US2345413A - Steam iron - Google Patents

Description

March 2a, 1944. E, o, MORTON 2,345,413

STEAM IRON Filed May 20, 1941 2 Sheets-Sheetl 5d aba l7 :7

INVENTOR ELDQE'D O. MORTON ATTOR EY March 28, 1944. E, o. MORTON STEAM IRON Filed May 20, 1941 2 Sheets-Sheet 2 Pie. "7.

INVENTOR Emma: O- MORTON S E S s E N H W ATTORE. E!

Patented Mar. 28. 1944 2,345,413

STEAM IRON Eldred 0. Morton, Mansfield, Ohio, assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania ApplicationMay 20, 1941, Serial No. 394,258

9 Claims.

This invention relates to steam irons and more particularly to that type of steam iron which is provided with a main heater for heating the soleplate and ironing surface of the iron and an auxiliary heater for supplying heat to the steam generator of the iron, and it has for an object to provide an improved steam iron of the character set forth.

It is a further object of the invention to pro- The soleplate l3 maybe of conventional outline, as illustrated in Fig. 2, and is provided with a U-shaped heating element ll secured thereto or imbedded therein as illustrated particularly in Figs. 1, 2 and 3. I'his heating element may be of well-known construction and comprises an outer metallic tube It (Fig. 3) having. a coiled resistance element it supported in spaced concentric relation thereto by means of suitable vide a construction of steam iron in which the heat-conducting, electrical insulating material. steam generator of the iron will be maintained Power for heating the soleplate is supplied to hot enough to assure that the water supplied the element ll by means of a cord all adapted thereto will be converted into steam. to be connected to an electrical outlet (not These and other objects are effected by the shown). This cord comprises conductors 22 invention as will be apparent from the following connected to the ends 2d of the resistance eledescription and claims taken in connection with. ment ill in series with a manually-adjustable the accompanying drawings, forming a part of thermostat 23 as shown in Fig. i. this application, in which: The thermostat 23 may be either a creep Fig. 1 is a side view, partly broken away along n type or snap-acting type of conventional dethe longitudinal center, of a steam iron made in sign. This thermostat is supported in a recess accordance with the present invention; provided in the soleplate and is adjustable to Fig. 2 is a top plan view of the soleplate of regulate the temperature of the soleplate in the the iron shown in Fig. 1, broken away along the usual manner, by means of a rod Zfil'extehding line 11-11 of Fig. l; through a sleeve 25 brazed or soldered in fluid- Fig. 3 is a fragmentary sectional view of the tight relation in the upper and lower walls of iron shown in Fig. 1, the section being taken the reservoir i5. A knob or handle 26 provided substantially along the line IIIIII of Fig. 1; with a suitable scale adapted to co'operate with Fig. 4 is a schematic wiring diagram of the a fixed index on the cover ii, to indicate varelectrical circuits employed in the iron illusous temperature settings, is fixed to the upper trated in Figs. 1 to 3, inclusive; end of the rod 2d. The thermostat adjusting Fi 5 is a view similar to Fig. l of a modified rod 2 3 carries an arm 2i which engages a curved form of the invention; finger 23 of a switch it to open the contacts Fig. 6 is a fragmentary sectional view taken thereof When the thermostat is turned to its ofi" substantially on the line Vl-VI of Fig. 5 to @5 position. As shown irrFigs. l and 4, this switch illustrate certain details of construction: 29 may comprise a U-shapeo': spring member 30 Fig. 7 is a schematic wiring diagram of the which insulatedly supports contacts connected, electrical circuits employed in the iron illusrespectively, to one of the conductors 22 and to trated in Figs. 5 and 6; and the conductor leading to the heating elements Fig. 8 is a schematic Wiring diagram similar i9 and E l. to that shown in Fig. '7 and showing a slightly The soleplate it is provided with a recess or modified circuit arrangement. hole 32 located within the loop or "eight 33 of Referring to the drawings and particularly to the heating element ll. This recess opens on the Figs. 1 to 4, inclusive, there has been illustrated ironing surface 34 of the soleplate and is noran electrically-heated steam iron indicated mally closed at ts ower end y means of a generally by the, reference character 10. The metallic plug or member 35 which is threaded iron 10 comprises a body including a cover or to removably engage mating threads formed on shell ll having a handle l2 secured to the top the side walls of the recess. It will be noted thereof and a metal soleplate or base H3 atthat the upper surface of this plug, together with tached to the bottom thereofi The interior of the lateral wall 36 and the upper wall Bl of the the cover it is provided with partit ons suci as recess, defines a chamber 32a. I4 which, together with the side and top walls The chamber 32a is divided into two communiof the cover, define a liquid storage chamber or eating compartments by an. annular rib or bafi e reservoir l5 having a filling opening normally 38, preferably formed integral with the plug. closed by aremovable, vented plug I5. The circular space within this bailie provides a steam-generating compartment 39,(Fig. 3) while the annular space between the bafile and the lateral wall 36 of the recess defines a steam-distributing' compartment 5!.

