US2777224A

US2777224A - Steam pressing iron

Info

Publication number: US2777224A
Application number: US457822A
Authority: US
Inventors: Herbert G Lehmann
Original assignee: Casco Products Corp
Current assignee: Casco Products Corp
Priority date: 1954-09-23
Filing date: 1954-09-23
Publication date: 1957-01-15
Anticipated expiration: 1974-01-15

Description

H. G. LEHMANN STEAM PRESSING IRON Filed Sept. 23, 1954 Jan. 15, 1957 [MyZ INVENTOR. h e/ 66m 6. Lehman/z ATTORNEYS United States Pat ent STEAM PRESSING IRON lHerbert G. Lehmann, Easton, Conn., assignor to Casco Products Corporation, Bridgeport, Conn., a corporation of Connecticut I Application September 23, 1954, Serial No. 457,822

11 Claims. 01. 38-77) 'This invention relates to domestic pressing irons of the type having heated'sole plates and steam generating means associated therewith, whereby steam may be brought out through openings in the sole plate to facilitate the ironing of fabrics.

In general there are two distinct types of domestic or household steam pressing irons in use, the boiler-type iron in which steam is formed as a result of a quantity of water being boiled in a container which is heated by the sole plate, and the flash-boiler type iron in which water globules are dropped on a heated flashing surface and quickly flashed into steam.

The present invention has utility and is of advantage in connection with both of the above types of steam irons.

Considering the flash-boiler .type of iron it has been recognized in the past that the quality of the steam is an important factor affecting the effectiveness of the ironing process. If the steam is too dry it does not have a sutficient dampening efiect, and if the steam is too moist it may contain or form actual droplets of water, which may stain the fabric being ironed.

The problem of quality of the steam is considered in some detail in the patent to McFarland et -al., No. 2,655,746, dated October 20, 1953. In this patent it is recognized that moist steam is most desirable, provided that it does not contain or form water droplets, and that dry steam is not particularly desirable. The patentees provide an organization which has an objective the producing ofsteam which is always of the proper quality, and claim to accomplish this by tying together the thermostatic heat control for the sole plate and the flow control or valve means for the water which is supplied by the water tank or reservoir. In this-patent the feeding of water is automatically shut off if the sole plate tempera ture becomes either too low or too high for the generation of the proper quality of steam. This arrangement would appear to be satisfactory, but it has a drawback in that moist steam cannot be generated in conjunction with.

a high sole plate temperature, and there are timeswhen it is desirable to press a fabric with a very hot sole plate and with a supply of moist steam. It has not been possible, heretofore, to attain this result in prior flash-boiler type steam irons, including the McFarland construction mentioned above.

The present invention obviates this drawback of prior iron constructions, and an object of the invention is to provide a novel and improved steam iron wherein moist steam may be produced from heat supplied by the sole plate even though the latter is at a very high temperature.

Another object of the invention is to provide an improved steam iron of the type producing steam from the heat of the sole plate, wherein the quality of the steam is closely controlled and the moisture content maintained at a desirable high value regardless of high temperatures or variations in the temperature of the sole plate.

A further object of the invention is to provide an improved steam iron as above set forth, wherein the quality of the steam may be maintained relatively constantde- .spite wide variations in the temperature of the sole plate.

Yet another object of the invention is to provide an improved steam iron in accordance with the above, wherein the sole plate temperatures may be automatically controlled and regulated by a settable control while at the same time the production of steam, within limits, is independent of the setting of the control.

Considering boiler-type steam irons, it frequently happens that droplets of water are either brought down the steam tube from the steam dome, or formed in-the steam chamber above the sole plate and are ejected through the steam discharge ports or openings in the sole plate along with the generated steam. This condition is more apt to occur when the sole plate is being operated at a high temperature, for example, in the region of 500 F. or 550 F. For such high sole plate temperatures, droplets of water existing in the steam chamber are not readily, quickly converted into steam but instead, because of the high sole plate temperature, ball up and bounce around and are ultimately ejected from the sole plate as discrete water particles.

The present invention also obviates this drawback, and accordingly a still further object of the invention is to provide an improved, boiler-type steam iron wherein there is minimized if not wholly prevented the discharge of water droplets from the sole plate, this being efifected through the quick and eife'ctive conversion of said droplets into steam in the steam chamber of the iron.

