of 250,

with a gasket interposed, by means of a clamping nut 253. By loosening this nut the tube 255 can be turned in any desired direction.

The reference character 256 indicates a rubber hose which leads to a main supply tank from which the water is fed to the tank in the iron by gravity. The height of the tank should be sufiicient to develop a head of about three pounds. When the water is turned on at the supply tank, the water will flow through the hose and valve 251 in the cap, iilling the tank in the iron. Some time before the water level reaches the top of tube l2, however, the air in the tank and boiler will be compressed enough to build up a pressure which will stop the ilow of water, the steam valve being closed. When water is admitted to the boiler, steam will be generated which maintains the pressure.l ,As the iron is being used the steam valve will be opened at intervals and at such times the pressure in the boiler and tank will fall far enough so that water can enter through valve 251. Thus the tank may be kept supplied with water during continuous use over long periods, which is especially desirable when the iron is in service in a laundry.

The cap shown in Fig. 8 is also desirable in the ordinary domestic use of the iron to facilitate refilling. Unless some care is taken in removing the cap |00, Fig. 1, there is danger of burning by hot steam, a difliculty which is avoided by the modified form of cap, since it does not have to be removed. Removal of the cap is unnecessary because of the passageway including the tube 25'5 and valve 251, through which water may be introduced in any suitable or desired manner.

'Ihe invention having been described, that which is believed to be new and for which the protection of letters Patent is desired will be pointed out in the appended claims.

I claim:

1. In a steam iron, a sole plate, a boiler superimposed on said sole plate and secured thereto with a heating element between them, a thermostatic device in said sole plate to control said heating element, ,said device comprising a bimetallic strip disposed lengthwise of the sole plate, steam outlets in the face of the sole plate, a valve-controlled steam passage leading from the boiler to the sole plate at a point near the toe thereof, and a channel in the sole plate through which the steam is conducted to the said outlets over a path which extends rearwardly parallel and close adjacent to said device, whereby the response of the device to a demand for heat is accelerated.

2. In a steam iron, a sole plate, a boiler superimposed on said sole plate and secured thereto with a heating element between them, a thermostatic device in said sole plate to control said heating element, a steam passage leading from the boiler to the sole plate, a manually controlled Valve in said passage, and a steam channel in the sole plate leading to outlets on the face thereof,'a partof said channel ahead of the said outlets being so related to the said device that in case moist steam is admitted through said valve the evaporation of the water in said moist steam will draw heat from the sole plate in the immediate vicinity of the device and accelerate the response thereof.

3. In a steam iron, a sole plate having a central recess therein for a thermostatic device, a steam channel in said sole plate starting at a point forward of said recess and extending in Atwo branches to the rear of the sole plate, said branches being located on opposite sides of said recess in good heat transfer relation to the device therein and after reversing at the rear of the sole plate extending forward to the toe of the iron where they join, steam outlets adjacent the junction of said branches, a boiler superimposed on said sole plate, and a steam passage leading from the boiler to the channel and connecting therewith where the channel starts.

4. In a steam iron, a sole plate, a boiler superimposed on said sole plate, a heating element between the boiler and sole plate, a one-piece means for securing said tank to said extension,v

and means includingv passages in said extension for establishing communication between the boiler and tank.

5. In a steam iron, a sole plate and boiler in superimposed relation, a heating element common to said boiler and sole plate, a cover of cast material enclosing the boiler and heating element, a terminal strip for making electrical connections to said element, and a water tank in the rear' of and Vabove the boiler, said tank being cast integrally with the said cover and having a recess in the front thereof to form a housing for said terminal strip.

6. In a steam iron, a sole plate, a boiler superimposed on said sole plate and having a solid extension in the rear thereof, a water` tank supported on said extension and secured thereto by hollow screws, and passageways connecting the interior of the boiler with the interior of the tank including said screws and holes drilled in said boiler extension.

7. In a steam iron which includes a boiler and a water tank, a water passage leading from the tank to the boiler, a normally closed valve in said passage, means foi` heating said boiler, and means responsive to the boiler temperature rising to a predetermined point for opening said valve.

8. In a steam iron which includes a boiler and a. Water tank, a water passage leading from the tank to the boiler, a normally closed valve in said passage, and a thermostatic device including a bi-metallic strip for opening said valve responsive to a predetermined boiler temperature.

9. In a steam iron which includes a boiler and a water tank, a, water passage leading from the tank to the boiler, a normally closed valve in said passage, means for heating said boiler, means for opening said valve responsive to the boiler temperature rising to a predetermined point, and means for closing said valve while the temperature remains above the opening point responsive to the pressure in the boiler increasing to a predetermined extent.

10. In a steam iron, a boiler, a tank from which water is fed to the boiler automatically, means including a thermostatic device for starting the feed of water responsive to a predetermined boiler temperature, and means for stop ping the feed responsive to a predetermined boiler pressure.

1l. In a steam iron, a boiler, a water tank, a passage leading from said tank to said boiler, a second passage for maintaining thepressure above the water in said tank nequal to the boiler pressure, a valve in said first passage, a ilegible diaphragm set in the wall of the boiler for controlling said valve, and means including said diaphragm for closing said valve responsive to the boiler pressure rising to a value which exceeds the atmospheric pressure by a predetermined amount.

12. In a steam iron which includes a boiler and a tank for supplying water to the boiler,

a closure member for said tank, a passage ex-,

tending through said member for nlling the tank, and a check valve in said passage.