A plurality of steam ports d2 extending inwardly from the outer surface of the plug communicate with the steam-distributing comparte. ment ii and serve to discharge steam on the material being ironed. These ports also serve as tool-receiving openings whereby a suitable tool maybe inserted therein for removing the plug from the'iron.

The reservoir i5 is adapted to contain a liquid such as water or the like which is supplied to they steam generator through a valved outlet pro= vided in the lower wall it of the reservoir. This outlet comprises a valve-stem guiding sleeve d3 which extends through and is preferably brazed or soldered in fluid-tight relation to the upper and lower walls of the reservoir 55. The lower end of this sleeve projects below the lower wall it and is externally threaded to be received in an internally threaded bushing member dd pref erably brazed, soldered or welded to the bottom wall of the reservoir. This bushing in turn extends through an aperture provided in the upper wall 3'11 of the soleplate l3 and is clamped thereto, in fluid-tight relation, by means of a nut 35 threaded thereon. The sleeve 33 is provided with holes 66 which afiord communication between the interior of the reservoir and a water passage ill provided in .the bushing 6 The upper end of this-water passage provides a valve seat 38.

The valve seat 88 is engageable by the lower tapered end of a valve stem 39, guided in the sleeve 13, for closing the passage (ill. The upper end of the valve stem carries a knob 5i and is preferably threaded, as indicated at 52, to engage complementary threads formed in the upper end of the sleeve t3. By turning the knob M in one. direction or the other, the valve stem is raised or lowered relative to the valve seat 48 to regulate the rate of water flow from the reservoir is into the steam generator. If desired, this knob may be provided with an index (not shown) to cooperate with a suitable scale which may be provided on the handle E2 to indicate the size of the valve opening for any given setting of the knob.

While the soleplate heating element i? will usually provide sufilcient heat to enable the steam generator to convert water, supplied thereto from the reservoir l5, into steam, under certain conditions the steam generator may be too cool to generate steam. For example, when the soleplate temperature is maintained at a very low value, such as 300 F., or even lower, as when ironing rayons, silks, and the like, it has been found that during the ofi cycle of the thermostat 23, the temperature of the steam generator may fall so low that the water entering therein is not evaporated into steam. In'order to obviate this disadvantage, the present iron has been provided with an auxiliary heating element 54 which is controlled by means of a second thermostat 55.

The auxiliary heating element 56 is preferably of the armored type similar to the heating ele-- ment l1 except that it may be of considerably less wattage. The heating element 54 may comprise a resistance element-56 arranged in zigzag or sinuous form within and insulated from a metallic sheath 51. The heating element substantially circumscribes the steam generating unit and. is carried by or imbeddedin t e s leplate 93 as shown in Figs. 1. 2 and 3, between the steam generating unit and the main or soleplate heating element ill. The terminals of the auxiliary heating element 5% are connected to the conductors 22 of the cord 28 in series with the bimetal thermostat and the line switch 29 as shown in Fig. i.