Still another object of this invention is to provide an improved steam iron in accordance with the foregoing, which is small and compact, simple and economical to fabricate, and reliable in its operation.

In accomplishing the above objects I provide, in conjunction with the heated sole plate of the iron, a novel steam-chamber means above the sole plate, having a movable wall juxtaposed to and in heat-receiving relation with the sole plate and arranged to be contacted by water droplets brought into the steam chamber. I further provide heat-responsive means for moving said wall either closer to or further from the sole plate in response to cooling or heating of the wall respectively. Thus, there is automatically controlled the heat which is transmitted from the sole plate to the movable wall, and the temperature of the movable wall itself. The temperature of the wall is thus, Within limits, independent of the temperature of the sole plate, and the latter may be at a relatively high temperature, as for example 450 F. to 550 F, while the movable wall temperature remains in a much lower range wherein it will effectively produce moist steam. Thus the steam generation is accomplished with low temperatures even though the sole plate temperatures are much higher, or varyconsiclerably. The quality of the steam may therefore be closely controlled and kept within a desirable, moisture range.

' In connection with boiler-type irons, I have found that when the temperature of the lower heated surface of the steam chamber is neither too high nor too low, water droplets which impinge upon said surface'will be quickly and wholly converted into steam. If the temperature of such surface becomes too low, however, the water will not be quickly or completely converted into steam, and if the temperature of the surface is too high, for example, between 450 F. and 550 F., the water droplets will ball up and bounce around instead of being 'fiashed into steam;

in both cases the water will pass out through the openings .I h a sqmn n i sdra ins igu 1 is a view, p t y i side .el ati and .Patt y in vertical section, of a steam electric iron of the boiler type, embodying the invention.

Fig. 2 .is a fragmentary, detail, sectional view of the steam-chamber portionof the iron of Fi g. 1.

.Fig. 3 is a view like Fig. 1 but of a steam ironof the flash-boiler type, embodying the invention.

Fig. 4 is a detaihsectional view like Fig. 2, but illustrating a modified =form of steam chamber made in accordance with the invention.

Fig. 5 is aperspective view of a heat-responsive member used in conjunction with the construction shown in Fig. .4.

Referring to Figs. 1 and 2 the improved boiler-type steam iron illustrated therein comprises a sole plate having an electric heating element 11, a casing 12 disposed above the sole plate 10, and a handle structure 13.mounted on the casing 12.

Within the casing '12 there is provided a water boiler .14, disposed in heat-receiving relation to the sole plate 10. "The boiler 14 communicates with a steam dome 15 into which an upright steam pipe 16 extends, said pipe being carried by a fitting 17 the lower end of which projects into a steam chamber 18 communicating with a steam manifold or channel 19 which distributes steam to ports or openings 20 in the sole plate.

.In accordance with the present invention a novel and improved means is provided, making up the steam chamber 18, whereby water droplets passing into the chamber from the steam tube 16 will be quickly and completely vaporized and thus prevented from passing out through the discharge openings 20 of the sole plate 10. As shown inFig. 2 the steam chamber 18 is constituted of a circular body 21 disposed in an upright position, with its upper edge 22 outwardly flanged and secured to a plate 23 which covers the channel 19. The lower edge or lip of the body 21 is provided with a crimp 24 receiving the peripheral portions of a bimetallic snap disk 25.

When the parts of the iron are cool, the disk 25 is bowed downward as shown in Fig. 2, and preferably contacts -a concave portion 26 of the sole plate 10 to receive heat therefrom. When the disk 25 is heated above a predetermined temperature it will snap upward to the broken-line position shown in Fig. 2, wherein it is spaced an appreciable distance from the portion 26 of the sole plate.

Operation of the improved iron and steam. chamber as above set forth, is a follows: When the heating element 11 of the iron is energized, the sole plate 10 will become hot, and heat will be transferred to the snap disk 25 and tothe boiler 14, causing the water contained in the latter to come to a boil and be converted into steam. This steam will pass upward intothe steam dome 15, and thence downward through the steam pipe 16 to the steam chamber 18. From the chamber 18, the steam will pass outward through openings 27 provided in the Walls of the body 21, and will be conducted by the channel 19 to the sole plate openings 20. If any water droplets pass downward through the steam pipe 16 into the steam chamber 18, or if steam which is in a cool portion of the steam chamber 18 condenses, the water will impinge upon the snap disk 25.