13. In a steam iron, a sole plate, a boiler supen imposed-on said plate, a steam valve for controlling the ilow of steam from the boilerV to the sole plate, a cover for the boiler, a handle and means for securing it to the iron including a bracket attached to said cover, means for controlling said valve including a bell crank lever pivoted on said bracket and located entirely in front thereof, a knob for actuating said lever, and a detachable recessed fore cap for the handle partially enclosing said lever.

14. In a steam iron which includes a boiler and a water tank, a water passage leading from the tank to the boiler, a valve for controlling the flow of water through said passage, a thermostatic device for opening said valve to admit water to the boiler, a passage for communicating boiler pressure to the tank, and means for closing said valve responsive to the said pressure rising to a predetermined point above atmospheric pressure.

15. In a steam iron, a boiler, a sole plate, a passage for conveying steam from the boiler to the sole plate, a normally closed manually controlled steam valve in said passage, a water tank, a passage for conveying water from said tank to said boiler, a water valve in said last mentioned passage, said water valve being closed when the iron is cold, means for heating the iron and boiler, temperature responsive means for opening said Water valve upon a predetermined temperature rise, and means for automatically closing said water valve in response to excessive boiler pressure due to continued closure of said steam valve.

16. In a steam iron, a boiler, a sole plate, a

water tank, an automatic water valve for controlling the now of water from the tank to the boiler, said valve being adjusted to shut oil the water upon a predetermined rise in boiler pres'- sure, and an automatic valve for controlling the :dow of steam from the boiler to the sole plate, said last mentioned valve being adjusted to open at a predetermined boiler pressure Which is greater than the pressure required to close said water valve.

1'7. In a steam iron, a boiler, a water tank for supplying water to said boiler, means for heating said boiler to generate steam, means including a lvalve for automatically shutting off the water supply to the boiler upon a predetermined rise in steam pressure, and thermostatically controlled means for automatically effectlng closure of said valve when the heat is turned off to prevent ilooding the boiler.

i8. In a steam iron, a sole plate, a boiler, a water tank, a passage for conveying water from said tank to said boiler, a passage for transmitting boiler pressure to said tank, a passage for conveying steam from the boiler to the sole plate of the iron, a steam valve in said last mentioned passage, a water supply pipe extending t said tank from a water supply source under pressure tending to deliver water to the tank, and a check valve operatively interposed betweenr said tank and the water supply source for preventing a reverse flow of water in case the boiler pressure rises above the water-supply pressure due to failure to open said steam valve.

19. In a steam iron which includes a boiler and a tank for supplying water to the boiler, said iron having a water passage extending from the tank to the boiler, a passage for communicating steam pressure in the boiler to the tank ata point above the level of water therein, a water supply pipe for delivering Water to the tank under pressure, said pipe terminating inside the tank below the water level, and a check valve in said pipe for preventing a reversal of water ow in case the steam pressure rises higher than the water pressure. y

20. In a hand operated steam iron, a boiler and a water tank both supported on and movable with the rest of the iron, a water passage'leadi118 from the tank to the boiler, a valve in said passage, means for maintaining equal pressures in the boiler and tank independent of said passageway, a diaphragm forming part of the wall of said passageway and subject to the pressure of the water therein, such water pressure being due to the steam pressure in the boiler acting on the water in said passageway, and means whereby said diaphragm is operative to eiIect closure of said valve in response t0 a predetermined pressure of the water in said passage.

21. In a steam iron adapted for to and fro manipulation by hand, a boiler and a water tank both supported on and forming part or the iron, the said boiler and tank being so arranged on the iron that the bottom of the tank cavity is approximately level with the bottom of the boiler cavity, a passage leading from the tank to the boiler, means independent of said passage for maintaining equal pressures in the tank and boiler to permit the iiow of water through said passage by gravity, a valve for closing said passage to stop the water flow, and means including a diaphragm responsive to the boiler pressure for controlling said valve.

22. In a hand manipulated steam iron, a boiler and a water tank both supported on and forming part of the iron, means for maintaining equal pressures in said tank and boiler, a passage for transferring water from the tank to the boiler by gravity, said passage including a water retaining cavity which is below the level of both the boilerI and tank and hence is incapable ot draining into either the boiler or tank, a valve for closing the said passage, and means including a. diaphragm in contact with the water in said cavity and responsive to the pressure of the steam in said boiler transmitted to the said diaphragm through the water in said cavity for operating said valve.

23. In a hand operated steam iron, a boiler and a Water tank secured together and movable as a unit with the remainder of the iron, said tank having a recess formed in the exterior bottom Wall thereof, a diaphragm closing said recess, means including a valve for admitting water from the tank to said recess, a passage for conducting water from said recess to said boiler, and means whereby said diaphragm is adapted to effect closure of said valve responsive to the pressure in said recess communicated thereto from the boiler via said passage.

24. In a steam iron, a sole plate, a boiler superimposed on said sole plate and secured thereto, a heating element between said boiler and sole plate, a one-piece casting comprising a water tank for supplying water` to the boiler and a cover enclosing said boiler and heating element, the cover portion of said casting having a rim which rests on the sole plate and the tank portion of the casting having a part engaging a corresponding part of the boiler, means for establishing communication between the tank and boiler through said parts, and means for securing said casting to the boiler, including means for clamping said parts together.

25. In a steam iron, a sole plate, a boiler superimposed on said sole plate, a heating element between said boiler and sole plate, a cover of cast material cooperating with said sole plate to enclose the boiler and heating element, a water tank cast integrally with said cover, said tank being located to the rear of the boiler and including a portion which extends upwardly from the rearl of the cover portion o! the casting, said tank also including a portion cooperating with the boiler through which communication between the boiler and tank is established, a handle for the iron, and means for securing said .handle to the forward end of said cover and to 5 said upwardly extending portion of said tank.

STANLEY WALLACE.