The thermostat 55 may be either a creep type or "snap-acting type and is supported within a recess provided in the soleplate closely adjacent the steam-generating unit so that it will operate in response to the temperature of that unit. This thermostat may be made adjustable in the usual manner as is well-known in the art, as by means of an adjusting screw 59, as shown in Figs. 1 and 4. This thermostat may be permanently adjusted by the manufacturer to operate at any desired temperature which will insure proper heating of the steam generator by the heating elements ii and 5!. A thermostat adjusted to operate between 275 and 300 F. is considered satisfactory.

It will be understood that when it is desired to use the iron for the purpose of steaming clothes or supplying moisture in the form of steam to an articlebein pressed, the operator fills the reservoir l5 with water and adjusts the thermostat 23 to maintain the ironing surface 35 0f the iron at the proper temperature for the particular material being ironed. When the iron has reached the correct heat and it is desired to supply moisture to the material to be ironed, the water-valve controlling knob 5i is adjusted to allow water to flow at a predetermined rate from the reservoir through the openings 56 inthe sleeve 63 and into the passage dll. The water falls on the surface of the plug 35 within the battle 38 where it is instantly flashed into steam. The steam thus generated will pass over the baille 38 and into the steam-distributing compartment ll and then through the steam outlet ports e2 to the material being pressed. It will be understood that the plug 35, due to its metal-to-metal contact with the soleplate which carries the heating elements, will be heated sufficiently to convert the water into steam. Further, by locating the plug within the loops or bights of the heating elements ii and 56, proper heating of the plug is insured.

If, during an ironing period, the temperature of the thermostat 55 falls below its critical or operating temperature, which indicates that the steam generator is not hot enough to convert the water into steam, a circuit for the auxiliary heater it will be completed from the conductors 22, as is apparent from an inspection of Fig. 4

to energize this heater and maintain the steam generator hot enough to convert the water supplied. thereto into steam. However, as long as the temperature of the steam generator or the portion of the soleplate surrounding the same is above the operating temperature of the thermo heating the iron when the iron is not in use and the operator has neglected to disconnect the cord .2l from the electrical outlet.

In Figs. 5, 6 and 7 there has been illustrated a modified form of the invention. -The modified iron generally indicated Ilia is similar tothe iron Ill described above and the same reference charactors are used. to identity elements of the iron lOa which are identical with corresponding elements of the iron Ill. Elements of the iron Illa which are similar in function to elements of the iron III are identified by the same reference characters with the addition of the letter a".

The soleplate-and cover construction of the iron 10a is substantially identical with that oi? the iron l except that a single, snap-acting bimetal thermostat 6| is provided in a recess in the soleplate and the valve-stem-guiding sleeve 43 has been omitted from the water reservoir. The handle of the iron Illa has also been modified slightly in that it is hollow and receives the water valve operating mechanism to be hereinafter described. This modifled handle l2a is preferably provided with an opening 62 along the top thereof which is closed by a removable cover plate 83.

As shown in Figs. 5 and '7, the single, snapacting thermostat 6|, which may be of any approved construction, is designed to complete a circuit from the conductors 22 to the main heater I! when in one position, and when snapped over to its other position, it completes a circuit from the conductors to the auxiliary heater 54.

The operation and construction of snap-acting thermostats is well-known and therefore need not be described in detail. However, to aid in un-..

derstanding the present invention, it may be well to point out that in the specific embodiment of the invention shown in the drawings, the thermostat 6 l, which has been shown somewhat schematically, comprises a bimetal element 54 of the snap-acting disc type supported at its center by an adjusting screw 65 threaded into the tube 25!; brazed or soldered in the upper and lower walls of the water reservoir I5. A knob 26a fixed to the upper end of this rod serves as a convenient means for adjusting the thermostat. The bi- ,;metal element 64 of the thermostat is provided with a pair of contacts 66 which are electrically connected aslby the metal of the bimetal element itself or by a copper or aluminum strip conductor carried-thereby, and are adapted to engage fixed contacts 6'! and 68 provided in the heater circuits as is apparent from an inspection of Fig. 7. I