Regardless of the operative setting ofthe thermostatic temperature control for the sole plate 10, the snap disk portion 26, and this greatly diminishes the transmission of heat fr om the sole plate to the disk. This reducti n in th tran f .Q heat, to he i the reflect o the disk of steam and water in the steam chamber 18 sired.

static control switch 32 operated by a knob 33.

4 will result in the disk remaining always cooler than the sole plate .tq hi h tempe ature 9 th latter a the range of temperature of the disk will thus be appreciably lower than the .high range of temperatures of the sole plate. Even though the sole plate temperatures reach 550 F., the temperature of the disk 25 will be very appreciably less than this. Preferably the disk characteristics, spacing of the disk and effect of the water and steam on the disk result in the temperature of the disk remaining below 0 F., and usually below 375 F. Because the disk 25 is always .in the proper temperature range for quick vaporization, water which impinges on it will be immediately completely flashed into steam and ,will thus be prevented from discharging through the sole plate openings 20, except as steam.

During operation of the steam iron the disk 25 will periodically snap up and down to maintain its quickllashing temperature range. The sole plate 10 may be operated at either low, moderate or high heats, as de- If the sole plate is operated at a lower heat, the disk 25 will be less active in snapping up and down, and vice versa.

Another embodiment of the invention is shown in Fig. 3, wherein the invention is applied to a flash-boiler type of steam iron. The iron shown in Fig. 3 has a sole plate 30 provided with a heating element 31 and a thermo- Above the sole plate 30 is a water tank or reservior 34 to which is attached a handle assembly 35. At the lower portion of the water tank 34 a needle valve 36 is provided, comprising a valve seat 37 secured to the container bottom and a metering needle 38 carried by a screw 39 thraded in the handle 35.

.By the present invention a novel means is provided for controlling the quality of steam produced from the water droplets passing through the metering valve 36, and for producing a uniform-quality, moist steam even though the temperature of the sole plate 30 is in the higher ranges, as for example between 400 F. and 550 F. In accomplishing this I provide, below the valve seat.37, a novel steam chamber 40 made in accordance with the invention, said chamber having a bottom plug 41 threaded into the sole plate 30 and having a concave upper surface, a top plate 42 fastened to the upper surface of the sole plate, a tubular, perforated body 43 secured to the underside of the plate 42, and a movable wall comprising a snap disk 44 carried by the lower edge of the body 43.

When the parts of the iron are cold, the disk 44 will be in engagement with the plug 41, as shown in Fig. 3.

When the temperature of the disk 44 exceeds a certain will snap to a raised position and be spaced from the plug 41, and as its temperature drops and approaches 275 F. it will again snap downward and come in contact with the plug 41. When droplets of water pass into the flash chamber 43 through the valve 36 they will strike the snap disk 44. With the disk 44 maintained in a temperature range from 275 F. to 375 F. the water droplets will not ball up or bounce around inside the steam chamber but instead will be quickly and completely cgnverted into moist steam. which will pass out through the openings 45. This action will take place even though the temperature of the sole plate 30 is maintained in a high range, as for example from 450 F. to 550 F. When the heat removed from the disk 44 by the vaporization of the water cools the disk sufficiently it will again snap downward, and as the sole plate 30 and ping 41 supply heat to the diskit willsnap upward,

.andfthis action will continually take place, maintaining the disk within the desired effective temperature range. Thus steam having an advantageous, moist quality will be produced at all times by the iron, and may be utilized in conjunction with either low, medium or high sole plate temperatures to produce effective pressing of various fabrics according to their individual requirements.

A modification of the invention is shown in Fig. 4. In this figure there is illustrated a sole plate 50, means providing a steam chamber 51 above the sole plate, and a steam-pipe fitting 52 for admitting steam and water droplets to the chamber 51. Above the sole plate 50 is a cover plate 53 to which are attached depending spring fingers 54 having crimped lower extremities 55 accommodating bimetallic arms 56.