It will be understood that the operator adjusts the thermostat ti by means of the knob 26a to maintain the soleplate at the proper ternperature for the particular material being pressed. As long as the temperature of the soleplate is below this temperature, the bimetal element will be in the position shown in full lines in Figs. 5 and 7. With the contacts 66 in the position shown in full lines in these two figures, a

circuit is completed from the conductors 22 to the heating element H, but the auxiliar heater circuit will be open. When the temperature of the bimetal element 64 reaches its critical or op- .erating temperature, the element will snap over to the position shown in dotted lines in Fig. '7 to open the circuit for the main heater and bridge the contacts 67 to complete the circuit for the auxiliary heating element 54. With this arrangement, a proper heating of the steam generator is insured even though the circuit for the main heater may be open for a substantial length of time as when the soleplate temperature is maintained at a very low temperature.

As in the case of the iron 10, the iron We is provided with a switch 29 which opens the circuits for the heating elements when the thermostat is turned to its off position.

In the event the iron is to be used as a dry iron, that is, without the use of steam, the auxiliary heater might raise the temperature of the soleplate too high during the ofi" cycle of the thermostat. The "01? cycle of the thermostat may be considered as the time during which the circuit for the main heater is held open. To prevent overheating under this condition, an interlock arrangement has been provided for opening the auxiliary heater circuit whenever the water valve is closed, so that during a period when steam is not being generated, the soleplate will be heated solely by the main heater.

This interlock, as shown particularly in Figs. 6 and 7, may comprise a switch, including contacts 69, which is operated by the water valve operat ing mechanism to be described in detail hereinafter. I

As distinguished from the iron illustrated in Figs. 1 to 4, inclusive, the iron lfla is provided with a sliding valve stem, although it will be understood that the irons ill or 10a may be provided with either a rotatable or slidable valve stem. The sliclable valve stem 49a is tapered at its lower end to engage the valve seat 8 for closing the passage 41 through the bushing 44. This valve stem is raised or lowered by means of a knob H movable along a slot l2 provided in the front support of the handle iZa. This knob is positioned to be conveniently engaged by the operator's thumb or fingers. A bracket l3 resiliently secured to the knob "ii by means of a screw M and a compression spring "it transmits the motion of the knob to the valve stem to raise and lower the same. The free end oi the bracket is provided with an open-ended siot 78 which receives the reduced portions "il provided on the upper end'oi the valve stem. B; particular reference to Fig. 6, it will be noted that this bracket carries one contact 59 of the "interlock switch, while the other contact til thereof is mounted on the inner wall of the handle by means of a resilient bracket l8.

In order to hold the water valve in either its open or closed position, there has been provided an off-center spring toggle mechanism like that described and claimed in the copending application of Kenneth L. Woodman, Serial No. 382,305, filed March 8, 1941, and assigned to the assignee of the present application. This spring toggle mechanism comprises a pair of flat springs 79 which are compressed between a pair of posts 8i and the valve stem 4511. When the knob H is in its lower position as shown in Fig. 6, the springs E9 bias the valve stem downwardly into engagement with the valve seat i i to stop the flow of water from the reservoir. On raising the knob to open the valve, the springs l9 snap over from the position shown in Fig. 5 to bias the valve stem upwardly and allow water flow into the steam generator.

"When the valve stem is in position to close the water passage to the steam generator, the interlock switch 69 will be open as shown in Fig. 6, so that as long as the steam generator is not being used to generate steam, the auxiliary heater 5i will be disconnected from the electric supply source. However, when the valve stem is raised to open the valve, this switch will be close and the auxiliary heater may be energized through a circuit (Fig. '2) controlled by the bimetal element 64 of the thermostat St.

The contacts 61 may be permanently bridged by a conductor 61a as shown in Fig. 8, if desired, so that the auxiliary heater 54 is energized whenever the switches 29 and t9 are closed. 'In this case, the operation of the auxiliary heater is controlled entirely by the switch 69 independent of the thermostat 6|.

While the invention is not to be construed as limited to heating elements of a specific wattage, it is considered satisfactory to use an 850 watt main heating element and a 300 watt auinliary heating element in the iron i illustrated in Figs. 1 to 4, inclusive. The main heating element of the iron illa may have a 1,000 watt input and the auxiliary heating element an input of 300 watts.

While the invention has been shown in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes ahd modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are speciiically set forth in the appended claims.

What I claim is:

1. A self-contained steam iron comprising a cover member having a liquid-storage chamber therein, a soleplate attached to said cover member, a U-shaped electrical resistance element carried by said soleplate for heating the same, a steam generator carried by said soleplate, said steam generator being located within the bight of said U-shaped resistance element and in' having a steam generator carried thereby, an

electric heating element for heating the soleplate, a thermostat responsive to the temperature of said soleplate for controlling said heating element, and an auxiliary heating element carried by said soleplate and localized adjacent said steam generator -for heating the same, said thermostat being adapted to control the operation of said auxiliary heating element.

3. A steam iron comprising a body having a steam generator carried thereby, means for supplying water to said steam generator, a soleplate carried by said body, means for heating said soleplate, auxiliary means for heating said steam generator, and temperature-responsive means for controlling said heating means, said temperature-responsive means being responsive to ris- 'ing .or falling of the iron temperature to a predetermined value to connect one or the other of said heating means to an energizing source.

4. A steam iron comprising a soleplate, a steam generator located, at least in part, within said soleplate, means for supplying a liquid to said steam generator, electric heating means embedded in said soleplate for heating said soleplate and said steam generator, second electric heating means carried by said soleplate and localized adjacent said steam generator, means for supplying electrical energy to said heating means, and thermostatic means for controlling the energization of both heating means.

aseaaie cover member having a liquid-storage chamber therein, a soleplate attached to said cover member, a u shaped electrical resistance element carried by said soleplate for heating the same, a steam generator carried by said soleplate and located within the bight of said U-shaped resistance element and adapted to be heated thereby, means for conveying liquid from said chamber to said steam generator, 9. second electrical resistance element carried by said soleplate and localized adjacent said steam generator for heating the same, whereby said steam generator may receive heat from each of said resistance elements, circuits connectible to a source of electrical energy for energizing said resistance elements, and temperature responsive means for controlling said circuits.

6. A self-contained steam iron comprising a body portion having a liquid-storage chamber therein, a soleplate attached to said body portion, electrical heating means embedded in said soleplate for heating the same, a steam genera tor carried by said soleplate and located in good heat-receiving relation to said heating means, means for conveying liquid from said chamber to said steam generator, second electrical heatlocated adjacent said steam generator, whereby said steam generator may receive heat from each of said resistance elements, and means for connecting said'elements to a source of electrical energy.

8. A steam iron comprising a soleplate having an ironing surface, a steam generator carried 5. A self-contained steam iron comprising a by said soleplate, means carried by said soleplate for supplying heat to said ironing surface and said steam generator, means responsive to the temperature of said ironing surface for controlling said heat supplyin'g means, auxiliary heating means carried by said soleplate and surrounding a substantial portion of said steam generator for supplying heat thereto, and means responsive to the temperature of said steam generator for controlling said auxiliary heating means.

9. A soleplate for a steam iron, said soleplate having a steam generating space formed therein, a main electric resistance element carried by said soleplate for heating the soleplate and steam-generating space, thermostatic means responsive to the temperature of said soleplate for controlling the energization of said main resistance element, an auxiliary electric resistance element localized adjacent said steam generator space for supplying heat thereto, and thermostatic means for controlling the energization of said auxiliary resistance element.

ELDRED O. MORTON.

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