Below the lower end of the steam pipe fitting 52 there is disposed a cup 57 having telescoped within it an inverted cup 58, the latter having an apertured bottom to receive the steam-pipe fitting 52. The bimetallic fingers 56 have curved portions 60 which are secured to the inside of the cup 57 by rivets 61 which also pass through the inverted cup 58.

When the parts of the iron are cool, the bimetallic fingers 56 will be straight as shown in Fig. 4, and the cup 57 will be held in contact with the sole plate 50. When the cup 57 attains a certain predetermined temperature, as for example 300 F., the arms 56 will become bowed as shown by the broken outline in Fig. 4 and the cup 57 will be raised from the sole plate 50. Thus the temperature of the cup 57 will be automatically controlled regardless of wide variations in the temperature of the sole plate, and will be maintained at a value best suited to quickly and completely flash water droplets into desirably moist steam.

In the embodiments of the invention shown in Figs. 1-3, wherein the bimetallic disk is employed, the continual change in the curvature of the disk will eflectively prevent the accumulation of scale on it which might impair the operation of the iron.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. In a steam iron having a heated sole plate, means providing a steam chamber above the sole plate and a passage to said chamber through which water may enter the chamber, said means having a movable wall juxtaposed to and in heat-receiving relation with the sole plate and arranged to be contacted by water droplets from said passage to convert said droplets into steam; and heatresponsive means for moving said wall away from the sole plate in response to heating of the wall above a predetermined temperature, thereby tending to obviate the transmission of excessive heat to said wall beyond that required to quickly convert water into moist steam.

2. The invention as defined in claim 1 in which the heat-responsive means and movable wall constitute a single member and comprise a bimetallic snap disk.

3. The invention as defined in claim 2 in which the disk engages the sole plate when the disk is below said predetermined temperature.

4. The invention as defined in claim 1 in which the movable wall comprises a cup, and in which the heatresponsive means comprises bimetallic arms connected with the cup and the sole plate.

5. The invention as defined in claim 4 in which the bimetallic arms are in good heat-conducting relation with the cup and in poor heat-conducting relation with the sole plate.

6. The invention as defined in claim 1 in which the movable wall comprises a snap action disk.

7. The invention as defined in claim 1 in which the movable wall is engageable with the sole plate and has a relatively large area for contact therewith.

8. The invention as defined in claim 1 in which the movable wall comprises a cup arranged with its bottom engaging the sole plate when the cup is cold, and in which the heat-responsive means is bimetallic, extends from the lip of the cup and is spaced from the sole plate, said means being in intimate heat-conducting relation with the cup.

9. In a steam iron having a heated sole plate, means providing a steam chamber above the sole plate and a passage to said chamber through which water may enter the chamber, said means having a movable wall juxtaposed to and in heat-receiving relation with the sole plate and arranged to be contacted by water droplets from said passage; and heat-responsive means for moving said wall away from the sole plate in response to heating of the wall above a predetermined temperature, thereby tending to obviate the transmission of excessive heat to said wall beyond that required to quickly convert water into steam, said means moving the wall toward the sole plate when the wall temperature drops from a value above said predetermined temperature.

10. A steam iron comprising a sole plate; means for heating the sole plate; a water reservoir mounted above the sole plate; means providing a steam chamber above the sole plate; a metering valve connected between the water reservoir and steam chamber, said steam-chamber means having a movable wall juxtaposed to and in heatreceiving relation with the sole plate and arranged to be contacted by water droplets from said metering valve; and heat-responsive means for moving said wall away from the sole plate in response to heating of the wall above a predetermined temperature, thereby tending to obviate the transmission of excessive heat to said wall beyond that requird o quickly convert water into steam.

11. A steam iron comprising a sole plate; means for heating the sole plate; a boiler mounted above the sole plate; means providing a steam chamber above the sole plate; a steam tube connecting the boiler and steam chamber, said steam-chamber means having a movable wall juxtaposed to and in heat-receiving relation with the sole plate and arranged to be contacted by water droplets from said passage; and heat-responsive means for moving said wall away from the sole plate in response to heating of the Wall above a predetermined temperature, thereby tending to obviate the transmission of excessive heat to said wall beyond that required to quickly convert water into steam.

References Cited in the file of this patent UNITED STATES PATENTS